753 results on '"Yu Chun Chen"'
Search Results
152. Study on steady state control schedule and characteristic calculation of hydrogen-fueled scramjet
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Zhihua Wang, Yu-sang Li, Yu-chun Chen, Tianhao Zhang, and Hao-min Li
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Schedule ,Steady state (electronics) ,Hydrogen ,chemistry ,Control theory ,Control (management) ,chemistry.chemical_element ,Scramjet ,Mathematics - Published
- 2019
153. Study on the Influence of Heat Transfer Effect on Performance Simulation of Engine Transition State
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Feng-ping Chen, Ke-ran Song, Yu-sang Li, and Yu-chun Chen
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Turboprop ,Overall pressure ratio ,020301 aerospace & aeronautics ,Transient state ,Materials science ,Computer simulation ,Airflow ,02 engineering and technology ,Mechanics ,01 natural sciences ,010305 fluids & plasmas ,Acceleration ,0203 mechanical engineering ,0103 physical sciences ,Heat transfer ,Gas compressor - Abstract
Based on the lumped parameter method and the equal power division pressure ratio method, the unsteady heat transfer model of the quasi-one-dimensional engine is derived, and the one-dimensional engine transition state performance calculation model considering the heat transfer between the airflow and the solids of the components is established. The numerical simulation of the Bodie acceleration process of a triple-spool turboprop engine is carried out. The results show that the effect of heat transfer on the performance of the whole machine is mainly reflected by the response delay of each component. Bodie accelerates the process and the heat transfer effect has a significant impact on compressor performance.
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- 2019
154. Research on Control Law of High Speed Turbofan Engine
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Yu-chun Chen, Ke-ran Song, Hao-min Li, and Tian Tan
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symbols.namesake ,Mach number ,Law ,Range (aeronautics) ,Nozzle ,symbols ,Rotational speed ,Thrust ,Thrust specific fuel consumption ,Turbine ,Turbofan ,Mathematics - Abstract
Based on the component maps based high speed turbine engine simulation model, the influence of design point parameters of the rotational speed of the fan, the corrected rotational speed of the fan, and the throat area of nozzle on engine’s performance and control law is studied. With thrust, specific thrust and specific fuel consumption as performance parameters, the engine with different control laws is compared and evaluated, which provides a reference for the selection of high-speed turbofan engine design point parameters. The results show that: increase the value of the corrected rotational speed of the fan to use at design point, the engine velocity characteristic becomes better, the specific fuel consumption increases, and the engine size increases. Under the same value of corrected rotational speed of the fan to use at design point, the value of the rotational speed of the fan to use at design point increases, the engine velocity characteristic becomes better, the specific fuel consumption increases, and the engine size increases. Adjusting the throat area of nozzle keeps the rotational speed of the fan at the maximum in the wide Mach number range, while keeping the turbine inlet temperature and the rotational speed of the fan at the maximum, increasing the engine’s thrust at high Mach numbers.
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- 2019
155. Design and Characteristic Calculation of Combustion Chamber of Hydrogen-Fueled Scramjet Based on 'Constant Static Temperature' Heating Method
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Jun-hui Zhou, Tian Tan, Yu-chun Chen, Chi Liu, Hao-min Li, and Jin-feng Du
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Materials science ,020209 energy ,020208 electrical & electronic engineering ,Airflow ,Thrust ,02 engineering and technology ,Mechanics ,Combustion ,Hydrogen fuel ,0202 electrical engineering, electronic engineering, information engineering ,Specific impulse ,Scramjet ,Combustion chamber ,Configuration design - Abstract
This article takes the hydrogen-fueled scramjet as the research object, considering the mixing and combustion of the hydrogen fuel with the airflow, to propose a variable specific heat calculation method which considering the chemical equilibrium of the hydrogen-fueled combustion products. And then, propose a one-dimensional lumped parameter calculation model based on integral form for the geometry configuration design and performance simulation of hydrogen-fueled scramjet. On the basis of this calculation model, the constant static temperature heating method is used to simulate the combustion heating process of the combustion chamber, and the geometry configuration of the combustion chamber is designed. Using this profile as the final geometry configuration of the combustion chamber, conduct engine characteristics research and the results were analyzed. At the same time, the specific thrust Fs and specific impulse I SP are selected as the overall performance parameters, in the flight range of Ma710, the constant static temperature design of the combustion chamber is respectively performed to obtain the engine performance parameters, and the performance comparison with the corresponding engine reference configuration is completed. The comparison results show that the constant static temperature heating method can obtain better performance, and the Fs and I SP are about 35% higher than the engine reference configuration.
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- 2019
156. A Design Method of Steady State Control Law for Civil Turbofan Engine
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Ke-ran Song, Feng-ping Chen, Tian Tan, and Yu-chun Chen
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Steady state (electronics) ,Thrust control ,Computer science ,Law ,Component (UML) ,Control (management) ,Cruise ,Climb ,ComputingMilieux_LEGALASPECTSOFCOMPUTING ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Thrust ,Turbofan - Abstract
In this article, based on the component method, the engine steady state performance calculation model is established. Based on the model, the performance of the take-off and the high altitude climb of the civil turbofan engine is studied. The influence of the single control law and the combined control law on the engine characteristics is analyzed. Based on the thrust demand of the aircraft at cruise and take-off, the maximum state control law of the engine and the corresponding thrust control law are designed.
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- 2019
157. Natural History of Acromegaly: Incidences, Re-operations, Cancers, and Mortality Rates in a National Cohort
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Wen Cheng Huang, Yu Chun Chen, Hsuan Kan Chang, Jiing Feng Lirng, Jau Ching Wu, and Chin Chu Ko
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Adult ,Male ,Reoperation ,Risk ,medicine.medical_specialty ,Adolescent ,National Health Programs ,Endocrinology, Diabetes and Metabolism ,Taiwan ,Comorbidity ,Rate ratio ,Cellular and Molecular Neuroscience ,Young Adult ,Endocrinology ,Internal medicine ,Neoplasms ,Acromegaly ,Risk of mortality ,Medicine ,Humans ,Age of Onset ,Mortality ,Child ,Aged ,Hypophysectomy ,Retrospective Studies ,Endocrine and Autonomic Systems ,business.industry ,Mortality rate ,Incidence (epidemiology) ,Incidence ,Infant ,Middle Aged ,medicine.disease ,Survival Analysis ,Natural history ,Standardized mortality ratio ,Child, Preschool ,Cohort ,Female ,business ,Follow-Up Studies - Abstract
Background: Acromegaly is so rare that its natural history, including incidence, risk of cancers, and mortality rates, remains elusive. This natural study utilized a nationwide database to provide a better understanding of acromegaly’s disease course. Methods: A cohort of 1,195 acromegaly patients were identified and followed-up from 1997 to 2013. Incidence, operation, and re-operation rates were calculated. Excessive mortality and cancer risk related to acromegaly were estimated by standardized mortality ratio (SMR) and standardized incidence ratio (SIR). Results: The incidence was 2.78 per million-person-years, with little gender predominance (female vs. male, 49.5 vs. 50.5%, respectively). There was female predominance only among 50 and 60 year-olds (incidence rate ratio: 1.37 and 1.43, p < 0.001 and p = 0.002). Among them, 673 (56.3%) had hypophysectomy surgery, and the young-onset (p = 0.01). The overall mortality rate was 22.3 per 1,000 person-years, with a median survival of 4.67 years (with no gender differences, p = 0.38). The overall SMR of acromegaly patients was 1.41, and the onset-age-specific SMRs of the early- and middle-onset patients were higher than for those with late-onset. There were 87 newly diagnosed cancers in the cohort, with an incidence rate of 10.6 per 1,000 person-years (median 5.4 years). The overall SIR of cancers was 1.91, and there were no differences among gender, onset-age, and disease duration (all SIR >1, approximately 2). Conclusion: Acromegaly is associated with an excessive risk of mortality and two-fold higher risk of cancers. Patients with acromegaly should be managed appropriately after the diagnosis.
