The uplift resistance of the soil overlying shield tunnels significantly impacts their anti-floating stability.However,research on uplift resistance concerning special-shaped shield tunnels is limited.This study combi...The uplift resistance of the soil overlying shield tunnels significantly impacts their anti-floating stability.However,research on uplift resistance concerning special-shaped shield tunnels is limited.This study combines numerical simulation with machine learning techniques to explore this issue.It presents a summary of special-shaped tunnel geometries and introduces a shape coefficient.Through the finite element software,Plaxis3D,the study simulates six key parameters—shape coefficient,burial depth ratio,tunnel’s longest horizontal length,internal friction angle,cohesion,and soil submerged bulk density—that impact uplift resistance across different conditions.Employing XGBoost and ANN methods,the feature importance of each parameter was analyzed based on the numerical simulation results.The findings demonstrate that a tunnel shape more closely resembling a circle leads to reduced uplift resistance in the overlying soil,whereas other parameters exhibit the contrary effects.Furthermore,the study reveals a diminishing trend in the feature importance of buried depth ratio,internal friction angle,tunnel longest horizontal length,cohesion,soil submerged bulk density,and shape coefficient in influencing uplift resistance.展开更多
In this study,an inverse design framework was established to find lightweight honeycomb structures(HCSs)with high impact resistance.The hybrid HCS,composed of re-entrant(RE)and elliptical annular re-entrant(EARE)honey...In this study,an inverse design framework was established to find lightweight honeycomb structures(HCSs)with high impact resistance.The hybrid HCS,composed of re-entrant(RE)and elliptical annular re-entrant(EARE)honeycomb cells,was created by constructing arrangement matrices to achieve structural lightweight.The machine learning(ML)framework consisted of a neural network(NN)forward regression model for predicting impact resistance and a multi-objective optimization algorithm for generating high-performance designs.The surrogate of the local design space was initially realized by establishing the NN in the small sample dataset,and the active learning strategy was used to continuously extended the local optimal design until the model converged in the global space.The results indicated that the active learning strategy significantly improved the inference capability of the NN model in unknown design domains.By guiding the iteration direction of the optimization algorithm,lightweight designs with high impact resistance were identified.The energy absorption capacity of the optimal design reached 94.98%of the EARE honeycomb,while the initial peak stress and mass decreased by 28.85%and 19.91%,respectively.Furthermore,Shapley Additive Explanations(SHAP)for global explanation of the NN indicated a strong correlation between the arrangement mode of HCS and its impact resistance.By reducing the stiffness of the cells at the top boundary of the structure,the initial impact damage sustained by the structure can be significantly improved.Overall,this study proposed a general lightweight design method for array structures under impact loads,which is beneficial for the widespread application of honeycomb-based protective structures.展开更多
Fusarium crown rot(FCR),predominantly caused by Fusarium pseudograminearum,has been listed as a Category Ⅱ disease in six provinces of China,posing a significant threat to wheat production.The phenylpyrrole fungicide...Fusarium crown rot(FCR),predominantly caused by Fusarium pseudograminearum,has been listed as a Category Ⅱ disease in six provinces of China,posing a significant threat to wheat production.The phenylpyrrole fungicide fludioxonil is a key agent for FCR control.Previous studies indicated that resistance to fludioxonil in F.pseudograminearum is primarily associated with altered expression levels of the FpOS1 gene,which encodes a hybrid histidine kinase.However,the roles of mutations in other FpOS genes and the molecular interactions between FpOS proteins and fludioxonil remain elusive.To address these gaps,we generated 16 fludioxonil-resistant mutants with heritable resistance traits by in vitro selection of four sensitive F.pseudograminearum isolates.These mutants exhibited high resistance levels,with resistance factors(RF)ranging from 633.73 to 8617.07.Compared to their parental isolates,the resistant mutants showed significantly reduced mycelial growth rate,sporulation capacity,and pathogenicity.They were also more sensitive to ionic,osmotic,and oxidative stresses and displayed compromised cell wall and membrane integrity.Fludioxonil demonstrated no cross-resistance with tebuconazole or pydiflumetofen;however,it exhibited weak positive crossresistance to pyraclostrobin and moderate positive cross-resistance to iprodione.Fludioxonil treatment significantly promoted glycerol synthesis and inhibited deoxynivalenol(DON)production in parental isolates,whereas these regulatory effects were markedly attenuated in the resistant mutants.Mutation analysis identified mutation sites in FpOS1,FpOS4,and FpOS5 genes,with a lower mutation frequency in FpOS1 and no mutations detected in FpOS2.Molecular docking indicated that amino acid substitutions in FpOS4 and FpOS5 significantly reduced the binding affinity of fludioxonil to these target proteins.In conclusion,F.pseudograminearum poses a moderate risk of resistance to fludioxonil.Point mutations in FpOS4 and FpOS5 genes emerge as key molecular drivers of resistance,likely by diminishing the binding affinity between the fungicide and its proteins.This study clarifies the molecular basis of fludioxonil resistance in F.pseudograminearum and provides a scientific rationale for the judicious use of this fungicide in managing FCR.展开更多
It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,...It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,and FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbents were prepared by coupling fly ash-based Si-Al carriers.The active components Fe-Ce-La oxides and Si-Al carriers were characterized by TPD,TG,XRF,BET and XPS,respectively.The effects of temperature,Si/Al ratio and FeCeLaO loading rate on the sulfur resistance were investigated.Results show that the SO_(2) promotes the arsenic removal of Fe_(2)O_(3),CeLaO and FeCeLaO.At 400℃,the arsenic removal efficiencies of the three oxides increase from 45.3%,72.5% and 81.3% without SO_(2) to 62.6%,80.5%and 91.0%,respectively.The SO_(2) inhibits the arsenic removal of La_(2)O_(2)CO_(3) and FeLaO,and the inhibition effect is pronounced at high temperatures.The sulfur poisoning resistance of Si-Al carriers increases with the increase of Si/Al ratio.When the Si/Al ratio is increased to 9.74,the arsenic removal efficiency in the SO_(2) environment is 13.9% higher than that in the absence of SO_(2).Introducing FeCeLaO active components is beneficial for enhancing the SO_(2) poisoning resistance of Si-Al carriers.The strong sulfur resistance of the FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbent results from multiple factors:protective effects of Ce on Fe,La and Al;sulfation-induced generation of Ce^(3+)and surface-adsorbed oxygen;and strong surface acidity of SiO_(2).展开更多
Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materi...Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.展开更多
