Diphylleia Grayi-Inspired Intelligent Temperature-Responsive Transparent Nanofiber Membranes

Nanofiber membranes(NFMs) have become attractive candidates for next-generation flexible transparent materials due to their exceptional flexibility and breathability. However, improving the transmittance of NFMs is a great challenge due to the enormous reflection and incredibly poor transmission generated by the nanofiber-air interface. In this research, we report a general strategy for the preparation of flexible temperature-responsive transparent(TRT) membranes,which achieves a rapid transformation of NFMs from opaque to highly transparent under a narrow temperature window. In this process, the phase change material eicosane is coated on the surface of the polyurethane nanofibers by electrospray technology. When the temperature rises to 37 ℃, eicosane rapidly completes the phase transition and establishes the light transmission path between the nanofibers, preventing light loss from reflection at the nanofiber-air interface. The resulting TRT membrane exhibits high transmittance(> 90%), and fast response(5 s). This study achieves the first TRT transition of NFMs, offering a general strategy for building highly transparent nanofiber materials, shaping the future of next-generation intelligent temperature monitoring, anti-counterfeiting measures, and other high-performance devices.

Large-Scale Preparation of Mechanically High-Performance and Biodegradable PLA/PHBV Melt-Blown Nonwovens with Nanofibers

Biodegradable polylactic acid(PLA)melt-blown nonwovens are attractive candidates to replace nondegradable polypropylene melt-blown nonwovens.However,it is still an extremely challenging task to prepare PLA melt-blown nonwovens with sufficient mechanical properties for practical application.Herein,we report a simple strategy for the large-scale preparation of biodegradable PLA/poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV)melt-blown nonwovens with high strength and excellent toughness.In this process,a small amount of PHBV is added to PLA to improve the latter’s crystallization rate and crystallinity.In addition,when the PHBV content increases from 0 to 7.5 wt%,the diameters of the PLA/PHBV melt-blown fibers decrease significantly(with the proportion of nanofibers increasing from 7.7%to 42.9%).The resultant PLA/PHBV(5 wt%PHBV)melt-blown nonwovens exhibit the highest mechanical properties.The tensile stress,elongation,and toughness of PLA/PHBV(5 wt%PHBV)melt-blown nonwovens reach 2.5 MPa,45%,and 1.0 MJm3,respectively.More importantly,PLA/PHBV melt-blown nonwovens can be completely degraded into carbon dioxide and water after four months in the soil,making them environmentally friendly.A general tensile-failure model of melt-blown nonwovens is proposed in this study,which may shed light on mechanical performance enhancement for nonwovens.

YBX1 inhibits mitochondrial-mediated apoptosis in ischemic heart through the PI3K/AKT signaling pathway

Background:Myocardial infarction(MI)is associated with higher morbidity and mortality in the world,especially in cold weather.YBX1 is an RNA-binding protein that is required for pathological growth of cardiomyocyte by regulating cell growth and protein synthesis.But YBX1,as an individual RNA-binding protein,regulates cardiomyocytes through signaling cascades during myocardial infarction remain largely unexplored.Methods:In vivo,the mouse MI model was induced by ligating the left anterior descending coronary artery(LAD),and randomly divided into sham operation group,MI group,MI+YBX1 knockdown/overexpression group and MI+negative control(NC)group.The protective effect of YBX1 was verified by echocardiography and triphenyltetrazolium chloride staining.In vitro,mitochondrial-dependent apoptosis was investigated by using CCK8,TUNEL staining,reactive oxygen species(ROS)staining and JC-1 staining in hypoxic neonatal mouse cardiomyocytes(NMCMs).Results:YBX1 expression of cardiomyocytes was downregulated in a mouse model and a cellular model on the ischemic condition.Compared to mice induced by MI,YBX1 overexpression mediated by adeno-associated virus serotype 9(AAV9)vector reduced the infarcted size and improved cardiac function.Knockdown of endogenous YBX1 by shRNA partially aggravated ischemia-induced cardiac dysfunction.In hypoxic cardiomyocytes,YBX1 overexpression decreased lactic dehydrogenase(LDH)release,increased cell viability,and inhibited apoptosis by affecting the expression of apoptosis related proteins,while knockdown of endogenous YBX1 by siRNA had the opposite effect.Overexpression of YBX1 restored mitochondrial dysfunction in hypoxic NMCMs by increasing mitochondrial membrane potential and ATP content and decreasing ROS.In hypoxic NMCMs,YBX1 overexpression increased the expression of phosphorylated phosphatidylinositol 3 kinase(PI3K)/AKT,and the anti-apoptosis effect of YBX1 was eliminated t by LY294002,PI3K/AKT inhibitor.Conclusion:YBX1 protected the heart from ischemic damage by inhibiting the mitochondrial-dependent apoptosis through PI3K/AKT pathway.It is anticipated that YBX1 may serve as a novel therapeutic target for MI.

