As shallow resources are increasingly depleted,the mechanics'theory and testing technology of deep insitu rock has become urgent.Traditional coring technologies obtain rock samples without retaining the in-situ en...As shallow resources are increasingly depleted,the mechanics'theory and testing technology of deep insitu rock has become urgent.Traditional coring technologies obtain rock samples without retaining the in-situ environmental conditions,leading to distortion of the measured parameters.Herein,a coring and testing systems retaining in-situ geological conditions is presented:the coring system that obtains in-situ rock samples,and the transfer and testing system that stores and analyzes the rocks under a reconstructed environment.The ICP-Coring system mainly consists of the pressure controller,active insulated core reactor and insulation layer and sealing film.The ultimate bearing strength of 100 MPa for pressurepreservation,temperature control accuracy of 0.97%for temperature-retained are realized.CH_(4)and CO permeability of the optimized sealing film are as low as 3.85 and 0.33 ppm/min.The average tensile elongation of the film is 152.4%and the light transmittance is reduced to 0%.Additionally,the pressure and steady-state temperature accuracy for reconstructing the in-situ environment of transfer and storage system up to 1%and±0.2 is achieved.The error recorded of the noncontact sensor ring made of lowdensity polymer is less than 6%than that of the contact test.The system can provide technical support for the deep in-situ rock mechanics research,improving deep resource acquisition capabilities and further clarifying deep-earth processes.展开更多
With the depletion of shallow resources,the exploration of deep earth resources has become a global strategy.The study of the different patterns in the physical mechanical properties of rocks at different occurrence d...With the depletion of shallow resources,the exploration of deep earth resources has become a global strategy.The study of the different patterns in the physical mechanical properties of rocks at different occurrence depths is the basis for exploring deep into the earth,with the core and premise being the acquisition and testing of deep in-situ core specimens.Based on the original idea of deep in-situ condition preserved coring(ICP-Coring)and testing,combined with theoretical modeling,numerical analysis,test platform development,indoor testing and engineering application,the principles and technologies of deep ICP-Coring are developed.This principle and technology consists of five parts:in-situ pressurepreserved coring(IPP-Coring),in-situ substance-preserved coring(ISP-Coring),in-situ temperaturepreserved coring(ITP-Coring),in-situ light-preserved coring(ILP-Coring),and in-situ moisturepreserved coring(IMP-Coring).The theory and technology of temperature and pressure reconstruction at different occurrence depths and in different environments are proposed,and prototype trial production was completed by following the principle of displacement and tests based on the in-situ reconstructed environment.The notable advances are as follows:(1)Deep in-situ coring system:A pressure-preserved controller with an ultimate bearing capacity greater than 140 MPa,highperformance(temperature-resistant,pressure-resistant,and low thermally conductive)temperaturepreserved materials,an active temperature control system,and high-barrier quality-preserved membrane materials were developed;a deep ICP-Coring capacity calibration platform was independently developed,a deep in-situ coring technology system was developed,and the acquisition of deep in-situ cores was realized.(2)In-situ storage displacement system:Following the dual-circuit hydraulic design idea,a single-drive source push-pull composite grabbing mechanism was designed;the design of the overall structure for the deep in-situ displacement storage system and ultrahigh pressure cabin structure was completed,which could realize docking the coring device and core displacement in the in-situ reconstructed environment.(3)Test analysis system:A noncontact acoustic-electric-magnetic test system was developed under the in-situ reconstructed environment,and the errors between the test results and traditional contact test results were mostly less than 10%;a detachable deep in-situ core true triaxial test system was developed,which could perform loading tests for deep in-situ cores.The relevant technological achievements were successfully applied to the exploration and development of deep resources,such as deep mines,deep-sea natural gas hydrates,and deep oil and gas.The research results provide technical and equipment support for the construction of a theoretical system for deep in-situ rock mechanics,the development of deep earth resources and energy,and the scientific exploration of different layers and occurrence depths(deep and ultradeep)of the Earth.展开更多