The in-flight heating process of cerium dioxide(CeO_(2))powders was investigated through experiments and numerical simulations.In the experiment,CeO_(2)powder(average size of 30μm)was injected into radio-frequency(RF...The in-flight heating process of cerium dioxide(CeO_(2))powders was investigated through experiments and numerical simulations.In the experiment,CeO_(2)powder(average size of 30μm)was injected into radio-frequency(RF)argon plasma,and the temperatures were measured using a DPV-2000 monitor.A model combining the electromagnetism,thermal flow,and heat transfer characteristics of powder during in-flight heating in argon plasma was proposed.The melting processes of CeO_(2)powders of different diameters,with and without thermal resistance effect,were investigated.Results show that the heating process of CeO_(2)powder particles consists of three main stages,one of which is relevant to a dimensionless parameter known as the Biot number.When the Biot value≥0.1,thermal resistance increases significantly,especially for the larger powders.The predicted temperature of the particles at the outlet(1800–2880 K)is in good agreement with the experimental result.展开更多
Development of lightweight and strong structural material using fast-growing poplar wood is promising for green and sustainable engineering.Herein,the overall performances of fast-growing natural poplar wood(NPW)are s...Development of lightweight and strong structural material using fast-growing poplar wood is promising for green and sustainable engineering.Herein,the overall performances of fast-growing natural poplar wood(NPW)are significantly enhanced via delignification,in situ growth of SiO_(2)followed by densification.The SiO_(2)/compresseddelignified-wood(SiO_(2)/CDW)nanocomposite obtained exhibits outstanding mechanical properties including a bending strength of 395.6 MPa,a tensile strength of 253.4 MPa,and a toughness of 7.1 MJ/m^(3),which is improved by 1548%,240%and 590%,respectively compared with NPW.In addition,the ignition time and burning time of SiO_(2)/CDW nanocomposite are prolonged by 700%and 112%compared to those of NPW.Moreover,the specific wear rate of SiO_(2)/CDW is 18×10^(-6)mm^(3)/Nm,which is 72.6%lower than that of NPW.Moreover,the spring-back ratios of SiO_(2)/CDW in 95%and in water are 45.2%and 66.7%,which are lower than those of CDW(64.6%and 92.4%).The SiO_(2)/CDW nanocomposite with enhanced mechanical,flame/water retardant and wear performances are promising to meet the needs of modern engineering as green and sustainable materials.展开更多
Freeze–thaw(F–T)cycle-induced cracking in silty clays poses a significant risk to engineering stability.Although the individual addition of fly ash(FA)or sisal fiber(SF)provides partial solutions,their simultaneous ...Freeze–thaw(F–T)cycle-induced cracking in silty clays poses a significant risk to engineering stability.Although the individual addition of fly ash(FA)or sisal fiber(SF)provides partial solutions,their simultaneous application may result in a synergistic effect to compensate for their respective shortcomings.In this study,the effects of SF and FA on the mechanical properties,crack resistance,water retention,and erosion resistance of improved soil were systematically investigated through unconfined compressive strength(UCS)tests,crack evolution analysis,simulated rainfall erosion tests,and microscopic characterization(laser particle size analysis and nitrogen adsorption).The results reveal that the volumetric stability of FA particles significantly inhibits cracking in soil after F–T cycles.However,FA contributes only slightly to soil strength and erosion resistance.SF,on the other hand,plays a substantial role in increasing both soil strength and erosion resistance.The synergy between FA and SF results in the simultaneous increase in crack resistance,erosion resistance,and strength.FA improves the aggregate stability during F–T cycles,whereas SF reinforces the bonds between these aggregates.A comprehensive evaluation of the improved soil during F–T cycles using the entropy weight-TOPSIS method reveal that the combination of 10%FA+18 mm SF performed the best,achieving a 246%higher composite score than the unmodified soil did.With respect to this optimal combination,compared with the unmodified soil,the SF–FA-improved soil exhibits a 30%reduction in the average crack width,a 30%reduction in the erosion rate,and a 46%increase in strength.The findings of this study provide a scientific basis for the design of soil improvement in disaster mitigation engineering in seasonally frozen soil regions.展开更多
Urinary tract infections(UTIs)are among the most prevalent pediatric bacterial infections,and undertreated episodes may lead to renal scarring,hypertension,or chronic kidney disease.Multidrug-resistant(MDR)Enterobacte...Urinary tract infections(UTIs)are among the most prevalent pediatric bacterial infections,and undertreated episodes may lead to renal scarring,hypertension,or chronic kidney disease.Multidrug-resistant(MDR)Enterobacterales have been increasingly reported in children,with higher rates in Asian and Middle Eastern settings than in high-income countries[1,2].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
Fusarium head blight(FHB),mainly caused by fungus Fusarium graminearum,is a devastating wheat disease worldwide,leading to reduced yield production and compromised grain quality due to contamination by mycotoxins,such...Fusarium head blight(FHB),mainly caused by fungus Fusarium graminearum,is a devastating wheat disease worldwide,leading to reduced yield production and compromised grain quality due to contamination by mycotoxins,such as deoxynivalenol(DON).Manipulating the specific gene expression in microorganisms through RNA interference(RNAi)presents an opportunity for new-generation double-stranded RNA(dsRNA)-based formulations to combat a large number of plant diseases.Here,we applied both spray-induced gene silencing(SIGS)and host-induced gene silencing(HIGS)to target five virulence-related and DON-synthesized genes in F.graminearum,including protein kinase gene Gpmk1,zinc finger protein gene Fg Chy1,transcription factor Fg SR,DON synthesis gene TRI5 and the cell-end marker protein gene Fg Tea A,aiming to effectively control FHB in wheat.Direct spraying of individual or combined small interfering RNA(siRNAs)from the fungus showed reduced expression of target genes and suppressed pathogenic symptoms during F.graminearum infection in wheat leaves,with the combination of all five siRNAs demonstrating superior resistance.Furthermore,we generated transgenic wheat lines expressing chimeric RNAi cassettes targeting these five genes,and two independent lines exhibited strong resistance to FHB and Fusarium crown rot,and the reduced DON accumulation.Notably,the HIGS transgenic lines did not adversely impact plant growth and yield traits.Collectively,our findings support that SIGS and HIGS represent effective strategies targeting key pathogenic genes for bolstering disease resistance in crops.展开更多
Antibiotic resistance genes(ARGs) are recognized as a primary threat to the sustainability of environment and human health in the 21^(st) century.Nanomaterials(NMs) have attracted substantial attention due to their un...Antibiotic resistance genes(ARGs) are recognized as a primary threat to the sustainability of environment and human health in the 21^(st) century.Nanomaterials(NMs) have attracted substantial attention due to their unique dimensions and structures.Unfortunately,emerging evidence suggests that NMs may facilitate the transmission of ARGs.It is crucial to elucidate how NMs affect the evolution and dissemination of ARGs.The current review comprehensively examines the role of NMs in the widespread transmission of ARGs in aquatic environments and the underlying mechanisms involved in the process.It aims to clarify the effects and mechanisms of NMs on the horizontal gene transfer processes that are associated with ARGs,including the enhancement of cell membrane permeability,the formation of nanopores on membranes,promotion of mutagenesis,and the generation of reactive oxygen species(ROSs).Furthermore,the trade-off between the removal of ARGs and horizontal transfer has been elucidated.The review aspires to guide future research directions,advance knowledge on the implications of NMs in the field of ARGs' transmission,and provide a theoretical foundation for the development of safer and more effective applications of NMs.展开更多
