Nitrogen removal from domestic sewage is usually limited by insufficient carbon source and electron donor.An economical solid carbon source was developed by composition of polyvinyl alcohol,sodium alginate,and corncob...Nitrogen removal from domestic sewage is usually limited by insufficient carbon source and electron donor.An economical solid carbon source was developed by composition of polyvinyl alcohol,sodium alginate,and corncob,which was utilized as external carbon source in the anaerobic anoxic oxic(AAO)-biofilter for the treatment of low carbon-to-nitrogen ratio domestic sewage,and the nitrogen removal was remarkably improved from 63.2%to 96.5%.Furthermore,the effluent chemical oxygen demand maintained at 35 mg/L or even lower,and the total nitrogenwas reduced to less than 2mg/L.Metagenomic analysis demonstrated that the microbial communities responsible for potential denitrification and organic matter degradation in both AAO and the biofilter reactors were mainly composed of Proteobacteria and Bacteroides,respectively.The solid carbon source addition resulted in relatively high abundance of functional enzymes responsible for NO_(3)^(−)-N to NO_(2)^(−)-N con-version in both AAO and the biofilter reactors,thus enabled stable reaction.The carbon source addition during glycolysis primarily led to the increase of genes associated with the metabolic conversion of fructose 1.6P2 to glycerol-3P The reactor maintained high abun-dance of genes related to the tricarboxylic acid cycle,and then guaranteed efficient carbon metabolism.The results indicate that the composite carbon source is feasible for denitri-fication enhancement of AAO-biofilter,which contribute to the theoretical foundation for practical nitrogen removal application.展开更多
Midbrain dopaminergic neurons play an important role in the etiology of neurodevelopmental and neurodegenerative diseases.They also represent a potential source of transplanted cells for therapeutic applications.In vi...Midbrain dopaminergic neurons play an important role in the etiology of neurodevelopmental and neurodegenerative diseases.They also represent a potential source of transplanted cells for therapeutic applications.In vitro differentiation of functional midbrain dopaminergic neurons provides an accessible platform to study midbrain neuronal dysfunction and can be used to examine obstacles to dopaminergic neuronal development.Emerging evidence and impressive advances in human induced pluripotent stem cells,with tuned neural induction and differentiation protocols,makes the production of induced pluripotent stem cell-derived dopaminergic neurons feasible.Using SB431542 and dorsomorphin dual inhibitor in an induced pluripotent stem cell-derived neural induction protocol,we obtained multiple subtypes of neurons,including 20%tyrosine hydroxylase-positive dopaminergic neurons.To obtain more dopaminergic neurons,we next added sonic hedgehog(SHH)and fibroblast growth factor 8(FGF8)on day 8 of induction.This increased the proportion of dopaminergic neurons,up to 75%tyrosine hydroxylase-positive neurons,with 15%tyrosine hydroxylase and forkhead box protein A2(FOXA2)co-expressing neurons.We further optimized the induction protocol by applying the small molecule inhibitor,CHIR99021(CHIR).This helped facilitate the generation of midbrain dopaminergic neurons,and we obtained 31-74%midbrain dopaminergic neurons based on tyrosine hydroxylase and FOXA2 staining.Thus,we have established three induction protocols for dopaminergic neurons.Based on tyrosine hydroxylase and FOXA2 immunostaining analysis,the CHIR,SHH,and FGF8 combined protocol produces a much higher proportion of midbrain dopaminergic neurons,which could be an ideal resource for tackling midbrain-related diseases.展开更多
Soil horizon and vegetation cover significantly impact the spatial patterns of soil fungal and bacterial communities.However,such impacts and their interactions are poorly characterized in dry–hot environments.Soil s...Soil horizon and vegetation cover significantly impact the spatial patterns of soil fungal and bacterial communities.However,such impacts and their interactions are poorly characterized in dry–hot environments.Soil samples were collected from two soil horizons(humus and mineral)along a vegetation gradient(shrubland,grassland,and shrub–grass ecotone)in a dry-hot valley of Southwestern China to assess the effects of vegetation versus soil horizons on shaping soil microbial communities.We used denaturing gradient gel electrophoresis to estimate the microbial spatial pattern change across the vegetation gradients and clone libraries targeting small subunit rRNA genes to characterize the microbial community structures between distinct vegetation types and soil horizons.Bacterial DNA profile patterns were not significantly different across vegetation types but strongly correlated with soil horizons,with significant interaction effects.By contrast,fungi were remarkably different across vegetation types and soil horizons,without significant interactions effect.Distinct vegetation types did not necessarily harbor distinct bacterial or fungal community compositions.Rather,both community compositions were most strongly affected by the soil horizons.Together with these results,the soil vertical heterogeneity rather than vegetation changes is suggested to best predict shifts in soil microbial communities in this dry-hot valley area.展开更多
