A new gold self-relay catalytic annulation/nucleophilic substitution cascade of 1,3-enyne acetates with cyclic ether acetals is reported,enabling highly diastereoselective access to cyclic etherified cyclopentenones w...A new gold self-relay catalytic annulation/nucleophilic substitution cascade of 1,3-enyne acetates with cyclic ether acetals is reported,enabling highly diastereoselective access to cyclic etherified cyclopentenones with cyclic quaternary centers in moderate to good yields and>19∶1 dr.This catalysis enables the direct construction of two types of carboncyclic skeletons by adjusting the olefin types of 1,3-enyne acetates.When 1,3-enyne acetates bearing a cyclic alkene unit were used,5~6 fused bicarbocyclic products were diastereoselectively synthesized,whereas the reaction of acyclic 1,3-enyne acetates resulted in five-memebered carbocyclic framework.Notably,cyclic ether acetals are commonly used as protecting groups in traditional multistep organic syntheses,and in this reaction,such reagents serve as electrophilic cyclic ether precursors,achieving new uses for old reagents.The current method demonstrates good functional group compatibility,a broad substrate scope and high diastereoselectivity,providing a new synthetic strategy toward functionalized cyclopentenones.展开更多
LiNi0.8Co0.1Mn0.1O2 cathode was synthesized using transition metal acetates under different synthesis conditions. Simultaneous thermogravimetric–differential scanning calorimetry–derivative thermogravimetric analysi...LiNi0.8Co0.1Mn0.1O2 cathode was synthesized using transition metal acetates under different synthesis conditions. Simultaneous thermogravimetric–differential scanning calorimetry–derivative thermogravimetric analysis was applied to investigating the mixture of transition metal acetates. X-ray powder diffraction and charge–discharge test were adopted to characterize the as-prepared LiNi0.8Co0.1Mn0.1O2. The mixture of transition metal acetates undergoes dehydration and decomposition during heating. All the examined LiNi0.8Co0.1Mn0.1O2 samples have a layered structure with R3 m space group. LiNi0.8Co0.1Mn0.1O2 samples prepared with different lithium sources under different synthesis conditions exhibit very different charge–discharge performances. The sample synthesized via the procedure of sintering at 800 °C after heating lithium carbonate and transition metal acetates at 550 °C achieves a highest capacity of 200.8 m A·h/g and an average capacity of 188.1 mA ·h/g in the first 20 cycles at 0.2C.展开更多
The logarithms of retention factors normalized to a hypothetical pure water eluent(log k w) were determined on a reversed phase high performance liquid chromatography(RP HPLC) column (Li Chrosorb RP 18 column...The logarithms of retention factors normalized to a hypothetical pure water eluent(log k w) were determined on a reversed phase high performance liquid chromatography(RP HPLC) column (Li Chrosorb RP 18 column) for 20 new α\|branched phenylsulfonyl acetates. The atomic charge method was applied to develop quantitative structure retention relationships(QSRRs). Among the available geometric and electronic descriptors, surface area (S), ovality (O), and the charge of carboxyl group(Q OC ) are significant. In the model, the contribution of surface area (S) is the greatest. The molecular mechanism of retention was demonstrated through the model. With the correlation coefficient ( r 2 adj , adjusted for degrees of freedom) of 0.964, the standard error of 0.164 and the F value of 170.39, the model has good predictive capacity.展开更多
Semicarbazones, 1,1-diacetates and acetals are efficiently converted to their corresponding carbonyl compounds using synergistic effect between KBrO3 and MoO3 in refluxing CH3CN-H2O in good to high yields.
A method for locating double bond in hexadecenyl acetates has been developed by analyzing the mass spectral patterns on a fuzzy classification. The procedure was tested with the spectra of Δ~2- to Δ^(15)-isomers and...A method for locating double bond in hexadecenyl acetates has been developed by analyzing the mass spectral patterns on a fuzzy classification. The procedure was tested with the spectra of Δ~2- to Δ^(15)-isomers and the original double-bond position in these acetates was located unambiguously.展开更多
A mild and efficient method for diacetylation reaction was developed,by which diacetate could be achieved through the reaction of aldehyde with acetic anhydride,in the presence of cobalt sulfate,with an admirable yiel...A mild and efficient method for diacetylation reaction was developed,by which diacetate could be achieved through the reaction of aldehyde with acetic anhydride,in the presence of cobalt sulfate,with an admirable yield,at room temperature,without solvent.The catalyst could be recycled six times without a distinct loss of activity.展开更多
Before proposing an innovative process for the coproduction of ethyl and butyl acetates, the individual syntheses of ethyl acetate and butyl acetate by two different routes were first studied. These syntheses involved...Before proposing an innovative process for the coproduction of ethyl and butyl acetates, the individual syntheses of ethyl acetate and butyl acetate by two different routes were first studied. These syntheses involved the reaction of ethanol or n-butanol with acetic acid or acetic anhydride in the presence of ion exchange resins: Amberlyst 15, Amberlyst 16, Amberlyst 36 and Dowex 50WX8. Kinetic and thermodynamic studies were performed with all resins. The lowest activation energy (Ea) value was obtained with Dowex 50WX8, which was identified as the best-performing resin, able to be reused at least in four runs without regeneration. The presence of water-azeotropes during the synthesis of ethyl acetate makes its purification difficult. A new strategy was adopted here, involving the use of ethanol and acetic anhydride as the starting material. In order to minimize acetic acid as co-product of this reaction, a novel two-step process for the coproduction of ethyl and butyl acetates was developed. The first step involves the production of ethyl acetate and its purification. Butyl acetate was produced in the second step: n-butanol was added to the mixture of acetic acid and the resin remaining after the first-step distillation. This process yields ethyl acetate and butyl acetate at high purity and shows an environmental benefit over the independent syntheses by green metrics calculation and life cycle assessment.展开更多