Generation of double pulses at the Shanghai soft X-ray free electron laser facility

In this article, we present the promise of a new method generating double electron pulses in picosecondscale pulse length and tunable interpulse spacing at several picoseconds. This has witnessed an impressive potential of application in pump–probe techniques, two-color X-ray free electron laser, high-gradient witness bunch acceleration in a plasma, etc. Three-dimensional simulations are carried out to analyze the dynamic of the electron beam in a linear accelerator. Comparisons are made between the new method and existing ways.

Ballistic penetration damages of hybrid plain-woven laminates with carbon,Kevlar and UHMWPE fibers in different stacking sequences

Hybrid composite materials combine different fibers in preform and take advantages of different mechanical behaviors for improving ballistic impact damage tolerances.Here we report ballistic impact damages of plain-woven laminates with different hybrids and stacking sequences.Three kinds of hybrid laminates,i.e.,carbon/Kevlar,carbon/ultra-high molecular weight polyethylene(UHMWPE),and UHMWPE/Kevlar,had been prepared and tested in ballistic penetration with fragment simulating projectiles(FSP).The residual velocities of the projectiles and impact damage morphologies of the laminates have been obtained to show impact energy absorptions for the different hybrid schemes.A microstructural model of the hybrid laminates had also been established to show impact damage mechanisms with finite element analysis(FEA).We found that the UHMWPE/Kevlar hybrid laminates with Kevlar layers as the front face have the highest energy absorption capacity,followed by the carbon/Kevlar hybrid laminates with carbon layers as the front face.The main damage modes are fiber breakages,matrix crack and interlayer delamination.The ballistic damage evolutions from the FEA results show that the major damage is shear failure for front layers,while tension failure for the back layers.We expect that the ballistic impact performance could be improved from the different hybrid schemes.

Laser-Induced Graphene Conductive Fabric Decorated with Copper Nanoparticles for Electromagnetic Interference Shielding Application

To meet the demands for flexible electromagnetic interference(EMI)shielding materials,a type of conductive fabric is prepared by generating three-dimensional(3D)porous laser-induced graphene(LIG)in situ on the surface of the aramid fabric(AF)and then electroless plating copper.After LIG treatment,the porous AF demonstrates admirable conductivity due to the generation of graphene.The superior surface resistance of the conductive fabric can reach 1.57Ω/sq after copper deposition,and the average EMI shielding effectiveness(SE)can reach 34.3 dB in a frequency range of 8.2 to 12.4 GHz,with the EMW absorption accounting for about 80%.The proposed technology provides a new idea for preparation of flexible EMI shielding materials.

Effect of Weft Binding Structure on Compression Properties of Three-Dimensional Woven Spacer Fabrics and Composites

With the wide use of three-dimensional woven spacer composites(3DWSCs),the market expects greater mechanical properties from this material.By changing the weft fastening method of the traditional I-shape pile yarns,we designed three-dimensional woven spacer fabrics(3DWSFs)and 3DWSCs with the weft V-shape to improve the compression performance of traditional 3DWSFs.The effects of weft binding structures,V-pile densities,and V-shaped angle were investigated in this paper.It is found that the compression resistance of 3DWSFs with the weft V-shape is improved compared to that with the weft I-shape,the fabric height recovery rate is as high as 95.7%,and the average elastic recovery rate is 59.39%.When the interlayer pile yarn density is the same,the weft V-shaped and weft I-shaped 3DWSCs have similar flatwise pressure and edgewise pressure performance.The compression properties of the composite improve as the density of the V-pile yarns increases.The flatwise compression load decreases as the V-shaped angle decreases.When the V-shaped angle is 28°and 42°,the latitudinal V-shaped 3DWSCs perform exceptionally well in terms of anti-compression cushioning.The V-shaped weft binding method offers a novel approach to structural design of 3DWSCs.

