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   340篇
  免费   17篇
  国内免费   2篇
耳鼻咽喉   5篇
儿科学   2篇
妇产科学   3篇
基础医学   37篇
口腔科学   6篇
临床医学   31篇
内科学   62篇
皮肤病学   24篇
神经病学   12篇
特种医学   7篇
外科学   90篇
综合类   5篇
预防医学   20篇
眼科学   15篇
药学   30篇
中国医学   1篇
肿瘤学   9篇
  2024年   1篇
  2023年   1篇
  2022年   8篇
  2021年   7篇
  2020年   8篇
  2019年   12篇
  2018年   11篇
  2017年   9篇
  2016年   9篇
  2015年   15篇
  2014年   27篇
  2013年   20篇
  2012年   36篇
  2011年   38篇
  2010年   25篇
  2009年   11篇
  2008年   14篇
  2007年   19篇
  2006年   16篇
  2005年   15篇
  2004年   16篇
  2003年   16篇
  2002年   11篇
  2001年   2篇
  2000年   1篇
  1999年   2篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1984年   1篇
  1978年   1篇
  1977年   1篇
  1974年   1篇
  1973年   1篇
排序方式: 共有359条查询结果,搜索用时 15 毫秒
81.
AIM: To evaluate the effects of genipin cross-linking on bullous keratopathy in rabbits. METHODS: Nine female New Zealand white rabbits with bullous keratopathy were used as an experimental model. They were randomized into three groups. Corneas in Group A (treatment group, n=3) were immersed in 0.25% genipin at 24℃ for 40min; those in Group B (control group, n=3) were immersed in 0.9% sodium chloride solution at 24℃ for 40min; and those in Group C (blank control group, n=3) received no treatment. Follow-up examinations were performed within 2wk after treatment, including slit-lamp microscopy, central corneal thickness (CCT), evaluations of body weight and stress responses, histopathological analyses, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) for detecting stromal cell apoptosis. RESULTS: Compared to Groups B and C, remission of corneal edema, corneal healing, disappearance of epithelial bullae, a significant decrease in CCT (P<0.05), and a significant increase in body weight (P<0.05) were found in Group A. Animals in Group A became more active and showed less aggression and violent resistance behavior. More regular and dense arrangement of collagen fibers in the corneal stroma and formation of blue strips of cross-linking products were observed in Group A. Cell apoptosis occasionally occurred in the corneal stroma of Group A, while no cell apoptosis was observed in Groups B and C. CONCLUSION: Genipin cross-linking treatment for bullous keratopathy in rabbits results in remission of corneal edema and relief of pain. We hypothesize that genipin cross-linking strengthens collagen fibers in corneal stroma to avoid the formation of corneal edema and bullae.  相似文献   
82.
A recent study showed an association between hookah/opium use and gastric cancer but no study has investigated the relationship with gastric precancerous lesions. We examined the association between hookah/opium and gastric precancerous lesions and subsequent gastric cancer. In a population‐based cohort study, 928 randomly selected, healthy, Helicobacter pylori‐infected subjects in Ardabil Province, Iran, were followed for 10 years. The association between baseline precancerous lesions and lifestyle risk factors (including hookah/opium) was analyzed using logistic regression and presented as odds ratios (ORs) and 95% confidence intervals (CIs). We also calculated hazard ratios (HRs) and 95% CIs for the associations of lifestyle risk factors and endoscopic and histological parameters with incident gastric cancers using Cox regression models. Additionally, the proportion of cancers attributable to modifiable risk factors was calculated. During 9,096 person‐years of follow‐up, 36 new cases of gastric cancer were observed (incidence rate: 3.96/1,000 persons‐years). Opium consumption was strongly associated with baseline antral (OR: 3.2; 95% CI: 1.2–9.1) and body intestinal metaplasia (OR: 7.3; 95% CI: 2.5–21.5). Opium (HR: 3.2; 95% CI: 1.4–7.7), hookah (HR: 3.4; 95% CI: 1.7–7.1) and cigarette use (HR: 3.2; 95% CI: 1.4–7.5), as well as high salt intake, family history of gastric cancer, gastric ulcer and histological atrophic gastritis and intestinal metaplasia of body were associated with higher risk of gastric cancer. The fraction of cancers attributable jointly to high salt, low fruit intake, smoking (including hookah) and opium was 93% (95% CI: 83–98). Hookah and opium use are risk factors for gastric cancer as well as for precancerous lesions. Hookah, opium, cigarette and high salt intake are important modifiable risk factors in this high‐incidence gastric cancer area.  相似文献   
83.
BackgroundMortality in sepsis remains high. Studies on small cohorts have shown that red cell distribution width (RDW) is associated with mortality. The aim of this study was to validate these findings in a large multicenter cohort.MethodsWe conducted this retrospective analysis of the multicenter eICU Collaborative Research Database in 16,423 septic patients. We split the cohort in patients with low (≤15%; n = 7,129) and high (>15%; n = 9,294) RDW. Univariable and multivariable multilevel logistic regressions were used to fit regression models for the binary primary outcome of hospital mortality and the secondary outcome intensive care unit (ICU) mortality with hospital unit as random effect. Optimal cutoffs were calculated using the Youden index.ResultsPatients with high RDW were more often older than 65 years (57% vs. 50%; p < 0.001) and had higher Acute Physiology and Chronic Health Evaluation (APACHE) IV scores (69 vs. 60 pts.; p < 0.001). Both hospital (adjusted odds ratios [aOR] 1.18; 95% CI: 1.16–1.20; p < 0.001) and ICU mortality (aOR 1.16; 95% CI: 1.14–1.18; p < 0.001) were associated with RDW as a continuous variable. Patients with high RDW had a higher hospital mortality (20 vs. 9%; aOR 2.63; 95% CI: 2.38–2.90; p < 0.001). This finding persisted after multivariable adjustment (aOR 2.14; 95% CI: 1.93–2.37; p < 0.001) in a multilevel logistic regression analysis. The optimal RDW cutoff for the prediction of hospital mortality was 16%.ConclusionWe found an association of RDW with mortality in septic patients and propose an optimal cutoff value for risk stratification. In a combined model with lactate, RDW shows equivalent diagnostic performance to Sequential Organ Failure Assessment (SOFA) score and APACHE IV score.  相似文献   
84.
Mechanisms of cardiac nerve sprouting after myocardial infarction in dogs   总被引:1,自引:0,他引:1  
Cardiac nerve sprouting and sympathetic hyperinnervation after myocardial infarction (MI) both contribute to arrhythmogenesis and sudden death. However, the mechanisms responsible for nerve sprouting after MI are unclear. The expression of nerve growth factor (NGF), growth associated protein 43 (GAP43), and other nerve markers were studied at the infarcted site, the noninfarcted left ventricle free wall (LVFW), and the left stellate ganglion (LSG) at several time points (30 minutes to 1 month) after MI. Transcardiac (difference between coronary sinus and aorta) NGF levels were also assayed. Acute MI resulted in the immediate elevation of the transcardiac NGF concentration within 3.5 hours after MI, followed by the upregulation of cardiac NGF and GAP43 expression, which was earlier and more pronounced at the infarcted site than the noninfarcted LVFW. However, cardiac nerve sprouting and sympathetic hyperinnervation were more pronounced in the noninfarcted than the infarcted LVFW site and peaked at 1 week after MI. The NGF and GAP43 protein levels significantly increased in the LSG from 3 days (P<0.01 for all) after MI, without a concomitant increase in mRNA. There was persistent elevation of NGF levels in aorta and coronary sinus within 1 month after MI. We conclude MI results in immediate local NGF release, followed by upregulation of NGF and GAP43 expression at the infarcted site. NGF and GAP43 are transported retrogradely to LSG, which triggers nerve sprouting at the noninfarcted LVFW. A rapid and persistent upregulation of NGF and GAP43 expression at the infarcted site underlies the mechanisms of cardiac nerve sprouting after MI.  相似文献   
85.
86.
Heart Failure Reviews - Transthyretin cardiac amyloidosis (ATTR-CM) is caused by the accumulation of misfolded transthyretin (TTR) protein in the myocardium. Diflunisal, an agent that stabilizes...  相似文献   
87.

