全文获取类型
收费全文 | 4193篇 |
免费 | 212篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 116篇 |
妇产科学 | 58篇 |
基础医学 | 666篇 |
口腔科学 | 428篇 |
临床医学 | 279篇 |
内科学 | 934篇 |
皮肤病学 | 105篇 |
神经病学 | 356篇 |
特种医学 | 41篇 |
外科学 | 403篇 |
综合类 | 14篇 |
预防医学 | 401篇 |
眼科学 | 56篇 |
药学 | 305篇 |
中国医学 | 22篇 |
肿瘤学 | 197篇 |
出版年
2024年 | 5篇 |
2023年 | 46篇 |
2022年 | 91篇 |
2021年 | 150篇 |
2020年 | 112篇 |
2019年 | 150篇 |
2018年 | 147篇 |
2017年 | 121篇 |
2016年 | 112篇 |
2015年 | 157篇 |
2014年 | 197篇 |
2013年 | 236篇 |
2012年 | 359篇 |
2011年 | 429篇 |
2010年 | 253篇 |
2009年 | 199篇 |
2008年 | 312篇 |
2007年 | 278篇 |
2006年 | 222篇 |
2005年 | 215篇 |
2004年 | 194篇 |
2003年 | 161篇 |
2002年 | 121篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 17篇 |
1998年 | 22篇 |
1997年 | 14篇 |
1996年 | 12篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 8篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有4427条查询结果,搜索用时 15 毫秒
101.
102.
Coronary artery embolism is an uncommon cause of myocardial infarction. We report a case of acute ST-segment elevation myocardial infarction due to a coronary embolism that originated from a calcified aortic valve. Coronary angiography demonstrated complete occlusion of the left anterior descending coronary artery. Primary percutaneous coronary intervention was successfully performed, with aspiration of the valve tissue and complete restoration of the coronary artery blood flow. This was followed by aortic valve replacement a few days later. 相似文献
103.
B Rodrigues L Jorge CT Mostarda KT Rosa A Medeiros C Malfitano AL de Souza KA Viegas S Lacchini R Curi PC Brum K De Angelis MC Irigoyen 《Journal of cardiac failure》2012,18(9):734-744
BackgroundExercise training (ET) has been used as a nonpharmacological strategy for treatment of diabetes and myocardial infarction (MI) separately. We evaluated the effects ET on functional and molecular left ventricular (LV) parameters as well as on autonomic function and mortality in diabetics after MI.Methods and ResultsMale Wistar rats were divided into control (C), sedentary-diabetic infarcted (SDI), and trained-diabetic infarcted (TDI) groups. MI was induced after 15 days of streptozotocin-diabetes induction. Seven days after MI, the trained group underwent ET protocol (90 days, 50-70% maximal oxygen consumption-VO2max). LV function was evaluated noninvasively and invasively; baroreflex sensitivity, pulse interval variability, cardiac output, tissue blood flows, VEGF mRNA and protein, HIF1-α mRNA, and Ca2+ handling proteins were measured. MI area was reduced in TDI (21 ± 4%) compared with SDI (38 ± 4%). ET induced improvement in cardiac function, hemodynamics, and tissue blood flows. These changes were probable consequences of a better expression of Ca2+ handling proteins, increased VEGF mRNA and protein expression as well as improvement in autonomic function, that resulted in reduction of mortality in TDI (33%) compared with SDI (68%) animals.ConclusionsET reduced cardiac and peripheral dysfunction and preserved autonomic control in diabetic infarcted rats. Consequently, these changes resulted in improved VO2max and survival after MI. 相似文献
104.
