首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   14203篇
  免费   667篇
  国内免费   393篇
耳鼻咽喉   36篇
儿科学   93篇
妇产科学   6篇
基础医学   594篇
口腔科学   480篇
临床医学   1138篇
内科学   324篇
皮肤病学   8篇
神经病学   106篇
特种医学   915篇
外科学   7457篇
综合类   2258篇
预防医学   433篇
眼科学   67篇
药学   889篇
  11篇
中国医学   359篇
肿瘤学   89篇
  2024年   19篇
  2023年   148篇
  2022年   334篇
  2021年   507篇
  2020年   442篇
  2019年   394篇
  2018年   411篇
  2017年   473篇
  2016年   579篇
  2015年   529篇
  2014年   1311篇
  2013年   1182篇
  2012年   1119篇
  2011年   1167篇
  2010年   901篇
  2009年   957篇
  2008年   717篇
  2007年   702篇
  2006年   668篇
  2005年   591篇
  2004年   441篇
  2003年   322篇
  2002年   260篇
  2001年   202篇
  2000年   167篇
  1999年   132篇
  1998年   79篇
  1997年   56篇
  1996年   42篇
  1995年   31篇
  1994年   39篇
  1993年   34篇
  1992年   32篇
  1991年   25篇
  1990年   19篇
  1989年   14篇
  1988年   24篇
  1987年   19篇
  1986年   6篇
  1985年   17篇
  1984年   13篇
  1983年   15篇
  1982年   27篇
  1981年   20篇
  1980年   15篇
  1979年   12篇
  1978年   14篇
  1977年   8篇
  1976年   12篇
  1975年   11篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
颧上颌复合体骨折的诊断与治疗   总被引:6,自引:0,他引:6  
颧上颌复合体是面部最突出的部位之一,由于其解剖部位的特殊性,颧上颌复合体骨折在面中部骨折中占有相当大的比例。骨折后不仅引起局部凹陷畸形,甚至导致开口受限、复视等功能障碍。作者结合文献复习和临床经验,对颧上颌复合体骨折的原因、临床表现、治疗方法、手术入路和术后并发症等进行了讨论。认为眉侧切口联合口内切口入路,可以避免冠状切口的种种弊端。此法可在直视下开放复位,较好地暴露颧骨、上颌骨连接处及眶下区骨折,切断颧骨咬肌附丽,松解颧骨骨折块,再进行内固定,效果良好。手术后瘢痕小,面神经功能无损伤,外形及功能恢复良好,值得推广。  相似文献   
72.
Abstract – This retrospective study consisted of 400 root‐fractured, splinted or non‐splinted incisors in young individuals aged 7–17 years (mean = 11.5 ± 2.7 SD) who were treated in the period 1959–1995 at the Department of Pediatric Dentistry, Eastman Dental Institute, Stockholm. Four hundred of these root fractures were diagnosed at the time of injury; and 344 teeth were splinted with either cap‐splints, orthodontic appliances, bonded metal wires, proximal bonding with composite resin or bonding with a Kevlar® or glass fiber splint. In 56 teeth, no splinting was carried out for various reasons. In the present study, only pre‐injury and injury factors were analyzed. In a second study, treatment variables will be analyzed. The average observation period was 3.1 years ± 2.6 SD. The clinical and radiographic findings showed that 120 teeth out of 400 teeth (30%) had healed by hard tissue fusion of the fragments. Interposition of periodontal ligament (PDL) and bone between fragments was found in 22 teeth (5%), whereas interposition of PDL alone was found in 170 teeth (43%). Finally, non‐healing, with pulp necrosis and inflammatory changes between fragments, was seen in 88 teeth (22%). In a univariate and multivariate stratified analysis, a series of clinical factors were analyzed for their relation to the healing outcome with respect to pulp healing vs. pulp necrosis and type of healing (hard tissue vs. interposition of bone and/or PDL or pulp necrosis). Young age, immature root formation and positive pulp sensibility at the time of injury were found to be significantly and positively related to both pulpal healing and hard tissue repair of the fracture. The same applied to concussion or subluxation (i.e. no displacement) of the coronal fragment compared to extrusion or lateral luxation (i.e. displacement). Furthermore, no mobility vs. mobility of the coronal fragment. Healing was progressively worsened with increased millimeter diastasis between fragments. Sex was a significant factor, as girls showed more frequent hard tissue healing than boys. This relationship could possibly be explained by the fact that girls experienced trauma at an earlier age (i.e. with more immature root formation) and their traumas were of a less severe nature. Thus, the pre‐injury or injury factors which had the greatest influence upon healing (i.e. whether hard tissue fusion or pulp necrosis) were: age, stage of root development (i.e. the size of the pulpal lumen at the fracture site) and mobility of the coronal fragment, dislocation of the coronal fragment and diastasis between fragments (i.e. rupture or stretching of the pulp at the fracture site).  相似文献   
73.
为寻找理想的单颌外固定方法,作者自制舌翼(牙合)垫夹板作单颌固定治疗牙列段下颌骨折。临床应用30例,其中单线骨折11例,双线骨折3例,粉碎骨折16例,取得全部治愈,一年复查疗效满意。讨论了其作用机理,适应证和优缺点。认为本法是一种可行的较好方法。  相似文献   
74.
