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Secondary Structural Elements of the hCV X-region Involved in Viral Replication

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Journal of Clinical and Translational hepatology 2015年第1期3卷 1-8页

作者： Nidhi Gupta catherine h.wu George Y.wu Department of Medicine Division of Gastroenterology-Hepatology University of Connecticut Health Center Farmington CT USA

Background and Aims:The noncoding regions in the 3'-untranslated region (UTR) of the hepatitis C virus (hCV)genome contain secondary structures that are important for *** aim of this study was to identify detailed conformational elements of the X-region involved in hCV ***:Ribonucleic acid (RNA) structural analogs X94,X12,and X12c were constructed to have identical conformation but 94%,12%,and 0% sequence identity,respectively,to the X region of hCV genotype *** of structural analogs on replication of hCV genotypes 1b and 2a hCV RNA were studied by quantitative reverse transcriptase polymerase chain ***:In replicon BB7 cells,a constitutive replication model,hCV RNA levels decreased to 55%,52%,53%,and 54% after transfection with expression plasmids generating RNA structural analogs 5B-46,X-94,X-12,and X-12c,respectively (phCV genotype 2a infection model,RNA analogs 5B-46,X-94,and X-12 in hepatic cells inhibited replication to 11%,9%,and 12%,*** the X-12 analog was only 12% identical to the corresponding sequence of hCV genotype 2a,the sequence per se,or antisense effects were unlikely to be ***:The data suggest that conformation of secondary structures in 3'-UTR of hCV RNA genome is required for hCV *** expression of RNA analogs predicted to have identical stem-loop structures might inhibit hCV infection of hepatocytes in liver and may represent a novel approach to design anti-hCV agents.

关键词： hCV RNA genome hCV X-region hepatitis C virus Infection Japanese Fulminant hepatitis Virus RNA secondary structure

hepatitis B virus infection of transplanted human hepatocytes causes a biochemical and histological hepatitis in immunocompetent rats

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World Journal of Gastroenterology 2003年第5期9卷 978-983页

作者： catherine h.wu Edwin C.Ouyang Cherie Walton Kittichai Promrat Faripour Forouhar George Y. wu Department of Medicine Division of Gastroenterology-HepatologyUniversity of Connecticut Health CenterFarmingtonCTUSA Department of Pathology University of Connecticut Health CenterFarmingtonCTUSA

AIM: To characterize the host response to hepatitis B virus (hBV) infection in human hepatocytes transplanted into immunocompetent rodent rats tolerized by, and transplanted with primary human ***: One week after the transplantation, rats were inoculated with hBV, and viral gene expression, replication,and host response was ***: hBV DNA was detectable in serum for at least 60 days. hBsAg levels rose steadily for 3 weeks postinoculation and then plateaued at a level of about 0.6 pg/mi. hBV RNA was also found in liver at levels that remained constant through the time course. Immunofluorescence revealed clusters of hepatocytes that stained positive for hBcAg. The presence of hBV covalently closed circular DNA (cccDNA) in liver was demonstrated using nuclease digestion of single-stranded DNA followed by PCR. Serum ALT levels rose and reached a peak level of 180 IU/L on day 18, but remained elevated for 60 days. histology revealed a progressive predominantly mononuclear lobular ***: These data indicate that human hepatocytestransplanted into rats rendered tolerant to these cells, when infected by hBV, results in biochemical as well as histological evidence of hepatitis that accompanies viral gene expression,and DNA replication.

关键词：肝实质细胞种植乙型肝炎病毒生物化学病理组织学免疫原性动物实验

The Molecular and Structural Basis of hBV-resistance to Nucleos(t)ide Analogs

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Journal of Clinical and Translational hepatology 2014年第3期2卷 202-211页

作者： Nidhi Gupta Milky Goyal catherine h.wu George Y.wu Department of Medicine Division of Gastroenterology-HepatologyUniversity of Connecticut Heath CenterFarmingtonUSA Department of Microbiology College of Basic Sciences and HumanitiesPunjab Agriculture UniversityLudhianaPunjabIndia

Infection with hepatitis B virus(hBV)is a worldwide health *** hepatitis B can lead to fibrosis,liver cirrhosis,and hepatocellular carcinoma(hCC).Management of the latter two conditions often requires liver *** with conventional interferon or pegylated interferon alpha can clear the virus,but the rates are very *** likelihood,however,of viral resistance to interferon is *** main problems with this therapy are the frequency and severity of side *** contrast,nucleos(t)ide analogs(NAs)have significantly lower side effects,but require long term treatment as sustained virological response rates are extremely ***,long term treatment with NAs increases the risk for the development of anti-viral drug *** by understanding the molecular basis of resistance and using agents with multiple sites of action can drugs be designed to optimally prevent the occurrence of hBV antiviral resistance.

