期刊文献+
共找到278,216篇文章
< 1 2 250 >
每页显示 20 50 100
STRUCTURE OF THERMOTROPIC LIQUID CRYSTALLINE VANILLIC ACID/P-HYDROXYBENZOIC ACID/ETHYLENE TEREPHTHALATE VHE TERPOLYESTERS
1
作者 Xin Gui LI Mei Rong HUANG +1 位作者 Gui He GUAN Tong SUN 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第3期207-210,共4页
Thermotropic liquid crystalline VHE terpolyesters made from vanillic acid (V),p-hydroxybenzoic acid (H) and poly(ethylene terephthalate) (E) were studied by 400 MHz NMR spectra, wide angle X-ray diffraction,scanning e... Thermotropic liquid crystalline VHE terpolyesters made from vanillic acid (V),p-hydroxybenzoic acid (H) and poly(ethylene terephthalate) (E) were studied by 400 MHz NMR spectra, wide angle X-ray diffraction,scanning electron and polarizing microscopes.It was found that the VHE terpolyesters had random sequence distribution.The VHE terpolyester films exhibited highly oriented fibrillar structure. 展开更多
关键词 acid STRUCTURE OF THERMOTROPIC LIQUID CRYSTALLINE VANILLIC acid/P-HYDROXYBENZOIC acid/ethylENE TEREPHTHALATE VHE TERPOLYESTERS OC MHZ
下载PDF
Syntheses,structures,and properties of three coordination polymers based on 5⁃ethylpyridine⁃2,3⁃dicarboxylic acid and N⁃containing ligands
2
作者 TANG Long BIAN Yaxin +3 位作者 CHEN Luyuan HOU Xiangyang WANG Xiao WANG Jijiang 《无机化学学报》 SCIE CAS CSCD 北大核心 2024年第10期1975-1985,共11页
Three coordination polymers[Mn(epda)(2,2'⁃bipy)(H_(2)O)](1),[Mn(epda)(phen)](2),and[Co_(2)(epda)2(bpe)2(H_(2)O)_(4)]·5H_(2)O(3)(H2epda=5⁃ethyl⁃pyridine⁃2,3⁃dicarboxylic acid,2,2'⁃bipy=2,2'⁃bipyridine,... Three coordination polymers[Mn(epda)(2,2'⁃bipy)(H_(2)O)](1),[Mn(epda)(phen)](2),and[Co_(2)(epda)2(bpe)2(H_(2)O)_(4)]·5H_(2)O(3)(H2epda=5⁃ethyl⁃pyridine⁃2,3⁃dicarboxylic acid,2,2'⁃bipy=2,2'⁃bipyridine,phen=phenanthroline,bpe=1,2⁃bis(4⁃pyridyl)ethylene)were synthesized by solvothermal reactions and characterized by single⁃crystal X⁃ray diffraction,thermogravimetric analyses,IR spectroscopy and elemental analysis.1 displays a 1D chain struc⁃ture,and these chains are joined by O-H…O hydrogen bonding andπ⁃πstacking interactions to generate a 2D layer structure.2 displays a 2D layer structure,and adjacent layers are generated 3D architecture throughπ⁃πstacking interactions.3 displays a 1D chain structure,and adjacent chains are generated double layer structure through O-H…O hydrogen bonding.The fluorescent properties of 1 and 3 indicate that they can potentially be used as a luminescent sensor.1 was highly selective and sensitive towards o⁃nitrophenol through different detection mechanisms,however,3 was highly selective and sensitive towards 2,4,6⁃trinitrophenol.In addition,the magnetic behavior of 2 has also been investigated.CCDC:2172533,1,2355773,2,2355774,3. 展开更多
关键词 coordination polymers 5⁃ethyl⁃pyridine⁃2 3⁃dicarboxylate ligand crystal structures fluorescent properties magnetic behavior
下载PDF
Al-modified yolk-shell silica particle-supported NiMo catalysts for ultradeep hydrodesulfurization of dibenzothiophene and 4,6-dimethyldibenzothiophene:Efficient accessibility of active sites and suitable acidity
3
作者 Ke Yu Wei-Min Kong +3 位作者 Zhen Zhao Ai-Jun Duan Lian Kong Xi-Long Wang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期654-666,共13页
Yolk-shell SiO2 particles(YP)with center-radial meso-channels were fabricated through a simple and effective method.Al-containing YP-supported NiMo catalysts with different Al amounts(NiMo/AYP-x,x=Si/Al molar proporti... Yolk-shell SiO2 particles(YP)with center-radial meso-channels were fabricated through a simple and effective method.Al-containing YP-supported NiMo catalysts with different Al amounts(NiMo/AYP-x,x=Si/Al molar proportion)were prepared and dibenzothiophene(DBT)and 4,6-dimethyl-dibenzothiophene(4,6-DMDBT)were employed as the probes to evaluate the hydrodesulfurization(HDS)catalytic performance.The as-prepared AYP-x carriers and corresponding catalysts were characterized by some advanced characterizations to obtain deeper correlations between physicochemical properties and the HDS performance.The average pore sizes of series AYP-x supports are above 6.0 nm,which favors the mass transfer of organic sulfides.The cavity between the yolk and the shell is beneficial for the enrichment of S-containing compounds and the accessibility between reactants and active metals.Aluminum embedded into the silica framework could facilitate the formation of Lewis(L)and Brønsted(B)acid sites and adjust the metal-support interaction(MSI).Among all the as-synthesized catalysts,NiMo/AYP-20 catalyst shows the highest HDS activities.The improved HDS activity of NiMo/AYP-20 catalyst is attributed to the perfect combination of excellent structural properties of the yolk-shell mesoporous silica,enhanced acidity,moderate MSI,and good accessibility/dispersion of active components. 展开更多
关键词 Al-containing yolk-shell silica particles ACCESSIBILITY acidITY Metal-support interaction Hydrodesulfurization
下载PDF
Oxygen-vacancy-rich MnO_(x)supported RuO_(x)for efficient base-free oxidation of 5-hydroxymethylfurfural and 5-methoxymethylfurfural to 2,5-furandicarboxylic acid
4
