47 results on '"Yap SL"'
Search Results
2. Cerebrospinal fluid in long-lasting delirium compared with Alzheimer's dementia.
- Author
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Caplan GA, Kvelde T, Lai C, Yap SL, Lin C, and Hill MA
- Abstract
BACKGROUND: Delirium is a common syndrome affecting older people in hospital, whose pathophysiology is poorly understood, but sequelae of increased cognitive and functional impairment suggest neuronal loss. METHODS: Cohort study comparing cerebrospinal fluid, blood, and clinical markers of delirium and neuronal cell death in 20 older hospitalized patients with delirium and 20 outpatients with Alzheimer's dementia. RESULTS: Compared with participants with dementia, patients with delirium demonstrated higher CSF lactate (1.87 vs 1.48 mmol/L, p < .001) and protein levels (0.62 vs 0.44 g/L, p = .036) and lower levels of neuron-specific enolase (4.84 vs 8.98 ng/mL, p < .001) but no difference in S100B. The changes correlated with clinical indices and outcomes. CONCLUSION: Older patients with delirium experience significant metabolic disturbance in the brain, which requires further investigation. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
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3. Cerebral composition and function in experimental brain injury in the rat
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R. G. Spector and Yap Sl
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Male ,Cell Membrane Permeability ,Sodium ,Citric Acid Cycle ,chemistry.chemical_element ,Biological Transport, Active ,Brain Edema ,Hemiplegia ,Electrolyte ,Brain damage ,Tritium ,Cell membrane ,Oxygen Consumption ,Chlorides ,Seizures ,medicine ,Premovement neuronal activity ,Animals ,Brain Chemistry ,Cerebral Cortex ,Neurons ,Multidisciplinary ,Chemistry ,Nervous tissue ,Lysine ,Water-Electrolyte Balance ,Rats ,medicine.anatomical_structure ,Glucose ,Biochemistry ,Cytoplasm ,Permeability (electromagnetism) ,Brain Injuries ,Biophysics ,Potassium ,Autoradiography ,Female ,medicine.symptom - Abstract
NEURONAL activity is dependent on the ability of nervous tissue to control the concentration of electrolytes across the nerve cell membrane. The most important component of this process is the active extrusion of sodium from the neuronal cytoplasm against an osmotic gradient. A nerve impulse is normally initiated by the production of an area of increased permeability on the cell surface which allows the outward flow of potassium ions and the inward flow of sodium ions1. After the passage of the impulse, energy is required to restore the electrolyte distribution associated with the resting polarized state1. Nerve impulses can also be initiated by altering the electrolyte content of the fluid surrounding the neurone. Electrolyte disturbances occur in oedematous brain following trauma and cold injury and have been studied in detail by Pappius and Gulati, but in such conditions the mechanism of water accumulation and other ionic changes are not known2. The following experiments were carried out on anoxic-ischaemic brain damage in rats3 in order to investigate the role of changes in the electrolyte and water content of the brain in the production of the hemiplegia and convulsions which occur in this condition, and their relationship to cerebral protein synthesis and energy production.
- Published
- 1967
4. Enhancement of the EUV emission of a metallic capillary discharge operated with argon ambient gas
- Author
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Solmaz Saboohi, S. L. Yap, L. S. Chan, C. S. Wong, D. Tan, International Meeting on Frontiers in Physics Kuala Lumpur, Malaysia 27-30 August 2014, Chan, LS, Tan, D, Saboohi, Solmaz, Yap, SL, and Wong, CS
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Argon ,argon capillary plasma ,Capillary action ,Extreme ultraviolet lithography ,Analytical chemistry ,chemistry.chemical_element ,Cathode ,Anode ,law.invention ,Metal ,chemistry ,law ,visual_art ,visual_art.visual_art_medium ,Cathode ray ,metallic Capillary plasma ,Atomic physics ,Voltage - Abstract
In this work, the metallic capillary discharge is operated with two different ambients: air and argon. In the experiments reported here, the chamber is first evacuated to 10−5 mbar. The discharge is initiated by the transient hollow cathode effect generated electron beam, with either air ambient or argon ambient at 10−4 mbar. The bombardment of electron beam at the tip of the stainless steel anode gives rise to a metallic vapor, which is injected into the capillary and initiates the main discharge through the capillary. The EUV emission is measured for different discharge voltages for both conditions and compared. It is found that the metallic capillary discharge with argon ambientis able to produce higher EUV energy compared to that with air ambient. Refereed/Peer-reviewed
- Published
- 2014
5. Operation of an electron beam initiated metallic plasma capillary discharge
- Author
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Solmaz Saboohi, Chiow San Wong, S.L. Yap, L.S. Chan, D. Tan, Chan, LS, Tan, D, Saboohi, S, Yap, SL, and Wong, CS
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electron beam ,Materials science ,Capillary action ,Plasma ,Condensed Matter Physics ,Cathode ,Surfaces, Coatings and Films ,law.invention ,Anode ,law ,metallic plasma ,Vaporization ,Cathode ray ,Electron temperature ,capillary discharge ,Atomic physics ,Current (fluid) ,Instrumentation - Abstract
In this work, a simple and different technique of generation of a metallic capillary discharge plasma is being studied. The capillary is initially evacuated to a low pressure of below 10-2 Pa. The transient hollow cathode discharge (THCD) produces high energy electron beam that subsequently is employed to vaporize the anode material that will inject into the capillary and initiates the discharge through the capillary. The EUV energy emission produced is calculated to be an estimation in the order of tens of milijoules. At the peak of the current of around 9 kA, the electron temperature of the plasma achieved is estimated to be around 11 eV. Refereed/Peer-reviewed
- Published
- 2014
6. Effects of experimental parameters on EUV emitted from tin vacuum spark plasma
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Seong Ling Yap, Chiow San Wong, Solmaz Saboohi, L. S. Chan, International Meeting on Frontiers in Physics Kuala Lumpur, Malaysia 27-30 August 2013, Saboohi, Solmaz, Yap, SL, Chan, LS, and Wong, CS
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Range (particle radiation) ,Materials science ,business.industry ,vacuum spark ,Extreme ultraviolet lithography ,chemistry.chemical_element ,tin plasma ,Plasma ,Spark discharge ,Anode ,Optics ,chemistry ,Spark (mathematics) ,EUV ,Atomic physics ,business ,Tin ,Voltage - Abstract
The effects of experimental parameters on the emission of Extreme Ultra Violet (EUV) from plasma produced by vacuum spark discharge using Tin as anode material were studied. The operating pressure for all the experiments carried out was maintained at below 10−4 mbar. The discharge voltage tested was from 10 kV to 25 kV. The inter-electrode distance suitable for high intensity and reproducible EUV emissions was obtained to be in the range of 3.6 mm to 5.6 mm. The output EUV energy was found to scale as ∼V20∼V02 , where V0 is the discharge voltag Refereed/Peer-reviewed
- Published
- 2014
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7. Effects of inter-electrode gap and discharge voltage on EUV emission from stainless steel vacuum spark plasma
- Author
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Saboohi, S, Yap, SL, Chan, LS, and Wong, CS
- Subjects
Extreme Ultra Violet (EUV) ,vacuum spark - Abstract
The emission of Extreme Ultra Violet (EUV) from plasma produced by vacuum spark discharge using stainless steel as anode material was investigated. The operating pressure for all the experiments carried out was maintained at below 10-4 mbar. The discharge voltage tested was from 8 kV to 20 kV. The inter-electrode distance suitable for high intensity and reproducible EUV emissions was found to be in the range of 2.6 mm to 4.6 mm. The output EUV energy scaled as ~ V02, where V0 is the discharge voltage. Refereed/Peer-reviewed
- Published
- 2012
8. Spectroscopic Modeling of Single Element Plasma
- Author
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Mostafa Ghomeishi, L. S. Chan, Solmaz Saboohi, Seong Ling Yap, C. S. Wong, Ghomeishi, Mostafa, Yap, SL, Wong, CS, Saboohi, S, Chan, LS, and Malaysia Annual Physics Conference 2010 Damai Laut, Malaysia 27-30 October 2010
- Subjects
education.field_of_study ,Electron density ,Chemistry ,Thermodynamic equilibrium ,Population ,Spectral line ,Radiative transfer ,Astrophysics::Solar and Stellar Astrophysics ,Electron temperature ,k-shell ,Emission spectrum ,Atomic physics ,education ,Spectroscopy ,computer modeling ,Astrophysics::Galaxy Astrophysics ,plasma spectroscopy - Abstract
A strategy for spectroscopic analysis of single element plasmas is through modeling. An experimental investigation or generation of a specified emission spectrum can be attempted based on the modeling results which are currently under investigating by many researchers in the world. In the emission spectroscopy, the K-shell emission is more interesting than emissions from other shells due to their unique EUV and SXR frequencies that can be applied in various scientific and industrial applications. Population information of our model is based on a steady state kinetic code which is calculated for a given electron temperature and an estimated electron density. Thus for each single element plasma it needs large amounts of experimental or theoretical database. Depending on the parameter of the plasma, theories based on local thermodynamic equilibrium (LTE) and non-LTE are considered. In the non-LTE case, the Corona model is used and the total absolute number densities are calculated based on the ion densities that are related to the electron density corresponds to the mean charge of the ions. The spectra generated by the model can then be compared with spectroscopic data obtained experimentally. Refereed/Peer-reviewed
- Published
- 2011
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9. Effect of inter-electrode gap on the emission of EUV and x-ray radiation from vacuum spark discharges
- Author
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Mostafa Ghomeishi, L. S. Chan, Seong Ling Yap, C. S. Wong, Solmaz Saboohi, Malaysia Annual Physics Conference 2010 Damai Laut, Malaysia 27-30 October 2010, Saboohi, Solmaz, Yap, SL, Ghomeishi, M, Chan, LS, and Wong, CS
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Materials science ,business.industry ,Extreme ultraviolet lithography ,vacuum spark ,Vacuum tube ,X-ray ,Plasma ,Radiation ,Anode ,law.invention ,Wavelength ,Optics ,x-ray ,law ,Electrode ,Optoelectronics ,EUV emission ,business ,plasma - Abstract
The emissions of X-ray and Extreme Ultra Violet (EUV) from plasmas produced by vacuum spark discharges are investigated. The vacuum spark plasma emits both continuum and characteristic line radiations that cover a wide range of wavelengths extending from the visible, UV, EUV, soft X-ray and to hard X-ray region. Experiments have been carried out with stainless steel anode. The applied voltages are from 6 kV to 20 kV. The operating pressure for all the experiments carried out is maintained at below 10-4 mbar. In order to have a good soft-X-ray emission (maximized), an optimization of the main experimental parameters (capacitor charging voltage, anode-cathode separation, and trigger pulse amplitude) has been performed. The inter-electrode gap is found to be a dominating parameter to determine the intensity of X-ray and EUV emission from the vacuum spark. The inter-electrode gap distance for high intensity and reproducible X-ray and EUV emission is found to be in the range of 2.6 mm to 6.7 mm. Refereed/Peer-reviewed
