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   16746篇
  免费   1418篇
  国内免费   294篇
耳鼻咽喉   19篇
儿科学   366篇
妇产科学   17篇
基础医学   2438篇
口腔科学   214篇
临床医学   1593篇
内科学   4779篇
皮肤病学   310篇
神经病学   137篇
特种医学   367篇
外科学   1831篇
综合类   2073篇
现状与发展   3篇
预防医学   468篇
眼科学   104篇
药学   1870篇
  7篇
中国医学   1798篇
肿瘤学   64篇
  2024年   50篇
  2023年   423篇
  2022年   637篇
  2021年   720篇
  2020年   728篇
  2019年   744篇
  2018年   704篇
  2017年   748篇
  2016年   656篇
  2015年   537篇
  2014年   1093篇
  2013年   2033篇
  2012年   809篇
  2011年   894篇
  2010年   636篇
  2009年   755篇
  2008年   709篇
  2007年   766篇
  2006年   623篇
  2005年   513篇
  2004年   457篇
  2003年   312篇
  2002年   324篇
  2001年   264篇
  2000年   246篇
  1999年   242篇
  1998年   243篇
  1997年   178篇
  1996年   179篇
  1995年   154篇
  1994年   139篇
  1993年   135篇
  1992年   110篇
  1991年   78篇
  1990年   80篇
  1989年   57篇
  1988年   51篇
  1987年   57篇
  1986年   59篇
  1985年   49篇
  1984年   53篇
  1983年   30篇
  1982年   53篇
  1981年   38篇
  1980年   22篇
  1979年   16篇
  1978年   14篇
  1977年   12篇
  1976年   11篇
  1975年   10篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
5.
Microvascular involvement represents one of the first apparent steps in many autoimmune diseases such as rheumatoid arthritis (RA). Early in the disease, peripheral microangiopathy may be easily recognized and studied by videocapillaroscopy. The aim of this study has been to observe the differences in labial microcirculation between healthy patients and patients suffering from RA. A total of 30 healthy patients and 30 patients suffering from RA were examined. The patients with conditions known to compromise microcirculation, such as diabetes, hypertension, or some pharmacological treatments were not included in the study. All the patients were non-smokers. Labial capillaroscopy was used to investigate the characteristics of microcirculation. Visibility, course, tortuosity, as well as the possible presence of microhemorrhages, the average caliber of the capillary loops and the number of visible capillary loops per square millimeter were evaluated for each patient. The investigation was simple, non-invasive, and repeatable for each patient. In patients suffering from RA, it was possible to observe a reduced caliber of capillaries, as well as greater elongated capillaries, in comparison to controls. This study shows that capillary alterations in patients suffering from RA occur in labial mucosa microcirculation; such evidence could be extremely important in the diagnosis of suspected RA.  相似文献   
6.
Despite the use of gold complexes in modern medicine for over 100 years and the use of gold complexes in the management of rheumatoid disease for more than 60 years, the definitive mechanisms of action for efficacy and for toxicity have not been established. Gold is a group 1b metal in the periodic table with several oxidation states but it is only Au(I) which is active in the biological milieu. Gold sodium thiomalate is not only a polymeric structure, but also has the chiral ligand, thiomalic acid. Gold sodium thiomalate thus can exist in several different physical states which may have different biological activity. In addition the pharmacokinetic profile of gold complexes has been of little value in the understanding of either the mechanism of action, efficacy or toxicity for both the injectable and the oral gold complexes. Many authors have misinterpreted research data on the activities of gold complexes because they compared gold complexes of different structures, and gold complexes which exist at different pH. Experimental work in our laboratory has identified that gold sodium thiomalate is a mixture and can exist as either a yellow or a colourless solution. These have some similar but several different biological activities. Many factors contribute to the lack of understanding of the action of gold complexes. Some of these factors are related to the wide variation in physical structure and biological activities exhibited by these compounds.  相似文献   
7.
8.
A morphological examination of synovial tissue from 25 patients with rheumatoid arthritis revealed that binucleated or multinucleated plasma cells were present in all samples and absent in synovia obtained from 16 control patients. Plasma cells containing two, three of four nuclei constitutet a mean 3% of the total plasma cell population. They were aways found amongst plasma cell infiltrates and in close association with small blood vessels. Ultrastructural analysis found no evidence of cellular membranes separating the individual nuclei in binucleated or multinucleated plasma cells, suggesting that the cells did not arise from fusion. Some of these plasma cells had a diameter approaching 100 μm, and many were in intimate contact with macrophages. The demonstration of a few cells with mitotic figures within the infiltrates suggests that the maintenance of plasma cell numbers in rheumatoid synovium may depend, in part, upon their local proliferation. Received: 25 August 1997 / Accepted: 2 October 1997  相似文献   
9.
Acute ischaemia of the vertebrobasilar circulation leads to a variety of clinical manifestation and is mostly due to cardiogenic or artery-to-artery embolism. We describe four neurological emergency situations involving vertebrobasilar artery aclusion of other origins: basilar migraine, extrinsic compression by rheumatoid inflammatory tissue, generalized vasculitis in subacute rheumatic fever and basilar artery dissection. The differential diagnosis of acute vertebrobasilar artery occlusion may have an important impact on patient management.  相似文献   
10.
BACKGROUND: Bowel-associated dermatosis-arthritis syndrome denotes the occurrence of diarrhoea with arthritis and skin lesions related to bowel disease with or without bowel bypass. In this condition, the histological finding of cutaneous aseptic neutrophilic cell infiltrate is non-specific and common to a wide spectrum of neutrophilic dermatoses, including pyoderma gangrenosum. OBSERVATION: We describe a 78-year-old woman with fever, abdominal discomfort and arthralgias, who developed grouped pustular lesions on her shins with histologically spongiform pustule formation. Aetiological assessment disclosed diverticular disease with sigmoid stenosis. CONCLUSION: Although clinical and histological features in our case fit the diagnosis of bowel-associated dermatosis-arthritis syndrome, they may also correspond to a pustular variant of pyoderma gangrenosum. Our observation raises the question of the nosological classification of bowel-associated dermatosis-arthritis syndrome within the spectrum of neutrophilic diseases.  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