Wound management continues to present major clinical challenges,often necessitating therapeutic strategies that extend beyond conventional dressings,which provide only passive protection.Magnesium(Mg),a biologically i...Wound management continues to present major clinical challenges,often necessitating therapeutic strategies that extend beyond conventional dressings,which provide only passive protection.Magnesium(Mg),a biologically indispensable element,has attracted considerable attention for its multifaceted role in wound repair,including modulation of inflammatory responses,stimulation of fibroblast and keratinocyte proliferation,promotion of angiogenesis,and enhancement of collagen synthesis.However,the direct application of Mg formulations is limited by uncontrolled Mg ion(Mg^(2+))release,localized cytotoxicity at elevated concentrations,and inadequate mechanical stability at the wound site.To address these challenges,Mg-incorporated polymeric scaffolds have been developed as advanced delivery platforms.These systems integrate the regenerative capacity of Mg with the tunable properties of polymers,enabling controlled degradation,mechanical reinforcement,and sustained Mg^(2+)release to establish a favorable microenvironment for tissue repair.This review critically examines the role of Mg in wound healing and the effectiveness of polymeric matrices for controlled Mg^(2+)delivery.It further provides a comprehensive evaluation of recent advances in Mg-incorporated polymeric scaffolds,including nanofibers,hydrogels,and sponges,with emphasis on fabrication strategies,structural characteristics,and therapeutic efficacy.Key challenges,such as optimizing ion release kinetics,enhancing scaffold stability,and facilitating clinical translation,are also discussed.Collectively,this work underscores the potential of Mg-polymeric scaffolds as a next-generation platform for advanced wound care and highlights perspectives for future research and development.展开更多
Estuaries are key areas for organic carbon cycling,where polymeric carbohydrates are abundant and chemically diverse.The recycling of these polymers by microbes depends on a variety of carbohydrate-active enzymes(CAZy...Estuaries are key areas for organic carbon cycling,where polymeric carbohydrates are abundant and chemically diverse.The recycling of these polymers by microbes depends on a variety of carbohydrate-active enzymes(CAZymes).However,it remains unclear whether other gene traits,particularly those related to cell motility toward polymeric carbohydrates,are intertwined with carbohydrate depolymerization and niche specialization in estuarine sediment soils.In this study,estuarine sediments were incubated with four prevalent polymeric carbohydrates(laminarin,fucan,cellulose,and chitin) under anaerobic conditions.Based on metagenomic analysis,we identified potential responses to the degradation and utilization of polymeric carbohydrate substrates from the perspectives of CAZymes and sugar transporters.The analysis of metagenomic gene data also revealed a positive correlation between chemotaxis and the abundance of CAZymes genes.Furthermore,metagenomes-assembled genomes(MAGs) that exhibited higher abundance in polysaccharide-treated samples compared to controls also featured elevated copies of genes involved in polysaccharide utilization loci(PULs),chemotaxis,as well as those associated with flagellar or gliding movement.SprB and CTDs associated with gliding proteins genes are essential for type Ⅸ secretion system-mediated secretion of CAZymes and gliding motility in Bacteroidota.The enhanced potential for mobility,coupled with the ability to degrade polymeric carbohydrates,may enable these bacteria to exploit nutrients beyond carbon sources,thereby potentially broadening their ecological niches.展开更多
We report first-principles predictions of a cage-like polymeric nitrogen phase(cage-N)composed of interlocked N10 clusters stabilized by mixed sp^(2)/sp^(3) hybridization.Under high pressure,cage-N exhibits exceptiona...We report first-principles predictions of a cage-like polymeric nitrogen phase(cage-N)composed of interlocked N10 clusters stabilized by mixed sp^(2)/sp^(3) hybridization.Under high pressure,cage-N exhibits exceptional mechanical performance,including an ideal compressive strength of 343 GPa at a pressure of 300 GPa,~33% higher than that of diamond.This ultrahigh strength arises from the synergistic interplay between its three-dimensional covalent framework and hybridized bonding topology,which enables isotropic stress accommodation and dynamic electronic rearrangement.These results establish cage-N as a promising non-carbon ultrahard material and provide a bonding-driven route toward designing superhard frameworks under extreme conditions.展开更多
The zigzag nitrogen chain,similar to the Ch-N structure,has long been considered as a potential high-energy-density structure.However,all the previously predicted zigzag N-chain structures,similar to Ch-N,exhibited im...The zigzag nitrogen chain,similar to the Ch-N structure,has long been considered as a potential high-energy-density structure.However,all the previously predicted zigzag N-chain structures,similar to Ch-N,exhibited imaginary frequencies in their phonon spectra at 0 GPa.Here,we conducted a systematic investigation of P-N compounds using first-principles calculations,uncovering a series of structurally similar stable phases,C2/m-PN_(x)(x=6,8,10,12,and 14),in which N forms zigzag N chains similar to those in Ch-N.In P-N compounds,the longest zigzag N-chain,which can theoretically remain stable under ambient pressure,is the N-chain composed of 14 N atoms in C2/m-PN14.If the N-chain continues to grow,imaginary interchain vibrational frequencies arise in the system.Notably,N chains with an even number of atoms were more likely to be energetically favorable.The five C2/m-PN_(x) phases and one metastable phase(R-PN_(6))exhibited remarkable stability and excellent detonability at ambient pressure,indicating that they are promising candidates for high-energy-density materials.In addition,R-PN_(6) was the first structure to stabilize the N_(6) ring through covalent bonding,with the covalent network contributing to its high hardness(47.59 GPa).展开更多
Molecular-level interactions between polymeric inhibitors and wax crystals are essential for mitigating wax deposition in crude oils,a major operational and environmental challenge.This study investigates the mechanis...Molecular-level interactions between polymeric inhibitors and wax crystals are essential for mitigating wax deposition in crude oils,a major operational and environmental challenge.This study investigates the mechanisms by which specific inhibitors target wax crystals to prevent aggregation.Extracted wax and inhibitor were characterized using gas chromatography,X-ray diffraction,and spectroscopy to determine the molecular structures.The wax primarily comprised of straight-chain nC28 alkanes,while the inhibitor was an ethylene/vinyl acetate copolymer.Rheological tests demonstrated a reduced gelation point upon inhibitor addition.Molecular dynamics(MD)simulations,performed using the COMPASS II force field,revealed interactions at the molecular level.Structural validation of molecules was done through comparative analysis of the experimental infrared and simulated vibrational analysis spectra whereas that of the rhombohedral wax crystal was achieved using the Pawley method,yielding a Profile R-factor of 9.26%.Morphological studies revealed five symmetrically unique facets,with the(110)plane being the fastestgrowing due to its inter-planar distance and attachment energy(-157.25 kcal/mol).Adsorption energy calculations(-180 kcal/mol)confirmed that the inhibitor effectively disrupted crystal growth on the surface by adsorbing its polar section onto the wax surface while repelling the non-polar groups,thereby reducing waxaggregation.展开更多