- Published
- 2011
10. Cubosome lipid nanocarriers for delivery of ultra-short antimicrobial peptides.
- Author
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Lakic B, Beh C, Sarkar S, Yap SL, Cardoso P, Valery C, Hung A, Jones NC, Hoffmann SV, Blanch EW, Dyett B, and Conn CE
- Subjects
- Microbial Sensitivity Tests, Molecular Dynamics Simulation, Antimicrobial Cationic Peptides chemistry, Antimicrobial Cationic Peptides pharmacology, Methicillin-Resistant Staphylococcus aureus drug effects, Lipids chemistry, Antimicrobial Peptides chemistry, Antimicrobial Peptides pharmacology, Particle Size, Drug Carriers chemistry, Escherichia coli drug effects, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents administration & dosage, Nanoparticles chemistry
- Abstract
Hypothesis: Although antimicrobial peptides (AMPs) are a promising class of new antibiotics, their inherent susceptibility to degradation requires nanocarrier-mediated delivery. While cubosome nanocarriers have been extensively studied for delivery of AMPs, we do not currently understand why cubosome encapsulation improves antimicrobial efficacy for some compounds but not others. This study therefore aims to investigate the link between the mechanism of action and permeation efficiency of the peptides, their encapsulation efficacy, and the antimicrobial activity of these systems., Experiments: Encapsulation and delivery of Indolicidin, and its ultra-short derivative, Priscilicidin, were investigated using SAXS, cryo-TEM and circular dichroism. Molecular dynamics simulations were used to understand the loading of these peptides within cubosomes. The antimicrobial efficacy was assessed against gram-negative (E. coli) and gram-positive (MRSA) bacteria., Findings: A high ionic strength solution was required to facilitate high loading of the cationic AMPs, with bilayer encapsulation driven by tryptophan and Fmoc moieties. Cubosome encapsulation did not improve the antimicrobial efficacy of the AMPs consistent with their high permeation, as explained by a recent 'diffusion to capture model'. This suggests that cubosome encapsulation may not be an effective strategy for all antimicrobial compounds, paving the way for improved selection of nanocarriers for AMPs, and other antimicrobial compounds., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [Biserka Lakic reports financial support was provided by European Union. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper]., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2025
- Full Text
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11. Cell interactions with lipid nanoparticles possessing different internal nanostructures: Liposomes, bicontinuous cubosomes, hexosomes, and discontinuous micellar cubosomes.
- Author
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Yap SL, Yu H, Li S, Drummond CJ, Conn CE, and Tran N
- Subjects
- Cricetinae, Animals, Liposomes, Micelles, Cricetulus, Nanoparticles chemistry, Nanostructures, Liquid Crystals chemistry
- Abstract
Hypothesis: Lyotropic liquid crystalline nanoparticles (LLCNPs) with complex internal nanostructures hold promise for drug delivery. Cubosomes, in particular, have garnered interest for their ability to fuse with cell membranes, potentially bypassing endosomal escape challenges and improving cellular uptake. The mesostructure of nanoparticles plays a crucial role in cellular interactions and uptake. Therefore, we hypothesise that the specific internal mesophase of the LLCNPs will affect their cellular interactions and uptake efficiencies, with cubosomes exhibiting superior cellular uptake compared to other LLCNPs., Experiments: LLCNPs with various mesophases, including liposomes, cubosomes, hexosomes, and micellar cubosomes, were formulated and characterised. Their physicochemical properties and cytotoxicity were assessed. Chinese Hamster Ovarian (CHO) cells were treated with fluorescently labelled LLCNPs, and their interactions were monitored and quantified through confocal microscopy and flow cytometry., Findings: The non-lamellar LLCNPs showed significantly higher cellular interactions compared to liposomes, with cubosomes exhibiting the highest level. However, there was no significant difference in relative cell uptake between cubosomes, hexosomes, and micellar cubosomes. Cell uptake experiments at 4 °C revealed the presence of an energy-independent uptake mechanism. This study provides the first comparative analysis of cellular interactions and uptake efficiencies among LLCNPs with varying mesophases, while maintaining similar size, composition, and surface charge., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
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12. Health-related quality of life amongst children with chronic kidney disease in Malaysia: performance of the Bahasa Melayu version of the PedsQL 3.0 ESRD Module : (PedsQL 3.0 VerBATIM: version in Bahasa Melayu. Translated for use in Malaysia).
- Author
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Bakar KA, Muhamad NA, Sarpin MA, Shaharudin S, Sidhu S, Yap SL, Hussain THT, Tan HL, Ong FN, Gan WC, Ilias MI, Othman J, and Eng CSY
- Subjects
- Humans, Child, Adolescent, Malaysia, Reproducibility of Results, Renal Dialysis, Male, Female, Renal Insufficiency, Chronic psychology, Renal Insufficiency, Chronic therapy, Quality of Life, Surveys and Questionnaires standards, Health Status
- Abstract
Background: The PedsQL 3.0 End Stage Renal Disease (ESRD) Module is a well-accepted instrument internationally but it is not available in the local language. We aimed to validate the Bahasa Melayu (Malay language) version and determine the health-related quality of life (HRQoL) scores amongst children with CKD in Malaysia., Methods: The source questionnaire in English was translated into Bahasa Melayu. Linguistic validation guidelines by the MAPI Research Institute were followed. The already validated Bahasa Melayu PedsQL 4.0 Generic Core Scales was used for comparison. Sociodemographic data were collected during the interview. Statistical analyses were performed using SPSS version 25.0., Results: Sixty-nine children aged 8 to 18 with CKD stages 4 and 5, with or without dialysis, and their caregivers were recruited. Mean age was 12.62 ± 2.77 (SD). Evaluation of the PedsQL 3.0 ESRD Module Bahasa Melayu version demonstrated good internal consistency (Cronbach alpha 0.82). There was good agreement between child self-report and parent proxy report in all domains; average intraclass correlation coefficients (ICC) were 0.78, 95% CI (0.71, 0.84). Scores obtained from Generic 4.0 scales correlated with the disease-specific ESRD 3.0 scale, Spearman's rho = 0.32, p = 0.007. The Kruskal-Wallis H test indicated that there were no significant differences between stages of CKD and their respective mean HRQoL score, χ
2 (2) = 2.88, p = 0.236., Conclusions: The PedsQL 3.0 ESRD Module Bahasa Melayu version is a reliable and feasible tool for cross-cultural adaptation. A longer prospective study may help better illustrate the quality of life in this group of children., (© 2022. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)- Published
- 2023
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13. High energy ion beams from the plasma focus.
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Roshan MV, Vahdat Roshan N, and Yap SL
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- Ions, Spectrum Analysis, Electrons
- Abstract
Instability development in the pinch induces a locally enhanced electric field that accelerates the charged particles to extraordinary high energies. Rapid discharge is the singular state of the ion source confirming high plasma impedance. High energy ion beam is correlated to the electrical discharge parameters and consequently the ion acceleration potential is directly related to the mean ion energy. Multi-MeV ions have been measured by magnetic spectrometry and nuclear activation yield-ratio to obtain the ion energy spectra and critically analyze the ion spectrum. A set of magnetic lens arranged in an optimized coil configuration results in medical grade radioactivity of 0.5GBq for a low energy plasma focus. High energy proton beams enables evaluating the sensitivity of link-board components and the error structure identification, with a significant probability of 0.1perproton., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
- Published
- 2022
- Full Text
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14. Demographic composition, not demographic diversity, predicts biomass and turnover across temperate and tropical forests.
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Needham JF, Johnson DJ, Anderson-Teixeira KJ, Bourg N, Bunyavejchewin S, Butt N, Cao M, Cárdenas D, Chang-Yang CH, Chen YY, Chuyong G, Dattaraja HS, Davies SJ, Duque A, Ewango CEN, Fernando ES, Fisher R, Fletcher CD, Foster R, Hao Z, Hart T, Hsieh CF, Hubbell SP, Itoh A, Kenfack D, Koven CD, Larson AJ, Lutz JA, McShea W, Makana JR, Malhi Y, Marthews T, Bt Mohamad M, Morecroft MD, Norden N, Parker G, Shringi A, Sukumar R, Suresh HS, Sun IF, Tan S, Thomas DW, Thompson J, Uriarte M, Valencia R, Yao TL, Yap SL, Yuan Z, Yuehua H, Zimmerman JK, Zuleta D, and McMahon SM
- Subjects
- Biomass, Demography, Ecosystem, Climate Change, Tropical Climate
- Abstract
The growth and survival of individual trees determine the physical structure of a forest with important consequences for forest function. However, given the diversity of tree species and forest biomes, quantifying the multitude of demographic strategies within and across forests and the way that they translate into forest structure and function remains a significant challenge. Here, we quantify the demographic rates of 1961 tree species from temperate and tropical forests and evaluate how demographic diversity (DD) and demographic composition (DC) differ across forests, and how these differences in demography relate to species richness, aboveground biomass (AGB), and carbon residence time. We find wide variation in DD and DC across forest plots, patterns that are not explained by species richness or climate variables alone. There is no evidence that DD has an effect on either AGB or carbon residence time. Rather, the DC of forests, specifically the relative abundance of large statured species, predicted both biomass and carbon residence time. Our results demonstrate the distinct DCs of globally distributed forests, reflecting biogeography, recent history, and current plot conditions. Linking the DC of forests to resilience or vulnerability to climate change, will improve the precision and accuracy of predictions of future forest composition, structure, and function., (© 2022 John Wiley & Sons Ltd.)
