Chlorine content and position of chlorinated phenols have many significant effects on the reactivity of oxido-reduction. The effects of chlorine content and position of chlorinated phenols on their oxidation kinetics ...Chlorine content and position of chlorinated phenols have many significant effects on the reactivity of oxido-reduction. The effects of chlorine content and position of chlorinated phenols on their oxidation kinetics by potassium permanganate were evaluated through different kinetics studies. Since chlorine was an electron withdrawing atom, the substitution of chlorine on the aromatic ring decreased the oxidation rate constant by σ-electron withdrawing conductive effect. The substitution of chlorine at ortho or para position on the aromatic ring increased the oxidation rate constant by π-electron donating conjugative effect, and the conjugative effect could counteract the negative impact of the conductive effect to some extent. On the other hand, the substitution of chlorine at ortho position on the aromatic ring decreased the oxidation rate constant by steric hindrance effect. The oxidation rate constants of phenol and chlorinated phenols studied decreased as follow order: 4-chlorophenol>2,4-dichlorophenol>phenol>2,6-dichlorophenol.展开更多
Synthetic phenolic antioxidants(SPAs)are widely used in diverse industries due to their exceptional antioxidant characteristics.However,human exposure to SPAs may cause health problems.In this study,226 dust samples w...Synthetic phenolic antioxidants(SPAs)are widely used in diverse industries due to their exceptional antioxidant characteristics.However,human exposure to SPAs may cause health problems.In this study,226 dust samples were collected from 10 provinces in China,and six SPAs(three parent SPAs and their three transformation products)were analyzed.The concentrations of6SPAs(the sum of six target compounds)ranged from 15.4 to 3210 ng/g(geometric mean(GM):169 ng/g).The highest concentration of6SPAswas found in Sichuan Province(GM:349 ng/g),which was approximately 4 times higher than that in Hubei Province(81.6 ng/g)(p<0.05).The concentrations of butylated hydroxytoluene(BHT),2,2'-methylene bis(4-methyl-6–tert-butylphenol)(AO2246),2,6-di–tert–butyl–1,4-benzoquinone(BHT-Q),2,6-di–tert–butyl–4-(hydroxymethyl)phenol(BHT-OH),and ∑_(p)-SPAs were substantially higher in dust from urban areas than rural areas(p<0.05).AO2246 concentration in dust from homes(GM:0.400 ng/g)was about 4 times higher than that in workplaces(0.116 ng/g)(p<0.01).Significantly higherp-SPAs concentrations were found in dust from homes(GM:17.5 ng/g)than workplaces(11.4 ng/g)(p<0.01).The estimated daily intakes(EDIs)of ∑_(6)SPAs exposed through dust ingestion were 0.582,0.342,0.197,0.076,and 0.080 ng/kg bw/day in different age groups,and exposed through dermal contact was 0.358,0.252,0.174,0.167,and 0.177 ng/kg bw/day.EDIs showed that the exposure risks of SPAs decreased with age.This is the first work to determine SPAs in dust from10 provinces in China and investigate the spatial distribution of SPAs in those regions.展开更多
Silica gel column chromatography(CC),Sephadex LH-20 CC and high performance liquid chromatography(HPLC)were used to study the chemical constituents of the fruits of the medicine-food plant Rubus idaeus Linnaeus.A new ...Silica gel column chromatography(CC),Sephadex LH-20 CC and high performance liquid chromatography(HPLC)were used to study the chemical constituents of the fruits of the medicine-food plant Rubus idaeus Linnaeus.A new tetrahydrogenated naphthol syringic acid ester,named rubusnolicester(1),two new phenolic glycoside derivatives,4-chloro-2,6-dimethoxylphenol-1-O-β-D-glucopyranoside(2)and salicylic acid-2-O-(6'-O-acetyl)-β-D-glucopyranoside(3),together with one known salicylic acid glycoside derivative(4)and three known flavonoids derivatives(5~7),were isolated.Their structures were elucidated by HRESI-MS,NMR spectroscopy,and a comparison of optical rotation(OR).Compounds 1~7 were evaluated the inhibitory activities against the nitric oxide(NO)production induced by lipopolysaccharide(LPS)in mouse macrophage RAW264.7 cells in vitro.Compound 1 exhibited inhibitory effect with the IC50 value of(12.28±1.25)μmol/L.展开更多
The technique for preparing phenol formaldehyde resin from phenolated wood (PWF) and its characters were studied and analyzed. Poplar (Populus spp.) wood meal was liquefied by phenol in the presence of sulfuric acid a...The technique for preparing phenol formaldehyde resin from phenolated wood (PWF) and its characters were studied and analyzed. Poplar (Populus spp.) wood meal was liquefied by phenol in the presence of sulfuric acid as a catalyst. After the liquefied products were cooled, alkaline catalyst and formaldehyde were added. The mixture was kept at (60?) C for 1h and then was heated to (85?) C for 1h. The influence of molar ratio of formaldehyde to phenol (F/P) was investigated. The results showed when the molar ratio of formaldehyde to phenol was over 1.8, the PWF adhesives had high bond quality, bond durability and extremely low aldehydes emissions.展开更多
The efficient mineralization of phenol and its derivatives in wastewater remains a great challenge.In this study,the bimetallic CuCeO_(2)-BTC was screened from a series of MOFs-derived MCeO_(2)-BTC(M=La,Cu,Co,Fe,and M...The efficient mineralization of phenol and its derivatives in wastewater remains a great challenge.In this study,the bimetallic CuCeO_(2)-BTC was screened from a series of MOFs-derived MCeO_(2)-BTC(M=La,Cu,Co,Fe,and Mn)catalysts,and the influence of the Cu/Ce ratio on phenol removal by catalytic ozonation was carefully examined.The results indicate that Cu_(2)Ce_(1)O_(y)-BTC was the best among the Cu_(x)Ce_(1)O_(y)-BTC(x=0,1,2,and 3)catalysts,with a phenol mineralization efficiency reaching close to 100%within 200 min,approximately 30.1%higher than CeO_(2)-BTC/O_(3)and 70.3%higher than O_(3)alone.The order of mineralization efficiency of phenol was Cu_(2)Ce_(1)O_(y)-BTC>Cu_(3)Ce_(1)O_(y)-BTC>Cu_(1)Ce_(1)O_(y)-BTC>CeO_(2)-BTC.CeO_(2)-BTC exhibited a broccoli-like morphology,and Cu_(x)Ce_(1)O_(y)-BTC(x=1,2,and 3)exhibited an urchin-like morphology.Compared with Cu_(x)Ce_(1)O_(y)-BTC(x=0,1,and 3),Cu_(2)Ce_(1)O_(y)-BTC exhibited a larger specific surface area and pore volume.This characteristic contributed to the availability of more active sites for phenol degradation.The redox ability was greatly enhanced as well.Besides,the surface of Cu_(2)Ce_(1)O_(y)-BTC exhibited a higher concentration of Ce^(3+)species and hydroxyl groups,which facilitated the dissociation of ozone and the generation of active radicals.Based on the results of radical quenching experiments and the intermediates detected by LC-MS,a potential mechanism for phenol degradation in the Cu_(2)Ce_(1)O_(y)-BTC/O_(3)system was postulated.This study offers novel perspectives on the advancement of MOFs-derived catalysts for achieving the complete mineralization of phenol in wastewater through catalytic ozonation.展开更多
Bio-oil is a renewable fuel that can be obtained from biomass waste,such as empty palm fruit bunches,sugarcane bagasse,and rice husks.Within a biorefinery framework,bio-oil had not met the standards as a fuel due to t...Bio-oil is a renewable fuel that can be obtained from biomass waste,such as empty palm fruit bunches,sugarcane bagasse,and rice husks.Within a biorefinery framework,bio-oil had not met the standards as a fuel due to the presence of impurities like corrosive phenol.Therefore,the separation of phenol from bio-oil is essential and can be achieved using the extraction method.In this study,biomass wastes(empty fruit bunches of oil palm,sugarcane bagasse,and rice husk)were pyrolyzed in a biorefinery framework to produce bio-oil,which was then refined through liquid-liquid extraction with a methanol-chloroform and ethyl acetate solvents to remove its phenolic compound.The extraction with methanol-chloroform solvent was carried out for 1 h at 50℃.Meanwhile,extraction with ethyl acetate solvent was carried out for 3 h at 70℃.Both extractions used the same variations,i.e.,bio-oil:solvent ratio at 1:1,1:2,1:3,and 1:4,and stirring speeds of 150 rpm,200 rpm,250 rpm,and 300 rpm.The bio-oil obtained from this study contained complex chemical compounds and had characteristics such as a pH of 5,a density of 1.116 g/mL,and a viscosity of 29.57 cSt.Theoptimization results using response surface methodology(RSM)showed that the best yield formethanolchloroform was 72.98%at a stirring speed of 250 rpm and a ratio of 1:3.As for ethyl acetate solvent,the highest yield obtained was 71.78%at a stirring speed of 237.145 rpm and a ratio of 1:2.展开更多