This study focuses on the transient analysis of nonlinear dispersion of a polymeric pollutant ejected by an external source into a laminar pipe flow of a Newtonian liquid under axi-symmetric conditions.The influence o...This study focuses on the transient analysis of nonlinear dispersion of a polymeric pollutant ejected by an external source into a laminar pipe flow of a Newtonian liquid under axi-symmetric conditions.The influence of density variation with pollutant concentration is approximated according to the Boussinesq approximation and the nonlinear governing equations of momentum,pollutant concentration are obtained together with and Oldroyd-B constitutive model for the polymer stress.The problem is solved numerically using a semi-implicit finite difference method.Solutions are presented in graphical form for various parameter values and given in terms of fluid velocity,pollutant concentration,polymer stress components,skin friction and wall mass transfer rate.The model can be a useful tool in understanding the dynamics of industrial pollution situations arising from improper discharge of hydrocarbon pollutants into,say,water bodies.The model can also be quite useful for available necessary early warning methods for detecting or predicting the scale of pollution and hence help mitigate related damage downstream by earlier instituting relevant decontamination measures.展开更多
Arsenic(As)pollution seriously threatens human and ecological health.Microalgal cell wall and extracellular polymeric substances(EPS)are known to interactwith As,but their roles in the As resistance,accumulation and s...Arsenic(As)pollution seriously threatens human and ecological health.Microalgal cell wall and extracellular polymeric substances(EPS)are known to interactwith As,but their roles in the As resistance,accumulation and speciation inmicroalgae remain unclear.Here,we used two strains of Chlamydomonas reinhardtii,namely CC-125(wild type)and CC-503(cell walldeficientmutant),to examine the algal growth,EPS synthesis,As adsorption,absorption and transformation under 10–1000μg/L As(III)and As(V)treatments for 96 h.In both strains,the As absorption increased after the EPS removal,but the growth,As adsorption,and transformation of C.reinhardtii declined.The CC-125 strain was more tolerant to As stress and more efficient in EPS production,As accumulation,and redox transformation than CC-503,irrespective of EPS presence or absence.Three-dimension excitation-emission matrix(3DEEM)and attenuated total reflectance infrared spectroscopy(ATR-IR)analyses showed that As was bound with functional groups in the EPS and cell wall,such as-COOH,NH and-OH in proteins,polysaccharides and amino acids.Together,this study demonstrated that EPS and cell wall acted as barriers to lower the As uptake by C.reinhardtii.However,the cell wall mutant strain wasmore susceptible to As toxicity due to lower EPS induction and higher As absorption.展开更多
Photocatalytic conversion of CO_(2) is pivotal for mitigating the global greenhouse effect and fostering sustainable energy development.Nowadays,polymeric carbon nitride(PCN)has gained widespread application in CO_(2)...Photocatalytic conversion of CO_(2) is pivotal for mitigating the global greenhouse effect and fostering sustainable energy development.Nowadays,polymeric carbon nitride(PCN)has gained widespread application in CO_(2) solar reduction due to its excellent visible light response,suitable conduction band position,and good cost-effectiveness.However,the amorphous nature and low conductivity of PCN limit its photocatalytic efficiency by leading to low carrier concentrations and facile electron–hole recombination during photocatalysis.Addressing this bottleneck,in this study,potassium-doped PCN(KPCN)/copper(Ⅱ)-complexed bipyridine hydroxyquinoline carboxylic acid(Cu(Ⅱ)(bpy)(H_(2)hqc))composite catalysts were synthesized through a multistep microwave heating process.In the composite,the formation of an S-scheme junction facilitates the enrichment of more negative electrons on the conduction band of KPCN via intermolecular electron–hole recombination between Cu(Ⅱ)(bpy)(H_(2)hqc)(CuPyQc)and KPCN,thereby promoting efficient photoreduction of CO_(2) to CO.Microwave heating enhances the amidation reaction between these two components,achieving the immobilization of homogeneous molecular catalysts and forming amidation chemical bonds that serve as key channels for the S-scheme charge transfer.This work not only presents a new PCN-based catalytic system for CO_(2) reduction applications,but also offers a novel microwave-practical approach for immobilizing homogeneous catalysts.展开更多
The effect of pre-shear flow on the subsequent crystallization process of polymeric melt was investigated and a flow-induced crystallization （FIC） model based on the conformation tensor incorporating the pre-shear e...The effect of pre-shear flow on the subsequent crystallization process of polymeric melt was investigated and a flow-induced crystallization （FIC） model based on the conformation tensor incorporating the pre-shear effect was proposed. The model is capable of predicting the overshoot phenomena of the stress and the flow-induced free energy change of the polymeric system at high pre-shear rates. Under the condition of flow, the increase in the activated nuclei number was contributed by the flow-induced free energy change, which showed an overwhelming effect on the nuclei formation during the pre-shear process at high shear rates. The half crystallization time （t1/2） of polypropylene （PP） as functions of pre-shear rate and pre-shear time at different crystallization temperatures was predicted and compared with the experiment data. Both numerical and experimental results showed that t1/2 of PP decreased dramatically when the flow started but leveled off at long times. It was found that two transformation stages in t1/2 existed within a wide range of shear rates. For the first stage where the melting polymer experienced a relatively weak shear flow, the acceleration of crystallization kinetics was mainly contributed by the steady value of free energy change while in the second stage for high shear rates, strong overshoot in flow-induced free energy change occurred and the crystallization kinetics was thus significantly enhanced. The overshoots in stress and flow-induced free energy change reflected an important role of flow on the primary nucleation especially when the flow was strong enough.展开更多
