全文获取类型
收费全文 | 408篇 |
免费 | 19篇 |
国内免费 | 61篇 |
专业分类
林业 | 1篇 |
农学 | 11篇 |
3篇 | |
综合类 | 137篇 |
农作物 | 5篇 |
水产渔业 | 19篇 |
畜牧兽医 | 310篇 |
园艺 | 2篇 |
出版年
2022年 | 7篇 |
2021年 | 3篇 |
2020年 | 7篇 |
2019年 | 12篇 |
2018年 | 9篇 |
2017年 | 15篇 |
2016年 | 16篇 |
2015年 | 19篇 |
2014年 | 12篇 |
2013年 | 20篇 |
2012年 | 23篇 |
2011年 | 38篇 |
2010年 | 28篇 |
2009年 | 27篇 |
2008年 | 31篇 |
2007年 | 30篇 |
2006年 | 26篇 |
2005年 | 25篇 |
2004年 | 13篇 |
2003年 | 12篇 |
2002年 | 5篇 |
2001年 | 12篇 |
2000年 | 10篇 |
1999年 | 12篇 |
1998年 | 16篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1993年 | 8篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 6篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1956年 | 2篇 |
排序方式: 共有488条查询结果,搜索用时 16 毫秒
21.
22.
23.
B Larsson 《Acta veterinaria Scandinavica》1988,29(1):1-8
Recent research has shown that cattle that develop mucosal disease (MD) often, if not always, have been persistently infected with bovine viral diarrhea virus (BVDV) since birth. The purpose of the present study was to determine whether MD could be induced by immunosuppression of persistently BVDV-infected cattle. For that purpose, adrenocorticotropic hormone (ACTH) was injected intramuscularly, twice daily for 5 consecutive days in 4 persistently BVDV-infected cattle and in 3 control cattle. Before the ACTH treatment, the numbers of leukocytes, neutrophils and mononuclear cells (MNC) per litre of blood in BVDV-infected cattle were in the same range as in the controls. Similarly, the proportions of B cells, T cells, monocytes and Fcγ+ cells (cells with receptor for the Fc part of IgG) were the same in the 2 groups of animals. On the other hand, the proliferative response to mitogen stimulation of MNC obtained from the control animals was twice as high as the corresponding value of the persistently BVDV-infected cattle.In all animals, ACTH treatment caused increased Cortisol concentrations, leukocytosis, neutrophilia and decreased mitogen-induced lymphocyte stimulation. However, the MNC count and the proportions of B cells, T cells, Fcγ+ cells and monocytes remained unaltered. In spite of the immunosuppression, indicated by the decrease in mitogen-induced lymphocyte stimulation. ACTH treatment did not provoke any clinical signs of MD in the persistently BVDV-infected cattle. 相似文献
24.
本研究用禽波氏杆菌(Bordetella avium,B.avium)和禽网状内皮增生症病毒(reticuloendotheliosis virus,REV)人工感染SPF鸡胚和SPF雏鸡后,测定鸡胚死亡率和孵化率,检测SPF雏鸡的免疫器官指数、淋巴细胞比率和淋巴细胞转化率(LTR),探究REV和B.avium共感染对SPF鸡免疫系统的影响.结果显示,二者同时感染时鸡胚的孵化率只有27.85%,且SPF雏鸡的免疫器官指数和淋巴细胞转化率(LTR)显著低于正常对照组.因此,B.avium和REV共感染可造成SPF鸡胚孵化率大幅降低、1日龄SPF雏鸡免疫系统严重损伤及免疫功能低下. 相似文献
25.
Lin CM Jeng CR Chang HW Guo IC Huang YL Tsai YC Chia MY Pang VF 《Veterinary immunology and immunopathology》2008,124(3-4):355-366
Information regarding the susceptibility of swine lymphocytes to PCV2 is rather limited. To further explore and characterize the PCV2 infection in swine lymphocytes, an in vitro model using concanavalin A (Con A)-stimulated peripheral blood lymphocytes (PBLs) obtained from clinically healthy PCV2-carrier pigs was introduced. It was found that the PCV2 antigen-containing rate was below 2% in PBLs from healthy PCV2-free pigs following treated simultaneously with Con A and PCV2. However, significantly higher PCV2 antigen- and nucleic acid-containing rates could be seen in Con A-stimulated PBLs from clinically healthy PCV2-carrier pigs. Prior to Con A treatment, both of the PCV2 antigen- and nucleic acid-containing rates in PBLs from healthy PCV2-carrier pigs were less than 1%; however, they reached 22.1+/-5.7% by flow cytometry and 27.1+/-6.5% by in situ hybridization, respectively, at 4-day post-incubation with Con A. Phenotyping of PCV2 antigen-containing cells revealed that PCV2-positive cells could be detected in both T and B lymphocyte populations within which IgM-positive B lymphocytes appeared to have a relatively higher positive rate. The Con A-stimulated PBLs also displayed a significantly higher viral load by the measurement of either PCV2 DNA copy number or viral titer when compared with the non-treated PBLs from healthy PCV2-carrier pigs. The results indicate that PBLs, especially IgM-bearing B lymphocytes, are indeed susceptible to PCV2 infection and PCV2 is capable of replicating in dividing lymphocytes. This activation-induced replication may explain in part the pathogenesis of lymphoid depletion in PMWS-affected pigs. 相似文献
26.