With an increased utilization of carbon fiber reinforced polymers(CFRPs)in high temperature environments,investigating their effects on materials becomes exceedingly important.This study presents a comparative investi...With an increased utilization of carbon fiber reinforced polymers(CFRPs)in high temperature environments,investigating their effects on materials becomes exceedingly important.This study presents a comparative investigation of thermo-oxidative aging effects on the flexural performance of two carbon fiber reinforced composite laminates(CFRCLs):a quasi-isotropic plain-woven CFRCL and a quasi-isotropic unidirectional layup CFRCL(designated as PW-CFRCL and UD-CFRCL,respectively).The CFRCLs were subjected to thermo-oxidative aging for specific durations,and their flexural strength was evaluated through three-point bending tests.The flexural strength of the laminates decreased with the prolonged aging duration.Despite having lower fiber content,PW-CFRCLs showed higher flexural strength than UD-CFRCLs.After eight days of aging,the flexural strength of PW-CFRCLs decreased by merely 4%-5%,while that of UD-CFRCLs decreased by 11%-14%.After 32 days of aging,the thinner PW-CFRCL with the lowest fiber content exhibited the highest flexural strength(595.52 MPa),followed by the thinner UD-CFRCL(549.83 MPa),then the thicker PW-CFRCL(445.29 MPa)and finally,the thicker UD-CFRCL(393.90 MPa).The decline in flexural properties of the laminates was primarily attributed to matrix cracking and interface debonding resulting from matrix oxidation.To validate the universality of this result,the finite element method was employed,showing a good correlation with the experimental findings.展开更多
Background:Effective inhibition of pathological cardiac hypertrophy is critical for managing various cardiovascular diseases,especially in cold environments.The communication between cardiomyocytes and fibroblasts,med...Background:Effective inhibition of pathological cardiac hypertrophy is critical for managing various cardiovascular diseases,especially in cold environments.The communication between cardiomyocytes and fibroblasts,mediated by secreted proteins,plays a significant role in the development and progression of pathological cardiac hypertrophy.Serpin Family E Member 2(serpinE2),secreted by fibroblasts into the extracellular space,has been implicated in this process.However,whether serpinE2 can be internalized by cardiomyocytes and whether cold exposure influences this process remains unclear.Materials and methods:Mice were subjected to cold exposure(4°C,12 h/day for 8 weeks),and cardiac hypertrophy was induced by transverse aortic constriction(TAC).SerpinE2 expression was silenced by short interfering RNA(siRNA).Cardiac fibroblasts were stimulated with angiotensin II(Ang II)to induce serpinE2 secretion.Exogenous recombinant serpinE2,labeled with DyLight 488 or His-tag,was used to evaluate its internalization and functional role in cardiomyocytes.Internalization was inhibited by using antibodies against serpinE2,heparin,or endocytosis inhibitors(β-cyclodextrin,nystatin,dynasore,and chlorpromazine).Chromatin immunoprecipitation followed by quantitative polymerase chain reaction(PCR)was used to assess the binding of the transcription factor CDX1 to the serpinE2 promoter.Results:Cold exposure significantly increased serpinE2 mRNA and protein expression in mouse hearts.SerpinE2 levels were also upregulated in plasma and cardiac tissue following TAC.Knockdown of serpinE2 attenuated TAC-induced hypertrophy,restored left ventricular function,and reduced atrial natriuretic peptide,brain natriuretic peptide,andβ-myosin heavy chain fragment levels.Exogenous serpinE2 promoted cardiomyocyte hypertrophy,an effect that was reversed by serpinE2 knockdown.Co-culture with conditioned medium from Ang II-stimulated fibroblasts increased serpinE2 expression in cardiomyocytes.Exogenous serpinE2 was internalized via endocytosis,which was inhibited by antibodies,heparin,and endocytosis blockers.Internalized serpinE2 activated the protein kinase B(AKT)/β-catenin pathway in cardiomyocytes.CDX1 bound to the serpinE2 promoter and promoted its transcription in fibroblasts.CDX1 overexpression increased serpinE2 and collagen expression,while its suppression had the opposite effect.Administration of exogenous fibroblast growth factor 4(FGF4)or overexpression of FGF4 plasmid upregulated CDX1,serpinE2,and collagen expression in fibroblasts.Conclusions:SerpinE2 expression is responsive to cold stress and mediates intercellular communication between fibroblasts and cardiomyocytes.Fibroblast-secreted serpinE2 is internalized by cardiomyocytes via endocytosis,promoting hypertrophy through activation of the phosphatidylinositol 3-kinase(PI3K)-AKT/β-catenin pathway.The FGF4-CDX1 axis regulates serpinE2 expression and secretion in cardiac fibroblasts.展开更多
