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排序方式: 共有243条查询结果,搜索用时 515 毫秒
1.
本文记述采自新疆南部的裸蝗属Conophyma Zub.二新种.新种“友谊裸蝗”Conophyma amica近似于昭苏裸蝗C.zhaosuensis Huang,以下列特征区别于后者:1)雄性肛上板两后角明显突出,后缘中央锐角形突出;2)后足胫节红褐色.新种“红胫裸蝗”C.rufitibia与C.alajense Misth.相似,其区别为:1)新种雄性尾片显著较大;2)雄性尾须较长,明显长过肛上板后缘中央的突起,3)雌性下产卵瓣下外缘缺一明显的大齿.红胫裸蝗亦近似于C.alamasyi(Kuthy),但可以下述特征区别之:1)雄性肛上板近方形,侧缘中部具一钝瘤状突起;2)雄性腹部背面具二条淡色纵带.模式标本均保存在新疆八一农学院植保系. 相似文献
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昆虫迁飞行为的参数化Ⅱ.模式与检验 总被引:2,自引:1,他引:1
对通过昆虫迁飞行为分析得到的迁飞时间参数、高度参数、速度和方向参数等分别以一定的数学形式加以表达。其中,起飞时间以日出日没及晨昏朦影时刻为基准,用天文公式求出;边界层顶与飞行低温阈限所在高度及运行高度上的风速、风向由一维湍能(TKE)模式以E-ε闭合做数值模拟:对飞行力较弱的小型或微小昆虫做随风运行处理,而对大型昆虫则根据其自身的飞行速度和定向方位与其飞行高度上的风向风速做矢量运算,求得位移方向和速度。通过我国小地老虎和草地螟标放回收试验结果的检验,表明本文提出的迁飞行为参数化方案是合理可行的。以此为基础组建数值模型进行昆虫迁飞轨迹分析,可望进一步提高迁飞性害虫异地预测的水平 相似文献
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Duan Yali Li Changchong Deng Li An Shuhua Zhu Yun Wang Wei Zhang Meng Xu Lili Xu Baoping Chen Xiangpeng Xie Zhengde 《中国病毒学》2021,36(3):382-392
To investigate the molecular epidemiology and genetic variation of human adenovirus type 7(HAdV-7) in children with acute respiratory infections(ARI) in China. HAdV-7-positive respiratory samples collected from children with ARI in Beijing, Shijiazhuang, Wenzhou and Guangzhou from 2014–2018 were selected for gene amplification and sequence analysis. Fifty-seven HAdV-7 clinical strains with hexon, penton base and fiber gene sequences were obtained. Meanwhile17 strains were selected randomly from different cities for whole genome sequencing. Phylogenetic and variation analyses were performed based on the obtained sequences, HAdV-7 prototype strain Gomen(AY594255), vaccine strains(AY495969 and AY594256) and representative sequences of strains. The phylogenetic trees constructed based on whole genome sequences, major capsid protein genes(hexon, penton base and fiber) and the early genes(E1, E2, E3 and E4) were not completely consistent. The HAdV-7 strains obtained in this study always clustered with most of the circulating strains worldwide from the 1980 s to the present. Compared with the HAdV-7 prototype strain Gomen(AY594255), some amino acid mutations in loop1 and loop2 of hexon and the RGD loop region of the penton base gene were observed. Recombination analysis showed that partial regions of 55 k Da protein and 100 kDa hexon-assembly associated protein genes among all HAdV-7 strains in this study were from HAdV-16 and HAdV-3, respectively. Our study demonstrated the molecular evolution characteristics of HAdV-7 strains circulating in China and provided basic reference data for the prevention, control and vaccine development of HAdV-7. 相似文献
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Zhu Yun Xu Baoping Li Changchong Chen Zhimin Cao Ling Fu Zhou Shang Yunxiao Chen Aihuan Deng Li Bao Yixiao Sun Yun Ning Limin Yu Shuilian Gu Fang Liu Chunyan Yin Ju Shen Adong Xie Zhengde Shen Kunling 《中国病毒学》2021,36(6):1543-1553
Virologica Sinica - Community-acquired pneumonia (CAP) is one of the leading causes of morbidity and mortality in children worldwide. In this study, we aimed to describe the aetiology of viral... 相似文献
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Background
Expanded criteria donors (ECDs) are currently accepted as potential sources to increase the donor pool and to provide more chances of kidney transplantation for elderly recipients who would not survive long waiting periods. Hypothermic machine perfusion (HMP) is designed to mitigate the deleterious effects of simple cold storage (CS) on the quality of preserved organs, particularly when the donor is in a marginal status.Methods
We compared the transplant outcomes in patients receiving ECD kidneys with either HMP or CS graft preservation. Articles from the MEDLINE, EMBASE and Cochrane Library databases were searched and all studies reporting outcomes from HMP versus CS methods of kidney preservation were included in this meta-analysis. The parameters analyzed included the incidence of delayed graft function (DGF), primary non-function (PNF) and one-year graft and patient survival.Results
A total of seven studies qualified for the review, involving 2374 and 8716 kidney grafts with HMP or CS preservation respectively, all from ECD donors. The incidence of delayed graft function (DGF) was significantly reduced with an odd ratio(OR) of 0.59 (95% CI 0.54–0.66, P<0.001) and one-year graft survival was significantly improved with an OR of 1.12 (95% CI 1.03–1.21, P = 0.005) in HMP preservation compared to CS. However, there was no difference in the incidence of PNF (OR 0.54, 95% CI 0.21–1.40, P = 0.20), and one-year patient survival (OR 0.98, 95% CI 0.94–1.02, P = 0.36) between HMP and CS preservation.Conclusions
HMP was associated with a reduced incidence of DGF and an with increased one-year graft survival, but it was not associated with the incidence of PNF and one-year patient survival. 相似文献7.
