Phonics在小学英语词汇教学中的有效策略

随着经济全球化和改革开放的发展,英语成为个人发展的基本技能。我国更是在小学三年级就开设英语课程,让小学生从小养成学习英语的好习惯。英语的学习主要分为词汇,语法,听力等,词汇是英语学习的基础,掌握词汇的多少直接决定着英语的能力。所以说在小学英语教学中,词汇是老师讲述的重点。phonics教学法法和传统的国际音标教学法不同,它又称为自然拼读法,是专门根据小学生的学习习惯而创造出来的注音系统,这和汉语的拼音相似。应用这种教学法,极大的降低了小学生在词汇学习方面的难度,提高了学生的学习效率。本文主要就phonics在小学英语词汇教学过程中所采取的策略进行研究。

Variants of genes encoding collagens and matrix metalloproteinase system increased the risk of aortic dissection

Aortic dissection （AD） is a devastating, heterogeneous condition of aorta. The homeostasis between collagens and matrix metalloproteases （MMPs）/tissue inhibitors of MMPs （TIMPs） system in the extracellular matrix plays an important role for structure and functions of aorta. However, our knowledge on association between variants of genes in this system and pathogenesis of AD is very limited. We analyzed all yet known coding human genes of collagens （45 genes）, MMPs/TIMPs （27 genes） in 702 sporadic AD patients and in 163 matched healthy controls, by using massively targeted next-generation and Sanger sequencing. To define the pathogenesis of potential disease-causing candidate genes, we performed transcriptome sequencing and pedigree co-segregation analysis in some genes and generated Col5a2 knockout rats. We identified 257 pathogenic or likely pathogenic variants which involved 88.89% （64/72） genes in collagens-MMPs/TIMPs system and accounted for 31.05% （218/702） sporadic AD patients. In them, 84.86% patients （185/218） carried one variant, 12.84% two variants and 2.30% more than two variants. Importantly, we identified 52 novel probablY pathogenic loss-of-function （LOF） variants （20 nonsense, 16 frameshift, 14 splice sites, one stop-loss, one initiation codon） in 11.06% （50/452） AD patients, which were absent in 163 controls （P=2.5-10-5）. Transcriptome sequencing revealed that identified variants induced dyshomeostasis in expression of collagens-TIMPs/MMPs systems. The Col5a2-/- rats manifested growth retardation and aortic dysplasia. Our study provides a first comprehensive map of genetic alterations in collagens-MMPs/TIMPs system in sporadic AD patients and suggests that variants of these genes contribute largely to AD pathogenesis.

Role of cholinergic anti-inflammatory pathway in regulating host response and its interventional strategy for inflammatory diseases

The cholinergic anti-inflammatory pathway （CAP） is a neurophysiological mechanism that regulates the immune system. The CAP inhibits inflammation by suppressing cytokine synthesis via release of acetylcholine in organs of the reticuloendothelial system, including the lungs, spleen, liver, kidneys and gastrointestinal tract. Acetylcholine can interact with a 7 nicotinic acetylcholine receptors （ a 7 nAchR） expressed by macrophages and other cytokine producing cells, down-regulate pro-inflammatory cytokine synthesis and prevent tissue damage. Herein is a review of the neurophysiological mechanism in which the CAP regulates inflammatory response, as well as its potential interventional strategy for inflammatory diseases.

Template-module assembly to prepare low-molecular-weight gene transport system with enhanced transmembrane capability

Based on specific host-guest interactions between amine-modified [3-cyclodextrin （CD-TAEA） and functional adamantane （AD） derivatives, a module-template strategy has been proposed for the construction of low-molecular-weight cationic assem- blies for gene transport. This strategy offers great flexibility in terms of the introduction of mono- or multi-functionality by the inclusion of one or more adamantane-based modules with the desired functionalities. As proof of concept, phenylboronic acid （PB） containing adamantane （PB-AD） was used as a model module in the hope of offering enhanced cytosolic delivery in con- sideration of the special affinity of PB groups with cell membranes. The physicochemical properties of the complexes formed with plasmid DNA, such as particle size, zeta potential and morphology were investigated. Confocal laser scanning microsco- py and flow cytometry experiments demonstrated the important contribution of the functional PB-AD module to the consider- ably enhanced intracellular internalization and uptake by cellular nuclei. Compared to the parent CD-TAEA, PB-AD/CD- TAEA assemblies mediated higher transfection rates, which were even comparable to that of PEI25K. In addition, PB-AD/CD- TAEA displayed much lower cytotoxicity than PEI25K in both 293T and HeLa cell lines. The encouraging results suggest that CD-TAEA can be developed as a powerful template capable of readily accommodating various AD-based modules giving versatile functionalities for improved transfection.

Cell biology and immunology lessons taught by Legionella pneumophila

Legionella pneumophila is a facultative intracellular pathogen capable of replicating within a broad range of hosts. One unique feature of this pathogen is the cohort of ca. 300 virulence factors(effectors) delivered into host cells via its Dot/Icm type IV secretion system. Study of these proteins has produced novel insights into the mechanisms of host function modulation by pathogens, the regulation of essential processes of eukaryotic cells and of immunosurveillance. In this review, we will briefly discuss the roles of some of these effectors in the creation of a niche permissive for bacterial replication in phagocytes and recent advancements in the dissection of the innate immune detection mechanisms by challenging immune cells with L. pneumophila.