Phenolic compounds represent a broad and structurally diverse class of plant secondary metabolites with importance for both plant biology and human health.This review provides a comprehensive overview of their biosynt...Phenolic compounds represent a broad and structurally diverse class of plant secondary metabolites with importance for both plant biology and human health.This review provides a comprehensive overview of their biosynthesis,chemical diversity,multifaceted functions in plants,roles in the wider ecosystem,and significance in human nutrition and biotechnology.Primarily synthesized via the phenylpropanoid pathway,these compounds encompass major classes such as lignin,flavonoids,and tannins.Within the plant,they perform critical functions including providing structural support(lignin),defending against biotic stresses(e.g.,pathogens,herbivores),mediating ecological interactions(pollination,symbiosis,allelopathy),and protecting against abiotic stresses likeUVradiation and oxidative damage.Phenolic compounds extend their influence beyond the plant itself by shaping soil ecosystems through rhizodeposition,where they interact with microbial communities and nutrient cycles.At the same time,they play a central role in the health benefits of plant-rich diets,with strong epidemiological evidence linking their regular consumption to a reduced risk of chronic diseases such as cardiovascular disease,cancer,and obesity.Thereviewfurther examines the significant variation of phenolic content in different food sources and explores the impact of processing methods,highlighting germination as a key strategy for enhancing the nutritional and bioactive value of cereals and legumes.Finally,the potential of phenolic compounds as a source for modern drugs and their targeted production through biotechnological approaches are discussed,underscoring their position as a cornerstone of phytochemical research with ongoing and future applications in health,agriculture,and industry.This paper employs a semi-systematic(or narrative)literature review methodology.A strategic search of key academic databases,including PubMed,Scopus,Web of Science,Google Scholar,was conducted to identify relevant literature and highly influential works.This review aims to synthesize the existing knowledge on phenolic compounds and to emphasize their undeniable impact on human health through an interdisciplinary approach.展开更多
Prolonged lack of rain and high-temperature lead to soil water deficits,inhibiting cereal crop growth in early ontogenesis and reducing grain quality and yield.Rye(Secale cereale L.)is a key grain crop,particularly in...Prolonged lack of rain and high-temperature lead to soil water deficits,inhibiting cereal crop growth in early ontogenesis and reducing grain quality and yield.Rye(Secale cereale L.)is a key grain crop,particularly in regions where wheat cultivation is challenging or unfeasible.To clarify its drought adaptation mechanisms,we analyzed the effects of moderate soil drought on growth,hormonal homeostasis,and the dynamics and distribution of free amino acids and phenolic compounds in rye at early vegetative stages and post-recovery.Drought triggered both general and organ-specific changes in endogenous phytohormones.A nonspecific response involved the accumulation of stress hormones abscisic acid(ABA)and salicylic acid(SA),alongside the suppression of growth hormones indole-3-acetic acid(IAA)and gibberellins.However,hormone dynamics and localization varied across plant organs.ABA and SA levels significantly increased in shoots of drought-stressed and recovered plants,corresponding with inhibited growth.Prolonged drought further enhanced ABA accumulation in both shoots and roots of recovered plants,while SA levels declined in roots but remained elevated in shoots.Drought also caused a substantial reduction in IAA,particularly in shoots,while gibberellins(GA_(3)+GA_(4))significantly decreased in roots.GA_(3)was predominant in most samples,except in the shoots of 2-day-old control plants.Post-recovery,IAA levels increased but remained below control values,while GA_(4)accumulation in roots led to a rise in total gibberellin levels.In contrast,shoot GA_(3)+GA_(4)levels declined,primarily due to GA_(3)reduction.The dominant free amino acids:aspartic acid,glutamic acid,glycine,alanine,and leucinedecreased significantly,underscoring their key role in stress adaptation.Increased flavonoid accumulation,especially in roots,suggests their involvement in antioxidant defense against oxidative stress.A significant increase in ABA and SA levels,along with a marked reduction in IAA and GA content in stressed rye plants occurred alongside a reduction in free amino acid content,accumulation of phenolic compounds,and an increase in flavonoid levels.These findings indicate distinct adaptation strategies in rye shoots and roots undermoderate soil drought.They provide a foundation for further research on drought resistance mechanisms in cereals and the development of strategies to enhance their adaptive potential.展开更多
Phenol is extensively utilized in various industries involving paints,rubber,textiles,explosives,plastics,etc.Compared to the conventional distillation or extraction technologies,pervaporation(PV)membrane process can ...Phenol is extensively utilized in various industries involving paints,rubber,textiles,explosives,plastics,etc.Compared to the conventional distillation or extraction technologies,pervaporation(PV)membrane process can be operated at a low temperature and has a low energy consumption as well as a high separation efficiency for phenol recovery.Thus,to meet the high demand for phenol recovery,the application of PV has been encouraged,and reached a new level.The PV process is governed by the properties of the membrane materials that significantly influence the energy costs associated with the separation unit,and the membrane types include polymer membranes,inorganic membranes,and mixed matrix membranes.Although recent literatures show that PV membranes have been continuously updated,no review has reported the latest development about it.In this work,the material types,separation properties and preparation methods of hydrophobic PV membranes for phenol recovery are summarized.Furthermore,the key preparation methods and application challenges associated with membranes are summarized,along with an overview of the opportunities and challenges posed by hydrophobic PV membranes for phenol recovery.展开更多
Chrysanthemum morifolium Ramat.is an important industrial crop with a high medicinal value,whose capitulum consists of ray and disc florets containing numerous bioactive components,such as flavonoids and phenolic acid...Chrysanthemum morifolium Ramat.is an important industrial crop with a high medicinal value,whose capitulum consists of ray and disc florets containing numerous bioactive components,such as flavonoids and phenolic acids.However,the distribution and accumulations of the bioactive metabolites in florets of Chrysanthemum morifolium were unclear.Herein,the ray and disc florets of Chrysanthemum morifolium were separated for comparing the bioactive metabolites.The contents of phenolic compounds and antioxidant activities were significantly different between the two florets.The metabolomic analysis identified 203 and 241 differential metabolites between ray and disc florets at two flowering stages.The derivatives of quercetin,isorhamnetin,tricin,and caffeoylquinic acid were enriched in the disc florets,while apigenin,kaempferol,acacetin,and their glycosides mainly accumulated in the ray florets.Besides,the results of transcriptome and qRT-PCR suggested that the F3H,F3'H,and FLS genes highly expressed in disc florets,while the FNS gene was well expressed in ray florets,which explained the different distribution of phenolic compounds between ray and disc florets.Furthermore,the expression of CmCYC2 genes was found to be significantly related to the distribution of flavones by correlation analysis.It was proved by the luciferase reporter assay that CmCYC2a and CmCYC2d factors could bind and activate the CmFNS promoter to regulate the flavones biosynthesis in ray florets.These results revealed the significant difference of metabolite contents and gene expression profile between ray and disc floret in Chrysanthemum morifolium and demonstrated that the quality of Chrysanthemum morifolium‘Hangju'was closely relevant to its flower morphology.展开更多
