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991.
体型大小与昆虫在温度胁迫下的适应性有关。本文旨在研究入侵杂草空心莲子草Alternanthera philoxeroides生防天敌莲草直胸跳甲Agasicles hygrophila SelmanVogt不同地理种群对高温的形态响应机制。以恒温25℃作为对照,分别测定莲草直胸跳甲长沙种群和海南种群在模拟夏季特定12∶00-16∶00时段30℃、33℃、36℃高温条件下的幼虫体重、初羽化成虫体重、后足胫节长、鞘翅长、前胸背板宽等指标。结果表明,莲草直胸跳甲两地理种群幼虫体重均随温度升高而增加。两种群雌虫及长沙种群雄虫的体重、后足胫节长、鞘翅长、前胸背板宽度随温度上升显著下降;海南种群雄虫的后足胫节长、鞘翅长、前胸背板宽在各温度处理间无显著差异。在33℃、36℃高温条件下,长沙种群的幼虫体重、雌虫体重及雌虫的后足胫节长、鞘翅长、前胸背板宽显著高于海南种群,而长沙种群雄虫的后足胫节长、鞘翅长、前胸背板宽显著低于海南种群。试验表明,不同地理种群的莲草直胸跳甲形态大小对高温的响应存在差异。本研究结果为探究莲草直胸跳甲种间进化以及人工培育耐热种群的实践提供了一定的参考依据。 相似文献
992.
人SR-AI转基因小鼠模型的主要形态学特性、血液学指标和血脂水平的研究 总被引:5,自引:0,他引:5
目的明确人SR-AI转基因小鼠的一些形态、脏器、血液学和血浆脂质参数,为人SR-AI转基因小鼠模型的应用提供相关依据.方法用游标卡尺和电子称量天平测量人SR-AI转基因小鼠的吻长、眶间距、体长、尾长及12个脏器系数并与C57BL/6J小鼠进行比较分析;用SysmexK-4500型全血自动多参数血液分析仪检测其血液学指标;并用酶法分别测定血浆总胆固醇、甘油三酯和高密度脂蛋白胆固醇含量.结果人SR-AI转基因小鼠外部形态指标和脏器系数与C57BL/6J小鼠比较差异没有显著意义(P>0.05);转基因小鼠的各项血液学指标无明显改变,血脂蛋白成分的改变亦未显示统计学意义(P>0.05),甘油三酯的浓度略有增高(P<0.05).结论人SR-AI转基因小鼠的外部形态指标、脏器系数及各项血液学指标均无明显改变,适合用作动脉粥样硬化模型的研究. 相似文献
993.
The effect of Schisandra fructus extract (SFE) on doxorubicin (Dox)-induced cardiotoxicity was investigated in H9c2 cardiomyocytes. Dox, which is an antineoplastic drug known to induce cardiomyopathy possibly through production of reactive oxygen species, induced significant cytotoxicity, intracellular reactive oxygen species (ROS), and lipid peroxidation. SFE treatment significantly increased cell survival up to 25%, inhibited intracellular ROS production in a time- and dose-dependent manner, and inhibited lipid peroxidation induced by Dox. In addition, SFE treatment induced expression of cellular glutathione S-transferases (GSTs), which function in the detoxification of xenobiotics, and endogenous toxicants including lipid peoxides. Analyses of 31,100 genes using Affymetrix cDNA microarrays showed that SFE treatment up-regulated expression of genes involved in glutathione metabolism and detoxification [GST theta 1, mu 1, and alpha type 2, heme oxygenase 1 (HO-1), and microsomal epoxide hydrolase (mEH)] and energy metabolism [carnitine palmitoyltransferase-1 (CPT-1), transaldolase, and transketolase]. These data indicated that SFE might increase the resistance to cardiac cell injury by Dox, at least partly, together with altering gene expression, especially induction of phase II detoxification enzymes. 相似文献
994.
995.
996.
