期刊文献+
共找到294,366篇文章
< 1 2 250 >
每页显示 20 50 100
Direct conversion of furfural to levulinic acid/ester in dimethoxymethane:Understanding the mechanism for polymerization 被引量:3
1
作者 Yuewen Shao Xun Hu +7 位作者 Zhanming Zhang Kai Sun Guanggang Gao Tao Wei Shu Zhang Song Hu Jun Xiang Yi Wang 《Green Energy & Environment》 SCIE CSCD 2019年第4期400-413,共14页
This study investigated the conversion of furfural to 5-hydroxymethylfurfural(HMF)and further to levulinic acid/ester in dimethoxymethane under acidic conditions,with the particular focus on understanding the mechanis... This study investigated the conversion of furfural to 5-hydroxymethylfurfural(HMF)and further to levulinic acid/ester in dimethoxymethane under acidic conditions,with the particular focus on understanding the mechanism for polymer formation.The results showed that furfural could react with dimethoxymethane via electrophilic substitution reaction to form HMF or the ether/acetal of HMF,which were further converted to levulinic acid and methyl levulinate.The polymerization of furfural and the cross-polymerization between dimethoxymethane and the levulinic acid/ester produced were the main side reactions leading to the decreased yields of levulinic acid/ester.Comparing to the other solvent,methanol as the co-solvent helped to alleviate but not totally inhibited the occurrences of the polymerization,as the polymerization reactions via aldol condensation did not eliminate the C=O functionalities.As a consequence,the polymerization reactions continued to proceed.Other co-solvent used such as guaiacol,dimethyl sulfoxide and acetone interfered with the transformation of furfural to HMF or aided the polymerization reactions.The polymer produced from the reactions between furfural and DMM was different from that produced from levulinic acid/ester.The former had a higher crystallinity,while the latter was more aliphatic.The DRIFTS and TG-MS studies showed that the polymer had the carboxylic group,methyl group and the aliphatic structure in the skeleton.The removal of these functionalities was accompanied by the aromatization of the polymer.The condensation of DMM with levulinic acid/ester was the key reason for the diminished production of levulinic acid/ester. 展开更多
关键词 FURFURAL DIMETHOXYMETHANE Levulinic acid/ester Mechanism for polymerization Properties of the polymer
在线阅读 下载PDF
Using degrading endophytic bacteria to detoxify the phthalic acid esters in crops from contaminated soil 被引量:1
2
作者 Xiangyu Liu Xiangrui Du +4 位作者 Xiangzhi Zuo Zeming Wang Bozena Czech Patryk Oleszczuk Yanzheng Gao 《Journal of Environmental Sciences》 2025年第11期378-390,共13页
Phthalic acid esters(PAEs)are widely released into the environment due to industrial and agricultural activities.This poses significant risks,not only to crops grown on contaminated soil but also to humans.PAEs enter ... Phthalic acid esters(PAEs)are widely released into the environment due to industrial and agricultural activities.This poses significant risks,not only to crops grown on contaminated soil but also to humans.PAEs enter the human body through the food chain,causing potential health hazards.Endophytic bacteria have demonstrated a significant potential as effective bioremediation agents,with specialized mechanisms of PAEs degradation.Endophytic bacteria such as Rhodococcus,Pseudomonas and Sphingomona recognize root exudates,adhere to and penetrate root surfaces,and ultimately colonize crops.They form symbiotic relationships with crops,obtaining nutrients and habitats from crops,meanwhile,promoting plant growth and health through hormone production,nutrient regulation,and the suppression of pathogenic microorganisms.Furthermore,endophytic bacteria efficiently degrade PAEs in soil-crop systems through synergistic interactions with indigenous rhizosphere microflora and regulatory effects on enzyme activity in crops.Here,we review the role of endophytic bacteria in the bioremediation of PAEs-contaminated crops and soils.In addition,we discuss the scarcity of endophytic bacterial strains with a confirmed ability to degrade PAEs,and underscore the lack of the research on the mechanisms of PAEs degradation by these bacteria.This review also points out that future study should investigate the molecular mechanisms underlying the interaction between endophytic bacteria and PAEs to offer novel insights and solutions for environmental protection and sustainable agricultural development. 展开更多
关键词 Phthalic acid esters Endophytic bacteria COLONIZATION Plant growth promotion Degradative mechanisms
原文传递
Accumulation characteristics and fate modeling of phthalic acid esters in surface water from the Three Gorges Reservoir area,China 被引量:2
3
