The brain's extracellular matrix(ECM),which is comprised of protein and glycosaminoglycan(GAG)scaffolds,constitutes 20%-40% of the human brain and is considered one of the largest influencers on brain cell functio...The brain's extracellular matrix(ECM),which is comprised of protein and glycosaminoglycan(GAG)scaffolds,constitutes 20%-40% of the human brain and is considered one of the largest influencers on brain cell functioning(Soles et al.,2023).Synthesized by neural and glial cells,the brain's ECM regulates a myriad of homeostatic cellular processes,including neuronal plasticity and firing(Miyata et al.,2012),cation buffering(Moraws ki et al.,2015),and glia-neuron interactions(Anderson et al.,2016).Considering the diversity of functions,dynamic remodeling of the brain's ECM indicates that this understudied medium is an active participant in both normal physiology and neurological diseases.展开更多
Neuronal growth, extension, branching, and formation of neural networks are markedly influenced by the extracellular matrix—a complex network composed of proteins and carbohydrates secreted by cells. In addition to p...Neuronal growth, extension, branching, and formation of neural networks are markedly influenced by the extracellular matrix—a complex network composed of proteins and carbohydrates secreted by cells. In addition to providing physical support for cells, the extracellular matrix also conveys critical mechanical stiffness cues. During the development of the nervous system, extracellular matrix stiffness plays a central role in guiding neuronal growth, particularly in the context of axonal extension, which is crucial for the formation of neural networks. In neural tissue engineering, manipulation of biomaterial stiffness is a promising strategy to provide a permissive environment for the repair and regeneration of injured nervous tissue. Recent research has fine-tuned synthetic biomaterials to fabricate scaffolds that closely replicate the stiffness profiles observed in the nervous system. In this review, we highlight the molecular mechanisms by which extracellular matrix stiffness regulates axonal growth and regeneration. We highlight the progress made in the development of stiffness-tunable biomaterials to emulate in vivo extracellular matrix environments, with an emphasis on their application in neural repair and regeneration, along with a discussion of the current limitations and future prospects. The exploration and optimization of the stiffness-tunable biomaterials has the potential to markedly advance the development of neural tissue engineering.展开更多
This paper studies the problem of the spectral radius of the uniform hypergraph determined by the signless Laplacian matrix.The upper bound of the spectral radius of a uniform hypergraph is obtained by using Rayleigh ...This paper studies the problem of the spectral radius of the uniform hypergraph determined by the signless Laplacian matrix.The upper bound of the spectral radius of a uniform hypergraph is obtained by using Rayleigh principle and the perturbation of the spectral radius under moving the edge operation,and the extremal hypergraphs are characterized for both supertree and unicyclic hypergraphs.The spectral radius of the graph is generalized.展开更多
An in-depth description of an apparently forgotten matrix operation, the reversal operator, is developed. The properties of such an operation are also given, resulting in a new vector-matrix operation resembling the w...An in-depth description of an apparently forgotten matrix operation, the reversal operator, is developed. The properties of such an operation are also given, resulting in a new vector-matrix operation resembling the well-known ones of conjugation, transposition, and inversion. The reversal operator operates by ordering the object components where applied. Reversal is easy to perform as it is distributive regarding the vector sum and matrix product. Supplementary descriptions of matrix regions not often used in linear algebra, like the anti-diagonal concept, are also discussed. Some practical problems are given.展开更多
Mixed matrix membranes(MMMs)have demonstrated significant promise in energy-intensive gas separations by amalgamating the unique properties of fillers with the facile processability of polymers.However,achieving a sim...Mixed matrix membranes(MMMs)have demonstrated significant promise in energy-intensive gas separations by amalgamating the unique properties of fillers with the facile processability of polymers.However,achieving a simultaneous enhancement of permeability and selectivity remains a formidable challenge,due to the difficulty of achieving an optimal match between polymers and fillers.In this study,we incorporate a porous carbon-based zinc oxide composite(C@ZnO)into high-permeability polymers of intrinsic microporosity(PIMs)to fabricate MMMs.The dipole–dipole interaction between C@ZnO and PIMs ensures their exceptional compatibility,mitigating the formation of non-selective voids in the resulting MMMs.Concurrently,C@ZnO with abundant interconnected pores can provide additional low-resistance pathways for gas transport in MMMs.As a result,the CO_(2) permeability of the optimized C@ZnO/PIM-1 MMMs is elevated to 13,215 barrer,while the CO_(2)/N_(2) and CO_(2)/CH_(4) selectivity reached 21.5 and 14.4,respectively,substantially surpassing the 2008 Robeson upper bound.Additionally,molecular simulation results further corroborate that the augmented membrane gas selectivity is attributed to the superior CO_(2) affinity of C@ZnO.In summary,we believe that this work not only expands the application of MMMs for gas separation but also heralds a paradigm shift in the application of porous carbon materials.展开更多
