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   96059篇
  免费   4706篇
  国内免费   416篇
耳鼻咽喉   1798篇
儿科学   3290篇
妇产科学   2005篇
基础医学   12476篇
口腔科学   3062篇
临床医学   6455篇
内科学   23227篇
皮肤病学   3197篇
神经病学   7840篇
特种医学   2377篇
外国民族医学   1篇
外科学   11976篇
综合类   634篇
一般理论   28篇
预防医学   9288篇
眼科学   2173篇
药学   6532篇
中国医学   583篇
肿瘤学   4239篇
  2023年   694篇
  2022年   1466篇
  2021年   3249篇
  2020年   1522篇
  2019年   2974篇
  2018年   3793篇
  2017年   2267篇
  2016年   2101篇
  2015年   2169篇
  2014年   3150篇
  2013年   4624篇
  2012年   6873篇
  2011年   7481篇
  2010年   4029篇
  2009年   3137篇
  2008年   5527篇
  2007年   5747篇
  2006年   5286篇
  2005年   5372篇
  2004年   4880篇
  2003年   4590篇
  2002年   4161篇
  2001年   2614篇
  2000年   3097篇
  1999年   2115篇
  1998年   684篇
  1997年   586篇
  1996年   446篇
  1995年   423篇
  1994年   336篇
  1993年   279篇
  1992年   584篇
  1991年   479篇
  1990年   454篇
  1989年   374篇
  1988年   381篇
  1987年   322篇
  1986年   293篇
  1985年   315篇
  1984年   203篇
  1983年   185篇
  1982年   164篇
  1981年   159篇
  1980年   139篇
  1979年   155篇
  1978年   128篇
  1976年   94篇
  1974年   111篇
  1971年   93篇
  1969年   90篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
The aetiology of porphyria cutanea tarda (PCT) has not been elucidated, but the possibility of an autoimmune mechanism has been proposed. We report a case of an unknown clinical combination of PCT with autoimmune hypothyroidism, alopecia universalis and vitiligo with thyroid and parietal cell circulating antibodies. This is highly suggestive of underlying autoimmune damage in this patient.  相似文献   
92.
93.
94.
We studied the histories of patients who had visited our Department during the last 5 years, presenting food allergy with exclusively respiratory symptoms (18.5%). We studied the correlation between IgE levels and the histamine release test and the type of food implicated. Seventy-seven percent of patients presented sensitization to one food, and 23% presented polysensitization. We found that foods such as snails and eggs have a strong predilection for the bronchial tree as the shock organ. High total IgE was found in 85.2% of patients. The histamine release test was positive in 66% of cases. We conclude that this is a highly sensitive method for the in vitro diagnosis of food allergy.  相似文献   
95.
96.
A fibre optic potassium ion sensor has been developed based on reflectance measurements of the pH-dependent chromogenic crown ether 'Takagi reagent' immobilized on the non-ionic polymeric resin Amberlite XAD2. The sensor response is in the 1.5-100 mM range with a detection limit of 0.25 mM K+. The selectivity factor over sodium is 20. The proposed sensor works with a reproducibility of +/- 0.8% at the 5 mM K+ level. Advantageous design features include ease of construction, simplicity of use, reversibility, short response time (approximately 1 min) and an optimum working pH range (7.0-8.0) for biological fluids. This optical sensor was applied successfully to the direct determination of potassium in human serum. Aqueous potassium standards containing 0.13 M NaCl and a buffer of pH 8 were used for calibration.  相似文献   
97.
A debilitated patient with liver cirrhosis and poor haemostasis had a severe lower gastrointestinal haemorrhage. A superior mesenteric arteriogram revealed an early persistent and promiment draining vein in the ileocolic artery. Two fragments of Spongostan and silk were used to embolise the bleeding artery and the haemorhage ceased immediately. No infarction of the embolised area was observed and the bleeding was controlled.  相似文献   
98.
Back pain among nurses is a common problem. Prior studies of this problem have been based on cross-sectional or retrospective data. This 18-month prospective study involving nurses newly graduated from nursing school investigated personal, worksite, and training factors associated with future risk of back pain. Each nurse underwent a preliminary interview and periodic follow-ups to identify those with back injuries. Contingency tables and logistic regression analyses demonstrated that prior significant back pain episodes (evidenced by previous job changes because of back pain, frequent medication use, etc.) were associated with increased future risk. Training at nursing school or on the job did not have a protective effect. This pilot study therefore suggests factors useful in placement and counseling of new nurses and indicates the need for further implementation of mechanical lift assist device use. © 1994 Wiley-Liss, Inc.  相似文献   
99.
Lung cancer is the most prevalent malignancy in western countries and most of the patients present at advanced stages, but single splenic metastasis is exceptional instead. We report on a case of a seventy-three-year old male presenting with non-hemoptoic productive cough, constitutional syndrome and pain in the left lower quadrant. Physical examination and complementary radiological and hystologycal procedures revealed the presence of an adenocarcinoma of the left lung with probable splenic metastasis. The patient underwent splenectomy, which confirmed the diagnose of splenic metastasis of lung adenocarcinoma and, secondly, lung resection was performed. Topics about lung cancer metastasis are discussed.  相似文献   
100.
OBJECTIVE: To evaluate wound healing of incisions created in the upper aerodigestive tract. STUDY DESIGN AND SETTING: In this prospective and blind study, 186 adult rats were assigned to six groups to create incisions in the tongue. In the first three groups, the wounds were made with a steel scalpel; no substance was applied to the wound in the first group, but N-butyl-2-cyanoacrylate was applied in the second group, and trichloroacetic acid at 50 percent in the third group. In the fourth, fifth, and sixth groups, the wounds were caused by cryosurgery, electrocautery, and CO(2) laser. Hemostasis, postoperative oral intake, and wound healing were measured. Statistical analysis was performed with analysis of variance. RESULTS: The wounds to which N-butyl-2-cyanoacrylate was applied showed no hemorrhaging and faster reepithelialization and resolution of the inflammatory response. CONCLUSIONS: N-butyl-2-cyanoacrylate is a good hemostatic for managing wounds in the oral mucosa provoked by steel scalpel.  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