作者 Shuai Sun Bing Zhang +6 位作者 Junjie Hu Wen Gu Zhen Wang Deling Fan Feng Ge Lili Shi Lei Wang 《Journal of Environmental Sciences》 2025年第3期46-56,共11页
Phthalic acid esters(PAEs)are a group of compounds widespread in the environment.To investigate the occurrence and accumulation characteristics of PAEs,surface water samples were collected from the Three Gorges Reserv... Phthalic acid esters(PAEs)are a group of compounds widespread in the environment.To investigate the occurrence and accumulation characteristics of PAEs,surface water samples were collected from the Three Gorges Reservoir area,China.The total concentrations of∑_(11)analyzed PAEs(11PAEs)in the collected water samples ranging from 197.7 to 1,409.3 ng/L(mean±IQR:583.1±308.4 ng/L).While DEHP was the most frequently detected PAE,DnBP and DnNP were the most predominant PAEs in the analyzed water samples with a mean contribution of 63.3%of the∑_(11)PAEs.The concentrations of the∑_(11)PAEs in the water samples from the upper reaches of the Yangtze River were significantly higher than those from themiddle reaches.To better understand the transport and fate of the PAEs,seven detected PAEs were modeled by Quantitative Water Air Sediment Interaction(QWASI).The simulated and measured values were close for most PAEs,and differences are within one order of magnitude even for the worst one.For all simulated PAEs,water and particle inflow were main sources in the reservoir,whereas water outflow and degradation in water were important removal pathways.The contribution ratios of different sources/losses varied fromPAEs,depending on their properties.The calculated risk quotients of DnNP in the Three Gorges Reservoir area whether based onmonitoring or simulating results were all far exceeded the safety threshold value,implying the occurrence of this PAE compound may cause potential adverse effects for the aquatic ecology of the Three Gorges Reservoir area. 展开更多
关键词 Phthalic esters Surface water Transport and fate Three Gorges Reservoir area Risk assessment
原文传递
Nickel-catalyzed electrochemical carboxylation of propargylic esters with CO_(2) to 2,3-allenoic acids
4
作者 Yuqing Zhong Mengmeng Jiang +4 位作者 Deyong Yang Nan Feng Ying Sun Huimin Wang Feng Zhou 《Chinese Chemical Letters》 2025年第12期218-223,共6页
Here,we report a novel nickel-catalyzed electrochemical carboxylation of propargylic esters with CO_(2),characterized by the regioselective synthesis of 2,3-allenoic acids rather than propargylic carboxylic acids.Both... Here,we report a novel nickel-catalyzed electrochemical carboxylation of propargylic esters with CO_(2),characterized by the regioselective synthesis of 2,3-allenoic acids rather than propargylic carboxylic acids.Both acyclic propargylic esters and cyclic propargylic carbonates serve as effective substrates,facilitating the synthesis of mono-,di-,tri-,and tetra-substituted 2,3-allenoic acids with broad substrate scope under mild conditions.Mechanistic investigations indicate that the in situ generated Ni(Ⅰ)complex might serve as the active species to react with propargylic esters,forming the allenyl-Ni(Ⅰ)complex under electroreductive conditions.A possible γ-selective nucleophilic attack of allenyl-Ni(Ⅰ)complex on CO_(2) is likely involved in the formation of the desired 2,3-allenoic acids. 展开更多
关键词 CO_(2) Nickel-catalysis Electro-carboxylation Propargylic esters 2 3-Allenoic acids
原文传递
TfOH-Catalyzed O-H Insertion of Carboxylic Acids with α-Aryl Diazoesters
5
作者 Chen Guifang Li Hongqiang Zeng Xingrong 《有机化学》 北大核心 2025年第7期2537-2544,共8页
An efficient TfOH-catalyzed O—H insertion reaction of α-aryl diazoesters with carboxylic acids is reported.This metal-free protocol provides an operationally simple method for a one-pot assembly of diverse α-acylox... An efficient TfOH-catalyzed O—H insertion reaction of α-aryl diazoesters with carboxylic acids is reported.This metal-free protocol provides an operationally simple method for a one-pot assembly of diverse α-acyloxy esters in moderate to high yields with a broad substrate scope.All starting materials are readily available,and the reactions can be conducted in the open air at room temperature. 展开更多
关键词 carboxylic acids α-aryl diazoesters TfOH O-H insertion
原文传递
Readily Degradable and Recyclable High Molecular Weight Thiosalicylic Acid-based Copolyesters
6
作者 Ge Yao Fang-Ping Ren +5 位作者 Fei Chen Lu-Ya Cao Ji Xian Xiao-Bo Pan Hong-Zhang Cao Jin-Cai Wu 《Chinese Journal of Polymer Science》 2025年第6期924-932,I0007,共10页
