Effect of mesopore spatial distribution of HZSM-5 catalyst on zinc state and product distribution in 1-hexene aromatization

1-hexene aromatization is a promising technology to convert excess olefin in fluid catalytic cracking(FCC)gasoline to high-value benzene(B),toluene(T),and xylene.Besides,the increasing market demand of xylene has put forward higher requirements for new generation of catalyst.For increasing xylene yield in 1-hexene aromatization,the effect of mesopore structure and spatial distribution on product distribution and Zn loading was studied.Catalysts with different mesopore spatial distribution were prepared by post-treatment of parent HZSM-5 zeolite,including NaOH treatment,tetra-propylammonium hydroxide(TPAOH)treatment,and recrystallization.It was found the evenly distributed mesopore mainly prolongs the catalyst lifetime by enhancing diffusion properties but reduces the aromatics selectivity,as a result of damage of micropores close to the catalyst surface.While the selectivity of high-value xylene can be highly promoted when the mesopore is mainly distributed interior the catalyst.Besides,the state of loaded Zn was also affected by mesopores spatial distribution.On the optimized catalyst,the xylene selectivity was enhanced by 12.4%compared with conventional Zn-loaded parent HZSM-5 catalyst at conversion over 99%.It was attributed to the synergy effect of mesopores spatial distribution and optimized acid properties.This work reveals the role of mesopores in different spatial positions of 1-hexene aromatization catalysts in the reaction process and the influence on metal distribution,as well as their synergistic effect two on the improvement of xylene selectivity,which can improve our understanding of catalyst pore structure and be helpful for the rational design of high-efficient catalyst.

Molecular characterization of canine parvovirus type 2(CPV2)reveals a high prevalence of the CPV2c genotype among dogs sufering from diarrhea

Canine parvovirus 2(CPV-2)is a highly contagious virus in dogs that typically causes hemorrhagic enteritis and a high mortality rate in unvaccinated puppies.The genetic variability and antigenic diversity of CPV-2 hinder its efective prevention of infection by vaccination.To investigate the epidemiology and genetic characteristics of CPV-2 in China,rectal swabs from afected dogs were collected from diferent animal clinics in Kunshan from 2022 to 2023.Preliminary detection and capsid gene sequencing of CPV-2 were performed using previously described primers and protocols.The overall detection rate for CPV-2 was 16.5%(33/200).A signifcant association was found between the CPV-2-positivity and clinical signs,age,breed and vaccination status.Sequence analysis revealed the presence of CPV-2c genotypes in all positive samples,which were genetically similar to other Asian CPV-2c strains.Notably,four key mutations(A5G,F267Y,Y324I and Q370R)were detected in all isolates,and one novel mutation(I447M)was detected in three CPV-2 isolates.These mutations in the CPV-2 strains could impact vaccine efcacy and the efectiveness of the virus immune evasion.Surprisingly,no recombination events were observed between the identifed CPV-2c strains and reference strains from China.Our data revealed that amino acid residues 324,426 and 440 of VP2 may under strong selection pressure.This pattern of genetic variation in the CPV-2 lineage warrants continuous laboratory-based surveillance programs in other parts of China to better understand the pattern of seasonal distribution and association between emerging genotypes and the intensity of disease severity.

Medical appraisal of Chinese military aircrew with abnormal results of coronary computed tomographic angiography

BACKGROUND Coronary artery diseases can cause myocardial ischemia and hypoxia,angina pectoris,myocardial infarction,arrhythmia,and even sudden death led to inflight incapacitation of aircrew.As the main cause of grounding due to illness,they severe threats to the health and fighting strength of military aircrew.Early warning in an early and accurate manner and early intervention of diseases possibly resulting in inflight incapacitation are key emphases of aeromedical support in clinic.AIM To figure out the flight factors and clinical characteristics of military aircrew with abnormal results of coronary artery computed tomographic angiography(CTA),thereby rendering theoretical references for clinical aeromedical support of military flying personnel.METHODS The clinical data of 15 flying personnel who received physical examinations in a military medical center from December 2020 to June 2023 and were diagnosed with coronary artery diseases by coronary artery CTA were collected and retrospectively analyzed,and a descriptive statistical analysis was conducted on their onset age,aircraft type and clinical data.RESULTS The 15 military flying personnel diagnosed with coronary artery diseases by coronary artery CTA were composed of 9 pilots,1 navigator and 5 air combat service workers.Multi-vessel disease was detected in 9 flying personnel,among which 8(88.9%)were pilots.Flying personnel with multi-vessel disease had higher content of cholesterol,low-density lipoprotein cholesterol and apolipoprotein B than those with single-vessel disease.CONCLUSION Coronary artery diseases are the major heart disease for the grounding of flying personnel due to illness,which can lead to inflight incapacitation.Coronary artery CTA is conducive to early detection and early intervention treatment of such diseases in clinic.

