全文获取类型
收费全文 | 3610篇 |
免费 | 194篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 138篇 |
儿科学 | 214篇 |
妇产科学 | 35篇 |
基础医学 | 359篇 |
口腔科学 | 153篇 |
临床医学 | 327篇 |
内科学 | 628篇 |
皮肤病学 | 42篇 |
神经病学 | 521篇 |
特种医学 | 55篇 |
外科学 | 465篇 |
综合类 | 19篇 |
一般理论 | 4篇 |
预防医学 | 274篇 |
眼科学 | 70篇 |
药学 | 171篇 |
中国医学 | 1篇 |
肿瘤学 | 330篇 |
出版年
2023年 | 16篇 |
2022年 | 33篇 |
2021年 | 53篇 |
2020年 | 38篇 |
2019年 | 48篇 |
2018年 | 73篇 |
2017年 | 49篇 |
2016年 | 88篇 |
2015年 | 70篇 |
2014年 | 88篇 |
2013年 | 195篇 |
2012年 | 201篇 |
2011年 | 215篇 |
2010年 | 123篇 |
2009年 | 141篇 |
2008年 | 219篇 |
2007年 | 237篇 |
2006年 | 203篇 |
2005年 | 248篇 |
2004年 | 248篇 |
2003年 | 220篇 |
2002年 | 212篇 |
2001年 | 25篇 |
2000年 | 26篇 |
1999年 | 40篇 |
1998年 | 58篇 |
1997年 | 46篇 |
1996年 | 34篇 |
1995年 | 42篇 |
1994年 | 37篇 |
1993年 | 41篇 |
1992年 | 36篇 |
1991年 | 25篇 |
1990年 | 25篇 |
1989年 | 15篇 |
1988年 | 15篇 |
1987年 | 9篇 |
1986年 | 24篇 |
1985年 | 20篇 |
1984年 | 18篇 |
1983年 | 34篇 |
1982年 | 40篇 |
1981年 | 15篇 |
1980年 | 26篇 |
1979年 | 15篇 |
1978年 | 19篇 |
1977年 | 15篇 |
1976年 | 15篇 |
1975年 | 12篇 |
1974年 | 10篇 |
排序方式: 共有3806条查询结果,搜索用时 15 毫秒
31.
Ari Mennander Jari Laurikka Pekka Kuukasj?rvi Matti Tarkka 《European journal of cardio-thoracic surgery》2005,27(1):32-34
OBJECTIVE: To assess the impact of postoperative continuous pleural lavage (PCPL) after thoracotomy for the treatment of stage 2 pleural empyema in relation to postoperative length of stay and morbidity. METHODS: Stage 2 pleural empyema was diagnosed with computer tomography. Conservative treatment including antibiotics and pleural aspiration was introduced. 89 patients treated for stage 2 pleural empyema by thoracotomy, pleural discharge evacuation and irrigation after pleural decortication were identified after unsuccessful conservative treatment for 10 days. Whenever pleural discharge remained opaque after operation, PCPL was administered daily through the cranial chest tube and discharge evacuated through the caudal pleural suction (10-15 mmHg) tube. Risk factors related to pleural pus and patient outcome were sought for. RESULTS: Seventy-seven out of 89 patients (86.5%) had clear empyema discharge immediately after pleural decortication and irrigation. Pleural discharge remained opaque despite surgery in 12 out of 89 patients (13.5%) and PCPL was introduced. Presence of a combination of risk factors for pleural empyema, such as dental caries, alcohol abuse or previous inflammatory reaction, was predictive for persistence of opaque pleural discharge after operation (P<0.05). Need for re-thoracotomies (in 11 cases, P=ns) and postoperative deaths (P<0.05) were related with patients who did not have PCPL. The length of the hospital treatment was 20.1+/-3.1 (days+/-SEM) among patients with PCPL and 19.2+/-1.8 without PCPL before possible re-thoracotomy, respectively (P=ns). CONCLUSIONS: Early postoperative (1 day-11 months) mortality was statistically associated with patients having fibrinopurulent empyema but no PCPL. PCPL is a feasible method to clear pleural pus discharge without prolongation of hospitalization and may be recommended after thoracotomy for patients with fibrinopurulent stage 2 empyema. 相似文献
32.