- Published
- 2022
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15. Controlling the pH dependent transition between monoolein Fd3m micellar cubosomes and hexosomes using fatty acetate and fatty acid additive mixtures.
- Author
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Zhai J, Yap SL, Drummond CJ, and Tran N
- Subjects
- Acetates, Fatty Acids, Glycerides, Hydrogen-Ion Concentration, Micelles, Prospective Studies, Scattering, Small Angle, X-Ray Diffraction, Liquid Crystals, Nanoparticles
- Abstract
Hypothesis: Cubosomes made from the inverse micellar cubic mesophase (I
2 ) with Fd3m symmetry possess a unique structure of closely packed inverse micelles. These have prospective functionality in sustained drug release. In this study, we hypothesised that similar to fatty acids, various fatty acetate compounds can induce the formation of micellar Fd3m cubosomes in monoolein (MO) nanoparticles. They are different to micellar cubosomes made of MO and a fatty acid, which are pH responsive and can transition from an Fd3m phase to an inverse hexagonal phase (H2 ) as pH increases. We hypothesised that by co-doping a fatty acetate and fatty acid into MO, precise control of the Fd3m-H2 phase transition pH in nanoparticles can be achieved., Experiments: Five unsaturated fatty acetates with hydrocarbon chain lengths between 18 and 24 were added to MO at a weight ratio of 0.45 - 0.60 to form nanoparticles. The nanoparticles were prepared using high-throughput formulation and characterised with synchrotron small angle X-ray scattering (SAXS). MO nanoparticles doped with vaccenyl acetate and vaccenic acid were used to demonstrate the fine control over Fd3m-H2 phase transition pH., Findings: Micellar cubosomes (Fd3m phase) were found in MO nanoparticles doped with fatty acetates. The Fd3m structure was stable in a wide pH range of 2.6 - 8 and at temperatures up to 45 °C. In MO nanoparticles doped with the acetate/acid mixture, the Fd3m-H2 phase transition pH was tuned between pH 5 and pH 7 by adjusting the ratio of vaccenyl acetate and vaccenic acid. As a H2 phase generally offers faster drug release than an Fd3m phase, the pH responsive lipid nanoparticles developed here may find application in orally administrated formulation, where the vehicles must pass a low pH environment in the stomach before reaching neutral pH in the blood., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)- Published
- 2022
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16. Occult Kidney Dysfunction in Children With Transfusion-Dependent Thalassemia.
- Author
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Mohd Zikre N, Muhamad NA, Eng CSY, Zailanalhuddin NE, Lai CD, Foo JC, Yap SL, Ariffin H, and Abu Bakar K
- Abstract
Background: Thalassemia is the commonest hemoglobinopathy in Southeast Asia. Kidney dysfunction is an underreported sequelae in children with thalassemia. We conducted a retrospective study to identify the prevalence of and predisposing factors for kidney dysfunction in children with transfusion-dependent thalassemia (TDT). Method: Abnormal kidney function was defined as children with a glomerular filtration rate (GFR) of <90 ml/min/1.73 m
2 or a decline in GFR of >20 ml/min/1.73 m2 or presence of nephrotic range proteinuria within 3 years of commencing regular (every ≤6 weeks) red cell transfusion. Data analyzed were age at diagnosis of thalassemia, number of transfusion-years, iron chelation therapy, serum ferritin, and pre-transfusion hemoglobin levels. Results: Eighty-one children were studied. Mean age was 11.72 ± 5.275 years. Thirty out of 81 (37%) demonstrated abnormal kidney function. Evidence of glomerular hyperfiltration was seen in 29/81 patients (25.85%) at their last clinic visit. This fraction was doubled [48/81 (59.3%)] when the cohort was tracked back by 3 years from the last clinic encounter. Age at diagnosis (RR, 1.157; 95% CI, 1.014-1.319; p = 0.03) and duration of receiving transfusions (RR, 0.984; 95% CI, 0.974-0.994; p = 0.001) were associated with increased risk of developing abnormal kidney function. Conclusion: Abnormal kidney function in children with TDT may be overlooked by medical personnel without active screening measures. Children receiving regular red cell transfusions require systematic surveillance to enable early detection of kidney dysfunction and timely implementation of appropriate therapeutic interventions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Mohd Zikre, Muhamad, Eng, Zailanalhuddin, Lai, Foo, Yap, Ariffin and Abu Bakar.)- Published
- 2021
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17. Development and validation of a cognitive, affective and behaviour questionnaire on pet-associated zoonotic diseases (CAB-ZDQ).
- Author
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Yong TSM, Panting AJ, Juatan N, Perialathan K, Ahmad M, Ahmad Sanusi NH, Hassan L, Jahis R, Shamsudin N, Yap SL, Norshamsul NI, Pisol M, and Johari MZ
- Subjects
- Animals, Cognition, Humans, Reproducibility of Results, Surveys and Questionnaires, Family Characteristics, Zoonoses epidemiology
- Abstract
Background: Zoonoses among household pets are recognized as disease and infections transmitted between animals and humans. World Health Organization-estimated zoonotic diseases have contributed about one billion cases of illness and millions of mortalities every year. Despite the emerging and re-emerging zoonotic disease, most pet owners are unaware of the risks posed by their pets. As there are a lack of studies assessing infections at home, this study aimed to develop and validate a cognitive, affective and behaviour questionnaire (CAB-ZDQ) to assess household pets' zoonotic diseases., Methods: This paper covers detailed explanation on the various developmental and validation process stages of the CAB zoonotic disease questionnaire development. The development phase comprised thorough literature search, focus group discussion, expert panel assessment and review. The validation process included pre-test and pilot testing, data analysis of results, analysis of internal consistency and the development of the final version of the questionnaire. Participants selected represented main ethnicities, gender, levels of education and population type (urban/rural) in the Klang Valley area., Results: The items in the questionnaire has undergone various changes in structurally and linguistically. The final refined CAB questionnaire consists of 14 items cognitive (no items removed at pilot phase), nine items affective (one item removed at pilot phase) and five items behaviour (no items removed from pre-test phase), respectively. Reliability analysis revealed Cronbach's alpha values were 0.700 (cognitive) and 0.606 (affective) which indicated good internal consistency after item reduction., Conclusions: The developed questionnaire has proved its feasibility in assessing the Malaysian general population cognitive, affective and behavior regarding the household pets' zoonotic diseases., (© 2021 The Authors. Veterinary Medicine and Science published by John Wiley & Sons Ltd.)
- Published
- 2021
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18. Factors influencing primary care physicians' prescribing behavior of anticoagulant therapy for the management of patients with non-valvular atrial fibrillation in Singapore: a qualitative research study.
- Author
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Chaterji S, Lian LG, Lee TY, Chua L, Wee SY, Yap SL, K DL, and Tan NC
- Subjects
- Administration, Oral, Anticoagulants therapeutic use, Humans, Qualitative Research, Singapore, Atrial Fibrillation complications, Atrial Fibrillation drug therapy, Physicians, Primary Care, Stroke
- Abstract
Background: Oral anticoagulant therapy use in patients with atrial fibrillation (AF) remains suboptimal in Singapore, despite the availability of both warfarin and non-vitamin K antagonist oral anticoagulants (NOACs). Primary care physicians' (PCP) decision-making to initiate and select appropriate anticoagulant medication is pivotal in reducing complications among patients with AF. This study explored the factors influencing PCPs' decision-making in anticoagulant initiation and anticoagulant switch for patients with non-valvular AF., Method: The study design is qualitative research based on the theoretical framework of the Generalist Wheel of Knowledge, Understanding and Inquiry. In-depth interviews or focus group discussions were conducted with 27 PCPs in general practice in urban Singapore. The audio-recordings were transcribed and coded to identify themes, which are framed according to the "clinician", "patient", "medical condition and treatment" and "healthcare system and policy" domains., Results: Personal training and experience with anticoagulant therapy; understanding patient risk-stratification; AF detection during clinical practice; medication cost; clinical support services for anticoagulation monitoring and constraints in existing care model influenced PCPs in their anticoagulant prescription. PCPs preferred to seek guidance from cardiologists in managing patients with newly diagnosed AF and attempted to engage their patients in decision-making regarding anticoagulant therapy. Some PCPs perceived sub-specialized primary care clinics focusing on AF co-management with cardiologists as an ideal setting for initiation and maintenance of anticoagulant therapy., Conclusions: PCPs are influenced by multiple interrelated factors while making decisions on anticoagulant initiation and anticoagulant switch for patients with AF. Their proposed care model to address the barriers awaits feasibility and acceptance assessment in future research.
- Published
- 2021
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19. Species packing and the latitudinal gradient in beta-diversity.
