Centaurium erythraea Rafn(“Gosset El Haya”)has long been prized in North African folk medicine,yet Moroccan chemobiological data remain scarce.Ethanol extracts of northern Moroccan aerial parts were profiled by high...Centaurium erythraea Rafn(“Gosset El Haya”)has long been prized in North African folk medicine,yet Moroccan chemobiological data remain scarce.Ethanol extracts of northern Moroccan aerial parts were profiled by high-performance liquid chromatography(HPLC)and found rich in phenolics,dominated by 4-hydroxybenzoic acid(57.8%)and naringin(10.3%).The extract exhibited strong antioxidant power in the 2,2-diphenyl-1-picrylhydrazyl(DPPH)radical-scavenging assay,with a half-maximal inhibitory concentration(IC_(50))of≈74μg mL^(−1),and a total antioxidant capacity(TAC)of≈201μg mL^(−1)and selective antimicrobial activity,sharply inhibiting Aspergillus niger,Penicillium digitatum,and Rhodotorula glutinis while sparing Staphylococcus aureus.In-silico absorption,distribution,metabolism,excretion,and toxicity(ADMET)profiling predicted good oral bioavailability for low-molecular-weight acids and aglycones,lowtoxicity across all metabolites,but absorption liabilities for bulky glycosides.Molecular docking against A.niger esterase(1UKC),C.glabrata lanosterol 14-α-demethylase CYP51(5JLC),and P.digitatum ethyleneforming oxidoreductase(9EIR)corroborated bioassays:rutin and naringin bound more tightly than fluconazole(ΔG≈−9.1 to−10.0 kcal mol^(−1)),whereas quercetin and catechin offered balanced affinity pharmacokinetic profiles.Robust radical scavenging,targeted antifungal potency,and favorable in-silico pharmacokinetics thus position Moroccan C.erythraea as a promising,though standardization-dependent,source of nutraceutical,medicinal,and food-preservation agents.These results support the valorisation of Centaurium erythraea as a promising source for health promotion and green technology applications through its antioxidant,antimicrobial,and drug-like properties.展开更多
Water splitting hinges crucially on the availability of electrocatalysts for the oxygen evolution reaction.The surface reconstruction has been widely observed in perovskite catalysts,and the reconstruction degree has ...Water splitting hinges crucially on the availability of electrocatalysts for the oxygen evolution reaction.The surface reconstruction has been widely observed in perovskite catalysts,and the reconstruction degree has been often correlated with the activity enhancement.Here,a systematic study on the roles of Fe substitution in activation of perovskite LaNiO_(3)is reported.The substituting Fe content influences both current change tendency and surface reconstruction degree.LaNi_(0.9)Fe_(0.1)O_(3)is found exhibiting a volcano-peak intrinsic activity in both pristine and reconstructed among all substituted perovskites in the LaNi_(1-x)Fe_(x)O_(3)(x=0.00,0.10,0.25,0.50,0.75,1.00)series.The reconstructed LaNi_(0.9)Fe_(0.1)O_(3)shows a higher intrinsic activity than most reported NiFe-based catalysts.Besides,density functional theory calculations reveal that Fe substitution can lower the O 2p level,which thus stabilize lattice oxygen in LaNi0.9Fe0.1O3 and ensure its long-term stability.Furthermore,it is vital interesting that activity of the reconstructed catalysts relied more on the surface chemistry rather than the reconstruction degree.The effect of Fe on the degree of surface reconstruction of the perovskite is decoupled from that on its activity enhancement after surface reconstruction.This finding showcases the importance to customize the surface chemistry of reconstructed catalysts for water oxidation.展开更多
Thymus serpyllum L.,often known as wild thyme,has been used since ancient times due to its multifaceted culinary and medicinal attributes.It is usually utilized in folk medicine to manage different health issues.This ...Thymus serpyllum L.,often known as wild thyme,has been used since ancient times due to its multifaceted culinary and medicinal attributes.It is usually utilized in folk medicine to manage different health issues.This work aimed to investigate the chemical composition and biological characteristics of T.serpyllum essential oil(EO),including its antimicrobial,antioxidant,and anti-inflammatory capabilities.Moreover,we have prompted an in-silico simulation to reveal the underlying mode of action of these properties.The chemical characterization of T.serpyllum(EO)by Gas Chromatography-Mass Spectrometry(GC-MS)indicated sabinene(17.33%),terpinen-4-ol(11.73%),phellandral(13.18%),and thymol(10.54%)as main components.The antimicrobial screening utilized the disc-diffusion technique,MIC,and MBC assays.The disc-diffusion test’s results revealed significant anti-Candida activity and notable antibacterial efficacy.The MIC and MBC tests showed that T.serpyllum EO effectively stops bacterial growth,including Gram-positive and Gram-negative strains and Candida strains.The tolerance level ratio demonstrated that this EO exhibits bactericidal and fungicidal effects on all tested bacteria and Candida strains.Also,T.serpyllum EO presented effective inhibitory activity against the 5-lipoxygenase(5-LOX)enzyme(IC50=744.19±0.1µg/mL)(p<0.05).It also effectively affected FRAP,β-carotene,DPPH,and ABTS radicals.In light of these findings,T.serpyllum holds promise for diverse applications across pharmaceuticals,nutraceuticals,and the food industry.However,further research and collaboration between traditional knowledge and modern medicine are crucial to fully realizing its potential benefits in these fields.展开更多
In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented...In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented product FGPA-G 2-H on Aβ25-35-induced PC 12 cells were explored.The structure of GPA-G 2-H was determined by means of zeta potential analysis,FTIR,HPLC,XRD,GC-MS and NMR.The backbone of GPA-G 2-H was mainly composed of→4)-α-D-Glcp-(1→with branches substituted at O-3.Notably,GPA-G 2-H was degraded by intestinal microbiota in vitro with total sugar content and pH value decreasing,and short-chain fatty acids(SCFAs)increasing.Moreover,GPA-G 2-H significantly promoted the proliferation of Lactobacillus,Muribaculaceae and Weissella,thereby making positive alterations in intestinal microbiota composition.Additionally,FGPA-G 2-H activated the Nrf 2/HO-1 signaling pathway,enhanced HO-1,NQO 1,SOD and GSH-Px,while inhabited Keap 1,MDA and LDH,which alleviated Aβ-induced oxidative stress in PC 12 cells.These provide a solid theoretical basis for the further development of ginseng polysaccharides as functional food and antioxidant drugs.展开更多
Under solvothermal conditions,1,4‑naphthalenedicarboxylic acid(H_(2)ndc)and 9,9′‑dihexyl‑2,7‑di(pyridin‑4‑yl)fluorene(hfdp)reacted with Co^(2+)ions and Cd^(2+)ions to form two coordination polymers,[Co(hfdp)(ndc)(H2O...Under solvothermal conditions,1,4‑naphthalenedicarboxylic acid(H_(2)ndc)and 9,9′‑dihexyl‑2,7‑di(pyridin‑4‑yl)fluorene(hfdp)reacted with Co^(2+)ions and Cd^(2+)ions to form two coordination polymers,[Co(hfdp)(ndc)(H2O)]·DMA}n(1)and{[Cd(hfdp)(ndc)(H_(2)O)]·DMA}_(n)(2),respectively(DMA=N,N‑dimethylacetamide).Single‑crystal X‑ray diffraction analyses showed that both complexes 1 and 2 contain similar structures.Topological analysis indicates that complexes 1 and 2 have a{44·62}planar structure.In addition,both complexes reveal good thermal stability and fluorescence sensing performance.They exhibited good sensitivity and selectivity towards 2,4,6‑trinitrophenol(TNP)by fluorescent quenching.The limits of detection of 1 and 2 for TNP were 0.107 and 0.327μmol·L^(-1),respectively.CCDC:2475515,1;2475516,2.展开更多