The recent commercialization of gene products has sparked significant interest in gene therapy,necessitating efficient and precise gene delivery via various vectors.Currently,viral vectors and lipid-based nanocarriers...The recent commercialization of gene products has sparked significant interest in gene therapy,necessitating efficient and precise gene delivery via various vectors.Currently,viral vectors and lipid-based nanocarriers are the predominant choices and have been extensively investigated and reviewed.Beyond these vectors,polymeric nanocarriers also hold the promise in therapeutic gene delivery owing to their versatile functionalities,such as improving the stability,cellar uptake and endosomal escape of nucleic acid drugs,along with precise delivery to targeted tissues.This review presents a brief overview of the status quo of the emerging polymeric nanocarriers for therapeutic gene delivery,focusing on key cationic polymers,nanocarrier types,and preparation methods.It also highlights targeted diseases,strategies to improve delivery efficiency,and potential future directions in this research area.The review is hoped to inspire the development,optimization,and clinical translation of highly efficient polymeric nanocarriers for therapeutic gene delivery.展开更多
The preparation of polypeptide materials in continuous flow reactors shows great potential with improved reproducibility and scalability.However,conventional polypeptide synthesis from the polymerization of N-carboxya...The preparation of polypeptide materials in continuous flow reactors shows great potential with improved reproducibility and scalability.However,conventional polypeptide synthesis from the polymerization of N-carboxyanhydride(NCA)is conducted at relatively slow rates,requiring long tubing or ending up with low-molecular-weight polymers.Inspired by recent advances in accelerated NCA polymerization,we report the crown-ether-catalyzed,rapid synthesis of polypeptide materials in cosolvents in flow reactors.The incorporation of low-polarity dichloromethane and the use of catalysts enabled fast conversion of monomers in 30 min,yielding well-defined polypeptides(up to 30 k Da)through a 20-cm tubing reactor.Additionally,random or block copolypeptides were efficiently prepared by incorporating a second NCA monomer.We believe that this work highlights the accelerated polymerization design in flow polymerization processes,offering the continuous production of polypeptide materials.展开更多
Cutting-edge research has primarily focused on flow synthesis of linear block copolymers,lacking the ability for manipulating chain architectures for more extensive applications.Herein,we develop a flow chemistry plat...Cutting-edge research has primarily focused on flow synthesis of linear block copolymers,lacking the ability for manipulating chain architectures for more extensive applications.Herein,we develop a flow chemistry platform for the continuous microflow synthesis of bottlebrush block copolymers(BBCPs)using a grafting-through method.This involves performing ring-opening metathesis polymerization(ROMP)of two different macromonomers within two microfluidic reactors connected in series.The microflow environment allows for complete monomer conversion within a few tens of seconds,benefiting from the superior mixing efficiency achieved in Z-shaped channels as indicated by both theoretical simulations and experimental results.Consequently,a library of well-defined BBCPs of up to 528 distinct samples can be produced within one day through automation of the continuous procedure,while keeping precise control on degree of polymerization(DP<4)and polydispersity indices(PDI<1.2).The synthetic method is generally applicable to different macromonomers with different compositions and contour lengths,yielding libraries of branched block copolymers with great diversity in physiochemical properties and chain architectures.This work presents a powerful platform for high-throughput production of branched copolymers,significantly lowering the costs of the materials for real applications.展开更多
The dynamic analysis of semi-flexible polymers,such as DNA molecules,is an important multiscale problem with a wide range of applications in science and bioengineering.In this contribution,a dumbbell model with intern...The dynamic analysis of semi-flexible polymers,such as DNA molecules,is an important multiscale problem with a wide range of applications in science and bioengineering.In this contribution,a dumbbell model with internal viscosity was studied in steady shear flows of polymeric fluid.The tensors with moments other than second moment were approximated in the terms of second moment tensor.Then,the nonlinear algebraic equation of the second moment conformation tensor was calculated in closed form.Finally,substituting the resulting conformation tensor into the Kramers equation of Hookean spring force,the constitutive equations were obtained.The shear material properties were discussed for different internal viscosities and compared with the results of Brownian dynamics simulation.展开更多
The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-do...The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-dosage and high-efficiency CFIs for diesel,1,2,3,6-tetrahydrophthalic anhydride(THPA)was introduced as a third and polar monomer to enhance the depressive effects of alkyl methacrylatetrans anethole copolymers(C_(14)MC-TA).The terpolymers of alkyl methacrylate-trans anethole-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-TA-THPA)were synthesized and compared with the binary copolymers of C_(14)MC-TA and alkyl methacrylate-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-THPA).Results showed that C_(14)MC-THPA achieved the best depressive effects on the cold filter plugging point(CFPP)and solid point(SP)by 11℃and 16℃at a dosage of 1250 mg/L and monomer ratio of 6:1,while 1500mg/L C_(14)MC-TA(1:1)reached the optimal depressive effects on the CFPP and SP by 12℃and 18℃.THPA introduction significantly improved the depressive effects of C_(14)MC-TA.Lower dosages of C_(14)MCTA-THPA in diesel exerted better improvement effects on the CFPP and SP than that of C_(14)MC-TA and C_(14)MC-THPA.When the monomer ratio and dosage were 6:0.6:0.4 and 1000 mg/L,the improvement effect of C_(14)MC-TA-THPA on diesel reached the optimum level,and the CFPP and SP were reduced by 13℃and 19℃,respectively.A 3D nonlinear surface diagram fitted by a mathematical model was also used for the first time to better understand the relationships of monomer ratios,dosages,and depressive effects of CFIs in diesel.Surface analysis results showed that C_(14)MC-TA-THPA achieved the optimum depressive effects at a monomer ratio of 6:0.66:0.34 and dosage of 1000 mg/L,and the CFPP and SP decreased by 14℃ and 19℃,respectively.The predicted results were consistent with the actual ones.Additionally,the improvement mechanism of these copolymers in diesel was also explored.展开更多
The dumbbell model with internal viscosity for a dilute polymer solution is investigated based on a balance of viscous drag and restoring Brownian forces.An approximate method is used to obtain the solution of extensi...The dumbbell model with internal viscosity for a dilute polymer solution is investigated based on a balance of viscous drag and restoring Brownian forces.An approximate method is used to obtain the solution of extensional stress in closed form in the case of steady flow.For different internal viscosities,this parametric study shows different asymptotic regimes of the extensional viscosity as a function of strain rate.This analysis may explain the attenuation of pressure drop in strong flows from a phenomeno...展开更多
