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Theoretical Studies on Property and Structure of Silacyclohexane-based Liquid Crystal Compounds 被引量:1
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作者 YI Xing-Huan YI Xue-Feng +1 位作者 GONG Xue-Dong XIAO He-Ming(Department of Chemistry, Nanjing University of Science & Technology, Nanjing 210094) 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 1998年第2期129-132,共4页
SCF-MO-AM1 calculations have been per formed on 10 silacyclohex-ane-based liquid crystal compounds by energy gradient completed optimization. The stable configurations, electronic structures, heats of formation, dipol... SCF-MO-AM1 calculations have been per formed on 10 silacyclohex-ane-based liquid crystal compounds by energy gradient completed optimization. The stable configurations, electronic structures, heats of formation, dipole moments and ionization potentials of titled comPounds are first reported. The calculated results are.discussed relating to the classical organic electronic theory. 展开更多
关键词 silacyclohexane-based compounds liquid crystal AM1 method molecular geometry heat of formation
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Characterization and source apportionment of volatile organic compounds in Hong Kong:A 5-year study for three different archetypical sites 被引量:2
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作者 Yuchen Mai Vincent Cheung +5 位作者 Peter K.K.Louie Kenneth Leung Jimmy C.H.Fung Alexis K.H.Lau Donald R.B.lake Dasa Gu 《Journal of Environmental Sciences》 2025年第5期424-440,共17页
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
关键词 Volatile organic compounds Positive matrix factorization Source apportionment Ozone formation
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Emission characteristics and probabilistic health risk of volatile organic compounds from leather sofa 被引量:2
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作者 Chuanhui Mu Yuling Tang +2 位作者 Zhaohui Yang Jianfei Zhou Bi Shi 《Journal of Environmental Sciences》 2025年第2期79-87,共9页
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
关键词 Indoor environment LEATHER Volatile organic compounds(VOCs) Health risk assessment
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Chemical characteristics and sources apportionment of volatile organic compounds in the primary urban area of Shijiazhuang,North China Plain 被引量:2
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作者 Xiao Zhang Junfeng Wang +8 位作者 Jiangwei Zhao Junliang He Yali Lei Kai Meng RuiWei Xue Zhang Miaomiao Zhang Shuangying Ni Eleonora Aruffo 《Journal of Environmental Sciences》 2025年第3期465-475,共11页
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
关键词 Volatile organic compounds Pollution characteristics Ozone formation potential OH radical loss rate Source apportionment
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Comprehensive characterization of volatile organic compounds in Chinese chemical industry park soils:Spatial variation,source identification,and health risk assessment 被引量:1
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作者 Haibao Zhu Yuanchen Chen +3 位作者 Zheng Ruan Han Wang Danhua Liu Meirong Zhao 《Journal of Environmental Sciences》 2025年第9期48-59,共12页
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
关键词 Volatile organic compounds Chemical industry park soils Source appointment Risk assessment
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Evaluation of different solvents for phytochemical compounds,antioxidant activities,cholinesterase inhibition,and anti-HepG2 cell proliferation of three plant parts in Elaeagnus mollis 被引量:1
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作者 Hao Zhong Jingmiao Li +1 位作者 Changle Li Yulin Liu 《Journal of Chinese Pharmaceutical Sciences》 2025年第5期411-422,共12页
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
关键词 Elaeagnus mollis Phytochemical compounds Antioxidant activity Cholinesterase inhibitory Anti-HepG2 cell proliferation activities
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Emission characteristics of biogenic volatile organic compounds in a subtropical pristine forest of southern China 被引量:1
