期刊文献+
共找到1,349篇文章
< 1 2 68 >
每页显示 20 50 100
Interactions of extracellular DNA with aromatized biochar and protection against degradation by DNaseⅠ 被引量:4
1
作者 Jing Fang Liang Jin +2 位作者 Qingkang Meng Dengjun Wang Daohui Lin 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2021年第3期205-216,共12页
With increasing environmental application,biochar(BC)will inevitably interact with and impact environmental behaviors of widely distributed extracellular DNA(eDNA),which however still remains to be studied.Herein,the ... With increasing environmental application,biochar(BC)will inevitably interact with and impact environmental behaviors of widely distributed extracellular DNA(eDNA),which however still remains to be studied.Herein,the adsorption/desorption and the degradation by nucleases of eDNA on three aromatized BCs pyrolyzed at 700℃were firstly investigated.The results show that the eDNA was irreversibly adsorbed by aromatized BCs and the pseudo-second-order and Freundlich models accurately described the adsorption process.Increasing solution ionic strength or decreasing pH below 5.0 significantly increased the eDNA adsorption on BCs.However,increasing pH from 5.0 to 10.0 faintly decreased eDNA adsorption.Electrostatic interaction,Ca ion bridge interaction,andπ-πinteraction between eDNA and BC could dominate the eDNA adsorption,while ligand exchange and hydrophobic interactions were minor contributors.The presence of BCs provided a certain protection to eDNA against degradation by DNase I.BC-bound eDNA could be partly degraded by nuclease,while BC-bound nuclease completely lost its degradability.These findings are of fundamental significance for the potential application of biochar in eDNA dissemination management and evaluating the environmental fate of eDNA. 展开更多
关键词 aromatized biochar Extracellular DNA SORPTION DESORPTION Enzymatic degradation
原文传递
Ten ring-B aromatized ergosterols from Aspergillus spectabilis
2
作者 WEI Mengsha SUN Weiguang +9 位作者 LIU Linlin LI Yongqi LI Lanqin LI Qin CHEN Yu GUO Jieru GU Lianghu ZHU Hucheng CHEN Chunmei ZHANG Yonghui 《Chinese Journal of Natural Medicines》 SCIE CAS CSCD 2024年第7期654-662,共9页
Spectasterols F−O(1−10),ten interesting ergosterols with an aromatized B ring,were obtained from Aspergillus spectabilis.Their structures and absolute configurations were determined using a combination of high-resolut... Spectasterols F−O(1−10),ten interesting ergosterols with an aromatized B ring,were obtained from Aspergillus spectabilis.Their structures and absolute configurations were determined using a combination of high-resolution electrospray ionization mass spectrometry(HR-ESI-MS),nuclear magnetic resonance(NMR)spectroscopy,single-crystal X-ray diffraction analyses,and electronic circular dichroism(ECD)calculations.Structurally,these aromatic ergosterols feature versatile side chains.Notably,compound aromatic ergosterols featured versatile side chains,and compound 4 is an unusual C23 ergosterol characterized by a shorter side chain due to oxidative cleavage between C-23 and C-24.All compounds were evaluated for their neuroprotective activities,with compound 8 showing a dose-dependent ability to reduce apoptosis and protect mitochondrial function in glutamate-induced SH-SY5Y cells. 展开更多
关键词 STEROIDS Aspergillus spectabilis Aromatic ergosterols Neuroprotective activities Structure elucidation
原文传递
Adsorption capacity of single and twin-tailed cationic and anionic surfactant-modified chitosan hydrogel beads for PAH removal from aqueous solutions
3
作者 Hina Kouser Qadri Showkat Rashid +3 位作者 Arjumund Shaheen Firdaus Ahmad Ahanger Sohail Amin Malik Aijaz Ahmad Dar 《Journal of Environmental Sciences》 2026年第1期512-522,共11页
This study presents a thorough investigation into the use of single and twin-tailed cationic and anionic surfactant-modified chitosan(SMCS)hydrogel beads as effective adsorbents for the elimination of hazardous polycy... This study presents a thorough investigation into the use of single and twin-tailed cationic and anionic surfactant-modified chitosan(SMCS)hydrogel beads as effective adsorbents for the elimination of hazardous polycyclic aromatic hydrocarbons(PAHs)from aqueous solutions.The Chitosan(CS)hydrogel beads were modified with single/twin-tailed anionic surfactants,sodium dodecyl sulfate(SDS)and sodium bis(2-ethylhexyl)sulfosuccinate(AOT),and cationic surfactants,dodecyltrimethylammonium bromide(DTAB)and didodecyldimethylammonium bromide(DDAB),to enhance their adsorption capacity of PAHs.The CS and SMCS beads were evaluated for their structural,mechanical,and adsorption properties using a range of techniques,including infrared spectroscopy(IR),energy-dispersive X-ray spectroscopy(EDX),rheometry,and field emission scanning electron microscopy(FESEM).Adsorption experiments of naphthalene(Nap),acenaphthene(Ace),and phenanthrene(Phe)on SMCS beads demonstrate that they have significantly higher adsorption capacities than CS beads,due to increase in hydrophobic interactions.Adsorption capacity followed the trend,Phen>Ace>Nap for all the beads revealing that twin-tailed SMCS bead possess much higher adsorption capacities(Qmax)compared to single-tailed SMCS beads.For twin tailed surfactants,the maximum adsorption capacities for Nap,Ace and Phe varied as CS-AOT(CS-DDAB):430.0(323.8)611.60(538.18)633.39(536.99)mg/g respectively,outperforming other reported hydrogel beads.The study highlights the simplicity,eco-friendliness,and enhanced performance of surfactant modification for developing high-efficiency adsorbents,paving the way for cost-effective solutions in water re-mediation. 展开更多
