全文获取类型
收费全文 | 2205篇 |
免费 | 176篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 107篇 |
妇产科学 | 60篇 |
基础医学 | 321篇 |
口腔科学 | 142篇 |
临床医学 | 298篇 |
内科学 | 410篇 |
皮肤病学 | 40篇 |
神经病学 | 261篇 |
特种医学 | 57篇 |
外科学 | 152篇 |
综合类 | 5篇 |
一般理论 | 2篇 |
预防医学 | 214篇 |
眼科学 | 40篇 |
药学 | 147篇 |
中国医学 | 11篇 |
肿瘤学 | 112篇 |
出版年
2024年 | 3篇 |
2023年 | 24篇 |
2022年 | 57篇 |
2021年 | 92篇 |
2020年 | 79篇 |
2019年 | 91篇 |
2018年 | 80篇 |
2017年 | 72篇 |
2016年 | 84篇 |
2015年 | 92篇 |
2014年 | 100篇 |
2013年 | 137篇 |
2012年 | 189篇 |
2011年 | 199篇 |
2010年 | 98篇 |
2009年 | 85篇 |
2008年 | 125篇 |
2007年 | 136篇 |
2006年 | 125篇 |
2005年 | 118篇 |
2004年 | 105篇 |
2003年 | 78篇 |
2002年 | 88篇 |
2001年 | 8篇 |
2000年 | 11篇 |
1999年 | 12篇 |
1998年 | 22篇 |
1997年 | 10篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 10篇 |
1993年 | 10篇 |
1992年 | 9篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1983年 | 3篇 |
1977年 | 1篇 |
1941年 | 1篇 |
排序方式: 共有2394条查询结果,搜索用时 0 毫秒
61.
Anália S. Barhouch Alexandre V. Padoin Daniela S. Casagrande Raquel Chatkin Samanta P. Süssenbach Milene A. Pufal Carina Rossoni Cláudio C. Mottin 《Obesity surgery》2016,26(6):1178-1185
Background
The objective of this study was to analyze the factors associated with change in body mass index (BMI) and with percentage of excess weight loss (%EWL) in patients undergoing Roux-en-Y gastric bypass (RYGB). The following factors were analyzed: sex, age, surgical access (laparotomy vs. laparoscopy), preoperative BMI, waist circumference (WC), type 2 diabetes mellitus (T2DM), high blood pressure, and dyslipidemia.Methods
Retrospective cohort study using a convenience sample of 2070 patients of both sexes, aged 18 to 65 years, undergoing RYGB between 2000 and 2013. The outcomes of interest were BMI and %EWL at 0, 6, 12, 18, 24, 30, 36, 42, 48, 54, and 60 months after RYGB.Results
After 36, 48, and 60 months, approximately 50 % of patients had BMI >30 kg/m2. As for %EWL, 60-month results were poor for 17 % of patients (%EWL <50 %), good for 40 % of patients (%EWL 50–75 %), very good for 24 % of patients (%EWL from >75–90 %), and excellent for 19 % of patients (%EWL >90 %). The four most significant predictors of BMI change 60 months after RYGB (in descending order of magnitude) were preoperative BMI, preoperative WC, surgical access, and age; and of %EWL, surgical access, preoperative BMI, preoperative WC, and age.Conclusions
After 60 months of follow-up, the most relevant predictors of weight loss after RYGB were lower preoperative BMI and WC, videolaparoscopy as surgical access, and younger age. Further studies must be carried out to elucidate the impact of these factors on RYGB outcomes.62.
Prevalence and duration of breast milk feeding in very preterm infants: A 3‐year follow‐up study and a systematic literature review 下载免费PDF全文
63.
T cells are extremely sensitive in their ability to find minute amounts of antigenic peptide in the midst of many endogenous peptides presented on an antigen-presenting cell. The role of endogenous peptides in the recognition of foreign peptide and hence in T cell activation has remained controversial for CD8+ T cell activation. We showed previously that in a CD8+ T cell hybridoma, nonstimulatory endogenous peptides enhance T cell sensitivity to antigen by increasing the coreceptor function of CD8. However, others were not able to detect such enhancement in naive and activated CD8+ T cells. Here, we show that endogenous peptides substantially enhance the ability of T cells to detect antigen, an effect measurable by up-regulation of activation or maturation markers and by increased effector function. This enhancement is most pronounced in thymocytes, moderate in naive T cells, and mild in effector T cells. The importance of endogenous peptides is inversely proportional to the agonist activity of the stimulatory peptide presented. Unlike for CD4+ T cells, the T cell receptor of CD8+ T cells does not distinguish between endogenous peptides for their ability to enhance antigen recognition. 相似文献
64.
