Although enantiomers of 2-phenylpropionic acids (2-PPAs), or profens are important group of nonsteroidal anti-inflammatory drugs (NSAIDs) and have been in clinical use for many years, there is no literature covering i...Although enantiomers of 2-phenylpropionic acids (2-PPAs), or profens are important group of nonsteroidal anti-inflammatory drugs (NSAIDs) and have been in clinical use for many years, there is no literature covering its binding interaction in particular with cyclodextrins. NSAIDs are marketed as racemates, chiral discrimination and knowledge of enantiomeric bioavailability is essential. Circular dichroism (CD) spectroscopy is the technique of choice for elucidating chirality and monitoring and characterizing molecular recognition phenomena in solution. Methods em-ploying the fundamentals of the simultaneous measurements of absorbance and CD and a novel efficient titration method have been developed to study the binding of β-Cyclodextrin (β-CyD) and the two enantiomers of 2-PPA as a function of pH. The effect on physicochemical properties and bioavailability was investigated. The binding constant, stoichiometry and pKa for both the free and the bound drugs were determined using a Levenburg-Marquadt non-linear equation. The exact nature of the enantiomer discriminating interactions by cyclodextrins (CyDs) is not well understood. In this work, the interactions and co-conformations of both enantiomers of 2-PPA with β-CyD were explained and es-timated using spectroscopic variations upon complexation. The results indicated a change in the physicochemical prop-erties of 2-PPAs upon complexation and highlighted the enantioselective binding of β-CyD as a function of pH. The charge on the vip molecule and its stereochemistry are of great importance in regulating the stability of the vip/β-CyD complexes;hence the bioavailability of drugs. This work elucidates 2-PPAs/β-CyD binding interactions and highlights the effect of β-CyD on drugs with an effective novel method for binding titration and the potential of the simultaneous measurements of absorbance and CD in future chiral drug interactions studies.展开更多
（R）-2-hydroxy-3-phenylpropionic acid （PIP,） is an ideal antimicrobial compound with broad-spectrum activity against a wide range of Gram-positive bacteria, some Gram-negative bacteria, and fungi. We studied the bi...（R）-2-hydroxy-3-phenylpropionic acid （PIP,） is an ideal antimicrobial compound with broad-spectrum activity against a wide range of Gram-positive bacteria, some Gram-negative bacteria, and fungi. We studied the bioconversion of phenylpyruvate （PPA） to PLA using whole recombinant Escherichia coli cells in a series of buffer/organic solvent systems. Octane was found to be the best organic solvent. The optimum volume ratio of the water phase to the n-octane phase, conversion temperature, substrate concentration, and cell concentration were 6：4, 40 ℃, 12.5 g/L, and 30 g/L wet cells, respectively. Under the optimized conditions, the average PLA productivity in the aqueous/ n-octane system was 30.69% higher than that in the aqueous system, and 32.31 g/L PLA was obtained with the use of a stirred reactor （2-L scale）. Taken together, our findings indicated that PLA biosynthesis was more efficient in an aqueous/n-octane biphasic system than in a monophasic aqueous system. The proposed biphasic system is an effective strategy for enhancing PLA yield and the biosynthesis of its analogues.展开更多
Photoinduced[2+2]cycloaddition of biomass-derived cycloolefin is a promising approach to synthesize high-energy bio-fuels,however,the conversion efficiency and selectivity are still low.Herein,we provide an acid-promo...Photoinduced[2+2]cycloaddition of biomass-derived cycloolefin is a promising approach to synthesize high-energy bio-fuels,however,the conversion efficiency and selectivity are still low.Herein,we provide an acid-promoted photocycloaddition approach to synthesize a new kind of spiral fuel from biomass-derived cyclohexanone (CHOE) and camphene (CPE).BrΦnsted acids show higher catalytic activity than Lewis acids,and acetic acid (HOAc) possesses the best catalytic performance,with CHOE conversion up to 99.1%.Meanwhile,the HOAc-catalytic effect has been confirmed for[2+2]photocycloaddition of other biomass-derived ketenes and olefins.The catalytic mechanism and dynamics have been investigated,and show that HOAc can bond with C=O groups of CHOE to form H–CHOE complex,which leads to higher light adsorption and longer triplet lifetime.Meanwhile,H–CHOE complex reduces the energy gap between CHOE LUMO and CPE HOMO,shortens the distance of ring-forming atoms,and then decreases the energy barrier (from 103.3 kcal mol^(-1)to 95.8 kcal mol^(-1)) of rate-limiting step.After hydrodeoxygenation,the targeted bio-spiral fuel shows high density of 0.992 g cm^(-3),high neat heat of combustion of 41.89 MJ L^(-1),low kinetic viscosity of 5.69 mm^(2)s^(-1)at 20℃,which is very promising to serve as high-performance aerospace fuel.展开更多
The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain functio...The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain function and encoding behaviors associated with emotions.Specifically, astrocytes in the basolateral amygdala have been found to play a role in the modulation of anxiety-like behaviors triggered by chronic stress. Nevertheless, the precise molecular mechanisms by which basolateral amygdala astrocytes regulate chronic stress–induced anxiety-like behaviors remain to be fully elucidated. In this study, we found that in a mouse model of anxiety triggered by unpredictable chronic mild stress, the expression of excitatory amino acid transporter 2 was upregulated in the basolateral amygdala. Interestingly, our findings indicate that the targeted knockdown of excitatory amino acid transporter 2 specifically within the basolateral amygdala astrocytes was able to rescue the anxiety-like behavior in mice subjected to stress. Furthermore, we found that the overexpression of excitatory amino acid transporter 2 in the basolateral amygdala, whether achieved through intracranial administration of excitatory amino acid transporter 2agonists or through injection of excitatory amino acid transporter 2-overexpressing viruses with GfaABC1D promoters, evoked anxiety-like behavior in mice. Our single-nucleus RNA sequencing analysis further confirmed that chronic stress induced an upregulation of excitatory amino acid transporter 2 specifically in astrocytes in the basolateral amygdala. Moreover, through in vivo calcium signal recordings, we found that the frequency of calcium activity in the basolateral amygdala of mice subjected to chronic stress was higher compared with normal mice.After knocking down the expression of excitatory amino acid transporter 2 in the basolateral amygdala, the frequency of calcium activity was not significantly increased, and anxiety-like behavior was obviously mitigated. Additionally, administration of an excitatory amino acid transporter 2 inhibitor in the basolateral amygdala yielded a notable reduction in anxiety level among mice subjected to stress. These results suggest that basolateral amygdala astrocytic excitatory amino acid transporter 2 plays a role in in the regulation of unpredictable chronic mild stress-induced anxiety-like behavior by impacting the activity of local glutamatergic neurons, and targeting excitatory amino acid transporter 2 in the basolateral amygdala holds therapeutic promise for addressing anxiety disorders.展开更多
