Initial success has been achieved in Hong Kong in controlling primary air pollutants,but ambient ozone levels kept increasing during the past three decades.Volatile organic compounds(VOCs)are important for mitigating ...Initial success has been achieved in Hong Kong in controlling primary air pollutants,but ambient ozone levels kept increasing during the past three decades.Volatile organic compounds(VOCs)are important for mitigating ozone pollution as its major precursors.This study analyzed VOC characteristics of roadside,suburban,and rural sites in Hong Kong to investigate their compositions,concentrations,and source contributions.Herewe showthat the TVOC concentrations were 23.05±13.24,12.68±15.36,and 5.16±5.48 ppbv for roadside,suburban,and rural sites between May 2015 to June 2019,respectively.By using Positive Matrix Factorization(PMF)model,six sources were identified at the roadside site over five years:Liquefied petroleum gas(LPG)usage(33%–46%),gasoline evaporation(8%–31%),aged air mass(11%–28%),gasoline exhaust(5%–16%),diesel exhaust(2%–16%)and fuel filling(75–9%).Similarly,six sources were distinguished at the suburban site,including LPG usage(30%–33%),solvent usage(20%–26%),diesel exhaust(14%–26%),gasoline evaporation(8%–16%),aged air mass(4%–11%),and biogenic emissions(2%–5%).At the rural site,four sources were identified,including aged airmass(33%–51%),solvent usage(25%–30%),vehicular emissions(11%–28%),and biogenic emissions(6%–12%).The analysis further revealed that fuel filling and LPG usage were the primary contributors to OFP and OH reactivity at the roadside site,while solvent usage and biogenic emissions accounted for almost half of OFP and OH reactivity at the suburban and rural sites,respectively.These findings highlight the importance of identifying and characterizing VOC sources at different sites to help policymakers develop targeted measures for pollution mitigation in specific areas.展开更多
Furniture is identified as a vital volatile organic compound(VOC)emission source in the indoor environment.Leather has become the most common raw and auxiliary fabric material for upholstered furniture,particularly wi...Furniture is identified as a vital volatile organic compound(VOC)emission source in the indoor environment.Leather has become the most common raw and auxiliary fabric material for upholstered furniture,particularly with extensive consumption in sofas,due to its abundant resources and efficient functions.Despite being widely traded across the world,little research has been conducted on the VOCs released by leathermaterials and their health risk assessment in the indoor environment.Accordingly,this study investigated the VOC emissions of leather with different grades and the health risk of the inhalation exposure.Based on the ultra-fast gas phase electronic nose(EN)and GC-FID/Qtof,the substantial emissions of aliphatic aldehyde ketones(Aks),particularly hexanal,appear to be the cause of off-flavor in medium and low grade(MG and LG)sofa leathers.The health risk assessment indicated that leather materials barely pose non-carcinogenic and carcinogenic effects to residents.Given the abundance of VOC sources and the accumulation of health risks in the indoor environment,more stringent specifications concerning qualitative and quantitative content should be extended to provide VOC treatment basic for the manufacturing industry and obtain better indoor air quality.展开更多
VOCs(Volatile organic compounds)exert a vital role in ozone and secondary organic aerosol production,necessitating investigations into their concentration,chemical characteristics,and source apportionment for the effe...VOCs(Volatile organic compounds)exert a vital role in ozone and secondary organic aerosol production,necessitating investigations into their concentration,chemical characteristics,and source apportionment for the effective implementation of measures aimed at preventing and controlling atmospheric pollution.FromJuly to October 2020,onlinemonitoringwas conducted in the main urban area of Shijiazhuang to collect data on VOCs and analyze their concentrations and reactivity.Additionally,the PMF(positive matrix factorization)method was utilized to identify the VOCs sources.Results indicated that the TVOCs(total VOCs)concentration was(96.7±63.4μg/m^3),with alkanes exhibiting the highest concentration of(36.1±26.4μg/m^3),followed by OVOCs(16.4±14.4μg/m^3).The key active components were alkenes and aromatics,among which xylene,propylene,toluene,propionaldehyde,acetaldehyde,ethylene,and styrene played crucial roles as reactive species.The sources derived from PMF analysis encompassed vehicle emissions,solvent and coating sources,combustion sources,industrial emissions sources,as well as plant sources,the contribution of which were 37.80%,27.93%,16.57%,15.24%,and 2.46%,respectively.Hence,reducing vehicular exhaust emissions and encouraging neighboring industries to adopt low-volatile organic solvents and coatings should be prioritized to mitigate VOCs levels.展开更多
Ubiquitous contamination of the soil environment with volatile organic compounds(VOCs)has raised considerable concerns.However,there is still limited comprehensive surveying of soil VOCs on a national scale.Herein,65 ...Ubiquitous contamination of the soil environment with volatile organic compounds(VOCs)has raised considerable concerns.However,there is still limited comprehensive surveying of soil VOCs on a national scale.Herein,65 species of VOCswere simultaneously determined in surface soil samples collected from 63 chemical industrial parks(CIPs)across China.The results showed that the total VOC concentrations ranged from 7.15 to 1842 ng/g with a mean concentration of 326 ng/g(median:179 ng/g).Benzene homologs and halogenated hydrocarbons were identified as the dominant contaminant groups.Positive correlations between many VOC species indicated that these compounds probably originated from similar sources.Spatially,the hotspots of VOC pollution were located in eastern and southern China.Soils with higher clay content and a higher fraction of total organic carbon(TOC)content were significantly associated with higher soil VOC concentrations.Precipitation reduces the levels of highly water-soluble substances in surface soils.Both positive matrix factorization(PMF)and principal component analysis-multiple linear regression(PCA-MLR)identified a high proportion of industrial sources(PMF:59.2%and PCA-MLR:66.5%)and traffic emission sources(PMF:32.3%and PCA-MLR:33.5%).PMF,which had a higher R^(2) value(0.7892)than PCA-MLR(0.7683),was the preferred model for quantitative source analysis of soil VOCs.The health risk assessment indicated that the non-carcinogenic and carcinogenic risks of VOCs were at acceptable levels.Overall,this study provides valuable data on the occurrence of VOCs in soil from Chinese CIPs,which is essential for a comprehensive understanding of their environmental behavior.展开更多