Given that platinum-based drugs are widely used clinically as chemotherapeutic agents,their severe toxic side effects have attracted significant attention.Consequently,the development of novel nanoprodrugs based on lo...Given that platinum-based drugs are widely used clinically as chemotherapeutic agents,their severe toxic side effects have attracted significant attention.Consequently,the development of novel nanoprodrugs based on low-toxicity tetravalent platinum(Pt(Ⅳ))com plexes holds substantial research value.Herein,we discovered that coumarin derivatives exhibit inherent antitumor efficacy and significantly enhance superoxide anion radicals(·O_(2)^(-))generation in aqueous solutions under ultrasound(US)irradiation.Given that·O_(2)^(-)is known to mediate the reduction of Pt(Ⅳ)to divalent platinum(Pt(Ⅱ)),we engineered an US-responsive dual-drug nanoprodrug(P-cisPt(Ⅳ)@5-MOP).This nanoprodrug was prepared by covalently conjugating Pt(Ⅳ)and methoxy polyethylene glycol hydroxyl(m PEG-OH)to a poly(_(L)-glutamic acid)(PLG)carrier,followed by encapsulating coumarin derivatives.Under low-intensity US irradiation(1.5 W/cm^(2),1 MHz,10 min),P-cisPt(Ⅳ)@5-MOP achieved a Pt(Ⅳ)reduction rate of 91.4%.Furthermore,upon US exposure,its half-maximal inhibitory concentration(IC_(50))against 4T1 breast cancer cells decreased dramatically from 25.7μmol/L to 0.1μmol/L.Remarkably,this system combined with US therapy yielded a tumor inhibition rate of 90.9%,with 40%of tumor-bea ring mice achieving com plete eradication of tumors,while exhibiting low systemic toxicity.Collectively,this work not only identifies a novel sonosensitizer capable of generating·O_(2)^(-)but also develops a new class of ultrasound-activatable Pt(Ⅳ)nanoprodrug.展开更多
D-π hybridization is a key structural feature that may significantly affect the intrinsic electronic properties of metallopolymers.Herein,we present the electrosynthesis and memristive properties of metallopolymers u...D-π hybridization is a key structural feature that may significantly affect the intrinsic electronic properties of metallopolymers.Herein,we present the electrosynthesis and memristive properties of metallopolymers using the distinct d-π hybridization monomers R_(1) and R_(2).R_(1)(Ru^(Ⅱ)-(tpz)Cl_(2))features tetradentate ligands(tpz,6,6'-di(1H-pyrazol-1-yl)-2,2'-bipyridine)enforcing quasi-octahedral geometry;R_(2)(Ru^(Ⅱ)-(bpp)_(2))incorporates tridentate ligands(bpp,2,6-di(1H-pyrazol-1-yl)pyridine)inducing pronounced geometric distortion.The planar ligand(tpz)in R_(1) facilitates ordered molecular assembly through high conformational rigidity and extensive π-π stacking,resulting in increased molecular densities and enhanced morphological uniformity compared to R_(2) metallopolymers.Due to pyrazole’s weaker π-acceptance and strongerσ-donation compared to pyridine,R_(1) exhibits a 119 nm red-shift in metal-to-ligand charge transfer(MLCT)band and a 30 mV anodic shift in Ru^(+2/+3)redox potential relative to R_(2).Coupled with a reduced HOMO-LUMO gap,the uniform and ordered structure leads to a lower conductance decay constant in R_(1).Additionally,R_(2) metallopolymers exhibit superior memristive performance(characterized by lower switching voltage and higher switching ratio)via redox-induced aromatic transitions in axial ligands enhancing electronic delocalization.This work compares two metallopolymers with different ligand geometries,revealing how this difference leads to distinct charge transport and memristive behaviors.展开更多
Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catal...Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catalysts,but which substantially involve multi-step,tedious,and difficult synthesis.Herein,this study reports an intriguing approach to construct multi-nuclear catalysts for the milestoneα-diimine nickel catalysts using an oligomeric strategy.A polymerizable norbornene unit is incorporated into theα-diimine ligand backbone,leading to the formation of the monomeric nickel catalyst Ni_(1)and its corresponding oligomeric nickel catalysts(Ni_(3)and Ni_(5))with varying degrees of polymerization(DP=3 and 5).Notably,the oligomeric catalyst Ni_(5)was facilely scaled up(50 g-level),showed enhanced thermal stability,exhibited 4.6 times higher activity,and yielded polyethylene elastomer with a 379%increased molecular weight in ethylene polymerization,compared to the monomeric catalyst Ni_(1).Catalytic performance enhancements of oligomeric catalysts were found to be DP-dependent.The kilogram-scale polyethylene,produced using Ni_(5)in a 20 L reactor,presented a highly branched all-hydrocarbon structure,which demonstrated typical elastic properties(tensile strength:4 MPa,elastic recovery:SR=72%)along with great processability(MFI=3.0 g/10 min),insulating characteristics(volume resistivity=2×10^(16)Ω/m),and hydrophobicity(water vapor permeability:0.03 g/m^(2)/day),suggesting potentially practical applications.展开更多
The development of substitutable meniscus implants that can effectively protect articular cartilage remains a great challenge.Herein,a polyurethane with chemical crosslinking and sulfobetaine extenders containing hydr...The development of substitutable meniscus implants that can effectively protect articular cartilage remains a great challenge.Herein,a polyurethane with chemical crosslinking and sulfobetaine extenders containing hydrophobic chains(PU-CL-hSB)is developed,which could improve comprehensive properties and long-term stability simultaneously.By regulating the mole ratio of functional groups,PU-CL-hSB with appropriate mechanical properties,excellent tribological properties,and good fatigue resistance is used to prepare substitutable meniscus implant by hot-pressing.Due to the synergistic effect of functional groups,PU-CL-hSB meniscus implant presents comparable or even superior properties to native meniscus.It withstands a maximum force of 26.08 N versus 25.14 N for native meniscus,an energy dissipation from 45.93 to 39.17 N mm compared to 28.83 to 19.11 N mm for native meniscus over 300 cycles,and a friction coefficient from 0.08 to 0.19 compared to 0.11 to 0.26 for native meniscus.This PU-CL-hSB meniscus implant is further implanted into live rabbit knee joints for 8 and 25 weeks by a new approach,and in vivo data indicate that PU-CL-hSB meniscus implant not only protects articular cartilage from severe damage without eliciting inflammatory responses,but also can maintain normal physiological activities in the native state.Our findings present a substitutable meniscus implant that could be applied in vivo and propose evaluation methodologies for meniscus implants.展开更多
This study uses all-atom molecular dynamics simulations to investigate the dislocation propagation, stress transmission, and mechanical properties in poly(p-phenylene terephthalamide) fibers under uniaxial tension. Th...This study uses all-atom molecular dynamics simulations to investigate the dislocation propagation, stress transmission, and mechanical properties in poly(p-phenylene terephthalamide) fibers under uniaxial tension. The results indicate that the dislocation propagates and the stress transfers not only along the fiber axis but also between adjacent molecular chains through hydrogen bonds, demonstrating their influence on the yield behavior. As the degree of polymerization increases, breakage of covalent bonds and interchain slippage contribute to the yield of fibers together. This work provides theoretical guidance for the design and manufacturing of high-performance fibers.展开更多
Albeit notable endeavors in the construction of organophosphorodithioates,the direct catalytic enantioselective synthesis of organophosphorodithioates still stands for a long-lasting challenge.Herein,an efficient orga...Albeit notable endeavors in the construction of organophosphorodithioates,the direct catalytic enantioselective synthesis of organophosphorodithioates still stands for a long-lasting challenge.Herein,an efficient organocatalytic enantioselective nucleophilic addition of vinylidene ortho-quinone methide with phosphinothioic thioanhydride as nucleophilic reagent has been achieved by the dual catalysis of cinchona alkaloid-derived squaramide and 4-dimethylaminopyridine.This protocol provides a straightforward approach for accessing a variety of axially chiral phosphorodithiolated styrenes in good yields(up to 98 %yield) with high stereoselectivities(up to 97 % ee and >99:1 E/Z).展开更多
