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   412篇
  免费   13篇
林业   4篇
农学   9篇
  86篇
综合类   38篇
农作物   16篇
水产渔业   19篇
畜牧兽医   219篇
园艺   7篇
植物保护   27篇
  2023年   3篇
  2022年   3篇
  2021年   11篇
  2020年   14篇
  2019年   11篇
  2018年   10篇
  2017年   6篇
  2016年   9篇
  2015年   8篇
  2014年   11篇
  2013年   16篇
  2012年   32篇
  2011年   24篇
  2010年   16篇
  2009年   12篇
  2008年   22篇
  2007年   27篇
  2006年   27篇
  2005年   31篇
  2004年   20篇
  2003年   27篇
  2002年   24篇
  2001年   3篇
  2000年   5篇
  1999年   4篇
  1998年   3篇
  1997年   6篇
  1996年   1篇
  1995年   6篇
  1994年   4篇
  1993年   1篇
  1992年   3篇
  1991年   3篇
  1989年   4篇
  1988年   4篇
  1987年   2篇
  1986年   3篇
  1983年   2篇
  1981年   1篇
  1976年   2篇
  1975年   2篇
  1973年   1篇
  1971年   1篇
排序方式: 共有425条查询结果,搜索用时 156 毫秒
91.
92.
A nutritional plan should be incorporated into every treatment plan of the critically ill patient. Weight loss and cachexia are the result of prevalence of catabolic processes over anabolic processes in addition to absolute or relative increased demands and decreased food intake.  相似文献   
93.
Portable ultrasound imaging was examined as a noninvasive measure of skin including blubber thickness in captive subadult Steller sea lions (Eumetopias jubatus) and adult harbor seals (Phoca vitulina). This method was validated through comparison with blubber biopsy. Ultrasound images provided depth measurements that were accurate to 99.8% of the actual. This method allowed clear images of the epidermis, dermis, and blubber layer to be rapidly obtained, with minimal animal restraint, and allowed differentiation of phocid and otariid blubber structure.  相似文献   
94.
Objective: To describe a case of fatal anaphylaxis in a dog associated with a ‘routine’ dexamethasone suppression test. Case summary: An 8‐year‐old, spayed female dog, was treated with parenteral dexamethasone for a diagnosis of immune‐mediated thrombocytopenia. The dog had responded to treatment, but 9 months later was evaluated for endogenous hyperadrenocorticism, prior to surgery for a ruptured anterior cruciate ligament. A normal ACTH stimulation test was followed by a high‐dose dexamethasone suppression test. Immediately following the intravenous injection of dexamethasone, the dog developed severe anaphylactic shock and died. The postmortem examination findings supported the diagnosis of anaphylaxis. New information provided: The anaphylaxis in this dog was fulminating and by‐passed the usual early signs of drug hypersensitivity. This is the first case in the veterinary literature reporting on dexamethasone as the cause of this dog's catastrophic event.  相似文献   
95.
Multifocal hyperemic nodules and plaques associated with the cloacal mucosa of juvenile alligators (Alligator mississippiensis) at a public aquarium were investigated. Grossly, pale pink to dark red multifocal, circular lesions of varying degrees of severity were identified on the cloacal and, in males, phallus mucosa. Cloacal mucosa biopsies were obtained from 2 of the alligators. These samples were examined histologically and by polymerase chain reaction (PCR) using consensus primers targeting a conserved region of the herpesvirus polymerase gene. Microscopically, the lesions were characterized as submucosal lymphoid follicles with hyperemia and hemorrhage. No inclusion bodies were observed. Minimal to no anisokaryosis was present, and no etiologic agents were identified. Through PCR, a band consistent in size with herpesvirus was observed. Tissues showing similar clinical, histopathologic, and PCR findings were collected from animals at an alligator farm several months later. Sequencing of the PCR amplicon resulted in a 180-base pair sequence that shared 85% sequence identity with tortoise herpesvirus-1.  相似文献   
96.
A 10-yr-old female black bear (Ursus americanus) at the North Carolina Zoological Park presented with a 2-wk history of intermittent coughing and stertor. The animal was anesthetized for examination, and at intubation, a large mass associated with the tonsils and larynx was observed obstructing the airway. Cardiopulmonary collapse occurred during the procedure, and efforts at resuscitation were ineffective. At necropsy, an 8 cm times 6 cm times 5 cm mass was present in the larynx, infiltrating the epiglottis and obstructing the airway. Regional lymph nodes were mildly enlarged and contained tan inspissated substance. Histologically, the neoplasm was composed of nests of keratinizing squamous epithelial cells with evidence of lymphatic invasion and metastases to regional lymph nodes.  相似文献   
97.

Background  

Transient assays using protoplasts are ideal for processing large quantities of genetic data coming out of hi-throughput assays. Previously, protoplasts have routinely been prepared from dicot tissue or cell suspension cultures and yet a good system for rice protoplast isolation and manipulation is lacking.  相似文献   
98.
OBJECTIVE: To detect subclinical disseminated intravascular coagulation (DIC) in horses with colitis and to determine any association between the diagnosis of subclinical DIC and outcome or occurrence of complications in horses with colitis. DESIGN: Prospective study. ANIMALS: 37 horses admitted to a veterinary teaching hospital for treatment of acute colitis. PROCEDURE: Coagulation profiles were obtained on each horse 0, 24, and 48 hours after admission. Six tests were performed: platelet count, plasma fibrinogen concentration, prothrombin time, activated partial thromboplastin time, antithrombin activity, and serum fibrin degradation products concentration. RESULTS: A clinicopathologic diagnosis of subclinical DIC was made if 3 of the 6 tests had abnormal results at any 1 sample period. No horse had clinical signs of DIC at the time of sampling. Twelve of 37 (32%) horses met the criteria for diagnosis of subclinical DIC within a 1-year period. Outcome was defined as survival or nonsurvival. Five of 12 horses with subclinical DIC and 2 of 25 horses without subclinical DIC did not survive. Crude odds ratio analysis revealed a horse with acute colitis was 8 times as likely to die or be euthanatized if a diagnosis of subclinical DIC was made. CONCLUSIONS AND CLINICAL RELEVANCE: Clinicopathologic evidence of DIC is common and is significantly associated with a poor outcome in horses with acute colitis. Treatment of subclinical DIC may influence outcome in horses with acute colitis.  相似文献   
99.
100.
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