关键词 Hydrogel CHITOSAN SURFACTANT Polycyclic aromatic hydrocarbons(PAHs) Adsorption
原文传递
Long-lived metal-zeolite catalysts for polyolefin aromatization via synergistic tandem dehydroaromatization and hydrogenolysis
4
作者 Wenjun Chen Yiyi Fan +2 位作者 Yue Liu Xiaobin Xie Fan Zhang 《Journal of Energy Chemistry》 2026年第1期465-473,I0011,共10页
Converting waste plastics directly into valuable aromatic chemicals is a promising,cost-effective recycling strategy.Traditional zeolite-catalyzed cracking of polyolefins to produce aromatics often needs high temperat... Converting waste plastics directly into valuable aromatic chemicals is a promising,cost-effective recycling strategy.Traditional zeolite-catalyzed cracking of polyolefins to produce aromatics often needs high temperatures and faces issues like low selectivity for liquid aromatics,separation difficulties,and rapid catalyst deactivation due to coking.To address this,a multifunctional Ni/HZSM-5 catalyst was developed to efficiently upgrade various polyolefins—including polyvinyl chloride—into gaseous alkanes(C_(1)–C_(5))and easily separable liquid aromatics(C_(6)–C_(12))at 400°C,without added solvents or hydrogen.Aromatic products make up 57.1 wt%of total output,with more than 97.8%selectivity for the liquid phase and a BTX(benzene,toluene,and xylene)selectivity of 76.1%.The high activity and selectivity for aromatics stem from synergistic interactions between Ni nanoparticles(NPs)and acid sites in the zeolite,which promote selective C–C bond breaking and control hydrogenolysis and aromatization pathways.This synergy allows precise control over the distribution of products by carbon number and favors the formation of separable aromatics.Notably,the catalyst also prevents coking by hydrogenolyzing and hydrogenating reactive intermediates before they form stable graphite-like deposits.Consequently,Ni/ZSM-5 catalyst demonstrates excellent stability,maintaining consistent aromatics yield over 13 consecutive cycles and processing over 30 times its weight in plastics without regeneration.After regeneration,the activity of the catalyst was fully restored,highlighting its potential for industrial use.This work offers valuable insights for designing durable,high-activity catalysts,providing a practical route to improve plastic recycling technologies. 展开更多
关键词 POLYOLEFIN Catalytic conversion Ni/ZSM-5 AROMATICS Tandem reaction
在线阅读 下载PDF
Interface-directed porous aromatic framework nanoflakes for ultrafast quasi-homogeneous photocatalytic aerobic oxidation in air
5
作者 Hengtao Lei Yuhui Zhai +6 位作者 Jian Song Xiaojun Zhao Ayesha Javaid Geng Tan Yuyang Tian Qinhe Pan Guangshan Zhu 《Science China Chemistry》 2026年第2期900-906,共7页
The development of efficient photocatalysts for crucial organic transformation,such as aerobic oxidation,remains challenging.Although powdered porous materials offer abundant accessible active sites,their application ... The development of efficient photocatalysts for crucial organic transformation,such as aerobic oxidation,remains challenging.Although powdered porous materials offer abundant accessible active sites,their application in liquid-phase catalysis is often limited by insufficient light absorption and inevitable charge recombination,which are inherent drawbacks of conventional heterogeneous catalysts.Here,through rational design and nanoscale-engineering of porous aromatic frameworks(PAFs)comprising porphyrin and porous organic cage,a quasi-homogeneous porous photocatalyst with high catalytic activity and controllable dimension was developed.The interface-directed growth in oil-in-water emulsion shaped the morphology of photoactive PAFs from powders to nanoflakes,which facilitated the light absorbance and catalyst-substrate interaction.Compared with PAF powders,PAF nanoflakes exhibited superior photocatalytic activity for aerobic oxidation.For mustard gas simulant(2-chloroethyl ethyl sulfide,CEES),PAF nanoflakes exhibited ultrafast detoxification rates in room air with a half-life(t_(1/2))as fast as 26s,which even exceeded other catalysts in pure oxygen.It also completely catalyzed the aerobic oxidation of thioether within 15 min,which is almost the fastest rate among any reported organic photocatalysts.Furthermore,the efficient catalytic performance under mild conditions caused by improved light enrichment,surface charge transfer and carrier lifetime was elucidated. 展开更多
