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   43732篇
  免费   2749篇
  国内免费   1357篇
耳鼻咽喉   663篇
儿科学   1053篇
妇产科学   654篇
基础医学   4201篇
口腔科学   826篇
临床医学   4322篇
内科学   6520篇
皮肤病学   1866篇
神经病学   2912篇
特种医学   1102篇
外国民族医学   1篇
外科学   1917篇
综合类   6320篇
现状与发展   3篇
一般理论   2篇
预防医学   5004篇
眼科学   531篇
药学   6499篇
  31篇
中国医学   2266篇
肿瘤学   1145篇
  2024年   58篇
  2023年   505篇
  2022年   1077篇
  2021年   1516篇
  2020年   1330篇
  2019年   1197篇
  2018年   1252篇
  2017年   1256篇
  2016年   1266篇
  2015年   1342篇
  2014年   2624篇
  2013年   3033篇
  2012年   2679篇
  2011年   2880篇
  2010年   2357篇
  2009年   2168篇
  2008年   2208篇
  2007年   2290篇
  2006年   1889篇
  2005年   1769篇
  2004年   1428篇
  2003年   1260篇
  2002年   1007篇
  2001年   931篇
  2000年   804篇
  1999年   770篇
  1998年   595篇
  1997年   591篇
  1996年   539篇
  1995年   539篇
  1994年   483篇
  1993年   376篇
  1992年   416篇
  1991年   383篇
  1990年   312篇
  1989年   323篇
  1988年   316篇
  1987年   277篇
  1986年   240篇
  1985年   263篇
  1984年   204篇
  1983年   166篇
  1982年   184篇
  1981年   143篇
  1980年   129篇
  1979年   92篇
  1978年   83篇
  1977年   67篇
  1976年   55篇
  1975年   40篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
ObjectivesGrowing evidence of the importance of motor competence for developing a healthy lifestyle has been established in the last decade. Nonetheless, no single instrument or observation tool have been able to fully measure this construct, particularly because most were built for the diagnosis of children in risk for motor impairment; are limited to a few years of the developmental span; lack objectivity in the assessment protocols; or do not include the locomotor, stability, and manipulative components. This led to the difficulty of comparing researches, and longitudinally follow children into adulthood. Recently, a novel proposal to assess motor competence was presented - the Motor Competence Assessment (MCA) - and this study aims to present the MCA normative data from 3-to-23 years.Design and methodsTwo thousand and eighty-seven participants (1102 boys) between 3 and 23 years of age were evaluated in the MCA (standing long jump, 10 m shuttle run, throwing velocity, kicking velocity, lateral jumps, shifting platforms). Results for each test were introduced in the LMS Chartmaker 2.3. The best model for test and sex was used, resulting in normative curves and percentile values.ResultsFinal norms showed a good fit to the instrument developmental expectations, allowing to differentiate and classify performances along the age interval.ConclusionsThe MCA age- and sex- normative values allow to assess motor competence from childhood to early adulthood. Future directions will include obtaining a total MCA score and the normative scores for the MCA components (stability, locomotion, object control), and to expand the norms to adulthood and old age.  相似文献   
22.
23.
24.
25.
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   
26.
27.
《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   
28.
While decreasing trend in gender differences in alcohol use disorders was reported in Western countries, the change in Asian countries is unknown. This study aims to explore the shifts in gender difference in alcohol abuse (AA) and dependence (AD) in Korea. We compared the data from two nation-wide community surveys to evaluate gender differences in lifetime AA and AD by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). Face-to-face interviews using the Composite International Diagnostic Interview (CIDI) were applied to all subjects in 2001 (n=6,220) and 2011 (n=6,022). Male-to-female ratio of odds was decreased from 6.41 (95% CI, 4.81-8.54) to 4.37 (95% CI, 3.35-5.71) for AA and from 3.75 (95% CI, 2.96-4.75) to 2.40 (95% CI, 1.80-3.19) for AD. Among those aged 18-29, gender gap even became statistically insignificant for AA (OR, 1.59; 95% CI, 0.97-2.63) and AD (OR, 1.18; 95% CI, 0.80-2.41) in 2011. Men generally showed decreased odds for AD (0.55; 95% CI, 0.45-0.67) and women aged 30-39 showed increased odds for AA (2.13; 95% CI 1.18-3.84) in 2011 compared to 2001. Decreased AD in men and increased AA in women seem to contribute to the decrease of gender gap. Increased risk for AA in young women suggests needs for interventions.  相似文献   
29.
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   
30.
IntroductionCaloric testing is the most frequently used test to assess peripheral vestibular function since the beginning of the 20th century. However, the video head impulse test, vHIT, has gained prominence in the field of neurotology, as it is a faster examination, easier to perform and less uncomfortable for the patient.ObjectiveTo compare, through systematic review and meta-analysis, the proportion of altered cases between vHIT tests and caloric testing in patients with chronic dizziness, in addition to assessing the sensitivity and specificity of vHIT, with caloric testing as the gold standard.MethodsThe literature search was carried out in the PubMed, Scopus, BVS-Bireme, Web of Science, Embase, Cochrane and ProQuest indexed databases, with no restrictions regarding the publication period. All articles that contained the results of the two tests were included in the evaluation of patients with dizziness. Two researchers independently conducted data selection and extraction from the studies, strictly following the inclusion and exclusion criteria defined in the research protocol. In case of disagreement during the selection, a discussion was carried out with a third evaluator.ResultsEleven of the 1293 initial articles met the eligibility criteria and were analyzed. 2670 patients were evaluated, of which 1112 (41.6%) were males and 1558 (58.4%) females, with a mean age of 51.6 years. The proportion of altered results in the vHIT was 21% (95%CI 9% –33%), and 55% in the caloric testing (95%CI 43% –67%).ConclusionThe vHIT does not substitute for caloric testing. The tests are complementary in assessing the patient with dizziness, as they describe the tonotopy of the ampullary crest at different frequency ranges of stimulation. In chronic cases, the vHIT has a low sensitivity and high diagnostic specificity in comparison to caloric testing.  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