Chemodiversity of dissolved organic matter(DOM)is a crucial factor controlling soil nutrient availability,greenhouse gas emissions,and pollutant migration.Microplastics(MPs)are widespread pollutants in terrestrial eco...Chemodiversity of dissolved organic matter(DOM)is a crucial factor controlling soil nutrient availability,greenhouse gas emissions,and pollutant migration.Microplastics(MPs)are widespread pollutants in terrestrial ecosystems in many regions.However,the effects of MPs on DOM chemodiversity are not sufficiently understood,particularly under different types of polymers.Using UV-Vis spectroscopy,3D fluorescence spectroscopy,and Fourier-transform ion cyclotron resonance mass spectrometry,the effects of three prevalent MPs[polyethylene,polystyrene,and polyvinyl chloride(PVC)]on the chemical properties and composition of soil DOM were investigated via a 310-d soil incubation experiment.The results showed that MPs reduced the aromatic and hydrophobic soil DOM components by more than 20%,with PVC MPs having the greatest effect.Furthermore,as MP contents increase,the humification level of soil DOM significantly decreases.MPs increased DOM molecules with no heteroatom by 8.3%-14.0%,but decreased DOM molecules with nitrogen content by 17.0%-47.8%.This may be because MPs cause positive“priming effect,”resulting in the breakdown of bioavailable components in soil DOM.This is also related to MPs changing microbial richness and diversity and enriching microbial communities involved in lignin compositions degradation.In the presence of MPs,soil DOM chemodiversity depended on soil pH,electrical conductivity,dissolved organic carbon,soil organic matter,bacterial Shannon,and fungal Chao index.Specifically,DOM in MP-contaminated soils featured more lipids and less condensed aromatics and proteins/amino sugars,thereby conferring a lower DOM aromaticity and higher lability.展开更多
The aim of this work is to develop a venlafaxine hydrochloride sustained release system based on hollow mesoporous silica microspheres(HMSMs).HMSMs were innovatively prepared with tetraethyl silicate(TEOS)as the precu...The aim of this work is to develop a venlafaxine hydrochloride sustained release system based on hollow mesoporous silica microspheres(HMSMs).HMSMs were innovatively prepared with tetraethyl silicate(TEOS)as the precursor and volatile n-heptane as a soft template.The obtained HMSMs show a well-defined hollow structure with an average size of 967 nm and pore volume of 0.85 cm^(3)/g,implying it is a potential drug carrier.Subsequently,venlafaxine hydrochloride(VF)was absorbed in the HMSMs with a content of 37.67% or so.The sustained release effect is further measured by the dissolution in-strument at 37℃ and 50 rpm in ultrapure water.The results showed that the HMSMs/VF system shows good sustained release properties compared with sustained release tablets with hydroxypropyl meth-ylcellulose as the main component.This HMSMs sustained release system appears to be a promising candidate for a sustained drug release.展开更多
Fungi outperformed bacterial in maintaining the microbial co-occurrence networks.Fungi showed different elevational network co-occurrence pattern from bacteria.Distinct biotic/abiotic factors influenced bacterial and ...Fungi outperformed bacterial in maintaining the microbial co-occurrence networks.Fungi showed different elevational network co-occurrence pattern from bacteria.Distinct biotic/abiotic factors influenced bacterial and fungal network dynamics.The interplay between soil micro-organisms in mountain ecosystems critically influences soil biogeochemical cycles and ecosystem processes.However,factors affecting the co-occurrence patterns of soil microbial communities remain unclear.In an attempt to understand how these patterns shift with elevation and identify the key explanatory factors underpinning these changes,we studied soil bacterial and fungal co-occurrence networks on Mt.Seorak,Republic of Korea.Amplicon sequencing was used to target the 16S rRNA gene and ITS2 region for bacteria and fungi,respectively.In contrast to bacteria,we found that fungi were predominantly situated in the core positions of the network,with significantly weakened co-occurrence with increasing elevation.The different co-occurrence patterns of fungal and bacterial communities could be resulted from their distinct responses to various environments.Both abiotic and biotic factors contributed significantly to shaping co-occurrence networks of bacterial and fungal communities.Fungal richness,bacterial community composition(indicated by PCoA1),and soil pH were the predominant factors influencing the variation in the entire microbial co-occurrence network.Biotic factors,such as the composition and diversity of bacterial communities,significantly influenced bacterial co-occurrence networks.External biotic and abiotic factors,including climatic and vegetative conditions,had a significant influence on fungal co-occurrence networks.These findings enhance our understanding of soil microbiota co-occurrences and deepen our knowledge of soil microbiota responses to climatic changes across elevational gradients in mountain ecosystems.展开更多
基金supported by the Special Funds for Chengde national innovation demonstration area construction of science and technology special project sustainable development agenda(No.202104F001)the National Basic Research Program of China(No.2019YFC0408602).