关键词： hBV hCC Nucleos(t)ide analogs

The immune response to SARS-CoV-2 in people with hIV

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Cellular & Molecular Immunology 2024年第2期21卷 184-196页

作者： Maxine A.höft Wendy A.Burgers catherine Riou Institute of Infectious Disease and Molecular Medicine University of Cape TownCape TownSouth Africa Division of Medical Virology Department of PathologyUniversity of Cape TownCape TownSouth Africa Wellcome Centre for Infectious Diseases Research in Africa University of Cape TownCape TownSouth Africa

This review examines the intersection of the hIV and SARS-CoV-2 *** with hIV(PWh)are a heterogeneous group that differ in their degree of immune suppression,immune reconstitution,and viral *** COVID-19 in those with wellcontrolled hIV infection poses no greater risk than that for hIV-uninfected individuals,people with advanced hIV disease are more vulnerable to poor COVID-19 ***-19 vaccines are effective and well tolerated in the majority of PWh,though reduced vaccine efficacy,breakthrough infections and faster waning of vaccine effectiveness have been demonstrated in *** is likely a result of suboptimal humoral and cellular immune responses after *** with advanced hIV may also experience prolonged infection that may give rise to new epidemiologically significant variants,but initiation or resumption of antiretroviral therapy(ART)can effectively clear persistent ***-19 vaccine guidelines reflect these increased risks and recommend prioritization for vaccination and additional booster doses for PWh who are moderately to severely *** recommend continued research and monitoring of PWh with SARS-CoV-2 infection,especially in areas with a high hIV burden.

关键词： SARS-CoV-2 hIV Immune dysfunction Vaccine efficacy Prolonged infection Immunogenicity

Convexification of hybrid AC-DC Optimal Power Flow with Line-Commutated Converters

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 617-628页

作者： hongyuan Liang Zhigang Li J.h.Zheng Q.h.wu School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China

Line-commutated converter (LCC)-based high-voltage DC (hVDC) systems have been integrated with bulk AC power grids for interregional transmission of renewable power. The nonlinear LCC model brings additional nonconvexity to optimal power flow (OPF) of hybrid AC-DC power grids. A convexification method for the LCC station model could address such nonconvexity but has rarely been discussed. We devise an equivalent reformulation for classical LCC station models that facilitates second-order cone convex relaxation for the OPF of LCC-based AC-DC power grids. We also propose sufficient conditions for exactness of convex relaxation with its proof. Equivalence of the proposed LCC station models and properties, exactness, and effectiveness of convex relaxation are verified using four numerical simulations. Simulation results demonstrate a globally optimal solution of the original OPF can be efficiently obtained from relaxed model.

关键词： AC-DC power system convex relaxation linecommutated converter optimal power flow second-order cone programming

A hybrid Signal Processing Method Combining Mathematical Morphology and Walsh Theory for Power Quality Disturbance Detection and Classification

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 584-592页

作者： Zhi Ding Tianyao Ji Mengshi Li Q.h.wu School of Electric Power Engineering South China University of Technology(SCUT)Guangzhou 510641China

In this paper, a novel signal processing method combining mathematical morphology (MM) and Walsh theory is proposed, which uses Walsh functions to control the structuring element (SE) and MM operators. Based on the Walsh-MM method, a scheme for power quality disturbances detection and classification is developed, which involves three steps: denoising, feature extraction and morphological clustering. First, various evolution rules of Walsh function are used to generate groups of SEs for the multiscale Walsh-ordered morphological operation, so the original signal can be denoised. Next, the fundamental wave of the denoised signal is suppressed by hadamard matrix;thus, disturbances can be extracted. Finally, the Walsh power spectrum of the waveform extracted in the previous step is calculated, and the parameters of which are taken by morphological clustering to classify the disturbances. Simulation results reveal the proposed scheme can effectively detect and classify disturbances, and the Walsh-MM method is less affected by noise and only involves simple calculation, which has a potential to be implemented in hardware and more suitable for real-time application.

