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   2341416篇
  免费   178997篇
  国内免费   5042篇
耳鼻咽喉   32279篇
儿科学   74445篇
妇产科学   65642篇
基础医学   334411篇
口腔科学   69448篇
临床医学   208801篇
内科学   451034篇
皮肤病学   51863篇
神经病学   183371篇
特种医学   90419篇
外国民族医学   406篇
外科学   359489篇
综合类   58409篇
现状与发展   6篇
一般理论   751篇
预防医学   177194篇
眼科学   56361篇
药学   174043篇
  7篇
中国医学   5432篇
肿瘤学   131644篇
  2018年   25099篇
  2017年   19286篇
  2016年   21346篇
  2015年   24489篇
  2014年   34366篇
  2013年   50794篇
  2012年   69675篇
  2011年   73425篇
  2010年   43298篇
  2009年   40524篇
  2008年   68578篇
  2007年   73463篇
  2006年   73758篇
  2005年   71054篇
  2004年   68896篇
  2003年   65667篇
  2002年   63295篇
  2001年   114460篇
  2000年   116964篇
  1999年   97103篇
  1998年   25356篇
  1997年   22170篇
  1996年   22108篇
  1995年   22423篇
  1994年   20844篇
  1993年   19433篇
  1992年   76149篇
  1991年   73906篇
  1990年   71540篇
  1989年   68863篇
  1988年   63432篇
  1987年   62123篇
  1986年   58621篇
  1985年   56089篇
  1984年   41978篇
  1983年   35749篇
  1982年   20949篇
  1981年   18926篇
  1979年   38905篇
  1978年   27348篇
  1977年   23159篇
  1976年   21484篇
  1975年   22924篇
  1974年   28060篇
  1973年   27044篇
  1972年   25480篇
  1971年   23640篇
  1970年   22206篇
  1969年   21024篇
  1968年   19386篇
排序方式: 共有10000条查询结果,搜索用时 18 毫秒
101.
Zygomatic implants (ZIs) are used for the oral rehabilitation of patients with maxillectomy defects as an alternative to extensive bone grafting surgeries. New technologies such as computer-assisted navigation systems can improve the accuracy and safety of ZI placement. The intraoral anchorage of fiducial markers necessary for navigation registration is not possible in the case of a severe maxillary defect and lack of residual bone. This technical note presents a novel extraoral registration method for a dynamic navigation system guiding ZI placement in patients with maxillectomy defects. Titanium microscrews were inserted in the mastoid process, supraorbital ridge, and posterior zygomatic arch as registration markers. The mean fiducial registration error (FRE) was 0.53 ± 0.20 and the deviations between the planned and placed ZIs were 1.56 ± 0.54 mm (entry point), 1.87 ± 0.63 mm (exit point), and 2.52 ± 0.84° (angulation). The study results indicate that the placement of fiducial markers at extraoral sites can be used as a registration technique to overcome anatomical limitations in patients after maxillectomy, with a clinically acceptable registration accuracy.  相似文献   
102.
The aim of this study was to analyse the effect of body mass index (BMI), both low and high values, on the perioperative complication rate in patients with oral squamous cell carcinoma (OSCC). The medical records of 259 patients operated between 2014 and 2017 for OSCC were reviewed. Univariate and multivariate analyses were performed. Sixty of the 259 patients developed 87 complications. Low or high BMI was not associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade. Low BMI, American Society of Anesthesiologists score 2 and 3, a longer operating time, and increased blood loss were associated with a longer hospital stay. Low BMI was associated with a longer hospital stay. Neither low nor high BMI was associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade.  相似文献   
103.
