期刊文献+
共找到16,721篇文章
< 1 2 250 >
每页显示 20 50 100
On using an aerosol thermodynamic model to calculate aerosol acidity of coarse particles 被引量:1
1
作者 Zhengyang Fang Shuwei Dong +10 位作者 Chengpeng Huang Shiguo Jia Fu Wang Haoming Liu He Meng Lan Luo Yizhu Chen Huanhuan Zhang Rui Li Yujiao Zhu Mingjin Tang 《Journal of Environmental Sciences》 2025年第2期46-56,共11页
Thermodynamic modeling is still themostwidely usedmethod to characterize aerosol acidity,a critical physicochemical property of atmospheric aerosols.However,it remains unclear whether gas-aerosol partitioning should b... Thermodynamic modeling is still themostwidely usedmethod to characterize aerosol acidity,a critical physicochemical property of atmospheric aerosols.However,it remains unclear whether gas-aerosol partitioning should be incorporated when thermodynamicmodels are employed to estimate the acidity of coarse particles.In this work,field measurements were conducted at a coastal city in northern China across three seasons,and covered wide ranges of temperature,relative humidity and NH_(3) concentrations.We examined the performance of different modes of ISORROPIA-II(a widely used aerosol thermodynamic model)in estimating aerosol acidity of coarse and fine particles.The M0 mode,which incorporates gas-phase data and runs the model in the forward mode,provided reasonable estimation of aerosol acidity for coarse and fine particles.Compared to M0,the M1 mode,which runs the model in the forward mode but does not include gas-phase data,may capture the general trend of aerosol acidity but underestimates pH for both coarse and fine particles;M2,which runs the model in the reverse mode,results in large errors in estimated aerosol pH for both coarse and fine particles and should not be used for aerosol acidity calculations.However,M1 significantly underestimates liquid water contents for both fine and coarse particles,while M2 provides reliable estimation of liquid water contents.In summary,our work highlights the importance of incorporating gas-aerosol partitioning when estimating coarse particle acidity,and thus may help improve our understanding of acidity of coarse particles. 展开更多
关键词 Aerosol acidity Coarse particles Thermodynamic model Aerosol liquid water ISORROPIA-II Gas-aerosol partitioning
原文传递
Influence of bulk-phase acidity,organic fraction,and dissolved oxygen on the photosensitized renoxification of nitrate in NaNO_(3)/humic acid mixtures
2
作者 Qiong Li Wenkai Huang +2 位作者 Xinyuan Wu Yu Liu Hongbo Fu 《Journal of Environmental Sciences》 2025年第11期197-205,共9页
Nitrate renoxification significantly influences atmospheric nitrogen cycling and global OH budgets.Although numerous nitrite acid(HONO)formation pathways from nitrate photolysis have been widely reported,the influence... Nitrate renoxification significantly influences atmospheric nitrogen cycling and global OH budgets.Although numerous nitrite acid(HONO)formation pathways from nitrate photolysis have been widely reported,the influence of various environmental factors and aerosol properties on reactive nitrogen production remains largely unclear.In this work,we employed NaNO_(3)/humic acid(HA)as a model nitrate photosensitization system to investigate the crucial roles of aerosol acidity,organic fraction,and dissolved oxygen in the production of HONO,NO_(2),and NO_(2)^(-).The presence of HA at 10 mg/L resulted in a remarkable increase in HONO production rates by approximately 2–3 times and NO_(2)^(-) concentration by 3–6 times across a pH range of 5.2 to 2.0.Meanwhile,the molar fraction of gaseous HONO in total N(Ⅲ)production increased from4%to 69%as bulk-phase pH decreased from 5.2 to 2.0.The higher organic fraction(i.e.,20 and 50 mg/L HA concentration)instead inhibited HONO and NO_(2) release.The presence of dissolved oxygen was found to be adverse for reactive nitrogen production.This suggests that the HA photosensitizer promoted the secondary conversion of NO_(2) to HONO mainly via reduced ketyl radical intermediates,while superoxide radical formation might exert a negative effect.Our findings provide comprehensive insights into reactive nitrogen production from photosensitized nitrate photolysis mediated by various external and internal factors,potentially accounting for discrepancies between field observations and model simulations. 展开更多
关键词 Nitrate photolysis HONO Humic acid PHOTOSENSITIZATION Aerosol acidity Organic fraction
原文传递
Selective separation of vanadium from the high-acidity leaching liquor through chelating extraction by the ketoxime extractant
3
作者 Xile Tian Fancheng Meng +7 位作者 Xianglan Zhang Yongchao Wang Yahui Liu Jian Zhang Shuai Zhao Desheng Chen Lina Wang Tao Qi 《Chinese Journal of Chemical Engineering》 2025年第11期262-272,共11页
