全文获取类型
收费全文 | 2123篇 |
免费 | 147篇 |
国内免费 | 41篇 |
专业分类
耳鼻咽喉 | 30篇 |
儿科学 | 46篇 |
妇产科学 | 15篇 |
基础医学 | 269篇 |
口腔科学 | 309篇 |
临床医学 | 205篇 |
内科学 | 391篇 |
皮肤病学 | 37篇 |
神经病学 | 124篇 |
特种医学 | 78篇 |
外科学 | 279篇 |
综合类 | 32篇 |
一般理论 | 2篇 |
预防医学 | 176篇 |
眼科学 | 68篇 |
药学 | 128篇 |
中国医学 | 12篇 |
肿瘤学 | 110篇 |
出版年
2023年 | 21篇 |
2022年 | 40篇 |
2021年 | 71篇 |
2020年 | 45篇 |
2019年 | 64篇 |
2018年 | 78篇 |
2017年 | 70篇 |
2016年 | 65篇 |
2015年 | 84篇 |
2014年 | 104篇 |
2013年 | 125篇 |
2012年 | 149篇 |
2011年 | 169篇 |
2010年 | 90篇 |
2009年 | 94篇 |
2008年 | 136篇 |
2007年 | 120篇 |
2006年 | 105篇 |
2005年 | 99篇 |
2004年 | 86篇 |
2003年 | 46篇 |
2002年 | 39篇 |
2001年 | 32篇 |
2000年 | 34篇 |
1999年 | 30篇 |
1998年 | 31篇 |
1997年 | 27篇 |
1996年 | 22篇 |
1995年 | 20篇 |
1994年 | 17篇 |
1993年 | 8篇 |
1992年 | 24篇 |
1991年 | 24篇 |
1990年 | 11篇 |
1989年 | 15篇 |
1988年 | 18篇 |
1987年 | 7篇 |
1986年 | 12篇 |
1985年 | 10篇 |
1983年 | 6篇 |
1982年 | 3篇 |
1979年 | 5篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1976年 | 4篇 |
1975年 | 8篇 |
1974年 | 4篇 |
1969年 | 3篇 |
1968年 | 2篇 |
1967年 | 4篇 |
排序方式: 共有2311条查询结果,搜索用时 16 毫秒
71.
Ni Sann Khin Sze Huey Tan Michael LC Wang Tian Rui Siow Faye LWT Lim Fu Qiang Wang Matthew CH Ng Justina YC Lam Connie Yip 《The British journal of radiology》2021,94(1122)
Objective:Chemoradiation (CRT) may induce a change in systemic inflammatory state which could affect clinical outcomes in oesophageal cancer. We aimed to evaluate the changes and prognostic significance of systemic inflammatory markers following definitive CRT in oesophageal squamous cell carcinoma.Methods:A total of 53 patients treated with concurrent CRT were included in this retrospective analysis. We compared neutrophils, lymphocytes, platelets, neutrophil–lymphocyte ratio (NLR) and platelet–lymphocyte ratio (PLR) before and after CRT using Wilcoxon signed-rank test. Overall survival (OS) and progression-free survival (PFS) were calculated. Univariable and multivariable survival analysis were performed using Cox regression analysis. Clinical univariable survival prognostic factors with p < 0.1 were included in a multivariable cox regression analysis for backward stepwise model selection.Results:Both NLR (median ∆+2.8 [IQR −0.11, 8.62], p < 001) and PLR (median ∆+227 [81.3–523.5], p < 0.001) increased significantly after CRT. Higher levels of pre-CRT, post-CRT and change (∆) in NLR and PLR were associated with inferior OS and PFS. Post-CRT NLR (HR 1.04, 95% CI 1.02–1.07, p < 0.001), post-CRT platelets (HR 1.03, 95% CI 1.01–1.05, p = 0.005), cT-stage (HR 3.83, 95% CI 1.39–10.60, p = 0.01) and RT dose (HR 0.41, 95% CI 0.21–0.81, p = 0.01) were independent prognostic factors for OS in multivariable analysis. Change in NLR (HR 1.04, 95% CI 1.01–1.06, p = 0.001), post-CRT platelets (HR 1.03, 95% CI 1.01–1.05, p = 0.002), cT-stage (HR 3.98, 95% CI 1.55–10.25, p = 0.004) and RT dose (HR 0.41, 95% CI 0.21–0.80, p = 0.009) were independent prognostic factors for PFS.Conclusion:Both NLR and PLR increased following definitive CRT. Post-CRT NLR and ∆NLR were associated with adverse survival in oesophageal SCC.Advances in knowledge:We showed that CRT increased PLR and NLR, possibly reflecting a systemic inflammatory state which were associated with poor clinical outcomes in oesophageal SCC. 相似文献
72.