The surface of MoSi2-SiB6/phenolic resin matrix composites was modified by mica,and the thermal oxidation behavior of the composites and the mechanical properties of the pyrolysis products were studied.The results sho...The surface of MoSi2-SiB6/phenolic resin matrix composites was modified by mica,and the thermal oxidation behavior of the composites and the mechanical properties of the pyrolysis products were studied.The results showed that the mica improved the thermal properties of the composites,the thermal expansion coefficient decreased,and the liquid phase formation caused the composites to shrink and increase the density.The flexural strength of mica surface modified composites not only increased to 78.64MPa after thermal treatment at 800-1200℃,but reached 83.02 MPa after high temperature treatment at1400℃.The improvement of the mechanical properties of the residual product benefits from the formation of high temperature ceramic phases such as Mo_(2)C and MoB,and the improvement of the shear strength of the composites by the mica.The shear strength of MBm5-2 at room temperature reached 33.08 MPa,indicating that the improvement of the interlayer properties of the composites further improved its mechanical properties.展开更多
Moringa oleifera Lam.is a Moringa genus in the Moringaceae family that is high in nutrients and has a wide range of applications.Phenolic compounds are widely found in plants and have various health benefits for the h...Moringa oleifera Lam.is a Moringa genus in the Moringaceae family that is high in nutrients and has a wide range of applications.Phenolic compounds are widely found in plants and have various health benefits for the human body.With its high content and wide variety of phenolic compounds,M.oleifera Lam.has been widely studied for its health benefits.The phenolic compounds in M.oleifera Lam.(MOPCs)can be a potential source of functional food ingredients in pharmaceutical and industrial applications.Numerous studies have shown that MOPCs have antioxidant,anti-obesity,anti-diabetic,and antibacterial effects.Although the research on MOPCs has been gradually increasing,the extraction,isolation,identification,biological activities,and comprehensive application of MOPCs need a more systematic summary and generalization.Therefore,this paper reviews the isolation and extraction methods,structure identification,biological activities,and comprehensive applications to provide a further reference for the research and application of MOPCs.展开更多
In thermal protection structures,controlling and optimizing the surface roughness of carbon/phenolic(C/Ph)composites can effectively improve thermal protection performance and ensure the safe operation of carriers in ...In thermal protection structures,controlling and optimizing the surface roughness of carbon/phenolic(C/Ph)composites can effectively improve thermal protection performance and ensure the safe operation of carriers in high-temperature environments.This paper introduces a machine learning(ML)framework to forecast the surface roughness of carbon-phenolic composites under various thermal conditions by employing an ML algorithm derived from historical experimental datasets.Firstly,ablation experiments and collection of surface roughness height data of C/Ph composites under different thermal environments were conducted in an electric arc wind tunnel.Then,an ML model based on Ridge regression is developed for surface roughness prediction.The model involves incorporating feature engineering to choose the most concise and pertinent features,as well as developing an ML model.The ML model considers thermal environment parameters and feature screened by feature engineering as inputs,and predicts the surface height as the output.The results demonstrate that the suggested ML framework effectively anticipates the surface shape and associated surface roughness parameters in various heat flow conditions.Compared with the conventional 3D confocal microscope scanning,the method can obtain the surface topography information of the same area in a much shorter time,thus significantly saving time and cost.展开更多
[Objectives]To investigate the anti-tumor molecular mechanism of acetylenic phenols against triple-negative breast cancer(TNBC)using network pharmacology and molecular docking approaches.[Methods]Based on team s previ...[Objectives]To investigate the anti-tumor molecular mechanism of acetylenic phenols against triple-negative breast cancer(TNBC)using network pharmacology and molecular docking approaches.[Methods]Based on team s previous in vitro activity screening,the most active acetylenic phenols were selected for further analysis.Genes associated with triple-negative breast cancer(TNBC)were retrieved from the GAD and OMIM databases.Using Cytoscape software,a compound-target-pathway interaction network was constructed to visualize the relationships between the acetylenic phenols,their potential targets,and related pathways.Functional enrichment analysis of GO terms and KEGG pathways was performed using the DAVID database to identify key signaling mechanisms.Furthermore,molecular docking was conducted to evaluate the binding interactions between the acetylenic phenols and the potential core targets.[Results]Acetylenic phenols exhibit potential anticancer effects by modulating multiple signaling pathways,including the PI3K-Akt pathway,cell cycle pathway,and breast cancer pathway,which are closely associated with the pathophysiological processes of triple-negative breast cancer(TNBC)such as cell proliferation,apoptosis,and cell cycle regulation.Molecular docking results indicated that acetylenic phenols bind effectively to their targets via hydrogen bonding,hydrophobic interactions,andπ-stacking,indicating strong binding affinity.[Conclusions]Acetylenic phenols exert anti-TNBC effects by modulating key targets,including EGFR,RAF1,ESR1,CHEK1,and CDC25C,and influencing associated signaling pathways.These findings reveal the molecular mechanism underlying their anti-TNBC activity and provide a theoretical foundation for the potential application of acetylenic phenols in TNBC treatment.展开更多
Grapevine(Vitis vinifera L.)is one of the main crops worldwide,and ultraviolet-B(UV-B,280-315 nm)radiation is emerging as a promising technical tool to enhance secondary metabolites that can contribute to the quality ...Grapevine(Vitis vinifera L.)is one of the main crops worldwide,and ultraviolet-B(UV-B,280-315 nm)radiation is emerging as a promising technical tool to enhance secondary metabolites that can contribute to the quality and health-promoting properties of both grapes and the resulting wines.However,few studies have assessed the effectiveness of UV-B supplements under field conditions.Here,we compared the effects of two different field UV-B treatments(a single supplement applied at pre-harvest,and a double supplement applied at both veraison and pre-harvest)on the phenolic composition of Tempranillo grape skins and the resulting wines.The double supplement induced stronger changes than the single supplement,with responses being more pronounced in grape skins than in wines.In skins,UV-B supplements significantly increased flavonols,phenolic acids,and flavanols,consistent with previous reports highlighting flavonols as the most reliable UV-B-responsive compounds in grape skins.In wines,the clearest responses were increases in anthocyanins and color intensity.Overall,UV-B supplements improved grape and wine quality,although skin responses were only partially transmitted to the wines.Moreover,wine responses were more unpredictable than skin responses,likely reflecting not only the UV-B-induced changes in grape skins but also the complex chemical interactions among phenolic compounds(and also with other metabolites)during vinification.Further experimentation,particularly in the long term,is required to optimize the application of UV-B supplements as a viticultural and enological practice.展开更多
