全文获取类型
收费全文 | 1618篇 |
免费 | 63篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 19篇 |
妇产科学 | 27篇 |
基础医学 | 200篇 |
口腔科学 | 84篇 |
临床医学 | 116篇 |
内科学 | 584篇 |
皮肤病学 | 20篇 |
神经病学 | 79篇 |
特种医学 | 37篇 |
外科学 | 192篇 |
综合类 | 19篇 |
预防医学 | 100篇 |
眼科学 | 9篇 |
药学 | 119篇 |
中国医学 | 20篇 |
肿瘤学 | 38篇 |
出版年
2024年 | 6篇 |
2023年 | 23篇 |
2022年 | 29篇 |
2021年 | 51篇 |
2020年 | 32篇 |
2019年 | 59篇 |
2018年 | 47篇 |
2017年 | 39篇 |
2016年 | 42篇 |
2015年 | 56篇 |
2014年 | 63篇 |
2013年 | 70篇 |
2012年 | 110篇 |
2011年 | 121篇 |
2010年 | 63篇 |
2009年 | 66篇 |
2008年 | 104篇 |
2007年 | 109篇 |
2006年 | 77篇 |
2005年 | 91篇 |
2004年 | 93篇 |
2003年 | 70篇 |
2002年 | 44篇 |
2001年 | 41篇 |
2000年 | 38篇 |
1999年 | 10篇 |
1998年 | 8篇 |
1997年 | 7篇 |
1995年 | 7篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 10篇 |
1990年 | 6篇 |
1989年 | 6篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 7篇 |
1982年 | 3篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1970年 | 6篇 |
1968年 | 3篇 |
1967年 | 2篇 |
排序方式: 共有1683条查询结果,搜索用时 14 毫秒
51.
Felizardo KR Lemos LV de Carvalho RV Gonini Junior A Lopes MB Moura SK 《Brazilian dental journal》2011,22(6):468-472
This study analyzed the bond strength (BS) of HEMA versus HEMA-free self-etch adhesive systems to dentin. The occlusal surface of 20 third molars was removed and the dentin was abraded with 600-grit silicon carbide paper. The teeth were randomly assigned to 4 groups (n = 5) and restored with GO, Adper SE Plus, OptiBond All-In-One, and Clearfil 3S Bond adhesive systems and Filtek Z350 composite. After light curing (600 mW/cm2), the teeth were stored in distilled water at 37 oC for 24 h and were sectioned in the mesiodistal and buccolingual directions to obtain sticks (0.8 mm2). The sticks were subjected to tensile force using a universal testing machine (0.5 mm/min), and the modes of failure were analyzed by scanning electron microscopy and classified as adhesive, cohesive, or mixed. The BS data (in MPa) were treated using one-way ANOVA and Tukey's tests at 5% significance. GO presented the lowest mean bond strength value (10.57 ± 3.72) and differed significantly from the other materials (p = 0.001), which, in turn, presented statistically similar results (p>0.05) among themselves: Adper SE Plus (29.08 ± 8.93), OptiBond All-In-One (28.36 ± 6.49), and Clearfil 3S Bond (28.62 ± 6.97). Mixed fractures were the most prevalent. It was concluded that the influence of HEMA on BS to dentin was material dependent. 相似文献
52.
53.
OBJECTIVE:
The present study was designed to evaluate the effects of urban, traffic-related, fine particulate matter (PM2.5) on mice lung tumorigenesis under controlled exposure conditions.METHODS:
Four groups of female Swiss mice were treated with intraperitonial injections of urethane and saline solution. Urethane was used to start the carcinogenesis process. The animals were housed in two chambers receiving filtered and polluted air. In the polluted air chamber, pollutant levels were low. After two months of exposure, the animals were euthanized and lung tumoral nodules were counted.RESULTS:
Saline-treated animals showed no nodules. Urethane-treated animals showed 2.0+2.0 and 4.0+3.0 nodules respectively, in the filtered and non-filtered chambers (p = 0.02), thus showing experimental evidence of increased carcinogenic-induced lung cancer with increasing PM2.5 exposure.CONCLUSION:
Our data support the concept that low levels of PM2.5 may increase the risk of developing lung tumors. 相似文献54.