Metal ions play crucial roles in various biologi-cal functions,in-cluding maintain-ing homeostasis,regulating mus-cle contraction,and facilitating enzyme catalysis.However,accurately simulating the interaction between...Metal ions play crucial roles in various biologi-cal functions,in-cluding maintain-ing homeostasis,regulating mus-cle contraction,and facilitating enzyme catalysis.However,accurately simulating the interaction between metal ions and amino acid side chain analogs using high-level wave function theories remains challenging due to the significant computational costs involved.In this study,deep potential molecular dynamics(DeePMD)simulation was employed to investigate the solvation structure of the Mg^(2+)-Ac^(−)ion pair in aqueous solution.To address the computational bottleneck associated with expensive quan-tum mechanics(QM)methods,the Deep Kohn-Sham(DeePKS)approach was utilized,which allows us to generate highly accurate self-consistent energy functionals while significantly re-ducing computational costs.The root mean square error and mean absolute error of energies and atomic forces indicate close agreement between DeePKS predictions and QM strongly constrained and appropriately normed(SCAN)calculations.Moreover,the neural network potential(NNP)generated using the SCAN-level dataset predicted by DeePKS exhibits high-er accuracy compared to previous work,which employed a moderate BLYP functional.The potential of mean force for the Mg^(2+)-Ac−system was further examined,revealing a prefer-ence for monodentate coordination of Mg^(2+)with a~5.8 kcal/mol energy barrier between bidentate and monodentate geometries.Overall,this work provides a comprehensive,precise,and reliable methodology for investigating metal ions’properties in aqueous solutions.展开更多
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 ...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.展开更多
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-wo...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.展开更多
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...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.展开更多
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/pr...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.展开更多
The ability of human deciduous tooth dental pulp cells（HDDPCs） to differentiate into odontoblasts that generate mineralized tissue holds immense potential for therapeutic use in the field of tooth regenerative medic...The ability of human deciduous tooth dental pulp cells（HDDPCs） to differentiate into odontoblasts that generate mineralized tissue holds immense potential for therapeutic use in the field of tooth regenerative medicine. Realization of this potential depends on efficient and optimized protocols for the genetic manipulation of HDDPCs. In this study, we demonstrate the use of a Piggy Bac（PB）-based gene transfer system as a method for introducing nonviral transposon DNA into HDDPCs and HDDPC-derived inducible pluripotent stem cells. The transfection efficiency of the PB-based system was significantly greater than previously reported for electroporation-based transfection of plasmid DNA. Using the neomycin resistance gene as a selection marker, HDDPCs were stably transfected at a rate nearly 40-fold higher than that achieved using conventional methods. Using this system, it was also possible to introduce two constructs simultaneously into a single cell. The resulting stable transfectants, expressing td Tomato and enhanced green fluorescent protein, exhibited both red and green fluorescence. The established cell line did not lose the acquired phenotype over three months of culture. Based on our results, we concluded that PB is superior to currently available methods for introducing plasmid DNA into HDDPCs. There may be significant challenges in the direct clinical application of this method for human dental tissue engineering due to safety risks and ethical concerns. However, the high level of transfection achieved with PB may have significant advantages in basic scientific research for dental tissue engineering applications, such as functional studies of genes and proteins. Furthermore, it is a useful tool for the isolation of genetically engineered HDDPC-derived stem cells for studies in tooth regenerative medicine.展开更多
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 ...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.展开更多
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 ran...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.展开更多
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 r...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.展开更多
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...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.展开更多
Dear Editor,The mammalian cerebral cortex,responsible for all higherorder brain functions,is organized into six layers of neurons that form distinct projections and connections within and outside the cortex.During cor...Dear Editor,The mammalian cerebral cortex,responsible for all higherorder brain functions,is organized into six layers of neurons that form distinct projections and connections within and outside the cortex.During cortical development,neural progenitor cells(NPCs)in the proliferative ventricular zone(VZ)and subventricular zone(SVZ)of the dorsal telencephalon produce projection neurons that migrate toward the pial surface to form the cortical plate(CP).展开更多
