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   538篇
  免费   29篇
耳鼻咽喉   3篇
儿科学   29篇
妇产科学   19篇
基础医学   83篇
口腔科学   13篇
临床医学   52篇
内科学   99篇
皮肤病学   7篇
神经病学   72篇
特种医学   11篇
外科学   57篇
综合类   1篇
一般理论   1篇
预防医学   54篇
眼科学   8篇
药学   30篇
肿瘤学   28篇
  2024年   2篇
  2023年   4篇
  2022年   4篇
  2021年   8篇
  2020年   15篇
  2019年   18篇
  2018年   20篇
  2017年   13篇
  2016年   11篇
  2015年   8篇
  2014年   19篇
  2013年   27篇
  2012年   38篇
  2011年   40篇
  2010年   21篇
  2009年   36篇
  2008年   37篇
  2007年   43篇
  2006年   40篇
  2005年   37篇
  2004年   23篇
  2003年   16篇
  2002年   21篇
  2001年   12篇
  2000年   8篇
  1999年   13篇
  1998年   5篇
  1997年   3篇
  1996年   2篇
  1995年   4篇
  1994年   1篇
  1992年   1篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1988年   2篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1981年   1篇
  1979年   1篇
  1974年   2篇
  1972年   1篇
  1964年   1篇
排序方式: 共有567条查询结果,搜索用时 15 毫秒
561.
OBJECTIVES: To establish whether the relationship between interleukin-6 (IL-6) and plasma lipid and C-reactive protein (CRP) concentrations is different in Finnish nonagenarians than in middle-aged subjects with lower inflammatory status. DESIGN: Cross-sectional. SETTING: Observational cohort study concentrating on the oldest old. PARTICIPANTS: Nonagenarians (n=291, mean age+/-standard deviation 90+/-1; 68 men, 223 women) who lived in the Tampere municipality in southern Finland and a middle-aged control population from the same area (n=227, aged 44+/-8). MEASUREMENTS: Plasma high sensitive CRP and lipid concentrations were analyzed using an automatic analyzer and IL-6 levels using enzyme-linked immunosorbent assay. RESULTS: Plasma concentrations of IL-6 (4.39+/-5.25 vs 1.88+/-1.98 pg/mL) and CRP (3.54+/-4.98 vs 1.53+/-1.91 mg/L) were significantly higher in nonagenarians than in middle-aged subjects (P<.001). In nonagenarians, plasma CRP levels increased (P<.001) and plasma total cholesterol (P=.006), low-density lipoprotein cholesterol (P=.02), and high-density lipoprotein cholesterol (P=.002) levels decreased according to IL-6 quartiles. In middle-aged subjects, similar associations were not found. CONCLUSION: The relationship between IL-6 and plasma CRP and cholesterol levels in nonagenarians with enhanced systemic inflammation differs from that of middle-aged subjects.  相似文献   
562.
Assessment of right ventricular (RV) function is a challenge due to complex anatomy. We studied systolic and diastolic tricuspid annular excursion and longitudinal RV fractional shortening as geometry‐independent measures in patients with acute pulmonary embolism (PE). Forty patients with PE were studied within 24 hours after admission and after 3 months, and compared to 23 healthy subjects used as controls. We recorded tricuspid annular plane systolic (TAPSE) and diastolic (TAPDE) excursion from the four‐chamber view and calculated RV fractional shortening as TAPSE/RV diastolic length. The diastolic RV function was defined as the ratio of the amplitude of tricuspid annular plane excursion during atrial systole to total tricuspid annular plane diastolic excursion (atrial/total TAPDE). In the acute stage, the TAPSE was decreased in PE compared to healthy subjects (19 ± 5 vs. 26 ± 4 mm, P < 0.001), with greater reduction in patients with increased, compared to normal, RV pressure (16.6 ± 5 vs. 20.5 ± 5 mm, P < 0.05). The atrial/total TAPDE was increased in patients compared to healthy subjects (47 ± 13% vs. 38 ± 7%, P < 0.001) and normalized during the follow‐up. Although the patients were asymptomatic after 3 months, the TAPSE recovered incompletely as compared to healthy subjects (21.4 ± 4 vs. 26 ± 4 mm, P < 0.001). Both systolic and diastolic RV function are impaired in acute PE. Diastolic function recovers faster than systolic; therefore, the atrial contribution to RV filling may be a useful measure to follow changes in diastolic function in PE. (Echocardiography 2010;27:286‐293)  相似文献   
563.
