全文获取类型
收费全文 | 62787篇 |
免费 | 3390篇 |
国内免费 | 141篇 |
专业分类
耳鼻咽喉 | 623篇 |
儿科学 | 1718篇 |
妇产科学 | 1590篇 |
基础医学 | 9943篇 |
口腔科学 | 672篇 |
临床医学 | 5413篇 |
内科学 | 14079篇 |
皮肤病学 | 1233篇 |
神经病学 | 5615篇 |
特种医学 | 2066篇 |
外国民族医学 | 32篇 |
外科学 | 9046篇 |
综合类 | 327篇 |
一般理论 | 23篇 |
预防医学 | 4293篇 |
眼科学 | 992篇 |
药学 | 4070篇 |
中国医学 | 114篇 |
肿瘤学 | 4469篇 |
出版年
2023年 | 253篇 |
2022年 | 196篇 |
2021年 | 796篇 |
2020年 | 487篇 |
2019年 | 886篇 |
2018年 | 1462篇 |
2017年 | 1010篇 |
2016年 | 1064篇 |
2015年 | 1327篇 |
2014年 | 1447篇 |
2013年 | 2339篇 |
2012年 | 3732篇 |
2011年 | 3793篇 |
2010年 | 2082篇 |
2009年 | 1780篇 |
2008年 | 3618篇 |
2007年 | 3716篇 |
2006年 | 3635篇 |
2005年 | 3811篇 |
2004年 | 3658篇 |
2003年 | 3474篇 |
2002年 | 3487篇 |
2001年 | 1503篇 |
2000年 | 1540篇 |
1999年 | 1284篇 |
1998年 | 552篇 |
1997年 | 491篇 |
1996年 | 436篇 |
1995年 | 444篇 |
1994年 | 381篇 |
1993年 | 377篇 |
1992年 | 831篇 |
1991年 | 693篇 |
1990年 | 701篇 |
1989年 | 711篇 |
1988年 | 624篇 |
1987年 | 609篇 |
1986年 | 538篇 |
1985年 | 535篇 |
1984年 | 422篇 |
1983年 | 371篇 |
1982年 | 267篇 |
1981年 | 283篇 |
1980年 | 242篇 |
1979年 | 319篇 |
1978年 | 236篇 |
1977年 | 228篇 |
1976年 | 200篇 |
1975年 | 196篇 |
1974年 | 194篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
91.
Dr. Andrew G. Bostom M.D. Dr. Anne L. Hume Pharm.D. Dr. Charles B. Eaton M.D. Dr. Joseph P. Laurino Ph.D. Ms. Lisa R. Yanek B.A. Ms. Mary S. Regan B.S. Mr. William H. McQuade M.P.H. Dr. Wendy Y. Craig Ph.D. Ms. Gayle Perrone M.B.A. Dr. Paul F. Jacques Sc.D. 《Pharmacotherapy》1995,15(4):458-464
Study Objective . To determine the efficacy of high-dose ascorbate supplementation in lowering lipoprotein(a) [Lp(a)] levels in patients with premature coronary heart disease (CHD). Design . Randomized, double-blind, placebo-controlled trial. Setting . Outpatient clinic. Patients . Forty-four patients with documented premature CHD. defined as confirmed myocardial infarction and/or angiographically determined stenosis of 50% or greater in at least one major coronary artery before age 60 years. Interventions . Patients were block randomized on the basis of age, gender, and screening Lp(a) concentrations to receive ascorbate 4.5 g/day or placebo for 12 weeks. Measurements and Main Results . High-dose ascorbate was well tolerated and produced a marked elevation in mean plasma ascorbate levels (+1.2 mg/dl; p<0.001). Multiple linear regression analysis revealed no significant effect of supplementation on postintervention Lp(a) levels (p=0.39) in a model that included treatment group assignment, and baseline Lp(a) levels. Conclusions . Our findings do not support a clinically important lowering effect of high-dose ascorbate on plasma Lp(a) in patients with premature CHD. 相似文献
92.
H Riedmiller R Bürger S Müller J Thüroff R Hohenfellner 《The Journal of urology》1990,143(6):1115-1117
The submucosally embedded in situ appendix guarantees an ideal continence mechanism in patients with ileocecal urinary reservoirs. To date this modification of the Mainz pouch technique has been performed successfully in 13 patients. The appendicocutaneous stoma was placed at the lower right abdominal quadrant in 12 patients and into the umbilical funnel in 1. Urodynamic investigations of the submucosally embedded appendix showed a maximum closure pressure of more than 80 cm. water in pressure profiles. Only 1 case of stomal stenosis required reoperation. 相似文献
93.
94.