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...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.展开更多
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 dis...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.展开更多
Minipreparation (MiniPrep) analysis is an essential step for obtaining a recombinant plasmid that carries a DNA insert containing a gene of interest. The most commonly used method for this involves cultivation of tran...Minipreparation (MiniPrep) analysis is an essential step for obtaining a recombinant plasmid that carries a DNA insert containing a gene of interest. The most commonly used method for this involves cultivation of transformed Escherichia coli (E. coli) in liquid medium, brief centrifugation for precipitation of bacterial pellets, and subsequent lysis of the pellets. This process is time-consuming and laborious, especially when the sample number is high. Here, we describe a more convenient method for MiniPrep analysis that utilizes solid medium-based cultivation of bacteria.展开更多
AIM: To evaluate our experience and surgical technique of laparoscopic appendectomy via reduced port surgery(LARPS). METHODS: Sixteen patients(8 men and 8 women; median age: 31.0 years) who underwent LARPS between Nov...AIM: To evaluate our experience and surgical technique of laparoscopic appendectomy via reduced port surgery(LARPS). METHODS: Sixteen patients(8 men and 8 women; median age: 31.0 years) who underwent LARPS between November 2009 and May 2012 were included in the present study. We performed LARPS, in which access devices were inserted through an umbilical skin incision with 1 additional skin incision in the left lower abdomen. After setting access devices, pneumoperitoneum was maintained at 10 mmH g using CO2 and a 3 mm trocar was positioned(or direct puncture was performed by the Endo Relief system) under laparoscopic guidance. The mesoappendix was dissected using an ultrasonically activated device. After mesoappendix dissection, ligation was performed near the appendix base and the appendix was dissected using an ultrasonically activated device. The appendix was then removed. At the end of surgery, we administered local anesthesia with ropivacaine 1%(10 mL) for the skin incisions. The outcomes were evaluated in terms of operation time, intraoperative blood loss, length of postoperative hospital stay and surgical complications. RESULTS: Our surgical procedure allowed operators to use instruments as in conventional laparoscopic appendectomy. The basic principle of triangulation of instrumentation was maintained to some degree. LARPS was performed in 9 patients with catarrhal appendicitis, 5 with phlegmonous appendicitis, and 2 with gangrenous appendicitis. The median surgery time was 60 min and the median intraoperative blood loss was 1.2 mL. The median length of postoperative hospitalization was 4 d. There were no conversions to open surgery, no operation-related complications or mortality. CONCLUSION: Our experience and surgical technique suggest that LARPS is a safe and feasible procedure for patients with appendicitis.展开更多
基金supported by the Program for Guangdong Introducing Innovative and Enterpreneurial Teams(No.2019ZT08G315)National Natural Science Foundation of China(No.51827901,U2013603,and 52004166)。
文摘As shallow resources are increasingly depleted,the mechanics'theory and testing technology of deep insitu rock has become urgent.Traditional coring technologies obtain rock samples without retaining the in-situ environmental conditions,leading to distortion of the measured parameters.Herein,a coring and testing systems retaining in-situ geological conditions is presented:the coring system that obtains in-situ rock samples,and the transfer and testing system that stores and analyzes the rocks under a reconstructed environment.The ICP-Coring system mainly consists of the pressure controller,active insulated core reactor and insulation layer and sealing film.The ultimate bearing strength of 100 MPa for pressurepreservation,temperature control accuracy of 0.97%for temperature-retained are realized.CH_(4)and CO permeability of the optimized sealing film are as low as 3.85 and 0.33 ppm/min.The average tensile elongation of the film is 152.4%and the light transmittance is reduced to 0%.Additionally,the pressure and steady-state temperature accuracy for reconstructing the in-situ environment of transfer and storage system up to 1%and±0.2 is achieved.The error recorded of the noncontact sensor ring made of lowdensity polymer is less than 6%than that of the contact test.The system can provide technical support for the deep in-situ rock mechanics research,improving deep resource acquisition capabilities and further clarifying deep-earth processes.