Ahola TM  Manninen T  Alkio N  Ylikomi T 《Endocrinology》2002,143(9):3376-3384
The issue of how progesterone affects mammary gland growth is controversial, and the mechanism governing the effects of the hormone remains mostly unknown. We have previously shown that G protein-coupled receptor 30 (GPR30) is a progestin target gene whose expression correlates with progestin-induced growth inhibition in breast cancer cells. In this study, we investigate the role of GPR30 in regulating cell proliferation and mediating progestin-induced growth inhibition. When progestin failed to inhibit the growth of MCF-7 cells and instead stimulated growth, GPR30 was down-regulated. In this way, the inhibitory or stimulatory affects that progestin has on proliferation correlated with the level of expression of GPR30. Transient expression of GPR30 resulted in a marked inhibition of cell proliferation independent of estrogen treatment. GPR30 antisense was used to evaluate the role of GPR30 expression in progestin-induced growth inhibition. A diminished GPR30 mRNA expression by the antisense stimulated growth. Interestingly, GPR30 antisense abrogated the growth inhibitory effect of progestin and progesterone. Indeed, progestin induced 1) a reduction in cell proliferation, 2) G1-phase arrest, and 3) down-regulation of cyclin D1 was diminished. These data suggest that the orphan receptor, GPR30, is important for the inhibitory effect of progestin on growth.  相似文献   
564.
565.
ObjectiveThe increased plasma concentrations of pro-atherogenic and cardiomyocyte hypertrophic cytokine interleukin 18 (IL-18) predict mortality in patients with coronary heart disease (CHD) in addition to predicting the outcome of heart failure. The IL-18 gene has a functional ?137 G/C polymorphism (rs187238) in the promoter region. The C allele carriage is associated with attenuated IL-18 production. The effect of IL-18 genotype on SCD is unknown. We studied the association of the IL-18 gene ?137 G/C polymorphism with the occurrence of sudden cardiac death (SCD).MethodsUsing the TaqMan 5′ nuclease assay, we genotyped two independent consecutive and prospective autopsy series which were included in the Helsinki Sudden Death Study.ResultsOf the 663 men, 359 (54.1%) had the wild-type GG-genotype, 261 (39.4%) were heterozygotes (CG) and 43 (6.5%) were CC homozygotes. Compared to the GG homozygotes, the C allele carriers (i.e. subjects having CC or CG genotypes) had a lower adjusted risk for SCD from any cause (odds ratio [OR] 0.49; 95% confidence interval [CI], 0.31–0.77, p = 0.002), for SCD due to CHD (OR 0.51; 95% CI, 0.32–0.82, p = 0.005), and for SCD caused by non-coronary heart diseases (OR 0.34; 95% CI 0.13–0.90, p = 0.030).ConclusionIL-18 promoter ?137 G/C polymorphism, which regulates the expression of IL-18, is an important predictor of SCD from any cause as well as SCD in patients with and without underlying CHD.  相似文献   
566.
Mantle cell lymphoma (MCL) is a heterogenic non-Hodgkin lymphoma entity, with a median survival of about 5 years. In 2008 we reported the early - based on the median observation time of 4 years - results of the Nordic Lymphoma Group MCL2 study of frontline intensive induction immunochemotherapy and autologous stem cell transplantation (ASCT), with more than 60% event-free survival at 5 years, and no subsequent relapses reported. Here we present an update after a median observation time of 6·5 years. The overall results are still excellent, with median overall survival and response duration longer than 10 years, and a median event-free survival of 7·4 years. However, six patients have now progressed later than 5 years after end of treatment. The international MCL Prognostic Index (MIPI) and Ki-67-expression were the only independent prognostic factors. Subdivided by the MIPI-Biological Index (MIPI + Ki-67, MIPI-B), more than 70% of patients with low-intermediate MIPI-B were alive at 10 years, but only 23% of the patients with high MIPI-B. These results, although highly encouraging regarding the majority of the patients, underline the need of a risk-adapted treatment strategy for MCL. The study was registered at www.isrctn.org as ISRCTN 87866680.  相似文献   
567.
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