作者 Jiali Wu Weizhen Xie +7 位作者 Yining Zhang Xixian Ke Tianyuan Li Huayu Fang Yong Sun Xianhai Zeng Lu Lin Xing Tang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期670-683,I0015,共15页
2,5-Furandicarboxylic acid(FDCA)is a promising biomass-derived polymeric monomer that serves as an attractive alternative to terephthalic acid derived from fossil resources.However,the green and efficient production o... 2,5-Furandicarboxylic acid(FDCA)is a promising biomass-derived polymeric monomer that serves as an attractive alternative to terephthalic acid derived from fossil resources.However,the green and efficient production of FDCA through the oxidation of 5-hydroxymethylfurfural(HMF)and its derivatives is still rudimentary under base-free conditions.In this work,oxygen-vacancy-rich Mn Oxwas prepared and displayed a strong adsorption and anchoring ability to Ru species that mainly exposed the(210)plane of RuO_(2),bringing about highly dispersed and active interfacial Ru-O-Mn structures.Experimental results and density functional theory calculations confirm that these above features greatly facilitate the adsorption/activation of oxygen and the dehydrogenation-oxidation of HMF/5-methoxymethylfurfural(MMF),which enables an efficient FDCA production under base-free and mild conditions.Notably,a desirable FDCA yield of 86.56%was still obtained from concentrated HMF(10 wt%)under base-free conditions over oxygen-vacancy-rich Mn Oxsupported Ru Ox(1.0 MPaO_(2),120℃,6 h).This work delineates a facile catalyst preparation strategy for HMF/MMF oxidation,and might open a new avenue for the green synthesis of FDCA under base-free conditions. 展开更多
关键词 Base-free oxidation Oxygen-vacancy-rich 5-HYDROXYMethylFURFURAL 5-Methoxymethylfurfural 2 5-Furandicarboxylic acid
下载PDF
Transforming liquid flow fuel cells to controllable reactors for highlyefficient oxidation of 5-hydroxymethylfurfural to 2, 5-furandicarboxylic acid at low temperature
5
作者 Ye Qiang Xi Liu +2 位作者 Denghao Ouyang Zhao Jiang Xuebing Zhao 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期621-631,I0014,共12页
Highly-efficient oxidation of 5-hydroxymethylfurtural(HMF) to 2,5-furandicarboxylic acid(FDCA) at low temperature with air as the oxidant is still challenging.Herein,inspired by the respirato ry electron transport cha... Highly-efficient oxidation of 5-hydroxymethylfurtural(HMF) to 2,5-furandicarboxylic acid(FDCA) at low temperature with air as the oxidant is still challenging.Herein,inspired by the respirato ry electron transport chain(ETC) of living cells mediated by electron carriers,we constructed artificial ETCs and transformed liquid flow fuel cells(LFFCs) to flexible reactors for efficient oxidation of HMF to produce FDCA under mild conditions.This LFFC reactor employed an electrodeposition modified nickel foam as an anode to promote HMF oxidation and(VO_(2))_(2)SO_(4) as a cathode electron carrier to facilitate the electron transfer to air.The reaction rate could be easily controlled by selecting the anode catalyst,adjusting the external loading and changing the cathodic electron carrier or oxidants.A maximal power density of 44.9 mW cm^(-2) at room temperature was achieved,while for FDCA production,short-circuit condition was preferred to achieve quick transfer of electrons.For a single batch operation with 0.1 M initial HMF,FDCA yield reached 97.1%.By fed-batch operation,FDCA concentration reached 144.5 g L^(-1) with a total yield of 96%.Ni^(2+)/Ni^(3+) redox couple was the active species mediating the electron transfer,while both experimental and DFT calculation results indicated that HMFCA pathway was the preferred reaction mechanism. 展开更多
关键词 5-HYDROXYMethylFURFURAL 2 5-Furandicarboxylic acid ELECTRODEPOSITION Electron transport chain Liquid flow fuel cell
下载PDF
Methylmalonic Acidemia: An Unusual Cause of Chronic Renal Disease in Adults
6
作者 Kamel El Reshaid Abdulrahman Al Kanderi 《Open Journal of Nephrology》 2024年第3期334-339,共6页
Background: Methylmalonic aciduria (MMA) is a genetic disorder of aminoacid metabolism, due to mutations in methylmalonyl-CoA mutase, which leads to the accumulation of methylmalonic acid in body fluids. Patients typi... Background: Methylmalonic aciduria (MMA) is a genetic disorder of aminoacid metabolism, due to mutations in methylmalonyl-CoA mutase, which leads to the accumulation of methylmalonic acid in body fluids. Patients typically present at the age of 1 month to 1 year with dehydration, renal impairment as well as neurologic manifestations viz. seizure, encephalopathy, strokes and disease in the globus pallidi. The case: a 26-year-old man presented with severe acute on top of chronic renal disease with serum creatinine at 590 umol/L and bilateral 8 cm kidneys with thin and echogenic cortex. He had: (a) hypernatremic dehydration, metabolic acidosis and high ammonia level with (b) a history of multiple similar attacks since the age of 8 months. Diagnosis of MMA was confirmed by high serum and urine enzymatic levels as well as genetic testing. His initial management included support with replacements of fluids, electrolytes, and bicarbonates as well as intravenous dextrose, vitamin B12 and broad-spectrum antibiotic (Meropenem) for his chest infection. Subsequently, he received 1) CARBAGLU (carglumic acid) for 7 days to lower his ammonia level to Conclusion: Untreated homozygous MMA variants, can achieve adulthood with significant renal disease yet their morbidity and mortality can be ameliorated with diet and specific therapy. 展开更多
