全球挥发性有机化合物定义解析

论述了挥发性有机化合物的定义,分析了每种定义的优缺点,指出理想的VOCs定义应满足以下3个条件:一是涵盖所有已经使用的VOCs,二是容易区分化合物是否是VOCs,三是不仅包括环境效应,而且要包括健康效应。

Trends of chemical speciation profiles of anthropogenic volatile organic compounds emissions in China, 2005-2020

This study estimates the detailed chemical profiles of China＇s anthropogenic volatile organic com- pounds （VOCs） emissions for the period of 2005-2020. The chemical profiles of VOCs for seven activity sectors are calculated, based on which the Photochemical Ozone Creation Potential （POCP） of VOCs for these sectors is evaluated. At the national level, the VOCs species emitted in 2005 include alkanes, alkenes and alkynes, aromatic compounds, alcohols, ketones, aldehydes, esters, ethers and halocarbons, accounting for 26.4wt.%, 29.2wt.%, 21.3 wt.%, 4.7 wt.%, 5.4 wt.%, 1.7 wt.%, 2.1 wt.%, 0.7 wt. % and 2.2wt.% of total emissions, respectively. And during 2005-2020, their mass proportions would respec- tively grow or decrease by - 34.7%, -48.6%, 108.5%, 6.9%, -32.7%, 7.3%, 65.3%, 100.5%, and 55.4%. This change would bring about a 13% reduction of POCP for national VOCs emissions in the future. Thus, although the national VOCs emissions are expected to increase by 33% over the whole period, its ozone formation potential is estimated to rise only by 14%. Large discrepancies are found in VOCs speciation emissions among provinces. Compared to western provinces, the eastern provinces with a more developed economy would emit unsaturated hydrocarbons and benzene with lower mix ratios, and aromatic compounds except benzene, oxidized hydrocar- bons and halocarbons with higher mix ratios. Such differences lead to lower POCP of VOCs emitted in eastern provinces, and higher POCP of VOCs emitted in western provinces. However, due to the large VOCs emissions from Chinese eastern region, the ozone forma- tion potential of VOCs emission in eastern provinces would be much higher than those in western provinces by about 156%-235%.

High quality genome sequences of thirteen Hypoxylaceae(Ascomycota)strengthen the phylogenetic family backbone and enable the discovery of new taxa

The Hypoxylaceae(Xylariales,Ascomycota)is a diverse family of mainly saprotrophic fungi,which commonly occur in angiosperm-dominated forests around the world.Despite their importance in forest and plant ecology as well as a prolific source of secondary metabolites and enzymes,genome sequences of related taxa are scarce and usually derived from envi-ronmental isolates.To address this lack of knowledge thirteen taxonomically well-defined representatives of the family and one member of the closely related Xylariaceae were genome sequenced using combinations of Illumina and Oxford nanopore technologies or PacBio sequencing.The workflow leads to high quality draft genome sequences with an average N50 of 3.0 Mbp.A backbone phylogenomic tree was calculated based on the amino acid sequences of 4912 core genes reflecting the current accepted taxonomic concept of the Hypoxylaceae.A Percentage of Conserved Proteins(POCP)analysis revealed that 70%of the proteins are conserved within the family,a value with potential application for the definition of family boundaries within the order Xylariales.Also,Hypomontagnella spongiphila is proposed as a new marine derived lineage of Hypom.monticulosa based on in-depth genomic comparison and morphological differences of the cultures.The results showed that both species share 95%of their genes corresponding to more than 700 strain-specific proteins.This difference is not reflected by standard taxonomic assessments(morphology of sexual and asexual morph,chemotaxonomy,phylogeny),preventing species delimitation based on traditional concepts.Genetic changes are likely to be the result of environmental adaptations and selective pressure,the driving force of speciation.These data provide an important starting point for the establishment of a stable phylogeny of the Xylariales;they enable studies on evolution,ecological behavior and biosynthesis of natural products;and they significantly advance the taxonomy of fungi.