The heterogeneity and invasiveness of cancer cells pose serious challenges in cancer diagnosis and treatment.Advancements and innovations in metal-based nanomedicines provide novel avenues for addressing these challen...The heterogeneity and invasiveness of cancer cells pose serious challenges in cancer diagnosis and treatment.Advancements and innovations in metal-based nanomedicines provide novel avenues for addressing these challenges.Metal-based nanomedicines possess unique physicochemical properties that enable their interaction with living organisms,thereby inducing complex biological responses.These nanomaterials have been extensively used to enhance the contrast and sensitivity of cancer imaging and to amplify the distinction between cancerous and healthy tissues.Moreover,these nanomaterials can effectively combat a wide spectrum of cancers through various methods,including drug delivery,radiotherapy,photothermal therapy(PTT),photodynamic therapy(PDT),sonodynamic therapy(SDT),biocatalytic therapy,ion interference therapy(IIT),and immunotherapy.Currently,there is still a need for a comprehensive summary on the metal-based nanomaterials for cancer diagnosis and treatment.Herein,we present a systematic and complete overview of action mechanisms and the applications of metal-based nanomaterials in cancer theranostics.A summary of common strategies for synthesizing and modifying metal-based nanomedicines is presented,and their biosafety is analyzed.Then,the latest developments in their applications for cancer imaging and anticancer treatment are provided.Finally,the key technical challenges and reasonable perspectives of metal-based nanomedicines for cancer theranostics in clinical applications are discussed.展开更多
The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behav...The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behavior of dispersed long chains.Using molecular dynamics simulations based on the Kremer-Grest model,we systematically explore the N_(S)-dependence of static conformations,equilibrium dynamics,and nonlinear shear responses in unentangled long-chain/short-chain polymer blends.Our results demonstrate a decoupling between the static and dynamic sensitivity to N_(S):while the static chain size,R_g,follows Flory theory with slight swelling at small N_(S) due to incomplete excluded volume screening,the diffusion coefficient,D,and the relaxation time,τ_(0),exhibit a strong,non-monotonic N_(S)-dependence,transitioning from monomeric friction dominance at small N_(S) to collective segmental rearrangement at large N_(S).Additionally,we observe partial decoupling between the viscous and normal stress responses:while the zero-shear viscosity,η,is strongly N_(S)-dependent,the first and second normal stress coefficients,Ψ_(1) and Ψ_(2),collapse onto universal curves when scaled by the dimensionless shear rate,γτ_(0),suggesting a common mechanism of orientation and stretching.Under shear,long chains compress in the vorticity direction λ_(z)~Wi^(-0.2),which reduces collision frequency and contributes to shear thinning,while the scaling of weaker orientation resistance m_(G)~Wi^(0.35)reflects hydrodynamic screening by the short-chain matrix.These findings highlight the limitations of single-chain models and emphasize the necessity of considering N_(S)-dependent matrix dynamics and flow-induced structural changes in understanding the rheology of unentangled polymer blends.展开更多
Possessing excellent mechanical properties,a high-coverage slide-ring conductive gel is constructed by in situ polymerization ofα-cyclodextrin(α-CD)polyrotaxane(PR)and 1-vinyl-3-ethylimidazolium bromide([VEIM]Br)ion...Possessing excellent mechanical properties,a high-coverage slide-ring conductive gel is constructed by in situ polymerization ofα-cyclodextrin(α-CD)polyrotaxane(PR)and 1-vinyl-3-ethylimidazolium bromide([VEIM]Br)ionic liquid(IL),using 1-ethyl-3-methylimidazolium bromide([EMIM]Br)IL as solvent.Benefiting from the compatibility of ILs and alkene-PR,the cross-linked network slide-ring gel not only maintains excellent conductivity(1.52×10^(−2) S/m),but also has effectively improved mechanical properties(513%fracture strain,0.713 MPa fracture stress,211 kPa elastic modulus and 1366 kJ/m^(3) toughness)and adhesive properties(472.3±25.9 kPa).The supramolecular gel can be used as a strain sensor to efficiently monitor deformation signals in real-time at least 200 times.Especially,the slide-ring gel can self-power generated by triboelectric effect and electrostatic induction between the skin layer and the polydimethylsiloxane(PDMS)layer that encapsulates the gel,achieving reversible and durable motion sensing,which provides a convenient pathway for constructing supramolecular self-powered flexible electronic materials.展开更多
The composition−property relationship of 18 quaternary high entropy diborides(HEBs)consisting of boron and IVB,VB and VIB transition metals(TM)was investigated using first-principles calculations.A valence electron co...The composition−property relationship of 18 quaternary high entropy diborides(HEBs)consisting of boron and IVB,VB and VIB transition metals(TM)was investigated using first-principles calculations.A valence electron concentration−relative electronegativity(VEC−REN)composite descriptor was developed to effectively predict the mechanical properties of HEBs.The results demonstrate that with a fixed VEC,the rise of the REN makes HEBs harder but more brittle when the electronegativity of doped TM atoms is lower than that of boron atoms.However,HEBs become softer and more ductile as REN increases if the doped TM atoms have higher electronegativity than boron atoms.The VEC−REN composite descriptor can accurately classify and predict the mechanical properties of HEBs with different components,which provides important theoretical guidance for the rapid design and development of novel high-entropy ceramic materials.展开更多
Date palm(Phoenix dactylifera L.)seeds,often discarded as by-products during date fruit processing,represent approximately 6-20%of the fruit’s mass depending on cultivar and maturity stage.Although traditionally used...Date palm(Phoenix dactylifera L.)seeds,often discarded as by-products during date fruit processing,represent approximately 6-20%of the fruit’s mass depending on cultivar and maturity stage.Although traditionally used for producing activated charcoal and in environmental remediation,their pharmacological potential remains underexplored.This study aimed to evaluate the chemical composition,biological activity,and potential commercial value of seeds from four widely consumed Saharan cultivars(Assiane,Boufegouss,Aziza,and Majhoul)collected in the Figuig region.Soxhlet extraction was employed to obtain seed extracts,which were subsequently characterized by qualitative and quantitative phytochemical screening.The analyses revealed the presence of polyphenols,flavonoids,terpenoids,steroids,alkaloids,and other secondary metabolites.The Aziza and Boufegouss varieties were particularly rich in flavonoids(82.09-139.61 mg quercetin equivalents/100 g dry matter)and total polyphenols(69.81-1183.96 mg gallic acid equivalents/100 g dry matter).Mineral profiling confirmed the occurrence of essential trace elements,including Zn,Cu,Fe,and Co.To investigate their antidiabetic potential,in vitro assays ofα-glucosidase andα-amylase inhibition were performed.Acetone extracts demonstrated significant inhibitory activity against both enzymes,suggesting a promising role of P.dactylifera seed extracts as natural agents for the management of type 2 diabetes mellitus.展开更多
