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   1850篇
  免费   100篇
  国内免费   7篇
耳鼻咽喉   35篇
儿科学   34篇
妇产科学   35篇
基础医学   131篇
口腔科学   75篇
临床医学   131篇
内科学   546篇
皮肤病学   20篇
神经病学   81篇
特种医学   67篇
外科学   408篇
综合类   43篇
一般理论   4篇
预防医学   95篇
眼科学   56篇
药学   88篇
中国医学   2篇
肿瘤学   106篇
  2024年   1篇
  2023年   17篇
  2022年   40篇
  2021年   110篇
  2020年   49篇
  2019年   45篇
  2018年   62篇
  2017年   50篇
  2016年   65篇
  2015年   59篇
  2014年   81篇
  2013年   109篇
  2012年   143篇
  2011年   162篇
  2010年   102篇
  2009年   83篇
  2008年   124篇
  2007年   119篇
  2006年   74篇
  2005年   96篇
  2004年   68篇
  2003年   68篇
  2002年   73篇
  2001年   14篇
  2000年   12篇
  1999年   12篇
  1998年   21篇
  1997年   10篇
  1996年   10篇
  1995年   6篇
  1994年   3篇
  1993年   3篇
  1992年   3篇
  1991年   3篇
  1990年   2篇
  1989年   4篇
  1986年   4篇
  1985年   4篇
  1984年   7篇
  1983年   3篇
  1982年   7篇
  1981年   7篇
  1980年   8篇
  1978年   5篇
  1977年   2篇
  1976年   3篇
  1975年   2篇
  1969年   1篇
  1967年   1篇
排序方式: 共有1957条查询结果,搜索用时 265 毫秒
11.
12.
Detailed assessment of the tricuspid valve using two‐dimensional echocardiography is always challenging, as only two of three leaflets can be seen at a time. Three‐dimensional echocardiography can provide the enface view of the tricuspid valve that allows simultaneous visualization of all of the three leaflets. In a 42‐year‐old male patient scheduled for pulmonary endarterectomy, 3DTEE showed that the tricuspid valve is bileaflet, with one septal and another lateral leaflet. There were two commissures, one of them is anteriorly positioned and the other one is posterior. Our findings were confirmed intra‐operatively by direct surgical visualization of the tricuspid valve.  相似文献   
13.
The anti-anginal effects of allopurinol were assessed in experimental model rats of angina and their effects were evaluated with amlodipine. In the vasopressin-induced angina model, oral administration of allopurinol in dose of 10 mg/kg revealed remarkably analogous effects in comparison with amlodipine such as dose-dependent suppression of vasopressin-triggered time, duration and severity of ST depression. In addition, allopurinol produced dose dependent suppression of plasma Malondialdehyde (MDA) level, systolic blood pressure, cardiac contractility and cardiac oxygen consumption; while in contrast, amlodipine minimally suppressed the elevation of plasma MDA level. Endothelial NO synthase (eNOS) expression, serum nitrate were strikingly increased, however lipid profile was significantly reduced. Seemingly, allopurinol was found to be more potent than amlodipine – a calcium channel antagonist. To conclude, it was explicitly observed and verified that on the ischemic electrocardiography (ECG) changes in angina pectoris model in rats, allopurinol exerts a significant protective effects, reminiscent of enhancement of vascular oxidative stress, function of endothelial cells, improved coronary blood flow in addition to the potential enhancement in myocardial stress. Moreover, our findings were in conformity with several human studies.  相似文献   
14.
15.
The increasing availability of biosimilar medicines in Middle Eastern regions may provide an opportunity to increase the number of rheumatology patients who have access to traditionally more expensive biologic medicines. However, as well as a lack of real-world data on the use of biosimilar medicines in practice, the availability of intended copies in the region may undermine physician confidence in prescribing legitimate biosimilar medicines. There is a need for regional recommendations for healthcare professionals to ensure that biosimilar drugs can be used safely. Therefore, a literature search was performed with the aim of providing important recommendations for the regulation and use of biosimilar medicines in the Middle East from key opinion leaders in rheumatology from the region. These recommendations focus on improving the availability of relevant real-world data, ensuring that physicians are aware of the difference between intended copies and true biosimilars and ensuring that physicians are responsible for making any prescribing and switching decisions.  相似文献   
16.
17.
18.
19.

Purpose

In this study, we assessed the incidence, contributing factors and outcome of prolonged neutropenia above 7 days and of bacteraemia in patients with lymphoma and multiple myeloma who underwent autologous haematopoietic stem cell transplantation (AHSCT) without antibacterial prophylaxis.

Methods

This is a retrospective chart review of 190 adult patients who underwent AHSCT between 2005 and 2015 at a Lebanese hospital.

Results

Neutropenia of 7 days duration and longer was documented in 66% of the patient population. Through univariate analysis, patients with lymphoma were significantly more likely to have prolonged neutropenia (≥?7 days) compared to those with myeloma. Mucositis above grade 3, diarrhoea and fever were more likely to occur in patients with prolonged neutropenia. Bacteraemia was documented in 12.6% of the patients. Total mortality rate was 3.7%, and that attributed to bacteraemia was 12.5% in the bacteraemia subgroup. Among bacterial isolates recovered from clinical specimens (89 isolates), 70% were Gram-negative, of which 57% were fluoroquinolone susceptible. Ninety-five percent of the Gram-negative bacteria causing bacteraemia were susceptible to fluoroquinolones.

Conclusion

Bacterial pathogens causing bacteraemia were still highly susceptible to fluoroquinolones, despite the high prevalence of fluoroquinolone-resistant strains in the general bacterial ecology. Accordingly, the pertinence of fluoroquinolone prophylaxis in the AHSCT setting warrants further investigation. Moreover, continuous surveillance of local antibiograms in this patient population has become a must in an era of preponderant antibiotic resistance.
  相似文献   
20.
IntroductionEdible mushrooms have a great nutritional value including high protein, essential amino acids, fiber, vitamins (B1, B2, B12, C, and D), minerals (calcium [Ca], potassium [K], magnesium [Mg], sodium [Na], phosphorus [P], copper [Cu], iron [Fe], manganese [Mn], and selenium [Se]), low fatty foods, and sodium. The objective of this systematic review was to determine the relationship between edible mushroom consumption and overall cardiovascular risk.MethodsWe systematically searched Ovid MEDLINE, Embase, Ovid Cochrane Database of Systematic Reviews, Scopus, and Web of Science from database inception from 1966 through August 2020 for observational studies that reported the association between edible mushroom consumption and cardiovascular risk. Two investigators independently reviewed data. Conflicts were resolved through consensus discussion.ResultsOf 1479 studies, we identified 7 prospective studies. Edible mushroom consumption may have favorable effects on lipid profiles by changing some metabolic markers such as low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, total cholesterol, and triglycerides. Moreover, edible mushroom consumption is probably associated with reduced mean blood pressure. The beneficial overall cardiovascular risk, stroke risk, and coronary artery disease of edible mushroom consumption are not consistent.ConclusionsEdible mushroom consumption has not been shown to conclusively affect cardiovascular risk factors to date. However, potential health benefits may exist, including a favorable alteration of lipid profiles and blood pressure reduction.  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