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- 2019
158. Habitual physical activity mediates the acute exercise-induced modulation of anxiety-related amygdala functional connectivity
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Yu Chun Chen, Róger Marcelo Martínez, Chenyi Chen, Jennifer L. Etnier, and Yawei Cheng
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0301 basic medicine ,Adult ,Male ,medicine.drug_class ,media_common.quotation_subject ,Emotions ,Happiness ,lcsh:Medicine ,Anxiety ,Anxiolytic ,Amygdala ,Article ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Surveys and Questionnaires ,medicine ,Image Processing, Computer-Assisted ,Aerobic exercise ,Humans ,lcsh:Science ,Reactivity (psychology) ,Exercise ,media_common ,Multidisciplinary ,Cross-Over Studies ,lcsh:R ,Fear ,Magnetic Resonance Imaging ,Exercise Therapy ,030104 developmental biology ,medicine.anatomical_structure ,lcsh:Q ,Orbitofrontal cortex ,Female ,Perception ,medicine.symptom ,Psychology ,Insula ,030217 neurology & neurosurgery ,psychological phenomena and processes ,Clinical psychology ,Neuroscience - Abstract
Aerobic exercise, in relation to physical activity, has been shown to have beneficial effects on anxiety. However, the underlyig neural mechanism remains elusive. Using a within-subject crossover design, this fMRI study examined how exercise (12-min treadmill running versus walking) mediated amygdala reactivity to explicit and implicit (backward masked) perception of emotional faces in young adults (N = 40). Results showed that acute exercise-induced differences of state anxiety (STAI-S) varied as a function of individual’s habitual physical activity (IPAQ). Subjects with high IPAQ levels showed significant STAI-S reduction (P
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- 2019
159. A 38-GHz-Band Power Amplifier with Analog Pre-distortion for 1600-MHz Transmission Bandwidth 64-QAM OFDM Modulated Signal
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Jeng-Han Tsai, Tsung-Ching Tsai, Tian-Wei Huang, and Yu-Chun Chen
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Power gain ,Physics ,business.industry ,Orthogonal frequency-division multiplexing ,Amplifier ,020208 electrical & electronic engineering ,Electrical engineering ,020206 networking & telecommunications ,02 engineering and technology ,law.invention ,Capacitor ,IMD3 ,CMOS ,law ,0202 electrical engineering, electronic engineering, information engineering ,Wideband ,business ,Quadrature amplitude modulation - Abstract
A 38-GHz-band transformer based high linear power amplifier with analog pre-distortion for wideband modulated signal in 65-nm GP CMOS process is presented in this paper. The output power is based on the two-way transformer current combining structure. The driver amplifier which is biased in deep class-AB acts as an AM-AM pre-distorter to produce better OP1dB and improve the third order intermodulation distortion (IMD3). Also a PMOS capacitor is used to compensate the AM-PM distortion of the input capacitor at the driver stage. In the continuous-wave measurement, this power amplifier achieves 14.4-dB small-signal power gain, 20.7-dBm PSAT, 35% PAEMAX, 20.2-dBm OP1dB, and 32.8% PAE1dB at 39 GHz. In the modulated signal measurement, this power amplifier achieves 13.2-dBm output power, 7.1% PAE, and EVM < -25 dBc at 1600-MHz channel bandwidth of 64-QAM OFDM with 38-GHz carrier frequency. The highest transmission data rate of the proposed power amplifier reaches up to 6.98 Gb/s.
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- 2019
160. Recent advances in the management of cervical spondylotic myelopathy: bibliometric analysis and surgical perspectives
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Yu-Chun, Chen, Chao-Hung, Kuo, Chieh-Ming, Cheng, and Jau-Ching, Wu
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Bibliometrics ,Cervical Vertebrae ,Disease Management ,Humans ,Spondylosis ,Spinal Cord Diseases - Abstract
Cervical spondylotic myelopathy (CSM) has become a prevalent cause of spinal cord dysfunction among the aging population worldwide. Although great strides have been made in spine surgery in past decades, the optimal timing and surgical strategy to treat CSM have remained controversial. In this article the authors aimed to analyze the current trends in studies of CSM and to summarize the recent advances of surgical techniques in its treatment.The PubMed database was searched using the keywords pertaining to CSM in human studies that were published between 1975 and 2018. Analyses of both the bibliometrics and contents, including the types of papers, authors, affiliations and countries, number of patients, and the surgical approaches were conducted. A systematic review of the literature was also performed with emphasis on the diagnosis and treatment of mild CSM.A total of 1008 papers published during the span of 44 years were analyzed. These CSM studies mainly focused on the natural history, diagnosis, and treatment, and only a few prospective randomized trials were reported. For the authors and affiliations, there was a shift of clustering of papers toward Asian countries in the past decades. Regarding the treatment for CSM, there was an exponential growth of surgical series published, and there was a trend toward slightly more anterior than posterior approaches through the past decade. Patients with CSM had increased risks of neurological deterioration or spinal cord injury with nonoperative management. Because surgery might reduce the risks, and early surgery was likely to be correlated with better outcomes, there was a trend toward attention to mildly symptomatic CSM.There is emerging enthusiasm for research on CSM worldwide, with more publications originating in Asian countries over the past few decades. The surgical management of CSM is evolving continuously toward early and anterior approaches. More prospective investigations on the optimal timing and choices of surgery are therefore needed.
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- 2019
161. Long Term Outcomes and Effects of Surgery on Degenerative Spinal Deformity: A 14-Year National Cohort Study
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Wen Cheng Huang, Jau Ching Wu, Jiing Feng Lirng, Hsuan Kan Chang, and Yu Chun Chen
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Population ageing ,medicine.medical_specialty ,lcsh:Medicine ,respiratory problems ,Article ,National cohort ,surgery ,03 medical and health sciences ,0302 clinical medicine ,Long term outcomes ,Medicine ,030212 general & internal medicine ,Proportional hazards model ,business.industry ,lcsh:R ,Confounding ,Hazard ratio ,General Medicine ,mortality ,Degenerative Spinal Deformity (DSD) ,Surgery ,hip fractures ,Spinal deformity ,business ,030217 neurology & neurosurgery ,Cohort study - Abstract
Degenerative spinal deformity (DSD) has become a prevalent cause of disability and pain among the aging population worldwide. Though surgery has emerged as a promising option for DSD, the natural course, outcomes, and effects of surgery on DSD have remained elusive. This cohort study used a national database to comprehensively follow up patients of DSD for all-cause mortality, respiratory problems, and hip fracture-related hospitalizations. All patients were grouped into an operation or a non-operation group for comparison. An adjustment of demographics, comorbidities, and propensity-score matching was conducted to ameliorate confounders. A Cox regression hazard ratio (HR) model and Kaplan-Meier analysis were also applied. The study comprised 21,810 DSD patients, including 12,544 of the operation group and 9266 of the non-operation group. During the 14 years (total 109,591.2 person-years) of follow-up, the operation group had lower mortality (crude hazard ratio = 0.40), lower respiratory problems (cHR = 0.45), and lower hip fractures (cHR = 0.63) than the non-operation group (all p <, 0.001). After adjustment, the risks for mortality and respiratory problems remained lower (adjusted HR = 0.60 and 0.65, both p <, 0.001) in the operation than the non-operation group, while hip fractures were indifferent (aHR = 1.08, p >, 0.05). Therefore, surgery for DSD is invaluable since it could reduce the risks of mortality and of hospitalization for respiratory problems.
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- 2019
- Full Text
- View/download PDF
162. Factors of missed appointments at an academic medical center in Taiwan
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Shu Chiung Chiang, Tzeng Ji Chen, Yu Chun Chen, Wen Chien Tsai, and Wui Chiang Lee
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Adult ,Male ,medicine.medical_specialty ,Adolescent ,Cross-sectional study ,education ,MEDLINE ,030204 cardiovascular system & hematology ,Logistic regression ,03 medical and health sciences ,Appointments and Schedules ,Young Adult ,0302 clinical medicine ,Health care ,medicine ,Outpatient clinic ,Humans ,Child ,Weather ,health care economics and organizations ,Aged ,Aged, 80 and over ,Academic Medical Centers ,business.industry ,No-Show Patients ,Attendance ,Infant, Newborn ,Infant ,General Medicine ,Odds ratio ,Middle Aged ,humanities ,Cross-Sectional Studies ,Logistic Models ,030220 oncology & carcinogenesis ,Family medicine ,Child, Preschool ,Female ,business - Abstract
BACKGROUND Missed appointments mean appointments neither attended nor canceled by patients. Missed appointments belong to one of the important subjects of hospital management because they would incur the inactivity of medical professionals and devices, occupy the health resources for other patients, and thus impair the quality of healthcare services. The aim of this study was to explore the factors of missed appointments at the outpatient department of an academic medical center in Taiwan. METHODS This was a cross-sectional study based on registration records of an academic medical center in Northern Taiwan in 2015. Fifteen variables of patients, appointments, and weathers were taken into analysis. Logistic regression was used to calculate the adjusted odds ratio of each variable. For nonfirst visits, we further built a logistic regression model with the five most influential variables and the personal attendance pattern of the previous three appointments. RESULTS Of 2 132 577 eligible appointments in 2015, the overall no-show rate was 16.9%. The influential factors included the following: (1) patient characteristics: younger than 40 years, ≤6 visits, and a no-show rate between 50% and 75% in the previous year; (2) appointment characteristics: Saturdays, evenings, on the last third of the waiting list, only one appointment on the same day, online appointments, appointment-to-visit intervals (wait time) in 7 to 14 days, appointments to obstetrics/gynecology or pediatrics, first-time appointments, and the interval between the appointed visit and the previous visit in
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- 2019
163. Utilization and Safety of Percutaneous Lung Biopsy: A 10-Year Nationwide Population-Based Study
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Chun-Ku Chen, Hsiao-Ping Chou, Tzeng Ji Chen, Hsiao-Ting Chang, Shu-Chiung Chiang, and Yu Chun Chen
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Adult ,Lung Diseases ,Male ,medicine.medical_specialty ,Percutaneous ,lung biopsy ,procedure safety ,Health, Toxicology and Mutagenesis ,utilization ,lcsh:Medicine ,Lung biopsy ,Article ,03 medical and health sciences ,0302 clinical medicine ,Risk Factors ,medicine ,Humans ,Sampling (medicine) ,030212 general & internal medicine ,Lung ,Aged ,Retrospective Studies ,business.industry ,lcsh:R ,Biopsy, Needle ,Public Health, Environmental and Occupational Health ,Pneumothorax ,Middle Aged ,medicine.disease ,Hospitals ,Surgery ,Rural hospital ,Population based study ,medicine.anatomical_structure ,030228 respiratory system ,National health insurance ,Female ,business - Abstract
Percutaneous lung biopsy is a technique used for sampling peripherally located lung masses and has been gaining in popularity. However, its exact utilization is unknown, and its safety has not been well studied. The current study aimed to assess the trend of utilization and study the safety of this procedure. Using the National Health Insurance Research Database, we retrospectively determined the total number of procedures that were performed on subjects older than 20 years between 2001 and 2010. We also estimated the rates of major complications, such as pneumothorax, requiring intercostal drainage. A total of 630 percutaneous biopsies were performed in 2001, while 3814 were performed in 2010, representing a 6.1-fold increase. The compound annual growth rate was 22.1%. The number of hospitals that performed the procedure increased from 55 to 99. Pneumothorax requiring drainage occurred in 1.5% of the procedures. The factors associated with a higher complication rate included male gender, chronic obstructive pulmonary disease, rural hospital, and low-volume hospital. Percutaneous lung biopsies are a relatively safe procedure, and their performance has been rapidly increasing. The number of procedures performed by a hospital was associated with the complication rate.
