High Power Density Asymmetrical Full-Bridge Soft-Switching Inverter

Pei-Chin Chi,Cheng-Yen Chou,Marojahan Tampubolon,Yao-Ching Hsieh,Jing-Yuan Lin,Huang-Jen Chiu 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

This paper presents a Zero-Voltage-Switching (ZVS) technique eliminating the switching loss on a proposed single phase bi-directional full-bridge Buck inverter in which asymmetrical filter topology and control scheme are for each arm. Here Metal-Oxide-Field-Effect- Transistor(MOSFET) is chosen as the switching device, an L₁-C₁ filter is connected across the full-bridge, an L₂ filter is connected in series to load or grid. While the arm connecting with the C₁ is controlled by the polarity of 50Hz sinusoid reference command and the arm connecting with the L₁ is controlled by a Pulse-Width-Modulation(PWM) signal modulated by sinusoid, the L₁-C₁ then operates as an output filter of Buck, and the succeeding L₂ filter further attenuates ripple current flowing to load or grid. The ZVS technique sets the L₁ inductance such low that its current flows bi-directionally within a switching period, then the bidirectional current with sufficiently high peaks in turn charge and discharge the output capacitance Coss of MOSFETs of the switching arm within floating time, defined as the duration when both MOSFETs of an arm are off, to let the MOSFETs D-S channels be turned on or off at the state that Coss are fully discharged to zero voltage, so ZVS of MOSFET is achieved. Under the ZVS operation without frequency proportional switching loss, the switching frequency is possible to be raised to high to compact the sizes of passive components and heat sink of the inverter for achieving high power density. Simulation and experiment have been carried out to verify the ZVS operation.

Development of a self-centering tension-only brace for seismic protection of frame structures

Pei Chi,Tong Guo,Yang Peng,Dafu Cao,Jun Dong 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.26 No.5

This study develops and numerically verifies an innovative seismically resilient bracing system. The proposed selfcentering tension-only brace (SC-TOB) is composed of a tensioning system to provide a self-centering response, a frictional device for energy dissipation, and a high-strength steel cable as a bracing element. It is considered to be an improvement over the traditional self-centering braces in terms of lightness, high bearing capacity, load relief, and double-elongation capacity. In this paper, the mechanics of the system are first described. Governing equations deduced from the developed analytical model to predict the behavior of the system are then provided. The results from a finite element validation confirm that the SC-TOB performs as analytically predicted. Key parameters including the activation displacement and load, the self-centering parameter, and equivalent viscous damping are investigated, and their influences on the system behavior are discussed. Finally, a design procedure considering controlled softening behavior is developed and illustrated through a design example.

Identifying Post-translational Modification Crosstalks for Breast Cancer

Chi-Hua Tung,Pei-Wei Shueng,Yen-Wei Chu,Chi-Wei Chen,Chian-Ying Chen 한국정보과학회 2017 Journal of Computing Science and Engineering Vol.11 No.4

Post-translational modifications (PTMs) of proteins play substantial roles in the gene regulation of cell physiological functions and in the generation of major diseases. However, the majority of existing studies only explored a certain PTM of proteins, while very few have investigated the PTMs of two or more domains and the effects of their interactions. In this study, after collecting data regarding a large number of breast cancer-related and validated PTMs, a sequence and domain analysis of breast cancer proteins was carried out using bioinformatics methods. Then, protein-protein interaction network-related tools were applied in order to determine the crosstalks between the PTMs of the proteins. Finally, statistical and functional analyses were conducted to identify more modification sites of domains and proteins that may interact with at least two or more PTMs. In addition to exploring the associations between the interactive effects of PTMs, the present study also provides important information that would allow biologists to further explore the regulatory pathways of biological functions and related diseases.