Yong QC Lee SW Foo CS Neo KL Chen X Bian JS 《American journal of physiology. Heart and circulatory physiology》2008,295(3):H1330-H1340
The present study aimed to investigate the role of hydrogen sulphide (H2S) in the cardioprotection induced by ischemic postconditioning and to examine the underlying mechanisms. Cardiodynamics and myocardial infarction were measured in isolated rat hearts. Postconditioning with six episodes of 10-s ischemia (IPostC) significantly improved cardiodynamic function, which was attenuated by the blockade of endogenous H2S production with d-l-propargylglycine. Moreover, IPostC significantly stimulated H2S synthesis enzyme activity during the early period of reperfusion. However, d-l-propargylglycine only attenuated the IPostC-induced activation of PKC-alpha and PKC-epsilon but not that of PKC-delta, Akt, and endothelial nitric oxide synthase (eNOS). These data suggest that endogenous H2S contributes partially to the cardioprotection of IPostC via stimulating PKC-alpha and PKC-epsilon. Postconditioning with six episodes of a 10-s infusion of NaHS (SPostC) or 2 min continuous NaHS infusion (SPostC2) stimulated activities of Akt and PKC, improved the cardiodynamic performances, and reduced myocardial infarct size. The blockade of Akt with LY-294002 (15 microM) or PKC with chelerythrine (10 microM) abolished the cardioprotection induced by H2S postconditioning. SPostC2, but not SPostC, also additionally stimulated eNOS. We conclude that endogenous H2S contributes to IPostC-induced cardioprotection. H2S postconditioning confers the protective effects against ischemia-reperfusion injury through the activation of Akt, PKC, and eNOS pathways. 相似文献
997.
以烟酸(NA)、谷胱甘肽(GSH)和CrCl3·6H2O为原料,制备高纯度GSH-Cr3+-NA2螯合物,分析影响合成螯合物的主要因素,获得最佳合成工艺,并对获得的螯合物进行表征,确定其螯合比例。结果表明,在Cr3+/NA/GSH(mol/mol/mol)=1∶2∶4,pH 5.0、温度60℃下反应3h,制备出Cr3+/NA/GSH(mol/mol/mol)=1∶2∶1的GSH-Cr3+-NA2螯合物;红外分析显示,与GSH相比,螯合物的-NH2、-NH-特征吸收峰发生蓝移,-NHC=O中-C=O的特征吸收峰红移,-SH的伸缩振动峰消失,说明GSH上的-NH-、NHC=O中-C=O、-SH均参与相互作用;与NA相比,螯合物的-C=O的伸缩振动峰发生红移,-OH的特征吸收峰消失了,说明NA上的-C=O和-OH参与相互作用。原子力显微镜形貌分析结果指出,由两分子NA和一分子GSH链围绕一Cr3+形成GSH-Cr3+-NA2螯合物。 相似文献
998.
The cranial anatomy of Chinese placodonts and the phylogeny of Placodontia (Diapsida: Sauropterygia) 下载免费PDF全文
James M. Neenan Chun Li Olivier Rieppel Torsten M. Scheyer 《Zoological Journal of the Linnean Society》2015,175(2):415-428
Placodonts are Triassic marine reptiles that inhabited the eastern and western margins of the Tethys Ocean (modern South China and Europe/Middle East). Although the crania of European taxa are relatively well understood, those of Chinese taxa have not been extensively studied, and most of them have not been incorporated into a comprehensive phylogeny. Here we present the first reconstructions of all known Chinese placodont holotype skulls using micro‐computed tomographic (μCT) scanning and/or detailed anatomical study. We also present the first phylogenetic analyses that incorporate all placodont genera using a general diapsid matrix that includes postcranial characters, and a placodont‐only cranial matrix. Results vary between the matrices; however, both support a monophyletic Placodontia with eastern taxa interspaced throughout, indicating no major separation between the eastern and western Tethyan realms. Support is strong for a western Tethyan origin of Placodontia, although the highly nested Placochelyidae first appear in the upper Middle Triassic of the eastern Tethys. Thus, all placodont clades appear to have originated in a period of intense speciation during the Middle Triassic. © 2015 The Linnean Society of London 相似文献
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1000.
较大的腹壁缺损需要应用补片修复来缓解腹横筋膜的张力,人工合成补片的应用一定程度上实现了无张力修补的目的,但它在腹壁外科应用中有诸多的并发症,诸如复发率高,腹腔黏连,肠穿孔导致腹膜炎,侵袭性肠瘘等影响患者术后的正常生活,而脱细胞真皮基质(Acellular dermal matrix,ADM)作为一种新型的生物材料应用在腹壁外科中能解决上述人工合成补片所带来的并发症发挥强大作用且能与周围组织较好的融合,最后改建成宿主自身组织已并在多学科领域中广泛应用;骨髓间充质干细胞(Bone marrow mesenchymal stem cells,BMSCs)能参与组织自我修复,并能分化成为多种功能细胞,分泌各种生长因子,在ADM内源性转归过程中可发挥作用。本文就对骨髓间充质干细胞在ADM生物补片应用于临床疝修补术中转归机制的研究做一综述。 相似文献