Carbon fiber/phenolic resin composites have great potential application in the field of electronic information,where excellent structural-functional integration is required.In this work,the establishment of interfacia...Carbon fiber/phenolic resin composites have great potential application in the field of electronic information,where excellent structural-functional integration is required.In this work,the establishment of interfacial structures consisting of carbon nanotubes with different morphologies at the fiber/matrix interface is conducive to the further modulation of the mechanical,tribological,electromagnetic interference(EMI)shielding and thermal conductivity properties of carbon fiber/phenolic resin composites.Specially,array carbon nanotubes can deep into the resin matrix,effectively hindering crack extension,and constructing an electrically and thermally conductive network.Compared with the carbon fiber/phenolic composites,the tensile strength and modulus of elasticity(163.86±9.60 MPa,5.06±0.25 GPa)of the array carbon nanotubes reinforced carbon fiber/phenolic composites were enhanced by 57.09%and 22.22%.The average friction coefficient and wear rate(0.20±0.02,1.11×10^(-13)±0.13×10^(-13)m^(3)N^(−1)m^(−1))were reduced by 39.39%and 74.31%.EMI shielding effectiveness up to 40 dB in the X-band at 0.4 mm sample thickness,diffusion coefficient(0.39±0.003 mm^(2)/s)and thermal conductivity(0.54±0.004 W/(m K))were enhanced by up to 14.37%and 50.42%.This study reveals the beneficial effects of morphological changes of carbon nanotubes on the design of interfacial structure,proposes the reinforcement mechanism of array carbon nanotubes,and opens up the prospect of carbon fiber/phenolic composites for electronic applications.展开更多
A Ti_(3)SiC_(2)-modified high-silica oxygen/phenolic aerogel composite with excellent oxidation resistance and high-temperature performance was prepared.The experimental results show that the obtained composite has si...A Ti_(3)SiC_(2)-modified high-silica oxygen/phenolic aerogel composite with excellent oxidation resistance and high-temperature performance was prepared.The experimental results show that the obtained composite has significantly improved oxidation resistance.When the addition amount of Ti_(3)SiC_(2)is 75%,the carbonization volume shrinkage rate of the composite after aerobic static combustion is only 5.95%.At the same time,the LAR and MAR after 30 seconds of oxyacetylene ablation under a heat flux density of 1.5 MW/m2 are 0.0307 mm/s and 0.0149 g/s,respectively.The compressive strength after aerobic static combustion at 1000℃is up to 20.43%of that before aerobic static combustion,which is 1.99 times that of the unfilled material,significantly improving the high-temperature mechanical properties of the composite.展开更多
A series of graphitic carbon nitride supported vanadium catalysts（xV/g-C3N4） with different vanadium contents（x/%） were prepared by impregnation.XRD,FT-IR,TEM,TG-DTG,nitrogen adsorption and XPS characterizations w...A series of graphitic carbon nitride supported vanadium catalysts（xV/g-C3N4） with different vanadium contents（x/%） were prepared by impregnation.XRD,FT-IR,TEM,TG-DTG,nitrogen adsorption and XPS characterizations were conducted which revealed a strong interaction between the vanadium species and g-C3N4 support.8V/g-C3N4 exhibited the highest activity and showed stable recyclability in the benzene hydroxylation reaction with a benzene conversion of 24.6%and phenol selectivity of 99.2%under the optimized conditions.The excellent catalytic performance of xV/g-C3N4 was due to the integration of vanadium species with high catalytic activity and the g-C3N4support in their interaction with the benzene substrate.展开更多
The contents of seven different phenolic acids such as gallic acid, catechinic acid, pyrocatechol, caffeic acid, coumaric acid, ferulic acid and benzoic acid in the poplar leaves （Populus Simonii×Populus Pyramib...The contents of seven different phenolic acids such as gallic acid, catechinic acid, pyrocatechol, caffeic acid, coumaric acid, ferulic acid and benzoic acid in the poplar leaves （Populus Simonii×Populus Pyramibalis c.v and Populus deltoids） suffocated by Methyl jasmonate （MeJA） and Methyl salicylate （MeSA） were monitored for analyzing their functions in interplant communications by using high-pressure liquid chromatography （HPLC）.The results showed that the contents of phenolic acids had obviously difference in leaves exposed to either MeSA or MeJA.When P.deltoides leaves exposed to MeJA or MeSA, the level of gallic acid, coumaric acid, caffeic acid, ferulic acid and benzoic acid was increased, gallic acid in leaves treated with MeJA comes to a peak at 24 h while to a peak at 12-d having leaves treated with MeSA.When P.Simonii ×P.Pyramibalis c.v leaves were exposed to MeJA or MeSA, the level of gallic acid, pyrocatechol and ferulic acid was increased; The catechinic acid and benzoic acid had a little drop; The caffeic acid and coumaric acid were undetected in both suffocated and control leaves.This changed pattern indicated that MeJA and MeSA can act as airborne signals to induce defense response of plants.展开更多
The purpose of this study is to develop an HPLC-UV (280 nm) method for simultaneous determination of phenol, five chlorophenols (2-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol, 2,6-dichlorophenol, and 2,4,6-trichl...The purpose of this study is to develop an HPLC-UV (280 nm) method for simultaneous determination of phenol, five chlorophenols (2-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol, 2,6-dichlorophenol, and 2,4,6-trichlorophenol), and three phenylphenols (2-phenylphenol, 3-phenylphenol, and 4-phenylphenol) in tap water after pre-column derivatization with 4-nitrobenzoyl chloride. Standard curves were obtained after derivatization with 4-nitrobenzoyl chloride in borate buffer (pH 8.5) at 50°C for 1 min. The nine 4-nitrobenzoyl derivatives were well separated in less than 15 min on a Cholester column. Calibration plots were linear in the range of 0.02 ~ 0.12 to 0.9 mg/L, with r2 values ≥0.9928, for all compounds. The lower limits of detection were 0.006 to 0.05 mg/L. The coefficients of variation were less than 12.0%. The recovery values from tap water spiked with a standard mixture of test compounds were satisfactory. While the levels of phenol, five chlorophenols, and three phenylphenols in tap water were below the lower limit of determination, our method is expected to be useful for monitoring and/or identifying environmental water samples that are contaminated with these compounds, i.e., for assessing compliance with the official guidelines of the World Health Organization.展开更多
文摘Chlorine content and position of chlorinated phenols have many significant effects on the reactivity of oxido-reduction. The effects of chlorine content and position of chlorinated phenols on their oxidation kinetics by potassium permanganate were evaluated through different kinetics studies. Since chlorine was an electron withdrawing atom, the substitution of chlorine on the aromatic ring decreased the oxidation rate constant by σ-electron withdrawing conductive effect. The substitution of chlorine at ortho or para position on the aromatic ring increased the oxidation rate constant by π-electron donating conjugative effect, and the conjugative effect could counteract the negative impact of the conductive effect to some extent. On the other hand, the substitution of chlorine at ortho position on the aromatic ring decreased the oxidation rate constant by steric hindrance effect. The oxidation rate constants of phenol and chlorinated phenols studied decreased as follow order: 4-chlorophenol>2,4-dichlorophenol>phenol>2,6-dichlorophenol.
