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中国产前诊断杂志（电子版） 2010年第4期2卷 51-51页

作者： chung mk Suen SH Leung TY Lau TK Wong TW 香港中文大学妇产科系

方法:在2002～2009年期间,计算每个孕期月份的经本院诊断的胎儿非整倍体(包括21三体、18三体和13三体)平均每月发生率。发现胎儿非整倍体平均每月发生率与周围环境污染物的平均浓度变化有相关性(Spearman相关系数)。

关键词：非整倍体胎儿环境污染物周围环境发生率三体率相关性平均浓度相关系数污染物浓度

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血管紧张素转换酶抑制剂和血管紧张素受体拮抗剂的使用与2019冠状病毒疾病检测阳性之间的关系

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中华高血压杂志 2020年第5期28卷 499-499页

作者： Mehta N KalraA Nowacki AS Anjewierden S Han Z Bhat p Rubio AEC Jacob M Procop GW Harrington S Milinovich A Svensson LG Jehi L Young JB chung mk 周卫(译) 叶鹏(校) 不详

血管紧张素转换酶抑制剂(angiotensin-converting enzyme inhibitor,ACEI)和血管紧张素受体拮抗剂(angiotensin receptor blocker,ARB)在2019新型冠状病毒疾病(coronavirus disease 2019,COVID-19)全球大流行背景下的作用备受争议。此... 详细信息

关键词：血管紧张素受体拮抗剂血管紧张素转换酶抑制剂疾病检测冠状病毒 angiotensin 慢性病

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Two decades of suspect evidence for adaptive molecular evolution——negative selection confounding positive-selection signals

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National Science Review 2022年第5期9卷 129-141页

作者： Qipian Chen Hao Yang Xiao Feng Qingjian Chen Suhua Shi chung-Ⅰ Wu Ziwen He State Key Laboratory of Biocontrol Guangdong Key Laboratory of Plant Resources School of Life SciencesSouthern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Sun Yat-sen University

There has been a large literature in the last two decades affirming adaptive DNA sequence evolution between *** main lines of evidence are from(i) the McDonald-Kreitman(mk) test,which compares divergence and polymorphism data,and(ii) the phylogenetic analysis by maximum likelihood(PAML) test,which analyzes multispecies divergence ***,we apply these two tests concurrently to genomic data of Drosophila and *** our surprise,the> 100 genes identified by the two tests do not overlap beyond random *** the non-concordance could be due to low powers leading to high false negatives,we merge every 20-30 genes into a 'supergene'.At the supergene level,the power of detection is large but the calls still do not *** rule out methodological reasons for the *** particular,extensive simulations fail to find scenarios whereby positive selection can only be detected by either mk or PAML,but not *** molecular evolution is governed by positive and negative selection concurrently,a fundamental assumption for estimating one of these(say,positive selection) is that the other is ***,in a broad survey of primates,birds,Drosophila and Arabidopsis,we found that negative selection rarely stays constant for long in *** a consequence,the variation in negative selection is often misconstrued as a signal of positive *** conclusion,mk,PAML and any method that examines genomic sequence evolution has to explicitly address the variation in negative selection before estimating positive *** a companion study,we propose a possible path forward in two stages—first,by mapping out the changes in negative selection and then using this map to estimate positive *** now,the large literature on positive selection between species has to await reassessment.

关键词： molecular evolution neutral theory natural selection

Application of Piezoelectric Actuator and Compliant Structures to Achieve Flapping Wing Motion for a MAV

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材料科学与工程学报 2008年第4期26卷 642-646,515页

作者： Kranti. K. Lal Kummari S. J. Croucher N. J. Lawson E. E. Liani G. Allegri S. Guo Hsien-Chun chung Z. Huang School of Applied Science Cranfield University Cranfield Bedfordshire MK43 0AL United Kingdom

Micro Aerial Vehicles(MAVs) are the smallest artificial *** of the flapping wings MAVs are powered by electric motors of various *** report in this paper the application of piezoelectric actuators as power system for a flapping wing MAV using a compliant displacement amplification *** actuator used for this application is a pre-stressed cut piece of TH-7R type Thunder actuator.A two-bar compliant mechanism with two flexures has been developed to convert the linear displacement into angular movement and *** specimens were made from carbon fiber links and nylon *** also proposed to use the product of frequency(F) and tip displacement(D), F * D as a criteria for the characterization of an amplifying *** best specimen according to this criterion is obtained for a 5mm length flexure specimen made of three layers of *** F*D value obtained for this specimen was(0.58) *** finite element analysis results for different flexural thickness and lengths were obtained and have been compared to the experimental *** effect of both the thickness and length of the flexure on a particular arrangement has been discussed.

关键词：平板翼扑翼式微飞行器飞行技术控制方法材料结构

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