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Dear Editor, Coronary artery disease is a leading cause of mortality and morbidity worldwide.Blockade of effective blood flow to heart muscles results in cardi...  相似文献   
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The Qinghai-Tibet Plateau (QTP) is an important cushion plant hotspot. However, the distribution of cushion plants on the QTP is unknown, as are the factors that drive cushion plant distribution, limiting our understanding of the evolution of cushion species in the region. In this study, we assessed spatial patterns of total cushion plant diversity (including taxonomic and phylogenetic) over the entire QTP and compared patterns of diversity of cushion plants with different typologies (i.e., compact vs. loose). We also examined how these patterns were related to climatic features. Our results indicate that the southern QTP hosts the highest total cushion plant richness, especially in the south-central Hengduan Mountains subregion. The total number of cushion species declines from south to north and from southeast to northwest. Compact cushion plants exhibit similar patterns as the total cushion plant richness, whereas loose cushion plants show random distribution. Cushion plant phylogenetic diversity showed a similar pattern as that of the total cushion plant richness. In addition, cushion plant phylogenetic community structure was clustered in the eastern and southwestern QTP, whereas random or overdispersed in other areas. Climatic features represented by annual energy and water trends, seasonality and extreme environmental factors, had significant effects on cushion plant diversity patterns but limited effects on the phylogenetic community structure, suggesting that climatic features indeed promote the formation of cushion plants. Because cushion plants play vital roles in alpine ecosystems, our findings not only promote our understanding of the evolution and formation of alpine cushion plant diversity but also provide an indispensable foundation for future studies on cushion plant functions and thus alpine ecosystem sustainability in the entire QTP region.  相似文献   
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Lipid metabolism reprogramming is now accepted as a new hallmark of cancer.Hence,target-ing the lipogenesis pathway may be a potential avenue for cancer treatme...  相似文献   
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BackgroundThe association between the incidence of hand, foot, and mouth disease (HFMD) and ambient temperature has been well documented. Although the severity of symptoms is an important indicator of disease burden and varies significantly across cases, it usually was ignored in previous studies, potentially leading to biased estimates of the health impact of temperature.MethodsWe estimated the disability-adjusted life year (DALY) by considering the severity of symptoms for each HFMD case reported during 2010–2012 in Guangdong and used distributed lag-nonlinear models to estimate the association between the daily average temperature and daily DALY of HFMD cases at the city-level. We investigated the potential effect modifiers on the pathway between temperature and DALY and pooled city-specific estimates to a provincial association using a meta-regression. The overall impact of temperature was further evaluated by estimates of DALYs that could be attributed to HFMD.ResultsThe overall cumulative effect of daily mean temperature on the DALY of HFMD showed an inverse-U shape, with the maximum effect estimated to be β = 0.0331 (95%CI: 0.0199–0.0463) DALY at 23.8°C. Overall, a total of 6.432 (95%CI: 3.942–8.885) DALYs (attributable fraction = 2.721%, 95%CI: 1.660–3.759%) could be attributed to temperature exposure. All the demographic subgroups had a similar trend as the main analysis, while the magnitude of the peak of the temperature impact tended to be higher among the males, those aged ≥3yrs or from the Pear-River Delta region. Additionally, the impact of temperature on DALY elevated significantly with the increasing population density, per capita GDP, and per capita green space in parks.ConclusionsTemperature exposure was associated with increased burden of HFMD nonlinearly, with certain groups such as boys and those from areas with greater population density being more vulnerable.  相似文献   
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采用海南尖峰岭森林生态系统国家野外科学观测研究站天池气象站1980~2005年的地面常规气象观测资料,分析了光、水和风等气候因子的变化趋势,结果发现:26年来,尖峰岭热带山地雨林区年日照时数、年降水量、年蒸发量、年平均相对湿度、年平均水汽压和年平均风速的多年平均值分别为1467.4h、2449.0mm、1248.8mm、88.67%、20.77hPa、1.2m/s.年降水量、平均相对湿度、平均水汽压均呈上升趋势,其中平均水汽压升高趋势明显,每10a增加0.38hPa;日照时数、年蒸发量和年平均风速呈下降趋势,其中平均风速下降明显,每10a减小0.27m/s;月降水量和月蒸发量年代际变化规律不一,但10月份的降水量和9月份的蒸发量下降趋势明显.气候增暖作用分析表明,在全球气候变化背景下,尖峰岭山地雨林区气候增暖作用显著.  相似文献   
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改进实验种群生命表编制的方法——以黑肩绿盔盲蝽为例   总被引:5,自引:2,他引:3  
刘家莉  杨斌  陆永跃  黄寿山 《生态学报》2009,29(6):3206-3212
采用指形管单头饲养的方法,编制了稻飞虱的重要捕食性天敌黑肩绿盔盲蝽取食替代寄主米蛾卵的实验种群生命表.通过直接统计和加权平均2种方法的对比,推导出各虫龄历期的计算公式.针对特定时间生命表和特定年龄生命表两种编制方法中存在的不足进行了分析,并提出了可行的解决办法,即在特定时间生命表中导入幼期存活率,在特定年龄生命表中根据推导出的历期公式计算各个虫龄的历期,得到世代平均历期T(T=∑tx+tA ),进而得到rm值.通过对两种生命表编制方法的完善,为昆虫实验种群生命表的编制和参数的计算提供了方便和完整的计算方法.  相似文献   
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