Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]...Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]-containing carboxyl groups[PAEK-COOH]/UiO-66-NH_(2)@graphene oxide[GO])with superb fouling resistance and high permeability was prepared by the nonsolvent-induced phase separation method,by in-situ growth of UiO-66-NH_(2) on the GO layer,and by preparing hydrophilic PAEK-COOH.On the basis of the structure and performance analysis of the MMM,the maximum water flux reached 591.25 L·m^(-2)·h^(-1) for PAEK-COOH/UiO-66-NH_(2)@GO,whereas the retention rate for bovine serum albumin increased from 85.40%to 94.87%.As the loading gradually increased,the hydrophilicity of the MMMs increased,significantly enhancing their fouling resistance.The strongest anti-fouling ability observed was 94.74%,which was 2.02 times greater than that of the pure membrane.At the same time,the MMMs contained internal amide and hydrogen bonds during the preparation process,forming a cross-linked structure,which further enhanced the mechanical strength and chemical stability.In summary,the MMMs with high retention rate,strong permeability,and anti-fouling ability were successfully prepared.展开更多
The steel slag （SS） permeable concrete was prepared by SS. The influences of the aggregate-cement rate, the aggregate particle size, the water-cement rate, the admixture dosage and other factors on the permeability ...The steel slag （SS） permeable concrete was prepared by SS. The influences of the aggregate-cement rate, the aggregate particle size, the water-cement rate, the admixture dosage and other factors on the permeability coefficient of SS permeable concrete were analyzed. The law of influence was also investigated. The study serves as a technological reference for the construction and design of SS permeable concrete.展开更多
The physical properties of hydrocarbon reservoirs are important factors affecting the percolation ability of the reservoirs.Tight-sand reservoirs exhibit complex pore throat connectivity due to the extensive developme...The physical properties of hydrocarbon reservoirs are important factors affecting the percolation ability of the reservoirs.Tight-sand reservoirs exhibit complex pore throat connectivity due to the extensive development of micro-and nano-scale pore and throat systems.Characterizing the microscopic properties of these reservoirs using nondestructive,quantitative methods serves as an important means to determine the characteristics of microscopic pores and throats in tight-sand reservoirs and the mechanism behind the influence of these characteristics on reservoir porosity and permeability.In this study,a low-permeability sandstone sample and two tight sandstone samples collected from the Ordos Basin were nondestructively tested using high-resolution nano-CT technology to quantitively characterize their microscopic pore throat structures and model them three-dimensionally(in 3D)based on CT threshold differences and gray models.A thorough analysis and comparison reveal that the three samples exhibit a certain positive correlation between their porosity and permeability but the most important factor affecting both porosity and permeability is the microscopic pore throat structure.Although the number of pores in tight sandstones shows a minor impact on their porosity,large pores(more than 20μm)contribute predominantly to porosity,suggesting that the permeability of tight sandstones is controlled primarily by large pore throats.For these samples,higher permeability corresponds to larger average throat sizes.Therefore,throats with average radii greater than 2μm can significantly improve the permeability of tight sandstones.展开更多
Irregular bone scaffolds fabricated using the Voronoi tessellation method resemble the morphology and properties of human cancellous bones.This has become a prominent topic in bone tissue engineering research in recen...Irregular bone scaffolds fabricated using the Voronoi tessellation method resemble the morphology and properties of human cancellous bones.This has become a prominent topic in bone tissue engineering research in recent years.However,studies on the radial-gradient design of irregular bionic scaffolds are limited.Therefore,this study aims to develop a radial-gradient structure similar to that of natural long bones,enhancing the development of bionic bone scaffolds.A novel gradient method was adopted to maintain constant porosity,control the seed site-specific distribution within the irregular porous structure,and vary the strut diameter to generate radial gradients.The irregular scaffolds were compared with four conventional scaffolds(cube,pillar BCC,vintiles,and diamond)in terms of permeability,stress concentration characteristics,and mechanical properties.The results indicate that the radial-gradient irregular porous structure boasts the widest permeability range and superior stress distribution compared to conventional scaffolds.With an elastic modulus ranging from 4.20 GPa to 22.96 GPa and a yield strength between 68.37 MPa and 149.40 MPa,it meets bone implant performance requirements and demonstrates significant application potential.展开更多
Permeable roads generally exhibit inferior mechanical properties and shorter service life than traditional dense-graded/impermeable roads.Furthermore,the incorporation of recycled aggregates in their construction may ...Permeable roads generally exhibit inferior mechanical properties and shorter service life than traditional dense-graded/impermeable roads.Furthermore,the incorporation of recycled aggregates in their construction may exacerbate these limitations.To address these issues,this study introduced a novel cement-stabilized permeable recycled aggregate material.A total of 162 beam specimens prepared with nine different levels of cement-aggregate ratio were tested to evaluate their permeability,bending load,and bending fatigue life.The experimental results indicate that increasing the content of recycled aggregates led to a reduction in both permeability and bending load.Additionally,the inclusion of recycled aggregates diminished the energy dissipation capacity of the specimens.These findings were used to establish a robust relationship between the initial damage in cement-stabilized permeable recycled aggregate material specimens and their fatigue life,and to propose a predictive model for their fatigue performance.Further,a method for assessing fatigue damage based on the evolution of fatigue-induced strain and energy dissipation was developed.The findings of this study provide valuable insights into the mechanical behavior and fatigue performance of cement-stabilized permeable recycled aggregate materials,offering guidance for the design of low-carbon-emission,permeable,and durable roadways incorporating recycled aggregates.展开更多
Background To compare neural damage induced by ultra-high dose rate FLASH radiotherapy(FLASH-RT)with that induced by conventional dose rate radiotherapy(CONV-RT)in healthy mice.Methods Eighty adult male C57BL/6J mice ...Background To compare neural damage induced by ultra-high dose rate FLASH radiotherapy(FLASH-RT)with that induced by conventional dose rate radiotherapy(CONV-RT)in healthy mice.Methods Eighty adult male C57BL/6J mice were divided into five groups:Sham,CONV-RT10Gy,CONV-RT20Gy,FLASH-RT10Gy,and FLASH-RT20Gy.Three days post-irradiation,morphological changes in neurons within the dentate gyrus(DG),CA1,and CA3 were observed using hematoxylin and eosin and Nissl staining.The malondialdehyde(MDA),reduced glutathione(GSH),glutathione peroxidase(GSH-PX),superoxide dismutase(SOD),catalase(CAT),and hydroxyl radical(OH^(-))levels were measured using assay kits.Quantitative reverse transcription PCR was used to assess interleukin(IL)-1β,IL-6,inducible nitric oxide synthase(iNOS),and tumor necrosis factor(TNF)-αmRNA expression levels in hippocampus.Immunofluorescence was employed to observe microglial activation in the DG.Results Compared with Sham,CONV-RT10Gy and CONV-RT20Gy exhibited disorganized neuronal arrangements and blurred nucleoli in the DG;the number of Nissl body was reduced,but FLASH-RT10Gy and FLASH-RT20Gy alleviated these abnormalities.Moreover,FLASH-RT20Gy mitigated the upregulation of MDA and downregulation of GSH,GSH-PX,SOD,CAT,and OH^(-)levels in the hippocampus of mice subjected to CONV-RT20Gy.Additionally,FLASH-RT20Gy attenuated the upregulation of IL-1β,IL-6,iNOS,and TNF-αmRNA levels in hippocampus of mice subjected to CONV-RT20Gy and diminished microglial activation in the DG.Conclusion FLASH-RT mitigate the structural and functional disruptions in hippocampal neurons induced by CONV-RT and alleviate oxidative stress and inflammation in hippocampal tissue by reducing microglial activation.展开更多