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作者 Xi Chen Daocheng Gong +9 位作者 Youjing Lin Qiao Xu Yujin Wang Shiwei Liu Qinqin Li Fangyuan Ma Jiangyong Li Shuo Deng Hao Wang Boguang Wang 《Journal of Environmental Sciences》 2025年第2期665-682,共18页
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
关键词 Biogenic volatile organic compounds(BVOCs) Dynamic enclosure system Nanling Mountains Emission factors Emission rates Chemical reactivity
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Visible-Light-Mediated O-H Functionalization Reactions of Alkenyl Alcohols with Diazo Compounds
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作者 Xie Haochi Qin Yongkang +6 位作者 Yang Ting Li Hujin Sun Jiajia Qian Mingcheng Zhao Shuai Hou Ya'nan Chen Xin 《有机化学》 北大核心 2025年第8期3004-3016,共13页
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
关键词 VISIBLE-LIGHT O-H functionalization alkenyl alcohol diazo compound spirooxindole-fused oxacycle
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Rhodium(III)-Catalyzed Annulative Coupling between Sulfoxonium Ylides and Diazo Compounds
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作者 Yang Fan Fan Xiaomeng +4 位作者 Yao Xuejing Mi Ruijie Yu Songjie Li Xingwei Xiao Jian 《有机化学》 北大核心 2025年第1期331-342,共12页
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
关键词 rhodium catalysis sulfoxonium ylide C—H activation diazo compound ANNULATION
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Synthesis and Antitumor Activity of Innovative Homotriazine Compounds
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作者 He Tiantian Sun Lijiao +2 位作者 Lü Jiahui Li Jinjing Du Yonghong 《有机化学》 北大核心 2025年第7期2577-2585,共9页
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
关键词 s-triazine compounds α β-unsaturated ketones antitumor activity
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Rhodium(III)-Catalyzed Enantioselective Allylic C-H Alkylation of Unactivated Alkenes withα‑Diazocarbonyl Compounds
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作者 Zhou Qiang Yang Baozhen +5 位作者 Hao Guilin Luo Mupeng Cao Shi Zhao Bei Yuan Hua Wang Shouguo 《有机化学》 北大核心 2025年第6期2109-2120,共12页
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
关键词 C-H bond activation asymmetric allylic alkylation Rh(Ⅲ)-catalysis diazo compounds
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A comparative study on the formation of nitrogen-containing organic compounds in cloud droplets and aerosol particles
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作者 Guohua Zhang TaoWang +6 位作者 Qinhao Lin Kun Liu Wei Sun Duohong Chen Lei Li Xinming Wang Xinhui Bi 《Journal of Environmental Sciences》 2025年第3期456-464,共9页
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
关键词 Nitrogen-containing organic compounds Individual particles CLOUD Carbonyl compounds Mixing state
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Secondary Compounds Assessment in Some Street Plants Exposed to Air Pollution in Jeddah Governorate, Kingdom of Saudi Arabia
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作者 Thorya A. Fallatah 《Open Journal of Ecology》 2025年第1期115-134,共20页
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
关键词 Secondary compounds Street Plants Air Pollution Jeddah Governorate Gas Chromatography-Mass Spectrometry (GC-MS)
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Electrochemical synthesis strategy for the development of antitumor selenoheterocyclic compounds
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作者 Zhi-Lin Wu Rong-Nan Yi Chunlin Zhuang 《Chinese Chemical Letters》 2025年第10期4-5,共2页
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
关键词 selenoheterocyclic compounds SELENOPROTEINS vital elements antitumor compounds electrochemical synthesis SELENIUM glutathione peroxidase glutathione peroxidase gpx thioredoxin reductase trxr
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Oxidation-reduction process of Arabidopsis thaliana roots induced by bisphenol compounds based on RNA-seq analysis
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作者 Xiaotong Ji Weiwei Wang +2 位作者 Jiande Li Liangpo Liu Huifeng Yue 《Journal of Environmental Sciences》 2025年第2期188-197,共10页
