全文获取类型
收费全文 | 2198篇 |
免费 | 90篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 152篇 |
妇产科学 | 110篇 |
基础医学 | 154篇 |
口腔科学 | 60篇 |
临床医学 | 200篇 |
内科学 | 491篇 |
皮肤病学 | 48篇 |
神经病学 | 124篇 |
特种医学 | 115篇 |
外科学 | 459篇 |
综合类 | 33篇 |
预防医学 | 52篇 |
眼科学 | 42篇 |
药学 | 119篇 |
中国医学 | 4篇 |
肿瘤学 | 114篇 |
出版年
2023年 | 16篇 |
2022年 | 28篇 |
2021年 | 50篇 |
2020年 | 23篇 |
2019年 | 31篇 |
2018年 | 43篇 |
2017年 | 39篇 |
2016年 | 66篇 |
2015年 | 68篇 |
2014年 | 84篇 |
2013年 | 116篇 |
2012年 | 149篇 |
2011年 | 174篇 |
2010年 | 104篇 |
2009年 | 72篇 |
2008年 | 168篇 |
2007年 | 174篇 |
2006年 | 170篇 |
2005年 | 161篇 |
2004年 | 158篇 |
2003年 | 126篇 |
2002年 | 87篇 |
2001年 | 64篇 |
2000年 | 37篇 |
1999年 | 26篇 |
1998年 | 13篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1963年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有2300条查询结果,搜索用时 15 毫秒
91.
Demir B Guven S Guven ES Atamer Y Gunalp GS Gul T 《Journal of reproductive immunology》2007,75(2):145-149
INTRODUCTION: The aim of this study was to compare serum levels of leptin in women with unexplained infertility with fertile subjects. MATERIAL AND METHOD: Serum leptin levels of 27 infertile and 30 fertile women on day 3 of the menstrual cycle were assessed and compared in this prospective age and body mass index (BMI) comparable controlled study. RESULTS: The mean age in the infertile group was 29.3 (range, 23-38), while this figure was 28.9 (range, 19-39) in the fertile group; the mean BMIs were 24.5 (range, 20.6-27.8) and 25.0 (range, 21.8-28.7), respectively. The mean serum leptin level was significantly higher in women with unexplained infertility compared with fertile subjects. Considering normal weight subjects, mean serum leptin levels were increased significantly in the unexplained infertile group compared with the fertile group (7.2 (range, 4.3-10.4) versus 3.5 (range, 1.9-6.2)ng/ml, respectively; p<0.0001, Mann-Whitney U-test). The significant increase in serum leptin levels was observed also in overweight patients (6.8 (range, 1.3-5.2) versus 3.3 (range, 4.2-8.9)ng/ml, respectively; p<0.0001, Mann-Whitney U-test). CONCLUSION: A significant difference in serum leptin levels between unexplained infertile and fertile women suggests that this cytokine may be involved in pathophysiology of unexplained infertility. 相似文献
92.
93.
Muhammed H. Arikan Fatih Eroglu Volkan Eskizeybek Emine Feyza Sukur Mehmet Yildiz Hatice S. Sas 《Materials》2022,15(2)
Aerospace-grade composite parts can be manufactured using Vacuum Bag Only prepregs through an accurate process design. Quality in the desired part can be realized by following process modeling, process optimization, and validation, which strongly depend on a primary and systematic material characterization methodology of the prepreg system and material constitutive behavior. The present study introduces a systematic characterization approach of a Vacuum Bag Only prepreg by covering the relevant material properties in an integrated manner with the process mechanisms of fluid flow, consolidation, and heat transfer. The characterization recipe is practiced under the categories of (i) resin system, (ii) fiber architecture, and (iii) thermal behavior. First, empirical models are successively developed for the cure-kinetics, glass transition temperature, and viscosity for the resin system. Then, the fiber architecture of the uncured prepreg system is identified with X-ray tomography to obtain the air permeability. Finally, the thermal characteristics of the prepreg and its constituents are experimentally characterized by adopting a novel specimen preparation technique for the specific heat capacity and thermal conductivity. Thus, this systematic approach is designed to provide the material data to process modeling with the motivation of a robust and integrated Vacuum Bag Only process design. 相似文献
94.
Bilgul Mete Alper Gunduz Hayat Kumbasar Karaosmanoglu Fatma Gumuser Sibel Bolukcu Dilek Sevgi Yildiz Ozlem Altuntas Aydin Bilgenur Bilge Ilyas Dokmetas Fehmi Tabak 《African health sciences》2021,21(4):1593
BackgroundEfficacy of elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil (E/C/F/TDF) in treatment-naïve and experienced patients with HIV infection was demonstrated in phase 3 trials. The primary objective of this study was to evaluate effectiveness and safety of E/C/F/TDF in real world settings.MethodsRetrospective, observational data collected by the Turkish ACTHIV-IST study group between May 2015 and December 2016 were analysed.ResultsA total of 387 patients were prescribed E/C/F/TDF; 210 patients with available data at 6th month were eligible; 91.5% were male, and mean age was 35.2 (SD: 10.8) years; 54.0% of males identified themselves as MSM. Sixty-three percent (133) of the study population were treatment-naïve patients, and 37% (77) were treatment experienced. HIV RNA level was below 100 copies/mL in 78.9% of treatment-naïve patients and 89.9% of treatment experienced patients at month 6. Median increase in CD4 T lymphocyte count was 218 copies/mL in treatment-naïve patients and remained stable or increased in treatment experienced patients. Adverse events were observed in 15% of the patients, and the regimen was discontinued in only six patients.ConclusionReal world data on the effectiveness and safety of E/C/F/TDF is comparable with the phase 3 trial results Adverse events are uncommon and manageable. 相似文献
95.