High-performance MXene-based polymer nanocomposites are well-suited for various industrial applications owing to their excellent mechanical,thermal,and other properties.However,the fabrication of flame-retardant polym...High-performance MXene-based polymer nanocomposites are well-suited for various industrial applications owing to their excellent mechanical,thermal,and other properties.However,the fabrication of flame-retardant polymer/MXene nanocom-posites remains challenging owing to the limited flame-retardant properties of MXene itself.This study prepared a novel MXene@Ag@PA hybrid material via radiation modification and complexation reaction.This material was used to further enhance the key properties of ethylene-vinyl acetate(EVA),such as its mechanical properties,thermal conductivity,flame retardancy,and electromagnetic shielding.The addition of two parts of this hybrid material increased the thermal conduc-tivity of EVA by 44.2%and reduced its peak exothermic rate during combustion by 30.1%compared with pure EVA.The material also significantly reduced smoke production and increased the residue content.In the X-band,the electromagnetic shielding effectiveness of the EVA composites reached 20 dB.Moreover,the MXene@Ag@PA hybrid material could be used to further enhance the mechanical properties of EVA composites under electron-beam irradiation.Thus,this study contributes to the development of MXene-based EVA advanced materials that are fire-safe,have high strength,and exhibit good electromagnetic shielding performance for various applications.展开更多
Developing favorable bio-based polymers that replace petroleum-based plastics is an essential environmental demand.Lignin is a by-product of the chemical pulping industry.It is a natural UV protection ingredient in br...Developing favorable bio-based polymers that replace petroleum-based plastics is an essential environmental demand.Lignin is a by-product of the chemical pulping industry.It is a natural UV protection ingredient in broad-spectrum(UVA and UVB)sunscreens.It could be partially and selectively acetylated in a simple,fast,and more reliable process.In this work,a composite film was prepared with UV-resistant properties through a casting method.Bio-based cellulose acetate(CA)was employed as a major matrix while nano-acetylated kraft lignin(AL-NPs)was used as filler during synthesizing UV-shielding films loaded with various amounts(1–5 wt.%)of AL-NPs.Kraft lignin was acetylated through a simple and fast microwave-assisted process using acetic acid as a solvent and acetylating agent.The physicochemical and morphological characteristics of the prepared films were evaluated using different methods,including scanning electron microscopy(SEM),Fourier Transform Infrared Spectroscopy(FTIR),X-ray diffraction analysis(XRD),mechanical testing and contact angle measurement.The UV-Vis spectroscopy optical investigation of the prepared films revealed that AL-NPs in the CA matrix showed strong UV absorption.This feature demonstrated the effectiveness of our research in developing UV-resistant bio-based polymer films.Hence,the prepared films can be considered as successful candidates to be applied in packaging applications.展开更多
Formic and acetic acids are the most abundant gaseous organic acids and play the key role in the atmospheric chemistry.In iodine-adduct chemical ionizationmass spectrometry(CIMS),the low utilization efficiency of meth...Formic and acetic acids are the most abundant gaseous organic acids and play the key role in the atmospheric chemistry.In iodine-adduct chemical ionizationmass spectrometry(CIMS),the low utilization efficiency of methyl iodide and humidity interference are two major issues of the vacuum ultraviolet(VUV)lamp initiated CIMS for on-line gaseous formic and acetic acids analysis.In this work,we present a new CIMS based on VUV lamp,and the ion-molecular reactor is separated into photoionization and chemical ionization zones by a reducer electrode.Acetone was added to the photoionization zone,and the VUV photoionization acetone provided low-energy electrons for methyl iodide to generate I−,and the addition of acetone reduced the amount of methyl iodide by 2/3.In the chemical ionization zone,a headspace vial containing ultrapure water was added for humidity calibration,and the vial changes the sensitivity as a function of humidity from ambiguity to well linear correlation(R2>0.95).With humidity calibration,the CIMS can quantitatively measure formic and acetic acids in the humidity range of 0%-88%RH.In this mode,limits of detection of 10 and 50 pptv are obtained for formic and acetic acids,respectively.And the relative standard deviation(RSD)of quantitation stability for 6 days were less than 10.5%.This CIMS was successfully used to determine the formic and acetic acids in the underground parking and ambient environment of the Shandong University campus(Qingdao,China).In addition,we developed a simple model based formic acid concentration to assess vehicular emissions.展开更多
The neurotransmitter 5-hydroxytryptamine(5-HT),primarily produced by intestinal enterochromaffin(EC)cells,relies on tryptophan hydroxylase 1(TPH1)for synthesis.Research suggested Bifidobacterium breve CCFM1025’s pote...The neurotransmitter 5-hydroxytryptamine(5-HT),primarily produced by intestinal enterochromaffin(EC)cells,relies on tryptophan hydroxylase 1(TPH1)for synthesis.Research suggested Bifidobacterium breve CCFM1025’s potential in regulating Tph1 gene expression,maintaining 5-HT levels in stressed mice,but its precise mechanisms were unclear.This study used metabolomic techniques to assess probiotic fermentation products,revealing acetate as the crucial element in Bb-CCFM1025’s regulation of gut 5-HT synthesis.Further exploration correlated acetate with Tph1 transcription in intestinal organoids.Transcriptomic methods and quantitative reverse transcription polymerase chain reaction validation demonstrated how acetate facilitated 5-HT synthesis and secretion.It unveiled that acetate orchestrates signaling pathways(phosphoinositide 3-kinase-protein kinase B(PI3K-AKT),phospholipase C-phosphorylated extracellular signal-regulated kinase(PLC-pERK),and PLC-1,4,5-trisphosphate(IP3)-Ca^(2+))within EC,enabling 5-HT production.These findings elucidate the biochemical mechanisms behind specific probiotics’effects,aiding in the targeted selection of similar beneficial strains.This study offers theoretical support for choosing probiotics with analogous functionalities based on their physiological impacts.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