Anti-aging research has become a popular scientific field with the increasing prominence of population aging.Rare ginsenoside Compound K(CK)has attracted widespread attention as an emerging anti-aging active ingredien...Anti-aging research has become a popular scientific field with the increasing prominence of population aging.Rare ginsenoside Compound K(CK)has attracted widespread attention as an emerging anti-aging active ingredient.The anti-aging effect of ginsenosides is considered to be one of the important roles of ginsenosides,and Compound K,as the main deglycosylated metabolite of ginsenosides,has a comprehensive anti-aging effect as a highly active ingredient obtained by transformation under the action of microbiota.Recent studies have shown that ginsenosides have anti-photo-oxidation,anti-skin aging,free radical scavenging and immunostimulatory effects,which can effectively prevent skin photoaging.With the progress of modern natural medicine extraction technology and the deepening of the research on the anti-skin aging of ginsenosides'high active ingredients,it will promote the development and application of natural product protective skin photoaging preparations.The rare ginsenoside Compound K plays an important role in the improvement of skin health and anti-aging,which is mainly realized by increasing the activity of antioxidant enzymes,inducing the expression of related genes,reducing the content of oxidative damage substances,regulating the immune system,and influencing the expression of cell-cycle regulators and aging genes.A more comprehensive and in-depth study of the molecular mechanism of the anti-aging effect of rare ginsenoside Compound K will be one of the focuses of future research.展开更多
The current study aimed to evaluate the efficacy and safety of Compound Danshen Dripping Pills(CDDP)in improving cardiac function in patients with acute anterior ST-segment elevation myocardial infarction(AAMI).Betwee...The current study aimed to evaluate the efficacy and safety of Compound Danshen Dripping Pills(CDDP)in improving cardiac function in patients with acute anterior ST-segment elevation myocardial infarction(AAMI).Between February 2021 and February 2023,247 eligible patients with AAMI after primary percutaneous coronary intervention were enrolled and randomly assigned(1∶1)to receive CDDP(n=126)or placebo(n=121),with a follow-up of 48 weeks.Compared with the placebo group,the CDDP group demonstrated a significant increase in left ventricular ejection fraction values after 24 weeks of treatment(least squares mean:3.31;95%confidence interval[CI]:1.72–4.90;P<0.001)and at the 48-week follow-up(least squares mean:4.35;95%CI:2.76–5.94;P<0.001).Significant reductions in N-terminal pro-B-type natriuretic peptide levels were observed in both groups at the 24-and 48-week visits with no significant difference between the two groups(P>0.1 for all).The incidence of major adverse cardiovascular and cerebrovascular events was 6.35%in the CDDP group and 5.79%in the placebo group(P=0.822).Notably,no serious adverse events were attributed to CDDP.These findings suggest that CDDP may be well tolerated and could improve left ventricular ejection fraction in patients with AAMI at 24 and 48 weeks.展开更多
To explore the potential utilization of Elaeagnus mollis,we conducted a comprehensive assessment of its phytochemical composition,antioxidant properties,cholinesterase inhibition,and anti-HepG2 cell proliferation acti...To explore the potential utilization of Elaeagnus mollis,we conducted a comprehensive assessment of its phytochemical composition,antioxidant properties,cholinesterase inhibition,and anti-HepG2 cell proliferation activity across different plant parts(branch wood,branch bark,and pericarp)using various solvents(water,methanol,ethanol,and n-hexane).Our findings revealed that water extracts displayed superior antioxidant activities in ABTS and RP assays,while methanol extracts exhibited better performance in DPPH and FRAP assays.Moreover,methanol extracts demonstrated the highest effectiveness against anti-HepG2 cell proliferation,whereas n-hexane extracts showed greater efficiency in cholinesterase inhibition.Notably,branch bark extracts exhibited the highest levels of phytochemical compounds,with both branch bark and pericarp extracts demonstrating significant effects in cholinesterase inhibition and anti-HepG2 cell proliferation.Correlation analysis indicated that phytochemical compounds were primarily responsible for the observed biological activities.Overall,extracts from the branch bark and pericarp of E.mollis showed promising potential for antioxidant and anticancer activities,suggesting their suitability for applications in the pharmaceutical industry as health-promoting products.展开更多
Emission characteristics of biogenic volatile organic compounds(BVOCs)from dominant tree species in the subtropical pristine forests of China are extremely limited.Here we conducted in situ field measurements of BVOCs...Emission characteristics of biogenic volatile organic compounds(BVOCs)from dominant tree species in the subtropical pristine forests of China are extremely limited.Here we conducted in situ field measurements of BVOCs emissions from representative mature evergreen trees by using dynamic branch enclosures at four altitude gradients(600-1690ma.s.l.)in the Nanling Mountains of southern China.Composition characteristics as well as seasonal and altitudinal variations were analyzed.Standardized emission rates and canopyscale emission factors were then calculated.Results showed that BVOCs emission intensities in the wet season were generally higher than those in the dry season.Monoterpenes were the dominant BVOCs emitted from most broad-leaved trees,accounting for over 70%of the total.Schima superba,Yushania basihirsuta and Altingia chinensis had relatively high emission intensities and secondary pollutant formation potentials.The localized emission factors of isoprene were comparable to the defaults in the Model of Emissions of Gases and Aerosols fromNature(MEGAN),while emission factors of monoterpenes and sesquiterpenes were 2 to 58 times of those in the model.Our results can be used to update the current BVOCs emission inventory in MEGAN,thereby reducing the uncertainties of BVOCs emission estimations in forested regions of southern China.展开更多
