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   295768篇
  免费   34039篇
  国内免费   2481篇
耳鼻咽喉   9763篇
儿科学   10378篇
妇产科学   8589篇
基础医学   30233篇
口腔科学   5228篇
临床医学   33885篇
内科学   73457篇
皮肤病学   13762篇
神经病学   25615篇
特种医学   12646篇
外国民族医学   5篇
外科学   64973篇
综合类   836篇
现状与发展   72篇
一般理论   20篇
预防医学   12676篇
眼科学   9088篇
药学   6231篇
  1篇
中国医学   91篇
肿瘤学   14739篇
  2023年   4862篇
  2021年   3362篇
  2020年   6185篇
  2019年   2402篇
  2018年   7800篇
  2017年   7681篇
  2016年   8837篇
  2015年   11843篇
  2014年   19599篇
  2013年   21177篇
  2012年   9924篇
  2011年   9847篇
  2010年   14758篇
  2009年   18593篇
  2008年   10340篇
  2007年   8601篇
  2006年   11236篇
  2005年   8169篇
  2004年   7202篇
  2003年   4552篇
  2002年   3266篇
  2001年   4608篇
  2000年   3727篇
  1999年   4157篇
  1998年   4777篇
  1997年   4626篇
  1996年   4555篇
  1995年   4537篇
  1994年   3326篇
  1993年   2928篇
  1992年   2950篇
  1991年   2753篇
  1990年   2391篇
  1989年   2290篇
  1988年   2036篇
  1987年   1955篇
  1986年   1930篇
  1985年   1646篇
  1984年   1603篇
  1982年   1623篇
  1933年   1517篇
  1932年   1500篇
  1931年   1496篇
  1930年   1683篇
  1928年   1558篇
  1927年   1517篇
  1926年   1595篇
  1925年   1552篇
  1924年   1630篇
  1923年   1481篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
972.
973.
Coronary artery fistula is often considered to be a benign and rare congenital anomaly. It is usually an incidental finding encountered during routine cardiac catheterization. We report a case of a patient presenting with endocarditis involving a large coronary artery fistula connecting an aneurysmal circumflex coronary artery to the coronary sinus. The diagnosis was initially made by echocardiography and confirmed by cardiac catheterization. In addition, we briefly discuss the literature on management of this coronary anomaly.  相似文献   
974.
James H. Diaz  MD  DrPH 《Pain practice》2004,4(4):295-302
Abstract:   Spontaneous intracranial hypotension (SIH) is a postural headache syndrome unrelated to dural puncture. Because of the increasing failure of epidural blood patch (EBP) to relieve headache in SIH, we retrospectively investigated the epidemiological features and treatment outcomes in 55 cases of SIH. The study population was stratified by age and sex; continuous variables were compared for differences by t -tests; categorical variables were compared by Chi-squared analysis or Fisher exact tests. Significant differences were identified by P values of 0.05 or less. The mean age of the study population was 44 ± 12 years with a female to male ratio of 1.3:1.0. Men presented with subdural hematomas ( P  = 0.001) more often than women. Meningeal enhancement on contrast magnetic resonance imaging (MRI) was the most consistent radiographic finding. Radionuclide cisternography (RC) demonstrated thoracolumbar dural leaks in 16 of 22 patients. EBP failures were more common in patients aged 40 and younger than in older patients ( P  = 0.003). Postural headache from SIH was not uniformly responsive to EBP, and had significant comorbidities, especially in men. The management of postural headache in SIH by other techniques to restore brain position and cerebrospinal fluid dynamics should be investigated.  相似文献   
975.
976.
977.
Although symptom validity tests have become available to German test users during the last few years, there is very little research into measures of negative response bias in personality assessment. The present study investigates the effects of negative response bias as measured by the Word Memory Test (WMT) and the Structured Inventory of Malingered Symptomatology (SIMS) on self-report personality scales. A retrospective analysis was performed on data from 93 patients who had undergone neuropsychiatric assessment in the context of independent medical examination. Complete data sets were available for the WMT, the SIMS, and the Freiburg Personality Inventory-Revised (FPI-R). Significant differences were found for a number of personality scales, depending on WMT and SIMS classification. The FPI-R validity scale (Openness) was linked to neither WMT nor SIMS, whereas the results in the latter two instruments showed a significant overlap of classification results (φ=0.44). A principal axis analysis yielded corresponding results. It is concluded that self-report personality measures may be considerably distorted by negative response bias. FPI-R Openness scale scores do not allow any interpretation in terms of negative response bias. More effort should be directed in German-speaking countries towards the development and validation of appropriate validity scales.  相似文献   
978.
979.
BACKGROUND: The effective dose for treating glabellar lines with botulinum toxin type A in men has not been studied adequately. OBJECTIVE: To compare the safety, efficacy, and duration of response of four doses of botulinum toxin type A on glabellar rhytids in men. METHODS: Eighty men were randomized to receive a total dose of either 20, 40, 60, or 80 U of botulinum toxin type A (BOTOX, BOTOX Cosmetic, or Vistabel, Allergan, Inc., Irvine, CA, USA) in the glabellar area. Glabellar lines were assessed at rest and maximum frown by a trained observer at baseline, 2 and 4 weeks, and monthly thereafter. Patients provided self-evaluations at the same visits. Adverse events were monitored throughout. RESULTS: The 40, 60, and 80 U doses of botulinum toxin type A were consistently more effective in reducing glabellar lines than the 20 U dose (duration, peak response rate, improvement from baseline). There was a dose-dependent increase in both the response rate at maximum frown and the duration of effect assessed by the trained observer. In addition, the participants reported a dose-dependent reduction in the ability to frown, improvement in their global assessment, and increased feelings of attractiveness, self-confidence, and satisfaction. The incidence of adverse events was not increased with higher doses. CONCLUSION: Male participants with glabellar rhytids benefit from starting doses of at least 40 U of botulinum toxin type A.  相似文献   
980.
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