文摘Nitrogen removal from domestic sewage is usually limited by insufficient carbon source and electron donor.An economical solid carbon source was developed by composition of polyvinyl alcohol,sodium alginate,and corncob,which was utilized as external carbon source in the anaerobic anoxic oxic(AAO)-biofilter for the treatment of low carbon-to-nitrogen ratio domestic sewage,and the nitrogen removal was remarkably improved from 63.2%to 96.5%.Furthermore,the effluent chemical oxygen demand maintained at 35 mg/L or even lower,and the total nitrogenwas reduced to less than 2mg/L.Metagenomic analysis demonstrated that the microbial communities responsible for potential denitrification and organic matter degradation in both AAO and the biofilter reactors were mainly composed of Proteobacteria and Bacteroides,respectively.The solid carbon source addition resulted in relatively high abundance of functional enzymes responsible for NO_(3)^(−)-N to NO_(2)^(−)-N con-version in both AAO and the biofilter reactors,thus enabled stable reaction.The carbon source addition during glycolysis primarily led to the increase of genes associated with the metabolic conversion of fructose 1.6P2 to glycerol-3P The reactor maintained high abun-dance of genes related to the tricarboxylic acid cycle,and then guaranteed efficient carbon metabolism.The results indicate that the composite carbon source is feasible for denitri-fication enhancement of AAO-biofilter,which contribute to the theoretical foundation for practical nitrogen removal application.
基金supported by the National Natural Science Foundation of China,No.81771222(to LS)Guangzhou Key Research Program on Brain Science,Nos.202007030011,202206060001(to LS)the Program of Introducing Talents of Discipline to Universities of China,No.B14036(to KFS)。
文摘Midbrain dopaminergic neurons play an important role in the etiology of neurodevelopmental and neurodegenerative diseases.They also represent a potential source of transplanted cells for therapeutic applications.In vitro differentiation of functional midbrain dopaminergic neurons provides an accessible platform to study midbrain neuronal dysfunction and can be used to examine obstacles to dopaminergic neuronal development.Emerging evidence and impressive advances in human induced pluripotent stem cells,with tuned neural induction and differentiation protocols,makes the production of induced pluripotent stem cell-derived dopaminergic neurons feasible.Using SB431542 and dorsomorphin dual inhibitor in an induced pluripotent stem cell-derived neural induction protocol,we obtained multiple subtypes of neurons,including 20%tyrosine hydroxylase-positive dopaminergic neurons.To obtain more dopaminergic neurons,we next added sonic hedgehog(SHH)and fibroblast growth factor 8(FGF8)on day 8 of induction.This increased the proportion of dopaminergic neurons,up to 75%tyrosine hydroxylase-positive neurons,with 15%tyrosine hydroxylase and forkhead box protein A2(FOXA2)co-expressing neurons.We further optimized the induction protocol by applying the small molecule inhibitor,CHIR99021(CHIR).This helped facilitate the generation of midbrain dopaminergic neurons,and we obtained 31-74%midbrain dopaminergic neurons based on tyrosine hydroxylase and FOXA2 staining.Thus,we have established three induction protocols for dopaminergic neurons.Based on tyrosine hydroxylase and FOXA2 immunostaining analysis,the CHIR,SHH,and FGF8 combined protocol produces a much higher proportion of midbrain dopaminergic neurons,which could be an ideal resource for tackling midbrain-related diseases.
基金This study was funded by a grant(No.90302013)of National Natural Science Foundation of China.
文摘Soil horizon and vegetation cover significantly impact the spatial patterns of soil fungal and bacterial communities.However,such impacts and their interactions are poorly characterized in dry–hot environments.Soil samples were collected from two soil horizons(humus and mineral)along a vegetation gradient(shrubland,grassland,and shrub–grass ecotone)in a dry-hot valley of Southwestern China to assess the effects of vegetation versus soil horizons on shaping soil microbial communities.We used denaturing gradient gel electrophoresis to estimate the microbial spatial pattern change across the vegetation gradients and clone libraries targeting small subunit rRNA genes to characterize the microbial community structures between distinct vegetation types and soil horizons.Bacterial DNA profile patterns were not significantly different across vegetation types but strongly correlated with soil horizons,with significant interaction effects.By contrast,fungi were remarkably different across vegetation types and soil horizons,without significant interactions effect.Distinct vegetation types did not necessarily harbor distinct bacterial or fungal community compositions.Rather,both community compositions were most strongly affected by the soil horizons.Together with these results,the soil vertical heterogeneity rather than vegetation changes is suggested to best predict shifts in soil microbial communities in this dry-hot valley area.