南美斑潜蝇为害对黄瓜体内4种防御酶活性的影响 总被引:1,自引:0,他引:1
植物对昆虫取食产生的防御反应,在昆虫与植物相互作用关系中起着重要的作用。为明确南美斑潜蝇Liriomyza huidobrensis(Blanchard)取食与植物防御之间的作用关系,本文分别测定了南美斑潜蝇幼虫持续为害1、3、5、7及9d后黄瓜叶片中苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)、过氧化物酶(POD)及超氧化物歧化酶(SOD)活性的变化。结果表明:在南美斑潜蝇幼虫持续取食下,PAL、PPO、POD和SOD等4种酶活性显著上升;PAL、PPO和POD等3种酶活性随受害程度的加重而上升幅度加大,即重度受害>轻度受害>系统对照>健康对照,而SOD活性变化没有规律。在系统对照黄瓜叶片中,PAL、PPO、POD和SOD等4种酶活性最大值分别在第5、1、5和5d;在轻度受害黄瓜叶片中,PAL、PPO、POD和SOD等4种酶活性最大值分别在第5、9、5和9d;在重度受害黄瓜叶片中,PAL、PPO、POD和SOD等4种酶活性最大值分别在第7、7、5和5d。黄瓜叶片受害后,POD和PPO活性上升幅度较大,PAL和SOD活性上升幅度较小,说明POD和PPO对取食胁迫响应比PAL和SOD更灵敏。 相似文献
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寄生蜂卵成熟动态影响其产卵决策行为,因而对于认识寄生蜂搜寻行为生态学机理具有重要意义。以蝶蛹金小蜂(Pteromalus puparum)-菜粉蝶(Pieris rapae)为模式生物,首先连续3周每隔24 h详细观察子代蜂幼期不同发育阶段的体型、卵巢管以及寄主蛹的外部形态,以此为基础观察了低温处理(模拟越冬温度)被寄生蛹对子代蜂成熟卵数量动态的影响。蝶蛹金小蜂胚后发育历时约2周,其中卵期1 d;幼虫历期约7 d。初孵幼虫体透明;胚后第3—6天体积快速增大,然后减缓,体色由绿变黄;胚后第8天进入预蛹,第9—12天蛹淡色,复眼由淡黄变为深红,第13—14天蛹暗黑色,并逐渐带有金属光泽。卵巢管在羽化当天即开始沉积卵黄,并在羽化后1—4 d连续增加直到出现卵吸收;羽化后5—6 d成熟卵数量增速不明显甚至略有减小。寄主蛹随子代蜂从卵发育至幼虫再到蛹体色从绿色变为灰褐色再到土黄色。低温处理被寄生的寄主蛹(寄生蜂处于老熟幼虫或蛹期)后,羽化成虫的卵巢管略细,成熟卵数量较少。成熟卵数量的变化不仅受低温处理的影响,而且受雌蜂体型大小和日龄的影响;低温处理明显减缓卵成熟速率,各日龄期成熟卵数量均明显减少;适温下成熟卵数量于羽化后第4天达到峰值,而低温处理下成熟卵数量达到峰值的时间延迟至第7天。研究表明,越冬低温对来年羽化的蝶蛹金小蜂卵成熟动态具有不良影响。 相似文献
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Identification of the active site of human mitochondrial malonyl‐coenzyme a decarboxylase: A combined computational study 下载免费PDF全文
Malonyl‐CoA decarboxylase (MCD) can control the level of malonyl‐CoA in cell through the decarboxylation of malonyl‐CoA to acetyl‐CoA, and plays an essential role in regulating fatty acid metabolism, thus it is a potential target for drug discovery. However, the interactions of MCD with CoA derivatives are not well understood owing to unavailable crystal structure with a complete occupancy in the active site. To identify the active site of MCD, molecular docking and molecular dynamics simulations were performed to explore the interactions of human mitochondrial MCD (HmMCD) and CoA derivatives. The findings reveal that the active site of HmMCD indeed resides in the prominent groove which resembles that of CurA. However, the binding modes are slightly different from the one observed in CurA due to the occupancy of the side chain of Lys183 from the N‐terminal helical domain instead of the adenine ring of CoA. The residues 300 ? 305 play an essential role in maintaining the stability of complex mainly through hydrogen bond interactions with the pyrophosphate moiety of acetyl‐CoA. Principle component analysis elucidates the conformational distribution and dominant concerted motions of HmMCD. MM_PBSA calculations present the crucial residues and the major driving force responsible for the binding of acetyl‐CoA. These results provide useful information for understanding the interactions of HmMCD with CoA derivatives. Proteins 2016; 84:792–802. © 2016 Wiley Periodicals, Inc. 相似文献