The high-acidity vanadium-containing solution contains high concentrations of iron and aluminum with pH around 0.5,the ketoxime extractant with the active ingredient of 2-hydroxy-5-nonylacetophenone oxime(HNAO,HL) was... The high-acidity vanadium-containing solution contains high concentrations of iron and aluminum with pH around 0.5,the ketoxime extractant with the active ingredient of 2-hydroxy-5-nonylacetophenone oxime(HNAO,HL) was proposed to extract vanadium from the solution.Under the phase ratio(O/A)of 1:2,HNAO concentration of 0.542 mol·L^(-1) at 25℃ for 10 min,99.06% of vanadium was extracted after a three-stage countercurrent extraction,while the extraction of impurities was less than 1%,with the separation coefficients of vanadium from iron and aluminum were 137050 and 43197,respectively.The antioxidant properties of the extractant were studied.At 25℃,the extractant basically did not undergo oxidative degradation.Besides,about 91.2% of the loaded vanadium was effectively stripped using 2.5 mol·L^(-1)Na_(2)CO_(3) solution.The extraction mechanism of vanadium was investigated through the slope analysis method,the spectral characterizations and density functional theory calculations.It has been observed that VO_(2)^(+) substitutes the H atom on the phenolic hydroxyl and coordinates with the N atom on the oxime and the O atom on the phenolic hydroxyl to form of a six-membered ring,and the extraction complexes were determined to be VO_(2)(H_(2)O)L and VO_(2)L. 展开更多
关键词 VANADIUM Solvent extraction High acidity Ketoxime extractant CHELATING
在线阅读 下载PDF
Origin of Brönsted acidity in germanosilicates from neighboring Ge-hydroxyl groups
4
作者 Kun Lu Qian Liu +11 位作者 Liyu Chen Jilong Wang Zhenxuan Yuan Xiao Kong Yunxing Bai Jingang Jiang Yejun Guan Sicong Ma Hao Xu Weixin Huang Zhipan Liu Peng Wu 《Chinese Journal of Catalysis》 2025年第10期110-122,共13页
Constructing new Brönsted acid sites within zeolitic materials holds paramount importance for the advancement of solid-acid catalysis.Zeo-type germanosilicates,a class of metallosilicates with a neutral framework... Constructing new Brönsted acid sites within zeolitic materials holds paramount importance for the advancement of solid-acid catalysis.Zeo-type germanosilicates,a class of metallosilicates with a neutral framework composed of tetravalent Ge and Si oxygen tetrahedrons,are conventionally considered not to generate Brönsted acid sites.Herein,we disclose an abnormal phenomenon with Ge-rich IWW-type germanosilicate(IWW-A)as an example that Ge-enriched germanosilicates are featured by mild Brönsted acidity.Using the art-of-state density functional theory calculation,19F magic angle spinning nuclear magnetic resonance,microcalorimetric and ammonia infrared mass spectrometry-temperature-programmed desorption characterizations,the nature of germanosilicate's Brönsted acidity has been demonstrated to be closely related to the neighboring framework Ge-hydroxyl pairs.Besides,the contribution of Ge-OH groups to Brönsted acidity and the role of Ge-pair structure for maintaining mild acid strength have been elucidated.In catalytic cracking of n-hexane and methanol-to-olefins reaction,the IWW-A germanosilicate exhibit high light olefins selectivity,good recyclability and low carbon deposition,outperforming the benchmark zeolite catalyst,ZSM-5 aluminosilicate. 展开更多
关键词 Germanosilicates IWW Brönsted acidity Framework Ge-hydroxyl Alkane cracking Methanol-to-olefins
在线阅读 下载PDF
Thermal Treatment for Decreasing the Acidity of Crude Oil
5
作者 申海平 王玉章 李锐 《Petroleum Science》 SCIE CAS CSCD 2004年第3期78-81,96,共5页
Highly acidic crude oil is thermally soaked to investigate how the temperature and time involved affect the removal of organic acid in feedstock. Experimental results indicate that thermal treatment is an effective a... Highly acidic crude oil is thermally soaked to investigate how the temperature and time involved affect the removal of organic acid in feedstock. Experimental results indicate that thermal treatment is an effective approach to decreasing acidity and the acid removal rate reaches 80%. Temperature is one of the main factors that determine the acid removal reaction. When the temperature ranges from 420oC to 440oC, the acid removal rate increases with the rise of the reaction temperature, but the increase slows down gradually. At the reaction temperature below 440oC, the long reaction time favors the acid removal. The cracking and polymerization of hydrocarbon molecules take place so that the properties of the crude oil change at the same time when the highly acidic crude is thermally treated. 展开更多
关键词 Highly acidic crude naphthenic acid acid removal thermal treatment VISBREAKING
原文传递
Short-chain fatty acids mediate enteric and central nervous system homeostasis in Parkinson’s disease:Innovative therapies and their translation 被引量:1
6
作者 Shimin Pang Zhili Ren +1 位作者 Hui Ding Piu Chan 《Neural Regeneration Research》 2026年第3期938-956,共19页