Long-term outcome after mitral valve repair 总被引:3,自引:0,他引:3
Heikkinen J Biancari F Uusimaa P Satta J Juvonen J Ylitalo K Niemelä M Salmela E Juvonen T Lepojärvi M 《Scandinavian cardiovascular journal : SCJ》2005,39(4):229-236
BACKGROUND: Several studies reported excellent long-term results after mitral valve repair for regurgitation, however a number of patients still experience recurrent mitral valve regurgitation which requires reoperation. We have evaluated the long-term outcome of a consecutive series of patients who underwent mitral valve repair for regurgitation in an attempt to identify the risk factors associated with late failures. PATIENTS AND METHODS: One-hundred and sixty-four patients underwent mitral valve repair for ischemic and degenerative mitral valve regurgitation. Seventy-two patients underwent echocardiographic evaluation a median of 5.6 years after surgery. RESULTS: Ten-year survival freedom from any fatal cardiac event was 75.9% and survival freedom from redo mitral valve surgery was 93.8%. Multivariable analysis showed that residual mitral valve regurgitation grade>1 as assessed during the immediate postoperative period (at 10-year, 60.6% vs. 95.7%, p=0.001, RR 20.7, 95%C.I. 3.4-125.3) and chronic obstructive pulmonary disease/asthma (at 10-year 66.8% vs. 95.2%, p=0.013, RR 12.0, 95%C.I. 1.7-85.2) were predictors of redo mitral valve surgery. The same findings were observed also among patients with myxomatous degenerative disease. At echocardiographic follow-up, no significant improvement was detected in terms of left ventricular ejection fraction, whilst mitral valve regurgitation grade (median, 3 to 1), New York Heart Association class (median, 2 to 1) and left atrium diameter (median, 50 to 44 mm) decreased significantly. CONCLUSIONS: This study confirms the excellent clinical long-term results after mitral valve repair. An adequate repair technique is advocated in order to decrease the immediate postoperative rate of residual regurgitation>1 as this is a main determinant of late failures requiring redo mitral valve surgery. Further studies are required to better define the possible causative role of chronic obstructive pulmonary disease and any underlying connective tissue metabolic disorder in late failures after mitral valve repair. 相似文献
33.
Antibodies to human heat shock protein 60, hypertension and dyslipidemia. A study of joint effects on coronary risk 总被引:3,自引:0,他引:3
Kervinen H Huittinen T Vaarala O Leinonen M Saikku P Manninen V Mänttäri M 《Atherosclerosis》2003,169(2):339-344
OBJECTIVE: High IgA-class (but not IgG-class) Anti-Heat-shock-protein 60 antibody level is a predictor of coronary risk in dyslipidemic middle-aged men. In this paper we studied the joint effects of high Anti-Hsp60-antibody level and the classical coronary risk factors. METHODS: We used nested case-control design and logistic regression analyses. The cases consisted of 233 middle-aged men with myocardial infarction or coronary death during 8.5-year follow-up in Helsinki Heart Study, a coronary primary prevention study with gemfibrozil. The controls were subjects without coronary events, matched for drug treatment and the geographical area. RESULTS: The relative coronary risks (Odds Ratios (ORs); 95% confidence interval) were 1.41 (0.96-2.05) for high IgA-class Anti-Hsp60 antibody level and 1.98 (1.35-2.90) for hypertension, defined as mean arterial pressure >114 mmHg. With simultaneous occurrence of high Anti-Hsp60 antibody level and hypertension, the ORs were 2.32 (1.26-4.27) for systolic and 2.99 (1.63-5.48) for diastolic hypertension. Similar patterns of joint effects were found between high Anti-Hsp60 antibody and lipoprotein cholesterol levels as well as antibodies against oxidized low-density lipoprotein. CONCLUSIONS: Our results suggest that, while high IgA-class Anti-Hsp60 antibody level predicts coronary risk, the effect is modest without simultaneous occurrence of other classical risk factors. 相似文献
34.
