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   2066篇
  免费   165篇
  国内免费   25篇
耳鼻咽喉   6篇
儿科学   171篇
妇产科学   25篇
基础医学   206篇
口腔科学   117篇
临床医学   186篇
内科学   495篇
皮肤病学   80篇
神经病学   47篇
特种医学   342篇
外科学   186篇
综合类   23篇
预防医学   118篇
眼科学   19篇
药学   109篇
  1篇
中国医学   1篇
肿瘤学   124篇
  2021年   19篇
  2020年   14篇
  2019年   24篇
  2018年   46篇
  2017年   32篇
  2016年   29篇
  2015年   36篇
  2014年   32篇
  2013年   59篇
  2012年   28篇
  2011年   29篇
  2010年   51篇
  2009年   92篇
  2008年   43篇
  2007年   57篇
  2006年   66篇
  2005年   49篇
  2004年   41篇
  2003年   49篇
  2002年   46篇
  2001年   34篇
  2000年   44篇
  1999年   45篇
  1998年   111篇
  1997年   124篇
  1996年   119篇
  1995年   85篇
  1994年   87篇
  1993年   102篇
  1992年   31篇
  1991年   40篇
  1990年   38篇
  1989年   67篇
  1988年   55篇
  1987年   49篇
  1986年   42篇
  1985年   46篇
  1984年   25篇
  1983年   21篇
  1982年   25篇
  1981年   42篇
  1980年   27篇
  1979年   22篇
  1978年   17篇
  1977年   27篇
  1976年   23篇
  1975年   12篇
  1971年   6篇
  1970年   10篇
  1968年   5篇
排序方式: 共有2256条查询结果,搜索用时 0 毫秒
1.
Birth weight on 12,644 singleton infants from 6,196 sibships born in Maryland between 1980 and 1984 were used to estimate the effects of nine maternal and infant covariates on the sibship correlation in birth weight. Assuming a homogeneous correlation across all families, the estimated intraclass correlation was 0.4664 (+/- 0.0099). This high sibship correlation makes it possible to predict, with reasonable accuracy, the birth weight of a child given information on previous sibs, as well as covariates on the mother and/or infant pertinent to a given pregnancy. The reduction in variance associated with incorporating information on the nine covariates used here was approximately equal to that obtained by conditioning on a single previous sib. Testing for heterogeneity in correlation among different groups of families showed that a crude measure of parity (first live birth vs. other), time between births, mother's marital status, and maternal age at the birth of the last child significantly influenced the sibship correlation in birth weight.  相似文献   
2.
Background: Pemetrexed and cisplatin have recently been shown to significantly improve survival compared with cisplatin alone. However, there are only limited data reflecting teaching hospital experience outside a clinical trial. Pemetrexed has only been available in Australia on a restricted basis since 2002. We reviewed our experience of patients treated on the Australian ‘Special Access Scheme’ at three major thoracic oncology units. Methods: Charts were reviewed for all patients enrolled on the scheme. Data was extracted on age, World Health Organization (WHO) performance status, histology, prior therapy, time from diagnosis to starting pemetrexed, chemotherapy (pemetrexed alone or with a platinum), cycle number, response rate, actuarial progression‐free and overall survival. Doses were cisplatin 75 mg/m2 or carboplatin AUC = 5 and pemetrexed 500 mg/m2 every 21 days. Results: 52 patients (32 male and 20 female) were reviewed. Median age was 58 years and 88% were WHO 0–1. Histology included 54% epithelial, 17% biphasic (epithelial and sarcomatoid) and 21% undefined. The median time from diagnosis to administration of pemetrexed was 145 days. Sixty‐five percent had minimal surgical intervention with video assisted thoracoscopy, pleurodesis and biopsy, while 19% had received prior palliative radiation. Seventy‐one percent were chemotherapy naïve, the remaining 29% having received previous platinum and/or gemcitabine regimens. Twenty‐three percent had pemetrexed alone, 35% in combination with carboplatin and 42% with cisplatin. The median number of cycles was 4 (range 1–13). The response rate was 33%. No toxicity was observed in 20% grade 3–4 toxicity in 10% (majority nausea/vomiting). The median progression‐free and overall survival times from starting pemetrexed were 184 days and 298 days, respectively. Conclusions: Pemetrexed‐based regimens are safe and effective in a community setting in malignant mesothelioma.  相似文献   
3.
4.
1. The present study aimed to determine the feasibility of conducting a 5 year cardiovascular outcome trial of the treatment of 6000 elderly hypertensive patients in Australian general practices. 2. General practitioners (GPs) were invited to participate by mail and personal follow-up. Patient records were reviewed to identify subjects for a blood pressure (BP) screening programme. Blood pressure was measured on three occasions and eligible subjects were included if the average BP was 160 mmHg systolic or 90 mmHg diastolic if systolic BP was 140 mmHg. 3. Seven hundred and forty-one GPs were approached and 89 were enrolled in the study (12% of mail invites and 75% of those receiving a personal contact). In 16 practices where screening was completed, 82 000 records were reviewed to identify 4% patients eligible for screening. Twenty-two per cent of eligible subjects attended screening. Of 1938 subjects screened, 180 (9%) had BP 5=160/90 mmHg. Forty-seven percent of subjects (n = 916) were receiving antihypertensive therapy and 184 (20%) were withdrawn from therapy. One hundred and sixteen (63%) of these subjects had BP return to study entry levels within 6 weeks. Fifty-seven newly diagnosed and 81 previously treated subjects were randomized (7% of the screened population). 4. Based on the high participation rate of GPs, the response rate of patients to attend a BP screening programme and the 7% randomization to screening ratio for entry into the study, the ANBP2 pilot study has demonstrated that it is feasible to recruit subjects from Australian general practices to a cardiovascular outcome trial.  相似文献   
5.
6.
For more than two decades, the International Narcotic Control Board (INCB) has tried to stop harm reduction and its HIV prevention programs. This posture is based on a fundamental misunderstanding of their responsibilities and of drug addiction itself – i.e. as a public health and clinical care matter made criminal by decree. A recent focal point for the Board's action has been rejecting the use of supervised injection facilities to reduce morbidity and mortality of drug injectors. They single out individual countries and attempt to bully them into rejecting such programs under the banner of the United Nations (falsely) and in the name of international treaties. Their unrelenting and unjustified badgering of signatories to the international treaties that established the INCB is not only unjustified; it is an affront to one of the core purposes of the Board itself: to ensure adequate medical supplies and safe use of controlled substances. The INCB's ill-conceived obsession with intravenousaddiction as a crime flies in the face of the medical view and policies of the World Health Organization and the universally endorsed principles of the General Assembly of the United Nations.  相似文献   
7.
8.
9.
Pediatric knee MR imaging: pattern of injuries in the immature skeleton   总被引:3,自引:0,他引:3  
  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