Short-chain fatty acids,metabolites produced by the fermentation of dietary fiber by gut microbiota,have garnered significant attention due to their correlation with neurodegenerative diseases,particularly Parkinson’... Short-chain fatty acids,metabolites produced by the fermentation of dietary fiber by gut microbiota,have garnered significant attention due to their correlation with neurodegenerative diseases,particularly Parkinson’s disease.In this review,we summarize the changes in short-chain fatty acid levels and the abundance of short-chain fatty acid-producing bacteria in various samples from patients with Parkinson’s disease,highlighting the critical role of gut homeostasis imbalance in the pathogenesis and progression of the disease.Focusing on the nervous system,we discuss the molecular mechanisms by which short-chain fatty acids influence the homeostasis of both the enteric nervous system and the central nervous system.We identify key processes,including the activation of G protein-coupled receptors and the inhibition of histone deacetylases by short-chain fatty acids.Importantly,structural or functional disruptions in the enteric nervous system mediated by these fatty acids may lead to abnormalα-synuclein expression and gastrointestinal dysmotility,which could serve as an initiating event in Parkinson’s disease.Furthermore,we propose that short-chain fatty acids help establish communication between the enteric nervous system and the central nervous system via the vagal nerve,immune circulation,and endocrine signaling.This communication may shed light on their potential role in the transmission ofα-synuclein from the gut to the brain.Finally,we elucidate novel treatment strategies for Parkinson’s disease that target short-chain fatty acids and examine the challenges associated with translating short-chain fatty acid-based therapies into clinical practice.In conclusion,this review emphasizes the pivotal role of short-chain fatty acids in regulating gut-brain axis integrity and their significance in the pathogenesis of Parkinson’s disease from the perspective of the nervous system.Moreover,it highlights the potential value of short-chain fatty acids in early intervention for Parkinson’s disease.Future research into the molecular mechanisms of short-chain fatty acids and their synergistic interactions with other gut metabolites is likely to advance the clinical translation of innovative short-chain fatty acid-based therapies for Parkinson’s disease. 展开更多
关键词 ALPHA-SYNUCLEIN blood-brain barrier blood circulation central nervous system ENDOCRINE enteric nervous system glial cell gut-brain axis gut microbiota intestinal barrier neuron Parkinson’s disease short chain fatty acids vagus nerve
暂未订购
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
Syntheses,crystal structures,catalytic and anti-wear properties of zinc(Ⅱ),nickel(Ⅱ)and cadmium(Ⅱ)complexes constructed from a terphenyl-tricarboxylate ligand
9
作者 ZHAO Zhenghua LIU Yufeng +2 位作者 ZHANG Qing SHI Zifa GU Jinzhong 《无机化学学报》 北大核心 2026年第1期170-180,共11页
Three zinc(Ⅱ),nickel(Ⅱ),and cadmium(Ⅱ)complexes,namely[Zn(μ-Htpta)(py)_(2)]n(1),[Ni(H_(2)biim)2(H_(2)O)2][Ni(tpta)(H_(2)biim)2(H_(2)O)]2·3H_(2)O(2),and[Cd_(3)(μ4-tpta)2(μ-dpe)_(3)]_(n)(3),have been construc... Three zinc(Ⅱ),nickel(Ⅱ),and cadmium(Ⅱ)complexes,namely[Zn(μ-Htpta)(py)_(2)]n(1),[Ni(H_(2)biim)2(H_(2)O)2][Ni(tpta)(H_(2)biim)2(H_(2)O)]2·3H_(2)O(2),and[Cd_(3)(μ4-tpta)2(μ-dpe)_(3)]_(n)(3),have been constructed hydrothermally at 160℃ using H_(3)tpta([1,1':3',1″-terphenyl]-4,4',5'-tricarboxylic acid),py(pyridine),H_(2)biim(2,2'-biimidazole),dpe(1,2-di(4-pyridyl)ethylene),and zinc,nickel and cadmium chlorides,resulting in the formation of stable crystalline solids which were subsequently analyzed using infrared spectroscopy,element analysis,thermogravimetric analysis,as well as structural analyses conducted via single-crystal X-ray diffraction.The findings from these single-crystal Xray diffraction studies indicate that complexes 1-3 form crystals within the monoclinic system P2_(1)/c space group(1)or triclinic system P1 space group(2 and 3),and possess 1D,0D,and 3D structures,respectively.Complex 1 demonstrated substantial catalytic efficiency and excellent reusability as a heterogeneous catalyst in the reaction of Knoevenagel condensation under ambient temperature conditions.In addition,complex 1 also showcased notable anti-wear performance when used in polyalphaolefin synthetic lubricants.CCDC:2449810,1;2449811,2;2449812,3. 展开更多
关键词 COMPLEXES tricarboxylic acid catalytic properties Knoevenagel condensation reaction anti-wear performance
在线阅读 下载PDF
Ligand-directed construction of cobalt-oxo cluster-based organic frameworks:Structural modulation,semiconductor,and antiferromagnetic properties
10
作者 SHI Jinlian LIU Xiaoru XU Zhongxuan 《无机化学学报》 北大核心 2026年第1期45-54,共10页
Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully construct... Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully constructed by coordinatively assembling the semi-rigid multidentate ligand 5-(1-carboxyethoxy)isophthalic acid(H₃CIA)with the Nheterocyclic ligands 1,4-di(4H-1,2,4-triazol-4-yl)benzene(1,4-dtb)and 1,4-di(1H-imidazol-1-yl)benzene(1,4-dib),respectively,around Co^(2+)ions.Single-crystal X-ray diffraction analysis revealed that in both complexes HU23 and HU24,the CIA^(3-)anions adopt aκ^(7)-coordination mode,bridging six Co^(2+)ions via their five carboxylate oxygen atoms and one ether oxygen atom.This linkage forms tetranuclear[Co4(μ3-OH)2]^(6+)units.These Co-oxo cluster units were interconnected by CIA^(3-)anions to assemble into 2D kgd-type structures featuring a 3,6-connected topology.The 2D layers were further connected by 1,4-dtb and 1,4-dib,resulting in 3D pillar-layered frameworks for HU23 and HU24.Notably,despite the similar configurations of 1,4-dtb and 1,4-dib,differences in their coordination spatial orientations lead to topological divergence in the 3D frameworks of HU23 and HU24.Topological analysis indicates that the frameworks of HU23 and HU24 can be simplified into a 3,10-connected net(point symbol:(4^(10).6^(3).8^(2))(4^(3))_(2))and a 3,8-connected tfz-d net(point symbol:(4^(3))_(2)((4^(6).6^(18).8^(4)))),respectively.This structural differentiation confirms the precise regulatory role of ligands on the topology of metal-organic frameworks.Moreover,the ultraviolet-visible absorption spectra confirmed that HU23 and HU24 have strong absorption capabilities for ultraviolet and visible light.According to the Kubelka-Munk method,their bandwidths were 2.15 and 2.08 eV,respectively,which are consistent with those of typical semiconductor materials.Variable-temperature magnetic susceptibility measurements(2-300 K)revealed significant antiferromagnetic coupling in both complexes,with their effective magnetic moments decreasing markedly as the temperature lowered.CCDC:2457554,HU23;2457553,HU24. 展开更多
关键词 semi-rigid carboxylic acid ligands three-dimensional framework tetranuclear cobalt-oxo cluster semiconductor material antiferromagnetic magnetism
在线阅读 下载PDF
Thermodynamic Correlation Between Surface Carboxyl Configuration and Wettability
11
作者 GUO Zhuohuan WANG Dayang 《高等学校化学学报》 北大核心 2026年第1期255-266,共12页
In this study,polyacrylic acid(PAA)films were employed as a model system,and a series of PAA films with tunable water wettability was systematically prepared by varying molecular weight and curing temperature.Using at... In this study,polyacrylic acid(PAA)films were employed as a model system,and a series of PAA films with tunable water wettability was systematically prepared by varying molecular weight and curing temperature.Using attenuated total reflectance Fourier-transform infrared spectroscopy(ATR-FTIR),the molecular configurations of surface carboxyl groups(COOH),free carboxyl(COOH_(f))and hydrogen-bonded carboxyl(COOH_(HB),were directly correlated with the polar component of surface energy(γ^(s,p)).By decomposing theγ^(s,p)values of the PAA thin films as a sum of the contributions of COOH_(f)and COOH_(H B),the intrinsic polar component of surface energy of COOH_(H B)(γ_(H B)^(s,p*))was quantified for the first time as 8.34 mN/m,significantly lower than that of COOH_(f)(γ_(f)^(s,p*)=34 mN/m).This result highlights that hydrogen bonding markedly reduces theγ^(s,p),providing a rational explanation for the relatively large water contact angle observed on PAA thin films.Furthermore,it establishes a thermodynamic basis for estimating the fraction of surface COOH_(H B)groups(f H B)from wettability measurements.Further extension of the model to carboxyl-terminated self-assembled monolayers(COOH-SAMs)revealed that surface COOH density(ΣCOOH)critically regulates wetting behavior:whenΣCOOH ranges from 4.30 to 5.25 nm^(-2),COOH groups predominantly exist in a free state and facilitate effective hydration layers,thereby promoting superhydrophilicity.Overall,this study not only establishes a unified thermodynamic framework linking surface COOH configurations to macroscopic wettability,but also validates its universality by extending it to COOH-SAMs systems,thereby providing a unified theoretical framework for the controllable design of hydrophilicity in various COOH-functionalized surfaces. 展开更多
关键词 Polyacrylic acid film Hydrogen bonding Attenuated total reflectance Fourier-transform infrared spectroscopy Quantitative carboxyl configuration Polar component of surface energy
在线阅读 下载PDF
Intervention effect and mechanism of Compound Herba Gueldenstaedtiae in a mouse model of breast hyperplasia
12
作者 Wu Yilin Tian Hongying +8 位作者 Sun Jiale Jiao Jiajia Zhao Zihan Shao Jinhuan Zhao Kaiyue Zhou Min Li Qian Li Zexin Yue Changwu 《中国组织工程研究》 北大核心 2026年第17期4377-4389,共13页