Spectra of intracranial diseases in Chinese military pilots(cadets)unqualified for transfer to pilot modified high performance aircraft

BACKGROUND With very high mortality and disability rates,cerebrovascular diseases and intracranial tumors severely threaten the health and fighting strength of flying personnel,requiring great concern and intensive screening in clinic,early warning in an early and accurate manner and early intervention of diseases possibly resulting in inflight incapacitation are key emphases of aeromedical support in clinic.AIM To probe into the spectra of intracranial diseases,flight factors and medical imaging characteristics of military pilots(cadets)in the physical examination for transfer to pilot modified high performance aircraft,thus rendering theoretical references for clinical aeromedical support of pilots.METHODS A total of 554 military pilots(cadets)undergoing physical examination for transfer to pilot modified high performance aircraft from December 2020 to April 2024 in a military medical center were enrolled in this study.Then,a retrospective study was carried out on intracranial disease spectra and head magnetic resonance imaging(MRI)data of 36 pilots(cadets)who were unqualified for transfer to pilot modified high performance aircraft.Besides,a descriptive statistical analysis was conducted on the clinical data,age,fighter type and head MRI data of such pilots(cadets).RESULTS Abnormal head images were found in 36 out of 554 pilots(cadets)participating in the physical examination for transfer to pilot modified high performance aircraft,including arachnoid cyst in 17(3.1%)military pilots(cadets),suspected very small aneurysm in 11(2.0%),cavernous hemangioma in 4(0.7%),vascular malformation in 2(0.4%),and pituitary tumor in 3(0.5%,one of which developed cavernous hemangioma simultaneously).Among the 17 pilots(cadets)with arachnoid cyst,4 were identified as unqualified for transfer to pilot modified high performance aircraft because the marginal brain tissues were compressed by the cyst>6 cm in length and diameter.The 11 pilots(cadets)with suspected very small aneurysms identified by 3.0T MRI consisted of 6 diagnosed with conus arteriosus by digital subtraction angiography and qualified for transfer to pilot modified high performance aircraft,and 5 identified as very small intracranial aneurysms with diameter<3 mm and unqualified for transfer to pilot modified high performance aircraft.No symptoms and signs were observed in the 4 military pilots(cadets)with cavernous hemangioma,and the results of MRI revealed bleeding.The 1 of the 4 had the lesion located in pons and developed Rathke cyst in pituitary gland at the same time,and unqualified for transfer to pilot modified high performance aircraft.The 2 of the 4 were unqualified for flying,and 2 transferred to air combat service division.The 2 pilots(cadets)with vascular malformation were identified as unqualified for transfer to pilot modified high performance aircraft.Among the 3 pilots(cadets)with pituitary tumor,one pilot cadet was identified as unqualified for flying since the tumor compressed the optic chiasma,one had cavernous hemangioma in pons in the meantime and transferred to air combat service division,and one was diagnosed with nonfunctional microadenoma and qualified for transfer to pilot modified high performance aircraft.CONCLUSION High-resolution head MRI examination is of great significance for screening and detecting cerebrovascular diseases and intracranial tumors in military flying personnel,and attention should be paid to its clinical application to physical examination for transfer to pilot modified high performance aircraft.

Variations in stem radii of Larix principis-rupprechtii to environmental factors at two slope locations in the Liupan Mountains,northwest China

Relationships between stem growth and climatic and edaphic factors,notably air temperatures and soil moisture for different slopes,are not completely understood.Stem radial variations were monitored at the bottom and top slope positions in a Larix principis-rupprechtii plantation during the 2017 and 2018 growing seasons.Total precipitation during the growing season in 2017 and 2018 was 566 mm and 728 mm,respectively.Stem contractions typically occurred after mid-morning followed by swelling in the late afternoon in both plots,reflecting the diurnal cycle of water uptake and loss.Trees at the two locations showed the same growth initiation(mid-May)because of the small differences in air and soil temperatures.There were no significant differences in cumulative stem radial growth between the bottom plot(1.57±0.34 mm)and the top plot(1.55±0.26 mm)in 2018.However,in 2017,the main growth period of the bottom plot ceased 17 days earlier than in the top plot,while cumulative seasonal growth of the bottom plot(1.08±0.25 mm)was significantly less than the top plot(1.54±0.43 mm).Maximum daily stem shrinkage was positively correlated with air and soil temperatures,solar radiation,vapor pressure deficits,and negatively correlated with volumetric soil moisture content.The maximum daily shrinkage reflected transpiration rates as affected by environmental factors.Daily radial stem increment was correlated with precipitation and volumetric soil moisture in both years,but with air temperatures only in 2017.The seasonal growth of L.principis-rupprechtii Mayr thus shows interannual dynamics,while precipitation constitutes a key driving factor.