Most commercial plastics cannot easily degrade,which raises a number of sustainability issues.To address the current problem of plastic pollution,the research and development of easily degradable and recyclable polyme... Most commercial plastics cannot easily degrade,which raises a number of sustainability issues.To address the current problem of plastic pollution,the research and development of easily degradable and recyclable polymers has become an attractive subject.Herein,a new monomer of thiosalicylic methyl glycolide(TSMG)was synthesized using one-pot method and high molecular weight poly(thiosalicylic methyl glycolide)(PTSMG,M_(n) up to 300 kDa)can be obtained via the ring-opening polymerization(ROP)of TSMG.PTSMG exhibits good closed-loop recyclability and hydrolytic degradability,where PTSMG can generate pristine monomers through sublimation thermal depolymerization conditions due to the presence of thiophenol ester bond in the polymer chains,and can be degraded rapidly in aqueous solution,which provides a potential solution to the current plastic pollution problem. 展开更多
关键词 Hydrogen-bonding catalysts Closed-loop recycling Hydrolytic degradation Ring-opening polymerization Poly(thiophenol ester)
原文传递
Syntheses,structures,and catalytic performances of complexes with 4,4'-dihydroxy-[1,1'-biphenyl]-3,3'-dicarboxylic acid ligands
7
作者 LING Weizhong LIN Jingyi +3 位作者 ZHU Jianglin LIANG Yuyi DAI Shanshan LI Yu 《无机化学学报》 北大核心 2026年第1期152-160,共9页
Three copper(Ⅱ),nickel and cadmium(Ⅱ)complexes,namely[Cu_(2)(μ-H2dbda)2(phen)2]·2H_(2)O(1),[Ni(μ-H2dbda)(μ-bpb)(H_(2)O)2]n(2),and[Cd(μ-H2dbda)(μ-bpa)]n(3),have been constructed hydrothermally using H4dbda(... Three copper(Ⅱ),nickel and cadmium(Ⅱ)complexes,namely[Cu_(2)(μ-H2dbda)2(phen)2]·2H_(2)O(1),[Ni(μ-H2dbda)(μ-bpb)(H_(2)O)2]n(2),and[Cd(μ-H2dbda)(μ-bpa)]n(3),have been constructed hydrothermally using H4dbda(4,4'-dihydroxy-[1,1'-biphenyl]-3,3'-dicarboxylic acid),phen(1,10-phenanthroline),bpb(1,4-bis(pyrid-4-yl)benzene),bpa(bis(4-pyridyl)amine),and copper,nickel and cadmium chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and singlecrystal X-ray diffraction analyses.Single-crystal X-ray diffraction analyses revealed that three complexes crystallize in the monoclinic P21/n,tetragonal I42d,and orthorhombic P21212 space groups.The complexes exhibit molecular dimers(1)or 2D metal-organic networks(2 and 3).The catalytic performances in the Knoevenagel reaction of these complexes were investigated.Complex 1 exhibits an effective catalytic activity and excellent reusability as a heterogeneous catalyst in the Knoevenagel reaction at room temperature.CCDC:2463800,1;2463801,2;2463802,3. 展开更多
关键词 COMPLEX dicarboxylic acid catalytic properties Knoevenagel reaction
在线阅读 下载PDF
The study on citric acid-modified HUSY catalyzed alkylation of phenol with cyclohexanol
8
作者 HUA Canhao WU Jingfeng +2 位作者 ZHU Lingjun XU Guangwen WANG Shurong 《燃料化学学报(中英文)》 北大核心 2026年第3期58-70,共13页
Lignin-derived oxygenated aromatics,particularly phenols and aromatic ethers obtained through depolymerization,represent promising feedstocks for synthesizing high-density and high-heat-sink aviation fuels via alkylat... Lignin-derived oxygenated aromatics,particularly phenols and aromatic ethers obtained through depolymerization,represent promising feedstocks for synthesizing high-density and high-heat-sink aviation fuels via alkylation-hydrogenation processes.This study systematically evaluates the catalytic performance of various zeolites(Hβ,HZSM-5,MCM-41 and HUSY)in the alkylation reaction of phenol with cyclohexanol.Characterization results demonstrate that HUSY zeolite showed superior catalytic activity compared to other zeolites,attributable to its favorable pore architecture and well-balanced acid site distribution that synergistically facilitate molecular diffusion and catalytic transformations.To further enhance the catalytic properties,HUSY zeolite was modified with citric acid at various concentrations and compared with those treated with NaOH and oxalic acid.The results revealed that citric acid treatment preserved the crystallinity of the zeolite while modulating its acid distribution and pore structure.All modified zeolites enhanced phenol alkylation activity.Notably,the HUSY-0.5M catalyst,which exhibited the highest medium-strong acid to total acid ratio,achieved superior catalytic performance,80.4%conversion of phenol and 99.6%selectivity for alkylation products.The catalyst also exhibited high activity in the alkylation of various lignin-derived compounds,demonstrating its broad applicability.This work provides a new strategy for the valorization of lignin-derived phenols into high-value fuel precursors through alkylation. 展开更多
关键词 citric acid modification HUSY phenolic alkylation aviation fuel
在线阅读 下载PDF
Influence of the distance between Brønsted acid sites and Mo sites in Mo/HZSM-5 on the mechanism of methane dehydroaromatization performance
9
作者 WANG Ce WEI Lihong +2 位作者 ZHANG Qinghao ZHANG Hongxiang SUN Yuewen 《燃料化学学报(中英文)》 北大核心 2026年第4期68-81,共14页
