A 62-year-old man had chronic hepatitis B virus （HBV） infection and was diagnosed with liver cirrhosis. At the time of diagnosis the patient＇s virologic markers were positive for hepatitis B surface antigen （HBsAg...A 62-year-old man had chronic hepatitis B virus （HBV） infection and was diagnosed with liver cirrhosis. At the time of diagnosis the patient＇s virologic markers were positive for hepatitis B surface antigen （HBsAg）, antibody to hepatitis B e antigen （anti-HBe） and antibody to hepatitis B core antigen （anti-HBc）, while antibody to hepatitis B surface antigen （anti-HBs） and HBV DNA were negative. Later the patient received chemotherapy for malignancy. However, this was interrupted due to elevated liver enzymes. At the same time HBV DNA became positive. Lamivudine （LMV） therapy was administered immediately. However, the levels of serum aminotransferase and total bilirubin （TB） were still rising. Finally the patient died of fulminant hepatic failure. A sequence revealed HBV genotype C （HBsAg subtype adw） with immune escape mutations, F8L, $34L, F41S, G44V, F93C, V96G, Lll0I, C149Y and F161Y. The high morbidity and mortality of this complication is one of the major obstacles to completing the standard treatment for malignancy in HBV carriers. Therefore, the relative risk of antiviral prophylactic failure should be further assessed and the optimal strategy for antiviral prophylaxis in HBsAg-positive patients with oncologic and hematologic malignancies undergoing chemotherapy should be revised.展开更多
大气逃逸是影响火星宜居性演化的决定性要素之一.近几十年来,国内外学术界针对此问题开展了广泛而深入的研究,且多个探测任务均以火星大气逃逸作为重要科学目标.在火星演化历史的早期,以等离子体形态发生的大气逃逸占主导地位,而当前火...大气逃逸是影响火星宜居性演化的决定性要素之一.近几十年来,国内外学术界针对此问题开展了广泛而深入的研究,且多个探测任务均以火星大气逃逸作为重要科学目标.在火星演化历史的早期,以等离子体形态发生的大气逃逸占主导地位,而当前火星大气逃逸可能由中性逃逸主导.火星中性逃逸成分包括H, He, O, C, N等,其中H原子由于质量较轻,逃逸相对容易发生.本文聚焦火星大气H原子逃逸问题,对近年来的国内外研究状况进行了系统性回顾.目前火星大气H原子逃逸以金斯逃逸为主,这一过程对逃逸面处的H原子密度和温度十分敏感,展现出丰富的变化性.一般情况下,火星高层大气中的H原子主要通过电离层化学分解H2产生.近年来的研究表明,火星沙尘暴期间的H原子逃逸通量显著增加,主要是由于低层大气H2O分子可以有效抬升至高层大气并通过电离层化学释放出H原子.虽然学术界对火星H原子逃逸获得了丰富的认知,但依然存在一些悬而未决的问题,包括:(1)基于理想逃逸面假设的传统金斯理论能在何种程度上反映真实的火星H原子逃逸状况;(2)火星H冕结构是否存在额外的非热成分;(3)在太阳系演化早期,火星H原子逃逸如何发生以及如何影响火星气候演化历程.展开更多
基金National Basic Research Priorities Program of China(2011CB106303)The National Natural Science Foundation of China(31200699)The Fundamental Research Funds for the Central Universities(HUST:2012QN140)
文摘A 62-year-old man had chronic hepatitis B virus （HBV） infection and was diagnosed with liver cirrhosis. At the time of diagnosis the patient＇s virologic markers were positive for hepatitis B surface antigen （HBsAg）, antibody to hepatitis B e antigen （anti-HBe） and antibody to hepatitis B core antigen （anti-HBc）, while antibody to hepatitis B surface antigen （anti-HBs） and HBV DNA were negative. Later the patient received chemotherapy for malignancy. However, this was interrupted due to elevated liver enzymes. At the same time HBV DNA became positive. Lamivudine （LMV） therapy was administered immediately. However, the levels of serum aminotransferase and total bilirubin （TB） were still rising. Finally the patient died of fulminant hepatic failure. A sequence revealed HBV genotype C （HBsAg subtype adw） with immune escape mutations, F8L, $34L, F41S, G44V, F93C, V96G, Lll0I, C149Y and F161Y. The high morbidity and mortality of this complication is one of the major obstacles to completing the standard treatment for malignancy in HBV carriers. Therefore, the relative risk of antiviral prophylactic failure should be further assessed and the optimal strategy for antiviral prophylaxis in HBsAg-positive patients with oncologic and hematologic malignancies undergoing chemotherapy should be revised.
文摘大气逃逸是影响火星宜居性演化的决定性要素之一.近几十年来,国内外学术界针对此问题开展了广泛而深入的研究,且多个探测任务均以火星大气逃逸作为重要科学目标.在火星演化历史的早期,以等离子体形态发生的大气逃逸占主导地位,而当前火星大气逃逸可能由中性逃逸主导.火星中性逃逸成分包括H, He, O, C, N等,其中H原子由于质量较轻,逃逸相对容易发生.本文聚焦火星大气H原子逃逸问题,对近年来的国内外研究状况进行了系统性回顾.目前火星大气H原子逃逸以金斯逃逸为主,这一过程对逃逸面处的H原子密度和温度十分敏感,展现出丰富的变化性.一般情况下,火星高层大气中的H原子主要通过电离层化学分解H2产生.近年来的研究表明,火星沙尘暴期间的H原子逃逸通量显著增加,主要是由于低层大气H2O分子可以有效抬升至高层大气并通过电离层化学释放出H原子.虽然学术界对火星H原子逃逸获得了丰富的认知,但依然存在一些悬而未决的问题,包括:(1)基于理想逃逸面假设的传统金斯理论能在何种程度上反映真实的火星H原子逃逸状况;(2)火星H冕结构是否存在额外的非热成分;(3)在太阳系演化早期,火星H原子逃逸如何发生以及如何影响火星气候演化历程.