Chromatin remodeler INO80 mediates trophectoderm permeability barrier to modulate morula-to-blastocyst transition

Inositol requiring mutant 80(INO80)is a chromatin remodeler that regulates pluripotency maintenance of embryonic stem cells and reprogramming of somatic cells into pluripotent stem cells.However,the roles and mechanisms of INO80 in porcine preimplantation embryonic development remain largely unknown.Here,we show that INO80 modulates trophectoderm epithelium permeability to promote porcine blastocyst development.The INO80 protein is highly expressed in the nuclei during morula-toblastocyst transition.Functional studies revealed that RNA interference(RNAi)-mediated knockdown of INO80 severely blocks blastocyst formation and disrupts lineage allocation between the inner cell mass and trophectoderm.Mechanistically,singleembryo RNA sequencing revealed that INO80 regulates multiple genes,which are important for lineage specification,tight junction assembly,and fluid accumulation.Consistent with the altered expression of key genes required for tight junction assembly,a permeability assay showed that paracellular sealing is defective in the trophectoderm epithelium of INO80 knockdown blastocysts.Importantly,aggregation of 8-cell embryos from the control and INO80 knockdown groups restores blastocyst development and lineage allocation via direct complementation of the defective trophectoderm epithelium.Taken together,these results demonstrate that INO80 promotes blastocyst development by regulating the expression of key genes required for lineage specification,tight junction assembly,and fluid accumulation.

A Novel Magnetic Carbon Based Catalyst Synthesized from Reed Straw and Electric Furnace Dust for Biodiesel Production

In the era of serious greenhouse gas emission and energy shortage,it is necessary to use solid waste to prepare new renewable materials.In this work,the potential application of reed straw and electric furnace dust was explored.Firstly,magnetic carbon carrier(EFD&C)was prepared by high temperature calcination,and then magnetic carbon catalyst(SM@EFD&C)was prepared by activation of sodium methoxide.The catalyst was used to prepare biodiesel by transesterification reaction to test its activity and stability.Reed biochar,EFD&C and SM@EFD&C were detected by Diffraction of X-rays(XRD),Fourier transform infrared(FT-IR),Inductively coupled plasma(ICP),Scanning electron microscope(SEM),Transmission electron microscope(TEM),Brunauer-Emmett-Teller(BET),Vibrating sample magnetometer(VSM),Temperature programmed desorption of CO_(2)(CO_(2)-TPD)and Thermogravimetric analysis(TG-DTG).The results showed that SM@EFD&C catalyst had some characteristics including porous structure,easy adsorption and better magnetism.Under the reaction conditions of 65℃for 2 h with 6 wt%catalyst and methanol/oil molar ratio of 15:1,the biodiesel yields from reed biochar and EFD&C were only 4.88 wt%and 0.03 wt%,respectively,while the yield from SM@EFD&C catalyst reached 93.14 wt%(89.84 wt%after 7 cycles)under the same conditions,which proved that it had good catalytic activity and stability when used in biodiesel production.This study is of great significance of carbon dioxide emission reduction and environmental protection.

Cu(OH)_(2)/CMC one-dimensional composite-nanofiber-based electrochemical sensor for aspirin detection

Copper-based nanomaterials have been widely used in catalysis,electrodes,and other applications due to their unique electron-transfer properties.In this work,an efficient electrochemical sensor based on an electrode modified with one-dimensional Cu(OH)_(2)/carboxymethyl cellulose(CMC)composite nanofibers was fabricated and investigated for the detection of aspirin.Scanning electron microscopy was employed to examine the morphological characteristics of these composite nanofibers.Cyclic voltammetry and electrochemical impedance spectroscopy were used to assess the electrochemical performance of a Cu(OH)_(2)/CMC composite nanofiber-modified electrode.The findings indicate that the modified electrode has a very high sensitivity to aspirin.The observed enhanced performance could be a result of the high surface-to-volume ratio of the composite nanofibers and their superior electron-transport characteristics,which may hasten electron transfer between aspirin and the surfaces of the modified electrode.This detection technique also demonstrated strong selectivity for aspirin.These findings imply that the technique can be applied as a highly effective and selective approach to aspirin measurement in biological science.