2'-Fucosyllactose(2'-FL)shows the potential to support intestinal health as a natural prebiotic that bridges the gap between infant formula feeding and breastfeeding.However,the effect and mechanism of 2'-...2'-Fucosyllactose(2'-FL)shows the potential to support intestinal health as a natural prebiotic that bridges the gap between infant formula feeding and breastfeeding.However,the effect and mechanism of 2'-FL in improving intestinal permeability are not clear.In this study,we constructed human microbiota-associated(HMA)mouse models by colonizing healthy infant feces in mice with antibiotic-depleted intestinal microbiota.The protective effect of 2'-FL on the intestinal permeability was explored using the HMA mouse models,and the combination of metagenomics was used to analyze the possible mechanisms by which the microorganisms reduced the intestinal permeability.The results showed that 2'-FL decreased the concentration of markers of intestinal permeability(enterotoxin and diamine oxidase(DAO))and increased the expression levels of tight junctions(occludin and claudin).Metagenomics revealed the enrichment of Bifidobacterium and increased the expression of glycoside hydrolases(GHs),including GH31,GH28,and GH5.In conclusion,2'-FL strengthened intestinal permeability function by improving microbiota composition to control the translocation of harmful substance.展开更多
CO_(2)flooding enhanced oil recovery(CO_(2)-EOR)represents a significant technology in the low permeability reservoir.With the fractures and heterogeneity in low permeability reservoirs,CO_(2)-EOR is susceptible to pe...CO_(2)flooding enhanced oil recovery(CO_(2)-EOR)represents a significant technology in the low permeability reservoir.With the fractures and heterogeneity in low permeability reservoirs,CO_(2)-EOR is susceptible to pessimistic gas channeling.Consequently,there is a need to develop conformance control materials that can be used in CO_(2)-EOR.Herein,to address the challenges of low strength and poor stability of polymer gel in high temperature and low permeability reservoirs,a new organic/metal ion composite crosslinking polymer gel(AR-Gel)is reported,which is formed by low hydrolysis and medium to high molecular weight polymer(CX-305),organic crosslinking agent(phenolic resin),and aluminium citrate(AI(Ⅲ)).The crosslinking of AI(Ⅲ)with carboxyl group and organic/metal ion double crosslinking can construct a more complex and stable polymer gel structure on the basis of traditional chemical crosslinking,to cope with the harsh conditions such as high temperature.The structure-activity relationship of AR-Gel was revealed by rheology behavior and micro-morphology.The applicability of AR-Gel in reservoir was investigated,as was its strength and stability in supercritical CO_(2).The anti-gas channeling and enhanced oil recovery of AR-Gel were investigated using low permeability fractured cores,and the field process parameters were provided.The gel can be used to meet supercritical CO_(2)reservoirs at 110℃and 20,000 mg/L salinity,with long-term stability over 60 days.The plugging rate of AR-Gel for fractured co re was 97%,with subsequent CO_(2)flooding re sulting in an enhanced oil recovery by 34.5%.ARGel can effectively control CO_(2)gas channeling and enhanced oil recovery.It offers a new material with high strength and temperature resistance,which is particularly beneficial in the CO_(2)flooding for the conformance control of oil field.展开更多
Precast driven piles are extensively used for infrastructure on soft soils,but the buildup of excess pore water pressure associated with pile driving is a challenging issue.The process of soil consolidation could take...Precast driven piles are extensively used for infrastructure on soft soils,but the buildup of excess pore water pressure associated with pile driving is a challenging issue.The process of soil consolidation could take several months.Measures are sought to shorten the drainage path in the ground,and permeable pipe pile is a concept that involves drainage channels at the peak pore pressure locations around the pile circumference.Centrifuge tests were conducted to understand the responses of permeable pipe pile treated ground,experiencing the whole pile driving,soil consolidating,and axially loading process.Results show that the dissipation rate of pore pressures can be improved,especially at a greater depth or at a shorter distance from the pile,since the local hydraulic gradient was higher.Less significant buildup of pore pressures can be anticipated with the use of permeable pipe pile.For this,the bearing capacity of composite foundation with permeable pipe pile can be increased by over 36.9%,compared to the case with normal pipe pile at a specific time period.All these demonstrate the ability of permeable pipe pile in accelerating the consolidation process,mobilizing the bearing capacity of treated ground at an early stage,and minimizing the set-up effect.展开更多
This study investigates the bond performance at the interfacial region shared by Ultra-High Performance Concrete(UHPC)and steel tubes through push-out tests.This study examines how changes in steel fiber volumetric ra...This study investigates the bond performance at the interfacial region shared by Ultra-High Performance Concrete(UHPC)and steel tubes through push-out tests.This study examines how changes in steel fiber volumetric ratio and thickness of steel tube influence the bond strength characteristics.The results show that as the enhancement of the steel tube wall thickness,the ultimate bond strength at the interface improves significantly,whereas the initial bond strength exhibits only slight variations.The influence of steel fiber volumetric ratio presents a nonlinear trend,with initial bond strength decreasing at low fiber content and increasing significantly as fiber content rises.Additionally,finite element(FE)simulations were applied to replicate the experimental conditions,and the outcomes showed strong correlation with the experimental data,confirming the exactitude of the FE model in predicting the bond behavior at the UHPC-Steel interface.These findings provide valuable insights for optimizing the design of UHPC-Filled steel tubes in high-performance structure.展开更多
As the first gold mine discovered at the sea in China and the only coastal gold mine currently mined there,Sanshandao Gold Mine faces unique challenges.The mine's safety is under continual threat from its faulted ...As the first gold mine discovered at the sea in China and the only coastal gold mine currently mined there,Sanshandao Gold Mine faces unique challenges.The mine's safety is under continual threat from its faulted structure coupled with the overlying water.As the mining proceeds deeper,the risk of water inrush increases.The mine's maximum water yield reaches 15000 m3/day,which is attributable to water channels present in fault zones.Predominantly composed of soil–rock mixtures(SRM),these fault zones'seepage characteristics significantly impact water inrush risk.Consequently,investigating the seepage characteristics of SRM is of paramount importance.However,the existing literature mostly concentrates on a single stress state.Therefore,this study examined the characteristics of the permeability coefficient under three distinct stress states:osmotic,osmotic–uniaxial,and osmotic–triaxial pressure.The SRM samples utilized in this study were extracted from in situ fault zones and then reshaped in the laboratory.In addition,the micromechanical properties of the SRM samples were analyzed using computed tomography scanning.The findings reveal that the permeability coefficient is the highest under osmotic pressure and lowest under osmotic–triaxial pressure.The sensitivity coefficient shows a higher value when the rock block percentage ranges between 30%and 40%,but it falls below 1.0 when this percentage exceeds 50%under no confining pressure.Notably,rock block percentages of 40%and 60%represent the two peak points of the sensitivity coefficient under osmotic–triaxial pressure.However,SRM samples with a 40%rock block percentage consistently show the lowest permeability coefficient under all stress states.This study establishes that a power function can model the relationship between the permeability coefficient and osmotic pressure,while its relationship with axial pressure can be described using an exponential function.These insights are invaluable for developing water inrush prevention and control strategies in mining environments.展开更多