关键词 porous aromatic framework morphology control nanoflake photocatalysis aerobic oxidation
原文传递
Determination of Bioactive Potential in a Semi-domesticated Population of Oregano(Lippia graveolens Kunth)with Organic Fertilization
6
作者 Priscilla Yamilhet Montes-Orona Mercedes Georgina Ramírez-Aragón +3 位作者 Isaela Villalpando-De La Torre Urbano Nava-Camberos Jared Ceniceros-García JoséLuis García-Hernández 《Phyton-International Journal of Experimental Botany》 2026年第2期22-35,共14页
Mexican oregano(Lippia graveolens Kunth)is an aromatic species of high culinary and medicinal relevance.In Mexico,more than 40 taxa with characteristic aroma and flavor are commercially recognized as oregano,with L.gr... Mexican oregano(Lippia graveolens Kunth)is an aromatic species of high culinary and medicinal relevance.In Mexico,more than 40 taxa with characteristic aroma and flavor are commercially recognized as oregano,with L.graveolens being the most widely distributed and economically important.Despite its relevance,few domesticated or semi-domesticated cultivars exist,and wild populations remain the main source of raw material,raising concerns regarding sustainability and quality standardization.The essential oil and oleoresins of L.graveolens possess recognized bioactivity,including antioxidant,antifungal,antibacterial,and anti-inflammatory properties,largely attributed to phenolic compounds such as thymol and carvacrol.Given the increasing global demand for natural bioactives and functional foods,optimizing cultivation practices is essential to enhance both the yield and phytochemical quality of this species.This study evaluated the effect of organic fertilization(0,5,10,and 15 t ha^(−1)of vermicompost)on the phenolic profile,flavonoid content,and antioxidant capacity of oregano oleoresin obtained from a semi-domesticated population across three harvests.The highest phenolic concentration(≈500 mg GAE g^(−1)extract)and greatest antioxidant activity(ABTS>3.5×10^(5)μmol TE g^(−1)extract)were observed at the 5 t ha^(−1)dose during the second harvest.Flavonoid content peaked in the third harvest(480-620 mg QE g^(−1)extract),whereas the unfertilized control exhibited the highest DPPH activity in the first harvest.Overall,the results indicate that vermicompost dosage and harvest timing substantially influence the functional quality of L.graveolens.Moderate organic fertilization,particularly 5 t ha^(−1),enhances the biosynthesis of bioactive secondary metabolites,underscoring its potential for sustainable production systems. 展开更多
关键词 Antioxidant capacity aromatic herbs OLEORESIN phenolic compounds
在线阅读 下载PDF
Chemical characteristics of fine aerosols and associated speciated organic compounds in summer Nanjing,China
7
作者 Yuanjie Shan Daoming Li +7 位作者 Shijie Cui Jiukun Xian Yunjiang Zhang Junfeng Wang Haiwei Li Ming Wang Yun Wu Xinlei Ge 《Journal of Environmental Sciences》 2026年第1期349-361,共13页
Along with decrease of fine particulate matter(PM_(2.5))concentration in recent years in China,secondary species become increasingly important.This work focuses on characterizing secondary components,and a few importa... Along with decrease of fine particulate matter(PM_(2.5))concentration in recent years in China,secondary species become increasingly important.This work focuses on characterizing secondary components,and a few important groups of organics including organic nitrogen(ON),organonitrates(OrgN),organosulfates(OS)and polycyclic aromatic hydrocarbons(PAHs),via online measurement of submicron aerosols(PM_(1))in Nanjing,China,during 2022 summer.The average PM_(1) concentration was 15.39μg/m^(3),dominated by secondary components(69.1%),which were even more important at higher PM_(1) levels.The primary organic aerosols(POA)were from traffic,industry and cooking;the two secondary OA factors were both closely linked with photochemistry,with one(OOA1)being relatively fresh and important in early afternoon and another(OOA2)being aged and important in late afternoon.Sulfate formation was also governed by photochemistry but resembled that of OOA2 not OOA1;nitrate formation was associated strongly with heterogeneous hydrolysis and thermodynamic equilibrium.Results also reveal a possible photochemical reaction channel from POA to OOA1,then to OOA2.Case studies show that formations of secondary components responded differently to different weather conditions and governed summer PM_(1) pollution.The average ON,OrgN,OS and PAHs concentrations were determined to be 122.8,84.4,45.6 and 3.3 ng/m^(3),respectively.ON was dominated by primary sources(53.8%).OrgN varied similarly to nitrate.OS formation was linked with aqueous-phase reactions,which were insignificant therefore its level was low.PAHs was mainly from traffic,and photochemical oxidation might be its important sink during afternoon. 展开更多
关键词 Secondary organic aerosol Organic nitrogen Organonitrate Organosulfate Polycyclic aromatic hydrocarbons
原文传递
Planting nitrogen-rich motif into porous aromatic frameworks to boost redox potential and multi-ion storage for wide-temperature sodium-organic batteries
