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   200篇
  免费   15篇
儿科学   11篇
基础医学   20篇
口腔科学   54篇
临床医学   22篇
内科学   24篇
神经病学   4篇
特种医学   2篇
外科学   30篇
综合类   1篇
预防医学   19篇
眼科学   2篇
药学   9篇
肿瘤学   17篇
  2023年   2篇
  2022年   3篇
  2021年   4篇
  2020年   4篇
  2019年   6篇
  2018年   15篇
  2017年   7篇
  2016年   3篇
  2015年   7篇
  2014年   6篇
  2013年   15篇
  2012年   17篇
  2011年   17篇
  2010年   14篇
  2009年   4篇
  2008年   4篇
  2007年   7篇
  2006年   6篇
  2005年   17篇
  2004年   18篇
  2003年   9篇
  2002年   17篇
  2001年   3篇
  2000年   1篇
  1999年   2篇
  1995年   1篇
  1994年   1篇
  1992年   1篇
  1991年   3篇
  1980年   1篇
排序方式: 共有215条查询结果,搜索用时 46 毫秒
1.
2.
Pain sensitivity varies substantially among humans. A significantpart of the human population develops chronic pain conditionsthat are characterized by heightened pain sensitivity. We identifiedthree genetic variants (haplotypes) of the gene encoding catecholamine-O-methyltransferase(COMT) that we designated as low pain sensitivity (LPS), averagepain sensitivity (APS) and high pain sensitivity (HPS). We showthat these haplotypes encompass 96% of the human population,and five combinations of these haplotypes are strongly associated(P=0.0004) with variation in the sensitivity to experimentalpain. The presence of even a single LPS haplotype diminishes,by as much as 2.3 times, the risk of developing myogenous temporomandibularjoint disorder (TMD), a common musculoskeletal pain condition.The LPS haplotype produces much higher levels of COMT enzymaticactivity when compared with the APS or HPS haplotypes. Inhibitionof COMT in the rat results in a profound increase in pain sensitivity.Thus, COMT activity substantially influences pain sensitivity,and the three major haplotypes determine COMT activity in humansthat inversely correlates with pain sensitivity and the riskof developing TMD.  相似文献   
3.
4.

Assessment of size and growth are key radiological factors in low-grade gliomas (LGGs), both for prognostication and treatment evaluation, but the reliability of LGG-segmentation is scarcely studied. With a diffuse and invasive growth pattern, usually without contrast enhancement, these tumors can be difficult to delineate. The aim of this study was to investigate the intra-observer variability in LGG-segmentation for a radiologist without prior segmentation experience. Pre-operative 3D FLAIR images of 23 LGGs were segmented three times in the software 3D Slicer. Tumor volumes were calculated, together with the absolute and relative difference between the segmentations. To quantify the intra-rater variability, we used the Jaccard coefficient comparing both two (J2) and three (J3) segmentations as well as the Hausdorff Distance (HD). The variability measured with J2 improved significantly between the two last segmentations compared to the two first, going from 0.87 to 0.90 (p?=?0.04). Between the last two segmentations, larger tumors showed a tendency towards smaller relative volume difference (p?=?0.07), while tumors with well-defined borders had significantly less variability measured with both J2 (p?=?0.04) and HD (p?<?0.01). We found no significant relationship between variability and histological sub-types or Apparent Diffusion Coefficients (ADC). We found that the intra-rater variability can be considerable in serial LGG-segmentation, but the variability seems to decrease with experience and higher grade of border conspicuity. Our findings highlight that some criteria defining tumor borders and progression in 3D volumetric segmentation is needed, if moving from 2D to 3D assessment of size and growth of LGGs.

  相似文献   
5.
Endocarditis caused by Lactococcus cremoris   总被引:2,自引:0,他引:2  
We describe a case of subacute endocarditis due to Lactococcus cremoris associated with consumption of unpasteurized milk. Treatment with amoxicillin-clavulanic acid and subsequently penicillin resulted in prompt sterilization of this patient's bloodstream and full recovery.  相似文献   
6.
Congenital cardiac malformations in Iceland from 1990 through 1999   总被引:1,自引:0,他引:1  
INTRODUCTION AND BACKGROUND: About 1% of live-born children have congenital malformations of the heart. The aim of our study was to investigate the incidence of such defects in children born in Iceland during a period of 10 years, extending from 1990 through 1999. MATERIALS AND METHODS: Information about the patients was obtained from medical records from two hospitals that cover the whole country, a private clinic of pediatric cardiologists, an echocardiography database, autopsy reports, and death certificates. We investigated the distribution of specific malformations, the age at diagnosis, the symptoms leading to the diagnosis, the source of referral, and treatment and quality of life. RESULTS: Between 1990 and 1999, there were 44,013 live births in Iceland, of which 740 patients were diagnosed with congenital cardiac malformations, accounting for 1.7% of the live-born children. The distribution was made up of 338 patients with ventricular septal defect (45.7%), 90 with atrial septal defect (12.2%), 85 with patency of the arterial duct (11.5%), 48 with pulmonary valvar stenosis (6.5%), 38 with a bicuspid aortic valve (5.1%), 28 with aortic coarctation (3.8%), 22 with tetralogy of Fallot (3.0%), 14 with transposed great arteries (1.9%), 11 with aortic stenosis (1.5%), 10 with atrioventricular septal defect and common atrioventricular orifice (1.4%), 9 with mitral valvar regurgitation (1.2%), 7 with sub-aortic stenosis (0.9%), and 5 with hypoplasia of the left heart (0.7%). Extracardiac anomalies were seen in 89 patients (12.0%). Chromosomal defects were seen in 36 patients, of whom 28 had Down's syndrome. DISCUSSION: The annual incidence of diagnosis of patients with congenital cardiac malformations increased during the period of study. This was noted for minor defects, but the incidence of the major anomalies did not alter. Our observed yearly incidence, at 1.7%, was higher than noted in a previous study covering the years 1985 through 1989, and is also higher than in other population-based studies. The most likely explanation is the fact that access to pediatric cardiologists in Iceland is very good. Diagnosis, registration, and follow-up are conducted by only a few cardiologists, and take place at a single center for pediatric cardiology.  相似文献   
7.
Abstract