The strength of the sliding zone soil determines the stability of reservoir landslides.Fluctuations in water levels cause a change in the seepage field,which serves as both the external hydrogeological environment and...The strength of the sliding zone soil determines the stability of reservoir landslides.Fluctuations in water levels cause a change in the seepage field,which serves as both the external hydrogeological environment and the internal component of a landslide.Therefore,considering the strength changes of the sliding zone with seepage effects,they correspond with the actual hydrogeological circumstances.To investigate the shear behavior of sliding zone soil under various seepage pressures,24 samples were conducted by a self-developed apparatus to observe the shear strength and measure the permeability coefficients at different deformation stages.After seepage-shear tests,the composition of clay minerals and microscopic structure on the shear surface were analyzed through X-ray and scanning electron microscope(SEM)to understand the coupling effects of seepage on strength.The results revealed that the sliding zone soil exhibited strain-hardening without seepage pressure.However,the introduction of seepage caused a significant reduction in shear strength,resulting in strain-softening characterized by a three-stage process.Long-term seepage action softened clay particles and transported broken particles into effective seepage channels,causing continuous damage to the interior structure and reducing the permeability coefficient.Increased seepage pressure decreased the peak strength by disrupting occlusal and frictional forces between sliding zone soil particles,which carried away more clay particles,contributing to an overhead structure in the soil that raised the permeability coefficient and decreased residual strength.The internal friction angle was less sensitive to variations in seepage pressure than cohesion.展开更多
Understanding the storage mechanisms in CO_(2)flooding is crucial,as many carbon capture,utilization,and storage(CCUS)projects are related to enhanced oil recovery(EOR).CO_(2)storage in reservoirs across large timesca...Understanding the storage mechanisms in CO_(2)flooding is crucial,as many carbon capture,utilization,and storage(CCUS)projects are related to enhanced oil recovery(EOR).CO_(2)storage in reservoirs across large timescales undergoes the two storage stages of oil displacement and well shut-in,which cover mul-tiple replacement processes of injection-production synchronization,injection only with no production,and injection-production stoppage.Because the controlling mechanism of CO_(2)storage in different stages is unknown,the evolution of CO_(2)storage mechanisms over large timescales is not understood.A math-ematical model for the evaluation of CO_(2)storage,including stratigraphic,residual,solubility,and mineral trapping in low-permeability tight sandstone reservoirs,was established using experimental and theoret-ical analyses.Based on a detailed geological model of the Huaziping Oilfield,calibrated with reservoir permeability and fracture characteristic parameters obtained from well test results,a dynamic simulation of CO_(2)storage for the entire reservoir life cycle under two scenarios of continuous injection and water-gas alternation were considered.The results show that CO_(2)storage exhibits the significant stage charac-teristics of complete storage,dynamic storage,and stable storage.The CO_(2)storage capacity and storage rate under the continuous gas injection scenario(scenario 1)were 6.34×10^(4)t and 61%,while those under the water-gas alternation scenario(scenario 2)were 4.62×10^(4)t and 46%.The proportions of stor-age capacity under scenarios 1 and 2 for structural or stratigraphic,residual,solubility,and mineral trap-ping were 33.36%,33.96%,32.43%,and 0.25%;and 15.09%,38.65%,45.77%,and 0.49%,respectively.The evolution of the CO_(2)storage mechanism showed an overall trend:stratigraphic and residual trapping first increased and then decreased,whereas solubility trapping gradually decreased,and mineral trapping continuously increased.Based on these results,an evolution diagram of the CO_(2)storage mechanism of low-permeability tight sandstone reservoirs across large timescales was established.展开更多
Honey, an apicultural product with a complex chemical composition, contains numerous bioactive compounds with potential antimicrobial effects. This study investigated the effect of Apis mellifera honey from Brazil’s ...Honey, an apicultural product with a complex chemical composition, contains numerous bioactive compounds with potential antimicrobial effects. This study investigated the effect of Apis mellifera honey from Brazil’s Central-West Region, combined with antibiotics, on bacterial membrane permeability, exploring the contributions of bioactive compounds and the botanical origin of honey. Six fresh Apis mellifera honey samples and their fractions (hexane and ethyl acetate) were analyzed, for a total of 18 samples. The bacteria Staphylococcus epidermidis, Helicobacter pylori and Enterococcus faecalis were used for antibacterial activity tests, which included minimum inhibitory concentration (MIC) determination and synergistic effect (checkerboard) assays. The total polyphenol and flavonoid contents were quantified, and the botanical origin was determined based on pollen analysis. The tested honey samples significantly affected bacterial membrane permeability when combined with rifampicin and clarithromycin. Although many honey-derived bioactive compounds, when isolated, did not exhibit significant activity against these bacteria, the additive or synergistic effect of multiple compounds acting on different targets appears to potentiate the antibacterial action. Descriptive statistical analysis, including means and 95% confidence intervals, confirmed the relevance of the findings. This study has provided an important discovery: Honey has an effect on bacterial membrane permeability, although the specific mechanisms involved in this process require further investigation.展开更多
Current protective clothing often lacks sufficient comfort to ensure efficient performance of healthcare workers.Developing protective textiles with high air and moisture permeability is a potential and effective solu...Current protective clothing often lacks sufficient comfort to ensure efficient performance of healthcare workers.Developing protective textiles with high air and moisture permeability is a potential and effective solution to discomfort of medical protective clothing.However,realizing the facile production of a protective textile that combines safety and comfort remains a challenge.Herein,we report the fabrication of highly permeable protective textiles(HPPT)with micro/nano-networks,using non-solvent induced phase separation synergistically driven by CaCl_(2) and fluorinated polyurethane,combined with spraying technique.The HPPT demonstrates excellent liquid repellency and comfort,ensuring high safety and a dry microenvironment for the wearer.The textile exhibits not only a high hydrostatic pressure(12.86 kPa)due to its tailored small mean pore size(1.03μm)and chemical composition,but also demonstrates excellent air permeability(14.24 mm s^(−1))and moisture permeability(7.92 kg m^(−2)d^(−1))owing to the rational combination of small pore size and high porosity(69%).The HPPT offers superior comfort compared to the commercially available protective materials.Additionally,we elucidated a molding mechanism synergistically inducted by diffusion-dissolution-phase separation.This research provides an innovative perspective on enhancing the comfort of medical protective clothing and offers theoretical support for regulating of pore structure during phase separations.展开更多