Resveratrol Arrests Cell Cycle and Induces Apoptosis in Human Hepatocellular Carcinoma Huh-7 Cells

Pei-Chi Liao,Lean-Teik Ng,Liang-Tzung Lin,Christopher D. Richardson,Guey-Horng Wang,Chun-Ching Lin 한국식품영양과학회 2010 Journal of medicinal food Vol.13 No.6

Resveratrol has been shown to possess anticancer, anti-aging, anti-inflammatory, antimicrobial, and neuroprotective activities. In this study, we examined the antiproliferative properties of resveratrol and its molecular mechanism(s) of action in Huh-7 cells, a new human hepatoma cell line system for hepatitis C virus. Results showed that resveratrol significantly inhibited Huh-7 cell proliferation (50% inhibitory concentration=22.4μg/mL) and effectively induced cell cycle arrest and apoptosis. It up-regulated p21/WAF1 expression in a p53-independent manner, but the expressions of cyclin E, cyclin A, and cyclin-dependent kinase 2 were down-regulated. It also caused an increase in the ratio of pro-apoptotic/anti-apoptotic protein, which was associated with the mitochondrial membrane depolarization and the increase in caspase activity. Resveratrol showed no effect on Fas, Fas ligand, extracellular signal regulated kinase (ERK) 1/2, and p38 expression but down-regulated phospho-ERK and phospho-p38 expression. In addition, resveratrol was noted to trigger autophagic cell death through the increased expression of autophagy-related Atg5, Atg7, Atg9, and Atg12 proteins. These results suggest that resveratrol could be an important chemoprevention agent for hepatoma of hepatitis C virus infection.

Prediction of Motor Function Outcome in Patients with Brain Injury Using Computed Tomography and Diffusion Tensor Image

Tsung Pei-Chi,Sung Soon Ki,Son Dong Wuk,Lee Sang Weon,Song Geun Sung 대한말초신경학회 2019 The Nerve Vol.5 No.1

Objective Diffusion tensor imaging (DTI) was used to study motor function prognosis in stroke and intracerebral hemorrhage (ICH) patients. In this study, we investigated the correlation between DTI and computed tomography (CT) and compared the predictability of clinical outcome in patients with stoke, ICH, brain tumor, and traumatic brain injury. Methods We retrospectively reviewed 22 patients with brain injury who underwent DTI and CT. Motor weakness was assessed using the Medical Research Council (MRC) grade scores. The fractional anisotropy (FA) of the region of interest (ROI) of DTI was compared between the injured and non-injured sites. Results The differences in the encephalomalacic changes of corticospinal tract injury between DTI and CT were not statistically significant in patients with motor weakness (p=0.09). Neither modality could predict the motor recovery rate (CT, p=0.89; DTI, p=0.86). However, DTI showed a significant difference in initial MRC grade (p=0.003). We evaluated the possibility of more accurate evaluation of MRC grade change using DTI. FA ROI in injured (450.73±105.32) and non-injured (582.18±99.68) sites showed a significant difference (p=0.00). Pearson’s correlation coefficient showed that FA ROI ratio had a significant correlation with initial (p=0.43) and follow-up (p=0.012) MRC grades, but not with MRC grade change (p=0.67). Conclusion DTI is more accurate than CT for evaluating motor deficit. It aids the treatment and rehabilitation plans in patients with brain injury. However, the prediction of motor function recovery is still insufficient.

Prediction of the Duration to Next Admission for an Acute Affective Episode in Patients with Bipolar I Disorder

Pao-Huan Chen(Pao-Huan Chen),Chun-Ming Shih(Chun-Ming Shih),Chi-Kang Chang(Chi-Kang Chang),Chia-Pei Lin(Chia-Pei Lin),Yung-Han Chang(Yung-Han Chang),Hsin-Chien Lee(Hsin-Chien Lee),El-Wui Loh(El-Wui Lo 대한정신약물학회 2023 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.21 No.2

Objective: Predicting disease relapse and early intervention could reduce symptom severity. We attempted to identify potential indicators that predict the duration to next admission for an acute affective episode in patients with bipolar I disorder. Methods: We mathematically defined the duration to next psychiatric admission and performed single-variate regressions using historical data of 101 patients with bipolar I disorder to screen for potential variables for further multivariate regressions. Results: Age of onset, total psychiatric admissions, length of lithium use, and carbamazepine use during the psychiatric hospitalization contributed to the next psychiatric admission duration positively. The all-in-one found that hyperlipidemia during the psychiatric hospitalization demonstrated a negative contribution to the duration to next psychiatric admission; the last duration to psychiatric admission, lithium and carbamazepine uses during the psychiatric hospitalization, and heart rate on the discharge day positively contributed to the duration to next admission. Conclusion: We identified essential variables that may predict the duration of bipolar I patients’ next psychiatric admission. The correlation of a faster heartbeat and a normal lipid profile in delaying the next onset highlights the importance of managing these parameters when treating bipolar I disorder.

