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   939990篇
  免费   64796篇
  国内免费   2407篇
耳鼻咽喉   13116篇
儿科学   30394篇
妇产科学   27105篇
基础医学   131507篇
口腔科学   26509篇
临床医学   78349篇
内科学   191461篇
皮肤病学   20146篇
神经病学   74832篇
特种医学   37750篇
外国民族医学   336篇
外科学   148214篇
综合类   19155篇
一般理论   265篇
预防医学   67216篇
眼科学   21151篇
药学   66438篇
中国医学   1968篇
肿瘤学   51281篇
  2019年   7257篇
  2018年   10423篇
  2017年   8139篇
  2016年   8732篇
  2015年   9742篇
  2014年   13562篇
  2013年   21029篇
  2012年   28611篇
  2011年   30730篇
  2010年   18146篇
  2009年   16771篇
  2008年   28985篇
  2007年   30795篇
  2006年   30860篇
  2005年   30382篇
  2004年   29060篇
  2003年   28112篇
  2002年   27508篇
  2001年   42040篇
  2000年   43269篇
  1999年   36700篇
  1998年   10150篇
  1997年   9332篇
  1996年   9235篇
  1995年   8577篇
  1994年   8196篇
  1993年   7684篇
  1992年   28276篇
  1991年   27041篇
  1990年   26487篇
  1989年   25403篇
  1988年   23607篇
  1987年   23208篇
  1986年   22285篇
  1985年   21187篇
  1984年   15848篇
  1983年   13513篇
  1982年   8136篇
  1979年   14621篇
  1978年   10235篇
  1977年   8656篇
  1976年   8163篇
  1975年   8972篇
  1974年   10708篇
  1973年   10199篇
  1972年   9669篇
  1971年   8926篇
  1970年   8591篇
  1969年   8030篇
  1968年   7695篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
101.
Tear mucus crystallization in children with cystic fibrosis   总被引:1,自引:0,他引:1  
Cystic fibrosis is characterized by an abnormally high electrolyte concentration in exocrine secretions. The authors performed the tear mucus ferning test in 26 eyes of children with cystic fibrosis and compared the results to those in an equal number of age-matched normals. The results suggest that the increased electrolyte concentration could be responsible for the increased hyperviscosity of mucus. The tear mucus ferning test appears to be a suitable diagnostic test for the assessment of cystic fibrosis.  相似文献   
102.
103.
104.
Prat  F. 《Acta endoscopica》2002,32(2):507-510
Acta Endoscopica - L’hémorragie iatrogène en endoscopie digestive reste pour l’essentiel l’apanage des techniques de résection tumorale et de la...  相似文献   
105.
BACKGROUND: The risk for allergic reactions depends on the sensitivity of individuals and the quantities of offending food ingested. The sensitivity varies among allergic individuals, as does the threshold dose of a food allergen capable of inducing an allergic reaction. OBJECTIVE: This study aimed at determining the distribution of minimum provoking doses of hazelnut in a hazelnut-allergic population. METHODS: Thirty-one patients with a history of hazelnut-related allergic symptoms, a positive skin prick test to hazelnut and/or an elevated specific IgE level, were included. Double-blind, placebo-controlled food challenges (DBPCFC) were performed with seven increasing doses of dried hazelnut (1 mg to 1 g hazelnut protein) randomly interspersed with seven placebo doses. RESULTS: Twenty-nine patients had a positive challenge. Itching of the oral cavity and/or lips was the first symptom in all cases. Additional gastrointestinal symptoms were reported in five patients and difficulty in swallowing in one patient. Lip swelling was observed in two patients, followed by generalized urticaria in one of these. Threshold doses for eliciting subjective reactions varied from a dose of 1 mg up to 100 mg hazelnut protein (equivalent to 6.4-640 mg hazelnut meal). Extrapolation of the dose-response curve showed that 50% of our hazelnut-allergic population will suffer from an allergic reaction after ingestion of 6 mg (95% CI, 2-11 mg) of hazelnut protein. Objective symptoms were observed in two patients after 1 and 1,000 mg, respectively. CONCLUSION: DBPCFCs demonstrated threshold doses in half of the hazelnut-allergic patients similar to doses previously described to be hidden in consumer products. This stresses the need for careful labelling and strategies to prevent and detect contamination of food products with hazelnut residues.  相似文献   
106.
Polyploidization and centrosome hyperamplification in inflammatory bronchi   总被引:1,自引:0,他引:1  
OBJECTIVE AND DESIGN: Inflammatory and tumorous bronchi were screened in order to obtain new tumor relevant cytogenetic parameters. MATERIAL OR SUBJECTS: Bronchial cells of 32 patients were cultivated by standard cell culture procedures. METHODS: Tetraploidy and aneuploidy was determined by enumeration of chromosome 7 and 8 versus the number of centrosomes. The resulting data were correlated with histopathological data. RESULTS: Tetra- and aneuploidy of epithelial cells were detectable in 76% of tumor cell cultures, 75% of high grade inflammatory tissues and 40% of non- and low grade-inflammatory tissues. Additionally, we observed centrosome hyper-amplification and multipolar mitoses not only in the tumor but also in the early stages of inflammation. CONCLUSION: Inflammatory bronchi already show tumor-specific features and may consequently represent the preliminary genetic stage of cancer development in bronchi.  相似文献   
107.
Vibrio cholerae was isolated from the blood cultures of a neutropenic patient treated with chemotherapy for non-small-cell lung cancer. Attempts to isolate Vibrio spp. from a rectal swab and stool were unsuccessful. Piperacillin/tazobactam treatment resulted in eradication of the microorganism from the patient's blood. Although Vibrio spp. have occasionally been the source of infection in immunocompromised patients, this report describes the first case of non-0:1 Vibrio cholerae bacteremia in a neutropenic patient with a solid tumour. Electronic Publication  相似文献   
108.
The in vitro activities of povidone iodine, potassium peroxymonosulfate, and dimethyldidecylammonium chloride were investigated against 379 nosocomial isolates of Staphylococcus aureus and Pseudomonas aeruginosa responsible for surgical wound infections in patients operated on between July 1995 and June 2001. Overall, the isolates were inhibited by the antiseptics at concentrations below those used routinely. In spite of increasing resistance to the various antibiotics used to treat surgical wound infections, no significant variation in the susceptibility to antiseptics was demonstrated during this 6-year study. Electronic Publication  相似文献   
109.
110.
Can quality of life be quantified?   总被引:1,自引:0,他引:1  
  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