Sequence stratigraphy, paleogeography, and coal accumulation regularity of major coal-accumulating periods in China

There are 9 major coal-accumulating periods during geological history in China,including the Early Carboniferous,Late Carboniferous-Early Permian,Middle Permian,Late Permian,Late Triassic,Early-Middle Jurassic,Early Cretaceous,Paleogene and Neogene.The coal formed in these periods were developed in different coal-accumulating areas(CAA)including the North China,South China,Northwest China,Northeast China,the Qinghai–Tibet area,and China offshore area.In this paper,we investigated depositional environments,sequence stratigraphy,lithofacies paleogeography and coal accumulation pattern of five major coal-accumulating periods including the Late Carboniferous to Middle Permian of the North China CAA,the Late Permian of the South China CAA,the Late Triassic of the South China CAA,the Early-Middle Jurassic of the North and Northwest China CAA,and the Early Cretaceous in the Northeast China CAA.According to distribution of the coal-bearing strata and the regional tectonic outlines,we have identified distribution range of the coal-forming basins,sedimentary facies types and coal-accumulating models.The sequence stratigraphic frameworks of the major coal-accumulating periods were established based on recognition of a variety of sequence boundaries.The distribution of thick coals and migration patterns of the coal-accumulating centers in the sequence stratigraphic framework were analyzed.The lithofacies paleogeography maps based on third-order sequences were reconstructed and the distribution of coal accumulation centers and coal-rich belts were predicted.

Preparation and properties of supersonic atmospheric plasma sprayed TiB2−SiC coating

With the TiB2−SiC powders after spray granulation and vacuum calcination as raw materials,the TiB2−SiC coating was prepared by supersonic atmospheric plasma spraying(SAPS).The effects of spraying power and spraying distance on the properties of the TiB2−SiC coating were investigated and the fabrication processing of SAPS was optimized.The results show that the sprayed powders after calcination have a uniform particle size distribution,good sphericity and enhanced fluidity.The coating prepared by the calcined powders has a dense structure and high deposition efficiency.When the calcined TiB2−SiC powders are used and the spraying power is 95 kW and the spraying distance is 150 mm during supersonic plasma spraying,the obtained TiB2−SiC coating behaves the best comprehensive performance with the porosity,microhardness,bonding strength and resistivity equal to 5.6%,3.57 GPa,18.3 MPa and 10.8 mΩ·cm,respectively.

Influence of zinc state on the catalyst properties of Zn/HZSM-5 zeolite in 1-hexene aromatization and cyclohexane dehydrogenation

Rational design of Zn-containing HZSM-5 zeolite(Zn/HZSM-5)with high reactivity and excellent aromatization performance for olefin aromatization is crucially desired.We develop a new and uncomplicated method to synthesize Zn/HZSM-5(IMX/Z5)with superior aromatization performance in the paper.Compared to incipient wetness impregnation(IMP/Z5)and mechanical mixing(MIX/Z5),the asprepared IMX/Z5 presents a higher amount of surface ZnOH^(+)species(2.87%)while keeping identical bulk zinc content.As a result,more surface ZnOH^(+)favor both the aromatization of 1-hexene and cyclohexane dehydrogenation.For the two olefin aromatization pathways(hydrogen transfer and dehydrogenation),it is the first time found both the hydrogen transfer ability and the dehydrogenation ability increase linearly with the amount of surface ZnOH^(+)species while keeping identical bulk zinc content.We believe that the linear relationships are essential to design next generation olefin aromatization catalysts.

