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   1067391篇
  免费   73071篇
  国内免费   1347篇
耳鼻咽喉   14992篇
儿科学   34530篇
妇产科学   28610篇
基础医学   152371篇
口腔科学   29530篇
临床医学   94246篇
内科学   202116篇
皮肤病学   24454篇
神经病学   80867篇
特种医学   42916篇
外国民族医学   201篇
外科学   162519篇
综合类   21643篇
现状与发展   1篇
一般理论   263篇
预防医学   73993篇
眼科学   24347篇
药学   85868篇
  7篇
中国医学   2699篇
肿瘤学   65636篇
  2019年   7753篇
  2018年   11294篇
  2017年   8907篇
  2016年   10093篇
  2015年   11260篇
  2014年   15269篇
  2013年   22200篇
  2012年   30545篇
  2011年   32284篇
  2010年   18951篇
  2009年   17814篇
  2008年   29947篇
  2007年   32070篇
  2006年   32705篇
  2005年   31033篇
  2004年   29706篇
  2003年   28478篇
  2002年   27458篇
  2001年   59961篇
  2000年   61379篇
  1999年   50720篇
  1998年   11848篇
  1997年   10390篇
  1996年   10335篇
  1995年   10281篇
  1994年   9316篇
  1993年   8819篇
  1992年   37774篇
  1991年   36277篇
  1990年   35734篇
  1989年   34286篇
  1988年   30852篇
  1987年   29984篇
  1986年   28206篇
  1985年   26449篇
  1984年   19174篇
  1983年   16089篇
  1982年   8794篇
  1979年   16999篇
  1978年   11377篇
  1977年   10195篇
  1976年   8822篇
  1975年   10047篇
  1974年   11633篇
  1973年   11257篇
  1972年   10745篇
  1971年   10085篇
  1970年   9244篇
  1969年   8924篇
  1968年   7907篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.

Background

Physicians treating nonvalvular atrial fibrillation (AF) assess stroke and bleeding risks when deciding on anticoagulation. The agreement between empirical and physician-estimated risks is unclear. Furthermore, the association between patient and physician sex and anticoagulation decision-making is uncertain.

Methods

We pooled data from 2 national primary care physician chart audit databases of patients with AF (Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation and Coordinated National Network to Engage Physicians in the Care and Treatment of Patients with Atrial Fibrillation Chart Audit) with a combined 1035 physicians (133 female, 902 male) and 10,927 patients (4567 female and 6360 male).

Results

Male physicians underestimated stroke risk in female patients and overestimated risk in male patients. Female physicians estimated stroke risk well in female patients but underestimated the risk in male patients. Risk of bleeding was underestimated in all. Despite differences in risk assessment by physician and patient sex, > 90% of patients received anticoagulation across all subgroups. There was modest agreement between physician estimated and calculated (ie, CHADS2 score) stroke risk: Kappa scores were 0.41 (0.35-0.47) for female physicians and 0.34 (0.32-0.36) for male physicians.

Conclusions

Our study is the first to examine the association between patient and physician sex influences and stroke and bleeding risk estimation in AF. Although there were differences in agreement between physician estimated stroke risk and calculated CHADS2 scores, these differences were small and unlikely to affect clinical practice; further, despite any perceived differences in the accuracy of risk assessment by sex, most patients received anticoagulation.  相似文献   
994.

Background and aims

It is not known whether non alcoholic fatty liver disease (NAFLD) is a risk factor for diabetes in non obese, non centrally-obese subjects. Our aim was to investigate relationships between fatty liver, insulin resistance and a biomarker score for liver fibrosis with incident diabetes at follow up, in subjects who were neither obese nor centrally-obese.