Visible-light-mediated O-H functionalization reactions of alcohols with diazo compounds have been fully developed in recent years.However,alkenyl and acetylenic alcohols were rarely examined in these reactions due to ...Visible-light-mediated O-H functionalization reactions of alcohols with diazo compounds have been fully developed in recent years.However,alkenyl and acetylenic alcohols were rarely examined in these reactions due to the inevitable side reactions involving cycloaddition.Herein,the visible-light-mediated O-H functionalization reactions of alkenyl alcohols with diazo compounds were developed.This process competed favorably with the cycloaddition reaction.A series of multifunctional ethers were provided in low to high yields with aryldiazoacetates or 3-diazooxindoles.Biologically relevant spirooxindole-fused oxacycle could be easily accessed from the O-H functionalization product of alkenyl alcohol and 3-diazooxindole.展开更多
The Rh(III)-catalyzed C—H functionalization of sulfoxonium ylides and successively annulation with two classes of cyclic diazo compounds has been realized,affording structurally diverse fused-ring or spirocyclic comp...The Rh(III)-catalyzed C—H functionalization of sulfoxonium ylides and successively annulation with two classes of cyclic diazo compounds has been realized,affording structurally diverse fused-ring or spirocyclic compounds under redoxneutral conditions.The reaction proceeds via successive chelation-assisted C—H activation,carbene insertion,and intramolecular[3+3]/[4+1]annulation processes.展开更多
Employing the principle of active moiety concatenation, a novel series of symmetrical triazine compounds were designed. A series of novel triazine compounds were synthesized using cyanuric chloride, amines, and chalco...Employing the principle of active moiety concatenation, a novel series of symmetrical triazine compounds were designed. A series of novel triazine compounds were synthesized using cyanuric chloride, amines, and chalcones as the initial reactants. The structures of these compounds were characterized through FT-IR, 1H-NMR, 13C-NMR, high-resolution mass spectrometry (HRMS) and high performance liquid chromatography (HPLC). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetra- zolium bromide (MTT) assay was employed to evaluate the in vitro anti-proliferative activity of the new s-triazine compounds against human lung cancer cells (A549), human cervical cancer cells (HeLa), human breast cancer cells (MCF-7) and human colon cancer cells (SW620). The findings indicated that several compounds exhibited promising antitumor effects. Notably, (E)-1-(4-((4,6-dimorpholino-1,3,5-triazin-2-yl)oxy)phenyl)-3-(thiophen-2-yl)prop-2-en-1-one (3bg) demonstrated efficacy as a broad-spectrum anticancer agent, exhibiting significant activity against the A549, HeLa, and MCF-7 cell lines. Furthermore, (E)-1-(4-((4,6-dimorpholino-1,3,5-triazin-2-yl)oxy)phenyl)-3-phenylprop-2-en-1-one (3bb) displayed the most potent in vitro antitumor activity against the MCF-7 cell line with an IC_(50) value of 16.4 μmol/L, establishing it as the most active compound in assay.展开更多
Direct enantioselective allylic C—H functionalization has emerged as a powerful strategy for the asymmetric syn-thesis of highly valuable chiral products.Herein,a Rh(III)-catalyzed enantioselective allylic C—H alkyl...Direct enantioselective allylic C—H functionalization has emerged as a powerful strategy for the asymmetric syn-thesis of highly valuable chiral products.Herein,a Rh(III)-catalyzed enantioselective allylic C—H alkylation of unactivated alkenes withα-diazo carbonyl compounds is described,enabling direct access to chiral products with high efficiency(up to 77%yield,92%ee,and>10∶1 B/L(branched/linear)selectivity).This atom-and step-economical protocol directly converts simple,unactivated substrates into valuable enantioenriched products under mild conditions,providing an efficient catalytic system for asymmetric allylic C—H functionalization.展开更多
Nitrogen-containing organic compounds(NOCs)may potentially contribute to aqueous secondary organic aerosols,yet the different formation of NOCs in aerosol particles and cloud droplets remains unclear.With the in-situ ...Nitrogen-containing organic compounds(NOCs)may potentially contribute to aqueous secondary organic aerosols,yet the different formation of NOCs in aerosol particles and cloud droplets remains unclear.With the in-situ measurements performed at a mountain site(1690 m a.s.l.)in southern China,we investigated the formation of NOCs in the cloud droplets and the cloud-free particles,based on their mixing state information of NOCscontaining particles by single particle mass spectrometry.The relative abundance of NOCs in the cloud-free particles was significantly higher than those in cloud residual(cloud RES)particles.NOCs were highly correlated with carbonyl compounds(including glyoxalate and methylglyoxal)in the cloud-free particles,however,limited correlation was observed for cloud RES particles.Analysis of their mixing state and temporal variations highlights that NOCs was mainly formed from the carbonyl compounds and ammonium in the cloud-free particles,rather than in the cloud RES particles.The results support that the formation of NOCs from carbonyl compounds is facilitated in concentrated solutions in wet aerosols,rather than cloud droplets.In addition,we have identified the transport of biomass burning particles that facilitate the formation of NOCs,and that the observed NOCs is most likely contributed to the light absorption.These findings have implications for the evaluation of NOCs formation and their contribution to light absorption.展开更多