Nicotinamide mononucleotide(NMN),a precursor in nicotinamide adenine dinucleotide(NAD)biosynthesis,has long been recognized for its pivotal role in medicine.Recent investigations have suggested its potential as a plan...Nicotinamide mononucleotide(NMN),a precursor in nicotinamide adenine dinucleotide(NAD)biosynthesis,has long been recognized for its pivotal role in medicine.Recent investigations have suggested its potential as a plant immunity inducer for controlling fungal diseases.However,whether NMN confers plant broad-spectrum resistance against diverse phytopathogens,and its underlying mechanisms remain ambiguous.In this study,we investigate the effect of NMN against multiple phytopathogens in tobacco.Our results demonstrate that tobacco pretreated with NMN exhibits enhanced resistance against Ralstonia solanacearum CQPS-1,Pseudomonas syringae DC3000ΔhopQ1-1,Phytophthora parasitica,and tobacco mosaic virus(TMV).NMN displays effectiveness within the concentration range of 50–600μmol L^(–1),with75μmol L^(–1)NMN exhibiting the most pronounced effect.The impact of NMN pretreatment could persist for up to 10 days.Beyond tobacco,NMN pretreatment enhances disease resistance in tomato and pepper plants against diverse pathogens,underscoring NMN’s capacity to confer broad-spectrum disease resistance in crops.Moreover,RT-qPCR analysis reveals that NMN significantly upregulates the expression of the pattern-triggered immunity(PTI)marker gene NbCYP71D20 and salicylic acid(SA)marker gene NbPR1a.This suggests that NMN enhances plant resistance by inducing both PTI and SA-mediated immunity.Interestingly,the positive impact of NMN on plant disease resistance is not significantly compromised in both NMN adenylyltransferase(NMNAT)-silenced plants and NAD receptor mutant lecrk-I.8,suggesting the existence of NAD-independent signaling pathways for NMN-induced plant immunity.In conclusion,our study establishes that the bioactive molecule NMN imparts broad-spectrum disease resistance in plants,offering a simple,environmental-friendly,and promising strategy for safeguarding crops against diverse phytopathogens.These findings also provide valuable insights for future in-depth studies into the functional mechanisms of NMN.展开更多
Background Selective breeding for disease resistance is an effective strategy to control duck hepatitis A virus type 3(DHAV-3)in waterfowl.However,the mechanism underlying resistance remains poorly understood,particul...Background Selective breeding for disease resistance is an effective strategy to control duck hepatitis A virus type 3(DHAV-3)in waterfowl.However,the mechanism underlying resistance remains poorly understood,particularly those associated with antioxidant defense,intestinal development and host-microbiota interactions.Method A total of 1001-day-old Pekin ducklings were used in this study with 50 DHAV-3 susceptible and resistant ducks,respectively.Samples were collected at 7 days post-hatching(D7),D21 and D42,10 birds per group.We compared DHAV-3 resistant and susceptible ducks during early development with respect to immune organ indices,antioxidant capacity,intestinal morphology,barrier-related gene expression and cecal microbiota.Result Resistant ducks exhibited higher spleen indices and stronger antioxidant capacity,characterized by increased superoxide dismutase,reduced glutathione,and total antioxidant capacity,along with lower malondialdehyde levels at D7 and D21.In contrast,susceptible ducks showed compensatory thymus hypertrophy and delayed development of antioxidant defense and intestinal maturation.Ileal morphology revealed greater villus height and width with more regular arrangement in resistant ducks at D7,whereas these differences diminished at D21 and D42.Gene expression analysis demonstrated higher early expression of the tight junction proteins CLDN1 and CLDN3 in resistant ducks,while susceptible ducks displayed elevated MUC2 and OCLN,suggesting stress induced compensatory responses.Cecal microbiota analysis revealed distinct colonization patterns in early development.Resistant ducks were enriched with Firmicutes and beneficial genera such as Enterococcus and Lactobacillus,whereas susceptible ducks harbored higher abundances of Bacteroidota and potentially opportunistic taxa.Microbial diversity increased with age in both groups,but resistant ducks displayed more orderly succession and enrichment of SCFA producing genera,including Subdoligranulum and Phascolarctobacterium,which positively correlated with plasma antioxidant indices.Conclusion DHAV-3 resistant ducks exhibit early advantages in antioxidant defense,intestinal barrier development and colonization by beneficial microbiota,which collectively contribute to enhanced disease resistance.These findings highlight the synergistic roles of host physiology and gut microbiota in shaping resistance.In the future,integrating genomic selection with microbiota modulation and antioxidant interventions may accelerate the breeding of highly resistant duck lines and provide scientific evidence and practical strategies for controlling duck viral hepatitis.展开更多
Phosphogypsum,an industrial solid waste,is an effective binder for partially replacing cement in stabilizing dredged sediments.Acid rain,as a worldwide ecological problem,also affects the long-term stability and susta...Phosphogypsum,an industrial solid waste,is an effective binder for partially replacing cement in stabilizing dredged sediments.Acid rain,as a worldwide ecological problem,also affects the long-term stability and sustainability of geotechnical materials and structures.However,the research on leaching effects and long-term durability of phosphogypsum-stabilized soils under acid rain conditions is limited and remains a significant challenge for practical applications.This study investigates the leaching effects and long-term durability of phosphogypsum-stabilized soils by simulating acid rain erosion through semi-dynamic leaching tests.Key parameters,including leached Ca^(2+)concentration,leachate pH,and unconfined compressive strength after leaching,were evaluated.Microscopic analyses with X-ray diffraction(XRD)and scanning electron microscopy(SEM)were also conducted to explore the underlying mechanisms.The results indicate that the presence of phosphogypsum in stabilized soil with high water content shows a significant improvement in leaching resistance subjected to acid ions,evidencing a lower Ca^(2+)concentration and pH value in the leachate,and a higher strength after leaching compared to those samples without phosphogypsum.SEM images and XRD analysis revealed that samples with higher phosphogypsum content possess denser structures due to more needle-shaped ettringite and other minerals in the soil matrix,contributing to improved strength and leaching resistance.The enhanced strength and leaching resistance of phosphogypsum-stabilized soil can be attributed to additional gel formation,a rise in swelling potential,ettringite bridging,and a denser microstructure,which reduces Ca^(2+)availability for leaching in acidic environments.展开更多
A polylactide(PLA)blend with simultaneous enhancement of strength,toughness,and heat resistance was successfully achieved by adding biodegradable poly(propylene carbonate)(PPC)and uniaxial pre-stretching.The effects o...A polylactide(PLA)blend with simultaneous enhancement of strength,toughness,and heat resistance was successfully achieved by adding biodegradable poly(propylene carbonate)(PPC)and uniaxial pre-stretching.The effects of the PPC content(0 wt%-50 wt%)on the phase morphology and performance of the blends before and after pre-stretching were systematically investigated.Blending PPC initially reduced the strength,modulus,and heat resistance,but pre-stretching significantly enhanced these properties.In blends containing≤30 wt%PPC,where PPC formed a well-dispersed island-like phase within the PLA matrix,pre-stretching simultaneously enhanced strength,toughness,and heat resistance.The optimized pre-stretched 70/30 PLA/PPC(ps-70/30)blend achieved exceptional performance:tensile strength increased from 66.9MPa to 84.5 MPa,elongation at break dramatically improved from 6.8%to 115.1%,impact strength reached 55.1 k J/m^(2)(far exceeding neat PLA's 3.5 k J/m^(2)),and Vicat softening temperature(VST)increased by 60.6%to 101.8℃.Notably,the ps-70/30 blend retained excellent mechanical properties even after six months of aging.These improvements were attributed to the synergistic effects of the PPC incorporation and prestretching.PPC not only promoted the high orientation of the PLA molecular chains but also facilitated the formation of a stable crystalline phase during pre-stretching,thereby enhancing both the mechanical properties and heat resistance.However,when the PPC content exceeded 30wt%,phase inversion occurred,resulting in a continuous amorphous PPC phase that degraded the overall performance.This study demonstrated that a combination of controlled PPC incorporation and pre-stretching can effectively overcome PLA's brittleness of PLA while improving its heat resistance,offering a promising strategy for developing high-performance,fully biodegradable PLA materials suitable for industrial applications.展开更多
