全文获取类型
收费全文 | 2060篇 |
免费 | 95篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 31篇 |
妇产科学 | 32篇 |
基础医学 | 345篇 |
口腔科学 | 23篇 |
临床医学 | 162篇 |
内科学 | 396篇 |
皮肤病学 | 12篇 |
神经病学 | 204篇 |
特种医学 | 109篇 |
外科学 | 414篇 |
综合类 | 8篇 |
一般理论 | 1篇 |
预防医学 | 121篇 |
眼科学 | 6篇 |
药学 | 148篇 |
肿瘤学 | 139篇 |
出版年
2023年 | 12篇 |
2022年 | 13篇 |
2021年 | 28篇 |
2020年 | 12篇 |
2019年 | 28篇 |
2018年 | 28篇 |
2017年 | 39篇 |
2016年 | 37篇 |
2015年 | 48篇 |
2014年 | 49篇 |
2013年 | 83篇 |
2012年 | 87篇 |
2011年 | 101篇 |
2010年 | 73篇 |
2009年 | 67篇 |
2008年 | 88篇 |
2007年 | 112篇 |
2006年 | 83篇 |
2005年 | 110篇 |
2004年 | 106篇 |
2003年 | 101篇 |
2002年 | 95篇 |
2001年 | 63篇 |
2000年 | 61篇 |
1999年 | 40篇 |
1998年 | 31篇 |
1997年 | 19篇 |
1996年 | 16篇 |
1995年 | 19篇 |
1994年 | 14篇 |
1993年 | 15篇 |
1992年 | 26篇 |
1991年 | 21篇 |
1990年 | 26篇 |
1989年 | 28篇 |
1988年 | 21篇 |
1987年 | 21篇 |
1986年 | 19篇 |
1985年 | 22篇 |
1984年 | 23篇 |
1983年 | 24篇 |
1982年 | 9篇 |
1979年 | 16篇 |
1974年 | 15篇 |
1973年 | 12篇 |
1972年 | 8篇 |
1970年 | 8篇 |
1969年 | 9篇 |
1967年 | 8篇 |
1961年 | 8篇 |
排序方式: 共有2158条查询结果,搜索用时 15 毫秒
1.
Maximilian Kreibich Tobias Soekeland Friedhelm Beyersdorf Joseph E. Bavaria Holger Schröfel Martin Czerny Bartosz Rylski 《The Journal of thoracic and cardiovascular surgery》2019,157(1):26-34.e1
Objective
The study objective was to screen patients with acute type A aortic dissection for anatomic feasibility of ascending aortic endovascular treatment with a valve-carrying conduit.Methods
High-quality computed tomography scans of 167 patients were available for screening. Aortic dimensions were measured using multiplanar reconstruction in the plane perpendicular to the manually corrected aortic center line. The simulated stent-graft 10-mm–long landing zones were measured starting at the sinotubular junction (proximal landing zone) and ending at the brachiocephalic trunk (distal landing zone). Exclusion criterion was an entry within the aortic root or the landing zone.Results
In 113 patients (68%), the entry was in a coverable zone in the ascending aorta with sufficient proximal and distal landing zone or in more distal aortic segments. In these patients, the median distance between the proximal and distal landing zone was 89.1 (first quartile: 80.0 mm; third quartile: 101.2 mm) and the median diameter difference was 5.0 mm (2.0; 10.1) (12.3 [4.9; 23.0] %). The diameter difference was less than 2 mm in 32 patients (28%), between 6 mm and 10 mm in 20 patients (18%), between 10 mm and 14 mm in 11 patients (10%), and 14 mm or greater in 10 patients (9%).Conclusions
Two thirds of all patients who present with type A dissections are potential candidates for treatment with endovascular valve–carrying conduits, but most patients would require tapered stent-grafts. 相似文献2.
