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   204篇
  免费   9篇
儿科学   5篇
妇产科学   6篇
基础医学   24篇
口腔科学   4篇
临床医学   36篇
内科学   37篇
皮肤病学   5篇
神经病学   14篇
特种医学   11篇
外科学   12篇
综合类   2篇
预防医学   26篇
药学   12篇
中国医学   1篇
肿瘤学   18篇
  2023年   1篇
  2022年   1篇
  2021年   5篇
  2020年   4篇
  2019年   1篇
  2018年   7篇
  2017年   8篇
  2016年   9篇
  2015年   6篇
  2014年   9篇
  2013年   15篇
  2012年   20篇
  2011年   19篇
  2010年   12篇
  2009年   10篇
  2008年   13篇
  2007年   20篇
  2006年   13篇
  2005年   13篇
  2004年   9篇
  2003年   10篇
  2002年   2篇
  2001年   1篇
  2000年   1篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1983年   1篇
排序方式: 共有213条查询结果,搜索用时 15 毫秒
1.
2.
High plasma HDL-cholesterol (HDL-c) is a well-established protective factor in coronary artery disease (CAD). One of its potential protective mechanisms is the inhibition of the cytokine-induced upregulation of expression of cellular adhesion molecules (CAMs). High sCAM levels were found to be associated with low HDL-c in some studies performed mostly in hyperlipidemic subjects, but this association has not yet been investigated in CAD patients. In addition, conflicting results were obtained from in vitro studies that explored the proposed HDL effect on cytokine-induced CAM expression. The aim of the present case-control study was to investigate whether low HDL-c values are associated with CAM overexpression in normolipidemic CAD patients and healthy individuals, matched according to age and gender. Plasma HDL-c, sICAM-1, sVCAM-1, and sE-selectin were measured in 37 normolipidemic patients with angiographically verified coronary artery disease and in 52 healthy normolipidemic subjects. The sCAM values obtained in the subjects (patients or controls) with low HDL-c levels (< 1.03 mmol/L) were compared with the values in the subjects with high HDL-c (>or= 1.03 mmol/L). No significant difference was found between sICAM-1, sVCAM-1, and E-selectin values obtained in subjects with low and high HDL-c, either among the patients or the healthy controls. In conclusion, low HDL-c levels are not associated with CAM overexpression in normolipidemic CAD patients and healthy subjects.  相似文献   
3.
BACKGROUND: Most studies have shown that early post-infarction angina (EPA) implies an unfavorable long-term prognosis among patients with acute myocardial infarction (AMI). However, some studies have failed to establish a link between the occurrence of EPA and increased mortality and recurrent infarction rates. METHODS AND RESULTS: In order to evaluate a long-term prognosis in patients with EPA, we assessed the 5-year prognosis of 80 patients with AMI by the presence or absence of EPA. During the 5-year follow up, the occurrence of death, cardiac death, recurrent infarction, unstable angina, heart failure, revascularization and cardiac events were recorded. A cardiac event was defined as an occurrence of any of the following events: cardiac death, recurrent infarction, unstable angina, heart failure and revascularization. Survival analysis showed no differences between patients with and without EPA in the probability of death (p=NS), cardiac death (p=NS), recurrent myocardial infarction (p=NS) and unstable angina (p=NS). Patients with EPA had a higher probability of developing cardiac events (p=0.0285) and undergoing revascularization procedures (p=0.0188). CONCLUSIONS: EPA increases the risk of patients developing cardiac events and undergoing revascularization procedures, and thereby implies a poor long-term prognosis for patients with AMI.  相似文献   
4.
The KIR locus with genes involved in immune processes is among the most polymorphic and structurally diverse human loci. KIR genes encode activating and inhibitory receptors that differ in specificity for HLA class I ligands and signaling potential. These receptors are expressed principally by natural killer (NK) cells and subpopulations of T cells. This study represents the first report of the distribution of KIR genes, KIR genotypes and KIR/HLA pairs in 121 unrelated healthy Croatian individuals. Twenty-three different genotypes were observed in the Croatian population and all 16 KIR genes known to date were found. The most frequent KIR genotype was the AA genotype. All individuals had at least one inhibitory KIR/HLA pair with the majority of individuals with three inhibitory KIR/HLA pairs. The most frequent KIR/HLA pair was the KIR2DL3/C1 group. Our results demonstrated the similarity of the Croatian population’s KIR repertoire with other Caucasian populations reported so far.  相似文献   
5.
