全文获取类型
收费全文 | 1928篇 |
免费 | 131篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 30篇 |
儿科学 | 32篇 |
妇产科学 | 16篇 |
基础医学 | 246篇 |
口腔科学 | 291篇 |
临床医学 | 159篇 |
内科学 | 341篇 |
皮肤病学 | 30篇 |
神经病学 | 124篇 |
特种医学 | 54篇 |
外科学 | 263篇 |
综合类 | 14篇 |
一般理论 | 2篇 |
预防医学 | 180篇 |
眼科学 | 68篇 |
药学 | 115篇 |
中国医学 | 11篇 |
肿瘤学 | 97篇 |
出版年
2023年 | 22篇 |
2022年 | 33篇 |
2021年 | 77篇 |
2020年 | 46篇 |
2019年 | 61篇 |
2018年 | 73篇 |
2017年 | 68篇 |
2016年 | 61篇 |
2015年 | 82篇 |
2014年 | 105篇 |
2013年 | 117篇 |
2012年 | 151篇 |
2011年 | 171篇 |
2010年 | 82篇 |
2009年 | 84篇 |
2008年 | 133篇 |
2007年 | 109篇 |
2006年 | 101篇 |
2005年 | 87篇 |
2004年 | 84篇 |
2003年 | 46篇 |
2002年 | 32篇 |
2001年 | 25篇 |
2000年 | 30篇 |
1999年 | 22篇 |
1998年 | 10篇 |
1997年 | 9篇 |
1996年 | 6篇 |
1995年 | 7篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 21篇 |
1991年 | 21篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 13篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 6篇 |
1983年 | 6篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 4篇 |
1975年 | 5篇 |
1974年 | 4篇 |
1973年 | 2篇 |
1971年 | 2篇 |
1969年 | 3篇 |
1968年 | 2篇 |
1967年 | 4篇 |
排序方式: 共有2073条查询结果,搜索用时 31 毫秒
61.
Estela Kaminagakura Patrícia Luciana Batista Domingos Marize Raquel Diniz da Rosa Adriano Mota Loyola Sérgio Vitorino Cardoso Maria Cândida de Almeida Lopes Paulo Rogério Ferreti Bonan Paulo Rogério de Faria 《Annals of diagnostic pathology》2013,17(6):514-517
Calcifying cystic odontogenic tumors (CCOTs) are benign cystic lesions of odontogenic origin characterized by an ameloblastoma-like epithelium and the presence of a group of cells named ghost cells. The pattern of cytokeratin (Ck) expression on these lesions remains unclear and needs to be clarified. To this end, the expression of Ck6, Ck13, Ck14, Ck18, and Ck19 in the epithelium lining of 7 cases of CCOTs was evaluated by immunohistochemistry. For this, the epithelium lining was divided into 3 distinct regions: basal layer, suprabasal layer, and the compartment composed of ghost cells. In this study, 6 cases (85.7%) were classified as type 1 and 1 (14.3%) as type 4. All cases were negative for Ck13 and Ck18, despite the epithelial layer, as well as in the ghost cells. Ck6 was only positive in the ghost cells. Positivity for Ck14 and Ck19 was found in the basal and suprabasal layers, including the ghost cells. The results showing positivity for Ck14 and Ck19 in all of the analyzed cases reinforce CCOT as being of odontogenic origin, and the restricted expression of Ck6 in the ghost cells may be indicative that these cells suffer an altered differentiation into hair follicles in CCOTs. 相似文献
62.
Cunha Hugo Santos da Costa Moraes Cícero André de Faria Valle Dornelles Rodrigo da Rosa Everton Luis Santos 《Oral and maxillofacial surgery》2021,25(3):319-335
Oral and Maxillofacial Surgery - To assess whether virtual simulations of the projection of the soft tissues of the face after class II bimaxillary orthognathic surgery, generated from 3D... 相似文献
63.
64.
Isabel Mesquita Patrícia Coutinho Luciana De Martin-Silva Bruno Parente Mário Faria José Afonso 《Journal of Sports Science and Medicine》2015,14(3):657-668
This study aimed to examine the indirect teaching strategies adopted by a coach educator in terms of promoting student-coaches’ engagement in a positive and active learning environment. The participants were an expert coach educator and seven student-coaches from an academic coaching setting. A mix method approach was used to collect data. Whilst video-recording and participant observations were used to collect data from the lessons, focus groups were adopted to recall the perceptions of student-coaches. The results showed that indirect teaching strategies (i.e., asking questions, showing signs of autonomy by monitoring the pace at which they completed tasks and actively engaging in the search for solutions to tasks) implemented by the coach educator promoted a supportive and challenging learning environment which, in turn, encouraged student-coaches to be more actively involved in the lessons. Additionally, the affective aspects of the relationship established with student-coaches (tone of voice, gestures, facial expressions, eye contact, physical contact and humor) led them to feel confident in exposing their doubts and opinions, and in learning in a more autonomous manner. Moreover, the practical lessons proved to be crucial in helping student-coaches to reach broader and deeper forms of understanding by allowing the application of theory to coaching practice. In conclusion, this study reinforces the value of indirect teaching strategies to stimulate an active learning environment. It further highlights the value of practical learning environments to better prepare neophyte coaches for dealing with the complex and dynamic nature of their professional reality.