关键词 Methylmalonic acidemia Kidney Failure Metabolic acidosis Autosomal Recessive Amino acid Disorder Kreps Cycle Hyperammonia Vitamin 12 CARNITINE
下载PDF
Formation mechanisms of ethyl acetate and organic acids in Kluyveromyces marxianus L1-1 in Chinese acid rice soup 被引量:1
7
作者 Na Liu Likang Qin +1 位作者 Laili Hu Song Miao 《Food Science and Human Wellness》 SCIE CSCD 2023年第1期45-56,共12页
This study aims to explore the formation mechanism of ethyl acetate and organic acids in acid rice soup(rice-acid soup)inoculated with Kluyveromyces marxianus L1-1 through the complementary analysis of transcriptome a... This study aims to explore the formation mechanism of ethyl acetate and organic acids in acid rice soup(rice-acid soup)inoculated with Kluyveromyces marxianus L1-1 through the complementary analysis of transcriptome and proteome.The quantity of K.marxianus L1-1 varied significantly in the fermentation process of rice-acid soup and the first and third days were the two key turning points in the growth phase of K.marxianus L1-1.Importantly,the concentrations of ethyl acetate,ethanol,acetic acid,and L-lactic acid increased from day 1 to day 3.At least 4231 genes and 2937 proteins were identified and 610 differentially expressed proteins were annotated to 30 Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways based on the analysis results of transcriptome and proteome.The key genes and proteins including up-regulated alcohol dehydrogenase family,alcohol O-acetyltransferase,acetyl-CoA C-acetyltransferase,acyl-coenzyme A thioester hydrolase,and down-regulated aldehyde dehydrogenase family were involved in glycolysis/gluconeogenesis pathways,starch and sucrose metabolism pathways,amino sugar and nucleotide sugar metabolism pathways,tricarboxylic acid(TCA)cycle,and pyruvate metabolism pathways,thus promoting the formation of ethyl acetate,organic acids,alcohols,and other esters.Our results revealed the formation mechanisms of ethyl acetate and organic acids in rice-acid soup inoculated with K.marxianus L1-1. 展开更多
关键词 Kluyveromyces marxianus Fermented rice soup ethyl acetate Organic acid Formation mechanism
下载PDF
Diagnostic value of methylated branched chain amino acid transaminase 1/IKAROS family zinc finger 1 for colorectal cancer 被引量:1
8
作者 Ke Xu Ai-Ru Yu +1 位作者 Shen-Bin Pan Jie He 《World Journal of Gastroenterology》 SCIE CAS 2023年第36期5240-5253,共14页
BACKGROUND The diagnostic value of combined methylated branched chain amino acid transaminase 1(BCAT1)/IKAROS family zinc finger 1(IKZF1)in plasma for colorectal cancer(CRC)has been explored since 2015.Recently,severa... BACKGROUND The diagnostic value of combined methylated branched chain amino acid transaminase 1(BCAT1)/IKAROS family zinc finger 1(IKZF1)in plasma for colorectal cancer(CRC)has been explored since 2015.Recently,several related studies have published their results and showed its diagnostic efficacy.AIM To analyze the diagnostic value of methylated BCAT1/IKZF1 in plasma for screening and postoperative follow-up of CRC.METHODS The candidate studies were identified by searching the PubMed,Embase,Cochrane Library,CNKI,and Wanfang databases from May 31,2003 to June 1,2023.Sensitivity,specificity,and diagnostic accuracy were calculated by merging ratios or means.RESULTS Twelve eligible studies were included in the analysis,involving 6561 participants.The sensitivity of methylated BCAT1/IKZF1 in plasma for CRC diagnosis was 60%[95%confidence interval(CI)53-67]and specificity was 92%(95%CI:90-94).The positive and negative likelihood ratios were 8.0(95%CI:5.8-11.0)and 0.43(95%CI:0.36-0.52),respectively.Diagnostic odds ratio was 19(95%CI:11-30)and area under the curve was 0.88(95%CI:0.85-0.91).The sensitivity and specificity for CRC screening were 64%(95%CI:59-69)and 92%(95%CI:91-93),respectively.The sensitivity and specificity for recurrence detection during follow-up were 54%CONCLUSION The detection of methylated BCAT1/IKZF1 in plasma,as a non-invasive detection method of circulating tumor DNA,has potential CRC diagnosis,but the clinical application prospect needs to be further explored. 展开更多
关键词 Branched chain amino acid transaminase 1 IKAROS family zinc finger 1 MethylATION Liquid biopsy Colorectal cancer
下载PDF
Endogenous biosynthesis of docosahexaenoic acid(DHA)regulates fish oocyte maturation by promoting pregnenolone production 被引量:2
9
作者 Yi Li Xuehui Li +6 位作者 Ding Ye Ru Zhang Chengjie Liu Mudan He Houpeng Wang Wei Hu Yonghua Sun 《Zoological Research》 SCIE CSCD 2024年第1期176-188,共13页