基金supported by the National Key Research and Development Program of China(No.2020YFC1909502)the Yangtze River Join Phase II Program(No.2022-LHYJ-02-0509-05).
文摘Chemodiversity of dissolved organic matter(DOM)is a crucial factor controlling soil nutrient availability,greenhouse gas emissions,and pollutant migration.Microplastics(MPs)are widespread pollutants in terrestrial ecosystems in many regions.However,the effects of MPs on DOM chemodiversity are not sufficiently understood,particularly under different types of polymers.Using UV-Vis spectroscopy,3D fluorescence spectroscopy,and Fourier-transform ion cyclotron resonance mass spectrometry,the effects of three prevalent MPs[polyethylene,polystyrene,and polyvinyl chloride(PVC)]on the chemical properties and composition of soil DOM were investigated via a 310-d soil incubation experiment.The results showed that MPs reduced the aromatic and hydrophobic soil DOM components by more than 20%,with PVC MPs having the greatest effect.Furthermore,as MP contents increase,the humification level of soil DOM significantly decreases.MPs increased DOM molecules with no heteroatom by 8.3%-14.0%,but decreased DOM molecules with nitrogen content by 17.0%-47.8%.This may be because MPs cause positive“priming effect,”resulting in the breakdown of bioavailable components in soil DOM.This is also related to MPs changing microbial richness and diversity and enriching microbial communities involved in lignin compositions degradation.In the presence of MPs,soil DOM chemodiversity depended on soil pH,electrical conductivity,dissolved organic carbon,soil organic matter,bacterial Shannon,and fungal Chao index.Specifically,DOM in MP-contaminated soils featured more lipids and less condensed aromatics and proteins/amino sugars,thereby conferring a lower DOM aromaticity and higher lability.
基金supported by the National Natural Science Foundation of China(grant No.22075252).
文摘The aim of this work is to develop a venlafaxine hydrochloride sustained release system based on hollow mesoporous silica microspheres(HMSMs).HMSMs were innovatively prepared with tetraethyl silicate(TEOS)as the precursor and volatile n-heptane as a soft template.The obtained HMSMs show a well-defined hollow structure with an average size of 967 nm and pore volume of 0.85 cm^(3)/g,implying it is a potential drug carrier.Subsequently,venlafaxine hydrochloride(VF)was absorbed in the HMSMs with a content of 37.67% or so.The sustained release effect is further measured by the dissolution in-strument at 37℃ and 50 rpm in ultrapure water.The results showed that the HMSMs/VF system shows good sustained release properties compared with sustained release tablets with hydroxypropyl meth-ylcellulose as the main component.This HMSMs sustained release system appears to be a promising candidate for a sustained drug release.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea Government(MSIP)(Grant Nos.NRF-2018R1C1B6007755 and NRF-2022R1F1A1066643)supported by a grant(No.20SCIP-C158976-01)from Construction Technology Research Program funded by Ministry of Land,Infrastructure and Transport of Korean Government+2 种基金the Guangxi Natural Science Foundation(Grant No.2018GXNSFDA281006)the National Natural Science Foundation of China(Grant No.41966005)the‘One Hundred Talents’Project of Guangxi(Grant No.6020303891251).
文摘Fungi outperformed bacterial in maintaining the microbial co-occurrence networks.Fungi showed different elevational network co-occurrence pattern from bacteria.Distinct biotic/abiotic factors influenced bacterial and fungal network dynamics.The interplay between soil micro-organisms in mountain ecosystems critically influences soil biogeochemical cycles and ecosystem processes.However,factors affecting the co-occurrence patterns of soil microbial communities remain unclear.In an attempt to understand how these patterns shift with elevation and identify the key explanatory factors underpinning these changes,we studied soil bacterial and fungal co-occurrence networks on Mt.Seorak,Republic of Korea.Amplicon sequencing was used to target the 16S rRNA gene and ITS2 region for bacteria and fungi,respectively.In contrast to bacteria,we found that fungi were predominantly situated in the core positions of the network,with significantly weakened co-occurrence with increasing elevation.The different co-occurrence patterns of fungal and bacterial communities could be resulted from their distinct responses to various environments.Both abiotic and biotic factors contributed significantly to shaping co-occurrence networks of bacterial and fungal communities.Fungal richness,bacterial community composition(indicated by PCoA1),and soil pH were the predominant factors influencing the variation in the entire microbial co-occurrence network.Biotic factors,such as the composition and diversity of bacterial communities,significantly influenced bacterial co-occurrence networks.External biotic and abiotic factors,including climatic and vegetative conditions,had a significant influence on fungal co-occurrence networks.These findings enhance our understanding of soil microbiota co-occurrences and deepen our knowledge of soil microbiota responses to climatic changes across elevational gradients in mountain ecosystems.
