995 resultados para 7038-209
Resumo:
报道了采自云南片马的鼠兔属1新种,以其体色在鼠兔属中最为深黑为其主要特征而命名为片马黑鼠兔Ochotona nigritia sp. nov.。正模标本保存在中国科学院昆明动物研究所,副模标本保存在云南省流行病防治研究所。
Resumo:
In xenotransplantation, donor endothelium is the first target of immunological attack. Activation of the endothelial cell by preformed natural antibodies leads to platelet binding via the interaction of the glycoprotein (GP) Ib and von Willebrand factor (vWF). TMVA is a novel GPIb-binding protein purified from the venom of Trimeresurus mucrosquamatus. In this study, the inhibitory effect of TMVA on platelet aggregation in rats and the effect on discordant guinea pig-to-rat cardiac xenograft survival were investigated. Three doses (8, 20 or 40 mug/kg) of TMVA were infused intravenously to 30 rats respectively. Platelet aggregation rate was assayed 0.5, 12, and 24 h after TMVA administration. Wister rats underwent guinea pig cardiac cervical heterotopic transplantation using single dosing of TMVA (20 mug/kg, i.v., 0.5 h before reperfusion). Additionally, levels of TXB2 and 6-keto-PGF(1alpha) within rejected graft tissues were determined by radioimmunoassay. Treatment with TMVA at a dose of 20 or 40 mug/kg resulted in complete inhibition of platelet aggregation 0.5 h after TMVA administration. Rats receiving guinea pig cardiac xenografts after TMVA therapy had significantly prolonged xenograft survival. Histologic and immunopathologic analysis of cardiac xenografts in TMVA treatment group showed no intragraft platelet microthrombi formation and fibrin deposition. Additionally, the ratio of 6-keto-PGF(1alpha) to TXB2 in TMVA treatment group was significantly higher than those in control group. We conclude that the use of this novel GPIb-binding protein was very effective in preventing platelet microthrombi formation and fibrin deposition in a guinea pig-to-rat model and resulted in prolongation of xenograft survival. The increased ratio of PGI(2)/TXA(2) in TMVA treatment group may protect xenografts from the endothelial cell activation and contribute to the prolongation of xenograft survival.
Resumo:
从2003年3月到2004年2月,在水力负荷为600mm/d的条件下研究了人工湿地中试系统(mediumscaleplot,MSP)基质中藻类的组成.结果表明,栅藻、小球藻、盘星藻、空星藻、纤维藻、舟行藻、小环藻、平裂藻和颤藻属的一些种类在下行池基质各层不同季节均有出现,下行池表层藻类较丰;上行池基质中不同季节的藻类组成中念珠藻和鱼腥藻均为固氮种类,菱板藻、舟行藻和卵形藻属的一些种类在上行池表层出现较多,上行池藻类组成较下行池少.本实验探讨了在人工湿地基质中存在的藻类组成,为湿地除藻机理和评估系统的稳定性
Resumo:
黄颡鱼(Pelteobagrusfulvidraco)是近年被无意引入到抚仙湖的外来鱼类,自2002年以来在渔获物中已形成了较为稳定的产量。根据2002年9月至2005年5月采集的708尾标本对抚仙湖黄颡鱼种群的年龄和生长特征进行了研究。以脊椎骨作为年龄鉴定的材料,表明种群的年龄分别为雌性0+-5+龄6个龄组和雄性0+-7+龄8个龄组组成;拟合的VonBertalanffy生长参数为雄性L∞=294·68mm,k=0·2476/y,t0=-0·0298y,W∞=209·93g;雌性L∞=257·13mm,
Resumo:
对我国淡水产奥杜藻属植物的分类进行了研究总结,共有10种2变种,其中4个种为我国的新记录种,即赫曼奥杜藻Audouinellahermannii(Roth)Duby,大孢奥杜藻A.macrospora(Wood)SheathetBurkholder,优美奥杜藻A.eugenea(Skuja)Jao和矮小奥杜藻A.pygmaea(Kützing)Weber-VanBosse。