In order to reveal the effect of 2-hydroxy-3-naphthyl hydroxamic acid(H205)on the flotation behavior and action mechanism of bastnaesite,single-mineral flotation experiments of bastnaesite were conducted.The flotation...In order to reveal the effect of 2-hydroxy-3-naphthyl hydroxamic acid(H205)on the flotation behavior and action mechanism of bastnaesite,single-mineral flotation experiments of bastnaesite were conducted.The flotation recovery of bastnaesites can be achieved more than 90%when the aeration rate is 40 mL/min,the rotational speed is 200 r/min,the H205 dosage is 120 mg/L,and the pulp pH ranges from 7 to 9.The action mechanism of H205 on the surface of bastnaesite was studied by simultaneous thermogravimetry and differential scanning calorimetry(TG-DSC),Zeta potential measurements,Fourier transform-infrared spectra(FT-IR)and X-ray photoelectron spectroscopy(XPS).These analysis results show that under suitable flotation conditions,H205 has an obvious adsorption phenomenon on the surface of bastnaesite.The adsorption involves electrostatic interactions and chemical interactions,namely H205 has a strong collecting ability of bastnaesite due to the synergism of electrostatic adsorption and chemical adsorption.This study systematically reveals the flotation behavior and adsorption mechanism of H205 on the surface of bastnaesite,and provides useful theoretical guidance for efficient flotation separation of bastnaesite.展开更多
Carbon dioxide(CO_(2))marine sequestration by hydrate method is considered as one of the options to effectively achieve carbon reduction.However,the slow rate of hydrate formation becomes a major limiting factor.In vi...Carbon dioxide(CO_(2))marine sequestration by hydrate method is considered as one of the options to effectively achieve carbon reduction.However,the slow rate of hydrate formation becomes a major limiting factor.In view of the gas-water mass transfer problem which is the main obstacle,this paper explored the amphiphilic amino acids to promote the formation of CO_(2)hydrate and used low-field nuclear magnetic resonance(LNMR)to conduct an innovative study on its kinetics and spatiotemporal distribution.By comparing the promotion performance of L-methionine(L-met),L-cysteine(L-cys),and L-valine(L-val),the comprehensive kinetic promotion ability of L-met was the highest,reducing the induction time by 60.0%,achieving the maximum water conversion of about 57.0%within only 1 h,and reaching a final CO_(2)storage efficiency of 84.6%.LNMR results showed that hydrates were preferentially formed in large and medium pores in the reservoir region.Interestingly,we found that the combined effect of hydrophilic groups and the hydrophobic side chain of L-met not only promoted the rearrangement of water molecules and provided more nucleation sites,but also created a localized CO_(2)supersaturated environment and facilitated gas-water redistribution.Meanwhile,L-met promoted the formation of a hydrate porous structure to ensure the continuous formation of hydrates.This study innovatively explored CO_(2)hydrate formation behavior in amphiphilic amino acids and laid a theoretical foundation for the realization of CO_(2)marine sequestration by hydrate method.展开更多
The catalytic oxidation of HMF involves a cascading reaction with multiple intermediate products,making it crucial to enhance the oriented adsorption capacity of specific functional groups for accelerating the entire ...The catalytic oxidation of HMF involves a cascading reaction with multiple intermediate products,making it crucial to enhance the oriented adsorption capacity of specific functional groups for accelerating the entire process.To achieve the efficient selective oxidation of HMF to FDCA,a series of NiCo_(2)O_(4)catalysts with different morphologies,such as flaky,echinoids,pompon and corolla,were prepared and characterized by XRD,SEM,TEM,BET,XPS,and FTIR.Among the four catalysts,flaky NiCo_(2)O_(4)exhibited the most excellent catalytic activity and stability,with a FDCA yield of 60.1%within 12 h at 80℃without alkali participation.The excellent performance of flaky NiCo_(2)O_(4)catalyst is attributed to the oxygen vacancies and acid sites generated by the exposed(400)facets.The oxygen vacancies and acid sites on the catalyst surface can precisely adsorb-CHO and-CH_(2)-OH of HMF,respectively,and this synergistic effect promotes the efficient production of FDCA.This work is of great significance for fundamentally study the effect of micro-topography or crystal-plane reaction properties on surfaces.展开更多
Two different Mn-Ce-O_(x)/TiO_(2) catalysts were prepared by ordinary impregnation(denoted as MCT) and citric acid assisted impregnation(denoted as MCT-CA) methods,respectively.Excellent NOxremoval is achieved over MC...Two different Mn-Ce-O_(x)/TiO_(2) catalysts were prepared by ordinary impregnation(denoted as MCT) and citric acid assisted impregnation(denoted as MCT-CA) methods,respectively.Excellent NOxremoval is achieved over MCT-CA for selective catalytic reduction with NH3(NH_(3)-SCR),and 100% NOxconversion is obtained at 125℃ under weight hour space velocity(WHSV) of 80000 mL/(gcat·h).Particularly,100% NOxis converted on MCT-CA in the presence of 10 vol% H2O at 175℃.As H2O and SO2coexist in the reaction system for 9 h,NO_(x) conversion can still be maintained>90%,much higher than that(22%) of MCT.A series of characterization results indicates that MCT-CA exhibits a larger BET specific surface area,pore volume,and pore size,which enhances the dispersion of Mn and Ce oxides and promotes the rapid adsorption of reactants and desorption of products.Additionally,MCT-CA possesses more Mn^(4+),Ce^(3+),chemisorbed oxygen species,and stronger reducibility,facilitating the co nversion of NO to NO_(2).Specially,the amount of active NH_(3) species and active nitrate species on MCT-CA is much more than that over MCT,The combined effect of the aforementioned factors devotes to the excellent low-temperature SCR performance and tolerance to H2O/SO2over MCT-CA.展开更多