本试验旨在比较3种植物多糖对鸡外周血T淋巴细胞和脾脏B淋巴细胞体外增强免疫活性的研究.通过酶学检测法测定3种植物多糖对鸡胚成纤维细胞的安全浓度,MTT法比较3种植物多糖单独刺激和PHA协同刺激对鸡外周血T淋巴细胞增殖指数的影响,同时比较3种植物多糖单独刺激及与LPS协同刺激对鸡脾脏B淋巴细胞增殖率的影响.结果显示,黄芪多糖和桑叶多糖具有较高的细胞安全浓度,在64~512 μg/mL时,3种植物多糖对鸡外周血T淋巴细胞和脾脏B淋巴细胞的增殖作用较强.结果表明,3种植物多糖对鸡外周血和脾脏淋巴细胞都有不同程度的体外增殖作用,其中黄芪多糖的增殖作用最强,桑叶多糖其次,山药多糖最差. 相似文献
27.
以免疫信息学和反向疫苗学为理论根据,利用RT-PCR法获得了猪水泡病病毒(SVDV)HK/70株的基因组序列并测序,应用生物信息学相关软件和方法,对SVDV结构蛋白的二级结构的不同方面及其抗原特异性淋巴细胞表位进行了预测,综合评价了SVDV结构蛋白的抗原特异性细胞表位,并计算出一些潜在的抗原位点。结果表明,VP1蛋白含有的细胞优势抗原表位最多,但其他结构蛋白也含有抗原特异性淋巴细胞表位,有的甚至有可能成为优势抗原表位或对优势抗原表位有协同作用。 相似文献
28.
目的:探讨口服"开口健"对小鼠淋巴细胞功能以及营养生长因子的影响。方法:36只ICR小鼠随机分为4组,即生理盐水组",开口健"低、中、高剂量组。给小鼠连续灌胃10 d后,用MTT法检测淋巴细胞刺激指数,RT-PCR方法检测ConA刺激后淋巴细胞产生的IL-4、IL-10、IL-12和INF-γmRNA水平,ELISA方法检测小鼠血清胰岛素样生长因子(IGF-1)和生长激素释放肽(Ghrelin)水平。结果:口服"开口健"小鼠脾脏淋巴细胞SI显著高于对照组(P〈0.01),并随"开口健"剂量的增加而升高;口服"开口健"小鼠脾脏淋巴细胞产生IL-4、IL-10、IL-12和IFN-γmRNA水平显著高于对照组(P〈0.05)。口服"开口健"显著提高了小鼠血清的IGF-1和Ghrelin水平(P〈0.05),且与"开口健"剂量呈正相关性。结论:口服"开口健"可增强小鼠淋巴细胞功能并提高血清营养生长因子水平。 相似文献
29.
为可溶性表达重组鸡粒细胞巨噬细胞集落刺激因子(ChGM-CSF)与猪干扰素α1(PoIFNα1)融合蛋白,并研究其生物学活性,本研究分别提取鸡、猪肝脏细胞总RNA,采用RT-PCR方法扩增ChGM-CSF和PoIFNα1基因,经linker连接上述两种基因后将其克隆于pET-32a原核表达载体,转化E.coliBL21(DE3)菌株进行诱导表达,SDS-PAGE和western blot检测融合蛋白表达产物。在ST细胞/VSV病毒测定系统以细胞病变抑制法滴定该融合蛋白的抗病毒活性;同时用MTT法检测其对鸡淋巴细胞增殖活性的促进作用。结果显示,PCR扩增并融合后的ChGM-CSF和PoIFNα1融合基因约为1000bp,构建重组表达载体后,诱导表达的rChGM-CSF-PoIFNα1融合蛋白分子量约55ku,主要存在于破碎菌体的上清中,表达量较高。Westernblot检测结果显示,该融合蛋白分别能够与ChGM-CSF多抗和PoIFNα单克隆抗体特异性结合,其抗病毒比活性约为1.1×10^6IU/mg,并且具有促进鸡淋巴细胞增殖的活性。本研究为rChGM-CSF-PoIFNα1重组融合蛋白的研制及其相关活性的测定提供实验依据。 相似文献
30.
This case report describes tuberculosis (TB) due to infection with Mycobacterium bovis (M. bovis) in alpaca (Lama pacos) on a farm in Ireland. Two severely debilitated alpaca were presented to the University Veterinary Hospital, University College Dublin in November 2004. Bloods were taken, and haematology and biochemistry results were indicative of chronic infection. Radiological examination showed evidence of diffuse granulomatous pneumonia suggestive of tuberculosis. On necropsy there were granulomatous lesions present throughout many body organs including lung, liver, kidney, intestine as well on peritoneum and mesentery. Culture of acid-fast bacilli from lesions led to a diagnosis of tuberculosis due to M. bovis. The use of intradermal skin testing proved inefficient and unreliable for ante mortem diagnosis of tuberculosis in alpaca. Infection due to M. bovis should be considered among the differential diagnoses of debilitating diseases in alpaca, particularly those farmed in areas known to be traditional black spots for tuberculosis in cattle. 相似文献