Carbenes as one of the most important class of intermediates have been widely utilized in various organic synthetic transformations.Carbene insertion-initiated ring-opening reactions of cyclic ethers offer a valuable ...Carbenes as one of the most important class of intermediates have been widely utilized in various organic synthetic transformations.Carbene insertion-initiated ring-opening reactions of cyclic ethers offer a valuable strategy for constructing new carbon-oxygen bonds.In comparison with traditional thermal or metal-mediated carbene transfer reactions,visible-light-promoted multi-component reaction strategy provides a mild and eco-friendly approach to access densely functionalized molecules.Recently,visible-light-induced multi-component carbene transfer reactions of diazo compounds have been rapidly developed and attracted a great deal of research interest of chemists owing to their advantages of simple operation,mild condition,high atom economy and rich structural diversity.This paper summarizes the recent research progress on the visible-light-promoted multi-component carbene transfer reactions of diazo compounds via ring-opening of cyclic ethers with various nucleophiles.The reaction patterns of different nucleophiles and their corresponding mechanism are described in this review.The future research direction and challenges in this area are also discussed.展开更多
Zearalenone(ZEN)is a non-steroidal estrogenic mycotoxin that extensively contaminates feed and feed ingredients,posing a significant threat to animal health and food safety.Enzymatic degradation of ZEN is regarded as ...Zearalenone(ZEN)is a non-steroidal estrogenic mycotoxin that extensively contaminates feed and feed ingredients,posing a significant threat to animal health and food safety.Enzymatic degradation of ZEN is regarded as a promising strategy due to its high efficiency and safety.This review provides a comprehensive summary of recent advances in ZEN-degrading enzymes from a novel perspective,encompassing the types and catalytic mechanisms for characterizing ZEN-degrading enzymes,the methods for mining ZEN-degrading enzymes,the strategies for improving ZEN-degrading enzymes,and the applications of ZEN-degrading enzymes.The objective of this review is to offer a reliable reference framework for the enzymatic detoxification of ZEN in feed and feed ingredients,as well as to provide insights for mining other mycotoxin degrading enzyme in the future.展开更多
Background:Corchorus olitorius L.(Malvaceae)is a green leafy vegetable widely consumed in the Middle East and valued for its rich nutritional content.Its essential oils,an important class of secondary metabolites,are ...Background:Corchorus olitorius L.(Malvaceae)is a green leafy vegetable widely consumed in the Middle East and valued for its rich nutritional content.Its essential oils,an important class of secondary metabolites,are of growing interest for potential use in cosmetics and fragrance industries due to their bioactive properties.Methods:Leaves of C.olitorius cultivated in Egypt were extracted using microwave-assisted hydrodistillation(MAHD)and conventional hydrodistillation(HD).The oils were analyzed by gas chromatography-mass spectrometry(GC-MS)to characterize their chemical profiles.In vitro assays were conducted to evaluate their anti-elastase and anti-collagenase activities,and in silico studies were performed to predict the pharmacokinetic and pharmacodynamic properties of major constituents.Results:GC-MS analysis showed that aldehydes,alkanes,fatty alcohols,fatty acids,and their derivatives were the predominant compound classes in both oils.Notably,oxygenated diterpenes(11.22%)were present exclusively in the MAHD oil,while triterpenoids(16.37%)were found only in the HD oil.The MAHD oil demonstrated stronger In vitro anti-elastase(IC_(50)=42.5μg/mL)and anti-collagenase(IC_(50)=131.5μg/mL)activities compared to the HD oil(IC_(50)=66.7 and 206.8μg/mL,respectively),reflecting an approximate 36.3%improvement in elastase inhibition and 36.4%improvement in collagenase inhibition.In silico docking indicated that the triterpenoidβ-amyrin acetate showed the highest predicted binding affinity for porcine pancreatic elastase(PDB ID:6QEO,ΔG=−8.1 kcal/mol)and collagenase(PDB ID:456C,ΔG=−9.1 kcal/mol)among the major compounds analyzed.Conclusion:These findings demonstrate that MAHD is a greener and more efficient extraction method,yielding oil with enhanced enzyme inhibitory activity compared to conventional HD.The promising anti-elastase and anti-collagenase properties suggest that C.olitorius MAHD oil could serve as a potential candidate for anti-aging cosmetic formulations,following further validation.展开更多
Three-dimensional supramolecular organic frameworks with precisely tunable pore sizes are highly demanded for a wide range of applications,e.g.,encapsulating enzymes to enhance their stability,activity,and reusability...Three-dimensional supramolecular organic frameworks with precisely tunable pore sizes are highly demanded for a wide range of applications,e.g.,encapsulating enzymes to enhance their stability,activity,and reusability.However,precise control and tune the pore size of such frameworks still remains a significant challenge to date.In this study,we constructed supramolecular polymer frameworks using rigid tetrahedral star polyisocyanides with tunable length and sufficiently narrow distribution as building block.First,a series of tetrahedral four-arm star polyisocyanides with controlled chain lengths and narrow molecular weight distributions was prepared via the Pd(Ⅱ)-catalyzed living isocyanide polymerization.Then 2-ureido-4[1H]-pyrimidinone(Upy) unit was installed onto each chain-end of polyisocyanide arms via post-polymerization functionalization.Leveraging the supramolecular hydrogen bonding interactions between the terminal Upy units,well-ordered supramolecular polymer frameworks were readily obtained.Notably,the pore size was dependent on the chain length of the polyisocyanide arms.Precisely control the chain length of polyisocyanide arms,supramolecular polymer frameworks with pore sizes ranging from 5.06 nm to 9.72 nm were achieved.These frameworks,with tunable and large pore apertures,demonstrated exceptional capabilities in encapsulating enzymes of different sizes,such as lipase(TL),horseradish peroxidase(HRP),and glucose oxidase(GOx).The encapsulated enzymes exhibited significantly enhanced catalytic activity and durability.Moreover,the frameworks' tunable and large pore apertures facilitated the co-encapsulation of multiple enzymes,enabling efficient dual-enzyme cascade reactions.展开更多
Brown spot(BS)of rice,caused by Bipolaris oryzae,is a serious concern that not only causes quantitative losses but also affects grain quality.To manage this disease,the use of resistant genetic sources and QTLs is an ...Brown spot(BS)of rice,caused by Bipolaris oryzae,is a serious concern that not only causes quantitative losses but also affects grain quality.To manage this disease,the use of resistant genetic sources and QTLs is an eco-friendly and economical option.In the current study,F_(3) progenies derived from a cross of susceptible parent PMS-18-B(PAU 10845-1-1-1-1)×resistant parent RP Path 77(RP patho-17)were used to identify potential QTLs linked to BS resistance and to associate this resistance with a temporal spike in defense-related enzymes.展开更多