Eduardo A. Figueiredo Leonor Casilla Loyola Paulo S. Belangero Ândrea Kely Campos Ribeiro-dos-Santos Sidney Emanuel Batista Santos Carina Cohen Andre Wajnsztejn Adrielle Martins de Oliveira Marília C. Smith Alberto de Castro Pochini Carlos V. Andreoli Benno Ejnisman Moises Cohen Mariana F. Leal 《Journal of orthopaedic research》2020,38(1):192-201
Rotator cuff tears (RCT) is a multifactorial disease with genetic factors contributing for the disease etiology. We hypothesized that genetic variants in genes involved in extracellular matrix (ECM) homeostasis may alter susceptibility to RCT. We evaluated 20 polymorphisms of genes involved in ECM homeostasis in 211 cases of full-thickness tears of the supraspinatus (Nfemales = 130; Nmales = 81) and 567 age-matched controls (Nfemales = 317; Nmales = 250). Multivariate logistic regressions were carried out with age, gender, genetic ancestry (based on the analysis of 61 biallelic short insertion/deletion polymorphisms), and common co-morbidities (diabetes, dyslipidemia, and smoking habits) as covariates. We observed that carriers of the rare allele of both studied variants of TGFB1, as well as their G/A (rs1800470/rs1800469) haplotype, were less susceptible to RCT (p < 0.05). In contrast, carriers of the G allele of MMP9 rs17576 (p = 0.014) or G/G haplotype (rs17576/rs17577; p < 0.001) had an increased risk for tendon tears. The presence of the T allele of MMP2 rs2285053 (p = 0.033), the T allele of MMP3 rs679620 (p = 0.024), and the TT-genotype of TIMP2 rs2277698 (p = 0.01) was associated with susceptibility to tears, especially in females. In males, the A allele of COL5A1 rs3196378 (p = 0.032) and the G allele of TGFBR1 rs1590 (p = 0.039) were independent risk factors for RCT. The C/T COL5A1 (rs3196378/rs11103544) haplotype was associated with a reduced risk of tears in males (p = 0.03). In conclusion, we identified the genetic variants associated with RCT susceptibility, thereby reinforcing the role of genes involved in the structure and homeostasis of the ECM of tendons in disease development. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:192–201, 2020 相似文献
65.
Margot Fournier Carina Ferrari Philipp S. Baumann Andrea Polari Aline Monin Tanja Bellier-Teichmann Jacob Wulff Kirk L. Pappan Michel Cuenod Philippe Conus Kim Q. Do 《Schizophrenia bulletin》2014,40(5):973-983
Because increasing evidence point to the convergence of environmental and genetic risk factors to drive redox dysregulation in schizophrenia, we aim to clarify whether the metabolic anomalies associated with early psychosis reflect an adaptation to oxidative stress. Metabolomic profiling was performed to characterize the response to oxidative stress in fibroblasts from control individuals (n = 20) and early psychosis patients (n = 30), and in all, 282 metabolites were identified. In addition to the expected redox/antioxidant response, oxidative stress induced a decrease of lysolipid levels in fibroblasts from healthy controls that were largely muted in fibroblasts from patients. Most notably, fibroblasts from patients showed disrupted extracellular matrix- and arginine-related metabolism after oxidative stress, indicating impairments beyond the redox system. Plasma membrane and extracellular matrix, 2 regulators of neuronal activity and plasticity, appeared as particularly susceptible to oxidative stress and thus provide novel mechanistic insights for pathophysiological understanding of early stages of psychosis. Statistically, antipsychotic medication at the time of biopsy was not accounting for these anomalies in the metabolism of patients’ fibroblasts, indicating that they might be intrinsic to the disease. Although these results are preliminary and should be confirmed in a larger group of patients, they nevertheless indicate that the metabolic signature of reactivity to oxidative stress may provide reliable early markers of psychosis. Developing protective measures aimed at normalizing the disrupted pathways should prevent the pathological consequences of environmental stressors.Key words: mental disorder, glutathione, arginine, extracellular matrix, phospholipid, metabolism 相似文献
66.
67.
Lasse Paludan Malver Anne Brokj?r Camilla Staahl Carina Graversen Trine Andresen Asbj?rn Mohr Drewes 《British journal of clinical pharmacology》2014,77(1):72-95
To assess centrally mediated analgesic mechanisms in clinical trials with pain patients, objective standardized methods such as electroencephalography (EEG) has many advantages. The aim of this review is to provide the reader with an overview of present findings in analgesics assessed with spontaneous EEG and evoked brain potentials (EPs) in humans. Furthermore, EEG methodologies will be discussed with respect to translation from animals to humans and future perspectives in predicting analgesic efficacy. We searched PubMed with MeSH terms ‘analgesics’, ‘electroencephalography’ and ‘evoked potentials’ for relevant articles. Combined with a search in their reference lists 15 articles on spontaneous EEG and 55 papers on EPs were identified. Overall, opioids produced increased activity in the delta band in the spontaneous EEG, but increases in higher frequency bands were also seen. The EP amplitudes decreased in the majority of studies. Anticonvulsants used as analgesics showed inconsistent results. The N-methyl-D-aspartate receptor antagonist ketamine showed an increase in the theta band in spontaneous EEG and decreases in EP amplitudes. Tricyclic antidepressants increased the activity in the delta, theta and beta bands in the spontaneous EEG while EPs were inconsistently affected. Weak analgesics were mainly investigated with EPs and a decrease in amplitudes was generally observed. This review reveals that both spontaneous EEG and EPs are widely used as biomarkers for analgesic drug effects. Methodological differences are common and a more uniform approach will further enhance the value of such biomarkers for drug development and prediction of treatment response in individual patients. 相似文献
68.
Helena Staehler Carina Hopfner Masamichi Ono Jürgen Hörer 《Congenital heart disease》2022,17(1):25-30
We report a very rare case of successful intracardiac correction in a patient with heterotaxy syndrome. The cardiac malformations included dextrocardia, double outlet right ventricle, pulmonary stenosis, interrupted inferior vena cava, hemiazygos continuation and total anomalous pulmonary venous return. One-stage correction was performed. The atrial procedure consisted of intra- and extraatrial rerouting of the anomalous systemic and pulmonary venous return. The hepatic veins were detached and diverted to the left atrium via an extracardiac conduit. The correction of the double outlet right ventricle was accomplished by intraventricular redirection of the blood flow from the left ventricle to the aorta. The right ventricular outflow was ultimately remodeled using a valved conduit. For better perception of the complex morphology, a three-dimensional model was designed, using CT scan images. This proved to be very useful for surgical planning, especially with regard to the intraatrial reconstruction of the systemic and pulmonary venous rerouting. 相似文献
69.
70.
Thoracic Quantitative Dynamic MRI to Understand Developmental Changes in Normal Ventilatory Dynamics