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   1038篇
  免费   166篇
  国内免费   17篇
耳鼻咽喉   12篇
儿科学   49篇
妇产科学   15篇
基础医学   52篇
口腔科学   11篇
临床医学   165篇
内科学   251篇
皮肤病学   41篇
神经病学   61篇
特种医学   80篇
外科学   184篇
综合类   48篇
现状与发展   20篇
预防医学   100篇
眼科学   25篇
药学   38篇
中国医学   2篇
肿瘤学   67篇
  2024年   7篇
  2023年   43篇
  2021年   21篇
  2020年   26篇
  2019年   11篇
  2018年   51篇
  2017年   48篇
  2016年   33篇
  2015年   40篇
  2014年   43篇
  2013年   63篇
  2012年   32篇
  2011年   35篇
  2010年   48篇
  2009年   66篇
  2008年   39篇
  2007年   25篇
  2006年   36篇
  2005年   23篇
  2004年   20篇
  2003年   24篇
  2002年   17篇
  2001年   25篇
  2000年   21篇
  1999年   27篇
  1998年   33篇
  1997年   33篇
  1996年   47篇
  1995年   32篇
  1994年   20篇
  1993年   22篇
  1992年   13篇
  1991年   11篇
  1990年   14篇
  1989年   13篇
  1988年   16篇
  1987年   14篇
  1986年   14篇
  1985年   14篇
  1984年   5篇
  1983年   8篇
  1982年   9篇
  1980年   5篇
  1978年   12篇
  1977年   8篇
  1976年   7篇
  1975年   6篇
  1971年   5篇
  1964年   5篇
  1963年   4篇
排序方式: 共有1221条查询结果,搜索用时 0 毫秒
81.
We analysed adipose tissue concentrations of persistent organic pollutants (POPs) in 21 cases with exocrine pancreatic cancer. The comparison group consisted of 59 subjects. Significantly increased concentrations of polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), sum of chlordanes and polybrominated diphenylethers (PBDEs) were found in the cases. For 1,1,-dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p'-DDE) no significant difference was seen. For PCBs no odds ratio (OR) could be calculated since all cases had concentration>median in controls used as a cut-off. HCB yielded OR=53.0, 95% confidence interval (CI)=4.64-605 and sum of chlordanes OR=18.4, 95% CI=2.71-124 whereas OR was not significantly increased for p,p'-DDE or PBDEs. Body mass index (BMI) at the time of tissue sampling was significantly lower for the cases. This might have influenced the results. Using BMI one year previously or decreasing the concentrations of POPs with the same percentage as weight loss among the cases did not change the results. Survival of the cases was shorter in the group with the concentration of POPs>median among cases, significantly so for the sum of PCBs (147 vs. 294 days), p,p'-DDE (134 vs. 302 days), and sum of chlordanes (142 vs. 294 days) in the high and low group, respectively. The results were based on a low number of cases and should be interpreted with caution.  相似文献   
82.
83.
OBJECTIVE: Four programmes based on educational and cognitive principles but with a variation in total length and number of staff/patient contact hours were compared in order to gain further insight into the importance of the format of the programme for the final outcome. DESIGN: A prospective non-randomized intervention study with 191 persons with fibromyalgia. Data were collected before, after and at 1-year follow-up. Participants served as their own controls. Results within and between the programmes were calculated. METHODS: Clinical investigations before and after intervention. Questionnaires were answered before, after and at 1-year follow-up. RESULTS: Most instruments showed no significant improvements after the programme. However, some improvements were found in important variables such as attitudes, self-efficacy, vitality and "days feeling well". Results were unchanged at the 1-year follow-up and 16 persons had started working. Seven had ceased working. Participants reported frequent use of coping strategies in everyday life. No major differences could be found between the programmes. CONCLUSIONS: More comprehensive programmes did not produce better results at group level. Also short and less costly interventions based on educational and cognitive principles were valuable for persons with longstanding fibromyalgia. More attention must be given to evaluating the clinical effect of programmes.  相似文献   
84.
85.
86.

Background  

Obesity among children and adolescents is a growing public health problem. The aim of the present paper is to identify potential determinants of obesity and risk groups among 3- to 17-year old children and adolescents to provide a basis for effective prevention strategies.  相似文献   
87.
Whether low-intensity non-thermal microwave radiation alters the integrity of the blood–brain barrier has been debated since the late 1970s, yet no experimental study has been carried out on humans. The aim of this study was to test, using peripheral markers, whether exposure to a mobile phone-like signal alters the integrity of the human blood–brain and blood–cerebrospinal fluid barriers. A provocation study was carried out that exposed 41 volunteers to a 30 min GSM 890 MHz signal with an average specific energy absorption rate distribution of 1.0 W/kg in the temporal area of the head as measured over any 1 g of contiguous tissue. The outcome was assessed by changes in serum concentrations of two putative markers of brain barrier integrity, S100B and transthyretin. Repeated blood sampling before and after the provocation showed no statistically significant increase in the serum levels of S100B, while for transthyretin a statistically significant increase was seen in the final blood sample 60 min after the end of the provocation as compared to the prior sample taken immediately after provocation (p = 0.02). The clinical significance of this finding, if any, is unknown. Further randomized studies with use of additional more brain specific markers are needed.  相似文献   
88.

Background

Vitiligo was an autoimmune disease and some guidelines for the management of vitiligo encouraged the use of NB-UVB combination therapies to enhance repigmentation.

Objectives

To compare the effectiveness of current NB-UVB combination regimen at the improvement in repigmentation through a systematic review and network meta-analysis.

Methods

We searched the electronic databases for randomized controlled trials related to NB-UVB combination therapy for vitiligo till October 2022. STATA15.0 software was applied to carrying out data analysis.

Results

A total of 28 eligible studies involving 1194 participants were enrolled in the analysis. The NMA results revealed that compared with NB-UVB, carboxytherapy [OR = 32.35, 95% CI (1.79, 586.05)], Er: YAG laser+ topical 5% 5-FU [OR = 10.74, 95% CI (4.05, 28.49)], needling/micro-needling [OR = 3.42, 95% CI (1.18, 9.88)], betamethasone intramuscular injection [OR = 3.08, 95% CI (1.17, 8.13)], topical tacrolimus [OR = 2.54, 95% CI (1.30, 4.94)], and oral Chinese herbal medicine compound [OR = 2.51, 95% CI (1.40, 4.50)] integrated with NB-UVB were more efficacious in excellent to complete repigmentation response rate (≥75%). Besides, NB-UVB+ Er: YAG laser+ topical 5% 5-FU [OR = 0.17, 95% CI (0.04, 0.67)] and NB-UVB+ needling/micro-needling [OR = 0.24, 95% CI (0.06, 0.88)] were less likely evaluated as ineffective repigmentation response (≤25%).

Conclusions

All combination therapies ranked higher than NB-UVB monotherapy in inducing successful repigmentation and avoiding failed treatment in patients with vitiligo. Comprehensive consideration, NB-UVB+ Er: YAG laser+ topical 5% 5-FU and NB-UVB+ needling/microneedling would be the preferred therapeutic approaches.  相似文献   
89.
Lithium toxicity     
We report a case of severe lithium toxicity precipitated by a thiazide diuretic and compounded by an angiotensin converting enzyme inhibitor. There was severe vasodilatation refractory to noradrenaline.  相似文献   
90.
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