钙通道阻断剂对家兔起搏细胞自发活动的作用

目的 :为进一步阐明Ca2 + 通道在心脏起搏中所起的作用 ,及左心室流出道 (主动脉前庭 )自律细胞的特性。方法 :利用常规的玻璃微电极细胞内记录技术 ,观察了 2 6例家兔窦房结和左心室流出道自律细胞动作电位的特征。以分析钙通道阻断剂 -维拉帕米 (VER)和氯化镍 (NiCl2 )对窦房结和流出道自律细胞的影响。结果 :(1)用 1μmol/LVER灌流后窦房结及主动脉前庭自律细胞的APA、Vmax、MDP绝对值、VDD、RPF均明显下降 ,APD90 延长 (P <0 .0 5 )。 (2 )用 180 μmol/LNiCl2 灌流后两自律细胞自发慢反应电位的VDD、APA、Vmax、RPF均明显下降 (P <0 .0 1) ,而且窦房结细胞APD90 也显著延长 ;二者的MDP、APD50 均无明显改变 (P >0 .0 5 )。结论 :钙通道阻断剂对窦房结起搏细胞和主动脉前庭自律细胞动作电位 0相和 4相去极离子流有明显抑制作用。     

右心室流出道电生理特性及临床意义

目的:研究右心室流出道的电生理特性,并探讨其与心室流出道心律失常的关系.方法:利用细胞内微电极记录技术,观察豚鼠右心室流出道组织的电活动特性.结果:在23例豚鼠右室流出道组织标本中4例(17.39%)可记录到自律性电活动.在紧靠瓣膜下及流出道光滑部的局部区域可记录到非自律性慢反应电位(MDP:62.28±8.14mv,APA:65.22±15.18mV,Vmax:22.27±8.13v/s,APD90:176.24±10.13ms,APD50:123.47±12.3 6ms)及形态不典型的自律性慢反应电位,其0相去极化速度、幅度及动作电位时程变异较大.大部分区域为非自律快反应动作电位(MDP:71.23±6.62mv,APA:79.33±5.48mV,Vmax:103.13±9.03v/s,APD90:166.23±20.33ms,APD50:126.33±16.26ms),其特征与普通心室肌细胞动作电位相似.结论:右心室流出道组织的电生理特性与普通心室肌不同,其自律性和电生理异质性可能是某些流出道心律失常的电生理学基础.     

Identification of genetic variants the CCKAR gene and based on body measurement and carcass quality characteristics in Qinchuan beef cattle (Bos taurus)

BackgroundThis study aimed to explore genetic polymorphisms of the CCKAR gene and their relationship with the growth and development of Qinchuan cattle which could be used as molecular markers for the improvement of the breeding of Qinchuan cattle.ResultsHere, we have identified seven single nucleotide polymorphisms (SNPs) at loci g. 1463 C>G; g. 1532 T>A; g. 1570 G>A; g. 1594 C>A; g. 1640 T>C; g. 1677 G>C; and g. 1735 C>T in the coding region of the bovine CCKAR gene. The frequencies identified on allelic and genotypic characteristics have shown that all seven SNPs diverged from the Hardy-Weinberg-Equilibrium. The SNP2, SNP3, SNP6 and SNP7 had the lowest polymorphism information content values, and remaining SNPs were found to be moderate (0.25 < PIC < 0.50). The genotype CG in SNP1 at loci g.1463 C>G had the greatest association with WH, HW, CD and CCF, while the genotype TA at the very same loci was associated with BFT, ULA and IMF content in Qinchuan cattle. The CCKAR gene expression level in adipose tissue, small intestine, liver and skeleton muscle was found to be higher, whereas, the expression level of mRNA in organs of other digestive system including reticulum, abomasum and omasum was moderate. Some expression of CCKAR mRNA was found in the large intestine, kidney and rumen.ConclusionsIn summary, our finding suggested that the CCKAR gene could be used as a potential candidate for the improvement of carcass quality and body measurements of Qinchuan cattle.How to citeNurgulsim K, Raza SHA, Khan R, et al. Identification of genetic variants the CCKAR gene and based on body measurement and carcass quality characteristics in Qinchuan beef cattle (Bos taurus). Electron J Biotechnol 2021;51. https://doi.org/10.1016/j.ejbt.2021.02.001     

常见呼吸道感染病原菌菌群分布及其耐药性分析

目的研究临床呼吸道感染病原菌的分布和耐药性。方法对2005年1月-2006年12月襄樊市中心医院门诊和住院部送检的呼吸道感染痰标本进行细菌培养和鉴定,分离出病原菌536株,并按照NCCLS标准用K-B法对临床肺部感染患者分离的病原菌进行药物敏感试验。结果共从1327份合格痰液标本中检出536株病原菌,以革兰阴性杆菌居首位,占66.04%,对亚胺培南的耐药性最低;革兰阳性菌占33.96%,对万古霉素100%敏感。结论:引起呼吸道感染的病原菌以革兰阴性菌为主,且耐药菌株逐年增加,铜绿假单胞菌和金黄色葡萄球菌是引起呼吸道感染的主要细菌,且其耐药性严重,合理使用抗生素对有效控制呼吸道感染和避免越来越多的耐药菌株出现尤为关键。临床上有呼吸道感染证候的可疑患者,应做痰液标本的细菌培养和药物敏感性试验,以避免在临床上盲目用药。     

预应力混凝土筒形密封消化罐的有限元分析与设计

筒形消化罐的内力计算是消化罐设计的重要环节，由于消化罐容量不断增大，要求内力计算由近似向精确发展，采用大型有限元程序SAP2000对消化罐结构进行三维线弹性有限元计算其内力，并考虑了以往设计时经常忽略的弯曲内力，比较精确的计算了边缘效应。     

头孢匹胺治疗下呼吸道感染72例临床观察

将72例确诊为下呼吸道感染的患者随机分成2组,在常规治疗基础上,治疗组36例,静脉滴注头孢匹胺1g,每日两次;对照组36例静脉滴注头孢尼西2g,每日一次,两组疗程均为7～14天,观察两组的临床疗效.治疗组和对照组临床治愈率分别是94%和83%,总有效率分别为97%和88%,两组数据比较有统计学意义(P<0.05).结果表明头孢匹胺是第三代头孢菌素,安全抗菌活性强.在下呼吸道感染的治疗中疗效确切.     

Development of a non-cable whole tectorial membrane micro-robot for an endoscope

A novel non-cable whole tectorial membrane micro-robot for an endoscope is developed. The micro-robot we have fabricated and tested can propel itself in the intestine tract of a pig in an autonomous manner by earthworm-like locomotion. The silicone of bellow shape is laid over the outer surface of the micro-robot to reduce the affection of the viscoelastic properties of the intestine. Wireless power transfer and communication systems are employed to realize the non-cable locomotion of the micro-robot. The prototype of the micro-robot is 13.5 mm in diameter and 108 mm in length. The experimental results show that the towing force for the micro-robot is about 0.8 N, which is much smaller than the maximum driving force 2.55 N of the linear actuator. The supplying power of the wireless power transfer system fulfills the needs of the micro-robot system and the micro-robot can creep reliably in the large intestine of a pig and other contact environments.