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- 2019
164. Chemical Characteristics of Electron Shuttles Affect Extracellular Electron Transfer: Shewanella decolorationis NTOU1 Simultaneously Exploiting Acetate and Mediators
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Chang-Ping Yu, Yu-Chun Chen, Shiue-Lin Li, Shiu-Mei Liu, and Yu-Jie Wang
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electron-balance calculation ,Microbiology (medical) ,Cytochrome ,lcsh:QR1-502 ,Electrochemistry ,Microbiology ,lcsh:Microbiology ,Catalysis ,03 medical and health sciences ,Electron transfer ,Shewanella decolorationis ,Extracellular ,030304 developmental biology ,Original Research ,0303 health sciences ,extracellular electron transfer ,biology ,030306 microbiology ,Chemistry ,Substrate (chemistry) ,electron shuttle mediator ,biology.organism_classification ,Anode ,Shewanella decolorationis NTOU1 ,biology.protein ,outer membrane cytochrome ,Nuclear chemistry - Abstract
In the present study, we found that our isolate Shewanella decolorationis NTOU1 is able to degrade acetate under anaerobic condition with concomitant implementation of extracellular electron transfer (EET). With +0.63 V (vs. SHE) poised on the anode, in a 72-h experiment digesting acetate, only 2 mM acetate was consumed, which provides 6% of the electron equivalents derived from the initial substrate mass to support biomass (5%) and current generation (1%). To clarify the effects on EET of the addition of electron-shuttles, riboflavin, anthraquinone-2,6-disulfonate (AQDS), hexaammineruthenium, and hexacyanoferrate were selected to be spiked into the electrochemical cell in four individual experiments. It was found that the mediators with proton-associated characteristics (i.e., riboflavin and AQDS) would not enhance current generation, but the metal-complex mediators (i.e., hexaammineruthenium, and hexacyanoferrate) significantly enhanced current generation as the concentration increased. According to the results of electrochemical analyses, the i-V graphs represent that the catalytic current induced by the primitive electron shuttles started at the onset potential of -0.27 V and continued increasing until +0.73 V. In the riboflavin-addition experiment, the catalytic current initiated at the same potential but rapid saturated beyond -0.07 V; this indicated that the addition of riboflavin affects mediator secretion by S. decolorationis NTOU1. It was also found that the current was eliminated after adding 48 mM N-acetyl-L-methionine (i.e., the cytochrome inhibitor) when using acetate as a substrate, indicating the importance of outer-membrane cytochrome.
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- 2019
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165. Early Discharge for Anterior Cervical Fusion Surgery: Prediction of Readmission and Special Considerations for Older Adults
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Jau Ching Wu, Wen Cheng Huang, Yu Chun Chen, and Hsuan Kan Chang
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Male ,Reoperation ,medicine.medical_specialty ,Disc herniation ,Health, Toxicology and Mutagenesis ,Taiwan ,lcsh:Medicine ,Anterior cervical discectomy and fusion ,Patient Readmission ,Article ,Cohort Studies ,03 medical and health sciences ,0302 clinical medicine ,Medicine ,Humans ,030212 general & internal medicine ,Cervical fusion ,Early discharge ,Aged ,business.industry ,readmission ,Hazard ratio ,lcsh:R ,Public Health, Environmental and Occupational Health ,Middle Aged ,Patient Discharge ,Surgery ,Spinal Fusion ,Treatment Outcome ,anterior cervical discectomy and fusion (ACDF) ,Cervical Vertebrae ,early discharge (ED) ,Female ,incidence rates ,business ,030217 neurology & neurosurgery ,Cohort study - Abstract
Anterior cervical discectomy and fusion (ACDF) is the standard surgical management for disc herniation and spondylosis worldwide and reportedly performed with short hospitalization and early discharge (ED). However, it is unknown if ED improves the outcomes of ACDF including among older adults. This cohort study included patients who underwent ACDF surgery in Taiwan over two years analyzed in two groups: the ED group (discharged within 48 hours), and the comparison group (hospitalized for more than 48 h). Both groups were followed-up for at least 180 days. Pre- and post-operative comorbidities, re-admissions and re-operations were analyzed using a multivariate cox-regression model, with bootstrapping, and Kaplan&ndash, Meier analysis. Among 5565 ACDF patients, the ED group (n = 405) had a higher chance (crude and adjusted hazard ratio = 2.33 and 2.39, both p <, 0.001) of re-admission than the comparison group (n = 5160). The ED group had an insignificant trend toward more re-admissions for spinal problems and re-operations within 180 days. In the ED group, older age (&ge, 60) and hypertension were predictive of re-admission. For ACDF surgery, the ED group had higher rates of re-admission within 180 days of post-op, suggesting that the current approach to ED requires modification or more cautious selection criteria be adopted, particularly for older adults.
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- 2019
166. Risk factors of second surgery for adjacent segment disease following anterior cervical discectomy and fusion: A 16-year cohort study
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Hsuan Kan Chang, Jau Ching Wu, Wen Cheng Huang, and Yu Chun Chen
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Adult ,Male ,Reoperation ,medicine.medical_specialty ,Anterior cervical discectomy and fusion ,Cohort Studies ,03 medical and health sciences ,0302 clinical medicine ,Postoperative Complications ,Risk Factors ,Survivorship curve ,Medicine ,Humans ,Survival analysis ,Depression (differential diagnoses) ,Aged ,Retrospective Studies ,business.industry ,Incidence (epidemiology) ,Incidence ,Mental Disorders ,Age Factors ,General Medicine ,Middle Aged ,Surgery ,Young age ,Spinal Fusion ,030220 oncology & carcinogenesis ,Cervical Vertebrae ,030211 gastroenterology & hepatology ,Female ,Spinal Diseases ,Adjacent segment disease ,business ,Cohort study ,Diskectomy ,Follow-Up Studies - Abstract
Background Although the incidence of second surgery for adjacent segment disease (ASD) after anterior cervical discectomy and fusion (ACDF) has been reported, its risk factors remain elusive. Few studies have had a sufficiently large number of patients, long follow-up time, and high follow-up rate for investigation. To identify non-surgical risk factors of second surgery for ASD following ACDF, the study used a national cohort with comprehensive follow-up. Materials and methods All second ACDF surgery after one year from the first ACDF were identified as a consequence of ASD that required another surgery. A multivariate competing risk survival model, Kaplan-Meier survivorship, and average time to events were calculated. Results Among 38,149 patients who had the first ACDF, 1,092 (2.9%) later (mean 4.66 years) received a second ACDF surgery, during the nearly-perfect follow-up of 16 years. Young age and psychiatric disorders were independent risk factors. Patients who were aged under 40, 50, 60 and 70 years were, respectively, 4.56, 4.09, 3.09 and 2.17 times more likely than those older than 70 years. Also, patients with depression or psychoses were, respectively, 1.42 and 1.45 times more likely to have second surgery for ASD. (all p Conclusion Young age and psychiatric disorders are independent risk factors of second ACDF surgery for ASD. Personalized strategies to ameliorate or postpone the development of ASD are therefore warranted for patients who need ACDF surgery.