8
作者 Mimi Zhang Linqi Cheng +3 位作者 Zhaoli Liu Fengchao Cui Fang Luo Heng-Guo Wang 《Science China Chemistry》 2026年第2期979-985,共7页
Redox-active porous aromatic frameworks(PAFs)have emerged as hopeful candidates for sodium-ion batteries(SIBs)in view of their porous structures,chemical stability and tunable architectures.Herein,we successfully synt... Redox-active porous aromatic frameworks(PAFs)have emerged as hopeful candidates for sodium-ion batteries(SIBs)in view of their porous structures,chemical stability and tunable architectures.Herein,we successfully synthesized two redox-active PAFs(PAF-305 and PAF-306)with different nitrogen-containing motifs,and demonstrated their application as cathode materials for SIBs.Density functional theory(DFT)calculations reveal that nitrogen-rich PAF-305 exhibits a lower lowest unoccupied molecular orbital(LUMO)energy level(-3.35 eV)and a narrower energy gap(E_(g))(2.40 eV)compared with nitrogen-poor PAF-306.As expected,PAF-305 displays outstanding electrochemical performance,comprising a high reversible capacity of 145.2 mAh g^(-1)at 0.05 A g^(-1)and satisfactory cycling stability with 92% capacity retention over 1000 cycles at 0.2 A g^(-1).Remarkably,PAF-305 maintains robust electrochemical properties across a wide temperature range(-20℃ to 50℃).Through a combination of experimental characterizations and theoretical calculations,the sodium-ion storage mechanism of PAF-305 is elucidated.This study not only provides a promising strategy for exploring other redox-active organic units in the design of novel PAFs,but also expands the potential applications of PAFs in energy storage systems. 展开更多
关键词 porous aromatic framework nitrogen-rich motif multi-ion storage wide temperature sodium-organic batteries
原文传递
The variation of polycyclic aromatic hydrocarbon compound-specific carbon isotopic composition in crude oil during thermal evolution
9
作者 Caisheng FEI Tieguan WANG +4 位作者 Daofu SONG Jianfa CHEN Yuan LI Zhengang LU Dazheng SHAO 《Science China Earth Sciences》 2026年第2期647-659,共13页
Compound-specific carbon isotopic compositions(δ^(13)C)of aromatic hydrocarbons offer a promising solution to the long-standing challenge of correlating ultra-deep oils with their source rocks.However,systematic stud... Compound-specific carbon isotopic compositions(δ^(13)C)of aromatic hydrocarbons offer a promising solution to the long-standing challenge of correlating ultra-deep oils with their source rocks.However,systematic studies on the evolution of these isotopic signatures during thermal maturation remain scarce.In this study,we conducted closed-system anhydrous gold-tube pyrolysis experiments using a representative marine crude oil from the Tarim Basin to systematically investigate the evolution of polycyclic aromatic hydrocarbon(PAH)compositions and their compound-specific δ^(13)C values during thermal maturation.The results show that the abundance and relative distribution of the naphthalene,phenanthrene,fluorene,and dibenzothiophene series vary significantly with increasing maturity.Based on the variation patterns of δ^(13)C values,the aromatic hydrocarbons can be divided into two categories.The first category includes parent PAHs such as naphthalene,phenanthrene,fluorene,and dibenzothiophene,along with some alkylated dibenzothiophenes,whose δ^(13)C values remain essentially invariant during thermal evolution.The second category comprises other alkylated aromatic hydrocarbons,whose δ^(13)C values remain stable at lower temperatures but become progressively enriched in δ^(13)C at higher temperatures due to demethylation.Considering the diverse origins of PAH precursors and the thermal invariance of δ^(13)C in certain aromatic hydrocarbons,compound-specific carbon isotope analysis represents a powerful tool for identifying source rocks in ultra-deep petroleum systems,thereby advancing our understanding of ultra-deep hydrocarbon accumulation. 展开更多
关键词 Ultra-deep petroleum Gold-tube pyrolysis Aromatic hydrocarbons Compound-specific carbon isotopes Thermal evolution
原文传递
Risk assessment and environmental influencing factors of urinary polycyclic aromatic hydrocarbons metabolites in pregnant women in Zunyi,China
10
作者 Jing Yang Jing Jiang +9 位作者 Linfei Wu Pei Xu Nian Wu Rui Yu Yanling Xiao Xingting Zheng Rong Zeng Yuanzhong Zhou Yan Xie Xubo Shen 《Journal of Environmental Sciences》 2026年第1期617-623,共7页