Developing efficient,non-toxic,and low-cost emitters is a key issue in promoting the applications of electrochemiluminescence(ECL).Among varied ECL emitters,polymeric emitters are attracting dramatically increasing in...Developing efficient,non-toxic,and low-cost emitters is a key issue in promoting the applications of electrochemiluminescence(ECL).Among varied ECL emitters,polymeric emitters are attracting dramatically increasing interest due to tunable structure,large surface area,brilliant transfer capability,and sustainable raw materials.In this review,we present a general overview of recent advances in developing polymeric luminophores,including their structural and synthetic methodologies.Methods rooted in straightforward unique structural modulation have been comprehensively summarized,aiming at enhancing the efficiency of ECL along with the underlying kinetic mechanisms.Moreover,as several conjugated polymers were just discovered in recent years,promising prospects and perspectives have also been deliberated.The insight of this review may provide a new avenue for helping develop advanced conjugated polymer ECL emitters and decode ECL applications.展开更多
A novel laser-based additive manufacturing approach of metal additive manufacturing using powder sheets(MAPS)has been introduced recently.The method utilizes polymer-bound powder sheets for metal AM as a feedstock,ins...A novel laser-based additive manufacturing approach of metal additive manufacturing using powder sheets(MAPS)has been introduced recently.The method utilizes polymer-bound powder sheets for metal AM as a feedstock,instead of loose powders.Conventional laser beam powder bed fusion(LPBF)additive manufacturing(AM)is among the most widespread 3D printing technologies.However,LPBF faces challenges related to safety and the impracticality of changing materials due to its reliance on loose powders.Thus,MAPS demonstrates the capability to overcome the limitations of LPBF by offering enhanced safety and the ability to print multi-material structures without the risk of material cross-contamination.As a part of developing processes,we investigate the effects of polymeric binder content on the printability and microstructural characteristics of MAPS-printed stainless steel 316 L.The results indicate that the average layer thickness of solidified material improves as the scanning speed decreases from 1000 mm/s to 50 mm/s across three different polymeric binder contents:10 wt%,20 wt%,and 30 wt%PCL.Additionally,a higher polymeric binder content(i.e.20 wt%and 30 wt%)in the powder sheets reduces the likelihood of crack formation.Electron backscatter diffraction(EBSD)analysis reveals that an increase in scanning speed promotes the formation of more equiaxed grains,while an increase in polymer content results in a reduction in grain size.These findings provide valuable insights into optimizing MAPS configurations for enhanced productivity and functionality in metal component manufacturing.展开更多
Diabetic wounds are among the most challenging chronic wounds to heal,due to the presence of multiple factors,including continuous oxidative stress,impaired vascular integrity,and biofilm formation.The development of ...Diabetic wounds are among the most challenging chronic wounds to heal,due to the presence of multiple factors,including continuous oxidative stress,impaired vascular integrity,and biofilm formation.The development of innovative treatment strategies is of paramount importance for the management of diabetic wounds.Stemmed from the pleiotropic physicochemical properties of ferrocene and spermidine,this essay reported the ferrocene-spermidine co-polymer(Fc S)for the first time through facile amidation reaction.Molecular dynamics simulation revealed its self-assembly through hydrogen bonds,van der Waals forces instead of traditional nanoprecipitation.The self-assembled nanoparticles were demonstrated to exhibit great antioxidant property on cells to facilitate their migration and angiogenesis.Moreover,the integration with photocuring hydrogel,gelatin methacrylate(Gel MA),to construct Fc S nanoparticles loaded wound dressing(Gel MA@Fc S)further confirmed the potential on promoting diabetic wound enclosure through enhancement of re-epithelization and collagen deposition.Together with its great biocompatibility and biosafety,Gel MA@Fc S is expected to be developed into a wound dressing for clinical diabetic wounds management.展开更多
Photoswitchable fluorescent polymeric nanoparticles were widely concerned because of their excellent features including the flexible design,easy preparation and functionalization,and thus exhibited great application p...Photoswitchable fluorescent polymeric nanoparticles were widely concerned because of their excellent features including the flexible design,easy preparation and functionalization,and thus exhibited great application potential in information encryption,anti-counterfeiting,but remained challenging in improving the security.Herein,we described a self-erased time-resolved information encryption via using photoswitchable dual-color fluorescent polymeric nanoparticles(PDFPNs)containing two fluorescence dyes(blue and red)and photochromic spiroxazine derivatives.In view of the different thermo-induced isomerization rates of photochromic spiroxazine derivatives in different flexible substrates,the decoloration rate of PDFPNs can be programmatically tuned by regulating ratio between rigid polymer and flexible polymer.Therefore,after ultraviolet light(UV)irradiation,correct information could only be recognized in preestablished time during the self-erased process.Our results indicated that PDFPNs exhibited fast photo-responsibility(2 min),high fluorescence contrast,well-pleasing photo-reversibility(>20 times),and programmable thermo-responsiveness(24 s-6 h).We thus demonstrated their application in the selferased time-resolved information encryption and anti-counterfeiting with high security.展开更多
文摘Wound management continues to present major clinical challenges,often necessitating therapeutic strategies that extend beyond conventional dressings,which provide only passive protection.Magnesium(Mg),a biologically indispensable element,has attracted considerable attention for its multifaceted role in wound repair,including modulation of inflammatory responses,stimulation of fibroblast and keratinocyte proliferation,promotion of angiogenesis,and enhancement of collagen synthesis.However,the direct application of Mg formulations is limited by uncontrolled Mg ion(Mg^(2+))release,localized cytotoxicity at elevated concentrations,and inadequate mechanical stability at the wound site.To address these challenges,Mg-incorporated polymeric scaffolds have been developed as advanced delivery platforms.These systems integrate the regenerative capacity of Mg with the tunable properties of polymers,enabling controlled degradation,mechanical reinforcement,and sustained Mg^(2+)release to establish a favorable microenvironment for tissue repair.This review critically examines the role of Mg in wound healing and the effectiveness of polymeric matrices for controlled Mg^(2+)delivery.It further provides a comprehensive evaluation of recent advances in Mg-incorporated polymeric scaffolds,including nanofibers,hydrogels,and sponges,with emphasis on fabrication strategies,structural characteristics,and therapeutic efficacy.Key challenges,such as optimizing ion release kinetics,enhancing scaffold stability,and facilitating clinical translation,are also discussed.Collectively,this work underscores the potential of Mg-polymeric scaffolds as a next-generation platform for advanced wound care and highlights perspectives for future research and development.