Genome-wide association studies (GWAS) have identified over 46 SNPs associated with human prostate cancer (PCa). Some studies have shown correlation of the nitric oxide synthase (NOS) NOS3 gene polymorphisms with the risk and/or progression of PCa. This study aimed to evaluate the association of NOS3 gene polymorphisms (−786T>C, −764A>G, −714G>T, −690C>T, −649G>A and 894G>T) with PCa risk and progression. 150 patients with PCa, 150 patients with BPH and 100 age-matched healthy controls were recruited in this study. Genotyping of promoter polymorphisms was performed by bi-directional DNA sequencing, and for 894G>T by RFLP analysis. There was no significant association between the alleles and genotypes of these genetic variants and PCa risk. For −786T>C polymorphism, we found that C allele is associated with absence of metastases, assuming dominant genetic model (P = 0.049; OR, 0.50; 95% CI, 0.25–1.00). It was found that, compared with NOS3 −690C>T variant CC genotype, CT and TT genotypes confer decreased risk of developing metastases (dominant model, P = 0.015, OR, 0.24; 95% CI, 0.07–0.88) and show association with low clinical tumour stage, compared with stages T3 and T4 (dominant model, P = 0.046, OR, 0.20; 95% CI, 0.04–1.02). Genetic variants −764A>G, −714G>T, −649G>A were not detected in our study group. There is evidence of an inverse correlation of the NOS3 894G>T minor allele with high serum PSA (>20 ng/ml) (dominant model, P = 0.013, OR, 0.37; 95% CI, 0.17–0.82). Our results suggest that NOS3 gene polymorphisms are genetic susceptibility factors for the progression of PCa and patient outcome.  相似文献   
6.
The ability of random mutagenesis techniques to annotate the mammalian genome can be hampered due to genetic redundancy and compensatory pathways that mask heterozygous mutations under homeostatic conditions. The objective of this study was to devise a pharmacologically sensitized screen using the chemotherapeutic drug, 5-fluorouracil (5FU), to induce cytopenia. 5FU dose was optimized in the 129/SvImJ, C57BL/6J, BALB/cJ, and C3H/HeJ strains of laboratory mice. N-ethyl-N-nitrosourea (ENU) mutagenesis was performed on 129/SvImJ males and phenotypic variants were identified by backcrossing on to the C57BL/6J background. G1 animals were challenged with 100 μg/g 5FU and phenodeviants with altered platelet recovery were monitored. Of 546 G1 animals tested, 15 phenodeviants were identified that displayed increased baseline platelet number, a platelet overshoot, or delayed platelet recovery, thereby demonstrating the utility of this approach for uncovering mutations in megakaryocyte and platelet development. Four G1 mice were selected for further analysis. The phenotypes were heritable in all four strains and genetic mapping identified a chromosome location in two of the three G2 lines tested. In conclusion, our group has developed a sensitized random mutagenesis screen utilizing 5FU and has shown that the strain combination of 129/SvImJ × C57BL/6J is robust for identification of founder lines with defects in megakaryocyte and platelet development.  相似文献   
7.
8.
9.
10.
Background: Established causes of diabetes do not fully explain the present epidemic. High-level arsenic exposure has been implicated in diabetes risk, but the effect of low-level arsenic exposure in drinking water remains unclear.Objective: We sought to determine whether long-term exposure to low-level arsenic in drinking water in Denmark is associated with an increased risk of diabetes using a large prospective cohort.Methods: During 1993–1997, we recruited 57,053 persons. We followed each cohort member for diabetes occurrence from enrollment until 31 December 2006. We traced and geocoded residential addresses of the cohort members and used a geographic information system to link addresses with water-supply areas. We estimated individual exposure to arsenic using all addresses from 1 January 1971 until the censoring date. Cox proportional hazards models were used to model the association between arsenic exposure and diabetes incidence, separately for two definitions of diabetes: all cases and a more strict definition in which cases of diabetes based solely on blood glucose results were excluded.Results: Over a mean follow-up period of 9.7 years for 52,931 eligible participants, there were a total of 4,304 (8.1%) diabetes cases, and 3,035 (5.8%) cases of diabetes based on the more strict definition. The adjusted incidence rate ratios (IRRs) per 1-μg/L increment in arsenic levels in drinking water were as follows: IRR = 1.03 (95% CI: 1.01, 1.06) and IRR = 1.02 (95% CI: 0.99, 1.05) for all and strict diabetes cases, respectively.Conclusions: Long-term exposure to low-level arsenic in drinking water may contribute to the development of diabetes.Citation: Bräuner EV, Nordsborg RB, Andersen ZJ, Tjønneland A, Loft S, Raaschou-Nielsen O. 2014. Long-term exposure to low-level arsenic in drinking water and diabetes incidence: a prospective study of the Diet, Cancer and Health cohort. Environ Health Perspect 122:1059–1065; http://dx.doi.org/10.1289/ehp.1408198  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