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   3796篇
  免费   92篇
  国内免费   1篇
林业   2226篇
农学   28篇
基础科学   5篇
  184篇
综合类   15篇
农作物   196篇
水产渔业   54篇
畜牧兽医   878篇
园艺   41篇
植物保护   262篇
  2014年   37篇
  2013年   118篇
  2012年   37篇
  2011年   32篇
  2010年   51篇
  2009年   49篇
  2008年   35篇
  2006年   38篇
  2005年   78篇
  2004年   82篇
  2003年   62篇
  2002年   51篇
  2001年   35篇
  1997年   49篇
  1996年   77篇
  1995年   52篇
  1994年   56篇
  1993年   64篇
  1992年   75篇
  1991年   52篇
  1990年   43篇
  1989年   39篇
  1988年   44篇
  1987年   38篇
  1986年   50篇
  1985年   32篇
  1984年   50篇
  1983年   51篇
  1982年   61篇
  1981年   110篇
  1980年   52篇
  1979年   84篇
  1978年   43篇
  1954年   45篇
  1953年   66篇
  1938年   66篇
  1937年   55篇
  1936年   49篇
  1935年   49篇
  1934年   49篇
  1933年   54篇
  1932年   49篇
  1931年   41篇
  1930年   43篇
  1929年   35篇
  1928年   37篇
  1927年   47篇
  1926年   74篇
  1925年   56篇
  1898年   33篇
排序方式: 共有3889条查询结果,搜索用时 31 毫秒
51.
52.
53.
54.
55.

Objective

To describe hemostatic derangements associated with canine anaphylaxis and to assess for association with syndrome severity.

Design

Prospective observational study.

Setting

University teaching hospital.

Animals

Twenty-seven client-owned dogs, recruited from November 2018 to January 2022, diagnosed with anaphylaxis of varying severity were included. Study inclusion required presentation <6 hours after initiation of clinical signs, no medications or history of illness within the prior 2 weeks, lack of comorbidities expected to affect hemostasis, and lack of a disease state that could alternatively explain the clinical presentation.

Interventions

Blood samples were collected within the first hour of presentation for CBC, serum biochemistry, prothrombin time (PT), activated partial thromboplastin time (aPTT), and viscoelastic coagulation testing for use with a cartridge-based point-of-care device.

Measurements and main results

Clotting time and clot formation time were prolonged, alpha angle and maximum clot firmness were decreased, PT and aPTT were prolonged, and platelet counts were lower in severe cases compared to mild and moderate cases. There were no differences for any parameter between mild and moderate cases. The presence or absence of abdominal effusion was not associated with hemostatic status.

Conclusions

Global hemostatic derangements consistent with hypocoagulability are a prominent feature of severe anaphylaxis in dogs and should be considered for routine evaluation.  相似文献   
56.
57.
58.
After immunization of four calves with a live modified Mycobacterium paratuberculosis vaccine the course of the humoral and cell mediated immune reactions was studied during a 2-year clinical investigation. Furthermore, the possibility of shedding of the vaccine strain and the influence of the vaccination on the tuberculin skin test was determined. In addition to standard procedures recently developed diagnostic methods (antibody enzyme-linked immunosorbent assay, interferon-gamma test, polymerase chain reaction) were used. A cell-mediated immune reaction, reflected in an increased, specifically induced, interferon-gamma production developed much earlier (1-2 weeks post-immunization) than humoral immunity (8-16 weeks post-gamma immunization). While the increase in antibody titres was transient, declining to extremely low levels 48-60 weeks post-immunization, cell-mediated immunity remained detectable until the end of the investigation. Spread of the vaccine strain into the body and shedding were never detected during the whole course of the study except for one colon site in one calf. As late as 2 years after vaccine application positive or doubtful skin reactions against M. bovis purified protein derivative were measured, reflecting possible interference of the immunization with the diagnosis of bovine tuberculosis. At the end of the investigation, a positive cell-mediated immune reaction was detected the control animal although clinical, pathological and bacteriological examinations gave no indication for a mycobacterial infection.  相似文献   
59.
60.
Objective: This review discusses the different analgesic drugs and routes of administration used in large animals for acute pain management. General guidelines and doses are given to assist in choosing techniques that provide effective analgesia. Etiology: Noxious stimuli are perceived, recognized, and localized by specialized sensory systems located at spinal and supraspinal levels. Diagnosis: Localizing the source of the noxious stimulus as well as understanding the behavioral aspects and physiological changes that result from such insult is important to adequately diagnose and treat pain. Pain assessment is far from being definite and objective; not only are there species differences, but also individual variation. In addition, the behavioral and physiological manifestations vary with the acute or chronic nature of pain. Therapy: Pain management should include (1) selecting drugs that better control the type of pain elicited by the insult; (2) selecting techniques of analgesic drug administration that act on pathways or anatomical locations where the nociceptive information is being processed or originating from; (3) combining analgesic drugs that act on different pain pathways; and (4) provide the best possible comfort for the animal. Prognosis: Providing pain relief improves the animal's well being and outcome; however, interpreting and diagnosing pain remains difficult. Continuing research in pain management will contribute to the evaluation of the pathophysiology of pain, pain assessment, and newer analgesic drugs and techniques.  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