BACKGROUND:Breast hyperplasia is a common benign breast disease mainly caused by endocrine disorders,manifested as abnormal hyperplasia of breast tissue.In recent years,traditional Chinese medicine compounds and probi... BACKGROUND:Breast hyperplasia is a common benign breast disease mainly caused by endocrine disorders,manifested as abnormal hyperplasia of breast tissue.In recent years,traditional Chinese medicine compounds and probiotics have shown good potential in regulating the endocrine system and improving the intestinal microecology,providing new ideas for the treatment of breast hyperplasia.OBJECTIVE:To explore the effects and mechanisms of traditional Chinese medicine compounds and fermented probiotic compounds on breast hyperplasia in mice,providing new theoretical and experimental bases for the clinical treatment and prevention of breast hyperplasia.METHODS:(1)Network pharmacology tools were used to predict the anti-breast-hyperplasia activity of Herba Gueldenstaedtiae(Euphorbia humifusa),as well as its potential targets and signaling pathways.The databases included:TCMSP,OMIM,GeneCards database,UniProt website,Venny2.1.0 website,Metascape,HERB website,and STRING database,all of which are open-access databases.Network pharmacology can predict and screen key information such as the targets corresponding to the active ingredients of traditional Chinese medicine,disease targets,and action pathways through network analysis and computer-system analysis.Therefore,it has been increasingly widely used in the research of traditional Chinese medicine.(2)A breast hyperplasia model was induced in mice by injecting estrogen and progesterone.Mice in the normal blank group were injected intraperitoneally with normal saline every day.Mice in the model group and drugadministration groups were injected intraperitoneally with estradiol benzoate injection at a concentration of 0.5 mg/kg every day for 25 days.From the 26th day,the injection of estradiol benzoate injection was stopped.Mice in the normal blank group were injected intramuscularly with normal saline every day,and mice in the model group and drug-administration groups were injected intramuscularly with progesterone injection at a concentration of 5 mg/kg for 5 days.After the model was established,each group was given drugs respectively.The normal blank group and the model group were gavaged with 0.2 mL/d of normal saline;the positive blank group(Xiaozheng Pill group)was gavaged with an aqueous solution of Xiaozheng Pill at 0.9 mg/g;the low-,medium-and high-dose groups of Compound Herba Gueldenstaedtiae were gavaged with an aqueous solution of the compound medicine at 0.75,1.5,and 3.0 mg/(g·d)respectively;the low-,medium-and high-dose groups of traditional Chinese medicine-bacteria fermentation were gavaged with an aqueous solution of the compound medicine at 0.75,1.5,and 3.0 mg/(g·d)respectively.The administration was continuous for 30 days.RESULTS AND CONCLUSION:(1)The results of network pharmacology research showed that the Compound Herba Gueldenstaedtiae(Euphorbia humifusa)contained 46 active ingredients,which were related to 1213 potential targets.After comparison with 588 known breast-hyperplasia targets,it was speculated that 50 of these targets might be related to the direct effect of the compound on breast hyperplasia.(2)After drug intervention,there was no significant change in the high-dose group of Compound Herba Gueldenstaedtiae compared with the normal blank group.The liver indicators of the other intervention groups all significantly decreased(P<0.05).(3)In terms of kidney and uterine indicators,the medium-dose group of Compound Herba Gueldenstaedtiae decreased significantly compared with the normal blank group(P<0.05).In terms of the uterine index,the model group increased significantly compared with the normal blank group(P<0.01).(4)After 1-month drug treatment,the number of lobules and acini in the breast tissue of the Xiaozheng Pill group,the low,medium,and high-dose group of Compound Herba Gueldenstaedtiae,the low,medium,and highdose groups of traditional Chinese medicine-bacteria fermentation decreased,and the duct openings narrowed.With the increase of drug dose,diffuse hyperplasia of breast tissue was significantly improved.(5)The ELISA results showed that compared with the model group,the estrogen level was lower in the medium-dose group of traditional Chinese medicine-bacteria fermentation after the intervention(P<0.05).In addition,the follicle-stimulating hormone level in the low-dose group of Compound Herba Gueldenstaedtiae was lower than that of the model group(P<0.05).(6)The intervention in the mouse model led to changes in the abundance of short chain fatty acids and intestinal flora in all groups.To conclude,the Compound Herba Gueldenstaedtiae and its probiotic fermentation products significantly improved mammary gland hyperplasia in mice by regulating hormone levels,improving the structure of the gut microbiota,and increasing the content of shortchain fatty acids,providing new ideas and potential sources of drugs for the treatment of breast hyperplasia. 展开更多