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Cao K, Condit R, Mi X, Chen L, Ren H, Xu W, Burslem DFRP, Cai C, Cao M, Chang LW, Chu C, Cui F, Du H, Ediriweera S, Gunatilleke CSV, Gunatilleke IUAN, Hao Z, Jin G, Li J, Li B, Li Y, Liu Y, Ni H, O'Brien MJ, Qiao X, Shen G, Tian S, Wang X, Xu H, Xu Y, Yang L, Yap SL, Lian J, Ye W, Yu M, Su SH, Chang-Yang CH, Guo Y, Li X, Zeng F, Zhu D, Zhu L, Sun IF, Ma K, and Svenning JC
- Subjects
- Ecology, Asia, Eastern, Biodiversity, Trees
- Abstract
The decline in species richness at higher latitudes is among the most fundamental patterns in ecology. Whether changes in species composition across space (beta-diversity) contribute to this gradient of overall species richness (gamma-diversity) remains hotly debated. Previous studies that failed to resolve the issue suffered from a well-known tendency for small samples in areas with high gamma-diversity to have inflated measures of beta-diversity. Here, we provide a novel analytical test, using beta-diversity metrics that correct the gamma-diversity and sampling biases, to compare beta-diversity and species packing across a latitudinal gradient in tree species richness of 21 large forest plots along a large environmental gradient in East Asia. We demonstrate that after accounting for topography and correcting the gamma-diversity bias, tropical forests still have higher beta-diversity than temperate analogues. This suggests that beta-diversity contributes to the latitudinal species richness gradient as a component of gamma-diversity. Moreover, both niche specialization and niche marginality (a measure of niche spacing along an environmental gradient) also increase towards the equator, after controlling for the effect of topographical heterogeneity. This supports the joint importance of tighter species packing and larger niche space in tropical forests while also demonstrating the importance of local processes in controlling beta-diversity.
- Published
- 2021
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20. The interspecific growth-mortality trade-off is not a general framework for tropical forest community structure.
- Author
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Russo SE, McMahon SM, Detto M, Ledder G, Wright SJ, Condit RS, Davies SJ, Ashton PS, Bunyavejchewin S, Chang-Yang CH, Ediriweera S, Ewango CEN, Fletcher C, Foster RB, Gunatilleke CVS, Gunatilleke IAUN, Hart T, Hsieh CF, Hubbell SP, Itoh A, Kassim AR, Leong YT, Lin YC, Makana JR, Mohamad MB, Ong P, Sugiyama A, Sun IF, Tan S, Thompson J, Yamakura T, Yap SL, and Zimmerman JK
- Subjects
- Species Specificity, Trees, Forests, Tropical Climate
- Abstract
Resource allocation within trees is a zero-sum game. Unavoidable trade-offs dictate that allocation to growth-promoting functions curtails other functions, generating a gradient of investment in growth versus survival along which tree species align, known as the interspecific growth-mortality trade-off. This paradigm is widely accepted but not well established. Using demographic data for 1,111 tree species across ten tropical forests, we tested the generality of the growth-mortality trade-off and evaluated its underlying drivers using two species-specific parameters describing resource allocation strategies: tolerance of resource limitation and responsiveness of allocation to resource access. Globally, a canonical growth-mortality trade-off emerged, but the trade-off was strongly observed only in less disturbance-prone forests, which contained diverse resource allocation strategies. Only half of disturbance-prone forests, which lacked tolerant species, exhibited the trade-off. Supported by a theoretical model, our findings raise questions about whether the growth-mortality trade-off is a universally applicable organizing framework for understanding tropical forest community structure.
- Published
- 2021
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21. Assessing the Relationship between Socio-demographic, Clinical Profile and Financial Toxicity: Evidence from Cancer Survivors in Sarawak.
- Author
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Yap SL, Wong SS, Chew KS, Kueh JS, and Siew KL
- Subjects
- Aged, Cross-Sectional Studies, Female, Follow-Up Studies, Humans, Income, Malaysia epidemiology, Male, Middle Aged, Neoplasms epidemiology, Neoplasms therapy, Prognosis, Surveys and Questionnaires, Survival Rate, Cancer Survivors statistics & numerical data, Cost of Illness, Health Expenditures statistics & numerical data, Neoplasms economics, Quality of Life, Socioeconomic Factors
- Abstract
Background: Patient's financial ability is always the most critical imputes to treatment choice and adherence; as it translates into health outcomes such as survival rate and quality of life. Cancer care is likely to affect the patient's financial well-being, putting huge financial pressure to the families. Therefore, it is imperative to understand the confounding factors of financial toxicity among cancer survivors along the course of survivorship., Methods: This study was designed in the form of cross-sectional analysis, in which, cancer survivors were recruited from the Sarawak General Hospital, the largest tertiary and referral public hospital in Sarawak. To capture the financial toxicity of the cancer survivors, the Comprehensive Score for Financial Toxicity (COST) instrument in its validated form was adopted. Multivariable logistic regression analysis was applied to determine the relationship between financial toxicity (FT) and its predictors., Results: The median age of the 461 cancer survivors was 56 while the median score of COST was 22.0. Besides, finding from multivariable logistic regression revealed that low income households (OR: 6.893, 95% CI, 3.109-15.281) were susceptible to higher risk of financial toxicity, while elderly survivors above 50 years old reported a lower risk in financial toxicity. Also, survivors with secondary schooling (OR:0.240; 95%CI, 0.110-0.519) and above [College or university (OR: 0.242; 95% CI, 0.090-0.646)] suffer a lower risk of FT., Conclusion: Financial toxicity was found to be associated with survivors age, household income and educational level. In the context of cancer treatment within public health facility, younger survivors, households from B40 group and individual with educational attainment below the first level schooling in the Malaysian system of education are prone to greater financial toxicity. Therefore, it is crucial for healthcare policymakers and clinicians to deliberate the plausible risk of financial toxicity borne by the patient amidst the treatment process.
- Published
- 2020
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22. The incidence of obesity, venous sinus stenosis and cerebral hyperaemia in children referred for MRI to rule out idiopathic intracranial hypertension at a tertiary referral hospital: a 10 year review.
- Author
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Bateman GA, Subramanian GM, Yap SL, and Bateman AR
- Subjects
- Adolescent, Child, Child, Preschool, Comorbidity, Constriction, Pathologic diagnostic imaging, Humans, Incidence, Magnetic Resonance Angiography methods, Neuroimaging, Phlebography methods, Retrospective Studies, Tertiary Care Centers, Cerebrovascular Circulation physiology, Cerebrovascular Disorders diagnostic imaging, Cerebrovascular Disorders epidemiology, Cerebrovascular Disorders physiopathology, Cranial Sinuses diagnostic imaging, Hyperemia diagnostic imaging, Hyperemia epidemiology, Hyperemia physiopathology, Intracranial Hypertension diagnostic imaging, Intracranial Hypertension epidemiology, Intracranial Hypertension physiopathology, Magnetic Resonance Imaging methods, Pediatric Obesity epidemiology
- Abstract
Background: Children referred to a tertiary hospital for the indication, "rule out idiopathic intracranial hypertension (IIH)" may have an increased risk of raised venous sinus pressure. An increase in sinus pressure could be due to obesity, venous outflow stenosis or cerebral hyperemia. The purpose of this paper is to define the incidence of each of these variables in these children., Methods: Following a data base review, 42 children between the ages of 3 and 15 years were found to have been referred over a 10 year period. The body mass index was assessed. The cross sectional areas and circumferences of the venous sinuses were measured at 4 levels to calculate the hydraulic and effective diameters. The arterial inflow, sagittal and straight sinus outflows were measured. Automatic cerebral volumetry allowed the brain volume and cerebral blood flow (CBF) to be calculated. The optic nerve sheath diameter was used as a surrogate marker of raised intracranial pressure (ICP). The sagittal sinus percentage venous return was used as a surrogate marker of elevated venous pressure. Age and sex matched control groups were used for comparison., Results: Compared to controls, the obesity rates were not significantly different in this cohort. Compared to controls, those at risk for IIH had a 17% reduction in transverse sinus and 14% reduction in sigmoid sinus effective cross sectional area (p = 0.005 and 0.0009). Compared to controls, the patients at risk for IIH had an arterial inflow increased by 34% (p < 0.0001) with a 9% larger brain volume (p = 0.02) giving an increase in CBF of 22% (p = 0.005). The sagittal and straight sinus venous return were reduced by 11% and 4% respectively (p < 0.0001 and 0.0009) suggesting raised venous sinus pressure. Forty five percent of the patients were classified as hyperemic and these had optic nerve sheath diameters 17% larger than controls (p < 0.0002) suggesting raised ICP., Conclusion: In children with the chronic headache/ IIH spectrum, the highest associations were with cerebral hyperemia and mild venous sinus stenosis. Obesity was not significantly different in this cohort. There is evidence to suggest hyperemia increases the venous sinus pressure and ICP.
- Published
- 2020
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23. Soil nitrogen concentration mediates the relationship between leguminous trees and neighbor diversity in tropical forests.
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Xu H, Detto M, Fang S, Chazdon RL, Li Y, Hau BCH, Fischer GA, Weiblen GD, Hogan JA, Zimmerman JK, Uriarte M, Thompson J, Lian J, Cao K, Kenfack D, Alonso A, Bissiengou P, Memiaghe HR, Valencia R, Yap SL, Davies SJ, Mi X, and Yao TL
- Subjects
- Biodiversity, Fabaceae, Forests, Nitrogen Fixation, Tropical Climate, Nitrogen analysis, Soil chemistry, Trees
- Abstract
Legumes provide an essential service to ecosystems by capturing nitrogen from the atmosphere and delivering it to the soil, where it may then be available to other plants. However, this facilitation by legumes has not been widely studied in global tropical forests. Demographic data from 11 large forest plots (16-60 ha) ranging from 5.25° S to 29.25° N latitude show that within forests, leguminous trees have a larger effect on neighbor diversity than non-legumes. Where soil nitrogen is high, most legume species have higher neighbor diversity than non-legumes. Where soil nitrogen is low, most legumes have lower neighbor diversity than non-legumes. No facilitation effect on neighbor basal area was observed in either high or low soil N conditions. The legume-soil nitrogen positive feedback that promotes tree diversity has both theoretical implications for understanding species coexistence in diverse forests, and practical implications for the utilization of legumes in forest restoration.
- Published
- 2020
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24. The incidence of significant venous sinus stenosis and cerebral hyperemia in childhood hydrocephalus: prognostic value with regards to differentiating active from compensated disease.