Bisphenol compounds(BPs)have various industrial uses and can enter the environment through various sources.To evaluate the ecotoxicity of BPs and identify potential gene candidates involved in the plant toxicity,Arabi... Bisphenol compounds(BPs)have various industrial uses and can enter the environment through various sources.To evaluate the ecotoxicity of BPs and identify potential gene candidates involved in the plant toxicity,Arabidopsis thaliana was exposed to bisphenol A(BPA),BPB,BPE,BPF,and BPS at 1,3,10 mg/L for a duration of 14 days,and their growth status were monitored.At day 14,roots and leaves were collected for internal BPs exposure concentration detection,RNA-seq(only roots),and morphological observations.As shown in the results,exposure to BPs significantly disturbed root elongation,exhibiting a trend of stimulation at low concentration and inhibition at high concentration.Additionally,BPs exhibited pronounced generation of reactive oxygen species,while none of the pollutants caused significant changes in root morphology.Internal exposure concentration analysis indicated that BPs tended to accumulate in the roots,with BPS exhibiting the highest level of accumulation.The results of RNA-seq indicated that the shared 211 differently expressed genes(DEGs)of these 5 exposure groups were enriched in defense response,generation of precursormetabolites,response to organic substance,response to oxygen-containing,response to hormone,oxidation-reduction process and so on.Regarding unique DEGs in each group,BPS wasmainly associated with the redox pathway,BPB primarily influenced seed germination,and BPA,BPE and BPF were primarily involved in metabolic signaling pathways.Our results provide newinsights for BPs induced adverse effects on Arabidopsis thaliana and suggest that the ecological risks associated with BPA alternatives cannot be ignored. 展开更多
关键词 Bisphenol compounds Arabidopsis thaliana Root elongation RNA-SEQ ROS
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Characteristics of atmospheric reduced-sulfur compounds at a suburban site of Shanghai
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作者 Kai Deng Juntao Huo +8 位作者 Yuwei Wang Lihong Wang Sijia Yin Chuang Li Yueyang Li Gan Yang Lei Yao Qingyan Fu Lin Wang 《Journal of Environmental Sciences》 2025年第10期671-683,共13页
Atmospheric dimethyl sulfide(DMS,CH_(3)SCH_(3))and methanethiol(MeSH,CH_(3)SH)have been widely studied and recognized to significantly constrain the atmospheric sulfur budget.Nevertheless,while the role of DMS and MeS... Atmospheric dimethyl sulfide(DMS,CH_(3)SCH_(3))and methanethiol(MeSH,CH_(3)SH)have been widely studied and recognized to significantly constrain the atmospheric sulfur budget.Nevertheless,while the role of DMS and MeSH remains largely uncertain in inland regions,learning about dimethyl disulfide(DMDS,CH_(3)SSCH_(3))is also limited.In this study,we measured atmospheric DMS,MeSH and DMDS in winter,from 19 December 2022 to 30 January 2023,and spring,from 24 April to 2 June 2023 with a Vocus proton-transfer-reaction time-offlightmass spectrometer(Vocus PTR-TOF)at the Dianshan Lake(DSL)Air QualityMonitoring Supersite in a suburban area of Shanghai,China.The mixing ratios of DMS,MeSH and DMDS exhibited clear diurnal cycles,and were characterized by average and interquartile range values of 22.6(10.1-29.7),14.9(6.5-19.4)and 9.8(6.0-10.7)pptv,respectively,in the spring campaign,which are approximately twice as high as those in winter.MeSH and DMDS were found to be well correlated with DMS in the two campaigns.Wind analysis suggests that three reduced-sulfur compounds owned common sources from the DSL.Furthermore,the sulfur dioxide(SO_(2))production quantity fromthe three reduced-sulfur compounds over the DSL inMay 2023 was estimated to be 1.42±0.74 t with 84.8%originating fromDMDS,which was comparable to the monthly SO_(2) emissions fromships over the DSL.Our results highlight the prominent role of atmospheric DMDS in SO_(2) production when compared to DMS and MeSH in the suburban area of Shanghai,soliciting further investigation and consideration of DMDS in the sulfur budget. 展开更多
关键词 Reduced-sulfur compound Seasonal characteristics Sulfur dioxide
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Insight into the evolution of refractory basic and neutral nitrogen compounds during residue hydrotreating process