Key points
- Both instructional and affective teaching indirect strategies used by the coach educator promoted a positive and challenging learning environment to student-coaches.
- The directness profile used by this coach educator (questioning, giving autonomy for problem solving and responsibility to regulate the learning tasks development) promoted the awareness and the ability of student-coaches to explore alternative solutions and self-regulate their own learning.
- Using humor, touch, gestures and tone of voice, the coach educator showed great care for student-coaches, which impacted positively on their enthusiasm, confidence and desire to be actively engaged in their own learning.
65.
66.
Aliani Moura Fonseca Angélica Rosa Faria Fernandes Tenório Gomes Rodrigues Ronaldo Alves Pinto Nagem Rubens Daniel Miserani Magalhães João Luís Reis Cunha Daniella Castanheira Bartholomeu Hélida Monteiro de Andrade 《Acta tropica》2014
Visceral leishmaniasis (VL) is a neglected disease and is fatal if untreated. Dogs serve as reservoirs for Leishmania infantum (syn. L. chagasi) due to their susceptibility to infection and high skin parasitism. Therefore, VL control in Brazil involves the elimination of seropositive dogs, among other actions. However, the most frequently used serological tests have limitations regarding sensitivity and specificity. In this study, we have selected three Leishmania antigens (C1, C8 and C9) and have produced them as recombinant proteins using pET-28a-TEV vector and Escherichia coli BL-21 as expression system. When tested in ELISA with human samples, the C9 antigen was the one showing the most promising results, with 68% sensitivity and 78% specificity. When testing canine samples, the C1, C8 and C9 antigens showed a sensitivity range from 70% to 80% and specificity range from 60% to 90%. The C1 antigen presented higher sensitivity (80%) and the C8 antigen presented higher specificity (90%). Due to it, we decided to mix and test C1 and C8 antigens together, resulting in the C18 antigen. The mix also yielded high percentages of detected symptomatic and asymptomatic dogs however it did not improve the performance of the diagnostic. Comparison of our tests with the tests recommended by the Brazilian Ministry of Health revealed that our antigens’ sensitivities and the percentage of detected asymptomatic dogs were much higher. Our results suggest that the C1, C8, C18 and C9 recombinant proteins are good antigens to diagnose canine visceral leishmaniasis and could potentially be used in screening tests. To diagnose human visceral leishmaniasis, the C9 antigen presented reasonable results, but more optimization must be performed for this antigen to provide better performance. 相似文献
67.
68.
69.
Servato JP de Souza PE Horta MC Ribeiro DC de Aguiar MC de Faria PR Cardoso SV Loyola AM 《International journal of oral and maxillofacial surgery》2012,41(6):768-773
This study describes the oral and maxillofacial pathological characteristics of a series of odontogenic tumours in children and adolescents from three Brazilian reference centres. The records were reviewed for all odontogenic tumours in patients up to 18 years old based on criteria proposed by the World Health Organization (WHO) in 2005. Data concerning sex, age, skin colour and tumour location were collected and plotted. Four hundred and thirty one odontogenic tumours in children and adolescents were found, accounting for 37.5% of the total number of odontogenic tumours diagnosed. Benign tumours were predominant (99.8% of the cases), and odontoma was the most frequent type (41.4%), followed by keratocystic odontogenic tumours (25.5%) and ameloblastoma (14.6%). Odontogenic tumours were rarely detected in early childhood, and their prevalence increased with age. An almost equal distribution was observed with respect to sex and the site of the lesions. This study is the largest reported retrospective analysis describing odontogenic tumours in children and adolescents to date. The authors detected some variation in the relative frequency of odontogenic tumours compared with similar reports. Additional studies should be conducted based on the new WHO classification and predetermined age parameters to enable comparative analysis among different worldwide populations. 相似文献
70.
Marques DN da Mata AD Silveira JM Marques JR Amaral JP Guilherme NF 《Clinical oral investigations》2012,16(1):155-163
The objective of this study is to compare salivary hydrogen peroxide (HP) release kinetics and potential toxicity of systemic
exposure of four different whitening products. A double-blind, randomized controlled trial was conducted in a Portuguese dental
faculty clinic. Two hundred forty volunteers were randomized to eight intervention groups. Participants were randomly assigned
to receive active or placebo applications of one of four different products: Opalescence 10% PF™ (OPL), Vivastyle? 10%™ (VS10%),
Vivadent Paint On Plus™ (PO+), and Trés White Supreme™ (TWS). Saliva collection was obtained by established methods at different
times. The HP salivary content was determined by a photometric method. Salivary HP variations, total amount of salivary HP,
and counts of subjects above the safe daily HP dose were the main outcome measures. All whitening systems significantly released
HP to the saliva when compared to placebo, and all showed different release kinetics. The adaptable tray system (TWS) presented
a risk increase of 37% [20–54%, 95% confidence interval] when compared to the other systems. The use of an adaptable tray
whitening system with higher concentration of HP increases the toxicity potential. 相似文献