This research was carried out to identify the most effective plant species for air purification based on environmental factors. The existence of plants beside roadways can be considered a more efficient approach to im...This research was carried out to identify the most effective plant species for air purification based on environmental factors. The existence of plants beside roadways can be considered a more efficient approach to improving air quality and minimizing pollution exposure. The samples for this research were collected from various sites across the streets of Jeddah governorate. The primary sources of air pollution in the research area are vehicle traffic and emissions from cars. Eight species were gathered from various streets in Jeddah governorate, namely, Azadirachta indica, Senna sulfurea, Ziziphus spina-christi, Cordia sebestena, Tecoma stans, Bougainvillea spectabilis, Conocarpus lancifolius, and Ixora coccinea. The leaves of the studied plants were analyzed for secondary compounds using Gas chromatography-mass spectrometry (GC-MS) techniques. Gas-chromatographic analyses revealed that bis (2-ethylhexyl) phthalate was found in every plant. Bis-(2-ethylhexyl) phthalate, a widespread environmental pollutant. Moreover, Cordia sebestena was the sole plant that contained Phenol, 2,2’-methylenebis [6-(1,1-dimethylethyl)-4-methyl] which is part of the phenols category. Environmental conditions can affect the production of secondary metabolites. By tracking the concentrations of these substances, researchers can evaluate the well-being of ecosystems and identify pollution.展开更多
Al/steel bimetallic composites were prepared by compound casting,and the effects of the rotating magnetic field on the interfacial microstructure and shear property of bimetallic composite was investigated.The applica...Al/steel bimetallic composites were prepared by compound casting,and the effects of the rotating magnetic field on the interfacial microstructure and shear property of bimetallic composite was investigated.The application of rotating magnetic field refined the grain structure of the Al alloy matrix,changed the eutectic Si morphology from coarse lath to needle-like.The rotating magnetic field improved the temperature field and solute distribution of the Al alloy melt,enriched a layer of Si at the interface,and suppressed the growth of intermetallic compounds,the thickness of the interface layer decreased from 44.9μm to 22.8μm.The interfacial intermetallic compounds consisted ofη-Al_(5)Fe_(2),θ-Al_(13)Fe_(4),τ6-Al_(4.5)FeSi,τ_(5)-Al_(8)Fe_(2)Si andτ_(3)-Al_(2)FeSi,and the addition of the rotating magnetic field did not change phase composition.The rotating magnetic field improved the stress distribution within the interfacial intermetallic compounds,the presence of high-angle grain boundaries retarded crack extension,and the shear strength was enhanced from 31.27±3 MPa to 52.70±4 MPa.This work provides a feasible method for preparing Al/steel bimetallic composite with good bonding property.展开更多
Selenium(Se),an essential micronutrient among the 15 vital elements required for human physiology,exerts its biological functions primarily through its incorporation into selenoproteins.To date,approximately 25 seleno...Selenium(Se),an essential micronutrient among the 15 vital elements required for human physiology,exerts its biological functions primarily through its incorporation into selenoproteins.To date,approximately 25 selenoproteins have been characterized in mammalian systems,including glutathione peroxidase(GPX),thioredoxin reductase(TrxR),and iodothyronine deiodinases(DIOs),all of which exhibit indispensable physiological functions.展开更多
In the last decade,shell biorefinery,a novel concept referring to the extraction of the main components of crustacean shells and the transformation of each component into valuable products,was proposed and has attract...In the last decade,shell biorefinery,a novel concept referring to the extraction of the main components of crustacean shells and the transformation of each component into valuable products,was proposed and has attracted increasing attentions.Chitin is one of main components of crustacean shells.Owing to the bio-fixed nitrogen element,chitin biomass has been regarded as a good candidate to produce nitrogen-containing chemicals.Among these,3-acetamido-5-acetylfuran(3A5AF)is an interesting furanic compound derived from the hydrolysis and sequential dehydration of chitin.Similar to cellulose-derived platform chemical 5-hydromethylfurfural(HMF),3A5AF is an emerging platform compound and also can be converted into various useful chemicals by oxidation,reduction,hydrolysis,substitution,and so on.This review showcases the recent advances in the synthesis of 3A5AF from chitin and N-acetyl glucosamine(NAG)employing various catalytic systems.The conversion of 3A5AF into valuable compounds was introduced then.There are still some challenges in this area,for example,the rational design of green and efficient catalytic systems for the synthesis of 3A5AF and its derivatives.The outlooks also were discussed at the end of the review.展开更多
The particle swarm optimization algorithm has predicted a series of binary cadmium hydrides that could be dynamically stable at pressures between 100 GPa and 300 GPa.These low-energy phases are composed of both Cd ato...The particle swarm optimization algorithm has predicted a series of binary cadmium hydrides that could be dynamically stable at pressures between 100 GPa and 300 GPa.These low-energy phases are composed of both Cd atoms and H_(2)molecules.Here,we propose a hitherto unknown metastable Cmcm-CdH_(6)phase,consisting of one-dimensional zigzag graphite-like hydrogenic H_(6)chains,quasimolecular H_(2)units and Cd atoms,which is metallic above 290 GPa.Due to H_(2)s→Cd d donation and Cd d→H_(2)σ^(*)back-donation,the electrons occupy antibonding orbitals for both types of hydrogen atoms.This results in weakened chemical bonds in the Cmcm-CdH_(6)phase via a Kubas-like mechanism,promoting the emergence of high superconductivity,which is estimated to be up to~60 K at 290 GPa.This work will inspire the search for superconductivity in materials based on group IIB hydrides under pressure.展开更多
基金supported by Hong Kong Environment Protection Department(Quotation Ref.18-06532)Hong Kong Innovation and Technology Fund(ITS/193/20FP)Hong Kong Research Grants Council(No.26304921).
