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   346篇
  免费   19篇
  国内免费   6篇
耳鼻咽喉   1篇
儿科学   7篇
妇产科学   3篇
基础医学   58篇
口腔科学   11篇
临床医学   29篇
内科学   41篇
皮肤病学   5篇
神经病学   11篇
特种医学   45篇
外科学   26篇
综合类   74篇
预防医学   11篇
眼科学   28篇
药学   3篇
中国医学   1篇
肿瘤学   17篇
  2023年   1篇
  2022年   1篇
  2021年   2篇
  2019年   5篇
  2018年   3篇
  2017年   6篇
  2016年   7篇
  2015年   16篇
  2014年   7篇
  2013年   11篇
  2012年   11篇
  2011年   7篇
  2010年   20篇
  2009年   17篇
  2008年   23篇
  2007年   30篇
  2006年   23篇
  2005年   12篇
  2004年   14篇
  2003年   9篇
  2002年   6篇
  2001年   4篇
  2000年   4篇
  1999年   17篇
  1998年   22篇
  1997年   15篇
  1996年   15篇
  1995年   6篇
  1994年   10篇
  1993年   8篇
  1992年   1篇
  1991年   3篇
  1990年   2篇
  1989年   13篇
  1988年   3篇
  1987年   1篇
  1986年   2篇
  1985年   3篇
  1984年   1篇
  1983年   3篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
排序方式: 共有371条查询结果,搜索用时 15 毫秒
41.
42.
43.

Background  

Smoking cessation interventions in pregnancy could influence a woman's social behaviour and her partner's smoking behaviour, but this has not been examined in any published randomized trials.  相似文献   
44.

Background:

There have been an increasing number of reports world-wide relating improved outcomes after pancreatic resections to high volumes thereby supporting the idea of centralization of pancreatic resectional surgery. To date there has been no collective attempt from India at addressing this issue. This cohort study analysed peri-operative outcomes after pancreatoduodenectomy (PD) at seven major Indian centres.

Materials and Methods:

Between January 2005 and December 2007, retrospective data on PDs, including intra-operative and post-operative factors, were obtained from seven major centres for pancreatic surgery in India.

Results:

Between January 2005 and December 2007, a total of 718 PDs were performed in India at the seven centres. The median number of PDs performed per year was 34 (range 9–54). The median number of PDs per surgeon per year was 16 (range 7–38). Ninety-four per cent of surgeries were performed for suspected malignancy in the pancreatic head and periampullary region. The median mortality rate per centre was four (range 2–5%). Wound infections were the commonest complication with a median incidence per centre of 18% (range 9.3–32.2%), and the median post-operative duration of hospital stay was 16 days (range 4–100 days).

Conclusions:

This is the first multi-centric report of peri-operative outcomes of PD from India. The results from these specialist centers are very acceptable, and appear to support the thrust towards centralization.  相似文献   
45.
We describe nine previously unreported individuals from six families who have homozygous mutations of HOXA1 and either the Bosley-Salih-Alorainy syndrome (BSAS) or the Athabascan brainstem dysgenesis syndrome (ABDS). Congenital heart disease was present in four BSAS patients, two of whom had neither deafness nor horizontal gaze restriction, thus raising the possibility that cardiovascular malformations might be a clinically isolated, or relatively isolated, manifestation of homozygous HOXA1 mutations. Two ABDS probands had relatively mild mental retardation. These individuals blur the clinical distinctions between the BSAS and ABDS HOXA1 variants and broaden the phenotype and genotype of the homozygous HOXA1 mutation clinical spectrum.  相似文献   
46.
Silver-Russell syndrome (SRS MIM180860) is a disorder characterised by intrauterine and/or postnatal growth restriction and typical facies. However, the clinical picture is extremely diverse due to numerous diagnostic features reflecting a heterogeneous genetic disorder. The mode of inheritance is variable with sporadic cases also being described. Maternal uniparental disomy (mUPD) of chromosome 7 accounts for 10% of SRS cases and many candidate imprinted genes on 7 have been investigated. Chromosome 11 has moved to the forefront as the key chromosome in the aetiology, with reports of methylation defects in the H19 imprinted domain associated with the phenotype in 35-65% of SRS patients. Methylation aberrations have been described in a number of other imprinted growth related disorders such as Beckwith-Wiedmann syndrome. This review discusses these recent developments as well as the previous work on chromosome 7. Other candidate genes/chromosomal regions previously investigated are tabled.  相似文献   
47.

Background

Medical intelligence of disease vectors deals with understanding vector distribution and control.

Methods

An entomological baseline survey using standard vector sampling techniques was done as a pilot study to map the vectors of defence importance in two cantonments of Pune with a view to establish a vector databank and impart training to armed forces personnel in vector surveillance.