Objective: The tooth weakens due to removal of hard tissue during an endodontic procedure. Many dentists find it difficult to choose between different coronal restorations after root canal treatment (RCT). Studies show that the coronal restoration may affect the endodontic prognosis. This student-based study had three aims. (1) Examine the choice of coronal restoration of endodontically treated teeth at a Scandinavian dental school, (2) examine the survival of these restorations and (3) evaluate the influence of the coronal restoration on the outcome of the RCT.

Material and methods: Radiographic and clinical examination was performed on 127 posterior teeth. The quality of the root canal treatment and the periapical status (PAI-index) were evaluated.

Results: 43.8% of the teeth were restored with an indirect coronal restoration and 47.2% with a direct coronal restoration. The period from finished root canal treatment until placement of a permanent coronal restoration was significantly longer for an indirect restoration than a direct restoration. The teeth treated with a PAI score of 1 and 2 following pulpectomy, necrotic pulp treatment and endodontic retreatment was 93.8%, 82.6% and 69.4%, respectively.

Conclusion: There was no significant association between choice of coronal restoration and PAI-score.  相似文献   
8.
This study was conducted in three Ethiopian Rift Valley villages known for endemic fluorosis. Three-hundred-and-six adolescents (12-15 years) and 233 mothers participated. The aim was to study dental fluorosis in the youngsters and to assess the extent of agreement between clinical and self-rated discoloration and pitting of teeth, and also the level at which dental fluorosis is perceived as a problem both by children and their mothers. The children (154 M and 152 F) gave a simple self-assessment of tooth-color and quality of their teeth, and were subsequently examined for dental fluorosis. Finally, four color photographs of teeth with dental fluorosis (TF-scores 2, 3, 5, and 7) were used as references during a structured oral interview of the children, as well as their mothers. At TF score &#83 2, the prevalence of dental fluorosis on maxillary central incisors was 72% and 37% at TF score &#83 4. The mean TF score was significantly higher among boys than among girls of unemployed fathers compared to children of employed fathers. The likelihood of reporting problems with dental appearance increased with increasing individual TF scores. The child/mother pairs found teeth with TF scores 2 and 3 esthetically acceptable, while teeth with TF scores 5 and 7 were considered unacceptable. Mothers were more critical of severe fluorosis than were their children.  相似文献   
9.

Background

We recently demonstrated a survival benefit of early resection in unselected diffuse low-grade gliomas (LGG). However, heterogeneity within the LGG entity warrants investigation in a homogenous subgroup. Astrocytoma represents the largest subgroup of LGG, and is characterized by diffuse growth and inferior prognosis. We aimed to study the effects of early resection compared to biopsy and watchful waiting in this subgroup.

Methods

Patient data was retrospectively reviewed in two neurosurgical departments with regional referral practice. In one hospital, initial diagnostic biopsies and watchful waiting was favored, while early resections guided with three-dimensional (3D) ultrasound were advocated in the other hospital. This created a natural experiment with patient management heavy influenced by residential address. In the hospitals’ histopathology databases, all adult patients diagnosed with supratentorial LGG from 1998 through 2009 were screened (n?=?169) and underwent blinded histopathological review. Histopathological review concluded with 117 patients with grade II astrocytomas that were included in the present study. The primary end-point was overall survival assessed by a regional comparison.

Results

Early resections were performed in 51 (82 %) versus 12 (22 %) patients in the respective hospitals (p?<?0.001). The two patient populations were otherwise similar. Median survival was 9.7 years (95 % CI 7.5–11.9) if treated in the hospital favoring early resections compared to 5.6 years (95 % CI 3.5–7.6) if treated at the hospital favoring biopsy and watchful waiting (p?=?0.047). No difference in surgical-related neurological morbidity was seen (p?=?0.843).

Conclusions

Early 3D ultrasound guided resections improve survival, apparently without increased morbidity, compared to biopsy and watchful waiting in patients with diffuse World Health Organization (WHO) grade II astrocytomas.  相似文献   
10.

Background  

The aim of this study was to assess if widowers had an increased mortality rate during the first 6 to 9 years after the death of their wife, compared initially to an age-matched control group and also compared to the general population of Iceland.  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