The combined effects of macronutrients(Nitrogen,Phosphorus,and Potassium-N,P,K)and micronutrient fertilization on turmeric yield,soil enzymatic activity,microbial biomass,and nutrient dynamics remains poorly understoo...The combined effects of macronutrients(Nitrogen,Phosphorus,and Potassium-N,P,K)and micronutrient fertilization on turmeric yield,soil enzymatic activity,microbial biomass,and nutrient dynamics remains poorly understood,despite their significance for sustainable soil fertility management and optimizing crop productivity across diverse agroecosystems.To investigate,a net house experiment on sandy loam Haplic Chernozem was conducted to 03 fertilizer regimes,viz.N_(75)P_(50)K_(50)kg ha^(−1)(T-2),N_(12)5P_(100)K_(100)kg ha^(−1)(T-3),and N_(100)P_(75)K_(75)+B_(3)Zn_(6)Fe_(6)kg ha^(−1)(T-4).Furthermore,the influence of these treatments was systematically assessed on soil nutrient status(N,P,K),enzymatic activities(alkaline phosphomonoesterase,dehydrogenase,fluorescein diacetate hydrolysis),microbial biomass carbon(MBC)and soil organic carbon(SOC).Balanced fertilization significantly turmeric productivity and soil health.All three fertilizer treatments showed a clear yield increase compared to the unfertilized control.Compared to the control,N_(75)P_(50)K_(50)kg/ha T-2 increased rhizome number and biomass per plant by 44.7%and 16.3%,respectively,while N_(100)P_(75)K_(75)+B_(3)Zn_(6)Fe_(6)kg/ha T-4 further enhanced them by 86.6%and 27.7%.T-3 produced the most significant yield response by increasing the rhizome biomass by 38.0%and rhizome number per plant by 100%compared to the control.The nutrient availability was also substantially improved.T-2 enhanced the soil nitrogen contents by 83.3%with maximum N levels observed in T-3&T-4.Phosphorus increased by 61.5%in T-3 and 37.3%in T-4,while potassium was enhanced by 12.9%in T-3 relative to the control,respectively.Enzymatic activities were markedly enhanced as T-3 was recorded to improve alkaline phosphomonoesterase(APA),dehydrogenase(DHA)and fluorescein diacetate hydrolysis(FDA)by 50.6%,37.4%,and 43.4%,where T-4 increased by 32.2%,30.9%,and 35.9%,respectively compared to control.MBC and SOC also rose significantly,with SOC increased by 13.8%(T-2),41.6%(T-3),and 47.2%(T-3)relative to control.The result of this study demonstrates that the integrated macroµnutrient fertilization,particularly T-37 T-4 treatments,sustainably enhanced turmeric yield,soil nutrient availability,enzyme activity,microbial biomass,and organic carbon.These findings highlight the critical role of balanced nutrient management in sustaining soil fertility and crop productivity across agroecosystems.展开更多
Constructing a framework carrier to stabilize protein conformation,induce high embedding efficiency,and acquire low mass-transfer resistance is an urgent issue in the development of immobilized enzymes.Hydrogen-bonded...Constructing a framework carrier to stabilize protein conformation,induce high embedding efficiency,and acquire low mass-transfer resistance is an urgent issue in the development of immobilized enzymes.Hydrogen-bonded organic frameworks(HOFs)have promising application potential for embedding enzymes.In fact,no metal involvement is required,and HOFs exhibit superior biocompatibility,and free access to substrates in mesoporous channels.Herein,a facile in situ growth approach was proposed for the self-assembly of alcohol dehydrogenase encapsulated in HOF.The micron-scale bio-catalytic composite was rapidly synthesized under mild conditions(aqueous phase and ambient temperature)with a controllable embedding rate.The high crystallinity and periodic arrangement channels of HOF were preserved at a high enzyme encapsulation efficiency of 59%.This bio-composite improved the tolerance of the enzyme to the acid-base environment and retained 81%of its initial activity after five cycles of batch hydrogenation involving NADH coenzyme.Based on this controllably synthesized bio-catalytic material and a common lipase,we further developed a two-stage cascade microchemical system and achieved the continuous production of chiral hydroxybutyric acid(R-3-HBA).展开更多
Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)enters host cells via the angiotensin-converting enzyme 2(ACE2)receptor.Mounting evidence has indicated the presence of hepatic SARS-CoV-2 infection and liver...Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)enters host cells via the angiotensin-converting enzyme 2(ACE2)receptor.Mounting evidence has indicated the presence of hepatic SARS-CoV-2 infection and liver injury in pa-tients with coronavirus disease 2019(COVID-19).Understanding the mechanisms of hepatic SARS-CoV-2 infection is crucial for addressing COVID-19–related liver pathology and developing targeted therapies.This editorial discusses the signi-ficance of ACE2 in hepatic SARS-CoV-2 infection,drawing on the research by Jacobs et al.Their findings indicate that hepatic ACE2 expression,frequency of hepatic SARS-CoV-2 infection,and severity of liver injury are elevated in patients with pre-existing chronic liver diseases.These data suggest that hepatic ACE2 could be a promising therapeutic target for COVID-19.展开更多
This study was conducted at the scientific center of Brazzaville. The objective was to assess the microbial characteristics and enzymes activities in the rhizosphere soil of Cajanus cajan and Milletia lauurentii. Thes...This study was conducted at the scientific center of Brazzaville. The objective was to assess the microbial characteristics and enzymes activities in the rhizosphere soil of Cajanus cajan and Milletia lauurentii. These plants have great importance in food and forestry. Microbial diversity management in the rhizosphere is the key for sustainable crop production or forest durability. DNA metagenomic sequencing was used to analyze the whole bacterial diversity, the microbial biomass was determinate by the fumigation-extraction method and the enzymes by the p-nitrophenol-β-D-glucoside for β-glucosidase, the p-nitrophenyl-N-acetyl-β-D-glucosaminide for β-Glucosaminidase. Dehydrogenase and acid phosphatase were quantified using 2,3,5-tryphenyl tetrazolium chloride and p-nitophenylphosphate respectively. The results show that, in Cajanus cajan culturable bacteria genera were mainly Acidobacterium, Skermanella, Rhodoplanes, Bacillus, Chloroflexus, Steroidobacter, Sphingomonas and Bradyrhizobium while in Milletia laurentii: Rhodoplanes, Bradyrhizobium, Bacillus, Sphingobacterium, Acidobacterium, Mesorhizobium, Nitrospira were the principal genera. In the two rhizosphere soils investigated, the uncultured bacteria exhibited relatively higher abundance, often for the same genera, than culturable bacteria. Metagenomic studies have revealed more bacterial diversity in each compared to when culturable bacteria were taken into account alone. The MBC and MBN were higher in the rhizosphere of Milletia than in rhizosphere of Cajanus. The same trend was observed with the enzyme activities. PCA of culturable and NMDS of unculturable soil bacteria genera shows that factors mainly involved in the carbon cycle such as MBC, members of the microbial community i.e. Acidobacterium, Skermanella, Chloroflexus, sand, C, β-glucosaminidase and dehydrogenase, were strongly correlated with Cajanus cajan. On the other hand, the MBN, Mesorhizobium, Bradyrhizobium, Burkholderia, Nitrospira, Nitratireductor, N, NH4, β-glucosidase and acid phosphatase involved in the N cycling, silt and clay were predominantly founded in the rhizosphere soil of Milletia laurentii. This study showed that metagenomic sequencing could improve the assessment of the microbial diversity structure of the rhizosphere.展开更多
In recent years,chiral inorganic nanomaterials have become promising candidates for applications in sensing,catalysis,biomedicine,and photonics.Plasmonic nanomaterials with an intrinsic chiral structure exhibit intrig...In recent years,chiral inorganic nanomaterials have become promising candidates for applications in sensing,catalysis,biomedicine,and photonics.Plasmonic nanomaterials with an intrinsic chiral structure exhibit intriguing geometry‑dependent optical chirality,which benefits the combination of plasmonic characteristics with chirality.Recent advances in the biomolecule‑directed geometric control of intrinsically chiral plasmonic nanomaterials have further provided great opportunities for their widespread applications in many emerging technological areas.In this review,we present the recent progress in biosensing using chiral inorganic nanomaterials,with a particular focus on electrochemical and enzyme‑mimicking catalytic approaches.This paper commences with a review of the basic tenets underlying chiral nanocatalysts,incorporating the chiral ligand‑induced mechanism and the architectures of intrinsically chiral nanostructures.Additionally,it methodically expounds upon the applications of chiral nanocatalysts in the realms of electrochemical biosensing and enzyme‑mimicking catalytic biosensing respectively.Conclusively,it proffers a prospective view of the hurdles and prospects that accompany the deployment of chiral nanoprobes for nascent biosensing applications.By rational design of the chiral nanoprobes,it is envisioned that biosensing with increasing sensitivity and resolution toward the single‑molecule level can be achieved,which will substantially promote sensing applications in many emerging interdisciplinary areas.展开更多