Despite the widespread presence and frequent detection of polycyclic aromatic hydrocarbons(PAHs)in various aspects of life,there is limited research on their exposure levels in pregnant women and cumulative exposure f... Despite the widespread presence and frequent detection of polycyclic aromatic hydrocarbons(PAHs)in various aspects of life,there is limited research on their exposure levels in pregnant women and cumulative exposure from the living environment.This study included 1311 women in late pregnancy from the Zunyi birth cohort and measured the urinary concentrations of 10 hydroxylated PAH metabolites(OH-PAHs).Risk assessment was conducted based on the estimated daily intake to calculate the hazard quotient and hazard index(HI).A linear regression model was used to analyze the relationship between creatinine-adjusted OH-PAHs concentrations and living environment and lifestyle factors,while principal component analysis was applied to trace the sources of PAHs exposure.1-OHPYR was detected in all participants’urine,with naphthalene metabolites having the highest concentrations among creatinine-adjusted PAHs.OH-PAHs concentrations were associated with housing type,room number,cooking frequency,household size,exercise frequency,fuel type,distance from main road,and drinking water source.Pregnant women using traditional fuels and living in bungalows had higher health risks than those using clean energy and living in buildings.Those living within 100 m of a main road had higher HI than those farther away.Coal combustion was identified as the primary source of PAHs exposure.The study emphasizes the importance of reducing PAHs exposure,especially for pregnant women living in polluted environments.It recommends public health interventions such as improving indoor ventilation and providing clean energy to reduce related health risks. 展开更多
关键词 Polycyclic aromatic hydrocarbons Pregnant women Environmental factor Daily intake estimation Risk assessment
原文传递
Recent progress in the applications of presynaptic dopaminergic positron emission tomography imaging in parkinsonism 被引量:1
11
作者 Yujie Yang Xinyi Li +7 位作者 Jiaying Lu Jingjie Ge Mingjia Chen Ruixin Yao Mei Tian Jian Wang Fengtao Liu Chuantao Zuo 《Neural Regeneration Research》 SCIE CAS 2025年第1期93-106,共14页
Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.... Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.This review provides a comprehensive summary of the latest developments in the application of presynaptic dopaminergic positron emission tomography imaging in disorders that manifest parkinsonism.We conducted a thorough literature search using reputable databases such as PubMed and Web of Science.Selection criteria involved identifying peer-reviewed articles published within the last 5 years,with emphasis on their relevance to clinical applications.The findings from these studies highlight that presynaptic dopaminergic positron emission tomography has demonstrated potential not only in diagnosing and differentiating various Parkinsonian conditions but also in assessing disease severity and predicting prognosis.Moreover,when employed in conjunction with other imaging modalities and advanced analytical methods,presynaptic dopaminergic positron emission tomography has been validated as a reliable in vivo biomarker.This validation extends to screening and exploring potential neuropathological mechanisms associated with dopaminergic depletion.In summary,the insights gained from interpreting these studies are crucial for enhancing the effectiveness of preclinical investigations and clinical trials,ultimately advancing toward the goals of neuroregeneration in parkinsonian disorders. 展开更多
关键词 aromatic amino acid decarboxylase brain imaging dopamine transporter Parkinson’s disease PARKINSONISM positron emission tomography presynaptic dopaminergic function vesicle monoamine transporter type 2
暂未订购
Low-cost and fluoride-free synthesis of MFI zeolite nanosheets with enhanced stability for benzene alkylation with ethanol 被引量:2
12
作者 Peng Zhu Cun Liu +5 位作者 Yiren Yu Guoshu Gao Yumeng Zhao Xiongfu Zhang Guodong Liu Guohui Yang 《Journal of Energy Chemistry》 2025年第1期458-468,共11页
Zeolite nanosheets with a short b-axis thickness are highly desirable in lots of catalytic reactions due to their reduced diffusion resistance. Nevertheless, conventional synthesis methods usually require expensive st... Zeolite nanosheets with a short b-axis thickness are highly desirable in lots of catalytic reactions due to their reduced diffusion resistance. Nevertheless, conventional synthesis methods usually require expensive structure-directing agents(SDAs), pricey raw materials, and eco-unfriendly fluorine-containing additives. Here, we contributed a cost-effective and fluoride-free synthesis method for synthesizing high-quality MFI zeolite nanosheets through a Silicalite-1(Sil-1) seed suspension and urea cooperative strategy, only with inexpensive colloidal silica as the Si source. Our approach was effective for synthesizing both Sil-1 and aluminum-containing ZSM-5 nanosheets. By optimizing key synthesis parameters,including seed aging time, seed quantity, and urea concentration, we achieved precise control over the crystal face aspect ratio and b-axis thickness. We also revealed a non-classical oriented nanosheet growth mechanism, where Sil-1 seeds induced the formation of quasi-ordered precursor particles, and the(010)crystal planes of these particles facilitated urea adsorption, thereby promoting c-axis-oriented growth.The obtained ZSM-5 nanosheets exhibited exceptional catalytic performance in the benzene alkylation with ethanol, maintaining stability for over 500 h, which is 5 times longer than traditional ZSM-5 catalysts. Furthermore, large-scale production of ZSM-5 nanosheets was successfully carried out in a 3 L highpressure autoclave, yielding samples consistent with those from laboratory-scale synthesis. This work marks a significant step forward in the sustainable and efficient production of MFI nanosheets using inexpensive and environmentally friendly raw materials, offering the broad applicability in catalysis. 展开更多