基金supported by the National Natural Science Foundation of China(Nos.42073078,U1901211 and 41876126)the National Key Research and Development Program of China(Nos.2023YFC3905003,2023-67 and 2017FY100700)+4 种基金the Hainan Province Science and Technology Special Fund(ZDYF2023SHFZ172)the Natural Science Foundation of Guangdong Province(Nos.2020A1515011137,2023A1515012004 and 2024A1515011203)Nansha District High-Level Talent Innovation Team Project in 2021(Mangrove Wetland Blue Carbon Sequestration Technology Innovation Team)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA19060204)the Key Tasks Guarantee Special Fund Project for Green-Beautiful Guangdong Ecological Construction in 2024(Precise Restoration and Ecological Function Evaluation of Mangroves).
文摘Estuaries are key areas for organic carbon cycling,where polymeric carbohydrates are abundant and chemically diverse.The recycling of these polymers by microbes depends on a variety of carbohydrate-active enzymes(CAZymes).However,it remains unclear whether other gene traits,particularly those related to cell motility toward polymeric carbohydrates,are intertwined with carbohydrate depolymerization and niche specialization in estuarine sediment soils.In this study,estuarine sediments were incubated with four prevalent polymeric carbohydrates(laminarin,fucan,cellulose,and chitin) under anaerobic conditions.Based on metagenomic analysis,we identified potential responses to the degradation and utilization of polymeric carbohydrate substrates from the perspectives of CAZymes and sugar transporters.The analysis of metagenomic gene data also revealed a positive correlation between chemotaxis and the abundance of CAZymes genes.Furthermore,metagenomes-assembled genomes(MAGs) that exhibited higher abundance in polysaccharide-treated samples compared to controls also featured elevated copies of genes involved in polysaccharide utilization loci(PULs),chemotaxis,as well as those associated with flagellar or gliding movement.SprB and CTDs associated with gliding proteins genes are essential for type Ⅸ secretion system-mediated secretion of CAZymes and gliding motility in Bacteroidota.The enhanced potential for mobility,coupled with the ability to degrade polymeric carbohydrates,may enable these bacteria to exploit nutrients beyond carbon sources,thereby potentially broadening their ecological niches.
基金supported by the Natural Science Foundation of China(Grant Nos.T2325013,52288102,52090024,12034009,12474004,and 12304036)the National Key R&D Program of China Grant No.2023YFA1610000+1 种基金the Fundamental Research Funds for the Central Universitiesthe Program for Jilin University and Sun Yat-sen University.
文摘We report first-principles predictions of a cage-like polymeric nitrogen phase(cage-N)composed of interlocked N10 clusters stabilized by mixed sp^(2)/sp^(3) hybridization.Under high pressure,cage-N exhibits exceptional mechanical performance,including an ideal compressive strength of 343 GPa at a pressure of 300 GPa,~33% higher than that of diamond.This ultrahigh strength arises from the synergistic interplay between its three-dimensional covalent framework and hybridized bonding topology,which enables isotropic stress accommodation and dynamic electronic rearrangement.These results establish cage-N as a promising non-carbon ultrahard material and provide a bonding-driven route toward designing superhard frameworks under extreme conditions.
基金supported by the Anhui Provincial Natural Science Foundation (Grant No.2508085J006)CASHIPS Director's Fund (Grant No.YZJJ202207-CX)。
文摘The zigzag nitrogen chain,similar to the Ch-N structure,has long been considered as a potential high-energy-density structure.However,all the previously predicted zigzag N-chain structures,similar to Ch-N,exhibited imaginary frequencies in their phonon spectra at 0 GPa.Here,we conducted a systematic investigation of P-N compounds using first-principles calculations,uncovering a series of structurally similar stable phases,C2/m-PN_(x)(x=6,8,10,12,and 14),in which N forms zigzag N chains similar to those in Ch-N.In P-N compounds,the longest zigzag N-chain,which can theoretically remain stable under ambient pressure,is the N-chain composed of 14 N atoms in C2/m-PN14.If the N-chain continues to grow,imaginary interchain vibrational frequencies arise in the system.Notably,N chains with an even number of atoms were more likely to be energetically favorable.The five C2/m-PN_(x) phases and one metastable phase(R-PN_(6))exhibited remarkable stability and excellent detonability at ambient pressure,indicating that they are promising candidates for high-energy-density materials.In addition,R-PN_(6) was the first structure to stabilize the N_(6) ring through covalent bonding,with the covalent network contributing to its high hardness(47.59 GPa).
基金the China Sponsorship Council for the scholarship funding(2022GXZ006306)The authors would like to acknowledge contributions from colleagues and support from the Sinopec Company project(No.P23138)the National Natural Science Foundation of China(No.52174047).We also appreciate the editors and the anonymous reviewers for reviewing the manuscript.
