113 results on '"Henry, A. L."'
Search Results
2. Prospective evaluation of the comorbidity of obstructive sleep apnea in patients with glaucoma
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Yu-Lun Lo, Lan-Hsin Chuang, Pei-Wei Huang, Henry S L Chen, Yuan-Hsi Chan, Chung-Chieh Yu, Chi-Chun Lai, and Ling Yeung
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Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,genetic structures ,Glaucoma ,Polysomnography ,Comorbidity ,Prospective evaluation ,Microcirculation ,Internal medicine ,Medicine ,Humans ,In patient ,Low Tension Glaucoma ,skin and connective tissue diseases ,Sleep Apnea, Obstructive ,medicine.diagnostic_test ,business.industry ,medicine.disease ,Scientific Investigations ,eye diseases ,respiratory tract diseases ,Visual field ,Obstructive sleep apnea ,Neurology ,Cardiology ,Visual Field Tests ,sense organs ,Neurology (clinical) ,business - Abstract
STUDY OBJECTIVES: This study aimed to identify prospectively the correlation between obstructive sleep apnea (OSA) severity, ocular microcirculation changes, and visual function changes in patients with glaucoma. METHODS: We prospectively enrolled patients with glaucoma who were willing to undergo overnight polysomnography. The enrolled patients were further divided into normal tension glaucoma, high-tension glaucoma, and control. Visual field progression was analyzed using sequential standard automated perimetry. Peripapillary and macular vessel density were assessed through optical coherence tomography angiography (OCT-angiography). The associations between polysomnography parameters, OCT-angiography parameters, and visual field progression were analyzed. RESULTS: A total of 22 patients with normal tension glaucoma, 30 patients with high-tension glaucoma, and 24 control patients were enrolled. Through regression analysis, glaucoma was found to be an independent predictor of moderate-to-severe OSA (P = .035); furthermore, moderate-to-severe OSA was significantly associated with visual field progression (P = .008 in the high-tension glaucoma subgroup and P = .008 in the overall glaucoma). Additionally, OSA severity was negatively correlated with the ganglion cell complex thinning rate in the normal tension glaucoma subgroup. CONCLUSIONS: Presence of glaucoma increased the risk of moderate-to-severe OSA compared with the control group. OSA severity was related to visual field deterioration in patients with glaucoma and further associated with structural progression in the normal tension glaucoma subgroup. Careful monitoring of the comorbid OSA status of patients with glaucoma is essential to prevent disease progression. CITATION: Chan Y-H, Chuang L-H, Yu C-C, et al. Prospective evaluation of the comorbidity of obstructive sleep apnea in patients with glaucoma. J Clin Sleep Med. 2022;18(1):47–56.
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- 2023
3. Extrinsic and Intrinsic Factors Regulating Juvenile Refractive Development and Eye Growth
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Kai Yip Choi and Henry H. L. Chan
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accommodation ,Intrinsic Factor ,Male ,medicine.medical_specialty ,Central field ,Visual Acuity ,Eye ,Refraction, Ocular ,nearwork ,Ophthalmology ,Linear regression ,medicine ,Myopia ,Eye growth ,Juvenile ,Humans ,Child ,Mathematics ,Intrinsic factor ,business.industry ,Clinical and Epidemiologic Research ,peripheral refraction ,Accommodation, Ocular ,Refraction ,Visual accommodation ,Female ,business ,Accommodation ,environment - Abstract
Purpose Peripheral refraction and accommodation are intrinsic factors that were once hypothesized to trigger myopia but are now controversial. Previously, home nearwork environment (i.e., extrinsic factor) was reported to be associated with myopia progression. In this study, we aimed to evaluate the potential interaction between extrinsic and intrinsic factors with juvenile refractive development. Methods Nearwork environmental parameters were measured for 50 children (aged 9.3 ± 1.2 years), including net amount and dispersion of defocus. Refraction was measured at near distances and in central field (±30° horizontal) at 3m. The relative peripheral refraction (RPRE) was obtained and presented in a vectoral approach. The linear regression coefficient was extracted (mAcc) from the accommodative stimulus-response curve. RPRE was quadratically regressed against field eccentricity, and the first coefficients (aM, aJ0, aP90, and aP180) were extracted. Relationships between RPRE, baseline accommodation, and 1-year myopia progression (∆M), controlled for the nearwork environment, were evaluated. Results Coefficients of RPRE were independent of ∆M. However, additional nearwork environmental parameters significantly improved the variance in ∆M explained by aM and aP180 (P < 0.03). The relationship between intrinsic factor and ∆M was stronger when the extrinsic risk was low (P ≤ 0.01), whereas the relationship was abolished when extrinsic risk was high. For mAcc, it also significantly improved the variance in ∆M explained by nearwork environmental parameters. Conclusions The interaction between extrinsic (environment) and intrinsic (RPRE and accommodation) factors is speculated to contribute to juvenile myopia progression. Our findings may also explain the inconsistencies of such intrinsic factors in the literature.
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- 2021
4. Integrating Clinical Data and Tear Proteomics to Assess Efficacy, Ocular Surface Status, and Biomarker Response After Orthokeratology Lens Wear
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Henry H. L. Chan, Gigi T.K. Wong, Kai Yip Choi, Jimmy S.H. Tse, Andes Y.H. Sze, Gigi M.C. Yee, Katherine H.Y. So, Christie D.M. Lam, Thomas Chuen Lam, Jimmy Ka Wai Cheung, and Angel C.K. Wong
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Adult ,Proteomics ,medicine.medical_specialty ,Refractive error ,Visual acuity ,genetic structures ,medicine.medical_treatment ,Biomedical Engineering ,orthokeratology ,Refraction, Ocular ,law.invention ,Young Adult ,law ,Ophthalmology ,Cornea ,medicine ,Myopia ,Humans ,Clinical Trials ,business.industry ,Orthokeratology ,Corneal Topography ,medicine.disease ,elastic contact lenses ,eye diseases ,Lens (optics) ,medicine.anatomical_structure ,Biomarker (medicine) ,sense organs ,medicine.symptom ,business ,corneal biomechanics ,Ocular surface ,Biomarkers - Abstract
Purpose This study evaluated the efficacy and ocular surface status of Breath-O Correct, novel orthokeratology (OK) lenses, worn overnight for 3 months. Lens-induced changes in the tear proteome were evaluated. Methods Thirty-one subjects, aged 19 to 26 years with refractive error from -1.00 to -5.00 D, were randomly assigned 1:1 to the treatment or control group. Refraction, visual acuity, corneal integrity, biomechanics and endothelial health, ocular surface changes, and subjective symptoms were assessed at the baseline, one-month, and three-month visits. The tear proteome was characterized over time using sequential window acquisition of all theoretical ion spectra mass spectrometry. Results Lenses improved uncorrected visual acuity and reduced spherical powers with similar efficacy to other OK lenses. Significant reductions (P < 0.05) in corneal hysteresis (11.12 ± 1.12 to 10.38 ± 1.36 mm Hg) and corneal resistance factor (11.06 ± 1.32 to 9.90 ± 1.45 mm Hg) were observed in the treatment group after one month of lens wear, whereas other assessed factors remained unchanged. Thirteen and eight differentially expressed proteins were found after one month and three months of lens wear, respectively. Two proteins (proline-rich protein 27 and immunoglobulin V regions) were differentially expressed at both visits. Conclusions Over a three-month period, Breath-O Correct lenses were overall safe, well tolerated, efficacious in refractive power reduction, and comparable with other OK lenses. Furthermore, their use caused only minor noninflammatory protein expression changes in the tear proteome. Translational Relevance This study investigated the safety of orthokeratology contact lenses on the ocular surface in molecular aspects and standard clinical parameters.
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- 2021
5. Utilizing Advanced Technology to Facilitate Diagnosis of Rare Retinal Disorders
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Henry H. L. Chan, Kai Yip Choi, and Horace H. Y. Wong
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Adult ,Technology ,medicine.medical_specialty ,Retinal Disorder ,genetic structures ,Posterior pole ,Visual Acuity ,chemistry.chemical_compound ,Retinal Diseases ,Ophthalmology ,Retinitis pigmentosa ,medicine ,Humans ,Scotopic vision ,Fluorescein Angiography ,Corneal Dystrophies, Hereditary ,business.industry ,Blind spot ,Retinal Degeneration ,Retinal ,medicine.disease ,eye diseases ,chemistry ,Female ,sense organs ,business ,Erg ,Tomography, Optical Coherence ,Optometry ,Photopic vision - Abstract
SIGNIFICANCE Optometrists, as primary eye care providers, encounter patients with rare ocular disease such as Bietti crystalline dystrophy from time to time. Using advanced technologies, which are also useful in managing common ocular conditions, to facilitate a prompt diagnosis is highly recommended. PURPOSE This report describes a patient with clinically diagnosed Bietti crystalline dystrophy with findings on funduscopy, multimodal imaging, and visual electrophysiology. CASE REPORT A 41-year-old Chinese woman who had subjectively progressing dimmed vision (especially in the left eye) for 9 months was referred to our clinic to test for retinitis pigmentosa. Best-corrected visual acuities were 6/6 and 6/7.6 in the right and left eyes, respectively. Funduscopy revealed multiple crystalline deposits on the posterior pole in both eyes. The 30-2 perimetry displayed bi-inferotemporal scotoma (left > right eye). Scotopic flash electroretinogram (ERG) yielded a normal result, whereas photopic ERG was slightly attenuated. Electro-oculogram showed an abnormal adaptation time course of the retinal pigmented epithelium (RPE). Multifocal ERG revealed a decreased central retinal response, but paracentral responses were relatively better preserved. Optical coherence tomography showed multiple patches of RPE atrophy, with disruption of the left ellipsoid zone. Outer retinal tubulations, hyperreflective dots on RPE-Bruch's membrane interface, and intraretinal bright spots were also identified. CONCLUSIONS Rare ocular diseases like Bietti crystalline dystrophy can be encountered by optometrists. This case report shows the ophthalmic findings of a rare chorioretinal dystrophy and provides insight on how to better use advanced equipment in an optometric practice to facilitate prompt diagnoses.
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- 2021
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6. Local and Central Algorithms for Distributed Generation Micro-dispatch Control
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Luciana M. Iantorno, Carlos Gabriel Bianchin, Pedro A. B. Block, Zeno Luiz Iensen Nadal, Amanda C. de Almeida, and Henry L. L. Salamanca
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Total harmonic distortion ,Standardization ,Overvoltage ,Computer science ,business.industry ,Distributed generation ,Photovoltaic system ,Control (management) ,Communications protocol ,business ,Algorithm ,Power (physics) - Abstract
Global growth of distributed generation, especially photovoltaic, has given rise to new markets and new problems: large injection of power at daily intervals without increasing in the level of consumption. This scenario has already created, in certain places, overvoltage problems, harmonic distortion, etc. In Brazil, the standards regulate the connection of photovoltaic inverters, however, the control is not yet subject to standardization. For this reason, this paper presents a proposal of local and central algorithms for this power injection control in accordance with the solutions of problems such as the lack of standardization in the communication protocol of the inverters. The results of the pilot plant application are also presented.
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- 2020
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7. May Measurement Month 2019: an analysis of blood pressure screening results from Malawi
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Mary K Mbeba, Lucia D Mbulaje, Xin Xia, Henry L L Ndhlovu, Neil R Poulter, Nancy M Nyirenda, Maureen L Chirwa, and Thomas Beaney
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Pediatrics ,medicine.medical_specialty ,business.industry ,Early detection ,Mean age ,030229 sport sciences ,Articles ,030204 cardiovascular system & hematology ,Treatment ,03 medical and health sciences ,0302 clinical medicine ,Blood pressure ,Cardiovascular System & Hematology ,Control ,Hypertension ,medicine ,Screening ,Statistical analysis ,AcademicSubjects/MED00200 ,Cardiology and Cardiovascular Medicine ,business ,1102 Cardiorespiratory Medicine and Haematology - Abstract
May Measurement Month (MMM) is a global initiative that aims at raising awareness and screening people for high blood pressure (BP). Malawi has participated in MMM since 2017. A 2017 STEPwise Survey conducted in Malawi among 4187 participants found that 65.2% had never had their BP measured before, 26.8% had their BPs measured but not diagnosed, 3.9% were diagnosed but not within the last 12 months, and 4.1% were diagnosed within the last 12 months. An opportunistic cross-sectional survey of volunteers aged 18 and above was carried out in May and June 2019. All BP measurements, definition of hypertension and statistical analysis followed the standard MMM protocol. The screening took place in Nkhatabay, Lilongwe, and Blantyre. A total number of 9723 participants were screened with a mean age of 42.0 (SD 16.6) years. Of these 8444 (86.8%) had never had their BP measured within the last 12 months, 2559 (26.3%) had raised BP, 2169 (23.2%) of those with raised BP were not on treatment whereas 390 (4.0%) were on treatment. The results showed that many of the participants had not had their BP checked in the past year. There is a significant need to expand BP screening opportunities within Malawi for early detection of hypertension.
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- 2020
8. An Evolutionary Algorithm for Learning Interpretable Ensembles of Classifiers
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Henry E. L. Cagnini, Rodrigo C. Barros, Alex A. Freitas, Cerri, Ricardo, and Prati, Ronaldo C.
