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   395718篇
  免费   41797篇
  国内免费   2816篇
耳鼻咽喉   8379篇
儿科学   12957篇
妇产科学   7385篇
基础医学   38442篇
口腔科学   7042篇
临床医学   45972篇
内科学   100531篇
皮肤病学   14133篇
神经病学   36347篇
特种医学   13871篇
外国民族医学   103篇
外科学   71541篇
综合类   1406篇
现状与发展   72篇
一般理论   63篇
预防医学   29102篇
眼科学   8108篇
药学   18160篇
中国医学   728篇
肿瘤学   25989篇
  2023年   5926篇
  2022年   2056篇
  2021年   6572篇
  2020年   7944篇
  2019年   6094篇
  2018年   14767篇
  2017年   12105篇
  2016年   13232篇
  2015年   13771篇
  2014年   21156篇
  2013年   24899篇
  2012年   21897篇
  2011年   21936篇
  2010年   18442篇
  2009年   20272篇
  2008年   19865篇
  2007年   19181篇
  2006年   20471篇
  2005年   17631篇
  2004年   16066篇
  2003年   13945篇
  2002年   13424篇
  2001年   10437篇
  2000年   9698篇
  1999年   9215篇
  1998年   4683篇
  1997年   4308篇
  1996年   4139篇
  1995年   3934篇
  1994年   2596篇
  1993年   2134篇
  1992年   4795篇
  1991年   4532篇
  1990年   4009篇
  1989年   3888篇
  1988年   3563篇
  1987年   3240篇
  1986年   3159篇
  1985年   2798篇
  1984年   2072篇
  1983年   1839篇
  1982年   1261篇
  1979年   1644篇
  1978年   1272篇
  1977年   1279篇
  1974年   1322篇
  1973年   1321篇
  1972年   1346篇
  1971年   1221篇
  1970年   1190篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
Breast elastography has been available for more than 15 years but is not widely incorporated into clinical practice. Many publications report extremely high accuracy for various breast elastographic techniques. However, results in the literature are extremely variable. This variability is most likely due to variations in technique, a relatively steep learning curve, and variability in methods between vendors. This article describes our protocol for performing breast elastography using both strain elastography and shear wave elastography, which produces high sensitivity and specificity. Additionally, we will describe the most commonly known false-positive and false-negative lesions as well as how to detect them.  相似文献   
72.
Graefe's Archive for Clinical and Experimental Ophthalmology -  相似文献   
73.
Annals of Nuclear Medicine - Cardiac amyloidosis is a rare disease characterized by amyloid heart deposits and is usually a part of systemic amyloidosis, in relation to systemic light chain (AL)...  相似文献   
74.
75.
76.
Food-grade titanium dioxide (E171) is widely used as a food additive, and it is known that after oral consumption, E171 is translocated into the bloodstream reaching the highest titanium level at 6 h. E171 is accumulated in some organs triggering toxicity, but the effects on the blood parameters after oral consumption have been less studied. Recently, evidence shows that oral exposure to E171 induces behavioral signs of anxiety and depression. The relation between blood alterations and psychiatric disorders has been previously demonstrated. However, the oral exposure to E171 effects on alterations in blood parameters and effects linked to alterations in animal behavior has not been explored. In this short communication, we aimed to investigate the effects of E171 on specific blood parameters (hematocrit, hemoglobin, number of erythrocytes, and leukocytes) and anxiety and compulsive-like behavior in males and females orally exposed to ~5 mg/kg for 4 weeks. The results showed that E171 decreased hematocrit and hemoglobin in male but not in female mice while leukocyte and erythrocyte count remained unaltered. Oral consumption of E171 decreased the levels of anxiety-like behavior in females but not in male mice, while compulsive-like behavior was increased in both male and female mice.  相似文献   
77.
78.
79.
Magnetic resonance elastography aims to non-invasively and remotely characterize the mechanical properties of living tissues. To quantitatively and regionally map the shear viscoelastic moduli in vivo, the technique must achieve proper mechanical excitation throughout the targeted tissues. Although it is straightforward, ante manibus, in close organs such as the liver or the breast, which practitioners clinically palpate already, it is somewhat fortunately highly challenging to trick the natural protective barriers of remote organs such as the brain. So far, mechanical waves have been induced in the latter by shaking the surrounding cranial bones. Here, the skull was circumvented by guiding pressure waves inside the subject's buccal cavity so mechanical waves could propagate from within through the brainstem up to the brain. Repeatable, reproducible and robust displacement fields were recorded in phantoms and in vivo by magnetic resonance elastography with guided pressure waves such that quantitative mechanical outcomes were extracted in the human brain.  相似文献   
80.

Objective

To examine the experience of interracial anxiety among health professionals and how it may affect the quality of their interactions with patients from racially marginalized populations. We explored the influence of prior interracial exposure—specifically through childhood neighborhoods, college student bodies, and friend groups—on interracial anxiety among medical students and residents. We also examined whether levels of interracial anxiety change from medical school through residency.

Data Source

Web-based longitudinal survey data from the Medical Student Cognitive Habits and Growth Evaluation Study.

Study Design

We used a retrospective longitudinal design with four observations for each trainee. The study population consisted of non-Black US medical trainees surveyed in their 1st and 4th years of medical school and 2nd and 3rd years of residency. Mixed effects longitudinal models were used to assess predictors of interracial anxiety and assess changes in interracial anxiety scores over time.

Principal Findings

In total, 3155 non-Black medical trainees were followed for 7 years. Seventy-eight percent grew up in predominantly White neighborhoods. Living in predominantly White neighborhoods and having less racially diverse friends were associated with higher levels of interracial anxiety among medical trainees. Trainees' interracial anxiety scores did not substantially change over time; interracial anxiety was highest in the 1st year of medical school, lowest in the 4th year, and increased slightly during residency.

Conclusions

Neighborhood and friend group composition had independent effects on interracial anxiety, indicating that premedical racial socialization may affect medical trainees' preparedness to interact effectively with diverse patient populations. Additionally, the lack of substantial change in interracial anxiety throughout medical training suggests the importance of providing curricular tools and structure (e.g., instituting interracial cooperative learning activities) to foster the development of healthy interracial relationships.  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