Objective:To analyse the prevalence of serotypes,antibiotic resistance,and virulence genes of Group B Streptococcus(GBS)strains isolated from pregnant women at 35-37 weeks of gestation in Ho Chi Minh City,Vietnam,from...Objective:To analyse the prevalence of serotypes,antibiotic resistance,and virulence genes of Group B Streptococcus(GBS)strains isolated from pregnant women at 35-37 weeks of gestation in Ho Chi Minh City,Vietnam,from January 2022 to January 2023.Methods:GBS strains were isolated through selective culture methods and confirmed by PCR.Serotyping,virulence gene detection,and antibiotic susceptibility testing were performed using PCR,gel electrophoresis techniques and Kirby-Bauer test.Results:Totally,61 GBS isolated from 300 participants have been identified including seven GBS serotypes(Ⅰa,Ⅰb,Ⅱ,Ⅲ,Ⅳ,Ⅴ,andⅥ).SerotypesⅦ,Ⅷ,andⅨwere not detected in the study population.Antibiotic resistance patterns varied:13.1%of isolates were fully susceptible,while the majority showed multi-drug resistance,with 34.4%resistant to three antibiotics.SerotypeⅠa demonstrated high susceptibility(35.7%),while serotypeⅢshowed extensive resistance,with 87.5%being resistant to at least three antibiotics.All strains are susceptible to vancomycin andβ-lactams susceptibility also remained high,but resistance to clindamycin,erythromycin,and tetracycline was high(>65%).The virulence genes scpB,cylB,fbsB,and cfb were highly prevalent(90%-100%),indicating their potential for vaccine and diagnostic development.Conclusions:Our findings provide valuable insights into GBS serotypes,resistance,and virulence factors,contributing to community monitoring,preventive measures,diagnostics,and vaccine development.However,the limited sample size necessitates further research.展开更多
The plant pathogenic fungus Sclerotinia sclerotiorum is the causative agent of Sclerotinia stem rot(SSR)disease in most dicotyledons.Among the various proteins involved in drug efflux or substance transport,ATP-bindin...The plant pathogenic fungus Sclerotinia sclerotiorum is the causative agent of Sclerotinia stem rot(SSR)disease in most dicotyledons.Among the various proteins involved in drug efflux or substance transport,ATP-binding cassette(ABC)transporters constitute a superfamily of membrane-bound proteins that may play a crucial role in the survival of S.sclerotiorum.However,the expression patterns and functions of ABC transporter genes in S.sclerotiorum remain largely uncharacterized.This study characterized a highly expressed S.sclerotiorum ABC transporter gene during inoculation on host plants,Ss BMR1.Silencing Ss BMR1 resulted in a significant reduction in hyphal growth,infection cushion development,sclerotia formation,and virulence.Moreover,host-induced gene silencing(HIGS)of Ss BMR1 significantly enhanced plant resistance.Transcriptome and metabolomics analyses suggested that Ss BMR1 is involved in antioxidant and toxin transport,thereby influencing fungal defense and cell rescue mechanisms.In comparison to the wild-type strain,Ss BMR1 gene-silenced transformants exhibited a diminished response to extracellar oxidative stress and a decreased exporting of antioxidant glutathione.Tolerance assays further demonstrated the crucial role of Ss BMR1 in conferring resistance to the plant antifungal substances,camalexin and brassinin,as well as certain fungicides.Furthermore,Ss BMR1 gene-silenced transformants showed enhanced repression on virulence when sprayed with camalexin and brassinin on the leaves.Thus,Ss BMR1 likely contributes to virulence by facilitating the export of antioxidant and providing resistance against antifungal agents.The findings of this study provide valuable insights that could contribute to the development of novel management techniques for SSR.展开更多
Caffeic acid-O-methyltransferase(COMT)is a crucial enzyme in the phenylpropanoid metabolic pathway,with significant roles in both the lignin and coumarin pathways.The function of COMT in plant disease resistance has b...Caffeic acid-O-methyltransferase(COMT)is a crucial enzyme in the phenylpropanoid metabolic pathway,with significant roles in both the lignin and coumarin pathways.The function of COMT in plant disease resistance has been demonstrated in several species.Our research identified the potato COMT gene family on a genome-wide scale and StCOMT1 as a candidate gene for enhancing potato disease resistance under DON induction through phylogenetic analyses combined with previously identified metabolic differences and weighted gene co-expression network analysis(WGCNA)results.In order to better understand the function of StCOMT1,heterologous expression and overexpression assays were conducted.StCOMT1 is localized in chloroplasts and was found to catalyze the methylation of substrates to produce ferulic acid and melatonin in vitro.Physiological parameters showed that,compared with wild-type potato plants,StCOMT1-overexpressing plants infected with Fusarium sporotrichioides exhibited smaller lesion areas and lower reactive oxygen species(ROS)levels.High-performance liquid chromatography(HPLC)and RT-qPCR analyses revealed organ-specific accumulation of coumarin-related compounds and organ-specific expression of their corresponding genes in StCOMT1-overexpressing plants post-inoculation.The results indicate that StCOMT1 overexpression in potatoes enhanced resistance to F.sporotrichioides by enhancing reactive oxygen species clearance and promoting organ-specific accumulation of coumarin-related compounds.展开更多
基金Guangzhou Metro Scientific Research Project(No.JT204-100111-23001)Chongqing Municipal Special Project for Technological Innovation and Application Development(No.CSTB2022TIAD-KPX0101)Science and Technology Research and Development Program of China State Railway Group Co.,Ltd.(No.N2023G045)。
文摘The uplift resistance of the soil overlying shield tunnels significantly impacts their anti-floating stability.However,research on uplift resistance concerning special-shaped shield tunnels is limited.This study combines numerical simulation with machine learning techniques to explore this issue.It presents a summary of special-shaped tunnel geometries and introduces a shape coefficient.Through the finite element software,Plaxis3D,the study simulates six key parameters—shape coefficient,burial depth ratio,tunnel’s longest horizontal length,internal friction angle,cohesion,and soil submerged bulk density—that impact uplift resistance across different conditions.Employing XGBoost and ANN methods,the feature importance of each parameter was analyzed based on the numerical simulation results.The findings demonstrate that a tunnel shape more closely resembling a circle leads to reduced uplift resistance in the overlying soil,whereas other parameters exhibit the contrary effects.Furthermore,the study reveals a diminishing trend in the feature importance of buried depth ratio,internal friction angle,tunnel longest horizontal length,cohesion,soil submerged bulk density,and shape coefficient in influencing uplift resistance.