Shear stress overshoot in entangled polymer rheology is a hallmark of transient dynamics,but its microscopic origin remains under debate.Using molecular dynamics simulations,we investigate a two-step shear protocol co...Shear stress overshoot in entangled polymer rheology is a hallmark of transient dynamics,but its microscopic origin remains under debate.Using molecular dynamics simulations,we investigate a two-step shear protocol consisting of successive startup shears separated by a waiting period,with the first shear interrupted before the overshoot.In the homogeneous flow,the GLaMM theory captures the stress response during the first shear,but fails to reproduce the nonmonotonic dependence of the second stress overshoot(σ_(2max))on the waiting time.Contrary to the prediction of a nonmonotonic normal stress component σ_(yy)during the waiting period,our simulations show that σ_(yy),like the tube segment orientation(S_(xy)),the contour length of the primitive chain(L),and the entanglement number per chain(Z),relaxes monotonically toward equilibrium.At the strain corresponding to σ_(2max),both the tube segment orientation and the entanglement number per chain exhibit a nonmonotonic dependence on the waiting time that closely mirrors the behavior of σ_(2max),indicating that both factors play significant roles in governing(σ_(2max).Our findings are consistent with the interpretation of lanniruberto and Ma rrucci[ACS Macro.Lett.2014,3,552]for orientation effects and with the viewpoint of Wang et al.[Macromolecules 2013,46,3147]for entanglement effects,although the two explanations are rooted in distinct physical pictu res.These results provide new insights into the stress responses of entanglement polymer fluids and underscore the need for a more unified theoretical framework.展开更多
Electrically controlled solid propellant(ECSP)offers multiple ignition and adjustable burning rate,serving as fuel for next-generation intelligent propulsion systems.To further enhance the combustion performance of EC...Electrically controlled solid propellant(ECSP)offers multiple ignition and adjustable burning rate,serving as fuel for next-generation intelligent propulsion systems.To further enhance the combustion performance of ECSP,a method utilizing electrochemical and thermal decomposition catalysts has been proposed.In this work,we investigated the combustion characteristics of hydroxylamine nitrate(HAN)-based ECSP incorporating cerium oxide(CeO_(2))and graphene oxide(GO)by using an electrically controlled combustion test system.Electrochemical impedance spectroscopy(EIS)and linear sweep voltammetry(LSV)were used to measure the electrical conductibility and overpotential of ECSP with various additives,and Tafel curves were calculated.Thermogravimetric analysis coupled with differential scanning calorimetry(TG-DSC)was employed to investigate the thermal decomposition behavior of ECSP.While the addition of CeO_(2) and GO reduced the conductivity of ECSP,both catalysts exhibited strong electrocatalytic properties and facilitated the thermal decomposition of ECSP.Between two catalysts,GO demonstrated superior electrochemical catalytic performance but weaker thermal decomposition catalytic ability than CeO_(2).The addition of catalysts significantly enhanced the combustion performance of HAN-based ECSP.Specifically,the ignition delay time was shortened by 10%~20%.CeO_(2) raised the burning rate by approximately 20%but GO exhibited a remarkable boost of 40%in burning rate at high voltage.The combination of GO and PVA produced a flame-retardant substance that negatively impacted the ignition delay of ECSP and resulted in a smaller increase in the burning rate of ECSP at low ignition voltages.展开更多
Strategies for achieving high-energy-density lithium-ion batteries include using high-capacity materials such as high-nickel NCM,increasing the active material content in the electrode by utilizing high-conductivity c...Strategies for achieving high-energy-density lithium-ion batteries include using high-capacity materials such as high-nickel NCM,increasing the active material content in the electrode by utilizing high-conductivity carbon nanotubes(CNT)conductive materials,and electrode thickening.However,these methods are still limited due to the limitation in the capacity of high-nickel NCM,aggregation of CNT conductive materials,and nonuniform material distribution of thick-film electrodes,which ultimately damage the mechanical and electrical integrity of the electrode,leading to a decrease in electrochemical performance.Here,we present an integrated binder-CNT composite dispersion solution to realize a high-solids-content(>77 wt%)slurry for high-mass-loading electrodes and to mitigate the migration of binder and conductive additives.Indeed,the approach reduces solvent usage by approximately 30%and ensures uniform conductive additive-binder domain distribution during electrode manufacturing,resulting in improved coating quality and adhesive strength for high-mass-loading electrodes(>12 mAh cm^(−2)).In terms of various electrode properties,the presented electrode showed low resistance and excellent electrochemical properties despite the low CNT contents of 0.6 wt%compared to the pristine-applied electrode with 0.85 wt%CNT contents.Moreover,our strategy enables faster drying,which increases the coating speed,thereby offering potential energy savings and supporting carbon neutrality in wet-based electrode manufacturing processes.展开更多
Herein,we demonstrated the integration of BiVO_(4)-based photoanode with metallic Zn cathode for high-performance CO_(2)reduction,and a record CO production rate of 113.32μmol cm^(−2)h^(−1)with a FECO of 90.57%has be...Herein,we demonstrated the integration of BiVO_(4)-based photoanode with metallic Zn cathode for high-performance CO_(2)reduction,and a record CO production rate of 113.32μmol cm^(−2)h^(−1)with a FECO of 90.57%has been achieved under simulated sunlight(AM 1.5 G,100 mW),accompanying with an excellent stability.More importantly,the direct observation of spatial charge separation/transfer and dynamic surface catalysis for both H_(2)O oxidation and CO_(2)reduction has been firstly achieved by the combination of in situ X-ray photoelectron spectroscopy(IS-XPS)with Fourier transform infrared reflection(IS-FTIR).Under light irradiation,the electron-hole pairs have been generated on BiVO_(4) photoanode,and holes rapidly transfer to photoanode surfaces for participating in oxygen evolution reaction(OER)through the formation of*OH and*OOH intermediates.Simultaneously,the proton-coupled electron transfer to the Zn cathode surfaces drive the reduction of adsorbed CO_(2)molecules into CO via the formation*COOH and*CO intermediates.Thereby,this work offers new insights into fundamental understanding of CO_(2)reduction process,which facilitates the future development of highly efficient carbon fixation systems.展开更多
文摘Centaurium erythraea Rafn(“Gosset El Haya”)has long been prized in North African folk medicine,yet Moroccan chemobiological data remain scarce.Ethanol extracts of northern Moroccan aerial parts were profiled by high-performance liquid chromatography(HPLC)and found rich in phenolics,dominated by 4-hydroxybenzoic acid(57.8%)and naringin(10.3%).The extract exhibited strong antioxidant power in the 2,2-diphenyl-1-picrylhydrazyl(DPPH)radical-scavenging assay,with a half-maximal inhibitory concentration(IC_(50))of≈74μg mL^(−1),and a total antioxidant capacity(TAC)of≈201μg mL^(−1)and selective antimicrobial activity,sharply inhibiting Aspergillus niger,Penicillium digitatum,and Rhodotorula glutinis while sparing Staphylococcus aureus.In-silico absorption,distribution,metabolism,excretion,and toxicity(ADMET)profiling predicted good oral bioavailability for low-molecular-weight acids and aglycones,lowtoxicity across all metabolites,but absorption liabilities for bulky glycosides.Molecular docking against A.niger esterase(1UKC),C.glabrata lanosterol 14-α-demethylase CYP51(5JLC),and P.digitatum ethyleneforming oxidoreductase(9EIR)corroborated bioassays:rutin and naringin bound more tightly than fluconazole(ΔG≈−9.1 to−10.0 kcal mol^(−1)),whereas quercetin and catechin offered balanced affinity pharmacokinetic profiles.Robust radical scavenging,targeted antifungal potency,and favorable in-silico pharmacokinetics thus position Moroccan C.erythraea as a promising,though standardization-dependent,source of nutraceutical,medicinal,and food-preservation agents.These results support the valorisation of Centaurium erythraea as a promising source for health promotion and green technology applications through its antioxidant,antimicrobial,and drug-like properties.