UBE2O is a distinctive ubiquitin-conjugating enzyme characterized by its large size(1292 residues)and dual E2/E3 enzymatic activities,enabling diverse ubiquitylation types.Unlike typical E2 enzymes(150~200 residues),U...UBE2O is a distinctive ubiquitin-conjugating enzyme characterized by its large size(1292 residues)and dual E2/E3 enzymatic activities,enabling diverse ubiquitylation types.Unlike typical E2 enzymes(150~200 residues),UBE2O’s multifunctionality allows it to regulate substrate degradation,subcellular localization,and functional modulation.Emerging studies highlight its critical roles in protein quality control,erythroid differentiation,metabolic regulation,and maintenance of circadian rhythm.Dysregulation of UBE2O is implicated in various diseases,including cancers,neurodegenerative disorders,and metabolic diseases.This review extensively discusses the unique structural features,diverse biological functions,and pathological roles of UBE2O,as well as its therapeutic potential for associated diseases.展开更多
Background The environmental impact of feedlot operations is a growing concern,as cattle excrete a significant portion of feed nutrients as waste.Exogenous feed enzymes(EFE)have gained interest for their potential to ...Background The environmental impact of feedlot operations is a growing concern,as cattle excrete a significant portion of feed nutrients as waste.Exogenous feed enzymes(EFE)have gained interest for their potential to enhance feed efficiency in ruminants by improving nutrient digestion.However,EFE effects on ruminal parameters have shown inconsistencies,with limited research on nitrogen metabolism and rumen microbiome impacts.Moreover,the synergistic effects of combining different EFEs remain unclear.This study aimed to evaluate the effects of individual and combined EFE products in feedlot diets on ruminal fermentation parameters,nitrogen metabolism,and ruminal microbial communities.Ten rumen-cannulated Nellore steers[543±28.6 kg of body weight(BW)]were distributed in a replicated Latin-square design(5×5)in individual pens.Treatments included:control(CON,no EFE supplementation),amylase[AML,0.5 g/kg of diet dry matter(DM)],xylanase(FBL,0.9 g/kg DM),half dose combination(HD,0.25 g of AML+0.45 g of FBL/kg of DM),and full dose combination(FD,0.5 g of AML+0.90 g of FBL/kg of DM).The experimental period lasted 19 d and included total urine and feces collection(d 15 to 18)and rumen fluid sampling(d 19)at 0,4,8,12,and 16 h post-feeding for ammonia,volatile fatty acids(VFA),pH and microbiome analysis.Results EFE supplemented animals exhibited lower ruminal ammonia concentrations(P=0.040),and higher acetate proportions(P<0.001)compared to the control group.EFE supplementation resulted in reduced nitrogen(N)excretion in feces(P=0.049)and urine(P=0.036),contributing to improved N retention and efficiency(P=0.045).Additionally,EFE products induced shifts in various microbial taxa at family and genera levels(P≤0.10),which may be associated with the changes observed in ruminal fermentation.Conclusions Our findings demonstrate that EFE supplementation enhances nitrogen retention,reduces ruminal ammonia,and alters ruminal fermentation profiles and microbial populations in feedlot cattle.While the expected synergism between amylase and xylanase did not significantly impact rumen fermentation parameters,it did induce shifts in the rumen microbiome.These results suggest that EFE supplementation may be a promising strategy for improving nutrient utilization and potentially reducing the environmental impact of feedlot operations.展开更多
Natural enzymes are able to precisely bind substrates and catalyze activities because of their distinct framework structures.To mimic this ability,chemists are designing framework structures that resemble real enzymes...Natural enzymes are able to precisely bind substrates and catalyze activities because of their distinct framework structures.To mimic this ability,chemists are designing framework structures that resemble real enzymes.The use of metal-organic frameworks(MOFs)to mimic natural enzymes has advanced recently;this paper reviews these developments.This research specifically focuses on how the catalytically active center of natural enzymes can be exactly replicated by carefully controlling the composition and structure of MOFs.By identifying and attaching to substrates,MOFs can accelerate changes in a manner akin to that of real enzymes.The role of MOFs in simulating catalytic processes,enzyme activity,and potential uses in brain chemistry are also investigated in this work.It also discusses the most recent MOF applications in detecting and treating chemical abnormalities of the brain.The report finishes with a discussion of future research areas and potential applications,providing useful insights for researchers in the subject.展开更多
Extensive research focuses on developing costeffective,high-performance electrochemical non-enzyme glucose sensors,particularly using nanocomposites of metal oxides and multi-component alloys.In this paper,a batch of ...Extensive research focuses on developing costeffective,high-performance electrochemical non-enzyme glucose sensors,particularly using nanocomposites of metal oxides and multi-component alloys.In this paper,a batch of nano-flaky Cu_(x)O decorated CuCoNiFeSi(Cu_(x)O@Cu/Fe)and CuCoNiSi(Cu_(x)O@Cu)electrode was developed by melt-spinning following by anodization.According to the results,the sensitivity of Cu_(x)O@Cu/Fe-25/35 for glucose detection in the lower(0–1 mM)and higher region(1–15 and 15–21 mM)is 2.544,1.51 and0.64 mA mM^(-1)cm^(-2),respectively.The limit of detection(LOD)was estimated to be 0.88μM(signal noise ratio(S/N)=3).Furthermore,the Cu_(x)O@Cu/Fe-25/35 possessed various merits,such as excellent selectivity,good reusability,acceptable reproducibility,satisfying long-term stability,and high tolerance to chloride ions.The enhanced performances of the Cu_(x)O@Cu/Fe-25/35 electrodes are attributable to the feather-like Cu_(x)O and synergistic effect between Cu_(x)O and Ni(Fe,Co)_(3)Si_(2).The work provides a new pathway for detecting all glucose density by electrochemical non-enzymatic glucose sensor.展开更多
In the realm of nonlinear integrable systems,the presence of decompositions facilitates the establishment of linear superposition solutions and the derivation of novel coupled systems exhibiting nonlinear integrabilit...In the realm of nonlinear integrable systems,the presence of decompositions facilitates the establishment of linear superposition solutions and the derivation of novel coupled systems exhibiting nonlinear integrability.By focusing on single-component decompositions within the potential BKP hierarchy,it has been observed that specific linear superpositions of decomposition solutions remain consistent with the underlying equations.Moreover,through the implementation of multi-component decompositions within the potential BKP hierarchy,successful endeavors have been undertaken to formulate linear superposition solutions and novel coupled Kd V-type systems that resist decoupling via alterations in dependent variables.展开更多
Multi-component transition group metal borides(MMB_(2))have become a research hotspot due to their new composition design concepts and superior properties compared with conventional ceramics.Most of the current method...Multi-component transition group metal borides(MMB_(2))have become a research hotspot due to their new composition design concepts and superior properties compared with conventional ceramics.Most of the current methods,however,are complicated and time-consuming,the mass production remains a chal-lenge.Herein,we proposed a new high-efficiency strategy for synthesis of MMB_(2)using molten aluminum as the medium for the first time.The prepared Al-containing multi-component borides(TiZrHfNbTa)B_(2)microcrystals had a homogeneous composition with a hexagonal AlB_(2)structure and ultra-high hardness value of∼35.3 GPa,which was much higher than data reported in the literature and the rule of mix-ture estimations.Furthermore,combined with the First-principles calculation results,we found that the Poisson’s ratio(v)values exhibit a clearly ascending trend from 0.17 at VEC=3.5 to 0.18 at VEC=3.4,then to 0.201 at VEC=3.2 with the increasing of Al content.This indicates that the intrinsic toughness of multi-component boride microcrystals is obviously enhanced by the trace-doped Al elements.Besides,the fabricated Al-containing multi-component boride microcrystals have superior oxidation activation en-ergy and structural stability.The enhanced oxidation resistance is mainly attributed to the formation of a protective Al2 O3 oxide layer and the lattice distortion,both of which lead to sluggish diffusion of O_(2).These findings propose a new unexplored avenue for the fabrication of MMB_(2)materials with supe-rior comprehensive performance including ultra-hardness and intrinsically improved thermo-mechanical properties.展开更多
