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   1595篇
  免费   181篇
  国内免费   11篇
耳鼻咽喉   16篇
儿科学   152篇
妇产科学   27篇
基础医学   159篇
口腔科学   53篇
临床医学   229篇
内科学   330篇
皮肤病学   10篇
神经病学   179篇
特种医学   184篇
外科学   210篇
综合类   37篇
预防医学   65篇
眼科学   2篇
药学   50篇
中国医学   5篇
肿瘤学   79篇
  2022年   5篇
  2021年   13篇
  2020年   15篇
  2019年   10篇
  2018年   41篇
  2017年   51篇
  2016年   43篇
  2015年   39篇
  2014年   43篇
  2013年   89篇
  2012年   54篇
  2011年   48篇
  2010年   66篇
  2009年   70篇
  2008年   62篇
  2007年   56篇
  2006年   47篇
  2005年   35篇
  2004年   37篇
  2003年   33篇
  2002年   28篇
  2001年   55篇
  2000年   64篇
  1999年   44篇
  1998年   74篇
  1997年   72篇
  1996年   63篇
  1995年   55篇
  1994年   33篇
  1993年   44篇
  1992年   42篇
  1991年   33篇
  1990年   24篇
  1989年   25篇
  1988年   38篇
  1987年   34篇
  1986年   27篇
  1985年   20篇
  1984年   22篇
  1983年   23篇
  1982年   10篇
  1981年   19篇
  1980年   10篇
  1979年   8篇
  1978年   9篇
  1977年   16篇
  1976年   11篇
  1975年   6篇
  1974年   6篇
  1971年   4篇
排序方式: 共有1787条查询结果,搜索用时 31 毫秒
61.
62.
Age-related changes in visual spatial biases in children, young adults, and older adults were studied with unilateral and bilateral stimulus conditions in fast-paced linguistic and non-linguistic attention tasks. Only rightward spatial biases were observed. The incidence of the biases changed as a function of age: in childhood and in old age the rightward spatial biases were more common than in young adulthood. The present rightward spatial biases were similar to those observed in the corresponding auditory spatial linguistic and non-linguistic attention tests (Takio, Koivisto, Laukka, & Hämäläinen, 2011) and in the dichotic listening forced-attention task (Takio et al., 2009). We suggest that the multimodal rightward spatial bias observed under intensive attentional load is related to a right hemispace preference and modulated by age-dependent changes in executive functions.  相似文献   
63.

Background

The increased reports of ESBL dissemination from various centres in south western, Nigeria and the recent emergence of carbapenem resistant bacteria prompted the conception of this study.

Objectives

To demonstrate the relationship between high molecular weight plasmids and the expression of antibiotic multi-resistance including ESBL and carbapenemase.

Methods

We investigated 97 isolates of selected organisms consisting of 67 E. coli and 30 Klebseilla spp for the presence of plasmids expressing ESBL including carbapenem-hydrolysing enzymes. Beta-lactamase was determined using acidometric method, while ESBL and carbapenemase activity was determined using the double-disk diffusion test as well as the Modified Hodge test (MHT). Plasmid profiles of ESBL and carbapenemase positive isolates were determined according to standard protocols.

Results

An ESBL prevalence rate of 21.6% and carbapenem- resistance rate of 9.3% was recorded. Antibiotic susceptibility profile of ESBL isolates showed 100.0% resistance against Amoxicillin, Cotrimoxazole and Erythromycin. Moderate susceptibility was recorded against the Quinolone class of antibiotics; Meropenem remained the most active antibiotic against ESBL isolates with 62.5% against E. coli and 60% against K. pneumoniae. The plasmid profiles of our study isolates ranged from 11.8kbp to 35.5kbp.

Conclusion

Due to the relationship between high molecular weight plasmids and multi-drug resistance, we hereby recommend regular molecular surveillance of this form in our study setting.  相似文献   
64.
65.
66.
67.
非酒精性脂肪性肝炎(non—alcoholicsteatohepatitis,NASH)现已成为肝移植愈来愈重要的基础肝病。鉴于晚期NASH患者常并存多种影响肝移植转归的临床问题,而至今尚无针对NASH患者进行肝移植的评估和治疗指南,为此英国移植学会(British Transplant Society,BTS)邀请相关专家制定了指南,以指导肝移植前后NASH患者的处理。  相似文献   
68.