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- 2019
167. The Impact of Hemodialysis on Terminal Cancer Patients in Hospices: A Nationwide Retrospective Study in Taiwan
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Chih Ching Lin, Shih Chao Kang, Yu Chun Chen, and Wei Shu Wang
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Adult ,Male ,medicine.medical_specialty ,Palliative care ,medicine.medical_treatment ,Taiwan ,Disease ,urologic and male genital diseases ,Terminal cancer ,End stage renal disease ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,030502 gerontology ,Renal Dialysis ,Internal medicine ,Neoplasms ,medicine ,Humans ,Renal replacement therapy ,General Nursing ,Aged ,Retrospective Studies ,Aged, 80 and over ,Terminal Care ,business.industry ,Age Factors ,Cancer ,Retrospective cohort study ,General Medicine ,Middle Aged ,medicine.disease ,Anesthesiology and Pain Medicine ,Hospice Care ,030220 oncology & carcinogenesis ,Kidney Failure, Chronic ,Female ,Hemodialysis ,0305 other medical science ,business - Abstract
Hemodialysis (HD) is the most common renal replacement therapy for patients with end-stage renal disease in Taiwan. The use of HD in hospice care and its impact on terminal cancer patients remains unclear.Using claim data from the Taiwan National Health Insurance Research Database, all patients who died from cancer and claim data of their terminal admissions in hospice from 2007 to 2010. Those with a comorbid diagnosis of renal failure or who had health insurance claims data for HD were enrolled.A total of 5482 subjects were identified, of whom 4484 received HD and 998 did not. The HD group was significantly correlated with a younger age and high costs of terminal hospice admission. After adjusting for age and gender, the HD group was positively associated with a long hospice stay, in-hospice death, bone/connective tissue/breast cancers, and secondary/metastatic cancers, but negatively associated with genitourinary cancer. Compared with Department of Health/municipal hospitals, patients at both national and private university-affiliated hospitals were less likely to undergo HD.For terminal cancer patients under hospice care, HD was associated with a younger age, long terminal hospice stay, and high medical costs. Some types of cancers were associated with HD. University-affiliated hospitals played significant roles in non-HD renal supportive care. In-hospice HD is still common in Taiwan. Dialysis withdrawal and alternative care have space to promoting in hospice care.
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- 2019
168. Analysis of Overall Performance of Multi-stage Combustor Scramjet Engine
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Hao-min Li, Chun Guan, Zhihua Wang, Yu-chun Chen, and Jin-feng Du
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Thermal ,Combustor ,Mechanical engineering ,Environmental science ,Thrust ,Choke ,Scramjet ,Specific impulse ,Combustion chamber ,Fuel injection - Abstract
In this paper, based on the scramjet, by the mode of characteristic calculation of one-dimensional scramjet engine, the effect of three and four-section combustion chamber geometry, fuel distribution ratio on scramjet performance is studied. The results of the comparison and evaluation of engine performance provide a certain reference for the geometric configuration of the combustion chamber and fuel injection parameters of the design point. It is mainly to determine the appropriate combustion chamber geometry and fuel injection method to obtain better combustion chamber performance and overall engine performance. The results show that increasing the thermal throat area of the combustion chamber can effectively increase the thrust of the aircraft during low-speed flight condition, and increase the fuel distribution ratio and the length of the expansion section in the front section of the combustion chamber without thermal choke and without affecting the inlet start, can improve the specific impulse of the engine at high speed.
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- 2019
169. Enhancement of epithelial sodium channel expression in renal cortical collecting ducts cells by advanced glycation end products
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Chang, Chiz-Tzung, Wu, Mai-Szu, Tian, Ya-Chung, Chen, Kuan-Hsing, Yu, Chun-Chen, Liao, Chang-Hui, Hung, Cheng-Chieh, and Yang, Chih-Wei
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- 2007
170. DEVELOPMENT OF ENGINEERED CARTILAGE PRODUCT FROM BONE MARROW MESENCHYMAL STEM CELLS: AN EXAMPLE IN TAIWAN
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Chih-Hung Chang, Yu-Chun Chen, Feng-Huei Lin, and Hwa-Chang Liu
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030222 orthopedics ,Sports injury ,Friction force ,business.industry ,Cartilage ,030229 sport sciences ,Bone marrow mesenchymal stem cells ,Cell biology ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,Engineered cartilage ,medicine ,Orthopedics and Sports Medicine ,business - Abstract
Cartilage can redistribute human body’s daily loads and decrease the friction force in the diarthrodial joints. However, it may be injured due to trauma, sports injury, biomechanical imbalance, and genetic disease. Microfracture (MF), osteochondral autograft transplantation (OAT), and autologous chondrocyte implantation (ACI) are the most common treatment procedures in the hospital. Recently, the concept of tissue engineering involving the combination of cells, scaffolds, and bioactive signals has inspired researchers. Our team of researchers synthesized a tri-copolymer from biological polymer by using gelatin, chondroitin-6-sulfate, and hyaluronic acid through cross-linking reaction. Lacuna formation could be seen in the tri-copolymer surrounding the chondrocytes, and some newly formed glycosaminoglycan was found in the engineered cartilage. Considering the dedifferentiation possibility of chondrocyte, bone marrow mesenchymal stem cells (BMSCs) become an ideal cell source for cartilage tissue regeneration, since they can be easily harvested from adult tissue, and be expanded in vitro. In an in-vivo porcine pilot study, the results showed that the defect site could be regenerated by BMSCs/collagen gel, and is formed with fibro/hyaline mixed cartilage tissue after implantation for six months. Several clinical studies using BMSCs for cartilage defect treatment were also conducted recently; clinical outcomes such as IKDC, Lysholm, and Tegner scores improved when the cartilage defects were repaired by several millions of mesenchymal stem cells, and there is no tumor formation after being treated with BMSCs during the 10-year follow-up. Moreover, recently a commercial BMSCs/collagen gel composite for cartilage repair was developed in Taiwan and clinical trial was conducted in 2008; the results showed that there is an improvement in IKDC and MRI scores during the nine-year follow-up. It seems that using an engineered cartilage made from BMSCs/collagen gel for cartilage defect treatment is a promising method.
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- 2021
171. LACE Score-Based Risk Management Tool for Long-Term Home Care Patients: A Proof-of-Concept Study in Taiwan
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Yen Hsi Lin, Hsiao Ting Chang, Yu Chun Chen, Mei Chin Su, Li Hwa Lin, Mei Shu Huang, and Tzeng Ji Chen
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Acute hospitalization ,medicine.medical_specialty ,long-term care (LTC) ,Health, Toxicology and Mutagenesis ,Taiwan ,lcsh:Medicine ,030204 cardiovascular system & hematology ,Patient Readmission ,Risk Assessment ,Article ,predictive model ,03 medical and health sciences ,0302 clinical medicine ,Risk Factors ,readmission risk management ,LACE score ,medicine ,Humans ,Generalizability theory ,Screening tool ,030212 general & internal medicine ,Risk management ,Aged ,Retrospective Studies ,Risk Management ,Receiver operating characteristic ,readmission ,business.industry ,lcsh:R ,Public Health, Environmental and Occupational Health ,Length of Stay ,Readmission rate ,long-term home care (LTHC) ,Home Care Services ,Emergency medicine ,Cohort ,Emergency Service, Hospital ,business ,Readmission risk - Abstract
Background: Effectively predicting and reducing readmission in long-term home care (LTHC) is challenging. We proposed, validated, and evaluated a risk management tool that stratifies LTHC patients by LACE predictive score for readmission risk, which can further help home care providers intervene with individualized preventive plans. Method: A before-and-after study was conducted by a LTHC unit in Taiwan. Patients with acute hospitalization within 30 days after discharge in the unit were enrolled as two cohorts (Pre-Implement cohort in 2017 and Post-Implement cohort in 2019). LACE score performance was evaluated by calibration and discrimination (AUC, area under receiver operator characteristic (ROC) curve). The clinical utility was evaluated by negative predictive value (NPV). Results: There were 48 patients with 87 acute hospitalizations in Pre-Implement cohort, and 132 patients with 179 hospitalizations in Post-Implement cohort. These LTHC patients were of older age, mostly intubated, and had more comorbidities. There was a significant reduction in readmission rate by 44.7% (readmission rate 25.3% vs. 14.0% in both cohorts). Although LACE score predictive model still has room for improvement (AUC = 0.598), it showed the potential as a useful screening tool (NPV, 87.9%, 95% C.I., 74.2&ndash, 94.8). The reduction effect is more pronounced in infection-related readmission. Conclusion: As real-world evidence, LACE score-based risk management tool significantly reduced readmission by 44.7% in this LTHC unit. Larger scale studies involving multiple homecare units are needed to assess the generalizability of this study.