[Objectives]To prepare four kinds of fruit enzymes from pitaya(dragon fruit),papaya,orange and pineapple,and to detect their physicochemical properties and antioxidant activities.[Methods]Using pitaya,papaya,orange an...[Objectives]To prepare four kinds of fruit enzymes from pitaya(dragon fruit),papaya,orange and pineapple,and to detect their physicochemical properties and antioxidant activities.[Methods]Using pitaya,papaya,orange and pineapple as raw materials,pitaya enzyme,papaya enzyme,orange enzyme and pineapple enzyme were obtained by natural fermentation.The physical and chemical properties and antioxidant activity of the four fruit enzymes were analyzed,and the dominant strains in papaya ferment were identified.[Results]The pH of the four fruit enzymes ranged from 3.32 to 3.59.The sensory evaluation of orange and papaya enzymes was relatively superior;among them,the orange enzyme exhibited the highest hydroxyl radical scavenging rate(95.76%),while the pineapple enzyme had the highest total phenol content(27.21μg/mL).The papaya enzyme showed the highest values for DPPH,reducing power,and flavonoids,at 70.55,1.699,and 0.1216 mg/mL,respectively.Through the comprehensive comparing,the physicochemical properties and antioxidant activity of the papaya enzyme were relatively superior,with its dominant microbial species being Lactobacillus and Saccharomyces cerevisiae.[Conclusions]Papaya enzyme is a kind of functional food with great development potential,and this study can provide reference for the development of fruit enzyme with high added value.展开更多
Directed degradation of abundant renewable lignin into small aromatic compounds is crucial for lignin valorization but challenging.The degradation of lignin in natural environments typically involves multienzyme syner...Directed degradation of abundant renewable lignin into small aromatic compounds is crucial for lignin valorization but challenging.The degradation of lignin in natural environments typically involves multienzyme synergy.However,the proteinaceous characteristics of lignin-degrading enzymes restrict their accessibility to certain regions of intricate lignin,resulting in the multienzyme systems being unable to fully demonstrate their effectiveness.Herein,a de novo biomimetic enzyme-nanozyme hybrid system was constructed by combiningλ-MnO_(2) nanozyme with laccase CotA from Bacillus subtilis,aimed at facilitating lignin degradation under mild conditions.The lignin degradation rate of the CotA+λ-MnO_(2) hybrid system was determined to be 25.15%,which was much higher than those of the lignin degradation systems with only laccase CotA(15.32%)orλ-MnO_(2) nanozyme(14.90%).Notably,the proportion of aromatic chemicals in the products derived from the hybrid system reached as much as 48%,which was 41.2%and 118.2%higher than those of the CotA-andλ-MnO_(2)-catalyzed systems,respectively.Analysis of products mapping and lignin structure changes suggested that the higher proportion of aromatic compounds in the CotA+λ-MnO_(2)hybrid system was more likely to benefit from the laccase-mediated methoxylation.Moreover,electron paramagnetic resonance analysis indicated that the intensity and kind of free radicals such as·OH and·O_(2)^(-)are closely linked to the degradation rate and reaction type.This work is the inaugural application of an enzyme-nanozyme hybrid system for lignin degradation,demonstrating the potential of the synergistic interaction between enzyme and nanozyme in the directed degradation of lignin.展开更多
The hardening mechanism of multi-component carbide ceramic has been investigated in detail through a combination of experiments,first-principles calculations,and ab initio molecular dynamics(AIMD).Eight dense carbide ...The hardening mechanism of multi-component carbide ceramic has been investigated in detail through a combination of experiments,first-principles calculations,and ab initio molecular dynamics(AIMD).Eight dense carbide ceramics were prepared by spark plasma sintering.Compulsorily,all the multi-component carbide samples have similar carbon content,grain size,and uniform compositional distribution by optimizing the sintering process and adjusting the initial raw materials.Hence the interference of other factors on the hardness of multi-component carbide ceramics is minimized.The effects of changes in the elemental species on the lattice distortion,bond strength,bonding properties,and electronic structure of multi-component carbide ceramics were thoroughly analyzed.These results show that the hardening of multi-component carbide ceramic can be attributed to the coupling of solid solution strengthening caused by lattice distortion and covalent bond strengthening.Besides,the“host lattice”of multi-component carbide ceramics is defined based on the concept of supporting lattice.The present work is of great significance for a deeper understanding of the hardening mechanism of multi-component carbide ceramics and the design of superhard multi-component carbides.展开更多
In order to explore the remediation effects of lignite and biochar on Zn-contaminated soil,this experiment studied the impacts of adding lignite and biochar on soil respiration,soil enzyme activity,and organic carbon ...In order to explore the remediation effects of lignite and biochar on Zn-contaminated soil,this experiment studied the impacts of adding lignite and biochar on soil respiration,soil enzyme activity,and organic carbon in Zn-contaminated soil through soil culture experiments,which provided a theoretical basis for the remediation and improvement as well as for the development and utilization of Zn-contaminated soil.The study was an L8(4×2^(2))orthogonal experimental design with eight treatments,in which there were four levels of Zn contamination concentration(Z0:0;Z1:125 mg•kg^(-1);Z2:250 mg•kg^(-1);Z3:500 mg•kg^(-1)),low-Zn(125-250 mg•kg^(-1))and high-Zn(500 mg•kg^(-1)),two levels of lignite(H0:0;H1:13.33 g•kg^(-1)),two levels of biochar(C0:0;C1:3.33 g•kg^(-1)),with four replicates per treatment.The results showed that lignite or biochar and their interaction had extremely significant effects on both respiration rate and accumulation in Zn-contaminated soil.Among the high Zn-contaminated treatments,the mixed application of lignite and biochar(Z3H1C1 treatment)had the fastest soil respiration rate and the highest soil respiration accumulation.Lignite,biochar and their interaction had significant or extremely significant effects on sucrase,catalase and polyphenol oxidase activities in Zn-contaminated soil.Among the high Zn-contaminated treatments(Z3),the addition of biochar alone had the most significant effects on the increase of soil sucrase and catalase enzyme activities,while the mixed application of lignite and biochar had the most significant effects on the increase of soil polyphenol oxidase activity.Lignite,biochar and their interaction had significant or extremely significant effects on the total organic carbon,active organic carbon and microbial carbon content of Zn-contaminated soils.Soil total organic carbon content in general peaked at day 80.Among the high Zn-contaminated treatments,the addition of biochar alone had the most significant effects on the total organic carbon content of the soil,while the mixed application of lignite and biochar had the most significant effect on the microbiomass carbon content.展开更多
基金Science and Technology Foundation of Guizhou Province(No.QKHJC-ZK[2024]654)Guizhou Provincial University Key Laboratory of Advanced Functional Electronic Materials(No.QJ[2023]021).