Eduarda Helena Leandro Nascimento Rocharles Cavalcante Fontenele Priscila de Azeredo Lopes Gustavo Machado Santaella Karla Faria Vasconcelos Deborah Queiroz de Freitas Anne Caroline Oenning Francisco Carlos Groppo 《Dento maxillo facial radiology》2021,50(3)
Objectives:To present the ballistic gelatin as a new material capable of simulating the soft tissues in cone-beam CT (CBCT) images.Methods:CBCT images of three piglet heads were acquired with their soft tissues intact (standard group). Subsequently, the piglet heads were fixed in a container using metallic pins and moulded with acrylic resin; the soft tissues were then removed and replaced by ballistic gelatin, with the same thickness of the original soft tissues. The images were evaluated by two oral radiologists, to check the adaptation on bone surfaces, thickness and density, penetration into large bone cavities and cancellous bone, and the presence of air bubbles using a 5-score scale. Additionally, an objective analysis was carried out by one oral radiologist. For each CBCT scan, three axial reconstructions were selected to represent the mandibular, occlusal, and maxillary levels. The mean and standard deviation (SD) of the grey values were calculated in four regions of interest determined on soft tissue areas and compared by two-way ANOVA.Results:The ballistic gelatin showed subjective scores ranging from good to excellent for all parameters evaluated. There was no significant difference in the mean and SD values of the grey values between ballistic gelatin and the gold standard groups for all levels (p > 0.05). Higher SD values were observed in the occlusal level for both groups (p < 0.05).Conclusions:Ballistic gelatin has visual and objective similarity with the gold standard. Thus, the ballistic gelatin is a promising material capable of simulating soft tissues in CBCT images. 相似文献
73.
Guilherme Faria Moura Rafael Siqueira Luiz Meirelles Bartosz Maska Hom-Lay Wang Gustavo Mendonça 《The Journal of prosthetic dentistry》2021,125(5):726-731
The traditional protocol for guided surgery in a completely edentulous patient is time-consuming, requiring the fabrication of a radiographic guide and a dual cone beam computed tomography (CBCT) scan. Using intraoral scanners to scan the edentulous ridge and the existing denture has been advocated to simplify the process. This technique offers a versatile, precise, and predictable method for the digital planning workflow in edentulous patients for either a fixed or removable restoration. In addition, this approach can help improve the quality of the guide produced by reducing CBCT artifacts associated with the existing denture, as well as capture the soft-tissue contour to further improve the fit of the surgical guide. 相似文献
74.
Cintra Luciano Tavares Angelo Gomes Maximiliano Schünke da Silva Cristiane Cantiga Faria Flávio Duarte Benetti Francine Cosme-Silva Leopoldo Samuel Renata Oliveira Pinheiro Tiago Novaes Estrela Carlos González Alvaro Cruz Segura-Egea Juan José 《Odontology / the Society of the Nippon Dental University》2021,109(4):741-769
Odontology - Endodontics has gained emphasis in the scientific community in recent years due to the increase in clinical and in animal models studies focused on endodontic medicine, which aims to... 相似文献
75.
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
76.
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
77.
78.
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.
79.
80.
Objective:To investigate the wound healing properly of Napoleona vogelii leaf extract in folkloric medicine.Methods:Roth sexes of adult albino rats(n=25) were used in this study and another group(n=30) were subjected to acute toxicity test(LD_(50)) of the plant extract.For the LD_(50),three randomized groups of 5 rats were first treated with 10,100,1 000 mg/kg body weight(bw),orally.This w as followed by a second treatment of 1500,3000,and 5 000 mg/kg bw of the leaf extract with continual monitoring of the animals for mortality or non-mortality.Incision wounds(1.3cm) were created on the skin of five groups of 5 rals using surgical blade under anesthesia.The first group was topically treated with petroleum jelly alone,group 2 was topically applied 400 mg/mL w/v of the reference drug,Neobaein,while group 3-5 were topically treated with 5-50 mg/mL w/v of the plant extract,respectively.Results:The percentage yield of the extract was 49.80%w/w dry matter.The phytochemical analysis revealed several bioactive constituents including glycosides,tannins,alkaloids,perpenoids.saponins,steroids,proteins,and carbohydrates.The LD_(50) was beyond our experimental limit and was not determined.Increased concentrations(5,20,and 50mg/mL w/v) of the extract had significant(ANOVA,P0.05) healing effect on the incision wounds giving rise to 125%-140% while treatmentawith Neobacin resulted in 150% healing effect on the third treatment regimen compared to the control(100%).Conclusions:These data indicate that Napoleona vogelii leaf extract contains potent bioactive compounds containing wound healing activity,substantiating its use as a wound healer in folkloric medicine. 相似文献