Biodegradable plastics are types of plastics that can decompose into water and carbon dioxide the actions of living organisms,mostly by bacteria.Generally,biodegradable plastics are obtained from renewable raw materia...Biodegradable plastics are types of plastics that can decompose into water and carbon dioxide the actions of living organisms,mostly by bacteria.Generally,biodegradable plastics are obtained from renewable raw materials,microorganisms,petrochemicals,or a combination of all three.This study aims to develop an innovative bioplastic by combining chitosan and lignin.Bioplastic was prepared by casting method and characterized by measuring the mechanical properties like tensile strength,Young’smodulus,and elongation at break.The chemical structure,together with the interactions among chitosan and lignin and the presence of new chemical bonds,were evaluated by FTIR,while the thermal properties were assessed by thermogravimetric analysis.The water vapor permeability,tests and transparency as well as biodegradability,were also carried out.The results show a tensile strength value of 34.82 MPa,Young’s modulus of 18.54 MPa,and elongation at a break of 2.74%.Moreover,the interaction between chitosan and lignin affects the intensity of the absorption peak,leading to reduced transparency and increased thermal stability.The chitosan/lignin interactions also influence the crystalline size,making it easier to degrade andmore flexible rather than rigid.The contact angle shows the bioplastic’s ability to resist water absorption for 4minutes.In the biodegradation test,the sample began to degrade after 30 days of soil burial test observation.展开更多
The aim of this study is to isolate and identify the chemical compounds in ethanol extract of Cyclocarya paliurus.Some purification and analysis techniques like silica gel,D101-macroporous adsorptive resins,and Sephad...The aim of this study is to isolate and identify the chemical compounds in ethanol extract of Cyclocarya paliurus.Some purification and analysis techniques like silica gel,D101-macroporous adsorptive resins,and Sephadex LH-20 column chromatographies as well as high-performance liquid chromatography were used to isolate and analyze the compounds from ethanol extract of Cyclocarya paliurus.The structures of these constituents were identified by spectroscopic techniques such as nuclear magnetic resonance and high-resolution mass spectrometries.Twenty-eight compounds,including flavonoids and their glycoside,carbohydrate,coumarin and organic acid,were isolated from ethyl acetate and n-butanol fractions in ethanol extract of Cyclocarya paliurus,and they were identified as kaempferol(1),coumestrol(2),kaempferol 3-O-β-D-glucoside(3),methyl caffeoylquinic acid(4),coptichic aldehyde(5),schizandriside(6),kaempferol 3-O-α-L-rhamnoside(7),3-caffeoylquinic acid ethyl ester(8),quercetin(9),luteolin(10),protocatechuic acid(11),kaempferol-3-O-α-L-furan arabinose(12),trans-p-hydroxy-cinnamic acid(13),α-D-glucopyranosido-β-D-fructofuranoside,sucrose(14),peucedanol(15),chlorogenic acid(16),pyridoxine(17),quercetin-3-O-β-D-glucuronide(18),kaempferol-3-O-β-D-glucuronide(19),isoquercitrin(20),mururin A(21),citroside A(22),benzyl-6-O-α-L-arabinofuranosyl-β-D-glucopyranoside(23),(+)-(6S,9R)-9-O-β-D-glucopyranosyl-6-hydroxy-3-O-α-ionol(24),myricetin-3-O-β-D-glucopyranoside(25),(4R)-4-(3-Oxo-1-buten-1-ylidene)-3α,5,5-trimethylcyclohexane-1α,3β-diol(26),quercetin-3-O-α-L-rhamnopyranosyl(27)and 3,5-O-dicaffeoylquinic acid(28).Compounds 2,5,6,15,21,22,23,24,26 and 28 were isolated from Cyclocarya paliurus for the first time.展开更多
Gastrointestinal tract toxicity represents a serious adverse effect of chemotherapy,leading to reduced quality of life and survival.For instance,irinotecan(CPT-11)usually causes severe gastrointestinal toxicity,with a...Gastrointestinal tract toxicity represents a serious adverse effect of chemotherapy,leading to reduced quality of life and survival.For instance,irinotecan(CPT-11)usually causes severe gastrointestinal toxicity,with a lack of effective therapeutic interventions,making treatment often unsustainable.Therefore,development of an effective and safe therapy is crucial for improving chemotherapy efficacy and the patients’quality of life.In this work,we developed a novel approach involving the helical-shaped cyanobacterium microalgae,Spirulina platensis(SP),to carry the bornyl acetate(BA)-loaded chitosan nanoparticles to enhance drug retention in the small intestine.We demonstrated the protection effect of BA against chemotherapy-induced intestinal injury using an epithelial cell model.In a mouse model,orally administered BA-ChNPs@SP accumulated in the small intestine and attenuated inflammation by reducing dsDNA release and oxidative stress.This was concomitant with the restoration of the intestinal barrier and modulation of the immune microenvironment.This work suggests the promise of the microalgae-carrying nanomedicine strategy for treatment of intestinal diseases,emphasizing its potential in addressing chemotherapy-induced gastrointestinal complications.展开更多
Carbon-based low-dimensional materials(CLDM)with elemental carbon as the main component have unique physical and chemical properties,and become the focus of research in many fields including energy,environmental prote...Carbon-based low-dimensional materials(CLDM)with elemental carbon as the main component have unique physical and chemical properties,and become the focus of research in many fields including energy,environmental protection,and information technology.Notably,cellulose acetate,the main component of cigarette butts(CBs),is a one-dimensional precursor with a large specific surface area and aspect ratio.Still,their usefulness as building fillers has often been underestimated before.This review summarizes recent advances in CBs recycling and provides suggested guidelines for its use as a CLDM material in renewable energy.Specifically,we first describe the harmful effects of CBs as pollutants in our lives to emphasize the importance of proper recycling.We then summarize previous methods of recycling CBs waste,including clay bricks,asphalt concrete pavement,gypsum,acoustic materials,chemisorption,vector control,and corrosion control.The potential applications of CBs include triboelectric nanogenerator applications,flexible batteries,enhanced metal-organic framework material energy storage devices,and carbon-based hydrogen storage.Finally,the advantages of utilizing CBs-derived CLDM materials over conventional solutions in the energy field are discussed.This review will provide new avenues for solving the intractable problem of CBs and reducing the manufacturing costs of renewable materials.展开更多
