与烟草细胞质雄性不育相关的线粒体基因atp9的mRNA研究

已知导入未编辑atp9 mRNA的烟草表现细胞质雄性不育(CMS),因此认为线粒体基因atp9是引起高等植物CMS的主要基因。为了解atp9在CMS中的作用机制,从3对烟草不育系及其同型保持系中提取atp9,利用实验与理论结合来分析其mRNA在编辑前后以及在不育系及其同型保持系中的一维、三维信息差别。结果表明,atp9mRNA一维信息方面的差异,更重要的是二级结构的差异和稳定性,可能是影响ATP合成而导致CMS的根本原因。     

Effects of inhibitors of the renin-angiotensin system on reducing blood pressure and expression of inflammatory factors in CHD patients: A network meta-analysis

The renin-angiotensin system (RAS) is an ever-evolving endocrine system with considerable checks and balances on the production and catabolism of angiotensin peptides most likely due to the manifold effects of angiotensins. We aimed to explore the effects of different inhibitors of RAS on blood pressure and expression of inflammatory factors in patients with coronary heart disease (CHD). We initially searched PubMed, EMBASE and Cochrane Library electronic databases with nine eligible randomized controlled trials enrolled. Direct and indirect evidence was combined to calculate the weighted mean difference value and draw surface under the cumulative ranking curves. The results demonstrated that, compared with placebo and enalapril, ramipril had a better effect on reducing systolic blood pressure after short-term usage of drugs (<12 months), while perindopril had better effects on reducing diastolic blood pressure and C-reactive protein expression. Furthermore, after long-term usage of drugs (≥12 months), there was no significant difference among olmesartan, quinapril and candesartan in the treatment of patients with CHD. Perindopril and ramipril had better effects on inhibiting blood pressure and expression of inflammatory factors among eight inhibitors after short-term usage of drugs (<12 months); while quinapril had better effects on reducing blood pressure and expression of inflammatory factor after long-term usage of drugs, and there was little difference in the effects between olmesartan and candesartan (≥12 months). Perindopril may have better short-term effects on reducing blood pressure and expression of inflammatory factor, while quinapril may have better long-term effects on reducing blood pressure and expression of inflammatory factor.     

草原土壤微生物受放牧的影响及其季节变化

以内蒙古克什克腾旗西部的典型草原为对象,研究轻度放牧区(LG)、中度放牧区(MG)、重度放牧区(HG)土壤中的微生物数量、微生物生物量和土壤呼吸强度的季节变化以及放牧强度对它们的影响。结果表明,微生物数量、微生物生物量以及土壤的呼吸作用强度均有较明显的季节性变化,峰值均出现在8月份,而且三者之间具有极显著的正相关关系;轻度和中度放牧有利于土壤中的微生物数量、生物量的增加,而重度放牧则导致土壤中微生物数量和生物量的减少。     

荔枝蜜中挥发性成分的指纹图谱研究

蜂蜜中挥发性成分的指纹图谱分析,是科学评价及有效控制蜂蜜质量的重要依据。本文利用顶空固相微萃取-气相色谱-质谱联用法对我国常见5个荔枝品种的30个中意蜂荔枝蜜样品进行挥发性成分分离检测,并结合中药色谱指纹图谱技术建立其指纹图谱。结果表明,不同荔枝品种的荔枝蜜样品其挥发性成分相近,共分离鉴定出41种挥发性成分,建立了由16个共有峰组成的荔枝蜜挥发性成分指纹图谱。另外,发现不同蜂种所酿造荔枝蜜间的挥发性成分存在明显差异,其中1-庚醇、正壬醇和乙酸苯乙酯这3种挥发性成分均仅在中蜂所酿造的荔枝蜜中被检出,而在意蜂所酿造的荔枝蜜中无检出。本文所建立的荔枝蜜挥发性成分指纹图谱,可为荔枝蜜的质量控制提供依据,并为生产上不同蜂种所酿造荔枝蜜的区分提供理论基础。     

捕食线虫菌物玻片标本制作方法*

采用玻片培养——棉蓝染色法解决了食线虫菌物永久玻片制作中存在的一些问题;小室培养加盖玻片的方法解决了捕食器不能用高倍镜和油镜观察的难题,并且可以拍摄到高质量的显微图象;刮片法改进了临时玻片的制作方法。     

围垦后不同土地利用方式对长江口滩地土壤粒径分布的影响

土壤粒径分布影响土壤水分、肥力等传输与保持,是土壤的重要物理性质.崇明东滩滩地围垦后,表层0～20cm及20～40cm土层土壤粒径分布受土地利用方式和利用年限的显著影响.不同土地利用方式下,土壤平均粒径为高潮滩<稻田<菜地<林地.不同围垦年限下,土地利用15a间土壤平均粒径逐渐增加,但土地利用年限延长至38a时,平均粒径显著降低.不同土地利用方式下土壤水分、植被覆盖和受风蚀程度,以及不同土地利用年限下土壤有机质含量与受风蚀影响程度,改变了粘粒和细粉粒等土壤细颗粒的含量,引起土壤粒径分布的差异.     

基于贝叶斯统计的遗传连锁分析方法

贝叶斯学派是不同于经典数理统计的一个重要学派, 其发展的贝叶斯统计方法在现代科学的许多领域已有着广泛的应用。探讨了贝叶斯统计在遗传连锁分析中的应用, 包括遗传重组率的贝叶斯估计、遗传连锁的贝叶斯因子检验和基于马尔可夫链蒙特卡罗理论的遗传连锁图谱构建。用编制的SAS/IML程序进行了模拟研究和实例分析, 验证了贝叶斯方法在遗传连锁分析中的有效性和实用性。     

MKK7-mediated phosphorylation of JNKs regulates the proliferation and apoptosis of human spermatogonial stem cells

BACKGROUNDHuman spermatogonial stem cells (SSCs) are the basis of spermatogenesis. However, little is known about the developmental regulatory mechanisms of SSC due to sample origin and species differences.AIMTo investigates the mechanisms involved in the proliferation of human SSC.METHODSThe expression of mitogen-activated protein kinase kinase 7 (MKK7) in human testis was identified using immunohistochemistry and western blotting (WB). MKK7 was knocked down using small interfering RNA, and cell proliferation and apoptosis were detected by WB, EdU, cell counting kit-8 and fluorescence-activated cell sorting. After bioinformatic analysis, the interaction of MKK7 with c-Jun N-terminal kinases ( JNKs ) was verified by protein co-immunoprecipitation and WB. The phosphorylation of JNKs was inhibited by SP600125, and the phenotypic changes were detected by WB, cell counting kit-8 and fluorescence-activated cell sorting.RESULTSMKK7 is mainly expressed in human SSCs, and MKK7 knockdown inhibits SSC proliferation and promotes their apoptosis. MKK7 mediated the phosphorylation of JNKs, and after inhibiting the phosphorylation of JNKs, the phenotypic changes of the cells were similar to those after MKK7 downregulation. The expression of MKK7 was significantly downregulated in patients with abnormal spermatogenesis, suggesting that abnormal MKK7 may be associated with spermatogenesis impairment.CONCLUSIONMKK7 regulates the proliferation and apoptosis of human SSC by mediating the phosphorylation of JNKs.