Marie Warrer Petersen Tine Sylvest Meyhoff Marie Helleberg Maj-Brit Nørregaard Kjær Anders Granholm Carl Johan Steensen Hjortsø Thomas Steen Jensen Morten Hylander Møller Peter Buhl Hjortrup Mik Wetterslev Gitte Kingo Vesterlund Lene Russell Vibeke Lind Jørgensen Klaus Tjelle Thomas Benfield Charlotte Suppli Ulrik Anne Sofie Andreasen Thomas Mohr Morten H. Bestle Lone Musaeus Poulsen Mette Friberg Hitz Thomas Hildebrandt Lene Surland Knudsen Anders Møller Christoffer Grant Sølling Anne Craveiro Brøchner Bodil Steen Rasmussen Henrik Nielsen Steffen Christensen Thomas Strøm Maria Cronhjort Rebecka Rubenson Wahlin Stephan Jakob Luca Cioccari Balasubramanian Venkatesh Naomi Hammond Vivekanand Jha Sheila Nainan Myatra Christian Gluud Theis Lange Anders Perner 《Acta anaesthesiologica Scandinavica》2020,64(9):1365-1375
Introduction
Severe acute respiratory syndrome coronavirus-2 has caused a pandemic of coronavirus disease (COVID-19) with many patients developing hypoxic respiratory failure. Corticosteroids reduce the time on mechanical ventilation, length of stay in the intensive care unit and potentially also mortality in similar patient populations. However, corticosteroids have undesirable effects, including longer time to viral clearance. Clinical equipoise on the use of corticosteroids for COVID-19 exists.Methods
The COVID STEROID trial is an international, randomised, stratified, blinded clinical trial. We will allocate 1000 adult patients with COVID-19 receiving ≥10 L/min of oxygen or on mechanical ventilation to intravenous hydrocortisone 200 mg daily vs placebo (0.9% saline) for 7 days. The primary outcome is days alive without life support (ie mechanical ventilation, circulatory support, and renal replacement therapy) at day 28. Secondary outcomes are serious adverse reactions at day 14; days alive without life support at day 90; days alive and out of hospital at day 90; all-cause mortality at day 28, day 90, and 1 year; and health-related quality of life at 1 year. We will conduct the statistical analyses according to this protocol, including interim analyses for every 250 patients followed for 28 days. The primary outcome will be compared using the Kryger Jensen and Lange test in the intention to treat population and reported as differences in means and medians with 95% confidence intervals.Discussion
The COVID STEROID trial will provide important evidence to guide the use of corticosteroids in COVID-19 and severe hypoxia.3.
Claudia Hildebrandt Srikanth R. Gopireddy Alexander K. Fritsch Thomas Profitlich Regina Scherließ Nora A. Urbanetz 《Pharmaceutical development and technology》2019,24(1):35-47
The focus of this study is to establish a characterization method determining the powder flowability in context of tableting. At first, flowability of different materials is measured using the ring shear tester, and its prediction from particle size is established. Next, the model die-filling system is presented which is a modified version of previous studies. Using this system, flowability of different materials is measured at varying die speeds. A new curve fit to assess die fill ratio vs die speed is suggested improving predictability, and a novel flowability metric, “Die Fill Index” (DFI), is derived. The DFI is appropriate to describe flowability for most of the tested materials, and sensitivity of a material with respect to tableting speed. A correlation is generated predicting DFI from particle size. Additionally, it is shown that model die filling is the preferable method to assess flowability for tableting compared to ring shear tester. 相似文献
4.
5.
6.
Corinne Antignac James P. Calvet Gregory G. Germino Jared J. Grantham Lisa M. Guay-Woodford Peter C. Harris Friedhelm Hildebrandt Dorien J.M. Peters Stefan Somlo Vicente E. Torres Gerd Walz Jing Zhou Alan S.L. Yu 《Journal of the American Society of Nephrology : JASN》2015,26(9):2081-2095
Polycystic kidney disease (PKD) is one of the most common life-threatening genetic diseases. Jared J. Grantham, M.D., has done more than any other individual to promote PKD research around the world. However, despite decades of investigation there is still no approved therapy for PKD in the United States. In May 2014, the University of Kansas Medical Center hosted a symposium in Kansas City honoring the occasion of Dr. Grantham''s retirement and invited all the awardees of the Lillian Jean Kaplan International Prize for Advancement in the Understanding of Polycystic Kidney Disease to participate in a forward-thinking and interactive forum focused on future directions and innovations in PKD research. This article summarizes the contributions of the 12 Kaplan awardees and their vision for the future of PKD research. 相似文献
7.
Jasmin Hasmik Shahinian Eva A. Rog-Zielinska Manuel Schlimpert Bettina Mayer Stefan Tholen Bernd Kammerer Martin L. Biniossek Friedhelm Beyersdorf Oliver Schilling Matthias Siepe 《Artificial organs》2020,44(3):257-267
The changes in the myocardial proteome and metabolome associated with left ventricular assist device (LVAD) therapy in patients with ischemic cardiomyopathy (ICM) are poorly characterized. We investigated the impact of mechanical unloading following LVAD therapy on the myocardial proteome and metabolome. Matched samples of 5 patients’ myocardial tissue, harvested at the time of LVAD implant (“pre-LVAD”) or heart transplant (“post-LVAD”), were studied by quantitative proteomics and metabolomics as well as being probed for T-tubule structure and connexin-43 distribution. Moreover, pre-LVAD proteome profiles of ICM context were bioinformatically compared to pre-LVAD proteome profiles of dilated cardiac myopathy (DCM). More than 2120 proteins were reliably identified and quantified in paired patient samples. LVAD therapy led to proteomic remodeling, including reduced levels of α-1-antichymotrypsin together with an overall decrease of immune response proteins and an increase of proteins involved in membrane biology. Metabolomics highlighted increased glucose and glucose-6-phosphate levels in the left ventricle upon LVAD therapy. Wheat germ agglutinin staining demonstrated improved T-tubule structure. Connexin-43 displayed a trend for more pronounced intercalated disc localization. In comparing pre-LVAD proteome profiles of ICM context with pre-LVAD proteome profiles of dilated cardiac myopathy (DCM), we noticed an overrepresentation in ICM of proteins associated with humoral immune response. Our findings underline an impact of LVAD therapy on left ventricular biology in ICM. The proteomic, metabolomic, and structural alterations described here are typically associated with cardiac recovery. On the molecular level, our findings indicate the possibility of cardiac remodeling under LVAD therapy in ICM. 相似文献
8.
