全文获取类型
收费全文 | 2135篇 |
免费 | 117篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 86篇 |
妇产科学 | 38篇 |
基础医学 | 248篇 |
口腔科学 | 58篇 |
临床医学 | 186篇 |
内科学 | 489篇 |
皮肤病学 | 26篇 |
神经病学 | 295篇 |
特种医学 | 193篇 |
外科学 | 200篇 |
综合类 | 14篇 |
预防医学 | 132篇 |
眼科学 | 9篇 |
药学 | 153篇 |
中国医学 | 14篇 |
肿瘤学 | 113篇 |
出版年
2022年 | 21篇 |
2021年 | 56篇 |
2020年 | 32篇 |
2019年 | 36篇 |
2018年 | 51篇 |
2017年 | 26篇 |
2016年 | 36篇 |
2015年 | 62篇 |
2014年 | 66篇 |
2013年 | 91篇 |
2012年 | 90篇 |
2011年 | 97篇 |
2010年 | 81篇 |
2009年 | 64篇 |
2008年 | 83篇 |
2007年 | 89篇 |
2006年 | 80篇 |
2005年 | 69篇 |
2004年 | 69篇 |
2003年 | 85篇 |
2002年 | 53篇 |
2001年 | 52篇 |
2000年 | 53篇 |
1999年 | 37篇 |
1998年 | 49篇 |
1997年 | 55篇 |
1996年 | 61篇 |
1995年 | 49篇 |
1994年 | 29篇 |
1993年 | 30篇 |
1992年 | 36篇 |
1991年 | 40篇 |
1990年 | 30篇 |
1989年 | 44篇 |
1988年 | 52篇 |
1987年 | 41篇 |
1986年 | 43篇 |
1985年 | 30篇 |
1984年 | 25篇 |
1983年 | 12篇 |
1982年 | 12篇 |
1981年 | 20篇 |
1980年 | 10篇 |
1979年 | 17篇 |
1978年 | 17篇 |
1977年 | 15篇 |
1976年 | 17篇 |
1975年 | 15篇 |
1973年 | 4篇 |
1969年 | 6篇 |
排序方式: 共有2260条查询结果,搜索用时 250 毫秒
41.
Ventricular arrhythmias (VA) are a significant contributor to morbidity and mortality in patients with heart failure (HF). Implantable cardioverter defibrillators are effective in reducing mortality, but do not prevent arrhythmia recurrence. There is increasing recognition that frequent premature ventricular contractions or repetitive ventricular tachycardia may also lead to new onset ventricular dysfunction or deterioration of ventricular function in patients with pre-existing HF. Suppression of the arrhythmia may lead to recovery of ventricular function. Catheter ablation has emerged as a safe and effective treatment option for reducing arrhythmia recurrence and for suppression of PVCs but its efficacy is governed by the nature of the arrhythmias, the underlying HF substrate and the accessibility of the arrhythmia substrates to ablation. 相似文献
42.
43.
Jules Rimet Borges Bárbara Álvares Salum Ximenes Flávia Tandaya Grandi Miranda Giordana Bruna Moreira Peres Isabella Toscano Hayasaki Luiz César de Camargo Ferro Mayra Ianhez Marco Tulio Antonio Garcia-Zapata 《Anais brasileiros de dermatologia》2022,97(4):424-434
BackgroundChromoblastomycosis is a skin infection caused by dematiaceous fungi that take the form of muriform cells in the tissue. It mainly manifests as verrucous plaques on the lower limbs of rural workers in tropical countries.ObjectivesThe primary objective of this review is to evaluate the accuracy of diagnostic methods for the identification of chromoblastomycosis, considering the histopathological examination as the reference test.MethodsMEDLINE, LILACS and Scielo databases were consulted using the terms “chromoblastomycosis” AND “diagnosis”. The eligibility criteria were: studies that evaluated the accuracy of tests for the diagnosis of chromoblastomycosis. Eleven studies were selected. Statistical analysis included the calculation of sensitivity and specificity of the diagnostic methods.ResultsConsidering the histopathological examination as the reference test, the culture showed a sensitivity (S) of 37.5% - 90.9% and a specificity (Sp) of 100%; while direct mycological examination showed S = 50% - 91.6% and Sp of 100% . Considering the culture as the reference test, the serology (precipitation techniques) showed S of 36% - 99%; and Sp of 80% - 100%; while the intradermal test showed S of 83.3% - 100% and Sp of 99.4% - 100%.Study limitationsThe small number of studies and very discrepant sensitivity results among them do not allow the calculation of summary measures through a meta-analysis.ConclusionsDirect mycological examination, culture, intradermal test and serology show sensitivity and specificity values ??for the diagnosis of chromoblastomycosis with no significant difference between the studies. 相似文献
44.