Targeting Hypoxic Tumors with Hybrid Nanobullets for Oxygen-Independent Synergistic Photothermal and Thermodynamic Therapy

Hypoxia is a feature of solid tumors and it hinders the therapeutic efficacy of oxygen-dependent cancer treatment.Herein,we have developed all-organic oxygen-independent hybrid nanobullets ZPA@HA-ACVA-AZ for the“precise strike”of hypoxic tumors through the dual-targeting effects from surface-modified hyaluronic acid(HA)and hypoxia-dependent factor carbonic anhydrase IX(CA IX)-inhibitor acetazolamide(AZ).The core of nanobullets is the special zinc(II)phthalocyanine aggregates(ZPA)which could heat the tumor tissues upon 808-nm laser irradiation for photothermal therapy(PTT),along with the alkyl chain-functionalized thermally decomposable radical initiator ACVA-HDA on the side chain of HA for providing oxygen-independent alkyl radicals for ablating hypoxic cancer cells by thermodynamic therapy(TDT).The results provide important evidence that the combination of reverse hypoxia hallmarks CA IX as targets for inhibition by AZ and synergistic PTT/TDT possess incomparable therapeutic advantages over traditional(reactive oxygen species(ROS)-mediated)cancer treatment for suppressing the growth of both hypoxic tumors and their metastasis.

A study of sequence stratigraphy of the Early Cretaceous coal-bearing series in the southeastern Songliao Basin, NE China

The Early Cretaceous is an important coal accumulation period in China.Abundant coal resources were formed in the southeastern margin of Songliao Basin.Sequence stratigraphy and coal accumulation of the Early Cretaceous in the southeastern margin of Songliao Basin have been studied on the basis of extensive outcrop and borehole data.Based on regional unconformity,basal erosional surfaces of incised valley fills,and abrupt depositional facies-reversal surface,six sequence boundaries have been identified,which subdivide the Early Cretaceous coal-bearing series into 5 third-order sequences.Sequence I corresponds to Huoshiling Formation,sequences II and III correspond to member I and member II of Shahezi Formation.Sequences IV and V correspond to member I and member II of Yingcheng Formation.Sequence I developed at the initial subsiding stage,sequence II and III developed during the stable subsiding stage,while sequence IV and V developed during the basin shrinkage stage.The major coal seams were developed in the sequence II and III,which ensured the relative balance between the increase rate of the accommodation space and the rate of peat accumulation for a longer period,thus forming a thick coal seam.

Structural confirmation of sulconazole sulfoxide as the primary degradation product of sulconazole nitrate

Sulconazole has been reported to degrade into sulconazole sulfoxide via sulfur oxidation; however,structural characterization data was lacking and the potential formation of an N-oxide or sulfone could not be excluded. To clarify the degradation pathways and incorporate the impurity profile of sulconazole into the United States Pharmacopeia–National Formulary(USP–NF) monographs, a multifaceted approach was utilized to confirm the identity of the degradant. The approach combines stress testing of sulconazole nitrate, chemical synthesis of the degradant via a hydrogen peroxide-mediated oxidation reaction,semi-preparative HPLC purification, and structural elucidation by LC–MS/MS and NMR spectroscopy.Structural determination was primarily based on the comparison of spectroscopic data of sulconazole and the oxidative degradant. The mass spectrometric data have revealed a Mc Lafferty-type rearrangement as the characteristic fragmentation pathway for alkyl sulfoxides with a β-hydrogen atom, and was used to distinguish the sulfoxide from N-oxide or sulfone derivatives. Moreover, the generated sulconazole sulfoxide was utilized as reference material for compendial procedure development and validation, which provides support for USP monograph modernization.

Research on the Value Orientation of Higher Education under the Concept of“People Oriented”

The current development of higher education has been continuously deepened and upgraded.With the continuous implementation of the concept of“peopleoriented”,it has increasingly played a positive role in the deepening reform of higher education management.In order to grasp the scientific connotation of“peopleoriented”in higher education,we should deeply understand the necessity and internal requirements of“people-oriented”in higher education,which will help to further explore the value orientation of higher education under the concept of“people-oriented”and build a“higher education”for universities.The implementation path of the people-oriented concept provides some feasible countermeasures.

Mixed oligopoly,state-owned banks’shareholding reform and foreign capital penetration

This paper examines the impact of the policy on eliminating the ratio of foreign shareholding in banks in a mixed oligopoly model.Its analytic results show that state-owned banks should encourage privatisation along with an increasing proportion of the domestic share in multinational banks.Furthermore,we argue that the increase in domestic stockholding of multinational banks raises domestic private firms’profits but decreases their social welfare in the deposit market.The results of numerical simulation show that when the quantity of private banks is fixed,foreign banks tend to enlarge their stake and strengthen their controlling power.