基金the National Natural Science Foundation of China(No.51827901)the Program for Guangdong Introducing Innovative and Enterpreneurial Teams(No.2019ZT08G315)Shenzhen Key Research Projects(No.JSGG20220831105002005).
文摘With the depletion of shallow resources,the exploration of deep earth resources has become a global strategy.The study of the different patterns in the physical mechanical properties of rocks at different occurrence depths is the basis for exploring deep into the earth,with the core and premise being the acquisition and testing of deep in-situ core specimens.Based on the original idea of deep in-situ condition preserved coring(ICP-Coring)and testing,combined with theoretical modeling,numerical analysis,test platform development,indoor testing and engineering application,the principles and technologies of deep ICP-Coring are developed.This principle and technology consists of five parts:in-situ pressurepreserved coring(IPP-Coring),in-situ substance-preserved coring(ISP-Coring),in-situ temperaturepreserved coring(ITP-Coring),in-situ light-preserved coring(ILP-Coring),and in-situ moisturepreserved coring(IMP-Coring).The theory and technology of temperature and pressure reconstruction at different occurrence depths and in different environments are proposed,and prototype trial production was completed by following the principle of displacement and tests based on the in-situ reconstructed environment.The notable advances are as follows:(1)Deep in-situ coring system:A pressure-preserved controller with an ultimate bearing capacity greater than 140 MPa,highperformance(temperature-resistant,pressure-resistant,and low thermally conductive)temperaturepreserved materials,an active temperature control system,and high-barrier quality-preserved membrane materials were developed;a deep ICP-Coring capacity calibration platform was independently developed,a deep in-situ coring technology system was developed,and the acquisition of deep in-situ cores was realized.(2)In-situ storage displacement system:Following the dual-circuit hydraulic design idea,a single-drive source push-pull composite grabbing mechanism was designed;the design of the overall structure for the deep in-situ displacement storage system and ultrahigh pressure cabin structure was completed,which could realize docking the coring device and core displacement in the in-situ reconstructed environment.(3)Test analysis system:A noncontact acoustic-electric-magnetic test system was developed under the in-situ reconstructed environment,and the errors between the test results and traditional contact test results were mostly less than 10%;a detachable deep in-situ core true triaxial test system was developed,which could perform loading tests for deep in-situ cores.The relevant technological achievements were successfully applied to the exploration and development of deep resources,such as deep mines,deep-sea natural gas hydrates,and deep oil and gas.The research results provide technical and equipment support for the construction of a theoretical system for deep in-situ rock mechanics,the development of deep earth resources and energy,and the scientific exploration of different layers and occurrence depths(deep and ultradeep)of the Earth.
基金National Natural Science Foundation of China(No.12372130)。
文摘With an increased utilization of carbon fiber reinforced polymers(CFRPs)in high temperature environments,investigating their effects on materials becomes exceedingly important.This study presents a comparative investigation of thermo-oxidative aging effects on the flexural performance of two carbon fiber reinforced composite laminates(CFRCLs):a quasi-isotropic plain-woven CFRCL and a quasi-isotropic unidirectional layup CFRCL(designated as PW-CFRCL and UD-CFRCL,respectively).The CFRCLs were subjected to thermo-oxidative aging for specific durations,and their flexural strength was evaluated through three-point bending tests.The flexural strength of the laminates decreased with the prolonged aging duration.Despite having lower fiber content,PW-CFRCLs showed higher flexural strength than UD-CFRCLs.After eight days of aging,the flexural strength of PW-CFRCLs decreased by merely 4%-5%,while that of UD-CFRCLs decreased by 11%-14%.After 32 days of aging,the thinner PW-CFRCL with the lowest fiber content exhibited the highest flexural strength(595.52 MPa),followed by the thinner UD-CFRCL(549.83 MPa),then the thicker PW-CFRCL(445.29 MPa)and finally,the thicker UD-CFRCL(393.90 MPa).The decline in flexural properties of the laminates was primarily attributed to matrix cracking and interface debonding resulting from matrix oxidation.To validate the universality of this result,the finite element method was employed,showing a good correlation with the experimental findings.