关键词 Herba Gueldenstaedtiae traditional Chinese medicine compound mice with breast hyperplasia microbial fermentation gut microbiota network pharmacology short-chain fatty acids hormone levels inflammatory response endocrine disorders
暂未订购
Cell apoptosis in ischemic stroke:Focus on lipid metabolism
13
作者 Rong Sun Wenren Yang +4 位作者 Yuting Zhao Fumei Zhang Genping Wu Aiping Wang Ying Tian 《Neural Regeneration Research》 2026年第6期2205-2214,共10页
Ischemic stroke is a severe neurological disease with high global mortality and disability rates.Atherosclerosis has been identified as the primary cause of ischemic stroke,while abnormal lipid levels are significant ... Ischemic stroke is a severe neurological disease with high global mortality and disability rates.Atherosclerosis has been identified as the primary cause of ischemic stroke,while abnormal lipid levels are significant contributors to the development of this condition.Multiple pro-apoptotic mechanisms are involved in ischemic stroke caused by lipid metabolism disorders,while various lipids have a strong causal relationship with neuronal apoptosis.However,studies to date have focused on the individual roles of lipid metabolism and apoptosis in ischemic stroke,and an overview of how impaired lipid metabolism leads to apoptosis in ischemic stroke is still lacking in the literature.In this review,we summarize current research on lipids in ischemic stroke.We discuss the role of lipid metabolism in accelerating apoptosis in ischemic stroke as well as the associated mechanisms.Additionally,we highlight advances in drug development and the treatment of stroke,focusing on lipid metabolism.The purpose is to provide novel ideas and strategies for the treatment and prevention of ischemic stroke. 展开更多
关键词 docosahexaenoic acid eicosapentaenoic acid high-density lipoprotein low-density lipoprotein reactive oxygen species short-chain fatty acids TRIGLYCERIDES tumor necrosis factor
暂未订购
Lysophosphatidic acid signaling:Transmembrane modulators in the central nervous system
14
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
Taurodeoxycholic,taurocholic,and glycocholic acids promote hepatic gluconeogenesis via TGR5 in dairy cows
15
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
Gut microbiota and metabolites in lipid metabolism and intramuscular fat deposition:mechanisms and implications for meat quality
16
作者 Xiaofeng Song Chenglong Jin +2 位作者 Ruifan Wu Yongjie Wang Xiaofan Wang 《Journal of Animal Science and Biotechnology》 2026年第1期60-80,共21页
Intramuscular fat(IMF)content serves as the key determinants of meat quality.Emerging evidence indicates that gut microbiota and their metabolites significantly influence IMF deposition levels by modulating host lipid... Intramuscular fat(IMF)content serves as the key determinants of meat quality.Emerging evidence indicates that gut microbiota and their metabolites significantly influence IMF deposition levels by modulating host lipid metabolism through multiple pathways,positioning microbial regulation as a pivotal target for meat quality improvement.However,existing studies remain fragmented,predominantly focusing on isolated mechanisms or correlations without a systematic view of the regulatory network.This review consolidates the core mechanisms through which microbiota-derived metabolites including short-chain fatty acids,bile acids,branched-chain amino acids,trimethylamine N-oxide,tryptophan derivatives,succinate,polyamines etc.,regulate IMF deposition and proposes a targeted intervention framework,the“gut microbiota/metabolites-IMF axis”.By integrating these insights,we provide a theoretical foundation and define practical research pathways to assess the potential of microbial-based strategies for improving meat quality in swine production. 展开更多
关键词 Bile acids Branched-chain amino acids Gut microbiota Intramuscular fat deposition Short-chain fatty acids
在线阅读 下载PDF
Comparative Analysis of Nutrient Contents in Different Thallus Parts of Sargassum muticum
17
作者 MA Qianhui WANG Qiaohan +3 位作者 LIU Yan GONG Qingli LI Huiru GAO Xu 《Journal of Ocean University of China》 2026年第1期323-332,共10页