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business.industry ,Computer science ,Supervised learning ,Evolutionary algorithm ,02 engineering and technology ,Machine learning ,computer.software_genre ,Ensemble learning ,Random forest ,QA76 ,Ensembles of classifiers ,ComputingMethodologies_PATTERNRECOGNITION ,Estimation of distribution algorithm ,020204 information systems ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Artificial intelligence ,business ,computer ,Classifier (UML) ,Interpretability - Abstract
Ensembles of classifiers are a very popular type of method for performing classification, due to their usually high predictive accuracy. However, ensembles have two drawbacks. First, ensembles are usually considered a ‘black box’, non-interpretable type of classification model, mainly because typically there are a very large number of classifiers in the ensemble (and often each classifier in the ensemble is a black-box classifier by itself). This lack of interpretability is an important limitation in application domains where a model’s predictions should be carefully interpreted by users, like medicine, law, etc. Second, ensemble methods typically involve many hyper-parameters, and it is difficult for users to select the best settings for those hyper-parameters. In this work we propose an Evolutionary Algorithm (an Estimation of Distribution Algorithm) that addresses both these drawbacks. This algorithm optimizes the hyper-parameter settings of a small ensemble of 5 interpretable classifiers, which allows users to interpret each classifier. In our experiments, the ensembles learned by the proposed Evolutionary Algorithm achieved the same level of predictive accuracy as a well-known Random Forest ensemble, but with the benefit of learning interpretable models (unlike Random Forests).
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- 2020
9. Postmortem Neuroimaging of Cetacean Brains Using Computed Tomography and Magnetic Resonance Imaging
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Brian C. W. Kot, Henry C. L. Tsui, Tabris Y. T. Chung, and Amy P. Y. Lau
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0106 biological sciences ,010504 meteorology & atmospheric sciences ,lcsh:QH1-199.5 ,Ocean Engineering ,Computed tomography ,Aquatic Science ,decomposed brain ,lcsh:General. Including nature conservation, geographical distribution ,Oceanography ,01 natural sciences ,Neuroimaging ,medicine ,magnetic resonance imaging ,Putrefaction ,lcsh:Science ,0105 earth and related environmental sciences ,Water Science and Technology ,postmortem ,Global and Planetary Change ,medicine.diagnostic_test ,business.industry ,010604 marine biology & hydrobiology ,Brain morphometry ,Structural integrity ,Magnetic resonance imaging ,computed tomography ,Anatomy ,medicine.anatomical_structure ,cetacean ,lcsh:Q ,business ,Intracranial Gas ,Neuroanatomy - Abstract
Postmortem computed tomography (PMCT) and postmortem magnetic resonance (PMMR) imaging (PMMRI) have been applied to provide vital or additional information for conventional necropsy, along the pioneering virtopsy-driven cetacean stranding response program in Hong Kong waters. It is common for stranded carcasses to become badly degraded and susceptible to rapid cerebral autolysis and putrefaction. Necropsy on decomposed brains with limited sample analysis often defy a specific diagnosis. Studies on PMMR neuroimaging have focused on neuroanatomy and brain morphology in freshly deceased or preserved specimens. Moreover, the literature is devoid of any reference on the potential value of PMMRI examination of decomposed cetacean brains. To that end, this project evaluated the benefits of PMMR neuroimaging in situ in decomposed carcasses in comparison to PMCT. A total of 18 cetacean carcasses were studied by PMCT and PMMRI examinations. Anatomical brain structures and visible brain pathologies were evaluated and scored using Likert-scale rating. Intracranial gas accumulation was clearly depicted in all cases by all radiological techniques. Other features were more clearly depictable in PMMRI than in PMCT images. Results of this study indicated that superiority of PMMRI compared to PMCT increased with advanced putrefaction of the brain. The preservation of structural integrity was presented by PMMRI due to its superior capability to evaluate soft tissue. Brain PMMRI should be incorporated in postmortem investigation of decomposed stranded cetaceans.
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- 2020
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10. The Role of Multi-modality Imaging in the Diagnosis of Cardiac Amyloidosis: A Focused Update
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Shaun Khanna, Ivy Wen, Aditya Bhat, Henry H. L. Chen, Gary C. H. Gan, Faraz Pathan, and Timothy C. Tan
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0301 basic medicine ,medicine.medical_specialty ,lcsh:Diseases of the circulatory (Cardiovascular) system ,Mini Review ,Speckle tracking echocardiography ,Cardiovascular Medicine ,030204 cardiovascular system & hematology ,Multi modality ,03 medical and health sciences ,0302 clinical medicine ,pet scan ,Internal medicine ,medicine ,cardiac MRI ,speckle tracking echocardiography ,DPD scintigraphy ,biology ,business.industry ,Amyloidosis ,CT cardiac scan ,Restrictive cardiomyopathy ,Diastolic heart failure ,cardiac amyloidosis ,medicine.disease ,Transthyretin ,030104 developmental biology ,Cardiac amyloidosis ,lcsh:RC666-701 ,Heart failure ,Cardiology ,biology.protein ,business ,Cardiology and Cardiovascular Medicine ,global longitudinal strain - Abstract
Cardiac amyloidosis (CA) is a unique disease entity involving an infiltrative process, typically resulting in a restrictive cardiomyopathy with diastolic heart failure that ultimately progresses to systolic heart failure. The two most common subtypes are light-chain and transthyretin amyloidosis. Early diagnosis of this disease entity, especially light-chain CA subtype, is crucial, as it portends a poorer prognosis. This review focuses on the clinical utility of the various imaging modalities in the diagnosis and differentiation of CA subtypes. This review also aims to highlight the key advances in each of the imaging modalities in the diagnosis and prognostication of CA.
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- 2020
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11. Photogrammetric Three-dimensional Modeling and Printing of Cetacean Skeleton using an Omura's Whale Stranded in Hong Kong Waters as an Example
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Wo Wing Cheng, Henry C. L. Tsui, Brian C. W. Kot, Kent Mori, Tadasu K. Yamada, Richard Brown, Madelyn Y. L. Lo, Thomas Mui, and Tabris Y. T. Chung
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0106 biological sciences ,Models, Anatomic ,010504 meteorology & atmospheric sciences ,General Chemical Engineering ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Bone and Bones ,Baleen whale ,biology.animal ,medicine ,Animals ,Computer vision ,0105 earth and related environmental sciences ,Fibrous joint ,General Immunology and Microbiology ,biology ,Balaenoptera ,Whale ,business.industry ,010604 marine biology & hydrobiology ,General Neuroscience ,Whales ,Dimensional modeling ,biology.organism_classification ,Skeleton (computer programming) ,Omura's whale ,medicine.anatomical_structure ,Photogrammetry ,Printing, Three-Dimensional ,Hong Kong ,Female ,Artificial intelligence ,business ,Geology - Abstract
The preparation of cetacean, in particular baleen whale, skeletons presents a great challenge due to their high lipid content and uncommon size. Documentation of the skeletal morphology is important to produce accurate and reliable models for both research and educational purposes. In this paper, we used a 10.8-meter long Omura’s whale stranded in Hong Kong waters in 2014 as an example for the illustration. This rare and enormous specimen was defleshed, macerated, and sun-dried to yield the skeleton for research and public display. Morphology of each bone was then documented by photogrammetry. The complex contour of the skeleton made automated photoshoot inadequate and 3 manual methods were used on bones of different sizes and shapes. The captured photos were processed to generate three-dimensional (3D) models of 166 individual bones. The skeleton was printed half-size with polylactic acid for display purposes, which was easier to maintain than the actual cetacean bones with high residual fat content. The printed bones reflected most anatomical features of the specimen, including the bowing out rostral region and the caudal condylar facet that articulated with Ce1, yet the foramina on the parieto-squamosal suture, which are diagnostic character of Balaenoptera omurai, and an indented groove on the frontal bone at the posterior end of the lateral edge were not clearly presented. Extra photoshoots or 3D surface scanning should be performed on areas with meticulous details to improve precision of the models. The electronic files of the 3D skeleton were published online to reach a global audience and facilitate scientific collaboration among researchers worldwide.
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- 2020
12. May measurement month 2018: an analysis of blood pressure screening results from Malawi
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Neil R Poulter, Maureen L Chirwa, Nancy M Nyirenda, Tiyezge D Dhlamini, Thomas Beaney, Jones K Masiye, Anca Chis Ster, and Henry L L Ndhlovu
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business.industry ,Articles ,030229 sport sciences ,030204 cardiovascular system & hematology ,Treatment ,03 medical and health sciences ,0302 clinical medicine ,Blood pressure ,Cardiovascular System & Hematology ,Environmental health ,Health care ,Control ,Hypertension ,Screening ,Medicine ,AcademicSubjects/MED00200 ,Raised blood pressure ,Rural area ,Cardiology and Cardiovascular Medicine ,business ,Opportunistic screening ,1102 Cardiorespiratory Medicine and Haematology - Abstract
Raised blood pressure (BP) is a growing health care problem in the world leading to over 10 million deaths annually. May Measurement Month (MMM), which aims at raising awareness and screening people for raised BP, is assisting people to know their BP status. In 2018, an opportunistic cross-sectional survey was carried out during May and June in 10 791 volunteers aged 18 years and above following that done in 2017. The screening took place in Lilongwe, Blantyre, Dedza, Kasungu, and Nkhatabay districts mostly in hospitals/clinics, marketplaces, workplaces, and churches/mosques with Kasungu and Nkhatabay in rural areas. After multiple imputation, 2404 (22.3%) had hypertension. Of individuals not receiving antihypertensive treatment, 2101 (20.0%) were found to have raised BP. Only 303 (12.6%) of those with hypertension were receiving antihypertensive treatment, and of these 101 (33.3%) had uncontrolled BP. MMM was the largest BP screening campaign ever undertaken in Malawi. The results identified a large number of individuals with raised BP who were unaware and not on treatment and over one-third of those on treatment were uncontrolled, indicating the need for better management of cases. These results suggest that opportunistic screening can identify significant numbers with raised BP.
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- 2020
13. Optic disc hemorrhage in nonglaucomatous eyes: A cross-sectional study with average 8-year follow-up
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Wan-Chen Ku, Chi-Chun Lai, Yeo-Yang Koh, Henry S L Chen, Ling Yeung, and Lan-Hsin Chuang
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Pigments ,Male ,genetic structures ,Eye Diseases ,Cross-sectional study ,Vision ,Nerve fiber layer ,Glaucoma ,Social Sciences ,Cardiovascular Medicine ,Vascular Medicine ,Diagnostic Radiology ,chemistry.chemical_compound ,Medical Conditions ,Optic Nerve Diseases ,Medicine and Health Sciences ,Psychology ,Cardiovascular Imaging ,Materials ,Visual Impairments ,Optic disc hemorrhage ,Multidisciplinary ,medicine.diagnostic_test ,Radiology and Imaging ,Angiography ,Retinal Hemorrhage ,Middle Aged ,Visual field ,medicine.anatomical_structure ,Physical Sciences ,Disease Progression ,Medicine ,Sensory Perception ,Female ,Anatomy ,Tomography, Optical Coherence ,Optic disc ,Research Article ,medicine.medical_specialty ,Imaging Techniques ,Science ,Ocular Anatomy ,Materials Science ,Optic Disk ,Cardiology ,Vision Disorders ,Hemorrhage ,Research and Analysis Methods ,Optic Disc ,Retina ,Signs and Symptoms ,Ocular System ,Diagnostic Medicine ,Ophthalmology ,medicine ,Humans ,Aged ,Retrospective Studies ,business.industry ,Cognitive Psychology ,Biology and Life Sciences ,Retinal Vessels ,Retinal ,medicine.disease ,eye diseases ,Cross-Sectional Studies ,chemistry ,Eyes ,Cognitive Science ,Visual Field Tests ,Perception ,sense organs ,Clinical Medicine ,Visual Fields ,business ,Head ,Neuroscience ,Follow-Up Studies - Abstract
Purpose To characterize changes in the retinal nerve fiber layer (RNFL) and peripapillary vessel density (VD) at the site of disc hemorrhage (DH) in nonglaucomatous eyes. Materials and methods This retrospective cross-sectional study included nonglaucomatous eyes diagnosed with unilateral DH. The change of DH was recorded using disc photography. Both anatomical data and functional visual field (VF) data were collected using optical coherence tomography angiography and Humphrey VF examination. Results Sixteen patients were included with average follow-up duration of 95 months. Almost half of DH episodes was initially presented at the inferotemporal area of the optic disc. Pigment formation at the previous DH site after resolution was noted in 12.5% of eyes. Sectoral radial peripapillary VD at the DH site was significantly lower in DH eyes than in the control group; however, the sectoral RNFL thickness at the DH site was not significantly decreased. Progression of the VF defect corresponding to the DH site was found in 81.3% of eyes despite regular use of antiglaucoma agents. The mean change in the VF mean deviation was -0.64 dB/year in DH eyes. Conclusion During long follow-up periods, decreased peripapillary VD at the DH site and progression of the VF defect corresponding to the DH site were detected in nonglaucomatous eyes. Retinal pigmentation with an RNFL defect is a clue for DH, although RNFL showed no significant change. Antiglaucoma treatment may not prevent the deterioration of visual function.