基金the financial supports from National Key R&D Program for Young Scientists of China(Grant No.2022YFC3080900)National Natural Science Foundation of China(Grant No.52374181)+1 种基金BIT Research and Innovation Promoting Project(Grant No.2024YCXZ017)supported by Science and Technology Innovation Program of Beijing institute of technology under Grant No.2022CX01025。
文摘In this study,an inverse design framework was established to find lightweight honeycomb structures(HCSs)with high impact resistance.The hybrid HCS,composed of re-entrant(RE)and elliptical annular re-entrant(EARE)honeycomb cells,was created by constructing arrangement matrices to achieve structural lightweight.The machine learning(ML)framework consisted of a neural network(NN)forward regression model for predicting impact resistance and a multi-objective optimization algorithm for generating high-performance designs.The surrogate of the local design space was initially realized by establishing the NN in the small sample dataset,and the active learning strategy was used to continuously extended the local optimal design until the model converged in the global space.The results indicated that the active learning strategy significantly improved the inference capability of the NN model in unknown design domains.By guiding the iteration direction of the optimization algorithm,lightweight designs with high impact resistance were identified.The energy absorption capacity of the optimal design reached 94.98%of the EARE honeycomb,while the initial peak stress and mass decreased by 28.85%and 19.91%,respectively.Furthermore,Shapley Additive Explanations(SHAP)for global explanation of the NN indicated a strong correlation between the arrangement mode of HCS and its impact resistance.By reducing the stiffness of the cells at the top boundary of the structure,the initial impact damage sustained by the structure can be significantly improved.Overall,this study proposed a general lightweight design method for array structures under impact loads,which is beneficial for the widespread application of honeycomb-based protective structures.
基金Supported by Funding from the Henan Provincial Scientific and Technological Breakthrough Project(No.242102111113).
文摘Fusarium crown rot(FCR),predominantly caused by Fusarium pseudograminearum,has been listed as a Category Ⅱ disease in six provinces of China,posing a significant threat to wheat production.The phenylpyrrole fungicide fludioxonil is a key agent for FCR control.Previous studies indicated that resistance to fludioxonil in F.pseudograminearum is primarily associated with altered expression levels of the FpOS1 gene,which encodes a hybrid histidine kinase.However,the roles of mutations in other FpOS genes and the molecular interactions between FpOS proteins and fludioxonil remain elusive.To address these gaps,we generated 16 fludioxonil-resistant mutants with heritable resistance traits by in vitro selection of four sensitive F.pseudograminearum isolates.These mutants exhibited high resistance levels,with resistance factors(RF)ranging from 633.73 to 8617.07.Compared to their parental isolates,the resistant mutants showed significantly reduced mycelial growth rate,sporulation capacity,and pathogenicity.They were also more sensitive to ionic,osmotic,and oxidative stresses and displayed compromised cell wall and membrane integrity.Fludioxonil demonstrated no cross-resistance with tebuconazole or pydiflumetofen;however,it exhibited weak positive crossresistance to pyraclostrobin and moderate positive cross-resistance to iprodione.Fludioxonil treatment significantly promoted glycerol synthesis and inhibited deoxynivalenol(DON)production in parental isolates,whereas these regulatory effects were markedly attenuated in the resistant mutants.Mutation analysis identified mutation sites in FpOS1,FpOS4,and FpOS5 genes,with a lower mutation frequency in FpOS1 and no mutations detected in FpOS2.Molecular docking indicated that amino acid substitutions in FpOS4 and FpOS5 significantly reduced the binding affinity of fludioxonil to these target proteins.In conclusion,F.pseudograminearum poses a moderate risk of resistance to fludioxonil.Point mutations in FpOS4 and FpOS5 genes emerge as key molecular drivers of resistance,likely by diminishing the binding affinity between the fungicide and its proteins.This study clarifies the molecular basis of fludioxonil resistance in F.pseudograminearum and provides a scientific rationale for the judicious use of this fungicide in managing FCR.
文摘It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,and FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbents were prepared by coupling fly ash-based Si-Al carriers.The active components Fe-Ce-La oxides and Si-Al carriers were characterized by TPD,TG,XRF,BET and XPS,respectively.The effects of temperature,Si/Al ratio and FeCeLaO loading rate on the sulfur resistance were investigated.Results show that the SO_(2) promotes the arsenic removal of Fe_(2)O_(3),CeLaO and FeCeLaO.At 400℃,the arsenic removal efficiencies of the three oxides increase from 45.3%,72.5% and 81.3% without SO_(2) to 62.6%,80.5%and 91.0%,respectively.The SO_(2) inhibits the arsenic removal of La_(2)O_(2)CO_(3) and FeLaO,and the inhibition effect is pronounced at high temperatures.The sulfur poisoning resistance of Si-Al carriers increases with the increase of Si/Al ratio.When the Si/Al ratio is increased to 9.74,the arsenic removal efficiency in the SO_(2) environment is 13.9% higher than that in the absence of SO_(2).Introducing FeCeLaO active components is beneficial for enhancing the SO_(2) poisoning resistance of Si-Al carriers.The strong sulfur resistance of the FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbent results from multiple factors:protective effects of Ce on Fe,La and Al;sulfation-induced generation of Ce^(3+)and surface-adsorbed oxygen;and strong surface acidity of SiO_(2).
文摘Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.
基金National Natural Science Foundation of China(11875039)Shanxi Scholarship Council of China(2023-033)+2 种基金Fundamental Research Program of Shanxi Province(202303021221071)China Baowu Low Carbon Metallurgical Innovation Foundation(2022)2023 Anhui Major Industrial Innovation Plan Project。
文摘The in-flight heating process of cerium dioxide(CeO_(2))powders was investigated through experiments and numerical simulations.In the experiment,CeO_(2)powder(average size of 30μm)was injected into radio-frequency(RF)argon plasma,and the temperatures were measured using a DPV-2000 monitor.A model combining the electromagnetism,thermal flow,and heat transfer characteristics of powder during in-flight heating in argon plasma was proposed.The melting processes of CeO_(2)powders of different diameters,with and without thermal resistance effect,were investigated.Results show that the heating process of CeO_(2)powder particles consists of three main stages,one of which is relevant to a dimensionless parameter known as the Biot number.When the Biot value≥0.1,thermal resistance increases significantly,especially for the larger powders.The predicted temperature of the particles at the outlet(1800–2880 K)is in good agreement with the experimental result.