关键词： hadamard matrix mathematical morphology morphological clustering power quality disturbance Walsh theory

Data-Driven Fault Detection of Multiple Open-Circuit Faults for MMC Systems Based on Long Short-Term Memory Networks

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1563-1574页

作者： Chenxi Fan Kaishun Xiahou Lei Wang Q.h.wu School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China

This paper presents a long short-term memory(LSTM)-based fault detection method to detect the multiple open-circuit switch faults of modular multilevel converter(MMC)systems with full-bridge sub-modules(FB-SMs).Eighteen sensor signals of grid voltages,grid currents and capacitance voltages of MMC for single and multi-switch faults are collected as sampling *** output signal characteristics of four types of single switch faults of FB-SM,as well as double switch faults in the same and different phases of MMC,are analyzed under the conditions of load variations and control command changes.A multi-layer LSTM network is devised to deeply extract the fault characteristics of MMC under different faults and operation conditions,and a Softmax layer detects the fault *** results have confirmed that the proposed LSTM-based method has better detection performance compared with three other methods:K-nearest neighbor(KNN),naive bayes(NB)and recurrent neural network(RNN).In addition,it is highly robust to model uncertainties and Gaussian *** validity of the proposed method is further demonstrated by experiment studies conducted on a hardware-in-the-loop(hIL)testing platform.

关键词： Fault detection long short-term memory(LSTM) modular multilevel converter(MMC) open circuit fault

Location of Asymmetric Ground Fault Using Virtual Injected Current Ratio and Two-stage Recovery Strategy in Distribution Networks

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 151-161页

作者： haiting Shan Luliang Zhang Q.h.wu Mengshi Li School of Electric Power Engineering South China University of Technology(SCUT)Guangzhou 510641China

Sparse measurements challenge fault location in distribution *** paper proposes a method for asymmetric ground fault location in distribution networks with limited measurements.A virtual injected current vector is formulated to estimate the fault line,which can be reconstructed from voltage sags measured at a few buses using compressive sensing(CS).The relationship between the virtual injected current ratio(VICR)and fault position is deduced from circuit analysis to pinpoint the ***,a two-stage recovery strategy is proposed for improving reconstruction accuracy of the current vector,where two different sensing matrixes are utilized to improve the *** proposed method is validated in IEEE 34 node test *** results show asymmetric ground fault type,resistance,fault position and access of distributed generators(DGs)do not significantly influence performance of our *** addition,it works effectively under various scenarios of noisy measurement and line parameter *** on 134 node test feeders prove the proposed method is also suitable for systems with more complex structure.

关键词： Distribution networks fault location reconstruction accuracy two-stage recovery virtual injected current ratio

Observability Analysis of Integrated Electricity and heating Systems with Thermal Quasi-dynamics in Pipelines

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1145-1158页

作者： Zhigang Li Wenjian Zheng Junbo Zhao J.h.Zheng Q.h.wu School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China Fuzhou Changle District Power Supply Company of State Grid Fujian Electric Power Co. Ltd.Fuzhou 350000China Department of Electrical and Computer Engineering University of ConnecticutStorrsCT 06269USA CSEE IEEE

Observability analysis(OA)is vital to obtaining the available input measurements of state estimation(SE)in an integrated electricity and heating system(IEhS).Considering the thermal quasi-dynamics in pipelines,the measurement equations in heating systems are dependent on the estimated results,leading to an interdependency between OA and *** OA methods require measurement equations be known exactly before SE is performed,and they are not applicable to *** bridge this gap,a scenario-based OA scheme for IEhSs is devised that yields reliable analysis results for a predefined set of time-delay scenarios to cope with this *** its core procedure,the observable state identification and observability restoration are formulated in terms of integer linear *** tests are conducted to demonstrate the validity and superiority of the proposed formulation.

关键词： Integrated electricity and heating system measurement observability analysis state estimation thermal quasi-dynamics