Manuel Mendizabal Sebastián Marciano Luciana dos Santos Schraiber Rodrigo Zapata Rodolfo Quiros Maria Lucia Zanotelli María Marta Rivas Gustavo Kusminsky Roberto Humeres Angelo Alves de Mattos Adrián Gadano Marcelo O. Silva 《Clinical transplantation》2013,27(4):E469-E477
Post‐transplant lymphoproliferative disorder (PTLD) is a major and potentially life‐threatening complication after solid‐organ transplantation. The aim of this study was to describe the disease characteristics, clinical practices, and survival related to PTLD in adult orthotopic liver transplant (OLT) recipients in South America. We conducted a survey at four different transplant groups from Argentina, Brazil, and Chile. Among 1621 OLT recipients, 27 developed PTLD (1.7%); the mean age at diagnosis was 53.7 (±14) yr with a mean time of 39.7 (±35.2) months from OLT to PTLD diagnosis. Initial therapy included reduction in immunosuppression alone in 23.1% of the patients. Either rituximab or chemotherapy was employed as initial or second‐line therapy in 76.9% of the patients. PTLD location was frequently extranodal (80.7%) and mostly involving the transplanted liver (59.3%). The overall survival at one and five yr post‐PTLD diagnosis was 53.8% and 46.2%, respectively. Significant univariate risk factors for post‐PTLD mortality included lactate dehydrogenase ≥250 U/L (HR 9.66, p = 0.02), stage III/IV PTLD (HR 5.34, p = 0.004), and HCV infection (HR 7.68, p = 0.01). In conclusion, PTLD in OLT adult recipients is predominantly extranodal, and although mortality is high, long‐term survival is possible. 相似文献
105.
Patricia do Socorro Queiroz Feio Camilla Borges Ferreira Gomes Alexandre Simões Nogueira Luciana Yamamoto Almeida José Vassallo Fernando Augusto Soares Oslei Paes Almeida Jorge Esquiche León 《Head and neck pathology》2013,7(3):258-262
The 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) has become a standard procedure for the diagnosis, staging, and restaging in lymphoma patients. However, a relative high rate of false-positive results has been reported. We report a case of a 40-year-old man with a previous history of a nodal follicular lymphoma, stage IVA, treated with R-CHOP, which showed strong 18F-FDG uptake in the Waldeyer’s tonsillar ring during his follow-up, being considered highly suspicious of relapsed lymphoma. A surgical removal of the palatine tonsils and adenoids was performed, which showed reactive follicular hyperplasia. Furthermore, bone marrow biopsy revealed absence of neoplasia. The patient is still in follow-up with no signs of recurrent lymphoma. This case illustrates that, despite the high sensitivity for the detection of recurrent lymphoma, 18F-FDG uptake should be interpreted with great caution and confirmatory studies should be performed before any therapy. 相似文献
106.
ObjectiveLow-level laser therapy (LLLT) has been reported to be responsible for promoting photostimulatory and photobiomodulatory effects in vivo and in vitro, stimulating cell growth, increasing cell metabolism, improving cell regeneration and invoking an anti-inflammatory response. This study was performed in order to investigate whether low-level laser therapy could increase the proliferation and differentiation potentials of hDPSC isolated from healthy dental pulps and from inflamed pulps.DesignHuman dental pulp stem cells (hDPSC) were isolated from normal and inflamed dental pulps from different patients. STRO-1-positive cells were isolated and irradiated with a red low-level laser (660 nm) in four different energy fluences (0.05, 0.30, 7 and 42 J/cm2); the authors hypothesized that the first three fluences would promote biostimulatory effects, whereas the highest dose would induce antiproliferative effects. The two lower fluences were produced by irradiating the two higher fluences through a dentine disc, which was used to simulate a clinical condition. The proliferation and the cell odonto-osteogenic differentiation competence were compared.ResultsNo statistically significant differences were observed between the proliferation rates and the relative productions of mineralized nodules compared to the respective controls, either for hDPSC from normal or inflamed dental pulps.ConclusionsThe irradiation with low-level InGaAlP red low-level laser (660 nm) in four different energy fluences (0.05, 0.30, 7 and 42 J/cm2) potentiated neither proliferation nor odonto-osteogenic differentiation of hDPSC isolated from patients with normal and inflamed pulps. 相似文献
107.
