全文获取类型
收费全文 | 7413篇 |
免费 | 512篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 120篇 |
儿科学 | 182篇 |
妇产科学 | 89篇 |
基础医学 | 1310篇 |
口腔科学 | 95篇 |
临床医学 | 693篇 |
内科学 | 1322篇 |
皮肤病学 | 129篇 |
神经病学 | 1031篇 |
特种医学 | 355篇 |
外科学 | 1062篇 |
综合类 | 34篇 |
一般理论 | 3篇 |
预防医学 | 165篇 |
眼科学 | 280篇 |
药学 | 415篇 |
中国医学 | 15篇 |
肿瘤学 | 671篇 |
出版年
2023年 | 52篇 |
2022年 | 97篇 |
2021年 | 154篇 |
2020年 | 118篇 |
2019年 | 144篇 |
2018年 | 165篇 |
2017年 | 129篇 |
2016年 | 193篇 |
2015年 | 247篇 |
2014年 | 263篇 |
2013年 | 348篇 |
2012年 | 533篇 |
2011年 | 537篇 |
2010年 | 325篇 |
2009年 | 317篇 |
2008年 | 480篇 |
2007年 | 475篇 |
2006年 | 461篇 |
2005年 | 491篇 |
2004年 | 440篇 |
2003年 | 381篇 |
2002年 | 322篇 |
2001年 | 118篇 |
2000年 | 98篇 |
1999年 | 80篇 |
1998年 | 72篇 |
1997年 | 49篇 |
1996年 | 50篇 |
1995年 | 32篇 |
1994年 | 41篇 |
1993年 | 37篇 |
1992年 | 45篇 |
1991年 | 45篇 |
1990年 | 42篇 |
1989年 | 42篇 |
1988年 | 30篇 |
1987年 | 36篇 |
1986年 | 27篇 |
1985年 | 40篇 |
1984年 | 20篇 |
1983年 | 36篇 |
1982年 | 26篇 |
1981年 | 18篇 |
1979年 | 29篇 |
1978年 | 24篇 |
1977年 | 23篇 |
1975年 | 16篇 |
1974年 | 16篇 |
1973年 | 15篇 |
1972年 | 15篇 |
排序方式: 共有7971条查询结果,搜索用时 62 毫秒
1.
2.
Anders Elm Pedersen Esben Gjerløff Wedebye Schmidt Jesper Freddie Sørensen Carsten Faber Boye Schnack Nielsen Kim Holmstrøm Silje Haukali Omland Peter Tougaard Søren Skov Bo Bang 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2015,123(7):547-555
TL1A is a TNF‐like cytokine which has been shown to co‐stimulate TH1 and TH17 responses during chronic inflammation. The expression of this novel cytokine has been investigated in inflammatory disorders like rheumatoid arthritis and inflammatory bowel disease, but little is known about expression and induction in psoriasis. Indeed, the pathogenesis in psoriasis is still not fully understood and it is speculated that cytokines other than TNF‐α are important in subsets of patients. Also, for patients with severe disease that are treated with systemic anti‐TNF‐α blockade, novel candidates to be used as disease and response biomarkers are of high interest. Here, we demonstrate TL1A expression in biopsies from psoriatic lesions. Also, we investigated spontaneous and induced TL1A secretion from PBMCs and blood levels from a cohort of psoriasis patients. Here, increased spontaneous secretion from PBMCs was observed as compared to healthy controls and a small subset of patients had highly elevated TL1A in the blood. Interestingly, activation of PBMCs with various cytokines showed a decreased sensitivity for TL1A activation in psoriasis patients compared to healthy controls.TL1A levels in blood and biopsies could not be correlated with disease activity with this patient cohort. Thus, additional large‐scale studies are warranted to investigate TL1A as a biomarker. 相似文献
3.
4.
5.
6.
Marieke C Wichers Gunter Kenis Carsten Leue Ger Koek Geert Robaeys Michael Maes 《Neuropsychopharmacology》2006,60(1):77-79
BACKGROUND: Major depression has been associated cross-sectionally with increased cell-mediated immune activation but causality has been difficult to establish. This study prospectively investigated the hypothesis that baseline level of immune activation predicts the development of depression during interferon-alpha (IFN-alpha) treatment. METHODS: Sixteen hepatitis C patients without psychiatric disorder underwent IFN-alpha treatment. Proinflammatory and anti-inflammatory cytokines were determined before starting treatment. Presence of a major depressive disorder (MDD) was assessed at baseline and several times during treatment. RESULTS: Baseline soluble interleukin-2 receptor (sIL-2r), interleukin-6 (IL-6), and interleukin-10 (IL-10) concentrations were significantly increased in the five subjects that developed MDD during treatment compared with those that did not, with standardized effect sizes of 1.08, 1.16, and 1.25, respectively, controlling for marijuana use, cigarette smoking, and baseline level of depressive symptoms. CONCLUSIONS: Results suggest that increased immune activation, rather than an epiphenomenon, is a causal risk factor for the development of MDD. 相似文献
7.