Sargassum muticum is a globally distributed seaweed with high economic potential,yet its detailed nutritional composition remains undercharacterized.In this study,we analyzed the nutritional profiles of five thallus p... Sargassum muticum is a globally distributed seaweed with high economic potential,yet its detailed nutritional composition remains undercharacterized.In this study,we analyzed the nutritional profiles of five thallus portions,namely apical fronds,middle fronds,basal fronds,receptacles and air bladders,to assess their economic value accordingly.Results showed that middle fronds had the highest crude protein(31.98%)and crude fiber(7.10%)contents,indicating their suitability for protein-rich functional foods or dietary fiber supplements.Receptacles exhibited the highest levels of crude lipid(1.11%)and polyunsaturated fatty acids(123.01mg/g),suggesting potential for bioactive lipid extraction in nutraceutical applications.By contrast,basal fronds were enriched in saturated(86.41 mg/g)and monounsaturated fatty acids(38.38 mg/g).The essential amino acid index ranged from 0.74 to 0.87,and total amino acid content peaked in middle fronds(77.90 mg/g),highlighting their high protein quality.Apical fronds had the highest calcium content(15611.95 mg/kg),and receptacles contained the highest phosphorus content(1224.45 mg/kg),supporting targeted mineral supplementation.The maximum concentrations of all trace elements were found in receptacles,reinforcing their pharmaceutical potential.This study provides foundational data on the nutrient composition of different thallus parts of S.muticum,which may support future research and potential utilization efforts in China. 展开更多
关键词 Sargassum muticum amino acids fatty acids MINERAL commercial development
在线阅读 下载PDF
Mechanisms of montmorillonite-mediated high-temperature catalysis of organic matter under variable hydration states and implications for petroleum geology
18
作者 Xiaoyang ZHAO Guanghui YUAN +5 位作者 Yingchang CAO Fang HAO Keyu LIU Zihao JIN Xiaohan FU Fulin SHAO 《Science China Earth Sciences》 2026年第2期660-678,共19页
Clay minerals play a crucial role in catalyzing kerogen to form hydrocarbons,significantly influencing petroleum system evolution.Montmorillonite(MT)dehydrates upon heating;however,the catalytic mechanisms governing t... Clay minerals play a crucial role in catalyzing kerogen to form hydrocarbons,significantly influencing petroleum system evolution.Montmorillonite(MT)dehydrates upon heating;however,the catalytic mechanisms governing the thermal decomposition of organic matter at different dehydration levels remain unclear.Additionally,the mechanism by which external water suppresses MT’s catalytic efficiency remains debated.To resolve this issue,this study conducted pyrolysis simulation experiments(340℃,10 days)with various combinations of octadecanoic acid(OA),water,hydrochloric acid(HCl)solution,MT,dehydrated-MT,and illite.We integrated mineral/organic transformation analyses(XRD/FTIR/SSNMR/SEM),temperature-dependent characterization of solid acid sites(NH 3-TPD/FTIR),and quantitative product measurements(GC/GC-MS)to elucidate how clay-bound water and external water differentially regulate organic-matter cracking pathways.The results suggest that clay-bound water controls reaction pathways by tuning both the type(Brønsted vs.Lewis)and density of solid acid sites.External water inhibits catalytic efficiency by reducing direct contact between organic matter and solid acid sites.Compared with untreated MT,150°C-dehydrated MT-OA system exhibited strong interlayer water polarization,which increased Brønsted acid site density and enhanced the carbonium-ion mechanism,thereby promoting isoalkane production.In contrast,250℃-dehydrated MT-OA system,where interlayer water was nearly eliminated,had fewer Brønsted acid sites but greater exposure of Lewis acid sites,facilitating decarboxylation and increasing CO_(2) production.In hydrous systems,the addition of HCl solution did not enhance the carbonium-ion mechanism compared to the hydrous system with only water,indicating that only protons bound to solid acid sites,rather than liquid H+in water,can trigger the carbonium-ion reaction.This shows that the catalysis of organic-matter cracking by clay minerals such as MT is fundamentally an interfacial chemical process that requires direct mineral-organic contact;the presence of external water reduces catalytic efficiency primarily by physically separating OA from MT and hindering that contact.This study elucidates the controlling mechanisms of MT-catalyzed thermal cracking under different water conditions and deepens our understanding of hydrocarbon-generation pathways during kerogen maturation in sedimentary basins. 展开更多
关键词 MONTMORILLONITE Octadecanoic acid Pyrolysis experiments Brønsted and Lewis acids HYDROCARBON Water
原文传递
Advances in understanding the role of gut microbiota in fat deposition and lipid metabolism
19
作者 Yi Zhong Yuhang Lei +13 位作者 Shan Jiang Dujun Chen Xinyi Wang Kai Wang Tianci Liao Rongjie Liao Mailin Gan Lili Niu Ye Zhao Lei Chen Xiaofeng Zhou Yan Wang Li Zhu Linyuan Shen 《Journal of Animal Science and Biotechnology》 2026年第1期20-41,共22页