Here,we report a novel nickel-catalyzed electrochemical carboxylation of propargylic esters with CO_(2),characterized by the regioselective synthesis of 2,3-allenoic acids rather than propargylic carboxylic acids.Both...Here,we report a novel nickel-catalyzed electrochemical carboxylation of propargylic esters with CO_(2),characterized by the regioselective synthesis of 2,3-allenoic acids rather than propargylic carboxylic acids.Both acyclic propargylic esters and cyclic propargylic carbonates serve as effective substrates,facilitating the synthesis of mono-,di-,tri-,and tetra-substituted 2,3-allenoic acids with broad substrate scope under mild conditions.Mechanistic investigations indicate that the in situ generated Ni(Ⅰ)complex might serve as the active species to react with propargylic esters,forming the allenyl-Ni(Ⅰ)complex under electroreductive conditions.A possible γ-selective nucleophilic attack of allenyl-Ni(Ⅰ)complex on CO_(2) is likely involved in the formation of the desired 2,3-allenoic acids.展开更多
Poly(ethylene 2,5-furandicarboxylate)(PEF),a bioplastic synthesized via the polymerization of 2,5-furandicarboxylic acid(FDCA)with ethylene glycol,can be served as a substitute to petroleum-based polyethylene terephth...Poly(ethylene 2,5-furandicarboxylate)(PEF),a bioplastic synthesized via the polymerization of 2,5-furandicarboxylic acid(FDCA)with ethylene glycol,can be served as a substitute to petroleum-based polyethylene terephthalate(PET)due to its enhanced material properties.However,the fabrication of PEF with stable and desirable properties is still a challenge,largely due to the impurities in FDCA.In this study,a highly efficient purification strategy for FDCA was proposed,utilizing a dioxane/H_(2)O binary solvent system for effective crystallization.Furthermore,PEFs were synthesized from FDCA with varying impurity and the effects of these impurities were systematically characterized.The results revealed that impurities in FDCA could result in PEFs with relatively poor thermal properties.This study provides crucial insights for the impact of impurities on PEF properties and FDCA purification.展开更多
Background Deoxynivalenol(DON)is a mycotoxin that severely pollutes feed ingredients,and methods for reducing DON toxicity have become a significant research direction.Chlorogenic acid(CGA)is an active polyphenol foun...Background Deoxynivalenol(DON)is a mycotoxin that severely pollutes feed ingredients,and methods for reducing DON toxicity have become a significant research direction.Chlorogenic acid(CGA)is an active polyphenol found in some plants,which has anti-inflammatory and antioxidant properties and a protective effect on animal intestinal health.The effects of CGA on DON-induced pyroptosis in the intestinal porcine epithelial cell line-J2(IPEC-J2)and its potential mechanism were explored in this study.Results IPEC-J2 cells viability and membrane integrity were inversely correlated with DON concentration.Compared to those in the group treated with DON alone at 2,500 ng/mL,pretreatment with 80μmol/L CGA for 4 h significantly improved cell viability(P<0.01),and the alleviation of typical pyroptotic symptoms induced by DON were observed,including reduced cellular DNA fragmentation,decreased release of lactate dehydrogenase(LDH),normalized ROS levels,restoration of extracellularCa2+andK+contents to normal levels(P<0.01),as well as suppressed the enzyme activities of caspase-1 and caspase-4(P<0.01).Additionally,the mRNA expression levels of TNF,MDP,NOD2,TLR4,ASC and GSDMD were significantly improved(P<0.01),while both mRNA and protein expression levels of NF-κB,NLRP3,caspase-1,IL-1βand IL-18 were significantly upregulated(P<0.01)in the CGA+DON group,compare to those in the DON group.Conclusion Pretreatment with 80μmol/L CGA for 4 h effectively alleviated pyroptosis in IPEC-J2 cells induced by 2,500 ng/mL of DON through inhibiting activation of the NF-κB/NLRP3/capase-1 pathway.展开更多
Direct converting carbon dioxide(CO_(2))and propane(C_(3)H_(8))into aromatics with high carbon utilization offers a desirable opportunity to simultaneously mitigate CO_(2)emission and adequately utilize C_(3)H_(8) in ...Direct converting carbon dioxide(CO_(2))and propane(C_(3)H_(8))into aromatics with high carbon utilization offers a desirable opportunity to simultaneously mitigate CO_(2)emission and adequately utilize C_(3)H_(8) in shale gas.Owing to their thermodynamic resistance,converting CO_(2)and C_(3)H_(8) respectively remains difficult.Here,we achieve 60.2%aromatics selectivity and 48.8%propane conversion over H-ZSM-5-25 via a zeolite-catalyzing the coupling of CO_(2)and C_(3)H_(8).Operando dual-beam FTIR spectroscopy combined with ^(13)C-labeled CO_(2)tracing experiments revealed that CO_(2)is directly involved in the generation of aromatics,with its carbon atoms selectively embedded into the aromatic ring,bypassing the reverse water-gas shift pathway.Accordingly,a cooperative aromatization mechanism is proposed.Thereinto,lactones,produced from CO_(2)and olefins,are proven to be the key intermediate.This work not only provides an opportunity for simultaneous conversion of CO_(2)and C_(3)H_(8),but also expends coupling strategy designing of CO_(2)and alkanes over acidic zeolites.展开更多
Acidic environments enhance CO_(2) utilization during CO_(2) electrolysis via a buffering effect that converts carbonates formed at the electrode surface back into CO_(2).Nevertheless,further investigation into acidic...Acidic environments enhance CO_(2) utilization during CO_(2) electrolysis via a buffering effect that converts carbonates formed at the electrode surface back into CO_(2).Nevertheless,further investigation into acidic CO_(2) electrolysis is required to improve its selectivity towards certain CO_(2) reduction reaction(CO_(2)RR)products,such as multicarbon(C2+)species,while enhancing its overall stability.In this study,liquid product recirculation in the catholyte and local OH−accumulation were identified as primary factors contributing to the degradation of gas diffusion electrodes mounted in closed‐loop catholyte configurations.We demonstrate that a single‐pass catholyte configuration prevents liquid product recirculation and maintains a continuous flow of acidic‐pH catholyte throughout the reaction while using the same volume as a closed‐loop setup.This approach improves electrode durability and maintains a Faradaic efficiency of 67%for multicarbon products over 4 h of CO_(2) electrolysis at−600 mA cm^(-2).展开更多