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作者 Zhong-Huo Deng Si-Yang Guo +4 位作者 Xin-Peng Nie Xin-Heng Cai Yan-Zi Jia Wei Han Li-Shun Dai 《Petroleum Science》 2025年第4期1787-1801,共15页
A comprehensive insight into the evolution and molecular structure of basic and neutral nitrogen compounds during the residue hydrotreating(RHT)process was gained through ESI(+)/ESI(-)FT-ICR MS analysis of the feedsto... A comprehensive insight into the evolution and molecular structure of basic and neutral nitrogen compounds during the residue hydrotreating(RHT)process was gained through ESI(+)/ESI(-)FT-ICR MS analysis of the feedstock and its hydrogenated samples,with hydrodenitrogenation(HDN)ratios of 15.9%-70.1%.This study revealed that carbazoles,characterized by a double bond equivalent(DBE)of 9-11,were the refractory neutral nitrogen compounds during the RHT process.Their recalcitrant nature was primarily due to their low aromaticity and high steric hindrance.Conversely,quinolines(DBEs 7 to 9)were the most abundant basic nitrogen compounds.Through a meticulous analysis of DBE evolution,we revealed the intricate reaction mechanisms of benzocarbazoles and dibenzocarbazoles in residual oil,highlighting the crucial role of quinolines as key intermediates in eliminating these compounds.Interestingly,nitrogen compounds with either low or high carbon numbers(for a given DBE)exhibited higher reactivity than those with medium carbon numbers,which can be attributed to the low steric hindrance resulting from short alkyl chains and more naphthenic-aromatic structures,respectively.After hydrotreatment,the molecular structures of the most refractory or abundant nitrogen compounds could consist of two main types:those with multiple naphthenic-aromatic rings and those with long side chains near the nitrogen atom.This research has revealed nitrogen compounds'evolutionary mechanisms and refractory nature,and the molecular structure of the most resistant or abundant basic and neutral nitrogen compounds,providing a deeper understanding of the HDN process and ultimately paving the way for the rational RHT catalyst design and process development. 展开更多
关键词 Residual oils Nitrogen compounds HYDRODENITROGENATION Molecular structure Reaction mechanism
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Probing the biological efficacy and mechanistic pathways of natural compounds in breast cancer therapy via the Hedgehog signaling pathway
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作者 Yining Cheng Wenfeng Zhang +6 位作者 Qi Sun Xue Wang Qihang Shang Jingyang Liu Yubao Zhang Ruijuan Liu Changgang Sun 《Journal of Pharmaceutical Analysis》 2025年第4期704-722,共19页
Breast cancer(BC)is one of the most prevalent malignant tumors affecting women worldwide,with its incidence rate continuously increasing.As a result,treatment strategies for this disease have received considerable att... Breast cancer(BC)is one of the most prevalent malignant tumors affecting women worldwide,with its incidence rate continuously increasing.As a result,treatment strategies for this disease have received considerable attention.Research has highlighted the crucial role of the Hedgehog(Hh)signaling pathway in the initiation and progression of BC,particularly in promoting tumor growth and metastasis.Therefore,molecular targets within this pathway represent promising opportunities for the development of novel BC therapies.This study aims to elucidate the therapeutic mechanisms by which natural compounds modulate the Hh signaling pathway in BC.By conducting a comprehensive review of various natural compounds,including polyphenols,terpenes,and alkaloids,we reveal both common and unique regulatory mechanisms that influence this pathway.This investigation represents the first comprehensive analysis of five distinct mechanisms through which natural compounds modulate key molecules within the Hh pathway and their impact on the aggressive behaviors of BC.Furthermore,by exploring the structure-activity relationships between these compounds and their molecular targets,we shed light on the specific structural features that enable natural compounds to interact with various components of the Hh pathway.These novel insights contribute to advancing the development and clinical application of natural compound-based therapeutics.Our thorough review not only lays the groundwork for exploring innovative BC treatments but also opens new avenues for leveraging natural compounds in cancer therapy. 展开更多
