共查询到20条相似文献，搜索用时 78 毫秒
1.
采用鸡胚接种法从安徽凤阳某患病鹅群中分离到一株病毒。经HA与HI试验、血清中和接种鸡胚试验、病毒回归试验确认为鹅副粘病毒 ,并命名为WF0 0 G株。参照新城疫病毒毒力判定的标准及其方法 ,测定该分离株的鸡胚最小致死量平均死亡时间 (MDT)、1日龄鸡脑接种致病指数 (ICPI)和 6周龄鸡静脉内接种致病指数 (IVPI)分别为 4 4 8h、1 81和 2 32 ,结果表明该分离株具有与新城疫病毒 (NDV)速发型相类似的毒力 ,属强毒力毒株。 相似文献
2.
《河南职业技术师范学院学报(职业教育版)》2016,(3)
为了探究雏鸡感染传染性法氏囊病毒(IBDV)后盲肠扁桃体病理组织学变化的发展规律,用实验室保存的IBDV毒株感染19日龄雏鸡,分别在感染后0 h、24 h、48 h、72 h、96 h、120 h、144 h、168 h、192 h取盲肠扁桃体,通过石蜡切片、HE染色,观察盲肠扁桃体的病理组织学变化.结果表明:在IBDV感染24 h,盲肠扁桃体淋巴小结内淋巴细胞开始出现坏死凋亡;IBDV感染48~72 h,淋巴小结和弥散淋巴组织区淋巴细胞大量减少,空泡化程度严重;IBDV感染96 h,盲肠扁桃体固有层弥散淋巴组织区和淋巴小结内空泡减少,淋巴细胞增多;IBDV感染120~192 h,组织结构开始恢复正常形态.由IBDV感染造成的雏鸡盲肠扁桃体的损伤在感染72 h后最为严重,96 h后开始恢复. 相似文献
3.
鸽I型副粘病毒 (PPMV Ⅰ )JS株的尿囊液毒 ,经 1 0倍连续稀释后分别接种鸡成纤维细胞和非免疫鸡胚 ,测定其半数细胞培养感染量 (TCID50 )和鸡胚半数感染量 (EID50 )。结果显示 ,JS株TCID50 为 1 0 - 9.33/0 .1mL ,EID50 为 1 0 - 9.375/0 .1mL ,表明JS株病毒对鸡胚和鸡胚成纤维细胞的易感性相近。 相似文献
4.
选择 2 10只 1日龄新罗曼商品健康公鸡 ,随机分为 3组 ,每组 70只 ,研究日粮添加免疫生长促进剂C96和亚硒酸钠对鸡增重和睾丸发育影响。结果表明 :(1) 12 0d试验期 ,Se组 (0 .6 5mgSe/kg饲料 )和C96组 (11mgC96/kg饲料 )鸡体重均高于对照组 ,Se组 95d时显著性差异 (P <0 .0 5 ) ;Se组和C96组鸡体重和日增重差异不显著。 (2 )各组鸡睾丸发育均呈持续增长 ,睾丸重和睾丸相对系数 (睾丸重 /体重 ) ,30 - 95dSe组和C96组鸡均高于对照组 ,6 5d和Se组鸡睾丸相对系数显著高于对照组 (P <0 .0 5 ) .C96组鸡睾丸发育强度有高于Se组的趋势 ,但差异不显著 (P >0 .0 5 )。 相似文献
5.
8 0羽 2 1日龄罗曼蛋公鸡随机分成试验与对照两组 ,研究雏鸡在 2 1日龄人工感染E .tenella后第 1、2、3、4、5、6、7、8天鸡嗜酸性细胞的动态变化。结果表明 :感染E .tenella之后 ,试验组比对照组嗜酸性细胞明显增多 ,每日组间差异均极显著 (P <0 .0 1 ) ;在感染后第 1～6天 ,试验组日间差异不显著 (P >0 .0 5 ) ,在感染后第 6～ 7天 ,试验组日间差异极显著 (P <0 .0 1 ) ,而在感染后第 7～ 8天日间差异显著 (P <0 .0 5 )。 相似文献
6.
7.