- Author
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Bateman GA, Yap SL, Subramanian GM, and Bateman AR
- Subjects
- Adolescent, Child, Child, Preschool, Constriction, Pathologic diagnostic imaging, Constriction, Pathologic pathology, Cranial Sinuses diagnostic imaging, Female, Humans, Incidence, Infant, Magnetic Resonance Angiography, Male, Phlebography, Prognosis, Retrospective Studies, Cerebrovascular Disorders epidemiology, Cranial Sinuses pathology, Hydrocephalus diagnosis, Hydrocephalus epidemiology, Hyperemia epidemiology, Intracranial Hypertension epidemiology
- Abstract
Background: Symptomatic or active hydrocephalus in children is linked to an elevation in intracranial pressure (ICP), which is likely to be multifactorial in origin. The CSF outflow resistance, venous sinus resistance and total cerebral blood flow are likely factors in the ICP elevation. The purpose of this paper is to define the incidence, site and significance of venous sinus stenosis and/or cerebral hyperemia in a cohort of children diagnosed with hydrocephalus at a tertiary referral hospital., Methods: The imaging database was reviewed over a 10 year period and the index MRI of all children between the ages of 4 months and 15 years, who were diagnosed with treatment naive hydrocephalus of any type (excluding secondary to tumor) and had magnetic resonance venography (MRV) and flow quantification were selected. Patients were compared with children undergoing an MRI with MRV and flow quantification who were subsequently shown to have no abnormality. The cross-sectional area and circumference of the sinuses were measured at 4 levels. The hydraulic and effective diameters were calculated. An area stenosis of 65% or greater was deemed significant. A total cerebral blood flow greater than two standard deviations above the mean for controls was taken to be abnormal., Results: There were a total of 55 children with hydrocephalus compared to 118 age matched control MRV's and 35 control flow quantification studies. A high grade stenosis occurred in 56% of patients but in none of the controls (p < 0.0001). The commonest site of narrowing was in the distal sigmoid sinus. Cerebral hyperemia occurred in 13% of patients but did not occur in the controls., Conclusions: The elevation in ICP in symptomatic hydrocephalus is multifactorial. Both high grade venous stenosis and cerebral hyperemia are common in childhood hydrocephalus. High grade stenosis was noted to be a risk factor for conservative management failure. Hyperemia was a good prognostic indicator.
- Published
- 2020
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25. Photophysical and Electroluminescence Characteristics of Polyfluorene Derivatives with Triphenylamine.
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Zhang Q, Wang PI, Ong GL, Tan SH, Tan ZW, Hii YH, Wong YL, Cheah KS, Yap SL, Ong TS, Tou TY, Nee CH, Liaw J, and Yap SS
- Abstract
In this work, polymers of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-triphenylamine] with side chains containing: pyrene (C1), diphenyl (C2), naphthalene (C3), and isopropyl (C6) structures were synthesized via a Suzuki coupling reaction. The structures were verified using NMR and cyclic voltammetry measurements provide the HOMO and LUMO of the polymers. The polymer with pyrene (C1) and naphthalene (C3) produced photoluminescence in the green while the polymer with the side chain containing diphenyl (C2) and isopropyl (C6) produce dual emission peaks of blue-green photoluminescence (PL). In order to examine the electroluminescence properties of the polymers, the solutions were spin-coated onto patterned ITO anode, dried, and subsequently coated with an Al cathode layer to form pristine single layer polymer LEDs. The results are compared to a standard PFO sample. The electroluminescence spectra resemble the PL spectra for C1 and C3. The devices of C2, C3, and C6 exhibit voltage-dependent EL. An additional red emission peak was detected for C2 and C6, resulting in spectra with peaks at 435 nm, 490 nm, and 625 nm. The effects of the side chains on the spectral characteristics of the polymer are discussed.
- Published
- 2019
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26. Phylogenetic classification of the world's tropical forests.
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Slik JWF, Franklin J, Arroyo-Rodríguez V, Field R, Aguilar S, Aguirre N, Ahumada J, Aiba SI, Alves LF, K A, Avella A, Mora F, Aymard C GA, Báez S, Balvanera P, Bastian ML, Bastin JF, Bellingham PJ, van den Berg E, da Conceição Bispo P, Boeckx P, Boehning-Gaese K, Bongers F, Boyle B, Brambach F, Brearley FQ, Brown S, Chai SL, Chazdon RL, Chen S, Chhang P, Chuyong G, Ewango C, Coronado IM, Cristóbal-Azkarate J, Culmsee H, Damas K, Dattaraja HS, Davidar P, DeWalt SJ, Din H, Drake DR, Duque A, Durigan G, Eichhorn K, Eler ES, Enoki T, Ensslin A, Fandohan AB, Farwig N, Feeley KJ, Fischer M, Forshed O, Garcia QS, Garkoti SC, Gillespie TW, Gillet JF, Gonmadje C, Granzow-de la Cerda I, Griffith DM, Grogan J, Hakeem KR, Harris DJ, Harrison RD, Hector A, Hemp A, Homeier J, Hussain MS, Ibarra-Manríquez G, Hanum IF, Imai N, Jansen PA, Joly CA, Joseph S, Kartawinata K, Kearsley E, Kelly DL, Kessler M, Killeen TJ, Kooyman RM, Laumonier Y, Laurance SG, Laurance WF, Lawes MJ, Letcher SG, Lindsell J, Lovett J, Lozada J, Lu X, Lykke AM, Mahmud KB, Mahayani NPD, Mansor A, Marshall AR, Martin EH, Calderado Leal Matos D, Meave JA, Melo FPL, Mendoza ZHA, Metali F, Medjibe VP, Metzger JP, Metzker T, Mohandass D, Munguía-Rosas MA, Muñoz R, Nurtjahy E, de Oliveira EL, Onrizal, Parolin P, Parren M, Parthasarathy N, Paudel E, Perez R, Pérez-García EA, Pommer U, Poorter L, Qie L, Piedade MTF, Pinto JRR, Poulsen AD, Poulsen JR, Powers JS, Prasad RC, Puyravaud JP, Rangel O, Reitsma J, Rocha DSB, Rolim S, Rovero F, Rozak A, Ruokolainen K, Rutishauser E, Rutten G, Mohd Said MN, Saiter FZ, Saner P, Santos B, Dos Santos JR, Sarker SK, Schmitt CB, Schoengart J, Schulze M, Sheil D, Sist P, Souza AF, Spironello WR, Sposito T, Steinmetz R, Stevart T, Suganuma MS, Sukri R, Sultana A, Sukumar R, Sunderland T, Supriyadi, Suresh HS, Suzuki E, Tabarelli M, Tang J, Tanner EVJ, Targhetta N, Theilade I, Thomas D, Timberlake J, de Morisson Valeriano M, van Valkenburg J, Van Do T, Van Sam H, Vandermeer JH, Verbeeck H, Vetaas OR, Adekunle V, Vieira SA, Webb CO, Webb EL, Whitfeld T, Wich S, Williams J, Wiser S, Wittmann F, Yang X, Adou Yao CY, Yap SL, Zahawi RA, Zakaria R, and Zang R
- Subjects
- Biodiversity, Conservation of Natural Resources, Environmental Monitoring, Forests, Phylogeny, Plants classification, Plants genetics, Tropical Climate
- Abstract
Knowledge about the biogeographic affinities of the world's tropical forests helps to better understand regional differences in forest structure, diversity, composition, and dynamics. Such understanding will enable anticipation of region-specific responses to global environmental change. Modern phylogenies, in combination with broad coverage of species inventory data, now allow for global biogeographic analyses that take species evolutionary distance into account. Here we present a classification of the world's tropical forests based on their phylogenetic similarity. We identify five principal floristic regions and their floristic relationships: ( i ) Indo-Pacific, ( ii ) Subtropical, ( iii ) African, ( iv ) American, and ( v ) Dry forests. Our results do not support the traditional neo- versus paleotropical forest division but instead separate the combined American and African forests from their Indo-Pacific counterparts. We also find indications for the existence of a global dry forest region, with representatives in America, Africa, Madagascar, and India. Additionally, a northern-hemisphere Subtropical forest region was identified with representatives in Asia and America, providing support for a link between Asian and American northern-hemisphere forests., Competing Interests: Conflict of interest statement: V.A.-R., K.B.-G., B.B., F.Q.B., N.F., M.K., W.F.L., S. G. Letcher, C.B.S., D.S., T. Stevart, and S. Wiser have coauthored papers with Jens-Christian Svenning in the past 48 months. A.M.L. and Jens-Christian Svenning are both affiliated with Aarhus University., (Copyright © 2018 the Author(s). Published by PNAS.)
- Published
- 2018
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27. Time-resolved characteristics of deuteron-beam generated by plasma focus discharge.
- Author
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Lim LK, Yap SL, and Bradley DA
- Subjects
- Equipment Design, Microscopy, Time and Motion Studies, Deuterium, Plasma Gases
- Abstract
The plasma focus device discussed herein is a Z-pinch pulsed-plasma arrangement. In this, the plasma is heated and compressed into a cylindrical column, producing a typical density of > 1025 particles/m3 and a temperature of (1-3) × 107 oC. The plasma focus has been widely investigated as a radiation source, including as ion-beams, electron-beams and as a source of x-ray and neutron production, providing considerable scope for use in a variety of technological situations. Thus said, the nature of the radiation emission depends on the dynamics of the plasma pinch. In this study of the characteristics of deuteron-beam emission, in terms of energy, fluence and angular distribution were analyzed. The 2.7 kJ plasma focus discharge has been made to operate at a pressure of less than 1 mbar rather than at its more conventional operating pressure of a few mbar. Faraday cup were used to determine deuteron-beam energy and deuteron-beam fluence per shot while CR-39 solid-state nuclear track detectors were employed in studying the angular distribution of deuteron emission. Beam energy and deuteron-beam fluence per shot have been found to be pressure dependent. The largest value of average deuteron energy measured for present conditions was found to be (52 ± 7) keV, while the deuteron-beam fluence per shot was of the order of 1015 ions/m2 when operated at a pressure of 0.2 mbar. The deuteron-beam emission is in the forward direction and is observed to be highly anisotropic.