基金funded by the National Key R&D Program of China(2021YFA1501101)the National Natural Science Foundation of China(No.22471103,22425105,22201111,21931001,22221001,and 22271124)+5 种基金Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)the Special Fund Project of Guiding Scientific and Technological Innovation Development of Gansu Province(2019ZX-04)the 111 Project(B20027)as well as the National Natural Science Foundation of Gansu Province(22JR5RA470)the Fundamental Research Funds for the Central Universities(lzujbky-2023-eyt03)supported by the Agency for Science,Technology and Research(A*STAR)MTC Individual Research Grants(IRG)M22K2c0078.
文摘Water splitting hinges crucially on the availability of electrocatalysts for the oxygen evolution reaction.The surface reconstruction has been widely observed in perovskite catalysts,and the reconstruction degree has been often correlated with the activity enhancement.Here,a systematic study on the roles of Fe substitution in activation of perovskite LaNiO_(3)is reported.The substituting Fe content influences both current change tendency and surface reconstruction degree.LaNi_(0.9)Fe_(0.1)O_(3)is found exhibiting a volcano-peak intrinsic activity in both pristine and reconstructed among all substituted perovskites in the LaNi_(1-x)Fe_(x)O_(3)(x=0.00,0.10,0.25,0.50,0.75,1.00)series.The reconstructed LaNi_(0.9)Fe_(0.1)O_(3)shows a higher intrinsic activity than most reported NiFe-based catalysts.Besides,density functional theory calculations reveal that Fe substitution can lower the O 2p level,which thus stabilize lattice oxygen in LaNi0.9Fe0.1O3 and ensure its long-term stability.Furthermore,it is vital interesting that activity of the reconstructed catalysts relied more on the surface chemistry rather than the reconstruction degree.The effect of Fe on the degree of surface reconstruction of the perovskite is decoupled from that on its activity enhancement after surface reconstruction.This finding showcases the importance to customize the surface chemistry of reconstructed catalysts for water oxidation.
文摘Thymus serpyllum L.,often known as wild thyme,has been used since ancient times due to its multifaceted culinary and medicinal attributes.It is usually utilized in folk medicine to manage different health issues.This work aimed to investigate the chemical composition and biological characteristics of T.serpyllum essential oil(EO),including its antimicrobial,antioxidant,and anti-inflammatory capabilities.Moreover,we have prompted an in-silico simulation to reveal the underlying mode of action of these properties.The chemical characterization of T.serpyllum(EO)by Gas Chromatography-Mass Spectrometry(GC-MS)indicated sabinene(17.33%),terpinen-4-ol(11.73%),phellandral(13.18%),and thymol(10.54%)as main components.The antimicrobial screening utilized the disc-diffusion technique,MIC,and MBC assays.The disc-diffusion test’s results revealed significant anti-Candida activity and notable antibacterial efficacy.The MIC and MBC tests showed that T.serpyllum EO effectively stops bacterial growth,including Gram-positive and Gram-negative strains and Candida strains.The tolerance level ratio demonstrated that this EO exhibits bactericidal and fungicidal effects on all tested bacteria and Candida strains.Also,T.serpyllum EO presented effective inhibitory activity against the 5-lipoxygenase(5-LOX)enzyme(IC50=744.19±0.1µg/mL)(p<0.05).It also effectively affected FRAP,β-carotene,DPPH,and ABTS radicals.In light of these findings,T.serpyllum holds promise for diverse applications across pharmaceuticals,nutraceuticals,and the food industry.However,further research and collaboration between traditional knowledge and modern medicine are crucial to fully realizing its potential benefits in these fields.
基金Supported by the National Key Research and Development Program of Traditional Chinese Medicine Modernization Project,China(No.2023YFC3504000)the Science and Technology Development Project of Jilin Province,China(No.20240404043ZP)the Science and Technology Innovation Cooperation Project of Changchun Science and Technology Bureau and Chinese Academy of Sciences,China(No.23SH14)。
文摘In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented product FGPA-G 2-H on Aβ25-35-induced PC 12 cells were explored.The structure of GPA-G 2-H was determined by means of zeta potential analysis,FTIR,HPLC,XRD,GC-MS and NMR.The backbone of GPA-G 2-H was mainly composed of→4)-α-D-Glcp-(1→with branches substituted at O-3.Notably,GPA-G 2-H was degraded by intestinal microbiota in vitro with total sugar content and pH value decreasing,and short-chain fatty acids(SCFAs)increasing.Moreover,GPA-G 2-H significantly promoted the proliferation of Lactobacillus,Muribaculaceae and Weissella,thereby making positive alterations in intestinal microbiota composition.Additionally,FGPA-G 2-H activated the Nrf 2/HO-1 signaling pathway,enhanced HO-1,NQO 1,SOD and GSH-Px,while inhabited Keap 1,MDA and LDH,which alleviated Aβ-induced oxidative stress in PC 12 cells.These provide a solid theoretical basis for the further development of ginseng polysaccharides as functional food and antioxidant drugs.
文摘Under solvothermal conditions,1,4‑naphthalenedicarboxylic acid(H_(2)ndc)and 9,9′‑dihexyl‑2,7‑di(pyridin‑4‑yl)fluorene(hfdp)reacted with Co^(2+)ions and Cd^(2+)ions to form two coordination polymers,[Co(hfdp)(ndc)(H2O)]·DMA}n(1)and{[Cd(hfdp)(ndc)(H_(2)O)]·DMA}_(n)(2),respectively(DMA=N,N‑dimethylacetamide).Single‑crystal X‑ray diffraction analyses showed that both complexes 1 and 2 contain similar structures.Topological analysis indicates that complexes 1 and 2 have a{44·62}planar structure.In addition,both complexes reveal good thermal stability and fluorescence sensing performance.They exhibited good sensitivity and selectivity towards 2,4,6‑trinitrophenol(TNP)by fluorescent quenching.The limits of detection of 1 and 2 for TNP were 0.107 and 0.327μmol·L^(-1),respectively.CCDC:2475515,1;2475516,2.