Methane dehydroaromatization(MDA)presents a promising carbon-neutral pathway for benzene,toluene,and xylene(BTX)production,alternative to petroleumderived routes.Elucidating the regulatory mechanisms of Brønsted ... Methane dehydroaromatization(MDA)presents a promising carbon-neutral pathway for benzene,toluene,and xylene(BTX)production,alternative to petroleumderived routes.Elucidating the regulatory mechanisms of Brønsted acid site(BAS)strength on reaction pathways,alongside the spatial proximity effects between BAS and Mo active sites in bifunctional synergy,remains a critical scientific challenge in catalyst design.This study systematically tunes both BAS strength(via isomorphous metal substitution)and Mo-BAS spatial proximity in zeolites,integrating MDA catalytic evaluations with density functional theory(DFT)calculations to dissect their individual contributions.Strongly acidic BAS catalysts(compared to moderately acidic Fe/Ga-substituted counterparts)exhibit superior performance,evidenced by enhanced aromatic yields.Conversely,weakly acidic Bsubstituted zeolites demonstrate optimal mono-/bifunctional synergy,outperforming moderate-acid systems.DFT results reveal that acid strength dictates C−H activation mechanisms by modulating the energy barriers of rate-determining steps.While Al-zeolites deliver the highest activity,B-substituted systems display unique potential for mechanistic investigations.Spatial proximity analysis indicates that micrometer-scale Mo-BAS distances hinder effective synergy due to exceeding electron interaction and mass transfer limits,whereas nanometer-scale proximity enhances activity(via accelerated intermediate transport)and suppresses coke formation.These findings establish a theoretical framework for rationalizing zeolite catalyst optimization through BAS property engineering and spatial control of Mo-BAS cooperation,providing actionable guidelines for designing next-generation MDA catalysts. 展开更多
关键词 methane dehydroaromatization Brønsted acid catalytic mechanism ZEOLITE
在线阅读 下载PDF
Integrated Transcriptomic and Metabolomic Analysis Reveals the Adaptive Mechanism of Penicillium digitatum under Modified Atmosphere Packaging Based on Amino Acid Metabolism
10
作者 HAO Shanshan WANG Zhengli +3 位作者 XU Huihui JI Nana GUO Yanyin Abbas AQLEEM 《食品科学》 北大核心 2026年第6期129-144,共16页
This study employed integrated multi-omics approaches to elucidate,from the perspective of amino acid metabolism,the adaptive mechanism of Penicillium digitatum under modified atmosphere packaging(MAP)conditions.Compa... This study employed integrated multi-omics approaches to elucidate,from the perspective of amino acid metabolism,the adaptive mechanism of Penicillium digitatum under modified atmosphere packaging(MAP)conditions.Comparative analysis of natural air(Air),controlled atmosphere(CA),and MAP treatments revealed that MAP upregulated the expression of the hercynylcysteine S-oxide synthase(HCSOS),aldehyde dehydrogenase(ALDH),and monoamine oxidase(MAO)genes,thereby enhancing histidine-derived ergothioneine and methionine levels,and subsequently boosting glutathione-mediated redox homeostasis.Meanwhile,MAP induced the expression of the dihydroxyacid dehydratase(DHAD),saccharopine dehydrogenase(SDH),and arginosuccinate lyase(ASL)genes,redirecting valine,lysine,and arginine into the tricarboxylic acid(TCA)cycle to fuel ATP production.MAP also enhanced ASL-mediated arginine degradation and urea cycle activity,reducing arginine accumulation when compared to CA treatment.In contrast,while MAP induced upregulated expression of the pyrroline-5-carboxylate dehydrogenase(P5CDH)and D-amino acid oxidase(DAAO)genes,CA treatment promoted proline accumulation,reflecting stress-specific metabolic flexibility.Collectively,these findings demonstrate that MAP triggers transcriptional reprogramming of amino acid metabolism to coordinate oxidative defense,energy generation,and osmotic balance.By modulating these metabolic pathways and regulatory genes under MAP conditions,fungal adaptability can be disrupted.Hence,this study provides a promising strategy for suppressing green mold development,extending the postharvest shelf life,and improving the quality of fruits and vegetables. 展开更多
关键词 amino acid metabolism multi-omics Penicillium digitatum modified atmosphere packaging postharvest pathology
在线阅读 下载PDF
Photocatalytic Radical-Mediated Synthesis of Unnaturalα-Amino Acids from Heteroaryl Aldehydes
11
作者 Ren Ke Zhang Guanglu +3 位作者 Niu Yifan Wang Xiaomeng Chen Canyu Jiang Min 《有机化学》 北大核心 2026年第1期215-224,共10页