文摘Molecular-level interactions between polymeric inhibitors and wax crystals are essential for mitigating wax deposition in crude oils,a major operational and environmental challenge.This study investigates the mechanisms by which specific inhibitors target wax crystals to prevent aggregation.Extracted wax and inhibitor were characterized using gas chromatography,X-ray diffraction,and spectroscopy to determine the molecular structures.The wax primarily comprised of straight-chain nC28 alkanes,while the inhibitor was an ethylene/vinyl acetate copolymer.Rheological tests demonstrated a reduced gelation point upon inhibitor addition.Molecular dynamics(MD)simulations,performed using the COMPASS II force field,revealed interactions at the molecular level.Structural validation of molecules was done through comparative analysis of the experimental infrared and simulated vibrational analysis spectra whereas that of the rhombohedral wax crystal was achieved using the Pawley method,yielding a Profile R-factor of 9.26%.Morphological studies revealed five symmetrically unique facets,with the(110)plane being the fastestgrowing due to its inter-planar distance and attachment energy(-157.25 kcal/mol).Adsorption energy calculations(-180 kcal/mol)confirmed that the inhibitor effectively disrupted crystal growth on the surface by adsorbing its polar section onto the wax surface while repelling the non-polar groups,thereby reducing waxaggregation.
文摘This study focuses on the transient analysis of nonlinear dispersion of a polymeric pollutant ejected by an external source into a laminar pipe flow of a Newtonian liquid under axi-symmetric conditions.The influence of density variation with pollutant concentration is approximated according to the Boussinesq approximation and the nonlinear governing equations of momentum,pollutant concentration are obtained together with and Oldroyd-B constitutive model for the polymer stress.The problem is solved numerically using a semi-implicit finite difference method.Solutions are presented in graphical form for various parameter values and given in terms of fluid velocity,pollutant concentration,polymer stress components,skin friction and wall mass transfer rate.The model can be a useful tool in understanding the dynamics of industrial pollution situations arising from improper discharge of hydrocarbon pollutants into,say,water bodies.The model can also be quite useful for available necessary early warning methods for detecting or predicting the scale of pollution and hence help mitigate related damage downstream by earlier instituting relevant decontamination measures.
基金supported by the National Natural Science Foundation of China(Nos.32171623 and 31770548)the National Key Research and Development Program of China(Nos.2016YFD0800306 and 2017YFD0800305).
文摘Arsenic(As)pollution seriously threatens human and ecological health.Microalgal cell wall and extracellular polymeric substances(EPS)are known to interactwith As,but their roles in the As resistance,accumulation and speciation inmicroalgae remain unclear.Here,we used two strains of Chlamydomonas reinhardtii,namely CC-125(wild type)and CC-503(cell walldeficientmutant),to examine the algal growth,EPS synthesis,As adsorption,absorption and transformation under 10–1000μg/L As(III)and As(V)treatments for 96 h.In both strains,the As absorption increased after the EPS removal,but the growth,As adsorption,and transformation of C.reinhardtii declined.The CC-125 strain was more tolerant to As stress and more efficient in EPS production,As accumulation,and redox transformation than CC-503,irrespective of EPS presence or absence.Three-dimension excitation-emission matrix(3DEEM)and attenuated total reflectance infrared spectroscopy(ATR-IR)analyses showed that As was bound with functional groups in the EPS and cell wall,such as-COOH,NH and-OH in proteins,polysaccharides and amino acids.Together,this study demonstrated that EPS and cell wall acted as barriers to lower the As uptake by C.reinhardtii.However,the cell wall mutant strain wasmore susceptible to As toxicity due to lower EPS induction and higher As absorption.
基金supported by the National Natural Science Foundation of China(Nos.22106105 and 22201180)the Innovation Program of Shanghai Municipal Education Commission(No.2019-01-07-00-E00015)+2 种基金Shanghai Science and Technology Innovation Program(No.21DZ1206300)the Central Local Science and Technology Development Guidance Fund(No.YDZX20213100003002)Shanghai Science and Technology Commission Program(No.20060502200).
文摘Photocatalytic conversion of CO_(2) is pivotal for mitigating the global greenhouse effect and fostering sustainable energy development.Nowadays,polymeric carbon nitride(PCN)has gained widespread application in CO_(2) solar reduction due to its excellent visible light response,suitable conduction band position,and good cost-effectiveness.However,the amorphous nature and low conductivity of PCN limit its photocatalytic efficiency by leading to low carrier concentrations and facile electron–hole recombination during photocatalysis.Addressing this bottleneck,in this study,potassium-doped PCN(KPCN)/copper(Ⅱ)-complexed bipyridine hydroxyquinoline carboxylic acid(Cu(Ⅱ)(bpy)(H_(2)hqc))composite catalysts were synthesized through a multistep microwave heating process.In the composite,the formation of an S-scheme junction facilitates the enrichment of more negative electrons on the conduction band of KPCN via intermolecular electron–hole recombination between Cu(Ⅱ)(bpy)(H_(2)hqc)(CuPyQc)and KPCN,thereby promoting efficient photoreduction of CO_(2) to CO.Microwave heating enhances the amidation reaction between these two components,achieving the immobilization of homogeneous molecular catalysts and forming amidation chemical bonds that serve as key channels for the S-scheme charge transfer.This work not only presents a new PCN-based catalytic system for CO_(2) reduction applications,but also offers a novel microwave-practical approach for immobilizing homogeneous catalysts.
基金supported by the National Natural Science Foundation of China(No.10590355)the Shanghai Leading Academic Discipline Project(No.B202)
文摘The effect of pre-shear flow on the subsequent crystallization process of polymeric melt was investigated and a flow-induced crystallization （FIC） model based on the conformation tensor incorporating the pre-shear effect was proposed. The model is capable of predicting the overshoot phenomena of the stress and the flow-induced free energy change of the polymeric system at high pre-shear rates. Under the condition of flow, the increase in the activated nuclei number was contributed by the flow-induced free energy change, which showed an overwhelming effect on the nuclei formation during the pre-shear process at high shear rates. The half crystallization time （t1/2） of polypropylene （PP） as functions of pre-shear rate and pre-shear time at different crystallization temperatures was predicted and compared with the experiment data. Both numerical and experimental results showed that t1/2 of PP decreased dramatically when the flow started but leveled off at long times. It was found that two transformation stages in t1/2 existed within a wide range of shear rates. For the first stage where the melting polymer experienced a relatively weak shear flow, the acceleration of crystallization kinetics was mainly contributed by the steady value of free energy change while in the second stage for high shear rates, strong overshoot in flow-induced free energy change occurred and the crystallization kinetics was thus significantly enhanced. The overshoots in stress and flow-induced free energy change reflected an important role of flow on the primary nucleation especially when the flow was strong enough.
