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   1000篇
  免费   43篇
  国内免费   25篇
耳鼻咽喉   6篇
儿科学   32篇
妇产科学   12篇
基础医学   98篇
口腔科学   43篇
临床医学   57篇
内科学   196篇
皮肤病学   24篇
神经病学   59篇
特种医学   110篇
外科学   111篇
综合类   87篇
预防医学   39篇
眼科学   42篇
药学   90篇
中国医学   3篇
肿瘤学   59篇
  2024年   11篇
  2023年   13篇
  2022年   32篇
  2021年   51篇
  2020年   24篇
  2019年   24篇
  2018年   26篇
  2017年   28篇
  2016年   44篇
  2015年   29篇
  2014年   34篇
  2013年   51篇
  2012年   65篇
  2011年   76篇
  2010年   45篇
  2009年   33篇
  2008年   36篇
  2007年   47篇
  2006年   35篇
  2005年   41篇
  2004年   14篇
  2003年   29篇
  2002年   22篇
  2001年   10篇
  2000年   11篇
  1999年   13篇
  1998年   29篇
  1997年   17篇
  1996年   17篇
  1995年   13篇
  1994年   16篇
  1993年   17篇
  1992年   2篇
  1991年   4篇
  1990年   5篇
  1989年   11篇
  1988年   14篇
  1987年   6篇
  1986年   9篇
  1985年   7篇
  1984年   6篇
  1983年   9篇
  1982年   6篇
  1981年   10篇
  1980年   6篇
  1978年   3篇
  1975年   6篇
  1970年   2篇
  1924年   1篇
  1922年   1篇
排序方式: 共有1068条查询结果,搜索用时 15 毫秒
1.
2.

Introduction

Numerous antimicrobial agents are used to eliminate oral biofilm. However due to emergence of multi drug resistant microorganisms, the quest to find out biologically safe and naturally available antimicrobial agents continues.

Aim

To evaluate antimicrobial efficacy of silver nano-particles against five common oral pathogenic bacteria.

Objective

To determine antimicrobial activity of silver nanoparticles and chlorhexidine gluconate against oral pathogenic bacteria.

Material and Method

We used strains of Streptococcus mutans (MTCC 497), Streptococcus oralis (MTCC 2696), Lactobacillus acidophilus (MTCC 10307), Lactobacillus fermentum (MTCC 903), and Candida albicans (MTCC 183). We used commercially available silver nanoparticles (experimental group) and chlorhexidine gluconate (positive control). We determined minimum inhibitory concentration (MIC) minimum bactericidal concentration (MBC) of both agents and analyzed the data using paired ‘t’ test, one way ANOVA and Tucky’s post Hoc HSD.

Result

Silver nanoparticles inhibited bacterial growth moderately. The mean MIC of AgNP against S. mutans was 60?±?22.36?μg/ml, S. oralis – 45?±?11.18?μg/ml, L. acidophilus – 15?±?5.59?μg/ml, L. fermentum – 90?±?22.36?μg/ml, Candida albicans – 2.82?±?0.68?μg/ml respectively. For chlorhexidine gluconate, mean MIC for S. mutans was 300?±?111.80?μg/ml, S. oralis – 150?±?55.90?μg/ml, L. acidophilus – 450?±?111.80?μg/ml, L. fermentum – 450?±?111.80?μg/ml and Candida albicans – 150?±?55.90?μg/ml. MIC and MBC values of AgNP were significantly lower than chlorhexidine gluconate and statistically significant (p?<?0.05).

Conclusion

Silver nanoparticles exhibited better bacteriostatic and bactericidal effect with concentration less than five folds as compared to chlorhexidine. Silver nanoparticles when used in appropriate concentration as safe alternative to present chemically derived other antimicrobial agents.  相似文献   
3.
4.

Introduction

The present study was undertaken to know the effect of folic acid (FA) supplementation and FA absence diet during pregnancy on the number of implantation as well as their endometrial changes.

Methods

Eighteen Wistar strain Albino rats were randomly divided into three groups and given different diets: Control group with normal diet, group with FA supplementation diet, and group with FA absent diet (with added Succinyl Sulfathiazole) for 5 weeks. The number of coloured thickenings along the uterine horns were identified by injecting 1% Evan’s blue due solution. The sites of embryo implantation were fixed in 10% buffered formalin for 8 hours and embedded.

Result

Average number of implantation observed in pregnant dams fed with FA supplementation diet was 10 in contrast it was 7 in diet with FA absent diet and 8 in control groups. Histologically, implantation site in FA supplemented group showed favorable endometrial environment than the other groups.

Discussion

FA is essential in successful implantation by providing favorable receptive environment to receive the implantation-competent blastocyst for a successful pregnancy.  相似文献   
5.
The authors report a 14-d-old neonate who presented with lethargy, polyuria and dehydration and was found to have severe hypercalcemia with hyperparathyroidism. This neonate was treated with saline hydration, diuresis and injection pamidronate. Genetic analysis revealed a compound heterozygous mutation of CaSR.  相似文献   
6.
A novel technique was employed to optimize the CO2 sorption performance of spent shale at elevated pressure–temperature (PT) conditions. Four samples of spent shale prepared from the pyrolysis of oil shale under an anoxic condition were further modified with diethylenetriamine (DETA) and ethylenediamine (EDA) through the impregnation technique to investigate the variations in their physicochemical characteristics and sorption performance. The textural and structural properties of the DETA- and EDA- modified samples revealed a decrease in the surface area from tens of m2/g to a unit of m2/g due to the amine group dispersing into the available pores, but the pore sizes drastically increased to macropores and led to the creation of micropores. The N–H and C–N bonds of amine noticed on the modified samples exhibit remarkable affinity for CO2 sequestration and are confirmed to be thermally stable at higher temperatures by thermogravimetric (TG) analysis. Furthermore, the maximum sorption capacity of the spent shale increased by about 100% with the DETA modification, and the equilibrium isotherm analyses confirmed the sorption performance to support heterogenous sorption in conjunction with both monolayer and multilayer coverage since they agreed with the Sips, Toth, Langmuir, and Freundlich models. The sorption kinetics confirm that the sorption process is not limited to diffusion, and both physisorption and chemisorption have also occurred. Furthermore, the heat of enthalpy reveals an endothermic reaction observed between the CO2 and amine-modified samples as a result of the chemical bond, which will require more energy to break down. This investigation reveals that optimization of spent shale with amine functional groups can enhance its sorption behavior and the amine-modified spent shale can be a promising sorbent for CO2 sequestration from impure steams of the natural gas.  相似文献   
7.
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