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   46061篇
  免费   2949篇
  国内免费   1363篇
耳鼻咽喉   723篇
儿科学   1240篇
妇产科学   707篇
基础医学   4293篇
口腔科学   833篇
临床医学   5172篇
内科学   6774篇
皮肤病学   1939篇
神经病学   3416篇
特种医学   1089篇
外国民族医学   1篇
外科学   2163篇
综合类   6267篇
现状与发展   3篇
一般理论   2篇
预防医学   5354篇
眼科学   517篇
药学   6518篇
  30篇
中国医学   2196篇
肿瘤学   1136篇
  2024年   42篇
  2023年   571篇
  2022年   947篇
  2021年   1791篇
  2020年   1545篇
  2019年   1469篇
  2018年   1529篇
  2017年   1475篇
  2016年   1404篇
  2015年   1447篇
  2014年   2899篇
  2013年   3390篇
  2012年   2777篇
  2011年   3057篇
  2010年   2407篇
  2009年   2249篇
  2008年   2294篇
  2007年   2290篇
  2006年   1894篇
  2005年   1761篇
  2004年   1444篇
  2003年   1260篇
  2002年   1018篇
  2001年   959篇
  2000年   810篇
  1999年   771篇
  1998年   597篇
  1997年   614篇
  1996年   540篇
  1995年   537篇
  1994年   477篇
  1993年   382篇
  1992年   419篇
  1991年   375篇
  1990年   310篇
  1989年   319篇
  1988年   303篇
  1987年   277篇
  1986年   230篇
  1985年   255篇
  1984年   198篇
  1983年   159篇
  1982年   178篇
  1981年   139篇
  1980年   120篇
  1979年   89篇
  1978年   78篇
  1977年   64篇
  1976年   50篇
  1975年   39篇
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
31.
32.
33.
34.
35.
The main of this study was to evaluate the mutagenic and carcinogenic potential of (+) – usnic acid (UA), using Somatic Mutation and Recombination Test (SMART) and the test for detecting epithelial tumor clones (wts) in Drosophila melanogaster. Larvae from 72 ± 4 h from Drosophila were fed with UA (5.0, 10.0 or 20.0 mM); urethane (10.0 mM) (positive control); and solvent (Milli-Q water, 1% Tween-80 and 3% ethanol) (negative control). ST cross produced increase in total mutant spots in the individuals treated with 5.0, 10.0 or 20.0 mM of UA. HB cross produced spot frequencies in the concentration of 5.0 mM that were higher than the frequency for the same concentration in the ST cross. In the highest concentrations the result was negative, which means that the difference observed can be attributed, in part, to the high levels of P450, suggesting that increasing the metabolic capacity maximized the toxic effect of these doses. In the evaluation of carcinogenesis using the wts test, the results obtained for the same concentrations of UA show a positive result for the presence of tumors when compared to the negative control. We conclude that UA has recombinogenic, mutagenic and carcinogenic effects on somatic cells in D. melanogaster.  相似文献   
36.
37.
《Vaccine》2020,38(47):7517-7525
BackgroundUnknowing immunity status make migrants vaccine catch-up difficult. The interest of using a rapid tetanus immunotest as the Tétanos Quick Stick® (TQS®) to assess immunity status against tetanus has been evaluated in emergency rooms and it is now commonly used. The study aim was to evaluate TQS® as a tool for migrants’ vaccine catch-up.MethodsFrom December 2018 to February 2019, a prospective study was performed and included consecutively migrants who attented to the primary medicine outconsultation of a health care centre in Paris. Migrants above 18, without any records of tetanus immunization were included and a TQS® was performed during a medical consultation. Adapted vaccine catch-up was then proposed. Immunity against tetanus among migrants, factors associated with positive TQS® and costs savings were evaluated.ResultsTQS® test was positive for 32% of the 310 included patients. In the univariable analysis, factors associated to the presence of a positive TQS® test were a female gender (OR = 1.69 CI95% [1.02–2.80]) and an urban living in the country of origin (OR = 1.79 CI95% [1.07–3.02]). In the multivariable analysis, these factors were not significantly associated to a positive TQS®. Anamnesis was not correlated to the immunity status: only 26% of the migrants who reported vaccinations in childhood, adolescence and adulthood had a positive TQS® test. The use of TQS® test allowed savings of 6,522 US$ as compared to the immediate catch-up strategy for the 310 patients.ConclusionThe TQS® test is an acceptable, simple, rapid and cost saving test that could find a place in the migrants’ vaccine catch-up.  相似文献   
38.
《Australian critical care》2020,33(5):436-440
IntroductionBrown or dark brown eyes make it difficult to distinguish the contrast between a black pupil and the surrounding iris, which may result in clinical assessment errors. The pupillometer can be used to derive an indexed value, the Neurological Pupil index™ (NPi) for pupillary light reflex. However, there are limited data associating the NPi and iris colour. We examine the NPi and eye colour association.MethodsData were pooled from the Establishing Normative Data for Pupillometer Assessments in Neuroscience Intensive Care (END-PANIC) Registry. The analysis includes 14,168 observations collected from 865 patients with neurological conditions who were admitted to the intensive care unit. Summary statistics and statistical models were developed to examine the association using Statistical Analysis Software (SAS) summary procedure.ResultsThe mean age of the cohort was 56 years (standard deviation = 17). Eye colour included dark brown (n = 339), blue (n = 234), brown (n = 173), green (n = 82), and other (n = 37). There was significant differences (p < 0.0001) between mean NPi values by eye colour [blue = 4.08 (0.92), brown = 3.34 (1.45), dark = 3.71 (1.33), green = 4.08 (0.67), other = 3.76 (1.25)]. However, a further random-effects mixed model after controlling for confounding variables revealed no significant difference in NPi values among different eye colour groups.ConclusionsThe pupillary light reflex, when assessed using the pupillometer, is not dependent on the eye colour. Practitioners are not required to consider eye colour as a confounder when they perform pupillary assessment for examining patients with neurological conditions.  相似文献   
39.
40.
ABSTRACT

Purpose

New instrument-based techniques for anterior chamber (AC) cell counting can offer automation and objectivity above clinician assessment. This review aims to identify such instruments and its correlation with clinician estimates.  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