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   902篇
  免费   31篇
  国内免费   14篇
耳鼻咽喉   1篇
儿科学   9篇
妇产科学   9篇
基础医学   106篇
口腔科学   6篇
临床医学   120篇
内科学   221篇
皮肤病学   5篇
神经病学   59篇
特种医学   81篇
外科学   144篇
综合类   6篇
一般理论   3篇
预防医学   46篇
眼科学   7篇
药学   67篇
肿瘤学   57篇
  2023年   5篇
  2022年   9篇
  2021年   18篇
  2020年   7篇
  2019年   9篇
  2018年   22篇
  2017年   16篇
  2016年   15篇
  2015年   14篇
  2014年   37篇
  2013年   36篇
  2012年   65篇
  2011年   73篇
  2010年   33篇
  2009年   28篇
  2008年   67篇
  2007年   83篇
  2006年   63篇
  2005年   61篇
  2004年   51篇
  2003年   59篇
  2002年   51篇
  2001年   7篇
  2000年   2篇
  1999年   11篇
  1998年   14篇
  1997年   11篇
  1996年   5篇
  1995年   10篇
  1994年   11篇
  1993年   9篇
  1992年   3篇
  1991年   6篇
  1990年   3篇
  1989年   4篇
  1988年   7篇
  1987年   3篇
  1985年   2篇
  1984年   2篇
  1983年   3篇
  1982年   3篇
  1981年   1篇
  1980年   2篇
  1976年   1篇
  1975年   1篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1971年   1篇
排序方式: 共有947条查询结果,搜索用时 15 毫秒
71.
72.
A 60-year-old man, who presented two myocardial infarctions10 years and 6 years ago, was referred for dyspnoea. Clinicalexamination was unremarkable. Twelve-lead ECG  相似文献   
73.
A new nonpeptidic farnesyltransferase inhibitor, RPR-115135, in combination with 5-fluorouracil (5-FU) was studied in an isogenic cell line model system consisting of human colon cancer HCT-116 cells. HCT-116 cells were transfected with an empty control pCMV vector and with a dominant-negative mutated p53 transgene (248R/W). We found that, relative to control transfectants, there was a slight tendency for the p53 inactivated cells to be less sensitive to 5-FU after 6 days of continuous treatment. Simultaneous administration of RPR-115135 and 5-FU, at equitoxic concentrations, resulted in an enhancement of 5-FU cytotoxicity, especially in the CMV-2 clone. Growth inhibition could be accounted for on the basis of a specific cell cycle arrest phenotype (G(2)-M arrest in CMV-2 and S arrest in mutated clones), as assayed by flow cytometry. The combination RPR-115135 + 5-FU increases apoptotic events only in the CMV-2 clone.  相似文献   
74.
75.
OBJECTIVE: To provide further evidence for the efficacy and safety of drotrecogin alfa (activated) treatment in severe sepsis. DESIGN: Single-arm, open-label, trial of drotrecogin alfa (activated) treatment in severe sepsis patients. Enrollment began in March 2001 and day-28 follow-up completed in January 2003. SETTING: ENHANCE took place in 25 countries at 361 sites. PATIENTS: Patients with known or suspected infection, three or four systemic inflammatory response syndrome criteria, and one or more sepsis-induced organ dysfunctions. Of 2,434 adults entered, 2,378 received drotrecogin alfa (activated), and of these, 2,375 completed the protocol. INTERVENTIONS: Drotrecogin alfa (activated) was infused at a dose of 24 mug/kg/hr for 96 hrs. MEASUREMENTS AND MAIN RESULTS: The 28-day all-cause mortality approximated that observed in PROWESS (25.3% vs. 24.7%). Although patients in ENHANCE had increased serious bleeding rates compared with patients in the drotrecogin alfa (activated) arm of PROWESS (during infusion, 3.6% vs. 2.4%; postinfusion, 3.2% vs. 1.2%; 28-day, 6.5% vs. 3.5%), increased postinfusion bleeding suggested a higher background bleeding rate. Intracranial hemorrhage was more common in ENHANCE than PROWESS (during infusion, 0.6% vs. 0.2%; 28-day, 1.5% vs. 0.2%). The incidence of fatal intracranial hemorrhage was the same during infusion (0.2%) and higher at 28 days (0.5% vs. 0.2%). ENHANCE patients treated within 0-24 hrs from their first sepsis-induced organ dysfunction had lower observed mortality rate than those treated after 24 hrs (22.9% vs. 27.4%, p = .01). CONCLUSIONS: ENHANCE provides supportive evidence for the favorable benefit/risk ratio observed in PROWESS and suggests that more effective use of drotrecogin alfa (activated) might be obtained by initiating therapy earlier.  相似文献   
76.