Omega-3 polyunsaturated fatty acids(n-3 PUFAs),particularly docosahexaenoic acid(22:6n-3,DHA),play crucial roles in the reproductive health of vertebrates,including humans.Nevertheless,the underlying mechanism related... Omega-3 polyunsaturated fatty acids(n-3 PUFAs),particularly docosahexaenoic acid(22:6n-3,DHA),play crucial roles in the reproductive health of vertebrates,including humans.Nevertheless,the underlying mechanism related to this phenomenon remains largely unknown.In this study,we employed two zebrafish genetic models,i.e.,elovl2^(-/-)mutant as an endogenous DHAdeficient model and fat1(omega-3 desaturase encoding gene)transgenic zebrafish as an endogenous DHA-rich model,to investigate the effects of DHA on oocyte maturation and quality.Results show that the elovl2^(-/-)mutants had much lower fecundity and poorer oocyte quality than the wild-type controls,while the fat1 zebrafish had higher fecundity and better oocyte quality than wildtype controls.DHA deficiency in elovl2^(-/-)embryos led to defects in egg activation,poor microtubule stability,and reduced pregnenolone levels.Further study revealed that DHA promoted pregnenolone synthesis by enhancing transcription of cyp11a1,which encodes the cholesterol side-chain cleavage enzyme,thereby stabilizing microtubule assembly during oogenesis.In turn,the hypothalamic-pituitary-gonadal axis was enhanced by DHA.In conclusion,using two unique genetic models,our findings demonstrate that endogenously synthesized DHA promotes oocyte maturation and quality by promoting pregnenolone production via transcriptional regulation of cyp11a1. 展开更多
关键词 Docosahexaenoic acid Oocyte maturation Oocyte quality PREGNENOLONE MICROTUBULE
下载PDF
A comparison study on structure-function relationship of polysaccharides obtained from sea buckthorn berries using different methods:antioxidant and bile acid-binding capacity 被引量:5
10
作者 Qiaoyun Li Zuman Dou +5 位作者 Qingfei Duan Chun Chen Ruihai Liu Yueming Jiang Bao Yang Xiong Fu 《Food Science and Human Wellness》 SCIE CSCD 2024年第1期494-505,共12页
In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic... In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic(HRP-U),acid(HRP-C)and alkali(HRP-A)assisted extraction methods were investigated.The results demonstrated that extraction methods had significant effects on extraction yield,monosaccharide composition,molecular weight,particle size,triple-helical structure,and surface morphology of HRPs except for the major linkage bands.Thermogravimetric analysis showed that HRP-U with filamentous reticular microstructure exhibited better thermal stability.The HRP-A with the lowest molecular weight and highest arabinose content possessed the best antioxidant activities.Moreover,the rheological analysis indicated that HRPs with higher galacturonic acid content and molecular weight showed higher viscosity and stronger crosslinking network(HRP-C,HRP-W and HRP-U),which exhibited stronger bile acid binding capacity.The present findings provide scientific evidence in the preparation technology of sea buckthorn polysaccharides with good antioxidant and bile acid binding capacity which are related to the structure affected by the extraction methods. 展开更多
关键词 Sea buckthorn Extraction method STRUCTURE Rheological properties Antioxidant activity Bile acid binding capacity
下载PDF
Enabling heterogeneous catalysis to achieve carbon neutrality: Directional catalytic conversion of CO_(2) into carboxylic acids 被引量:5
11
作者 Xiaofei Zhang Wenhuan Huang +4 位作者 Le Yu Max García-Melchor Dingsheng Wang Linjie Zhi Huabin Zhang 《Carbon Energy》 SCIE EI CAS CSCD 2024年第3期1-35,共35页
The increase in anthropogenic carbon dioxide(CO_(2))emissions has exacerbated the deterioration of the global environment,which should be controlled to achieve carbon neutrality.Central to the core goal of achieving c... The increase in anthropogenic carbon dioxide(CO_(2))emissions has exacerbated the deterioration of the global environment,which should be controlled to achieve carbon neutrality.Central to the core goal of achieving carbon neutrality is the utilization of CO_(2) under economic and sustainable conditions.Recently,the strong need for carbon neutrality has led to a proliferation of studies on the direct conversion of CO_(2) into carboxylic acids,which can effectively alleviate CO_(2) emissions and create high-value chemicals.The purpose of this review is to present the application prospects of carboxylic acids and the basic principles of CO_(2) conversion into carboxylic acids through photo-,electric-,and thermal catalysis.Special attention is focused on the regulation strategy of the activity of abundant catalysts at the molecular level,inspiring the preparation of high-performance catalysts.In addition,theoretical calculations,advanced technologies,and numerous typical examples are introduced to elaborate on the corresponding process and influencing factors of catalytic activity.Finally,challenges and prospects are provided for the future development of this field.It is hoped that this review will contribute to a deeper understanding of the conversion of CO_(2) into carboxylic acids and inspire more innovative breakthroughs. 展开更多
关键词 carbon neutrality carboxylic acids CO_(2)conversion heterogeneous catalyst in situ technology
下载PDF
Abiotic stress treatment reveals expansin like A gene OfEXLA1 improving salt and drought tolerance of Osmanthus fragrans by responding to abscisic acid 被引量:1