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- 2020
14. Short term clinical outcomes and analysis of risk factors for pacemaker implantation: a single center experience of self-expandable TAVI valves
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Gary S.H. Cheung, Simon C.Y. Chow, Alex Pui-Wai Lee, Eugene B. Wu, Henry K. L. Chui, Randolph H.L. Wong, and Kent Chak-Yu So
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Male ,Pacemaker, Artificial ,medicine.medical_treatment ,Comorbidity ,Coronary Artery Disease ,Aortic valve stenosis ,030204 cardiovascular system & hematology ,Cardiac pacemaker ,Coronary artery disease ,Postoperative Complications ,0302 clinical medicine ,Risk Factors ,Atrial Fibrillation ,Odds Ratio ,030212 general & internal medicine ,Stroke ,Aged, 80 and over ,Cardiac Pacing, Artificial ,Atrial fibrillation ,General Medicine ,Cardiac surgery ,Treatment Outcome ,Cardiothoracic surgery ,Heart Valve Prosthesis ,Outcome studies ,Cardiology ,Female ,Cardiology and Cardiovascular Medicine ,Research Article ,Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,Bundle-Branch Block ,lcsh:Surgery ,lcsh:RD78.3-87.3 ,Transcatheter Aortic Valve Replacement ,03 medical and health sciences ,Internal medicine ,medicine ,Humans ,Aged ,Retrospective Studies ,Transcatheter aortic valve implantation ,business.industry ,lcsh:RD1-811 ,medicine.disease ,Stenosis ,Heart Block ,lcsh:Anesthesiology ,Surgery ,business - Abstract
Objectives Transcatheter aortic valve implantation is a recognized treatment for patients with severe aortic stenosis at all risk groups. However, permanent pacemaker rates remain high for self expandable transcatheter valves and permanent pacemaker implantation has been associated with increased morbidity. In this analysis we aim to evaluate short term clinical outcomes post self expandable transcatheter aortic valve implantation and determine risk factors for permanent pacemaker implantation. Methods 88 patients with severe aortic stenosis with transcatheter aortic valve implantation performed between the year 2016–2018 were retrospectively analyzed. Outcomes of interest included 1- year all cause mortality, 30-day major adverse cardiovascular events, permanent pacemaker and paravalvular leak rates. Survival analysis was performed with Kaplan Meier analysis and risk factors for survival and permanent pacemaker rates were identified with log rank test and regression analysis. Results The mean age of the cohort was 80.3 +/− 6.9 years. The mean STS score was 9.25. The 30 day all-cause mortality was 5.7% and 1-year all cause mortality was 16.7%. 80 patients had transfemoral transcatheter aortic valve implantation, and a majority of the patients (85.2%) were implanted with Corevalve Evolut R device. The device success rate was 88.6%. Multivariate analysis identified concomitant severe coronary artery disease (OR = 18.2 +/− 0.9; P = 0.002), pre transcatheter aortic valve implantation atrial fibrillation (OR = 8.6 +/− 0.91; P = 0.02) and post procedural disabling stroke (OR = 32.6 +/− 1.35; P = 0.01) as risk factors for 1-year mortality. The 30-day pacemaker rate was 17.6%. The presence of right bundle branch block (OR 11.1 +/− 0.86; P = 0.005), non-coronary cusp implantation depth (OR = 1.34 +/− 0.15; P = 0.05) and a non coronary cusp implantation depth / membranous septal length ratio of more than 50% were associated with post procedural pacemaker implantation (OR = 29.9 +/− 1.72; P = 0.05). Among the 15 patients with post procedural pacemaker implantation, 40% were found to be non-pacemaker dependent at 1 year. Conclusion Short term outcomes of transcatheter aortic valve implantation in severe aortic stenosis patients are promising. Pacemaker rates remain high. More studies are needed to evaluate the factors that influence pacemaker rates and dependence to further improve transcatheter aortic valve implantation outcomes.
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- 2020
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15. Use of contemporary live tele‐video conferencing for continuing surgical training at the time of COVID ‐19 pandemic
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Ismail Sagap, Henry C L Tan, and Jih Huei Tan
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2019-20 coronavirus outbreak ,Coronavirus disease 2019 (COVID-19) ,business.industry ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Malaysia ,MEDLINE ,COVID-19 ,General Medicine ,medicine.disease ,computer.software_genre ,Surgical training ,Education, Distance ,Videoconferencing ,General Surgery ,Pandemic ,Medicine ,Education, Medical, Continuing ,Surgery ,Medical emergency ,Letters to the Editor ,business ,Letter to the Editor ,computer - Published
- 2020
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16. Outcome of Cervical Lymph Nodes Dissection for Thyroid Cancer with Nodal Metastases: A Southeast Asian 3-Year Experience
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Juin Y Ooi, Raymond Zhun Ming Lim, Jih Huei Tan, Henry C L Tan, and Seniyah Md. Sikin
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Adult ,Male ,medicine.medical_specialty ,Article Subject ,medicine.medical_treatment ,030209 endocrinology & metabolism ,Southeast asian ,lcsh:RC254-282 ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Thyroid Neoplasms ,Lymph node ,Aged ,Retrospective Studies ,business.industry ,Thyroidectomy ,Retrospective cohort study ,Neck dissection ,Middle Aged ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,Central lymph ,Surgery ,Dissection ,Treatment Outcome ,medicine.anatomical_structure ,Oncology ,Cervical lymph nodes ,Lymphatic Metastasis ,030220 oncology & carcinogenesis ,Neck Dissection ,Female ,business ,Follow-Up Studies ,Research Article - Abstract
Introduction. Therapeutic nodal dissection is still the mainstay of treatment for patients with lymph node metastases in many centres. The local data, however, on the outcome of therapeutic LND remains limited. Hence, this study aims to inform practice by presenting the outcomes of LND for thyroid cancer patients and our experience in a tertiary referral centre.Methods. This is a single-centre retrospective observational study in a Malaysian tertiary endocrine surgery referral centre. Patients who underwent total thyroidectomy with lymph node dissection between years 2013 and 2015 were included and electronic medical records over a 3-year follow-up period were reviewed. The outcomes of different lymph node dissection (LND), including central neck dissection, lateral neck dissection, or both, were compared.Results. Of the 43 subjects included, 28 (65.1%) had Stage IV cancer. Among the 43 subjects included, 8 underwent central LND, and 15 had lateral LND while the remaining 20 had dissection of both lateral and central lymph nodes. Locoregional recurrence was found in 16 (37.2%) of our subjects included, with no statistical difference between the central (2/8), lateral (7/15), and both (7/20). Postoperative hypocalcaemia occurred in 7 (16.3%) patients, and vocal cord palsy occurred in 5 (11.6%), whereas 9 patients (20.9%) required reoperation. Death occurred in 4 of our patients.Conclusion. High recurrence and reoperative rates were observed in our centre. While the routine prophylactic LND remains controversial, high risk patients may be considered for prophylactic LND. The long-term risk and benefit of prophylactic LND with individualised patient selection in the local setting deserve further studies.
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- 2019
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17. Acute Septic Arthritis Following Supra-Patellar Nailing of an Open Diaphyseal Tibia Fracture in an Immune Compromised Patient
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E Krygier Jeffrey, Usa Clinics, E Hall Kimberley, Henry Goodnough L, and P Comstock Curt
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musculoskeletal diseases ,medicine.medical_specialty ,business.industry ,Tibia Fracture ,Medicine ,Septic arthritis ,musculoskeletal system ,business ,medicine.disease ,human activities ,Immune compromised ,Surgery - Abstract
The supra-patellar approach represents one approach to intramedullary nailing (IMN) of diaphyseal tibia fractures. Violation of the knee joint utilizing an intra-articular start point represents a risk for septic arthritis of the knee in the post-operative period. Previous retrospective studies of open tibia and femur fractures demonstrated that post-operative knee sepsis is rare, occurs in the chronic phase after injury, and due to extent of soft tissue injury rather than immune compromise. Here, we review current literature on post-operative knee sepsis, and present a case of acute septic arthritis of the knee following supra-patellar nailing of an open tibia fracture in a patient on chronic immune suppression. In this unique case, co-morbid patient factors likely led to this manifestation of a rare complication.
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- 2018
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18. Evaluation of the safety and efficacy of the dual wavelength picosecond laser for the treatment of benign pigmented lesions in Asians
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Henry H-L. Chan, Samantha Y N Shek, Chi K Yeung, and Ka-yee Kung
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medicine.medical_specialty ,Side effect ,Visual analogue scale ,business.industry ,Melasma ,Standard treatment ,Tattoo removal ,Dermatology ,medicine.disease ,01 natural sciences ,Hyperpigmentation ,010309 optics ,Lesion ,030207 dermatology & venereal diseases ,03 medical and health sciences ,0302 clinical medicine ,Patient satisfaction ,0103 physical sciences ,Medicine ,Surgery ,medicine.symptom ,business - Abstract
Background and objectives Cutaneous pigmentary disorders are both more common and more difficult to treat in patients with skin color given the higher melanin content in the epidermis. Although Q-switched lasers are widely considered to be the standard treatment for both epidermal and dermal pigmentary conditions, a very high risk of post-inflammatory hyperpigmentation (PIH) of up to 25% is seen in patients with skin of color. Recently, the novel picosecond laser with pulse durations operating at sub-nanosecond domains has been shown to be effective in tattoo removal and in the treatment of acne scars. The objective of this study is to examine the safety and efficacy of the dual wavelength picosecond laser for the treatment of benign pigmented skin lesions in Asian patients. Methods Twelve subjects with benign pigmentary disorders and Fitzpatrick skin types III to IV were recruited in a prospective clinical study to examine the safety and efficacy of the dual wavelength picosecond laser. Patients were treated at approximately 2-6 week intervals depending of the type of lesion. The primary efficacy endpoint is the global percent of clearance which was evaluated by blinded observers using post treatment photographs compared to baseline photographs. Safety was evaluated before and after each laser treatment and patients were asked to rate the level of pain according to the Visual Analog Scale after each treatment session. Patient satisfaction was assessed at the completion of treatment with questionnaires. All patients were followed up at 4, 8, and 12 weeks after the last treatment session. Results The pigmentary conditions treated included melasma, freckles, lentiginies, cafe au lait macules, and Hori's macules. Three months after treatment, 53.8% of all pigments achieved excellent response (75-94% lightening,) 30.8% of pigments achieved good response (50-74% lightening,) and 7.7% of pigments achieved both fair (25-49% lightening) and poor responses (0-24% lightening), respectively. The average number of treatment sessions required to reach at least 50% clearance was 4.5 for melasma, 1 for freckles, 1.5 for lentigines and 1 for cafe au lait. The patient with Hori's macules did not reach 50% clearance after a total of six treatments. Sixty three percent of patients reported satisfaction in the subjective assessment, while 27.3% were neutral and 9.1% were very dissatisfied. The post inflammatory hyperpigmentation rate was 4.8% and 6.5% of subjects developed blistering as a side effect of treatment. Conclusion The dual wavelength picosecond laser is a safe and effective treatment of benign pigmentary conditions in patients with skin of color. In particular, superior clinical efficacy is demonstrated for treatment of freckles and lentigines with a low risk of PIH. Lasers Surg. Med. 51:14-22, 2019. © 2018 Wiley Periodicals, Inc.
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- 2018
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19. Trapping effects and microwave power performance in AlGaN/GaN HEMTs
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Binari, Steven C., Ikossi, Kiki, Roussos, Jason A., Kruppa, Walter, Park, Doewon, Dietrich, Harry B., Koleske, Daniel D., Wickenden, Alma E., and Henry, Richard L.
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Field-effect transistors -- Research ,High-electron-mobility transistors -- Research ,Business ,Electronics ,Electronics and electrical industries - Abstract
The small-signal, dc, and microwave power output characteristics of GaN-based field-effect transistors are presented.
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- 2001
20. An optical communication design laboratory
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Buck, John A., Owen, Henry W. L., III, Uyemura, John P., Verber, Carl M., and Blumenthal, Daniel J.
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Fiber optics -- Study and teaching ,Laboratories -- Design and construction ,Optical communications -- Study and teaching ,Business ,Education ,Electronics ,Electronics and electrical industries - Abstract
A senior-level design laboratory course is described, in which an optical fiber communication network is expanded or improved by successive generations of students. In this evolutionary approach, student teams base their work on the final written reports of students in previous course offerings. In addition to its primary goal of providing a high-level technical experience, the course requires multidisciplinary teamwork and provides incentive for the development of effective oral and written communication skills. Results of four offerings of the course are presented. Index Terms - Capstone design, fiber optics, interdisciplinary design, optical communications.