基金financially supported by the National Natural Science Foundation of China(Nos.52533015,52495013,52403211,52573183,52273157,52073279 and 52025035)Jilin Province,China(Nos.20250601009RC and 20230508102RC)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2022224)。
文摘Given that platinum-based drugs are widely used clinically as chemotherapeutic agents,their severe toxic side effects have attracted significant attention.Consequently,the development of novel nanoprodrugs based on low-toxicity tetravalent platinum(Pt(Ⅳ))com plexes holds substantial research value.Herein,we discovered that coumarin derivatives exhibit inherent antitumor efficacy and significantly enhance superoxide anion radicals(·O_(2)^(-))generation in aqueous solutions under ultrasound(US)irradiation.Given that·O_(2)^(-)is known to mediate the reduction of Pt(Ⅳ)to divalent platinum(Pt(Ⅱ)),we engineered an US-responsive dual-drug nanoprodrug(P-cisPt(Ⅳ)@5-MOP).This nanoprodrug was prepared by covalently conjugating Pt(Ⅳ)and methoxy polyethylene glycol hydroxyl(m PEG-OH)to a poly(_(L)-glutamic acid)(PLG)carrier,followed by encapsulating coumarin derivatives.Under low-intensity US irradiation(1.5 W/cm^(2),1 MHz,10 min),P-cisPt(Ⅳ)@5-MOP achieved a Pt(Ⅳ)reduction rate of 91.4%.Furthermore,upon US exposure,its half-maximal inhibitory concentration(IC_(50))against 4T1 breast cancer cells decreased dramatically from 25.7μmol/L to 0.1μmol/L.Remarkably,this system combined with US therapy yielded a tumor inhibition rate of 90.9%,with 40%of tumor-bea ring mice achieving com plete eradication of tumors,while exhibiting low systemic toxicity.Collectively,this work not only identifies a novel sonosensitizer capable of generating·O_(2)^(-)but also develops a new class of ultrasound-activatable Pt(Ⅳ)nanoprodrug.
文摘D-π hybridization is a key structural feature that may significantly affect the intrinsic electronic properties of metallopolymers.Herein,we present the electrosynthesis and memristive properties of metallopolymers using the distinct d-π hybridization monomers R_(1) and R_(2).R_(1)(Ru^(Ⅱ)-(tpz)Cl_(2))features tetradentate ligands(tpz,6,6'-di(1H-pyrazol-1-yl)-2,2'-bipyridine)enforcing quasi-octahedral geometry;R_(2)(Ru^(Ⅱ)-(bpp)_(2))incorporates tridentate ligands(bpp,2,6-di(1H-pyrazol-1-yl)pyridine)inducing pronounced geometric distortion.The planar ligand(tpz)in R_(1) facilitates ordered molecular assembly through high conformational rigidity and extensive π-π stacking,resulting in increased molecular densities and enhanced morphological uniformity compared to R_(2) metallopolymers.Due to pyrazole’s weaker π-acceptance and strongerσ-donation compared to pyridine,R_(1) exhibits a 119 nm red-shift in metal-to-ligand charge transfer(MLCT)band and a 30 mV anodic shift in Ru^(+2/+3)redox potential relative to R_(2).Coupled with a reduced HOMO-LUMO gap,the uniform and ordered structure leads to a lower conductance decay constant in R_(1).Additionally,R_(2) metallopolymers exhibit superior memristive performance(characterized by lower switching voltage and higher switching ratio)via redox-induced aromatic transitions in axial ligands enhancing electronic delocalization.This work compares two metallopolymers with different ligand geometries,revealing how this difference leads to distinct charge transport and memristive behaviors.
基金financial support from the National Natural Science Foundation of China(Nos.22401274,U23B6011)the Jilin Provincial Science and Technology Department Program(No.20250102070JC)。
文摘Catalysts are key for olefin polymerization reactions and are also ubiquitous in catalysis science.Multinuclear metal catalysts have witnessed enhanced performances in catalytic reactions relative to mononuclear catalysts,but which substantially involve multi-step,tedious,and difficult synthesis.Herein,this study reports an intriguing approach to construct multi-nuclear catalysts for the milestoneα-diimine nickel catalysts using an oligomeric strategy.A polymerizable norbornene unit is incorporated into theα-diimine ligand backbone,leading to the formation of the monomeric nickel catalyst Ni_(1)and its corresponding oligomeric nickel catalysts(Ni_(3)and Ni_(5))with varying degrees of polymerization(DP=3 and 5).Notably,the oligomeric catalyst Ni_(5)was facilely scaled up(50 g-level),showed enhanced thermal stability,exhibited 4.6 times higher activity,and yielded polyethylene elastomer with a 379%increased molecular weight in ethylene polymerization,compared to the monomeric catalyst Ni_(1).Catalytic performance enhancements of oligomeric catalysts were found to be DP-dependent.The kilogram-scale polyethylene,produced using Ni_(5)in a 20 L reactor,presented a highly branched all-hydrocarbon structure,which demonstrated typical elastic properties(tensile strength:4 MPa,elastic recovery:SR=72%)along with great processability(MFI=3.0 g/10 min),insulating characteristics(volume resistivity=2×10^(16)Ω/m),and hydrophobicity(water vapor permeability:0.03 g/m^(2)/day),suggesting potentially practical applications.
基金supported by the Special Project for High-tech Industrialization of Science and Technology Cooperation between Jilin Province and Chinese Academy of Sciences(2023SYHZ0042)。
文摘The development of substitutable meniscus implants that can effectively protect articular cartilage remains a great challenge.Herein,a polyurethane with chemical crosslinking and sulfobetaine extenders containing hydrophobic chains(PU-CL-hSB)is developed,which could improve comprehensive properties and long-term stability simultaneously.By regulating the mole ratio of functional groups,PU-CL-hSB with appropriate mechanical properties,excellent tribological properties,and good fatigue resistance is used to prepare substitutable meniscus implant by hot-pressing.Due to the synergistic effect of functional groups,PU-CL-hSB meniscus implant presents comparable or even superior properties to native meniscus.It withstands a maximum force of 26.08 N versus 25.14 N for native meniscus,an energy dissipation from 45.93 to 39.17 N mm compared to 28.83 to 19.11 N mm for native meniscus over 300 cycles,and a friction coefficient from 0.08 to 0.19 compared to 0.11 to 0.26 for native meniscus.This PU-CL-hSB meniscus implant is further implanted into live rabbit knee joints for 8 and 25 weeks by a new approach,and in vivo data indicate that PU-CL-hSB meniscus implant not only protects articular cartilage from severe damage without eliciting inflammatory responses,but also can maintain normal physiological activities in the native state.Our findings present a substitutable meniscus implant that could be applied in vivo and propose evaluation methodologies for meniscus implants.
基金financially supported by the National Natural Science Foundation of China(Nos.22473105 and 22341302).
文摘This study uses all-atom molecular dynamics simulations to investigate the dislocation propagation, stress transmission, and mechanical properties in poly(p-phenylene terephthalamide) fibers under uniaxial tension. The results indicate that the dislocation propagates and the stress transfers not only along the fiber axis but also between adjacent molecular chains through hydrogen bonds, demonstrating their influence on the yield behavior. As the degree of polymerization increases, breakage of covalent bonds and interchain slippage contribute to the yield of fibers together. This work provides theoretical guidance for the design and manufacturing of high-performance fibers.