Nanostructured ceria has attracted much attention in the field of redox catalysts due to the numerous active sites with excellent redox ability.Based on the acidic medium etching strategy,we constructed the strong bin...Nanostructured ceria has attracted much attention in the field of redox catalysts due to the numerous active sites with excellent redox ability.Based on the acidic medium etching strategy,we constructed the strong binding centers(hydroxyl sites and strong acid sites)on the surfaces of nanostructured ceria,which regulate the adsorption process of KA-Oil(the mixture of cyclohexanol and cyclohexanone)and to promote high KA-Oil selectivity in cyclohexane oxidation.The three CeO_(2)(nanocube,nanorod and nanopolyhedron)with different exposed crystal planes were treated by acid etching to change the surface sites and catalytic properties.The transition behavior of surface sites during etching was revealed,abundant strong binding centers were proved to be constructed successfully.And especially for the nanorod treated by acid(Acid@CeO_(2)-NR)with the strongest response for sulfuric acid etching,the strong adsorption of cyclohexanone by strong binding centers was confirmed based on the in-situ DRIFTs.The sulfuric acid etching strategy to enhance the selective oxidation of cyclohexane based on the construction of strong binding centers was proved to be feasible and effective,Acid@CeO_(2)-NR with strongest etching response achieved the dramatic promotion of KA-Oil selectivity from 64.1%to 92.3%.展开更多
Post-etching method using dilute acid solutions is an effective technology to modulate the surface compositions of metal-oxide catalysts.Here theα-MnO_(2) catalyst treated with 0.1 mol/L nitric acid exhibits higher o...Post-etching method using dilute acid solutions is an effective technology to modulate the surface compositions of metal-oxide catalysts.Here theα-MnO_(2) catalyst treated with 0.1 mol/L nitric acid exhibits higher ozone decomposition activity at high relative humidity than the counterpart treated with acetic acid.Besides the increases in surface area and lattice dislocation,the improved activity can be due to relatively higher Mn valence on the surface and newly-formed Brønsted acid sites adjacent to oxygen vacancies.The remnant nitro species deposited on the catalyst by nitric acid treatment is ideal hydrophobic groups at ambient conditions.The decomposition route is also proposed based on the DRIFTS and DFT calculations:ozone is facile to adsorb on the oxygen vacancy,and the protonic H of Brønsted acid sites bonds to the terminal oxygen of ozone to accelerate its cleavage to O_(2),reducing the reaction energy barrier of O_(2) desorption.展开更多
Objective:To investigate the potential of ascorbic acid in mitigating reproductive toxicity induced by di-(2-ethyl hexyl)phthalate(DEHP)in female Wistar rats,focusing on oxidative stress,hormone levels,and gonadotropi...Objective:To investigate the potential of ascorbic acid in mitigating reproductive toxicity induced by di-(2-ethyl hexyl)phthalate(DEHP)in female Wistar rats,focusing on oxidative stress,hormone levels,and gonadotropin receptors expression.Methods:Forty female Wistar rats[30 days old,weighing(60±10)g]were randomly divided into five groups(n=8 per group).Group 1 received corn oil(control).Groups 2 and 3 were administered DEHP at 10 and 100 mg/kg body weight(b.wt.),respectively.Groups 4 and 5 received DEHP at 10 and 100 mg/kg b.wt.,respectively,plus ascorbic acid 100 mg/kg b.wt..All treatments were given orally for 30 days.Blood and ovarian tissues were collected to assess serum reproductive hormones,gonadotropin receptor gene expression,oxidative stress markers,and apoptosis.Results:DEHP,particularly at the higher dose,significantly decreased hormone levels(follicle-stimulating hormone,luteinizing hormone,estradiol)and gonadotropin receptor gene expression(FSHR,LHR),while increasing oxidative stress and apoptosis.Co-treatment with ascorbic acid significantly improved these parameters,reducing oxidative stress and apoptosis,and restoring hormone levels and gonadotropin receptor expression.Histopathology revealed fewer atretic follicles and less disruption in ovarian structure in DEHP and ascorbic acid-treated groups compared to those treated with DEHP alone.Conclusions:Ascorbic acid demonstrates protective effects against DEHP-induced reproductive toxicity in female rats,likely through mitigating oxidative stress and normalizing hormone levels and ovarian function.展开更多
文摘Although enantiomers of 2-phenylpropionic acids (2-PPAs), or profens are important group of nonsteroidal anti-inflammatory drugs (NSAIDs) and have been in clinical use for many years, there is no literature covering its binding interaction in particular with cyclodextrins. NSAIDs are marketed as racemates, chiral discrimination and knowledge of enantiomeric bioavailability is essential. Circular dichroism (CD) spectroscopy is the technique of choice for elucidating chirality and monitoring and characterizing molecular recognition phenomena in solution. Methods em-ploying the fundamentals of the simultaneous measurements of absorbance and CD and a novel efficient titration method have been developed to study the binding of β-Cyclodextrin (β-CyD) and the two enantiomers of 2-PPA as a function of pH. The effect on physicochemical properties and bioavailability was investigated. The binding constant, stoichiometry and pKa for both the free and the bound drugs were determined using a Levenburg-Marquadt non-linear equation. The exact nature of the enantiomer discriminating interactions by cyclodextrins (CyDs) is not well understood. In this work, the interactions and co-conformations of both enantiomers of 2-PPA with β-CyD were explained and es-timated using spectroscopic variations upon complexation. The results indicated a change in the physicochemical prop-erties of 2-PPAs upon complexation and highlighted the enantioselective binding of β-CyD as a function of pH. The charge on the vip molecule and its stereochemistry are of great importance in regulating the stability of the vip/β-CyD complexes;hence the bioavailability of drugs. This work elucidates 2-PPAs/β-CyD binding interactions and highlights the effect of β-CyD on drugs with an effective novel method for binding titration and the potential of the simultaneous measurements of absorbance and CD in future chiral drug interactions studies.
