全文获取类型
收费全文 | 18829篇 |
免费 | 1120篇 |
国内免费 | 90篇 |
专业分类
耳鼻咽喉 | 173篇 |
儿科学 | 256篇 |
妇产科学 | 205篇 |
基础医学 | 2577篇 |
口腔科学 | 652篇 |
临床医学 | 1778篇 |
内科学 | 3955篇 |
皮肤病学 | 518篇 |
神经病学 | 1997篇 |
特种医学 | 1232篇 |
外科学 | 3037篇 |
综合类 | 90篇 |
一般理论 | 6篇 |
预防医学 | 886篇 |
眼科学 | 378篇 |
药学 | 990篇 |
中国医学 | 51篇 |
肿瘤学 | 1258篇 |
出版年
2024年 | 15篇 |
2023年 | 139篇 |
2022年 | 283篇 |
2021年 | 533篇 |
2020年 | 356篇 |
2019年 | 423篇 |
2018年 | 537篇 |
2017年 | 436篇 |
2016年 | 587篇 |
2015年 | 663篇 |
2014年 | 809篇 |
2013年 | 1011篇 |
2012年 | 1585篇 |
2011年 | 1484篇 |
2010年 | 923篇 |
2009年 | 800篇 |
2008年 | 1316篇 |
2007年 | 1409篇 |
2006年 | 1304篇 |
2005年 | 1216篇 |
2004年 | 1093篇 |
2003年 | 991篇 |
2002年 | 875篇 |
2001年 | 169篇 |
2000年 | 107篇 |
1999年 | 164篇 |
1998年 | 156篇 |
1997年 | 135篇 |
1996年 | 80篇 |
1995年 | 52篇 |
1994年 | 41篇 |
1993年 | 45篇 |
1992年 | 43篇 |
1991年 | 22篇 |
1990年 | 22篇 |
1989年 | 20篇 |
1988年 | 25篇 |
1987年 | 14篇 |
1986年 | 6篇 |
1985年 | 7篇 |
1984年 | 11篇 |
1983年 | 6篇 |
1982年 | 15篇 |
1981年 | 7篇 |
1980年 | 10篇 |
1977年 | 7篇 |
1976年 | 5篇 |
1974年 | 7篇 |
1973年 | 11篇 |
1970年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Freddy Haryanto MSc Matthias Fippel Annemarie Bakai Fridtjof Nüsslin 《Strahlentherapie und Onkologie》2004,180(1):57-61
BACKGROUND: Nowadays, multileaf collimation of the treatment fields from medical linear accelerators is a common option. Due to the design of the leaf sides, the tongue and groove effect occurs for certain multileaf collimator applications such as the abutment of fields where the beam edges are defined by the sides of the leaves. MATERIAL AND METHODS: In this study, the tongue and groove effect was measured for two pairs of irregular multileaf collimator fields that were matched along leaf sides in two steps. Measurements were made at 10 cm depth in a polystyrene phantom using Kodak EDR2 films for a photon beam energy of 6 MV on an Elekta Sli-plus accelerator. To verify the measurements, full Monte Carlo simulations were done. In the simulations, the design of the leaf sides was taken into account and one component module of BEAM code was modified to correctly simulate the Elekta multileaf collimator. RESULTS AND CONCLUSION: The results of measurements and simulations are in good agreement and within the tolerance of film dosimetry. 相似文献
32.
Thomas Rosemann Michel Wensing Katharina Joest Matthias Backenstrass Cornelia Mahler Joachim Szecsenyi 《BMC musculoskeletal disorders》2006,7(1):48-9
Background
Osteoarthritis (OA) is highly prevalent and has substantial impact on quality of life as well as on healthcare costs. The general practitioner (GP) often is the first care provider for patients with this chronic disease. The aim of this study was to identify health care needs of patients with OA and to reveal possible obstacles for improvements in primary care management of OA patients. 相似文献33.
34.
35.
Rechtsanwalt Dr. iur. Matthias Dann LL.M. 《MedR Medizinrecht》2007,25(11):638-643
Ohne Zusammenfassung 相似文献
36.
RiLSG Matthias Willersinn 《MedR Medizinrecht》2007,25(11):684-690
Ohne Zusammenfassung 相似文献
37.
Matthias Siepe Claudia Heilmann Patrick von Samson Philippe Menasché Friedhelm Beyersdorf 《European journal of cardio-thoracic surgery》2005,28(2):318-324
Several human organs are not capable of functional regeneration following a tissue defect and react with scar formation. In stem cell transplantation, undifferentiated or partly differentiated precursor cells are applied to defective tissue for therapeutic regeneration. After promising preclinical investigations, the transplantation of autologous stem cells for myocardial infarction treatment is being transferred to clinical use. Mesenchymal stem cells and endothelial precursor cells derived from the bone marrow or circulating blood as well as skeletal myoblasts are employed in clinical trials. Furthermore, indications for cell transplantation and delivery routes vary considerably throughout current investigations. Initial results suggest a potential for restoration of cardiac function in stem cell-treated patients; however, the mechanisms are not fully understood. This overview will focus on objectives, recent achievements, and future perspectives of diverse stem cell transplantation approaches. 相似文献
38.