Background

Carvedilol belongs to a group of medicines termed non-selective beta-adrenergic blocking agents. In the presented approach, a practical and environmentally friendly microextraction method based on the application of ionic liquids (ILs) was followed by fluorescence spectrometry for trace determination of carvedilol in pharmaceutical and biological media.

Methods

A rapid and simple ionic liquid phase microextraction was utilized for preconcentration and extraction of carvedilol. A hydrophobic ionic liquid (IL) was applied as a microextraction solvent. In order to disperse the IL through the aqueous media and extract the analyte of interest, IL was injected into the sample solution and a proper temperature was applied and then for aggregating the IL-phase, the sample was cooled in an ice water-bath. The aqueous media was centrifuged and IL-phase collected at the bottom of the test tube was introduced to the micro-cell of spectrofluorimeter, in order to determine the concentration of the enriched analyte.

Results

Main parameters affecting the accuracy and precision of the proposed approach were investigated and optimized values were obtained. A linear response range of 10–250 μg l−1 and a limit of detection (LOD) of 1.7 μg l−1 were obtained.

Conclusion

Finally, the presented method was utilized for trace determination of carvedilol in commercial pharmaceutical preparations and biological media.  相似文献   
88.
89.
OBJECTIVE: This study was undertaken to investigate the previously reported association of the STAT4 polymorphism rs7574865 with rheumatoid arthritis (RA) in 3 different European populations from Spain, Sweden, and The Netherlands, comprising a total of 2,072 patients and 2,474 controls. METHODS: Three different cohorts were included in the study: 923 RA patients and 1,296 healthy controls from Spain, 273 RA patients and 285 healthy controls from Sweden, and 876 RA patients and 893 healthy controls from The Netherlands. DNA from patients and controls was obtained from peripheral blood. Samples were genotyped for the STAT4 single-nucleotide polymorphism rs7574865 using a TaqMan 5'-allele discrimination assay. The chi-square test was performed to compare allele and genotype distributions. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. RESULTS: We observed a significantly increased frequency of the minor T allele in RA patients compared with healthy controls in the Spanish population (24.8% versus 20.8%; P = 0.001, OR 1.26 [95% CI 1.09-1.45]). This association was confirmed in both the Swedish population (P = 0.03, OR 1.35 [95% CI 1.03-1.77]) and the Dutch population (P = 0.03, OR 1.45 [95% CI 1.21-1.73]). The overall P value for all 3 populations was 9.79 x 10(-6) (OR 1.25 [95% CI 1.13-1.37]). No association between rs7574865 and the presence of rheumatoid factor or anti-cyclic citrullinated peptide autoantibodies was observed. A meta-analysis of all published STAT4 associations revealed an OR of 1.25 (95% CI 1.19-1.33) (P = 1 x 10(-5)). CONCLUSION: Our findings indicate an association between the STAT4 polymorphism rs7574865 and RA in 3 different populations, from Spain, Sweden, and The Netherlands, thereby confirming previous data.  相似文献   
90.

Abstracts

The 4th International Congress on Early Onset Scoliosis and Growing Spine, November 19–20, 2010, Toronto, Canada  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