基金the financial support from the National Natural Science Foundation of China(No.52303082)Natural Science Foundation of Hubei Province(No.2023AFB375)Fundamental Research Funds for Central Universities of China(No.2022CDJQY-004)。
文摘Development of lightweight and strong structural material using fast-growing poplar wood is promising for green and sustainable engineering.Herein,the overall performances of fast-growing natural poplar wood(NPW)are significantly enhanced via delignification,in situ growth of SiO_(2)followed by densification.The SiO_(2)/compresseddelignified-wood(SiO_(2)/CDW)nanocomposite obtained exhibits outstanding mechanical properties including a bending strength of 395.6 MPa,a tensile strength of 253.4 MPa,and a toughness of 7.1 MJ/m^(3),which is improved by 1548%,240%and 590%,respectively compared with NPW.In addition,the ignition time and burning time of SiO_(2)/CDW nanocomposite are prolonged by 700%and 112%compared to those of NPW.Moreover,the specific wear rate of SiO_(2)/CDW is 18×10^(-6)mm^(3)/Nm,which is 72.6%lower than that of NPW.Moreover,the spring-back ratios of SiO_(2)/CDW in 95%and in water are 45.2%and 66.7%,which are lower than those of CDW(64.6%and 92.4%).The SiO_(2)/CDW nanocomposite with enhanced mechanical,flame/water retardant and wear performances are promising to meet the needs of modern engineering as green and sustainable materials.
基金supported by the Jilin Science and Technology Program(20230203130SF)。
文摘Freeze–thaw(F–T)cycle-induced cracking in silty clays poses a significant risk to engineering stability.Although the individual addition of fly ash(FA)or sisal fiber(SF)provides partial solutions,their simultaneous application may result in a synergistic effect to compensate for their respective shortcomings.In this study,the effects of SF and FA on the mechanical properties,crack resistance,water retention,and erosion resistance of improved soil were systematically investigated through unconfined compressive strength(UCS)tests,crack evolution analysis,simulated rainfall erosion tests,and microscopic characterization(laser particle size analysis and nitrogen adsorption).The results reveal that the volumetric stability of FA particles significantly inhibits cracking in soil after F–T cycles.However,FA contributes only slightly to soil strength and erosion resistance.SF,on the other hand,plays a substantial role in increasing both soil strength and erosion resistance.The synergy between FA and SF results in the simultaneous increase in crack resistance,erosion resistance,and strength.FA improves the aggregate stability during F–T cycles,whereas SF reinforces the bonds between these aggregates.A comprehensive evaluation of the improved soil during F–T cycles using the entropy weight-TOPSIS method reveal that the combination of 10%FA+18 mm SF performed the best,achieving a 246%higher composite score than the unmodified soil did.With respect to this optimal combination,compared with the unmodified soil,the SF–FA-improved soil exhibits a 30%reduction in the average crack width,a 30%reduction in the erosion rate,and a 46%increase in strength.The findings of this study provide a scientific basis for the design of soil improvement in disaster mitigation engineering in seasonally frozen soil regions.
文摘Urinary tract infections(UTIs)are among the most prevalent pediatric bacterial infections,and undertreated episodes may lead to renal scarring,hypertension,or chronic kidney disease.Multidrug-resistant(MDR)Enterobacterales have been increasingly reported in children,with higher rates in Asian and Middle Eastern settings than in high-income countries[1,2].
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financially supported by the National Key R&D Program of China(2022YFD1400105)the Jiangsu Agricultural Science and Technology Innovation Fund(CX(22)2005)+3 种基金the Jiangsu Key R&D Plan(Modern Agriculture),China(BE2022346)the China Agricultural Research System Program(CARS-03)the National Science Fund for Excellent Young Scholars(Overseas),Chinathe Start-Up Grant from Nanjing Agricultural University,China。
文摘Fusarium head blight(FHB),mainly caused by fungus Fusarium graminearum,is a devastating wheat disease worldwide,leading to reduced yield production and compromised grain quality due to contamination by mycotoxins,such as deoxynivalenol(DON).Manipulating the specific gene expression in microorganisms through RNA interference(RNAi)presents an opportunity for new-generation double-stranded RNA(dsRNA)-based formulations to combat a large number of plant diseases.Here,we applied both spray-induced gene silencing(SIGS)and host-induced gene silencing(HIGS)to target five virulence-related and DON-synthesized genes in F.graminearum,including protein kinase gene Gpmk1,zinc finger protein gene Fg Chy1,transcription factor Fg SR,DON synthesis gene TRI5 and the cell-end marker protein gene Fg Tea A,aiming to effectively control FHB in wheat.Direct spraying of individual or combined small interfering RNA(siRNAs)from the fungus showed reduced expression of target genes and suppressed pathogenic symptoms during F.graminearum infection in wheat leaves,with the combination of all five siRNAs demonstrating superior resistance.Furthermore,we generated transgenic wheat lines expressing chimeric RNAi cassettes targeting these five genes,and two independent lines exhibited strong resistance to FHB and Fusarium crown rot,and the reduced DON accumulation.Notably,the HIGS transgenic lines did not adversely impact plant growth and yield traits.Collectively,our findings support that SIGS and HIGS represent effective strategies targeting key pathogenic genes for bolstering disease resistance in crops.
基金supported by the State Key Laboratory of Urban Water Resource and Environment (Harbin Institute of Technology) (No.2022TS13)the key projects of National Natural Science Foundation of China (No.2019YFC0408503)the Key Research Program of Wuhan (No.2022022202015015)。
文摘Antibiotic resistance genes(ARGs) are recognized as a primary threat to the sustainability of environment and human health in the 21^(st) century.Nanomaterials(NMs) have attracted substantial attention due to their unique dimensions and structures.Unfortunately,emerging evidence suggests that NMs may facilitate the transmission of ARGs.It is crucial to elucidate how NMs affect the evolution and dissemination of ARGs.The current review comprehensively examines the role of NMs in the widespread transmission of ARGs in aquatic environments and the underlying mechanisms involved in the process.It aims to clarify the effects and mechanisms of NMs on the horizontal gene transfer processes that are associated with ARGs,including the enhancement of cell membrane permeability,the formation of nanopores on membranes,promotion of mutagenesis,and the generation of reactive oxygen species(ROSs).Furthermore,the trade-off between the removal of ARGs and horizontal transfer has been elucidated.The review aspires to guide future research directions,advance knowledge on the implications of NMs in the field of ARGs' transmission,and provide a theoretical foundation for the development of safer and more effective applications of NMs.
