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排序方式: 共有170条查询结果,搜索用时 15 毫秒
1.
大壁虎的染色体及减数分裂联会复合体的研究   总被引:7,自引:1,他引:6  
王蕊芳  马昆 《动物学研究》1989,10(4):271-275
大壁虎(Gekko gecko)的染色体数目为2n=38,核型由2对中着丝粒(Nos.1.4.)、3对亚中着丝粒(Nos.2.3.5)及14对端着丝粒和亚端着丝粒(Nos.6—19)染色体组成。一对核仁组织者(NOR_s),位于第7对端着丝粒染色体的末端。同时,本文还对大壁虎的减数分裂以及联会复合体(S.C)的结构和组型,进行了详细的观察和分析。  相似文献   
2.
本文使用蝌蚪红细胞微核率作为指示器研究明通河污水和用污水土地处理系统处理后水质的致突变性。蝌蚪在各种水样品中暴露7天。采心脏血制片。在对照组中,微核率分别为4.40‰和4.68‰。1/4明通河污水组诱发蝌蚪的微核率是17.01‰。同对照组相比有明显的差异。  相似文献   
3.
滇池是云南高原最大的淡水湖,是昆明地区工农业生产及人民生活用水的水源,又是昆明市的重要风景区。近年来,滇池水质污染,越来越引起人们的关注。昆明市的工业废水和生活污水经大观河等流入滇池,其中有毒有害物质多达30多种,包括镉、汞、砷、铅、铬、氟、有机磷、氰化物等。其中砷(Léonard et al., 1980;Katsuhiko,  相似文献   
4.
糖外排转运蛋白(Sugars will eventually be exported transporters, SWEETs)在植物生理活动和发育过程中起重要作用。为探究SWEET基因家族在毛竹(Phyllostachys edulis)的生长发育过程中起的作用,基于毛竹基因组数据,通过生物信息学方法对SWEET基因家族成员进行鉴定,并对其编码的蛋白质理化性质、系统进化及共线性关系、基因结构、启动子元件及表达模式、蛋白互作网路分析、GO注释等进行细致分析。研究结果表明:该家族基因结构、基序和结构域相对保守,所有成员均含有MtN3_slv结构域。上游启动子序列中含有多个同非生物胁迫以及生长发育相关元件,结合转录组表达量分析显示,多个家族成员在毛竹不同组织器官均有表达。共线性分析揭示毛竹SWEET家族在演化过程中存在全基因组多倍化事件。蛋白互作网路分析挖掘出2个重要核心家族成员,GO注释分析进一步证实毛竹SWEET主要负责体内糖类物质的转运。以上结果为毛竹SWEET基因功能鉴定提供了重要参考,对于毛竹快速生长分子机制研究打下了基础。  相似文献   
5.
Zhang  Jian  Yang  Yang  Tian  Ye  Xu  Ruifang  Lin  Jun 《Diagnostic pathology》2021,16(1):1-9
Quick and reliable testing of EGFR and KRAS is needed in non-small cell lung cancer (NSCLC) to ensure optimal decision-making for targeted therapy. The Idylla™ platform was designed for Formalin-Fixed Paraffin-Embedded (FFPE) tissue sections but recently several studies were published that evaluated its potential for cytological specimens. This study aimed to validate the Idylla™ platform for the detection of EGFR/KRAS mutations in cytological NSCLC samples prepared as cytoblocks using AGAR and paraffin embedding. The KRAS Idylla™ test were performed on 11 specimens with a known KRAS mutation. The EGFR Idylla™ test was performed on 18 specimens with a known primary EGFR mutation and 7 specimens with a primary EGFR-EGFR T790M resistance mutation combination. Concordant KRAS and primary EGFR mutations were detected for both KRAS and primary EGFR mutations. Samples with a total CQ value of < 26 could be considered negative. Samples with a total CQ value of > 26 could not be assessed (probability of false-negative). In specimens with a primary EGFR-EGFR T790M resistance mutation combination, 5/7 cases were not concordant. Our results confirm the conclusion of recent reports that the Idylla™EGFR assay is not suitable in a resistance to EGFR TKI setting, also not in our cytological NSCLC samples prepared as cytoblocks using AGAR and paraffin embedding. KRAS and primary EGFR mutations were detected using the Idylla™ assays in virtually all cytological NSCLC samples. This analysis was rapid and time-saving compared to other mutation detection assays and may be useful if the amount of material is insufficient to perform a full set of molecular tests.  相似文献   
6.
