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   9284篇
  免费   891篇
  国内免费   52篇
耳鼻咽喉   22篇
儿科学   226篇
妇产科学   175篇
基础医学   301篇
口腔科学   141篇
临床医学   966篇
内科学   1159篇
皮肤病学   14篇
神经病学   182篇
特种医学   71篇
外科学   546篇
综合类   445篇
现状与发展   1篇
一般理论   10篇
预防医学   5000篇
眼科学   20篇
药学   765篇
  2篇
中国医学   41篇
肿瘤学   140篇
  2024年   8篇
  2023年   282篇
  2022年   237篇
  2021年   604篇
  2020年   596篇
  2019年   601篇
  2018年   535篇
  2017年   485篇
  2016年   430篇
  2015年   424篇
  2014年   590篇
  2013年   812篇
  2012年   487篇
  2011年   514篇
  2010年   423篇
  2009年   439篇
  2008年   364篇
  2007年   395篇
  2006年   306篇
  2005年   249篇
  2004年   221篇
  2003年   185篇
  2002年   163篇
  2001年   152篇
  2000年   137篇
  1999年   101篇
  1998年   72篇
  1997年   73篇
  1996年   59篇
  1995年   47篇
  1994年   34篇
  1993年   28篇
  1992年   35篇
  1991年   27篇
  1990年   26篇
  1989年   17篇
  1988年   13篇
  1987年   6篇
  1986年   9篇
  1985年   10篇
  1984年   4篇
  1983年   8篇
  1982年   3篇
  1981年   6篇
  1980年   3篇
  1977年   2篇
  1974年   1篇
  1973年   1篇
  1972年   2篇
  1970年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
65.
Kratom (Mitragyna speciosa) is a tree-like plant indigenous to Southeast Asia. Its leaves, and the teas brewed from them have long been used by people in that region to stave off fatigue and to manage pain and opioid withdrawal. Evidence suggests kratom is being increasingly used by people in the United States and Europe for the self-management of opioid withdrawal and treatment of pain. Recent studies have confirmed that kratom and its chemical constituents have potentially useful pharmacological actions. However, there have also been increasing numbers of reports of adverse effects resulting from use of kratom products. In August 2016, the US Drug Enforcement Administration announced plans to classify kratom and its mitragynine constituents as Schedule I Controlled Substances, a move that triggered a massive response from pro-kratom advocates. The debate regarding the risks, and benefits and safety of kratom continues to intensify. Kratom proponents tout kratom as a safer and less addictive alternative to opioids for the management of pain and opioid addiction. The anti-kratom faction argues that kratom, itself, is a dangerous and addictive drug that ought to be banned. Given the widespread use of kratom and the extensive media attention it is receiving, it is important for physicians, scientists and policy makers to be knowledgeable about the subject. The purpose of this commentary is to update readers about recent developments and controversies in this rapidly evolving area. All of the authors are engaged in various aspects of kratom research and it is our intention to provide a fair and balanced overview that can form the basis for informed decisions on kratom policy. Our conclusions from these analyses are: (a) User reports and results of preclinical studies in animals strongly suggest that kratom and its main constituent alkaloid, mitragynine may have useful activity in alleviating pain and managing symptoms of opioid withdrawal, even though well-controlled clinical trials have yet to be done. (b) Even though kratom lacks many of the toxicities of classic opioids, there are legitimate concerns about the safety and lack of quality control of purported “kratom” products that are being sold in the US. (c) The issues regarding the safety and efficacy of kratom and its mitragynine constituent can only be resolved by additional research. Classification of the Mitragyna alkaloids as Schedule I controlled substances would substantially impede this important research on kratom.  相似文献   
66.
67.
68.
69.

Objective

To analyse and understand vaccination hesitancy discourses, particularly those of people who have decided not to vaccinate their sons and daughters.

Methods

Qualitative study of five individual interviews and two focus groups with people who chose not to vaccinate their children in the province of Granada (Spain).

Results

Mothers and fathers manifest a system of health beliefs different to the biomedical paradigm. From an ethical point of view, they justify their position based on the right to autonomy and responsibility for their decisions. Alleged specific reasons: they doubt administration of several vaccines simultaneously at an early age in a systematic way and without individualising each case; they fear adverse effects and do not understand the variations of the vaccination schedule.

Conclusions

These vaccination hesitancy discourses respond to the individual vs collective conflict; parents defend their right to bring up their children without any interference from the state and focus their responsibility on the individual welfare of their sons and daughters, regardless of the consequences that their actions might have on the collective. In their management of risks, they consider those derived from vaccination more relevant than the individual or collective consequences of not doing so. The vaccines generating most doubts are the more controversial ones within the scientific world. Transparency in communication of adverse effects; authorities respect for other health/disease concepts; banishment of the term “anti-vaccines” from the media and scientific vocabulary, and developing spaces for dialogue are bridges to be built.  相似文献   
70.
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