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- 1999
21. Childhood exposure to constricted living space: a possible environmental threat for myopia development
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Henry H. L. Chan, Zhe Chuang Li, Yamunadevi Lakshmanan, Kai Yip Choi, Wing Yan Yu, Man Pan Chin, Christie Hang I Lam, Paul H. Lee, Francisca Siu Yin Wong, and Chi Wai Do
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Male ,Refractive error ,medicine.medical_specialty ,Living space ,Demographics ,Living environment ,Refraction, Ocular ,Population density ,03 medical and health sciences ,0302 clinical medicine ,Epidemiology ,Myopia ,Prevalence ,medicine ,Humans ,Child ,Retrospective Studies ,business.industry ,Confounding ,Environmental Exposure ,Axial length ,medicine.disease ,Sensory Systems ,Axial Length, Eye ,Ophthalmology ,030221 ophthalmology & optometry ,Hong Kong ,Optometry ,Female ,business ,030217 neurology & neurosurgery ,Follow-Up Studies ,Demography - Abstract
Purpose People in Hong Kong generally live in a densely populated area and their homes are smaller compared with most other cities worldwide. Interestingly, East Asian cities with high population densities seem to have higher myopia prevalence, but the association between them has not been established. This study investigated whether the crowded habitat in Hong Kong is associated with refractive error among children. Methods In total, 1075 subjects [Mean age (S.D.): 9.95 years (0.97), 586 boys] were recruited. Information such as demographics, living environment, parental education and ocular status were collected using parental questionnaires. The ocular axial length and refractive status of all subjects were measured by qualified personnel. Results Ocular axial length was found to be significantly longer among those living in districts with a higher population density (F2,1072 = 6.15, p = 0.002) and those living in a smaller home (F2,1072 = 3.16, p = 0.04). Axial lengths were the same among different types of housing (F3,1071 = 1.24, p = 0.29). Non-cycloplegic autorefraction suggested a more negative refractive error in those living in districts with a higher population density (F2,1072 = 7.88, p
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- 2017
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22. Longitudinal outcomes of circumlimbal suture model-induced chronic ocular hypertension in Sprague-Dawley albino rats
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Henry H. L. Chan, Yamunadevi Lakshmanan, Bang V. Bui, Bing Zuo, and Francisca Siu Yin Wong
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medicine.medical_specialty ,Intraocular pressure ,genetic structures ,Ocular hypertension ,Glaucoma ,Rats, Sprague-Dawley ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,0302 clinical medicine ,Suture (anatomy) ,Ophthalmology ,medicine ,Animals ,Intraocular Pressure ,Sutures ,business.industry ,Retinal ,medicine.disease ,eye diseases ,Sensory Systems ,Ganglion ,Rats ,Disease Models, Animal ,medicine.anatomical_structure ,Retinal ganglion cell ,chemistry ,030221 ophthalmology & optometry ,Ocular Hypertension ,sense organs ,business ,Erg ,030217 neurology & neurosurgery - Abstract
To characterise longitudinal structural and functional changes in albino Sprague-Dawley rats following circumlimbal suture ocular hypertension (OHT) induction. Ten-week-old rats (n = 24) underwent suture implantation around the limbal region in both eyes. On the next day, the suture was removed from one eye (control eyes) and left intact in the other eye (OHT eyes) of each animal. Intraocular pressure (IOP) was monitored weekly twice for the next 15 weeks. Optical coherence tomography (OCT) and electroretinogram (ERG) were measured at baseline and weeks 4, 8, 12, and 15, and eyes were then collected for histological assessment. Sutured eyes (n = 12) developed IOP elevation of ~ 50% in the first 2 weeks that was sustained at ~ 25% above the control eye up to week 15 (p = 0.001). Animals with insufficient IOP elevation (n = 6), corneal changes (n = 3), and attrition (n = 3) were excluded from the analysis. OHT eyes developed significant retinal nerve fibre layer (RNFL) thinning (week 4: − 19 ± 14%, p = 0.10; week 8: − 17 ± 12%, p = 0.04; week 12: − 16 ± 10%, p = 0.04, relative to baseline) and reduction in retinal ganglion cell (RGC) density (− 32 ± 26%, p = 0.02). At week 15, both inner (9 ± 7%, p = 0.01) and outer retinal layer thicknesses (6.0 ± 5%, p = 0.001) showed a mild increase in thicknesses. The positive scotopic threshold response (− 28 ± 25%, p = 0.04) and a-wave were significantly reduced at week 12 (− 35 ± 21%; p = 0.04), whereas b-wave was not significantly affected (week 12: − 18 ± 27%, p = 0.24). The circumlimbal suture model produced a chronic, moderate IOP elevation in an albino strain that led to RNFL thinning and reduced RGC density along with the reductions in ganglion and photoreceptoral cell functions. There was a small thickening in both outer and inner retinal layers.
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- 2020
23. A Novel Method of Nasojejunal Feeding and Gastric Decompression Using a Double Lumen Silicone Tube for Upper Gastrointestinal Obstruction
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Yun R Tan, Henry C L Tan, Mahendran Hans Alexander, Gunasunthari Sivadurai, Jih Huei Tan, and Shukri Jahit
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Adult ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Silicones ,Lumen (anatomy) ,Enteral administration ,03 medical and health sciences ,0302 clinical medicine ,Enteral Nutrition ,medicine ,Intubation ,Humans ,Prospective Studies ,Esophagus ,Feeding tube ,Intubation, Gastrointestinal ,Aged ,business.industry ,Gastric Outlet Obstruction ,Gastric outlet obstruction ,Endoscopy ,Nasojejunal Tube ,Jejunal Diseases ,Middle Aged ,medicine.disease ,Surgery ,medicine.anatomical_structure ,Parenteral nutrition ,030220 oncology & carcinogenesis ,030211 gastroenterology & hepatology ,Female ,business ,Intestinal Obstruction - Abstract
Background Provision of enteral nutrition with jejunal feeding in upper gastrointestinal obstruction is highly recommended. Access to jejunum can be obtained surgically, percutaneously, or endoscopically. Our institution routinely and preferentially utilizes a silicone nasojejunal tube that is inserted past the obstruction endoscopically. We use a custom dual channel tube that allows feeding at the distal tip and another channel 40 cm from the tip that enables decompression proximally. This is a report of our experience with this custom nasojejunal tube. Methods This is a prospective observational study of 201 patients who underwent endoscopic nasojejunal wire-guided feeding tube insertions for obstruction of either the esophagus or the stomach including both benign and malignant pathologies between January 2015 to June 2018 in Hospital Sungai Buloh and Hospital Sultanah Aminah, Malaysia. The indications for tube insertion, insertion technique, and tube-related problems were described. Results The nasojejunal tube was used to establish enteral feeding in patients with obstructing tumors of the distal esophagus in 65 patients (32.3%) and gastric outlet obstruction in 72 patients (35.8%). There were 54 patients (26.9%) who required reinsertion. The most common reason for reinsertion was unintentional dislodgement, where 32 patients (15.9%) followed by tube blockage 20 patients (10.0%). Using our method of advancement under direct vision, we had only 2 cases of malposition due to severely deformed anatomy. We had no incidence of aspiration in this group of patients and overall, the patients tolerated the tube well. Conclusions The novel nasojejunal feeding tube with gastric decompression function is a safe and effective method of delivery of enteral nutrition in patients with upper gastrointestinal obstruction. These tubes if inserted properly are well tolerated with almost no risk of malposition and are tolerated well even for prolonged periods of time until definitive surgery could be performed.
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- 2020
24. Posttreatment Intervention With Lycium Barbarum Polysaccharides is Neuroprotective in a Rat Model of Chronic Ocular Hypertension
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Henry H. L. Chan, Francisca Siu Yin Wong, Yamunadevi Lakshmanan, Kwok-Fai So, Bing Zuo, and Bang V. Bui
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0301 basic medicine ,Retinal Ganglion Cells ,Intraocular pressure ,medicine.medical_specialty ,genetic structures ,Ocular hypertension ,Glaucoma ,Retinal ganglion ,Retina ,Rats, Sprague-Dawley ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Nerve Fibers ,Ophthalmology ,medicine ,Electroretinography ,Animals ,Ganglion cell layer ,Intraocular Pressure ,medicine.diagnostic_test ,business.industry ,Retinal ,medicine.disease ,eye diseases ,Rats ,Disease Models, Animal ,030104 developmental biology ,medicine.anatomical_structure ,Neuroprotective Agents ,chemistry ,Chronic Disease ,Nerve Degeneration ,030221 ophthalmology & optometry ,Female ,Ocular Hypertension ,sense organs ,business ,Erg ,Tomography, Optical Coherence ,Drugs, Chinese Herbal - Abstract
Purpose To investigate the neuroprotective effects of Lycium barbarum polysaccharides (LBP) against chronic ocular hypertension (OHT) in rats and to consider if effects differed when treatment was applied before (pretreatment) or during (posttreatment) chronic IOP elevation. Methods Sprague-Dawley rats (10-weeks old) underwent suture implantation around the limbus for 15 weeks (OHT) or 1 day (sham). Four experimental groups were studied, three OHT groups (n = 8 each) treated either with vehicle (PBS), LBP pretreatment or posttreatment, and a sham control (n = 5) received no treatment. LBP (1 mg/kg) pre- and posttreatment were commenced at 1 week before and 4 weeks after OHT induction, respectively. Treatments continued up through week 15. IOP was monitored twice weekly for 15 weeks. Optical coherence tomography and ERG were measured at baseline, week 4, 8, 12, and 15. Eyes were collected for ganglion cell layer (GCL) histologic analysis at week 15. Results Suture implantation successfully induced approximately 50% IOP elevation and the cumulative IOP was similar between the three OHT groups. When compared with vehicle control (week 4: -23 ± 5%, P = 0.03), LBP pretreatment delayed the onset of retinal nerve fiber layer (RNFL) thinning (week 4, 8: -2 ± 7%, -11 ± 3%, P > 0.05) and arrested further reduction up through week 15 (-10 ± 4%, P > 0.05). LBP posttreatment intervention showed no significant change in rate of loss (week 4, 15: -25 ± 4.1%, -28 ± 3%). However, both LBP treatments preserved the retinal ganglion cells (RGC) and retinal functions up to week 15, which were significantly reduced in vehicle control. Conclusions LBP posttreatment arrested the subsequent neuronal degeneration after treatment commencement and preserved RGC density and retinal functions in a chronic OHT model, which was comparable with pretreatment outcomes.
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- 2019
25. Data on assessment of safety and tear proteome change in response to orthokeratology lens - Insight from integrating clinical data and next generation proteomics
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Henry H. L. Chan, Thomas Chuen Lam, Tsz King Wong, Jimmy S.H. Tse, Ying Hon Sze, and Jimmy Kai Wai Cheung
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SWATH ,medicine.medical_specialty ,genetic structures ,medicine.medical_treatment ,Proteomics ,lcsh:Computer applications to medicine. Medical informatics ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,law ,Ophthalmology ,Biochemistry, Genetics and Molecular Biology ,medicine ,Myopia ,lcsh:Science (General) ,030304 developmental biology ,0303 health sciences ,Multidisciplinary ,Special design ,business.industry ,Orthokeratology ,Public repository ,Mass spectrometric ,eye diseases ,Lens (optics) ,Tears ,Proteome ,lcsh:R858-859.7 ,sense organs ,business ,Ocular surface ,030217 neurology & neurosurgery ,lcsh:Q1-390 - Abstract
Breath-O™ Correct Ortho-K lenses are newly designed ortho-K lenses which are made from a silicon and fluoride containing methacrylate compound. This compound is said to be more flexible, durable and less likely to break compared to traditional Ortho-K lenses. The special design of this Ortho-K lens can reshape the corneal profile to induce temporary myopic reduction while producing beneficial peripheral hyperopic defocus for myopia control. To evaluate the safety and ocular surface responses of overnight Ortho-K wear over 1 and 3 months using this new type of material, we evaluated the clinical parameters (corneal integrity, corneal biomechanics, corneal endothelial health, non-invasive keratographical break-up time) and profiled the change of global tear proteome on healthy young subjects using next generation proteomics (SWATH-MS). The acquired mass spectrometric data were processed and analyzed using a cloud based Oneomics™ bioinformatic platform. All raw data generated from Information-dependent acquisition (IDA) and SWATH acquisitions were accepted and published in the Peptide Atlas public repository for general release (http://www.peptideatlas.org/PASS/PASS01367). Keywords: Tears, Orthokeratology, SWATH, Myopia
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- 2019
26. Algorithm for Distributed Generation Micro-dispatch Control
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Zeno Luiz Iensen Nadal, Carlos Gabriel Bianchin, Luciana M. Iantorno, Pedro Augusto Biasuz Block, Henry L. L. Salamanca, and Amanda Canestraro
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Total harmonic distortion ,Standardization ,Computer science ,business.industry ,020209 energy ,020208 electrical & electronic engineering ,Photovoltaic system ,02 engineering and technology ,Power (physics) ,Overvoltage ,Distributed generation ,0202 electrical engineering, electronic engineering, information engineering ,Inverter ,Communications protocol ,business ,Algorithm - Abstract
Global growth of distributed generation, especially photovoltaic, has given rise to new markets and new problems: large injection of power at daily intervals without increasing in the level of consumption. This scenario has already created, in certain places, overvoltage problems, harmonic distortion, etc. In Brazil, the standards regulate the connection of photovoltaic inverters, however, the control is not yet subject to standardization. For this reason, this paper presents a proposal of algorithm for this power injection control in accordance with the solutions of problems such as the lack of standardization in the communication protocol of the inverters. The results of the pilot plant application are also presented.
