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   4995篇
  免费   248篇
  国内免费   77篇
耳鼻咽喉   94篇
儿科学   32篇
妇产科学   47篇
基础医学   852篇
口腔科学   108篇
临床医学   494篇
内科学   958篇
皮肤病学   103篇
神经病学   455篇
特种医学   296篇
外科学   709篇
综合类   16篇
预防医学   204篇
眼科学   53篇
药学   442篇
中国医学   76篇
肿瘤学   381篇
  2024年   1篇
  2023年   44篇
  2022年   167篇
  2021年   239篇
  2020年   107篇
  2019年   121篇
  2018年   149篇
  2017年   123篇
  2016年   192篇
  2015年   333篇
  2014年   344篇
  2013年   378篇
  2012年   561篇
  2011年   533篇
  2010年   258篇
  2009年   234篇
  2008年   323篇
  2007年   281篇
  2006年   230篇
  2005年   155篇
  2004年   108篇
  2003年   96篇
  2002年   84篇
  2001年   74篇
  2000年   66篇
  1999年   41篇
  1998年   24篇
  1997年   6篇
  1996年   7篇
  1995年   7篇
  1994年   4篇
  1993年   7篇
  1992年   12篇
  1991年   2篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1987年   3篇
  1986年   2篇
  1977年   1篇
排序方式: 共有5320条查询结果,搜索用时 15 毫秒
11.
BACKGROUND: DNA repair gene XRCC1 Arg399Gln polymorphism has been associated with the risk of several human tumours. In the present study we investigated whether the XRCC1 polymorphism is related to the risk of uterine leiomyoma, the most common neoplasm of the female genital tract. METHODS: Three hundred and twenty-seven patients with uterine leiomyoma and 197 normal controls were enrolled, and XRCC1 genotyping was determined by PCR and restriction fragment length polymorphism. RESULTS: The proportions of individuals homozygous for 399Arg allele, heterozygous and homozygous for the 399Gln allele were 85.8%, 13.7% and 0.5% among the control group, and 46.2%, 53.2% and 0.6% in those with leiomyoma (P < 0.001), respectively. Logistic regression analysis (after adjusting for age, parity, menarche age and body mass index) showed a significant increased risk of uterine leiomyoma in women with the Arg/Gln genotype versus the Arg/Arg genotype (odds ratio 6.79; 95% confidence interval 4.20-10.99; P < 0.001). CONCLUSIONS: In Korean women, the 399Gln polymorphism of XRCC1 is associated with an increased risk of uterine leiomyoma.  相似文献   
12.
Won MH  Kang T  Park S  Jeon G  Kim Y  Seo JH  Choi E  Chung M  Cho SS 《Neuroscience letters》2001,301(2):139-142
Delayed neuronal death in the CA1 of the hippocampus following global ischemia has been evoked by both the activation of N-methyl-D-aspartate receptor (NR) and the generate reactive oxygen species in the neurons. In the present study, we investigated whether oxidative DNA damages may be correlated with NR subunits (NR1 and NR2A/B) expression following ischemia insults in vivo. Thirty minutes after ischemia-reperfusion, the intensities of both NR and 8-hydroxy-2'-deoxyguanosine (8-OHdG) immunoreactivities were markedly increased in neurons of CA1. However, NR2A/B and 8-OHdG immunoreactivities were enhanced in CA1 over 24 h after ischemia although NR1 immunoreactivity was decreased. These results suggest that oxidative stress and excitotoxicity in the CA1 may simultaneously trigger neuronal damages at early time after ischemia, and free radical damage including oxidative DNA damage may eventually promote the delayed neuronal death in this region.  相似文献   
13.
The available data on the association between micronutrients in the blood and non-alcoholic fatty liver disease (NAFLD) are limited. To investigate the clinical implications of this relationship, we sought to identify the difference in the serum levels of vitamins A and E according to NAFLD status using data from the seventh Korea National Health and Nutrition Examination Survey. In this cross-sectional study of the Korean population, NAFLD and its severity were defined using prediction models. Differences in the prevalence and severity of NAFLD were analyzed according to serum retinol (vitamin A) and alpha (α)-tocopherol (vitamin E) levels. Serum levels of retinol and α-tocopherol were positively correlated with the prevalence of NAFLD. In most prediction models of the NAFLD subjects, serum retinol deficiency was significantly correlated with advanced fibrosis, while serum α-tocopherol levels did not differ between individuals with or without advanced fibrosis. Similar trends were also noted with cholesterol-adjusted levels of α-tocopherol. In summary, while circulating concentrations of retinol and α-tocopherol were positively associated with the presence of NAFLD, advanced liver fibrosis was only correlated with serum retinol levels. Our findings could provide insight into NAFLD patient care at a micronutrient level.  相似文献   
14.
International Urology and Nephrology - Late onset hypogonadism (LOH) is an age-dependent reduction of testosterone associated with alterations of metabolic profile, including glucose control,...  相似文献   
15.
16.
17.
18.
Activation of NF-kappaB/Rel in angelan-stimulated macrophages.   总被引:3,自引:0,他引:3  
  相似文献   
19.
Cytotoxicities of four urushiols, congeners isolated from the sap of Korean lacquer tree (Rhus vernicifera Stokes), to 29 human cancer cell lines originated from 9 organs were evaluated. Their values of 50% growth inhibition were below 4 microg/ml, and showed cell line specific cytotoxicity. The present result is the first report on the cytotoxicity of urushiols suggesting that they would have an anticancer activity to human cancer cells.  相似文献   
20.
PURPOSE: To describe a randomized trial of a cognitive behavioral intervention on reducing symptom severity among patients diagnosed with solid tumors and undergoing a first course of chemotherapy and to determine whether the intervention had an additive or interactive effect on symptom severity in the presence of supportive care medications. PATIENTS AND METHODS: Patients (N = 237) were accrued from comprehensive and community cancer centers, interviewed, and randomly assigned to either the experimental intervention (n = 118) or conventional care (n = 119). A symptom severity index, based on summed severity scores across 15 symptoms, was the primary outcome. Each patient's site of cancer, stage at diagnosis, chemotherapy protocols, and use of supportive medications were learned from medical records. RESULTS: Groups were equivalent at baseline, and attrition by characteristics by group was not different. The proportion of patients not receiving chemotherapy at 10 and 20 weeks did not differ by group. At the 10- and 20-week observations, there was a significant interaction between the experimental group and baseline symptom severity. Patients in the experimental group who entered the trial with higher symptom severity reported significantly lower severity at 10 and 20 weeks. Controlling for chemotherapy treatment status at follow-up and supportive care medications did not alter the effect of the experimental intervention. CONCLUSION: Compared with conventional care alone, the experimental intervention was effective among patients who entered the trial with higher levels of symptom severity. Age, sex, site or stage of cancer, and supportive medications did not modify the effect of this cognitive behavioral intervention on symptom severity.  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