关键词 Natural compounds Hedgehog signaling pathway Breast cancer
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Effects of photo-oxidation and transition metals on the formation of reactive oxygen species from aromatic compounds using spectroscopic method
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作者 Xiaoyu Hu Juanjuan Qin +5 位作者 Yuanyuan Qin Tianyi Zhao Yuxuan Cao Qinghe Cai Lijia Zhang Yang Zhang 《Journal of Environmental Sciences》 2025年第5期1-11,共11页
Particulate matter(PM)can cause adverse health effects by overproducing reactive oxygen species(ROS).Although the ability of PM to induce ROS generation depends on its composi-tion and environmental factors.This study... Particulate matter(PM)can cause adverse health effects by overproducing reactive oxygen species(ROS).Although the ability of PM to induce ROS generation depends on its composi-tion and environmental factors.This study explores how photo-oxidation affects ROS gen-eration from aromatic compounds(ACs,including catechol(CAT),phthalic acid(PA),and 4,4-oxydibenzoic acid(4,4-OBA))and their mixtures with transition metals(TMs,includ-ing Fe(II),Mn(II),and Cu(II))using Fourier-transform infrared(FTIR)and Ultraviolet-visible spectroscopy(UV-Vis).Results showed that photo-oxidation facilitated ROS generation from ACs.CAT-Fe(II)/Cu(II)showed synergistic effects,but 4,4-OBA-Fe(II)/Cu(II)showed antag-onistic effects.ACs-Mn(II)and PA-Fe(II)/Cu(II)exhibited synergistic effects first and then showed antagonistic effects.The different interactions were due to complexation between ACs and TMs.The photo-oxidized ACs-TMs significantly enhanced ROS generation com-pared with ACs-TMs.The study suggested the photo-oxidation mechanism involved that the transfer ofπ-electrons from the ground to an excited state in benzene rings and func-tional groups,leading to the breakage and formation of chemical bonds or easierπ-electron transfer from ACs to TMs.The former could generate ROS directly or produce polymers that promoted ROS generation,while the latter promoted ROS generation by transferringπ-electrons to dissolved oxygen quickly.Our study revealed that both interactions among components and photo-oxidation significantly influenced ROS generation.Future studies should integrate broader atmospheric factors and PM components to fully assess oxidative potential and health impacts. 展开更多
关键词 Reactive oxygen species Aromatic compounds Transitional metals PHOTO-OXIDATION
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Recent advances in the biosynthesis of natural products from C1 compounds
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作者 Xinzhe Zhang Aipeng Li +1 位作者 Xiaohan Huang Qiang Fei 《Chinese Journal of Chemical Engineering》 2025年第7期277-285,共9页
One-carbon(C1)compounds,such as CO_(2),methane,and methanol,are emerging as promising feedstocks for next-generation biomanufacturing due to their abundance and low cost.In recent years,there has been growing interest... One-carbon(C1)compounds,such as CO_(2),methane,and methanol,are emerging as promising feedstocks for next-generation biomanufacturing due to their abundance and low cost.In recent years,there has been growing interest in harnessing microorganisms to convert these carbon sources into valuable natural products(NPs),which offers great potential for sustainable development.This review systematically outlines recent advancements in biocatalysts,synthetic biology,and process optimization aimed at improving the feasibility and scalability of producing C1-based NPs.Current challenges and insights into NPs biomanufacturing from C1 compounds are thoroughly examined in the areas of multi-gene editing,metabolic regulation,and synthetic microbial consortium.With ongoing progress in biosynthetic tools and fermentation techniques,C1-based biomanufacturing is becoming a versatile and sustainable platform for generating diverse value-added products. 展开更多
关键词 Synthetic biology One-carbon compounds Natural products BIOCATALYSIS Carbon neutralization BIOTECHNOLOGY
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