全文获取类型
收费全文 | 24494篇 |
免费 | 1577篇 |
国内免费 | 176篇 |
专业分类
耳鼻咽喉 | 235篇 |
儿科学 | 529篇 |
妇产科学 | 467篇 |
基础医学 | 3661篇 |
口腔科学 | 259篇 |
临床医学 | 2330篇 |
内科学 | 6145篇 |
皮肤病学 | 364篇 |
神经病学 | 2121篇 |
特种医学 | 1071篇 |
外国民族医学 | 8篇 |
外科学 | 4217篇 |
综合类 | 69篇 |
一般理论 | 4篇 |
预防医学 | 1348篇 |
眼科学 | 211篇 |
药学 | 1352篇 |
中国医学 | 41篇 |
肿瘤学 | 1815篇 |
出版年
2023年 | 135篇 |
2022年 | 220篇 |
2021年 | 607篇 |
2020年 | 364篇 |
2019年 | 585篇 |
2018年 | 690篇 |
2017年 | 465篇 |
2016年 | 560篇 |
2015年 | 712篇 |
2014年 | 938篇 |
2013年 | 1205篇 |
2012年 | 1914篇 |
2011年 | 1893篇 |
2010年 | 1093篇 |
2009年 | 1102篇 |
2008年 | 1681篇 |
2007年 | 1700篇 |
2006年 | 1659篇 |
2005年 | 1705篇 |
2004年 | 1572篇 |
2003年 | 1481篇 |
2002年 | 1390篇 |
2001年 | 204篇 |
2000年 | 151篇 |
1999年 | 218篇 |
1998年 | 266篇 |
1997年 | 233篇 |
1996年 | 190篇 |
1995年 | 159篇 |
1994年 | 116篇 |
1993年 | 142篇 |
1992年 | 106篇 |
1991年 | 80篇 |
1990年 | 78篇 |
1989年 | 52篇 |
1988年 | 57篇 |
1987年 | 40篇 |
1986年 | 50篇 |
1985年 | 44篇 |
1984年 | 38篇 |
1983年 | 49篇 |
1982年 | 41篇 |
1981年 | 48篇 |
1980年 | 37篇 |
1979年 | 21篇 |
1978年 | 16篇 |
1977年 | 15篇 |
1976年 | 14篇 |
1975年 | 18篇 |
1972年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Jürgen Vogt Torsten Schwarz Daniel Gras Johannes Sperzel Philippe Ritter Willem de Voogt Jean-Pierre Cebron Martin Seifert Bruce Tockman Bernd Schubert Eric Johnson Annette Doelger Thierry Pochet Elisabeth Mouton Christian Butter 《Journal of interventional cardiac electrophysiology》2007,19(1):61-68
Introduction Failure to enter the coronary sinus (CS) with a guiding catheter and entering its tributaries remains challenging in left
ventricle (LV) pacing lead implants for cardiac resynchronization therapy (CRT). A dual telescoping catheter system (8F outer/6F
inner) is designed to provide the ability to adjust the catheter curve size, shape and/or reach to the patients’ anatomy avoiding
the need for catheter change.
Methods Five different designs for CS cannulation were randomly tested in 64 patients scheduled for CRT device implant.
Results In 33 consecutive patients three adaptable telescoping guiding catheter systems were tested per patient, the adaptable catheters
had higher overall cannulation success rates (68, 63 and 62%) compared to the fixed shape catheter (46%) and an greater cannulation
success rate when the CS location was not known (70, 53 and 72% vs 33% for the fixed shape). In a second group of 31 CRT patients
the two telescoping catheters had similar high levels of success (71–80%), with or without using the inner catheter.
Conclusions The telescopic system is adaptable to a wide range of anatomical variations in patients and can result in a higher CS cannulation
success rate due to its adjustability in the RA in search for the CS ostium. On top of this the inner catheter allows for
sub-selecting the CS tributaries. 相似文献
82.