Agricultural waste is a potentially interesting resource due to the compounds present.In this study,cellulose was extracted from corn stalks(Zea mays)and subsequently converted into cellulose acetate(CA).Before the ex...Agricultural waste is a potentially interesting resource due to the compounds present.In this study,cellulose was extracted from corn stalks(Zea mays)and subsequently converted into cellulose acetate(CA).Before the extraction process,the waste sample was characterized by pH,moisture,ash,protein content,total reducing sugars(TRS),carbohydrates,cellulose,hemicellulose,and lignin.Acid and alkaline hydrolysis were performed with different reagents,concentrations,and extraction times.Sulfuric acid(H_(2)SO_(4))and acetic acid(CH_(3)COOH)were used in the acid hydrolysis,while sodium hydroxide(NaOH)was used in the alkaline hydrolysis.Three concentrations(0.62,1.25,2.5)%and two reaction times(60,120)min were established.An ANOVA was performed on the hydrolysis results to determine the existence of significant differences.The extracted cellulose was revalued by acetylation,and finally,the CA was characterized by Fourier Transform Infrared Spectroscopy(FT-IR)spectroscopy.The highest cellulose extraction yield was obtained by alkaline hydrolysis,with an extraction time of 120 min and a yield of 65%.The statistical analysis indicated that the reagent used,its concentration,reaction time,and their interaction significantly affect the process yield.After obtaining CA and performing an infrared analysis of the compound’s structure,it was determined that the byproduct corresponds to CA,demonstrating the possibility of revaluing the waste through the studied process.Future studies could improve the results obtained here to promote the development of biobased products within a circular economy framework.展开更多
Objective: This study assessed the effects of consuming acetic acid bacteria (Gluconacetobacter hansenii GK-1) for 12 weeks on fatigue induced by temporary mental stress. Methods: This randomized, double-blind, placeb...Objective: This study assessed the effects of consuming acetic acid bacteria (Gluconacetobacter hansenii GK-1) for 12 weeks on fatigue induced by temporary mental stress. Methods: This randomized, double-blind, placebo-controlled, parallel-group study included 100 healthy male and female adults aged 20 - 64 years. Participants consumed either the G. hansenii GK-1 supplement (9 × 10⁹ cells/day) or a placebo daily for 12 weeks. The impact of temporary mental stress on fatigue in G. hansenii GK-1 was assessed using a Visual Analog Scale (VAS) before the study began and after 12 weeks of supplementation. Results: Subjective fatigue measured by Visual Analog Scale (VAS) showed a significant decrease in fatigue induced by temporary mental stress after 12 weeks of consumption in the G. hansenii GK-1 group compared with the placebo group. No adverse events were attributed to G. hansenii GK-1. These findings confirm that continuous oral ingestion of G. hansenii GK-1 by healthy Japanese adults reduces feelings of fatigue caused by temporary mental stress.展开更多
The current quality standard for polyvinyl alcohol eye drops lacks an impurity assessment,despite the potential impact of raw material impurities on product safety.To strengthen quality control and ensure drug safety,...The current quality standard for polyvinyl alcohol eye drops lacks an impurity assessment,despite the potential impact of raw material impurities on product safety.To strengthen quality control and ensure drug safety,an investigation into the impurity profile of the formulation was conducted,and an HPLC-UV method was developed for impurity quantification.The method validation was performed using an H-type cation exchange column.A total of 116 batches of polyvinyl alcohol eye drops from four manufacturers and two batches of the innovator drug were analyzed.Formic acid was detected exclusively in 0.4 mL samples from Company A and the innovator drug,with concentrations below 0.002%in both cases.Acetic acid was identified in samples from all manufacturers,with levels not exceeding 0.1%.The method demonstrated high specificity and sensitivity,making it well-suited for the quantification of formic and acetic acids in polyvinyl alcohol eye drops.The presence of formic acid was attributed to excipients,whereas acetic acid originated from raw materials and was further generated during pH adjustment in manufacturing.Although the overall impurity levels were low and posed minimal risk to drug safety,manufacturers should remain vigilant regarding impurity control to maintain product quality.展开更多
Secondary aluminum dross(SAD)is a rich source of recyclable aluminum but poses considerable risk due to its high AlN con-tent.Therefore,thoroughly removing AlN is essential,but intricate aluminum components and expens...Secondary aluminum dross(SAD)is a rich source of recyclable aluminum but poses considerable risk due to its high AlN con-tent.Therefore,thoroughly removing AlN is essential,but intricate aluminum components and expensive additives pose challenges to the process.In this study,waste sodium acetate is proposed as an environmentally friendly additive for completely removing AlN and enhancing the extraction of aluminum from SAD.Through the exothermic decomposition of NaAc,reactions can occur at 850℃.AlN removal efficiency reached 93.19%after sintering,whereas Al leaching efficiency in the subsequent leaching process reached 90.49%,which were 37.86%and 375.26%higher than the removal efficiency of the control,respectively.These favorable results were attributed to the comprehensive transformation of aluminum species.The formation of soluble phase Na_(1.95)Al_(1.95)Si_(0.05)O_(4) occurred during the destruction of the Al_(2)O_(3) layer surrounding AlN and the transformation of other aluminum components.AlN decomposed upon contact with NaAc.There-fore,this study utilizes the decomposition properties of NaAc to provide an efficient and environmentally friendly route for removing AlN and extracting Al from SAD.展开更多
文摘A new gold self-relay catalytic annulation/nucleophilic substitution cascade of 1,3-enyne acetates with cyclic ether acetals is reported,enabling highly diastereoselective access to cyclic etherified cyclopentenones with cyclic quaternary centers in moderate to good yields and>19∶1 dr.This catalysis enables the direct construction of two types of carboncyclic skeletons by adjusting the olefin types of 1,3-enyne acetates.When 1,3-enyne acetates bearing a cyclic alkene unit were used,5~6 fused bicarbocyclic products were diastereoselectively synthesized,whereas the reaction of acyclic 1,3-enyne acetates resulted in five-memebered carbocyclic framework.Notably,cyclic ether acetals are commonly used as protecting groups in traditional multistep organic syntheses,and in this reaction,such reagents serve as electrophilic cyclic ether precursors,achieving new uses for old reagents.The current method demonstrates good functional group compatibility,a broad substrate scope and high diastereoselectivity,providing a new synthetic strategy toward functionalized cyclopentenones.