- Published
- 2018
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28. Comparison of the sagittal sinus cross-sectional area between patients with multiple sclerosis, hydrocephalus, intracranial hypertension and spontaneous intracranial hypotension: a surrogate marker of venous transmural pressure?
- Author
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Bateman GA, Lechner-Scott J, Copping R, Moeskops C, and Yap SL
- Subjects
- Adult, Biomarkers, Female, Humans, Hydrocephalus diagnostic imaging, Image Processing, Computer-Assisted, Intracranial Hypertension diagnostic imaging, Intracranial Hypotension diagnostic imaging, Magnetic Resonance Imaging, Male, Middle Aged, Multiple Sclerosis diagnostic imaging, Cranial Sinuses diagnostic imaging, Hydrocephalus pathology, Intracranial Hypertension pathology, Intracranial Hypotension pathology, Multiple Sclerosis pathology, Venous Pressure physiology
- Abstract
There is evidence that patients with multiple sclerosis (MS) and hydrocephalus share some common pathophysiological mechanisms. Alterations in CSF pressure are known to affect cerebral venous sinus geometry. To further explore these mechanisms, we measured the superior sagittal sinus (SSS) cross-sectional area 3 cm above the torcular using T2 images in 20 MS, 10 spontaneous intracranial hypotension (SIH), 21 hydrocephalus and 20 idiopathic intracranial hypertension (IIH) patients and compared with 20 matched controls. The SSS area was reduced by 25% in hydrocephalus (p = 0.0008), increased by 22% (p = 0.037) in SIH and unchanged in IIH compared to matched controls. In MS there was a 16% increase in SSS area (p = 0.01).The findings suggest that changes in SSS cross-sectional are common between MS and SIH patients, while in hydrocephalus and IIH these are different.
- Published
- 2017
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29. Direct synthesis of nanodiamonds by femtosecond laser irradiation of ethanol.
- Author
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Nee CH, Yap SL, Tou TY, Chang HC, and Yap SS
- Abstract
Carbon nanomaterials exhibit novel characteristics including enhanced thermal, electrical, mechanical, and biological properties. Nanodiamonds; first discovered in meteorites are found to be biocompatible, non-toxic and have distinct optical properties. Here we show that nanodiamonds with the size of <5 nm are formed directly from ethanol via 1025 nm femtosecond laser irradiation. The absorption of laser energy by ethanol increased non-linearly above 100 μJ accompanied by a white light continuum arises from fs laser filamentation. At laser energy higher than 300 μJ, emission spectra of C, O and H in the plasma were detected, indicating the dissociation of C
2 H5 OH. Nucleation of the carbon species in the confined plasma within the laser filaments leads to the formation of nanodiamonds. The energy dependence and the roles of the nonlinear phenomenon to the formation of homogeneous nanodiamonds are discussed. This work brings new possibility for bottom-up nanomaterials synthesis based on nano and ultrafast laser physics.- Published
- 2016
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30. Non-thermal plasma for air and water remediation.
- Author
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Hashim SA, Samsudin FN, Wong CS, Abu Bakar K, Yap SL, and Mohd Zin MF
- Subjects
- Biodegradation, Environmental, Biological Oxygen Demand Analysis, Electricity, Nitric Oxide chemistry, Rubber, Wastewater, Air, Oxygen chemistry, Plasma Gases chemistry, Water chemistry, Water Pollutants, Chemical analysis, Water Purification methods
- Abstract
A modular typed dielectric barrier discharge (DBD) device is designed and tested for air and water remediation. The module is made of a number of DBD tubes that can be arranged in series or parallel. Each of the DBD tubes comprises inner electrode enclosed with dielectric barrier and arranged as such to provide a gap for the passage of gases. Non-thermal plasma generated in the gap effectively creates gaseous chemical reactions. Its efficacy in the remediation of gas stream containing high NOx, similar to diesel emission and wastewater containing latex, are presented. A six tubes DBD module has successfully removed more than 80% of nitric oxide from the gas stream. In another arrangement, oxygen was fed into a two tubes DBD to generate ozone for treatment of wastewater. Samples of wastewater were collected from a treatment pond of a rubber vulcanization pilot plant. The water pollution load was evaluated by the chemical oxygen demand (COD) and biological oxygen demand (BOD5) values. Preliminary results showed some improvement (about 13%) on the COD after treatment and at the same time had increased the BOD5 by 42%. This results in higher BOD5/COD ratio after ozonation which indicate better biodegradability of the wastewater., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2016
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31. Cold plasma inactivation of chronic wound bacteria.
- Author
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Mohd Nasir N, Lee BK, Yap SS, Thong KL, and Yap SL
- Subjects
- Atmospheric Pressure, Bacterial Infections prevention & control, Cell Proliferation, Cold Temperature, Drug Resistance, Bacterial, Humans, Methicillin chemistry, Wounds and Injuries therapy, Plasma Gases, Pseudomonas aeruginosa, Staphylococcus aureus, Wound Healing, Wounds and Injuries microbiology
- Abstract
Cold plasma is partly ionized non-thermal plasma generated at atmospheric pressure. It has been recognized as an alternative approach in medicine for sterilization of wounds, promotion of wound healing, topical treatment of skin diseases with microbial involvement and treatment of cancer. Cold plasma used in wound therapy inhibits microbes in chronic wound due to its antiseptic effects, while promoting healing by stimulation of cell proliferation and migration of wound relating skin cells. In this study, two types of plasma systems are employed to generate cold plasma: a parallel plate dielectric barrier discharge and a capillary-guided corona discharge. Parameters such as applied voltage, discharge frequency, treatment time and the flow of the carrier gas influence the cold plasma chemistry and therefore change the composition and concentration of plasma species that react with the target sample. Chronic wound that fails to heal often infected by multidrug resistant organisms makes them recalcitrant to healing. Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (Pseudomonas aeruginosa) are two common bacteria in infected and clinically non-infected wounds. The efficacies of the cold plasma generated by the two designs on the inactivation of three different isolates of MRSA and four isolates of P. aeruginosa are reported here., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2016
- Full Text
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32. Effect of Argon Plasma Treatment on Tribological Properties of UHMWPE/MWCNT Nanocomposites.
- Author
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Naresh Kumar N, Yap SL, Bt Samsudin FND, Khan MZ, and Pattela Srinivasa RS
- Abstract
Ultra-high molecular weight polyethylene (UHMWPE) is widely used in artificial joints in the replacement of knee, hip and shoulder that has been impaired as a result of arthritis or other degenerative joint diseases. The UHMWPE made plastic cup is placed in the joint socket in contact with a metal or ceramic ball affixed to a metal stem. Effective reinforcement of multi-walled carbon nanotubes (MWCNTs) in UHMWPE results in improved mechanical and tribological properties. The hydrophobic nature of the nanocomposites surface results in lesser contact with biological fluids during the physiological interaction. In this project, we investigate the UHMWPE/MWCNTs nanocomposites reinforced with MWCNTs at different concentrations. The samples were treated with cold argon plasma at different exposure times. The water contact angles for 60 min plasma-treated nanocomposites with 0.0, 0.5, 1.0, 1.5, and 2.0 wt % MWCNTs were found to be 55.65°, 52.51°, 48.01°, 43.72°, and 37.18° respectively. Increasing the treatment time of nanocomposites has shown transformation from a hydrophobic to a hydrophilic nature due to carboxyl groups being bonded on the surface for treated nanocomposites. Wear analysis was performed under dry, and also under biological lubrication, conditions of all treated samples. The wear factor of untreated pure UHMWPE sample was reduced by 68% and 80%, under dry and lubricated conditions, respectively, as compared to 2 wt % 60 min-treated sample. The kinetic friction co-efficient was also noted under both conditions. The hardness of nanocomposites increased with both MWCNTs loading and plasma treatment time. Similarly, the surface roughness of the nanocomposites was reduced.
- Published
- 2016
- Full Text
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33. An estimate of the number of tropical tree species.
- Author
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Slik JW, Arroyo-Rodríguez V, Aiba S, Alvarez-Loayza P, Alves LF, Ashton P, Balvanera P, Bastian ML, Bellingham PJ, van den Berg E, Bernacci L, da Conceição Bispo P, Blanc L, Böhning-Gaese K, Boeckx P, Bongers F, Boyle B, Bradford M, Brearley FQ, Breuer-Ndoundou Hockemba M, Bunyavejchewin S, Calderado Leal Matos D, Castillo-Santiago M, Catharino EL, Chai SL, Chen Y, Colwell RK, Chazdon RL, Clark C, Clark DB, Clark DA, Culmsee H, Damas K, Dattaraja HS, Dauby G, Davidar P, DeWalt SJ, Doucet JL, Duque A, Durigan G, Eichhorn KA, Eisenlohr PV, Eler E, Ewango C, Farwig N, Feeley KJ, Ferreira L, Field R, de Oliveira Filho AT, Fletcher C, Forshed O, Franco G, Fredriksson G, Gillespie T, Gillet JF, Amarnath G, Griffith DM, Grogan J, Gunatilleke N, Harris D, Harrison R, Hector A, Homeier J, Imai N, Itoh A, Jansen PA, Joly CA, de Jong BH, Kartawinata K, Kearsley E, Kelly DL, Kenfack D, Kessler M, Kitayama K, Kooyman R, Larney E, Laumonier Y, Laurance S, Laurance WF, Lawes MJ, Amaral IL, Letcher SG, Lindsell J, Lu X, Mansor A, Marjokorpi A, Martin EH, Meilby H, Melo FP, Metcalfe DJ, Medjibe VP, Metzger JP, Millet J, Mohandass D, Montero JC, de Morisson Valeriano M, Mugerwa B, Nagamasu H, Nilus R, Ochoa-Gaona S, Onrizal, Page N, Parolin P, Parren M, Parthasarathy N, Paudel E, Permana A, Piedade MT, Pitman NC, Poorter L, Poulsen AD, Poulsen J, Powers J, Prasad RC, Puyravaud JP, Razafimahaimodison JC, Reitsma J, Dos Santos JR, Roberto Spironello W, Romero-Saltos H, Rovero F, Rozak AH, Ruokolainen K, Rutishauser E, Saiter F, Saner P, Santos BA, Santos F, Sarker SK, Satdichanh M, Schmitt CB, Schöngart J, Schulze M, Suganuma MS, Sheil D, da Silva Pinheiro E, Sist P, Stevart T, Sukumar R, Sun IF, Sunderland T, Suresh HS, Suzuki E, Tabarelli M, Tang J, Targhetta N, Theilade I, Thomas DW, Tchouto P, Hurtado J, Valencia R, van Valkenburg JL, Van Do T, Vasquez R, Verbeeck H, Adekunle V, Vieira SA, Webb CO, Whitfeld T, Wich SA, Williams J, Wittmann F, Wöll H, Yang X, Adou Yao CY, Yap SL, Yoneda T, Zahawi RA, Zakaria R, Zang R, de Assis RL, Garcia Luize B, and Venticinque EM
- Subjects
- Conservation of Natural Resources, Databases, Factual, Ecosystem, Phylogeography, Rainforest, Species Specificity, Statistics, Nonparametric, Biodiversity, Forests, Trees classification, Tropical Climate
- Abstract
The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher's alpha and an approximate pantropical stem total to estimate the minimum number of tropical forest tree species to fall between ∼ 40,000 and ∼ 53,000, i.e., at the high end of previous estimates. Contrary to common assumption, the Indo-Pacific region was found to be as species-rich as the Neotropics, with both regions having a minimum of ∼ 19,000-25,000 tree species. Continental Africa is relatively depauperate with a minimum of ∼ 4,500-6,000 tree species. Very few species are shared among the African, American, and the Indo-Pacific regions. We provide a methodological framework for estimating species richness in trees that may help refine species richness estimates of tree-dependent taxa.