12
作者 Bin Dong Qianqian Wang +7 位作者 Dan Zhou Yiguang Wang Yunfeng Miao Shiwei Zhong Qiu Fang Liyuan Yang Zhen Xiao Hongbo Zhao 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第2期573-585,共13页
Sweet osmanthus(Osmanthus fragrans) is a having general approval aromatic tree in China that is widely applied to landscaping and gardening. However, the evergreen tree adaptability is limited by many environmental st... Sweet osmanthus(Osmanthus fragrans) is a having general approval aromatic tree in China that is widely applied to landscaping and gardening. However, the evergreen tree adaptability is limited by many environmental stresses. Currently, limited information is available regarding the genetic analysis and functional identification of expansin genes in response to abiotic stress in sweet osmanthus. In this study, a total of 29 expansin genes were identified and divided into four groups by genome-wide analysis from the sweet osmanthus genome. Transcriptome and quantitative Real-time PCR analysis showed that the cell wall-localized protein expansin-like A(OfEXLA1) gene was significantly induced by salt and drought treatment. Histochemical GUS staining of transgenic Arabidopsis lines in which GUS activity was driven with the OfEXLA1 promoter, GUS activity was significantly induced by salt, drought, and exogenous abscisic acid(ABA). In yeast, we found OfEXLA1overexpression significantly improved the population of cells compared with wild-type strains after NaCl and polyethylene glycol(PEG)treatment. Additionally, OfEXLA1 overexpression not only promoted plant growth, but also improved the salt and drought tolerance in Arabidopsis. To gain insight into the role of ABA signaling in the regulation of OfEXLA1 improving abiotic tolerance in sweet osmanthus, four differentially expressed ABA Insensitive 5(ABI5)-like genes(OfABL4, OfABL5, OfABL7, and OfABL8) were identified from transcriptome, and dualluciferase(dual-LUC) and yeast one hybrid(Y1H) assay showed that OfABL4 and OfABL5 might bind to OfEXLA1 promoter to accumulate the OfEXLA1 expression by responding to ABA signaling to improve abiotic tolerance in sweet osmanthus. These results provide the information for understanding the molecular functions of expansin-like A gene and molecular breeding of sweet osmanthus in future. 展开更多
关键词 Osmanthus fragrans Abiotic tolerance EXPANSIN Abscisic acid
下载PDF
Dietary supplementation of benzoic acid and essential oils combination enhances intestinal resilience against LPS stimulation in weaned piglets 被引量:1
13
作者 Chang Cui Yulong Wei +9 位作者 Yibo Wang Wen Ma Xiaoyu Zheng Jun Wang Ziwei Ma Caichi Wu Licui Chu Shihai Zhang Wutai Guan Fang Chen 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第2期878-897,共20页
Background The benefits of combining benzoic acid and essential oils(BAO)to mitigate intestinal impairment during the weaning process have been well established,while the detailed underlying mechanism has not been ful... Background The benefits of combining benzoic acid and essential oils(BAO)to mitigate intestinal impairment during the weaning process have been well established,while the detailed underlying mechanism has not been fully elucidated.Previous research has primarily focused on the reparative effects of BAO on intestinal injury,while neglecting its potential in enhancing intestinal stress resistance.Methods In this study,we investigated the pre-protective effect of BAO against LPS-induced stress using a modified experimental procedure.Piglets were pre-supplemented with BAO for 14 d,followed by a challenge with LPS or saline to collect blood and intestinal samples.Results Our findings demonstrated that BAO supplementation led to significant improvements in piglets’final weight,average daily gain,and feed intake/body gain ratio.Additionally,BAO supplementation positively influenced the composition of intestinal microbiota,increasing beneficial Actinobacteriota and Alloprevotella while reducing harmful Desulfobacterota,Prevotella and Oscillospira.Furthermore,BAO supplementation effectively mitigated oxidative disturbances and inflammatory responses induced by acute LPS challenge.This was evidenced by elevated levels of T-AOC,SOD,and GSH,as well as decreased levels of MDA,TNF-α,and IL-6 in the plasma.Moreover,piglets subjected to LPS challenge and pre-supplemented with BAO exhibited significant improvements in intestinal morphological structure and enhanced integrity,as indicated by restored expression levels of Occludin and Claudin-1 compared to the non-supplemented counterparts.Further analysis revealed that BAO supplementation enhanced the jejunal antioxidative capacity by increasing GSH-Px levels and decreasing MDA levels under the LPS challenge and stimulated the activation of the Nrf2 signaling pathway.Additionally,the reduction of TLR4/NF-κB/MAPK signaling pathways activation and proinflammatory factor were also observed in the jejunal of those piglets fed with BAO.Conclusions In summary,our study demonstrates that pre-supplementation of BAO enhances the anti-stress capacity of weaned piglets by improving intestinal microbiota composition,reinforcing the intestinal barrier,and enhancing antioxidative and anti-inflammatory capabilities.These effects are closely associated with the activation of Nrf2 and TLR4/NF-κB/MAPK signaling pathways. 展开更多
