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   4219081篇
  免费   331296篇
  国内免费   13867篇
耳鼻咽喉   58640篇
儿科学   134885篇
妇产科学   110370篇
基础医学   651151篇
口腔科学   113477篇
临床医学   382278篇
内科学   760115篇
皮肤病学   105966篇
神经病学   350079篇
特种医学   163707篇
外国民族医学   503篇
外科学   647122篇
综合类   119270篇
现状与发展   23篇
一般理论   2571篇
预防医学   353258篇
眼科学   98944篇
药学   294616篇
  26篇
中国医学   11302篇
肿瘤学   205941篇
  2021年   55727篇
  2020年   35475篇
  2019年   58425篇
  2018年   73651篇
  2017年   56280篇
  2016年   62305篇
  2015年   75354篇
  2014年   109685篇
  2013年   174831篇
  2012年   120764篇
  2011年   126390篇
  2010年   125259篇
  2009年   126550篇
  2008年   112647篇
  2007年   120088篇
  2006年   128808篇
  2005年   124041篇
  2004年   124304篇
  2003年   114664篇
  2002年   103920篇
  2001年   149720篇
  2000年   144568篇
  1999年   134331篇
  1998年   70097篇
  1997年   66218篇
  1996年   64425篇
  1995年   59696篇
  1994年   53782篇
  1993年   50049篇
  1992年   96072篇
  1991年   92675篇
  1990年   89081篇
  1989年   86838篇
  1988年   80041篇
  1987年   78530篇
  1986年   73881篇
  1985年   73001篇
  1984年   61682篇
  1983年   55442篇
  1982年   46029篇
  1981年   43123篇
  1980年   40511篇
  1979年   53117篇
  1978年   44050篇
  1977年   38903篇
  1976年   36281篇
  1975年   36282篇
  1974年   39426篇
  1973年   37643篇
  1972年   35251篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
132.
133.
134.
Bernard–Soulier syndrome (BSS) is a rare autosomal recessively inherited bleeding disorder. Pregnancy in patients with BSS is characterized by ante‐, intra‐, or postpartum haemorrhage, which may be delayed and severe. There is no consensus in the management of BSS in pregnancy and so far only 16 pregnancies in nine patients have been described. We report a further three pregnancies in two women with the syndrome. We also outline our management of pregnant patients with BSS.  相似文献   
135.
Landgraf  R. 《Der Diabetologe》2006,2(1):S5-S8
NAFDM, the National Action Forum for Diabetes Mellitus, is an umbrella organisation for the leading diabetes organisations in Germany. Since its foundation at the end of 2004, NAFDM has brought together the activities of these organisations, which up to now were frequently working independently of each other, under a single ‘roof’. Supported by a central coordination unit, three project groups work successfully on the topics scientific research and healthcare research, patient care and prevention. Activities and results are shared and thus integrated into the network. The working groups are supported by NAFDM’s medical and health-policy steering groups. Apart from a number of successful events, two key publications have meanwhile come out: one on the status of prevention and one analysing the healthcare situation for diabetics in Germany. All people interested in diabetology are invited to join in and work with the NAFDM.  相似文献   
136.
It is often difficult for medical professionals to understand the behaviour of people with diabetic foot syndrome. We describe the different psychological factors that play a role in the maintenance of intermittent implementation of medical recommendations. In particular we look at the consequences of neuropathy and of the recommendation to offload pressure, as well as the contradictions between the realities of the patient and the medical professionals involved in their care. We show that the solutions that patients develop are based on normal psychological processes and we encourage professionals to consider these aspects in their relationship to people with DFS and when developing individualised preventative measures.  相似文献   
137.
138.
SPECT with 99mTc-labeled agents is better able to detect viability after nitrate administration. Nitrates induce vasodilation and may increase blood flow to severely hypoperfused but viable myocardium, thereby enhancing tracer delivery and improving the detection of viability. Quantitative data on the changes in blood flow are lacking in SPECT but can be provided by PET. The aim of the present study was to use PET to evaluate whether nitrate administration increases blood flow to chronically dysfunctional but viable myocardium. METHODS: 13N-Ammonia PET was used to quantitatively assess blood flow, and 18F-FDG PET was used as the gold standard to detect viable myocardium. Twenty-five patients with chronic ischemic left ventricular dysfunction underwent 13N-ammonia PET at rest and after nitrate administration. RESULTS: A significant increase in nitrate-enhanced blood flow was observed in viable segments (from 0.55 +/- 0.15 to 0.68 +/- 0.24 mL/min/g, P < 0.05). No statistically significant change in blood flow was observed in nonviable segments (0.60 +/- 0.20 vs. 0.55 +/- 0.18 mL/min/g). A ratio of at least 1.1 for nitrate-enhanced flow to resting flow allowed optimal detection of viable myocardium, yielding a sensitivity of 82% with a specificity of 100%. CONCLUSION: 13N-Ammonia PET showed a significant increase in nitrate-enhanced blood flow in viable myocardium, whereas blood flow remained unchanged after nitrate administration in nonviable myocardium. Nitrate use during myocardial perfusion imaging will lead to improved assessment of myocardial viability.  相似文献   
139.
Conclusion  Several quality-control measures take place before (patient and camera preparation) and during SPECT acquisition to achieve high-quality images. Not uncommonly, technologists and physicians are left with suboptimal images that have to be addressed to reach the “right answer” for patient diagnosis and hence management. In many cases patients may be reimaged, especially if the problem is detected early, but in other cases either the patient has left the nuclear laboratory or there is an inevitable problem that, even with reimaging, will not be resolved. In these situations the technologist and physician have to seek the available techniques to obtain the best images possible. These resources are discussed in this issue as an aid in quality control to obtain the best possible images.  相似文献   
140.
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