Martins MD Russo MP Lemos JB Fernandes KP Bussadori SK Corrêa CT Martins MA 《Oral diseases》2007,13(3):270-273
AIM: The aim of the present study was to clinically evaluate the oral mucosa lesions of leprosy patients during and after multi-drug therapy. METHODS: Clinical examination, medical and dental history examination was performed in 100 leprosy patients. RESULTS: The results revealed that 71 patients, 50 men and 21 women, exibited oral lesions. The most frequent lesions were: fissured tongue (18 cases), inflammatory papillary hyperplasia (16 cases), chronic atrophic candidiasis (10 cases), fibroma (10 cases), erythematous candidiasis (eight cases), and traumatic ulceration (seven cases). CONCLUSION: We conclude that leprosy-related lesions are not present in patients undergoing treatment for leprosy, probably due to response to multidrug therapy. 相似文献
55.
56.
Vartanian JG Carvalho AL Yueh B Furia CL Toyota J McDowell JA Weymuller EA Kowalski LP 《Head & neck》2006,28(12):1115-1121
BACKGROUND: The University of Washington Quality of Life (UW-QOL) questionnaire is an English-language survey instrument used worldwide to assess the quality of life of patients with head and neck cancer. To be used in other cultures, such instruments require careful translation and psychometric validation in other languages. METHODS: The translation and cultural adaptation of the questionnaire were performed following accepted international guidelines. The psychometric validation was performed on a consecutive series of patients with at least 1 year of disease-free survival after treatment for squamous cell carcinoma of the upper aerodigestive tract, recruited from October 2004 to January 2005 from a tertiary cancer center hospital. Eligible subjects were invited to complete the Portuguese version of the UW-QOL questionnaire during routine clinical consultation and complete it again within 15 days. They also completed a validated Portuguese version of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and a questionnaire to evaluate anxiety and depression symptoms (Hospital Anxiety and Depression Scale [HADS]). RESULTS: A Portuguese version of the questionnaire was developed in iterative fashion. In the psychometric validation process, a total of 109 patients were analyzed. Reliability was excellent, including both internal consistency (Cronbach's alpha [alpha] of 0.744) and test retest reliability (intraclass correlation coefficient [ICC] of 0.882). Construct validity was supported by statistically significant relationships between the SF-36 and HAD questionnaires and the translated UW-QOL questionnaire. CONCLUSIONS: The Brazilian-Portuguese version of the UW-QOL questionnaire appears to be culturally appropriate and psychometrically valid. This version is a valuable tool to evaluate accurately the quality of life of Brazilian patients with head and neck cancer. 相似文献
57.
BACKGROUND: Accurate assessment of kidney function level is the key to the identification and management of chronic kidney disease (CKD). Glomerular filtration rate (GFR) is the best measure of overall kidney function in health and disease. There is no consensus about the method to be used routinely to measure and/or estimate GFR. The objectives of this study were to assess which method correlates better with creatinine (Cr) clearance, extensively used in medical practice, as well as assessing the efficacy of the modification of diet in renal disease (MDRD) equation, in our population. METHODS: We studied 262 adult out-patients with stable CKD on conservative treatment. GFR was evaluated by Cr clearance, Cockcroft-Gault (CG) formula, the mean of urea and Cr clearances (total clearance (TCl)), the MDRD study equation, with and without the variable for African-Americans (MDRD1) and the simplified one (MDRDs). Data were analyzed by Pearson's correlation coefficient (r) and Bland & Altman plot analysis. RESULTS: Pearson's correlation showed that all methods where similar when compared to Cr clearance. A high correlation was observed between CG and MDRD equations, and TCl and MDRD equations showed the worst correlation. Among the MDRD equations, no differences were found. Bland-Altman plot analysis indicated a concordance among the studied methods. CONCLUSION: The CG formula could replace Cr clearance in our population, being simpler than and equally as sensitive as the MDRD equation. 相似文献
58.
