全文获取类型
收费全文 | 6872篇 |
免费 | 285篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 25篇 |
儿科学 | 274篇 |
妇产科学 | 156篇 |
基础医学 | 693篇 |
口腔科学 | 397篇 |
临床医学 | 657篇 |
内科学 | 1672篇 |
皮肤病学 | 81篇 |
神经病学 | 687篇 |
特种医学 | 221篇 |
外科学 | 802篇 |
综合类 | 27篇 |
一般理论 | 2篇 |
预防医学 | 291篇 |
眼科学 | 83篇 |
药学 | 494篇 |
1篇 | |
中国医学 | 4篇 |
肿瘤学 | 613篇 |
出版年
2024年 | 21篇 |
2023年 | 48篇 |
2022年 | 67篇 |
2021年 | 143篇 |
2020年 | 85篇 |
2019年 | 121篇 |
2018年 | 154篇 |
2017年 | 131篇 |
2016年 | 120篇 |
2015年 | 143篇 |
2014年 | 202篇 |
2013年 | 239篇 |
2012年 | 345篇 |
2011年 | 375篇 |
2010年 | 215篇 |
2009年 | 180篇 |
2008年 | 366篇 |
2007年 | 402篇 |
2006年 | 358篇 |
2005年 | 345篇 |
2004年 | 292篇 |
2003年 | 276篇 |
2002年 | 264篇 |
2001年 | 220篇 |
2000年 | 229篇 |
1999年 | 244篇 |
1998年 | 72篇 |
1997年 | 61篇 |
1996年 | 51篇 |
1995年 | 54篇 |
1994年 | 31篇 |
1993年 | 36篇 |
1992年 | 138篇 |
1991年 | 137篇 |
1990年 | 121篇 |
1989年 | 109篇 |
1988年 | 92篇 |
1987年 | 88篇 |
1986年 | 81篇 |
1985年 | 61篇 |
1984年 | 57篇 |
1983年 | 43篇 |
1982年 | 21篇 |
1981年 | 29篇 |
1980年 | 23篇 |
1979年 | 50篇 |
1978年 | 23篇 |
1976年 | 25篇 |
1969年 | 25篇 |
1966年 | 19篇 |
排序方式: 共有7180条查询结果,搜索用时 62 毫秒
51.
52.
Value of P-glycoprotein and clinicopathologic factors as the basis for new treatment strategies in high-grade osteosarcoma of the extremities. 总被引:8,自引:0,他引:8
Massimo Serra Katia Scotlandi Gemma Reverter-Branchat Stefano Ferrari Maria C Manara Stefania Benini Marina Incaprera Franco Bertoni Mario Mercuri Antonio Briccoli Gaetano Bacci Piero Picci 《Journal of clinical oncology》2003,21(3):536-542
PURPOSE: To evaluate the prognostic value of P-glycoprotein and clinicopathologic parameters in a large series of high-grade osteosarcoma (OS) patients treated at the Rizzoli Institute. PATIENTS AND METHODS: With the use of immunohistochemistry, P-glycoprotein was assessed in 149 patients with primary, nonmetastatic, high-grade OS who were homogeneously treated with chemotherapy protocols based on doxorubicin, high-dose methotrexate, and cisplatin and the addition of ifosfamide in the postoperative phase. RESULTS: P-glycoprotein positivity was found in 47 of 149 cases (32%) and was significantly associated with a higher incidence of relapse and a worse outcome, as was age younger than 12 years and tumor volume greater then 150 mL at diagnosis. Multivariate analysis further confirmed the prognostic value of these parameters, which all were independent adverse prognostic factors. Event-free survival and proportional hazards regression analyses confirmed that overexpression of P-glycoprotein at clinical onset is the most important adverse prognostic factor for high-grade OS patients treated with these chemotherapy protocols. CONCLUSION: Increased P-glycoprotein levels, together with tumor volume and age, should be taken into consideration to identify, at time of diagnosis, subgroups of OS patients with a higher risk of recurrence. This subgroup identification will constitute the basis for drawing individualized treatment protocols on the basis of risk evaluation, with the aim of using more aggressive chemotherapy, or combination chemotherapy with other adjuvants, only in those patients for which more aggressive regimens are strictly necessary and warranted. 相似文献
53.
Augusto Ferrari MD Luigi Frigerio MD 《American journal of obstetrics and gynecology》1997,177(6):1426-1431
OBJECTIVE: We describe an alternative sling procedure that permits concomitant correction of urethral hypermobility and urinary incontinence through a single surgical exposure. STUDY DESIGN: Fifteen women with severe urinary stress incontinence and urethral hypermobility underwent a sling procedure by creation of a simple triangular patch from the anterior vaginal wall. RESULTS: The mean operative time for the vaginal sling procedure was 38 minutes (range 29 to 65 minutes) in addition to other operations. The mean postoperative hospital stay was 7.7 days (range 5 to 13 days) and all patients were routinely discharged with an indwelling Foley catheter. Spontaneous micturition occurred in 12 patients after a mean period of 25 days (range 13 to 36 days). In three cases long-term catheterization was necessary. By subjective and objective evaluations, all the patients were cured of their stress incontinence. CONCLUSION: The triangular vaginal patch with the single sutures on each side provides an alternative approach for bladder neck stabilization that may permit a more anatomic suspension of a hypermobile urethra.(Am J Obstet Gynecol 1997;177:31) 相似文献
54.
