全文获取类型
收费全文 | 256636篇 |
免费 | 12845篇 |
国内免费 | 2250篇 |
专业分类
耳鼻咽喉 | 3262篇 |
儿科学 | 7583篇 |
妇产科学 | 5050篇 |
基础医学 | 36462篇 |
口腔科学 | 5762篇 |
临床医学 | 21466篇 |
内科学 | 55304篇 |
皮肤病学 | 6495篇 |
神经病学 | 22024篇 |
特种医学 | 8040篇 |
外国民族医学 | 116篇 |
外科学 | 31420篇 |
综合类 | 4408篇 |
现状与发展 | 6篇 |
一般理论 | 64篇 |
预防医学 | 22635篇 |
眼科学 | 5095篇 |
药学 | 18766篇 |
13篇 | |
中国医学 | 1692篇 |
肿瘤学 | 16068篇 |
出版年
2023年 | 1548篇 |
2022年 | 1620篇 |
2021年 | 4431篇 |
2020年 | 2836篇 |
2019年 | 4523篇 |
2018年 | 8189篇 |
2017年 | 5494篇 |
2016年 | 5497篇 |
2015年 | 6378篇 |
2014年 | 6904篇 |
2013年 | 10174篇 |
2012年 | 17545篇 |
2011年 | 17585篇 |
2010年 | 8934篇 |
2009年 | 6754篇 |
2008年 | 14866篇 |
2007年 | 15827篇 |
2006年 | 14621篇 |
2005年 | 14623篇 |
2004年 | 13229篇 |
2003年 | 12140篇 |
2002年 | 11445篇 |
2001年 | 6626篇 |
2000年 | 6837篇 |
1999年 | 6182篇 |
1998年 | 1418篇 |
1997年 | 1273篇 |
1996年 | 1141篇 |
1995年 | 1033篇 |
1994年 | 881篇 |
1992年 | 3467篇 |
1991年 | 3102篇 |
1990年 | 2942篇 |
1989年 | 2726篇 |
1988年 | 2556篇 |
1987年 | 2383篇 |
1986年 | 2221篇 |
1985年 | 2040篇 |
1984年 | 1451篇 |
1983年 | 1243篇 |
1979年 | 1221篇 |
1978年 | 860篇 |
1977年 | 811篇 |
1975年 | 816篇 |
1974年 | 987篇 |
1973年 | 997篇 |
1972年 | 936篇 |
1971年 | 922篇 |
1970年 | 863篇 |
1969年 | 905篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
J. Rodríguez-Carrio A. Martínez-Zapico I. Cabezas-Rodríguez L. Benavente Á.I. Pérez-Álvarez P. López J.B. Cannata-Andía M. Naves-Díaz A. Suárez 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(2):135-143
Background and aims
Since accelerated atherosclerosis has been reported in systemic lupus erythematosus (SLE), predictive biomarkers of cardiovascular disease (CVD) are needed. Among non-traditional risk factors, bone mineral density (BMD) has been related to CVD. However, its role in SLE remains controversial. This study aims to analyze the associations of subclinical atherosclerosis with traditional and non-traditional CV risk factors.Methods and results
In a cross-sectional study, atherosclerosis burden was compared between 112 female SLE patients and 31 controls. Plaque number and carotid intima-media wall thickness (cIMT) were assessed by ultrasonography. In a retrospective study, BMD determinations obtained 5-years before the ultrasonography assessment were analyzed in a subgroup of 62 patients. Plaque frequency was increased in SLE, even in patients without CV events or carotid wall thickening. cIMT was increased in patients with CVD, positively correlated with body mass index (BMI). Interestingly, a paradoxical effect of BMI on carotid parameters was observed. Whereas underweight patients (BMI < 20) showed increased prevalence of carotid plaques with low cIMT, those with BMI > 30 showed higher cIMT and plaque burden. Overweight patients (25 < BMI<30) exhibited both elevated cIMT and plaque number. BMI was an independent predictor of BMD. In our retrospective study, patients with either clinical or subclinical CVD exhibited lower BMD levels than their CV-free counterparts. A low lumbar spine BMD independently predicted CVD development after adjusting for confounders.Conclusion
SLE was associated with a higher subclinical atherosclerosis burden, a bimodal effect being observed for BMI. Decreased BMD can be a CV risk biomarker in SLE. 相似文献52.
