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基于国内外有关文献和笔者的研究结果,对番石榴叶药用成分的提取方法,已鉴定的组成成分以及提取物的药理作用进行了全面的总结. 相似文献
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为了便于常规PCR技术在鸡性别鉴定上的推广和应用,本研究以成年家鸡全血为模板,应用常规PCR反应缓冲液和Tap DNA聚合酶直接进行PCR扩增,对50 μL PCR反应体系中的血样(0.05~4.0 μL)和Tap DNA聚合酶的使用量(0.05~1.5 μL),以及循环次数(30~40)进行了优化,在此基础上对血样的抗凝剂和保存温度进行了探讨,并对62只1日龄雏鸡、80枚12日龄和80枚16日龄鸡胚的血样直接PCR进行了性别鉴定。结果表明,采集血样时可以使用ACD、肝素或EDTA作为抗凝剂,血样可以在4、－20或－80 ℃至少保存3个月;使用0.1 μL全血就能完成雏鸡和鸡胚性别鉴定,全血PCR鉴定性别与性腺性别的符合度为100%。与常规PCR相比,全血PCR节约了检测成本,提高了检测效率,减少了交叉污染可能。 相似文献
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基于国内外有关文献和笔者的研究结果，对番石榴叶药用成分的提取方法，已鉴定的组成成分以及提取物的药理作用进行了全面的总结． 相似文献
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本研究旨在探究弓形虫表面抗原SAG1黏附宿主细胞表面硫化肝素的特性及其在虫体入侵宿主细胞过程中的作用。通过提取弓形虫ME49株DNA,利用PCR方法扩增SAG1基因片段并将其克隆至原核表达载体pGEX-4T-1,获得重组质粒pGEX-SAG1。将获得的重组质粒pGEX-SAG1转入大肠杆菌BL21 CodonPlus-RIPL后利用IPTG诱导表达重组蛋白质GST-SAG1。将纯化后的重组蛋白质进行SAG1与肝素的特异性结合分析,并利用间接免疫荧光试验(IFA)和Western blot方法检测SAG1黏附宿主细胞的活性。通过体内和体外肝素抑制虫体入侵试验进一步分析外源肝素对SAG1黏附宿主细胞表面硫化肝素的阻断作用。结果显示:成功构建重组表达载体pGEX-SAG1,并表达和纯化了重组蛋白质GST-SAG1。肝素结合与竞争抑制试验发现SAG1能够与肝素结合,且肝素能够以浓度依赖的方式抑制这种结合。IFA和Western blot分析结果表明,SAG1能黏附至Vero细胞和HEK293A细胞表面。肝素阻断虫体入侵试验表明,外源肝素可竞争抑制SAG1与宿主细胞表面硫化肝素结合,进而阻断弓形虫的入侵。结果表明弓形虫表面抗原SAG1参与黏附宿主细胞表面的硫化肝素并促进弓形虫的入侵。此研究进一步揭示了弓形虫表面抗原SAG1作为弓形虫入侵的重要因子在虫体入侵过程中与宿主细胞表面硫化肝素的互作关系,同时也为进一步阐明肝素在弓形虫入侵过程中的分子机制奠定基础。 相似文献
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家畜的体型外貌可以从不同方面反映出家畜的生产性能 ,因此 ,可以用它来作为家畜鉴定等级的依据。但以往的鉴定存在许多缺陷 ,主观性大 ,精确度差。已有许多研究人员对家畜的体尺进行研究 ,提出了一些新的等级鉴定方法。对家畜体尺资料的深入分析 ,可以发现家畜不同部位的体尺所能够反映的信息是不同的 ,且其对生产性能的反映程度也不一样。基于这种考虑 ,我们运用主成分分析的方法 ,首先将测定出的家畜各种不同体尺 ,按其主成分分类 ,依次构成多级体尺资料 ,进行多级Ｆｕｚｚｙ综合评判 ,以对肉用杂交羊进行外貌鉴定。1 材料与方法1 1 材… 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献