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   33134篇
  免费   2579篇
  国内免费   98篇
耳鼻咽喉   387篇
儿科学   845篇
妇产科学   459篇
基础医学   4268篇
口腔科学   652篇
临床医学   3066篇
内科学   7105篇
皮肤病学   500篇
神经病学   3741篇
特种医学   1342篇
外国民族医学   3篇
外科学   4839篇
综合类   715篇
一般理论   70篇
预防医学   2935篇
眼科学   642篇
药学   2063篇
中国医学   20篇
肿瘤学   2159篇
  2023年   117篇
  2022年   197篇
  2021年   459篇
  2020年   276篇
  2019年   464篇
  2018年   596篇
  2017年   442篇
  2016年   509篇
  2015年   570篇
  2014年   872篇
  2013年   1364篇
  2012年   2072篇
  2011年   2219篇
  2010年   1192篇
  2009年   1129篇
  2008年   2119篇
  2007年   2234篇
  2006年   2215篇
  2005年   2419篇
  2004年   2138篇
  2003年   1952篇
  2002年   1988篇
  2001年   382篇
  2000年   314篇
  1999年   385篇
  1998年   441篇
  1997年   410篇
  1996年   396篇
  1995年   382篇
  1994年   300篇
  1993年   295篇
  1992年   294篇
  1991年   296篇
  1990年   276篇
  1989年   243篇
  1988年   207篇
  1987年   241篇
  1986年   203篇
  1985年   228篇
  1984年   268篇
  1983年   249篇
  1982年   296篇
  1981年   294篇
  1980年   248篇
  1979年   163篇
  1978年   167篇
  1977年   115篇
  1976年   146篇
  1975年   104篇
  1974年   120篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
Six of 175 Angus heifers died after ingesting excessive amounts of Durango root (Datisca glomerata). Animals had rumens full of Durango root, were extremely lethargic, and had diarrhea prior to death. The animals had nonspecific postmortem lesions. This case is discussed in light of previous findings from trials in which Durango root was experimentally fed to cattle.  相似文献   
32.
33.
34.
An outbreak of Salmonella dublin infection occurred in England and Wales in October to December 1989. Forty-two people were affected, mainly adults, and most lived in south-east England. Microbiological and epidemiological investigations implicated an imported Irish soft unpasteurized cows' milk cheese as the vehicle of infection. A case-control study showed a statistically significant association between infection and consumption of the suspect cheese (p = 0.001). Salmonella dublin was subsequently isolated from cheeses obtained from the manufacturer's premises. Initial control measures included the withdrawal of the cheese from retail sale and a Food Hazard Warning to Environmental Health Departments, as well as a press release, from the Department of Health. Subsequently, a decision was taken by the manufacturer to pasteurize milk used in the production of cheese for the UK market and importation of the cheese resumed in June 1990.  相似文献   
35.
Summary: We report a series of 8 patients with ictal déjà vu. Subdural strip electrocorticographic (ECoG) monitoring localized the ictal epileptogenic focus as follows: right (n = 6) and left (n = 2) mesiotemporal lobe. In all 8 patients, the left hemisphere was dominant for language function based on intracarotid amytal testing. In 6 right-handed patients, ictal déjà vu was associated with a right temporal lobe focus. However, in the 2 left-handed patients, the ictal focus was left temporal lobe. Although ictal déjà vu localizes the epileptic focus to temporal lobe, this experiential phenomenon appears to lateralize to the hemisphere nondominant for handedness.  相似文献   
36.
37.
In 6 patients with Parkinson's disease (PD) and 6 age-matched controls, transcranial magnetic stimulation was applied at 56 regions over the motor cortex and premotor cortex of each hemisphere, with the first dorsal interosseous (FDI) muscle of both hands activated at 15% maximum voluntary contraction during stimulation. For each site, motor evoked potential (MEP) landmarks were recovered, including MEP amplitude, MEP onset latency, and silent period duration. Scaled MEP amplitudes were used to construct individual cortical maps of the FDI muscles. The maps revealed an anterior displacement of the muscle representation in PD patients. This anterior shift over motor cortical areas may reflect increased contributions of corticocortical connections between motor cortex and premotor cortical areas, possibly enhanced by the visual feedback aspect of the task. These alterations may reflect adaptations to the impairments in striatocortical circuits in PD.  相似文献   
38.
39.
40.
Throughout history, societies have developed their own codes of ethics, including those pertaining to the practice of medicine. In the United States, physicians have adopted a set of ethics based on religious values and historical teachings. We, as physicians, have been presented several codes of ethics, including the American Medical Association Code of Ethics and the American College of Radiology Code of Ethics. Over time, we have learned to appropriately apply these codes to our daily practice. With the advent of new technologies in imaging, we may lose sight as to the transfer of these principles to reflect current conditions. Recent history has shown a trend of new technology leading to potential misuse of this technology and further leading to stricter governmental regulations. It is the purpose of this review to give guidelines for dealing with new technologies, such as PET imaging, and we describe a radiologist's ethical responsibility in a doctor-patient relationship. A historical review of medical ethics will lead to discussions about various issues affecting radiologists and nuclear physicians. To be sure, not all ethical situations are black and white, and therefore there are many gray areas. The opinions expressed in this article are those of the authors and are based on extension of already established rules of ethical conduct.  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