Utilizing Creative Quality Management to Enhance Hand Hygiene among Healthcare Personnel

Pei-Yu Lee,Ju-Chen Yen,Ching-Chi Wang 한국간호과학회 2023 한국간호과학회 학술대회 Vol.2023 No.11

Sulforaphane Inhibits TNF-α-Induced Adhesion Molecule Expression Through the Rho A/ROCK/NF-κB Signaling Pathway

Chi-Nan Hung,Hui-Pei Huang,Chau-Jong Wang,Kai-Li Liu,Chong-Kuei Lii 한국식품영양과학회 2014 Journal of medicinal food Vol.17 No.10

Endothelial dysfunction is an early indicator of cardiovascular diseases. Increased stimulation of tumor necrosis factor-a (TNF-a) triggers the inflammatory mediator secretion of endothelial cells, leading to atherosclerotic risk. In this study, we investigated whether sulforaphane (SFN) affected the expression of intracellular adhesion molecule-1 (ICAM-1) in TNF-a-induced ECV 304 endothelial cells. Our data showed that SFN attenuated TNF-a-induced expression of ICAM-1 in ECV 304 cells. Pretreatment of ECV 304 cells with SFN inhibited dose-dependently the secretion of proinflammatory cytokines, such as interleukin (IL)-1b, IL-6, and IL-8. SFN inhibited TNF-a-induced nuclear factor-jB (NF-jB) DNA binding activity. Furthermore, SFN decreased TNF-a-mediated phosphorylation of IjB kinase (IKK) and IjBa, Rho A, ROCK, ERK1/2, and plasminogen activator inhibitor-1 (PAI-1) levels. Collectively, SFN inhibited the NF-jB DNA binding activity and downregulated the TNF-a-mediated induction of ICAM-1 in endothelial cells by inhibiting the Rho A/ROCK/NF-jB signaling pathway, suggesting the beneficial effects of SFN on suppression of inflammation within the atherosclerotic lesion.

Comparison of Short- and Long-term Hearing Outcomes of Successful Inlay Cartilage Tympanoplasty Between Small and Large Eardrum Perforations

Pei-Wen Wu,Wen-Hung Wang,Chi-Che Huang,Ta-Jen Lee,Chien-Chia Huang 대한이비인후과학회 2015 Clinical and Experimental Otorhinolaryngology Vol.8 No.4

Objectives. To compare the short- and long-term hearing outcomes after successful inlay cartilage tympanoplasty between patients with small (≤25%) and large (≥50%) eardrums perforations. Methods. This is a retrospective case series study conducted in a tertiary referral center. Twenty-five patients who underwent 27 procedures were enrolled. Their mean age was 60.26 years (range, 42 to 76 years). The mean follow-up time was 18.86 months (range, 12.30 to 35.83 months). The preoperative, initial postoperative, and long-term hearing results in patients with total repair of the eardrum were analyzed. Results. In the small size group, the average (±standard deviation) air-bone gap (ABG) closure was 1.08±7.53 dB in the short-term and 2.33±11.56 dB in the long-term hearing examinations. There was no difference between short- and long-term ABG closure (P=0.689). In the large size group, the average ABG closure was 9.77±9.40 dB in the short-term and 16.25±6.01 dB in the long-term hearing examinations. There was a significant difference between short- and long-term ABG closure (P=0.029). Conclusion. Patients with large perforations have continuous hearing improvement and ABG closure for more than one year. In contrast, the short- and long-term postoperative ABGs are almost the same in patients with small perforations. More long-term postoperative follow-up of hearing results is necessary for large perforations.

SEASONAL VARIABILITY OF CARBONATE SYSTEM CHARACTERISTICS IN A CORAL REEF ECOSYSTEM, SOUTHERN TAIWAN

Pei-Jie Meng,Ming-Yih Leu,Cheng-Hao Tang,Chung-Chi Chen,Kwee-Siong Tew,Chia-Ming Chang 한국수산과학회 양식분과 2015 한국수산과학회 양식분과 학술대회 Vol.2015 No.5