关键词 ANTI-STRESS Benzoic acid Essential oils INTESTINE LPS Weaned piglets
下载PDF
Bile acids,gut microbiota,and therapeutic insights in hepatocellular carcinoma 被引量:1
14
作者 Yang Song Harry CH Lau +1 位作者 Xiang Zhang Jun Yu 《Cancer Biology & Medicine》 SCIE CAS CSCD 2024年第2期144-162,共19页
Hepatocellular carcinoma(HCC)is a prevalent and aggressive liver malignancy.The interplay between bile acids(BAs)and the gut microbiota has emerged as a critical factor in HCC development and progression.Under normal ... Hepatocellular carcinoma(HCC)is a prevalent and aggressive liver malignancy.The interplay between bile acids(BAs)and the gut microbiota has emerged as a critical factor in HCC development and progression.Under normal conditions,BA metabolism is tightly regulated through a bidirectional interplay between gut microorganisms and BAs.The gut microbiota plays a critical role in BA metabolism,and BAs are endogenous signaling molecules that help maintain liver and intestinal homeostasis.Of note,dysbiotic changes in the gut microbiota during pathogenesis and cancer development can disrupt BA homeostasis,thereby leading to liver inflammation and fibrosis,and ultimately contributing to HCC development.Therefore,understanding the intricate interplay between BAs and the gut microbiota is crucial for elucidating the mechanisms underlying hepatocarcinogenesis.In this review,we comprehensively explore the roles and functions of BA metabolism,with a focus on the interactions between BAs and gut microorganisms in HCC.Additionally,therapeutic strategies targeting BA metabolism and the gut microbiota are discussed,including the use of BA agonists/antagonists,probiotic/prebiotic and dietary interventions,fecal microbiota transplantation,and engineered bacteria.In summary,understanding the complex BA-microbiota crosstalk can provide valuable insights into HCC development and facilitate the development of innovative therapeutic approaches for liver malignancy. 展开更多
关键词 Bile acid gut microbiota hepatocellular carcinoma THERAPEUTICS microbiota modulation
下载PDF
Blood glucose-lowering activity of protocatechuic acid is mediated by inhibiting a-glucosidase 被引量:1
15
作者 Huafang Ding Shouhe Huang +6 位作者 Chui Yiu Chook Erika Kwek Chi Yan Kaying Ma Jianhui Liu Hanyue Zhu Zhenyu Chen 《Food Science and Human Wellness》 SCIE CSCD 2024年第3期1212-1219,共8页
α-Glucosidase inhibitors are effective in controlling postprandial hyperglycemia,which play crucial roles in the management of type 2 diabetes.Protocatechuic acid(PCA)is one of phenolic acids existing not only in var... α-Glucosidase inhibitors are effective in controlling postprandial hyperglycemia,which play crucial roles in the management of type 2 diabetes.Protocatechuic acid(PCA)is one of phenolic acids existing not only in various plant foods but also as a major microbial metabolite of dietary anthocyanins in the large colon.The present study investigated the inhibitory mechanism of PCA on a-glucosidase in vitro and examined its effect on postprandial blood glucose levels in vivo.Results from in vitro experiments demonstrated that PCA was a mix-type inhibitor of a-glucosidase.Driven by hydrogen bonds and van der Waals interactions,PCA reversibly bound withα-glucosidase to form a stable a-glucosidase-PCA complex in a spontaneous manner.The computational simulation found that PCA could insert into the active cavity of a-glucosidase and establish hydrogen bonds with catalytic amino acid residues.PCA binding aroused the steric hindrance for substrates to enter active sites and caused the structural changes of interacted catalytic amino acid residues.PCA also exhibited postprandial hypoglycemic capacity in diabetic mice.This study may provide the theoretical basis for the application of PCA as an active ingredient of functional foods in dietary management of diabetes. 展开更多
关键词 Protocatechuic acid Α-GLUCOSIDASE Postprandial hyperglycemia Inhibition mechanism
下载PDF
Facile synthesis of efficient pentaethylenehexamine-phosphotungstic acid heterogeneous catalysts for oxidative desulfurization
16
作者 Chongfu Wu Changsheng Chen +4 位作者 Zhaoyang Qi Jie Chen Qinglian Wang Changshen Ye Ting Qiu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第11期140-147,共8页
The ultra-deep desulfurization of oil needs to be solved urgently due to various problems,including environmental pollution and environmental protection requirements.Oxidative desulfurization(ODS)was considered to be ... The ultra-deep desulfurization of oil needs to be solved urgently due to various problems,including environmental pollution and environmental protection requirements.Oxidative desulfurization(ODS)was considered to be the most promising technology.The facile synthesis of highly efficient and stable HPW-based heterogeneous catalysts for oxidative desulfurization is still a challenging task.In this paper,pentamethylene hexamine(PEHA)and phosphotungstic acid(HPW)were combined by a simple one-step method to prepare a heterogeneous catalyst of PEHA-HPW for the production of ultra-deep desulfurization fuel oil.The composite material exhibited excellent catalytic activity and high recyclability,which could reach a 100% dibenzothiophene(DBT)removal rate in 30 min and be recycled at least 5 times.Experiments and DFT simulations were used to better examine the ODS mechanism of PEHA-HPW.It was proved that the rich amino groups on the surface of PEHA-HPW play a crucial role.This work provides a simple and feasible way for the manufacture of efficient HPW-based catalysts. 展开更多