Christina Rautenberg Sabrina Pechtel Barbara Hildebrandt Beate Betz Ariane Dienst Kathrin Nachtkamp Mustafa Kondakci Stefanie Geyh Dagmar Wieczorek Rainer Haas Ulrich Germing Guido Kobbe Thomas Schroeder 《Biology of blood and marrow transplantation》2018,24(11):2337-2343
Overexpression of the Wilms' tumor 1 (WT1) gene is informative in many patients with acute myelogenous leukemia (AML) and myelodysplastic syndromes (MDS) and is measurable in peripheral blood (PB). Despite these advantages, WT1 has not broadly been established as a marker for minimal residual disease (MRD) monitoring after allogeneic hematopoietic stem cell transplantation (allo-HSCT) due to limited patient numbers, differing sample sources, and nonstandardized in-house methods. To estimate the value of WT1 as an MRD marker, we serially quantified PB WT1 expression using a standardized European LeukemiaNet-certified assay in 59 patients with AML and MDS after allo-HSCT. We compared its performance with routine methods such as chimerism, XY-fluorescence in situ hybridization (FISH), disease-specific cytogenetic, and molecular analyses, which were accessible in 100%, 34%, 68%, and 37%, respectively. Twenty-four patients (41%) relapsed within a median of 126 days after allo-HSCT, and 20 of them showed at least 1 elevated WT1 value above the validated cutoff. The other 35 patients (59%) remained in complete remission, and only 1 patient had a transient increase in WT1 expression. This reflects a sensitivity of 83% and a specificity of 97% for WT1 and appears to be favorable compared with the sensitivities and specificities observed for chimerism (33% and 91%), XY-FISH (67% and 73%), cytogenetic (33% and 77%), and molecular (78% and 85%) analyses. Further supporting its predictive impact, elevated WT1 expression prompted an earlier BM biopsy and consecutively the diagnosis of relapse in 62% of patients. The results of this real-life experience imply that PB WT1 expression is measurable by a standardized assay and predicts imminent relapse after allo-HSCT with high sensitivity and specificity in most patients with AML and MDS. 相似文献
9.
Biedler AE Wilhelm W Kreuer S Soltesz S Bach F Mertzlufft FO Molter GP 《The American journal of emergency medicine》2003,21(7):520-524
This study was designed to assess the pCO(2) accuracy of portable mainstream (Tidal Wave, Novametrix; Propaq 106, Protocol) and sidestream capnometers (Capnocheck 8200, BCI; Capnocount mini, Weinmann; NPB-75, Nellcor Puritan Bennett; SC-210, Pryon) with respect to international standards and preclinical emergency conditions. Measurements were performed under temperature conditions of +22 degrees C and -20 degrees C using dry gas mixtures with different CO(2) concentrations (STPD) and in patients ventilated with pure oxygen (BTPS). Accuracy presented to be between +1% (Capnocheck) and +12% (Propaq) (STPD) and between -0.4% (Capnocheck) and +11% (Tidal Wave) (BTPS). The measurements were affected by low ambient temperature only in the NPB-75 (+15%). Our results indicate that portable quantitative capnometers are able to fulfill accuracy requirements as requested by international standards but can be affected by changing ambient temperatures. 相似文献
10.
Visual scenes are frequently composed of objects that move in different directions. To segment such scenes into distinct objects or image planes, local motion cues have to be evaluated and integrated according to criteria of global coherence. When several populations of coherently moving random dots penetrate each other, the visual system tends to assign them to different planes-perceived as transparent motion. This process of integration was studied by changing the angle of motion trajectories with which groups of dots penetrate each other or by varying the spatial constellation of dots moving in opponent directions. Psychophysical testing revealed that stimuli providing almost identical local motion cues could be perceived in three very different ways: (1) as a matrix of stationary flickering dots, (2) as a single surface of coherently moving dots, and (3) as two transparent dot matrices moving in different directions. Behaviorally controlled functional magnetic resonance imaging (fMRI) was used to identify brain regions that contribute to the integration of local motion cues into coherently moving surfaces. Activation of the human motion complex (hMT+/V5) and of areas in the fusiform gyrus (FG) as well as in the intraparietal sulcus (IPS-occ) was correlated with the perception of coherent motion and especially hMT+/V5 took a central role in differentiating transparent motion from single-surface coherent motion. 相似文献