Olivier Chataigner Elie Fadel Bedrettin Yildizeli Abdallah Achir Sacha Mussot Dominique Fabre Olaf Mercier Philippe G. Dartevelle 《European journal of cardio-thoracic surgery》2008,33(5):837-843
Objective: To identify factors that affect operative mortality and morbidity and long-term survival after completion pneumonectomy. Methods: We retrospectively reviewed the charts of consecutive patients who underwent completion pneumonectomy at our cardiothoracic surgery department from January 1996 to December 2005. Results: We identified 69 patients, who accounted for 17.8% of all pneumonectomies during the study period; 22 had benign disease and 47 malignant disease (second primary lung cancer, n = 19; local recurrence, n = 17; or metastasis, n = 11). There were 50 males and 19 females with a mean age of 60 years (range, 29–80 years). Postoperative mortality was 12% and postoperative morbidity 41%. Factors associated with postoperative mortality included obesity (p = 0.005), coronary artery disease (p = 0.03), removal of the right lung (p = 0.02), advanced age (p = 0.02), and renal failure (p < 0.0001). Preoperative renal failure was the only significant risk factor for mortality by multivariate analysis (p = 0.036). Bronchopleural fistula developed in seven patients (10%), with risk factors being removal of the right lung (p = 0.04) and mechanical stump closure (p = 0.03). Overall survival was 65% after 3 years and 46% after 5 years. Long-term survival was not affected by the reason for completion pneumonectomy. Conclusion: Although long-term survival was acceptable, postoperative mortality and morbidity rates remained high, confirming the reputation of completion pneumonectomy as a challenging procedure. Significant comorbidities and removal of the right lung were the main risk factors for postoperative mortality. Improved patient selection and better management of preoperative renal failure may improve the postoperative outcomes of this procedure, which offers a chance for prolonged survival. 相似文献
83.
84.
85.
86.
Hinrich Staecker Stefan Dazert Brigitte Malgrange Philippe P. Lefebvre Allen F. Ryan Thomas R. Van de water 《International journal of developmental neuroscience》1997,15(4-5)
To determine if transforming growth factor alpha (TGFα) pretreatment protects hair cells from aminoglycoside induced injury by modifying their intracellular calcium concentration, we assayed hair cell calcium levels in organ of Corti explants both before and after aminoglycoside (i.e. neomycin, 10−3M) exposure either with or without growth factor pretreatment. After TGFα (500ng/ml) treatment, the intracellular calcium level of hair cells showed a five-fold increase as compared to the levels observed in the hair cells of control cultures. After ototoxin exposure, calcium levels in hair cells of control explants showed an increase relative to their baseline levels, while in the presence of growth factors pretreatment, hair cells showed a relative reduction in calcium levels. Pretreatment of organ of Corti explants afforded significant protection of hair cell stereocilia bundle morphology from ototoxic damage when compared to explants exposed to ototoxin alone. This study correlates a rise in hair cell calcium levels with the otoprotection of hair cells by TGFα in organ of Corti explants. 相似文献
87.
Philippe Dege Philippe Dubois Robert Jrme 《Macromolecular chemistry and physics.》1997,198(6):1985-1995
The thermal stability of poly(L -lactide) and L /D -lactide stereocopolymers polymerized in bulk with aluminium isopropoxide as initiator was investigated by thermogravimetric analysis, and time and temperature dependence of molecular weight and polydispersity. Compared to poly(L -lactide) prepared with stannous octoate as catalyst the thermal stability of polylactides is remarkably enhanced when the ring-opening polymerization is initiated by aluminium alkoxide. Ultimate mechanical properties and viscoelasticity of these melt-stable thermoplastics have also been studied in relation to the polyester enantiomeric composition. 相似文献
88.
89.
Kim Hahn Le Quan Sang Jean-Luc Elghozi Philippe Meyer Marie-Aude Devynck 《Clinical and experimental pharmacology & physiology》1987,14(3):187-189
1. Plasma renin activity (PRA) and platelet cytosolic free calcium concentration ([Ca2+]i) were simultaneously determined in 18 untreated essential hypertensive subjects and 17 normotensive controls. A significant positive correlation was found between [Ca2+]i and PRA (slope = 42 nmol/l/ng/ml/h) in these 35 subjects. 2. Two determinations more than one week apart in nine subjects confirmed the parallel fluctuations of [Ca2+]i and PRA. A strict sodium restriction produced a progressive PRA elevation associated with a parallel rise in [Ca2+]i in one subject. 3. These results are consistent with the hypothesis that angiotensin II causes a concentration-dependent calcium mobilization. 相似文献
90.
Patrick Fransen MD Jacques Favre MD Philippe Maeder MD Heinz Fankhauser MD 《Journal of clinical neuroscience》1994,1(4):274-276
Lhermitte-Duclos disease (dysplastic gangliocytoma of the cerebellum) is a rare pseudo-neoplastic disorder of the cerebellum with typical MRI findings. A 25-year-old man presenting with progressive neck pain, dizziness, and impaired vision is reported. CT and MRI revealed a left cerebellar haemispheric mass and obstructive hydrocephalus. Lhermitte-Duclos disease was histologically confirmed after surgical removal of the lesion. The typical MRI appearance of a nonenhancing haemispheric cerebellar mass with preservation and exaggeration of the normal gyral pattern allows pre-operative diagnosis of this condition. The literature is reviewed and clinical presentation, radiology and histopathology are discussed. 相似文献