文摘Carbenes as one of the most important class of intermediates have been widely utilized in various organic synthetic transformations.Carbene insertion-initiated ring-opening reactions of cyclic ethers offer a valuable strategy for constructing new carbon-oxygen bonds.In comparison with traditional thermal or metal-mediated carbene transfer reactions,visible-light-promoted multi-component reaction strategy provides a mild and eco-friendly approach to access densely functionalized molecules.Recently,visible-light-induced multi-component carbene transfer reactions of diazo compounds have been rapidly developed and attracted a great deal of research interest of chemists owing to their advantages of simple operation,mild condition,high atom economy and rich structural diversity.This paper summarizes the recent research progress on the visible-light-promoted multi-component carbene transfer reactions of diazo compounds via ring-opening of cyclic ethers with various nucleophiles.The reaction patterns of different nucleophiles and their corresponding mechanism are described in this review.The future research direction and challenges in this area are also discussed.
基金funding support from the National Natural Science Foundation of China(31772637)。
文摘Zearalenone(ZEN)is a non-steroidal estrogenic mycotoxin that extensively contaminates feed and feed ingredients,posing a significant threat to animal health and food safety.Enzymatic degradation of ZEN is regarded as a promising strategy due to its high efficiency and safety.This review provides a comprehensive summary of recent advances in ZEN-degrading enzymes from a novel perspective,encompassing the types and catalytic mechanisms for characterizing ZEN-degrading enzymes,the methods for mining ZEN-degrading enzymes,the strategies for improving ZEN-degrading enzymes,and the applications of ZEN-degrading enzymes.The objective of this review is to offer a reliable reference framework for the enzymatic detoxification of ZEN in feed and feed ingredients,as well as to provide insights for mining other mycotoxin degrading enzyme in the future.
基金Egyptian Science and Technology and Innovation Fund(STIFA)for the support of the study through grant No.46667 entitled“Sustainability of Lab Capacities of the Center of Drug Discovery Research and Development”.
文摘Background:Corchorus olitorius L.(Malvaceae)is a green leafy vegetable widely consumed in the Middle East and valued for its rich nutritional content.Its essential oils,an important class of secondary metabolites,are of growing interest for potential use in cosmetics and fragrance industries due to their bioactive properties.Methods:Leaves of C.olitorius cultivated in Egypt were extracted using microwave-assisted hydrodistillation(MAHD)and conventional hydrodistillation(HD).The oils were analyzed by gas chromatography-mass spectrometry(GC-MS)to characterize their chemical profiles.In vitro assays were conducted to evaluate their anti-elastase and anti-collagenase activities,and in silico studies were performed to predict the pharmacokinetic and pharmacodynamic properties of major constituents.Results:GC-MS analysis showed that aldehydes,alkanes,fatty alcohols,fatty acids,and their derivatives were the predominant compound classes in both oils.Notably,oxygenated diterpenes(11.22%)were present exclusively in the MAHD oil,while triterpenoids(16.37%)were found only in the HD oil.The MAHD oil demonstrated stronger In vitro anti-elastase(IC_(50)=42.5μg/mL)and anti-collagenase(IC_(50)=131.5μg/mL)activities compared to the HD oil(IC_(50)=66.7 and 206.8μg/mL,respectively),reflecting an approximate 36.3%improvement in elastase inhibition and 36.4%improvement in collagenase inhibition.In silico docking indicated that the triterpenoidβ-amyrin acetate showed the highest predicted binding affinity for porcine pancreatic elastase(PDB ID:6QEO,ΔG=−8.1 kcal/mol)and collagenase(PDB ID:456C,ΔG=−9.1 kcal/mol)among the major compounds analyzed.Conclusion:These findings demonstrate that MAHD is a greener and more efficient extraction method,yielding oil with enhanced enzyme inhibitory activity compared to conventional HD.The promising anti-elastase and anti-collagenase properties suggest that C.olitorius MAHD oil could serve as a potential candidate for anti-aging cosmetic formulations,following further validation.
基金The National Natural Science Foundation of China (NSFC,Nos.92256201,52273006,22071041,92356302,and 21971052)Natural Science Foundation of Jilin Province (No.20240101181JC) are gratefully appreciated for financial the supportssupported by the User Experiment Assist System of Shanghai Synchrotron Radiation Facility (SSRF)。
文摘Three-dimensional supramolecular organic frameworks with precisely tunable pore sizes are highly demanded for a wide range of applications,e.g.,encapsulating enzymes to enhance their stability,activity,and reusability.However,precise control and tune the pore size of such frameworks still remains a significant challenge to date.In this study,we constructed supramolecular polymer frameworks using rigid tetrahedral star polyisocyanides with tunable length and sufficiently narrow distribution as building block.First,a series of tetrahedral four-arm star polyisocyanides with controlled chain lengths and narrow molecular weight distributions was prepared via the Pd(Ⅱ)-catalyzed living isocyanide polymerization.Then 2-ureido-4[1H]-pyrimidinone(Upy) unit was installed onto each chain-end of polyisocyanide arms via post-polymerization functionalization.Leveraging the supramolecular hydrogen bonding interactions between the terminal Upy units,well-ordered supramolecular polymer frameworks were readily obtained.Notably,the pore size was dependent on the chain length of the polyisocyanide arms.Precisely control the chain length of polyisocyanide arms,supramolecular polymer frameworks with pore sizes ranging from 5.06 nm to 9.72 nm were achieved.These frameworks,with tunable and large pore apertures,demonstrated exceptional capabilities in encapsulating enzymes of different sizes,such as lipase(TL),horseradish peroxidase(HRP),and glucose oxidase(GOx).The encapsulated enzymes exhibited significantly enhanced catalytic activity and durability.Moreover,the frameworks' tunable and large pore apertures facilitated the co-encapsulation of multiple enzymes,enabling efficient dual-enzyme cascade reactions.
基金supported by Punjab Agricultural University,Ludhiana,India,for providing the infrastructure and other facilities for conducting experiments.All other forms of support and financial assistance are duly acknowledged.
文摘Brown spot(BS)of rice,caused by Bipolaris oryzae,is a serious concern that not only causes quantitative losses but also affects grain quality.To manage this disease,the use of resistant genetic sources and QTLs is an eco-friendly and economical option.In the current study,F_(3) progenies derived from a cross of susceptible parent PMS-18-B(PAU 10845-1-1-1-1)×resistant parent RP Path 77(RP patho-17)were used to identify potential QTLs linked to BS resistance and to associate this resistance with a temporal spike in defense-related enzymes.
