全文获取类型
收费全文 | 5644篇 |
免费 | 328篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 77篇 |
儿科学 | 141篇 |
妇产科学 | 124篇 |
基础医学 | 822篇 |
口腔科学 | 368篇 |
临床医学 | 501篇 |
内科学 | 1311篇 |
皮肤病学 | 128篇 |
神经病学 | 576篇 |
特种医学 | 72篇 |
外科学 | 507篇 |
综合类 | 22篇 |
一般理论 | 2篇 |
预防医学 | 529篇 |
眼科学 | 71篇 |
药学 | 386篇 |
中国医学 | 39篇 |
肿瘤学 | 327篇 |
出版年
2024年 | 4篇 |
2023年 | 63篇 |
2022年 | 153篇 |
2021年 | 284篇 |
2020年 | 155篇 |
2019年 | 256篇 |
2018年 | 288篇 |
2017年 | 148篇 |
2016年 | 163篇 |
2015年 | 208篇 |
2014年 | 287篇 |
2013年 | 311篇 |
2012年 | 543篇 |
2011年 | 586篇 |
2010年 | 288篇 |
2009年 | 264篇 |
2008年 | 385篇 |
2007年 | 335篇 |
2006年 | 315篇 |
2005年 | 240篇 |
2004年 | 217篇 |
2003年 | 199篇 |
2002年 | 175篇 |
2001年 | 17篇 |
2000年 | 9篇 |
1999年 | 19篇 |
1998年 | 16篇 |
1997年 | 13篇 |
1996年 | 11篇 |
1995年 | 14篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 2篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有6003条查询结果,搜索用时 31 毫秒
151.
Mariana A. Coutinho-Myrrha Rosangela C. Dias Aline A. Fernandes Christiano G. Araújo Mark A. Hlatky Danielle G. Pereira Raquel R. Britto 《Arquivos brasileiros de cardiologia》2014,102(4):383-390
Background
The Duke Activity Status Index (DASI) assesses the functional capacity of patients with cardiovascular disease (CVD), but there is no Portuguese version validated for CVD.Objectives
To translate and adapt cross-culturally the DASI for the Portuguese-Brazil language, and to verify its psychometric properties in the assessment of functional capacity of patients with CVD.Methods
The DASI was translated into Portuguese, then checked by back-translation into English and evaluated by an expert committee. The pre-test version was first evaluated in 30 subjects. The psychometric properties and correlation with exercise testing was performed in a second group of 67 subjects. An exploratory factor analyses was performed in all 97 subjects to verify the construct validity of the DASI.Results
The intraclass correlation coefficient for test-retest reliability was 0.87 and for the inter-rater reliability was 0.84. Cronbach''s α for internal consistency was 0.93. The concurrent validity was verified by significant positive correlations of DASI scores with the VO2max (r = 0.51, p < 0.001). The factor analysis yielded two factors, which explained 54% of the total variance, with factor 1 accounting for 40% of the variance. Application of the DASI required between one and three and a half minutes per patient.Conclusions
The Brazilian version of the DASI appears to be a valid, reliable, fast and easy to administer tool to assess functional capacity among patients with CVD. 相似文献152.
Carlos Alberto de Castro Pereira Andrezza Araujo Oliveira Duarte Andrea Gimenez Maria Raquel Soares 《Jornal brasileiro de pneumologia》2014,40(4):397-402
OBJECTIVE:
To evaluate the spirometry values predicted by the 2012 Global Lung Function Initiative (GLI) equations, which are recommended for international use, in comparison with those obtained for a sample of White adults used for the establishment of reference equations for spirometry in Brazil.METHODS:
The sample comprised 270 and 373 healthy males and females, respectively. The mean differences between the values found in this sample and the predicted values calculated from the GLI equations for FVC, FEV1, and VEF1/FVC, as well as their lower limits, were compared by paired t-test. The predicted values by each pair of equations were compared in various combinations of age and height.RESULTS:
For the males in our study sample, the values obtained for all of the variables studied were significantly higher than those predicted by the GLI equations (p < 0.01 for all). These differences become more evident in subjects who were shorter in stature and older. For the females in our study sample, only the lower limit of the FEV1/FVC ratio was significantly higher than that predicted by the GLI equation.CONCLUSIONS:
The predicted values suggested by the GLI equations for White adults were significantly lower than those used as reference values for males in Brazil. For both genders, the lower limit of the FEV1/FVC ratio is significantly lower than that predicted by the GLI equations. 相似文献153.
