茶叶主要特征性化合物抗心血管炎症研究进展

慢性炎症是诱发动脉粥样硬化、高血压、心肌梗死等心血管疾病的重要原因之一。炎症因子如IL-6、TNF-α、IL-1β等均能导致心肌肥大、心肌纤维化和血管平滑肌细胞异常增殖。茶叶中富含的多种特征性化合物如茶多酚、茶氨酸、茶黄素、咖啡碱等,它们通过抑制重要炎症介质的产生和调控NF-κB、MAPK、Tolls样受体等信号通路,抑制心血管炎症的发生及发展,对心血管疾病具有预防和治疗作用。本文综述了近几年茶叶中的茶多酚、茶氨酸、茶黄素等特征成分通过抑制心血管炎症预防心血管疾病的作用及其机制的研究进展。     

红蓝光处理草莓组培苗的转录组测序与分析

【目的】光质对草莓的生理生化关键通路及基因的调控极为重要,为进一步研究草莓光敏基因奠定基础,同时也为草莓无毒种苗的繁育提供一定理论依据。【方法】以‘章姬’草莓组培苗为试材,以红蓝光的6种光配比处理为条件,采用转录组测序分析、pathway分析、KEGG数据库分析等技术试图从分子水平进行研究光处理对草莓组培苗的影响机制。【结果】获得了6个转录组文库,分别获得的Clean reads为34,325,533、34,870,504、36,127,081、22,665,945、23,731,628、26,593,530,基于KEGG数据库的分析,对受光质调节的4个通路糖酵解/糖异生代谢通路、卟啉和叶绿素代谢通路、光合作用、植物激素信号转导通路中差异性表达基因的数量及位置进行了具体分析。【结论】不同配比的红蓝光对草莓组培苗的有机物的积累与代谢、光合作用、叶绿素的产生与代谢、植物激素的产生均有明显作用,为下一步进行具体基因的研究提供方向和依据。     

蛋氨酸及其羟基类似物的吸收和代谢

本文概述了蛋氨酸及其类似物的吸收、转运机制和代谢途径等方面内容,并结合实际分析了二者生物学效价存在较大争议的各方面原因,指出要解决分歧的关键在于更加深入地了解二者吸收和代谢的机制。     

杂交水稻的根呼吸--四种耗氧途径的活力和P/O比

对杂交水稻赣化７号和其亲本之一广抗粳２号的根系耗氧特征进行了研究,稻株种植在通气的营养液中,４种耗氧途径的活力被量化分析。过氧化物酶耗氧占了较大的比例,龙胆酸可抑制稻根中的过氧化物酶活力。杂交水稻的过氧化物酶和抗氰酸呼吸途径耗氧率比其亲本高５０％以上,杂交水稻和其亲本根系过氧化物酶的耗氧分别占总量的２６．５％和２２．６％,细胞色素氧化酶途径分别占３５．５％和４０．５％,抗氰酸呼吸途径分别占２７．８     

Effects of plant roots on soil preferential pathways and soil matrix in forest ecosystems

To characterize effects of plant roots on preferential flow(PF),we measured root length density(RLD)and root biomass(RB) in Jiufeng National Forest Park,Beijing,China.Comparisons were made for RLD and RB between soil preferential pathways and soil matrices.RLD and RB declined with the increasing soil depth(0–10,10–20,20–30,30–40,40–50,50–60 cm) in all experimental plots.RLD was greater in soil preferential pathways than in the surrounding soil matrix and was 69.5,75.0 and72.2 % for plant roots of diameter(d) \1,1 \ d \ 3 and3 \ d \ 5 mm,respectively.Fine root systems had the most pivotal influence on soil preferential flow in this forest ecosystem.In all experimental plots,RB content was the sum of RB from soil preferential pathways and the soil matrix in each soil depth.With respect to 6 soil depth gradient(0–10,10–20,20–30,30–40,40–50,50–60 cm) in each plot,the number of soil depth gradient that RB content was greater in soil preferential pathways than in the soil matrix was characterized,and the proportion was68.2 % in all plots.     

节杆菌(Arthrobacter)42-1菌株的分离、鉴定及产肌氨酸氧化酶条件研究

从42 ℃的恒化富集培养物中分离到一株产肌氨酸氧化酶(SOX)的节杆菌.对菌株42-1产酶发酵条件的研究表明,SOX可以被诱导物如肌氨酸、肌酸、肌酐和氯化胆碱诱导产生.在发酵过程中适当减少通气量对SOX的产生有显著的促进作用.葡萄糖等容易利用碳源的存在对SOX合成不产生降解代谢产物的抑制作用.而尿素的存在则对SOX生成有强抑制作用.因而SOX分解肌氨酸的主要作用是为细胞提供生长所需的氮源.     

Diversity and development domains in the Ethiopian highlands

In the discussion on targeting of development interventions there is an ongoing debate on the usefulness of geographic targeting versus targeting of specific household types. In this paper, we examine the degree to which there is heterogeneity in the diversity of livelihood strategies in comparable geographic areas in northern Ethiopia. We use the concept of development domains to quantify differences amongst specific geographic areas (communities) and estimate the degree to which development domain dimensions account for differences in production systems indicators and to what extent variability between the overall results and the observed patterns can be attributed to these development domain dimensions. Our research shows that development domain dimensions matter both for production indicators (choice of technology, investment, cropping pattern and livestock use), as well as for the occurrence of heterogeneity in those indicators. Diversity is especially linked to better market access, homogeneity in agricultural production indicators to poor soils. This offers scope for targeting development interventions.     

Soil pH is a good predictor of the dominating N2O production processes under aerobic conditions

It is commonly believed that nitrification is the dominant process for N₂O production under aerobic conditions. However, this has been challenged by recent studies on acidic soils, where denitrification has been found to dominate N₂O production. Analyzing the data collected from peer‐reviewed literature, we found that pH was a critical factor regulating N₂O production pathways under aerobic conditions. There is a pH threshold of approx. 4.4, below which denitrification dominated N₂O production and vice versa. A decrease in soil pH can significantly increase the contribution of denitrification to N₂O production. Overall, this mini‐review increases our understanding of N₂O sources in soils under aerobic conditions.