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   21656篇
  免费   2116篇
  国内免费   43篇
耳鼻咽喉   193篇
儿科学   826篇
妇产科学   492篇
基础医学   2797篇
口腔科学   448篇
临床医学   2431篇
内科学   4425篇
皮肤病学   166篇
神经病学   2087篇
特种医学   757篇
外科学   3088篇
综合类   385篇
一般理论   12篇
预防医学   2382篇
眼科学   457篇
药学   1500篇
中国医学   26篇
肿瘤学   1343篇
  2021年   307篇
  2020年   202篇
  2019年   394篇
  2018年   389篇
  2017年   260篇
  2016年   318篇
  2015年   340篇
  2014年   576篇
  2013年   868篇
  2012年   1205篇
  2011年   1221篇
  2010年   675篇
  2009年   600篇
  2008年   1125篇
  2007年   1219篇
  2006年   1139篇
  2005年   1113篇
  2004年   1088篇
  2003年   1066篇
  2002年   1055篇
  2001年   483篇
  2000年   503篇
  1999年   436篇
  1998年   230篇
  1997年   182篇
  1996年   208篇
  1995年   226篇
  1994年   213篇
  1993年   204篇
  1992年   362篇
  1991年   303篇
  1990年   331篇
  1989年   334篇
  1988年   274篇
  1987年   282篇
  1986年   307篇
  1985年   276篇
  1984年   249篇
  1983年   235篇
  1982年   183篇
  1981年   193篇
  1980年   148篇
  1979年   215篇
  1978年   181篇
  1977年   124篇
  1976年   147篇
  1975年   140篇
  1974年   148篇
  1973年   145篇
  1972年   126篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Background: Advances in social technologies offer new tools for large scale data collection and analysis of peer influence and social networks on substance use attitudes and behaviors. Objective: The objective of this study was to determine if text message content can predict alcohol and marijuana use attitudes and behaviors. Methods: Text messages from 91 males ages 18–25 were monitored over a period of 6 months and examined for content related to alcohol and marijuana. Self-report data indicating alcohol and marijuana use attitudes and behaviors were used to determine relationships between text message content, social network structure, and substance use attitudes and behaviors. Results: In total, 23,173 text messages were analyzed with 166 text messages including alcohol related terms and 195 text messages including drug related terms. Individuals who sent text messages related to alcohol use were more likely to have problem alcohol use and positive attitudes toward alcohol use, and individuals who sent text messages related to marijuana use reported higher frequency of marijuana use and more positive attitudes toward marijuana use. Individuals with multiple daily marijuana use were in positions that had less control over network structure. Conclusions: The results of this study indicate that monitoring text message content and social network structure among emerging adult males can potentially predict alcohol and marijuana use attitudes and behaviors. Text message content analysis is a novel technique increasing our understanding of the role of peer influence and social network on substance use attitudes and behaviors.  相似文献   
4.
5.
Brain networks are increasingly characterized at different scales, including summary statistics, community connectivity, and individual edges. While research relating brain networks to behavioral measurements has yielded many insights into brain‐phenotype relationships, common analytical approaches only consider network information at a single scale. Here, we designed, implemented, and deployed Multi‐Scale Network Regression (MSNR), a penalized multivariate approach for modeling brain networks that explicitly respects both edge‐ and community‐level information by assuming a low rank and sparse structure, both encouraging less complex and more interpretable modeling. Capitalizing on a large neuroimaging cohort (n = 1, 051) , we demonstrate that MSNR recapitulates interpretable and statistically significant connectivity patterns associated with brain development, sex differences, and motion‐related artifacts. Compared to single‐scale methods, MSNR achieves a balance between prediction performance and model complexity, with improved interpretability. Together, by jointly exploiting both edge‐ and community‐level information, MSNR has the potential to yield novel insights into brain‐behavior relationships.  相似文献   
6.
7.
8.
9.
The novel coronavirus disease SARS-CoV-2 (COVID-19) outbreak rapidly generated an unprecedented global, national, and state public health crisis with the need to rapidly develop alternate care sites (ACS) to care for COVID-19 patients within an overburdened health care system. A hospital care model ACS to increase the health care capacity, provide care for mild to moderately symptomatic patients, and offer local self-sustainment for a surge of patients was developed in Memphis, Tennessee located in Shelby County. We completed a temporary conversion of a large unused newspaper publication building to a health care facility for COVID-19 patients. Developing an ACS from ground zero was met with many challenges, and throughout the process important lessons were learned. With the goal to complete the building conversion within a 28-day timeframe, collaboration among the numerous governmental, health care, and private agencies was critical and nursing leadership was key to this process. The purpose of this paper is to describe the development of a COVID-19 ACS in Memphis, TN, which has a large at-risk population with limited access to health care. Specifically, we will discuss the strong leadership role of nursing faculty, key challenges, and lessons learned, as well as provide checklists and models for others in similar circumstances.  相似文献   
10.
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