The gut microbiota has emerged as a pivotal regulator of host lipid metabolism and energy homeostasis.A growing body of evidence reveals that variations in the composition and metabolic activity of intestinal microbes... The gut microbiota has emerged as a pivotal regulator of host lipid metabolism and energy homeostasis.A growing body of evidence reveals that variations in the composition and metabolic activity of intestinal microbes are closely associated with differences in adipose tissue deposition across species.Notably,increased abundance of Firmicutes and a reduced proportion of Bacteroidetes and butyrate-producing bacteria have been linked to enhanced fat accumulation.Key microbial metabolites such as short-chain fatty acids(SCFAs)influence lipid metabolism through multiple pathways,including the activation of GPR41/43 receptors,modulation of the bile acid–FXR/TGR5 axis,and regulation of hepatic lipogenesis.Additionally,the gut–brain axis plays a critical role in controlling feeding behavior via neuroendocrine signaling.This review summarizes current advances in understanding the roles of dominant bacterial phyla and beneficial genera—including Clostridium butyricum and Faecalibacterium prausnitzii—in fat metabolism.We further explore the mechanisms by which gut microbiota modulate lipid synthesis and catabolism through SCFA production,bile acid signaling,and AMPK/PPAR-related pathways.These insights highlight the potential of microbiota-targeted strategies to restore lipid metabolic balance,offering novel opportunities for applications in health management,nutritional interventions,and microbial therapeutics. 展开更多
关键词 Bile acids Fat deposition Gut-brain axis Gut-liver axis Gut microbiota Short-chain fatty acids
暂未订购
Blood serum from individuals with Alzheimer’s disease alters microglial phagocytosis in vitro
20
作者 Barbara Altendorfer Rodolphe Poupardin +21 位作者 Sophie Lefèvre-Arbogast Claudine Manach Dorrain Y.Low Mireia Urpi-Sarda Cristina Andres-Lacueva Raúl González-Domínguez Thomas K.Felder Julia Tevini Marco Zattoni Andreas Koller Reinhold Schmidt Paul J.Lucassen Silvie R.Ruigrok Chiara de Lucia Andrea Du Preez Catherine Helmer Jeanne Neuffer Cécile Proust-Lima Aniko Korosi Cécilia Samieri Sandrine Thuret Ludwig Aigner 《Neural Regeneration Research》 2026年第6期2433-2439,共7页
In Alzheimer’s disease,microglial phagocytosis is engaged in the pathogenesis as it clears abnormal protein accumulations,debris,and apoptotic cells in the early stages of Alzheimer’s disease,but fuels neuroinflamma... In Alzheimer’s disease,microglial phagocytosis is engaged in the pathogenesis as it clears abnormal protein accumulations,debris,and apoptotic cells in the early stages of Alzheimer’s disease,but fuels neuroinflammation and accelerates disease progression in later stages.In vivo parabiosis experiments in aged animals have demonstrated that blood-born factors modulate synaptic plasticity,neurogenesis,and microglial responses.We hypothesize that peripheral factors can modulate microglial function and thereby possibly influence Alzheimer’s disease pathology.The objective of this study is to investigate the effects of Alzheimer’s disease serum on microglial phagocytosis.Here,we use an immortalized human microglial cell line in an in vitro parabiosis assay to investigate the impact of the serum from individuals diagnosed with Alzheimer’s disease(n=30)and age-matched controls(n=30)(PRODEM study)on microglial phagocytosis.Exposure to Alzheimer’s disease serum increased microglial phagocytic uptake of pH-sensitive fluorescent particles and downregulated expression of the lysosomal master regulator transcription factor EB(TFEB)and of ATPase H^(+)transporting lysosomal V1 subunit B2(ATP6V1B2),a component of the vacuolar ATPase.To identify serum components that may relate to changes in phagocytosis,serum samples of the Three-City Study(3C Study)were used.In the 3C Study,blood samples were collected up to 12 years before the onset of cognitive decline or dementia and their serum metabolome is well-defined.Microglia exposed to the serum of future Alzheimer’s disease patients from the 3C Study displayed an increased phagocytic uptake compared with the serum of matched controls,depending on the presence of the apolipoprotein Eε4 allele in the Alzheimer’s disease patients.Furthermore,microglial phagocytosis correlated inversely with serum levels of the omega-3 fatty acid eicosapentaenoic acid.We confirmed this inverse correlation between eicosapentaenoic acid and phagocytosis in the serum samples of the PRODEM cohort.In addition,in vitro testing of eicosapentaenoic acid on microglial phagocytosis showed a concentration-dependent decrease in phagocytic uptake.In conclusion,following incubation with Alzheimer’s disease blood serum,we observed increased microglial phagocytic uptake and the downregulation of TFEB and ATP6V1B2,possibly indicating lysosomal dysfunction.Furthermore,microglial phagocytosis was inversely correlated with serum eicosapentaenoic acid levels,suggesting an important role for dietary eicosapentaenoic acid in microglial function. 展开更多
关键词 Alzheimer’s disease blood serum eicosapentaenoic acid in vitro parabiosis METABOLOME microglia omega-3 fatty acids PHAGOCYTOSIS
暂未订购
上一页 1 2 250 下一页 到第
使用帮助 返回顶部