77.
We compared tobacco withdrawal in pregnant and non-pregnant smokers abstaining from smoking for 24h. Female smokers completed an internet-based questionnaire, including the Minnesota Nicotine Withdrawal Scale-Revised (MNWS). They also rated additional withdrawal items and strength of urge to smoke. Consenting women were randomized to either: (i) abstain from smoking for 24h or (ii) smoke as usual. After 24h they rated their withdrawal again. We included a 'smoking as usual' group as we wished to establish that smoking abstinence increased withdrawal symptoms. Two-hundred and seventy-five women completed both the initial and the 24h questionnaire and reported abstaining (n=115, 17% pregnant) or smoking (n=160, 21% pregnant) as requested. Exclusively among abstinent smokers, we compared symptoms for the pregnant and non-pregnant groups. After 24h pregnant women had significantly lower scores than non-pregnant women for the mean MNWS (p=0.004) and for three individual MNWS symptoms (angry, p=0.010; anxious, p=0.048; impatient, p=0.011), with adjustments for baseline cigarette consumption and baseline withdrawal scores. Overall, on the first day of smoking abstinence, pregnant women are likely to report less severe tobacco withdrawal than non-pregnant women.  相似文献   
78.
79.
Objective: Balloon-expandable stent valves require flow reduction during implantation (rapid pacing). The present study was designed to compare a self-expanding stent valve with annular fixation versus a balloon-expandable stent valve. Methods: Implantation of a new self-expanding stent valve with annular fixation (Symetis®, Lausanne, Switzerland) was assessed versus balloon-expandable stent valve, in a modified Dynatek Dalta® pulse duplicator (sealed port access to the ventricle for transapical route simulation), interfaced with a computer for digital readout, carrying a 25 mm porcine aortic valve. The cardiovascular simulator was programmed to mimic an elderly woman with aortic stenosis: 120/85 mmHg aortic pressure, 60 strokes/min (66.5 ml), 35% systole (2.8 l/min). Results: A total of 450 cardiac cycles was analysed. Stepwise expansion of the self-expanding stent valve with annular fixation (balloon-expandable stent valve) resulted in systolic ventricular increase from 120 to 121 mmHg (126 to 830 ± 76 mmHg)*, and left ventricular outflow obstruction with mean transvalvular gradient of 11 ± 1.5 mmHg (366 ± 202 mmHg)*, systolic aortic pressure dropped distal to the valve from 121 to 64.5 ± 2 mmHg (123 to 55 ± 30 mmHg) N.S., and output collapsed to 1.9 ± 0.06 l/min (0.71 ± 0.37 l/min* (before complete obstruction)). No valve migration occurred in either group. (* = p < 0.05). Conclusions: Implantation of this new self-expanding stent valve with annular fixation has little impact on haemodynamics and has the potential for working heart implantation in vivo. Flow reduction (rapid pacing) is not necessary.  相似文献   
80.

Background  

The European System for Cardiac Operative Risk Evaluation (EuroSCORE) is a widely used risk assessment tool in patients with severe aortic stenosis to determine operability and to select patients for alternative therapies such as transcatheter aortic valve implantation. The objective of this study was to determine the accuracy of the EuroSCORE in predicting mortality following aortic valve replacement (AVR).  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