基金supported by the National Key Research and Development Program of China(No.2023YFC3706602)the National Natural Science Foundation of China(Nos.22225605 and 22193051)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0750200).
文摘Synthetic phenolic antioxidants(SPAs)are widely used in diverse industries due to their exceptional antioxidant characteristics.However,human exposure to SPAs may cause health problems.In this study,226 dust samples were collected from 10 provinces in China,and six SPAs(three parent SPAs and their three transformation products)were analyzed.The concentrations of6SPAs(the sum of six target compounds)ranged from 15.4 to 3210 ng/g(geometric mean(GM):169 ng/g).The highest concentration of6SPAswas found in Sichuan Province(GM:349 ng/g),which was approximately 4 times higher than that in Hubei Province(81.6 ng/g)(p<0.05).The concentrations of butylated hydroxytoluene(BHT),2,2'-methylene bis(4-methyl-6–tert-butylphenol)(AO2246),2,6-di–tert–butyl–1,4-benzoquinone(BHT-Q),2,6-di–tert–butyl–4-(hydroxymethyl)phenol(BHT-OH),and ∑_(p)-SPAs were substantially higher in dust from urban areas than rural areas(p<0.05).AO2246 concentration in dust from homes(GM:0.400 ng/g)was about 4 times higher than that in workplaces(0.116 ng/g)(p<0.01).Significantly higherp-SPAs concentrations were found in dust from homes(GM:17.5 ng/g)than workplaces(11.4 ng/g)(p<0.01).The estimated daily intakes(EDIs)of ∑_(6)SPAs exposed through dust ingestion were 0.582,0.342,0.197,0.076,and 0.080 ng/kg bw/day in different age groups,and exposed through dermal contact was 0.358,0.252,0.174,0.167,and 0.177 ng/kg bw/day.EDIs showed that the exposure risks of SPAs decreased with age.This is the first work to determine SPAs in dust from10 provinces in China and investigate the spatial distribution of SPAs in those regions.
文摘Silica gel column chromatography(CC),Sephadex LH-20 CC and high performance liquid chromatography(HPLC)were used to study the chemical constituents of the fruits of the medicine-food plant Rubus idaeus Linnaeus.A new tetrahydrogenated naphthol syringic acid ester,named rubusnolicester(1),two new phenolic glycoside derivatives,4-chloro-2,6-dimethoxylphenol-1-O-β-D-glucopyranoside(2)and salicylic acid-2-O-(6'-O-acetyl)-β-D-glucopyranoside(3),together with one known salicylic acid glycoside derivative(4)and three known flavonoids derivatives(5~7),were isolated.Their structures were elucidated by HRESI-MS,NMR spectroscopy,and a comparison of optical rotation(OR).Compounds 1~7 were evaluated the inhibitory activities against the nitric oxide(NO)production induced by lipopolysaccharide(LPS)in mouse macrophage RAW264.7 cells in vitro.Compound 1 exhibited inhibitory effect with the IC50 value of(12.28±1.25)μmol/L.
文摘The technique for preparing phenol formaldehyde resin from phenolated wood (PWF) and its characters were studied and analyzed. Poplar (Populus spp.) wood meal was liquefied by phenol in the presence of sulfuric acid as a catalyst. After the liquefied products were cooled, alkaline catalyst and formaldehyde were added. The mixture was kept at (60?) C for 1h and then was heated to (85?) C for 1h. The influence of molar ratio of formaldehyde to phenol (F/P) was investigated. The results showed when the molar ratio of formaldehyde to phenol was over 1.8, the PWF adhesives had high bond quality, bond durability and extremely low aldehydes emissions.
基金supported by the National Natural Science Foundation of China(No.22206013).
文摘The efficient mineralization of phenol and its derivatives in wastewater remains a great challenge.In this study,the bimetallic CuCeO_(2)-BTC was screened from a series of MOFs-derived MCeO_(2)-BTC(M=La,Cu,Co,Fe,and Mn)catalysts,and the influence of the Cu/Ce ratio on phenol removal by catalytic ozonation was carefully examined.The results indicate that Cu_(2)Ce_(1)O_(y)-BTC was the best among the Cu_(x)Ce_(1)O_(y)-BTC(x=0,1,2,and 3)catalysts,with a phenol mineralization efficiency reaching close to 100%within 200 min,approximately 30.1%higher than CeO_(2)-BTC/O_(3)and 70.3%higher than O_(3)alone.The order of mineralization efficiency of phenol was Cu_(2)Ce_(1)O_(y)-BTC>Cu_(3)Ce_(1)O_(y)-BTC>Cu_(1)Ce_(1)O_(y)-BTC>CeO_(2)-BTC.CeO_(2)-BTC exhibited a broccoli-like morphology,and Cu_(x)Ce_(1)O_(y)-BTC(x=1,2,and 3)exhibited an urchin-like morphology.Compared with Cu_(x)Ce_(1)O_(y)-BTC(x=0,1,and 3),Cu_(2)Ce_(1)O_(y)-BTC exhibited a larger specific surface area and pore volume.This characteristic contributed to the availability of more active sites for phenol degradation.The redox ability was greatly enhanced as well.Besides,the surface of Cu_(2)Ce_(1)O_(y)-BTC exhibited a higher concentration of Ce^(3+)species and hydroxyl groups,which facilitated the dissociation of ozone and the generation of active radicals.Based on the results of radical quenching experiments and the intermediates detected by LC-MS,a potential mechanism for phenol degradation in the Cu_(2)Ce_(1)O_(y)-BTC/O_(3)system was postulated.This study offers novel perspectives on the advancement of MOFs-derived catalysts for achieving the complete mineralization of phenol in wastewater through catalytic ozonation.
基金supported by theUniversitasNegeri Semarang throughDPAUNNES 2024The grant number is No.271.26.2/UN37/PPK.10/2024.
