首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   432篇
  免费   45篇
林业   22篇
农学   17篇
基础科学   7篇
  38篇
综合类   81篇
农作物   3篇
水产渔业   32篇
畜牧兽医   253篇
园艺   1篇
植物保护   23篇
  2021年   5篇
  2020年   6篇
  2019年   7篇
  2018年   5篇
  2017年   13篇
  2016年   11篇
  2015年   7篇
  2014年   11篇
  2013年   30篇
  2012年   9篇
  2011年   16篇
  2010年   10篇
  2009年   4篇
  2008年   19篇
  2007年   20篇
  2006年   15篇
  2005年   13篇
  2004年   10篇
  2003年   10篇
  2002年   6篇
  2001年   14篇
  2000年   8篇
  1999年   9篇
  1998年   17篇
  1997年   5篇
  1996年   9篇
  1995年   9篇
  1994年   5篇
  1993年   6篇
  1992年   5篇
  1991年   5篇
  1990年   6篇
  1989年   11篇
  1988年   6篇
  1987年   6篇
  1986年   7篇
  1981年   3篇
  1979年   3篇
  1976年   6篇
  1975年   3篇
  1974年   7篇
  1973年   8篇
  1972年   3篇
  1971年   8篇
  1970年   9篇
  1969年   9篇
  1968年   16篇
  1967年   5篇
  1966年   7篇
  1965年   5篇
排序方式: 共有477条查询结果,搜索用时 31 毫秒
1.
2.
Conidiobolus coronatus is one of the most commonly identified upper respiratory fungal pathogens in horses. This article includes a review of clinical signs, diagnostics, treatment and outcomes in previously reported cases of equine conidiobolomycosis, as well as six additional cases seen at our hospital. Each of the six horses presented with a complaint of serosanguinous or haemorrhagic nasal discharge and conidiobolomycosis was confirmed by histopathology and fungal culture. Five horses recovered after administration of antifungal drugs alone (n = 4) or in combination with extensive nasal septum resection (n = 1). Surgical treatment alone was ineffective. One horse was euthanised without treatment because of the extent of the disease.  相似文献   
3.
4.
5.
ABSTRACT Geminiviruses are a group of single-stranded DNA viruses that cause major losses on a number of important crops throughout the world. Bean golden mosaic virus (BGMV) is a typical bipartite, whitefly-transmitted geminivirus that causes a severe disease on beans (Phaseolus vulgaris) in the Western Hemisphere. The lack of natural resistance to geminiviruses has led to attempts to engineer resistance, particularly through the use of pathogen-derived resistance strategies. The rep gene contains several conserved domains including nucleoside triphosphate (NTP)-binding and DNA-nicking domains and is the only geminiviral gene necessary for replication. Previous analysis by our group and others has demonstrated that the NTP-binding and DNA-nicking domains are necessary for geminiviral DNA replication. The ability of the rep gene and rep gene mutants to interfere with geminiviral DNA replication, when expressed in trans, was examined using a transient assay in a tobacco suspension cell culture system. Wild-type (wt) and mutant rep genes were cloned into plasmids under the control of the cauliflower mosaic virus 35S promoter for in planta expression and coinoculated into tobacco cells with infectious clones of various geminiviruses. The wt rep gene from BGMV-GA was able to support replication of BGMV-GA DNA-B. Several different rep gene mutants, with function-abolishing mutations in the NTP-binding or DNA-nicking domains, were potent trans-dominant inhibitors of geminiviral DNA replication.  相似文献   
6.
7.
8.
9.
10.
OBJECTIVE: To evaluate short-term hemodynamic effects of ecadotril in a model of congestive heart failure in dogs. ANIMALS: 6 conscious adult male dogs. PROCEDURES: Instruments were placed in dogs to measure left ventricular, aortic, and atrial blood pressures. Heart failure was induced by repeated coronary embolization with latex microspheres. Four times, and in random order, dogs were given vehicle or active drug (3, 10, or 30 mg/kg of body weight) orally. Hemodynamic variables, urine flow, and urinary electrolyte excretion were measured before and 30, 90, and 150 minutes, and 10 and 21 hours after drug administration. RESULTS: Changes in urine flow, heart rate, mean arterial pressure, or peak positive and negative rate of change in ventricular pressure were not apparent. Urinary sodium excretion significantly increased in response to the low and high doses of ecadotril but not in response to the 10 mg/kg dose. Left ventricular end diastolic pressure (LVEDP) consistently decreased in dose- and time-dependent manner. Maximal group-averaged reductions in LVEDP were 5.2, 8.1, and 10 mm Hg for the low, middle, and high doses, respectively. The magnitude of the decrease in LVEDP was not related to cumulative change in urine flow. CONCLUSIONS AND CLINICAL RELEVANCE: Orally administered ecadotril reduced left ventricular filling pressures in these dogs by a mechanism that does not require a substantial diuretic effect. Ecadotril may be effective for alleviating clinical signs in dogs with left-sided heart failure and may be particularly beneficial for use in dogs that are refractory to traditional diuretic therapy.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号