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   548322篇
  免费   28626篇
  国内免费   551篇
耳鼻咽喉   6995篇
儿科学   17887篇
妇产科学   12981篇
基础医学   94111篇
口腔科学   12674篇
临床医学   49963篇
内科学   99861篇
皮肤病学   12136篇
神经病学   34954篇
特种医学   20422篇
外国民族医学   53篇
外科学   81311篇
综合类   8010篇
现状与发展   2篇
一般理论   110篇
预防医学   39521篇
眼科学   12721篇
药学   42783篇
  2篇
中国医学   1192篇
肿瘤学   29810篇
  2021年   4615篇
  2019年   4458篇
  2018年   6380篇
  2017年   4575篇
  2016年   5320篇
  2015年   5834篇
  2014年   7830篇
  2013年   11399篇
  2012年   16931篇
  2011年   18606篇
  2010年   10727篇
  2009年   9415篇
  2008年   16593篇
  2007年   18359篇
  2006年   17797篇
  2005年   17068篇
  2004年   16596篇
  2003年   15848篇
  2002年   15337篇
  2001年   22852篇
  2000年   23414篇
  1999年   19267篇
  1998年   5382篇
  1997年   4482篇
  1996年   4496篇
  1995年   4219篇
  1992年   14631篇
  1991年   16020篇
  1990年   16125篇
  1989年   15798篇
  1988年   14439篇
  1987年   14335篇
  1986年   13288篇
  1985年   12816篇
  1984年   9512篇
  1983年   8108篇
  1982年   4232篇
  1979年   9024篇
  1978年   6448篇
  1977年   5203篇
  1976年   5553篇
  1975年   6662篇
  1974年   7469篇
  1973年   7246篇
  1972年   6674篇
  1971年   6364篇
  1970年   5936篇
  1969年   5495篇
  1968年   5195篇
  1967年   4642篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
OBJECTIVE: This study was conducted to compare an otolaryngologist's experience with a cohort of epilepsy patients implanted with a vagal nerve stimulator (VNS) to previously published data. METHODS: Demographics, preoperative seizure frequency, medications, and complications were retrospectively collected from patients implanted by the senior author. Postoperative medications and seizure frequency were obtained from referring neurologists. RESULTS: Seventeen patients were implanted over a 24-month period. Average age was 28.3 years. Patients presented with petit mal (n = 3), tonic-clonic (n = 6), complex partial (n = 5), and grand mal (n = 8) seizures. Mean follow-up postimplantation was 13.5 months. Most patients had at least a 50% reduction of seizure frequency, with 3 patients being seizure free. There were no postoperative infections. One patient had left vocal cord immobility. The most common side effect was voice disturbance during device activation. CONCLUSION: Otolaryngologists are well equipped to perform VNS implantation and to diagnose and treat possible laryngeal side effects. EBM rating: C-4.  相似文献   
94.
A rapid procedure for determining angiotensin II in the blood by inverse voltammetry using a TA-2 device (Tekhnoanalit Company, Tomsk) with a graphite electrode has been developed. The results of analyses using the proposed technique agree with the clinical data. The rapid analytical procedure favors optimization of cardiotropic drug therapy. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 12, pp. 54–56, December, 2006.  相似文献   
95.
96.
CXCL12 and its receptor, CXCR4, are emerging as promising targets for modulating growth, angiogenesis, and metastasis in several human cancers. Indeed, blocking the receptor is sufficient to prevent metastasis and angiogenesis in experimental breast cancer xenografts. Recently, the biological effect of the CXCR4 in pancreatic cancer, one of the most deadly neoplastic diseases, has been reported. However, the molecular mechanism by which CXCR4 contributes to these properties is not completely understood. In this paper, we characterize the signaling pathways activated by CXCR4 in pancreatic cancer. We show that after CXCR4 activation, EGFR becomes tyrosine phosphorylated, and the kinase activity of this receptor, together with the activation of MMPs, Src, and PI3-Kinase, is required for CXCR4-mediated ERK activation. Analysis of this cascade in pancreatic cancer cells revealed that the ERK-mediated pathway regulates genes involved in angiogenesis, such as VEGF, CD44, HIF1α, and IL-8. Furthermore, ERK blockage inhibits the migration and tube formation of endothelial cells induced by CXCL12. Considering that inhibitors for several components of this pathway, including CXCR4 itself, are at different stages of clinical trials, this study provides theoretical justification for the clinical testing of these drugs in pancreatic cancer, thus extending the list of potential targets for treating this dismal disease.  相似文献   
97.
98.
The purposes of this study were to examine how hospital patients' backgrounds and clinical illness are related to their perceptions of the individualized care they receive and to test the sensitivity of the Individualized Care Scale (ICS). Cross-sectional explorative survey data were obtained using questionnaires completed by 861 (response rate = 88%) predischarge hospital patients from six hospitals in Southern Finland in 2004. Self-administered questionnaires included the ICS as well as the 15D, a measure of health-related quality of life, and gathered information about the patients' backgrounds. Based on association tests, younger age, poorer state of health, and higher level of education were associated with more critical perceptions of individualized care. Using simultaneous regression analysis and presenting the results from stronger to weaker, we found age to be the strongest predictor of patients' positive perceptions of the individualized care they received. This was followed by health-related quality of life (HRQoL) as measured by the 15D, vocational education, and type of admission. The ICS was found to be a valid tool for the measurement of individualized care in hospitals. The self-reported patient data from this survey suggest that some patient characteristics are associated with the patients' perceptions about the individualized care they receive. There is now a need to consider how these characteristics can be taken into account in nursing care delivery to increase individualized care for hospital patients. The results also support use of the ICS in the measurement of individualized care in hospitals.  相似文献   
99.
Conclusions Limitation of this analysis is participation of limited centers. Though all the regions of the country are represented total number of procedures reported are less. Isolated CABG is commonest procedure performed in 2004. Congenital surgical procedures are more than the valvular heart disease procedure. For appropriate categorization we need standard nomenclature for various congenital surgical procedures.  相似文献   
100.
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