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   617篇
  免费   42篇
  国内免费   15篇
耳鼻咽喉   4篇
儿科学   41篇
妇产科学   3篇
基础医学   65篇
口腔科学   12篇
临床医学   64篇
内科学   124篇
皮肤病学   16篇
神经病学   10篇
特种医学   117篇
外科学   42篇
综合类   106篇
预防医学   28篇
眼科学   2篇
药学   18篇
中国医学   1篇
肿瘤学   21篇
  2023年   2篇
  2022年   3篇
  2021年   7篇
  2020年   3篇
  2019年   5篇
  2018年   4篇
  2017年   8篇
  2016年   9篇
  2015年   17篇
  2014年   24篇
  2013年   16篇
  2012年   26篇
  2011年   14篇
  2010年   31篇
  2009年   33篇
  2008年   32篇
  2007年   22篇
  2006年   12篇
  2005年   9篇
  2004年   7篇
  2003年   9篇
  2002年   10篇
  2001年   16篇
  2000年   7篇
  1999年   15篇
  1998年   46篇
  1997年   40篇
  1996年   31篇
  1995年   19篇
  1994年   27篇
  1993年   22篇
  1992年   5篇
  1991年   7篇
  1990年   5篇
  1989年   12篇
  1988年   12篇
  1987年   25篇
  1986年   8篇
  1985年   12篇
  1984年   4篇
  1983年   7篇
  1982年   14篇
  1981年   5篇
  1980年   5篇
  1979年   1篇
  1978年   8篇
  1977年   4篇
  1976年   8篇
  1975年   5篇
  1967年   1篇
排序方式: 共有674条查询结果,搜索用时 31 毫秒
51.
Lymphoceles: imaging characteristics and percutaneous management   总被引:3,自引:0,他引:3  
Twenty-five patients who had lymphoceles underwent sectional imaging and interventional radiologic procedures. Viewed using sonography, lymphoceles were hypoechoic to anechoic, occasionally with internal septa and debris. Low numbers (occasionally negative values) were observed using computed tomography (CT); these numbers strongly suggest the diagnosis of lymphocele. Calcification was observed on CT images of one patient. Diagnostic aspiration revealed tan to yellow fluid containing many lymphocytes; pathognomonic fat globules were observed in four cases. Malignant cells were found in two collections, an unusual occurrence. Therapeutic needle aspiration and short-term catheter drainage were usually unsuccessful (only one of five patients [20%] was cured). Long-term (1-5-week) catheter drainage cured 11 of 14 patients (78.6%). Sclerosing agents may have been beneficial for lymphocele obliteration in three of four patients. For most patients, lymphoceles may be diagnosed and treated successfully using radiologic means.  相似文献   
52.
The Concorde trial compared immediate (Imm) with deferred (Def) AZT monotherapy in asymptomatic HIV-positive participants. Haematological and immunological markers and weight were measured throughout, and correlated with clinical endpoints. Markers associated with disease progression (CD4 lymphocyte count and percentage, platelets, p24 antigen and beta 2 microglobulin favoured Imm: those associated with toxicity (haemoglobin, neutrophils and white cell count) favoured Def. CD8 and total lymphocyte count did not differ significantly between groups. In multivariate analysis, the combination of baseline CD4, p24 antigen and beta 2m was the best baseline predictor of disease. Including change in CD4 and beta 2m at 12 weeks, or changes over follow- up in these markers significantly improved the fit. Markers were also incorporated into the definition of 'clinical' endpoints. Hazard ratio estimates from end-points that included CD4 < 50 and CD4 < 25 were closest to those for AIDS or death alone, but added very few extra events. Use of other landmark CD4 counts (100 or greater) or relative decreases in counts (25% or more) increased the number of events, but overestimated the effect of immediate AZT. Although AZT had a beneficial effect on the surrogate markers of efficacy evaluated, these changes did not predict clinical outcome, nor could the markers be usefully incorporated into an endpoint definition.   相似文献   
53.
54.
The mouse monoclonal antibody M2A1 of IgG1 class, which is highly specific for blood group M antigen, was obtained and characterized by means of hemagglutination, enzyme-linked immunosorbent assay, immunoblotting, and inhibition assays. The use of modified M glycoprotein preparations for inhibition tests and of variant McN and Henshaw red cell membranes for immunoblotting showed that M2A1 recognized an epitope including the NH2-terminal serine and sialic acid residues of glycophorin A, whereas the fifth glycine residue was not involved. The reactivity of the antibody with M antigen was distinctly dependent on ionic strength and pH; the optimum was at pH 8 to 9. The alpha-amino group of terminal serine residue was not necessary for the reaction with M2A1 antibody, and the results obtained suggested that the positive charge of this group contributed to decreasing antigen-antibody reactions at pH below 8. The reaction of the antibody with blood group N antigen was not detectable in any of the assays used.  相似文献   
55.
This study was designed to examine the "true sensitivity" of a specific head-up tilt (HUT) testing protocol using clinical findings. The HUT protocol used 45 minutes at 60 degrees for the baseline portion and intermittent boluses of 2, 4, and 6 micrograms of isoproterenol in the second phase. Eighty-eight patients (40 men and 48 women; mean age of 33.8 +/- 16 years) with recurrent syncope and high pretest likelihood of neurally mediated syncope were included. The following were considerated as high pretest likelihood criteria: (1) at least two syncopal episodes; (2) no structural heart disease and normal baseline ECG; (3) age < 65 years; (4) a typical history of neurally mediated syncope, triggering factors plus premonitory signs; and (5) short duration of symptoms and fast recovery without neurological sequelae. Fifty-four patients (61%) had a positive tilt test (34/88 baseline [39%] and 20/50 with isoproterenol [40%]). The shorter time interval between the last syncopal episode and baseline HUT test was the only predictor for a positive response (P < 0.003). Conversely, this time interval was not predictor of positive responses during isoproterenol-tilt testing. In conclusion: (1) we claim a "sensitivity" for this combined protocol of 61%; and (2) our results indicate that patients with syncope of unknown origin must be tilted nearest as possible to the last syncope to increase the positive responses of HUT test.  相似文献   
56.
57.
India has a high prevalence of diabetes mellitus and the numbers are increasing at an alarming rate. In India alone, diabetes is expected to increase from 40.6 million in 2006 to 79.4 million by 2030. Studies have shown that the prevalence of diabetes in urban Indian adults is about 12.1%, the onset of which is about a decade earlier than their western counterparts and the prevalence of Type 2 diabetes is 4–6 times higher in urban than in rural areas. The risk factors peculiar for developing diabetes among Indians include high familial aggregation, central obesity, insulin resistance and life style changes due to urbanization. Screening for gestational diabetes and impaired glucose tolerance among pregnant women provides a scope for primary prevention of the disease in mothers as well as in their children. The problems of obesity and impaired glucose tolerance (IGT) (important predisposing factors) are not confined to adults alone but children are also increasingly getting affected. Most long standing macro and micro vascular complications are also more common among Indian diabetics as compared to other races and ethnic groups. A strong familial clustering of diabetic nephropathy among Indian Type 2 diabetics has also been noted. Clustering of cardiovascular risk factor like Syndrome X is common among urban Indians. The rising incidence of diabetes and its complications are going to pose a grave health care burden on our country. Timely effective interventions/measures and screening tests for complications at the time of diagnosis becomes imperative not only for early detection, but also to prevent progression to end stage disease. Screening for gestational diabetes among pregnant women would also go a long way in primary prevention of the disease. Life style changes/interventions and drugs like rosiglitazone are the current strategies that can prevent and/or delay the onset of diabetes. Simple interventional strategies like “Eat less, Eat on time and Walk more” can go a long way in preventing these chronic disorders among present as well as in the future generations.  相似文献   
58.
59.