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- 2021
172. Flexible Five-in-One Microsensor for Real-Time Wireless Microscopic Diagnosis inside Electric Motorcycle Fuel Cell Stack Range Extender
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Chi-Yuan Lee, Ti-Ju Lee, Chia-Hung Chen, Yu-Chun Chen, John-Shong Cheong, and Yi-Cheng Liu
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range extender ,electric motorcycle ,Materials science ,lcsh:Mechanical engineering and machinery ,020209 energy ,wireless microscopic diagnosis ,Proton exchange membrane fuel cell ,02 engineering and technology ,Article ,Automotive engineering ,law.invention ,Reliability (semiconductor) ,Stack (abstract data type) ,law ,Range (aeronautics) ,0202 electrical engineering, electronic engineering, information engineering ,lcsh:TJ1-1570 ,Electrical and Electronic Engineering ,Power density ,Mechanical Engineering ,Extender ,021001 nanoscience & nanotechnology ,Volume (thermodynamics) ,Control and Systems Engineering ,PEMFC stack ,flexible five-in-one microsensor ,0210 nano-technology ,Voltage - Abstract
The focus of research and development on electric motorcycle range extender are system integration and energy regulation and management but the present fuel cell stack range extender still has defects, such as large volume, heavy weight and high cost. Its volume and weight will have a strong impact on the endurance of electric motorcycle. The bipolar plate takes most volume and weight of a proton exchange membrane fuel cell (PEMFC) stack and it is the key component influencing the overall power density and cost. Therefore, how to thin and lighten the bipolar plate and to enhance the performance and life of PEMFC stack is an urgent research subject to be solved for the moment and will be the key to whether the PEMFC stack range extender can be put in the electric motorcycle or not. In addition, the internal temperature, humidity, flow, voltage and current in the operation of PEMFC stack will influence its performance and life and the overall performance and life of fuel cell stack will be directly influenced by different external operating conditions. As nonuniform distribution of temperature, humidity, flow, voltage and current will occur in various regions inside the fuel cell stack, this study will use micro-electro-mechanical systems (MEMS) technology to develop a flexible five-in-one microsensor, which is embedded in the PEMFC stack range extender for real-time wireless microscopic diagnosis and the reliability test is performed, so that the actual operating condition inside the fuel cell stack range extender can be mastered instantly and correctly and the internal information is fed back instantly, the fuel cell stack range extender control system can be modified to the optimum operating parameters immediately, so as to enhance the performance and prolong the lifetime effectively.
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- 2021
173. Does hepatitis C virus affect the reactivation of hepatitis B virus following renal transplantation?
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Yen, Tzung-Hai, Huang, Chiu-Ching, Lin, Hsin-Hung, Huang, Jeng-Yi, Tian, Ya-Chun, Yang, Chih-Wei, Wu, Mai-Szu, Fang, Ji-Tseng, Yu, Chun-Chen, Chiang, Yang-Jen, and Chu, Sheng-Hsieh
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- 2006
174. Leptospiral membrane proteins stimulate pro-inflammatory chemokines secretion by renal tubule epithelial cells through toll-like receptor 2 and p38 mitogen activated protein kinase
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Hung, Cheng-Chieh, Chang, Chiz-Tzung, Tian, Ya-Chung, Wu, Mai-Szu, Yu, Chun-Chen, Pan, Ming-Jeng, Vandewalle, Alain, and Yang, Chih-Wei
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- 2006
175. Xanthogranulomatous pyelonephritis and malacoplakia of the bladder in a middle aged female
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Wu, I-Wen, Yu, Chun-Chen, Wu, Chun-Te, Jung, Shih-Ming, and Huang, Jeng-Yi
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- 2006
176. Aristolochic acid-related nephropathy associated with the popular Chinese herb Xi Xin
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Yang, Huang-Yu, Lin, Ja-Liang, Chen, Kuan-Hsing, Yu, Chun-Chen, Hsu, Po-Yaur, and Lin, Chun-Liang
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- 2006
177. Clinical distinction and evaluation of leptospirosis in Taiwan - A case-control study
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Yang, Huang-Yu, Hsu, Po-Yaur, Pan, Ming-Jeng, Wu, Mai-Szu, Lee, Chih-Hsiung, Yu, Chun-Chen, Hung, Cheng-Chieh, and Yang, Chih-Wei
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- 2005
178. Impact of HCV infection on first cadaveric renal transplantation, a single center experience
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Lin, Hsin-Hung, Huang, Chiu-Ching, Huang, Jeng-Yi, Yang, Chih-Wei, Wu, Mai-Szu, Fang, Ji-Tseng, Yu, Chun-Chen, Chiang, Yang-Jen, and Chu, Sheng-Hsieh
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- 2004
179. Environmental Exposure to Lead and Progression of Chronic Renal Diseases: A Four-Year Prospective Longitudinal Study
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Yu, Chun-Chen, Lin, Ja-Liang, and Lin-Tan, Dan-Tzu
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- 2004
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180. Environmental Lead Exposure and Chronic Renal Disease
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Lin, Ja-Liang, Yu, Chun-Chen, and Lin-Tan, Dan-Tzu.
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- 2003
181. Multi-Weather Evaluation of Nowcasting Methods Including a New Empirical Blending Scheme
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Chih Chien Tsai, Hsin Hung Lin, Yu Chun Chen, Kao Shen Chung, Jia Chyi Liou, Lee Yaw Lin, and Chung Yi Lin
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Atmospheric Science ,010504 meteorology & atmospheric sciences ,Nowcasting ,Computer science ,0208 environmental biotechnology ,Extrapolation ,nowcasting ,02 engineering and technology ,lcsh:QC851-999 ,Environmental Science (miscellaneous) ,01 natural sciences ,law.invention ,Data assimilation ,law ,reflectivity ,Statistics ,radar echo extrapolation ,Predictability ,Radar ,0105 earth and related environmental sciences ,Event (probability theory) ,blending ,extrapolation adjusted by model prediction ,radar data assimilation ,020801 environmental engineering ,Ranking ,lcsh:Meteorology. Climatology ,Lead time - Abstract
This study utilized a radar echo extrapolation system, a high-resolution numerical model with radar data assimilation, and three blending schemes including a new empirical one, called the extrapolation adjusted by model prediction (ExAMP), to carry out 150 min reflectivity nowcasting experiments for various heavy rainfall events in Taiwan in 2019. ExAMP features full trust in the pattern of the extrapolated reflectivity with intensity adjustable by numerical model prediction. The spatial performance for two contrasting events shows that the ExAMP scheme outperforms the others for the more accurate prediction of both strengthening and weakening processes. The statistical skill for all the sampled events shows that the nowcasts by ExAMP and the extrapolation system obtain the lowest and second lowest root mean square errors at all the lead time, respectively. In terms of threat scores and bias scores above certain reflectivity thresholds, the ExAMP nowcast may have more grid points of misses for high reflectivity in comparison to extrapolation, but serious overestimation among the points of hits and false alarms is the least likely to happen with the new scheme. Moreover, the event type does not change the performance ranking of the five methods, all of which have the highest predictability for a typhoon event and the lowest for local thunderstorm events.
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- 2020
182. Prognostic significance of general immune competence in acute leukemia
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Bai-Ling, Li, Jie, Hu, Jia, Ye, Xiao-Feng, Wan, Yi-Gao, Shen, Bing-Bing, Li, Yu-Chun, Chen, Xin-Shun, Lin, and Yuan-Qing, Chen
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- 1990
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183. Combined initial cyclophosphamide with repeated methylprednisolone pulse therapy for severe paraquat poisoning from dermal exposure
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Lin, Nan-Chieh, Lin, Ja-Liang, Lin-Tan, Dan-Tzu, and Yu, Chun-Chen
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Cyclophosphamide -- Physiological aspects ,Cyclophosphamide -- Usage ,Herbicides -- Adverse and side effects ,Herbicides -- Physiological aspects ,Poisoning -- Care and treatment ,Environmental issues ,Health ,Pharmaceuticals and cosmetics industries - Abstract
The article presents a patient with severe paraquat poisoning from dermal exposure, who had chemical burns to more than 10% of his body surface area, serum paraquat level 0.13 [micro]g/mL 60 hr after exposure, and severe hypoxemia (Pa[O.sub.2] 41.6 mmHg). The patient was successfully treated with combined initial megadoses of cyclophosphamide (15 mg/kg/day, total 2 days) with repeated methylprednisolone pulse therapy (15 mg/kg/day, total 6 days) and continuous dexamethasone administration (5 mg every 8 hr), and recovered completely without sequelae 3 months later. This treatment deserves further investigation in future clinical trials. Key Words: Paraquat poisoning; Dermal Exposure; Cyclophosphamide; Methylprednisolone pulse therapy; Dexamethasone., INTRODUCTION Paraquat is a popular bipyridal herbicide which has a good safety record if applied properly High mortality rate (60% to 70%) has been noted in paraquat-poisoned patients, caused by [...]