基金Project(2010ZC051)supported by the Natural Science Foundation of Yunnan Province,ChinaProject(20140439)supported by the Analysis and Testing Foundation from Kunming University of Science and Technology,ChinaProject(14118245)supported by the Starting Research Fund from Kunming University of Science and Technology,China
文摘LiNi0.8Co0.1Mn0.1O2 cathode was synthesized using transition metal acetates under different synthesis conditions. Simultaneous thermogravimetric–differential scanning calorimetry–derivative thermogravimetric analysis was applied to investigating the mixture of transition metal acetates. X-ray powder diffraction and charge–discharge test were adopted to characterize the as-prepared LiNi0.8Co0.1Mn0.1O2. The mixture of transition metal acetates undergoes dehydration and decomposition during heating. All the examined LiNi0.8Co0.1Mn0.1O2 samples have a layered structure with R3 m space group. LiNi0.8Co0.1Mn0.1O2 samples prepared with different lithium sources under different synthesis conditions exhibit very different charge–discharge performances. The sample synthesized via the procedure of sintering at 800 °C after heating lithium carbonate and transition metal acetates at 550 °C achieves a highest capacity of 200.8 m A·h/g and an average capacity of 188.1 mA ·h/g in the first 20 cycles at 0.2C.
基金TheNationalNaturalScienceFoundationofChina (No .2 9837180 )
文摘The logarithms of retention factors normalized to a hypothetical pure water eluent(log k w) were determined on a reversed phase high performance liquid chromatography(RP HPLC) column (Li Chrosorb RP 18 column) for 20 new α\|branched phenylsulfonyl acetates. The atomic charge method was applied to develop quantitative structure retention relationships(QSRRs). Among the available geometric and electronic descriptors, surface area (S), ovality (O), and the charge of carboxyl group(Q OC ) are significant. In the model, the contribution of surface area (S) is the greatest. The molecular mechanism of retention was demonstrated through the model. With the correlation coefficient ( r 2 adj , adjusted for degrees of freedom) of 0.964, the standard error of 0.164 and the F value of 170.39, the model has good predictive capacity.
基金The partial support of this work by the University of Guilan Research Council is gratefully acknowledged.
文摘Semicarbazones, 1,1-diacetates and acetals are efficiently converted to their corresponding carbonyl compounds using synergistic effect between KBrO3 and MoO3 in refluxing CH3CN-H2O in good to high yields.
文摘A method for locating double bond in hexadecenyl acetates has been developed by analyzing the mass spectral patterns on a fuzzy classification. The procedure was tested with the spectra of Δ~2- to Δ^(15)-isomers and the original double-bond position in these acetates was located unambiguously.
文摘A mild and efficient method for diacetylation reaction was developed,by which diacetate could be achieved through the reaction of aldehyde with acetic anhydride,in the presence of cobalt sulfate,with an admirable yield,at room temperature,without solvent.The catalyst could be recycled six times without a distinct loss of activity.
基金supported by the European Union’s Seventh Framework Program for research,technological development and demonstration(FP7/2007-2013)[Grant Agreement No.605215]CONACyT for providing funding through PhD scholarship no.383910.
文摘Before proposing an innovative process for the coproduction of ethyl and butyl acetates, the individual syntheses of ethyl acetate and butyl acetate by two different routes were first studied. These syntheses involved the reaction of ethanol or n-butanol with acetic acid or acetic anhydride in the presence of ion exchange resins: Amberlyst 15, Amberlyst 16, Amberlyst 36 and Dowex 50WX8. Kinetic and thermodynamic studies were performed with all resins. The lowest activation energy (Ea) value was obtained with Dowex 50WX8, which was identified as the best-performing resin, able to be reused at least in four runs without regeneration. The presence of water-azeotropes during the synthesis of ethyl acetate makes its purification difficult. A new strategy was adopted here, involving the use of ethanol and acetic anhydride as the starting material. In order to minimize acetic acid as co-product of this reaction, a novel two-step process for the coproduction of ethyl and butyl acetates was developed. The first step involves the production of ethyl acetate and its purification. Butyl acetate was produced in the second step: n-butanol was added to the mixture of acetic acid and the resin remaining after the first-step distillation. This process yields ethyl acetate and butyl acetate at high purity and shows an environmental benefit over the independent syntheses by green metrics calculation and life cycle assessment.