154.
155.
Bajo R Castellanos NP López ME Ruiz JM Montejo P Montenegro M Llanero M Gil P Yubero R Baykova E Paul N Aurtenetxe S Del Pozo F Maestu F 《Age (Dordrecht, Netherlands)》2012,34(2):497-506
It is still an open question whether subjective memory complaints (SMC) can actually be considered to be clinically relevant predictors for the development of an objective memory impairment and even dementia. There is growing evidence that suggests that SMC are associated with an increased risk of dementia and with the presence of biological correlates of early Alzheimer's disease. In this paper, in order to shed some light on this issue, we try to discern whether subjects with SMC showed a different profile of functional connectivity compared with subjects with mild cognitive impairment (MCI) and healthy elderly subjects. In the present study, we compare the degree of synchronization of brain signals recorded with magnetoencephalography between three groups of subjects (56 in total): 19 with MCI, 12 with SMC and 25 healthy controls during a memory task. Synchronization likelihood, an index based on the theory of nonlinear dynamical systems, was used to measure functional connectivity. Briefly, results show that subjects with SMC have a very similar pattern of connectivity to control group, but on average, they present a lower synchronization value. These results could indicate that SMC are representing an initial stage with a hypo-synchronization (in comparison with the control group) where the brain system is still not compensating for the failing memory networks, but behaving as controls when compared with the MCI subjects. 相似文献
156.
Hernandez-Morante JJ Gomez-Santos C Margareto J Formiguera X Martínez CM González R Martínez-Augustín O Madrid JA Ordovas JM Garaulet M 《Age (Dordrecht, Netherlands)》2012,34(6):1369-1380
Menopausal women exhibit a loss of circadian coordination, a process that runs parallel with a redistribution of adipose tissue. However, the specific genetic mechanisms underlying these alterations have not been studied. Thus, the aim of the present study was to determine whether the development of menopause induces an alteration of the genes that control biological rhythms in human subcutaneous (SAT) and visceral (VAT) adipose tissue, and whether changes in clock gene expression are involved in the increased risk of developing metabolic syndrome (MetS), which is frequently associated with menopause. To this end, VAT and SAT biopsies were taken in pre- (n = 7) and postmenopausal (n = 7) women at similar hours in the morning. RNA was extracted, and a microarray analysis was made. Data were confirmed by quantitative real-time polymerase chain reaction. Western blot and immunohistochemical analysis were also performed. When clock gene expression was compared between both groups of women, data in SAT showed that expression of the core clock gene period3 was significantly higher in postmenopausal women, while casein kinase-1δ, E1A-binding protein and cAMP-responsive element were preferentially expressed in the premenopausal group. In VAT, period2 (PER2) and v-myc myelocytomatosis viral oncogene expressions were significantly higher in the postmenopausal group. Western blot analysis indicated that PER2 and PER3 protein expression was also increased in postmenopausal women. In addition, several genes, including PER2, were differentially expressed depending on whether or not the patient met the MetS criteria. We conclude that menopause transition induces several changes in the genotype of the adipose tissue chronobiological machinery related to an increased risk of developing MetS.
Electronic supplementary material
The online version of this article (doi:10.1007/s11357-011-9309-2) contains supplementary material, which is available to authorized users. 相似文献157.
Balaban R Aguiar CM da Silva Araújo AC Dias Filho EB 《International journal of paediatric dentistry / the British Paedodontic Society [and] the International Association of Dentistry for Children》2012,22(4):286-291
International Journal of Paediatric Dentistry 2012; 22: 286–291 Background. In dentistry, clinical practice is directed towards attitudes that promote oral health and the paediatricians occupy a privileged position in this process. Aim. To assess the knowledge and attitudes of paediatricians in relation to the oral health of their patients. Design. A cross‐sectional study was carried out at the Institute of Integrative Medicine Professor Fernando Figueira, Recife, Brazil. A total of 182 paediatricians participated by filling out a questionnaire. Results. A total of 63.9% believed the first visit to the dentist should occur before the child completes 1 year of life. Moreover, 67.8% considered their knowledge on oral health to be insufficient. Approximately 78% of the paediatricians diagnosed caries through an analysis of cavities. Only 29.9% always recommended fluoride dentifrice. The term ‘fluorosis’ was unknown by 48.3% of the respondents. Concerning pacifiers, 32.6% did not allow it and 66.9% did not either recommend it or restrict it. A total of 83.4% classified the oral health content in their medical education as either nonexistent or deficient; this figure remained high (72.4%) in relation to residency. Conclusions. It is important to develop oral health information programmes to paediatricians. Information on oral health should be included in medical curricula and residency. 相似文献
158.