An evaluation method for self-healing capacity was designed,which includes the control of initial cracks and subsequent permeability testing.This method was employed to evaluate the self-healing behavior of mortars in...An evaluation method for self-healing capacity was designed,which includes the control of initial cracks and subsequent permeability testing.This method was employed to evaluate the self-healing behavior of mortars incorporating crystalline admixtures(CAs)under various conditions,including water immersion,limewater soaking,and wet-dry cycles,with varying CA dosages and crack widths.The experimental results indicate that cement possesses inherently self-healing capability.Limewater environments inhibits healing compared with water immersion;however,wet-dry cycles enhance the effectiveness of higher CA dosages.Increasing the CA content can not improve healing performance,and wide cracks(0.3 mm)substantially reduce the intrinsic self-healing potential of cement.展开更多
Poly(vinylidene fluoride)(PVDF)foam has received widespread attention due to its high strength,and excellent combination of flame-retardancy,antibacterial performance,and chemical stability.However,the foaming ability...Poly(vinylidene fluoride)(PVDF)foam has received widespread attention due to its high strength,and excellent combination of flame-retardancy,antibacterial performance,and chemical stability.However,the foaming ability of conventional PvDF is severely limited by its rapid crystallization kinetics and poor melt strength.Although ultra-high molecular weight PVDF(H-PVDF)theoretically offers prolonged melt elasticity favorable for foaming,the extremely high melt viscosity poses substantial processing challenges,and its foaming behavior has remained largely unexplored.To address these issues,this study proposes a novel fabrication strategy combining solvent casting with microcellular foaming to prepare H-PVDF foams.Dynamic mechanical analysis and differential scanning calorimetry reveal that extensive chain entanglements in H-PVDF impose constraints on crystallization and significantly enhance melt strength.By tuning the processing parameters,the distinctive foaming be-havior of H-PVDF under various conditions is systematically elucidated.Remarkably,a record-high expansion ratio of 55.6-fold is achieved,ac-companied by a highly uniform and fine cellular structure.The resulting H-PVDF foams exhibit a low thermal conductivity of 31.8 mW·m^(-1).K^(-1),while retaining excellent compressive strength,flame-retardancy,and hydrophobicity.These outstanding properties highlight the great potential of H-PVDF foams as the thermal insulation materials for applications in aerospace,energy infrastructure,and other extreme environments.展开更多
Permeability is affected by complex factors such as the subsurface geological structure and porosity-permeability correlation.For highly heterogeneous reservoirs with complex pore structures,it is extremely challengin...Permeability is affected by complex factors such as the subsurface geological structure and porosity-permeability correlation.For highly heterogeneous reservoirs with complex pore structures,it is extremely challenging to spatially characterize(predict)permeability using seismic data.The conventional way of permeability prediction intends to convert underground refl ection data into the elastic parameters sensitive to underground fluids,build a universal low-dimensional template via petrophysical modeling and ultimately deliver spatial prediction of permeability.However,this method is restrained by the actual subsurface condition,selected well-logging sensitive parameters and the accuracy of the computed elastic parameters and fails to simulate the petrophysical mechanisms of complex reservoir permeability,which reduces the permeability prediction accuracy.The method proposed in this paper combines petrophysics and artificial intelligence and integrates multiple types of information to build the high-dimensional petrophysical template for permeability,in an attempt to improve the spatial characterization and prediction accuracy of permeability.The field testing demonstrates the high application performance and effective improvement in prediction accuracy and fluvial channel characterization.展开更多
BACKGROUND Although an association between gut microbiota and cholestatic liver disease(CLD)has been reported,the precise functional roles of these microbes in CLD pathogenesis remain largely unknown.AIM To explore th...BACKGROUND Although an association between gut microbiota and cholestatic liver disease(CLD)has been reported,the precise functional roles of these microbes in CLD pathogenesis remain largely unknown.AIM To explore the function of gut microbes in CLD pathogenesis and the effects of gut microbiota on intestinal barrier and bile acid(BA)metabolism in CLD.METHODS Male C57BL/6J mice were fed a 0.05%3,5-diethoxycarbonyl-1,4-dihydrocollidine diet for 2 weeks to induce CLD.The sterile liver tissues of mice were then meticulously harvested,and bacteria in homogenates were identified through culture methods.Furthermore,16S ribosomal DNA sequencing was employed to analyze sterile liver samples collected from eight patients with primary biliary cholangitis(PBC)and three control individuals with hepatic cysts.The functional roles of the identified bacteria in CLD pathogenesis were assessed through microbiota transfer experiments,involving the evaluation of changes in intestinal permeability and BA dynamics.RESULTS Ligilactobacillus murinus(L.murinus)and Lactococcus garvieae(L.garvieae)were isolated from the bacterial culture of livers from CLD mice.L.murinus was prevalently detected in PBC patients and controls,whereas L.garvieae was detected only in patients with PBC but not in controls.Mice inoculated with L.garvieae exhibited increased susceptibility to experimental CLD,with both in vitro and in vivo indicating that L.garvieae disrupted the intestinal barrier function by down-regulating the expression of occludin and zonula occludens-1.Moreover,L.garvieae administration significantly upregulated the expression of the apical sodium-dependent BA transporter in the terminal ileum and increased serum BA levels.CONCLUSION L.garvieae contributes to excessive BA-induced hepatobiliary injury and liver fibrosis by increasing intestinal permeability and enhancing BA reabsorption.展开更多
Ultra-high strength steel(UHSS)fabricated via laser additive manufacturing(LAM)holds significant promise for applications in defense,aerospace,and other high-performance sectors.However,its response to high-impact loa...Ultra-high strength steel(UHSS)fabricated via laser additive manufacturing(LAM)holds significant promise for applications in defense,aerospace,and other high-performance sectors.However,its response to high-impact loading remains insufficiently understood,particularly regarding the influence of energy density on its dynamic mechanical behavior.In this study,scanning electron micro-scopy,electron backscatter diffraction,and image recognition techniques were employed to investigate the microstructural variations of LAM-fabricated UHSS under different energy density conditions.The dynamic mechanical behavior of the material was characterized using a Split Hopkinson Pressure Bar system in combination with high-speed digital image correlation.The study reveals the spatiotemporal evolution of surface strain and crack formation,as well as the underlying dynamic fracture mechanisms.A clear correlation was established between the microstructures formed under varying energy densities and the resulting dynamic mechanical strength of the material.Results demonstrate that optimal material density is achieved at energy densities of 292 and 333 J/mm^(3).In contrast,energy densities exceeding 333 J/mm^(3) induce keyhole defects,compromising structural integrity.Dynamic performance is strongly dependent on material density,with peak impact resistance observed at 292 J/mm^(3)-where strength is 8.4%to 17.6%higher than that at 500 J/mm^(3).At strain rates≥2000 s^(-1),the material reaches its strength limit at approximately 110μs,with the initial crack appearing within 12μs,followed by rapid failure.Conversely,at strain rates≤1500 s^(-1),only microcracks and adiabatic shear bands are detected.A transition in fracture surface morphology from ductile to brittle is observed with increasing strain rate.These findings offer critical insights into optimizing the dynamic mechanical properties of LAM-fabricated UHSS and provide a valuable foundation for its deployment in high-impact environments.展开更多
基金support of this work by National Natural Science Foundation of China(22075031,51673030,51603017 and 51803011)Jilin Provincial Science&Technology Department(20220201105GX)Chang Bai Mountain Scholars Program of Jilin Province.