Non-naturalα-amino acids(α-AAs)are pivotal in drug and catalysis,yet their synthesis remains challenges.A photocatalytic strategy for the direct construction of N-heteroaryl-containingα-AAs from heteroaryl aldehyde... Non-naturalα-amino acids(α-AAs)are pivotal in drug and catalysis,yet their synthesis remains challenges.A photocatalytic strategy for the direct construction of N-heteroaryl-containingα-AAs from heteroaryl aldehydes via acyl radical intermediates is reported.This method exhibits exceptional functional group tolerance and enables late-stage diversification of peptides and carbonyl-group derivatization.Mechanistic studies confirm a radical-based pathway,while applications in peptide modification highlight its utility in bioorganic chemistry. 展开更多
关键词 PHOTOCATALYTIC non-natural amino acids heteroaryl aldehydes acyl radical electron paramagnetic resonance
原文传递
Efficient leaching and separation of iron,aluminum,and calcium from carbon-rich components in coal gasification fine slag using organic acids
12
作者 NAN Tianhao ZHOU Anning +4 位作者 HAN Rui HAN Chunmeng CHEN Heng ZHANG Ningning LI Bingying 《燃料化学学报(中英文)》 北大核心 2026年第4期1-16,共16页
The efficient extraction and separation of valuable metal elements from coal gasification fine slag(CGFS)are crucial for the comprehensive high-value utilization of its constituents.This study focused on the carbon-ri... The efficient extraction and separation of valuable metal elements from coal gasification fine slag(CGFS)are crucial for the comprehensive high-value utilization of its constituents.This study focused on the carbon-rich components of CGFS(CGFS-H)and systematically investigates the selective leaching behavior of Fe^(3+),Al^(3+)and Ca^(2+)using three organic acid extractants,i.e.,citric acid,tartaric acid,and tetrasodium iminodisuccinate.Additionally,the stepwise leaching of iron,aluminum and calcium from CGFS-H is explored.The selective dissolution mechanisms of these metals by different organic acids are elucidated through X-ray diffraction(XRD),X-ray fluorescence(XRF),and scanning electron microscopy(SEM)analyses.The results indicate that tetrasodium iminodisuccinate exhibits the highest leaching selectivity for Fe^(3+),while tartaric acid demonstrateds a comparable affinity for both Fe^(3+)and Al^(3+).In contrast citric acid shows superior selectivity toward Ca^(2+).The leaching yield of Fe^(3+),Al^(3+)and Ca^(2+)after sequential leaching with the three organic acids were 79.8%,65.08%and 78.6%,respectively.These findings confirm that effective and selective separation of Fe^(3+),Al^(3+)and Ca^(2+)from CGFS-H can be achieved via optimized organic acid-based leaching strategies.This advancement provides a critical foundation for developing Ca/Fe/Al hydrotalcite materials using CGFS-H as a sustainable feedstock,thereby facilitating the transformation of waste residue into high-value functional materials and promoting resourceefficient utilization of coal gasification fine slag. 展开更多
关键词 coal gasification fine slag carbon-rich components organic acids LEACHING stepwise extraction
在线阅读 下载PDF
Linoleic acid alleviates mood disorders in mice by modulating microglia differentiation and arachidonic acid metabolism
13
作者 Meishan Lu Yanjun Liu +4 位作者 Mengxue He Jiachen Shi Yanan Wang Xue Li Yuanfa Liu 《Food Science and Human Wellness》 2026年第2期892-907,共16页
In previous research,we demonstrated that long-term consumption of thermally oxidized oil leads to neuroinflammation and anxiety in mice.Therefore,in this study,we employed polar lipid components from thermo-induced o... In previous research,we demonstrated that long-term consumption of thermally oxidized oil leads to neuroinflammation and anxiety in mice.Therefore,in this study,we employed polar lipid components from thermo-induced oxidized oil to induce neurodamage.Behavioral assessments revealed that both the linoleic acid and AUDA(a classical inhibitor of soluble epoxide hydrolase)groups exhibited significantly reduced anxiety-like behaviors compared to the model group(P<0.05).Immunofluorescence analysis indicated that microglial activation in the hippocampus was attenuated in both the linoleic acid and AUDA groups relative to the model group,accompanied by a reduction in the m RNA expression of pro-inflammatory cytokines(IL-1β,IL-6,NOS2,TNF-α)and an upregulation of neuroprotective factors(IL-4,IL-10,BDNF).Lipidomic profiling of hippocampal tissue revealed that the lipid composition of the linoleic acid group closely resembled that of the AUDA group,with a significant downregulation of cardiolipin(CL)compared to the control group,consistent with alterations in the membrane potential channel receptor TRPC1.Both linoleic acid and AUDA inhibited the m RNA expression of EPHX2,leading to an increase in epoxyeicosatrienoic acids(EETs)levels.Furthermore,linoleic acid upregulated the expression of cytochrome P450 enzymes(CYP2J6)and lipoxygenase(LOX2S),which further upregulated the synthesis of EETs,and increased the content of 9-HODE and 13-HODE.These findings collectively suggest that linoleic acid alleviates neuroinflammation by modulating microglial differentiation and attenuates neurodegeneration induced by thermally oxidized oil through the regulation of arachidonic acid metabolism and the linoleic acid metabolic pathway,leading to the production of neuroprotective lipid mediators.Therefore,linoleic acid may serve as a potential neuro-nutrient for the treatment of anxiety disorders.This provided a scientific basis for the development of specialized medical foods aimed at protecting neural health. 展开更多
