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   542672篇
  免费   28395篇
  国内免费   567篇
耳鼻咽喉   6785篇
儿科学   17288篇
妇产科学   12930篇
基础医学   94300篇
口腔科学   12552篇
临床医学   49322篇
内科学   98026篇
皮肤病学   12160篇
神经病学   34950篇
特种医学   20130篇
外国民族医学   54篇
外科学   79900篇
综合类   7769篇
现状与发展   2篇
一般理论   115篇
预防医学   39672篇
眼科学   12208篇
药学   42264篇
  1篇
中国医学   1188篇
肿瘤学   30018篇
  2021年   4190篇
  2019年   4113篇
  2018年   6048篇
  2017年   4352篇
  2016年   5107篇
  2015年   5667篇
  2014年   7500篇
  2013年   11044篇
  2012年   16274篇
  2011年   18081篇
  2010年   10447篇
  2009年   9242篇
  2008年   16307篇
  2007年   18072篇
  2006年   17543篇
  2005年   16826篇
  2004年   16448篇
  2003年   15814篇
  2002年   15361篇
  2001年   22885篇
  2000年   23383篇
  1999年   19297篇
  1998年   5398篇
  1997年   4494篇
  1996年   4528篇
  1995年   4258篇
  1992年   14652篇
  1991年   16021篇
  1990年   16148篇
  1989年   15818篇
  1988年   14462篇
  1987年   14315篇
  1986年   13302篇
  1985年   12803篇
  1984年   9492篇
  1983年   8076篇
  1982年   4221篇
  1979年   8991篇
  1978年   6401篇
  1977年   5179篇
  1976年   5536篇
  1975年   6652篇
  1974年   7453篇
  1973年   7192篇
  1972年   6625篇
  1971年   6331篇
  1970年   5922篇
  1969年   5502篇
  1968年   5204篇
  1967年   4648篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
Molecular characterization of Wuchereria bancrofti is essential to develop suitable anti-filarial drugs and vaccines. We describe here isolation, sequence analysis and cloning of a partial cDNA of an enzyme superoxide dismutase from this parasite. The immunoscreening of a lambda zap W. bancrofti microfilarial (Mf) cDNA library with microfilaremic sera had resulted in the isolation of several seroreactive clones including, WbSOD. This clone contained a 309 bp insert and showed significant nucleotide and deduced amino acid sequence homologies to the superoxide dismutases of other nematode parasites. The antioxidant property of this enzyme may have important contribution in the defense mechanism of the parasite against host immune response.  相似文献   
102.
103.
104.
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   
105.
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   
106.
107.
108.
BACKGROUND: To investigate the degree of systemic inflammation, as reflected by serum C-reactive protein (CRP) levels, associated with controlled ovarian hyperstimulation (COH) with human chorionic gonadotropin (hCG) or gonadotropin-releasing hormone (GnRH) agonist for the induction of final follicular maturation. DESIGN: Prospective, observational study. SETTING: An in vitro fertilization (IVF) unit of an academic medical center. PATIENTS: Twenty-four women undergoing COH and IVF with the flexible GnRH antagonist protocol were prospectively assigned to receive hCG or GnRH agonist for the induction of final follicular maturation. METHODS: Blood was drawn three times during COH for measurement of sex-steroid and CRP levels: the day on which adequate suppression was obtained (Day-0); the day of or prior to administration of hCG (Day-hCG); and (3) the day of ovum pick-up (Day-OPU). Levels were compared among the three time points in the two groups. RESULTS: No between-group differences were observed in terms of patient age, gonadotropin dosage, duration of stimulation or number of oocytes retrieved. Serum CRP levels were significantly higher on Day-OPU than on Day-hCG and Day-0, but the difference was significant only in the hCG group (p<0.03 for both). The percentage change in CRP levels after hCG administration (Day-OPU vs. Day-hCG) (96%) was higher than that after GnRH administration (23%). CONCLUSION: Administration of GnRH agonist in patients undergoing COH for IVF yields a lesser degree of systemic inflammation, as reflected by CRP levels, than hCG.  相似文献   
109.
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   
110.
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   
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