基金Project supported by the National Natural Science Foundation of China(Nos.31470092 and 31501459)the Natural Science Youth Foundation of Jiangsu Province(No.BK20130380)China
文摘（R）-2-hydroxy-3-phenylpropionic acid （PIP,） is an ideal antimicrobial compound with broad-spectrum activity against a wide range of Gram-positive bacteria, some Gram-negative bacteria, and fungi. We studied the bioconversion of phenylpyruvate （PPA） to PLA using whole recombinant Escherichia coli cells in a series of buffer/organic solvent systems. Octane was found to be the best organic solvent. The optimum volume ratio of the water phase to the n-octane phase, conversion temperature, substrate concentration, and cell concentration were 6：4, 40 ℃, 12.5 g/L, and 30 g/L wet cells, respectively. Under the optimized conditions, the average PLA productivity in the aqueous/ n-octane system was 30.69% higher than that in the aqueous system, and 32.31 g/L PLA was obtained with the use of a stirred reactor （2-L scale）. Taken together, our findings indicated that PLA biosynthesis was more efficient in an aqueous/n-octane biphasic system than in a monophasic aqueous system. The proposed biphasic system is an effective strategy for enhancing PLA yield and the biosynthesis of its analogues.
基金the support from National Key R&D Program of China (2021YFC2103704)the National Natural Science Foundation of China (22222808)+4 种基金the Natural Science Foundation of Shandong Province (ZR2023QB152)the Youth Innovation Team Plan of Shandong Province (2022KJ270)the China National Postdoctoral Program for Innovative Talents (BX20240251)the Aeronautical Science Foundation of China (2023Z073048003)the Haihe Laboratory of Sustainable Chemical Transformations。
文摘Photoinduced[2+2]cycloaddition of biomass-derived cycloolefin is a promising approach to synthesize high-energy bio-fuels,however,the conversion efficiency and selectivity are still low.Herein,we provide an acid-promoted photocycloaddition approach to synthesize a new kind of spiral fuel from biomass-derived cyclohexanone (CHOE) and camphene (CPE).BrΦnsted acids show higher catalytic activity than Lewis acids,and acetic acid (HOAc) possesses the best catalytic performance,with CHOE conversion up to 99.1%.Meanwhile,the HOAc-catalytic effect has been confirmed for[2+2]photocycloaddition of other biomass-derived ketenes and olefins.The catalytic mechanism and dynamics have been investigated,and show that HOAc can bond with C=O groups of CHOE to form H–CHOE complex,which leads to higher light adsorption and longer triplet lifetime.Meanwhile,H–CHOE complex reduces the energy gap between CHOE LUMO and CPE HOMO,shortens the distance of ring-forming atoms,and then decreases the energy barrier (from 103.3 kcal mol^(-1)to 95.8 kcal mol^(-1)) of rate-limiting step.After hydrodeoxygenation,the targeted bio-spiral fuel shows high density of 0.992 g cm^(-3),high neat heat of combustion of 41.89 MJ L^(-1),low kinetic viscosity of 5.69 mm^(2)s^(-1)at 20℃,which is very promising to serve as high-performance aerospace fuel.
基金supported by the National Natural Science Foundation of China,Nos.32371070 (to JT),31761163005 (to JT),32100824 (to QX)the Shenzhen Science and Technology Program,Nos.RCBS20210609104606024 (to QX),JCY20210324101813035 (to DL)+4 种基金the Guangdong Provincial Key S&T Program,No.2018B030336001 (to JT)the Key Basic Research Program of Shenzhen Science and Technology Innovation Commission,Nos.JCYJ20200109115405930 (to JT),JCYJ20220818101615033 (to DL),JCYJ20210324115811031 (to QX),JCYJ20200109150717745 (to QX)Shenzhen Key Laboratory of Neuroimmunomodulation for Neurological Diseases,No.ZDSYS20220304163558001 (to JT)Guangdong Provincial Key Laboratory of Brain Connectome and Behavior,No.2023B1212060055 (to JT)the China Postdoctoral Science Foundation,No.2021M693298 (to QX)。
文摘The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain function and encoding behaviors associated with emotions.Specifically, astrocytes in the basolateral amygdala have been found to play a role in the modulation of anxiety-like behaviors triggered by chronic stress. Nevertheless, the precise molecular mechanisms by which basolateral amygdala astrocytes regulate chronic stress–induced anxiety-like behaviors remain to be fully elucidated. In this study, we found that in a mouse model of anxiety triggered by unpredictable chronic mild stress, the expression of excitatory amino acid transporter 2 was upregulated in the basolateral amygdala. Interestingly, our findings indicate that the targeted knockdown of excitatory amino acid transporter 2 specifically within the basolateral amygdala astrocytes was able to rescue the anxiety-like behavior in mice subjected to stress. Furthermore, we found that the overexpression of excitatory amino acid transporter 2 in the basolateral amygdala, whether achieved through intracranial administration of excitatory amino acid transporter 2agonists or through injection of excitatory amino acid transporter 2-overexpressing viruses with GfaABC1D promoters, evoked anxiety-like behavior in mice. Our single-nucleus RNA sequencing analysis further confirmed that chronic stress induced an upregulation of excitatory amino acid transporter 2 specifically in astrocytes in the basolateral amygdala. Moreover, through in vivo calcium signal recordings, we found that the frequency of calcium activity in the basolateral amygdala of mice subjected to chronic stress was higher compared with normal mice.After knocking down the expression of excitatory amino acid transporter 2 in the basolateral amygdala, the frequency of calcium activity was not significantly increased, and anxiety-like behavior was obviously mitigated. Additionally, administration of an excitatory amino acid transporter 2 inhibitor in the basolateral amygdala yielded a notable reduction in anxiety level among mice subjected to stress. These results suggest that basolateral amygdala astrocytic excitatory amino acid transporter 2 plays a role in in the regulation of unpredictable chronic mild stress-induced anxiety-like behavior by impacting the activity of local glutamatergic neurons, and targeting excitatory amino acid transporter 2 in the basolateral amygdala holds therapeutic promise for addressing anxiety disorders.