关键词 Linoleic acid ANXIETY MICROGLIA Arachidonic acid
在线阅读 下载PDF
Taurodeoxycholic,taurocholic,and glycocholic acids promote hepatic gluconeogenesis via TGR5 in dairy cows
14
作者 Miaomiao Zhu Yining Zheng +7 位作者 Shiyang Lou Ruixu Zhang Dingping Feng Xinjian Lei Lei Chen Jianguo Wang Junhu Yao Lu Deng 《Journal of Animal Science and Biotechnology》 2026年第1期500-515,共16页
Background Ruminants and monogastric animals exhibit significant differences in gluconeogenic efficiency.In dairy cows,hepatic gluconeogenesis serves as the primary source of glucose.Metabolites modulate gluconeogenes... Background Ruminants and monogastric animals exhibit significant differences in gluconeogenic efficiency.In dairy cows,hepatic gluconeogenesis serves as the primary source of glucose.Metabolites modulate gluconeogenesis efficiency through allosteric regulation,redox state,and signal transduction pathways.However,the liver-enriched metabolites that regulate hepatic gluconeogenesis in dairy cows and their specific regulatory mechanisms remain incompletely characterized.Results Six Holstein dairy cows and six Duroc×(Landrace×Yorkshire)(DLY)crossbred pigs served as research subjects.Employing non-targeted and targeted metabolomics,we discovered that three bile acids—taurodeoxycholic acid(TDCA),taurocholic acid(TCA),and glycocholic acid(GCA)—were highly enriched in Holstein dairy cows'livers.In bovine hepatocytes,individual or combined stimulation of these bile acids significantly upregulated the expression of gluconeogenesis genes(FBP1,PCK1 and G6PC)and enhanced glucose production.In fasting mice with induced gluconeogenesis,TDCA,TCA,and GCA increased fasting blood glucose levels,and pyruvate tolerance tests further revealed their capacity to enhance hepatic gluconeogenesis,enabling more efficient glucose synthesis from pyruvate.Mechanistically,these bile acids activated Takeda G protein-coupled receptor 5(TGR5),elevated intracellular cAMP levels,and ultimately enhanced gluconeogenesis via the transcription factor cAMP-response element binding protein(CREB).Notably,a TGR5 inhibitor abrogated the stimulatory effects of TDCA,TCA,and GCA on hepatic gluconeogenesis in fasting mice.Conclusion TDCA,TCA,and GCA are key metabolites promoting hepatic gluconeogenesis in dairy cows,with TGR5 as the pivotal receptor and the cAMP/PKA/CREB pathway as the critical downstream mechanism. 展开更多
关键词 cAMP-response element binding protein GLUCONEOGENESIS Glycocholic acid Takeda G protein-coupled receptor 5 Taurocholic acid Taurodeoxycholic acid
在线阅读 下载PDF
The evolution of lipid nanoparticles: Paving the way for next-generation nucleic acid medicines
15
作者 Xuan Lin Hongguang Xiang +7 位作者 Jiong Wu Ruixi Liao Yuhao Li Bohui Xu Ying Xu Yan Shen Qian Li Yu Tian 《Asian Journal of Pharmaceutical Sciences》 2026年第1期75-108,共34页
Nucleic acid-based therapies have emerged as promising strategies for the regulation of gene expression and the production of therapeutic antigens or proteins for a series of diseases, including cancers, rare diseases... Nucleic acid-based therapies have emerged as promising strategies for the regulation of gene expression and the production of therapeutic antigens or proteins for a series of diseases, including cancers, rare diseases, and infectious diseases. However, their clinical application faces challenges. These include high molecular weight, limited cellular uptake,and susceptibility to enzymatic degradation by nucleases in vivo. Both viral and non-viral delivery vectors have been developed as a means of addressing these limitations, including lipid nanoparticles(LNPs), exosomes, polymers, and inorganic nanoparticles. Among these,LNPs have garnered significant attention due to their superior biocompatibility, high delivery efficiency and customizable design potential, as demonstrated by the clinical success of the FDA-approved si RNA drug Onpattro®. The critical role of nucleic acid drug carriers is discussed in this review. It also outlines the major types of carriers under development and examines the advancements and applications in LNP-based systems for nucleic acid delivery. By conducting a review of recent advancements in LNP design, delivery mechanisms, and clinical applications, this article aims to clarify the ways in which LNPs overcome delivery barriers, compare LNPs with other carriers, and identify key trends that can inform the development of next-generation LNP platforms for nucleic acid therapeutics. 展开更多