Result

The project trained 142 armed forces personnel in surveillance techniques in three years. Seventeen species of mosquitoes comprising of eight vector species were collected. Three other vectors viz. Rhipicephalus sanguineus, Xenopsylla cheopis and Leptotrombidium deliense are reported.

Conclusion

The study emphasizes the need for vector mapping /surveillance in each area for preventing morbidity and mortality amongst troops. It also focuses on indigenous fabrication of vector sampling tools and training of personnel for capacity building which in turn will enable such surveys to be undertaken in other units and deployment areas.Key Words: Leptotrombidium, Mosquitoes, Rhipicephalus, Surveillance, Xenopsylla  相似文献   
48.
49.

Objectives:

To compare the mean total antioxidant status (TAS) among 3 glaucoma types, namely: pseudoexfoliation glaucoma (PEG), primary open angle glaucoma (POAG), and primary angle closure glaucoma (PACG), and study its potential association with various clinical glaucoma-parameters.

Methods:

In this case-control study, plasma samples were obtained between September 2013 and October 2014 from 340 glaucoma patients (PEG [n=54]; POAG [n=147]; PACG [n=139]), and 351 controls of matching age, gender, ethnicity, and 5 different systemic co-morbidities from King Abdulaziz University Hospital, Riyadh, Saudi Arabia. The TAS in all samples was determined by a colorimetric-based assay.

Results:

The mean±standard deviation of TAS was significantly lower among cases: 0.77±0.32 than controls: 1.1±0.22, p<0.0001. Moreover, the TAS levels were significantly different across the 3 types of glaucoma: 0.86±0.24 in PEG, 0.47±0.32 in POAG, and 0.98±0.41 in PACG (all p<0.0001). In addition, there was a significant correlation between TAS and age at onset (Pearson correlation coefficient [R] 0.17, p<0.0001), cup/disc ratio (R: -0.13, p=0.004), and number of anti-glaucoma medications (R: -0.16, p=0.001).

Conclusion:

Our findings provide evidence that plasma TAS levels are decreased in patients with glaucoma, more so in POAG and PEG than PACG, supporting the hypothesis that decreased antioxidative defense and/or increased oxidative stress may have a critical role in the pathogenesis of glaucoma.Glaucoma is a progressive optic neuropathy associated with optic nerve damage, and is one of the most leading cause of blindness worldwide.1 Elevated intraocular pressure (IOP) as a result of reduction in normal aqueous outflow is a major causal risk factor that is well supported by animal studies.2-4 Although IOP is considered a major risk factor for glaucoma,2,3 other concomitant factors affecting the pathophysiology of glaucomatous retinal ganglion cell (RGC) death include retinal ischemia,5 nutritional status,6 and oxidative stress.7 There is evidence of oxidative damage in ocular diseases, such as cataract and age-related macular degeneration.8 In addition, significant oxidative damage has been demonstrated in human trabecular meshwork (TM) cells of patients with glaucoma,7 causing elevated IOP and visual field damage.9 Furthermore, our previous studies have documented mitochondrial abnormalities10-12 (oxidative stress marker), and glutathione-S-transferase (antioxidant) gene (GST) polymorphisms to be associated with various types of glaucoma.13 It is clearly evident from the literature, and our own studies, that oxidative stress mechanisms play a critical role in the pathogenesis of glaucoma. Previous studies had demonstrated reduced total antioxidant capacity in aqueous humor and blood samples from patients with glaucoma.14-17 To evaluate the role of oxidative stress in different types of glaucoma we had previously investigated total antioxidants status (TAS) in the plasma of pseudoexfoliation glaucoma (PEG) patients,18 primary angle closure glaucoma (PACG) patients,19 and in the plasma of primary open angle glaucoma (POAG) patients.20 As an extension to these studies, here, we compare the mean TAS level among these 3 glaucoma types, and study the potential association between the TAS level and various clinical parameters important to each type of glaucoma.18-20  相似文献   
50.
Needle biopsy of renal allografts: comparison of two techniques   总被引:2,自引:0,他引:2  
Two techniques for renal allograft biopsy were retrospectively evaluated to compare relative safety and efficacy. After ultrasound (US) localization of the kidney and biopsy with a hand-held 14-gauge cutting needle, an adequate specimen was obtained in 74 of 77 cases (96%). Major complications occurred in six of these 77 cases (8%). One hundred four biopsies were performed by using a smaller 18-gauge cutting needle with a spring-loaded biopsy "gun" and real-time US guidance. With this newer technique, specimens adequate for diagnosis were obtained in 99 biopsies (95%). There was a single major complication with this technique (1%). The 18-gauge needle with real-time US guidance yields comparably adequate specimens with a lower frequency of complications.  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