文摘Initial success has been achieved in Hong Kong in controlling primary air pollutants,but ambient ozone levels kept increasing during the past three decades.Volatile organic compounds(VOCs)are important for mitigating ozone pollution as its major precursors.This study analyzed VOC characteristics of roadside,suburban,and rural sites in Hong Kong to investigate their compositions,concentrations,and source contributions.Herewe showthat the TVOC concentrations were 23.05±13.24,12.68±15.36,and 5.16±5.48 ppbv for roadside,suburban,and rural sites between May 2015 to June 2019,respectively.By using Positive Matrix Factorization(PMF)model,six sources were identified at the roadside site over five years:Liquefied petroleum gas(LPG)usage(33%–46%),gasoline evaporation(8%–31%),aged air mass(11%–28%),gasoline exhaust(5%–16%),diesel exhaust(2%–16%)and fuel filling(75–9%).Similarly,six sources were distinguished at the suburban site,including LPG usage(30%–33%),solvent usage(20%–26%),diesel exhaust(14%–26%),gasoline evaporation(8%–16%),aged air mass(4%–11%),and biogenic emissions(2%–5%).At the rural site,four sources were identified,including aged airmass(33%–51%),solvent usage(25%–30%),vehicular emissions(11%–28%),and biogenic emissions(6%–12%).The analysis further revealed that fuel filling and LPG usage were the primary contributors to OFP and OH reactivity at the roadside site,while solvent usage and biogenic emissions accounted for almost half of OFP and OH reactivity at the suburban and rural sites,respectively.These findings highlight the importance of identifying and characterizing VOC sources at different sites to help policymakers develop targeted measures for pollution mitigation in specific areas.
基金supported by the National Key Research and Development Program of China (No.2019YFC1904501).
文摘Furniture is identified as a vital volatile organic compound(VOC)emission source in the indoor environment.Leather has become the most common raw and auxiliary fabric material for upholstered furniture,particularly with extensive consumption in sofas,due to its abundant resources and efficient functions.Despite being widely traded across the world,little research has been conducted on the VOCs released by leathermaterials and their health risk assessment in the indoor environment.Accordingly,this study investigated the VOC emissions of leather with different grades and the health risk of the inhalation exposure.Based on the ultra-fast gas phase electronic nose(EN)and GC-FID/Qtof,the substantial emissions of aliphatic aldehyde ketones(Aks),particularly hexanal,appear to be the cause of off-flavor in medium and low grade(MG and LG)sofa leathers.The health risk assessment indicated that leather materials barely pose non-carcinogenic and carcinogenic effects to residents.Given the abundance of VOC sources and the accumulation of health risks in the indoor environment,more stringent specifications concerning qualitative and quantitative content should be extended to provide VOC treatment basic for the manufacturing industry and obtain better indoor air quality.
基金supported by the Natural Science Foundation of Hebei Province(Nos.D2019106042,D2020304038,and D2021106002)the National Natural Science Foundation of China(No.22276099)+1 种基金the State Environmental Protection Key Laboratory of Formation and Prevention of Urban Air Pollution Complex(No.2021080544)the Environmental Monitoring Research Foundation of Jiangsu Province(No.2211).
文摘VOCs(Volatile organic compounds)exert a vital role in ozone and secondary organic aerosol production,necessitating investigations into their concentration,chemical characteristics,and source apportionment for the effective implementation of measures aimed at preventing and controlling atmospheric pollution.FromJuly to October 2020,onlinemonitoringwas conducted in the main urban area of Shijiazhuang to collect data on VOCs and analyze their concentrations and reactivity.Additionally,the PMF(positive matrix factorization)method was utilized to identify the VOCs sources.Results indicated that the TVOCs(total VOCs)concentration was(96.7±63.4μg/m^3),with alkanes exhibiting the highest concentration of(36.1±26.4μg/m^3),followed by OVOCs(16.4±14.4μg/m^3).The key active components were alkenes and aromatics,among which xylene,propylene,toluene,propionaldehyde,acetaldehyde,ethylene,and styrene played crucial roles as reactive species.The sources derived from PMF analysis encompassed vehicle emissions,solvent and coating sources,combustion sources,industrial emissions sources,as well as plant sources,the contribution of which were 37.80%,27.93%,16.57%,15.24%,and 2.46%,respectively.Hence,reducing vehicular exhaust emissions and encouraging neighboring industries to adopt low-volatile organic solvents and coatings should be prioritized to mitigate VOCs levels.
基金supported by the Medical and Health Projects in Zhejiang Province(No.2022PY049)the Basic Scientific Research Project of Hangzhou Medical College(No.YS2021006)Key Discipline of Zhejiang Province in Public Health and Preventive Medicine(First Class,Category A),Hangzhou Medical College.
