2,621 research outputs found

    The association of HBV core promoter double mutations (A1762T and G1764A) with viral load differs between HBeAg positive and anti-HBe positive individuals: A longitudinal analysis

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    Background/Aims: Although there have been a few reports regarding the effect of basal core promoter (BCP) double mutations (A1762T and G1764A) on hepatitis B viral loads, the association remains uncertain. We aim to determine the association after controlling for HBeAg - a strong confounding factor.Methods: We selected randomly 190 individuals from a Chinese cohort of 2258 subjects for cross-sectional analysis and 56 of the 190 for longitudinal analysis of viral loads.Results: In multivariable analysis of the cross-sectional data, BCP double mutations are significantly associated with lower viral loads in HBeAg positive subjects but no difference was found in anti-HBe positive subjects. Triple mutations at nucleotide (nt) 1753, 1762 and 1764 and mutations between nt 1809 and 1817, precore stop mutation (nt 1896) and genotype are not associated with viral loads in either HBeAg or anti-HBe positive subjects. Analysis of the longitudinal data yielded similar results to the cross-sectional data. Viral loads differ significantly between individuals infected with wild-type and BCP double mutations prior to HBeAg seroconversion but this difference is lost after seroconversion.Conclusions: BCP double mutations are associated with lower viral loads in HBeAg positive individuals but have no effect on the viral loads of anti-HBe positive individuals. (C) 2008 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved

    The Changes in China's Forests: An Analysis Using the Forest Identity

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    Changes in forest carbon stocks are a determinant of the regional carbon budget. In the past several decades, China has experienced a pronounced increase in forest area and density. However, few comprehensive analyses have been conducted. In this study, we employed the Forest Identity concept to evaluate the changing status of China's forests over the past three decades, using national forest inventory data of five periods (1977–1981, 1984–1988, 1989–1993, 1994–1998, and 1999–2003). The results showed that forest area and growing stock density increased by 0.51% and 0.44% annually over the past three decades, while the conversion ratio of forest biomass to growing stock declined by 0.10% annually. These developments resulted in a net annual increase of 0.85% in forest carbon sequestration, which is equivalent to a net biomass carbon uptake of 43.8 Tg per year (1 Tg = 1012 g). This increase can be attributed to the national reforestation/afforestation programs, environmentally enhanced forest growth and economic development as indicated by the average gross domestic product

    Biomass carbon stocks and their changes in northern China's grasslands during 1982-2006

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    Grassland covers approximately one-third of the area of China and plays an important role in the global terrestrial carbon (C) cycle. However, little is known about biomass C stocks and dynamics in these grasslands. During 2001-2005, we conducted five consecutive field sampling campaigns to investigate above-and below-ground biomass for northern China's grasslands. Using measurements obtained from 341 sampling sites, together with a NDVI (normalized difference vegetation index) time series dataset over 1982-2006, we examined changes in biomass C stock during the past 25 years. Our results showed that biomass C stock in northern China's grasslands was estimated at 557.5 Tg C (1 Tg=10(12) g), with a mean density of 39.5 g C m(-2) for above-ground biomass and 244.6 g C m(-2) for below-ground biomass. An increasing rate of 0.2 Tg C yr(-1) has been observed over the past 25 years, but grassland biomass has not experienced a significant change since the late 1980s. Seasonal rainfall (January-July) was the dominant factor driving temporal dynamics in biomass C stock; however, the responses of grassland biomass to climate variables differed among various grassland types. Biomass in arid grasslands (i.e., desert steppe and typical steppe) was significantly associated with precipitation, while biomass in humid grasslands (i.e., alpine meadow) was positively correlated with mean January-July temperatures. These results suggest that different grassland ecosystems in China may show diverse responses to future climate changes

    The optical microscopy with virtual image breaks a record: 50-nm resolution imaging is demonstrated

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    We demonstrate a new 'microsphere nanoscope' that uses ordinary SiO2 microspheres as superlenses to create a virtual image of the object in near field. The magnified virtual image greatly overcomes the diffraction limit. We are able to resolve clearly 50-nm objects under a standard white light source in both transmission and reflection modes. The resolution achieved for white light opens a new opportunity to image viruses, DNA and molecules in real time

    Identification of genes differentially expressed in Jining Grey and Liaoning Cashmere goats ovaries

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    To search for genes controlling high prolificacy of Chinese indigenous goats, differential display reverse transcription-polymerase chain reaction (DDRT-PCR) was used to screen differentially expressed cDNA bands in the sexually matured ovaries of 3-year-old prolific Jining Grey goats and monotocous Liaoning Cashmere goats with 24 combinations of three anchored primers and eight arbitrary primers. 22 expressed sequence tags (ESTs) were proved to be the positive bands by Northern hybridization. They comprised 10 known ESTs and 12 ESTs without homologous sequences in the GenBank. These results indicate that several genes such as GATA-4, metallothionein-like protein, CAT genes and unknown ESTs (CV983340 and CV983341) were expressed only in Jining Grey goats.Keywords: Differential display reverse transcription-polymerase chain reaction, goat, ovary, prolificacyAfrican Journal of Biotechnology Vol. 12(27), pp. 4408-441