Briel M Schwartz GG Thompson PL de Lemos JA Blazing MA van Es GA Kayikçioglu M Arntz HR den Hartog FR Veeger NJ Colivicchi F Dupuis J Okazaki S Wright RS Bucher HC Nordmann AJ 《JAMA》2006,295(17):2046-2056
Context The short-term effects of early treatment with statins in patients after the onset of acute coronary syndromes (ACS) for the outcomes of death, myocardial infarction (MI), and stroke are unclear. Objective To evaluate relevant outcomes of patients from randomized controlled trials comparing early statin therapy with placebo or usual care at 1 and 4 months following ACS. Data Sources and Study Selection Systematic search of electronic databases (MEDLINE, EMBASE, PASCAL, Cochrane Central Register) from their inception to August 2005, which was supplemented by contact with experts in the field. Two reviewers independently determined the eligibility of randomized controlled trials that compared treatment with statins with a control, were initiated within 14 days after onset of ACS, and had a minimal follow-up of 30 days. Trials with cerivastatin were only included in a sensitivity analysis. Data Extraction Information on baseline characteristics of included trials and patients, reported methodological quality, lipid levels, and clinical outcome was independently extracted by 2 investigators. Investigators from each included trial contributed additional data if necessary. Data Synthesis Twelve trials involving 13 024 patients with ACS were included in the meta-analysis. The risk ratios for the combined end point of death, MI, and stroke for patients treated with early statin therapy compared with control therapy were 0.93 (95% confidence interval [CI], 0.80-1.09; P = .39) at 1 month and 0.93 (95% CI, 0.81-1.07; P = .30) at 4 months following ACS. There were no statistically significant risk reductions from statins for total death, total MI, total stroke, cardiovascular death, fatal or nonfatal MI, or revascularization procedures (percutaneous coronary intervention or coronary artery bypass graft surgery). Sensitivity analyses with restriction to trials of high quality or with additional data from a large trial using cerivastatin indicated summary risk ratios even closer to 1. Conclusion Based on available evidence, initiation of statin therapy within 14 days following onset of ACS does not reduce death, MI, or stroke up to 4 months. 相似文献
59.
Lemos AA Siegel MJ Rossi G Somalvico F Cioffi U Biondetti PR 《La Radiologia medica》2006,111(7):911-920
PURPOSE: The aim of this study was to determine whether the use of multidetector computed tomography (MDCT) is associated with decreased sedation, frequency of motion artefacts and conventional angiograms compared with single-detector CT (SDCT). MATERIALS AND METHODS: CT examinations performed in young children between January 1993 and June 2005 were reviewed retrospectively. Prior to September 2000, SDCT was used; after that period, MDCT was used. The examinations obtained during these two periods were compared for the frequency of sedation, motion artefacts, and conventional angiograms. Statistical comparison between the two groups was determined by using the chi(2) test. RESULTS: A total of 126 infants and children younger than 6 years of age underwent 134 CT examinations. Eighty-eight were obtained with a SDCT (65%) (group 1) and 46 with a MDCT (35%) (group 2). Sedation was required in 31/88 (35%) CT examinations in group 1 and in 6/46 (13%) in group 2. Conventional angiography was performed in 20/88 (22%) cases in group 1 and in 6/46 (13%) in group 2. Motion artefacts were present in 8/88 (9%) CT examinations in group 1 and in 4/46 (8%) in group 2. There was significant statistical difference with regard to sedation and angiography rates between the two groups (p<0.001) whereas there was no significant difference with regard to motion artefacts (p>1). CONCLUSIONS: MDCT can reduce the need for sedation and conventional angiography in children after liver transplantation. There is no effect on patient motion artefacts. 相似文献
60.
Sbragia-Neto L Melo-Filho AA Guerra-Júnior G Valente de Lemos Marini SH Baptista MT Sabino de Matos PS Gonçalves de Oliveira-Filho A Bustorff-Silva JM 《Journal of pediatric surgery》2000,35(8):1269-1271
The authors report a case of a virilizing adrenal tumor that developed in a 2-year-old child with Beckwith-Wiedemann syndrome (BWS). He had a fetal diagnosis of omphalocele and a history of neonatal adrenal cysts. The importance of prenatal diagnosis of BWS and postnatal follow-up of tumors is discussed. The differential diagnosis of adrenal pathologies occurring in BWS also is reviewed. 相似文献