8.
The case report presents a 25-year-old woman who got pregnant twice in 1 year. Both pregnancies were terminated after ultrasound examination demonstrated limb abnormalities. Radiological and pathological examinations showed diastrophic dysplasia, a rare form of an osteochondrodysplasia with autosomal recessive inheritance. Here the histopathological findings in the cartilage and prenatal diagnosis by ultrasound are discussed. 相似文献
9.
Biodistribution and pharmacokinetics of the alphavbeta3-selective tracer 18F-galacto-RGD in cancer patients. 总被引:5,自引:0,他引:5
Ambros J Beer Roland Haubner Michael Goebel Stephan Luderschmidt Mary E Spilker Hans-Jürgen Wester Wolfgang A Weber Markus Schwaiger 《Journal of nuclear medicine》2005,46(8):1333-1341
(18)F-Galacto-RGD has been developed for PET of alpha(v)beta(3) integrin expression, a receptor involved in, for example, angiogenesis and metastasis. Our aim was to study the kinetics and biodistribution of (18)F-Galacto-RGD in cancer patients. METHODS: Nineteen patients with metastases of malignant melanoma (n = 7), sarcomas (n = 10), or osseous metastases (n = 2) were examined. After injection of 133-200 MBq (18)F-Galacto-RGD, 3 consecutive emission scans from the pelvis to the thorax or dynamic emission scans of the tumor over 60 min, followed by 1 static emission scan of the body, were acquired. Time-activity curves and standardized uptake values (SUVs) were derived by image region-of-interest analysis with image-based arterial input functions. Compartmental modeling was used to derive the distribution volume for muscle tissue and tumors. RESULTS: (18)F-Galacto-RGD showed rapid blood clearance and primarily renal excretion. SUVs in tumors ranged from 1.2 to 9.0. Tumor-to-blood and tumor-to-muscle ratios increased over time, with peak ratios of 3.1 +/- 2.0 and 7.7 +/- 4.3, respectively, at 72 min. The tumor kinetics were consistent with a 2-tissue compartment model with reversible specific binding. Distribution volume values were, on average, 4 times higher for tumor tissue (1.5 +/- 0.8) than those for muscle tissue (0.4 +/- 0.1). The data suggest that there was only minimal free and bound (specific or nonspecific) tracer in muscle tissue. CONCLUSION: (18)F-Galacto-RGD demonstrates a highly favorable biodistribution in humans with specific receptor binding. Most important, this study shows that (18)F-Galacto-RGD allows visualization of alpha(v)beta(3) expression in tumors with high contrast. Consequently, this tracer offers a new strategy for noninvasive monitoring of molecular processes and may supply helpful information for planning and controlling of therapeutic approaches targeting the alpha(v)beta(3) integrin. 相似文献
10.
Dr. Carsten Rist T.R. Johnson A. Becker A.W. Leber A. Huber S. Busch C.R. Becker M.F. Reiser K. Nikolaou 《Der Radiologe》2007,47(4):287-294
In a newly developed dual-source computed tomography system (DSCT) the relation of heart rate and image quality and the possible advantages of the system’s superior temporal resolution in the evaluation of left ventricular parameters as compared to results of cardiac magnetic resonance imaging (MRI) were assessed. Coronary CT angiography was performed using a DSCT (Somatom Defintion, Siemens Medical Solutions, Forchheim, Germany) in 21 patients (mean age 62±8; 15 male, 6 female). Image quality of the coronary arteries, the heart valves, and the left ventricular myocardium was assessed using a three-point grading scale. Ten of these patients also underwent cardiac MRI for the assessment of left ventricular function, using a SSFP (steady-state free precession) sequence. Left ventricular ejection fractions (LV-EF), the end-systolic volumes (ESV), and the end-diastolic volumes (EDV) were measured employing MRI and DSCT datasets. The image quality ratings for the coronary arteries at the optimal reconstruction interval were diagnostic even in patients with high heart rates (1.42±0.49). Analysis of global LV function using DSCT quantified from CTA datasets showed a good correlation with results of cardiac MRI [EF: r=0.75 (p=0.01); ESV: r=0.72 (p=0.19); EDV: r=0.71 (p=0.02)]. The dual-source CT system offers robust image quality of the coronary arteries, independent of the heart rate, and provides combined diagnostic imaging of coronary arteries, the heart valves, the myocardium, and the global left ventricular function. 相似文献