孵化至18d的肉仔鸡活胚蛋240枚,随机分成4个处理组,每组6个重复,每个重复10枚蛋。处理组Ⅰ羊膜腔注射1mL0．75％生理盐水作为对照,处理组Ⅱ、Ⅲ、Ⅳ分别向羊膜腔内注射质量浓度为0．5％、1．0％、1．5％的谷氨酰胺营养液1mL。继续孵化及出壳后分析表明：胚胎注射对胚蛋孵化率没有影响（P〉0。05％）;胚胎注射谷氨酰胺对肉仔鸡出壳重和出壳重／蛋重无显著影响（P〉O．05）;出壳后第3天,试验组体重较对照组有提高的趋势（P〉0．05）,出壳后第7天,1．0％注射组体重比对照组提高10．89％（P〈0．01）,1．5％注射组较对照组体重增加7．33％（P〈O．05）;3日龄肉仔鸡0．5％注射组血浆T4含量较对照组提高23．67％（P〈0．05）;7日龄肉仔鸡1．0％和1．5％注射组血浆T3含量比对照组分别提高了36．63％和26．16％（P〈0．05）。总之,鸡胚注射G1n可促进肉仔鸡早期生长发育,注射对胚蛋孵化率及出壳重无明显影响。 相似文献
8.
1999年11月安阳某种鸽场饲养美国王鸽陆续出现死亡，为查清病因，我们用病死鸽进行细菌培养呈阴性，取脾脏病料接种SPF鸡胚分离到新城疫病毒，对病毒的部分特性进行测定，结果报告如下：1 材料与方法1.1 SPF鸡胚及SPF鸡山东家禽研究所提供，鸽由某鸽场提供。NDV、EDS-76病毒，禽流感病毒(AIVH9亚型)PMV-2血清均由中国农大动物医学院提供。1.2 病料处理取脾脏加适量灭菌PBS剪碎后用玻璃研磨器研磨，4℃8000r／min离心20min，取上清液经220nm针头滤器滤过后，即成脾悬液。1.3 鸡胚接种接种10日龄SPF鸡胚(尿囊腔途径0．2ml／枚)收集尿囊液进行HA和HI试验。 相似文献
9.
余亮彬 《黄冈职业技术学院学报》2004,6(3):65-67
选用一日龄艾维因鸡180只,随机分成6组,每组30只,对其中四组日粮分别加入23ppm、25ppm、27ppm的抗球I号与5ppm的马杜霉素(Maduramicin ameonium),另外两组分别为阴、阳性空白对照组,对其进行抗球虫效果比较试验.试验结果表明以上三种不同剂量的抗球I号药组均具有非常有效的抗球虫效果(ACI均在180以上),而5ppm的马杜霉素组只有中等的抗球虫效果(ACI只有1(71),在全期增重量效果上,以23ppm的抗球I号药组最佳(平均只增重1.895kg)与5ppm马杜霉素组(1.645kg)比较,差异极显(P<0.001);与未曾感染鸡球虫病的阴性对照组(1.840kg)比较,差异不明显(F<1,P>0.05).因此建议选用23ppm的抗球I号用于防治肉鸡的球虫病具有良好效果. 相似文献
10.
选用健康的 36头“大×长×杜”仔猪 ,随机分为三组 ,不同来源的猪用预混料按 4 %的比例分别添加到各试验基础日粮中 ,试验期为 2 5天。结果表明三组仔猪的日增重依次为Ⅰ组 6 4 3G、Ⅱ组为 6 5 5G、Ⅲ组为 6 0 4G ,Ⅰ、Ⅱ组之间差异不显著 (P >0 0 5 ) ,Ⅰ、Ⅱ组与Ⅲ组间的差异显著 (P <0 0 1) ;三组仔猪的平均料重比分别为 198、196、2 14,增重 1KG分别消耗预混料成本 0 .6 1元、0 .5 2元和 0 5 1元 ,三组饲喂养效果以Ⅱ组仔猪的生长速度最快 ,Ⅲ组预混料成本最低 ,Ⅱ组的料重比低于Ⅲ组 ,日增重高于Ⅲ。 相似文献
11.
罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
12.
Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
13.
Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
14.
15.
16.
《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
17.
陈美曦 《山东教育学院学报》2008,23(2):103-107
Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language. 相似文献
18.
邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
19.
《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
20.
Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献