Raquel Guijarro-Martínez Federico Hernández-Alfaro 《Journal of cranio-maxillo-facial surgery》2012,40(1):11-16
Background
Möbius sequence implies significant maxillofacial hard and soft tissue anomalies which nevertheless have not been addressed thoroughly in the scientific literature.Objectives
To report a case of complete Möbius sequence and discuss the management of maxillofacial hard and soft tissue anomalies.Patients and methods
A 15-year-old girl with complete Möbius underwent bimaxillary orthognathic surgery, horizontal sliding genioplasty and mentalis muscles reinsertion. Vestibuloplasty and bilateral canthopexy were performed to address lip deficiency and attenuate hypotonic depression of the lower eyelids, respectively. Cheekbone augmentation was achieved with an autologous fat transfer. The authors review the scientific literature and discuss surgical planning for the correction of maxillofacial discrepancy.Results
The patient exhibits significant functional and aesthetic improvement, with excellent integration of the transferred fat and adequate bone healing.Conclusions
Orthognathic bimaxillary surgery combined to soft tissue management can improve aesthetics and orofacial function in Möbius patients, thereby contributing to facilitate social interaction and increase patients’ self-esteem. 相似文献159.
Oyagüe RC Sánchez-Turrión A López-Lozano JF Montero J Albaladejo A Suárez-García MJ 《Odontology / the Society of the Nippon Dental University》2012,100(2):249-253
This study evaluated the vertical discrepancy of implant-fixed 3-unit structures. Frameworks were constructed with laser-sintered Co-Cr, and vacuum-cast Co-Cr, Ni-Cr-Ti, and Pd-Au. Samples of each alloy group were randomly luted in standard fashion using resin-modified glass-ionomer, self-adhesive, and acrylic/urethane-based cements (n = 12 each). Discrepancies were SEM analyzed. Three-way ANOVA and Student-Newman-Keuls tests were run (P < 0.05). Laser-sintered structures achieved the best fit per cement tested. Within each alloy group, resin-modified glass-ionomer and acrylic/urethane-based cements produced comparably lower discrepancies than the self-adhesive agent. The abutment position did not yield significant differences. All misfit values could be considered clinically acceptable. 相似文献
160.
Estrella Osorio Fátima S. Aguilera Raquel Osorio Franklin García-Godoy Miguel A. Cabrerizo-Vilchez Manuel Toledano 《Medicina oral, patología oral y cirugía bucal》2012,17(5):e833-e840
Objectives: This paper aims to assess the effectiveness of 3D nanoroughness and 2D microroughness evaluations, by their correlation with contact angle measurements and shear bond strength test, in order to evaluate the effect of two different acids conditioning on the bonding efficacy of a leucite-based glass-ceramic to a composite resin.
Study Design: Ceramic (IPS Empress) blocks were treated as follows: 1) no treatment, 2) 37% phosphoric acid (H3PO4), 15 s, 3) 9% hydrofluoric acid (HF), 5 min. Micro- and nano-roughness were assessed with a profilometer and by means of an atomic force microscopy (AFM). Water contact angle (CA) measurements were determined to assess wettability of the ceramic surfaces with the asixymetric drop shape analysis contact diameter technique. Shear bond strength (SBS) was tested to a resin composite (Z100) with three different adhesive systems (Scotchbond Multipurpose Plus, Clearfil New Bond, ProBOND). Scanning electron microscopy (SEM) images were performed.
Results: Nanoroughness values assessed in 50x50 μm areas were higher for the HF group, these differences were not detected by profilometric analysis. HF treatment created the nano- roughest surfaces and the smallest CA (p<0.05), producing the highest SBS to the composite resin with all tested adhesive systems (p<0.05). No differences existed between the SBS produced by the adhesive systems evaluated with any of the surface treatments tested.
Conclusions: Nano-roughness obtained in a 50x50 µm scan size areas was the most reliable data to evaluate the topographical changes produced by the different acid treatments on ceramic surfaces.
Key words:Dental ceramic, acid etching, bonding efficacy, resin composite, adhesive systems, contact angle, roughness. 相似文献