G Gualdrini P Battisti R Biagini P De Felice A Fazio P Ferrari 《Applied radiation and isotopes》2000,53(1-2):387-393
The investigation of actinides' internal contamination in human body makes use of a variety of techniques. In large scale screening the technique of "in vivo" evaluation of bone 241Am burden via the determination of the nuclide activity in the skull is often used. For this purpose, adequate calibration procedures and standard phantoms are needed. The present paper summarises the studies and technical procedures followed for the development of a calibration phantom based on a commercial Alderson angiographic head in which a set of 24 241Am point sources were embedded. A theoretical study was first carried out, at the ENEA Institute for Radiation Protection, using the MCNP4-B Monte Carlo code to determine the point source distribution that closely approximates a homogeneous bone contamination. The numerical models were also used to evaluate the resulting degree of approximation. The point sources were prepared at the ENEA National Metrology Institute for ionising radiation quantities and were traceable to the Italian national standard of radionuclide activity. The sources were prepared by quantitatively dispensing a liquid solution onto a plastic disc. The activity of each source was checked by gamma-ray spectrometry and the reproducibility of the activity values was determined. Each source was then placed in the optimum position in the skull, given by the Monte Carlo modelling, by a precision mechanical device. The phantom was finally used to calibrate a whole body counter operating at the ENEA Institute for Radiation Protection. The paper reports the main theoretical and experimental aspects of this work, and also discusses the results of the first calibrations. 相似文献
55.
56.
Pignatti G Ferrari D Tigani D Scardovi M Trentanti P Trentani F Giunti A 《La Chirurgia degli Organi di Movimento》2000,85(4):381-387
The authors present the results observed in 12 patients affected with post-traumatic stiffness of the elbow treated by an external fixator in distraction to obtain functional recovery of range of movement; in all of the cases anterior and posterior release and resection of the apex of the olecranon was carried out, while in 2 cases interposition arthroplasty with freeze-dried dura madre was associated. The series includes 12 cases with a long-term follow-up that ranges from 8 to 33 months after surgery. The mean arch of movement during the preoperative phase was 35 degrees (minimum 0 degree-maximum 90 degrees) in flexion extension and 80 degrees (minimum 0 degree-maximum 150 degrees) in pronosupination. Recovery of mean joint excursion in flexion-extension was 91 degrees and in pronosupination it was 127 degrees. Complications included loosening of the nails in 2 cases, breakage of the nails in 1 case, and transitory deficit of the ulnar nerve in 4 cases. A total of 11 patients (91.66%) declared that they were satisfied with the considerable improvement in their ability to do daily activities. The results of arthroplasty in distraction in the elbow are satisfactory even if much attention must be paid to the selection of the patients because of the intense collaboration that is required during postoperative rehabilitation. 相似文献
57.
目的:比较4种不同树脂粘结材料在不同深度根管内粘固纤维桩的推出强度。方法:28个单根管离体前牙截冠后行根管充填和桩道预备,随机分为4组,分别用不同的粘结材料(Ⅰ:XP Bond-Dual Cure Calibra resincement;Ⅱ:XP Bond-Dual Cure Fluorocore2;Ⅲ:Excite DSC MultiCore Flow;Ⅳ:Multilink Primer A/B MultilinkAutomix)粘固纤维桩。粘固了纤维桩的牙根切割为1mm厚的试件并将其按照根管的深度分为上部、中部和下部3组,测试其推出强度。结果:Ⅰ组、Ⅱ组上部的推出强度均显著高于下部(P<0.05),Ⅲ组、Ⅳ组的推出强度在不同深度根管间无显著性差异(P>0.05)。结论:材料的类型和根管的深度对纤维桩的固位有影响。 相似文献
58.
Ivabradine, the first representative of a new class of exclusive heart rate-reducing agents, selectively inhibits the I(f) current in the sinoatrial node. The direct electrophysiological consequence of this inhibition is a reduction in the slope of the diastolic depolarisation curve and a decrease in heart rate. Pharmacological inhibition of the I(f) current with ivabradine has been shown to preserve coronary vasodilatation upon exercise, i.e., myocardial perfusion, with no negative inotropic effects and maintenance of cardiac contractility. Ivabradine protects the myocardium during ischaemia, improves left ventricular function in congestive heart failure, and reduces remodelling subsequent to myocardial infarction. Pure heart rate reduction by specific and selective I(f) inhibition decreases oxygen demand, improves myocardial energetics and improves perfusion of the ischaemic myocardium. We can expect distinct clinical benefits from long-term heart rate reduction in patients with chronic ischaemic disease. 相似文献
59.
M Ferrari M Armani P Melacini C Egloff G Scattolin G Fasoli G Cardin G Miraglia C Angelini S Dalla Volta 《Giornale italiano di cardiologia》1980,10(10):1288-1298
17 patients with myotonic dystrophy have been studied. The skeletal muscle disease has been assessed by history, physical examination, electro-myography and muscle biopsy. Cardiac evaluation has been obtained by history, physical examination, chest X-ray, ecg at rest and after exercise, vectorcardiography and echocardiography. Only two patients presented symptoms and clinical findings of cardiac disease, otherwise conduction disturbances have been founded in 15 cases, pseudoinfarct pattern in 5 cases and loss of anterior vectors in 2 cases. Has to be remembered that in myotonic dystrophy sudden death has a very high incidence, which could be explained by the development of complete a-v block, because of the impairment of the conduction system. Therefore, in those patients with bifascicular blocks (3 cases), the electrophysiological study may be useful in order to evaluate the opportunity to put on a permanent pace-maker, to prevent sudden death. 相似文献
60.