关键词 Nucleic acid therapeutics Nucleic acid drugs Delivery systems Nucleic acid delivery challenges Lipid nanoparticle carriers
暂未订购
Contents of linoleic acid,α-linolenic acid and their ratio in human milk,influence factors,and effects on infant health
16
作者 Jiahui Yu Lili Zheng +7 位作者 Shengyuan Ye Xingwang Ye Shuangshuang Chen Zhiyuan Yan Zhengdong Liu Yuanyuan Yan Wei Wei Xingguo Wang 《Food Science and Human Wellness》 2026年第1期28-37,共10页
Both linoleic acid(18:2 n-6,LA)andα-linolenic acid(18:3 n-3,ALA)are essential fatty acids for infants.The contents of LA and ALA,and their ratio exhibited significant changes in human milk over the past 4 decades,whi... Both linoleic acid(18:2 n-6,LA)andα-linolenic acid(18:3 n-3,ALA)are essential fatty acids for infants.The contents of LA and ALA,and their ratio exhibited significant changes in human milk over the past 4 decades,which were not well summarized.Here,we summarized these values in 9898 human breast milk samples of 6664 mothers from 50 countries in 81 studies.A literature search was conducted using PubMed,Embase,and Web of Science between January 1980 and October 2023.The 95%confidence interval of LA/ALA ratio across lactation and gestation ranged from 14.24 to 31.26.The LA content was higher in China and Turkey(>20%)whereas the ALA content was below 1%in Africa.The LA/ALA ratio in countries along the Mediterranean coast exceeded 20 or even 30.LA and ALA contents increased significantly(P<0.01)while the ratio remained stable over the last 40 years.Multivariate meta-regression results showed that regions significantly(P<0.01)determined the LA,ALA,and LA/ALA ratio.Especially,maternal diet could definitely explain the variation while the effects of gestational age,lactation period was not significant.Clinical trials demonstrated that decreasing the LA/ALA ratio increased docosahexaenoic acid(22:6 n-3,DHA)status,reduced arachidonic acid(20:4 n-6,AA)contents,exerted no effect on the visual function of infants,and reached no consensus on growth.The current review aims to provide an overview on the LA and ALA contents and their ratio in human breast milk to raise concern in infant formula. 展开更多
关键词 Human milk Linoleic acid α-Linolenic acid Essential fatty acid Infant nutrition Clinical trial Lactation period Maternal diet
暂未订购
Dioscorea bulbifera L.induces liver injury in mice partly through bile acids metabolic disorders and gut microbiota dysbiosis mediated by the YY1-FXR/Nrf2 signaling pathway
17
作者 Bo-Shen Zhao Yun-Dong Xie +8 位作者 Xin Wang Yu-Han Zhang Hong-Zhe Zhu Lei-Lei Shi Hui-Zi Shangguan Ling Ding Shu-Hong Zhu Cui-Cui Ren Ji-Ping Liu 《Traditional Medicine Research》 2026年第8期15-27,共13页
Background:This study aimed to comprehensively elucidate the hepatotoxic effects of Dioscorea bulbifera L.(DBL)in mice and to explore the underlying molecular mechanisms.Methods:Mice were administered different doses ... Background:This study aimed to comprehensively elucidate the hepatotoxic effects of Dioscorea bulbifera L.(DBL)in mice and to explore the underlying molecular mechanisms.Methods:Mice were administered different doses of DBL via intragastric gavage for 21 days.Organ indices of multiple organs were then measured,and histopathological changes were systematically evaluated.Particular attention was paid to biochemical markers and hepatic histopathological alterations associated with liver injury.Subsequently,the composition of the gut microbiota in colonic contents was analyzed using 16S rDNA sequencing,and the levels of short-chain fatty acids(SCFAs)were determined by gas chromatography(GC).Furthermore,protein expression levels of YinYang 1(YY1),Farnesoid X Receptor(FXR),Nuclear factor erythroid 2-related factor 2(Nrf2),and bile acids(BAs)-related proteins in the liver were assessed by Western blot analysis.Results:Our findings revealed that DBL induced varying degrees of multi-organ toxicity in mice,with the most pronounced hepatotoxicity observed.Liver injury was induced in a dose-dependent manner,accompanied by increased hepatic inflammation and oxidative stress,as well as enhanced hepatocyte apoptosis.Furthermore,DBL may modulate the YY1-FXR/Nrf2 signaling pathway,leading to upregulation of BAs-related proteins such as cholesterol 7α-hydroxylase(CYP7A1),while downregulating other BAs-related proteins,including sodium taurocholate cotransporting polypeptide(NTCP),bile salt export pump(BSEP),multidrug resistance protein 2(MRP2),and P-glycoprotein(P-gp).These changes promoted excessive BAs synthesis and impaired the excretion and reabsorption of BAs,ultimately disturbing BAs homeostasis.Additionally,DBL induces gut microbiota dysbiosis and reduces SCFAs production,leading to intestinal damage and disruption of intestinal barrier integrity.Conclusion:DBL-induced hepatotoxicity may be associated with altered expression of the YY1-FXR/Nrf2 signaling pathway and BAs–related proteins,accompanied by increased hepatic BAs accumulation and gut microbiota dysbiosis. 展开更多