Bifunctional RNAs that possess both protein-coding and noncoding functional properties were less explored and poorly understood. Here we systematically explored the characteristics and functions of such human bifunctional RNAs by integrating tandem mass spectrometry and RNA-seq data. We first constructed a pipeline to identify and annotate bifunctional RNAs, leading to the characterization of 132 high-confidence bifunctional RNAs. Our analyses indicate that bifunctional RNAs may be involved in human embryonic development and can be functional in diverse tissues. Moreover, bifunctional RNAs could interact with multiple miRNAs and RNA-binding proteins to exert their corresponding roles. Bifunctional RNAs may also function as competing endogenous RNAs to regulate the expression of many genes by competing for common targeting miRNAs. Finally, somatic mutations of diverse carcinomas may generate harmful effect on corresponding bifunctional RNAs. Collectively, our study not only provides the pipeline for identifying and annotating bifunctional RNAs but also reveals their important gene-regulatory functions.  相似文献   
7.
<正>Cancer has become one of the biggest challenges in the development of modern medical science. In particular, many problems, such as low efficiency, severe side effects, metastasis, and tumor invasion, challenge the development of precise cancer therapy. Continuous advancements in medicine, however, have allowed clear differentiation between tumors and normal tissues that can be exploited for cancer  相似文献   
8.
The dipeptidyl peptidase 4 inhibitor vildagliptin (VLD), a widely used anti‐diabetic drug, exerts favourable effects on vascular endothelium in diabetes. We determined for the first time the improving effects of VLD on mitochondrial dysfunction in diabetic mice and human umbilical vein endothelial cells (HUVECs) cultured under hyperglycaemic conditions, and further explored the mechanism behind the anti‐diabetic activity. Mitochondrial ROS (mtROS) production was detected by fluorescent microscope and flow cytometry. Mitochondrial DNA damage and ATP synthesis were analysed by real time PCR and ATPlite assay, respectively. Mitochondrial network stained with MitoTracker Red to identify mitochondrial fragmentation was visualized under confocal microscopy. The expression levels of dynamin‐related proteins (Drp1 and Fis1) were determined by immunoblotting. We found that VLD significantly reduced mtROS production and mitochondrial DNA damage, but enhanced ATP synthesis in endothelium under diabetic conditions. Moreover, VLD reduced the expression of Drp1 and Fis1, blocked Drp1 translocation into mitochondria, and blunted mitochondrial fragmentation induced by hyperglycaemia. As a result, mitochondrial dysfunction was alleviated and mitochondrial morphology was restored by VLD. Additionally, VLD promoted the phosphorylation of AMPK and its target acetyl‐CoA carboxylase in the setting of high glucose, and AMPK activation led to a decreased expression and activation of Drp1. In conclusion, VLD improves endothelial mitochondrial dysfunction in diabetes, possibly through inhibiting Drp1‐mediated mitochondrial fission in an AMPK‐dependent manner.  相似文献   
9.
10.
乌梁素海湖滨湿地细菌群落结构多样性   总被引:12,自引:0,他引:12  
杜瑞芳  李靖宇  赵吉 《微生物学报》2014,54(10):1116-1128
【目的】了解乌梁素海湖滨湿地水陆过渡带细菌群落结构及多样性变化,探讨富营养化湖泊湿地基质条件对细菌群落结构的影响。【方法】应用变性梯度凝胶电泳(PCR-DGGE)技术,分析和比较了依陆向分布的4个水陆过渡带样点的湿地细菌群落结构多样性,采用典型对应分析(CCA)探讨了湿地基质因子对细菌多样性的影响。【结果】DGGE图谱显示依湖泊水体沉积物(S-1)→湖滨芦苇沼泽沉积物(S-2)→湖滨碱蓬盐化草甸土壤(S-3)→岸上白刺荒漠土壤(S-4),4个样点的条带数依次减少,对应菌群结构及多样性变化显著;多样性指数分析结果显示,Shannon-Wiener指数(H)、均匀度(E)、丰富度(S)以及Simpson指数(DS)均显示依陆向分布逐步下降的规律,即:S-1S-2S-3S-4。序列比对结果显示,沉积物及土壤细菌分属于变形菌门(78.6%)、酸杆菌门(7.1%)、拟杆菌门(14.3%)这3个细菌类群,优势菌门为变形菌门,而变形菌门又分为5个亚群,其中ε变形菌纲为优势亚群;CCA结果表明,图中各条带对应物种的分布受铵态氮、总氮、有机碳、水溶盐总量、氯离子以及钾离子影响最大。【结论】乌梁素海富营养化湖泊的水陆过渡带湿地细菌群落结构存在较大差异,富营养化相关基质因子对细菌多样性影响较大。这为研究富营养化湖泊湿地水陆过渡带的细菌结构多样性及空间异质性提供了科学依据。  相似文献   
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