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   66758篇
  免费   5727篇
  国内免费   3282篇
耳鼻咽喉   1207篇
儿科学   798篇
妇产科学   793篇
基础医学   9366篇
口腔科学   1183篇
临床医学   7507篇
内科学   11381篇
皮肤病学   1336篇
神经病学   4268篇
特种医学   3594篇
外国民族医学   21篇
外科学   7272篇
综合类   6294篇
现状与发展   13篇
一般理论   6篇
预防医学   3607篇
眼科学   1529篇
药学   6719篇
  38篇
中国医学   2623篇
肿瘤学   6212篇
  2024年   185篇
  2023年   966篇
  2022年   2514篇
  2021年   3530篇
  2020年   2433篇
  2019年   2406篇
  2018年   2466篇
  2017年   2186篇
  2016年   2382篇
  2015年   3370篇
  2014年   3947篇
  2013年   3903篇
  2012年   5491篇
  2011年   5627篇
  2010年   3542篇
  2009年   2813篇
  2008年   3640篇
  2007年   3511篇
  2006年   3151篇
  2005年   2976篇
  2004年   2201篇
  2003年   1987篇
  2002年   1683篇
  2001年   1182篇
  2000年   1155篇
  1999年   1174篇
  1998年   657篇
  1997年   638篇
  1996年   499篇
  1995年   450篇
  1994年   401篇
  1993年   236篇
  1992年   380篇
  1991年   300篇
  1990年   286篇
  1989年   251篇
  1988年   230篇
  1987年   200篇
  1986年   164篇
  1985年   124篇
  1984年   89篇
  1983年   70篇
  1982年   27篇
  1981年   38篇
  1980年   26篇
  1979年   39篇
  1978年   22篇
  1977年   23篇
  1976年   32篇
  1974年   26篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
A 25-year-old female has had brown to erythematous telangiectatic patches and grouped papules on her face, neck, arm, and trunk since childhood following B.C.G. vaccination. Histopathologically, the lesions consisted of hyperkeratosis, slight acanthosis, tuberculoid granulomas with some Langerhans type giant cells in the mid-dermis. Although various forms of cutaneous tuberculosis after B.C.G. vaccination have been reported, it was difficult for us to assign the patient's skin lesion to any specific disease entity. Remission of her cutaneous lesions occurred clinically and histopathologically after treatment with isoniazid and rifampin.  相似文献   
22.
23.
24.
A diospyrobezoar is a type of phytobezoar that is considered to be harder than any other types of phytobezoars. Here, we describe a new treatment modality, which effectively and easily disrupted huge gastric diospyrobezoars. A 41-year-old man with a history of diabetes mellitus was admitted with lower abdominal pain and vomiting. Upper gastrointestinal endoscopy revealed three huge, round diospyrobezoars in the stomach. He was made to drink two cans of Coca-Cola every 6 h. At endoscopy the next day, the bezoars were partially dissolved and turned to be softened. We performed direct endoscopic injection of Coca-Cola into each bezoar. At repeated endoscopy the next day, the bezoars were completely dissolved.  相似文献   
25.
Q P Ma  Y S Shi  J S Han 《Brain research》1992,583(1-2):292-295
Previous findings from this laboratory with the intracerebral microinjection technique suggested that the periaqueductal gray (PAG), nucleus accumbens, and habenula might constitute a unidirectional loop to play their roles in pain modulation. In the present study we demonstrate that intra-habenular injection of naloxone antagonizes the analgesia elicited by morphine injected into the periaqueductal gray (PAG) and that intra-accumbens injection of naloxone is capable of attenuating the analgesic effects of morphine injected into the habenula. These results indicate that the relationships between these nuclei may be more complex than the putative unidirectional loop.  相似文献   
26.
Effects of sodium salts of various monovalent inorganic anions on transdermal permeation of salicylic acid were investigated. In in-vitro experiment using a Franz-type diffusion cell and excised mouse skin, the permeation-enhancing activities of the sodium salts of inorganic anions were roughly proportional to lyotropic Hofmeister swelling abilities of the anions; F?<SO4 2?<Cl? <ClO4 ?<NO3 <SCN? <Br <I?, i.e. l, Br and SCN increased the flux of drugs through the mouse skin, while F?, SO4 2?, Cl?, ClO4 ? and NO3 ? decreased or did not affect the flux. In invivo experiment using the rabbit as the test animal, the plasma concentration of salicylic acid of the rabbit to which 10%-salicylic acid ointment containing 5%-Nal or NaBr was applied was significantly higher than that of the rabbit to which the ointment without the electrolytes was applied. The amounts of sterol leached out of stratum corneum sheet when the sheet was immersed in aqueous solutions of Nal, NaBr, or NaSCN were much more than that of stratum corneum immersed in aqueous solutions of the other inorganic anions. The FTIR/ATR spectroscopy showed that the peaks at 2853 cm?1 and 2924 cm?1 in the IR absorption spectrum of the stratum corneum sheet of the mouse were shifted to higher frequencies by the anions which enhanced the transdermal drug permeation, while not shifted by the anions which did not have any permeation-enhancing activities or have permeation-reducing activities. These results suggest that sodium salts of some anions such as iodide, bromide and thiocyanate enhance transdermal permeation of salicylic acid through swelling and perturbation of the skin structure by these anions.  相似文献   
27.
28.
29.
AIM To clone novel gastric cancer-associated genes and investigate their roles in gastric cancer occurrence.METHODS A method called differential display was used which allows the identification of differentially expressed genes by using PAGE to display PCR-amplified cDNA fragments between gastric cancer cells and normal gastric mucosa cells. These fragments were cloned into plasmid vector pUC18. Homology analysis was made after sequencing these fragments.RESULTS Two novel genes were identified compared with sequences from GenBank. One was registered with the AD number AF 051783. In situ hybridization showed that these two novel genes expressed specifically in gastric cancer tissues.CONCLUSION The two novel genes obtained by differential display were confirmed to be gastric cancer-associated genes using in situ hybridization.  相似文献   
30.
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