文摘High-performance MXene-based polymer nanocomposites are well-suited for various industrial applications owing to their excellent mechanical,thermal,and other properties.However,the fabrication of flame-retardant polymer/MXene nanocom-posites remains challenging owing to the limited flame-retardant properties of MXene itself.This study prepared a novel MXene@Ag@PA hybrid material via radiation modification and complexation reaction.This material was used to further enhance the key properties of ethylene-vinyl acetate(EVA),such as its mechanical properties,thermal conductivity,flame retardancy,and electromagnetic shielding.The addition of two parts of this hybrid material increased the thermal conduc-tivity of EVA by 44.2%and reduced its peak exothermic rate during combustion by 30.1%compared with pure EVA.The material also significantly reduced smoke production and increased the residue content.In the X-band,the electromagnetic shielding effectiveness of the EVA composites reached 20 dB.Moreover,the MXene@Ag@PA hybrid material could be used to further enhance the mechanical properties of EVA composites under electron-beam irradiation.Thus,this study contributes to the development of MXene-based EVA advanced materials that are fire-safe,have high strength,and exhibit good electromagnetic shielding performance for various applications.
文摘Developing favorable bio-based polymers that replace petroleum-based plastics is an essential environmental demand.Lignin is a by-product of the chemical pulping industry.It is a natural UV protection ingredient in broad-spectrum(UVA and UVB)sunscreens.It could be partially and selectively acetylated in a simple,fast,and more reliable process.In this work,a composite film was prepared with UV-resistant properties through a casting method.Bio-based cellulose acetate(CA)was employed as a major matrix while nano-acetylated kraft lignin(AL-NPs)was used as filler during synthesizing UV-shielding films loaded with various amounts(1–5 wt.%)of AL-NPs.Kraft lignin was acetylated through a simple and fast microwave-assisted process using acetic acid as a solvent and acetylating agent.The physicochemical and morphological characteristics of the prepared films were evaluated using different methods,including scanning electron microscopy(SEM),Fourier Transform Infrared Spectroscopy(FTIR),X-ray diffraction analysis(XRD),mechanical testing and contact angle measurement.The UV-Vis spectroscopy optical investigation of the prepared films revealed that AL-NPs in the CA matrix showed strong UV absorption.This feature demonstrated the effectiveness of our research in developing UV-resistant bio-based polymer films.Hence,the prepared films can be considered as successful candidates to be applied in packaging applications.
基金supported by the National Special Fund for the Development of Major Research Equipment and Instrument(No.2020YFF01014503)the Young Taishan Scholars(No.tsqn201909039)the College 20 Project fromJi Nan Science&Technology Bureau(No.2021GXRC058).
文摘Formic and acetic acids are the most abundant gaseous organic acids and play the key role in the atmospheric chemistry.In iodine-adduct chemical ionizationmass spectrometry(CIMS),the low utilization efficiency of methyl iodide and humidity interference are two major issues of the vacuum ultraviolet(VUV)lamp initiated CIMS for on-line gaseous formic and acetic acids analysis.In this work,we present a new CIMS based on VUV lamp,and the ion-molecular reactor is separated into photoionization and chemical ionization zones by a reducer electrode.Acetone was added to the photoionization zone,and the VUV photoionization acetone provided low-energy electrons for methyl iodide to generate I−,and the addition of acetone reduced the amount of methyl iodide by 2/3.In the chemical ionization zone,a headspace vial containing ultrapure water was added for humidity calibration,and the vial changes the sensitivity as a function of humidity from ambiguity to well linear correlation(R2>0.95).With humidity calibration,the CIMS can quantitatively measure formic and acetic acids in the humidity range of 0%-88%RH.In this mode,limits of detection of 10 and 50 pptv are obtained for formic and acetic acids,respectively.And the relative standard deviation(RSD)of quantitation stability for 6 days were less than 10.5%.This CIMS was successfully used to determine the formic and acetic acids in the underground parking and ambient environment of the Shandong University campus(Qingdao,China).In addition,we developed a simple model based formic acid concentration to assess vehicular emissions.
基金supported by the National Natural Science Foundation of China(32201988)Natural Science Foundation of Jiangsu Province(BK20210456)+3 种基金Special Fund for Science and Technology Program of Jiangsu Province(BM2022019)the National Key R&D Program of China(2023YFC2506004)the Fundamental Research Funds for the Central Universities(JUSRP123047)the Program of Collaborative Innovation Centre of Food Safety and Quality Control in Jiangsu Province.
文摘The neurotransmitter 5-hydroxytryptamine(5-HT),primarily produced by intestinal enterochromaffin(EC)cells,relies on tryptophan hydroxylase 1(TPH1)for synthesis.Research suggested Bifidobacterium breve CCFM1025’s potential in regulating Tph1 gene expression,maintaining 5-HT levels in stressed mice,but its precise mechanisms were unclear.This study used metabolomic techniques to assess probiotic fermentation products,revealing acetate as the crucial element in Bb-CCFM1025’s regulation of gut 5-HT synthesis.Further exploration correlated acetate with Tph1 transcription in intestinal organoids.Transcriptomic methods and quantitative reverse transcription polymerase chain reaction validation demonstrated how acetate facilitated 5-HT synthesis and secretion.It unveiled that acetate orchestrates signaling pathways(phosphoinositide 3-kinase-protein kinase B(PI3K-AKT),phospholipase C-phosphorylated extracellular signal-regulated kinase(PLC-pERK),and PLC-1,4,5-trisphosphate(IP3)-Ca^(2+))within EC,enabling 5-HT production.These findings elucidate the biochemical mechanisms behind specific probiotics’effects,aiding in the targeted selection of similar beneficial strains.This study offers theoretical support for choosing probiotics with analogous functionalities based on their physiological impacts.