基金supported by the National Natural Science Foundation of China(82370279,82170299,82330011,82003757).
文摘Background:Effective inhibition of pathological cardiac hypertrophy is critical for managing various cardiovascular diseases,especially in cold environments.The communication between cardiomyocytes and fibroblasts,mediated by secreted proteins,plays a significant role in the development and progression of pathological cardiac hypertrophy.Serpin Family E Member 2(serpinE2),secreted by fibroblasts into the extracellular space,has been implicated in this process.However,whether serpinE2 can be internalized by cardiomyocytes and whether cold exposure influences this process remains unclear.Materials and methods:Mice were subjected to cold exposure(4°C,12 h/day for 8 weeks),and cardiac hypertrophy was induced by transverse aortic constriction(TAC).SerpinE2 expression was silenced by short interfering RNA(siRNA).Cardiac fibroblasts were stimulated with angiotensin II(Ang II)to induce serpinE2 secretion.Exogenous recombinant serpinE2,labeled with DyLight 488 or His-tag,was used to evaluate its internalization and functional role in cardiomyocytes.Internalization was inhibited by using antibodies against serpinE2,heparin,or endocytosis inhibitors(β-cyclodextrin,nystatin,dynasore,and chlorpromazine).Chromatin immunoprecipitation followed by quantitative polymerase chain reaction(PCR)was used to assess the binding of the transcription factor CDX1 to the serpinE2 promoter.Results:Cold exposure significantly increased serpinE2 mRNA and protein expression in mouse hearts.SerpinE2 levels were also upregulated in plasma and cardiac tissue following TAC.Knockdown of serpinE2 attenuated TAC-induced hypertrophy,restored left ventricular function,and reduced atrial natriuretic peptide,brain natriuretic peptide,andβ-myosin heavy chain fragment levels.Exogenous serpinE2 promoted cardiomyocyte hypertrophy,an effect that was reversed by serpinE2 knockdown.Co-culture with conditioned medium from Ang II-stimulated fibroblasts increased serpinE2 expression in cardiomyocytes.Exogenous serpinE2 was internalized via endocytosis,which was inhibited by antibodies,heparin,and endocytosis blockers.Internalized serpinE2 activated the protein kinase B(AKT)/β-catenin pathway in cardiomyocytes.CDX1 bound to the serpinE2 promoter and promoted its transcription in fibroblasts.CDX1 overexpression increased serpinE2 and collagen expression,while its suppression had the opposite effect.Administration of exogenous fibroblast growth factor 4(FGF4)or overexpression of FGF4 plasmid upregulated CDX1,serpinE2,and collagen expression in fibroblasts.Conclusions:SerpinE2 expression is responsive to cold stress and mediates intercellular communication between fibroblasts and cardiomyocytes.Fibroblast-secreted serpinE2 is internalized by cardiomyocytes via endocytosis,promoting hypertrophy through activation of the phosphatidylinositol 3-kinase(PI3K)-AKT/β-catenin pathway.The FGF4-CDX1 axis regulates serpinE2 expression and secretion in cardiac fibroblasts.
基金supported by the National Natural Sci-ence Foundation of China(No.22373065,No.62072296,No.22222303,No.22173032,No.21933010)the Nation-al Key R&D Program of China(No.2023YFF1204903)NYU-ECNU Center for Computational Chemistry at NYU Shanghai,the Opening Project of Shanghai Frontiers Science Research Center for Druggability of Cardiovascular noncoding RNA.
