网络版《英语国家概况1》课件的设计开发

本文主要针对网络版《英语国家概况1》课件设计开发的目的、结构及特点进行阐述。由此也可窥视网络版教学软件的设计开发要义以及在教学中运用的优势。     

High-throughput sequencing identifies salivary microbiota in Chinese caries-free preschool children with primary dentition

Objectives: The study aimed at identifying salivary microbiota in caries-free Chinese preschool children using highthroughput sequencing. Methods: Saliva samples were obtained from 35 caries-free preschool children(18 boys and 17 girls)with primary dentition, and 16 S ribosomal DNA(r DNA) V3–V4 hypervariable regions of the microorganisms were analyzed using Illumina MiSeq. Results: At 97% similarity level, all of these reads were clustered into 334 operational taxonomic units(OTUs). Among these, five phyla(Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, and Candidate division TM7) and13 genera(Streptococcus, Rothia, Granulicatella, Prevotella, Enterobacter, Veillonella, Neisseria, Staphylococcus, Janthinobacterium, Pseudomonas, Brevundimonas, Devosia, and Gemella) were the most dominant, constituting 99.4% and 89.9% of the salivary microbiota, respectively. The core salivary microbiome comprised nine genera(Actinomyces, Capnocytophaga, Gemella,Granulicatella, Lachnoanaerobaculum, Neisseria, Porphyromonas, Rothia, and Streptococcus). Analysis of microbial diversity and community structure revealed a similar pattern between male and female subjects. The difference in microbial community composition between them was mainly attributed to Neisseria(P=0.023). Furthermore, functional prediction revealed that the most abundant genes were related to amino acid transport and metabolism. Conclusions: Our results revealed the diversity and composition of salivary microbiota in caries-free preschool children, with little difference between male and female subjects.Identity of the core microbiome, coupled with prediction of gene function, deepens our understanding of oral microbiota in cariesfree populations and provides basic information for associating salivary microecology and oral health.     

武术运动员赛前的心理状态及其自我调节

武术运动员在赛前产生不同的心理状态,将会影响运动员技术水平的发挥。在比赛中如何进行自我调节和控制,这是许多教练员和运动员所研究的一项重要课题。我们通过多次的自我体会和实践,总结出数种自我调节的方法,供同行们借鉴。     

生本教育视野中高中数学教学探究

生本教育是一种以学生为本,为学生好学的教育。生本教育在高中数学教学中的运用具有提高教学有效性的理论和实践意义。当前高中数学教学中存在学生学习数学的兴趣不高,不善于自主学习、主动反思和探究等问题。本文认为应做好前置性学习、问题情景的设计、培养学生的反思意识和有效学习意识,切实提高数学教学的实效性。