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   11392篇
  免费   592篇
  国内免费   40篇
耳鼻咽喉   217篇
儿科学   372篇
妇产科学   206篇
基础医学   1328篇
口腔科学   316篇
临床医学   729篇
内科学   2941篇
皮肤病学   353篇
神经病学   741篇
特种医学   237篇
外国民族医学   1篇
外科学   1789篇
综合类   121篇
一般理论   4篇
预防医学   822篇
眼科学   299篇
药学   830篇
中国医学   50篇
肿瘤学   668篇
  2023年   62篇
  2022年   106篇
  2021年   319篇
  2020年   165篇
  2019年   313篇
  2018年   471篇
  2017年   264篇
  2016年   262篇
  2015年   270篇
  2014年   362篇
  2013年   498篇
  2012年   826篇
  2011年   913篇
  2010年   431篇
  2009年   362篇
  2008年   745篇
  2007年   752篇
  2006年   762篇
  2005年   695篇
  2004年   635篇
  2003年   570篇
  2002年   530篇
  2001年   184篇
  2000年   199篇
  1999年   187篇
  1998年   60篇
  1997年   46篇
  1996年   54篇
  1995年   48篇
  1994年   38篇
  1993年   22篇
  1992年   66篇
  1991年   58篇
  1990年   55篇
  1989年   52篇
  1988年   45篇
  1987年   59篇
  1986年   51篇
  1985年   44篇
  1984年   38篇
  1983年   43篇
  1982年   31篇
  1981年   27篇
  1980年   20篇
  1979年   31篇
  1978年   22篇
  1977年   19篇
  1975年   17篇
  1974年   33篇
  1973年   18篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
BackgroundColorectal cancer is one of the most frequent cancers in both sexes and the most frequent in the developed countries, if men and women are considered together as a group. It has an important associated morbidity and mortality in all countries and constitutes a public health problem with a high direct and indirect economic cost. The number of workdays lost due to temporary disability (TD) is one of the quantifiable references of these indirect costs.AimsTo determine the indirect cost associated with TD due to colorectal cancer in Spain during the year 2011, a cost that aids in the prevention cost/benefit estimation.MethodsThe number of TD processes, the number of workdays lost due to TD, and the mean duration of those processes, based on the CIE 9-MC codes related to this pathology, as well as the calculated cost, using the Spanish minimum wage as a reference, during the period of January to December 2011, were all reviewed.ResultsColorectal cancer in Spain during 2011 represented 1,046 TD processes, 202,784 workdays lost, and a mean process duration of 194 days/year. The resulting cost of the pathology due to TD was 4,335,521.92 euros.ConclusionsThese results are beneficial for evaluating the usefulness of implementing public health support strategies for a greater reduction in colorectal cancer prevalence and mortality, and an improvement in quality of life of the affected individuals and their families, together with an economic savings resulting from a reduction in TD as a consequence of this disease.  相似文献   
62.
63.
64.
65.
ObjectiveSeveral studies have reported the association of genes related to vascular tone, hypertension, oxidative stress and preeclampsia. We investigated the possible association among three polymorphisms in eNOS (as well their haplotypes): one of MTHFR, one of GSTP1 and one of AGT, with severe preeclampsia in Mexican-Mestizo women.MethodsTwo hundred thirty women with severe preeclampsia and 350 control subjects were genotyped; for rs2070744 and rs1799983 of eNOS, rs1801133 of MTHFR, rs1695 of GSTP1 and rs699 of AGT we used real-time PCR allelic discrimination and for VNTR of eNOS, PCR. Allele frequency differences were assessed by χ2. Logistic regression was used to test for associations and for haplotype frequencies using Haploview 4.2.ResultsGenotypic and allelic distribution of the polymorphisms was similar between cases and controls; likewise, haplotype frequencies of the three polymorphisms of eNOS did not differ significantly.ConclusionsTo our knowledge, this is the first time that these polymorphisms have been analyzed together and exclusively in women with severe preeclampsia. However, we did not find an association between polymorphisms of eNOS, MTHFR, GSTP1 and AGT with severe preeclampsia in our population. Additionally, we observed differences in the distribution of the alleles and genotypes of these polymorphisms in our population in comparison to those described in other ethnic groups.  相似文献   
66.
67.
Cannabinoid agonists such as Δ9-tetrahydrocannabinol (THC) are more potent and/or efficacious antinociceptive agents in female than male rats using acute pain models. We tested the hypothesis that THC is more effective in females than males using a model of longer-lasting, inflammatory pain. THC’s anti-allodynic, anti-hyperalgesic, and anti-edema effects were examined 1, 3, and 7 days after injection of complete Freund’s adjuvant (CFA) into the hind paw. Systemically administered THC (0.32–3.2 mg/kg, intraperitoneally [i.p.], same dose each day) was significantly more effective in females than males in attenuating CFA-induced thermal hyperalgesia, but was also more sedative in females. When administered locally into the inflamed hind paw, THC (250–500 μg intraplantar, i.pl.) did not affect locomotor activity in either sex, yet produced greater anti-allodynic and anti-hyperalgesic effects in females than males. Despite THC’s greater anti-allodynic and anti-hyperalgesic effects in females, both i.p. and i.pl. THC reduced hind paw thickness (edema) more in males. The anti-hyperalgesic effect of i.p. THC was blocked by the CB1 receptor-selective antagonist rimonabant in both sexes. Similarly, i.pl. rimonabant antagonized i.pl. THC’s effects in both sexes; in contrast, the CB2 antagonist SR144528 significantly attenuated i.pl. THC’s anti-allodynic effect only in females. Intraplantar SR144528 also antagonized i.pl. THC’s anti-edema effect in males. This study suggests that cannabinoids may be better at reducing edema in males while being more effective against inflammatory pain in females. Furthermore, sex differences in THC’s peripheral effects against inflammatory pain may be a result of activation of both types of cannabinoid receptors in females, in contrast to predominantly CB1 receptors in males.  相似文献   
68.
Seventeen strains of alcoholic yeasts were screened for petite mutation frequency and killer phenotypes with an objective to develop them as industrial strains. The frequency of petite mutations varied with the strain. Though some strains have shown high frequency mutations, a few strains were found to be genetically stable. The killer property was found to vary with the strains. Interestingly, though some strains proved to be sensitive, some strains were found to be killer strains for marker killer strain also. Thus, the study provides the evidence that the killer principle varies with the strain.  相似文献   
69.
70.
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