- Published
- 2015
- Full Text
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34. Second Toe Systolic Pressure Measurements are Valid Substitutes for First Toe Systolic Pressure Measurements in Diabetic Patients: A Prospective Study.
- Author
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Bhamidipaty V, Dean A, Yap SL, Firth J, Barron M, Allard B, and Chan ST
- Subjects
- Adult, Aged, Aged, 80 and over, Blood Pressure Determination instrumentation, Diabetic Angiopathies diagnosis, Diabetic Angiopathies physiopathology, Diabetic Foot physiopathology, Equipment Design, Female, Humans, Male, Middle Aged, Peripheral Arterial Disease physiopathology, Prospective Studies, Reproducibility of Results, Systole, Blood Pressure Determination methods, Diabetes Mellitus physiopathology, Diabetic Foot diagnosis, Peripheral Arterial Disease diagnosis, Toes blood supply
- Abstract
Objective: Toe systolic pressure is a component of the standard vascular and diabetic foot assessment. Until now,clinicians have measured only first toe pressure given a lack of evidence for measurements of the other toes. In diabetic patients, first toe measurements are often not possible because of ulceration or amputation. It was hypothesized that the adjacent second toe systolic pressure measurements would be interchangeable with those of the first toe., Methods: A prospective study was performed on 100 participants with diabetes mellitus. Duplicate systolic toe pressures were measured in the first toe and adjacent second toe using the Systoe Automated Toe Pressure System, Systoe Photophlethysmograph Sensor Cuff, and occlusion cuffs measuring 120 x 25 mm for the first toe and 90 x 15 mm for the second toe. Correlation analysis was followed by Ordinary Least Products regression to detect and distinguish fixed and proportional bias between the two toe measurements. The acceptable limits of interchangeable results were defined as 5-10 mmHg., Results: Correlation coefficient r ¼ 0.908; p < 0.001. Eighty-two percent of the variations in the second toe measurements were accounted for by knowing the first toe measurements and vice versa. Ordinary Least Products regression showed no fixed or proportional bias between the two methods of measurement: second toe systolic pressure = (-0.579) + (1.038) * first toe systolic pressure. Repeatability analysis showed a 0.5%variation between duplicate measurements., Conclusions: This is the first study which demonstrates that second toe systolic pressures are interchangeable with those of the first toe. Second toe pressures can be used in diabetic patients whose first toe pressures cannot be assessed.
- Published
- 2015
- Full Text
- View/download PDF
35. Matrix metalloproteinases and tissue inhibitors of metalloproteinases in the aqueous humour of patients with primary angle closure glaucoma - a quantitative study.
- Author
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Nga AD, Yap SL, Samsudin A, Abdul-Rahman PS, Hashim OH, and Mimiwati Z
- Subjects
- Aged, Case-Control Studies, Cross-Sectional Studies, Female, Humans, Intraoperative Period, Male, Middle Aged, Aqueous Humor metabolism, Glaucoma, Angle-Closure metabolism, Matrix Metalloproteinase 2 metabolism, Matrix Metalloproteinase 3 metabolism, Tissue Inhibitor of Metalloproteinase-1 metabolism, Tissue Inhibitor of Metalloproteinase-2 metabolism
- Abstract
Background: Altered levels of specific matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in the aqueous humour of primary open-angle glaucoma (POAG) eyes have been described. In this study, levels of specific MMPs and TIMPs in the aqueous humour of primary angle-closure glaucoma (PACG) eyes were measured and compared with those of POAG as well as non-glaucoma control eyes., Methods: Aqueous humour from 16 PACG, 28 POAG and 27 control eyes were sampled during intraocular surgery. Levels of total protein, MMP-2, MMP-3, TIMP-1 and TIMP-2 were quantified by protein assay and enzyme immunoassay., Results: Total protein levels were significantly higher in PACG (0.426 ± 0.126 mg/ml, p = 0.043) and POAG (0.578 ± 0.360 mg/ml, p = 0.007) compared to controls (0.292 ± 0.192 mg/ml). The difference between PACG and POAG was not significant (p = 0.158). MMP-2 was significantly higher in PACG (p = 0.032) and POAG (p < 0.001) compared to controls. The difference between PACG and POAG was also not significant (p = 0.133). MMP-3 was significantly higher in POAG compared to controls (p = 0.002) and PACG (p = 0.029). The difference between PACG and controls was not significant (p = 0.962). TIMP-1 was significantly higher in PACG (p = 0.049) and POAG (p = 0.010) compared to controls. The difference between PACG and POAG was also not significant (p = 0.961). TIMP-2 was significantly higher in POAG (p = 0.004) compared to controls. The difference between PACG and either controls or POAG was not significant (p > 0.05). Although not statistically significant (p > 0.05), the MMP-2/TIMP-2 ratio was highest in PACG (2.83 ± 7.40), followed by POAG (1.38 ± 1.55) and controls (1.34 ± 3.05). Similarly, the MMP-2/TIMP-1 ratio was highest in PACG (1.50 ± 1.69), followed by POAG (1.40 ± 0.77) and controls (1.15 ± 0.92). The MMP-2 + MMP-3/TIMP-1 + TIMP-2 ratio was higher in PACG (0.83 ± 0.80) and POAG (0.82 ± 0.53) compared to controls (0.70 ± 0.63). In both POAG and PACG, there were no significant differences in the levels of total protein, MMP-2, MMP-3, TIMP-1 and TIMP-2 between patients on prostaglandin analogues and those not., Conclusion: We found altered levels of MMPs and TIMPs as well as imbalance of MMP:TIMP ratios in the aqueous humour of PACG eyes that were different from POAG and non-glaucoma control eyes.
- Published
- 2014
- Full Text
- View/download PDF
36. External aortic wrap for repair of type 1 endoleak.
- Author
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Dean A, Yap SL, Bhamidipaty V, and Pond F
- Abstract
Introduction: Type 1 endoleak is a rare complication after endovascular abdominal aortic aneurysm repair (EVAR) with a reported frequency up to 2.88%. It is a major risk factor for aneurysmal enlargement and rupture., Presentation of Case: We present a case of a 68 year old gentleman who was found to have a proximal type 1 endoleak with loss of graft wall apposition on routine surveillance imaging post-EVAR. An initial attempt at endovascular repair was unsuccessful. Given the patient's multiple medical co-morbidities, which precluded the possibility of conventional graft explantation and open repair, we performed a novel surgical technique which did not require aortic cross-clamping. A double-layered Dacron wrap was secured around the infra-renal aorta with Prolene sutures, effectively hoisting the posterior bulge to allow wall to graft apposition and excluding the endoleak. Post-operative CT angiogram showed resolution of the endoleak and a stable sac size., Discussion: Several anatomical factors need to be considered when this technique is proposed including aortic neck angulation, position of lumbar arteries and peri-aortic venous anatomy. While an external wrap technique has been investigated sporadically for vascular aneurysms, to our knowledge there is only one similar case in the literature., Conclusion: Provided certain anatomical features are present, an external aortic wrap is a useful and successful option to manage type 1 endoleak in high-risk patients who are unsuitable for aortic clamping., (Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
37. Multispecies coexistence of trees in tropical forests: spatial signals of topographic niche differentiation increase with environmental heterogeneity.
- Author
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Brown C, Burslem DF, Illian JB, Bao L, Brockelman W, Cao M, Chang LW, Dattaraja HS, Davies S, Gunatilleke CV, Gunatilleke IA, Huang J, Kassim AR, Lafrankie JV, Lian J, Lin L, Ma K, Mi X, Nathalang A, Noor S, Ong P, Sukumar R, Su SH, Sun IF, Suresh HS, Tan S, Thompson J, Uriarte M, Valencia R, Yap SL, Ye W, and Law R
- Subjects
- Forestry, Tropical Climate, Ecosystem, Models, Theoretical, Trees physiology
- Abstract
Neutral and niche theories give contrasting explanations for the maintenance of tropical tree species diversity. Both have some empirical support, but methods to disentangle their effects have not yet been developed. We applied a statistical measure of spatial structure to data from 14 large tropical forest plots to test a prediction of niche theory that is incompatible with neutral theory: that species in heterogeneous environments should separate out in space according to their niche preferences. We chose plots across a range of topographic heterogeneity, and tested whether pairwise spatial associations among species were more variable in more heterogeneous sites. We found strong support for this prediction, based on a strong positive relationship between variance in the spatial structure of species pairs and topographic heterogeneity across sites. We interpret this pattern as evidence of pervasive niche differentiation, which increases in importance with increasing environmental heterogeneity.