Abstract This study was conducted to determine the effectiveness of a method to prevent intracanal breakage of endodontic files. An application schedule with a predetermined number of periods of use for K-files of all sizes was implemented at the author's clinic for a 3-year period. All the files used under this schedule were discarded after the predetermined periods of use, whether they displayed any deformity or not. During the 3-year period, 1933 files (53.7 per month) were discarded after preparation of 3269 root canals. There were 5 file fractures (0.1 per month) compared with 1.4 fractures per month before the adaption of this system. The monthly average of files discarded during the 3-year research period was 53.7. Before the adoption of the trial system, the monthly average of discarded files was 76.5. It is concluded that the experimental system effectively reduced the incidence of intracanal instrument fractures and the total number of files consumed.  相似文献   
75.
A retrospective study of 22 root fractures in 21 patients was performed. Ten patients were less than 11 years of age, and boys were involved more often than girls. Ten patients had more than one injured tooth, but there was no case of alveolar fracture. Twenty-one of the teeth were upper central incisors. Only 11 teeth were seen within the first week, so that not all teeth were splinted and not all displaced teeth were repositioned. Long-term clinical and radiographic review showed that loss of vitality of the coronal pulp could not be reliably detected for at least 1 year. No tooth became abscessed or developed a sinus tract, and resorption of bone at the fracture line was observed in only one out of five non-vital teeth. Lack of displacement and placing of a splint increased the chances of the pulp remaining vital and healing of the fracture occurring with hard tissue. Sclerosis of the coronal pulp occurred mainly when healing was by connective tissue. The apical pulp always remained vital, and there was sclerosis of the apical pulp in almost every case.  相似文献   
76.
目的:探讨下颌下径路经口气管内插管在复杂颌面部骨折治疗中的应用。方法:对16例颌面部复杂骨折患者实施下颌下径路经口气管内插管麻醉,术中使用自行研制的引管装置辅助引管。结果:16例患者均一次引管成功,在无麻醉干扰的状态下顺利完成手术。术后未发现严重并发症。结论:下颌下径路经口气管内插管操作简便、安全、创伤小,避免了麻醉导管对口腔手术野的干扰,是对传统麻醉插管方式的改进和补充,是复杂面部骨折手术麻醉的较好选择。  相似文献   
77.
螺旋CT及三维重建技术在髁突骨折中的临床应用   总被引:5,自引:2,他引:5  
目的:研究螺旋CT及三维重建技术在髁突骨折中的诊断价值和对治疗的指导作用。方法:对58例75侧髁突骨折通过三维螺旋CT技术进行扫描检查。结果:螺旋CT及三维重建技术可以确诊髁突骨折并明确骨折的部位、旋转、方向、移位情况等,对治疗方法和手术方案的选择有重要的参考意义。结论:螺旋CT及三维重建技术能全面而直观的显示髁突骨折的情况,对髁突骨折的诊断、治疗方案的确定和疗效的评价有重要作用。  相似文献   
78.
小型钛板内固定治疗下颌骨骨折   总被引:15,自引:1,他引:15  
目的:评估小型钛板内固定治疗下颌骨骨折的临床疗效。方法:对68例下颌骨骨折的患者行切开复位术,使用小型钛板内固定,保留骨折线上的牙齿。结果:68例患者创口均I期愈合,骨折愈合良好,64例恢复到术前咬合关系,仅4例出现咬合关系不良。结论:小型钛板内固定具有良好的稳定性,缩短了领间固定的时间,可早期恢复张口运动,对骨折线上牙齿可以保留,是一种较好的下颌骨骨折内固定方法。  相似文献   
79.
Abstract The prevalence and yearly incidence of traumatic tooth injury between 1 and 16 years of age were studied in a cohort of 16 year-olds, born in 1975, and residing in the County of Västerbotten, northern Sweden. The study comprised 3007 dental records from the public denial health service. The general distribution was 50.3% girls and 49.7% boys. The records showed that 35% of the children on one or more occasions had sustained injury to their primary or permanent dentition. The frequency was nearly twice as high for boys (64%) as for girls (36%). Twenty-five percent of the 16-year-olds had met with tooth injury more than once and this group consisted predominantly of boys. The incidence of injury episodes to primary and permanent teeth was 28 per 1000 per year. The boys had sustained trauma to their teeth most frequently when they were 4 years of age and between the ages of 8 and 11. This was also true for girls at 4 and at 9 years of age, although less evidently so. In the primary dentition, the majority of dental injuries had affected the supporting tissue of the maxillary incisors. In the permanent dentition, 75% of the traumatised teeth were upper incisors. Fractures of varying severity constituted 60% of all registered diagnoses in this dentition, followed by subluxation (19%) and concussion (11%).  相似文献   
80.
Clinical and epidemiological study of traumatic root fractures   总被引:2,自引:1,他引:2  
Abstract    The aim of this work was to study the prevalence and clinical presentation of root fractures in a series of patients with dental trauma. Treatment strategies were classified and outcomes after a 6-month period presented. The study population comprised 76 patients (between the ages of 2 and 55 years) with 93 root fractures in their teeth (18 primary, 75 permanent). Data were collected following the taking of a detailed clinical history, objective clinical examination and photographic and radiological investigation. Since most of the primary teeth were extracted, only cases with root fracture of permanent teeth were followed-up: in all, 24 patients with 31 teeth with root fractures. The prevalence of root fractures in permanent teeth was 7.7% of all injuries, while in primary teeth it was 3.8%. The most frequently involved teeth were the maxillary incisors with a percentage of 75% in permanent teeth. Moreover, 40% of root fractures in permanent teeth were associated with fracture of the alveolar bone and of the soft tissues and in 45% of cases, the adjacent teeth were also injured. The results of this study reaffirm the necessity for scrupulous diagnosis of teeth after a traumatic injury. Adjacent teeth and those in the opposing arch should not be ignored. Treatment is multi-disciplinary, requiring surgical, orthodontic, operative and prosthetic compliance. Periodic check-up is essential.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号