文摘Ubiquitous contamination of the soil environment with volatile organic compounds(VOCs)has raised considerable concerns.However,there is still limited comprehensive surveying of soil VOCs on a national scale.Herein,65 species of VOCswere simultaneously determined in surface soil samples collected from 63 chemical industrial parks(CIPs)across China.The results showed that the total VOC concentrations ranged from 7.15 to 1842 ng/g with a mean concentration of 326 ng/g(median:179 ng/g).Benzene homologs and halogenated hydrocarbons were identified as the dominant contaminant groups.Positive correlations between many VOC species indicated that these compounds probably originated from similar sources.Spatially,the hotspots of VOC pollution were located in eastern and southern China.Soils with higher clay content and a higher fraction of total organic carbon(TOC)content were significantly associated with higher soil VOC concentrations.Precipitation reduces the levels of highly water-soluble substances in surface soils.Both positive matrix factorization(PMF)and principal component analysis-multiple linear regression(PCA-MLR)identified a high proportion of industrial sources(PMF:59.2%and PCA-MLR:66.5%)and traffic emission sources(PMF:32.3%and PCA-MLR:33.5%).PMF,which had a higher R^(2) value(0.7892)than PCA-MLR(0.7683),was the preferred model for quantitative source analysis of soil VOCs.The health risk assessment indicated that the non-carcinogenic and carcinogenic risks of VOCs were at acceptable levels.Overall,this study provides valuable data on the occurrence of VOCs in soil from Chinese CIPs,which is essential for a comprehensive understanding of their environmental behavior.
文摘Anti-aging research has become a popular scientific field with the increasing prominence of population aging.Rare ginsenoside Compound K(CK)has attracted widespread attention as an emerging anti-aging active ingredient.The anti-aging effect of ginsenosides is considered to be one of the important roles of ginsenosides,and Compound K,as the main deglycosylated metabolite of ginsenosides,has a comprehensive anti-aging effect as a highly active ingredient obtained by transformation under the action of microbiota.Recent studies have shown that ginsenosides have anti-photo-oxidation,anti-skin aging,free radical scavenging and immunostimulatory effects,which can effectively prevent skin photoaging.With the progress of modern natural medicine extraction technology and the deepening of the research on the anti-skin aging of ginsenosides'high active ingredients,it will promote the development and application of natural product protective skin photoaging preparations.The rare ginsenoside Compound K plays an important role in the improvement of skin health and anti-aging,which is mainly realized by increasing the activity of antioxidant enzymes,inducing the expression of related genes,reducing the content of oxidative damage substances,regulating the immune system,and influencing the expression of cell-cycle regulators and aging genes.A more comprehensive and in-depth study of the molecular mechanism of the anti-aging effect of rare ginsenoside Compound K will be one of the focuses of future research.
基金supported by Tasly Pharmaceutical Group Co.,Ltd.(Grant No.303100031BA20)。
文摘The current study aimed to evaluate the efficacy and safety of Compound Danshen Dripping Pills(CDDP)in improving cardiac function in patients with acute anterior ST-segment elevation myocardial infarction(AAMI).Between February 2021 and February 2023,247 eligible patients with AAMI after primary percutaneous coronary intervention were enrolled and randomly assigned(1∶1)to receive CDDP(n=126)or placebo(n=121),with a follow-up of 48 weeks.Compared with the placebo group,the CDDP group demonstrated a significant increase in left ventricular ejection fraction values after 24 weeks of treatment(least squares mean:3.31;95%confidence interval[CI]:1.72–4.90;P<0.001)and at the 48-week follow-up(least squares mean:4.35;95%CI:2.76–5.94;P<0.001).Significant reductions in N-terminal pro-B-type natriuretic peptide levels were observed in both groups at the 24-and 48-week visits with no significant difference between the two groups(P>0.1 for all).The incidence of major adverse cardiovascular and cerebrovascular events was 6.35%in the CDDP group and 5.79%in the placebo group(P=0.822).Notably,no serious adverse events were attributed to CDDP.These findings suggest that CDDP may be well tolerated and could improve left ventricular ejection fraction in patients with AAMI at 24 and 48 weeks.
基金National Natural Science Foundation of China(Grant No.31600549).
文摘To explore the potential utilization of Elaeagnus mollis,we conducted a comprehensive assessment of its phytochemical composition,antioxidant properties,cholinesterase inhibition,and anti-HepG2 cell proliferation activity across different plant parts(branch wood,branch bark,and pericarp)using various solvents(water,methanol,ethanol,and n-hexane).Our findings revealed that water extracts displayed superior antioxidant activities in ABTS and RP assays,while methanol extracts exhibited better performance in DPPH and FRAP assays.Moreover,methanol extracts demonstrated the highest effectiveness against anti-HepG2 cell proliferation,whereas n-hexane extracts showed greater efficiency in cholinesterase inhibition.Notably,branch bark extracts exhibited the highest levels of phytochemical compounds,with both branch bark and pericarp extracts demonstrating significant effects in cholinesterase inhibition and anti-HepG2 cell proliferation.Correlation analysis indicated that phytochemical compounds were primarily responsible for the observed biological activities.Overall,extracts from the branch bark and pericarp of E.mollis showed promising potential for antioxidant and anticancer activities,suggesting their suitability for applications in the pharmaceutical industry as health-promoting products.
基金supported by the National Natural Science Foundation of China (NSFC)Projects (Nos.42205105,42121004,and 42077190)the Science and Technology Project of Shaoguan (No.210811164532141)+3 种基金the National Key R&D Program of China (2022YFC3700604)the Science and Technology Program of Guangzhou City (No.202201010400)the Fundamental Research Funds for the Central Universities (No.21622319)the Research Center of Low Carbon Economy for Guangzhou Region (No.22JNZS50).
