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   4267961篇
  免费   341893篇
  国内免费   14445篇
耳鼻咽喉   60107篇
儿科学   136261篇
妇产科学   111000篇
基础医学   651781篇
口腔科学   114154篇
临床医学   392743篇
内科学   773003篇
皮肤病学   109832篇
神经病学   355699篇
特种医学   165619篇
外国民族医学   503篇
外科学   661836篇
综合类   119311篇
现状与发展   91篇
一般理论   2586篇
预防医学   354782篇
眼科学   100408篇
药学   294644篇
  26篇
中国医学   11300篇
肿瘤学   208613篇
  2021年   56641篇
  2020年   37767篇
  2019年   59031篇
  2018年   76632篇
  2017年   59294篇
  2016年   65611篇
  2015年   78549篇
  2014年   115545篇
  2013年   180527篇
  2012年   122515篇
  2011年   128034篇
  2010年   129345篇
  2009年   132007篇
  2008年   114374篇
  2007年   121027篇
  2006年   130597篇
  2005年   124959篇
  2004年   124861篇
  2003年   115007篇
  2002年   104213篇
  2001年   150878篇
  2000年   145365篇
  1999年   135227篇
  1998年   71419篇
  1997年   67340篇
  1996年   65232篇
  1995年   60444篇
  1994年   54227篇
  1993年   50358篇
  1992年   96326篇
  1991年   93039篇
  1990年   89339篇
  1989年   87125篇
  1988年   80271篇
  1987年   78738篇
  1986年   74093篇
  1985年   73131篇
  1984年   61756篇
  1983年   55504篇
  1982年   46088篇
  1981年   43156篇
  1980年   40548篇
  1979年   53129篇
  1978年   44060篇
  1977年   38923篇
  1976年   36293篇
  1975年   36289篇
  1974年   39431篇
  1973年   37650篇
  1972年   35269篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
982.
983.
984.
985.
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   
986.
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   
987.
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   
988.
989.
Gorlin syndrome (naevoid basal cell carcinoma syndrome) is a genetically linked disorder characterized by the development of multiple basal cell carcinomas (BCCs) throughout life. Cumulative surgery, cryotherapy and other conventional interventions can result in significant disfigurement by middle age. Radiotherapy is contra-indicated because the mutated gene underlying the syndrome, ‘PTCH’, increases sensitivity to ionising radiation, so there is significant likelihood of inducing further tumours in and around the irradiated area. Photodynamic therapy offers a non-invasive treatment option for patients with this condition, with the added advantage of causing minimal scarring.  相似文献   
990.
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   
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