Blomgren K Alho OP Ertama L Huovinen P Korppi M Mäkelä M Penttilä M Pitkäranta A Savolainen S Varonen H Suonpää J;Finnish Society of Otorhinolaryngology committee 《Scandinavian journal of infectious diseases》2005,37(4):245-250
These clinical practice guidelines aim at providing assistance mainly to primary health care physicians for the diagnosis and management of acute sinusitis. Despite the huge impact of upper respiratory infections, criteria for diagnoses are often vague, and physicians are often uncertain of their diagnoses. This is not surprising, as the sole definition of acute sinusitis is somewhat confusing, not to mention the existing discrepancies between treatments, even among specialists. The Finnish Society of Otorhinolaryngology has set up a committee to evaluate existing data on acute sinusitis and to formulate these guidelines. The committee comprised Finnish experts in adult and paediatric otorhinolaryngology, clinical microbiology, radiology, paediatrics, and epidemiology. Recommendations given are based on the principles of evidence-based medicine, with the level of evidence presented. 相似文献
35.
36.
37.
38.
39.
Aapo Nummenmaa Matti Stenroos Risto J. Ilmoniemi Yoshio C. Okada Matti S. Hämäläinen Tommi Raij 《Clinical neurophysiology》2013,124(10):1995-2007
Objective
MRI-guided real-time transcranial magnetic stimulation (TMS) navigators that apply electromagnetic modeling have improved the utility of TMS. However, their accuracy and speed depends on the assumed volume conductor geometry. Spherical models found in present navigators are computationally fast but may be inaccurate in some areas. Realistically shaped boundary-element models (BEMs) could increase accuracy at a moderate computational cost, but it is unknown which model features have the largest influence on accuracy. Thus, we compared different types of spherical models and BEMs.Methods
Globally and locally fitted spherical models and different BEMs with either one or three compartments and with different skull-to-brain conductivity ratios (1/1–1/80) were compared against a reference BEM.Results
The one-compartment BEM at inner skull surface was almost as accurate as the reference BEM. Skull/brain conductivity ratio in the range 1/10–1/80 had only a minor influence. BEMs were superior to spherical models especially in frontal and temporal areas (up to 20 mm localization and 40% intensity improvement); in motor cortex all models provided similar results.Conclusions
One-compartment BEMs offer a good balance between accuracy and computational cost.Significance
Realistically shaped BEMs may increase TMS navigation accuracy in several brain areas, such as in prefrontal regions often targeted in clinical applications. 相似文献40.
Esa Pekkala Eeva-Liisa Hietala Matti Puukka Markku Larmas 《Acta odontologica Scandinavica》2013,71(4):155-159
Previous studies show that a high sucrose diet reduces the rate of primary dentinogenesis and increases dental caries, although their cause-effect relationship is still obscure. The purpose of this study was to explore whether the effect of sucrose load on the dentinogenesis and dental caries of young rat molars is mediated by systemic (intragastric) or by systemic and local (dietary) factors. At weaning (19 days), animals were randomized into the control, intragastric sucrose, and dietary sucrose groups for 4 weeks. The areas of dentin appositions and dentinal caries lesions were measured planimetrically. Caries was also determined with Shiff's staining and the width of predentin by histology. Urinary Ca, K, and Na levels were measured by flame photometry, urinary P levels using an UV method, and serum insulin levels using radioimmunoassay. Systemic and local sucrose load reduced dentin appositions and intragastric sucrose increased urinary Ca excretion. No differences in the width of predentin were noticed. Only dietary sucrose enhanced the occurrence and progression of caries. The present findings show that sucrose load reduces dentinogenesis by impairing the synthesis of dentin matrix, but also point out the crucial importance of the local sucrose challenge in the initiation of dental caries. 相似文献