基金financial support from Natural Science Foundation of China (No.22161005)Guangxi Natural Science Foundation (Nos.2021GXNSFDA075005,2024GXNSFFA010001)。
文摘Albeit notable endeavors in the construction of organophosphorodithioates,the direct catalytic enantioselective synthesis of organophosphorodithioates still stands for a long-lasting challenge.Herein,an efficient organocatalytic enantioselective nucleophilic addition of vinylidene ortho-quinone methide with phosphinothioic thioanhydride as nucleophilic reagent has been achieved by the dual catalysis of cinchona alkaloid-derived squaramide and 4-dimethylaminopyridine.This protocol provides a straightforward approach for accessing a variety of axially chiral phosphorodithiolated styrenes in good yields(up to 98 %yield) with high stereoselectivities(up to 97 % ee and >99:1 E/Z).
基金supported by the National Natural Science Foundation of China(82071981)the Program of Youth Science and Technology Innovation and Entrepreneurship Outstanding Talents(Team)of Jilin Province,China(20230508063RC)+3 种基金the Excellent Youth Training Foundation of Jilin University,China(419080520665)the Innovation and Entrepreneurship Talent Funding Program of Jilin Province,Chinathe Health Special Project of the Finance Department of Jilin Province,Chinathe Graduate Innovation Fund of Jilin University,China(2025CX297)。
文摘The heterogeneity and invasiveness of cancer cells pose serious challenges in cancer diagnosis and treatment.Advancements and innovations in metal-based nanomedicines provide novel avenues for addressing these challenges.Metal-based nanomedicines possess unique physicochemical properties that enable their interaction with living organisms,thereby inducing complex biological responses.These nanomaterials have been extensively used to enhance the contrast and sensitivity of cancer imaging and to amplify the distinction between cancerous and healthy tissues.Moreover,these nanomaterials can effectively combat a wide spectrum of cancers through various methods,including drug delivery,radiotherapy,photothermal therapy(PTT),photodynamic therapy(PDT),sonodynamic therapy(SDT),biocatalytic therapy,ion interference therapy(IIT),and immunotherapy.Currently,there is still a need for a comprehensive summary on the metal-based nanomaterials for cancer diagnosis and treatment.Herein,we present a systematic and complete overview of action mechanisms and the applications of metal-based nanomaterials in cancer theranostics.A summary of common strategies for synthesizing and modifying metal-based nanomedicines is presented,and their biosafety is analyzed.Then,the latest developments in their applications for cancer imaging and anticancer treatment are provided.Finally,the key technical challenges and reasonable perspectives of metal-based nanomedicines for cancer theranostics in clinical applications are discussed.
基金financially supported by the National Natural Science Foundation of China(Nos.22341304,22303100 and 12205270)the National Key R&D Program of China(Nos.2023YFA1008800 and 2020YFA0713601)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDC0180303)。
文摘The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behavior of dispersed long chains.Using molecular dynamics simulations based on the Kremer-Grest model,we systematically explore the N_(S)-dependence of static conformations,equilibrium dynamics,and nonlinear shear responses in unentangled long-chain/short-chain polymer blends.Our results demonstrate a decoupling between the static and dynamic sensitivity to N_(S):while the static chain size,R_g,follows Flory theory with slight swelling at small N_(S) due to incomplete excluded volume screening,the diffusion coefficient,D,and the relaxation time,τ_(0),exhibit a strong,non-monotonic N_(S)-dependence,transitioning from monomeric friction dominance at small N_(S) to collective segmental rearrangement at large N_(S).Additionally,we observe partial decoupling between the viscous and normal stress responses:while the zero-shear viscosity,η,is strongly N_(S)-dependent,the first and second normal stress coefficients,Ψ_(1) and Ψ_(2),collapse onto universal curves when scaled by the dimensionless shear rate,γτ_(0),suggesting a common mechanism of orientation and stretching.Under shear,long chains compress in the vorticity direction λ_(z)~Wi^(-0.2),which reduces collision frequency and contributes to shear thinning,while the scaling of weaker orientation resistance m_(G)~Wi^(0.35)reflects hydrodynamic screening by the short-chain matrix.These findings highlight the limitations of single-chain models and emphasize the necessity of considering N_(S)-dependent matrix dynamics and flow-induced structural changes in understanding the rheology of unentangled polymer blends.
基金Natural Science Foundation of China(NSFC,No.22131008)Natural Science Foundation of Tianjin(No.22JCYBJC00500)the Haihe Laboratory of Sustainable Chemical Transformations for financial support.
文摘Possessing excellent mechanical properties,a high-coverage slide-ring conductive gel is constructed by in situ polymerization ofα-cyclodextrin(α-CD)polyrotaxane(PR)and 1-vinyl-3-ethylimidazolium bromide([VEIM]Br)ionic liquid(IL),using 1-ethyl-3-methylimidazolium bromide([EMIM]Br)IL as solvent.Benefiting from the compatibility of ILs and alkene-PR,the cross-linked network slide-ring gel not only maintains excellent conductivity(1.52×10^(−2) S/m),but also has effectively improved mechanical properties(513%fracture strain,0.713 MPa fracture stress,211 kPa elastic modulus and 1366 kJ/m^(3) toughness)and adhesive properties(472.3±25.9 kPa).The supramolecular gel can be used as a strain sensor to efficiently monitor deformation signals in real-time at least 200 times.Especially,the slide-ring gel can self-power generated by triboelectric effect and electrostatic induction between the skin layer and the polydimethylsiloxane(PDMS)layer that encapsulates the gel,achieving reversible and durable motion sensing,which provides a convenient pathway for constructing supramolecular self-powered flexible electronic materials.
基金the National Natural Science Foundation of China (Nos. 52071179, 52271033)the Key Program of National Natural Science Foundation of China (No. 51931003)+2 种基金the Natural Science Foundation of Jiangsu Province, China (No. BK20221493)the Jiangsu Province Leading Edge Technology Basic Research Major Project, China (No. BK20222014)the Foundation of “Qinglan Project” for Colleges and Universities in Jiangsu Province, China。
文摘The composition−property relationship of 18 quaternary high entropy diborides(HEBs)consisting of boron and IVB,VB and VIB transition metals(TM)was investigated using first-principles calculations.A valence electron concentration−relative electronegativity(VEC−REN)composite descriptor was developed to effectively predict the mechanical properties of HEBs.The results demonstrate that with a fixed VEC,the rise of the REN makes HEBs harder but more brittle when the electronegativity of doped TM atoms is lower than that of boron atoms.However,HEBs become softer and more ductile as REN increases if the doped TM atoms have higher electronegativity than boron atoms.The VEC−REN composite descriptor can accurately classify and predict the mechanical properties of HEBs with different components,which provides important theoretical guidance for the rapid design and development of novel high-entropy ceramic materials.
