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   316篇
  免费   27篇
儿科学   5篇
妇产科学   18篇
基础医学   24篇
口腔科学   2篇
临床医学   29篇
内科学   89篇
皮肤病学   8篇
神经病学   13篇
特种医学   3篇
外科学   35篇
综合类   7篇
预防医学   29篇
眼科学   3篇
药学   16篇
肿瘤学   62篇
  2022年   1篇
  2021年   5篇
  2020年   2篇
  2019年   2篇
  2018年   7篇
  2017年   1篇
  2016年   6篇
  2015年   4篇
  2014年   7篇
  2013年   10篇
  2012年   13篇
  2011年   18篇
  2010年   10篇
  2009年   15篇
  2008年   15篇
  2007年   15篇
  2006年   20篇
  2005年   17篇
  2004年   17篇
  2003年   14篇
  2002年   14篇
  2001年   10篇
  2000年   13篇
  1999年   19篇
  1998年   6篇
  1997年   5篇
  1996年   3篇
  1995年   2篇
  1994年   4篇
  1993年   5篇
  1992年   10篇
  1991年   12篇
  1990年   6篇
  1989年   8篇
  1988年   6篇
  1987年   3篇
  1986年   3篇
  1985年   4篇
  1984年   1篇
  1983年   3篇
  1979年   1篇
  1978年   3篇
  1974年   1篇
  1971年   1篇
  1966年   1篇
排序方式: 共有343条查询结果,搜索用时 562 毫秒
1.
Dietary factors in the risk of bladder cancer   总被引:2,自引:0,他引:2  
The relationship between selected dietary factors and the risk of bladder cancer was investigated in a case-control study conducted in northern Italy. The study included 163 cases and 181 controls who were hospitalized for acute, nonneoplastic or urinary tract diseases. The frequency of consumption of green vegetables and carrots was lower in the cases; thus, the estimated relative risks for the upper vs. the lower tertiles were 0.6 for green vegetables and 0.5 for carrots. Significant inverse trends in risk emerged with estimated carotenoid (as well as retinoid) intake. The apparent protection conveyed by vitamin A was stronger in current smokers. The risk of bladder cancer was not related to scores of fat and measures of alcohol consumption; the risk was elevated in coffee drinkers (although there was no tendency to rise with higher consumption), but it was reduced in tea drinkers. These findings were not explainable in terms of selection, information, or confounding bias. Thus, although available information is too uncertain for any precise definition of specific (micro)nutrients related to bladder cancer risk, the confirmation that several aspects of a less-affluent diet adversely affect the risk is still of interest in terms of a better understanding of bladder carcinogenesis.  相似文献   
2.
The experience acquired over the last four years in developing a program of cooperation in mental health in Nicaragua is reported. The concept of 'transfer' underlying the intervention and the general framework of Nicaragua's mental health system is discussed together with the results of the cooperative work. This included organizing training for mental health workers in six teaching and supervision modules, drawing up a mental health manual for primary health care workers, and survey of patterns of care in the 15 existing psychiatric services. Besides the key aspects of general reform of the psychiatric system after the revolution, the paper focuses on differences between organization and patterns of care in urban and rural areas.  相似文献   
3.
A review of 150 published randomized trials on the treatment of lung cancer showed serious methodological drawbacks. Handling of withdrawals (only 7 trials had no dropouts), a priori estimates of sample size (only 9 trials specified the required number of patients), blinding of randomization (only 22 trials had a satisfactory procedure), and information on eligible nonrandomized patients (only 13 studies reported it precisely) were areas of major concern. Although trial quality improved over time both in design/execution (study size estimation and analysis by prognostic factors became more frequent) and reporting (information on patients' characteristics and side effects were more thoroughly reported), their evolution was inconsistent. For non-small-cell lung cancer-despite the persistent lack of proof of efficacy of any active treatment-an untreated control arm was prematurely abandoned and a wide variety of tested regimens prevailed even in better-quality studies. Slightly more promising is the picture for small-cell lung cancer, where research indicates somewhat more reliable-though limited-progress. While clinical research in lung cancer has contributed little to defining the best standard care, we conclude that its heterogeneity makes it unlikely that quantitative meta-analysis of existing trials will be constructive.  相似文献   
4.
5.
6.
7.
The impact of a national education program based on the dissemination of written guidelines for the treatment of breast, colorectal, and ovarian cancer was investigated in Italy. Through a survey of 770 physicians exploring their knowledge and attitudes and a review of medical records of 1,483 patients assessing current clinical practice, this study examined whether 1) the guidelines reached the target population of physicians, 2) they were effective in shaping doctors' opinions, and 3) care patterns conformed with the guidelines. Overall, the net effect of the intervention appeared to be limited in terms of actual diffusion, attributable influence, and impact. As for diffusion, only 60%, 47%, and 44% of doctors were aware of breast, colorectal, and ovarian cancer guidelines, respectively. Although doctors who were aware of the guidelines had more appropriate opinions than those who were not, overall agreement with recommendations was often unsatisfactory. With reference to guidelines recommendations, quality of care was far from optimal, especially in relation to diagnosis and staging. Marked variations in compliance with recommendations emerged with values ranging from 37% to 89%, from 48% to 82%, and from 10% to 97% for breast, colorectal, and ovarian cancer, respectively, and this held true even in hospitals where the larger awareness of the guidelines might have been expected to result in better quality care. It was concluded that any thorough assessment of the impact of educational interventions should include a careful analysis of the strategy and process of dissemination. The availability of clinically relevant messages must also be realistically considered before deciding whether the "guidelines approach" is the strategy most likely to succeed.  相似文献   
8.
9.
10.
Fetal growth restriction and preeclampsia are both conditions of placental etiology and associated to increased risk for the long-term development of cardiovascular disease in the mother. At presentation, preeclampsia is associated with maternal global diastolic dysfunction, which is determined, at least in part, by increased afterload and myocardial stiffness. The aim of this study is to test the hypothesis that women with normotensive fetal growth-restricted pregnancies also exhibit global diastolic dysfunction. This was a prospective case-control study conducted over a 3-year period involving 29 preterm fetal growth-restricted pregnancies, 25 preeclamptic with fetal growth restriction pregnancies, and 58 matched control pregnancies. Women were assessed by conventional echocardiography and tissue Doppler imaging at diagnosis of the complication and followed-up at 12 weeks postpartum. Fetal growth-restricted pregnancies are characterized by a lower cardiac index and higher total vascular resistance index than expected for gestation. Compared with controls, fetal growth-restricted pregnancy was associated with significantly increased prevalence (P<0.001) of asymptomatic left ventricular diastolic dysfunction (28% versus 4%) and widespread impaired myocardial relaxation (59% versus 21%). Unlike preeclampsia, cardiac geometry and intrinsic myocardial contractility were preserved in fetal growth-restricted pregnancy. Fetal growth-restricted pregnancies are characterized by a low output, high resistance circulatory state, as well as a higher prevalence of asymptomatic global diastolic dysfunction and poor cardiac reserve. These findings may explain the increased long-term cardiovascular risk in these women who have had fetal growth-restricted pregnancies. Further studies are needed to clarify the postnatal natural history of cardiac dysfunction in these women.  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