关键词 MFI zeolite ZSM-5 NANOSHEETS Scale-up synthesis Aromatic alkylation
在线阅读 下载PDF
Decoding the mechanism of P450-catalyzed aromatic hydroxylation:Uncovering the arene oxide pathway and insights into the regioselectivity 被引量:2
13
作者 Qun Huang Xuan Zhang +8 位作者 Guangwu Sun Rui-ying Qiu Lan Luo Cuizhen Wang Longwei Gao Bing Gao Bo Chen Binju Wang Jian-bo Wang 《Chinese Journal of Catalysis》 2025年第3期420-430,共11页
P450 enzymes-catalyzed aromatic hydroxylation plays an important role in detoxification,biosynthesis,and potential carcinogenic effect of aromatic compounds.Though it has been explored for decades,the actual process o... P450 enzymes-catalyzed aromatic hydroxylation plays an important role in detoxification,biosynthesis,and potential carcinogenic effect of aromatic compounds.Though it has been explored for decades,the actual process of aromatic hydroxylation and mechanism of regioselectivity catalyzed by cytochrome P450 monooxygenases remained ambiguous.Here,we have resolved these issues.With a stable chiral organofluorine probe,and especially with X-ray data of two isolated arene oxides derivatives,we demonstrate that an arene oxide pathway is definitely involved in P450-catalyzed aromatic hydroxylation.By the capture,isolation,identification and reactivity exploration of the arene 1,2-oxide and arene 2,3-oxide intermediates,together with advanced QM calculations,the mechanism of how two intermediates go to the same product has been elucidated.In addition to the model substrate,we also confirmed that an arene oxide intermediate is involved in the P450-catalyzed hydroxylation pathway of a natural product derivative methyl cinnamate,which indicates that this intermediate appears to be universal in P450-catalyzed aromatic hydroxylation.Our work not only provides the most direct evidence for the arene oxide pathway and new insights into the regioselectivity involved in P450-catalyzed aromatic hydroxylation,but also supplies a new synthetic approach to achieve the dearomatization of aromatic compounds. 展开更多
关键词 Aromatic hydroxylation Cytochrome P450 Arene oxide Regioselectivity DEAROMATIZATION
在线阅读 下载PDF
Preferential association of PBDEs and PAHs with mineral particles vs.dissolved organic carbon:Implications for groundwater contamination at e-waste sites 被引量:2
14
作者 Cuiyi Yang Lin Duan +3 位作者 Jing Wang Chuanjia Jiang Tong Zhang Wei Chen 《Journal of Environmental Sciences》 2025年第4期288-296,共9页
Polybrominated biphenyl ethers(PBDEs)and polycyclic aromatic hydrocarbons(PAHs)are commonly detected contaminants at e-waste recycling sites.Against the conventional wisdom that PBDEs and PAHs are highly immobile and ... Polybrominated biphenyl ethers(PBDEs)and polycyclic aromatic hydrocarbons(PAHs)are commonly detected contaminants at e-waste recycling sites.Against the conventional wisdom that PBDEs and PAHs are highly immobile and persist primarily in shallowsurface soils,increasing evidence shows that these compounds can leach into the groundwater.Herein,we compare the leachabilities of PBDEs vs.PAHs from contaminated soils collected at an e-waste recycling site in Tianjin,China.Considerable amounts of BDE-209(0.3–2 ng/L)and phenanthrene(42–106 ng/L),the most abundant PBDE and PAH at the site,are detected in the effluents of columns packed with contaminated soils,with the specific concentrations varying with hydrodynamic and solution chemistry conditions.Interestingly,the leaching potential of BDE-209 appears to be closely related to the release of colloidal mineral particles,whereas the leachability of phenanthrene correlates well with the concentration of dissolved organic carbon in the effluent,but showing essentially no correlation with the concentration of mineral particles.The surprisingly different trends of the leachability observed between BDE-209 and phenanthrene is counterintuitive,as PBDEs and PAHs often co-exist at e-waste recycling sites(particularly at the sites wherein incineration is being practiced)and share many similarities in terms of physicochemical properties.One possible explanation is that due to its extremely low solubility,BDE-209 predominantly exists in free-phase(i.e.,as solid(nano)particles),whereas the more soluble phenanthrene is mainly sorbed to soil organic matter.Findings in this study underscore the need to better understand the mobility of highly hydrophobic organic contaminants at contaminated sites for improved risk management. 展开更多