文摘Metal ions play crucial roles in various biologi-cal functions,in-cluding maintain-ing homeostasis,regulating mus-cle contraction,and facilitating enzyme catalysis.However,accurately simulating the interaction between metal ions and amino acid side chain analogs using high-level wave function theories remains challenging due to the significant computational costs involved.In this study,deep potential molecular dynamics(DeePMD)simulation was employed to investigate the solvation structure of the Mg^(2+)-Ac^(−)ion pair in aqueous solution.To address the computational bottleneck associated with expensive quan-tum mechanics(QM)methods,the Deep Kohn-Sham(DeePKS)approach was utilized,which allows us to generate highly accurate self-consistent energy functionals while significantly re-ducing computational costs.The root mean square error and mean absolute error of energies and atomic forces indicate close agreement between DeePKS predictions and QM strongly constrained and appropriately normed(SCAN)calculations.Moreover,the neural network potential(NNP)generated using the SCAN-level dataset predicted by DeePKS exhibits high-er accuracy compared to previous work,which employed a moderate BLYP functional.The potential of mean force for the Mg^(2+)-Ac−system was further examined,revealing a prefer-ence for monodentate coordination of Mg^(2+)with a~5.8 kcal/mol energy barrier between bidentate and monodentate geometries.Overall,this work provides a comprehensive,precise,and reliable methodology for investigating metal ions’properties in aqueous solutions.
基金supported by the National Key Research and Development Program of China(2022YFB3804903 and 2022YFB3804900)the National Natural Science Foundation of China(52273052)+1 种基金the Program of Shanghai Academic/Technology Research Leader(21XD1420100)the International Cooperation Fund of Science and Technology Commission of Shanghai Municipality(21130750100).
文摘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.
文摘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.
基金Shanghai Sailing Program,Shanghai,China(No.22YF1400500)Fundamental Research Funds for the Central Universities,China(Nos.2232022D-11 and 22D128102/007)Shanghai Natural Science Foundation of Shanghai Municipal Science and Technology Commission,Shanghai,China(No.20ZR1401600)。
文摘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.
基金supported by the Laboratory Animal Welfare and Ethics Committee of the Clinical Center of Shanghai First People's Hospital (No. 2020AWS0065)financially supported by the National Natural Science Foundation of China (Nos. 21978165, 92156020)+1 种基金Science and Technology Commission of Shanghai (No. 20DZ2255900)Class Ⅲ Peak Discipline of Shanghai—Materials Science and Engineering (High-Energy Beam Intelligent Processing and Green Manufacturing)。
文摘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.
基金supported in part by a Grant-in-Aid for Scientific Research (C) (grant no. 25463192) from the Ministry of Education, Science, Sports, Culture, and Technology of Japan
文摘The ability of human deciduous tooth dental pulp cells（HDDPCs） to differentiate into odontoblasts that generate mineralized tissue holds immense potential for therapeutic use in the field of tooth regenerative medicine. Realization of this potential depends on efficient and optimized protocols for the genetic manipulation of HDDPCs. In this study, we demonstrate the use of a Piggy Bac（PB）-based gene transfer system as a method for introducing nonviral transposon DNA into HDDPCs and HDDPC-derived inducible pluripotent stem cells. The transfection efficiency of the PB-based system was significantly greater than previously reported for electroporation-based transfection of plasmid DNA. Using the neomycin resistance gene as a selection marker, HDDPCs were stably transfected at a rate nearly 40-fold higher than that achieved using conventional methods. Using this system, it was also possible to introduce two constructs simultaneously into a single cell. The resulting stable transfectants, expressing td Tomato and enhanced green fluorescent protein, exhibited both red and green fluorescence. The established cell line did not lose the acquired phenotype over three months of culture. Based on our results, we concluded that PB is superior to currently available methods for introducing plasmid DNA into HDDPCs. There may be significant challenges in the direct clinical application of this method for human dental tissue engineering due to safety risks and ethical concerns. However, the high level of transfection achieved with PB may have significant advantages in basic scientific research for dental tissue engineering applications, such as functional studies of genes and proteins. Furthermore, it is a useful tool for the isolation of genetically engineered HDDPC-derived stem cells for studies in tooth regenerative medicine.