基金Project supported by the Natural Science Foundation Innovation Group Project of Hubei Province(2023AFA044)the National Natural Science Foundation of China(52222405)+1 种基金the Science and Technology Research Project of Education Department of Hubei Province(Q20221505)the China Postdoctoral Science(2023M731041)。
文摘In order to reveal the effect of 2-hydroxy-3-naphthyl hydroxamic acid(H205)on the flotation behavior and action mechanism of bastnaesite,single-mineral flotation experiments of bastnaesite were conducted.The flotation recovery of bastnaesites can be achieved more than 90%when the aeration rate is 40 mL/min,the rotational speed is 200 r/min,the H205 dosage is 120 mg/L,and the pulp pH ranges from 7 to 9.The action mechanism of H205 on the surface of bastnaesite was studied by simultaneous thermogravimetry and differential scanning calorimetry(TG-DSC),Zeta potential measurements,Fourier transform-infrared spectra(FT-IR)and X-ray photoelectron spectroscopy(XPS).These analysis results show that under suitable flotation conditions,H205 has an obvious adsorption phenomenon on the surface of bastnaesite.The adsorption involves electrostatic interactions and chemical interactions,namely H205 has a strong collecting ability of bastnaesite due to the synergism of electrostatic adsorption and chemical adsorption.This study systematically reveals the flotation behavior and adsorption mechanism of H205 on the surface of bastnaesite,and provides useful theoretical guidance for efficient flotation separation of bastnaesite.
基金supported by the National Key Research and Development Program of China for Young Scientists(Grant No.2023YFB4104100)the National Natural Science Foundation of China(Grant 52176057)+3 种基金the National Key Research and Development Program of China(Grant No.2023YFB4104201)supported by the Unveiling and Commanding Foundation of Liaoning Province(Grant 2023JH1/10400003)the Shenzhen Science and Technology Program(No.JCYJ20220818095605012)supported by the Young Changjiang Scholars programme of China。
文摘Carbon dioxide(CO_(2))marine sequestration by hydrate method is considered as one of the options to effectively achieve carbon reduction.However,the slow rate of hydrate formation becomes a major limiting factor.In view of the gas-water mass transfer problem which is the main obstacle,this paper explored the amphiphilic amino acids to promote the formation of CO_(2)hydrate and used low-field nuclear magnetic resonance(LNMR)to conduct an innovative study on its kinetics and spatiotemporal distribution.By comparing the promotion performance of L-methionine(L-met),L-cysteine(L-cys),and L-valine(L-val),the comprehensive kinetic promotion ability of L-met was the highest,reducing the induction time by 60.0%,achieving the maximum water conversion of about 57.0%within only 1 h,and reaching a final CO_(2)storage efficiency of 84.6%.LNMR results showed that hydrates were preferentially formed in large and medium pores in the reservoir region.Interestingly,we found that the combined effect of hydrophilic groups and the hydrophobic side chain of L-met not only promoted the rearrangement of water molecules and provided more nucleation sites,but also created a localized CO_(2)supersaturated environment and facilitated gas-water redistribution.Meanwhile,L-met promoted the formation of a hydrate porous structure to ensure the continuous formation of hydrates.This study innovatively explored CO_(2)hydrate formation behavior in amphiphilic amino acids and laid a theoretical foundation for the realization of CO_(2)marine sequestration by hydrate method.
基金supported by the Swedish Energy Agency(P47500-1)the National Key R&D Program of China(2020YFA0710200)+2 种基金the National Natural Science Foundation of China(22378401 and U22A20416)the financial support from STINT(CH2019-8287)financial support from the European Union and Swedish Energy Agency(P2020-90066).
文摘The catalytic oxidation of HMF involves a cascading reaction with multiple intermediate products,making it crucial to enhance the oriented adsorption capacity of specific functional groups for accelerating the entire process.To achieve the efficient selective oxidation of HMF to FDCA,a series of NiCo_(2)O_(4)catalysts with different morphologies,such as flaky,echinoids,pompon and corolla,were prepared and characterized by XRD,SEM,TEM,BET,XPS,and FTIR.Among the four catalysts,flaky NiCo_(2)O_(4)exhibited the most excellent catalytic activity and stability,with a FDCA yield of 60.1%within 12 h at 80℃without alkali participation.The excellent performance of flaky NiCo_(2)O_(4)catalyst is attributed to the oxygen vacancies and acid sites generated by the exposed(400)facets.The oxygen vacancies and acid sites on the catalyst surface can precisely adsorb-CHO and-CH_(2)-OH of HMF,respectively,and this synergistic effect promotes the efficient production of FDCA.This work is of great significance for fundamentally study the effect of micro-topography or crystal-plane reaction properties on surfaces.
