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   15717篇
  免费   1370篇
  国内免费   43篇
耳鼻咽喉   143篇
儿科学   510篇
妇产科学   396篇
基础医学   2066篇
口腔科学   376篇
临床医学   1716篇
内科学   2843篇
皮肤病学   280篇
神经病学   1392篇
特种医学   600篇
外科学   2567篇
综合类   301篇
一般理论   18篇
预防医学   1385篇
眼科学   386篇
药学   1256篇
  3篇
中国医学   8篇
肿瘤学   884篇
  2021年   222篇
  2020年   139篇
  2019年   228篇
  2018年   254篇
  2017年   182篇
  2016年   223篇
  2015年   263篇
  2014年   365篇
  2013年   519篇
  2012年   752篇
  2011年   827篇
  2010年   415篇
  2009年   397篇
  2008年   660篇
  2007年   685篇
  2006年   690篇
  2005年   592篇
  2004年   582篇
  2003年   582篇
  2002年   479篇
  2001年   462篇
  2000年   500篇
  1999年   409篇
  1998年   199篇
  1997年   131篇
  1996年   159篇
  1995年   152篇
  1994年   124篇
  1993年   142篇
  1992年   394篇
  1991年   357篇
  1990年   370篇
  1989年   349篇
  1988年   346篇
  1987年   319篇
  1986年   308篇
  1985年   338篇
  1984年   259篇
  1983年   212篇
  1982年   146篇
  1981年   125篇
  1980年   123篇
  1979年   235篇
  1978年   171篇
  1977年   123篇
  1976年   117篇
  1974年   119篇
  1973年   128篇
  1972年   112篇
  1970年   115篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.

Introduction

Physician communication impacts patient outcomes. However, communication skills, especially around difficult conversations, remain suboptimal, and there is no clear way to determine the validity of entrustment decisions. The aims of this study were to 1) describe the development of a simulation-based mastery learning (SBML) curriculum for breaking bad news (BBN) conversation skills and 2) set a defensible minimum passing standard (MPS) to ensure uniform skill acquisition among learners.

Innovation

An SBML BBN curriculum was developed for fourth-year medical students. An assessment tool was created to evaluate the acquisition of skills involved in a BBN conversation. Pilot testing was completed to confirm improvement in skill acquisition and set the MPS.

Outcomes

A BBN assessment tool containing a 15-item checklist and six scaled items was developed. Students' checklist performance improved significantly at post-test compared to baseline (mean 65.33%, SD = 12.09% vs mean 88.67%, SD = 9.45%, P < 0.001). Students were also significantly more likely to have at least a score of 4 (on a five-point scale) for the six scaled questions at post-test. The MPS was set at 80%, requiring a score of 12 items on the checklist and at least 4 of 5 for each scaled item. Using the MPS, 30% of students would require additional training after post-testing.

