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苏云金芽孢杆菌毒素对羊捻转血矛线虫第三期幼虫毒力研究 总被引：3，自引：0，他引：3
从人工感染捻转血矛线虫山羊的直肠内取出粪便，在２５℃温箱中培养７ｄ，用贝尔曼法分离出第三期幼虫，将它们加入含苏云金芽孢杆菌以色列亚种伴孢晶体毒素的培养液中，置２５℃下培养。当伴孢晶体蛋白含量为４００ｇ／ｍｌ时，幼虫的死亡率２４ｈ后为９４．７％，４８ｈ后为９７．３％。毒素对幼虫作用２４ｈ与４８ｈ，其毒力无显著差异（Ｐ〉０．０５），并且作用２４ｈ与４８ｈ，其ＬＤ５０值伴孢晶体蛋白含量分别为８４．０５μ 相似文献
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将出生后５０～７０日龄的羔山羊，经超数排卵处理以后，从卵泡中抽取卵母细胞，取外观形态正常的卵母细胞分成五组，在含有１０％胎牛血清（ＦＣＳ）的ＴＣＭ－１９９培养液中分别经１２、１６、１８、２０和２４ｈ的体外成熟培养后进行体外受精，探索不同体外成熟培养时间对体外受精及卵裂率的影响。另外，在成熟用培养基内还分别添加了发情母羊血清（ＥＮＧＳ）和ＦＣＳ以观察其培养效果。结果表明，经过１２～２４ｈ体外成熟培养的卵母细胞，在体外受精后的４８ｈ检查卵裂率分别为１０％、３７．１％、５０．０％，４１．２％和２５．０％，卵母细胞经体外成熟培养１６～２０ｈ的卵裂率显著高于１２ｈ和２４ｈ的卵裂率。在成熟培养基内分别添加ＥＮＧＳ和ＦＣＳ，其体外受精卵的卵裂率分别为６０．３和４６．８％，卵裂率在添加两种血清的培养基之间无显著差异。 相似文献
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嗜水气单胞菌疫苗的研制 总被引：20，自引：0，他引：20
取致病性嗜水气单胞菌（Ａｈ）Ｊ－１株接种改良肉汤，摇床培养１８０ｒｐｍ２８℃２４ｈ，用福尔马林灭活制得全菌苗。另将上述培养物离心，取上清经福尔马林灭活制得毒素苗。用全菌苗和毒素苗分别免疫小鼠，２周后强化免疫，而后用Ｊ－１株５０ＬＤ＿（５０）腹腔注射攻击，免疫组均保护，对照组全部死亡。在鲫鱼的免疫保护试验中，分别采用全菌苗及毒素亩作腹腔注射或浸泡免疫，４周后强化免疫。用ＡｈＪ－１株５０ＬＤ＿（５０）腹腔注射攻击。结果全菌苗注射组保护８７％（１３／１５）；毒素苗注射组保护４０％（８、２０）；全菌苗浸泡组保护４０％（６／１５）；毒素苗浸泡组保护６７％（１０／１５）；对照组全部死亡。免疫持续期试验表明，在两次免疫６个月后攻击，全菌苗或毒素苗均仍显示一定的保护力。在平均水温２７℃±２℃下，鲫鱼的抗体动态为：全菌苗注射免疫组在强化免疫后１周全菌凝集抗体达２￣６，此时可检测到鲫鱼体表粘液中有低滴度凝集抗体存在，较高滴度的血清凝集抗体至少可维持６个月。全菌苗浸泡组在强化免疫后约１０天血清中才出现凝集抗体，滴度较低。毒素苗注射免疫用的毒素溶血抑制抗体在初次免疫第２８天达２￣７，强化免疫后高滴度抗体可维持１７天；毒素苗浸泡组的? 相似文献
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家兔显微受精影响因素及显微受精胚胎超微结构 总被引：2，自引：0，他引：2
以家兔为实验动物，利用胞质内精子注射技术和透明带下精子注射技术，对卵龄、精子获能、注射针管口径、操作室温和操作方法等影响显微受精的因素以及显微受精胚胎的超微结构进行了研究。结果显示：（１）胞质内单精子注射，ｈＣＧ后１５－１７ｈ卵的存活率为６９．４％，显著（Ｐ〈０．０５）高于ｈＣＧ后１９－２１ｈ卵的存活率（４７．３％）；而受精率和卵裂率（分别为５２．９％和４１．２％）分别低于ｈＣＧ后１９－２１ｈ卵的 相似文献
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绿脓杆菌外毒素A的纯化 总被引：1，自引：0，他引：1