Osvaldo Vilela‐Filho Fernando P. Ferraz Breno A. Barros Luciana O. Silva Suzana F. Anunciação Joaquim T. Souza Delson J. Silva Mauricio B. Leite Ingrid B. Atayde Paulo C. Ragazzo Paula G. Barreto Mariana A. Nobrega Maisa R. Araujo Mayra R. Santos Victor H. Ala Stefano T. Queiroz 《Journal of neuroscience research》2013,91(10):1328-1337
Although long known and the most prevalent movement disorder, pathophysiology of essential tremor (ET) remains controversial. The most accepted hypothesis is that it is caused by a dysfunction of the olivocerebellar system. Vilela Filho et al. [2001; Stereotact Funct Neurosurg 77:149–150], however, reported a patient with unilateral hand ET that was completely relieved after a stroke restricted to the contralateral posterior putamen and suggested that ET could be the clinical manifestation of posterior putamen hyperactivity. The present study was designed to evaluate this hypothesis in the most often used model of ET, harmaline‐induced tremor in rats. Fifty‐four male Wistar rats were randomly distributed into three groups: experimental (EG), surgical control (SCG), and pharmacological control (PCG) groups. EG animals underwent stereotactic unilateral posterior striatotomy. SCG rats underwent sham lesion at the same target. PCG served exclusively as controls for harmaline effects. All animals received, postoperatively, intraperitoneal harmaline, and the induced tremor was video‐recorded for later evaluation by a blind observer. Thirteen animals were excluded from the study. Limb tremor was reduced ipsilaterally to the operation in 20 of 21 rats of EG and in two of nine of SCG, being asymmetric in one of 10 of PCG rats. Comparisons between EG × SCG and EG × PCG were statistically significant, but not between SCG × PCG. Limb tremor reduction was greater in anterior than in posterior paws. Lateral lesions yielded better results than medial lesions. These results suggest that the posterior striatum is involved with harmaline‐induced tremor in rats and support the hypothesis presented. © 2013 Wiley Periodicals, Inc. 相似文献
108.
Maria Aparecida Camargos Bicalho Fausto Aloísio Pimenta Luciana Bastos‐Rodrigues Érika de Oliveira Hansen Samara Canguçu Neves Marina Melo Daniela Valadão Rosa Renan Pedra de Souza Débora Marques de Miranda Edgar Nunes de Moraes Marco Aurélio Romano‐Silva Luiz De Marco 《International journal of geriatric psychiatry》2013,28(6):640-646
109.
Joseph Murray Luciana Anselmi Erika Alejandra Giraldo Gallo Bacy Fleitlich-Bilyk Isabel A. Bordin 《Social psychiatry and psychiatric epidemiology》2013,48(10):1527-1538
Purpose
This study aimed to review evidence on the prevalence of and risk factors for conduct problems in Brazil.Methods
We searched electronic databases and contacted Brazilian researchers up to 05/2012. Studies were included in the review if they reported the prevalence of or risk factors for conduct problems, conduct disorder, or oppositional defiant disorder for 100 + Brazilian children aged ≤18 years, systematically sampled in schools or the community. Prevalence rates and sex differences were meta-analysed. Risk factor studies were reviewed one by one.Results
The average prevalence of conduct problems in screening questionnaires was 20.8 %, and the average prevalence of conduct disorder/oppositional defiant disorder was 4.1 %. There was systematic variation in the results of screening studies according to methodology: recruitment location, informants, instruments, impairment criterion for case definition, and response rates. Risk factors previously identified in high-income countries were mainly replicated in Brazil, including comorbid mental health problems, educational failure, low religiosity, harsh physical punishment and abuse, parental mental health problems, single parent family, and low socioeconomic status. However, boys did not always have higher risk for conduct problems than girls.Conclusions
Studies using screening questionnaires suggest that Brazilian children have higher rates of conduct problems than children in other countries, but diagnostic studies do not show this difference. Risk factors in Brazil were similar to those in high-income countries, apart from child sex. Future research should investigate developmental patterns of antisocial behaviour, employ a variety of research designs to identify causal risk mechanisms, and examine a broader range of risk factors. 相似文献110.
Abou-Id LR Morgan LF Silva GA Poletto LT Lanza LD Albuquerque Rde C 《Brazilian dental journal》2012,23(2):116-121
This in vitro study evaluated the adhesive interface of intraradicular fiber glass posts and root dentin using scanning electron microscopy (SEM). Forty-eight single-rooted premolars were randomly divided into 6 groups consisting of chemical, dual, or light cured adhesive systems combined with either chemical or dual cure resin cements. Scanning electron microscopic analysis showed the best results for continuity, density and morphology of the hybrid layer and resin tags for the combination of a self-cure adhesive with self-cure cement resin, followed by a dual-cure adhesive with self-cure cement resin, and finally a light-cure adhesive with self-cure cement. For the dual-cure resin cement, the same relation may be observed. The apical third was the most critical region for evaluated the criteria for all combinations of materials (Kruskal-Wallis and Friedman tests; p<0.001). Generally, the simplification of steps in the adhesive system and the polymerization reaction of resin adhesives and cements produced a direct effect on the quality of the adhesive post/dentin substrate interface. 相似文献