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51.
祁连山是我国西部重要的生态屏障,拥有大量的草地资源。研究草地土壤细菌群落组成及其与土壤环境因子间的关系,可对维持草地生态及了解祁连山土壤细菌群落组成提供一定的数据基础。采用高通量测序技术检测并分析了祁连山默勒镇3种类型草地 (高寒草甸、人工草地、沼泽化草甸)0~10 cm土壤细菌群落结构及多样性,并对上述土壤细菌群落与土壤理化因子的相关性进行了系统的研究。结果表明:1)沼泽化草甸土壤全氮、全磷、有机质碳、含水量和硝态氮显著高于高寒草甸和人工草地(P<0.05)。2)3地共测得有效序列1022446条,以97%的一致性将序列聚类,高寒草甸、人工草地、沼泽化草甸OTU聚类均值分别是4917、5233、5075条。3)Shannon和Simpson多样性指数3地间差异不显著,Chao1指数表现为人工草地>高寒草甸>沼泽化草甸(P<0.05)。4)在门水平上,3地均以变形菌门、酸杆菌门、放线菌门和浮霉菌门为主要类群;在属水平上,表现出不同类型草地细菌富集类型不同。5)有机质碳、全磷、土壤含水量与土壤细菌群落的组成表现出极显著相关(P<0.01)。综上,祁连山地区小生境内3种草地土壤微生物群落存在差异,有机质碳、全磷、土壤含水量是影响群落的主要驱动因子。 相似文献
52.
试验旨在通过新型莫西菌素(moxidectin,MOX)浇泼剂对羊的驱虫试验,评价MOX浇泼剂对羊蜱蝇和消化道线虫的临床药效。将150只阿勒泰羊经产母羊随机分为6组,每组25只,分别为不用药对照组、螨净药浴组、MOX注射组和MOX低(0.05 mL/(kg·BW))、中(0.1 mL/(kg·BW))和高(0.2 mL/(kg·BW))剂量浇泼组,试验期为1周。试验第1天按前述分组中方法和剂量驱虫1次。观察受试动物临床表现,测定给药前1天和给药后第7天体温、脉搏和呼吸(TPR),血液生理、生化和尿常规指标;测定羊蜱蝇减虫率、治愈率。采取粪样测定消化道线虫每克粪中虫卵个数(EPG)减少率及转阴率。结果显示,与不用药对照组相比,给药后第7天各驱虫组TPR、血液生理、生化及尿常规指标均无显著差异(P>0.05)。螨净药浴组羊蜱蝇减虫率为43.7%,而MOX注射组及MOX低、中、高剂量浇泼组均为100%。螨净药浴组治愈率为13.0%,而MOX注射组及MOX低、中、高剂量浇泼组均为100%;与不用药对照组相比,螨净药浴组消化道线虫卵减少率为0,而MOX注射组及MOX低、中、高剂量浇泼组分别为91.6%、93.1%、94.9%和97.8%。螨净药浴组虫卵转阴率为0,而MOX注射组及MOX低、中、高剂量浇泼组分别为77.0%、69.2%、69.2%和84.6%。本试验结果表明,新型MOX浇泼剂对体外寄生虫和消化道线虫均有显著疗效,且优于螨净药浴,与MOX注射剂等效。实践应用中最适MOX浇泼剂量推荐为0.05 mL/(kg·BW)(即0.25 mg/(kg·BW))。 相似文献
53.