基金supported by the Technology Innovation Leading Program of Shaanxi,China(2023QYPY2-01)the National Natural Science Foundation of China(32072399,32302296,and 32372483)+1 种基金the Fundamental Research Funds for the Central Universities(GK202201017 and GK202207024)the Program of Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests,China(MIMCP-202203)。
文摘Nicotinamide mononucleotide(NMN),a precursor in nicotinamide adenine dinucleotide(NAD)biosynthesis,has long been recognized for its pivotal role in medicine.Recent investigations have suggested its potential as a plant immunity inducer for controlling fungal diseases.However,whether NMN confers plant broad-spectrum resistance against diverse phytopathogens,and its underlying mechanisms remain ambiguous.In this study,we investigate the effect of NMN against multiple phytopathogens in tobacco.Our results demonstrate that tobacco pretreated with NMN exhibits enhanced resistance against Ralstonia solanacearum CQPS-1,Pseudomonas syringae DC3000ΔhopQ1-1,Phytophthora parasitica,and tobacco mosaic virus(TMV).NMN displays effectiveness within the concentration range of 50–600μmol L^(–1),with75μmol L^(–1)NMN exhibiting the most pronounced effect.The impact of NMN pretreatment could persist for up to 10 days.Beyond tobacco,NMN pretreatment enhances disease resistance in tomato and pepper plants against diverse pathogens,underscoring NMN’s capacity to confer broad-spectrum disease resistance in crops.Moreover,RT-qPCR analysis reveals that NMN significantly upregulates the expression of the pattern-triggered immunity(PTI)marker gene NbCYP71D20 and salicylic acid(SA)marker gene NbPR1a.This suggests that NMN enhances plant resistance by inducing both PTI and SA-mediated immunity.Interestingly,the positive impact of NMN on plant disease resistance is not significantly compromised in both NMN adenylyltransferase(NMNAT)-silenced plants and NAD receptor mutant lecrk-I.8,suggesting the existence of NAD-independent signaling pathways for NMN-induced plant immunity.In conclusion,our study establishes that the bioactive molecule NMN imparts broad-spectrum disease resistance in plants,offering a simple,environmental-friendly,and promising strategy for safeguarding crops against diverse phytopathogens.These findings also provide valuable insights for future in-depth studies into the functional mechanisms of NMN.
基金supported by the National Key R&D Program of China(2022YFD1301800)grants from the National Natural Science Foundation of China(grant number 32502899)+1 种基金China Agriculture Research System of MOF and MARA(CARS-42-10)the Agricultural Science and Technology Innovation Program of CAAS(CAAS-ASTIP-2023-IFR-13)。
文摘Background Selective breeding for disease resistance is an effective strategy to control duck hepatitis A virus type 3(DHAV-3)in waterfowl.However,the mechanism underlying resistance remains poorly understood,particularly those associated with antioxidant defense,intestinal development and host-microbiota interactions.Method A total of 1001-day-old Pekin ducklings were used in this study with 50 DHAV-3 susceptible and resistant ducks,respectively.Samples were collected at 7 days post-hatching(D7),D21 and D42,10 birds per group.We compared DHAV-3 resistant and susceptible ducks during early development with respect to immune organ indices,antioxidant capacity,intestinal morphology,barrier-related gene expression and cecal microbiota.Result Resistant ducks exhibited higher spleen indices and stronger antioxidant capacity,characterized by increased superoxide dismutase,reduced glutathione,and total antioxidant capacity,along with lower malondialdehyde levels at D7 and D21.In contrast,susceptible ducks showed compensatory thymus hypertrophy and delayed development of antioxidant defense and intestinal maturation.Ileal morphology revealed greater villus height and width with more regular arrangement in resistant ducks at D7,whereas these differences diminished at D21 and D42.Gene expression analysis demonstrated higher early expression of the tight junction proteins CLDN1 and CLDN3 in resistant ducks,while susceptible ducks displayed elevated MUC2 and OCLN,suggesting stress induced compensatory responses.Cecal microbiota analysis revealed distinct colonization patterns in early development.Resistant ducks were enriched with Firmicutes and beneficial genera such as Enterococcus and Lactobacillus,whereas susceptible ducks harbored higher abundances of Bacteroidota and potentially opportunistic taxa.Microbial diversity increased with age in both groups,but resistant ducks displayed more orderly succession and enrichment of SCFA producing genera,including Subdoligranulum and Phascolarctobacterium,which positively correlated with plasma antioxidant indices.Conclusion DHAV-3 resistant ducks exhibit early advantages in antioxidant defense,intestinal barrier development and colonization by beneficial microbiota,which collectively contribute to enhanced disease resistance.These findings highlight the synergistic roles of host physiology and gut microbiota in shaping resistance.In the future,integrating genomic selection with microbiota modulation and antioxidant interventions may accelerate the breeding of highly resistant duck lines and provide scientific evidence and practical strategies for controlling duck viral hepatitis.
基金supported by the National Natural Science Foundation of China(Grant Nos.52178361,52178328,and 42377190).
文摘Phosphogypsum,an industrial solid waste,is an effective binder for partially replacing cement in stabilizing dredged sediments.Acid rain,as a worldwide ecological problem,also affects the long-term stability and sustainability of geotechnical materials and structures.However,the research on leaching effects and long-term durability of phosphogypsum-stabilized soils under acid rain conditions is limited and remains a significant challenge for practical applications.This study investigates the leaching effects and long-term durability of phosphogypsum-stabilized soils by simulating acid rain erosion through semi-dynamic leaching tests.Key parameters,including leached Ca^(2+)concentration,leachate pH,and unconfined compressive strength after leaching,were evaluated.Microscopic analyses with X-ray diffraction(XRD)and scanning electron microscopy(SEM)were also conducted to explore the underlying mechanisms.The results indicate that the presence of phosphogypsum in stabilized soil with high water content shows a significant improvement in leaching resistance subjected to acid ions,evidencing a lower Ca^(2+)concentration and pH value in the leachate,and a higher strength after leaching compared to those samples without phosphogypsum.SEM images and XRD analysis revealed that samples with higher phosphogypsum content possess denser structures due to more needle-shaped ettringite and other minerals in the soil matrix,contributing to improved strength and leaching resistance.The enhanced strength and leaching resistance of phosphogypsum-stabilized soil can be attributed to additional gel formation,a rise in swelling potential,ettringite bridging,and a denser microstructure,which reduces Ca^(2+)availability for leaching in acidic environments.
