T cells promote the regeneration of neural precursor cells in the hippocampus of Alzheimer's disease mice

Alzheimer＇s disease is closely associated with disorders of neurogenesis in the brain, and growing evidence supports the involvement of immunological mechanisms in the development of the disease. However, at present, the role of T cells in neuronal regeneration in the brain is unknown. We injected amyloid-beta 1-42 peptide into the hippocampus of six BALB/c wild-type mice and six BALB/c-nude mice with T-cell immunodeficiency to establish an animal model of Alzhei- mer＇s disease. A further six mice of each genotype were injected with same volume of normal saline. Immunohistochemistry revealed that the number of regenerated neural progenitor cells in the hippocampus of BALB/c wild-type mice was significantly higher than that in BALB/c-nude mice. Quantitative fluorescence PCR assay showed that the expression levels of peripheral T cell-associated cytokines （interleukin-2, interferon-y） and hippocampal microglia-related cyto- kines （interleukin-113, tumor necrosis factor-a） correlated with the number of regenerated neural progenitor cells in the hippocampus. These results indicate that T cells promote hippocampal neurogenesis in Alzheimer＇s disease and T-cell immunodeficiency restricts neuronal regeneration in the hippocampus. The mechanism underlying the promotion of neuronal regeneration by T cells is mediated by an increased expression of peripheral T cells and central microglial cytokines in Alzheimer＇s disease mice. Our findings provide an experimental basis for understanding the role of T cells in Alzheimer＇s disease.

Effect of mangrove restoration on crab burrow density in Luoyangjiang Estuary,China

Background： Mangrove restoration seeks to restore or rebuild degraded mangrove systems. The methods of mangrove restoration include ecological projects and restoration-oriented technologies, the latter of which are designed to restore the structure, processes as well as related physical, chemical and biological characteristics of wetlands and to ensure the provision of ecosystem services. As important components of mangrove ecosystem, benthic organisms and crabs play a key role in nutrient cycling. In addition, mangrove restoration, such as vegetation restoration measures, can lead to changes in the benthic faunal communities. This study investigates whether the presence of different mangrove species, age and canopy cover of mangrove communities affect the density of crab burrows. Methods： The Luoyangjiang Estuary, in the southeast of Fujian Province, was selected as our research area. A survey, covering 14 sites, was conducted to investigate the impacts of mangrove restoration on the density of crab burrows in four rehabilitated forests with different stand ages and canopy. Results： It was found that differences in vegetation types had a large impact on crab density and that the density of crab burrows was lower on exposed beaches （non-mangrove） than under mature Kondelio condel, Aegiceros corniculatum and Avicennio morina communities. In general, the amount of leaf litter and debris on mangrove mudfiats was greater than on the beaches as food sources for crabs. Two-factor analysis of variance （ANOVA） shows that changes in mangrove species and age since restoration had different effects on crab burrow density. The effect of canopy cover was highly significant on crab burrow density. Conclusions： The results suggest that in the process of mangrove restoration the combined effects of mangrove stand age, canopy cover and other factors should be taken into account. This study further supports the findings of the future scientific research and practice on mangrove restoration and management measures.

2013-2022年病理性近视研究现状和热点的可视化文献计量学分析

目的:基于文献计量学软件CiteSpace和VOSviewer探讨病理性近视(PM)领域的研究现状及热点。方法:文献计量学分析法。于2023年3月检索Web of Science核心数据库2013-2022年发表的PM领域的相关文献。利用CiteSpace和VOSviewer软件进行分析,分析内容包括作者、机构、国家/地区、期刊及关键词等。结果:筛选文献后最终纳入文献713篇。近10年PM领域的发文量呈现平稳上升趋势。期刊分布显示发文量最多的期刊为JCR一区的《Retina-the Journal of Retinal and Vitreous Diseases》;作者分布显示发文量最高及被引量最高的均是来自日本东京的Ohno-matsui K教授;研究机构分布显示,发文量最多的为东京医科齿科大学,其次为复旦大学、中山大学,中国研究机构在该领域发文较多,前10位机构中占据7位;国家/地区发文量统计分析显示中国(278篇)、日本(124篇)及美国(98篇)在PM领域最活跃,但中国中心性很低;关键词聚类主要为PM的流行病学研究、诊断及管理、并发症脉络膜新生血管的防治,另外关键词突现分析显示PM的分类及近视相关黄斑病变为新的研究热点。结论:2013-2022年PM的研究中,中国和日本是发文量最多的国家,中国发文机构虽多,但机构间的联系较少。PM的分类以及近视相关黄斑病变的诊治研究为近年该领域的主要研究热点。

Significant enhancement of crystallization kinetics of polylactide in its immiscible blends through an interfacial effect from comb-like grafted side chains

A significant enhancement in isothermal crystallization kinetics of biodegradable polylactide(PLA) in its immiscible blends can be accomplished through blending it with a comb-like copolymer. PLA was blended with poly(ethylene glycol) methyl ether acrylate(PEGA) and poly[poly(ethylene glycol) methyl ether acrylate](PPEGA, a comb-like copolymer), respectively. The results measured from phase contrast optical microscopy(PCOM) and differential scanning calorimetry(DSC) indicate that PLA and PEGA components are miscible, whereas PLA and PPEGA components are immiscible. The study of crystallization kinetics for PLA/PEGA and PLA/PPEGA blends by means of polarized optical microscopy(POM) and DSC indicates that both PEGA and PPEGA significantly increase the PLA spherulitic growth rates, G, although PLA/PPEGA blends are immiscible and the glass transition temperatures of PLA only have slight decreases. PPEGA component enhances nucleation for PLA crystallization as compared with PEGA component owing to the heterogeneous nucleation effect of PPEGA at the low composition of 20 wt%, while PLA crystallization-induced phase separation for PLA/PEGA blend might cause further nucleation at the high composition of 50 wt%. DSC measurement further demonstrates that isothermal crystallization kinetics can be relatively more enhanced for PLA/PPEGA blends than for PLA/PEGA blends. The "abnormal" enhancement in G for PLA in its immiscible blends can be explained by local interfacial interactions through the densely grafted PEGA side chains in the comb-like PPEGA, even though the whole blend system(PLA/PPEGA blends) represents an immiscible one.

咖啡因预防白内障发生的研究进展

咖啡因又称1,3,7-三甲基黄嘌呤,是一种生物碱,其在神经病学、内科学、妇产科学以及儿科学等领域被广泛研究。近年来,眼科领域对咖啡因也有了一些新的认识。白内障作为人类第一大致盲眼病,目前手术是其唯一根治的方法,部分研究发现咖啡因可以通过抗氧化及抑制细胞凋亡等作用来预防白内障的发生。鉴于此,咖啡因与白内障的关系值得进一步深入研究。笔者就咖啡因在预防白内障发生中的作用机制进行探讨,以期为防治白内障提供新的理论依据。