Methods and results

As many as 70,303 subjects with a body mass index (BMI) < 25 kg/m2 and without diabetes were followed up for a maximum of 7.9 years. At baseline, fatty liver was identified by liver ultrasound, insulin resistance (IR) by homeostatic model assessment of insulin resistance (HOMA-IR) ≥2.0, and central obesity by waist circumference (waist circumference ≥90 cm (men) and ≥85 cm (women). The Fibrosis-4 (FIB-4 score) was used to estimate extent of liver fibrosis. Cox proportional hazards models adjusted for confounders were used to estimate hazard ratios (aHRs) for incident diabetes. As many as 852 incident cases of diabetes occurred during follow up (median [IQR] 3.71 [2.03] years). Mean ± SD BMI was 22.8 ± 1.8 and 21.7 ± 2.0 kg/m2 in subjects with and without diabetes at follow up. In subjects without central obesity and with fatty liver, aHRs (95% CI) for incident diabetes at follow up were 2.17 (1.56, 3.03) for men, and 2.86 (1.50,5.46) for women. Similar aHRs for incident diabetes occurred with fatty liver, IR and the highest quartile of FIB-4 combined, in men; and there was a non significant trend toward increased risk in women.

Conclusions

In normal weight, non-centrally obese subjects NAFLD is an independent risk factor for incident diabetes.  相似文献   
995.
996.
In this work, we propose a semiparametric method for estimating the optimal treatment for a given patient based on individual covariate information for that patient when data from a crossover design are available. Here, we assume there are carry-over effects for patients switching from one treatment to another. For the K treatment (K ≥ 2) scenario, we show that nonparametric estimation of carry-over effects can have the undesirable property that comparison of treatment means can only be done using independent outcome measurements from different groups of patients rather than using available joint measurements for each patient. To overcome this barrier, we compare probabilities of outcome variable of each treatment dominating outcome variables for all other treatments conditional on patient-specific scores constructed from patient covariates. We suggest single-index models as appropriate models connecting outcome variables to covariates and our empirical investigations show that frequencies of correct treatment assignments are highly accurate. The proposed method is also rather robust against departures from a single-index model structure. We also conduct a real data analysis to show the applicability of the proposed procedure.  相似文献   
997.
Pharmaceutical Chemistry Journal - The purpose of this work was to validate the method of UV absorption spectrophotometry for the determination of thiamazole in transdermal patches during their...  相似文献   
998.
During an Ebola outbreak, the WHO recommends that health professionals consider people as suspect cases (SCs) when they show key signs such as the sudden onset of high fever or specific symptoms after having had contact with a suspect or confirmed Ebola case. SCs should then get care, be isolated and be reported to health authorities until the Ebola virus disease is confirmed through a lab test. This exploratory study aims to understand this identification process in the field based on a qualitative analysis of the diagnosis and therapeutic itineraries of 19 SCs in Cote d’Ivoire and Senegal (2014–2015). Results indicate that the main criteria for SC identification at the field level were fever (understood broadly) and provenance from a highly affected country (applied indiscriminately). WHO criteria were not followed in at least 9 of the 19 cases. Several medical, social and cultural factors favour over-identification of people as SCs, including relativism in defining ‘high fever’, placism, humanitarian or securitarian bias, issues in categorising SC's contact cases, and the context of fear. To avoid undue categorisation and its possible harmful social effects, the WHO definition should be implemented more carefully in various contexts and with greater consideration for ethical issues, while prioritising diagnosis strategies with higher specificity.  相似文献   
999.
1000.
Health scholars have long been calling for a new approach to understanding and responding to public health challenges, recognizing the dynamic influence of social and ecological processes and the importance of respecting different ways of knowing. With daunting new challenges to collective health, we sought to ascertain how future generations of public health researchers and practitioners are being prepared with the knowledge, attitudes, and skills needed for the tasks ahead. We found that of the 76 graduate level programs listed by the Public Health Agency of Canada, 65% required at least one quantitative methods course, but only 26% required qualitative methods and only 16% required a course in community engagement. While 25% had at least one required course related to social theory or social determinants of health, only 3% required a course on the ecological determinants. Our examination suggests that the majority of schools of public health may still be frozen in old paradigms wherein interdisciplinary inquiry and the development of skills to work with communities to implement and evaluate interventions to promote and protect collective health are still only peripheral considerations. With the intensification of public distrust in experts in this post-truth era, greater emphasis is needed now more than ever to develop skills in understanding and engaging the public in addressing the underlying issues threatening health. We argue that as the challenges of the Anthropocene are upon us, it is urgent that we rethink the skills we are teaching and prepare ourselves to radically adjust our approach.  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