文摘Emission characteristics of biogenic volatile organic compounds(BVOCs)from dominant tree species in the subtropical pristine forests of China are extremely limited.Here we conducted in situ field measurements of BVOCs emissions from representative mature evergreen trees by using dynamic branch enclosures at four altitude gradients(600-1690ma.s.l.)in the Nanling Mountains of southern China.Composition characteristics as well as seasonal and altitudinal variations were analyzed.Standardized emission rates and canopyscale emission factors were then calculated.Results showed that BVOCs emission intensities in the wet season were generally higher than those in the dry season.Monoterpenes were the dominant BVOCs emitted from most broad-leaved trees,accounting for over 70%of the total.Schima superba,Yushania basihirsuta and Altingia chinensis had relatively high emission intensities and secondary pollutant formation potentials.The localized emission factors of isoprene were comparable to the defaults in the Model of Emissions of Gases and Aerosols fromNature(MEGAN),while emission factors of monoterpenes and sesquiterpenes were 2 to 58 times of those in the model.Our results can be used to update the current BVOCs emission inventory in MEGAN,thereby reducing the uncertainties of BVOCs emission estimations in forested regions of southern China.
文摘Visible-light-mediated O-H functionalization reactions of alcohols with diazo compounds have been fully developed in recent years.However,alkenyl and acetylenic alcohols were rarely examined in these reactions due to the inevitable side reactions involving cycloaddition.Herein,the visible-light-mediated O-H functionalization reactions of alkenyl alcohols with diazo compounds were developed.This process competed favorably with the cycloaddition reaction.A series of multifunctional ethers were provided in low to high yields with aryldiazoacetates or 3-diazooxindoles.Biologically relevant spirooxindole-fused oxacycle could be easily accessed from the O-H functionalization product of alkenyl alcohol and 3-diazooxindole.
文摘The Rh(III)-catalyzed C—H functionalization of sulfoxonium ylides and successively annulation with two classes of cyclic diazo compounds has been realized,affording structurally diverse fused-ring or spirocyclic compounds under redoxneutral conditions.The reaction proceeds via successive chelation-assisted C—H activation,carbene insertion,and intramolecular[3+3]/[4+1]annulation processes.
文摘Employing the principle of active moiety concatenation, a novel series of symmetrical triazine compounds were designed. A series of novel triazine compounds were synthesized using cyanuric chloride, amines, and chalcones as the initial reactants. The structures of these compounds were characterized through FT-IR, 1H-NMR, 13C-NMR, high-resolution mass spectrometry (HRMS) and high performance liquid chromatography (HPLC). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetra- zolium bromide (MTT) assay was employed to evaluate the in vitro anti-proliferative activity of the new s-triazine compounds against human lung cancer cells (A549), human cervical cancer cells (HeLa), human breast cancer cells (MCF-7) and human colon cancer cells (SW620). The findings indicated that several compounds exhibited promising antitumor effects. Notably, (E)-1-(4-((4,6-dimorpholino-1,3,5-triazin-2-yl)oxy)phenyl)-3-(thiophen-2-yl)prop-2-en-1-one (3bg) demonstrated efficacy as a broad-spectrum anticancer agent, exhibiting significant activity against the A549, HeLa, and MCF-7 cell lines. Furthermore, (E)-1-(4-((4,6-dimorpholino-1,3,5-triazin-2-yl)oxy)phenyl)-3-phenylprop-2-en-1-one (3bb) displayed the most potent in vitro antitumor activity against the MCF-7 cell line with an IC_(50) value of 16.4 μmol/L, establishing it as the most active compound in assay.
文摘Direct enantioselective allylic C—H functionalization has emerged as a powerful strategy for the asymmetric syn-thesis of highly valuable chiral products.Herein,a Rh(III)-catalyzed enantioselective allylic C—H alkylation of unactivated alkenes withα-diazo carbonyl compounds is described,enabling direct access to chiral products with high efficiency(up to 77%yield,92%ee,and>10∶1 B/L(branched/linear)selectivity).This atom-and step-economical protocol directly converts simple,unactivated substrates into valuable enantioenriched products under mild conditions,providing an efficient catalytic system for asymmetric allylic C—H functionalization.
基金supported by the National Key Research and Development Program of China(No.2022YFC3701103)the National Natural Science Foundation of China(No.42222705)+1 种基金the Youth Innovation Promotion Association CAS(No.2021354)Guangdong Foundation for Program of Science and Technology Research(No.2023B1212060049).
文摘Nitrogen-containing organic compounds(NOCs)may potentially contribute to aqueous secondary organic aerosols,yet the different formation of NOCs in aerosol particles and cloud droplets remains unclear.With the in-situ measurements performed at a mountain site(1690 m a.s.l.)in southern China,we investigated the formation of NOCs in the cloud droplets and the cloud-free particles,based on their mixing state information of NOCscontaining particles by single particle mass spectrometry.The relative abundance of NOCs in the cloud-free particles was significantly higher than those in cloud residual(cloud RES)particles.NOCs were highly correlated with carbonyl compounds(including glyoxalate and methylglyoxal)in the cloud-free particles,however,limited correlation was observed for cloud RES particles.Analysis of their mixing state and temporal variations highlights that NOCs was mainly formed from the carbonyl compounds and ammonium in the cloud-free particles,rather than in the cloud RES particles.The results support that the formation of NOCs from carbonyl compounds is facilitated in concentrated solutions in wet aerosols,rather than cloud droplets.In addition,we have identified the transport of biomass burning particles that facilitate the formation of NOCs,and that the observed NOCs is most likely contributed to the light absorption.These findings have implications for the evaluation of NOCs formation and their contribution to light absorption.
