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   29281篇
  免费   2647篇
  国内免费   95篇
耳鼻咽喉   290篇
儿科学   719篇
妇产科学   508篇
基础医学   3715篇
口腔科学   879篇
临床医学   3799篇
内科学   6208篇
皮肤病学   694篇
神经病学   2365篇
特种医学   1055篇
外科学   3896篇
综合类   491篇
一般理论   28篇
预防医学   3081篇
眼科学   417篇
药学   2219篇
中国医学   25篇
肿瘤学   1634篇
  2022年   219篇
  2021年   579篇
  2020年   353篇
  2019年   517篇
  2018年   543篇
  2017年   387篇
  2016年   494篇
  2015年   528篇
  2014年   716篇
  2013年   1080篇
  2012年   1490篇
  2011年   1476篇
  2010年   806篇
  2009年   744篇
  2008年   1306篇
  2007年   1375篇
  2006年   1351篇
  2005年   1346篇
  2004年   1215篇
  2003年   1159篇
  2002年   1130篇
  2001年   995篇
  2000年   1015篇
  1999年   862篇
  1998年   327篇
  1997年   273篇
  1996年   253篇
  1995年   263篇
  1994年   209篇
  1993年   218篇
  1992年   609篇
  1991年   635篇
  1990年   592篇
  1989年   519篇
  1988年   491篇
  1987年   481篇
  1986年   478篇
  1985年   475篇
  1984年   341篇
  1983年   297篇
  1982年   219篇
  1981年   209篇
  1979年   327篇
  1978年   240篇
  1977年   202篇
  1974年   217篇
  1973年   207篇
  1972年   172篇
  1971年   192篇
  1970年   171篇
排序方式: 共有10000条查询结果,搜索用时 390 毫秒
141.
142.
143.
144.
Acute hypertensive responses during nitrous oxide-opioid-relaxant anesthesia are a common clinical problem. In adult men undergoing radical prostatectomy procedures and anesthetized with a standardized technique, we evaluated the effectiveness of alfentanil, isoflurane, and trimethaphan in treating acute hemodynamic and stress hormone responses to surgical stimulation. Stress hormone concentrations were measured 1 min before skin incision, after the onset of an acute hypertensive response, and after returning the mean arterial pressure to within 10% of the preincision values with one of the three treatment modalities. Pretreatment plasma alfentanil concentrations (151 +/- 47 to 156 +/- 47 ng.ml-1) and end-tidal nitrous oxide concentrations (66 +/- 2 to 68 +/- 2%) were similar in all three groups. Acute hypertensive events were associated with significantly increased concentrations of catecholamines and vasopressin (antidiuretic hormone [ADH]). Whereas intravenous alfentanil returned all hormone concentrations to preincision values, norepinephrine and glucose concentrations were significantly increased after adjunctive isoflurane administration. Although trimethaphan decreased the norepinephrine concentration, the epinephrine, beta-endorphin, cortisol, ADH, and glucose concentrations were significantly increased compared to preincision values. However, the persistent elevation in the posttreatment ADH concentration in the trimethaphan group was the only significant difference between the three groups. Mean (+/- standard deviation) times to awakening (2.8 +/- 3.3 to 3.8 +/- 4.2 min), extubation (8.1 +/- 4.8 to 10.3 +/- 8.5 min), and orientation (19.6 +/- 20.4 to 24.6 +/- 19.1 min) were similar in all three groups. Naloxone was required more frequently in patients in the alfentanil (35%) and isoflurane (24%) groups than in the trimethaphan group (4%).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
145.
146.
Neuropsychological tests of frontal lobe functions were undertaken in 46 chronic schizophrenic patients who were also rated for movement disorders. Tardive dyskinesia was found to have significant associations with most of these psychological tests. The possible mechanisms are discussed within the context of known neostriatal psychological functions.  相似文献   
147.
148.
149.
We report the first three cases of peritonitis due to the fungus Coccidioides immitis occurring during continuous ambulatory peritoneal dialysis (CAPD). At the time of diagnosis, none of the patients had evidence of active infection outside of the peritoneal cavity. Clues suggesting the diagnosis including a previous history of pulmonary coccidioidomycosis, an excess number of eosinophils in the peritoneal fluid, and failure to respond to therapy directed against bacteria. C immitis in peritoneal fluid was more readily isolated on specific fungal culture media than on routine bacterial culture media. In no instances did potassium hydroxide (KOH) preparations of the fluid reveal fungi. Coccidioidal peritonitis during CAPD appears to be a localized form of extrapulmonary coccidioidomycosis that has a relatively benign course once the peritoneal catheter is removed.  相似文献   
150.
1. Thiophene and its two monobromo derivatives were administered to rats and the amounts of thioether excreted in urine were measured by an assay based on Ellman's reagent. This assay, which involves extraction and hydrolysis, was validated by determining extraction and hydrolysis efficiencies for several authentic thioethers including N-acetyl-S-(2-thienyl)-L-cysteine, a previously reported metabolite of thiophene and 2-bromothiophene. 2. The thioethers present in urine of animals dosed with thiophenes have been examined chromatographically. Contrary to previous reports, the present work indicates that S-substituted, N-acetyl-L-cysteines (mercapturic acids) are not important thioether metabolites of thiophene in rats, and the small quantity of such compounds formed does not include either of the two simple S-thienyl derivatives. 3. The two monobromo thiophenes form higher proportions of thioethers than does thiophene, and one of these thioethers, arising from 3-bromothiophene, was identified, chromatographically, as N-acetyl-S-(3-thienyl)-L-cysteine.  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