The Naturally Occurring YMDD Mutation among Patients Chronically Infected HBV and Untreated with Lamivudine: A Systematic Review and Meta-Analysis

Background: Several recent reports have demonstrated that tyrosine (Y)-methionine (M)-aspartic acid (D)-aspartic acid (D) (YMDD) motif mutations can naturally occur in chronic HBV patients without antiviral treatment such as lamivudine therapy. This paper aims to assess the overall spontaneous incidence and related risk factors of YMDD-motif mutations among lamivudine-naïve chronic HBV carriers, so as to provide some clue for clinical treatment of hepatitis B. Methodology/Principal Findings: Chinese and English literatures were searched for studies reporting natural YMDD mutations among untreated chronic HBV patients from 2001 to 2010. The incidence estimates were summarized and analyzed by meta-analyses. Forty-seven eligible articles from eight countries were selected in this review (13 in English and 34 in Chinese). The pooled incidence of YMDD-motif mutation among untreated chronic HBV patients from eight countries was 12.21 % (95 % CI: 9.69%–14.95%). China had an incidence of 13.38 % (95 % CI: 10.90%–16.07%) and seven other countries had an incidence of 9.90 % (95 % CI: 3.28%–19.55%), respectively. Lamivudine therapy would increase the risk of mutations 5.23 times higher than the untreated patients. A higher HBV DNA copy number was associated with increased incidence of natural YMDD mutation. No significant difference was found in YMDD mutation incidence between groups of different gender, age, HBeAg status, patients ’ ALT (alanine aminotransferase) level, and between the groups of HBV genotype B and C. Conclusions: The YMDD-motif mutations can occur spontaneously with a relatively high incidence in CHB patient

Prevalence and trend of hepatitis C virus infection among blood donors in Chinese mainland: a systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>Blood transfusion is one of the most common transmission pathways of hepatitis C virus (HCV). This paper aims to provide a comprehensive and reliable tabulation of available data on the epidemiological characteristics and risk factors for HCV infection among blood donors in Chinese mainland, so as to help make prevention strategies and guide further research.</p> <p>Methods</p> <p>A systematic review was constructed based on the computerized literature database. Infection rates and 95% confidence intervals (95% CI) were calculated using the approximate normal distribution model. Odds ratios and 95% CI were calculated by fixed or random effects models. Data manipulation and statistical analyses were performed using STATA 10.0 and ArcGIS 9.3 was used for map construction.</p> <p>Results</p> <p>Two hundred and sixty-five studies met our inclusion criteria. The pooled prevalence of HCV infection among blood donors in Chinese mainland was 8.68% (95% CI: 8.01%-9.39%), and the epidemic was severer in North and Central China, especially in Henan and Hebei. While a significant lower rate was found in Yunnan. Notably, before 1998 the pooled prevalence of HCV infection was 12.87% (95%CI: 11.25%-14.56%) among blood donors, but decreased to 1.71% (95%CI: 1.43%-1.99%) after 1998. No significant difference was found in HCV infection rates between male and female blood donors, or among different blood type donors. The prevalence of HCV infection was found to increase with age. During 1994-1995, the prevalence rate reached the highest with a percentage of 15.78% (95%CI: 12.21%-19.75%), and showed a decreasing trend in the following years. A significant difference was found among groups with different blood donation types, Plasma donors had a relatively higher prevalence than whole blood donors of HCV infection (33.95% <it>vs </it>7.9%).</p> <p>Conclusions</p> <p>The prevalence of HCV infection has rapidly decreased since 1998 and kept a low level in recent years, but some provinces showed relatively higher prevalence than the general population. It is urgent to make efficient measures to prevent HCV secondary transmission and control chronic progress, and the key to reduce the HCV incidence among blood donors is to encourage true voluntary blood donors, strictly implement blood donation law, and avoid cross-infection.</p

Sci. China Ser. B-Chem.

Random characteristics of the dynamic heterogeneous structure in gas-solid fluidization have been studied by reconstructing voidage time series. It is indicated that the dense phase, the dilute phase and the dense/dilute cycle elements show random dynamic behavior satisfying the so-called Weibull distribution, three parameters of which change regularly with operating conditions.Random characteristics of the dynamic heterogeneous structure in gas-solid fluidization have been studied by reconstructing voidage time series. It is indicated that the dense phase, the dilute phase and the dense/dilute cycle elements show random dynamic behavior satisfying the so-called Weibull distribution, three parameters of which change regularly with operating conditions

Powder Technol.

A method was established to quantitatively describe nonlinear dynamic behavior of heterogeneous flow structure in gas-solid fluidization by carrying out multiple resolution and time series reconstruction of experimental signals. Optimum sampling frequency was proposed by analyzing the dependence of Kolmogorov entropy of time series on sampling frequencies. Original signals could be resolved with respect first to scale, and then to time and amplitude into a periodic function and three irregular changes (micro-scale fluctuations, and meso-scale irregular amplitude and time fluctuations). Statistical analysis indicated that the three kinds of irregular components are of random characteristics, with a complicated evolution of their probability density distributions with changing operating conditions. A new distribution function, called Compound Weibull distribution with seven parameters, was developed to describe the irregular fluctuations of flow structure, leading to a nonlinear dynamic model for simulating dynamic behaviors of heterogeneous flow structure in gas-solid fluidization, which has been coded into a software package. (C) 2000 Elsevier Science S.A. All rights reserved.A method was established to quantitatively describe nonlinear dynamic behavior of heterogeneous flow structure in gas-solid fluidization by carrying out multiple resolution and time series reconstruction of experimental signals. Optimum sampling frequency was proposed by analyzing the dependence of Kolmogorov entropy of time series on sampling frequencies. Original signals could be resolved with respect first to scale, and then to time and amplitude into a periodic function and three irregular changes (micro-scale fluctuations, and meso-scale irregular amplitude and time fluctuations). Statistical analysis indicated that the three kinds of irregular components are of random characteristics, with a complicated evolution of their probability density distributions with changing operating conditions. A new distribution function, called Compound Weibull distribution with seven parameters, was developed to describe the irregular fluctuations of flow structure, leading to a nonlinear dynamic model for simulating dynamic behaviors of heterogeneous flow structure in gas-solid fluidization, which has been coded into a software package. (C) 2000 Elsevier Science S.A. All rights reserved

Facile synthesis of Zn2Ti3O8 hollow spheres based on ion exchange as promising anodes for lithium ion batteries

A new approach has been designed to convert typical Stober silica spheres to Zn2Ti3O8 (ZTO) hollow spheres with different shell thicknesses as anode materials for Lithium ion batteries. The morphologies, structures and synthesis process of ZTO hollow spheres are systematically investigated. X-ray diffraction (XRD) analysis shows that the good ZTO crystal is formed after being sintered at 500 degrees C for 2 h. The galvanostatic cycle tests exhibit excellent cycling stability, reversibility and low voltage. At a current density of 200 mA g(-1), the discharge specific capacities of 186.2 mAh g(-1), 173.6 mAh g(-1) and 169.9 mAh g(-1) have been achieved after 100 cycles, 200 cycles and 300 cycles, respectively. The superior electrochemical performance could be attributed to the hollow structure and characteristics of ZTO crystals. Cyclic voltammetry (CV) curves show symmetrical and stable redox peaks at 1.1 V and 1.5 V for ZTO hollow spheres after the first cycle. Electrochemical impedance spectroscopy (EIS) measurement analysis also indicates that ZTO hollow spheres as anode materials for LIBs have excellent electrochemical performance. (C) 2016 Published by Elsevier Ltd