Giorgio Gandaglia Guillaume Ploussard Massimo Valerio Agostino Mattei Cristian Fiori Nicola Fossati Armando Stabile Jean-Baptiste Beauval Bernard Malavaud Mathieu Roumiguié Daniele Robesti Paolo Dell’Oglio Marco Moschini Stefania Zamboni Arnas Rakauskas Francesco De Cobelli Francesco Porpiglia Francesco Montorsi Alberto Briganti 《European urology》2019,75(3):506-514
Background
Available models for predicting lymph node invasion (LNI) in prostate cancer (PCa) patients undergoing radical prostatectomy (RP) might not be applicable to men diagnosed via magnetic resonance imaging (MRI)-targeted biopsies.Objective
To assess the accuracy of available tools to predict LNI and to develop a novel model for men diagnosed via MRI-targeted biopsies.Design, setting, and participants
A total of 497 patients diagnosed via MRI-targeted biopsies and treated with RP and extended pelvic lymph node dissection (ePLND) at five institutions were retrospectively identified.Outcome measurements and statistical analyses
Three available models predicting LNI were evaluated using the area under the receiver operating characteristic curve (AUC), calibration plots, and decision curve analyses. A nomogram predicting LNI was developed and internally validated.Results and limitations
Overall, 62 patients (12.5%) had LNI. The median number of nodes removed was 15. The AUC for the Briganti 2012, Briganti 2017, and MSKCC nomograms was 82%, 82%, and 81%, respectively, and their calibration characteristics were suboptimal. A model including PSA, clinical stage and maximum diameter of the index lesion on multiparametric MRI (mpMRI), grade group on targeted biopsy, and the presence of clinically significant PCa on concomitant systematic biopsy had an AUC of 86% and represented the basis for a coefficient-based nomogram. This tool exhibited a higher AUC and higher net benefit compared to available models developed using standard biopsies. Using a cutoff of 7%, 244 ePLNDs (57%) would be spared and a lower number of LNIs would be missed compared to available nomograms (1.6% vs 4.6% vs 4.5% vs 4.2% for the new nomogram vs Briganti 2012 vs Briganti 2017 vs MSKCC).Conclusions
Available models predicting LNI are characterized by suboptimal accuracy and clinical net benefit for patients diagnosed via MRI-targeted biopsies. A novel nomogram including mpMRI and MRI-targeted biopsy data should be used to identify candidates for ePLND in this setting.Patient summary
We developed the first nomogram to predict lymph node invasion (LNI) in prostate cancer patients diagnosed via magnetic resonance imaging-targeted biopsy undergoing radical prostatectomy. Adoption of this model to identify candidates for extended pelvic lymph node dissection could avoid up to 60% of these procedures at the cost of missing only 1.6% patients with LNI. 相似文献53.
Renaud Snanoudj Nassim Kamar Elisabeth Cassuto Sophie Caillard Marie Metzger Pierre Merville Antoine Thierry Isabelle Jollet Philippe Grimbert Dany Anglicheau Marc Hazzan Gabriel Choukroun Bruno Hurault De Ligny Bénedicte Janbon Vincent Vuiblet Anne Devys Yann Le Meur Michel Delahousse Jean-Luc Taupin 《Kidney international》2019,95(6):1471-1485
54.
55.
Solid-state reactions between sodium hydride and sodium hydroxide are unusual among hydride-hydroxide systems since hydrogen can be stored reversibly. In order to understand the relationship between hydrogen uptake/release properties and phase/structure evolution, the dehydrogenation and hydrogenation behavior of the Na-O-H system has been investigated in detail both ex- and in-situ. Simultaneous thermogravimetric-differential thermal analysis coupled to mass spectrometry (TG-DTA-MS) experiments of NaH-NaOH composites reveal two principal features: Firstly, an H2 desorption event occurring between 240 and 380 °C and secondly an additional endothermic process at around 170 °C with no associated weight change. In-situ high-resolution synchrotron powder X-ray diffraction showed that NaOH appears to form a solid solution with NaH yielding a new cubic complex hydride phase below 200 °C. The Na-H-OH phase persists up to the maximum temperature of the in-situ diffraction experiment shortly before dehydrogenation occurs. The present work suggests that not only is the inter-phase synergic interaction of protic hydrogen (in NaOH) and hydridic hydrogen (in NaH) important in the dehydrogenation mechanism, but that also an intra-phase Hδ+… Hδ– interaction may be a crucial step in the desorption process. 相似文献
56.
57.
58.
M. Masson Regnault J. Castañeda-Sanabria M.H.T. Diep Tran M. Beylot-Barry H. Bachelez N. Beneton O. Chosidow A. Dupuy P. Joly D. Jullien E. Mahé M.-A. Richard M. Viguier F. Tubach E. Sbidian C. Paul The PsoBioTeq Study Group 《Journal of the European Academy of Dermatology and Venereology》2020,34(2):293-300
59.
Wan-Jie Gu 《Journal of thoracic disease》2015,7(11):1885-1886
It is well known that a meta-analysis of randomized controlled trials aims to increase the power and precision of the estimated intervention effects. However, when a meta-analysis includes a limited number of patients and a small number of events, overestimation of intervention effect estimates may occur and could cause spurious results. Although many biases can cause the overestimation, random error may be the most common cause. Trial sequential analysis (TSA) can explore the independent effect of random error on intervention effect estimates in meta-analyses and protect meta-analyses against overestimation due to random error. 相似文献