关键词 OXIDATION CATALYST DESULFURIZATION FUEL Phosphotungstic acid AMINO
下载PDF
Shikimic acid accelerates phase change and flowering in Chinese jujube 被引量:1
17
作者 Xianwei Meng Zhiguo Liu +11 位作者 Li Dai Weiqiang Zhao Jiurui Wang Lili Wang Yuanpei Cui Ying Li Yinshan Cui Yao Zhang Luyao Wang Fengjiao Yu Jin Zhao Mengjun Liu 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第2期413-424,共12页
The juvenile-to-adult phase change with first flowering as the indicator plays a crucial role in the lifecycle of fruit trees. However, the molecular mechanisms underlying phase change in fruit trees remain largely un... The juvenile-to-adult phase change with first flowering as the indicator plays a crucial role in the lifecycle of fruit trees. However, the molecular mechanisms underlying phase change in fruit trees remain largely unknown. Shikimic acid (ShA) pathway is a main metabolic pathway closely related to the synthesis of hormones and many important secondary metabolites participating in plant phase change. So,whether ShA regulates phase change in plants is worth clarifying. Here, the distinct morphological characteristics and the underlying mechanisms of phase change in jujube (Ziziphus jujuba Mill.), an important fruit tree native to China with nutritious fruit and outstanding tolerance abiotic stresses, were clarified. A combined transcriptome and metabolome analysis found that ShA is positively involved in jujube(Yuhong’×Xing 16’) phase change. The genes in the upstream of ShA synthesis pathway (ZjDAHPS, ZjDHQS and ZjSDH), the contents of ShA and the downstream secondary metabolites like phenols were significantly upregulated in the phase change period. Further, the treatment of spraying exogenous ShA verified that ShA at a very low concentration (60 mg·L^(-1)) can substantially speed up the phase change and flowering of jujube and other tested plants including Arabidopsis, tomato and wheat. The exogenous ShA (60 mg·L^(-1)) treatment in jujube seedlings could increase the accumulation of endogenous ShA, enhance leaf photosynthesis and the synthesis of phenols especially flavonoids and phenolic acids, and promote the expression of genes (ZjCOs, ZjNFYs and ZjPHYs) involved in flowering pathway. Basing on above results, we put forward a propose for the underlying mechanism of ShA regulating phase change, and a hypothesis that ShA could be considered a phytohormone-like substance because it is endogenous, ubiquitous, movable and highly efficient at very low concentrations. This study highlights the critical role of ShA in plant phase change and its phytohormone-like properties. 展开更多
关键词 Ziziphus jujuba Mill. Phase change FLOWERING Shikimic acid TRANSCRIPTOME METABOLOME
下载PDF
Gut microbiota induced abnormal amino acids and their correlation with diabetic retinopathy 被引量:1
18
作者 Sheng-Qun Jiang Su-Na Ye +4 位作者 Yin-Hua Huang Yi-Wen Ou Ke-Yang Chen Jian-Su Chen Shi-Bo Tang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第5期883-895,共13页
AIM:To explore the correlation of gut microbiota and the metabolites with the progression of diabetic retinopathy(DR)and provide a novel strategy to elucidate the pathological mechanism of DR.METHODS:The fecal samples... AIM:To explore the correlation of gut microbiota and the metabolites with the progression of diabetic retinopathy(DR)and provide a novel strategy to elucidate the pathological mechanism of DR.METHODS:The fecal samples from 32 type 2 diabetes patients with proliferative retinopathy(PDR),23 with nonproliferative retinopathy(NPDR),27 without retinopathy(DM),and 29 from the sex-,age-and BMI-matched healthy controls(29 HC)were analyzed by 16S rDNA gene sequencing.Sixty fecal samples from PDR,DM,and HC groups were assayed by untargeted metabolomics.Fecal metabolites were measured using liquid chromatographymass spectrometry(LC-MS)analysis.Associations between gut microbiota and fecal metabolites were analyzed.RESULTS:A cluster of 2 microbiome and 12 metabolites accompanied with the severity of DR,and the close correlation of the disease progression with PDR-related microbiome and metabolites were found.To be specific,the structure of gut microbiota differed in four groups.Diversity and richness of gut microbiota were significantly lower in PDR and NPDR groups,than those in DM and HC groups.A cluster of microbiome enriched in PDR group,including Pseudomonas,Ruminococcaceae-UCG-002,Ruminococcaceae-UCG-005,Christensenellaceae-R-7,was observed.Functional analysis showed that the glucose and nicotinate