- Published
- 2013
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- View/download PDF
38. Ultra-performance liquid chromatography/time-of-flight mass spectrometry based metabolomics of raw and steamed Panax notoginseng.
- Author
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Chan EC, Yap SL, Lau AJ, Leow PC, Toh DF, and Koh HL
- Subjects
- Chromatography, High Pressure Liquid, Cooking, Hot Temperature, Metabolic Networks and Pathways, Panax notoginseng chemistry, Plant Extracts chemistry, Panax notoginseng metabolism, Spectrometry, Mass, Electrospray Ionization
- Abstract
At present, metabolite profiling is of growing importance in herbal medicine fields such as breeding, formulation, quality control and clinical trials. This preliminary study indicated that ultra-performance liquid chromatography/time-of-flight mass spectrometry (UPLC/TOFMS)-based metabolomics allows direct detection of down-stream derivatives of metabolites, arising from the herbal formulation process. This analytical approach allows the discrimination and tentative authentication of unique biomarkers related to different herbal extracts using unsupervised multivariate principal component analysis (PCA). The tentative identification of biomarkers is complemented significantly by the accurate mass measurement of TOFMS and the high resolution and high retention time reproducibility rendered by UPLC. The application of this approach in herbal extract discrimination and ginsenoside biomarker discovery of raw and steamed Panax notoginseng (Burk.) F.H. Chen is demonstrated and discussed., (Copyright (c) 2007 John Wiley & Sons, Ltd.)
- Published
- 2007
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39. Clinical and radiologic outcome of total hip arthroplasty performed by trainee compared with consultant orthopedic surgeons.
- Author
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Moran M, Yap SL, Walmsley P, and Brenkel IJ
- Subjects
- Aged, Chi-Square Distribution, Female, Hip Joint diagnostic imaging, Humans, Male, Prospective Studies, Quality of Health Care, Radiography, Regression Analysis, Treatment Outcome, Arthroplasty, Replacement, Hip standards, Clinical Competence, Internship and Residency
- Abstract
Data were prospectively collected on 139 total hip arthroplasties (THAs) performed by supervised specialist registrars (residents) and 397 THAs performed by consultants. The Harris Hip Score and data on comorbidity, blood loss, transfusion requirements, re-operation, dislocation, and death were recorded. Radiologic assessment of acetabular and femoral component alignment and cementation was made using 114 trainee radiographs that were available for review at 6 months. These were compared with 114 matched consultant radiographs. At 18 months, there was no significant difference in clinical outcome. Acetabular anteversion was significantly less in trainee-performed THA. This article reveals no difference in the short-term clinical results of THA performed by consultants and supervised trainees. There is radiographic evidence of decreased anteversion of the acetabulum by trainees, although the dislocation rates are not different. Our results show that quality can be maintained while training juniors to perform surgery.
- Published
- 2004
- Full Text
- View/download PDF
40. Replacement of animal fat with fractionated and partially hydrogenated palm oil in beef burgers.
- Author
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Babji AS, Alina AR, Seri Chempaka MY, Sharmini T, Basker R, and Yap SL
- Subjects
- Animals, Cattle, Cooking, Fats analysis, Fatty Acids analysis, Fatty Acids, Nonesterified analysis, Fatty Acids, Unsaturated analysis, Food Handling, Humans, Hydrogenation, Iodine analysis, Taste, Meat Products analysis, Plant Oils chemistry
- Abstract
Four formulations of burgers, prepared with 65% lean meat and 15% fat consisting of RBD palm stearin (PS), Socfat 4000P and Socfat 4100P and beef fat (BF) as control were evaluated for solid fat content (SFC), slip melting point (SMP), cooking loss, proximate analysis (moisture, fat and protein), colour, i.e. lightness ('L'), redness ('a') and yellowness ('b'), free fatty acid (FFA), iodine value (IV), thiobarbituric acid (TBA) and texture profile analysis (TPA). Sensory evaluation was carried out for texture, juiciness, aroma, oiliness and overall acceptance. SFC and SMP for raw and cooked SF4000P beef burgers were closest to BF control burgers, falling into the range of 35-40 degrees C. Cooking loss was highest for PS burgers, there were no significant differences (P > 0.05) amongst BF, SF4000P and SF4100P burgers. Proximate analysis on raw burgers showed SF4000P to contain high fat and lowest moisture contents. Objective textural measurements using texture profile analysis (TPA) for all cooked burgers showed no significant differences (P > 0.05) for springiness and cohesiveness. Variation of values among the formulations for hardness, gumminess and chewiness are explained by the differences of SFC for beef burgers with various types of fats. Raw and cooked PS burgers have the lightest 'L' values compared with other fat-substituted burgers while BF, SF4000P and SF4100P indicated no significant differences (P > 0.05) for 'L', 'a' and 'b' values. Beef fat showed the highest amount of free fatty acids (FFA) compared to palm oil samples. For the iodine value (IV), SF4000P showed the highest value which means that it contained the highest level of unsaturated fatty acids followed by PS, BF and SF4100P successively. SF4000P had the highest TBA values followed successively by BF, PS and SF4100P. For sensory evaluation, PS burgers had the least oily taste. This may be due to its high cooking loss. Taste panelists could not differentiate burgers with substituted vegetable fats against the control burgers.
- Published
- 1998
- Full Text
- View/download PDF
41. The uptake and rate of clearance of 125I gamma-G globulin in lampreys (Lampetra fluviatilis).
- Author
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Adinolfi M, Gardner B, Spector R, and Yap SL
- Subjects
- Animals, Autoradiography, Iodine Isotopes, Liver metabolism, Macrophages metabolism, Peritoneum cytology, Antigens metabolism, Fishes metabolism, gamma-Globulins metabolism
- Published
- 1969
- Full Text
- View/download PDF
42. Lactate dehydrogenase isoenzymes, glutamate dehydrogenase, glutamate-alanyl aminotransferase and creatine phosphokinase in the peripheral blood of brain-damaged rats.
- Author
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Ramsey A, Yap SL, and Spector RG
- Subjects
- Animals, Electrophoresis, Isoenzymes, Rats, Alanine Transaminase blood, Brain Injuries enzymology, Cerebrovascular Disorders enzymology, Creatine Kinase blood, Glutamate Dehydrogenase blood, L-Lactate Dehydrogenase blood
- Published
- 1968
- Full Text
- View/download PDF
43. The effect of chlorpromazine on cerebral glucose, ATP, ADP, AMP and ATPase in the mouse.
- Author
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Chowdhury AK, Skinner A, Spector RG, and Yap SL
- Subjects
- Adenosine Triphosphatases metabolism, Adenosine Triphosphate analysis, Animals, Brain enzymology, Cyclic AMP analysis, Female, Injections, Intraperitoneal, Liver analysis, Magnesium, Male, Mice, Adenine Nucleotides analysis, Adenosine Triphosphatases analysis, Brain Chemistry drug effects, Chlorpromazine pharmacology, Glucose analysis
- Abstract
1. Administration of chlorpromazine 10 mg/kg intraperitoneally to mice produced no alteration in cerebral adenosine triphosphate (ATP), adenosine diphosphate (ADP) or adenosine monophosphate (AMP). In these animals there was an increase in the glucose content of the supernatants of homogenates of liver and brain following acid hydrolysis.2. Chlorpromazine 40 mg/kg intraperitoneally did not affect Mg(++) activated adenosine triphosphatase (ATPase) activity in the brain.
- Published
- 1968
- Full Text
- View/download PDF
44. Cerebral protein synthesis in anoxic-ischaemic brain injury in the rat.
- Author
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Yap SL and Spector RG
- Subjects
- Animals, Autoradiography, Carbon Isotopes, Female, Glucose metabolism, In Vitro Techniques, Rats, Brain metabolism, Hypoxia, Brain metabolism, Ischemic Attack, Transient metabolism, Protein Biosynthesis
- Published
- 1965
- Full Text
- View/download PDF
45. Cerebral composition and function in experimental brain injury in the rat.
- Author
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Yap SL and Spector RG
- Subjects
- Animals, Autoradiography, Biological Transport, Active, Brain Chemistry, Brain Edema pathology, Cell Membrane Permeability, Cerebral Cortex cytology, Chlorides metabolism, Citric Acid Cycle, Female, Glucose metabolism, Hemiplegia metabolism, Lysine metabolism, Male, Neurons metabolism, Oxygen Consumption, Potassium metabolism, Rats, Seizures, Sodium metabolism, Tritium, Brain Injuries metabolism, Brain Injuries physiopathology, Water-Electrolyte Balance
- Published
- 1967
- Full Text
- View/download PDF
46. Intracellular enzyme changes in post-anoxic rat brain.
- Author
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Yap SL and Spector RG
- Subjects
- Animals, Histocytochemistry, Rats, Acid Phosphatase metabolism, Adenosine Triphosphatases metabolism, Alcohol Oxidoreductases metabolism, Alkaline Phosphatase metabolism, Brain enzymology, DNA metabolism, Hypoxia, Brain metabolism, Hypoxia, Brain pathology, Leucyl Aminopeptidase metabolism, Monoamine Oxidase metabolism, Nucleotidases metabolism, RNA metabolism
- Published
- 1965
47. Oxygen consumption of ischaemic rat brain in vitro.
- Author
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Skinner A, Spector RG, and Yap SL
- Subjects
- Adenine Nucleotides metabolism, Adenosine Triphosphate metabolism, Animals, Citric Acid Cycle, Female, Hypoxia metabolism, In Vitro Techniques, Ischemia metabolism, Lactates metabolism, Malates metabolism, Rats, Seizures etiology, Succinates metabolism, Brain metabolism, Cerebrovascular Disorders metabolism, Oxygen Consumption
- Published
- 1969
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