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   237篇
  免费   8篇
  国内免费   1篇
耳鼻咽喉   12篇
儿科学   6篇
妇产科学   4篇
基础医学   22篇
口腔科学   8篇
临床医学   11篇
内科学   37篇
神经病学   6篇
特种医学   5篇
外科学   72篇
综合类   9篇
预防医学   3篇
眼科学   16篇
药学   16篇
肿瘤学   19篇
  2023年   3篇
  2022年   7篇
  2021年   18篇
  2020年   12篇
  2019年   8篇
  2018年   15篇
  2017年   7篇
  2016年   6篇
  2015年   7篇
  2014年   7篇
  2013年   15篇
  2012年   36篇
  2011年   34篇
  2010年   17篇
  2009年   8篇
  2008年   9篇
  2007年   9篇
  2006年   2篇
  2005年   5篇
  2004年   4篇
  2002年   2篇
  2001年   2篇
  2000年   3篇
  1999年   2篇
  1998年   3篇
  1997年   2篇
  1993年   1篇
  1991年   1篇
  1977年   1篇
排序方式: 共有246条查询结果,搜索用时 31 毫秒
1.
X-ray fluorescence analysis has been used for measurement of lead in paint for more than a decade. The early systems provided a nondestructive alternative technology to laboratory-based technologies, but were somewhat time consuming and often led to inconclusive results. The procedure required manual substrate correction, multiple measurements, operator's discretion in validating a measurement due to interfering elements and laboratory analysis of inconclusive samples. A new instrument, the RMD LPA-1 system, has been developed based on X-ray fluorescence technology that addresses all of the drawbacks to the older systems. This new system uses a carefully designed and controlled geometry and modern microprocessor technology to automatically provide a rapid quantitative measurement of lead in paint with a 95% confidence level. The improved precision and accuracy achieved with this system are due to geometric enhancements and a mathematical approach which incorporates corrections for both random and systematic errors such as matrix effects and Compton scatter. This technology has been incorporated in a hand-held X-ray fluorescence lead paint analyzer system. A key design philosophy for this system was to maintain a very narrow, task-specific focus, the system was not designed to be an all purpose XRF analyzer, rather it is optimized to meet regulatory requirements of lead paint testing in the most efficient manner. The development of the LPA-1 system is an example of what can be accomplished by listening to the needs and desires of the users, rethinking the design of an existing technique and incorporating modern microprocessor technology.  相似文献   
2.
3.
Bulletin of Environmental Contamination and Toxicology - Halogenated compounds are one of the largest groups of environmental-hazardous chemicals. The removal of the halogen atom from the substrate...  相似文献   
4.
5.
Amoebiasis is a parasitic infectious disease caused by the enteric protozoan Entamoeba histolytica, a leading basis of deaths accounted to parasites, succeeding malaria and schistosomiasis. Conventional treatment methodologies used to deal with amoebiasis mainly rely on the administration of anti‐amoebic compounds and vaccines but are often linked with substantial side‐effects on the patient. Besides, cases of development of drug resistance in protozoans have been recorded, contributing further to the reduction in the efficiency of the treatment. Loopholes in the efficacious management of the disease call for the development of novel methodologies to manage amoebiasis. A way to achieve this is by targeting the essential metabolic processes of ‘encystation’ and ‘excystation’, and the associated biomolecules, thus interrupting the biphasic life cycle of the parasite. Technologies like the CRISPR‐Cas9 system can efficiently be exploited to discover novel and essential molecules that regulate the protozoan's metabolism, while efficiently manipulating and managing the known drug targets, leading to an effective halt and forestall to the enteric infection. This review presents a perspective on these essential metabolic processes and the associated molecules that can be targeted efficaciously to prevent the transmission of amoebiasis, thus managing the disease and proving to be a fruitful endeavour.  相似文献   
6.
7.

Background

Although the retrograde approach to nerve sparing (NS) aimed at maximizing NS during robot-assisted radical prostatectomy (RARP) has been described, its significant benefits compared to the antegrade approach have not yet been investigated.

Objective

To evaluate the impact of NS approaches on perioperative, pathologic, and functional outcomes.

Design, setting, and participants

Five hundred one potent (Sexual Health Inventory for Men [SHIM] score >21) men underwent bilateral full NS and were followed up for a minimum of 1 yr. After propensity score matching, 344 patients were selected and were then categorized into two groups.

Surgical procedure

RARP with antegrade NS (n = 172) or RARP with retrograde NS (n = 172).

Outcome measurements and statistical analysis

Functional outcomes were assessed using validated questionnaires. Multivariable logistic regression models were applied.

Results and limitations

Positive margin rates were similar (11.1% vs 6.9%; p = 0.192), and no correlation with the NS approach was found on regression analysis. At 3, 6, and 9 mo, the potency rate was significantly higher in the retrograde approach (65% vs 80.8% and 72.1% vs 90.1% and 85.3% vs 92.9%, respectively). The multivariable model indicated that the NS approach was an independent predictor for potency recovery at 3, 6, and 9 mo, along with age, gland size, and hyperlipidemia. After adjusting for these predictors, the hazard ratio (HR) for the retrograde relative to the antegrade approach was 2.462 (95% confidence interval [CI], 1.482–4.089; p = 0.001) at 3, 4.024 (95% CI, 2.171–7.457; p < 0.001) at 6, and 2.145 (95% CI, 1.019–4.514; p = 0.044) at 9 mo. Regarding continence, the recovery rates at each time point and the mean time to regaining it were similar, and the method of NS had no effect on multivariable analysis. The absence of randomization is a major limitation of this study.

Conclusions

In patients with normal erectile function who underwent bilateral full NS, a retrograde NS approach facilitated early recovery of potency compared to that with an antegrade NS approach without compromising cancer control.  相似文献   
8.
9.
10.
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