Coskun U Orta Kilickesmez K Abaci O Kocas C Bostan C Yildiz A Baskurt M Arat A Ersanli M Gurmen T 《Angiology》2011,62(6):504-508
Chronic kidney disease (CKD) is associated with increased risk of cardiovascular disease and death. We evaluated the association between CKD and severity of coronary artery stenosis by calculating SYNTAX Score in patients with left main coronary artery and/or 3-vessel coronary artery disease. Coronary angiograms of 217 patients were assessed. Chronic kidney disease was staged using the estimated glomerular filtration rate (eGFR, mL/min per 1.73 m(2)) prior to coronary angiography. Patients were divided into 5 groups according to the National Kidney Foundation Kidney Disease Outcome Quality Initiative (NKF KDOQI) Clinical Practice Guidelines (14). Patients with eGFR >90 mL/min per 1.73 m(2) (group 1), patients with eGFR 60 to 89 mL/min per 1.73 m(2) (group 2), patients with eGFR 30 to 59 mL/min per 1.73 m(2) (group 3), patients with eGFR >15 to < 30 per 1.73 m(2) and dialysis patients with eGFR < 15 per 1.73 m(2) were combined as group 4. The risk of significant lesion complexity increased progressively with decreasing kidney function (P = .001). Estimated glomerular filtration rate was a strong predictor of higher SYNTAX Score. 相似文献
96.
97.
Guilmot Antoine Maldonado Slootjes Sofia Sellimi Amina Bronchain Maroussia Hanseeuw Bernard Belkhir Leila Yombi Jean Cyr De Greef Julien Pothen Lucie Yildiz Halil Duprez Thierry Fillée Catherine Anantharajah Ahalieyah Capes Antoine Hantson Philippe Jacquerye Philippe Raymackers Jean-Marc London Frederic El Sankari Souraya Ivanoiu Adrian Maggi Pietro van Pesch Vincent 《Journal of neurology》2021,268(3):751-757
Journal of Neurology - Evidence of immune-mediated neurological syndromes associated with the severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection is limited. We therefore... 相似文献
98.
Arterial elasticity measurement in renal transplant recipients 总被引:1,自引:0,他引:1
Yildiz A Fazlioglu M Ersoy A Gullulu M Gullulu S Yurtkuran M 《Transplantation proceedings》2007,39(5):1455-1457
Arterial distensibility is reduced in chronic kidney disease (CKD) and after kidney transplantation. Pulse counter analysis provides an assessment of compliance or elasticity of the large conduit arteries (C1) and small arteries (C2). Decreased compliance has been shown to be predictive of primary coronary events in CKD patients. The aim of the present study was to compare elasticity measurements in hemodialysis (HD) patients, renal transplant recipients (RTR), and healthy subjects whose coronary angiographies were without lesion. Twenty-three RTRs, 18 HD patients, and 20 healthy subjects were included in the study. Pulse wave analysis was used to determine large and small vessel compliances. The C1 and C2 levels were significantly lower in HD patients compared with recipients and healthy subjects. Recipients showed lower C2 level compared with healthy subjects. There was no difference in C1 and C2 measurements between recipients receiving tacrolimus versus cyclosporine. Transplantation improves large and to some extend small artery elasticities in CKD patients. 相似文献
99.
Simşek T Eroglu L Engin MS Kaplan S Yildiz L 《Journal of reconstructive microsurgery》2006,22(8):631-640
This paper reports a continuous horizontal mattress suture technique with advantages such as decreased time for anastomosis, minimized anastomotic leakage, eversion around the vessel edges, and other advantages which the continuous anastomosis technique has. This technique was compared with the classical interrupted and classical continuous suture techniques on a total of 59 Sprague-Dawley rat common carotid arteries: Group 1 (n = 19), interrupted suture technique; Group 2 (n = 20), standard continuous technique, and Group 3 (n = 20), continuous horizontal mattress technique. Early (30 min) and late (21 days) patency rates, anastomosis time, leakage on clamp release, oozing duration, additional sutures needed, and total number of sutures placed were statistically compared between groups. Specimens were taken at the 21st day randomly, and light microscopy (LM), scanning electron microscopy (SEM), and angiographic studies were performed. Results revealed that the continuous mattress suture technique has the advantages of providing a water-tight anastomosis with less suture materials in a shorter time, and minimal intraluminal suture material which can incite thrombosis. On the other hand, a tendency to anastomotic stricture was found to be the sole disadvantage of this technique. 相似文献
100.
Contribution of diffusion‐weighted imaging to dynamic contrast‐enhanced MRI in the characterization of papillary breast lesions
下载免费PDF全文
![点击此处可从《The breast journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Seyma Yildiz MD Huseyin Toprak MD Yeliz Emine Ersoy MD Fatma Ümit Malya MD Ayşe Ahsen Bakan MD Ayşe Aralaşmak MD Zuhal Gucin MD 《The breast journal》2018,24(2):176-179
Papillary lesions have a broad spectrum of appearances on magnetic resonance imaging (MRI ). The purpose of this study was to evaluate whether apparent diffusion coefficient (ADC ) values of papillary lesions can be used to characterize lesion as benign or malignant. This retrospective study included 29 papillary lesions. Diagnostic values of dynamic contrast‐enhanced MRI (DCE‐MRI), DWI ‐ADC , and DCE ‐MRI plus DWI ‐ADC were separately calculated. The malignant papillary lesions (0.744×10?3 mm2/s) exhibited significantly lower mean ADC values than the benign lesions (1.339×10?3 mm2/s). Addition of DWI to standard DCE ‐MRI provided 100% sensitivity. We hypothesized that this combination may prevent unnecessary excisional biopsies. 相似文献