Power-law Distribution and Scale-invariant Structure from the First CHIME/FRB Fast Radio Burst Catalog

We study the statistical property of fast radio bursts(FRBs) based on a selected sample of 190 one-off FRBs in the first CHIME/FRB catalog.Three power law models are used in the analysis,and we find the cumulative distribution functions of energy can be well fitted by bent power law and thresholded power law models.The distribution functions of fluctuations of energy well follow the Tsallis q-Gaussian distribution.The q values in the Tsallis q-Gaussian distribution are constant with small fluctuations for different temporal scale intervals,indicating a scale-invariant structure of the bursts.The earthquakes and soft gamma repeaters show similar properties,which are consistent with the predictions of self-organized criticality systems.

Modeling and Analysis of Production Logistics Spatio-Temporal Graph Network Driven by Digital Twin

In the process of logistics distribution of manufacturing enterprises, the automatic scheduling method based on the algorithm model has the advantages of accurate calculation and stable operation, but it excessively relies on the results of data calculation, ignores historical information and empirical data in the solving process, and has the bottleneck of low processing dimension and small processing scale. Therefore, in the digital twin(DT) system based on virtual and real fusion, a modeling and analysis method of production logistics spatio-temporal graph network model is proposed, considering the characteristics of road network topology and time-varying data. In the DT system, the temporal graph network model of the production logistics task is established and combined with the network topology, and the historical scheduling information about logistics elements is stored in the nodes. When the dynamic task arrives, a multi-stage links probability prediction method is adopted to predict the possibility of loading, driving, and other link relationships between task-related entity nodes at each stage. Several experiments are carried out, and the prediction accuracy of the digital twin-based temporal graph network(DTGN) model trained by historical scheduling information reaches 99.2% when the appropriate batch size is selected. Through logistics simulation experiments, the feasibility and the effectiveness of production logistics spatio-temporal graph network analysis methods based on historical scheduling information are verified.

A wide-linear-range and low-hysteresis resistive strain sensor made of double-threaded conductive yarn for human movement detection

Yarn-based flexible strain sensors with advantages in wearability and integrability have attracted wide at-tention.However,it is still a big challenge to achieve yarn-based strain sensors with a wide linear strain range,low hysteresis,and durability synchronously that can be used for full range detection of human body motions.Herein,a new structure,double-threaded conductive yarn with rhythmic strain distribu-tion,is reported to markedly widen the linear strain range of microcrack-based stretchable strain sensors.A new method of winding and thermally adhering hot-melt filaments on the surface of the elastic fiber is used to achieve double-threaded yarn(DTY)with rhythmic strain distribution.The proposed strategy,the integration of heterogeneous materials,is reported to significantly reduce the mechanical hysteresis of composite yarns.Rhythmic strain distribution of the DTY during stretching causes multi-level micro-cracks in different regions of the carbon nanotube(CNT)conductive layer deposited on the surface of the DTY.Besides,the sensing performance of DTY-based strain sensor can be adjusted by designing the structural parameters.The final prepared flexible strain sensor has the advantages of a wide linear strain range(100%),great sensitivity(GF=12.43),low hysteresis,rapid response(158 ms),high repeatability(>2000 cycles at 50%strain),and hydrophobicity,etc.The sensor can monitor human motion repeatedly and stably well,and shows great advantages in flexible wearable devices.

