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   1697篇
  免费   88篇
  国内免费   3篇
耳鼻咽喉   9篇
儿科学   34篇
妇产科学   32篇
基础医学   267篇
口腔科学   29篇
临床医学   185篇
内科学   284篇
皮肤病学   49篇
神经病学   220篇
特种医学   65篇
外科学   221篇
综合类   10篇
现状与发展   1篇
一般理论   2篇
预防医学   99篇
眼科学   14篇
药学   152篇
中国医学   8篇
肿瘤学   107篇
  2023年   7篇
  2022年   25篇
  2021年   39篇
  2020年   31篇
  2019年   35篇
  2018年   29篇
  2017年   24篇
  2016年   34篇
  2015年   40篇
  2014年   40篇
  2013年   65篇
  2012年   83篇
  2011年   104篇
  2010年   59篇
  2009年   63篇
  2008年   104篇
  2007年   117篇
  2006年   110篇
  2005年   102篇
  2004年   78篇
  2003年   101篇
  2002年   78篇
  2001年   44篇
  2000年   33篇
  1999年   35篇
  1998年   23篇
  1997年   12篇
  1996年   8篇
  1995年   11篇
  1994年   12篇
  1992年   14篇
  1991年   23篇
  1990年   16篇
  1989年   15篇
  1988年   7篇
  1987年   11篇
  1986年   12篇
  1985年   13篇
  1984年   13篇
  1981年   5篇
  1979年   9篇
  1978年   7篇
  1975年   5篇
  1973年   8篇
  1972年   6篇
  1971年   6篇
  1970年   6篇
  1969年   7篇
  1961年   6篇
  1959年   5篇
排序方式: 共有1788条查询结果,搜索用时 2 毫秒
51.
52.
BackgroundWhen the coronavirus pandemic 2019 (COVID‐19) emerged, concerns were also raised regarding the safety of allergen immunotherapy (AIT). The German Society for Allergology and Clinical Immunology (DGAKI) conducted a survey to collect real‐world data on the daily routine of administering subcutaneous AIT (SCIT) and sublingual AIT (SLIT) during the COVID‐19 pandemic.MethodsA web‐based retrospective survey using the online platform survio with 26 standardized questions was used to survey physicians treating allergic patients during the pandemic.ResultsThree hundred and forty‐five physicians who regularly offer and perform AIT in German‐speaking countries responded to the questions. 70.4% of the respondents stated that they regularly initiated and dosed up SCIT for inhalant allergies (41.4% venom‐SCIT, 73.6% SLIT), and 85.2% of the respondents stated that they continued SCIT for inhalant allergies during the maintenance phase in a regular way (59.1% venom‐SCIT, 90.4% SLIT) in healthy patients without current symptoms indicating an infection with COVID‐19. With regard to tolerability, there was no evidence for increased occurrence of adverse events in patients without current symptoms of COVID‐19 infection during the pandemic.ConclusionsThis retrospective study demonstrated adherence to national and international position papers of AIT during the COVID‐19 pandemic in German‐speaking countries. Besides, the survey has confirmed a good tolerability of AIT for both SCIT and SLIT.  相似文献   
53.
54.
~~New multi protein patterns differentiate liver fibrosis stages and hepatocellular carcinoma in chronic hepatitis C serum samples@Thomas Gbel$Klinik für Gastroenterologie,Hepatologie und Infektiologie,Heinrich-Heine-UniversitatDusseldorf,Moorenstr.e,D…  相似文献   
55.
