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   11204篇
  免费   1055篇
  国内免费   8篇
耳鼻咽喉   213篇
儿科学   287篇
妇产科学   537篇
基础医学   1560篇
口腔科学   345篇
临床医学   1152篇
内科学   2487篇
皮肤病学   99篇
神经病学   1474篇
特种医学   316篇
外国民族医学   1篇
外科学   1512篇
综合类   184篇
一般理论   2篇
预防医学   657篇
眼科学   232篇
药学   626篇
中国医学   1篇
肿瘤学   582篇
  2021年   114篇
  2019年   126篇
  2018年   147篇
  2017年   129篇
  2016年   115篇
  2015年   143篇
  2014年   192篇
  2013年   317篇
  2012年   412篇
  2011年   443篇
  2010年   262篇
  2009年   275篇
  2008年   392篇
  2007年   431篇
  2006年   445篇
  2005年   435篇
  2004年   403篇
  2003年   375篇
  2002年   402篇
  2001年   363篇
  2000年   370篇
  1999年   283篇
  1998年   105篇
  1997年   112篇
  1996年   104篇
  1994年   90篇
  1993年   88篇
  1992年   251篇
  1991年   254篇
  1990年   281篇
  1989年   280篇
  1988年   275篇
  1987年   269篇
  1986年   239篇
  1985年   274篇
  1984年   213篇
  1983年   164篇
  1982年   127篇
  1981年   132篇
  1979年   199篇
  1978年   157篇
  1977年   133篇
  1976年   108篇
  1975年   96篇
  1974年   159篇
  1973年   146篇
  1972年   117篇
  1971年   105篇
  1970年   108篇
  1969年   96篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
In October 1985, the Food and Drug Administration approved a new indication of aspirin for the secondary prevention of recurrent myocardial infarction (MI) and death in patients with MI or unstable angina. Clinical trials have demonstrated the efficacy of this drug, especially when treatment is begun soon after the initial event. The antiplatelet actions of aspirin seem to be the most plausible explanation for its efficacy in reducing mortality and the rate of reinfarction. A single daily 325-mg tablet is effective and produces side-effect incidences of only zero to two percent above those produced by placebo. This article assesses the current state of knowledge regarding the value of aspirin therapy in survivors of acute MI and the implications for clinical practice.  相似文献   
52.
53.
54.
On July 25, 1989, President Bush signed a bill declaring the 1990's to be the Decade of the Brain. This offers the clinical and basic neuroscience communities an opportunity to join with the National Institute of Neurological Disorders and Stroke in moving ahead vigorously with research aimed at preventing and treating neurological disease. Neurosurgery must be an active participant in this national endeavor; its influence, skills, and contributions are needed.  相似文献   
55.
The federal Medicare Diagnosis Related Group payment mechanism is undergoing constant change. Significant interest has been generated at the health policy level regarding reimbursement for patients with complications and comorbidities. The purpose of this study was to analyze hospital resource consumption for patients in the seventeen urology non-complicating condition (CC) stratified Diagnostic Related Groups (DRGs), currently 45 percent of urology DRGs. We analyzed 185 Medicare patients in these non-CC stratified urology DRGs and found that patients with more CCs per patient had higher total hospital costs per patient, financial risk under DRGs, a greater percentage of outliers, and a higher mortality, than patients in these same DRGs with fewer CCs per patient. These findings suggest that the current DRG system is inequitable to some patients and certain hospitals vis-a-vis non-CC stratified urology DRGs. The Health Care Financing Administration has not significantly changed the complicating condition urology DRG classification, as of its recent May, 1988 legislation. Financial disincentives to treat these patients may affect both their access and quality of care in the future.  相似文献   
56.
Inhalation of benzene produces a prolongation of mouse red blood cell glycerol hemolysis time. This was not observed in red blood cells directly incubated in benzene. Increased resistance to the hemolytic action of glycerol should be explored as a potentially useful biological monitoring procedure in the red blood cells of benzene-exposed humans.  相似文献   
57.
缺血性卒中或短暂性脑缺血发作患者的卒中预防指南   总被引:8,自引:0,他引:8  
这份新声明旨在为缺血性卒中或短暂性脑缺血发作存活者的缺血性卒中预防提供全面和及时的循证推荐,循证推荐包括对危险因素的控制,动脉粥样硬化性疾病的干预措施,心源性栓塞的抗栓治疗以及非心源性卒中抗血小板药的应用。另外,还为其他多种特殊情况下复发性卒中的预防提供了推荐、包括动脉夹层分离、卵圆孔未闭、高同型半胱氨酸血症、高凝状态、镰状细胞病、脑静脉窦血栓形成、女性卒中(特别是与妊娠和绝经后激素替代治疗相关卒中),脑出血后肮凝药的应用,以及该指南在高危人群中执行和应用的特殊措施。  相似文献   
58.
Nutritional deprivation is associated with poor growth and decreased levels of net circulating somatomedin activity, as measured by bioassay. Since somatomedin activity reflects the contributions both of somatomedins (which stimulate cartilage) and of somatomedin inhibitors (which antagonize the ability of the somatomedins to stimulate cartilage), we asked if changes in net somatomedin activity could involve progressive underlying alterations in levels of both somatomedins and somatomedin inhibitors. Groups of rats were killed during three days of fasting and 24 hours of refeeding. Fasting was associated with a rise in serum beta-hydroxybutyrate from 1.6 to 12.6 mmol/L after one day, followed by a decline to 4 mmol/L at three days. Somatomedins (low-MW) were separated from somatomedin inhibitors (high-MW) by gel permeation chromatography at acid pH on Sephadex G-50 and TSK-2000 HPLC. Somatomedins fell 35% after one day of fasting, and decreased to 59% below control levels after three days (P less than .05). Somatomedins did not change with six hours of refeeding, but then rose rapidly, reaching control levels after 24 hours. Somatomedins were correlated with change in weight (r = .41, P less than .05), but not with glucose or beta-hydroxybutyrate. Inhibitors rose to 195% above control-levels after one day of fasting, and continued to rise to 375% above control after three days (P less than .01). In contrast to the delayed change in somatomedins with refeeding, there was an abrupt fall in inhibitors (41% below three-day fasted levels after six hours), returning to control levels after 24 hours.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
59.
The comparative susceptibility of over 400 strains of aerobic and anaerobic pathogens, isolated from clinical specimens in late 1987 and early 1988, to imipenem and 15 other antimicrobial agents was studied using a uniform broth microdilution technique recommended by the National Committee for Clinical Laboratory Standards. Imipenem had the widest spectrum of activity and was consistently the most active agent tested. It was active against aerobic gram-positive cocci, aerobic gram-negative bacilli, and anaerobic bacteria.  相似文献   
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