Smart Fibers for Self‑Powered Electronic Skins

Smart fibers are considered as promising materials for the fabrication of wearable electronic skins owing to their features such as superior flexibility,light weight,high specific area,and ease of modification.Besides,piezoelectric or triboelectric electronic skins can respond to mechanical stimulation and directly convert the mechanical energy into electrical power for self-use,thereby providing an attractive method for tactile sensing and motion perception.The incorporation of sensing capabilities into smart fibers could be a powerful approach to the development of self-powered electronic skins.Herein,we review several aspects of the recent advancements in the development of self-powered electronic skins constructed with smart fibers.The summarized aspects include functional material selection,structural design,pressure sensing mechanism,and proof-to-concept demonstration to practical application.In particular,various fabrication strategies and a wide range of practical applications have been systematically introduced.Finally,a critical assessment of the challenges and promising perspectives for the development of fiber-based electronic skins has been presented.

Degradable nanocatalyst enables antitumor/antibacterial therapy and promotion of wound healing for diabetes via self-enhanced cascading reaction

Diabetic patients often have problems such as residual tumor and wound infection after tumor resection,causing severe clinical problems.It is urgent to develop effective therapies to reach oncotherapy/antiinfection/promotion of wound healing combined treatment.Herein,we propose CS/MnO_(2)-GO_x (CMGO_x)nanocatalysts for the specific catalytic generation of ~·OH to inhibit tumors and bacteria in a hyperglycemic environment.The good biocompatible chitosan (CS),as a carrier for the catalyst,exhibits excellent antibacterial effect as well as promotes wound healing.Glucose oxidase (GO_x) is loaded on the surface of CS nanoparticles to generate H_(2)O_(2) and gluconic acid by consuming glucose (starvation therapy,ST) and O_(2).The MnO_(2) depletes glutathione (GSH) to produce Mn^(2+),amplifying oxidative stress and further promoting the activity of Mn^(2+)-mediated Fenton-like reaction to produce~·OH (chemodynamic therapy,CDT)in weak acidic environment.Moreover,the produced gluconic acid lowers the p H of the environment,enhancing chemodynamic therapy (ECDT).The tumor cells and bacteria are efficiently eliminated by the synergistic effect of ST and ECDT.The MnO_(2) nanoparticles at neutral environment decomposes H_(2)O_(2) into O_(2),which cooperate with CS to promote healing.The self-enhanced cascade reaction of CMGO_x in situ exhibits excellent effects of antitumor/antibacterial therapy and promotion of wound healing,offering a promising integrated treatment for diabetic patients after tumor surgical resection.

A review collection on immunometabolism

Recent studies indicate an intimate link between immunity and metabolism,spawning the now burgeoning field of immunometabolism.What is the rationale for such a link?On the one hand,immune responses are energetically very demanding.Clonal expansion of T and B cells,increased production of inflammatory cytokines and antibodies by activated macrophages and plasma cells,and recruitment of immune cells to the site of infection are all thought to impose a high metabolic and energetic demand.This may explain why cellular metabolism regulates the activation/differentiation and proliferation of T and B cells.

Double-network hydrogel enhanced by SS31-loaded mesoporous polydopamine nanoparticles:Symphonic collaboration of near-infrared photothermal antibacterial effect and mitochondrial maintenance for full-thickness wound healing in diabetes mellitus

Diabetic wound healing has become a serious healthcare challenge.The high-glucose environment leads to persistent bacterial infection and mitochondrial dysfunction,resulting in chronic inflammation,abnormal vascular function,and tissue necrosis.To solve these issues,we developed a double-network hydrogel,constructed with pluronic F127 diacrylate(F127DA)and hyaluronic acid methacrylate(HAMA),and enhanced by SS31-loaded mesoporous polydopamine nanoparticles(MPDA NPs).As components,SS31,a mitochondria-targeted peptide,maintains mitochondrial function,reduces mitochondrial reactive oxygen species(ROS)and thus regulates macrophage polarization,as well as promoting cell proliferation and migration,while MPDA NPs not only scavenge ROS and exert an anti-bacterial effect by photothermal treatment under near-infrared light irradiation,but also control release of SS31 in response to ROS.This F127DA/HAMA-MPDA@SS31(FH-M@S)hydrogel has characteristics of adhesion,superior biocompatibility and mechanical properties which can adapt to irregular wounds at different body sites and provide sustained release of MPDA@SS31(M@S)NPs.In addition,in a diabetic rat full thickness skin defect model,the FH-M@S hydrogel promoted macrophage M2 polarization,collagen deposition,neovascularization and wound healing.Therefore,the FH-M@S hydrogel exhibits promising therapeutic potential for skin regeneration.