文摘Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]-containing carboxyl groups[PAEK-COOH]/UiO-66-NH_(2)@graphene oxide[GO])with superb fouling resistance and high permeability was prepared by the nonsolvent-induced phase separation method,by in-situ growth of UiO-66-NH_(2) on the GO layer,and by preparing hydrophilic PAEK-COOH.On the basis of the structure and performance analysis of the MMM,the maximum water flux reached 591.25 L·m^(-2)·h^(-1) for PAEK-COOH/UiO-66-NH_(2)@GO,whereas the retention rate for bovine serum albumin increased from 85.40%to 94.87%.As the loading gradually increased,the hydrophilicity of the MMMs increased,significantly enhancing their fouling resistance.The strongest anti-fouling ability observed was 94.74%,which was 2.02 times greater than that of the pure membrane.At the same time,the MMMs contained internal amide and hydrogen bonds during the preparation process,forming a cross-linked structure,which further enhanced the mechanical strength and chemical stability.In summary,the MMMs with high retention rate,strong permeability,and anti-fouling ability were successfully prepared.
文摘The steel slag （SS） permeable concrete was prepared by SS. The influences of the aggregate-cement rate, the aggregate particle size, the water-cement rate, the admixture dosage and other factors on the permeability coefficient of SS permeable concrete were analyzed. The law of influence was also investigated. The study serves as a technological reference for the construction and design of SS permeable concrete.
文摘The physical properties of hydrocarbon reservoirs are important factors affecting the percolation ability of the reservoirs.Tight-sand reservoirs exhibit complex pore throat connectivity due to the extensive development of micro-and nano-scale pore and throat systems.Characterizing the microscopic properties of these reservoirs using nondestructive,quantitative methods serves as an important means to determine the characteristics of microscopic pores and throats in tight-sand reservoirs and the mechanism behind the influence of these characteristics on reservoir porosity and permeability.In this study,a low-permeability sandstone sample and two tight sandstone samples collected from the Ordos Basin were nondestructively tested using high-resolution nano-CT technology to quantitively characterize their microscopic pore throat structures and model them three-dimensionally(in 3D)based on CT threshold differences and gray models.A thorough analysis and comparison reveal that the three samples exhibit a certain positive correlation between their porosity and permeability but the most important factor affecting both porosity and permeability is the microscopic pore throat structure.Although the number of pores in tight sandstones shows a minor impact on their porosity,large pores(more than 20μm)contribute predominantly to porosity,suggesting that the permeability of tight sandstones is controlled primarily by large pore throats.For these samples,higher permeability corresponds to larger average throat sizes.Therefore,throats with average radii greater than 2μm can significantly improve the permeability of tight sandstones.
基金the National Natural Science Foundation of China(No.52165026)。
文摘Irregular bone scaffolds fabricated using the Voronoi tessellation method resemble the morphology and properties of human cancellous bones.This has become a prominent topic in bone tissue engineering research in recent years.However,studies on the radial-gradient design of irregular bionic scaffolds are limited.Therefore,this study aims to develop a radial-gradient structure similar to that of natural long bones,enhancing the development of bionic bone scaffolds.A novel gradient method was adopted to maintain constant porosity,control the seed site-specific distribution within the irregular porous structure,and vary the strut diameter to generate radial gradients.The irregular scaffolds were compared with four conventional scaffolds(cube,pillar BCC,vintiles,and diamond)in terms of permeability,stress concentration characteristics,and mechanical properties.The results indicate that the radial-gradient irregular porous structure boasts the widest permeability range and superior stress distribution compared to conventional scaffolds.With an elastic modulus ranging from 4.20 GPa to 22.96 GPa and a yield strength between 68.37 MPa and 149.40 MPa,it meets bone implant performance requirements and demonstrates significant application potential.
基金Project(2024JJ2073)supported by the Science Fund for Distinguished Young Scholars of Hunan Province,ChinaProjects(2023YFC3807205,2019YFC1904704)+4 种基金supported by the National Key R&D Program of ChinaProject(52178443)supported by the National Natural Science Foundation of ChinaProject(2024ZZTS0109)supported by Fundamental Research Funds for the Central Universities of Central South University,China。
文摘Permeable roads generally exhibit inferior mechanical properties and shorter service life than traditional dense-graded/impermeable roads.Furthermore,the incorporation of recycled aggregates in their construction may exacerbate these limitations.To address these issues,this study introduced a novel cement-stabilized permeable recycled aggregate material.A total of 162 beam specimens prepared with nine different levels of cement-aggregate ratio were tested to evaluate their permeability,bending load,and bending fatigue life.The experimental results indicate that increasing the content of recycled aggregates led to a reduction in both permeability and bending load.Additionally,the inclusion of recycled aggregates diminished the energy dissipation capacity of the specimens.These findings were used to establish a robust relationship between the initial damage in cement-stabilized permeable recycled aggregate material specimens and their fatigue life,and to propose a predictive model for their fatigue performance.Further,a method for assessing fatigue damage based on the evolution of fatigue-induced strain and energy dissipation was developed.The findings of this study provide valuable insights into the mechanical behavior and fatigue performance of cement-stabilized permeable recycled aggregate materials,offering guidance for the design of low-carbon-emission,permeable,and durable roadways incorporating recycled aggregates.
文摘Background To compare neural damage induced by ultra-high dose rate FLASH radiotherapy(FLASH-RT)with that induced by conventional dose rate radiotherapy(CONV-RT)in healthy mice.Methods Eighty adult male C57BL/6J mice were divided into five groups:Sham,CONV-RT10Gy,CONV-RT20Gy,FLASH-RT10Gy,and FLASH-RT20Gy.Three days post-irradiation,morphological changes in neurons within the dentate gyrus(DG),CA1,and CA3 were observed using hematoxylin and eosin and Nissl staining.The malondialdehyde(MDA),reduced glutathione(GSH),glutathione peroxidase(GSH-PX),superoxide dismutase(SOD),catalase(CAT),and hydroxyl radical(OH^(-))levels were measured using assay kits.Quantitative reverse transcription PCR was used to assess interleukin(IL)-1β,IL-6,inducible nitric oxide synthase(iNOS),and tumor necrosis factor(TNF)-αmRNA expression levels in hippocampus.Immunofluorescence was employed to observe microglial activation in the DG.Results Compared with Sham,CONV-RT10Gy and CONV-RT20Gy exhibited disorganized neuronal arrangements and blurred nucleoli in the DG;the number of Nissl body was reduced,but FLASH-RT10Gy and FLASH-RT20Gy alleviated these abnormalities.Moreover,FLASH-RT20Gy mitigated the upregulation of MDA and downregulation of GSH,GSH-PX,SOD,CAT,and OH^(-)levels in the hippocampus of mice subjected to CONV-RT20Gy.Additionally,FLASH-RT20Gy attenuated the upregulation of IL-1β,IL-6,iNOS,and TNF-αmRNA levels in hippocampus of mice subjected to CONV-RT20Gy and diminished microglial activation in the DG.Conclusion FLASH-RT mitigate the structural and functional disruptions in hippocampal neurons induced by CONV-RT and alleviate oxidative stress and inflammation in hippocampal tissue by reducing microglial activation.