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- 2019
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27. Lycium Barbarum Polysaccharides Rescue Neurodegeneration in an Acute Ocular Hypertension Rat Model Under Pre- and Posttreatment Conditions
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Serena Zhe Chuang Li, Kai Yip Choi, Wing Yan Yu, Francisca Siu Yin Wong, Yamunadevi Lakshmanan, Kwok-Fai So, and Henry H. L. Chan
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Retinal Ganglion Cells ,medicine.medical_specialty ,Intraocular pressure ,Ocular hypertension ,Polysaccharide ,Rats, Sprague-Dawley ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Internal medicine ,medicine ,Electroretinography ,Animals ,Ganglion cell layer ,Intraocular Pressure ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,medicine.diagnostic_test ,biology ,business.industry ,Neurodegeneration ,Retinal ,medicine.disease ,biology.organism_classification ,Rats ,Disease Models, Animal ,medicine.anatomical_structure ,Endocrinology ,Treatment Outcome ,chemistry ,Female ,Ocular Hypertension ,Lycium ,Visual Fields ,business ,030217 neurology & neurosurgery ,Tomography, Optical Coherence ,Drugs, Chinese Herbal ,Follow-Up Studies - Abstract
To investigate the posttreatment neuronal rescue effects of Lycium barbarum polysaccharides (LBP) in an acute ocular hypertensive (AOH) model.Intraocular pressure (IOP) was elevated manometrically to 80 mm Hg (AOH) or 15 mm Hg (sham) for 120 minutes in adult Sprague-Dawley rats. Five experimental groups were considered: Three AOH groups were pretreated with PBS (vehicle) (n = 9), LBP 1 mg/kg (n = 8), or 10 mg/kg (n = 13), and one AOH group was posttreated with LBP 10 mg/kg (n = 8), once daily. The sham cannulation group (n = 5) received no treatment. Pretreatments commenced 7 days before and posttreatment 6 hours after AOH, and continued up through postcannulation day 28. All the animals underwent optical coherence tomography and electroretinogram measurements at baseline and postcannulation days 10 and 28. The ganglion cell layer (GCL) densities were quantified at day 28.Both inner retinal layer thickness (IRLT) and positive scotopic threshold response (pSTR) underwent significant reduction (≥50% of thickness and amplitude) in the vehicle group (P0.05). Pretreatment with LBP 1 and 10 mg/kg retained 77 ± 11% and 89 ± 8% of baseline IRLT, respectively, and preserved pSTR functions. The posttreatment group showed a significant reduction in IRLT (-35 ± 8%, P0.001) and pSTR (∼48% of baseline, P0.001) on day 10. By day 28, there was an improvement in functional pSTR (∼72% of baseline, P0.05) with no significant further thinning (-40 ± 8%, P = 0.15) relative to day 10. GCL density was reduced in vehicle control (P = 0.0001), but did not differ between sham and pre- and posttreated AOH groups.The rescue effect of LBP posttreatment was observed later, which arrested the secondary degeneration and improved the retinal function.
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- 2019
28. May Measurement Month 2017: results of a blood pressure screening campaign in Malawi-Sub-Saharan Africa
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Mary K Mbeba, Elsa Kobeissi, Jones K Masiye, Maureen L Chirwa, Neil R Poulter, Thomas Beaney, Georgina Chinula, Henry L L Ndhlovu, and Xin Xia
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Blood pressure ,Sub saharan ,Cardiovascular System & Hematology ,business.industry ,Environmental health ,MEDLINE ,Medicine ,Articles ,Cardiology and Cardiovascular Medicine ,business ,1102 Cardiorespiratory Medicine and Haematology - Abstract
Elevated blood pressure (BP) is a growing burden worldwide, leading to over 10 million deaths each year. May Measurement Month (MMM) is a global initiative aimed at raising awareness of high BP and to act as a temporary solution to the lack of screening programs worldwide. A World Health Organization and Ministry of Health STEPS Survey conducted in 2009 in Malawi found that 32.9% tested positive for age-standardized hypertension. The survey further showed that three-quarters (75%) of the participants never had their BP measured before and 94.9% with high BP were unaware of the hypertensive condition. An opportunistic cross-sectional survey of volunteers aged ≥18 was carried out in May 2017. BP measurement, the definition of hypertension and statistical analysis followed the standard MMM protocol. The screening took place in cities of Lilongwe and Blantyre mostly in hospitals, clinics, marketplaces, workplaces, and churches. About 4009 individuals were screened during MMM17. After multiple imputations, 849 (22.3%) had hypertension. Of individuals not receiving antihypertensive medication, 697 (19.1%) were found to have hypertension. Only 152 individuals were receiving antihypertensive medication, and of these 78 (51.4%) had uncontrolled BP. MMM17 was the largest BP screening campaign ever undertaken in Malawi. The results identified a large number with hypertension who were not on treatment and over half of those on antihypertensive treatment who were uncontrolled, indicating the need for better management of cases. These results suggest that opportunistic screening can identify significant numbers with raised BP.
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- 2019
29. May Measurement Month 2018: a pragmatic global screening campaign to raise awareness of blood pressure by the International Society of Hypertension
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Beaney, Thomas, Burrell, Louise M, Castillo, Rafael R, Charchar, Fadi J, Cro, Suzie, Damasceno, Albertino, Kruger, Ruan, Nilsson, Peter M, Prabhakaran, Dorairaj, Ramirez, Agustin J, Schlaich, Markus P, Schutte, Aletta E, Tomaszewski, Maciej, Touyz, Rhian, Wang, Ji-Guang, Weber, Michael A, Poulter, Neil R, Burazeri, Genc, Qirjako, Gentiana, Roshi, Enver, Cunashi, Rudina, Fernandes, Mario J C C, Victória Pereira, Savarino S, Neto, Marisa F M P, Oliveira, Pombalino N M, Feijão, Ana C G, Cerniello, Yamila, Marin, Marcos J, Garcia Vasquez, Fortunato, Espeche, Walter G, Stisman, Diego, Fuentes, Inés A, Zilberman, Juith M, Rodriguez, Pablo, Babinyan, Kamsar Yu, Engibaryan, Anna H, Avagyan, Avag M, Minasyan, Arsen A, Gevorkyan, Ani T, Carnagarin, Revathy, Carrington, Melinda J, Sharman, James E, Lee, Rebecca, Perl, Sabine, Niederl, Ella, Malik, Fazila-Tun-Nesa, Choudhury, Sohel R, Al Mamun, Mohammad A, Ishraquzzaman, Mir, Anthony, Fiona, Connell, Kenneth, De Backer, Tine L M, Krzesinski, Jea, Houenassi, Martin D, Houehanou, Corine Y, Sokolovic, Sekib, Bahtijarevic, Rankica, Tiro, Mary B, Mosepele, Mosepele, Masupe, Tiny K, Barroso, Weimar S, Gomes, Marco A M, Feitosa, Audes D M, Brandão, Andrea A, Miranda, Roberto D, Azevedo, Vanda M A A, Dias, Luis M, Garcia, Glenda D N, Martins, Idiana P P, Dzudie, Anastase, Kingue, Samuel, Djomou, Florent A N, Njume, Epie, Khan, Nadia, Lanas, Fernando T, Garcia, Maria S, Paccot, Melanie F, Torres, Pamela I, Li, Yan, Liu, Min, Xu, Liying, Li, Li, Chen, Xin, Deng, Junping, Zhao, Wenwu, Fu, Lingjuan, Zhou, Yi, Lopez-Jaramillo, Patricio, Otero, Johanna, Camacho, Paul A, Accini, Jose L, Sanchez, Gregorio, Arcos, Edgar, M’Buyamba-Kabangu, Jean-René, Katamba, Fortunat K, Ngoyi, Georges N, Buila, Nathan M, Bayauli, Pascal M, Ellenga Mbolla, Bertrand F, Bakekolo, Paterne R, Kouala Landa, Christian M, Kimbally Kaky, Gisele S, Kramoh, Euloge K, Ngoran, Yves N K, Olsen, Michael H, Valdez Valoy, Laura, Santillan, Marcos, Angel Rafael, Gonzalez Medina, Peñaherrera, Carlos E, Villalba, Jose, Ramirez, Maria I, Arteaga, Fabricio, Delgado, Patricia, Beistline, Holly, Cappuccio, Francesco P, Keitley, James, Tay, Tricia, Goshu, Dejuma Y, Kassie, Desalew M, Gebru, Sintayehu A, Pathak, Atul, Denolle, Thierry, Tsinamdzgvrishvili, Bezhan, Trapaidze, Dali, Sturua, Lela, Abesadze, Tamar, Grdzelidze, Nino, Grabfelder, Mark, Krämer, Bernhard K, Schmeider, Roland E, Twumasi-Ankrah, Betty, Tannor, Elliot K, Lincoln, Mary D, Deku, Enoch M, Wyss Quintana, Fernando S, Kenerson, John, Jean Baptiste, Emmanuela D, Saintilmond, Wideline W, Barrientos, Ana L, Peiger, Briggitte, Lagos, Ashley R, Forgas, Marcelo A, Lee, Vivian W Y, Tomlinson, Brian W Y, Járai, Zoltán, Páll, Dénes, More, Arun, Maheshwari, Anuj, Verma, Narsingh, Sharma, Meenakshi, Mukherjee, Tapan K, Patil, Mansi, Pulikkottil Jose, Arun, Takalkar, Anant, Turana, Yuda, Widyantoro, Bambang, Danny, Siska S, Djono, Suhar, Handari, Saskia D, Tambunan, Marihot, Tiksnadi, Badai B, Hermiawaty, Eka, Tavassoli, Elham, Zolfaghari, Mahsa, Dolan, Eamon, O'Brien, Eoin, Borghi, Claudio, Ferri, Claudio, Torlasco, Camilla, Parati, Gianfranco, Nwokocha, Chukwuemeka R, Nwokocha, Magdalene I, Ogola, Elijah N, Gitura, Bernard M, Barasa, Anders L, Barasa, Felix A, Wairagu, Anne W, Nalwa, Wafula Z, Najem, Robert N, Abu Alfa, Ali K, Fageh, Hatem A, Msalam, Omar M, Derbi, Hawa A, Bettamar, Kzaki A, Zakauskiene, Urte, Vickiene, Alvita, Calmes, Jessica, Alkerwi, Ala'a, Gantenbein, Manon, Ndhlovu, Henry L L, Masiye, Jones K, Chirwa, Maureen L, Nyirenda, Nancy M, Dhlamini, Tiyezge D, Chia, Yook C, Ching, Siew M, Devaraj, Navin K, Ouane, Nouhoum, Fane, Tidiani, Kowlessur, Sudhir, Ori, Bhooshun, Heecharan, Jaysing, Alcocer, Luis, Chavez, Adolfo, Ruiz, Griselda, Espinosa, Cutberto, Gomez-Alvarez, Enrique, Neupane, Dinesh, Bhattarai, Harikrishna, Ranabhat, Kamal, Adhikari, Tara B, Koirala, Sweta, Toure, Ibrahim A, Soumana, Kabirou H, Wahab, Kolawole W, Omotoso, Ayodele B, Sani, Mahmoud U, Okubadejo, Njideka U, Nadar, Sunil K, Al-Riyami, Hassan A, Ishaq, Mohammad, Memon, Feroz, Sidique, Sualat, Choudhry, Hafeez A, Khan, Rasheed A, Ayala, Myrian, Maidana, Angel J O, Bogado, Graciela GG, Ona, Deborah I, Atilano, Alberto, Granada, Carmela, Bartolome, Regina, Manese, Loudes, Mina, Arnold, Dumlao, Maria C, Villaruel, Mariyln C, Gomez, lynn, Jóźwiak, Jacek, Małyszko, Jolanta, Banach, Maciej, Mastej, Mirosław, de Carvalho Rodrigues, Manuel M, Martins, Luis L, Paval, Alexandra, Dorobantu, Maria, Konradi, Alexandra O, Chazova, Irina E, Rotar, Oxana, Spoares, Miryan C, Viegas, Deolsanik, Almustafa, Bader A, Alshurafa, Saleh A, Brady, Adrian, Bovet, Pascal, Viswanathan, Bharathi, Oladapo, Olulola O, Russell, James W, Brguljan-Hitij, Jana, Bozic, Nina, Knez, Judita, Dolenc, Primoz, Hassan, Mohammed M, Woodiwiss, Angela J, Myburgh, Caitlynd, Vally, Muhammed, Ruilope, Luis M, Molinero, Ana, Rodilla, Enrique, Gijón-Conde, Teresa, Beheiry, Hind M, Ali, I A, Osman, Asma A A, fahal, Naiema A W, Osman, Hana A, Altahir, Fatima, Persson, Margaretha, Wuerzner, Gregoire, Burkard, Thilo, Wang, Tzung-Dau, Lin, Hung-Ju, Pan, Heng-Yu, Chen, Wen-Jone, Lin, Eric, Mondo, Charles K, Ingabire, Prossie M, Khomazyuk, Tatyana TA, Krotova, Viktoriia V-Yu, Negresku, Elena, Evstigneeva, Olena, Bazargani, Nooshin NB, Agrawal, Amrish, Bin Belaila, Buthaina A, Suhail, Aisha M, Muhammed, Khalifa O, Shuri, Hassan H, Wainford, Richard D, Levy, Philip D, Boggia, José JG, Garré, Laura L, Hernandez-Hernandez, Rafael, Octavio-Seijas, Jose A, Lopez-Rivera, Jesus A, Morr, Igor, Duin, Amanda, Huynh, Minh V, Cao, Sinh T, Nguyen, Viet L, To, Muoi, Phan, Hung N, Cockroft, John, McDonnell, Barry, Goma, Fastone M, Syatalimi, Charity, Chifamba, Jephat, Gwini, Rudo, Tiburcio, Osiris Valdez, Xia, Xin, 20035632 - Kruger, Ruan, 10922180 - Schutte, Aletta Elisabeth, Beaney T., Burrell L.M., Castillo R.R., Charchar F.J., Cro S., Damasceno A., Kruger R., Nilsson P.M., Prabhakaran D., Ramirez A.J., Schlaich M.P., Schutte A.E., Tomaszewski M., Touyz R., Wang J.-G., Weber M.A., Poulter N.R., and Borghi C
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Male ,Cardiac & Cardiovascular Systems ,Cross-sectional study ,Blood Pressure ,030204 cardiovascular system & hematology ,Global Burden of Disease ,0302 clinical medicine ,Surveys and Questionnaires ,MMM Investigators ,Mass Screening ,030212 general & internal medicine ,1102 Cardiorespiratory Medicine and Haematology ,Antihypertensive medication ,RISK ,Global ,Awareness ,Middle Aged ,PREVALENCE ,Hypertension ,Blood pressure ,Screening ,Raised blood pressure ,Female ,Cardiology and Cardiovascular Medicine ,BURDEN ,Life Sciences & Biomedicine ,Control ,Adult ,medicine.medical_specialty ,Fast Track Clinical Research ,Opportunistic Sampling ,03 medical and health sciences ,Internal medicine ,medicine ,SYSTEMATIC ANALYSIS ,MANAGEMENT ,Humans ,Mass screening ,Disease burden ,Antihypertensive Agents ,Science & Technology ,business.industry ,Case-control study ,Blood Pressure Determination ,Treatment ,Editor's Choice ,RAMADAN ,Cross-Sectional Studies ,Cardiovascular System & Hematology ,Case-Control Studies ,Cardiovascular System & Cardiology ,business ,Hypertension, Blood pressure, Screening, Global, Treatment, Control - Abstract
Aims Raised blood pressure (BP) is the biggest contributor to mortality and disease burden worldwide and fewer than half of those with hypertension are aware of it. May Measurement Month (MMM) is a global campaign set up in 2017, to raise awareness of high BP and as a pragmatic solution to a lack of formal screening worldwide. The 2018 campaign was expanded, aiming to include more participants and countries. Methods and results Eighty-nine countries participated in MMM 2018. Volunteers (≥18 years) were recruited through opportunistic sampling at a variety of screening sites. Each participant had three BP measurements and completed a questionnaire on demographic, lifestyle, and environmental factors. Hypertension was defined as a systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg, or taking antihypertensive medication. In total, 74.9% of screenees provided three BP readings. Multiple imputation using chained equations was used to impute missing readings. 1 504 963 individuals (mean age 45.3 years; 52.4% female) were screened. After multiple imputation, 502 079 (33.4%) individuals had hypertension, of whom 59.5% were aware of their diagnosis and 55.3% were taking antihypertensive medication. Of those on medication, 60.0% were controlled and of all hypertensives, 33.2% were controlled. We detected 224 285 individuals with untreated hypertension and 111 214 individuals with inadequately treated (systolic BP ≥ 140 mmHg or diastolic BP ≥ 90 mmHg) hypertension. Conclusion May Measurement Month expanded significantly compared with 2017, including more participants in more countries. The campaign identified over 335 000 adults with untreated or inadequately treated hypertension. In the absence of systematic screening programmes, MMM was effective at raising awareness at least among these individuals at risk.
