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   2056篇
  免费   165篇
  国内免费   6篇
耳鼻咽喉   8篇
儿科学   58篇
妇产科学   55篇
基础医学   333篇
口腔科学   21篇
临床医学   225篇
内科学   400篇
皮肤病学   54篇
神经病学   199篇
特种医学   46篇
外科学   148篇
综合类   11篇
一般理论   2篇
预防医学   240篇
眼科学   22篇
药学   237篇
中国医学   2篇
肿瘤学   166篇
  2023年   27篇
  2022年   20篇
  2021年   97篇
  2020年   69篇
  2019年   76篇
  2018年   92篇
  2017年   68篇
  2016年   62篇
  2015年   82篇
  2014年   89篇
  2013年   142篇
  2012年   188篇
  2011年   198篇
  2010年   96篇
  2009年   84篇
  2008年   105篇
  2007年   111篇
  2006年   119篇
  2005年   110篇
  2004年   94篇
  2003年   89篇
  2002年   59篇
  2001年   13篇
  2000年   5篇
  1999年   7篇
  1998年   8篇
  1997年   4篇
  1996年   3篇
  1995年   10篇
  1994年   3篇
  1992年   5篇
  1991年   9篇
  1990年   6篇
  1989年   3篇
  1987年   4篇
  1986年   3篇
  1985年   3篇
  1984年   3篇
  1983年   5篇
  1982年   3篇
  1981年   4篇
  1978年   5篇
  1971年   3篇
  1955年   2篇
  1954年   3篇
  1932年   2篇
  1930年   2篇
  1929年   2篇
  1927年   2篇
  1921年   2篇
排序方式: 共有2227条查询结果,搜索用时 15 毫秒
91.
92.

Background  

High accrual to clinical trials enables new treatment strategies to be tested rapidly, accurately and with generalisability. Ethical standards also must be high so that participation is voluntary and informed. However, this can be difficult to achieve in trials with complex designs and in those which are closely embedded in clinical practice. Optimal recruitment requires a balance of both ethical and accrual considerations. In the context of a trial of stratified treatments for children with acute lymphoblastic leukaemia (UKALL2003) we examined how recruitment looked to an observer and how it felt to the parents, to identify how doctors' communication could promote or inhibit optimal recruitment.  相似文献   
93.
94.
This paper presents the findings of a study designed to increase empirical knowledge of prevention and promotion practices targeted directly or indirectly at children, youth, and their families in the province of Quebec. A profile of these practices emerged from our analysis of the problems and concerns addressed by projects and programs in Quebec, targets for action, activities, strategies, links between organizations, and types of funding. These prevention and promotion practices are discussed in light of recent analyses and critiques in this field. It is hoped that this examination will encourage a healthy criticism of preventive efforts in Quebec, broaden of the scope of our interventions, and stimulate the creation of links between the actors involved in the welfare of children, youth, and families.  相似文献   
95.
96.
97.
98.
Adult male Sprague-Dawley rats were given 0, 0.02, 0.05, and 0.1% nickel sulfate (NiSO4 6H2O) or 0, 44.7, 111.75, and 223.5 mg Ni/L, respectively, in their drinking water for 13 wk. Twenty-four hours following the end of such treatment, all animals survived and no apparent clinical signs of toxicity were noted. The final mean body weights of various nickel sulfate-treated rats were not significantly decreased except for the 0.1% nickel sulfate treated group when compared to those in the control. The absolute and relative organ weights were either increased or decreased or remained unchanged, depending on the organ and the dose of nickel sulfate. Total plasma proteins, plasma albumin and globulins, and plasma glutamic pyruvic transaminase activity were all significantly decreased in 0.1% nickel sulfate-treated rats. Lymphocyte subpopulations (T and B cells) were induced at lower dose levels, but suppressed at the highest (0.1 %) dose group. A significant decrease in urine volume and an increase in BUN were observed at the highest dose group. Biochemical analysis of bronchoalveolar lavage fluid and lung tissue showed some lung damage, whereas no damage to the testis or DNA in liver and kidneys were found. No gross or microscopic changes were seen in any of the various tissues examined. The relative order of bioaccumulation of nickel in different organs of rats when treated at 0.1% nickel sulfate (223.5 mg Ni/L) was kidneys > testes > lung = brain > spleen > heart = liver. But with regard to order of toxicity, both immune and pulmonary systems were found to be very sensitive targets, followed by kidney.  相似文献   
99.
Nurses use several conservative methods for treating urinary incontinence after radical prostatectomy. Functional electrical stimulation (FES) has a recognized role, while extracorporeal magnetic innervation (ExMI) is still under evaluation in the international guidelines. Few data are available in literature, regarding comparisons between these two treatments. The aim of the study is to compare electrical stimulation and magnetic innervation for treating urinary incontinence after radical prostatectomy. Twenty‐two patients treated with ExMI and 18 treated with FES were enrolled in a retrospective study. ExMI was available for 6 weeks; the number of times ExMI was required by the patients to reduce their leakages to 10 g/d or less was compared. The groups had comparable age and body mass index. Initial leakages showed clinically relevant differences (median = 80 g/d in the ExMI patients and 150 g/d in the FES group). After 6 weeks, 71·9% of ExMI patients and 29·2% of FES patients had completed rehabilitation. The difference was statistically significant even after adjusting the analyses for initial leakages (p = 0·008). Six patients treated with ExMI had already undergone FES, with no clinically relevant results after five sessions (leakages reduction <50 g/d). The difference remained even after removing the data of these patients from the analysis (p = 0·004). Both FES and ExMI produce muscle strengthening, which is just one step of rehabilitation. Our findings suggest the possibility of using ExMI instead of FES to reduce the times required to improve muscular performance. Pelvic muscle exercises remain essential to develop the ability to automatically perform the contractions needed to avoid leakages.  相似文献   
100.
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