关键词 DIOSCOREA bulbifera L. liver injury BILE acidS metabolism gut microbiota short-chain fatty acidS
暂未订购
Lysophosphatidic acid signaling:Transmembrane modulators in the central nervous system
18
作者 Alexandra Polyzou Alexandros Κ.Tsiouris +2 位作者 Charalampos Labrakakis Britta J.Eickholt George Leondaritis 《Neural Regeneration Research》 2026年第3期1104-1105,共2页
Lysophosphatidic acid(LPA)is a pleiotropic lipid agonist essential for functions of the central nervous system(CNS).It is abundant in the developing and adult brain while its concentration in biological fluids,includi... Lysophosphatidic acid(LPA)is a pleiotropic lipid agonist essential for functions of the central nervous system(CNS).It is abundant in the developing and adult brain while its concentration in biological fluids,including cerebrospinal fluid,varies significantly(Figure 1Α;Yung et al.,2014).LPA actually corresponds to a variety of lipid species that include different stereoisomers with either saturated or unsaturated fatty acids bearing likely differentiated biological activities(Figure 1Α;Yung et al.,2014;Hernández-Araiza et al.,2018). 展开更多
关键词 transmembrane modulators cerebrospinal fluidvaries variety lipid species lysophosphatidic acid biological fluidsincluding lysophosphatidic acid lpa saturated unsaturated fatty acids pleiotropic lipid agonist
暂未订购
Synthesis,structure,and properties of hydrated tricyclohexyltin theophylline-7-acetic acid complex
19
作者 HE Lifang LUO Yaoze +3 位作者 SHI Qiying TANG Jianxin ZHANG Fuxing ZHU Xiaoming 《无机化学学报》 北大核心 2026年第3期632-640,共9页
The hydrated tricyclohexyltin theophylline-7-acetic acid(tpH)complex[Sn(C_(6)H_(11))_(3)(tp)(H_(2)O)]was synthesized via an ethanol solvothermal method using tricyclohexyltin hydroxide and tpH in a 1∶1 molar ratio.Th... The hydrated tricyclohexyltin theophylline-7-acetic acid(tpH)complex[Sn(C_(6)H_(11))_(3)(tp)(H_(2)O)]was synthesized via an ethanol solvothermal method using tricyclohexyltin hydroxide and tpH in a 1∶1 molar ratio.The complex was characterized by IR,^(1)H(^(13)C)NMR,elemental analysis,and powder X-ray diffraction,and the crystal structure was determined by single-crystal X-ray diffraction.The crystal belongs to the orthorhombic system with space group Iba2,and the central tin atom is in a five-coordinated trigonal bipyramidal configuration.Quantum chemistry ab initio calculations were performed to investigate the stability,molecular orbital energy,and frontier molecular orbital characteristics of the complex.Additionally,its thermal stability,electrochemical properties,and in vitro anticancer activity were evaluated.CCDC:2380308. 展开更多
关键词 hydrated tricyclohexyltin theophylline-7-acetic acid complex SYNTHESIS crystal structure in vitro antitumor activity
在线阅读 下载PDF
Efficient continuous synthesis of 2-[3-(trifluoromethyl)phenyl]malonic acid,a key intermediate of Triflumezopyrim,coupling with esterification-condensation-hydrolysis
20
作者 Yuexiang Liu Xiangqiao Yang +6 位作者 Tong Lin Guantian Yang Xiaoyong Xu Bubing Zeng Zhong Li Weiping Zhu Xuhong Qian 《Chinese Chemical Letters》 2025年第1期234-238,共5页
Triflumezopyrim(TFM)is a novel mesoionic pyrido[1,2-α]pyrimidinones insecticide,which acts on nicotinic acetylcholine receptors(n ACh Rs)and has no cross-resistance with other insecticides.Herein,we firstly developed... Triflumezopyrim(TFM)is a novel mesoionic pyrido[1,2-α]pyrimidinones insecticide,which acts on nicotinic acetylcholine receptors(n ACh Rs)and has no cross-resistance with other insecticides.Herein,we firstly developed a new continuous flow approach to synthesis 2-[3-(trifluoromethyl)phenyl]malonic acid,a key intermate of TFM,coupling with esterification,condensation,and hydrolysis.All three-step reactions were optimized and transformed into a continuous synthesis mode by three micro reaction units.Compared with the batch mode,the total reaction time and overall separation yield were improved from more than 12 h and 60%to 18 min and 73.38%,respectively.The solvent consumption and waste emission were significantly reduced,which also provides an eco-friendly and efficient potential tool for the development and production of mesoionic pyrido[1,2-α]pyrimidinones insecticide. 展开更多
关键词 Triflumezopyrim(TFM) 2-[3-(Trifluoromethyl)phenyl]malonic acid Continuous flow synthesis MICRO-REACTOR
原文传递
上一页 1 2 250 下一页 到第
使用帮助 返回顶部