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   38771篇
  免费   2560篇
  国内免费   138篇
耳鼻咽喉   412篇
儿科学   859篇
妇产科学   757篇
基础医学   4617篇
口腔科学   991篇
临床医学   4040篇
内科学   8125篇
皮肤病学   408篇
神经病学   3259篇
特种医学   1294篇
外国民族医学   1篇
外科学   6683篇
综合类   541篇
一般理论   26篇
预防医学   3141篇
眼科学   1197篇
药学   2459篇
中国医学   39篇
肿瘤学   2620篇
  2023年   177篇
  2022年   308篇
  2021年   712篇
  2020年   437篇
  2019年   634篇
  2018年   770篇
  2017年   554篇
  2016年   651篇
  2015年   767篇
  2014年   1117篇
  2013年   1710篇
  2012年   2453篇
  2011年   2548篇
  2010年   1447篇
  2009年   1355篇
  2008年   2325篇
  2007年   2393篇
  2006年   2394篇
  2005年   2578篇
  2004年   2488篇
  2003年   2278篇
  2002年   2166篇
  2001年   281篇
  2000年   221篇
  1999年   367篇
  1998年   511篇
  1997年   412篇
  1996年   348篇
  1995年   343篇
  1994年   279篇
  1993年   264篇
  1992年   217篇
  1991年   192篇
  1990年   159篇
  1989年   155篇
  1988年   148篇
  1987年   160篇
  1986年   148篇
  1985年   178篇
  1984年   264篇
  1983年   259篇
  1982年   370篇
  1981年   332篇
  1980年   308篇
  1979年   153篇
  1978年   194篇
  1977年   201篇
  1976年   191篇
  1975年   149篇
  1973年   149篇
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
81.
OBJECTIVE: To investigate the relation between psychiatric distress and road rage, paying particular attention to the potential link between psychiatric illness and frequent involvement in serious forms of road rage. METHOD: This study reports data on road rage involvement, demographic characteristics, and mental health for a representative sample of 2610 adults in Ontario. The mental health indicator was the 12-item General Health Questionnaire. RESULTS: A cluster analysis revealed 5 distinct groups of people affected by road rage. The most serious offenders (referred to hereafter as the hard core road rage group), representing 5.5% of those affected, exhibited frequent involvement in the most severe forms of road rage and were the most likely (27.5%) to report psychiatric distress. CONCLUSIONS: Road rage, particularly experiences of victimization, is related to psychiatric distress. Evidence of psychiatric distress was highest among hard core road rage perpetrators, individuals noted for frequent involvement in serious aggressive and violent conduct. Further research is needed on violence and road rage and its link to mental health.  相似文献   
82.
In this paper the authors evaluate the long-term results of treatment for articular calcaneus fractures with Westhues method. This evaluation is performed with regard to triple measurement of B?hler's angle value and to subjective criteria. The clinical material from years 1985-2002 consists of 47 patients aged between 24 and 56 years (mean age 32 years) with articular calcaneus fractures--namely, 41 male patients (87.2%) and 6 female patients (12.8%). The follow-up examination was performed in 24 patients (51% of all patients), namely, in 23 male patients (48.8%) and in one female patient (2.2%). Minimum follow-up time was 12 months and maximum was 9 years. Acquired results suggest that Westhues method restores normal B?hler's angle value only in tongue-type calcaneous fractures.  相似文献   
83.
Numerous advances in technology have been made in the last several years in the diagnosis and treatment of the infertile man. Using case presentations, this article highlights these important new developments and reviews the basics of a comprehensive male infertility evaluation. The use of ultrasound as a critical, indispensable, yet noninvasive tool in the evaluation of possible male reproductive tract obstruction is discussed. Since assisted reproductive techniques (ARTs) have be come increasingly important in the management of the otherwise untreatable infertile man, specialized testing of sperm function, e.g., the sperm penetration assay (SPA), and strict morphology assessment are often useful prior to the initiation of some of these assisted reproductive procedures such as intrauterine insemination (IUI) or in vitro fertilization (IVF). Testicular touch preparation cytology and image analysis are also important additions to routine testicular biopsy for quantifying the extent of spermatogenesis. Finally, the revolutionary micromanipulation procedure of intracytoplasmic sperm injection (ICSI) has forever changed the practice of andrology by enabling men previously thought to be irreversibly infertile the chance to initiate their own biologic pregnancy.  相似文献   
84.
NMR microimages of single neural cells were acquired at 500 MHz using a conventional spin echo pulse sequence and a line-narrowing sequence that eliminates susceptibility effects. The data show that any contribution to the measured T2 relaxation rate arising from diffusion in local field inhomogeneities using spin echo sequences at high fields and high spatial resolution is relatively small. We conclude that the measured T2 difference between the nucleus and cytoplasm in these cells represents primarily a true T2 relaxation effect arising from the interactions of water with macromolecules in the two compartments and does not result from microsusceptibility differences. These observations have implications regarding water compartmentation in single cells and the interpretation of the MR characteristics of tissues in vivo.  相似文献   
85.
86.
Thirty-five cardiomyoplasty procedures were performed in five patients with dilated and 30 patients with ischemic cardiomyopathies. Russian-made cardiomyostimulators (CMS) were implanted in these patients. Twenty-one patients underwent a one-step procedure using a left thoracotomy for cardiomyoplasty, while in 14 patients, a two-step procedure that included a mid-line sternotomy was carried out. During the average follow-up period of 9 ± 2.1 months, studies were carried out that showed in survivors improved clinical functional status and decreased heart failure symptoms. Evidence of revascularization of the ischemic myocardium from the latissimus dorsi muscle (LDM) wrap was obtained by angiography and radioactive scintigraphy. In five patients, the CMS had to be removed due to complications, and in all these patients, their clinical functional status deteriorated following the cessation of cardiomyostimulation.  相似文献   
87.
Preventive education in the United States about the dangers of alcohol had failed to create a temperate society by 1840. But in that year, interest in medical treatment of the “habitual drunkard” rekindled in Philadelphia. It was the year an organization of reformed drunkards revitalized American temperance societies by emphasizing practical concern for the inebriate. The author describes Philadelphia's treatment of alcoholics from 1840 through the beginning of the 20th century, when entrepreneurs were marketing secret cures.  相似文献   
88.
In this study we demonstrate byin situ binding that trypsin interacts with the senile plaques found in Alzheimer disease. Characterization of various potential trypsin binding proteins shows that trypsin binding is mediated by β-protein precursor (βPP)—the progenitor of amyloid-β in senile plaques. Using specific antisera against various proteins to sterically block trypsin blocking, we found that only those antibodies raised against proteins or peptides containing the Kunitz protease inhibitor domain were able to abolish binding. By analogy with other protease/inhibitor interactions, we speculate that the binding of trypsin to βPP could involve concomitant βPP cleavage. Therefore, βPP in protecting against potentially damaging proteolysis could simultaneously liberate βPP fragments or intermediate precursors of amyloid-β deposits.  相似文献   
89.
90.
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