The effects of low molecular weight lymphokine-derived oligopeptides (LK-OPs) on PMNLs effector functions and receptor mediated biochemical events were studied in the case of healthy young and aged subjects. In the case of young subjects the low mol. wt. LK-OPs stimulated the Fc gamma receptor-mediated effector functions of PMNLs, whereas an inhibition was observed in PMNLs of the elderly (extracellular cytotoxicity and intracellular killing). The underlying biochemical events, induced by low mol. wt. LK-OPs stimulation, were also investigated. In PMNLs of young subjects the oxidative metabolism was stimulated (enhanced O2 consumption, O2 and H2O2 production) by low mol. wt. LK-OPs, while in elderly subjects it was inhibited. The cyclic nucleotides regulating the Fc gamma receptor mediated effector functions and the oxygen radicals formation showed an altered dynamic response under low mol. wt. LK-OPs stimulation with aging i.e. the cGMP level could not be changed at all. Our results suggest that low mol. wt. LK-OPs induced inhibition of Fc gamma receptor mediated effector functions with aging could be partly explained by an altered post receptorial coupling switch and as a consequence the lymphokines could not play their role of immunomodulators further impairing the altered immune response with aging.  相似文献   
56.
We examined 142 biopsy specimens of smokeless tobacco-associated oral mucosal lesions from 133 professional baseball players. Four types of epithelial change were observed in the specimens: hyperparakeratosis, hyperorthokeratosis, pale surface staining, and basal cell hyperplasia. These types of epithelial change were associated with the type of smokeless tobacco used (snuff or chewing tobacco) but not with the duration (years) or amount (hours per day) of use. The thickness of hyperkeratosis in a specimen correlated directly with the amount of smokeless tobacco use. The use of snuff was more frequently associated with development of oral mucosal lesions than was the use of chewing tobacco, and snuff appeared to cause a greater variety and severity of epithelial change than did chewing tobacco.  相似文献   
57.
Purpose:To evaluate the detection rate of intracranial aneurysms on reconstructed thin slice non enhanced CT (NECT) scans.Methods:NECT scans from 34 patients with 35 aneurysms and 35 individuals without aneurysms were collected. Thin slice maximum intensity projections of the NECT scans were reconstructed. One observer evaluated the native images twice with a time interval of six month between both passes with respect to the prevalence and location of an aneurysm. The size and location of the aneurysms were evaluated in corresponding CT-Angiography and Time of flight datasets. A logit regression analysis was performed with size and location as dependent variables. 2 × 2 tables were constructed. The sensitivity and false negative rate were calculated for aneurysms with 0–6.9 mm, 7–9.9 mm and 10–20 mm and the under the curve (AUC) was calculated.Results:The overall detection rate of the aneurysms was 63% for the first pass and 66% for the second pass in the reconstructed NECT scans. The detection rate of aneurysms is size dependent. The sensitivity to detect aneurysms with a size of 0–6.9 mm was 0.09 and 0.03, for aneurysms with a size of 7–9.9. mm was 0.8 and 0.7 and for aneurysms with a size of 10–20 mm was 0.92 for both passes.The AUC was 0.77 for the first pass and 0.78 for the second pass.Conclusions:NECT scans can be used to detect a significant proportion of intracranial aneurysms larger than 7 mm if properly displayed and reconstructed. These patients should receive further vascular imaging to prevent future aneurysm related subarachnoid hemorrhage.  相似文献   
58.
The coincident occurrence of tricuspid atresia and aortopulmonary window (APW) is exceedingly rare, with one previous case reported in the literature. We present a patient with tricuspid atresia, pulmonary atresia, and APW. Postnatal echocardiograms demonstrated no visible pulmonary valve, and additional defects including a bicuspid aortic valve, right aortic arch and anomalous coronary arteries raised suspicion for tricuspid atresia with persistent truncus arteriosus. However, fetal echocardiography and direct visualization of the anatomy confirmed the alternate diagnosis. The patient underwent successful palliation consisting of APW repair, atrial septectomy and a 3.5 mm modified Blalock–Taussig shunt, followed by a bidirectional cavopulmonary connection.  相似文献   
59.
60.

Background  

Doxorubicin is considered one of the most potent established chemotherapeutics in the treatment of liposarcoma; however, the response rates usually below 30%, are still disappointing. This study was performed to identify gene expression changes in liposarcoma after doxorubicin treatment.  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