    Early responses to H7N9 in southern mainland China

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    This article is made available through the Brunel Open Access Publishing Fund. © 2014 Goodwin and Sun; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background: H7N9 posed potentially serious health challenges for Chinese society. The previous SARS outbreak in this country was accompanied by contradictory information, while worries about wide-spread influenza led to discrimination worldwide. Early understanding of public threat perceptions is therefore important for effective public health communication and intervention. Methods: We interviewed 1011 respondents by phone two weeks after the first case. Questions examined risk awareness and media use, beliefs about the emergence of the threat and those most at risk, anxiety about infection and preventive and avoidant behaviours. Results: Results demonstrate moderate levels of anxiety but relatively high levels of trust towards government officials. Threat emergence was associated with hygiene levels, temperature change, floating pigs in the Huangpu River and migration to the city. Anxiety predicted both recommended and non-recommended behavioural changes. Conclusions: Comparatively high levels of trust in Chinese government advice about H7N9 contrast positively with previous pandemic communications in China. Anxiety helped drive both recommended and non-recommended behaviours, with potentially important economic and social implications. This included evidence of 'othering’ of those associated with the threat (e.g. migrants). Findings emphasise the need to manage public communications early during new influenza outbreaks.Fudan Tydall Centre and Fudan Media and Public Opinion Center

    Therapeutic Lung Lavage with Diluted Surfactant in Neonates with Severe Meconium Aspiration Syndrome

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    Meconium aspiration syndrome (MAS) may result in considerable morbidity and mortality in newborn infants. The current standard treatment is still in need of improvement for the most severe patients. We report 3 cases with devastating MAS that was successfully treated with therapeutic lung lavage. These cases were all delivered in local obstetrics clinics or hospitals with meconium-stained amniotic fluid and non-vigorous appearance at birth. However, no endotracheal suction was performed when they were born. All of them suffered from severe hypoxia and unstable vital signs despite there being high ventilatory settings when they were transferred to the tertiary medical center. Therapeutic lung lavage with diluted surfactant (Survanta, 5 mg/mL, 30 mL/kg in 2 aliquots) was performed within 24 hours of age. Bloody fluid (about 40–50% of total lavage amount) was recovered in all 3 cases. Although brief desaturation and bradycardia were observed during the procedures, 2 of them tolerated the procedures well and improved soon after lavage. The other patient received lung lavage in a relatively unstable condition and needed chest tapping to relieve bilateral pleural effusion. Their respiratory condition improved after the procedures, and they were all discharged within 1 month without major respiratory complications. These successful experiences are compatible with previous animal studies and other case reports with different lavage protocols. We conclude that therapeutic lung lavage may improve the outcome in newborn infants with severe MAS, and there were no significant adverse side effects observed. Before performing lung lavage, stabilization and optimal support may prevent unexpected results during and after lavage

    Protective efficacy against pandemic influenza of seasonal influenza vaccination in children in Hong Kong: a randomized controlled trial

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    BACKGROUND: The efficacy of seasonal influenza vaccination against 2009 pandemic influenza A(H1N1) remains unclear. METHODS: One child aged 6-17 years in each of 796 households was randomized to receive 2009-2010 seasonal trivalent inactivated influenza vaccine (TIV) or saline placebo between August 2009 and February 2010. Households were followed up with serology, symptom diaries, and collection of respiratory specimens during illnesses. The primary outcomes were influenza infection confirmed by reverse-transcription polymerase chain reaction (RT-PCR) or a >/=4-fold rise in serum antibody titer measured by hemagglutination inhibition assay. RESULTS: Receipt of TIV led to 8-13-fold mean geometric rises in antibody titers against seasonal A and B viruses, but only 1.5-fold mean geometric rises against the pandemic A(H1N1) virus that was not included in the vaccine. Children who received TIV had a reduced risk of seasonal influenza B confirmed by RT-PCR, with a vaccine efficacy estimate of 66% (95% confidence interval [CI], 31%-83%). Children who received TIV also a had reduced risk of pandemic influenza A(H1N1) indicated by serology, with a vaccine efficacy estimate of 47% (95% CI, 15%-67%). CONCLUSIONS: Seasonal TIV prevented pandemic influenza A(H1N1) and influenza B infections in children. Pandemic A(H1N1) circulated at the time of vaccination and for a short time afterward with no substantial seasonal influenza activity during that period. The potential mechanism for seasonal TIV to provide protection, possibly short lived, for children against pandemic A(H1N1) infection despite poor cross-reactive serologic response deserves further investigation. Clinical Trials Registration. NCT00792051.postprin
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