文摘Bio-oil is a renewable fuel that can be obtained from biomass waste,such as empty palm fruit bunches,sugarcane bagasse,and rice husks.Within a biorefinery framework,bio-oil had not met the standards as a fuel due to the presence of impurities like corrosive phenol.Therefore,the separation of phenol from bio-oil is essential and can be achieved using the extraction method.In this study,biomass wastes(empty fruit bunches of oil palm,sugarcane bagasse,and rice husk)were pyrolyzed in a biorefinery framework to produce bio-oil,which was then refined through liquid-liquid extraction with a methanol-chloroform and ethyl acetate solvents to remove its phenolic compound.The extraction with methanol-chloroform solvent was carried out for 1 h at 50℃.Meanwhile,extraction with ethyl acetate solvent was carried out for 3 h at 70℃.Both extractions used the same variations,i.e.,bio-oil:solvent ratio at 1:1,1:2,1:3,and 1:4,and stirring speeds of 150 rpm,200 rpm,250 rpm,and 300 rpm.The bio-oil obtained from this study contained complex chemical compounds and had characteristics such as a pH of 5,a density of 1.116 g/mL,and a viscosity of 29.57 cSt.Theoptimization results using response surface methodology(RSM)showed that the best yield formethanolchloroform was 72.98%at a stirring speed of 250 rpm and a ratio of 1:3.As for ethyl acetate solvent,the highest yield obtained was 71.78%at a stirring speed of 237.145 rpm and a ratio of 1:2.
基金funded as a part of the institutional scientific project entitled“Treatment of seed and plantlets with wild plant-derived products”financed by Faculty of Agrobiotechnical Sciences Osijek.
文摘Phenolic compounds represent a broad and structurally diverse class of plant secondary metabolites with importance for both plant biology and human health.This review provides a comprehensive overview of their biosynthesis,chemical diversity,multifaceted functions in plants,roles in the wider ecosystem,and significance in human nutrition and biotechnology.Primarily synthesized via the phenylpropanoid pathway,these compounds encompass major classes such as lignin,flavonoids,and tannins.Within the plant,they perform critical functions including providing structural support(lignin),defending against biotic stresses(e.g.,pathogens,herbivores),mediating ecological interactions(pollination,symbiosis,allelopathy),and protecting against abiotic stresses likeUVradiation and oxidative damage.Phenolic compounds extend their influence beyond the plant itself by shaping soil ecosystems through rhizodeposition,where they interact with microbial communities and nutrient cycles.At the same time,they play a central role in the health benefits of plant-rich diets,with strong epidemiological evidence linking their regular consumption to a reduced risk of chronic diseases such as cardiovascular disease,cancer,and obesity.Thereviewfurther examines the significant variation of phenolic content in different food sources and explores the impact of processing methods,highlighting germination as a key strategy for enhancing the nutritional and bioactive value of cereals and legumes.Finally,the potential of phenolic compounds as a source for modern drugs and their targeted production through biotechnological approaches are discussed,underscoring their position as a cornerstone of phytochemical research with ongoing and future applications in health,agriculture,and industry.This paper employs a semi-systematic(or narrative)literature review methodology.A strategic search of key academic databases,including PubMed,Scopus,Web of Science,Google Scholar,was conducted to identify relevant literature and highly influential works.This review aims to synthesize the existing knowledge on phenolic compounds and to emphasize their undeniable impact on human health through an interdisciplinary approach.
基金This publication presents findings from research conducted under Project No.III-99-24.489Natural Growth Regulators in the Induction of Resistance of Cereal Plants to HeavyMetals(2024-2028)funded by the NationalAcademy of Sciences of Ukraine.
文摘Prolonged lack of rain and high-temperature lead to soil water deficits,inhibiting cereal crop growth in early ontogenesis and reducing grain quality and yield.Rye(Secale cereale L.)is a key grain crop,particularly in regions where wheat cultivation is challenging or unfeasible.To clarify its drought adaptation mechanisms,we analyzed the effects of moderate soil drought on growth,hormonal homeostasis,and the dynamics and distribution of free amino acids and phenolic compounds in rye at early vegetative stages and post-recovery.Drought triggered both general and organ-specific changes in endogenous phytohormones.A nonspecific response involved the accumulation of stress hormones abscisic acid(ABA)and salicylic acid(SA),alongside the suppression of growth hormones indole-3-acetic acid(IAA)and gibberellins.However,hormone dynamics and localization varied across plant organs.ABA and SA levels significantly increased in shoots of drought-stressed and recovered plants,corresponding with inhibited growth.Prolonged drought further enhanced ABA accumulation in both shoots and roots of recovered plants,while SA levels declined in roots but remained elevated in shoots.Drought also caused a substantial reduction in IAA,particularly in shoots,while gibberellins(GA_(3)+GA_(4))significantly decreased in roots.GA_(3)was predominant in most samples,except in the shoots of 2-day-old control plants.Post-recovery,IAA levels increased but remained below control values,while GA_(4)accumulation in roots led to a rise in total gibberellin levels.In contrast,shoot GA_(3)+GA_(4)levels declined,primarily due to GA_(3)reduction.The dominant free amino acids:aspartic acid,glutamic acid,glycine,alanine,and leucinedecreased significantly,underscoring their key role in stress adaptation.Increased flavonoid accumulation,especially in roots,suggests their involvement in antioxidant defense against oxidative stress.A significant increase in ABA and SA levels,along with a marked reduction in IAA and GA content in stressed rye plants occurred alongside a reduction in free amino acid content,accumulation of phenolic compounds,and an increase in flavonoid levels.These findings indicate distinct adaptation strategies in rye shoots and roots undermoderate soil drought.They provide a foundation for further research on drought resistance mechanisms in cereals and the development of strategies to enhance their adaptive potential.
基金funded by National Natural Science Foundation of China(22278023,22208010)S&T Program of Hebei(24464301D)SINOPEC Group(24-ZS-0447).
文摘Phenol is extensively utilized in various industries involving paints,rubber,textiles,explosives,plastics,etc.Compared to the conventional distillation or extraction technologies,pervaporation(PV)membrane process can be operated at a low temperature and has a low energy consumption as well as a high separation efficiency for phenol recovery.Thus,to meet the high demand for phenol recovery,the application of PV has been encouraged,and reached a new level.The PV process is governed by the properties of the membrane materials that significantly influence the energy costs associated with the separation unit,and the membrane types include polymer membranes,inorganic membranes,and mixed matrix membranes.Although recent literatures show that PV membranes have been continuously updated,no review has reported the latest development about it.In this work,the material types,separation properties and preparation methods of hydrophobic PV membranes for phenol recovery are summarized.Furthermore,the key preparation methods and application challenges associated with membranes are summarized,along with an overview of the opportunities and challenges posed by hydrophobic PV membranes for phenol recovery.
