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91.
92.
犬冠状病毒病的免疫预防研究进展 总被引:1,自引:0,他引:1
犬冠状病毒病是由犬冠状病毒引起的以胃肠炎为主的一种高度接触性传染病,对幼犬危害尤其严重,发病率和死亡率都很高,是目前对养犬业危害较大的疾病之一.文章就犬冠状病毒感染的流行病学、发病机理、机体免疫、免疫程序和免疫预防进行了综述,特别是对犬冠状病毒病的免疫类型、疫苗种类以及免疫预防存在的问题进行了详细阐述. 相似文献
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94.
狂犬病是由狂犬病病毒引起的一种重要的人兽共患传染病,在人主要表现为急性、几乎不可逆转的脑脊髓炎,目前没有有效的治疗方法,病死率几乎100%。目前对狂犬病病毒感染和狂犬病发病机理的认识还很不透彻,但近年来的研究也取得了不少进展,主要涉及狂犬病病毒受体、神经细胞功能失调的原因和神经细胞凋亡机制、狂犬病病毒与机体免疫系统相互作用机制,狂暴型和麻痹型狂犬病的发病机制,这些都将为狂犬病的治疗研究起到推动作用。 相似文献
95.
Ravi M Ngeleka M Kim SH Gyles C Berthiaume F Mourez M Middleton D Simko E 《Veterinary microbiology》2007,120(3-4):308-319
In order to evaluate the role of the AIDA-I of porcine diarrheagenic Escherichia coli strain PD20 serogroup O143 (AIDA-I+, STb+), a mutant strain PD20M (AIDA-I−, STb+) was generated from strain PD20 by an allelic exchange procedure. In addition, the full-length aidA gene was reintroduced into strain PD20M to generate the complemented strain PD20C (pTaidA, AIDA-I+, STb+). A non-pathogenic E. coli strain PD71 was used as negative control. Each strain was inoculated to newborn pigs via stomach tube. Severity of diarrhea was evaluated clinically and intestinal colonization was assessed by histology, immunohistochemistry (IHC), and transmission electron microscopy (TEM) including immunogold electron microscopy (IGEM). The adhesion pattern to HeLa cells, bacterial auto-aggregation and biofilm formation were evaluated in vitro. Pigs infected with strains PD20 or PD20C developed diarrhea 16 and 28 h after inoculation, respectively, in contrast to pigs infected with strains PD20M or PD71. Histology, IHC, TEM and IGEM examinations showed heavy bacterial colonization with biofilm formation in the large intestine, and marked in vivo expression of AIDA-I protein in pigs infected with strains PD20 or PD20C in contrast to pigs infected with strains PD20M or PD71. The in vitro assays showed marked diffuse adherence to HeLa cells, enhanced bacterial auto-aggregation and significant biofilm formation (p < 0.05) by the AIDA-I+ strains, when compared to AIDA-I− strains. These results demonstrate that expression of AIDA-I is essential for intestinal colonization and in vitro bacterial autoaggregation and biofilm formation. Thus, AIDA-I may be considered a significant virulence determinant in development of diarrhea caused by porcine diarrheagenic AIDA-I+ E. coli PD20 in piglets. 相似文献
96.
Ganesh K Raghavan R Gowda RN Satyanarayana ML Suryanarayana VV 《Tropical animal health and production》2002,34(1):7-17
Hydropericardium hepatitis syndrome in broiler chickens is an acute, infectious disease characterized by high mortality, excess pericardial fluid and multifocal hepatic necrosis. The aetiological agent was purified to homogeneity from infected liver tissues from field outbreaks. Electron-microscopic and serological confirmation of the virus were undertaken and the disease was reproduced experimentally in broiler chicks. The results indicated that an adenovirus, fowl adenovirus serotype 4, was alone responsible for the disease in the materials studied. 相似文献
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98.
Clinton F. Hodges Douglas A. Campbell 《European journal of plant pathology / European Foundation for Plant Pathology》1999,105(8):825-829
Infection of Poa pratensis leaf blades and callus tissue by Bipolaris sorokiniana increases the production of ethylene and ethane. The ethylene is responsible for most of the chlorosis that occurs during pathogenesis. The nonselective toxin(s) produced by B. sorokiniana is known to disrupt membranes and to damage chlorophyll, but it is not known whether it can induce an increase in ethylene or ethane. Research was initiated to determine the effect of a biologically-active extract of B. sorokiniana on the endogenous ethylene and ethane of intact P. pratensis leaf blades and on subsequent development of chlorosis. The extract did not increase endogenous ethylene of treated leaves, but it was associated with an increase in endogenous ethane between 24 and 96h after treatment. Chlorophyll loss occurred 96h after treatment and persisted for the duration of the study (168h). The chlorophyll content of treated leaf blades ranged from 72% to 80% of control leaf blades. The observations suggest that the extract of B. sorokiniana can induce chlorophyll loss from treated leaf blades independent of an increase in endogenous ethylene by directly damaging chloroplasts with a concurrent release of ethane. The ethane is believed to be a by-product of pathogenesis. 相似文献
99.
The right mammary gland of 12 lactating goats was inoculated intracisternally with 1 ml of Mycoplasma capricolum subsp. capripneumoniae (Mcc) containing 10>6 colony-forming units (CFU), while their left mammary halves received 1 ml of sterile PPLO broth only. Two goats served as uninfected controls. The clinical mastitis that developed in the infected mammary halves within 24 h was initially acute but became increasingly chronic by the end of the experiment at 24 days post inoculation (DPI). The disease was characterized by atrophy of the infected mammary halves, leading to marked agalactia and an increase in somatic cell counts, with a preponderance of neutrophils initially and lymphocytes later. The Mycoplasma was re-isolated from infected mammary secretions up to 16 DPI but not from blood. Histopathology revealed that the mastitis was acute and purulent initially, followed by infiltration of lymphonuclear cells and fibroplasia in the lymphomononuclear cells and fibroplasia in the interacinar tissue, and later by massive fibrosis. Immunohistology demonstrated the presence of Mycoplasma-like bodies localized mainly on the surface of acinar/duct epithelial cells. The studies showed that Mcc was highly pathogenic in the caprine mammary gland. 相似文献
100.
口腔黏膜下纤维性变(Oral Submucous Fibrosis,OSF)是一种以炎症和渐进性黏膜改变导致进行性张口困难为特征的口腔黏膜慢性病症.近年来相当多的流行病学研究资料指出槟榔是OSF的主要病源因子,在OSF的发病上,不论是嚼食槟榔的频率还是持续的时间都呈现了剂量依赖性.在嚼食槟榔时粗糙纤维对口腔黏膜产生的强烈机械刺激作用、槟榔中的生物碱与单宁对细胞外基质分子的影响以及槟榔中的铜在纤维化疾病中的作用等方面对槟榔在OSF发病原因与发病机制中的作用加以综述,旨在分析迄今为止国内外学者对槟榔在OSF上所做的研究,以期让基础科研人员、公共卫生工作者以及广大槟榔嗜好者对槟榔在人类OSF中的作用有更深入的了解. 相似文献