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   10224篇
  免费   601篇
  国内免费   29篇
耳鼻咽喉   128篇
儿科学   396篇
妇产科学   260篇
基础医学   1347篇
口腔科学   150篇
临床医学   933篇
内科学   1985篇
皮肤病学   170篇
神经病学   1241篇
特种医学   212篇
外国民族医学   55篇
外科学   740篇
综合类   81篇
一般理论   13篇
预防医学   1240篇
眼科学   216篇
药学   1013篇
中国医学   23篇
肿瘤学   651篇
  2024年   12篇
  2023年   103篇
  2022年   272篇
  2021年   513篇
  2020年   251篇
  2019年   335篇
  2018年   348篇
  2017年   305篇
  2016年   320篇
  2015年   300篇
  2014年   420篇
  2013年   582篇
  2012年   884篇
  2011年   885篇
  2010年   456篇
  2009年   394篇
  2008年   644篇
  2007年   703篇
  2006年   649篇
  2005年   557篇
  2004年   540篇
  2003年   473篇
  2002年   410篇
  2001年   47篇
  2000年   25篇
  1999年   48篇
  1998年   63篇
  1997年   35篇
  1996年   31篇
  1995年   33篇
  1994年   29篇
  1993年   24篇
  1992年   13篇
  1991年   10篇
  1990年   12篇
  1989年   9篇
  1988年   9篇
  1987年   7篇
  1986年   8篇
  1985年   5篇
  1983年   7篇
  1982年   9篇
  1981年   14篇
  1980年   7篇
  1979年   5篇
  1978年   5篇
  1977年   4篇
  1976年   5篇
  1974年   5篇
  1971年   4篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
GeroScience - A complex picture of factors influencing cognition is necessary to be drawn for a better understanding of the role of potentially modifiable factors in dementia. The aim was to assess...  相似文献   
102.
Atomic force microscopy – infrared (AFM-IR) spectroscopy allows spectroscopic studies in the mid-infrared (mid-IR) spectral region with a spatial resolution better than is allowed by the diffraction limit. We show that the high spatial resolution can be used to perform spectroscopic and imaging studies at the subcellular level in fixed eukaryotic cells. We collect AFM-IR images of subcellular structures that include lipid droplets, vesicles and cytoskeletal filaments, by relying on the intrinsic contrast from IR light absorption. We also obtain AFM-IR absorption spectra of individual subcellular structures. Most spectra show features that are recognizable in the IR absorption spectra of cells and tissue obtained with FTIR technology, including absorption bands characteristic of phospholipids and polypeptides. The quality of the spectra and of the images opens the way to structure and composition studies at the subcellular level using mid-IR absorption spectroscopy.

Atomic force microscopy – infrared (AFM-IR) spectroscopy allows spectroscopic studies in the mid-infrared (mid-IR) spectral region with a spatial resolution better than is allowed by the diffraction limit.  相似文献   
103.
104.

Background

Tobacco remains the world’s leading preventable cause of death, with the majority of tobacco-caused deaths occurring in low- and middle-income countries. The first global health treaty, the Framework Convention on Tobacco Control (FCTC), outlines a set of policy initiatives that have been demonstrated as effective in reducing tobacco use. Article 11 of the FCTC focuses on using the tobacco package to communicate tobacco-caused harms; it also seeks to restrict the delivery of misleading information about the product on the pack.

Objective

The objective of this study was to establish a surveillance system for tobacco packs in the 14 low- and middle-income countries with the greatest number of smokers. The Tobacco Pack Surveillance System (TPackSS) monitors whether required health warnings on tobacco packages are being implemented as intended, and identifies pack designs and appeals that might violate or detract from the communication of harm-related information and undermine the impact of a country’s tobacco packaging laws. The protocol outlined is intended to be applicable or adaptable for surveillance efforts in other countries.

Methods

Tobacco packs were collected in 14 countries during 2013. The intention was, to the extent possible, to construct a census of “unique” pack presentations available for purchase in each country. The TPackSS team partnered with in-country field staff to implement a standardized protocol for acquiring packs from 36 diverse neighborhoods across three cities in each country. At the time of purchase, data on price and place of acquisition of each pack was recorded. The field staff, according to a standardized protocol, then photographed packs before they were shipped to the United States for coding and archiving.

Results

Each pack was coded for compliance with the country-specific health warning label laws, as well as for key design features of the pack and appeals of the branding elements. The coding protocols were developed based upon prior research, expert opinion, and communication theories. Each pack was coded by two independent coders, with consistency of personnel across the project. We routinely measured intercoder reliability, and only retained variables for which a good level of reliability was achieved. Variables where reliability was too low were not included in final analyses, and any inconsistencies in coding were resolved on a daily basis.

Conclusions

Across the 14 countries, the TPackSS team collected 3307 tobacco packs. We have established a publicly accessible, Internet archive of these packs that is intended for use by the tobacco control policy advocacy and research community.  相似文献   
105.
106.
107.
108.
109.
110.
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