基金supported by the Science and Technology Development Plan of Jilin Province(No.YDZJ202403009CGZH)Engineering Research Center of Coalbased Ecological Carbon Sequestration Technology of the Ministry of Education(No.MJST2025-1)+2 种基金Chinese Academy of Sciences(Changchun Branch)(No.2024SYHZ0038)Development and Reform Commission of Jilin Province of China(No.2024C019-5)Science and Technology Bureau of Changchun City of China(No.23SH08)。
文摘A polylactide(PLA)blend with simultaneous enhancement of strength,toughness,and heat resistance was successfully achieved by adding biodegradable poly(propylene carbonate)(PPC)and uniaxial pre-stretching.The effects of the PPC content(0 wt%-50 wt%)on the phase morphology and performance of the blends before and after pre-stretching were systematically investigated.Blending PPC initially reduced the strength,modulus,and heat resistance,but pre-stretching significantly enhanced these properties.In blends containing≤30 wt%PPC,where PPC formed a well-dispersed island-like phase within the PLA matrix,pre-stretching simultaneously enhanced strength,toughness,and heat resistance.The optimized pre-stretched 70/30 PLA/PPC(ps-70/30)blend achieved exceptional performance:tensile strength increased from 66.9MPa to 84.5 MPa,elongation at break dramatically improved from 6.8%to 115.1%,impact strength reached 55.1 k J/m^(2)(far exceeding neat PLA's 3.5 k J/m^(2)),and Vicat softening temperature(VST)increased by 60.6%to 101.8℃.Notably,the ps-70/30 blend retained excellent mechanical properties even after six months of aging.These improvements were attributed to the synergistic effects of the PPC incorporation and prestretching.PPC not only promoted the high orientation of the PLA molecular chains but also facilitated the formation of a stable crystalline phase during pre-stretching,thereby enhancing both the mechanical properties and heat resistance.However,when the PPC content exceeded 30wt%,phase inversion occurred,resulting in a continuous amorphous PPC phase that degraded the overall performance.This study demonstrated that a combination of controlled PPC incorporation and pre-stretching can effectively overcome PLA's brittleness of PLA while improving its heat resistance,offering a promising strategy for developing high-performance,fully biodegradable PLA materials suitable for industrial applications.
文摘Objective:To analyse the prevalence of serotypes,antibiotic resistance,and virulence genes of Group B Streptococcus(GBS)strains isolated from pregnant women at 35-37 weeks of gestation in Ho Chi Minh City,Vietnam,from January 2022 to January 2023.Methods:GBS strains were isolated through selective culture methods and confirmed by PCR.Serotyping,virulence gene detection,and antibiotic susceptibility testing were performed using PCR,gel electrophoresis techniques and Kirby-Bauer test.Results:Totally,61 GBS isolated from 300 participants have been identified including seven GBS serotypes(Ⅰa,Ⅰb,Ⅱ,Ⅲ,Ⅳ,Ⅴ,andⅥ).SerotypesⅦ,Ⅷ,andⅨwere not detected in the study population.Antibiotic resistance patterns varied:13.1%of isolates were fully susceptible,while the majority showed multi-drug resistance,with 34.4%resistant to three antibiotics.SerotypeⅠa demonstrated high susceptibility(35.7%),while serotypeⅢshowed extensive resistance,with 87.5%being resistant to at least three antibiotics.All strains are susceptible to vancomycin andβ-lactams susceptibility also remained high,but resistance to clindamycin,erythromycin,and tetracycline was high(>65%).The virulence genes scpB,cylB,fbsB,and cfb were highly prevalent(90%-100%),indicating their potential for vaccine and diagnostic development.Conclusions:Our findings provide valuable insights into GBS serotypes,resistance,and virulence factors,contributing to community monitoring,preventive measures,diagnostics,and vaccine development.However,the limited sample size necessitates further research.
基金received financial support from the Natural Science Foundation of Chongqing,China(CSTB2023NSCQMSX0355)the Fundamental Research Funds for the Central Universities,China(SWU120075)the National Natural Science Foundation of China(32372077)。
文摘The plant pathogenic fungus Sclerotinia sclerotiorum is the causative agent of Sclerotinia stem rot(SSR)disease in most dicotyledons.Among the various proteins involved in drug efflux or substance transport,ATP-binding cassette(ABC)transporters constitute a superfamily of membrane-bound proteins that may play a crucial role in the survival of S.sclerotiorum.However,the expression patterns and functions of ABC transporter genes in S.sclerotiorum remain largely uncharacterized.This study characterized a highly expressed S.sclerotiorum ABC transporter gene during inoculation on host plants,Ss BMR1.Silencing Ss BMR1 resulted in a significant reduction in hyphal growth,infection cushion development,sclerotia formation,and virulence.Moreover,host-induced gene silencing(HIGS)of Ss BMR1 significantly enhanced plant resistance.Transcriptome and metabolomics analyses suggested that Ss BMR1 is involved in antioxidant and toxin transport,thereby influencing fungal defense and cell rescue mechanisms.In comparison to the wild-type strain,Ss BMR1 gene-silenced transformants exhibited a diminished response to extracellar oxidative stress and a decreased exporting of antioxidant glutathione.Tolerance assays further demonstrated the crucial role of Ss BMR1 in conferring resistance to the plant antifungal substances,camalexin and brassinin,as well as certain fungicides.Furthermore,Ss BMR1 gene-silenced transformants showed enhanced repression on virulence when sprayed with camalexin and brassinin on the leaves.Thus,Ss BMR1 likely contributes to virulence by facilitating the export of antioxidant and providing resistance against antifungal agents.The findings of this study provide valuable insights that could contribute to the development of novel management techniques for SSR.
基金supported by the National Natural Science Foundation of China(U22A20443)the Heilongjiang Provincial Research Institutes Scientific Research Operating Expenses Project,China(CZKYF2023-1-B020)+1 种基金the Key Research and Development Plan Project of Heilongjiang Province,China(GA23B015)the Young Scientists Fund of the National Natural Science Foundation of China(32201717)。
文摘Caffeic acid-O-methyltransferase(COMT)is a crucial enzyme in the phenylpropanoid metabolic pathway,with significant roles in both the lignin and coumarin pathways.The function of COMT in plant disease resistance has been demonstrated in several species.Our research identified the potato COMT gene family on a genome-wide scale and StCOMT1 as a candidate gene for enhancing potato disease resistance under DON induction through phylogenetic analyses combined with previously identified metabolic differences and weighted gene co-expression network analysis(WGCNA)results.In order to better understand the function of StCOMT1,heterologous expression and overexpression assays were conducted.StCOMT1 is localized in chloroplasts and was found to catalyze the methylation of substrates to produce ferulic acid and melatonin in vitro.Physiological parameters showed that,compared with wild-type potato plants,StCOMT1-overexpressing plants infected with Fusarium sporotrichioides exhibited smaller lesion areas and lower reactive oxygen species(ROS)levels.High-performance liquid chromatography(HPLC)and RT-qPCR analyses revealed organ-specific accumulation of coumarin-related compounds and organ-specific expression of their corresponding genes in StCOMT1-overexpressing plants post-inoculation.The results indicate that StCOMT1 overexpression in potatoes enhanced resistance to F.sporotrichioides by enhancing reactive oxygen species clearance and promoting organ-specific accumulation of coumarin-related compounds.