Background

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemoperfusion (HIPEC) are frequently used to treat appendiceal carcinomatosis. Some patients require multivisceral resection because of the volume of disease. It is unclear whether extent of CRS impacts survival in appendiceal carcinomatosis.

Methods

We analyzed 282 patients undergoing attempted CRS/HIPEC for appendiceal carcinomatosis. Patients were defined as having undergone Extensive CRS (n = 60) if they had >3 organ resections or >2 anastomoses; a subgroup of Extreme CRS patients (n = 10) had ≥5 organ resections and ≥3 anastomoses. Kaplan–Meier survival curves and multivariate Cox-regression models were used to identify prognostic factors affecting outcomes.

Results

Relative to the comparison group, patients undergoing Extensive CRS had a higher median peritoneal carcinomatosis index, operative duration, blood loss, and length of stay. No difference in completeness of cytoreduction, severe morbidity, or 60-day mortality was evident. Subgroup analysis of 10 patients undergoing extreme CRS likewise revealed no increase in severe morbidity or mortality. Median progression-free (PFS) and overall survival (OS) were 23.5 and 74 months in the comparison group; 18.5 (p = 0.086) and 51 (p = 0.85) months in the Extensive CRS group; and 40 months and not reached in the Extreme CRS subgroup. In a multivariable analysis, extent of CRS was not independently associated with PFS or OS.

Conclusions

Extensive CRS is associated with greater OR time, blood loss, and length of stay, but is not associated with higher morbidity, mortality, or inferior oncologic outcomes in patients with appendiceal carcinomatosis.  相似文献   
69.
Background/Objective: Intrathecal baclofen (ITB) has been shown to be an effective treatment for severe spasticity of spinal or cerebral origin. Although most patients respond well to an ITB trial, there are often difficulties in achieving and/or maintaining such effectiveness with ITB pump treatment. There are few published guidelines for dosing efficacy and no studies looking at the effect of concentration of ITB on spasticity management.

Methods: Case series of 3 adults with severe spasticity treated with ITB pump: a 44-year-old man with C7 tetraplegia using a 40-mL Medtronic SynchroMed II pump with 500-μg/mL concentration; a 35-year-old woman with traumatic brain injury with right spastic hemiplegia using a 18-mL Medtronic SynchroMed EL pump with 2,000-μg/mL concentration; and a 43-year-old woman with spastic diplegic cerebral palsy using a 40-mL Medtronic SynchroMed II pump with 2,000-μg/mL concentration.

Results: After reducing ITB concentrations in the pump, either as part of a standard protocol for dye study to assess the integrity of pump and catheter system or secondary to plateau in therapeutic efficacy, patients experienced temporary, significant reduction in spasticity based on range of motion, Modified Ashworth scores, and verbal feedback.

Conclusions: Decreasing the concentration of ITB seems to affect spasticity control. Further research in this area is needed for those patients with refractory spasticity to optimize efficacy of ITB therapy.  相似文献   
70.
Fathers' reports concerning their children have seldom been considered in the previous studies on maternal depression and child development. The literature on parental reports in general suggests that discrepancies in mothers' and fathers' perceptions are associated with the psychological state of the parent and the gender of the child. As part of a prospective follow-up study, fathers' and mothers' perceptions of children's social competence and behavioural/ emotional problems were assessed by the Child Behavior Checklists (CBCLs) when the firstborn children were 8–9 years old. The depressive symptoms of the mothers were screened by the Edinburgh Postnatal Depression Scale (EPDS) at the same time point. The level of children's social competence and behavioural/emotional problems reported by the fathers were analysed by background factors. The reports of both parents were explored by the gender of the child and by the presence of maternal depressive symptoms. The concordance of parental reports concerning child's social competence was high, but fathers usually reported lower problem levels than mothers, particularly for boys' problems. The presence of maternal depressive symptoms was associated with child's high problem levels from both fathers' and mothers' perspective. Parental ratings of children's externalizing problems in particular were associated with high maternal depressive symptom level.  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