Intraoperative coronary artery endarterectomy with excimer laser 总被引:1,自引:0,他引:1
J P Ollivier I Gandjbakhch S Avrillier E Delettre J L Bussière C Cabrol 《The Journal of thoracic and cardiovascular surgery》1990,100(4):606-611
Compared with continuous-wave lasers, excimer lasers exhibit several in vitro advantages: nonthermal ablation process and linear relation between the number of pulses and the depth of the crater. A 308 nm, 20 nsec pulse duration, 1 to 5 repetition rate laser was specifically designed for clinical application. At the time of cardiopulmonary bypass in 10 symptomatic patients, before bypass grafting, a 1 mm diameter core specifically ultraviolet-tipped fiberoptic scope was introduced via the coronary arteriotomy and placed upstream (seven patients) and downstream (three patients) in contact with the stenosis. Laser power was increasingly delivered up to the clearing of the stenosis or occlusion. Quality of angioplasty was controlled by calibration of the neolumen, cardioplegic solution output through the laser-treated segment, and an eighth day or sixth month coronary arteriogram. In the first three patients studied on the eighth day, all laser-treated coronary artery segments showed an early parallel-linked patent neolumen despite competitive bypass graft flow. In the patients studied after 6 months, all recanalized segments were patent except one; in one patient the venous graft was occluded, but the upstream laser angioplasty was patent. The main limitation of the method lies in the fact that laser coronary recanalization is confined to the fiber core diameter. We conclude that (1) excimer laser angioplasty may be safe and efficient during surgical procedure and (2) as catheter flexibility remains the most critical problem, we are now assuming an appropriate tool with a multifiber system that is suitable for intraoperative as well as percutaneous routes. 相似文献
95.
96.
Maud Bessems Benedict M Doorschodt Arlène K van Vliet Thomas M van Gulik 《Liver transplantation》2005,11(5):539-546
For experimental machine perfusion (MP) of the liver, the modified University of Wisconsin solution (UW-G) is most often used. In our search for an enriched MP preservation solution, Polysol was developed. Polysol is enriched with various amino acids, vitamins, and other nutrients for the liver metabolism. The aim of this study was to compare Polysol with UW-G for MP preservation of the liver. Rat livers were preserved during 24 hours with hypothermic MP using UW-G (n = 5) or Polysol (n = 5). Hepatocellular damage (aspartate aminotransferase [AST], alanine aminotransferase [ALT], lactate dehydrogenase [LDH], alpha-glutathione-S-transferase [alpha-GST]) and bile production were measured during 60 minutes of reperfusion (37 degrees C) with Krebs-Henseleit buffer. Control livers were reperfused after 24 hours of cold storage in UW (n = 5). MP using UW-G or Polysol showed less liver damage when compared with controls. Livers machine perfused with Polysol showed less enzyme release when compared to UW-G. Bile production was higher after MP using either UW-G or Polysol compared with controls. In conclusion, machine perfusion using Polysol results in better quality liver preservation than cold storage with UW and machine perfusion using UW-G. 相似文献
97.
Ch. Offergeld J. Kromeier A. Aschendorff W. Maier Th. Klenzner Th. Beleites Th. Zahnert J. Schipper R. Laszig 《European archives of oto-rhino-laryngology》2007,264(4):345-351
Imaging is an essential diagnostic tool in reconstructive middle ear surgery, especially in pre-operative planning. Due to ongoing improvement of imaging quality and development of new imaging techniques like e.g. rotational tomography (RT) post-operative follow-up and immediate evaluation of surgical results may become more important. The aim of this experimental study was to evaluate RT as a new tool for postoperative determination of middle ear anatomy and implant position in temporal bones. RT was performed in ten temporal bone specimen after insertion of different middle ear prostheses concerning material, shape and length (PORP; TORP; Stapes piston). An implantable hearing device (Symphonix Soundbridge®) was also implanted and visualized. For comparison some specimen additionally underwent conventional computed tomography (CT), including the newest technology. Characterization of anatomical structures of the temporal bone using RT was of comparable quality to conventional CT-scans in all investigated specimen while requiring approximately 30% of the CT’s irradiation exposure. Unlike CT the RT showed almost no problems due to metallic artefacts of the implanted prostheses. Furthermore RT enabled a 3-dimensional view of the temporal bone and angle determination of inserted prostheses towards the tympanic membrane and/or the malleus handle. Detailed imaging of the prostheses allowed determination of shape, material and localization within the specimen’s reconstructed middle ear. The new imaging technique of RT allows precise presentation of anatomical structures and middle ear implants in temporal bones. Following these experimental results it will be our future work to evaluate this method in clinical practise. 相似文献
98.
C. Pieh W.A. Lagrèze 《Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft》2007,104(12):1083-1096
Congenital cranial dysinnervation disorders (CCDDs) are responsible for 1–2% of infant strabismus cases. Insufficient innervation and misinnervation of aberrant nerve fibres lead to motility restrictions and synkinesis. We present the most common CCDDs and explain their pathogenesis and the resulting clinical features. Furthermore, we emphasize essential diagnostic steps and treatment aspects. 相似文献
99.
Hans Bosma Martin PJ van Boxtel Gertrudis IJM Kempen Jacques ThM van Eijk Jelle Jolles 《BMC public health》2007,7(1):179
Background
The aims of this study were to examine the extent to which higher intellectual abilities protect higher socio-economic groups from functional decline and to examine whether the contribution of intellectual abilities is independent of childhood deprivation and low birth weight and other socio-economic and developmental factors in early life. 相似文献100.
G Giuffrè 《Metabolic, pediatric, and systemic ophthalmology (New York, N.Y. : 1985)》1989,12(4):100-102
A 24-year old woman displayed a coloboma of the right optic nerve with multiple small parapapillary retinochoroidal colobomas. This rare association makes one suspect that the pathogenesis of colobomatous defects of the optic disc area are caused by a faulty closure of the embryonic fissure and an abnormal maturation of the cells of the anlage of the optic nerve head. 相似文献