基金financially supported by grants from the National Natural Science Foundation of China(Grant No.81503180)the Opening Project of Zhejiang Provincial Key Laboratory of Resources Protection and Innovation of Traditional Chinese Medicine(Grant No.2021E10013)+1 种基金the Opening Project of NMPA Key Laboratory for Quality Research and Evaluation of Traditional Chinese Medicine(Grant No.AHYJ-KFKT-202101)the Earmarked fund for Jiangsu Agricultural Industry Technology System(Grant No.JATS[2022]460)。
文摘Chrysanthemum morifolium Ramat.is an important industrial crop with a high medicinal value,whose capitulum consists of ray and disc florets containing numerous bioactive components,such as flavonoids and phenolic acids.However,the distribution and accumulations of the bioactive metabolites in florets of Chrysanthemum morifolium were unclear.Herein,the ray and disc florets of Chrysanthemum morifolium were separated for comparing the bioactive metabolites.The contents of phenolic compounds and antioxidant activities were significantly different between the two florets.The metabolomic analysis identified 203 and 241 differential metabolites between ray and disc florets at two flowering stages.The derivatives of quercetin,isorhamnetin,tricin,and caffeoylquinic acid were enriched in the disc florets,while apigenin,kaempferol,acacetin,and their glycosides mainly accumulated in the ray florets.Besides,the results of transcriptome and qRT-PCR suggested that the F3H,F3'H,and FLS genes highly expressed in disc florets,while the FNS gene was well expressed in ray florets,which explained the different distribution of phenolic compounds between ray and disc florets.Furthermore,the expression of CmCYC2 genes was found to be significantly related to the distribution of flavones by correlation analysis.It was proved by the luciferase reporter assay that CmCYC2a and CmCYC2d factors could bind and activate the CmFNS promoter to regulate the flavones biosynthesis in ray florets.These results revealed the significant difference of metabolite contents and gene expression profile between ray and disc floret in Chrysanthemum morifolium and demonstrated that the quality of Chrysanthemum morifolium‘Hangju'was closely relevant to its flower morphology.
基金Funded by the National Natural Science Foundation of China(Nos.52171045,52162013,and 51932006)。
文摘The surface of MoSi2-SiB6/phenolic resin matrix composites was modified by mica,and the thermal oxidation behavior of the composites and the mechanical properties of the pyrolysis products were studied.The results showed that the mica improved the thermal properties of the composites,the thermal expansion coefficient decreased,and the liquid phase formation caused the composites to shrink and increase the density.The flexural strength of mica surface modified composites not only increased to 78.64MPa after thermal treatment at 800-1200℃,but reached 83.02 MPa after high temperature treatment at1400℃.The improvement of the mechanical properties of the residual product benefits from the formation of high temperature ceramic phases such as Mo_(2)C and MoB,and the improvement of the shear strength of the composites by the mica.The shear strength of MBm5-2 at room temperature reached 33.08 MPa,indicating that the improvement of the interlayer properties of the composites further improved its mechanical properties.
基金supported by Major Project of Science and Technology Department of Yunnan Province(202002AA100005,202102AE090027-2)National Natural Science Foundation of China(82260703)+1 种基金Cassava Industrial Technology System of China(CARS11-YNTY)Yunnan Province Ten Thousand Plan Industrial Technology Talents Project(YNWR-CYJS-2020-010)。
文摘Moringa oleifera Lam.is a Moringa genus in the Moringaceae family that is high in nutrients and has a wide range of applications.Phenolic compounds are widely found in plants and have various health benefits for the human body.With its high content and wide variety of phenolic compounds,M.oleifera Lam.has been widely studied for its health benefits.The phenolic compounds in M.oleifera Lam.(MOPCs)can be a potential source of functional food ingredients in pharmaceutical and industrial applications.Numerous studies have shown that MOPCs have antioxidant,anti-obesity,anti-diabetic,and antibacterial effects.Although the research on MOPCs has been gradually increasing,the extraction,isolation,identification,biological activities,and comprehensive application of MOPCs need a more systematic summary and generalization.Therefore,this paper reviews the isolation and extraction methods,structure identification,biological activities,and comprehensive applications to provide a further reference for the research and application of MOPCs.
基金supported by the National Natural Science Foundation of China(Grant Nos.U2241240,12172045,and 12221002).
文摘In thermal protection structures,controlling and optimizing the surface roughness of carbon/phenolic(C/Ph)composites can effectively improve thermal protection performance and ensure the safe operation of carriers in high-temperature environments.This paper introduces a machine learning(ML)framework to forecast the surface roughness of carbon-phenolic composites under various thermal conditions by employing an ML algorithm derived from historical experimental datasets.Firstly,ablation experiments and collection of surface roughness height data of C/Ph composites under different thermal environments were conducted in an electric arc wind tunnel.Then,an ML model based on Ridge regression is developed for surface roughness prediction.The model involves incorporating feature engineering to choose the most concise and pertinent features,as well as developing an ML model.The ML model considers thermal environment parameters and feature screened by feature engineering as inputs,and predicts the surface height as the output.The results demonstrate that the suggested ML framework effectively anticipates the surface shape and associated surface roughness parameters in various heat flow conditions.Compared with the conventional 3D confocal microscope scanning,the method can obtain the surface topography information of the same area in a much shorter time,thus significantly saving time and cost.
基金Supported by General Program of Natural Science Foundation of Sichuan Province(2024NSFSC0706)Program of Sichuan Administration of Traditional Chinese Medicine(25MSZX326)+1 种基金Research Initiation Fund for High-level Talents of Sichuan College of Traditional Chinese Medicine(24ZRBS05)School-level Project of Sichuan College of Traditional Chinese Medicine(24SD02).
文摘[Objectives]To investigate the anti-tumor molecular mechanism of acetylenic phenols against triple-negative breast cancer(TNBC)using network pharmacology and molecular docking approaches.[Methods]Based on team s previous in vitro activity screening,the most active acetylenic phenols were selected for further analysis.Genes associated with triple-negative breast cancer(TNBC)were retrieved from the GAD and OMIM databases.Using Cytoscape software,a compound-target-pathway interaction network was constructed to visualize the relationships between the acetylenic phenols,their potential targets,and related pathways.Functional enrichment analysis of GO terms and KEGG pathways was performed using the DAVID database to identify key signaling mechanisms.Furthermore,molecular docking was conducted to evaluate the binding interactions between the acetylenic phenols and the potential core targets.[Results]Acetylenic phenols exhibit potential anticancer effects by modulating multiple signaling pathways,including the PI3K-Akt pathway,cell cycle pathway,and breast cancer pathway,which are closely associated with the pathophysiological processes of triple-negative breast cancer(TNBC)such as cell proliferation,apoptosis,and cell cycle regulation.Molecular docking results indicated that acetylenic phenols bind effectively to their targets via hydrogen bonding,hydrophobic interactions,andπ-stacking,indicating strong binding affinity.[Conclusions]Acetylenic phenols exert anti-TNBC effects by modulating key targets,including EGFR,RAF1,ESR1,CHEK1,and CDC25C,and influencing associated signaling pathways.These findings reveal the molecular mechanism underlying their anti-TNBC activity and provide a theoretical foundation for the potential application of acetylenic phenols in TNBC treatment.
基金the project PID2023-150695NB-I00,funded by MCIU/AEI/10.13039/501100011033/FEDER,UEAdditional funding from the Agencia de Desarrollo Economico de La Rioja(ADER,Government of La Rioja)through the Project S-UV-STAINABLE Rioja(2022-I-IDI-00064)is also acknowledged.
