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   37123篇
  免费   3307篇
  国内免费   132篇
耳鼻咽喉   439篇
儿科学   1022篇
妇产科学   752篇
基础医学   4493篇
口腔科学   890篇
临床医学   4360篇
内科学   7428篇
皮肤病学   614篇
神经病学   3458篇
特种医学   1147篇
外国民族医学   5篇
外科学   5701篇
综合类   871篇
一般理论   35篇
预防医学   3270篇
眼科学   865篇
药学   2662篇
中国医学   44篇
肿瘤学   2506篇
  2022年   269篇
  2021年   571篇
  2020年   354篇
  2019年   566篇
  2018年   642篇
  2017年   501篇
  2016年   490篇
  2015年   628篇
  2014年   857篇
  2013年   1330篇
  2012年   1900篇
  2011年   1907篇
  2010年   1124篇
  2009年   1044篇
  2008年   1764篇
  2007年   1952篇
  2006年   1951篇
  2005年   1896篇
  2004年   1808篇
  2003年   1707篇
  2002年   1710篇
  2001年   860篇
  2000年   829篇
  1999年   797篇
  1998年   447篇
  1997年   378篇
  1996年   404篇
  1995年   356篇
  1994年   328篇
  1993年   295篇
  1992年   562篇
  1991年   523篇
  1990年   553篇
  1989年   457篇
  1988年   484篇
  1987年   462篇
  1986年   459篇
  1985年   453篇
  1984年   406篇
  1983年   373篇
  1982年   316篇
  1981年   326篇
  1980年   315篇
  1979年   389篇
  1978年   282篇
  1977年   248篇
  1976年   251篇
  1974年   263篇
  1973年   241篇
  1972年   231篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
Electrocardiographic observations on a patient with myocardial infarction and severe cardiac decompensation revealed transitions between normal intraventricular conduction, bundle branch block, and ventricular tachycardia. The terminal cardiac mechanism was progressive slowing of the ventricular rate and ventricular standstill.  相似文献   
53.
54.
55.
56.
57.
Objectives:  Among children with cerebrospinal fluid (CSF) pleocytosis, the task of separating aseptic from bacterial meningitis is hampered when the CSF Gram stain result is unavailable, delayed, or negative. In this study, the authors derive and validate a clinical decision rule for use in this setting.
Methods:  This was a review of peripheral blood and CSF test results from 78 children (<19 years) presenting to Children's Hospital Columbus from 1998 to 2002. For those with a CSF leukocyte count of >7/μL, a rule was created for separating bacterial from viral meningitis that was based on routine laboratory tests, but excluded Gram stain. The rule was validated in 158 subjects seen at the same site (Columbus, 2002–2004) and in 871 subjects selected from a separate site (Boston, 1993–1999).
Results:  One point each (maximum, 6 points) was assigned for leukocytes >597/μL, neutrophils >74%, glucose <38 mg/dL, and protein >97 mg/dL in CSF and for leukocytes >17,000/mL and bands to neutrophils >11% in peripheral blood. Areas under receiver-operator-characteristic curves (AROCs) for the resultant score were 0.98 for the derivation set and 0.90 and 0.97, respectively, for validation sets from Columbus and Boston. Sensitivity and specificity pairs for the Boston data set were 100 and 44%, respectively, at a score of 0 and 97 and 81% at a score of 1. Likelihood ratios (LRs) increased from 0 at a score of 0 to 40 at a score of ≥4.
Conclusions:  Among children with CSF pleocytosis, a prediction score based on common tests of CSF and peripheral blood and intended for children with unavailable, negative, or delayed CSF Gram stain results has value for diagnosing bacterial meningitis.  相似文献   
58.
OBJECTIVE: The objective of this study was to determine if temporomandibular joint (TMJ) samples positive for Chlamydia trachomatis have a greater presence of tumor necrosis factor-alpha (TNFalpha) or interleukin-6 (IL-6) when compared with Chlamydia-negative samples. STUDY DESIGN: Posterior bilaminar tissue samples removed during TMJ surgery from 70 patients were evaluated. Cryosections were stained using monoclonal antibody that identifies C. trachomatis. The presence of IL-6 and TNFalpha were evaluated by immunostaining in 15 samples positive and in 25 samples negative for the presence of C. trachomatis. RESULTS: Of the 70 TMJ samples, 32 (46%) were positive for C. trachomatis. In 15 samples positive for C. trachomatis, 10 (67%) were positive for TNFalpha and 7 (47%) for IL-6. In 25 samples negative for C. trachomatis, only 4 (16%) were positive for TNFalpha and only 2 (8%) for IL-6. Differences in C. trachomatis-positive samples versus negative were significant for both TNFalpha (P < .002) and IL-6 (P < .008). CONCLUSION: The presence of C. trachomatis in the TMJ is associated with a significantly increased presence of TNFalpha and IL-6.  相似文献   
59.
60.
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