Structural understanding of T cell receptor triggering

The T cell receptor(TCR)is one of the most complicated receptors in mammalian cells,and its triggering mechanism remains mysterious.As an octamer complex,TCR comprises an antigen-binding subunit(TCRαβ)and three CD3 signaling subunits(CD3ζζ,CD3δε,and CD3γε).Engagement of TCRαβwith an antigen peptide presented on the MHC leads to tyrosine phosphorylation of the immunoreceptor tyrosine-based activation motif(ITAM)in CD3 cytoplasmic domains(CDs),thus translating extracellular binding kinetics to intracellular signaling events.Whether conformational change plays an important role in the transmembrane signal transduction of TCR is under debate.Attracted by the complexity and functional importance of TCR,many groups have been studying TCR structure and triggering for decades using diverse biochemical and biophysical tools.Here,we synthesize these structural studies and discuss the relevance of the conformational change model in TCR triggering.

Structural studies on MRG701 chromodomain reveal a novel dimerization interface of MRG proteins in green plants

MRG proteins are conserved during evolution in fungi, flies, mammals and plants, and they can exhibit diversified functions. The animal MRGs were found to form various complexes to activate gene expression. Plant MRGI/2 and MRG702 were reported to be involved in the regulation of flowering time via binding to H3K36me3- marked flowering genes. Herein, we determined the crystal structure of MRG701 chromodomain （MRG701CD）. MRG701co forms a novel dimerization fold both in crystal and in solution. Moreover, we found that the dimerization of MRG chromodomains is conserved in green plants. Our findings may provide new insights into the mechanism of MRGs in regulation of gene expression in green plants.

Lipid metabolism in tumor-infiltrating T cells: mechanisms and applications

As an essential part of adaptive immunity,T cells coordinate the immune responses against pathogens and cancer cells.Lipid metabolism has emerged as a key regulator for the activation,differentiation,and effector functions of T cells.Therefore,uncovering the molecular mechanisms by which lipid metabolism dictates T cell biology is of vital importance.The tumor microenvironment is a hostile milieu,i.e.often characterized by nutrient restriction.In this environment,various cells,such as T cells and cancer cells,reprogram their metabolism,including their lipid metabolism,to meet their energy and functional needs.Here,we review the participation of fatty acid and cholesterol metabolism homeostasis in orchestrating T cell biology.We demonstrate how the tumor microenvironment reshapes the lipid metabolism in T cells.Importantly,we highlight the current cancer therapeutic interventions that target fatty acid and cholesterol metabolism of T cells.By offering a holistic understanding of how lipid metabolic adaption by T cells facilitates their immunosurveillance in the tumor microenvironment,we believe this review and the future studies might inspire the next-generation immunotherapies.

Synthesis of nitrogen-tethered 1,6-enynes through CuI/TFA catalysis

A novel method for the concise and effective construction of nitrogen-tethered 1,6-enynes in moderate to good yields was developed.This transformation involves a TFA-promoted Pictet-Spengler reaction/iminium formation,copper-catalyzed alkyne-iminium ene reaction/alkynylation of a 2-arylethan-1-amine,formaldehyde solution,and a terminal alkyne.The process features exclusive chemoselectivity,simple operation,and high atom economy.Preliminary experimental studies suggest that the alkyne-iminium ene reaction involving an intermolecular hydride transfer is the key step in the current methodology.

Structural basis for DAXX interaction with ATRX

Alpha-thalassemia/mental retardation syndrome X-linked protein （ATRX） is a member of the switch 2/sucrose non- fermentable 2 （SWl2/SNF2） family of chromatin-remodelidg proteins （Clynes et al., 2013; Dyer et al., 2017）.