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- 2003
184. Environmental lead exposure and urate excretion in the general population
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Lin, Ja-Liang, Tan, Dan-Tzu, Ho, Huei-Hong, and Yu, Chun-Chen
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Lead poisoning -- Physiological aspects ,Gout -- Risk factors ,Hyperuricemia -- Causes of ,Health ,Health care industry - Published
- 2002
185. Mycophenolate mofetil reduces renal cortical inducible nitric oxide synthase mRNA expression and diminishes glomerulosclerosis in MRL/ lpr mice
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Yu, Chun-Chen, Yang, Chih-Wei, Wu, Mai-Szu, Ko, Yi-Ching, Huang, Chiung-Tseng, Hong, Jenn-Jye, and Huang, Chiu-Ching
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- 2001
186. Lead chelation therapy and urate excretion in patients with chronic renal diseases and gout
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Lin, Ja-Liang, Yu, Chun-Chen, Lin-Tan, Dan-Tzu, and Ho, Huei-Hong
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- 2001
187. Prediction of vascular dementia and Alzheimer's disease in patients with atrial fibrillation or atrial flutter using CHADS2 score
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Po Hsun Huang, Chin Chou Huang, Shing Jong Lin, Ruey Hsing Chou, Hsin Bang Leu, Tzeng Ji Chen, Chun Chih Chiu, Jaw Wen Chen, Chia Min Chung, Wan Leong Chan, and Yu Chun Chen
- Subjects
Adult ,Male ,medicine.medical_specialty ,Multivariate analysis ,Disease ,030204 cardiovascular system & hematology ,CHADS2 score ,03 medical and health sciences ,0302 clinical medicine ,Alzheimer Disease ,Internal medicine ,mental disorders ,medicine ,Humans ,Dementia ,atrial fibrillation ,Vascular dementia ,Stroke ,Aged ,Aged, 80 and over ,Medicine(all) ,lcsh:R5-920 ,business.industry ,Dementia, Vascular ,Atrial fibrillation ,General Medicine ,Middle Aged ,Alzheimer's disease ,medicine.disease ,stroke ,Confidence interval ,Atrial Flutter ,Cardiology ,Female ,business ,lcsh:Medicine (General) ,030217 neurology & neurosurgery ,Atrial flutter ,dementia - Abstract
Background: Atrial fibrillation (AF) is associated with an increased risk of dementia. However, limited data are available on the predictors of dementia in patients with AF. This study aimed to evaluate whether the CHADS2 score could be a useful tool for risk stratification with regard to dementia occurrence among patients with AF. Methods: AF patients were identified from the National Health Insurance sampling database, which has accumulated a total of 1,000,000 participants since 2000. After excluding patients diagnosed with dementia prior to the index day of enrollment, CHADS2 score was measured to investigate its association with the occurrence of dementia, including vascular dementia and Alzheimer's disease. Results: During the mean follow-up period of 3.71 ± 2.78 years, 1135 dementia cases (7.36%) were identified, including 241 cases of vascular dementia and 894 cases of Alzheimer's disease. In multivariate analysis, an increase of 1 point in the CHADS2 score was independently associated with a 54% increase in the risk of vascular dementia (hazard ratio = 1.54; 95% confidence interval, 1.41–1.69; p
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- 2016
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188. Environmental Lead Exposure and Progressive Renal Insufficiency
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Lin, Ja-Liang, Tan, Dan-Tzu, Hsu, Kuan-Huang, and Yu, Chun-Chen
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- 2001
189. Carbon Nanotube-Mediated Photothermal Disruption of Endosomes/Lysosomes Reverses Doxorubicin Resistance in MCF-7/ADR Cells
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Chin-Ling Pai, Yu-Chun Chen, Chia-Yen Hsu, Ping-Shan Lai, and Hong-Lin Su
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Anthracycline ,Cell Survival ,Infrared Rays ,Endosome ,Biomedical Engineering ,Pharmaceutical Science ,Medicine (miscellaneous) ,Apoptosis ,Bioengineering ,Endosomes ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Diffusion ,Nanocapsules ,medicine ,Humans ,General Materials Science ,Doxorubicin ,Viability assay ,Antibiotics, Antineoplastic ,Nanotubes, Carbon ,Chemistry ,Neoplasms, Experimental ,Photothermal therapy ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Treatment Outcome ,Photochemotherapy ,Biochemistry ,Drug Resistance, Neoplasm ,Delayed-Action Preparations ,Cancer cell ,MCF-7 Cells ,Biophysics ,Nanocarriers ,Lysosomes ,0210 nano-technology ,Drug carrier ,medicine.drug - Abstract
Cancer is the leading cause of human death worldwide. Although many scientists work to fight this disease, multiple drug resistance is a predominant obstacle for effective cancer therapy. In drug-resistant MCF-7/ADR cells, the acidic organelles with lower pH value than normal one can cause the protonation of anthracycline drugs, inducing drug accumulation in these organelles. In this study, single-walled carbon nanotubes with polyethylene glycol phospholipids surface modification (PEGylated SWNTs) were utilized as near infrared-activated drug carriers for doxorubicin (DOX) delivery against MCF-7/ADR cells. Our results showed that a concentration-dependent temperature increase was observed in a solution of PEGylated SWNTs with 808 nm laser irradiation, whereas a water solution showed no significant changes in temperature under a thermal camera using the same irradiation dose. Interestingly, PEGylated DOX-SWNTs enhanced the nuclear accumulation of DOX with 808 nm irradiation whereas free DOX or PEGylated DOX-SWNTs revealed discrete red spots in MCF-7/ADR cells by confocal microscopic observation. Cell viability of PEGylated DOX-SWNTs-treated cells was also significantly decreased after 808 nm laser irradiation. Thus, photothermally activated PEGylated SWNTs can be a potential nanocarrier to deliver DOX into cancer cells and successfully overcome drug-resistant behavior in MCF-7/ADR breast cancer cells.
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- 2016
190. Enhancing Drug Release From Antibiotic-loaded Bone Cement Using Porogens
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Chih-Hung Chang, Yu-Chun Chen, Karl Wu, and Yuan-Ming Hsu
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Ceramics ,Polymethyl methacrylate ,Scanning electron microscope ,medicine.drug_class ,Antibiotics ,03 medical and health sciences ,0302 clinical medicine ,Tensile Strength ,Materials Testing ,Ultimate tensile strength ,Humans ,Polymethyl Methacrylate ,Medicine ,Orthopedics and Sports Medicine ,Ceramic ,Fourier transform infrared spectroscopy ,Porosity ,030222 orthopedics ,Fourier Analysis ,business.industry ,Bone Cements ,Fibrin Foam ,Bone cement ,Anti-Bacterial Agents ,Drug Liberation ,030220 oncology & carcinogenesis ,visual_art ,Microscopy, Electron, Scanning ,visual_art.visual_art_medium ,Surgery ,Gentamicins ,business ,Nuclear chemistry - Abstract
Objective To evaluate whether the addition of porogens to polymethyl methacrylate (PMMA) enhances the antibiotic elution rate from antibiotic-loaded bone cement. Methods Two porogens, gelatin sponge (Spongostan, Ferrosan Medical Devices) and ceramic granules (Bicera, Wiltrom), were added to liquid gentamicin-loaded PMMA at increasing concentrations. Porosity was analyzed using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy. Young's modulus and drug elution were also measured. The gentamicin content of the eluents was evaluated by o-phthaldialdehyde (OPA) assay on days 1, 2, 5, 7, 10, and 14. Results After day 5, the drug-releasing rate of Spongostan was significantly higher than that of Bicera in the order G3 > G2 > T3 > G1 > T2 > T1 > bone cement, where G represents the concentration of Spongostan and T represents the concentration of Bicera. The addition of Bicera and Spongostan increased the drug-releasing efficiency of PMMA by 3.75-fold and 5.65-fold, respectively. Spongostan also resulted in larger pores (ie, 70 to approximately 200 μm) compared with Bicera (5 to 10 μm) but reduced biomechanical strength. Conclusion Both gelatin sponge and ceramic granules improved the local antibiotic elution rate, although the drug-releasing rate of Spongostan was significantly higher than that of Bicera.
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- 2016
191. Effect of surface configurations on the room-temperature magnetism of pure ZnO
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Thomas Tietze, Zumin Wang, Eberhard Goering, Johannes Baier, Yu-Chun Chen, Andreas Leineweber, Gisela Schütz, and Fritz Phillipp
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010302 applied physics ,Materials science ,Magnetism ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Grain size ,Paramagnetism ,Adsorption ,Ferromagnetism ,Unpaired electron ,Chemical physics ,0103 physical sciences ,Materials Chemistry ,Diamagnetism ,0210 nano-technology - Abstract
We unambiguously discovered the existence of room-temperature ferromagnetic-like behavior (RTFM) in pure ZnO pellets, which are made from the nanoparticles showing only paramagnetism and diamagnetism. In contrast to previous reports, our systematic work shows that thermal annealing of ZnO at different temperatures can either enhance or reduce ferromagnetic-like ordering regardless of post-treatment in argon and oxygen. After post-annealing under different conditions, the treated pellets show significant and complicated variation in surface configurations, including for example different levels of surface dehydrogenation, carbon adsorption, grain size and Zn/O ratio. The quantitative analysis indicates that the RTFM of ZnO is affected mainly by surface oxygen vacancies and hydrogenation. The observed dependence of intrinsic RTFM on the energy position of the Zn 3d photoemission peak suggests the presence of unpaired electrons leading to vacancy-mediated ferromagnetism. On the other hand, we also found that the RTFM of ZnO can be easily modified by adsorbed species, which give rise to charge-transfer at the surface. Based on this result, we further identified that surface carbon contamination is a potential source for the reported controversies, related to poor reproducibility of experimental results in the area of so-called d0 ferromagnetism.