The contemporary literature is discordant regarding the role of delayed diagnosis in the prognosis of patients with oral cancer. This study examined data on a previously reported cohort of 101 patients with oral squamous cell carcinoma diagnosed at a single institution between 2008 and 2010. The time interval between symptom onset and initial histological diagnosis (diagnostic delay) was recorded for each patient, as were demographic data and cancer features such as T stage, nodal status, and smoking status. The mean follow-up period was 4 years 10 months. The mean diagnostic delay was 4 months, mean overall survival was 5 years 6 months, and mean disease-specific survival was 4 years 9 months. No significant correlation was found between diagnostic delay and overall survival, disease-specific survival, or recurrence rates. Patients with node-positive disease were more likely to be diagnosed earlier, whereas women and non-smokers were more likely to have a delayed diagnosis. Inherent tumour biology is likely an important prognostic factor separate to diagnostic delay. Public education efforts should focus on symptom recognition and encourage early presentation for investigation of oral lesions, particularly for females and non-smokers, so that more aggressive tumours can be treated sooner to give the best chance at survival.  相似文献   
104.
The selection and implementation of a plan for maxillary surgery is of the utmost importance in achieving the desired outcome for the patient undergoing two-jaw orthognathic surgery. Some splint-based and splintless methods, accompanied by computer-assisted techniques, are helpful in improving surgical plan implementation. However, randomized controlled trials focused on this procedure are lacking. This study included 61 patients who underwent bimaxillary surgeries. The patients were randomly assigned to a conventional resin occlusal splint (CROS) group, a digital occlusal splint (DOS) group, or a digital templates (DT) group, in a 1:1:1 ratio. The mean linear distance between the planned and actual postoperative positions of eight selected points on the surfaces of the maxillary teeth was selected as the outcome measure. The distance was significantly smaller in the DT group (1.17 ± 0.66 mm) when compared to both the CROS group (2.55 ± 0.95 mm, P < 0.05) and DOS group (2.15 ± 1.12 mm, P < 0.05). However, the difference between the CROS group and DOS group was not statistically significant. These findings indicate that using digital templates results in the best performance in transferring the surgical plan to the operation environment as compared to the other two types of splints. This suggests that the application of digital templates could provide a reliable treatment option.  相似文献   
105.
A local pedicled vascularized bone flap can prevent the morbidity and cost of free bone flap surgery in small segmental bone defects or long cartilaginous defects of the head and neck. Such flaps can also be useful in patients who are high risk for surgery. The periosteal vascularity of the mandible can be used to design islanded facial artery-based bone flaps, which can be utilized to that extent. Two patients with a small segmental mandibulectomy defect and one patient with a long cricotracheal resection defect underwent reconstruction using three different designs of islanded facial artery osteomyomucosal/osseous flap (iFOMM). The patients had a minimum follow-up period of 18 months. All flaps were successful, with satisfactory healing and without any functional deficit or disease at last follow-up.  相似文献   
106.
Dental caries continues to be a severe oral health problem despite a decrease in its prevalence over the past few decades. The contemporary philosophy of caries management has shifted from the traditional approach to a newer medical one, that frequently includes utilization of fluoridated and antimicrobial agents. Among these different agents, Silver Diamine Fluoride (SDF)1 has gained significant recognition. Dr Nishino and Dr Yamaga in Japan, pioneered its application to arrest caries. It is an alkaline, colourless solution composed of diamine-silver and fluoride ions having silver's antibacterial and fluoride's remineralising property. It has been used successfully to arrest and prevent caries in deciduous and permanent teeth, prevent recurrence of secondary caries and treat dentinal hypersensitivity. No adverse systemic effects due to SDF have been noted although black discolouration following its application has raised concerns. When used wisely it is an effective, sustainable and inexpensive option for children with high caries risk, for individuals who cannot endure conventional modalities of restorative treatment and those with special health-care needs. The current review is an insight into the clinical significance and application of SDF based on published literature.  相似文献   
107.
108.
109.
Journal of Neurology - To investigate associations of social support to psychological well-being, cognition, and motor functioning in patients with multiple sclerosis (MS). Secondarily, we were...  相似文献   
110.
European Child & Adolescent Psychiatry - There is growing evidence that adolescent positive attributes and social aptitudes are associated with beneficial outcomes, including higher educational...  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