58 research outputs found

    Response of "Glacier-Runoff" system in a typical monsoonal temperate glacier region, Hailuogou Basin in Mt. Gongga of China, to global warming

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    International audienceThe method of correlation analysis and trend analysis were used in this research in order to confirm the response of "glacier-runoff" system to global warming. Hailuogou glacier had retreated by 1871.8 m over the past 76 years, Hailuogou No. 2 glacier had also retreated by 1100 m. Glaciers retreats are contrary to the climatic warming trend in China and the Northern Hemisphere. Glaciers in Hailuogou basin were in the loss with a fluctuating manner since 1950s, and accumulative value of mass balance is ?10 825.5 mm water equivalent with an annual mean value of ?240.6 mm. The inverse correlation is highly significant between mass balance variation and climatic fluctuation of China and the Northern Hemisphere after 1950s. Glacier ablation is intensive with a ratio of 7.86 m yr?1. A steady rise tendency toward glaciers runoff has been observed since 1980s, and the runoff rise is mainly responsible for melt water in Hailuogou basin. It is noticeable that climatic warming not only strengthened ablation extent and enlarged ablation area, but also prolonged ablation period. Global warming is the main cause of glacier retreat, mass loss and runoff rise in Hailuogou basin

    Inhibition of Influenza A Virus (H1N1) Fusion by Benzenesulfonamide Derivatives Targeting Viral Hemagglutinin

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    Hemagglutinin (HA) of the influenza virus plays a crucial role in the early stage of the viral life cycle by binding to sialic acid on the surface of host epithelial cells and mediating fusion between virus envelope and endosome membrane for the release of viral genomes into the cytoplasm. To initiate virus fusion, endosome pH is lowered by acidification causing an irreversible conformational change of HA, which in turn results in a fusogenic HA. In this study, we describe characterization of an HA inhibitor of influenza H1N1 viruses, RO5464466. One-cycle time course study in MDCK cells showed that this compound acted at an early step of influenza virus replication. Results from HA-mediated hemolysis of chicken red blood cells and trypsin sensitivity assay of isolated HA clearly showed that RO5464466 targeted HA. In cell-based assays involving multiple rounds of virus infection and replication, RO5464466 inhibited an established influenza infection. The overall production of progeny viruses, as a result of the compound's inhibitory effect on fusion, was dramatically reduced by 8 log units when compared with a negative control. Furthermore, RO5487624, a close analogue of RO5464466, with pharmacokinetic properties suitable for in vivo efficacy studies displayed a protective effect on mice that were lethally challenged with influenza H1N1 virus. These results might benefit further characterization and development of novel anti-influenza agents by targeting viral hemagglutinin

    Optimizing the extraction yield of polyprenols from needles of Cunninghamia lanceolata (Lamb.) Hook using response surface methodology and its antioxidative activities

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    An improved optimization method was used, combining a single-factor experiment and Response Surface Methodology to optimize the medium for the extraction yield of polyprenols from the needles of Cunninghamia lanceolata (Lamb.) Hook. A three-factor, three-level Box-Behnken design was used with extraction temperatures, extraction times, and liquid-solid ratio as independent variables to understand and optimize the extraction yield of polyprenols. A mathematical model with a high coefficient of determination was obtained and could be employed to optimize polyprenols extraction. From the optimized values of extraction temperature 71.4 ℃, extraction time 5.96 h, and liquid-solid ratio 9.3:1, the extraction yield of polyprenols was 1.22 ± 0.04% (N = 3), which agreed closely with the predicted value (1.27%). Besides, polyprenols were demonstrated to have a strong antioxidative ability in vitro. Scavenging percentages of superoxide radical and DPPH by polyprenols were up to 75.6% and 56.9%, respectively

    Correlation between reported human infection with avian influenza A H7N9 virus and cyber user awareness: what can we learn from digital epidemiology?