基金supported by the Department of Biotechnology,Government of India(DBT),TWAS,and the Ministry of Innovative Development of Uzbekistan。
文摘The combined effects of macronutrients(Nitrogen,Phosphorus,and Potassium-N,P,K)and micronutrient fertilization on turmeric yield,soil enzymatic activity,microbial biomass,and nutrient dynamics remains poorly understood,despite their significance for sustainable soil fertility management and optimizing crop productivity across diverse agroecosystems.To investigate,a net house experiment on sandy loam Haplic Chernozem was conducted to 03 fertilizer regimes,viz.N_(75)P_(50)K_(50)kg ha^(−1)(T-2),N_(12)5P_(100)K_(100)kg ha^(−1)(T-3),and N_(100)P_(75)K_(75)+B_(3)Zn_(6)Fe_(6)kg ha^(−1)(T-4).Furthermore,the influence of these treatments was systematically assessed on soil nutrient status(N,P,K),enzymatic activities(alkaline phosphomonoesterase,dehydrogenase,fluorescein diacetate hydrolysis),microbial biomass carbon(MBC)and soil organic carbon(SOC).Balanced fertilization significantly turmeric productivity and soil health.All three fertilizer treatments showed a clear yield increase compared to the unfertilized control.Compared to the control,N_(75)P_(50)K_(50)kg/ha T-2 increased rhizome number and biomass per plant by 44.7%and 16.3%,respectively,while N_(100)P_(75)K_(75)+B_(3)Zn_(6)Fe_(6)kg/ha T-4 further enhanced them by 86.6%and 27.7%.T-3 produced the most significant yield response by increasing the rhizome biomass by 38.0%and rhizome number per plant by 100%compared to the control.The nutrient availability was also substantially improved.T-2 enhanced the soil nitrogen contents by 83.3%with maximum N levels observed in T-3&T-4.Phosphorus increased by 61.5%in T-3 and 37.3%in T-4,while potassium was enhanced by 12.9%in T-3 relative to the control,respectively.Enzymatic activities were markedly enhanced as T-3 was recorded to improve alkaline phosphomonoesterase(APA),dehydrogenase(DHA)and fluorescein diacetate hydrolysis(FDA)by 50.6%,37.4%,and 43.4%,where T-4 increased by 32.2%,30.9%,and 35.9%,respectively compared to control.MBC and SOC also rose significantly,with SOC increased by 13.8%(T-2),41.6%(T-3),and 47.2%(T-3)relative to control.The result of this study demonstrates that the integrated macroµnutrient fertilization,particularly T-37 T-4 treatments,sustainably enhanced turmeric yield,soil nutrient availability,enzyme activity,microbial biomass,and organic carbon.These findings highlight the critical role of balanced nutrient management in sustaining soil fertility and crop productivity across agroecosystems.
基金supported by the National Key Research and Development Program of China(2019YFA0905100)the National Natural Science Foundation of China(21991102,22378227).
文摘Constructing a framework carrier to stabilize protein conformation,induce high embedding efficiency,and acquire low mass-transfer resistance is an urgent issue in the development of immobilized enzymes.Hydrogen-bonded organic frameworks(HOFs)have promising application potential for embedding enzymes.In fact,no metal involvement is required,and HOFs exhibit superior biocompatibility,and free access to substrates in mesoporous channels.Herein,a facile in situ growth approach was proposed for the self-assembly of alcohol dehydrogenase encapsulated in HOF.The micron-scale bio-catalytic composite was rapidly synthesized under mild conditions(aqueous phase and ambient temperature)with a controllable embedding rate.The high crystallinity and periodic arrangement channels of HOF were preserved at a high enzyme encapsulation efficiency of 59%.This bio-composite improved the tolerance of the enzyme to the acid-base environment and retained 81%of its initial activity after five cycles of batch hydrogenation involving NADH coenzyme.Based on this controllably synthesized bio-catalytic material and a common lipase,we further developed a two-stage cascade microchemical system and achieved the continuous production of chiral hydroxybutyric acid(R-3-HBA).
基金Supported by National Natural Science Foundation of China,No.82172915,No.81972648,and No.81773011Chongqing Medical University Program for Youth Innovation in Future Medicine,No.W0084+1 种基金Science and Technology Innovation Project of Chongqing Medical Universityand Chongqing Postdoctoral Science Foundation,No.CSTB2023NSCQ-BHX0134.
文摘Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)enters host cells via the angiotensin-converting enzyme 2(ACE2)receptor.Mounting evidence has indicated the presence of hepatic SARS-CoV-2 infection and liver injury in pa-tients with coronavirus disease 2019(COVID-19).Understanding the mechanisms of hepatic SARS-CoV-2 infection is crucial for addressing COVID-19–related liver pathology and developing targeted therapies.This editorial discusses the signi-ficance of ACE2 in hepatic SARS-CoV-2 infection,drawing on the research by Jacobs et al.Their findings indicate that hepatic ACE2 expression,frequency of hepatic SARS-CoV-2 infection,and severity of liver injury are elevated in patients with pre-existing chronic liver diseases.These data suggest that hepatic ACE2 could be a promising therapeutic target for COVID-19.
文摘This study was conducted at the scientific center of Brazzaville. The objective was to assess the microbial characteristics and enzymes activities in the rhizosphere soil of Cajanus cajan and Milletia lauurentii. These plants have great importance in food and forestry. Microbial diversity management in the rhizosphere is the key for sustainable crop production or forest durability. DNA metagenomic sequencing was used to analyze the whole bacterial diversity, the microbial biomass was determinate by the fumigation-extraction method and the enzymes by the p-nitrophenol-β-D-glucoside for β-glucosidase, the p-nitrophenyl-N-acetyl-β-D-glucosaminide for β-Glucosaminidase. Dehydrogenase and acid phosphatase were quantified using 2,3,5-tryphenyl tetrazolium chloride and p-nitophenylphosphate respectively. The results show that, in Cajanus cajan culturable bacteria genera were mainly Acidobacterium, Skermanella, Rhodoplanes, Bacillus, Chloroflexus, Steroidobacter, Sphingomonas and Bradyrhizobium while in Milletia laurentii: Rhodoplanes, Bradyrhizobium, Bacillus, Sphingobacterium, Acidobacterium, Mesorhizobium, Nitrospira were the principal genera. In the two rhizosphere soils investigated, the uncultured bacteria exhibited relatively higher abundance, often for the same genera, than culturable bacteria. Metagenomic studies have revealed more bacterial diversity in each compared to when culturable bacteria were taken into account alone. The MBC and MBN were higher in the rhizosphere of Milletia than in rhizosphere of Cajanus. The same trend was observed with the enzyme activities. PCA of culturable and NMDS of unculturable soil bacteria genera shows that factors mainly involved in the carbon cycle such as MBC, members of the microbial community i.e. Acidobacterium, Skermanella, Chloroflexus, sand, C, β-glucosaminidase and dehydrogenase, were strongly correlated with Cajanus cajan. On the other hand, the MBN, Mesorhizobium, Bradyrhizobium, Burkholderia, Nitrospira, Nitratireductor, N, NH4, β-glucosidase and acid phosphatase involved in the N cycling, silt and clay were predominantly founded in the rhizosphere soil of Milletia laurentii. This study showed that metagenomic sequencing could improve the assessment of the microbial diversity structure of the rhizosphere.
文摘In recent years,chiral inorganic nanomaterials have become promising candidates for applications in sensing,catalysis,biomedicine,and photonics.Plasmonic nanomaterials with an intrinsic chiral structure exhibit intriguing geometry‑dependent optical chirality,which benefits the combination of plasmonic characteristics with chirality.Recent advances in the biomolecule‑directed geometric control of intrinsically chiral plasmonic nanomaterials have further provided great opportunities for their widespread applications in many emerging technological areas.In this review,we present the recent progress in biosensing using chiral inorganic nanomaterials,with a particular focus on electrochemical and enzyme‑mimicking catalytic approaches.This paper commences with a review of the basic tenets underlying chiral nanocatalysts,incorporating the chiral ligand‑induced mechanism and the architectures of intrinsically chiral nanostructures.Additionally,it methodically expounds upon the applications of chiral nanocatalysts in the realms of electrochemical biosensing and enzyme‑mimicking catalytic biosensing respectively.Conclusively,it proffers a prospective view of the hurdles and prospects that accompany the deployment of chiral nanoprobes for nascent biosensing applications.By rational design of the chiral nanoprobes,it is envisioned that biosensing with increasing sensitivity and resolution toward the single‑molecule level can be achieved,which will substantially promote sensing applications in many emerging interdisciplinary areas.