Background

A spinal cord injury is devastating and produces profound changes in the life style of the individual and his family. It is difficult to predict bladder and sphincter behaviour on the basis of clinical somatic neurological deficits.

Methods

A prospective study of 100 spinal cord injury patients was conducted to establish a bladder management protocol. The urodynamic variables were assessed frequently. Clean Intermittent Catheterization (CIC) along with antimuscarinic drugs was instituted and response monitored. Nonresponders were offered Intradetrusor Botulinum toxin.

Result

Spinal shock lasted for upto six months and only 8% could be converted to CIC during the acute phase. A total of 82% patients underwent three to four urodynamic studies which revealed an increase in cystometric capacity and a decrease in the maximum detrusor pressures. This lowered the incidence of incontinence episodes and prevented upper urinary tract damage. Botulinum toxin provided only temporary relief.

Conclusion

Aggressive management of neurogenic bladder (NB) dysfunction is a crucial component of the rehabilitation programme for spinal cord injury patients. Repeated urodynamic studies are an essential aid in managing the evolving nature of the bladder dysfunction. Meticulous bladder management protocol can prevent upper urinary tract complications.Key Words: Spinal cord injury, Neurogenic bladder, Urodynamics  相似文献   
60.
Background Post‐inflammatory hyperpigmentation (PIH) is a common occurrence in patients with acne vulgaris, particularly in those with skin of colour. Aims A previous study has demonstrated the benefit of tretinoin (retinoic acid) in the treatment of PIH; however, there is currently no standard protocol to evaluate change in PIH following treatment. Based on these findings, we performed a pilot, exploratory, blinded, intraindividual‐controlled methodology study that consisted of a photographic assessment protocol with facial mapping. Materials and methods The study was based on a secondary analysis of a phase 4, community‐based trial of 544 acne patients who were treated with tretinoin gel microsphere 0.04% or 0.1%. Only patients with Fitzpatrick types III–V (skin of colour) were included in the study; subjects with Fitzpatrick skin type VI were excluded because the photographic assessment did not allow for proper evaluation. Results Despite the small number of subjects evaluated (n = 25), the results revealed consistent assessment of improvement in PIH between two independent graders (weighted κ = 0.84). Conclusion Further study with a larger population is recommended to validate the accuracy of this method.  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