基金financially supported by the National Key Research and Development Program of China(2022YFF1100402)National Center of Technology Innovation for Dairy(2022-Open subject-11)+1 种基金Young Elite Scientist Sponsorship Program by CAST(YESS20200271)the National Natural Science Foundation of China(32101919)。
文摘2'-Fucosyllactose(2'-FL)shows the potential to support intestinal health as a natural prebiotic that bridges the gap between infant formula feeding and breastfeeding.However,the effect and mechanism of 2'-FL in improving intestinal permeability are not clear.In this study,we constructed human microbiota-associated(HMA)mouse models by colonizing healthy infant feces in mice with antibiotic-depleted intestinal microbiota.The protective effect of 2'-FL on the intestinal permeability was explored using the HMA mouse models,and the combination of metagenomics was used to analyze the possible mechanisms by which the microorganisms reduced the intestinal permeability.The results showed that 2'-FL decreased the concentration of markers of intestinal permeability(enterotoxin and diamine oxidase(DAO))and increased the expression levels of tight junctions(occludin and claudin).Metagenomics revealed the enrichment of Bifidobacterium and increased the expression of glycoside hydrolases(GHs),including GH31,GH28,and GH5.In conclusion,2'-FL strengthened intestinal permeability function by improving microbiota composition to control the translocation of harmful substance.
基金project was supported by the Fund of State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China)(No.SKLDOG2024-ZYRC-06)Key Program of National Natural Science Foundation of China(52130401)+1 种基金National Natural Science Foundation of China(52104055,52374058)Shandong Provincial Natural Science Foundation,China(ZR2021ME171,ZR2024YQ043)。
文摘CO_(2)flooding enhanced oil recovery(CO_(2)-EOR)represents a significant technology in the low permeability reservoir.With the fractures and heterogeneity in low permeability reservoirs,CO_(2)-EOR is susceptible to pessimistic gas channeling.Consequently,there is a need to develop conformance control materials that can be used in CO_(2)-EOR.Herein,to address the challenges of low strength and poor stability of polymer gel in high temperature and low permeability reservoirs,a new organic/metal ion composite crosslinking polymer gel(AR-Gel)is reported,which is formed by low hydrolysis and medium to high molecular weight polymer(CX-305),organic crosslinking agent(phenolic resin),and aluminium citrate(AI(Ⅲ)).The crosslinking of AI(Ⅲ)with carboxyl group and organic/metal ion double crosslinking can construct a more complex and stable polymer gel structure on the basis of traditional chemical crosslinking,to cope with the harsh conditions such as high temperature.The structure-activity relationship of AR-Gel was revealed by rheology behavior and micro-morphology.The applicability of AR-Gel in reservoir was investigated,as was its strength and stability in supercritical CO_(2).The anti-gas channeling and enhanced oil recovery of AR-Gel were investigated using low permeability fractured cores,and the field process parameters were provided.The gel can be used to meet supercritical CO_(2)reservoirs at 110℃and 20,000 mg/L salinity,with long-term stability over 60 days.The plugging rate of AR-Gel for fractured co re was 97%,with subsequent CO_(2)flooding re sulting in an enhanced oil recovery by 34.5%.ARGel can effectively control CO_(2)gas channeling and enhanced oil recovery.It offers a new material with high strength and temperature resistance,which is particularly beneficial in the CO_(2)flooding for the conformance control of oil field.
基金supported by the National Natural Science Foundation of China(Grant Nos.52168046 and 52178321)the Natural Science Foundation of Guangxi Province,China(Grant No.2021AC18019).
文摘Precast driven piles are extensively used for infrastructure on soft soils,but the buildup of excess pore water pressure associated with pile driving is a challenging issue.The process of soil consolidation could take several months.Measures are sought to shorten the drainage path in the ground,and permeable pipe pile is a concept that involves drainage channels at the peak pore pressure locations around the pile circumference.Centrifuge tests were conducted to understand the responses of permeable pipe pile treated ground,experiencing the whole pile driving,soil consolidating,and axially loading process.Results show that the dissipation rate of pore pressures can be improved,especially at a greater depth or at a shorter distance from the pile,since the local hydraulic gradient was higher.Less significant buildup of pore pressures can be anticipated with the use of permeable pipe pile.For this,the bearing capacity of composite foundation with permeable pipe pile can be increased by over 36.9%,compared to the case with normal pipe pile at a specific time period.All these demonstrate the ability of permeable pipe pile in accelerating the consolidation process,mobilizing the bearing capacity of treated ground at an early stage,and minimizing the set-up effect.
基金supported by grants from the Natural Science Foundation of Fujian Province(2021J011062)Minjiang Scholars Funding(GY-633Z21067).
文摘This study investigates the bond performance at the interfacial region shared by Ultra-High Performance Concrete(UHPC)and steel tubes through push-out tests.This study examines how changes in steel fiber volumetric ratio and thickness of steel tube influence the bond strength characteristics.The results show that as the enhancement of the steel tube wall thickness,the ultimate bond strength at the interface improves significantly,whereas the initial bond strength exhibits only slight variations.The influence of steel fiber volumetric ratio presents a nonlinear trend,with initial bond strength decreasing at low fiber content and increasing significantly as fiber content rises.Additionally,finite element(FE)simulations were applied to replicate the experimental conditions,and the outcomes showed strong correlation with the experimental data,confirming the exactitude of the FE model in predicting the bond behavior at the UHPC-Steel interface.These findings provide valuable insights for optimizing the design of UHPC-Filled steel tubes in high-performance structure.
基金State Key Research Development Program of China,Grant/Award Number:2021YFC3001301。
文摘As the first gold mine discovered at the sea in China and the only coastal gold mine currently mined there,Sanshandao Gold Mine faces unique challenges.The mine's safety is under continual threat from its faulted structure coupled with the overlying water.As the mining proceeds deeper,the risk of water inrush increases.The mine's maximum water yield reaches 15000 m3/day,which is attributable to water channels present in fault zones.Predominantly composed of soil–rock mixtures(SRM),these fault zones'seepage characteristics significantly impact water inrush risk.Consequently,investigating the seepage characteristics of SRM is of paramount importance.However,the existing literature mostly concentrates on a single stress state.Therefore,this study examined the characteristics of the permeability coefficient under three distinct stress states:osmotic,osmotic–uniaxial,and osmotic–triaxial pressure.The SRM samples utilized in this study were extracted from in situ fault zones and then reshaped in the laboratory.In addition,the micromechanical properties of the SRM samples were analyzed using computed tomography scanning.The findings reveal that the permeability coefficient is the highest under osmotic pressure and lowest under osmotic–triaxial pressure.The sensitivity coefficient shows a higher value when the rock block percentage ranges between 30%and 40%,but it falls below 1.0 when this percentage exceeds 50%under no confining pressure.Notably,rock block percentages of 40%and 60%represent the two peak points of the sensitivity coefficient under osmotic–triaxial pressure.However,SRM samples with a 40%rock block percentage consistently show the lowest permeability coefficient under all stress states.This study establishes that a power function can model the relationship between the permeability coefficient and osmotic pressure,while its relationship with axial pressure can be described using an exponential function.These insights are invaluable for developing water inrush prevention and control strategies in mining environments.