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- 2019
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30. Comparing yard waste and sludge compost
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Henry, Charles L. and Harrison, Robert B.
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Compost -- Composition ,Business ,Environmental issues ,Environmental services industry - Abstract
The predictability of nutrient contents and the effects on the soil of yard waste compost and sludge compost were compared. Sludge compost has long been known for its predictability and has thus gained wide use and acceptance. On the other hand, the results of the study showed that the effects of yard waste compost are unpredictable. To avoid setbacks in market acceptability of yard waste compost, it is suggested that management try to ensure a predictable material before full-scale production and marketing.
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- 1992
31. Normal tension glaucoma in obstructive sleep apnea syndrome
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Henry S L Chen, Ling Yeung, Chung-Chieh Yu, Chi-Chun Lai, Yu-Lun Lo, Yeo-Yang Koh, and Lan-Hsin Chuang
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medicine.medical_specialty ,genetic structures ,medicine.diagnostic_test ,business.industry ,Sleep apnea ,General Medicine ,Polysomnography ,medicine.disease ,eye diseases ,nervous system diseases ,respiratory tract diseases ,Obstructive sleep apnea ,03 medical and health sciences ,0302 clinical medicine ,Signal strength ,030220 oncology & carcinogenesis ,Ophthalmology ,Normal tension glaucoma ,Retinal capillary ,Severity of illness ,medicine ,sense organs ,030212 general & internal medicine ,Risk factor ,business - Abstract
This study characterized and evaluated normal tension glaucoma (NTG) in obstructive sleep apnea syndrome (OSAS).In this retrospective, cross-sectional study, all participants were examined with polysomnography (PSG). Functional parameters of standard automated perimetry (SAP) were recorded. Structural parameters in optical coherence tomography angiography (OCTA) included peripapillary superficial vessel density (VD RPC), peripapillary whole-layer (VD NH), and superficial and deep macular area VD. Participants were categorized into perimetric and nonperimetric groups by SAP result. Low reliability of SAP and signal strength index
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- 2020
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32. Delay of cone degeneration in retinitis pigmentosa using a 12-month treatment with Lycium barbarum supplement
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Wing Yan Yu, Serena Zhe Chuang Li, Henry H. L. Chan, Kwok-Fai So, Jimmy Shiu-Ming Lai, Hang i. Lam, Raymond Chuen-Chung Chang, Yamunadevi Lakshmanan, and Kai Yip Choi
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Retinal degeneration ,Adult ,Male ,medicine.medical_specialty ,genetic structures ,Placebo ,Placebos ,03 medical and health sciences ,0302 clinical medicine ,food ,Double-Blind Method ,Ophthalmology ,Drug Discovery ,Retinitis pigmentosa ,medicine ,Electroretinography ,Humans ,Scotopic vision ,Medicine, Chinese Traditional ,Adverse effect ,030304 developmental biology ,Pharmacology ,0303 health sciences ,biology ,business.industry ,Goji berry ,Lycium ,Middle Aged ,biology.organism_classification ,medicine.disease ,food.food ,Neuroprotective Agents ,Treatment Outcome ,030220 oncology & carcinogenesis ,Dietary Supplements ,Retinal Cone Photoreceptor Cells ,Female ,sense organs ,business ,Retinitis Pigmentosa ,Photopic vision ,Drugs, Chinese Herbal - Abstract
Ethnopharmacological relevance Lycium barbarum L. (also known as “Goji berry”), a traditional Chinese herbal medicine, has been a common herb in the traditional Chinese pharmacopoeia for centuries. The main active component is the Lycium barbarum polysaccharides and its antioxidative effect has been widely shown to provide neuroprotection to the eye, and it would, therefore, be interesting to determine if Lycium barbarum help delay vision deterioration in patients with retinitis pigmentosa. Aim of the study Cone rescue is a potential method for delaying deterioration of visual function in Retinitis pigmentosa (RP). This study aimed to investigate the treatment effect of Lycium barbarum L. (LB) supplement on retinal functions and structure in RP patients after a 12-month intervention trial. Methods The investigation was a double-masked and placebo-controlled clinical study. Each of forty-two RP subjects who completed the 12-month intervention (23 and 19 in the treatment and placebo groups respectively) received a daily supply of LB or placebo granules for oral administration. The primary outcome was change of best corrected visual acuity (VA) (90% and 10% contrast) from the baseline to the end of treatment. The secondary outcomes were sensitivity changes of the central visual field, amplitude of full-field electroretinogram (ffERG) (including scotopic maximal response and photopic cone response), and average macular thickness. Results The compliance rates for both groups exceeded 80%. There were no deteriorations of either 90% or 10% contrast VA in the LB group compared with the placebo group (p = 0.001). A thinning of macular layer was observed in the placebo group, which was not observed in the LB group (p = 0.008). However, no significant differences were found in the sensitivity of visual field or in any parameters of ffERG between the two groups. No significant adverse effects were reported in the treatment group. Conclusions LB supplement provides a neuroprotective effect for the retina and could help delay or minimize cone degeneration in RP. Classifications Clinical Studies (1.05). Trial registration clinicaltrials.gov Identifier NCT02244996.
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- 2018
33. Merging the Professional with the Layperson: Optometric Services for the Community
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Henry H. L. Chan, Horace H. Y. Wong, Ann Chan, Vivian W. Y. Lo, Ada H. T. Ma, Natalie Y. Y. Chan, Geoffrey Chu, Savio Lee, Lily Y.L. Chan, and Chi Wai Do
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medicine.medical_specialty ,business.industry ,Public health ,Service-learning ,Special needs ,Subject (documents) ,Public relations ,Bridge (interpersonal) ,Layperson ,Work (electrical) ,medicine ,Sociology ,business ,Structured prediction - Abstract
In this subject, we aim to integrate community services with students’ learning opportunities. Students work in groups and organize and implement a vision screening project by themselves under supervision. Through this subject, students are given opportunities to act upon their roles as community service providers, care, work, and communicate with various disciplines to bridge together knowledge they have acquired during their university studies and then share and apply their special interests with others. The project not only benefits service users, but also provides a very structured learning environment for students to gain experience working with a number of people in different levels of the community and to better understand societal needs, especially in this major public health concern of blindness prevention.
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- 2018
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34. Diagnosis of atlanto-occipital dissociation: Standardised measurements of normal craniocervical relationship in finless porpoises (genus Neophocaena) using postmortem computed tomography
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Henry C. L. Tsui, Adams Hei Long Yuen, Derek K. P. Chan, and Brian C. W. Kot
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0301 basic medicine ,Male ,040301 veterinary sciences ,Joint Dislocations ,lcsh:Medicine ,Computed tomography ,Porpoises ,Article ,Finless porpoise ,0403 veterinary science ,03 medical and health sciences ,medicine ,Animals ,lcsh:Science ,Multidisciplinary ,medicine.diagnostic_test ,biology ,business.industry ,lcsh:R ,04 agricultural and veterinary sciences ,Anatomy ,biology.organism_classification ,030104 developmental biology ,Atlanto-Occipital Joint ,lcsh:Q ,Female ,business ,Tomography, X-Ray Computed - Abstract
Due to the different craniocervical structures in humans and cetaceans, a standardised method assessing the normal craniocervical relationship in cetaceans is lacking, causing difficulties in defining the presence of atlanto-occipital dissociation (AOD) in cetaceans. The present study aimed to 1) describe a novel standardised method of determining the normal craniocervical relationships, and 2) define the 95% accuracy range of the normal craniocervical relationship in finless porpoises (genus Neophocaena), that allowed AOD diagnosis. Fifty-five out 83 stranded or by-caught finless porpoise carcasses were analyzed in term of their craniocervical relationship in dorsal-ventral and medial-lateral dimension, using postmortem computed tomography measurements. The normal craniocervical relationship in both dorsal-ventral (mean BD/OV: 0.87 ± 0.24 [2 SD]) and medial-lateral dimension (mean VR/VL: 0.98 ± 0.17 [2 SD]) was first defined. The 95% accuracy ranges of the normal craniocervical relationship in dorsal-ventral (0.63–1.11) and medial-lateral dimension (0.82–1.15) were proposed. The baseline ranges could facilitate AOD assessment, and provide an objective means of record for AOD related injury and death of cetaceans caused by anthropogenic trauma. The technique developed may be applied to live cetaceans with abnormal craniocervical relationship to aid diagnosis and guide corrective therapy.
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- 2018
35. A character-based convolutional neural network for language-agnostic Twitter sentiment analysis
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Joonatas Wehrmann, Willian Becker, Henry E. L. Cagnini, and Rodrigo C. Barros
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Vocabulary ,Artificial neural network ,Machine translation ,Computer science ,Character (computing) ,business.industry ,Process (engineering) ,media_common.quotation_subject ,InformationSystems_INFORMATIONSTORAGEANDRETRIEVAL ,Sentiment analysis ,Context (language use) ,02 engineering and technology ,computer.software_genre ,Machine learning ,Convolutional neural network ,020204 information systems ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Artificial intelligence ,business ,computer ,Natural language processing ,media_common - Abstract
Most work on tweet sentiment analysis is mono-lingual and the models that are generated by machine learning strategies do not generalize across multiple languages. Cross-language sentiment analysis is usually performed through machine translation approaches that translate a given source language into the target language of choice. Machine translation is expensive and the results that are provided by theses strategies are limited by the quality of the translation that is performed. In this paper, we propose a language-agnostic translation-free method for Twitter sentiment analysis, which makes use of deep convolutional neural networks with character-level embeddings for pointing to the proper polarity of tweets that may be written in distinct (or multiple) languages. The proposed method is more accurate than several other deep neural architectures while requiring substantially less learnable parameters. The resulting model is capable of learning latent features from all languages that are employed during the training process in a straightforward fashion and it does not require any translation process to be performed whatsoever. We empirically evaluate the efficiency and effectiveness of the proposed approach in tweet corpora based on tweets from four different languages, showing that our approach comfortably outperforms the baselines. Moreover, we visualize the knowledge that is learned by our method to qualitatively validate its effectiveness for tweet sentiment classification.