基金the Alliance Project of Shanghai City in China(LM201641)。
文摘Two different Mn-Ce-O_(x)/TiO_(2) catalysts were prepared by ordinary impregnation(denoted as MCT) and citric acid assisted impregnation(denoted as MCT-CA) methods,respectively.Excellent NOxremoval is achieved over MCT-CA for selective catalytic reduction with NH3(NH_(3)-SCR),and 100% NOxconversion is obtained at 125℃ under weight hour space velocity(WHSV) of 80000 mL/(gcat·h).Particularly,100% NOxis converted on MCT-CA in the presence of 10 vol% H2O at 175℃.As H2O and SO2coexist in the reaction system for 9 h,NO_(x) conversion can still be maintained>90%,much higher than that(22%) of MCT.A series of characterization results indicates that MCT-CA exhibits a larger BET specific surface area,pore volume,and pore size,which enhances the dispersion of Mn and Ce oxides and promotes the rapid adsorption of reactants and desorption of products.Additionally,MCT-CA possesses more Mn^(4+),Ce^(3+),chemisorbed oxygen species,and stronger reducibility,facilitating the co nversion of NO to NO_(2).Specially,the amount of active NH_(3) species and active nitrate species on MCT-CA is much more than that over MCT,The combined effect of the aforementioned factors devotes to the excellent low-temperature SCR performance and tolerance to H2O/SO2over MCT-CA.
基金financial support from the National Natural Science Foundation of China(Nos.22171090,21871090)National Key Research and Development Program of China(No.2020YFA0710200)+1 种基金the Innovation Program of Shanghai Municipal Education Commission(No.2023ZKZD37)the Fundamental Research Funds for the Central Universities are highly appreciated。
文摘Here,we report a novel nickel-catalyzed electrochemical carboxylation of propargylic esters with CO_(2),characterized by the regioselective synthesis of 2,3-allenoic acids rather than propargylic carboxylic acids.Both acyclic propargylic esters and cyclic propargylic carbonates serve as effective substrates,facilitating the synthesis of mono-,di-,tri-,and tetra-substituted 2,3-allenoic acids with broad substrate scope under mild conditions.Mechanistic investigations indicate that the in situ generated Ni(Ⅰ)complex might serve as the active species to react with propargylic esters,forming the allenyl-Ni(Ⅰ)complex under electroreductive conditions.A possible γ-selective nucleophilic attack of allenyl-Ni(Ⅰ)complex on CO_(2) is likely involved in the formation of the desired 2,3-allenoic acids.
基金supported by the National Natural Science Foundation of China(22378338,U22A20421)the Project for Science and Technology Plan of Fujian Province of China(2024H4007)。
文摘Poly(ethylene 2,5-furandicarboxylate)(PEF),a bioplastic synthesized via the polymerization of 2,5-furandicarboxylic acid(FDCA)with ethylene glycol,can be served as a substitute to petroleum-based polyethylene terephthalate(PET)due to its enhanced material properties.However,the fabrication of PEF with stable and desirable properties is still a challenge,largely due to the impurities in FDCA.In this study,a highly efficient purification strategy for FDCA was proposed,utilizing a dioxane/H_(2)O binary solvent system for effective crystallization.Furthermore,PEFs were synthesized from FDCA with varying impurity and the effects of these impurities were systematically characterized.The results revealed that impurities in FDCA could result in PEFs with relatively poor thermal properties.This study provides crucial insights for the impact of impurities on PEF properties and FDCA purification.
基金supported by the National Natural Science Foundation of China(32373062)the Natural Science Foundation of Shandong Province(ZR2023MC144)Funds of Shandong Province Modern Agricultural Technology System Innovation Team Program(SDAIT-21-10).
文摘Background Deoxynivalenol(DON)is a mycotoxin that severely pollutes feed ingredients,and methods for reducing DON toxicity have become a significant research direction.Chlorogenic acid(CGA)is an active polyphenol found in some plants,which has anti-inflammatory and antioxidant properties and a protective effect on animal intestinal health.The effects of CGA on DON-induced pyroptosis in the intestinal porcine epithelial cell line-J2(IPEC-J2)and its potential mechanism were explored in this study.Results IPEC-J2 cells viability and membrane integrity were inversely correlated with DON concentration.Compared to those in the group treated with DON alone at 2,500 ng/mL,pretreatment with 80μmol/L CGA for 4 h significantly improved cell viability(P<0.01),and the alleviation of typical pyroptotic symptoms induced by DON were observed,including reduced cellular DNA fragmentation,decreased release of lactate dehydrogenase(LDH),normalized ROS levels,restoration of extracellularCa2+andK+contents to normal levels(P<0.01),as well as suppressed the enzyme activities of caspase-1 and caspase-4(P<0.01).Additionally,the mRNA expression levels of TNF,MDP,NOD2,TLR4,ASC and GSDMD were significantly improved(P<0.01),while both mRNA and protein expression levels of NF-κB,NLRP3,caspase-1,IL-1βand IL-18 were significantly upregulated(P<0.01)in the CGA+DON group,compare to those in the DON group.Conclusion Pretreatment with 80μmol/L CGA for 4 h effectively alleviated pyroptosis in IPEC-J2 cells induced by 2,500 ng/mL of DON through inhibiting activation of the NF-κB/NLRP3/capase-1 pathway.
文摘Direct converting carbon dioxide(CO_(2))and propane(C_(3)H_(8))into aromatics with high carbon utilization offers a desirable opportunity to simultaneously mitigate CO_(2)emission and adequately utilize C_(3)H_(8) in shale gas.Owing to their thermodynamic resistance,converting CO_(2)and C_(3)H_(8) respectively remains difficult.Here,we achieve 60.2%aromatics selectivity and 48.8%propane conversion over H-ZSM-5-25 via a zeolite-catalyzing the coupling of CO_(2)and C_(3)H_(8).Operando dual-beam FTIR spectroscopy combined with ^(13)C-labeled CO_(2)tracing experiments revealed that CO_(2)is directly involved in the generation of aromatics,with its carbon atoms selectively embedded into the aromatic ring,bypassing the reverse water-gas shift pathway.Accordingly,a cooperative aromatization mechanism is proposed.Thereinto,lactones,produced from CO_(2)and olefins,are proven to be the key intermediate.This work not only provides an opportunity for simultaneous conversion of CO_(2)and C_(3)H_(8),but also expends coupling strategy designing of CO_(2)and alkanes over acidic zeolites.