基金supported by the Major Program of the National Natural Science Foundation of China (Grant No.42090055)the National Major Scientific Instruments and Equipment Development Projects of China (Grant No.41827808)the National Nature Science Foundation of China (Grant No.42207216).
文摘The strength of the sliding zone soil determines the stability of reservoir landslides.Fluctuations in water levels cause a change in the seepage field,which serves as both the external hydrogeological environment and the internal component of a landslide.Therefore,considering the strength changes of the sliding zone with seepage effects,they correspond with the actual hydrogeological circumstances.To investigate the shear behavior of sliding zone soil under various seepage pressures,24 samples were conducted by a self-developed apparatus to observe the shear strength and measure the permeability coefficients at different deformation stages.After seepage-shear tests,the composition of clay minerals and microscopic structure on the shear surface were analyzed through X-ray and scanning electron microscope(SEM)to understand the coupling effects of seepage on strength.The results revealed that the sliding zone soil exhibited strain-hardening without seepage pressure.However,the introduction of seepage caused a significant reduction in shear strength,resulting in strain-softening characterized by a three-stage process.Long-term seepage action softened clay particles and transported broken particles into effective seepage channels,causing continuous damage to the interior structure and reducing the permeability coefficient.Increased seepage pressure decreased the peak strength by disrupting occlusal and frictional forces between sliding zone soil particles,which carried away more clay particles,contributing to an overhead structure in the soil that raised the permeability coefficient and decreased residual strength.The internal friction angle was less sensitive to variations in seepage pressure than cohesion.
基金supported by the National Key Research and Development Program of China(2022YFE0206700).
文摘Understanding the storage mechanisms in CO_(2)flooding is crucial,as many carbon capture,utilization,and storage(CCUS)projects are related to enhanced oil recovery(EOR).CO_(2)storage in reservoirs across large timescales undergoes the two storage stages of oil displacement and well shut-in,which cover mul-tiple replacement processes of injection-production synchronization,injection only with no production,and injection-production stoppage.Because the controlling mechanism of CO_(2)storage in different stages is unknown,the evolution of CO_(2)storage mechanisms over large timescales is not understood.A math-ematical model for the evaluation of CO_(2)storage,including stratigraphic,residual,solubility,and mineral trapping in low-permeability tight sandstone reservoirs,was established using experimental and theoret-ical analyses.Based on a detailed geological model of the Huaziping Oilfield,calibrated with reservoir permeability and fracture characteristic parameters obtained from well test results,a dynamic simulation of CO_(2)storage for the entire reservoir life cycle under two scenarios of continuous injection and water-gas alternation were considered.The results show that CO_(2)storage exhibits the significant stage charac-teristics of complete storage,dynamic storage,and stable storage.The CO_(2)storage capacity and storage rate under the continuous gas injection scenario(scenario 1)were 6.34×10^(4)t and 61%,while those under the water-gas alternation scenario(scenario 2)were 4.62×10^(4)t and 46%.The proportions of stor-age capacity under scenarios 1 and 2 for structural or stratigraphic,residual,solubility,and mineral trap-ping were 33.36%,33.96%,32.43%,and 0.25%;and 15.09%,38.65%,45.77%,and 0.49%,respectively.The evolution of the CO_(2)storage mechanism showed an overall trend:stratigraphic and residual trapping first increased and then decreased,whereas solubility trapping gradually decreased,and mineral trapping continuously increased.Based on these results,an evolution diagram of the CO_(2)storage mechanism of low-permeability tight sandstone reservoirs across large timescales was established.
文摘Honey, an apicultural product with a complex chemical composition, contains numerous bioactive compounds with potential antimicrobial effects. This study investigated the effect of Apis mellifera honey from Brazil’s Central-West Region, combined with antibiotics, on bacterial membrane permeability, exploring the contributions of bioactive compounds and the botanical origin of honey. Six fresh Apis mellifera honey samples and their fractions (hexane and ethyl acetate) were analyzed, for a total of 18 samples. The bacteria Staphylococcus epidermidis, Helicobacter pylori and Enterococcus faecalis were used for antibacterial activity tests, which included minimum inhibitory concentration (MIC) determination and synergistic effect (checkerboard) assays. The total polyphenol and flavonoid contents were quantified, and the botanical origin was determined based on pollen analysis. The tested honey samples significantly affected bacterial membrane permeability when combined with rifampicin and clarithromycin. Although many honey-derived bioactive compounds, when isolated, did not exhibit significant activity against these bacteria, the additive or synergistic effect of multiple compounds acting on different targets appears to potentiate the antibacterial action. Descriptive statistical analysis, including means and 95% confidence intervals, confirmed the relevance of the findings. This study has provided an important discovery: Honey has an effect on bacterial membrane permeability, although the specific mechanisms involved in this process require further investigation.
基金the Fundamental Research Funds for the Central Universities(No.2232023Y-01)the National Natural Science Foundation of China(Nos.52073052)the Fundamental Research Funds for the Central Universities and Graduate Student Innovation Fund of Donghua University(No.CUSF-DH-D-2023015).
文摘Current protective clothing often lacks sufficient comfort to ensure efficient performance of healthcare workers.Developing protective textiles with high air and moisture permeability is a potential and effective solution to discomfort of medical protective clothing.However,realizing the facile production of a protective textile that combines safety and comfort remains a challenge.Herein,we report the fabrication of highly permeable protective textiles(HPPT)with micro/nano-networks,using non-solvent induced phase separation synergistically driven by CaCl_(2) and fluorinated polyurethane,combined with spraying technique.The HPPT demonstrates excellent liquid repellency and comfort,ensuring high safety and a dry microenvironment for the wearer.The textile exhibits not only a high hydrostatic pressure(12.86 kPa)due to its tailored small mean pore size(1.03μm)and chemical composition,but also demonstrates excellent air permeability(14.24 mm s^(−1))and moisture permeability(7.92 kg m^(−2)d^(−1))owing to the rational combination of small pore size and high porosity(69%).The HPPT offers superior comfort compared to the commercially available protective materials.Additionally,we elucidated a molding mechanism synergistically inducted by diffusion-dissolution-phase separation.This research provides an innovative perspective on enhancing the comfort of medical protective clothing and offers theoretical support for regulating of pore structure during phase separations.