基金financially supported by National Key Research and Development Program of China (2022YFB3804903, 2022YFB3804900)the National Natural Science Foundation of China (No. 52273052)+2 种基金the Fundamental Research Funds for the Central Universities (No. 2232023Y01)the Program of Shanghai Academic/Technology Research Leader (No. 21XD1420100)the International Cooperation Fund of Science and Technology Commission of Shanghai Municipality (No. 21130750100)。
文摘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.
基金supported by the Natural Science Foundation of Shanghai(Nos.20ZR1400500,22ZR1400800)the Fundamental Research Funds for the Central Universities and Graduate Student Innovation Fund of Donghua University(No.CUSF-DH-D-2022043).
文摘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.
基金National Key Research and Development Plan of China (No.2019YFB1706300)Shanghai Frontier Science Research Center for Modern Textiles (Donghua University),China。
文摘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.
基金Fundamental Research Funds for the Central Universities,China(Nos.2232022D-11 and 22D128102/007)Jiangsu Transformation and Upgrading Funding Program for Industrial and Information Industry,ChinaShanghai Natural Science Foundation of Shanghai Municipal Science and Technology Commission,China(No.20ZR1401600)。
文摘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.
基金supported by the National Natural Science Foundation of China (31371093 and 31671068)the Tsinghua Center for Life Sciences, and Tongji Hospital and School of Life Sciences and Technology, Tongji University, China
文摘Dear Editor,The mammalian cerebral cortex,responsible for all higherorder brain functions,is organized into six layers of neurons that form distinct projections and connections within and outside the cortex.During cortical development,neural progenitor cells(NPCs)in the proliferative ventricular zone(VZ)and subventricular zone(SVZ)of the dorsal telencephalon produce projection neurons that migrate toward the pial surface to form the cortical plate(CP).
基金This project was supported by Science and technology project of Xiamen Medical College(K2023-08)the National Natural Science Foundation of China(No.82170299 to Shan Hongli,No.82003757 to Lyu Lifang).
文摘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.
基金supported by the National Natural Science Foundation of China under Grant Nos.12005184 and 12005183the Natural Science Foundation of the Jiangsu Higher Education Institutions of China under Grant No.20KJD140002。
文摘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.
文摘Minipreparation (MiniPrep) analysis is an essential step for obtaining a recombinant plasmid that carries a DNA insert containing a gene of interest. The most commonly used method for this involves cultivation of transformed Escherichia coli (E. coli) in liquid medium, brief centrifugation for precipitation of bacterial pellets, and subsequent lysis of the pellets. This process is time-consuming and laborious, especially when the sample number is high. Here, we describe a more convenient method for MiniPrep analysis that utilizes solid medium-based cultivation of bacteria.
文摘AIM: To evaluate our experience and surgical technique of laparoscopic appendectomy via reduced port surgery(LARPS). METHODS: Sixteen patients(8 men and 8 women; median age: 31.0 years) who underwent LARPS between November 2009 and May 2012 were included in the present study. We performed LARPS, in which access devices were inserted through an umbilical skin incision with 1 additional skin incision in the left lower abdomen. After setting access devices, pneumoperitoneum was maintained at 10 mmH g using CO2 and a 3 mm trocar was positioned(or direct puncture was performed by the Endo Relief system) under laparoscopic guidance. The mesoappendix was dissected using an ultrasonically activated device. After mesoappendix dissection, ligation was performed near the appendix base and the appendix was dissected using an ultrasonically activated device. The appendix was then removed. At the end of surgery, we administered local anesthesia with ropivacaine 1%(10 mL) for the skin incisions. The outcomes were evaluated in terms of operation time, intraoperative blood loss, length of postoperative hospital stay and surgical complications. RESULTS: Our surgical procedure allowed operators to use instruments as in conventional laparoscopic appendectomy. The basic principle of triangulation of instrumentation was maintained to some degree. LARPS was performed in 9 patients with catarrhal appendicitis, 5 with phlegmonous appendicitis, and 2 with gangrenous appendicitis. The median surgery time was 60 min and the median intraoperative blood loss was 1.2 mL. The median length of postoperative hospitalization was 4 d. There were no conversions to open surgery, no operation-related complications or mortality. CONCLUSION: Our experience and surgical technique suggest that LARPS is a safe and feasible procedure for patients with appendicitis.