用绿脓杆菌ＰＡ１０３株接种于ＴＳＡ甘油培养基３２℃培养，产生绿脓杆菌外毒素Ａ（ＰＥＡ），经流水透析除盐、ＤＥ－５２纤维素阶段洗脱、硫酸铵分级沉淀、ＳｅｐｈａｄｅｘＧ－２５除盐、ＤＥ－５２纤维素梯度洗脱、ＳｅｐｈａｄｅｘＧ－２００分子筛层析，纯化了绿脓杆菌外毒素Ａ。ＳＤＳ－ＰＡＧＥ分析，纯化后的毒素为单一蛋白带，分子量约６６０００；对普通小鼠ＬＤ５０为０．２４μｇ蛋白。用ＰＥＡ抗血清作免疫印迹分析，进一步证实纯化的蛋白为ＰＥＡ，毒素约纯化了５００倍，总蛋白回收率约０．０２４％，毒素回收率约１１％。 相似文献
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用８～１２周龄ＢＡＬＢ／ｃ公鼠采取皮肤移植和脾细胞腹腔注射２种方式免疫同日龄纯系ＢＡＬＢ／ｃ母鼠,制备Ｈ－Ｙ抗血清。经精子微量细胞毒性试验,筛选的抗血清用于胚胎体外培养,以鉴定附植前小鼠胚胎上Ｈ－Ｙ抗原的表达。选用８ｃｅｌｌ－早期囊胚进行体外培养,分别于５～６、１８和２４ｈ观察胚胎发育情况。５～６ｈ后,Ｈ－Ｙ抗血清培养的胚胎退化率高达４０％,且发育迟缓,与自然性比例差异不明显（Ｐ〉０．０５）。正常 相似文献
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人工瘤胃中半胱胺的稳定性及其对瘤胃发酵的影响 总被引：14，自引：0，他引：14
在人工瘤胃中半胱胺具有较高的稳定性，培养２４ｈ后，可检测到初始浓度的７４．３％，实验还发现，实验组的总脱氢酶活力较对照组显著提高，ＮＨ３－Ｎ浓度降低２８．６９％（Ｐ〈０．０１），ＭＣＰ浓度提高９．０７％（Ｐ〈０．０１），ＴＶＦＡ浓度较对照升高，２５．５６％（Ｐ〈０．０５），同时，乙酸比例升高，丙酸比例降低，结果表明半胱胺可影响瘤胃微生物的活动及其区系结构。 相似文献
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鸡T淋巴细胞IL－2的体外诱生及活性检测 总被引：1，自引：0，他引：1
经Ｌ１６（４５）正交试验选择，并经实验验证，鸡脾脏Ｔ淋巴细胞白细胞介素２（ＩＬ－２）体外诱生和活性检测的最优水平组合及适宜条件为２．５μｇ／ｍＬ伴刀豆蛋白Ａ（ＣｏｎＡ）、ＩＬ－２体外诱生时间２０ｈ、１×１０７／ｍＬ淋巴细胞、１０％小牛血清、靶细胞培养时间４８ｈ、４×１０６／ｍＬ靶细胞、靶细胞接触时间３６ｈ、５ｍｇ／ｍＬＭＴＴ、ＭＴＴ加入时间３ｈ和甲溶解时间２ｈ；胸腺Ｔ淋巴细胞ＩＬ－２体外诱生和活性检测的最优水平组合及适宜条件为５μｇ／ｍＬＣｏｎＡ、ＩＬ－２体外诱生时间４８ｈ，余同脾脏Ｔ淋巴细胞ＩＬ－２体外诱生及活性检测。比较试验表明，ＭＴＴ比色分析法和３Ｈ－胸腺嘧啶核苷（３Ｈ－ＴｄＲ）掺入法有显著的直线回归关系。 相似文献
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鸡T淋巴细胞IL—2的体外诱生及活性检测 总被引：2，自引：0，他引：2
经Ｌ１６正交试验选择，并经实验验证，鸡脾脏Ｔ淋巴细胞白细胞介素２（ＩＬ－２）体外诱生和活性检测的最优水平组合及适宜条件的２．５μｇ／ｍＬ伴刀豆蛋白Ａ，ＩＬ－２体外诱生时间２０ｈ，１×１０＾７／ｍＬ淋巴细胞、１０％小牛血清、靶细胞培养时间４８ｈ，４×１０＾６／ｍＬ靶细胞，靶细胞接触时间３６ｈ，５ｍｇ／ｍＬＭＴＴ，ＭＴＴ加入时间３ｈ和甲替溶解时间２ｈ；胸腺Ｔ淋巴细胞ＩＬ－２体外诱生和活性检测的最优水平 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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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
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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