基金supported by National Natural Science Foundation of China(82104082)Natural Science Foundation of Qinghai Province(2024-ZJ-911).
文摘The recent commercialization of gene products has sparked significant interest in gene therapy,necessitating efficient and precise gene delivery via various vectors.Currently,viral vectors and lipid-based nanocarriers are the predominant choices and have been extensively investigated and reviewed.Beyond these vectors,polymeric nanocarriers also hold the promise in therapeutic gene delivery owing to their versatile functionalities,such as improving the stability,cellar uptake and endosomal escape of nucleic acid drugs,along with precise delivery to targeted tissues.This review presents a brief overview of the status quo of the emerging polymeric nanocarriers for therapeutic gene delivery,focusing on key cationic polymers,nanocarrier types,and preparation methods.It also highlights targeted diseases,strategies to improve delivery efficiency,and potential future directions in this research area.The review is hoped to inspire the development,optimization,and clinical translation of highly efficient polymeric nanocarriers for therapeutic gene delivery.
基金financially supported by the National Natural Science Foundation of China(No.22101194)Natural Science Foundation of Jiangsu Province(No.BK20210733)+3 种基金Suzhou Municipal Science and Technology Bureau(No.ZXL2021447)Collaborative Innovation Center of Suzhou Nano Science&Technologythe 111 ProjectJoint International Research Laboratory of Carbon-Based Functional Materials and Devices。
文摘The preparation of polypeptide materials in continuous flow reactors shows great potential with improved reproducibility and scalability.However,conventional polypeptide synthesis from the polymerization of N-carboxyanhydride(NCA)is conducted at relatively slow rates,requiring long tubing or ending up with low-molecular-weight polymers.Inspired by recent advances in accelerated NCA polymerization,we report the crown-ether-catalyzed,rapid synthesis of polypeptide materials in cosolvents in flow reactors.The incorporation of low-polarity dichloromethane and the use of catalysts enabled fast conversion of monomers in 30 min,yielding well-defined polypeptides(up to 30 k Da)through a 20-cm tubing reactor.Additionally,random or block copolypeptides were efficiently prepared by incorporating a second NCA monomer.We believe that this work highlights the accelerated polymerization design in flow polymerization processes,offering the continuous production of polypeptide materials.
基金financially supported by the National Natural Science Foundation of China(No.22071176)。
文摘Cutting-edge research has primarily focused on flow synthesis of linear block copolymers,lacking the ability for manipulating chain architectures for more extensive applications.Herein,we develop a flow chemistry platform for the continuous microflow synthesis of bottlebrush block copolymers(BBCPs)using a grafting-through method.This involves performing ring-opening metathesis polymerization(ROMP)of two different macromonomers within two microfluidic reactors connected in series.The microflow environment allows for complete monomer conversion within a few tens of seconds,benefiting from the superior mixing efficiency achieved in Z-shaped channels as indicated by both theoretical simulations and experimental results.Consequently,a library of well-defined BBCPs of up to 528 distinct samples can be produced within one day through automation of the continuous procedure,while keeping precise control on degree of polymerization(DP<4)and polydispersity indices(PDI<1.2).The synthetic method is generally applicable to different macromonomers with different compositions and contour lengths,yielding libraries of branched block copolymers with great diversity in physiochemical properties and chain architectures.This work presents a powerful platform for high-throughput production of branched copolymers,significantly lowering the costs of the materials for real applications.
基金Project(10702045) supported by the National Natural Science Foundation of China
文摘The dynamic analysis of semi-flexible polymers,such as DNA molecules,is an important multiscale problem with a wide range of applications in science and bioengineering.In this contribution,a dumbbell model with internal viscosity was studied in steady shear flows of polymeric fluid.The tensors with moments other than second moment were approximated in the terms of second moment tensor.Then,the nonlinear algebraic equation of the second moment conformation tensor was calculated in closed form.Finally,substituting the resulting conformation tensor into the Kramers equation of Hookean spring force,the constitutive equations were obtained.The shear material properties were discussed for different internal viscosities and compared with the results of Brownian dynamics simulation.
基金supported from the Natural Science Foundation Project of Shanghai(Nos.23ZR1425300 and 22ZR1426100)Experimental Technical Team Construction Project of Shanghai Education Commission(No.10110N230080)+1 种基金National Natural Science Foundation of China(No.22075183)Research and Innovation Project of Shanghai Municipal Education Commission(No.2023ZKZD54).
文摘The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-dosage and high-efficiency CFIs for diesel,1,2,3,6-tetrahydrophthalic anhydride(THPA)was introduced as a third and polar monomer to enhance the depressive effects of alkyl methacrylatetrans anethole copolymers(C_(14)MC-TA).The terpolymers of alkyl methacrylate-trans anethole-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-TA-THPA)were synthesized and compared with the binary copolymers of C_(14)MC-TA and alkyl methacrylate-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-THPA).Results showed that C_(14)MC-THPA achieved the best depressive effects on the cold filter plugging point(CFPP)and solid point(SP)by 11℃and 16℃at a dosage of 1250 mg/L and monomer ratio of 6:1,while 1500mg/L C_(14)MC-TA(1:1)reached the optimal depressive effects on the CFPP and SP by 12℃and 18℃.THPA introduction significantly improved the depressive effects of C_(14)MC-TA.Lower dosages of C_(14)MCTA-THPA in diesel exerted better improvement effects on the CFPP and SP than that of C_(14)MC-TA and C_(14)MC-THPA.When the monomer ratio and dosage were 6:0.6:0.4 and 1000 mg/L,the improvement effect of C_(14)MC-TA-THPA on diesel reached the optimum level,and the CFPP and SP were reduced by 13℃and 19℃,respectively.A 3D nonlinear surface diagram fitted by a mathematical model was also used for the first time to better understand the relationships of monomer ratios,dosages,and depressive effects of CFIs in diesel.Surface analysis results showed that C_(14)MC-TA-THPA achieved the optimum depressive effects at a monomer ratio of 6:0.66:0.34 and dosage of 1000 mg/L,and the CFPP and SP decreased by 14℃ and 19℃,respectively.The predicted results were consistent with the actual ones.Additionally,the improvement mechanism of these copolymers in diesel was also explored.
