Establishment of human cerebral organoid systems to model early neural development and assess the central neurotoxicity of environmental toxins

Human brain development is a complex process,and animal models often have significant limitations.To address this,researchers have developed pluripotent stem cell-derived three-dimensional structures,known as brain-like organoids,to more accurately model early human brain development and disease.To enable more consistent and intuitive reproduction of early brain development,in this study,we incorporated forebrain organoid culture technology into the traditional unguided method of brain organoid culture.This involved embedding organoids in matrigel for only 7 days during the rapid expansion phase of the neural epithelium and then removing them from the matrigel for further cultivation,resulting in a new type of human brain organoid system.This cerebral organoid system replicated the temporospatial characteristics of early human brain development,including neuroepithelium derivation,neural progenitor cell production and maintenance,neuron differentiation and migration,and cortical layer patterning and formation,providing more consistent and reproducible organoids for developmental modeling and toxicology testing.As a proof of concept,we applied the heavy metal cadmium to this newly improved organoid system to test whether it could be used to evaluate the neurotoxicity of environmental toxins.Brain organoids exposed to cadmium for 7 or 14 days manifested severe damage and abnormalities in their neurodevelopmental patterns,including bursts of cortical cell death and premature differentiation.Cadmium exposure caused progressive depletion of neural progenitor cells and loss of organoid integrity,accompanied by compensatory cell proliferation at ectopic locations.The convenience,flexibility,and controllability of this newly developed organoid platform make it a powerful and affordable alternative to animal models for use in neurodevelopmental,neurological,and neurotoxicological studies.

Target the neglected VOCs emission from iron and steel industry in China for air quality improvement

Recent years have witnessed significant improvement in China’s air quality.Strict environmental protection measures have led to significant decreases in sulfur dioxide(SO2),nitrogen oxides(NOx),and particulate matter(PM)emissions since 2013.But there is no denying that the air quality in 135 cities is inferior to reaching the Ambient Air Quality Standards(GB 3095–2012)in 2020.In terms of temporal,geographic,and historical aspects,we have analyzed the potential connections between China’s air quality and the iron and steel industry.The non-target volatile organic compounds(VOCs)emissions from iron and steel industry,especially from the iron ore sinter process,may be an underappreciated index imposing a negative effect on the surrounding areas of China.Therefore,we appeal the authorities to pay more attention on VOCs emission from the iron and steel industry and establish new environmental standards.And different iron steel flue gas pollutants will be eliminated concurrently with the promotion and application of new technology.

Catalytic and highly stereoselectiveβ-mannopyranosylation using a 2,6-lactone-bridged mannopyranosyl ortho-hexynylbenzoate as donor

An efficient and catalytic protocol for highly stereoselective construction ofβ-mannopyranosylation has been developed.Glycosylation of 2,6-lactone-bridged mannopyranosyl ortho-hexynylbenzoate with various acceptors proceeded smoothly in the presence of 5%Hg(Ⅱ)at room temperature,resulting in the correspondingβ-mannosides in high yield and exclusiveβ-stereoselectivity.