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   25111篇
  免费   2330篇
  国内免费   73篇
耳鼻咽喉   261篇
儿科学   580篇
妇产科学   348篇
基础医学   3075篇
口腔科学   809篇
临床医学   3267篇
内科学   5353篇
皮肤病学   616篇
神经病学   1860篇
特种医学   996篇
外科学   3555篇
综合类   460篇
一般理论   24篇
预防医学   2668篇
眼科学   352篇
药学   1985篇
中国医学   23篇
肿瘤学   1282篇
  2021年   361篇
  2020年   208篇
  2019年   343篇
  2018年   376篇
  2017年   272篇
  2016年   334篇
  2015年   386篇
  2014年   524篇
  2013年   823篇
  2012年   1129篇
  2011年   1121篇
  2010年   632篇
  2009年   580篇
  2008年   1033篇
  2007年   1052篇
  2006年   1098篇
  2005年   1091篇
  2004年   1020篇
  2003年   971篇
  2002年   975篇
  2001年   977篇
  2000年   1003篇
  1999年   845篇
  1998年   313篇
  1997年   268篇
  1996年   247篇
  1995年   256篇
  1994年   214篇
  1993年   215篇
  1992年   613篇
  1991年   629篇
  1990年   583篇
  1989年   516篇
  1988年   489篇
  1987年   480篇
  1986年   478篇
  1985年   477篇
  1984年   342篇
  1983年   293篇
  1982年   220篇
  1981年   209篇
  1979年   324篇
  1978年   239篇
  1977年   201篇
  1975年   166篇
  1974年   214篇
  1973年   204篇
  1972年   169篇
  1971年   192篇
  1970年   170篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
12.
13.
14.
15.
16.
An immunofluorescent (IF) method that detects Burkholderia pseudomallei in clinical specimens within 10 min was devised. The results of this rapid method and those of an existing IF method were prospectively compared with the culture results for 776 specimens from patients with suspected melioidosis. The sensitivities of both IF tests were 66%, and the specificities were 99.5 and 99.4%, respectively.  相似文献   
17.
R K Parker  B Holtmann  P F White 《JAMA》1991,266(14):1947-1952
OBJECTIVE.--To assess the influence of a continuous (basal) morphine infusion as part of a patient-controlled analgesia (PCA) system on the postoperative analgesic requirement and on recovery parameters following abdominal hysterectomy. DESIGN.--Single-center, randomized, controlled protocol. SETTING.--University medical center. PARTICIPANTS.--A total of 230 adult women were randomly assigned to receive no morphine infusion (control group) or a continuous 0.5-, 1.0-, or 2.0-mg/h morphine infusion. Each patient was able to self-administer supplemental intravenous bolus doses of morphine (1 to 2 mg) using a PCA infuser. MAIN OUTCOME MEASURES.--Use of the PCA device, opioid-related side effects, recovery times, and the patients' assessment of pain and sedation on linear visual analog scales were recorded during the 72-hour study period. Follow-up questionnaires were completed by the patients and their health care professionals to assess the overall adequacy of PCA therapy. RESULTS.--Patients who received the 2-mg/h morphine infusions received significantly more opioid medication 9 to 72 hours after their operation than those who received no infusion (control group). The presence of a continuous morphine infusion of 0.5 to 2 mg/h did not significantly decrease the number of patient demands or supplemental bolus doses administered compared with the control group. Overall, 168 (84%) of the 199 patients who completed the 72-hour study were able to achieve adequate analgesia without requiring changes in the PCA regimen or experiencing major side effects. Recovery times and outcome variables were similar in all four groups. CONCLUSION.--The routine use of a continuous opioid infusion in combination with a standard PCA regimen does not improve pain management compared with PCA alone after abdominal hysterectomy.  相似文献   
18.
19.
Stereoisomers of remacemide (racemate form) were compared for anticonvulsant efficacy and safety in mice. In the maximal electroshock seizure (MES) test for oral efficacy, the (-) stereoisomer, FPL 14145, was more potent than the racemate or the (+) stereoisomer, FPL 14144. Respective ED50 values (expressed as mg/kg) were: remacemide, 58; FPL 14145, 45; FPL 14144, 79. In 2 of 3 tests for neural impairment, FPL 14145 yielded significantly better therapeutic indices (toxic dose 50/ED50) than the racemate. The margin of safety (estimated median lethal dose ED50) was more favorable for FPL 14144: remacemide, 15.1; FPL 14144, 18.9; FPL 14145, 15.7. The duration of protection against MES indicated the stereoisomers were longer acting than the racemate. After intravenous administration the order of potency against MES was similar: FPL 14145 greater than remacemide greater than FPL 14144. Following daily administration of the oral ED98 for 4 days, with a dose response curve run on day 5, the MES ED50 values for all compounds were increased. The test indicates tolerance. In the pentylenetetrazol infusion test the racemate and FPL 14144 demonstrated more proconvulsant properties than FPL 14145. Intraperitoneal administration of 50 mg/kg or more produced changes in behavior with all compounds. At higher doses the racemate and FPL 14145 elicited more severe symptoms with death at 200 mg/kg.  相似文献   
20.
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