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 by the joint research collaboration of the Research Organization of Agriculture and Food National Research and Innovation Agency(BRIN)FY 2024(Grant number:6/III.11/HK/2024),with Widya Fatriasari as the Principal Investigator.
文摘Biodegradable plastics are types of plastics that can decompose into water and carbon dioxide the actions of living organisms,mostly by bacteria.Generally,biodegradable plastics are obtained from renewable raw materials,microorganisms,petrochemicals,or a combination of all three.This study aims to develop an innovative bioplastic by combining chitosan and lignin.Bioplastic was prepared by casting method and characterized by measuring the mechanical properties like tensile strength,Young’smodulus,and elongation at break.The chemical structure,together with the interactions among chitosan and lignin and the presence of new chemical bonds,were evaluated by FTIR,while the thermal properties were assessed by thermogravimetric analysis.The water vapor permeability,tests and transparency as well as biodegradability,were also carried out.The results show a tensile strength value of 34.82 MPa,Young’s modulus of 18.54 MPa,and elongation at a break of 2.74%.Moreover,the interaction between chitosan and lignin affects the intensity of the absorption peak,leading to reduced transparency and increased thermal stability.The chitosan/lignin interactions also influence the crystalline size,making it easier to degrade andmore flexible rather than rigid.The contact angle shows the bioplastic’s ability to resist water absorption for 4minutes.In the biodegradation test,the sample began to degrade after 30 days of soil burial test observation.
文摘The aim of this study is to isolate and identify the chemical compounds in ethanol extract of Cyclocarya paliurus.Some purification and analysis techniques like silica gel,D101-macroporous adsorptive resins,and Sephadex LH-20 column chromatographies as well as high-performance liquid chromatography were used to isolate and analyze the compounds from ethanol extract of Cyclocarya paliurus.The structures of these constituents were identified by spectroscopic techniques such as nuclear magnetic resonance and high-resolution mass spectrometries.Twenty-eight compounds,including flavonoids and their glycoside,carbohydrate,coumarin and organic acid,were isolated from ethyl acetate and n-butanol fractions in ethanol extract of Cyclocarya paliurus,and they were identified as kaempferol(1),coumestrol(2),kaempferol 3-O-β-D-glucoside(3),methyl caffeoylquinic acid(4),coptichic aldehyde(5),schizandriside(6),kaempferol 3-O-α-L-rhamnoside(7),3-caffeoylquinic acid ethyl ester(8),quercetin(9),luteolin(10),protocatechuic acid(11),kaempferol-3-O-α-L-furan arabinose(12),trans-p-hydroxy-cinnamic acid(13),α-D-glucopyranosido-β-D-fructofuranoside,sucrose(14),peucedanol(15),chlorogenic acid(16),pyridoxine(17),quercetin-3-O-β-D-glucuronide(18),kaempferol-3-O-β-D-glucuronide(19),isoquercitrin(20),mururin A(21),citroside A(22),benzyl-6-O-α-L-arabinofuranosyl-β-D-glucopyranoside(23),(+)-(6S,9R)-9-O-β-D-glucopyranosyl-6-hydroxy-3-O-α-ionol(24),myricetin-3-O-β-D-glucopyranoside(25),(4R)-4-(3-Oxo-1-buten-1-ylidene)-3α,5,5-trimethylcyclohexane-1α,3β-diol(26),quercetin-3-O-α-L-rhamnopyranosyl(27)and 3,5-O-dicaffeoylquinic acid(28).Compounds 2,5,6,15,21,22,23,24,26 and 28 were isolated from Cyclocarya paliurus for the first time.
基金the National Key Research and Development Program of China(2022YFE0203600,China)NFSC(81925035,82341232)+2 种基金Program of Shanghai Committee of Science and Technology(21ZR1475200,China)Department of Science and Technology of Guangdong Province(High-Level R&D and Innovative Research Institute 2021B0909050003)SciTech Projects of Zhongshan(CXTD2022011,LJ2021001).
文摘Gastrointestinal tract toxicity represents a serious adverse effect of chemotherapy,leading to reduced quality of life and survival.For instance,irinotecan(CPT-11)usually causes severe gastrointestinal toxicity,with a lack of effective therapeutic interventions,making treatment often unsustainable.Therefore,development of an effective and safe therapy is crucial for improving chemotherapy efficacy and the patients’quality of life.In this work,we developed a novel approach involving the helical-shaped cyanobacterium microalgae,Spirulina platensis(SP),to carry the bornyl acetate(BA)-loaded chitosan nanoparticles to enhance drug retention in the small intestine.We demonstrated the protection effect of BA against chemotherapy-induced intestinal injury using an epithelial cell model.In a mouse model,orally administered BA-ChNPs@SP accumulated in the small intestine and attenuated inflammation by reducing dsDNA release and oxidative stress.This was concomitant with the restoration of the intestinal barrier and modulation of the immune microenvironment.This work suggests the promise of the microalgae-carrying nanomedicine strategy for treatment of intestinal diseases,emphasizing its potential in addressing chemotherapy-induced gastrointestinal complications.
基金supported by Hubei Province Technology Innovation Program Project(2024BCB073)the National Natural Science Foundation of China(52402249)the China Postdoctoral Science Foundation(2021M690930).