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- 2016
192. Hospice palliative care article publications: An analysis of the Web of Science database from 1993 to 2013
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I-Hsuan Hwang, Chun-Ku Chen, Shinn Jang Hwang, Ming-Hwai Lin, Hsiao-Ting Chang, and Yu Chun Chen
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medicine.medical_specialty ,Time Factors ,Palliative care ,Databases, Factual ,hospice palliative care ,Specialty ,computer.software_genre ,Annual growth % ,terminal care ,World Wide Web ,03 medical and health sciences ,0302 clinical medicine ,Nursing ,Terminal care ,Asian country ,Humans ,end of life care ,Medicine ,Palliative Care Medicine ,030212 general & internal medicine ,publications ,Medicine(all) ,lcsh:R5-920 ,Database ,business.industry ,Palliative Care ,General Medicine ,Hospice Care ,030220 oncology & carcinogenesis ,Family medicine ,Web of Science ,lcsh:Medicine (General) ,business ,Citation ,computer ,End-of-life care - Abstract
Background Academic publications are important for developing a medical specialty or discipline and improvements of quality of care. As hospice palliative care medicine is a rapidly growing medical specialty in Taiwan, this study aimed to analyze the hospice palliative care-related publications from 1993 through 2013 both worldwide and in Taiwan, by using the Web of Science database. Methods Academic articles published with topics including “hospice”, “palliative care”, “end of life care”, and “terminal care” were retrieved and analyzed from the Web of Science database, which includes documents published in Science Citation Index-Expanded and Social Science Citation Indexed journals from 1993 to 2013. Compound annual growth rates (CAGRs) were calculated to evaluate the trends of publications. Results There were a total of 27,788 documents published worldwide during the years 1993 to 2013. The top five most prolific countries/areas with published documents were the United States (11,419 documents, 41.09%), England (3620 documents, 13.03%), Canada (2428 documents, 8.74%), Germany (1598 documents, 5.75%), and Australia (1580 documents, 5.69%). Three hundred and ten documents (1.12%) were published from Taiwan, which ranks second among Asian countries (after Japan, with 594 documents, 2.14%) and 16 th in the world. During this 21-year period, the number of hospice palliative care-related article publications increased rapidly. The worldwide CAGR for hospice palliative care publications during 1993 through 2013 was 12.9%. As for Taiwan, the CAGR for publications during 1999 through 2013 was 19.4%. The majority of these documents were submitted from universities or hospitals affiliated to universities. Conclusion The number of hospice palliative care-related publications increased rapidly from 1993 to 2013 in the world and in Taiwan; however, the number of publications from Taiwan is still far below those published in several other countries. Further research is needed to identify and try to reduce the barriers to hospice palliative care research and publication in Taiwan.
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- 2016
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193. Reduction of advanced glycation end product levels by on-line hemodiafiltration in long-term hemodialysis patients
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Lin, Chun-Liang, Huang, Chiu-Ching, Yu, Chun-Chen, Yang, Huan-Yu, Chuang, Feng-Rong, and Yang, Chih-Wei
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- 2003
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194. Methicillin-resistant Staphylococcus aureus nasal carriage among patients receiving hemodialysis in Taiwan: prevalence rate, molecular characterization and de-colonization
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Kang Yu-Chuan, Tai Wei-Chen, Yu Chun-Chen, Kang Je-Ho, and Huang Yhu-Chering
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Methicillin-resistant Staphylococcus aureus ,Nasal colonization ,Hemodialysis ,Decolonization ,Taiwan ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Staphylococcus aureus, particularly methicillin resistant (MRSA), is a common pathogen among patients receiving hemodialysis. To evaluate nasal carriage, molecular characterization and effectiveness of decolonization of MRSA among patients receiving hemodialysis in Taiwan, we conducted this study. Methods From January to June 2011, two nasal samplings with a 3-month interval were obtained from patients undergoing hemodialysis in a medical center (CGMH), and in a local hospital (YMH) and sent for detection of MRSA. For MRSA carriers, decolonization procedures were administered. All patients in CGMH were observed if MRSA infections occurred during the study period. Results A total of 529 nasal specimens (265 from CGMH and 264 from YMH) were collected from 296 patients (161 from CGMH and 135 from YMH). 233 patients participated in both surveys. Average one-time point MRSA carriage rate was 3.8%, and the rate was up to 6.9% for those with two-time point surveys. No additional significant factor for MRSA carriage was identified. Seventy percent of the 20 colonizing MRSA isolates, though categorized as healthcare-associated strains epidemiologically, shared common molecular characteristics of the local community-associated strains. Only one of the 20 MRSA-colonized patients failed decolonization and had persistent colonization, while without any intervention, 17 (61%) of 28 patients with methicillin-sensitive S. aureus colonization in the first survey had persistent colonization of a genetically indistinguishable strain. Within the study period, two patients (1.24%) in CGMH, one with MRSA colonization (9.1%), developed MRSA infection. Conclusion A substantial proportion of patients receiving hemodialysis in Taiwan had MRSA colonization, mostly genetically community strains. Decolonization procedures may effectively eliminate MRSA colonization and might reduce subsequent MRSA infection in these patients.
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- 2012
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195. Role of Calcitonin Gene-Related Peptide in Cooling-Induced Hemodynamic Perturbations in Rats: Investigation by Spectrum Analysis
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Che-Se Tung, Yu-Chun Chen, Po-Lei Lee, Yu-Chieh Lin, Yia-Ping Liu, and Yi-Hsien Lin
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medicine.medical_specialty ,Chemistry ,Antagonist ,Hemodynamics ,Vasodilation ,General Medicine ,Calcitonin gene-related peptide ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,Heart rate ,medicine ,Hexamethonium ,Receptor ,Guanethidine ,medicine.drug - Abstract
Calcitonin gene-related peptide (CGRP) and its receptors are widely distributed in the nervous and cardiovascular systems as a potent vasodilator; however, the underlying mechanisms of action of CGRP on cardiovascular regulation, such as cooling-elicited hemodynamic perturbation (CEHP), are still unclear. We used spectral and crossspectral analyses to explore such questions in this study. Conscious rats were pretreated with the CGRP antagonist CGRP_(8-37)-only, or following the removal of sympathetic influences using hexamethonium (HEX) or guanethidine (GUA) and then subjected the treated rats to a stressful cooling trial (CS). Cardiovascular indices were monitored via an implanted telemetric device throughout the experiment. The analyses included measurements of blood pressure (BP), heart rate (HR), cardiovascular variabilities (BPV, HRV), coherence linkage at very-low, low and high frequency regions (VLF: 0.02 to 0.2 Hz, LF: 0.2 to 0.6 Hz, and HF: 0.6 to 3.0 Hz), and dicrotic notch (Dn). Key findings of the hemodynamic indices and spectral changes in efferent sympathetic oscillations (LF) and myogenic oscillations (VLF) in comparison with the control vehicle were demonstrated: (I) under resting condition, CGRP_(8-37)- only increased the BP, HR and powers of VLF_(BPV), LF_(BPV). In contrast, the effects of CGRP_(8-37)-only were generally diminished or further reduced when the rats were pretreated with HEX or GUA. (II) Under CS condition, CGRP_(8-37)-only increased the HR but attenuated the power of LF_(BPV), converted the negative correlation (NC) into positive correlation (PC) for VLF_(HRV) with VLF_(BPV) (VLF pair) and LF_(HRV) with LF_(BPV) (LF pair). On the other hand, when pretreated with sympathetic removals, both HEX+CGRP_(8-37) and GUA+CGRP_(8-37) generally abolished the control coolinginduced pressor and tachycardia, attenuated or further reduced the effects of CGRP_(8-37)-only on VLF_(BPV), VLF_(HRV) and LF_(BPV). In addition, HEX+CGRP_(8-37) generally persisted the CGRP_(8-37)-only effect of PC for VLF and LF pairs, but GUA reversed the PC of VLF pair back to a NC tendency. Furthermore, cross-spectral analyses indicated that throughout the experiment, CGRP8-37-only enhanced the coherence linkage between BPV and HRV at the LF region but weakened that at the HF region. HEX+CGRP_(8-37) abolished the CGRP_(8-37)-only effect on the LF region but GUA+CGRP_(8-37) persisted the CGRP_(8-37)-only effects. Taken together, our results indicate that CGRP is dependent on the status of intrinsic sympathetic tonus to exert its function on cardiovascular regulation.