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- 2017
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36. Potential emmissions of synthetic VOCs from MSW composting
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Kissel, John C., Henry, Charles L., and Harrison, Robert B
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Volatile organic compounds -- Health aspects ,Compost plants -- Health aspects ,Air pollution -- Environmental aspects ,Business ,Environmental issues ,Environmental services industry - Abstract
Municipal solid (MSW) waste composting may have negative effects on the public health. Researches have discovered that MSW produce air emissions of volatile organic compounds (VOCs) whose commercial kinds include components such as paints and coatings, aerosols, cosmetics and cleaning agents. Sufficient exposure to these VOCs may lead to health risks. In a related development, the US EPA's Total Exposure Assessment Methodolody reports that US residents usually are exposed to VOCs. In addition, indoor concentrations of VOCs are higher because of the VOCs in commercial prodcts used and stored in side homes.
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- 1993
37. The Multifocal On- and Off-Responses in the Human Diabetic Retina
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Jenny C. Y. Lung, Henry H. L. Chan, and Peter G. Swann
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Blood Glucose ,Male ,genetic structures ,Light ,Vision ,lcsh:Medicine ,Social Sciences ,Stimulation ,chemistry.chemical_compound ,0302 clinical medicine ,Endocrinology ,Medicine and Health Sciences ,Psychology ,lcsh:Science ,Multidisciplinary ,medicine.diagnostic_test ,Physics ,Electromagnetic Radiation ,Diabetic retinopathy ,Middle Aged ,medicine.anatomical_structure ,Physical Sciences ,Retinal Disorders ,Sensory Perception ,Female ,Anatomy ,Research Article ,Adult ,medicine.medical_specialty ,Visible Light ,Color vision ,Endocrine Disorders ,Ocular Anatomy ,Surgical and Invasive Medical Procedures ,Stimulus (physiology) ,Retina ,03 medical and health sciences ,Ocular System ,Diabetes mellitus ,Internal medicine ,medicine ,Diabetes Mellitus ,Electroretinography ,Reaction Time ,Humans ,Retinopathy ,Analysis of Variance ,Diabetic Retinopathy ,Functional Electrical Stimulation ,Color Vision ,business.industry ,lcsh:R ,Biology and Life Sciences ,Retinal ,medicine.disease ,Ophthalmology ,Luminance ,chemistry ,Diabetes Mellitus, Type 2 ,Metabolic Disorders ,030221 ophthalmology & optometry ,Eyes ,lcsh:Q ,sense organs ,business ,Head ,030217 neurology & neurosurgery ,Biomarkers ,Photic Stimulation ,Neuroscience - Abstract
The characteristics of the on- and off-responses in the human diabetic retina by a "long-duration" multifocal electroretinogram (mfERG) paradigm were investigated. Changes in the retinal antagonistic interaction were also evaluated in the early stage of diabetes mellitus (DM). Twenty type II diabetic patients with no or mild non-proliferative diabetic retinopathy (NPDR) and twenty-one age-matched healthy controls were recruited for "long-duration" mfERG measurements. A 61-hexagon mfERG stimulus was displayed under two chromatic conditions (white/black and blue/black) at matched luminance. The amplitudes and implicit times of the on-response components (N1, P1 and N2) and off-response (P2) components were analysed. The blue stimulation generally triggered greater mfERG amplitudes in P1, N2 and P2 (p
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- 2016
38. Early local functional changes in the human diabetic retina: a global flash multifocal electroretinogram study
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Peter G. Swann, Jenny C. Y. Lung, and Henry H. L. Chan
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Blood Glucose ,medicine.medical_specialty ,genetic structures ,media_common.quotation_subject ,Visual Acuity ,Retina ,Contrast Sensitivity ,Cellular and Molecular Neuroscience ,Diabetes mellitus ,Ophthalmology ,Electroretinography ,Humans ,Medicine ,Contrast (vision) ,media_common ,Diabetic Retinopathy ,medicine.diagnostic_test ,Diabetic retina ,business.industry ,Diabetic retinopathy ,Middle Aged ,medicine.disease ,eye diseases ,Sensory Systems ,Retinal adaptation ,Diabetes Mellitus, Type 2 ,sense organs ,business ,Retinal Defect ,Photic Stimulation ,Retinopathy - Abstract
To investigate early functional changes of local retinal defects in type II diabetic patients using the global flash multifocal electroretinogram (MOFO mfERG). Thirty-eight diabetic patients and 14 age-matched controls were recruited. Nine of the diabetics were free from diabetic retinopathy (DR), while the remainder had mild to moderate non-proliferative diabetic retinopathy. The MOFO mfERG was performed at high (98 %) and low (46 %) contrast levels. MfERG responses were grouped into 35 regions for comparison with DR classification at those locations. Z-scores of the regional mfERG responses were compared across different types of DR defects. The mfERG waveform consisted of the direct component (DC) and the induced component (IC). Local reduction in DC and IC amplitudes were found in diabetic patients with and without DR. With increasing severity of retinopathy, there was a further deterioration in amplitude of both components. Under MOFO mfERG paradigm, amplitude was a useful screening parameter. The MOFO mfERG can help in detecting early functional anomalies before the appearance of visible signs, and may assist in monitoring further functional deterioration in diabetic patients.
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- 2012
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39. Effect of inner retinal dysfunction on slow double-stimulation multifocal electroretinogram
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Yiu-Fai Ng, Patrick H W Chu, Chi Ho To, Henry H. L. Chan, Wing-Cheung Ho, Patrick W. K. Ting, Kwok-Fai So, and Jenny C. Y. Lung
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Adult ,medicine.medical_specialty ,Intraocular pressure ,N-Methylaspartate ,genetic structures ,Glaucoma ,Stimulation ,Tetrodotoxin ,Retina ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Retinal Diseases ,Ophthalmology ,Electroretinography ,medicine ,Animals ,Humans ,business.industry ,Retinal ,Anatomy ,Middle Aged ,medicine.disease ,Adaptation, Physiological ,eye diseases ,Sensory Systems ,Retinal adaptation ,Disease Models, Animal ,Early Diagnosis ,medicine.anatomical_structure ,chemistry ,Case-Control Studies ,NMDA receptor ,sense organs ,Visual Fields ,Gerbillinae ,business ,Glaucoma, Open-Angle ,Photic Stimulation - Abstract
Purpose This study investigated the retinal adaptive mechanism in inner retinal dysfunction using the slow double-stimulation multifocal electroretinogram (mfERG) paradigm. Methods Slow double-stimulation mfERG responses were recorded from 15 eyes of 15 4-month-old Mongolian gerbils in control conditions and after suppression of inner retinal responses with injections of tetrodotoxin (TTX) and N -methyl-d-aspartic acid (NMDA). The stimulation consisted of five video frames: the two initial frames with multifocal flashes were triggered by two independent m-sequences, followed by three dark video frames. The results were compared with findings in humans: 7 subjects with glaucoma and 31 age-matched normal subjects were measured using the same mfERG protocol. Results The stimulation generates two responses (M 1 and M 2 ) from the two independent multifocal frames. The M 1 :M 2 ratio showed a significant reduction after administration of TTX+NMDA in the animal study. This matched with the human glaucoma findings. Glaucoma subjects generally have a reduced M 1 :M 2 ratio; this ratio showed a sensitivity of 86%, with a specificity of 84% for differentiating normal eyes from glaucomatous eyes. Conclusion This stimulation paradigm provides a method of measuring temporal visual characteristics. The M 1 :M 2 ratio acts as an indirect functional indicator of retinal adaptation, which may be abnormal in the diseased retina. Further development of this method may help to describe the functional variation in the diseased retina and to predict the occurrence of a range of retinopathies.
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- 2011
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40. Retinal function and morphology of severe non‐proliferative diabetic retinopathy before and after retinal photocoagulation
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Yan Shan Xu, Patrick Wing Cheung Ho, Henry H. L. Chan, Bei Du, Jian Tao Wang, and Hong Zhang
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Adult ,Male ,Severe NPDR ,medicine.medical_specialty ,genetic structures ,Light Coagulation ,Retina ,Optical coherence tomography ,Diabetes mellitus ,Ophthalmology ,Electroretinography ,medicine ,Humans ,Macula Lutea ,Aged ,Diabetic Retinopathy ,medicine.diagnostic_test ,business.industry ,Diabetic retinopathy ,Middle Aged ,medicine.disease ,eye diseases ,Macular function ,Female ,Retinal function ,sense organs ,business ,Tomography, Optical Coherence ,After treatment ,Retinal photocoagulation ,Optometry - Abstract
Purpose: The purpose of this project was to investigate the changes in macular function and macular morphology of severe non-proliferative diabetic retinopathy (NPDR), due to photocoagulation, using the multifocal electroretinogram (mfERG) and optical coherence tomography (OCT). Methods: Thirty-five volunteers were in the control group, with one eye per person examined with the mfERG. Both the mfERG and OCT were conducted on 30 patients with diabetes who had severe NPDR before, and two, seven and 14 days after, treatment with photocoagulation. Results: Compared with the control group, the P1 and N1 response densities in the patients with NPDR appeared to decrease significantly at rings 2–3 and rings 3–4, respectively, whereas no difference was seen in the implicit times. At two days after photocoagulation, the P1 and N1 response densities decreased significantly in ring 1 and they were still lower than the pre-photocoagulation values at 14 days after photocoagulation. In addition, no change was found in the implicit times before and after photocoagulation. There was no obvious difference in the macular thickness after treatment. At two days after treatment, the P1 response density in ring 1 negatively correlated with the corresponding macular thickness. Conclusion: The para-macular function was significantly impaired in those patients with severe NPDR and photocoagulation reduced the central macular function. Even after 14 days, the central macular function had not returned to pre-photocoagulation levels.
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- 2011
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41. The characteristics of multifocal electroretinogram in isolated perfused porcine eye
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Henry H. L. Chan, Yiu-Fai Ng, Chi Ho To, and Maurice Yap
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medicine.medical_specialty ,N-Methylaspartate ,genetic structures ,Swine ,Tetrodotoxin ,Retina ,chemistry.chemical_compound ,In vivo ,Physiology (medical) ,Ophthalmology ,Electroretinography ,Excitatory Amino Acid Agonists ,medicine ,Animals ,Propofol ,Isoflurane ,medicine.diagnostic_test ,business.industry ,Aminobutyrates ,Retinal ,Anatomy ,eye diseases ,Sensory Systems ,In vitro ,medicine.anatomical_structure ,chemistry ,Pipecolic Acids ,Anesthetics, Inhalation ,Anesthetic ,NMDA receptor ,sense organs ,business ,Excitatory Amino Acid Antagonists ,Anesthetics, Intravenous ,Sodium Channel Blockers ,medicine.drug - Abstract
We investigated characteristics of multifocal electroretinograms (mfERG) from in vitro perfused porcine eyes. TTX, NMDA, APB, and PDA were used to identify contributions to the mfERG from inner retinal neurons, ON-pathway, OFF-pathway, and photoreceptors. The cellular contributions of the first-order kernel (K1) in an isolated perfused porcine mfERG came from both inner and outer retina, and were similar to those of in vivo porcine mfERG. In addition, application of isoflurane and propofol caused interference with the mfERG response which resembled inner retinal activities sensitive to TTX + NMDA application. Improved understanding of the cellular origins of the perfused porcine mfERG, in the absence of anesthetic agents, is useful for identifying changes shown in the waveform under anesthesia.
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- 2008
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42. A New Computational Model for the Design of an Urban Inter-modal Public Transit Network
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Henry S. L. Fan and Sheng Peng
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Transportation planning ,Decision support system ,Operations research ,business.industry ,Computer science ,Flow network ,Computer Graphics and Computer-Aided Design ,Computer Science Applications ,Scheduling (computing) ,Transport engineering ,Modal ,Computational Theory and Mathematics ,Urban planning ,Public transport ,Systems design ,business ,Civil and Structural Engineering - Abstract
This article presents a computational model for the optimum design of an urban inter-modal public transit network. A software tool based on this model was developed to provide useful reference for transport planners in carrying out service planning, routing, and scheduling for an inter-modal transit network. The development of this model is briefly described here. A numerical example is used to illustrate its implementation. Results of sensitivity analyses demonstrate that it is capable of providing reasonable solutions and is responsive to changes in the planning environment.
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- 2007
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43. Changes of retinal functions following the induction of ocular hypertension in rats using argon laser photocoagulation
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Rachel S. Li, David Tay, Kwok-Fai So, and Henry H L Chan
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Retina ,medicine.medical_specialty ,Intraocular pressure ,genetic structures ,medicine.diagnostic_test ,business.industry ,Ocular hypertension ,Retinal ,medicine.disease ,eye diseases ,Hypertonic saline ,Ophthalmology ,chemistry.chemical_compound ,medicine.anatomical_structure ,Retinal ganglion cell ,chemistry ,medicine ,sense organs ,business ,Erg ,Electroretinography - Abstract
Background: Electroretinography (ERG) provides a longitudinal monitoring of pathological changes in retina. Scotopic threshold response (STR) of ERG was shown to reflect inner retinal activity and is particularly useful in the evaluation of inner retinal changes in ocular hypertension models. Recently, STR was demonstrated to be attenuated after the induction of ocular hypertension using injection of hypertonic saline into episcleral veins which indicates an impairment of retinal function. However, little is known on the changes of retinal function in an ocular hypertension model induced by laser photocoagulation at episcleral veins and limbal veins. Methods: Ocular hypertension was induced unilaterally using laser photocoagulation at episcleral veins and limbal veins in adult Sprague–Dawley rats. Intraocular pressure was monitored and the number of retinal ganglion cell loss was counted across the 8-week experimental period. The animals were dark adapted overnight and flash ERGs were measured before the laser treatment, 5 and 8 weeks after treatment. The changes of STR, scotopic negative response, a-wave and b-wave were analysed. Results: Approximately 1.6-fold elevation of intraocular pressure was induced in the experimental eyes and 3% retinal ganglion cell loss per week was found. The amplitude of STR was significantly attenuated which indicates an impairment of inner retinal activities. There was also a reduction of scotopic negative response, a-wave and b-wave after the induction of ocular hypertension. Conclusions: The laser-induced ocular hypertension model in the present study produced a substantial reduction of retinal functions. Understanding the characteristic of pathological changes is crucial for further study using this model.