Immunogenic-cell-killing and immunosuppression-inhibiting nanomedicine

Combining chemo-therapeutics with immune checkpoint inhibitors facilitates killing cancer cells and activating the immune system through inhibiting immune escape.However,their treatment effects remain limited due to the compromised accumulation of both drugs and inhibitors in certain tumor tissues.Herein,a new poly(acrylamide-co-acrylonitrile-co-vinylimidazole-co-bis(2-methacryloyl)oxyethyl disulfide)(PAAVB)polymer-based intelligent platform with controllable upper critical solution temperature(UCST)was used for the simultaneous delivery of paclitaxel(PTX)and curcumin(CUR).Additionally,a hyaluronic acid(HA)layer was coated on the surface of PAAVB NPs to target the CD44-overexpressed tumor cells.The proposed nanomedicine demonstrated a gratifying accumulation in tumor tissue and uptake by cancer cells.Then,the acidic microenvironment and high level of glutathione(GSH)in cancer cells could spontaneously decrease the UCST of polymer,leading to the disassembly of the NPs and rapid drug release at body temperature without extra-stimuli.Significantly,the released PTX and CUR could induce the immunogenic cell death(ICD)to promote adaptive anti-tumor immunogenicity and inhibit immunosuppression through suppressing the activity of indoleamine 2,3-dioxygenase 1(IDO1)enzyme respectively.Therefore,the synergism of this intelligent nanomedicine can suppress primary breast tumor growth and inhibit their lung metastasis.

Novel self-assembled porous yolk-shell NiO nanospheres with excellent electrochromic performance for smart windows

With the rapid development of optoelectronics,electrochromic(EC)materials(ECMs)with the advan-tages of low power consumption,easy viewing,high contrast ratio,etc have attached more and more attention from the fields of smart windows,electronic billboards,emerging wearable and portable electronics,and other next-generation displays.Nickel oxide(NiO)is a promising candidate for high-performance ECMs because of its neutral-colored states and low cost.However,NiO-based ECMs still face the problem of slow switching speed due to their low electrical conductivity and small lattice spacing.Metal-organic frameworks(MOFs)are promising candidates to fabricate hollow and porous transition metal oxides(TMOs)with high ion transport efficiency,excellent specific capacitance,and electrochemical activities.In this work,porous yolk-shell NiO nanospheres(PYS-NiO NSs)were syn-thesized via a solvothermal and subsequent calcination process of Ni-MOF,which exhibited outstanding EC performance.Because the large specific surface areas and hollow porous nanostructures were conducive to ionic transport,PYS-NiO NSs exhibited a fast coloring/bleaching speed(3.6/3.9 s per one coloring/bleaching cycle)and excellent cycling stability(82%of capacity retention after 3000 cycles).These superior EC properties indicated that the PYS-NiO NSs was a promising candidate for high-performance EC devices.This work provides a new and feasible strategy for the efficient preparation of TMOs ECMs with good EC performance,especially fast switching speed.

Prevalence of Reproductive Tract Infections and Association with Human Papillomavirus Infection Among Reproductive-Age Women—Six Tertiary Hospitals,China,June 2021-December 2022

Summary What is already known about this topic?Previous studies have indicated a possible association between reproductive tract infections(RTIs)and highrisk human papillomavirus(HPV)infection,but the evidence is still inconclusive.What is added by this report?This multicenter study found significantly higher positive rates of HPV,including general HPV,highrisk HPV.

An NIR photothermal-responsive hybrid hydrogel for enhanced wound healing

Moderately regulating vascularization and immune microenvironment of wound site is necessary to achieve scarless wound healing of the skin.Herein,we have prepared an angiogenesis-promoting and scar-preventing band-aid with a core-shell structure,that consists of MXene-loaded nanofibers(MNFs)as the core and dopamine-hyaluronic acid hydrogel(H)as the shell(MNFs@V-H@DA)to encapsulate a growth factor(vascular endothelial growth factor,VEGF,abbreviated as V)and H2S donor(diallyl trisulfide,DATS,abbreviated as DA).The continuous release of DA from this system produced H2S,which would successfully induce macrophages to polarize into M2-lile phenotype,regulating the immune microenvironment and inhibiting an excessive inflammatory response at the wound sites.It is conducive to the proliferation of skin cells,facilitating the wound healing.In addition,an appropriate amount of VEGF can be released from the MXene nanofibrous skeleton by adjusting the time of near-infrared(NIR)light exposure,preventing excessive neovascularization and extracellular matrix deposition at the wound sites.Collectively,this NIR photothermal-responsive band-aid achieved scarless wound healing through gradient-controlled vascularization and a related immune sequential reaction of damaged skin tissue.