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- 2015
196. Novel Noncontact Dry Electrode With Adaptive Mechanical Design for Measuring EEG in a Hairy Site
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Yu Chun Chen, Bor-Shyh Lin, and Jeng-Shyang Pan
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Artifact (error) ,Materials science ,medicine.diagnostic_test ,Clinical diagnosis ,Electrode ,medicine ,Mechanical design ,Electrical and Electronic Engineering ,Electroencephalography ,Instrumentation ,Electrical impedance ,Biomedical engineering - Abstract
Electroencephalography (EEG) can provide important and useful information in clinical diagnosis. The conventional EEG electrode with conductive gel (wet electrode) is most frequently used for measuring EEG. However, the wet electrode encounters the issue of dehydration for long-term measurement. Recently, different types of dry electrodes were proposed to overcome the above issue, but measuring EEG in a hairy site is still a challenge for these electrodes. In this paper, a novel noncontact dry electrode with adaptive mechanical design is proposed to measure EEG in a hairy site without conductive gel. The proposed noncontact dry electrode can measure EEG across the hair layer to reduce the influence of hair. By the adaptive mechanical design, the influence of motion artifact can also be effectively improved. From the experimental results, the proposed noncontact dry electrode can provide a good performance of measuring EEG in a hairy site and a good ability to avoid the influence of motion artifact.
- Published
- 2015
197. Lower Risk of Stroke after Deformity Surgery: Long Term Benefit Demonstrated by a National Cohort Study
- Author
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Li Fu Chen, Peng Yuan Chang, Laura Liu, Yu Chun Chen, Shih Wei Liu, Henrich Cheng, Wen Cheng Huang, Liang Chung Huang, Jau Ching Wu, Su Shun Lo, and Wu Fu Chung
- Subjects
Male ,medicine.medical_specialty ,Health, Toxicology and Mutagenesis ,Taiwan ,lcsh:Medicine ,adult spinal deformity (ASD), spinal fusion surgery, stroke, National Health Insurance Research Database (NHIRD) ,Lower risk ,Article ,Cohort Studies ,Risk Factors ,Deformity ,medicine ,Humans ,spinal fusion surgery ,Stroke ,Aged ,Proportional Hazards Models ,Retrospective Studies ,Proportional hazards model ,business.industry ,Incidence ,lcsh:R ,Hazard ratio ,Public Health, Environmental and Occupational Health ,Retrospective cohort study ,Middle Aged ,Thoracic Surgical Procedures ,medicine.disease ,stroke ,Spine ,Surgery ,National Health Insurance Research Database (NHIRD) ,adult spinal deformity (ASD) ,Cohort ,Regression Analysis ,Female ,medicine.symptom ,business ,Cohort study - Abstract
Objectives: This study aimed to investigate the long-term risk of stroke in adult patients with spinal deformity. Specifically, the study addressed the possible protective effect of surgery for spinal deformity against stroke. Methods: Using the National Health Insurance Research Database (NHIRD), a monopolistic national database in Taiwan, this retrospective cohort study analyzed the incidence of stroke in patients with adult spinal deformity (ASD) in a 11-year period. A total of 13,503 patients, between 55 and 75 years old, were identified for the diagnosis of ASD. The patients were grouped into two: the surgical group (n = 10,439) who received spinal fusion surgery, and the control group (n = 2124) who received other medical treatment. The incidence rates of all subsequent cerebrovascular accidents, including ischemic and hemorrhagic strokes, were calculated. Hazard ratios for stroke were calculated use a full cohort and a propensity score matched cohort. Adjustments for co-morbidities that may predispose to stroke, including hypertension, diabetes mellitus, arrhythmia and coronary heart disease were conducted. Kaplan-Meier and Cox regression analyses were performed to compare the risk of stroke between the two groups. Results: During the total observation period of 50,450 person-years, the incidence rate of stroke in the surgical group (15.55 per 1000 person-years) was significantly lower than that of the control group (20.89 per 1000 person-years, p <, 0.001). Stroke was more likely to occur in the control group than in the surgical group (crude hazard ratio 1.34, p <, 0.001, adjusted HR 1.28, p <, 0.001, by a propensity score matched model). Conclusions: In this national cohort of more than 13,000 ASD patients covering 10 years, stroke was approximately 25% less likely to happen in patients who underwent spinal fusion surgery than those who received medical management. Therefore, spinal fusion surgery may provide a protective effect against stroke in adult patients with spinal deformity.
- Published
- 2015
198. Unique high-temperature performance of highly condensed MnBi permanent magnets
- Author
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Helmut Kronmüller, Thomas Tietze, Eberhard Goering, Andreas Leineweber, Yu-Chun Chen, Fei Qu, Gisela Schütz, Chia-Chin Chen, and Giuliano Gregori
- Subjects
Materials science ,Condensed matter physics ,Mechanical Engineering ,Isotropy ,Metals and Alloys ,Nucleation ,Coercivity ,Condensed Matter Physics ,Microstructure ,Magnetization ,Grain growth ,Mechanics of Materials ,Magnet ,General Materials Science ,Thermal stability - Abstract
High-performance MnBi isotropic magnets have been prepared via spark-plasma-sintering, which achieves bulk magnets with high densification and little grain growth. The sintered magnets in this work show high saturation magnetization at high temperatures. Moreover, hard magnetic behavior is still present after heating beyond its phase transition temperature. The exceptional thermal stability could be due to the observed fine-grained microstructure. The analysis of temperature dependence of coercivity behavior demonstrates that the magnetization process can be explained by nucleation model.
- Published
- 2015
199. Magnetic and microstructural properties of anisotropic MnBi magnets compacted by spark plasma sintering
- Author
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Wenting Huang, Bastian Rheingans, Gisela Schütz, Giuliano Gregori, Helmut Kronmüller, Eberhard Goering, and Yu-Chun Chen
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chemistry.chemical_classification ,Materials science ,Mechanical Engineering ,Metals and Alloys ,Spark plasma sintering ,02 engineering and technology ,Polymer ,Coercivity ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Grain size ,0104 chemical sciences ,chemistry ,Mechanics of Materials ,Magnet ,Materials Chemistry ,Coupling (piping) ,Composite material ,0210 nano-technology ,Anisotropy - Abstract
In this study, we present that anisotropic MnBi bulk magnets can be obtained using spark-plasma-sintering technique (SPS). Grain misalignment was suppressed by either external field or addition of appropriate polymer binder. Various microstructures were effectively achieved during SPS processing, and lead to distinct magnetic performance. Microstructure analysis reveals that the coercive field of the SPS-compacted magnets declines strongly with increasing grain size. Bi-rich residue clearly plays a role in magnetic decoupling to enhance the coercive field, whereas the exchange coupling mediated by excess Mn reduces it dramatically. In addition, the amount and distribution of Mn and Bi residue has a profound influence on the thermal magnetic stability of sintered MnBi magnets. We suggest that fast consolidation methods like SPS technique enable to tailor the microstructure of bulk magnetic products to meet specific application requirements.
- Published
- 2020
200. A shrimp glycosylase protein, PmENGase, interacts with WSSV envelope protein VP41B and is involved in WSSV pathogenesis
- Author
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Shin Jen Lin, Jiun Yan Huang, Po Sue Wang, Yun-Shiang Chang, Hao Ching Wang, Chu Fang Lo, Kuan Fu Liu, and Yu Chun Chen
- Subjects
0301 basic medicine ,Glycosylation ,viruses ,Immunology ,White spot syndrome ,Aquaculture ,Biology ,Virus ,Arthropod Proteins ,Cell Line ,Penaeus monodon ,03 medical and health sciences ,chemistry.chemical_compound ,Ribonucleases ,White spot syndrome virus 1 ,Penaeidae ,Viral Envelope Proteins ,Two-Hybrid System Techniques ,Animals ,chemistry.chemical_classification ,030102 biochemistry & molecular biology ,Lipid bilayer fusion ,biology.organism_classification ,Virology ,Recombinant Proteins ,Up-Regulation ,Shrimp ,Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase ,030104 developmental biology ,chemistry ,DNA glycosylase ,Host-Pathogen Interactions ,RNA Interference ,Glycoprotein ,Protein Binding ,Developmental Biology - Abstract
Viral glycoproteins are expressed by many viruses, and during infection they usually play very important roles, such as receptor attachment or membrane fusion. The mature virion of the white spot syndrome virus (WSSV) is unusual in that it contains no glycosylated proteins, and there are currently no reports of any glycosylation mechanisms in the pathogenesis of this virus. In this study, we cloned a glycosylase, mannosyl-glycoprotein endo-β-N-acetylglucosaminidase (ENGase, EC 3.2.1.96), from Penaeus monodon and found that it was significantly up-regulated in WSSV-infected shrimp. A yeast two-hybrid assay showed that PmENGase interacted with both structural and non-structural proteins, and GST-pull down and co-immunoprecipitation (Co-IP) assays confirmed its interaction with the envelope protein VP41B. In the WSSV challenge tests, the cumulative mortality and viral copy number were significantly decreased in the PmEngase-silenced shrimp, from which we conclude that shrimp glycosylase interacts with WSSV in a way that benefits the virus. Lastly, we speculate that the deglycosylation activity of PmENGase might account for the absence of glycosylated proteins in the WSSV virion.
- Published
- 2020
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