Urban Sester Barbara C. Gärtner Heinrike Wilkens Bernhard Schwaab Rolf Wössner Ingrid Kindermann Matthias Girndt reas Meyerhans Nikolaus Mueller-Lantzsch Hans-Joachim Schäfers Gerhard W. Sybrecht Hans Köhler Martina Sester 《American journal of transplantation》2005,5(6):1483-1489
Patients after kidney, heart and lung transplantation differ in their immunosuppressive drug regimens and in susceptibility to infectious complications with cytomegalovirus (CMV). In this study, CMV-specific T-cell responses were characterized in long-term transplant recipients and associated with the frequency of infectious complications. CMV-reactive CD4 T cells from 50 healthy controls, 68 renal, 14 heart and 24 lung transplant recipients were flow cytometrically quantified by the induction of cytokines after specific stimulation. Moreover, the immunosuppressive effect of calcineurin inhibitors on specific T-cell reactivity was quantified in vitro and compared with responses in vivo. Median CMV-specific T-cell frequencies in long-term renal (1.48%; range 0.06-17.26%) and heart transplant recipients (0.90%; 0.13-12.49%) did not differ from controls (1.82%; 0.26-21.00%). In contrast, CMV-specific T-cell levels were significantly lower in lung transplant recipients (0.50%; <0.05-4.98%) and showed a significant correlation with the frequency of infectious episodes (r =-0.57, p = 0.005). The differences within the groups were associated with increasing dosages of immunosuppressive drugs, as exemplified for calcineurin inhibitors that dose dependently reduced specific T-cell reactivity in vitro. In conclusion, monitoring CMV-specific CD4 T cells may serve as a measure for long-term disease susceptibility and may contribute to an improved management of CMV complications after lung transplantation. 相似文献
39.
Elektrophysiologische Untersuchungen (EPU) und programmierte Ventrikelstimulationen (PVS) werden vor der Implantation eines Defibrillators (ICD) empfohlen, wenn Patienten ohne nachweisbare strukturelle Herzerkrankung oder mit hypertrophischer obstruktiver Kardiomyopathie (HOCM) einen Herzstillstand überlebt haben, weil die Prävalenz von prinzipiell kurierbaren Rhythmusstörungen wie idiopathischen ventrikulären Tachykardien (VT), bei diesen Patienten hoch ist. Gleiches gilt für Patienten nach überlebtem Herzstillstand mit einer kurzen PQ-Zeit oder einer Deltawelle. Patienten mit Tachykardien, bei denen die Diagnose VT unsicher ist, sollten ebenfalls einer EPU unterzogen werden. Wenn sich Patienten mit nicht anhaltenden Tachykardien oder Synkopen vorstellen, sind eine EPU und PVS zur Risikostratifizierung indiziert. Bei den übrigen Patienten mit eingeschränkter linksventrikulärer Pumpfunktion nach überlebtem Herzstillstand oder instabiler VT, die Kandidaten für eine ICD-Implantation sind, haben die EPU und PVS möglicherweise nur einen geringen Nutzen. 相似文献
40.
Matthias Peltz Tian-Teng He Glenn A Adams Robert Y Chao Michael E Jessen Dan M Meyer 《The Journal of heart and lung transplantation》2005,24(7):896-903
BACKGROUND: Lungs harvested for transplantation are stored while inflated with oxygen, which can serve to support oxidative metabolism. However, strategies aimed at increasing graft metabolism during storage have received little attention. In this study, we added pyruvate to the preservation solution Perfadex and measured the effects on oxidative metabolism and reperfusion lung function. METHODS: Rat lungs were stored for 6 and 24 hours in low-potassium dextran solution at 10 degrees C containing either 5 mmol/liter uniformly carbon-13 (U-(13)C) labeled glucose (Perfadex), 32 mmol/liter 3-(13)C pyruvate (pyruvate), or both (combined). Oxidation of exogenous substrates was measured as the incorporation of (13)C into tricarboxylic acid cycle intermediates by magnetic resonance spectroscopy. Additional groups of lungs with each substrate modification were preserved for 6 or 24 hours and then reperfused. RESULTS: Enrichment of tricarboxylic acid cycle intermediates was low in the Perfadex group (9% at 6 hours and 32% at 24 hours of storage, respectively). In contrast, enrichment was significantly increased in both the pyruvate group (50% and 59%, respectively) and combined group (39% and 54%, respectively) compared with the Perfadex group (p<0.01). Graft function was excellent after 6-hour storage in all groups. All lungs stored for 24 hours exhibited inferior lung function, but oxygenation, pulmonary artery pressures, and airway pressures in the combined group were significantly improved compared with the Perfadex group (p<0.05). CONCLUSIONS: Preservation solution substrate composition influences graft metabolism during storage. The addition of pyruvate to Perfadex increases metabolism during storage and improves reperfusion lung function. 相似文献