基金supported by the EPFL,EMPA and the National Research Foundation of Singapore(Urban Solutions and Sustainability,Industry Alignment Fund[Pre‐Positioning]Programme)(A‐0004543‐00‐00)。
文摘Acidic environments enhance CO_(2) utilization during CO_(2) electrolysis via a buffering effect that converts carbonates formed at the electrode surface back into CO_(2).Nevertheless,further investigation into acidic CO_(2) electrolysis is required to improve its selectivity towards certain CO_(2) reduction reaction(CO_(2)RR)products,such as multicarbon(C2+)species,while enhancing its overall stability.In this study,liquid product recirculation in the catholyte and local OH−accumulation were identified as primary factors contributing to the degradation of gas diffusion electrodes mounted in closed‐loop catholyte configurations.We demonstrate that a single‐pass catholyte configuration prevents liquid product recirculation and maintains a continuous flow of acidic‐pH catholyte throughout the reaction while using the same volume as a closed‐loop setup.This approach improves electrode durability and maintains a Faradaic efficiency of 67%for multicarbon products over 4 h of CO_(2) electrolysis at−600 mA cm^(-2).
基金supported by National Natural Science Fund for Excellent Young Scholars(22222813)the National Natural Science Foundation of China(22078338)+2 种基金the National Key Research and Development Program of China(2023YFA1506803)the Postdoctoral Fellowship Program of CPSF(GZC20232700)the“Special Research Assistant Project”of the Chinese Academy of Sciences.
文摘Nanostructured ceria has attracted much attention in the field of redox catalysts due to the numerous active sites with excellent redox ability.Based on the acidic medium etching strategy,we constructed the strong binding centers(hydroxyl sites and strong acid sites)on the surfaces of nanostructured ceria,which regulate the adsorption process of KA-Oil(the mixture of cyclohexanol and cyclohexanone)and to promote high KA-Oil selectivity in cyclohexane oxidation.The three CeO_(2)(nanocube,nanorod and nanopolyhedron)with different exposed crystal planes were treated by acid etching to change the surface sites and catalytic properties.The transition behavior of surface sites during etching was revealed,abundant strong binding centers were proved to be constructed successfully.And especially for the nanorod treated by acid(Acid@CeO_(2)-NR)with the strongest response for sulfuric acid etching,the strong adsorption of cyclohexanone by strong binding centers was confirmed based on the in-situ DRIFTs.The sulfuric acid etching strategy to enhance the selective oxidation of cyclohexane based on the construction of strong binding centers was proved to be feasible and effective,Acid@CeO_(2)-NR with strongest etching response achieved the dramatic promotion of KA-Oil selectivity from 64.1%to 92.3%.
基金supported by the National Natural Science Foundation of China(Nos.22206155 and T2341002)the Fundamental Research Funds for the Central Universities of China(Nos.2682022CX035 and 2682022KJ035)+2 种基金China Postdoctoral Science Foundation(Nos.2022M712632 and 2023T160547)Sichuan Science and Technology Program(No.2023JDRC0066)the State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex(No.SCAPC202109).
文摘Post-etching method using dilute acid solutions is an effective technology to modulate the surface compositions of metal-oxide catalysts.Here theα-MnO_(2) catalyst treated with 0.1 mol/L nitric acid exhibits higher ozone decomposition activity at high relative humidity than the counterpart treated with acetic acid.Besides the increases in surface area and lattice dislocation,the improved activity can be due to relatively higher Mn valence on the surface and newly-formed Brønsted acid sites adjacent to oxygen vacancies.The remnant nitro species deposited on the catalyst by nitric acid treatment is ideal hydrophobic groups at ambient conditions.The decomposition route is also proposed based on the DRIFTS and DFT calculations:ozone is facile to adsorb on the oxygen vacancy,and the protonic H of Brønsted acid sites bonds to the terminal oxygen of ozone to accelerate its cleavage to O_(2),reducing the reaction energy barrier of O_(2) desorption.
文摘Objective:To investigate the potential of ascorbic acid in mitigating reproductive toxicity induced by di-(2-ethyl hexyl)phthalate(DEHP)in female Wistar rats,focusing on oxidative stress,hormone levels,and gonadotropin receptors expression.Methods:Forty female Wistar rats[30 days old,weighing(60±10)g]were randomly divided into five groups(n=8 per group).Group 1 received corn oil(control).Groups 2 and 3 were administered DEHP at 10 and 100 mg/kg body weight(b.wt.),respectively.Groups 4 and 5 received DEHP at 10 and 100 mg/kg b.wt.,respectively,plus ascorbic acid 100 mg/kg b.wt..All treatments were given orally for 30 days.Blood and ovarian tissues were collected to assess serum reproductive hormones,gonadotropin receptor gene expression,oxidative stress markers,and apoptosis.Results:DEHP,particularly at the higher dose,significantly decreased hormone levels(follicle-stimulating hormone,luteinizing hormone,estradiol)and gonadotropin receptor gene expression(FSHR,LHR),while increasing oxidative stress and apoptosis.Co-treatment with ascorbic acid significantly improved these parameters,reducing oxidative stress and apoptosis,and restoring hormone levels and gonadotropin receptor expression.Histopathology revealed fewer atretic follicles and less disruption in ovarian structure in DEHP and ascorbic acid-treated groups compared to those treated with DEHP alone.Conclusions:Ascorbic acid demonstrates protective effects against DEHP-induced reproductive toxicity in female rats,likely through mitigating oxidative stress and normalizing hormone levels and ovarian function.