degradations were significantly higher in PDR group than those in HC group.Arginine,serine,ornithine,and arachidonic acid were significantly enriched in PDR group,while proline was enriched in HC group.Functional analysis illustrated that arginine biosynthesis,lysine degradation,histidine catabolism,central carbon catabolism in cancer,D-arginine and D-ornithine catabolism were elevated in PDR group.Correlation analysis revealed that Ruminococcaceae-UCG-002 and Christensenellaceae-R-7 were positively associated with L-arginine,ornithine levels in fecal samples.CONCLUSION:This study elaborates the different microbiota structure in the gut from four groups.The relative abundance of Ruminococcaceae-UCG-002 and Parabacteroides are associated with the severity of DR.Amino acid and fatty acid catabolism is especially disordered in PDR group.This may help provide a novel diagnostic parameter for DR,especially PDR. 展开更多
关键词 proliferative retinopathy gut microbiota Ruminococcaceae amino acid metabolism ARGININE
下载PDF
Ethylenediamine tetramethylenephosphonic acid as a selective collector for the improved separation of chalcopyrite against pyrite at low alkalinity
19
作者 Jianjun Wang Gaogui Jing +3 位作者 Renji Zheng Zijie Huang Wei Sun Zhiyong Gao 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第7期873-882,共10页
Chalcopyrite is the main Cu-containing mineral and cannot be separated well from pyrite using traditional xanthate collectors with large amounts of lime depressant, resulting in difficulties of the tailing treatment a... Chalcopyrite is the main Cu-containing mineral and cannot be separated well from pyrite using traditional xanthate collectors with large amounts of lime depressant, resulting in difficulties of the tailing treatment and associated precious metals recovery. Therefore, in this study, the green and odourless ethylenediamine tetramethylenephosphonic acid(EDTMPA) was introduced as a novel chalcopyrite collector. Flotation results from the binary mineral mixture and real ore demonstrated that EDTMPA could realize the selective separation of chalcopyrite from pyrite relative to ethyl xanthate(EX) without any depressants within the wide p H range of 6.0–11.0, and might replace the traditional high-alkaline lime process. Electrochemical and Fourier transform infrared spectra measurements indicated that the difference in adsorption performance of EDTMPA on chalcopyrite and pyrite was larger than that of EX, suggesting a better selectivity for EDTMPA. Density functional theory calculations demonstrated that there were stronger chemical bonds between P—O groups of EDTMPA and the Fe/Cu atoms on chalcopyrite in the form of a stable six-membered ring. Crystal chemistry calculations further revealed that the activity of metal atoms of chalcopyrite was higher than that of pyrite. Therefore, these basic theoretical results and practical application provide a guidance for the industrial application of EDTMPA in chalcopyrite flotation. 展开更多
关键词 CHALCOPYRITE PYRITE Flotation ethylenediamine tetramethylenephosphonic acid COLLECTOR
下载PDF
Elaidic acid leads to mitochondrial dysfunction via mitochondria-associated membranes triggers disruption of mitochondrial calcium fluxes 被引量:2
20
作者 Hui Liu Xuenan Li +4 位作者 Ziyue Wang Lu Li Yucai Li Haiyang Yan Yuan Yuan 《Food Science and Human Wellness》 SCIE CSCD 2024年第1期287-298,共12页
Elaidic acid(EA)stimulation can lead to endoplasmic reticulum stress(ERS),accompanied by a large release of Ca^(2+),and ultimately the activation of NLRP3 inflammasome in Kupffer cells(KCs).Mitochondrial instability o... Elaidic acid(EA)stimulation can lead to endoplasmic reticulum stress(ERS),accompanied by a large release of Ca^(2+),and ultimately the activation of NLRP3 inflammasome in Kupffer cells(KCs).Mitochondrial instability or dysfunction may be the key stimulating factors to activate NLRP3 inflammasome,and sustained Ca^(2+)transfer can result in mitochondrial dysfunction.We focused on KCs to explore the damage to mitochondria by EA.After EA stimulation,cells produced an oxidative stress(OS)response with a significant increase in ROS release.Immunoprecipitation experiments and the addition of inhibitors revealed that the increase in the level of intracellular Ca^(2+)led to Ca^(2+)accumulation in the mitochondrial matrix via mitochondria-associated membranes(MAMs).This was accompanied by a significant release of m ROS,loss of MMP and ATP,and a significant increase in mitochondrial permeability transition pore opening,ultimately leading to mitochondrial instability.These findings confirmed the mechanism that EA induced mitochondrial Ca^(2+)imbalance in KCs via MAM,ultimately leading to mitochondrial dysfunction.Meanwhile,EA induced OS and the decrease of MMP and ATP in rat liver,and significant lesions were found in liver mitochondria.Swelling of the inner mitochondrial cristae and mitochondrial vacuolization occurred,with a marked increase in lipid droplets. 展开更多
关键词 Elaidic acid(EA) Mitochondria-associated membranes(MAMs) Calcium Endoplasmic reticulum Mitochondria dysfunction
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部