文摘Date palm(Phoenix dactylifera L.)seeds,often discarded as by-products during date fruit processing,represent approximately 6-20%of the fruit’s mass depending on cultivar and maturity stage.Although traditionally used for producing activated charcoal and in environmental remediation,their pharmacological potential remains underexplored.This study aimed to evaluate the chemical composition,biological activity,and potential commercial value of seeds from four widely consumed Saharan cultivars(Assiane,Boufegouss,Aziza,and Majhoul)collected in the Figuig region.Soxhlet extraction was employed to obtain seed extracts,which were subsequently characterized by qualitative and quantitative phytochemical screening.The analyses revealed the presence of polyphenols,flavonoids,terpenoids,steroids,alkaloids,and other secondary metabolites.The Aziza and Boufegouss varieties were particularly rich in flavonoids(82.09-139.61 mg quercetin equivalents/100 g dry matter)and total polyphenols(69.81-1183.96 mg gallic acid equivalents/100 g dry matter).Mineral profiling confirmed the occurrence of essential trace elements,including Zn,Cu,Fe,and Co.To investigate their antidiabetic potential,in vitro assays ofα-glucosidase andα-amylase inhibition were performed.Acetone extracts demonstrated significant inhibitory activity against both enzymes,suggesting a promising role of P.dactylifera seed extracts as natural agents for the management of type 2 diabetes mellitus.
基金financially supported by the National Natural Science Foundation of China(Nos.22341303,22103079,and 22503003)the Shandong Provincial Natural Science Foundation(No.ZR2023QB232)the Beijing Institute of Technology Research Fund Program for Young Scholars(No.RCPT-6120250009)。
文摘Shear stress overshoot in entangled polymer rheology is a hallmark of transient dynamics,but its microscopic origin remains under debate.Using molecular dynamics simulations,we investigate a two-step shear protocol consisting of successive startup shears separated by a waiting period,with the first shear interrupted before the overshoot.In the homogeneous flow,the GLaMM theory captures the stress response during the first shear,but fails to reproduce the nonmonotonic dependence of the second stress overshoot(σ_(2max))on the waiting time.Contrary to the prediction of a nonmonotonic normal stress component σ_(yy)during the waiting period,our simulations show that σ_(yy),like the tube segment orientation(S_(xy)),the contour length of the primitive chain(L),and the entanglement number per chain(Z),relaxes monotonically toward equilibrium.At the strain corresponding to σ_(2max),both the tube segment orientation and the entanglement number per chain exhibit a nonmonotonic dependence on the waiting time that closely mirrors the behavior of σ_(2max),indicating that both factors play significant roles in governing(σ_(2max).Our findings are consistent with the interpretation of lanniruberto and Ma rrucci[ACS Macro.Lett.2014,3,552]for orientation effects and with the viewpoint of Wang et al.[Macromolecules 2013,46,3147]for entanglement effects,although the two explanations are rooted in distinct physical pictu res.These results provide new insights into the stress responses of entanglement polymer fluids and underscore the need for a more unified theoretical framework.
基金supported by the National Natural Science Foundation of China(Grant No.12074187).
文摘Electrically controlled solid propellant(ECSP)offers multiple ignition and adjustable burning rate,serving as fuel for next-generation intelligent propulsion systems.To further enhance the combustion performance of ECSP,a method utilizing electrochemical and thermal decomposition catalysts has been proposed.In this work,we investigated the combustion characteristics of hydroxylamine nitrate(HAN)-based ECSP incorporating cerium oxide(CeO_(2))and graphene oxide(GO)by using an electrically controlled combustion test system.Electrochemical impedance spectroscopy(EIS)and linear sweep voltammetry(LSV)were used to measure the electrical conductibility and overpotential of ECSP with various additives,and Tafel curves were calculated.Thermogravimetric analysis coupled with differential scanning calorimetry(TG-DSC)was employed to investigate the thermal decomposition behavior of ECSP.While the addition of CeO_(2) and GO reduced the conductivity of ECSP,both catalysts exhibited strong electrocatalytic properties and facilitated the thermal decomposition of ECSP.Between two catalysts,GO demonstrated superior electrochemical catalytic performance but weaker thermal decomposition catalytic ability than CeO_(2).The addition of catalysts significantly enhanced the combustion performance of HAN-based ECSP.Specifically,the ignition delay time was shortened by 10%~20%.CeO_(2) raised the burning rate by approximately 20%but GO exhibited a remarkable boost of 40%in burning rate at high voltage.The combination of GO and PVA produced a flame-retardant substance that negatively impacted the ignition delay of ECSP and resulted in a smaller increase in the burning rate of ECSP at low ignition voltages.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2022M3H4A6A0103720142)the National Research Council of Science&Technology(NST)grant by the Korea government(MSIT)(No.GTL24011-000)+1 种基金the Technology Innovation Program(RS-2024-00404165)through the Korea Planning&Evaluation Institute of Industrial Technology(KEIT)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)supported by the Samsung SDI Co.Ltd.and the Korea Institute of Science and Technology(KIST)institutional program(2E33942,2E3394B)。
文摘Strategies for achieving high-energy-density lithium-ion batteries include using high-capacity materials such as high-nickel NCM,increasing the active material content in the electrode by utilizing high-conductivity carbon nanotubes(CNT)conductive materials,and electrode thickening.However,these methods are still limited due to the limitation in the capacity of high-nickel NCM,aggregation of CNT conductive materials,and nonuniform material distribution of thick-film electrodes,which ultimately damage the mechanical and electrical integrity of the electrode,leading to a decrease in electrochemical performance.Here,we present an integrated binder-CNT composite dispersion solution to realize a high-solids-content(>77 wt%)slurry for high-mass-loading electrodes and to mitigate the migration of binder and conductive additives.Indeed,the approach reduces solvent usage by approximately 30%and ensures uniform conductive additive-binder domain distribution during electrode manufacturing,resulting in improved coating quality and adhesive strength for high-mass-loading electrodes(>12 mAh cm^(−2)).In terms of various electrode properties,the presented electrode showed low resistance and excellent electrochemical properties despite the low CNT contents of 0.6 wt%compared to the pristine-applied electrode with 0.85 wt%CNT contents.Moreover,our strategy enables faster drying,which increases the coating speed,thereby offering potential energy savings and supporting carbon neutrality in wet-based electrode manufacturing processes.
基金supported by the National Natural Science Foundation of China(21832005,22372181,22072168,22002175)Major Program of the Lanzhou Institute of Chemical Physics,CAS(ZYFZFX-3),Major Science and Technology Projects in Gansu Province(22ZD6GA003)the CAS“Light of West China”Program and West Light Foundation of The Chinese Academy of Sciences(xbzg-zdsys-202209).
文摘Herein,we demonstrated the integration of BiVO_(4)-based photoanode with metallic Zn cathode for high-performance CO_(2)reduction,and a record CO production rate of 113.32μmol cm^(−2)h^(−1)with a FECO of 90.57%has been achieved under simulated sunlight(AM 1.5 G,100 mW),accompanying with an excellent stability.More importantly,the direct observation of spatial charge separation/transfer and dynamic surface catalysis for both H_(2)O oxidation and CO_(2)reduction has been firstly achieved by the combination of in situ X-ray photoelectron spectroscopy(IS-XPS)with Fourier transform infrared reflection(IS-FTIR).Under light irradiation,the electron-hole pairs have been generated on BiVO_(4) photoanode,and holes rapidly transfer to photoanode surfaces for participating in oxygen evolution reaction(OER)through the formation of*OH and*OOH intermediates.Simultaneously,the proton-coupled electron transfer to the Zn cathode surfaces drive the reduction of adsorbed CO_(2)molecules into CO via the formation*COOH and*CO intermediates.Thereby,this work offers new insights into fundamental understanding of CO_(2)reduction process,which facilitates the future development of highly efficient carbon fixation systems.
