Effects on cytotoxicity and antibacterial properties of the incorporations of silver nanoparticles into the surface coating of dental alloys     

Xiao-ting Shen  Yan-zhen Zhang  Fang Xiao  Jing Zhu  Xiao-dong Zheng 《Journal of Zhejiang University. Science. B》2017,18(7):615-625

The aim of this study was to research the changes in cytotoxicity and antibacterial properties after silver nanoparticles (AgNPs) were incorporated into the surface coating of dental alloys. AgNPs were attached to cobalt chromium alloys and pure titanium using a hydrothermal method, according to the reaction: AgNO₃+NaBH₄→ Ag+1/2H₂+1/2B₂H₆+NaNO₃. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate the cytotoxicity of the alloys when in contact with osteogenic precursor cells (MC3T3-E1) from mice and mesenchymal stem cells (BMSC) from rats. The antibacterial properties of dental alloys incorporating three different concentrations (10, 4, and 2 μmol/L) of AgNPs were tested on Staphylococcus aureus (SA) and Streptococcus mutans (MS). High cytotoxicity values were observed for all dental alloys that contained 0% of AgNPs (the control groups). The incorporation of AgNPs reduced cytotoxicity values. No significant difference was observed for antibacterial performance when comparing dental alloys containing AgNPs to the respective control groups. The results demonstrated that the cobalt chromium alloys and pure titanium all had cytotoxicity to MC3T3-E1 and BMSC and that the incorporation of AgNPs could reduce this cytotoxicity. The concentrations of AgNPs adopted in this study were found to have no antibacterial action against SA or MS.  相似文献   

The effectiveness of self-regulated learning scaffolds on academic performance in computer-based learning environments: a meta-analysis     

Lanqin Zheng 《Asia Pacific Education Review》2016,17(2):187-202

This meta-analysis examined research on the effects of self-regulated learning scaffolds on academic performance in computer-based learning environments from 2004 to 2015. A total of 29 articles met inclusion criteria and were included in the final analysis with a total sample size of 2648 students. Moderator analyses were performed using a random effects model that focused on the three main areas of scaffold characteristics (including the mechanism, functions, delivery forms, mode, and number of scaffolds; how to promote self-regulated learning by scaffolds); demographics of the selected studies (including sample groups, sample size, learning domain, research settings, and types of computer-based learning environments); and research methodological features (including research methods, types of research design, types of organization for treatment, and duration of treatment). Findings revealed that self-regulated learning scaffolds in computer-based learning environments generally produced a significantly positive effect on academic performance (ES = 0.438). It is also suggested that both domain-general and domain-specific scaffolds can support the entire process of self-regulated learning since they demonstrated substantial effects on academic performance. Different impacts of various studies and their methodological features are presented and discussed.  相似文献   

普通高校健美操运动员赛后心理调适方法研究     

王嵘  陈亮  王峥 《嘉应学院学报》2008,26(3)

随着我国各高校竞技健美操训练水平的提高,运动员在比赛中所感受到的赛场心理压力体验势必更加深刻和久远。比赛结果的好坏往往都会对运动员造成一定的心理影响,如果不及时采取措施进行干预,这将会影响运动员赛后正常的训练和比赛。本文尝试分析竞技健美操运动员在赛后可能会出现的心理体验表现,探讨了在赛后的训练中可以采用的几种较实用的心理调适手段。  相似文献   

一个概率问题的求解与推广     

侯新昌  王建功 《陕西广播电视大学学报》2008,10(4):91-93

本文分别给出了一个典型概率问题的常规法求解和递推法求解,由常规法得到了一个组合数和式：^[N/2]∑K=0C^kn-k（1/2）^n-k=2/3＋1/3（-1/2）^n．由递推法可见其是求解与有关的概率问题的一种很有效的途径和方法。  相似文献   

基于profiling系统的软硬件划分方法研究     

吕争  湛宁 《荆门职业技术学院学报》2008,23(3):56-61

通过对path profiling和loop profiling对软硬件划分作用的分析,发现了在特定条件下pathprofiling相对于loop profiling的优点,并提出了一个新的基于profiling系统的软硬件划分的方法。  相似文献   

美、中教师评价指标体系比较研究     

孙河川  郑丹  葛辉 《教育发展研究》2008,(20)

本文就美中两国最新教师评价体系的一、二级指标进行比较,对两国的相通之处和各自关注的重点予以探讨,并进一步分析美国教师评价指标体系的特点,以期对我国教师评价指标体系的科学构建和完善有所借鉴.  相似文献   

学校对研究性学习的回应行为分析   总被引：2，自引：0，他引：2  

柯政 《教育发展研究》2008,(24)

本文通过调查发现,学校执行研究性学习课程政策时表现出共同的行为方式,即:在课时上,不能按相关要求开足课程;在实施方式上,利用节假日"集中"进行;在教学过程中,重形式轻实质.学校的这种现实回应使研究性学习课程政策在实践中面临被消解的境地.对此,我们不能简单地将其归咎于学校执行政策不力,而应从整个课程政策的制订、执行和调整系统的角度来考量.  相似文献   

多媒体技术在中学化学实验教学中的运用     

郑丽红 《丽水学院学报》2008,30(2):94-96

多媒体是教学的辅助手段,尤其是中学化学实验教学的必要辅助手段,教师应该在化学实验教学中恰当运用多媒体教学技术辅助化学教学,使这种现代化教学手段与传统教学互相结合、互相渗透、互相补充和完善,进一步优化化学实验教学,提高教学效果。  相似文献   

网络背景下高校思政工作的挑战与对策     

郑伟芬 《丽水学院学报》2008,30(1):76-79

上网已成为当今中国在校大学生一项不可或缺的生活内容。网络时代高校思想政治工作面临诸多挑战：大学生道德价值判断能力降低,大学生身心健康受到影响。为此应针对性地把握机遇应对挑战：教育工作者应大力弘扬文化主旋律,树立以人为本的教育理念,加强大学生网络心理健康教育。  相似文献   

数学软件包Mathematica在《高等数学》教学中的应用     

邱筝  陆健 《南通职业大学学报》2008,22(1):100-104

围绕高职《高等数学》的基本教学内容,结合教学中的具体实例,探讨了数学软件包Mathematica的绘图功能与数值计算功能在高职数学教学中的应用。  相似文献