Comments

We developed a SBML curriculum with a comprehensive assessment of BBN skills and a defensible competency standard. Future efforts will expand the mastery model to larger cohorts and assess the impact of rigorous education on patient care outcomes.  相似文献   
2.
3.
Summary To evaluate the potential effect of androgens on the development and growth of human colorectal adenomas, the prevalence and concentration of cytosolic androgen receptors (AR) were analysed in 26 adenomas and 19 samples of normal colonic mucosa by a hybrid ligand receptor-binding assay. AR were detected in 7 of the adenomas (26.9%), and in 6 of the normal mucosa samples (31.6%). In the adenomas, AR levels demonstrated were low, ranging from 6 to 31 fmol/mg cytosol protein, and dissociation constants (Kds) ranged from 0.17–2.7x10-9 M. Of 13 adenomas excised from men, 6 (46%) had positive receptor activity, whereas only 1 of 13 (7.7%) from women was positive (P=0.03, Fisher's exact test). There was no correlation between AR titre and patient age, or between adenoma size and histological type or degree of dysplasia. In normal mucosa, AR levels ranged from 7 to 33 fmol/mg and Kds ranges from 0.24–3.1x10-9 M. There was no significant difference between either AR prevalence or levels in the adenomas and normal mucosa. The sex difference was exclusive to the adenoma. Endogenous androgen may play a role in adenoma development early in the promotional process.  相似文献   
4.
Recurrent erosion   总被引:1,自引:0,他引:1  
  相似文献   
5.
A tracer kinetic procedure was developed for the measurement of monoamine oxidase type B (MAO-B) activity using L-[11C]deprenyl and positron emission tomography (PET). The kinetic model consisted of two tissue compartments with irreversible binding to the second compartment (three rate constants). In addition, a blood volume component was included. Special attention was given to the accurate measurement of the plasma and whole blood input functions. The method was applied to the measurement of the dose-response curve of a reversible MAO-B inhibitor (Ro 19-6327). From the results, it followed that the rate constant for irreversible binding (k3) appeared to be a better index of MAO-B activity than the net influx constant Ki. Furthermore, regional analysis demonstrated that Ki, but not k3, was flow dependent. This implies that full kinetic analysis is required for an accurate assessment of MAO-B activity.  相似文献   
6.
A cohort of 1163 pregnant women in two small towns in South Wales, UK, was identified and followed until the children born to them were five years of age. Growth in these children is described and a number of determinants identified. Social-class differences were very small at birth but differences in height became clear by the age of two years and in head circumference before this. In height the differences were largely accounted for by greater growth in social class I, but there was a gradient in head circumference throughout all the social classes. The social class effects gradually increased as the children became older. Parity of the mothers had a small effect on size at birth but age of the mother had no effect once parity was allowed for. Data on illnesses in the children were collected but no effect on growth could be detected. By far the most important determinant of growth which could be controlled is maternal smoking. About 40% of the women smoked, about 17% heavily (15 or more cigarettes per day) and the prevalence of smoking altered little during pregnancy. There was a graded effect of smoking on growth up to a 9% deficit in birth-weight, a 2% deficit in length at birth and a 1.5% deficit in head circumference in the babies born to the mothers who smoked most heavily (25 or more cigarettes per day) compared with non-smokers. There effects decreased with age but there were still residual effects at age five years.  相似文献   
7.
8.
The expression of ras oncogene in normal and pathological liver disease   总被引:1,自引:0,他引:1  
Activation of the ras oncogene is associated with overproduction of the normal gene product (p21). Ninety one paraffin-embedded specimens were used to map the distribution of the normal form of p21 in normal, inflamed, cirrhotic and carcinomatous liver parenchyma. Monoclonal antibodies (Mo-RAP) were raised against the normal form of the ras-oncogene product and histological sections were stained by the peroxidase-antiperoxidase technique. Normal, inflamed and cirrhotic liver showed either minimal or moderate cytoplasmic staining. By contrast primary (n = 13) and secondary (n = 41) liver carcinomas exhibited intense staining. The differential pattern observed in p21 distribution could have useful clinical applications.  相似文献   
9.
10.
Objectives: To determine interobserver agreement between radiologists for computed tomography (CT) angiography and venography. CT venography of the lower extremities combined with standard CT angiography of the chest may result in an increased overall diagnosis rate of venous thromboembolism (pulmonary embolism or deep venous thrombosis).
Methods: The study had a retrospective cohort design. The population consisted of emergency department patients who were evaluated for suspected pulmonary embolism. A random sample of 50 patients diagnosed and treated for venous thromboembolism and 50 age- and gender-matched patients whose CT angiograms and venograms were read as negative were enrolled. The original reading (R1) was compared with readings of two study radiologists: R2, a general radiologist, and R3, a radiologist with fellowship training in cross-sectional imaging. All readers were blinded to each other.
Results: Both R2 and R3 found both CT angiogram and venogram components technically adequate in 95% (95% CI = 89% to 98%) and 86% (95% CI = 78% to 92%) of studies, respectively. The agreement was very good for CT angiography (lowest agreement = 92%; lowest κ = 0.83) and was good for CT venography (85%, κ = 0.65). In nine cases, R1 read the CT angiogram as negative but the venogram as positive for DVT, whereas both R2 and R3 read both components as negative in four of these nine, suggesting a false-positive isolated DVT rate of 44% (95% CI = 19% to 73%). In no case did R1 read both scan components as negative when R2 and R3 agreed on presence of pulmonary embolism or DVT.
Conclusions: Diagnosis of pulmonary embolism on CT angiography is more reliable than diagnosis of isolated DVT on CT venography.  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