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    SummaryData on the topic of novel avian influenza A (H7N9) were collected based on the web analysis tool ‘Baidu Index’, a major Chinese search engine. We found a positive correlation between the volume of H7N9-related ‘cyber user awareness’ and the epidemic situation during the H7N9 outbreak in China (r=0.98, p<0.01, cumulative; r=0.43, p=0.018, daily) except in the early stage; the ranks of H7N9-related topics changed at different epidemic stages. This study may improve our understanding of the role of web-based media in infectious disease surveillance in China

    Identify Potential Regulators in HIV-1 Latency by Joint microRNA and mRNA Analysis

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    Background/Aims: The main obstacle to cure HIV infection is the existence of long-lasting latent reservoirs. Many efforts have been made to understand basal mechanisms of HIV-1 latency, in which miRNAs play an important role. However, integrated analysis of miRNA and mRNA expression in HIV-1 latency is lacking. Methods and Results: Global miRNA and mRNA expression was determined by microarrays and quantitative reverse transcription PCR in well-characterized HIV-1 latently and actively infected cells, respectively. Interactions of miRNA-mRNA, mRNA-mRNA, and transcription factor-miRNA pairs were assembled into the function network. Our results show that transcription regulation related genes were mostly enriched in HIV-1 latently infected cells. Gene set enrichment analysis revealed nuclear transport related pathways were up-regulated in the latency group. Network dynamic analysis highlighted many gene-pairs sharing the largest changes in different HIV-1 infection state. 83.33% miRNA-target pairs were validated against database, and RHOB related genes constitute the interface between HIV-1 latency and replication state. Conclusion: We show for the first time a joint miRNA and mRNA expression profile related to a HIV-1 latency phenotype, outline a dynamic network of potential regulators involving in HIV-1 latency or replication state, and gain new insights into the source messages for affecting HIV-1 latency

    A Decline in HIV and Syphilis Epidemics in Chinese Female Sex Workers (2000–2011): A Systematic Review and Meta-Analysis

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    <div><p>Background</p><p>Female sex workers (FSWs) play an important role in transmitting HIV and syphilis from high-risk groups to the general population. However, the trends in HIV and syphilis epidemics in Chinese FSWs in the period after 2000 are unclear to date.</p><p>Methods</p><p>The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement was followed. Seven databases were searched for published peer-reviewed articles. The incidence of HIV and syphilis in FSWs in different time periods, provinces and workplaces in China were separately pooled by meta-analysis. Correlation analysis was conducted between HIV and syphilis incidence and study time, respectively.</p><p>Results</p><p>After 1,662 articles were screened, 190 published papers were included in the final analysis. Estimated HIV prevalence was 0.284% (95% CI: 0.080–0.488%) in the period 2000–2002, 0.211% (95% CI: 0.149–0.273%) in 2003–2005, 0.242% (95% CI: 0.190–0.294%) in 2006–2008 and 0.041% (95% CI: 0.024–0.058%) in 2009–2011. The corresponding syphilis prevalence was 9.669% (95% CI: 7.810–11.529%), 4.970% (95% CI: 4.384–5.556%), 4.404% (95% CI: 4.032–4.775%) and 3.169% (95% CI: 2.738–3.600%), respectively. Spearman rank correlation coefficients were −0.165 (<i>p</i> = 0.002) between HIV prevalence and study time, and −0.209 (<i>p</i> = 0.000) between syphilis prevalence and study time. The combined HIV prevalence was 0.318% (95% CI: 0.156–0.479%) in medium and high-tier workplaces and 0.393% (95% CI: 0.176–0.610%) in low-tier workplaces. The corresponding syphilis prevalence was 3.216% (95% CI: 2.192–4.240%) and 13.817% (95% CI: 10.589–17.044%), respectively.</p><p>Conclusions</p><p>Our data suggested a decline in HIV and syphilis epidemics in FSWs in China on a national level during the study period (2000–2011). FSWs in low-tier workplaces should be given more attention in the future to ensure they are included in prevention programs for HIV and sexually transmitted diseases.</p></div

    Diagram showing the selection of studies for meta-analysis.

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    <p>Diagram showing the selection of studies for meta-analysis.</p

    Forest plot showing estimated HIV prevalence in Chinese female sex workers in different workplaces.

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    <p>Workplaces were categorized into two grades: Medium and high-tier (Hotels, Karaoke halls, Salons, Leisure centers, Massage parlors, Night clubs, Dancing halls, Bars, Bath centers and Footbath rooms) and Low-tier (Street-based, Rental houses, Inns, Lanes, Lakefront and Rural entertainment venues).</p
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