文摘Carbon-based low-dimensional materials(CLDM)with elemental carbon as the main component have unique physical and chemical properties,and become the focus of research in many fields including energy,environmental protection,and information technology.Notably,cellulose acetate,the main component of cigarette butts(CBs),is a one-dimensional precursor with a large specific surface area and aspect ratio.Still,their usefulness as building fillers has often been underestimated before.This review summarizes recent advances in CBs recycling and provides suggested guidelines for its use as a CLDM material in renewable energy.Specifically,we first describe the harmful effects of CBs as pollutants in our lives to emphasize the importance of proper recycling.We then summarize previous methods of recycling CBs waste,including clay bricks,asphalt concrete pavement,gypsum,acoustic materials,chemisorption,vector control,and corrosion control.The potential applications of CBs include triboelectric nanogenerator applications,flexible batteries,enhanced metal-organic framework material energy storage devices,and carbon-based hydrogen storage.Finally,the advantages of utilizing CBs-derived CLDM materials over conventional solutions in the energy field are discussed.This review will provide new avenues for solving the intractable problem of CBs and reducing the manufacturing costs of renewable materials.
文摘Agricultural waste is a potentially interesting resource due to the compounds present.In this study,cellulose was extracted from corn stalks(Zea mays)and subsequently converted into cellulose acetate(CA).Before the extraction process,the waste sample was characterized by pH,moisture,ash,protein content,total reducing sugars(TRS),carbohydrates,cellulose,hemicellulose,and lignin.Acid and alkaline hydrolysis were performed with different reagents,concentrations,and extraction times.Sulfuric acid(H_(2)SO_(4))and acetic acid(CH_(3)COOH)were used in the acid hydrolysis,while sodium hydroxide(NaOH)was used in the alkaline hydrolysis.Three concentrations(0.62,1.25,2.5)%and two reaction times(60,120)min were established.An ANOVA was performed on the hydrolysis results to determine the existence of significant differences.The extracted cellulose was revalued by acetylation,and finally,the CA was characterized by Fourier Transform Infrared Spectroscopy(FT-IR)spectroscopy.The highest cellulose extraction yield was obtained by alkaline hydrolysis,with an extraction time of 120 min and a yield of 65%.The statistical analysis indicated that the reagent used,its concentration,reaction time,and their interaction significantly affect the process yield.After obtaining CA and performing an infrared analysis of the compound’s structure,it was determined that the byproduct corresponds to CA,demonstrating the possibility of revaluing the waste through the studied process.Future studies could improve the results obtained here to promote the development of biobased products within a circular economy framework.
文摘Objective: This study assessed the effects of consuming acetic acid bacteria (Gluconacetobacter hansenii GK-1) for 12 weeks on fatigue induced by temporary mental stress. Methods: This randomized, double-blind, placebo-controlled, parallel-group study included 100 healthy male and female adults aged 20 - 64 years. Participants consumed either the G. hansenii GK-1 supplement (9 × 10⁹ cells/day) or a placebo daily for 12 weeks. The impact of temporary mental stress on fatigue in G. hansenii GK-1 was assessed using a Visual Analog Scale (VAS) before the study began and after 12 weeks of supplementation. Results: Subjective fatigue measured by Visual Analog Scale (VAS) showed a significant decrease in fatigue induced by temporary mental stress after 12 weeks of consumption in the G. hansenii GK-1 group compared with the placebo group. No adverse events were attributed to G. hansenii GK-1. These findings confirm that continuous oral ingestion of G. hansenii GK-1 by healthy Japanese adults reduces feelings of fatigue caused by temporary mental stress.
基金National Drug Sampling Inspection Project(No.NMPA Drug Admin[2024]1).
文摘The current quality standard for polyvinyl alcohol eye drops lacks an impurity assessment,despite the potential impact of raw material impurities on product safety.To strengthen quality control and ensure drug safety,an investigation into the impurity profile of the formulation was conducted,and an HPLC-UV method was developed for impurity quantification.The method validation was performed using an H-type cation exchange column.A total of 116 batches of polyvinyl alcohol eye drops from four manufacturers and two batches of the innovator drug were analyzed.Formic acid was detected exclusively in 0.4 mL samples from Company A and the innovator drug,with concentrations below 0.002%in both cases.Acetic acid was identified in samples from all manufacturers,with levels not exceeding 0.1%.The method demonstrated high specificity and sensitivity,making it well-suited for the quantification of formic and acetic acids in polyvinyl alcohol eye drops.The presence of formic acid was attributed to excipients,whereas acetic acid originated from raw materials and was further generated during pH adjustment in manufacturing.Although the overall impurity levels were low and posed minimal risk to drug safety,manufacturers should remain vigilant regarding impurity control to maintain product quality.
基金supported by the National Natural Science Foundation of China(No.22276062)the Guangdong Science and Technology Program,China(No.2020B121201003).
文摘Secondary aluminum dross(SAD)is a rich source of recyclable aluminum but poses considerable risk due to its high AlN con-tent.Therefore,thoroughly removing AlN is essential,but intricate aluminum components and expensive additives pose challenges to the process.In this study,waste sodium acetate is proposed as an environmentally friendly additive for completely removing AlN and enhancing the extraction of aluminum from SAD.Through the exothermic decomposition of NaAc,reactions can occur at 850℃.AlN removal efficiency reached 93.19%after sintering,whereas Al leaching efficiency in the subsequent leaching process reached 90.49%,which were 37.86%and 375.26%higher than the removal efficiency of the control,respectively.These favorable results were attributed to the comprehensive transformation of aluminum species.The formation of soluble phase Na_(1.95)Al_(1.95)Si_(0.05)O_(4) occurred during the destruction of the Al_(2)O_(3) layer surrounding AlN and the transformation of other aluminum components.AlN decomposed upon contact with NaAc.There-fore,this study utilizes the decomposition properties of NaAc to provide an efficient and environmentally friendly route for removing AlN and extracting Al from SAD.