基金Funded by the International Science and Technology Cooperation Project of the Key R&D Program of Science and Technology Innovation Yongjiang 2035。
文摘An evaluation method for self-healing capacity was designed,which includes the control of initial cracks and subsequent permeability testing.This method was employed to evaluate the self-healing behavior of mortars incorporating crystalline admixtures(CAs)under various conditions,including water immersion,limewater soaking,and wet-dry cycles,with varying CA dosages and crack widths.The experimental results indicate that cement possesses inherently self-healing capability.Limewater environments inhibits healing compared with water immersion;however,wet-dry cycles enhance the effectiveness of higher CA dosages.Increasing the CA content can not improve healing performance,and wide cracks(0.3 mm)substantially reduce the intrinsic self-healing potential of cement.
基金supported by the National Natural Science Foundation of China(No.52175341)Shandong Provincial Natural Science Foundation(No.ZR2022JQ24)+2 种基金Funding Project of Jinan City's New Twenty Items for Colleges and Universities(No.202333038)Excellent Young Team Project of Central Universities(No.2023QNTD002)Qingdao Key Technology Research and Industrialization Demonstration Project(No.24-1-2-qljh-10-gx).
文摘Poly(vinylidene fluoride)(PVDF)foam has received widespread attention due to its high strength,and excellent combination of flame-retardancy,antibacterial performance,and chemical stability.However,the foaming ability of conventional PvDF is severely limited by its rapid crystallization kinetics and poor melt strength.Although ultra-high molecular weight PVDF(H-PVDF)theoretically offers prolonged melt elasticity favorable for foaming,the extremely high melt viscosity poses substantial processing challenges,and its foaming behavior has remained largely unexplored.To address these issues,this study proposes a novel fabrication strategy combining solvent casting with microcellular foaming to prepare H-PVDF foams.Dynamic mechanical analysis and differential scanning calorimetry reveal that extensive chain entanglements in H-PVDF impose constraints on crystallization and significantly enhance melt strength.By tuning the processing parameters,the distinctive foaming be-havior of H-PVDF under various conditions is systematically elucidated.Remarkably,a record-high expansion ratio of 55.6-fold is achieved,ac-companied by a highly uniform and fine cellular structure.The resulting H-PVDF foams exhibit a low thermal conductivity of 31.8 mW·m^(-1).K^(-1),while retaining excellent compressive strength,flame-retardancy,and hydrophobicity.These outstanding properties highlight the great potential of H-PVDF foams as the thermal insulation materials for applications in aerospace,energy infrastructure,and other extreme environments.
文摘Permeability is affected by complex factors such as the subsurface geological structure and porosity-permeability correlation.For highly heterogeneous reservoirs with complex pore structures,it is extremely challenging to spatially characterize(predict)permeability using seismic data.The conventional way of permeability prediction intends to convert underground refl ection data into the elastic parameters sensitive to underground fluids,build a universal low-dimensional template via petrophysical modeling and ultimately deliver spatial prediction of permeability.However,this method is restrained by the actual subsurface condition,selected well-logging sensitive parameters and the accuracy of the computed elastic parameters and fails to simulate the petrophysical mechanisms of complex reservoir permeability,which reduces the permeability prediction accuracy.The method proposed in this paper combines petrophysics and artificial intelligence and integrates multiple types of information to build the high-dimensional petrophysical template for permeability,in an attempt to improve the spatial characterization and prediction accuracy of permeability.The field testing demonstrates the high application performance and effective improvement in prediction accuracy and fluvial channel characterization.
基金Supported by Tianjin Health Research Project,No.TJWJ2024QN005Beijing iGandan Public Welfare Foundation Artificial Liver Special Fund,No.iGandanF-1082024-RGG122.
文摘BACKGROUND Although an association between gut microbiota and cholestatic liver disease(CLD)has been reported,the precise functional roles of these microbes in CLD pathogenesis remain largely unknown.AIM To explore the function of gut microbes in CLD pathogenesis and the effects of gut microbiota on intestinal barrier and bile acid(BA)metabolism in CLD.METHODS Male C57BL/6J mice were fed a 0.05%3,5-diethoxycarbonyl-1,4-dihydrocollidine diet for 2 weeks to induce CLD.The sterile liver tissues of mice were then meticulously harvested,and bacteria in homogenates were identified through culture methods.Furthermore,16S ribosomal DNA sequencing was employed to analyze sterile liver samples collected from eight patients with primary biliary cholangitis(PBC)and three control individuals with hepatic cysts.The functional roles of the identified bacteria in CLD pathogenesis were assessed through microbiota transfer experiments,involving the evaluation of changes in intestinal permeability and BA dynamics.RESULTS Ligilactobacillus murinus(L.murinus)and Lactococcus garvieae(L.garvieae)were isolated from the bacterial culture of livers from CLD mice.L.murinus was prevalently detected in PBC patients and controls,whereas L.garvieae was detected only in patients with PBC but not in controls.Mice inoculated with L.garvieae exhibited increased susceptibility to experimental CLD,with both in vitro and in vivo indicating that L.garvieae disrupted the intestinal barrier function by down-regulating the expression of occludin and zonula occludens-1.Moreover,L.garvieae administration significantly upregulated the expression of the apical sodium-dependent BA transporter in the terminal ileum and increased serum BA levels.CONCLUSION L.garvieae contributes to excessive BA-induced hepatobiliary injury and liver fibrosis by increasing intestinal permeability and enhancing BA reabsorption.
基金supported by the Science and Technology Project of Fire Rescue Bureau of Ministry of Emergency Management,China(No.2022XFZD05)the S&T Program of Hebei,China(No.22375419D).
文摘Ultra-high strength steel(UHSS)fabricated via laser additive manufacturing(LAM)holds significant promise for applications in defense,aerospace,and other high-performance sectors.However,its response to high-impact loading remains insufficiently understood,particularly regarding the influence of energy density on its dynamic mechanical behavior.In this study,scanning electron micro-scopy,electron backscatter diffraction,and image recognition techniques were employed to investigate the microstructural variations of LAM-fabricated UHSS under different energy density conditions.The dynamic mechanical behavior of the material was characterized using a Split Hopkinson Pressure Bar system in combination with high-speed digital image correlation.The study reveals the spatiotemporal evolution of surface strain and crack formation,as well as the underlying dynamic fracture mechanisms.A clear correlation was established between the microstructures formed under varying energy densities and the resulting dynamic mechanical strength of the material.Results demonstrate that optimal material density is achieved at energy densities of 292 and 333 J/mm^(3).In contrast,energy densities exceeding 333 J/mm^(3) induce keyhole defects,compromising structural integrity.Dynamic performance is strongly dependent on material density,with peak impact resistance observed at 292 J/mm^(3)-where strength is 8.4%to 17.6%higher than that at 500 J/mm^(3).At strain rates≥2000 s^(-1),the material reaches its strength limit at approximately 110μs,with the initial crack appearing within 12μs,followed by rapid failure.Conversely,at strain rates≤1500 s^(-1),only microcracks and adiabatic shear bands are detected.A transition in fracture surface morphology from ductile to brittle is observed with increasing strain rate.These findings offer critical insights into optimizing the dynamic mechanical properties of LAM-fabricated UHSS and provide a valuable foundation for its deployment in high-impact environments.