45.
46.
47.
48.
Forfori F Ferro B Mancini B Letizia R Abramo A Anselmino M Di Salvo C Giunta F 《Obesity surgery》2012,22(1):113-118
Background
Thromboelastography is a technique that surveys the properties of viscoelastic blood clot. The purpose of this paper was to evaluate the hypercoagulability state and the effect of antithrombotic prophylaxis on thromboelastogram (TEG) results in bariatric surgery. 相似文献49.
Tumour necrosis factor alpha upregulates platelet CD40L in patients with heart failure 总被引:1,自引:0,他引:1
Pignatelli P Cangemi R Celestini A Carnevale R Polimeni L Martini A Ferro D Loffredo L Violi F 《Cardiovascular research》2008,78(3):515-522
AIMS: Patients with heart failure (HF) have elevated values of the pro-inflammatory protein CD40L but the underlying mechanism is unclear. This study was performed to evaluate the interplay between tumour necrosis factor alpha (TNFalpha) and CD40L in HF. METHODS AND RESULTS: In patients with HF (n=86) and healthy subjects (HS, n=43), plasma levels of soluble CD40L (sCD40L), TNFalpha, soluble receptors of TNFalpha such as soluble TNF receptors I and II (sTNFR1 and sTNFR2), and 8OH-dG, a marker of oxidative stress, were determined. Also, an in vitro study was performed by determining platelet CD40L regulation upon platelet stimulation with TNFalpha. Compared with HS, HF patients had higher plasma values of sCD40L, TNFalpha, sTNFR1 and sTNFR2, and higher platelet expression of TNFR1 and TNFR2 with a progressive increase from NYHA I to NYHA IV classification. sCD40L significantly correlated with TNFalpha, sTNFR1, and sTNFR2; plasma levels of TNFalpha significantly correlated with sCD40L. Incubation of platelets from HF patients with a TNFalpha receptor inhibitor significantly decreased platelet CD40L expression. The in vitro study demonstrated that TNFalpha significantly increased CD40L expression, an effect weakly influenced by aspirin but significantly reduced by AACOCF3, an inhibitor of PLA(2), apocynin, an inhibitor of NADPH oxidase, or staurosporine, an inhibitor of PKC. CONCLUSION: The study shows that in HF patients, platelet CD40L is upregulated by TNFalpha via a cyclooxygenase-1-independent, arachidonic acid-mediated oxidative stress mechanism. 相似文献
50.
Membrane-associated sickle hemoglobin: a major determinant of sickle erythrocyte rigidity 总被引:1,自引:0,他引:1
Micropipette aspiration tests on single erythrocytes have previously shown that the static rigidity (membrane shear modulus) of oxygenated sickle cells increased with increasing hemoglobin concentration, whereas the rigidity of normal cells was independent of hemoglobin concentration. Moreover, it was observed that after mechanical extension, sickle cells exhibited persistent deformation more frequently and to a greater extent than normal cells. To ascertain if differences in association of normal and sickle hemoglobin with the membrane could account for these observations, we measured rheologic properties of normal membranes reconstituted with sickle hemoglobin and sickle membranes reconstituted with normal hemoglobin. The static rigidity of normal ghosts reloaded with sickle hemoglobin was higher than those of either normal ghosts reloaded with normal hemoglobin or native normal cells. On the other hand, the increased rigidity of native sickle cells decreased to near-normal values following reconstitution with normal hemoglobin. Furthermore, we observed that normal ghosts reconstituted with sickle hemoglobin exhibited persistent bumps after mechanical extension, but no bumps formed on normal ghosts reconstituted with normal hemoglobin. Moreover residual bumps were not produced on sickle cells reloaded with normal hemoglobin. Since mechanical characteristics peculiar to sickle cells could be induced in normal cells by incorporation of sickle hemoglobin, and since normal characteristics could be restored to sickle cells by incorporation of normal hemoglobin, we suggest that the interaction of sickle hemoglobin with the cell membrane is responsible for augmented static rigidity of oxygenated sickle erythrocytes. 相似文献