基金supported by the National Natural Science Foundation of China (No.10702045).
文摘The dumbbell model with internal viscosity for a dilute polymer solution is investigated based on a balance of viscous drag and restoring Brownian forces.An approximate method is used to obtain the solution of extensional stress in closed form in the case of steady flow.For different internal viscosities,this parametric study shows different asymptotic regimes of the extensional viscosity as a function of strain rate.This analysis may explain the attenuation of pressure drop in strong flows from a phenomeno...
基金supported by the National Natural Science Foundation of China(Nos.22174014 and 22074015)China Postdoctoral Science Foundation(No.2023M740595)+1 种基金Postdoctoral Fellowship Program of CPSF(No.GZC20230427)Jiangsu Funding Program for Excellent Postdoctoral Talent(No.2023ZB353).
文摘Developing efficient,non-toxic,and low-cost emitters is a key issue in promoting the applications of electrochemiluminescence(ECL).Among varied ECL emitters,polymeric emitters are attracting dramatically increasing interest due to tunable structure,large surface area,brilliant transfer capability,and sustainable raw materials.In this review,we present a general overview of recent advances in developing polymeric luminophores,including their structural and synthetic methodologies.Methods rooted in straightforward unique structural modulation have been comprehensively summarized,aiming at enhancing the efficiency of ECL along with the underlying kinetic mechanisms.Moreover,as several conjugated polymers were just discovered in recent years,promising prospects and perspectives have also been deliberated.The insight of this review may provide a new avenue for helping develop advanced conjugated polymer ECL emitters and decode ECL applications.
基金supported by PoSAddive–Powder Sheet Additive Manufacturing(co-funded by EIT Raw Materials,Grant No.22021)the AML in Trinity College Dublin.EIT Raw Materials is supported by EIT,a body of the European Union.
文摘A novel laser-based additive manufacturing approach of metal additive manufacturing using powder sheets(MAPS)has been introduced recently.The method utilizes polymer-bound powder sheets for metal AM as a feedstock,instead of loose powders.Conventional laser beam powder bed fusion(LPBF)additive manufacturing(AM)is among the most widespread 3D printing technologies.However,LPBF faces challenges related to safety and the impracticality of changing materials due to its reliance on loose powders.Thus,MAPS demonstrates the capability to overcome the limitations of LPBF by offering enhanced safety and the ability to print multi-material structures without the risk of material cross-contamination.As a part of developing processes,we investigate the effects of polymeric binder content on the printability and microstructural characteristics of MAPS-printed stainless steel 316 L.The results indicate that the average layer thickness of solidified material improves as the scanning speed decreases from 1000 mm/s to 50 mm/s across three different polymeric binder contents:10 wt%,20 wt%,and 30 wt%PCL.Additionally,a higher polymeric binder content(i.e.20 wt%and 30 wt%)in the powder sheets reduces the likelihood of crack formation.Electron backscatter diffraction(EBSD)analysis reveals that an increase in scanning speed promotes the formation of more equiaxed grains,while an increase in polymer content results in a reduction in grain size.These findings provide valuable insights into optimizing MAPS configurations for enhanced productivity and functionality in metal component manufacturing.
基金supported by National Natural Science Foundation of China(Nos.52173150 and U22A20315)the Guangzhou Science and Technology Program City-University Joint Funding Project(No.2024A03J0604)+2 种基金the Science and Technology Program of Guangzhou(No.2024A03J0431)the start-up funding for the Seventh Affiliated Hospital of Sun Yat-sen University(Shenzhen)(No.ZSQYRSFPD0053)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515111126)。
文摘Diabetic wounds are among the most challenging chronic wounds to heal,due to the presence of multiple factors,including continuous oxidative stress,impaired vascular integrity,and biofilm formation.The development of innovative treatment strategies is of paramount importance for the management of diabetic wounds.Stemmed from the pleiotropic physicochemical properties of ferrocene and spermidine,this essay reported the ferrocene-spermidine co-polymer(Fc S)for the first time through facile amidation reaction.Molecular dynamics simulation revealed its self-assembly through hydrogen bonds,van der Waals forces instead of traditional nanoprecipitation.The self-assembled nanoparticles were demonstrated to exhibit great antioxidant property on cells to facilitate their migration and angiogenesis.Moreover,the integration with photocuring hydrogel,gelatin methacrylate(Gel MA),to construct Fc S nanoparticles loaded wound dressing(Gel MA@Fc S)further confirmed the potential on promoting diabetic wound enclosure through enhancement of re-epithelization and collagen deposition.Together with its great biocompatibility and biosafety,Gel MA@Fc S is expected to be developed into a wound dressing for clinical diabetic wounds management.
基金financially supported by the National Key R&D Program of China(Nos.2023YFB3812400,2023YFB3812403)National Natural Foundation of China(Nos.52273206,52350233)+1 种基金Hunan Provincial Natural Science Foundation(No.2021JJ10029)Huxiang High-level Talent Gathering Project(No.2022RC4039).
文摘Photoswitchable fluorescent polymeric nanoparticles were widely concerned because of their excellent features including the flexible design,easy preparation and functionalization,and thus exhibited great application potential in information encryption,anti-counterfeiting,but remained challenging in improving the security.Herein,we described a self-erased time-resolved information encryption via using photoswitchable dual-color fluorescent polymeric nanoparticles(PDFPNs)containing two fluorescence dyes(blue and red)and photochromic spiroxazine derivatives.In view of the different thermo-induced isomerization rates of photochromic spiroxazine derivatives in different flexible substrates,the decoloration rate of PDFPNs can be programmatically tuned by regulating ratio between rigid polymer and flexible polymer.Therefore,after ultraviolet light(UV)irradiation,correct information could only be recognized in preestablished time during the self-erased process.Our results indicated that PDFPNs exhibited fast photo-responsibility(2 min),high fluorescence contrast,well-pleasing photo-reversibility(>20 times),and programmable thermo-responsiveness(24 s-6 h).We thus demonstrated their application in the selferased time-resolved information encryption and anti-counterfeiting with high security.