文摘Grapevine(Vitis vinifera L.)is one of the main crops worldwide,and ultraviolet-B(UV-B,280-315 nm)radiation is emerging as a promising technical tool to enhance secondary metabolites that can contribute to the quality and health-promoting properties of both grapes and the resulting wines.However,few studies have assessed the effectiveness of UV-B supplements under field conditions.Here,we compared the effects of two different field UV-B treatments(a single supplement applied at pre-harvest,and a double supplement applied at both veraison and pre-harvest)on the phenolic composition of Tempranillo grape skins and the resulting wines.The double supplement induced stronger changes than the single supplement,with responses being more pronounced in grape skins than in wines.In skins,UV-B supplements significantly increased flavonols,phenolic acids,and flavanols,consistent with previous reports highlighting flavonols as the most reliable UV-B-responsive compounds in grape skins.In wines,the clearest responses were increases in anthocyanins and color intensity.Overall,UV-B supplements improved grape and wine quality,although skin responses were only partially transmitted to the wines.Moreover,wine responses were more unpredictable than skin responses,likely reflecting not only the UV-B-induced changes in grape skins but also the complex chemical interactions among phenolic compounds(and also with other metabolites)during vinification.Further experimentation,particularly in the long term,is required to optimize the application of UV-B supplements as a viticultural and enological practice.
基金supported by the National Natural Science Foundation of China(No.51872232)the Key Scientific and Technological Innovation Research Team of Shaanxi Province(No.2022TD-31)the Key R&D Program of Shaanxi Province(No.2021ZDLGY14-04).
文摘Carbon fiber/phenolic resin composites have great potential application in the field of electronic information,where excellent structural-functional integration is required.In this work,the establishment of interfacial structures consisting of carbon nanotubes with different morphologies at the fiber/matrix interface is conducive to the further modulation of the mechanical,tribological,electromagnetic interference(EMI)shielding and thermal conductivity properties of carbon fiber/phenolic resin composites.Specially,array carbon nanotubes can deep into the resin matrix,effectively hindering crack extension,and constructing an electrically and thermally conductive network.Compared with the carbon fiber/phenolic composites,the tensile strength and modulus of elasticity(163.86±9.60 MPa,5.06±0.25 GPa)of the array carbon nanotubes reinforced carbon fiber/phenolic composites were enhanced by 57.09%and 22.22%.The average friction coefficient and wear rate(0.20±0.02,1.11×10^(-13)±0.13×10^(-13)m^(3)N^(−1)m^(−1))were reduced by 39.39%and 74.31%.EMI shielding effectiveness up to 40 dB in the X-band at 0.4 mm sample thickness,diffusion coefficient(0.39±0.003 mm^(2)/s)and thermal conductivity(0.54±0.004 W/(m K))were enhanced by up to 14.37%and 50.42%.This study reveals the beneficial effects of morphological changes of carbon nanotubes on the design of interfacial structure,proposes the reinforcement mechanism of array carbon nanotubes,and opens up the prospect of carbon fiber/phenolic composites for electronic applications.
基金Funded by by the Wuhan Science and Technology Project(No.2024010702030141)。
文摘A Ti_(3)SiC_(2)-modified high-silica oxygen/phenolic aerogel composite with excellent oxidation resistance and high-temperature performance was prepared.The experimental results show that the obtained composite has significantly improved oxidation resistance.When the addition amount of Ti_(3)SiC_(2)is 75%,the carbonization volume shrinkage rate of the composite after aerobic static combustion is only 5.95%.At the same time,the LAR and MAR after 30 seconds of oxyacetylene ablation under a heat flux density of 1.5 MW/m2 are 0.0307 mm/s and 0.0149 g/s,respectively.The compressive strength after aerobic static combustion at 1000℃is up to 20.43%of that before aerobic static combustion,which is 1.99 times that of the unfilled material,significantly improving the high-temperature mechanical properties of the composite.
基金supported by the National Natural Science Foundation of China(21371035,21473036)SINOPEC(X514005)
文摘A series of graphitic carbon nitride supported vanadium catalysts（xV/g-C3N4） with different vanadium contents（x/%） were prepared by impregnation.XRD,FT-IR,TEM,TG-DTG,nitrogen adsorption and XPS characterizations were conducted which revealed a strong interaction between the vanadium species and g-C3N4 support.8V/g-C3N4 exhibited the highest activity and showed stable recyclability in the benzene hydroxylation reaction with a benzene conversion of 24.6%and phenol selectivity of 99.2%under the optimized conditions.The excellent catalytic performance of xV/g-C3N4 was due to the integration of vanadium species with high catalytic activity and the g-C3N4support in their interaction with the benzene substrate.
基金This research is supported by National Natural Science Foundation of China (No.30170764)
文摘The contents of seven different phenolic acids such as gallic acid, catechinic acid, pyrocatechol, caffeic acid, coumaric acid, ferulic acid and benzoic acid in the poplar leaves （Populus Simonii×Populus Pyramibalis c.v and Populus deltoids） suffocated by Methyl jasmonate （MeJA） and Methyl salicylate （MeSA） were monitored for analyzing their functions in interplant communications by using high-pressure liquid chromatography （HPLC）.The results showed that the contents of phenolic acids had obviously difference in leaves exposed to either MeSA or MeJA.When P.deltoides leaves exposed to MeJA or MeSA, the level of gallic acid, coumaric acid, caffeic acid, ferulic acid and benzoic acid was increased, gallic acid in leaves treated with MeJA comes to a peak at 24 h while to a peak at 12-d having leaves treated with MeSA.When P.Simonii ×P.Pyramibalis c.v leaves were exposed to MeJA or MeSA, the level of gallic acid, pyrocatechol and ferulic acid was increased; The catechinic acid and benzoic acid had a little drop; The caffeic acid and coumaric acid were undetected in both suffocated and control leaves.This changed pattern indicated that MeJA and MeSA can act as airborne signals to induce defense response of plants.
文摘The purpose of this study is to develop an HPLC-UV (280 nm) method for simultaneous determination of phenol, five chlorophenols (2-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol, 2,6-dichlorophenol, and 2,4,6-trichlorophenol), and three phenylphenols (2-phenylphenol, 3-phenylphenol, and 4-phenylphenol) in tap water after pre-column derivatization with 4-nitrobenzoyl chloride. Standard curves were obtained after derivatization with 4-nitrobenzoyl chloride in borate buffer (pH 8.5) at 50°C for 1 min. The nine 4-nitrobenzoyl derivatives were well separated in less than 15 min on a Cholester column. Calibration plots were linear in the range of 0.02 ~ 0.12 to 0.9 mg/L, with r2 values ≥0.9928, for all compounds. The lower limits of detection were 0.006 to 0.05 mg/L. The coefficients of variation were less than 12.0%. The recovery values from tap water spiked with a standard mixture of test compounds were satisfactory. While the levels of phenol, five chlorophenols, and three phenylphenols in tap water were below the lower limit of determination, our method is expected to be useful for monitoring and/or identifying environmental water samples that are contaminated with these compounds, i.e., for assessing compliance with the official guidelines of the World Health Organization.