基金Supported by Special Projects in Key Areas for Guangdong Provincial Colleges and Universities (No.2021ZDZX2009)Guangzhou Medical University Discipline Construction Funds (Basic Medicine)(No.JCXKJS2022A05)。
文摘UBE2O is a distinctive ubiquitin-conjugating enzyme characterized by its large size(1292 residues)and dual E2/E3 enzymatic activities,enabling diverse ubiquitylation types.Unlike typical E2 enzymes(150~200 residues),UBE2O’s multifunctionality allows it to regulate substrate degradation,subcellular localization,and functional modulation.Emerging studies highlight its critical roles in protein quality control,erythroid differentiation,metabolic regulation,and maintenance of circadian rhythm.Dysregulation of UBE2O is implicated in various diseases,including cancers,neurodegenerative disorders,and metabolic diseases.This review extensively discusses the unique structural features,diverse biological functions,and pathological roles of UBE2O,as well as its therapeutic potential for associated diseases.
基金supported by the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo(FAPESP,Sao Paulo,SP,BRAZIL)for the scholarship of the first authors(2019/24820-3 and 2022/00989-1)and the PDIP grant(2017/50339-5).
文摘Background The environmental impact of feedlot operations is a growing concern,as cattle excrete a significant portion of feed nutrients as waste.Exogenous feed enzymes(EFE)have gained interest for their potential to enhance feed efficiency in ruminants by improving nutrient digestion.However,EFE effects on ruminal parameters have shown inconsistencies,with limited research on nitrogen metabolism and rumen microbiome impacts.Moreover,the synergistic effects of combining different EFEs remain unclear.This study aimed to evaluate the effects of individual and combined EFE products in feedlot diets on ruminal fermentation parameters,nitrogen metabolism,and ruminal microbial communities.Ten rumen-cannulated Nellore steers[543±28.6 kg of body weight(BW)]were distributed in a replicated Latin-square design(5×5)in individual pens.Treatments included:control(CON,no EFE supplementation),amylase[AML,0.5 g/kg of diet dry matter(DM)],xylanase(FBL,0.9 g/kg DM),half dose combination(HD,0.25 g of AML+0.45 g of FBL/kg of DM),and full dose combination(FD,0.5 g of AML+0.90 g of FBL/kg of DM).The experimental period lasted 19 d and included total urine and feces collection(d 15 to 18)and rumen fluid sampling(d 19)at 0,4,8,12,and 16 h post-feeding for ammonia,volatile fatty acids(VFA),pH and microbiome analysis.Results EFE supplemented animals exhibited lower ruminal ammonia concentrations(P=0.040),and higher acetate proportions(P<0.001)compared to the control group.EFE supplementation resulted in reduced nitrogen(N)excretion in feces(P=0.049)and urine(P=0.036),contributing to improved N retention and efficiency(P=0.045).Additionally,EFE products induced shifts in various microbial taxa at family and genera levels(P≤0.10),which may be associated with the changes observed in ruminal fermentation.Conclusions Our findings demonstrate that EFE supplementation enhances nitrogen retention,reduces ruminal ammonia,and alters ruminal fermentation profiles and microbial populations in feedlot cattle.While the expected synergism between amylase and xylanase did not significantly impact rumen fermentation parameters,it did induce shifts in the rumen microbiome.These results suggest that EFE supplementation may be a promising strategy for improving nutrient utilization and potentially reducing the environmental impact of feedlot operations.
基金financially supported by the National Natural Science Foundation,China(Nos.22074095&22374103(Y.Lin))Beijing Natural Science Foundation(No.2222005(Y.Lin))。
文摘Natural enzymes are able to precisely bind substrates and catalyze activities because of their distinct framework structures.To mimic this ability,chemists are designing framework structures that resemble real enzymes.The use of metal-organic frameworks(MOFs)to mimic natural enzymes has advanced recently;this paper reviews these developments.This research specifically focuses on how the catalytically active center of natural enzymes can be exactly replicated by carefully controlling the composition and structure of MOFs.By identifying and attaching to substrates,MOFs can accelerate changes in a manner akin to that of real enzymes.The role of MOFs in simulating catalytic processes,enzyme activity,and potential uses in brain chemistry are also investigated in this work.It also discusses the most recent MOF applications in detecting and treating chemical abnormalities of the brain.The report finishes with a discussion of future research areas and potential applications,providing useful insights for researchers in the subject.
基金supported by the Natural Science Foundation of Jiangsu Province(No.BK20230098)the National Natural Science Foundation of China(Nos.52101195 and 52222104)+2 种基金Key Laboratory of Advanced Nano Structures and Functional Materials Jiangsu Province Universities,the National Key R&D Program of China(No.2021YFB3802800)the Fundamental Research Funds for the Central Universities(Nos.30919011404 and 30920021156)the support by the Qing Lan project and the specially-appointed professor project of Jiangsu province
文摘Extensive research focuses on developing costeffective,high-performance electrochemical non-enzyme glucose sensors,particularly using nanocomposites of metal oxides and multi-component alloys.In this paper,a batch of nano-flaky Cu_(x)O decorated CuCoNiFeSi(Cu_(x)O@Cu/Fe)and CuCoNiSi(Cu_(x)O@Cu)electrode was developed by melt-spinning following by anodization.According to the results,the sensitivity of Cu_(x)O@Cu/Fe-25/35 for glucose detection in the lower(0–1 mM)and higher region(1–15 and 15–21 mM)is 2.544,1.51 and0.64 mA mM^(-1)cm^(-2),respectively.The limit of detection(LOD)was estimated to be 0.88μM(signal noise ratio(S/N)=3).Furthermore,the Cu_(x)O@Cu/Fe-25/35 possessed various merits,such as excellent selectivity,good reusability,acceptable reproducibility,satisfying long-term stability,and high tolerance to chloride ions.The enhanced performances of the Cu_(x)O@Cu/Fe-25/35 electrodes are attributable to the feather-like Cu_(x)O and synergistic effect between Cu_(x)O and Ni(Fe,Co)_(3)Si_(2).The work provides a new pathway for detecting all glucose density by electrochemical non-enzymatic glucose sensor.
基金sponsored by the National Natural Science Foundations of China under Grant Nos.12301315,12235007,11975131the Zhejiang Provincial Natural Science Foundation of China under Grant No.LQ20A010009。
文摘In the realm of nonlinear integrable systems,the presence of decompositions facilitates the establishment of linear superposition solutions and the derivation of novel coupled systems exhibiting nonlinear integrability.By focusing on single-component decompositions within the potential BKP hierarchy,it has been observed that specific linear superpositions of decomposition solutions remain consistent with the underlying equations.Moreover,through the implementation of multi-component decompositions within the potential BKP hierarchy,successful endeavors have been undertaken to formulate linear superposition solutions and novel coupled Kd V-type systems that resist decoupling via alterations in dependent variables.
基金financially supported by the National Natural Science Foundation of China(Nos.52271033 and 52071179)the Key program of National Natural Science Foundation of China(No.51931003)+2 种基金Natural Science Foundation of Jiangsu Province,China(No.BK20221493)Jiangsu Province Leading Edge Technology Basic Research Major Project(No.BK20222014)Foundation of“Qinglan Project”for Colleges and Universities in Jiangsu Province.