关键词 Polybrominated diphenyl ethers Polycyclic aromatic hydrocarbons Colloidal mineral particles Dissolved organic carbon e-Waste recycling
原文传递
Stable Eu(Ⅲ)-based metal-organic framework for fluorescence sensing of benzaldehyde and its analogues 被引量:1
15
作者 Xin Chen Meng Zhao Yan-Yuan Jia 《Chinese Journal of Structural Chemistry》 2025年第3期18-20,共3页
Volatile aromatic aldehydes,including benzaldehyde(BzH),4-fluorobenzaldehyde(4-F-BzH),4-isobutylbenzaldehyde(4-iBu-BzH),3-trifluoromethylbenzaldehyde(3-CF_(3)-BzH),p-methoxybenzaldehyde(4-MeO-BzH),and o-trifluoromethy... Volatile aromatic aldehydes,including benzaldehyde(BzH),4-fluorobenzaldehyde(4-F-BzH),4-isobutylbenzaldehyde(4-iBu-BzH),3-trifluoromethylbenzaldehyde(3-CF_(3)-BzH),p-methoxybenzaldehyde(4-MeO-BzH),and o-trifluoromethylbenzaldehyde(2-CF_(3)-BzH),are crucial raw materials for the synthesis of various pesticides and pharmaceuticals[1]. 展开更多
关键词 ANALOGUES volatile aromatic aldehydes Eu III raw materials volatile aromatic aldehydesincluding fluorescence sensing BENZALDEHYDE metal organic framework
原文传递
Oxidative depolymerization of lignin enhanced by synergy of polyoxometalate and acetic acid 被引量:1
16
作者 Jiaming Cao Yuting Liu +3 位作者 Huifang Liu Chunguang Liu Junyou Shi Ning Li 《Chinese Journal of Catalysis》 2025年第7期352-364,共13页
Oxidative catalysis enables lignin depolymerization to yield carbonyl-containing aromatic chemicals for sustainable lignocellulose valorization.The oxidative depolymerization of lignin requires high oxygen pressure an... Oxidative catalysis enables lignin depolymerization to yield carbonyl-containing aromatic chemicals for sustainable lignocellulose valorization.The oxidative depolymerization of lignin requires high oxygen pressure and harsh conditions to trade off lignin’s structural complexity and limited solubility.Herein,we developed an oxidation system for lignin depolymerization using a single phosphomolybdic acid(H_(3)PMo_(12)O_(40))catalyst in acetic acid solvent to address the aforementioned issues.The entire catalytic system was operated under only 0.1 MPa O_(2) pressure,providing over 20 wt% of aromatic compounds containing aldehydes and carboxylic acids.Theoretical calculations combined with experimental analyses reveal structural transformations and redox behavior driven by the synergistic interaction between H_(3)PMo_(12)O_(40) and acetic acid.Mechanistic studies detected superoxide radicals,confirming the joint role of catalyst and solvent in oxygen activation,radicals stabilization,and enhanced reaction efficiency.A low-cost,commercially available catalyst with minimal oxygen demand offers a promising route to industrial-scale biomass refining. 展开更多
关键词 Oxidative catalysis Lignin valorization Aromatic chemicals Phosphomolybdic acid Organic acid
在线阅读 下载PDF
Effects of photo-oxidation and transition metals on the formation of reactive oxygen species from aromatic compounds using spectroscopic method 被引量:1
17
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
原文传递
Associations of polycyclic aromatic hydrocarbons exposure with serum uric acid and hyperuricemia in US adults:The role of systemic inflammation 被引量:1
18
作者 Yang Liu Xuejie Ding +7 位作者 Linling Yu Da Shi Ruyi Liang Wei Liu Xuezan Huang Xiuyu Cao Min Zhou Weihong Chen 《Journal of Environmental Sciences》 2025年第4期412-421,共10页
The associations of polycyclic aromatic hydrocarbon(PAH)exposure with serum uric acid(SUA)or hyperuricemia have been rarely assessed.We aimed to investigate the relationships between urinary PAH metabolites and SUA or... The associations of polycyclic aromatic hydrocarbon(PAH)exposure with serum uric acid(SUA)or hyperuricemia have been rarely assessed.We aimed to investigate the relationships between urinary PAH metabolites and SUA or hyperuricemia among US adults and to explore the mediating role of systemic inflammation in the associations.A total of 10,307 US adults were conducted to assess the associations of seven urinary hydroxy–PAH with SUA and hyperuricemia and evaluate the role of C-reactive protein(CRP),a biomarker of systemic inflammation,in such associations.Results showed that each 1-unit increase in ln-transformed 2-hydroxynaphthalene(2-OHNa),1-hydroxyphenanthrene(1-OHPh),2&3-hydroxyphenanthrene(2&3-OHPh)and total hydroxyphenanthrene(OHPh)was associated with a 1.68(95%confidence interval(CI):0.19 to 3.17),2.46(0.78 to 4.13),3.34(1.59 to 5.09),and 2.99(1.23 to 4.75)μmol/L increase in SUA,and a 8%(odds ratio(OR):1.08,1.02 to 1.15),9%(OR:1.09,1.02 to 1.18),13%(OR:1.13,1.05 to 1.22),and 12%(OR:1.12,95%CI:1.03,1.21)increase in hyperuricemia,respectively.Co-exposure of seven PAHs was positively associated with SUA and hyperuricemia,with 2&3-OHPh showing the highest weight(components weights:0.83 and 0.78,respectively).The CRP mediated 11.47%and 10.44%of the associations ofΣOHPh and 2&3-OHPh with SUA and mediated 8.60%and 8.62%in associations ofΣOHPh and 2&3-OHPh with hyperuricemia,respectively.In conclusion,internal levels of PAH metabolites were associated with elevated SUA levels and the increased risk of hyperuricemia among US adults,and CRP played a mediating role in the associations. 展开更多