文摘This research was carried out to identify the most effective plant species for air purification based on environmental factors. The existence of plants beside roadways can be considered a more efficient approach to improving air quality and minimizing pollution exposure. The samples for this research were collected from various sites across the streets of Jeddah governorate. The primary sources of air pollution in the research area are vehicle traffic and emissions from cars. Eight species were gathered from various streets in Jeddah governorate, namely, Azadirachta indica, Senna sulfurea, Ziziphus spina-christi, Cordia sebestena, Tecoma stans, Bougainvillea spectabilis, Conocarpus lancifolius, and Ixora coccinea. The leaves of the studied plants were analyzed for secondary compounds using Gas chromatography-mass spectrometry (GC-MS) techniques. Gas-chromatographic analyses revealed that bis (2-ethylhexyl) phthalate was found in every plant. Bis-(2-ethylhexyl) phthalate, a widespread environmental pollutant. Moreover, Cordia sebestena was the sole plant that contained Phenol, 2,2’-methylenebis [6-(1,1-dimethylethyl)-4-methyl] which is part of the phenols category. Environmental conditions can affect the production of secondary metabolites. By tracking the concentrations of these substances, researchers can evaluate the well-being of ecosystems and identify pollution.
基金supported by the Natural Science Foundation of Shanxi Province(202103021224193).
文摘Al/steel bimetallic composites were prepared by compound casting,and the effects of the rotating magnetic field on the interfacial microstructure and shear property of bimetallic composite was investigated.The application of rotating magnetic field refined the grain structure of the Al alloy matrix,changed the eutectic Si morphology from coarse lath to needle-like.The rotating magnetic field improved the temperature field and solute distribution of the Al alloy melt,enriched a layer of Si at the interface,and suppressed the growth of intermetallic compounds,the thickness of the interface layer decreased from 44.9μm to 22.8μm.The interfacial intermetallic compounds consisted ofη-Al_(5)Fe_(2),θ-Al_(13)Fe_(4),τ6-Al_(4.5)FeSi,τ_(5)-Al_(8)Fe_(2)Si andτ_(3)-Al_(2)FeSi,and the addition of the rotating magnetic field did not change phase composition.The rotating magnetic field improved the stress distribution within the interfacial intermetallic compounds,the presence of high-angle grain boundaries retarded crack extension,and the shear strength was enhanced from 31.27±3 MPa to 52.70±4 MPa.This work provides a feasible method for preparing Al/steel bimetallic composite with good bonding property.
基金Financial support from the Science and Technology Innovation Program of Hunan Province(No.2022RC4044)。
文摘Selenium(Se),an essential micronutrient among the 15 vital elements required for human physiology,exerts its biological functions primarily through its incorporation into selenoproteins.To date,approximately 25 selenoproteins have been characterized in mammalian systems,including glutathione peroxidase(GPX),thioredoxin reductase(TrxR),and iodothyronine deiodinases(DIOs),all of which exhibit indispensable physiological functions.
基金support of the National Natural Science Foundation of China(22408032)the Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN202000826 and KJQN202300836)+2 种基金Research Start-up Funding project of Chongqing Technology and Business University(1856011)Science and Technology Project of Chongqing Technology and Business University(2152027)Graduate Innovative Research Project from Chongqing Technology and Business University(yjscxx2024-284-29).
文摘In the last decade,shell biorefinery,a novel concept referring to the extraction of the main components of crustacean shells and the transformation of each component into valuable products,was proposed and has attracted increasing attentions.Chitin is one of main components of crustacean shells.Owing to the bio-fixed nitrogen element,chitin biomass has been regarded as a good candidate to produce nitrogen-containing chemicals.Among these,3-acetamido-5-acetylfuran(3A5AF)is an interesting furanic compound derived from the hydrolysis and sequential dehydration of chitin.Similar to cellulose-derived platform chemical 5-hydromethylfurfural(HMF),3A5AF is an emerging platform compound and also can be converted into various useful chemicals by oxidation,reduction,hydrolysis,substitution,and so on.This review showcases the recent advances in the synthesis of 3A5AF from chitin and N-acetyl glucosamine(NAG)employing various catalytic systems.The conversion of 3A5AF into valuable compounds was introduced then.There are still some challenges in this area,for example,the rational design of green and efficient catalytic systems for the synthesis of 3A5AF and its derivatives.The outlooks also were discussed at the end of the review.
基金supported by the Jilin Provincial Natural Science Foundation(Grant No.20230101183JC)the Center for Computational Research at Jilin Province.
文摘The particle swarm optimization algorithm has predicted a series of binary cadmium hydrides that could be dynamically stable at pressures between 100 GPa and 300 GPa.These low-energy phases are composed of both Cd atoms and H_(2)molecules.Here,we propose a hitherto unknown metastable Cmcm-CdH_(6)phase,consisting of one-dimensional zigzag graphite-like hydrogenic H_(6)chains,quasimolecular H_(2)units and Cd atoms,which is metallic above 290 GPa.Due to H_(2)s→Cd d donation and Cd d→H_(2)σ^(*)back-donation,the electrons occupy antibonding orbitals for both types of hydrogen atoms.This results in weakened chemical bonds in the Cmcm-CdH_(6)phase via a Kubas-like mechanism,promoting the emergence of high superconductivity,which is estimated to be up to~60 K at 290 GPa.This work will inspire the search for superconductivity in materials based on group IIB hydrides under pressure.