JIANG Ling-ling CHEN Hong-yu SHI Kai-zhi ZHOU Si-xuan YU Bo BU Shi-jin 《中国畜牧兽医》2016,43(11):3073-3079
In order to understand the security of a new kind of antidiarrheal Chinese herbal medicine compound preparation for livestock,acute and sub-chronic toxicity test were conducted.Acute toxicity test used the largest drug dose method,20 Wistar rats were orally treated with the Chinese medicine compound preparation.In the sub-chronic toxicity test,80 rats were randomly divided into 4 groups with 20 rats in each group and orally given a dose of 3 000,1 500,750 and 0 mg/(kg·BW)of Chinese medicine compound preparation once a day for 30 days.The general clinical status was observed,rats weight were measured and the dose was adjusted every week during the test,after the test measured blood routine index,biochemistry index,and preceded the gross anatomy observation,weighing each major organs and calculated the viscera coefficient,and proceded main viscera histopathological observation between the high dose group and the control group.The acute toxicity results showed that every rat would be alive gavaged with the lethal dose(LD50)of compound preparation larger 5 g/(kg·BW).The sub-chronic toxicity autopsy showed that except heart,lung,and testicles in individual rats appeared mild bleeding in the high dose group,the other dose group organs found no abnormal change.The haematological index showed except mononuclear cell rate(P<0.05),and hematocrit declined significantly(P<0.05)in the high dose group,all the indexes of the other groups were in the normal range,there was no significant difference from the control group.The test suggested the Chinese medicine compound preparation was no toxicity under the condition of this test according to acute toxicity classification standard of exogenous chemicals by WTO,there was no effect on the growth and development of rats in the sub-chronic toxicity test,and there was no chronic toxicity at least 1 500 mg/kg feeding conditions in short-term repeated application. 相似文献
54.
为实现对玉米黄花叶病毒(maize yellow mosaic virus,MaYMV)的血清学检测,丰富该病毒的检测方法,将编码MaYMV运动蛋白(movement protein,MP)的基因连接到原核表达载体pDBHis-MBP上,将构建成功的原核表达质粒转化到大肠杆菌Escherichia coli中诱导表达融合蛋白,将纯化后的融合蛋白对新西兰大白兔Oryctolagus cuniculus进行免疫并制备MaYMV MP多克隆抗血清,并采用Western blot对抗血清的效价、灵敏度和特异性进行检测。结果显示,利用成功构建的原核表达载体经诱导表达获得分子量大小约为62 kD的融合蛋白,纯化后对新西兰大白兔进行免疫获得MaYMV MP抗血清,该抗血清的效价为1∶128 000,灵敏度为1∶32,且该抗血清能够特异性地检测到本氏烟Nicotiana benthamiana中瞬时表达的MaYMV MP,而不与马铃薯卷叶病毒属Polerovirus及黄症病毒属Luteovirus的其他病毒发生血清学交叉反应,证明该抗血清具有良好的特异性。表明本研究制备的MaYMV MP抗血清能特异性... 相似文献
55.
56.
Investment on construction projects has become an important factor in improving the development of economy in China.The non-price bottom bidding is a representation that the investment on projects is becoming standardized.During the years of trying out the non-price bottom bidding,the colluding in bidding or bidding below the cost has happened several times,which have damaged the benefits of owners.To solve theses problems,this paper firstly studies the reason of these problems-the failure in the normal relationship between principal and agent.Then,some measures have been presented as follows: building systematic and scientific system of qualification prejudication,judging behaviors of colluding in bidding and bidding below the cost with reason and providing a surety mechanism of the project.The authors hope that these measures are beneficial to non-price bottom bidding. 相似文献
57.
Novel surface treatment technique by silane film is developing for metallic anti corrosion and coat improvement. The key points, hydrolysis and condensation, for the stability of the Silane agent(SA) solution is investigated, and the effective factors of stability for silane agent solution and the relative rule are discussed. It is found that stability of SA solution is related to the temperature, pH, solvents, SA concentration and additive by studying the state of the solution and the conductivity-time curve of SA solution. Meanwhile, controlling factors and improving methods for SA stability are proposed to guide the practical application of metallic surface anti-corrosion treatment by SA. 相似文献
58.
Intrusion detection system is an essential component of network security protection mechanisms. Most intrusion detection system can not adapt the variation of network environment. Aiming at this problem, an adaptive strategy that composed of condition space and strategy space is proposed. The condition space describes the network environment and the strategy space describes the strategy. There is an exclusive strategy corresponds to a certain environment state in condition space. On the base of the adaptive strategy, an adaptive intrusion detection system based on agent and data mining is designed. The simulation experiments indicate that the adaptive strategy is effective. 相似文献
59.
The agent - construction system, as a new public project management mode, has been practiced in some cities and attracted attention from the society. This paper firstly studies the features and operation modes of agent - construction system, and discusses the agent - construction system from the viewpoints of promoting competition, nourishing agent -construction enterprises, setting up a supervisory and encouraging mechanism, and its connection with the governmental project procurement system etc. 相似文献
60.