关键词 Polycyclic aromatic hydrocarbon Serum uric acid HYPERURICEMIA C-reactive protein General population
原文传递
Profiles,exposure assessment and expanded screening of PAHs and their derivatives in one petroleum refinery facility of China 被引量:1
19
作者 Ning Wang Fengjiao Jiang +1 位作者 Lin Xu Yaqi Cai 《Journal of Environmental Sciences》 2025年第1期550-560,共11页
This study investigated environmental distribution and human exposure of polycyclic aromatic hydrocarbons(PAHs)and their derivatives in one Chinese petroleum refinery facility.It was found that,following with high con... This study investigated environmental distribution and human exposure of polycyclic aromatic hydrocarbons(PAHs)and their derivatives in one Chinese petroleum refinery facility.It was found that,following with high concentrations of 16 EPA PAHs(∑Parent-PAHs)in smelting subarea of studied petroleum refinery facility,total derivatives of PAHs[named as XPAHs,including nitro PAHs(NPAHs),chlorinated PAHs(Cl-PAHs),and brominated PAHs(Br-PAHs)]in gas(mean=1.57×10^(4)ng/m^(3)),total suspended particulate(TSP)(mean=4.33×10^(3) ng/m^(3))and soil(mean=4.37×10^(3) ng/g)in this subarea had 1.76-6.19 times higher levels than those from other subareas of this facility,surrounding residential areas and reference areas,indicating that petroleum refining processes would lead apparent derivation of PAHs.Especially,compared with those in residential and reference areas,gas samples in the petrochemical areas had higher∑NPAH/∑PAHs(mean=2.18),but lower∑Cl-PAH/∑PAHs(mean=1.43×10^(-1))and∑Br-PAH/∑PAHs ratios(mean=7.49×10^(-2)),indicating the richer nitrification of PAHs than chlorination during petrochemical process.The occupational exposure to PAHs and XPAHs in this petroleum refinery facility were 24-343 times higher than non-occupational exposure,and the ILCR(1.04×10^(-4))for petrochemical workers was considered to be potential high risk.Furthermore,one expanded high-resolution screening through GC Orbitrap/MS was performed for soils from petrochemical area,and another 35 PAHs were found,including alkyl-PAHs,phenyl-PAHs and other species,indicat-ing that profiles and risks of PAHs analogs in petrochemical areas deserve further expanded investigation. 展开更多
关键词 Polycyclic aromatic hydrocarbons(PAHs) DERIVATIVES Petroleum refinery Human exposure Non-targeted screening
原文传递
Surface defect engineering of ZnCoS in ZnCdS with twin crystal structure for visible-light-driven H_(2) production coupled with benzyl alcohol oxidation 被引量:1
20
作者 Tan Ji Siang Peipei Zhang +1 位作者 Binghui Chen Wee-Jun Ong 《Chinese Journal of Catalysis》 2025年第2期84-98,共15页
Photoredox dual reaction of organic synthesis and H2 evolution opens up a novel pathway for collaboratively generating clean fuels and high-quality chemicals,providing a more effective approach of solar energy convers... Photoredox dual reaction of organic synthesis and H2 evolution opens up a novel pathway for collaboratively generating clean fuels and high-quality chemicals,providing a more effective approach of solar energy conversion.Herein,a surface defect-engineered ZnCoS/ZnCdS heterostructure with zinc blende(ZB)/wurtzite(WZ)phase junctions is synthesized for photocatalytic cooperative coupling of benzaldehyde(BAD)and H_(2) production.This surface defect-engineered ZnCoS/ZnCdS heterostructure elaborately integrates the mixed phase junction advantage of ZnCdS semiconductor and the cocatalytic function of ZnCoS possessing Zn(VZn-ZnCoS/ZnCdS)or S vacancies(VS-ZnCoS/ZnCdS).The optimum VS-ZnCoS/ZnCdS simultaneously exhibits a superior H2 production rate of 14.23 mmol h^(-1) g^(-1) accompanied with BAD formation rate of 12.29 mmol h^(-1) g^(-1) under visible-light irradiation,which is approximately two-fold greater than that of pristine ZnCdS.Under simulated sunlight irradiation(AM 1.5),VS-ZnCoS/ZnCdS achieves H2 evolution(27.43 mmol gcat^(-1) h^(-1))with 0.52%of STH efficiency,accompany with 26.31 mmol gcat^(-1) h^(-1) of BAD formation rate.The underlying solar-driven mechanism is elucidated by a series of in-situ characterization and control experiments,which reveals the synergistic effect of interfacial ZB/WZ phase junctions in ZnCdS and S vacancies of ZnCoS on enhancement of the photoredox dual reaction.The VS-ZnCoS/ZnCdS follows a predominant oxygen-centered radical integrating with carbon-centered radical pathways for BAD formation and a simultaneous electron-driven proton reduction for H_(2) production.Interestingly,the nature of surface vacancies not only facilitates the separation of photoinduced charge carriers but also able to selectively adjust the mechanism pathway for BAD production via tuning the oxygen-centered radical and carbon-centered radical formation. 展开更多
关键词 Photoredoxdual reaction Aromatic alcohol conversion Surface vacancy Organic synthesis H_(2)production
在线阅读 下载PDF
上一页 1 2 68 下一页 到第
使用帮助 返回顶部