文摘Multi-component transition group metal borides(MMB_(2))have become a research hotspot due to their new composition design concepts and superior properties compared with conventional ceramics.Most of the current methods,however,are complicated and time-consuming,the mass production remains a chal-lenge.Herein,we proposed a new high-efficiency strategy for synthesis of MMB_(2)using molten aluminum as the medium for the first time.The prepared Al-containing multi-component borides(TiZrHfNbTa)B_(2)microcrystals had a homogeneous composition with a hexagonal AlB_(2)structure and ultra-high hardness value of∼35.3 GPa,which was much higher than data reported in the literature and the rule of mix-ture estimations.Furthermore,combined with the First-principles calculation results,we found that the Poisson’s ratio(v)values exhibit a clearly ascending trend from 0.17 at VEC=3.5 to 0.18 at VEC=3.4,then to 0.201 at VEC=3.2 with the increasing of Al content.This indicates that the intrinsic toughness of multi-component boride microcrystals is obviously enhanced by the trace-doped Al elements.Besides,the fabricated Al-containing multi-component boride microcrystals have superior oxidation activation en-ergy and structural stability.The enhanced oxidation resistance is mainly attributed to the formation of a protective Al2 O3 oxide layer and the lattice distortion,both of which lead to sluggish diffusion of O_(2).These findings propose a new unexplored avenue for the fabrication of MMB_(2)materials with supe-rior comprehensive performance including ultra-hardness and intrinsically improved thermo-mechanical properties.
文摘[Objectives]To prepare four kinds of fruit enzymes from pitaya(dragon fruit),papaya,orange and pineapple,and to detect their physicochemical properties and antioxidant activities.[Methods]Using pitaya,papaya,orange and pineapple as raw materials,pitaya enzyme,papaya enzyme,orange enzyme and pineapple enzyme were obtained by natural fermentation.The physical and chemical properties and antioxidant activity of the four fruit enzymes were analyzed,and the dominant strains in papaya ferment were identified.[Results]The pH of the four fruit enzymes ranged from 3.32 to 3.59.The sensory evaluation of orange and papaya enzymes was relatively superior;among them,the orange enzyme exhibited the highest hydroxyl radical scavenging rate(95.76%),while the pineapple enzyme had the highest total phenol content(27.21μg/mL).The papaya enzyme showed the highest values for DPPH,reducing power,and flavonoids,at 70.55,1.699,and 0.1216 mg/mL,respectively.Through the comprehensive comparing,the physicochemical properties and antioxidant activity of the papaya enzyme were relatively superior,with its dominant microbial species being Lactobacillus and Saccharomyces cerevisiae.[Conclusions]Papaya enzyme is a kind of functional food with great development potential,and this study can provide reference for the development of fruit enzyme with high added value.
文摘Directed degradation of abundant renewable lignin into small aromatic compounds is crucial for lignin valorization but challenging.The degradation of lignin in natural environments typically involves multienzyme synergy.However,the proteinaceous characteristics of lignin-degrading enzymes restrict their accessibility to certain regions of intricate lignin,resulting in the multienzyme systems being unable to fully demonstrate their effectiveness.Herein,a de novo biomimetic enzyme-nanozyme hybrid system was constructed by combiningλ-MnO_(2) nanozyme with laccase CotA from Bacillus subtilis,aimed at facilitating lignin degradation under mild conditions.The lignin degradation rate of the CotA+λ-MnO_(2) hybrid system was determined to be 25.15%,which was much higher than those of the lignin degradation systems with only laccase CotA(15.32%)orλ-MnO_(2) nanozyme(14.90%).Notably,the proportion of aromatic chemicals in the products derived from the hybrid system reached as much as 48%,which was 41.2%and 118.2%higher than those of the CotA-andλ-MnO_(2)-catalyzed systems,respectively.Analysis of products mapping and lignin structure changes suggested that the higher proportion of aromatic compounds in the CotA+λ-MnO_(2)hybrid system was more likely to benefit from the laccase-mediated methoxylation.Moreover,electron paramagnetic resonance analysis indicated that the intensity and kind of free radicals such as·OH and·O_(2)^(-)are closely linked to the degradation rate and reaction type.This work is the inaugural application of an enzyme-nanozyme hybrid system for lignin degradation,demonstrating the potential of the synergistic interaction between enzyme and nanozyme in the directed degradation of lignin.
基金financially supported by the National Natural Science Foundation of China(Nos.52032002,52372060,51972081,and U22A20128)the National Safety Academic Foundation(No.U2130103)+1 种基金the National Key Laboratory of Precision Hot Processing of Metals(No.61429092300305)Heilongjiang Touyan Team Program are gratefully acknowledged.
文摘The hardening mechanism of multi-component carbide ceramic has been investigated in detail through a combination of experiments,first-principles calculations,and ab initio molecular dynamics(AIMD).Eight dense carbide ceramics were prepared by spark plasma sintering.Compulsorily,all the multi-component carbide samples have similar carbon content,grain size,and uniform compositional distribution by optimizing the sintering process and adjusting the initial raw materials.Hence the interference of other factors on the hardness of multi-component carbide ceramics is minimized.The effects of changes in the elemental species on the lattice distortion,bond strength,bonding properties,and electronic structure of multi-component carbide ceramics were thoroughly analyzed.These results show that the hardening of multi-component carbide ceramic can be attributed to the coupling of solid solution strengthening caused by lattice distortion and covalent bond strengthening.Besides,the“host lattice”of multi-component carbide ceramics is defined based on the concept of supporting lattice.The present work is of great significance for a deeper understanding of the hardening mechanism of multi-component carbide ceramics and the design of superhard multi-component carbides.
基金Supported by the Special Fund for Agro-scientific Research in Public Interest in China(201503119-06-01)。
文摘In order to explore the remediation effects of lignite and biochar on Zn-contaminated soil,this experiment studied the impacts of adding lignite and biochar on soil respiration,soil enzyme activity,and organic carbon in Zn-contaminated soil through soil culture experiments,which provided a theoretical basis for the remediation and improvement as well as for the development and utilization of Zn-contaminated soil.The study was an L8(4×2^(2))orthogonal experimental design with eight treatments,in which there were four levels of Zn contamination concentration(Z0:0;Z1:125 mg•kg^(-1);Z2:250 mg•kg^(-1);Z3:500 mg•kg^(-1)),low-Zn(125-250 mg•kg^(-1))and high-Zn(500 mg•kg^(-1)),two levels of lignite(H0:0;H1:13.33 g•kg^(-1)),two levels of biochar(C0:0;C1:3.33 g•kg^(-1)),with four replicates per treatment.The results showed that lignite or biochar and their interaction had extremely significant effects on both respiration rate and accumulation in Zn-contaminated soil.Among the high Zn-contaminated treatments,the mixed application of lignite and biochar(Z3H1C1 treatment)had the fastest soil respiration rate and the highest soil respiration accumulation.Lignite,biochar and their interaction had significant or extremely significant effects on sucrase,catalase and polyphenol oxidase activities in Zn-contaminated soil.Among the high Zn-contaminated treatments(Z3),the addition of biochar alone had the most significant effects on the increase of soil sucrase and catalase enzyme activities,while the mixed application of lignite and biochar had the most significant effects on the increase of soil polyphenol oxidase activity.Lignite,biochar and their interaction had significant or extremely significant effects on the total organic carbon,active organic carbon and microbial carbon content of Zn-contaminated soils.Soil total organic carbon content in general peaked at day 80.Among the high Zn-contaminated treatments,the addition of biochar alone had the most significant effects on the total organic carbon content of the soil,while the mixed application of lignite and biochar had the most significant effect on the microbiomass carbon content.