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- 2006
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44. Heavy Flow-Based Incident Detection Algorithm Using Information From Two Adjacent Detector Stations
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Chin Long Mak and Henry S. L. Fan
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Engineering ,business.industry ,Applied Mathematics ,Detector ,Aerospace Engineering ,Poison control ,Magnitude (mathematics) ,Signal ,Computer Science Applications ,Flow (mathematics) ,Control and Systems Engineering ,Automotive Engineering ,Code (cryptography) ,Heavy traffic ,business ,Algorithm ,Intelligent transportation system ,Software ,Information Systems - Abstract
In heavy traffic flow conditions, vehicles have limited manouverability which affects the magnitude of response to incident-induced traffic disturbances and how fast changes in these traffic variables can signal the occurrence of an incident. Such characteristics are usually used to formulate a loop-based algorithm. A recent study reported that some existing algorithms were not able to maintain a desired level of effectiveness when these algorithms were used to detect incidents with a video-based detector system. Two new video-based automatic incident detection algorithms, the INdividual Detection Evaluation (INDE) and COmbined Detection Evaluation (CODE) algorithms were, therefore, developed for the detection of lane-blocking incidents in heavy traffic flow conditions using the Central Expressway in Singapore as a case study. The algorithms detect incident-induced traffic speed and occupancy disturbances differently: INDE processes information at each individual detector station and CODE processes inform...
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- 2006
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45. Human electroretinal responses to grating patterns and defocus changes by global flash multifocal electroretinogram
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Allen M. Y. Cheong, Henry H. L. Chan, Man Pan Chin, and Patrick H W Chu
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Adult ,genetic structures ,media_common.quotation_subject ,lcsh:Medicine ,Grating ,Luminance ,Retina ,Young Adult ,chemistry.chemical_compound ,Optics ,Electroretinography ,Myopia ,medicine ,Humans ,Eccentricity (behavior) ,lcsh:Science ,Intraocular Pressure ,media_common ,Physics ,Multidisciplinary ,medicine.diagnostic_test ,business.industry ,lcsh:R ,Reproducibility of Results ,Signal Processing, Computer-Assisted ,Retinal ,Refractive Errors ,eye diseases ,Amplitude ,medicine.anatomical_structure ,chemistry ,Evoked Potentials, Visual ,lcsh:Q ,Spatial frequency ,sense organs ,business ,Photic Stimulation ,Research Article - Abstract
The electrical response of the retina was examined as a function of retinal region, using stimuli of various spatial frequencies in the first experiment. In the second experiment, the regional response of the retina to defocus at high and low spatial frequencies was investigated. Twenty three subjects were recruited for global flash multifocal electroretinogram (mfERG) in experiment 1. Black and white gratings (printed on plastic transparent sheets) of four spatial frequencies (SF), 0.24, 1.2, 2.4 and 4.8 cycle per degree were presented in front of the mfERG stimulation. The amplitudes and implicit times of the direct (DC) and induced (IC) components of mfERG responses were pooled into six concentric rings for analysis. There was low amplitude DC at low SF, which increased with increasing SF, and which decreased with increasing eccentricity. The IC was high in amplitude at all SF and reduced in amplitude with increasing eccentricity. Our findings suggested that outer and inner retina had different characteristics in processing spatial details. In experiment 2, Twenty-three young adults were recruited for mfERG measurement. The retinal electrical responses for low (0.24cpd) and high (4.8cpd) SF under fully corrected conditions of short-term negative defocus (-2D) and short term positive defocus (+2D) conditions were measured. There was a sign-dependent response to defocus in the DC response, mainly in peripheral regions. The sign dependent response at low SF was more obvious than that at high SF, and was located more peripherally. The IC response showed no clear trends for either defocus condition. The human retina seems to have a decoding system for optical defocus, which was tuned for low spatial frequency, and was located in the retinal near periphery.
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- 2015
46. Subclinical Decrease in Central Inner Retinal Activity Is Associated With Myopia Development in Children
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Yamunadevi Lakshmanan, Christie Hang I Lam, Kai Yip Choi, Henry H. L. Chan, Wing-Yan Yu, Serena Zhe-Chuang Li, and Francisca Siu Yin Wong
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Refractive error ,medicine.medical_specialty ,genetic structures ,media_common.quotation_subject ,Emmetropia ,050105 experimental psychology ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Ophthalmology ,medicine ,Contrast (vision) ,0501 psychology and cognitive sciences ,Vision test ,Dioptre ,media_common ,medicine.diagnostic_test ,business.industry ,05 social sciences ,Retinal ,medicine.disease ,Refraction ,eye diseases ,chemistry ,030221 ophthalmology & optometry ,sense organs ,business ,Electroretinography - Abstract
Purpose To investigate the characteristics of retinal electrophysiological activity in relation to early myopia development in children. Methods Fifty-six children aged 6 to 9 years with emmetropic refractive error (defined as ≥ -0.5 diopter [D] and ≤ +0.5 D) were recruited. Cycloplegic refraction, axial length, and global flash multifocal electroretinogram (MOFO mfERG) at 49% and 96% contrast levels were recorded in all children at their first visit. The refraction and axial length measurements were repeated after 1 year. The amplitudes and implicit times of the direct component (DC) and the induced component (IC) of the MOFO mfERG obtained at the initial visit were analyzed. Correlations between the MOFO mfERG parameters and changes in refractive error and axial length were investigated. Results The mean spherical equivalent refractive error and axial length of the eyes of the children at the first visit were +0.19 ± 0.33 D and 23.14 ± 0.6 mm, respectively. After 1 year, the mean refractive error increased by -0.55 ± 0.53 D, whereas axial length increased by 0.37 ± 0.22 mm. The changes in refractive error and axial length were significantly correlated with the central IC amplitudes at 49% contrast level measured at the initial visit (ρ = 0.46, P < 0.001 and ρ = -0.34, P = 0.01, respectively). Conclusions The prospective changes we have shown are believed to derive from central inner retina. These changes appear to precede myopia and could be a potential reference for juvenile myopia development.
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- 2017
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47. Prevalence of visual impairment and refractive errors among different ethnic groups in schoolchildren in Turpan, China
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Henry H. L. Chan, Chi Wai Do, Allen M. Y. Cheong, Man Pan Chin, Ka Ho Chan, and Kar Ho Siong
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Male ,Refractive error ,medicine.medical_specialty ,China ,genetic structures ,Adolescent ,Visual impairment ,Ethnic group ,Vision Disorders ,Visual Acuity ,Astigmatism ,Young Adult ,Ophthalmology ,medicine ,Myopia ,Prevalence ,Humans ,Child ,Life Style ,Retinoscopy ,medicine.diagnostic_test ,business.industry ,Vision Tests ,medicine.disease ,Refractive Errors ,Subjective refraction ,eye diseases ,Sensory Systems ,Eyeglasses ,Eye examination ,Child, Preschool ,Female ,medicine.symptom ,business ,Optometry ,Demography - Abstract
Background There is currently limited information about ethnic differences in myopia prevalence within mainland China, especially in rural or semi-rural areas. We examined the prevalence of refractive errors, visual impairment and spectacle coverage in school children of varying ethnicity in Turpan, Xinjiang province. Methods A community eye care service was provided for five schools. Presenting monocular distance and near visual acuity (VA), and ocular alignment were assessed. Retinoscopy and cycloplegic subjective refraction were performed for participants with presenting visual impairment (distance VA worse than 0.3 logMAR; Snellen 6/12 or 20/40) or abnormal binocular vision. Questionnaires administered prior to the eye examinations were used to collect information regarding personal lifestyle and parental myopia. Results A total of 646 out of 690 (94%) subjects aged four to 19 years (11.9 ± 2.6; mean ± S.D.) completed the eye examination. Three hundred and eighty-two (59%) of participants were of Uyghur ethnicity, followed by Han, 176 (27%) and Hui, 74 (12%). The mean age of Uyghur, Han and Hui students was 12.3 ± 2.7, 11.4 ± 2.6 and 11.4 ± 2.3 years respectively, in which the Uyghur students were significantly older than the Han and Hui students (F(3,631) = 5.58 p Hui > Uyghur). As reported previously, uncorrected/under-corrected refractive error was the main cause of presenting visual impairment.
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- 2014
48. Power quality analyses of a large scale photovoltaic system
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Henry L. L. Salamanca, Antonio R. Donadon, Pedro A. B. Block, João Camargo, Diogo Biasuz Dahlke, Otavio M. Shiono, and Mateus D. Teixeira
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Engineering ,Stand-alone power system ,Electric power system ,Power rating ,Switched-mode power supply ,business.industry ,Electrical engineering ,Grid-connected photovoltaic power system ,Power factor ,business ,Maximum power point tracking ,Nominal power (photovoltaic) - Abstract
This work presents the results and analysis of a power quality measurement realized in a large scale PV system. The evaluated system is a 1 MVA centralized PV plant with different technologies of photovoltaic panels and inverters. The power quality measurement was made in accordance with the Brazilian and international power quality regulation. The magnitudes measured were voltage, current, power, power factor, unbalance and harmonic distortion. Additionally with the results of the measurements was evaluated the behavior of the inverters in different power demand situations. The inverter response for low power generation periods was worse than for high power generation periods. In photovoltaic system, low power periods occur at sunrise and sunset. Along these periods, high current harmonic distortion and low power factor levels were monitored. The results and analysis presented in this work contribute with the evaluation of the impact of large scale PV systems upon the power quality of the electric grid and the behavior of the commercial inverters for difference power generation levels.
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- 2014
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49. Intraocular Lens Implantation After Penetrating Keratoplasty
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Ching-Hsi Hsiao, James J. Y. Chen, Henry S. L. Chen, and Phil Y. F. Chen
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Adult ,Male ,medicine.medical_specialty ,Visual acuity ,Adolescent ,genetic structures ,medicine.medical_treatment ,Visual Acuity ,Emmetropia ,Cell Count ,Intraocular lens ,Cataract Extraction ,Astigmatism ,Refraction, Ocular ,Postoperative Complications ,Lens Implantation, Intraocular ,Suture (anatomy) ,Ophthalmology ,medicine ,Humans ,Decompensation ,Dioptre ,Aged ,Retrospective Studies ,Anisometropia ,business.industry ,Endothelium, Corneal ,Suture Techniques ,Middle Aged ,medicine.disease ,eye diseases ,Treatment Outcome ,Female ,sense organs ,medicine.symptom ,business ,Keratoplasty, Penetrating ,Follow-Up Studies - Abstract
PURPOSE We evaluated the clinical results of nonsimultaneous penetrating keratoplasty, cataract extraction, and intraocular lens (IOL) implantation (two-stage surgery) for combined corneal disease and cataract. METHODS Twenty-six eyes of 24 patients with an average age of 46 years who underwent two-stage surgery were studied retrospectively. Variables included visual acuity, refractive status, specular microscopy before and after IOL implantation (6 months), and the occurrence of graft failure. Astigmatism was corrected by suture removal and relaxing incision. The mean follow-up after IOL placement was 16 months. RESULTS Unaided visual acuity was 20/100 or better in 22 (83%) eyes after the second procedure. Twenty-one (81%) eyes had an aided visual acuity of at least 20/40. The mean refractive and absolute errors were -1.49 +/- 1.39 diopters (D) and 1.55 +/- 1.30 D, respectively. The mean keratometric and refractive cylinders were 3.50 D and 2.26 D, respectively. Nineteen (73%) eyes had a spherical equivalent refraction within 2 D of emmetropia. Anisometropia (> or =3 D) occurred in four (15%) eyes. The endothelial cell density, the coefficient of variation, and the percentage of hexagonal cells documented by specular microscopy were not significantly different before and after IOL implantation. Complications included three rejections, two cases of herpetic recurrence, and one late decompensation. Two graft failures (8%) occurred after secondary surgery. CONCLUSION The two-stage surgery is a safe and effective modality.
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- 2001
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50. How to Light Hazardous Environments
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Henry, Steven L.
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Electrical engineering -- Analysis ,Hazardous occupations -- Analysis ,Hazardous occupations -- Safety and security measures ,Industrial engineering -- Analysis ,Electrical engineering ,Business ,Electronics and electrical industries - Abstract
Lighting fixtures play a critical role in the safe, efficient, and productive operation of any industrial facility or production process. Darkened, enclosed, and around-the-clock operations rely on them exclusively for [...]
- Published
- 2009
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