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   6218篇
  免费   458篇
  国内免费   26篇
耳鼻咽喉   76篇
儿科学   192篇
妇产科学   111篇
基础医学   763篇
口腔科学   111篇
临床医学   535篇
内科学   1671篇
皮肤病学   55篇
神经病学   537篇
特种医学   183篇
外科学   811篇
综合类   109篇
一般理论   9篇
预防医学   638篇
眼科学   173篇
药学   419篇
中国医学   16篇
肿瘤学   293篇
  2023年   27篇
  2022年   44篇
  2021年   125篇
  2020年   62篇
  2019年   103篇
  2018年   126篇
  2017年   112篇
  2016年   128篇
  2015年   168篇
  2014年   187篇
  2013年   326篇
  2012年   353篇
  2011年   423篇
  2010年   276篇
  2009年   213篇
  2008年   397篇
  2007年   438篇
  2006年   391篇
  2005年   417篇
  2004年   379篇
  2003年   361篇
  2002年   327篇
  2001年   79篇
  2000年   64篇
  1999年   83篇
  1998年   82篇
  1997年   51篇
  1996年   43篇
  1995年   51篇
  1994年   42篇
  1993年   50篇
  1992年   34篇
  1991年   41篇
  1990年   41篇
  1989年   29篇
  1988年   25篇
  1987年   32篇
  1986年   21篇
  1985年   33篇
  1984年   48篇
  1983年   37篇
  1982年   45篇
  1981年   41篇
  1980年   39篇
  1979年   18篇
  1978年   31篇
  1977年   28篇
  1975年   25篇
  1973年   19篇
  1972年   20篇
排序方式: 共有6702条查询结果,搜索用时 31 毫秒
1.
2.
3.
OBJECTIVE: To evaluate the effect of statins on aneurysm growth in a group of consecutive patients under surveillance for infrarenal aortic aneurysms (AAA). MATERIALS AND METHODS: All patients (59 statin users, 91 non-users) under surveillance between January 2002 and August 2005 with a follow-up for aneurysm growth of at least 12 months and a minimum of three diameter evaluations were retrospectively included in the analysis. Multiple regression analysis, weighted with the number of observations, was performed to test the influence of statins on AAA growth rate. RESULTS: During a median period of 3.1 (1.1-13.1) years the overall mean aneurysm growth rate was 2.95+/-2.8 mm/year. Statin users had a 1.16 mm/year lower AAA growth rate compared to non-users (95% CI 0.33-1.99 mm/year). Increased age was associated with a slower growth (-0.09 mm/year per year, p = 0.003). Female gender (+1.82 mm/year, p = 0.008) and aneurysm diameter (+0.06 mm/year per mm, p = 0.049) were associated with increased AAA growth. The use of non-steroidal anti-inflammatory drugs, chronic lung disease, or other cardiovascular risk factors were not independently associated with AAA growth. CONCLUSIONS: Statins appear to be associated with attenuation of AAA growth, irrespective of other known factors influencing aneurysm growth.  相似文献   
4.
OBJECTIVES: This study investigates posttraumatic stress disorder (PTSD) and its associated risk factors in a random, national, Canadian sample of United Nations peacekeeping veterans with service-related disabilities. METHODS: Participants included 1016 male veterans (age < 65 years) who served in the Canadian Forces from 1990 to 1999 and were selected from a larger random sample of 1968 veterans who voluntarily and anonymously completed a general health survey conducted by Veterans Affairs Canada in 1999. Survey instruments included the PTSD Checklist-Military Version (PCL-M), Center for Epidemiological Studies-Depression Scale (CES-D), and questionnaires regarding life events during the past year, current stressors, sociodemographic characteristics, and military history. RESULTS: We found that rates of probable PTSD (PCL-M score > 50) among veterans were 10.92% for veterans deployed once and 14.84% for those deployed more than once. The rates of probable clinical depression (CES-D score > 16) were 30.35% for veterans deployed once and 32.62% for those deployed more than once. We found that, in multivariate analyses, probable PTSD rates and PTSD severity were associated with younger age, single marital status, and deployment frequency. CONCLUSIONS: PTSD is an important health concern in the veteran population. Understanding such risk factors as younger age and unmarried status can help predict morbidity among trauma-exposed veterans.  相似文献   
5.
On the Bubble     
Thompson  Don 《JAMA》2006,296(14):1698
  相似文献   
6.
7.
Summary Cytosine arabinsodie (ara-C) and etoposide (VP-16) display synergy in the laboratory. Twenty-six patients participated in a phase I study of high-dose ara-C in combination with VP-16. The dose of VP-16 was held constant at 50 mg/m2 as an intermittent infusion over 33 h; escalating doses of ara-C were given as infusions during hours 9–12 and 21–24. Myelosuppression was the dose-limiting toxicity and occurred with doses considerably less than those expected from studies of the two drugs as single agents. The suggested initial doses for phase II trials with this schedule are 750 mg/m2×2 doses of ara-C and 50 mg/m2 of VP-16. Nonhematologic toxicity was minimal; therefore, further dose escalation is feasible in patients in whom myelosuppression is acceptable.Supported in part by grants from the National Cancer Institute (CA-12197 and CA-09422) and the American Cancer Society CF-85-182  相似文献   
8.
9.
Background: The American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for Perioperative Cardiovascular Evaluation for Noncardiac Surgery recommend an algorithm for a stepwise approach to preoperative cardiac assessment in vascular surgery patients. The authors' main objective was to determine adherence to the ACC/AHA guidelines on perioperative care in daily clinical practice.

Methods: Between May and December 2004, data on 711 consecutive peripheral vascular surgery patients were collected from 11 hospitals in The Netherlands. This survey was conducted within the infrastructure of the Euro Heart Survey Programme. The authors retrospectively applied the ACC/AHA guideline algorithm to each patient in their data set and subsequently compared observed clinical practice data with these recommendations.

Results: Although 185 of the total 711 patients (26%) fulfilled the ACC/AHA guideline criteria to recommend preoperative noninvasive cardiac testing, clinicians had performed testing in only 38 of those cases (21%). Conversely, of the 526 patients for whom noninvasive testing was not recommended, guidelines were followed in 467 patients (89%). Overall, patients who had not been tested, irrespective of guideline recommendation, received less cardioprotective medications, whereas patients who underwent noninvasive testing were significantly more often treated with cardiovascular drugs ([beta]-blockers 43% vs. 77%, statins 52% vs. 83%, platelet inhibitors 80% vs. 85%, respectively; all P < 0.05). Moreover, the authors did not observe significant differences in cardiovascular medical therapy between patients with a normal test result and patients with an abnormal test result.  相似文献   

10.
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