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   34026篇
  免费   2116篇
  国内免费   123篇
耳鼻咽喉   527篇
儿科学   1513篇
妇产科学   705篇
基础医学   3308篇
口腔科学   734篇
临床医学   2718篇
内科学   7904篇
皮肤病学   626篇
神经病学   1817篇
特种医学   1136篇
外国民族医学   5篇
外科学   5769篇
综合类   823篇
一般理论   11篇
预防医学   2017篇
眼科学   1259篇
药学   2923篇
  2篇
中国医学   231篇
肿瘤学   2237篇
  2023年   277篇
  2022年   611篇
  2021年   1449篇
  2020年   802篇
  2019年   1165篇
  2018年   1314篇
  2017年   880篇
  2016年   975篇
  2015年   988篇
  2014年   1405篇
  2013年   1751篇
  2012年   2622篇
  2011年   2443篇
  2010年   1546篇
  2009年   1147篇
  2008年   1738篇
  2007年   1756篇
  2006年   1594篇
  2005年   1479篇
  2004年   1280篇
  2003年   1063篇
  2002年   961篇
  2001年   675篇
  2000年   683篇
  1999年   565篇
  1998年   238篇
  1997年   181篇
  1996年   163篇
  1995年   161篇
  1994年   153篇
  1993年   129篇
  1992年   351篇
  1991年   338篇
  1990年   299篇
  1989年   291篇
  1988年   223篇
  1987年   242篇
  1986年   206篇
  1985年   212篇
  1984年   187篇
  1983年   164篇
  1982年   87篇
  1981年   103篇
  1980年   87篇
  1979年   156篇
  1978年   111篇
  1977年   84篇
  1974年   94篇
  1973年   128篇
  1972年   105篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
ABSTRACT

Purpose

To investigate the expression of IL-11 and its receptor IL-11Rα and to quantify density of CD163+ M2 macrophages in proliferative diabetic retinopathy (PDR).  相似文献   
5.
6.
Demographic projections for hip fragility fractures indicate a rising annual incidence by virtue of a multimorbid, ageing population with more noncommunicable diseases (NCDs). NCDs are characterised by slow progression and long duration ranging from ischaemic cardiovascular disease, cerebrovascular disease, diabetes, chronic obstructive pulmonary disease to various cancers. Management of this disease burden often involves commencing patients on oral anticoagulants to reduce the risk of thromboembolic events. The use of direct oral anticoagulants (DOACs) in clinical practice has increased due to their rapid onset of action, short half-life and predictable anticoagulant effects, without the need for routine monitoring. Safe and timely surgical intervention relies on reversal of anticoagulants. However, the lack of specific evidence-based guidelines for the perioperative management of patients on DOACs with hip fractures has proved challenging; in particular, the accessibility of DOAC-specific assays, justification of the cost-benefit ratio of targeted reversal agents and indications for neuraxial anaesthesia. This has led to potentially avoidable delays in surgical intervention. Following a literature review of the pharmacokinetic and pharmacodynamics of commonly used DOACs in our region including the role of surrogate markers, we propose a systematic, evidence-based guideline to the perioperative management of hip fractures DOACs. We believe this standardised protocol can be easily replicated between hospitals. We recommend that if patients are deemed suitable for a general anaesthesia, with satisfactory renal function, optimal surgical time should be 24 h following the last ingested dose of DOAC.  相似文献   
7.
8.
Doxorubicin (DOX) is the most commonly used anticancer drug; however, it has limited use because prolonged administration may result in severe cardiotoxicity. Simvastatin (SIM), generally prescribed for hypercholesterolaemia, has also shown salubrious results in the monotherapy or combinational drug therapy of different cancers in various models. Nanoparticle drug delivery systems are a novel way of improving therapeutics and also improving the absorption and specificity of drugs towards tumour cells. In this study, we exploited this technology to increase drug specificity and minimize imminent adverse effects. In this study, the antitumour activity of the combination formulas of DOX and SIM, either loaded in water (DOX‐SIM‐Solution) or nanoemulsions (NEs) (DOX‐SIM‐NE), was evaluated in a Swiss albino mouse model of Ehrlich ascites carcinoma. The anticancer effect was assessed by quantifying the change in body weight, mean survival time, and percent increase in lifespan (%ILS), determining haematological and serum biochemical parameters (liver function test, kidney function test and lipid profile parameters) as well as studying the histopathological alterations in liver tissues. We observed a clear increase in %ILS of the DOX‐SIM‐Solution group (265.30) that was double the %ILS of the DOX‐SIM‐NE group (134.70). However, DOX‐SIM‐NE had a non‐toxic effect on the haematological parameters, whereas DOX‐SIM‐Solution increased the levels of haemoglobin and lymphocytes. Furthermore, the encapsulation of SIM and DOX into NEs improved the levels of all serum biochemical parameters compared to the DOX‐SIM‐Solution. A reduction in the side effects of DOX‐SIM‐NE on the liver was also established using light microscopy, which revealed that the morphologies of the hepatocytes of the mice were less affected by administration of the DOX‐SIM‐NE treatment than with the DOX‐SIM‐Solution treatment. The study showed that incorporating SIM into the DOX‐loaded‐NE formulation remarkably improved its efficiency and simultaneously reduced its adverse effects.  相似文献   
9.
This bibliometric study assessed periodontal/implant articles that were part of the five most‐cited dental articles in each of the years 2005‐2019. Periodontal/implant articles made up one to four articles in each of 14 years and totaled 40% of the yearly five most‐cited dental articles. The three core periodontal journals (Journal of Clinical Periodontology, Journal of Periodontology, and Periodontology 2000) increased ~50%‐100% in Journal Impact Factor from 2005 to 2015 and were among the 10 most‐cited dental journals in the 2015‐2019 period. The Journal of Clinical Periodontology and Periodontology 2000 were in several years assigned the highest Journal Impact Factor in dentistry. In summary, periodontal journals continue to publish high‐impact articles that are relevant for both oral health care and medicine.  相似文献   
10.
Melatonin receptors play important roles in the regulation of circadian and seasonal rhythms, sleep, retinal functions, the immune system, depression, and type 2 diabetes development. Melatonin receptors are approved drug targets for insomnia, non‐24‐hour sleep‐wake disorders, and major depressive disorders. In mammals, two melatonin receptors (MTRs) exist, MT1 and MT2, belonging to the G protein‐coupled receptor (GPCR) superfamily. Similar to most other GPCRs, reliable antibodies recognizing melatonin receptors proved to be difficult to obtain. Here, we describe the development of the first monoclonal antibodies (mABs) for mouse MT1 and MT2. Purified antibodies were extensively characterized for specific reactivity with mouse, rat, and human MT1 and MT2 by Western blot, immunoprecipitation, immunofluorescence, and proximity ligation assay. Several mABs were specific for either mouse MT1 or MT2. None of the mABs cross‐reacted with rat MTRs, and some were able to react with human MTRs. The specificity of the selected mABs was validated by immunofluorescence microscopy in three established locations (retina, suprachiasmatic nuclei, pituitary gland) for MTR expression in mice using MTR‐KO mice as control. MT2 expression was not detected in mouse insulinoma MIN6 cells or pancreatic beta‐cells. Collectively, we report the first monoclonal antibodies recognizing recombinant and native mouse melatonin receptors that will be valuable tools for future studies.  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