Capacitive voltage transformers (CVTs) are essential in high-voltage systems. An accurate error assessment is crucial for precise energy metering. However, tracking real-time quantitative changes in capacitive voltage...Capacitive voltage transformers (CVTs) are essential in high-voltage systems. An accurate error assessment is crucial for precise energy metering. However, tracking real-time quantitative changes in capacitive voltage transformer errors, particularly minor variations in multi-channel setups, remains challenging. This paper proposes a method for online error tracking of multi-channel capacitive voltage transformers using a Co-Prediction Matrix. The approach leverages the strong correlation between in-phase channels, particularly the invariance of the signal proportions among them. By establishing a co-prediction matrix based on these proportional relationships, The influence of voltage changes on the primary measurements is mitigated. Analyzing the relationships between the co-prediction matrices over time allows for inferring true measurement errors. Experimental validation with real-world data confirms the effectiveness of the method, demonstrating its capability to continuously track capacitive voltage transformer measurement errors online with precision over extended durations.展开更多
Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug deliv...Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug delivery often results in a burst release of the drug,leading to transient retention(inefficacy)and undesirable diffusion(toxicity)in vivo.Therefore,a drug delivery system that responds to changes in the microenvironment of tissue regeneration and controls vascular endothelial growth factor release is crucial to improve the treatment of ischemic stroke.Matrix metalloproteinase-2(MMP-2)is gradually upregulated after cerebral ischemia.Herein,vascular endothelial growth factor mimic peptide QK was self-assembled with MMP-2-cleaved peptide PLGLAG(TIMP)and customizable peptide amphiphilic(PA)molecules to construct nanofiber hydrogel PA-TIMP-QK.PA-TIMP-QK was found to control the delivery of QK by MMP-2 upregulation after cerebral ischemia/reperfusion and had a similar biological activity with vascular endothelial growth factor in vitro.The results indicated that PA-TIMP-QK promoted neuronal survival,restored local blood circulation,reduced blood-brain barrier permeability,and restored motor function.These findings suggest that the self-assembling nanofiber hydrogel PA-TIMP-QK may provide an intelligent drug delivery system that responds to the microenvironment and promotes regeneration and repair after cerebral ischemia/reperfusion injury.展开更多
Flexible X-ray detectors have garnered considerable attention owing to their extensive applications in three-dimensional (3D) image reconstruction, disease diagnosis and nondestructive testing^([1-3]). Conventional X-...Flexible X-ray detectors have garnered considerable attention owing to their extensive applications in three-dimensional (3D) image reconstruction, disease diagnosis and nondestructive testing^([1-3]). Conventional X-ray detectors typically employ active-matrix backplanes fabricated on rigid glass substrates, which integrate switching transistors and photodetectors^([4, 5]).展开更多
BACKGROUND One of the main characteristics of oral squamous cell carcinoma(OSCC)is that it metastasizes to cervical lymph nodes frequently with a high degree of local invasiveness.A primary feature of malignant tumors...BACKGROUND One of the main characteristics of oral squamous cell carcinoma(OSCC)is that it metastasizes to cervical lymph nodes frequently with a high degree of local invasiveness.A primary feature of malignant tumors is their penetration of neighboring tissues,such as lymphatic and blood arteries,due to the tumor cells'capacity to break down the extracellular matrix(ECM).Matrix metalloproteinases(MMPs)constitute a family of proteolytic enzymes that facilitate tissue remodeling and the degradation of the ECM.MMP-9 and MMP-13 belong to the group of extracellular matrix degrading enzymes and their expression has been studied in OSCC because of their specific functions.MMP-13,a collagenase family member,is thought to play an essential role in the MMP activation cascade by breaking down the fibrillar collagens,whereas MMP-9 is thought to accelerate the growth of tumors.Elevated MMP-13 expression has been associated with tumor behavior and patient prognosis in a number of malignant cases.AIM To assess the immunohistochemical expression of MMP-9 and MMP-13 in OSCC.METHODS A total of 40 cases with histologically confirmed OSCC by incisional biopsy were included in this cross-sectional retrospective study.The protocols for both MMP-9 and MMP-13 immunohistochemical staining were performed according to the manufacturer’s recommendations along with the normal gingival epithelium as a positive control.All the observations were recorded and Pearson’sχ²test with Fisher exact test was used for statistical analysis.RESULTS Our study showed no significant correlation between MMP-9 and MMP-13 staining intensity and tumor size.The majority of the patients were in advanced TNM stages(III and IV),and showed intense expression of MMP-9 and MMP-13.CONCLUSION The present study suggests that both MMP-9 and MMP-13 play an important and independent role in OSCC progression and invasiveness.Intense expression of MMP-9 and MMP-13,irrespective of histological grade of OSCC,correlates well with TNM stage.Consequently,it is evident that MMP-9 and MMP-13 are important for the invasiveness and progression of tumors.The findings may facilitate the development of new approaches for evaluating lymph node metastases and interventional therapy techniques,hence enhancing the prognosis of patients diagnosed with OSCC.展开更多
Quantum dot(QD)-based infrared photodetector is a promising technology that can implement current monitoring,imaging and optical communication in the infrared region. However, the photodetection performance of self-po...Quantum dot(QD)-based infrared photodetector is a promising technology that can implement current monitoring,imaging and optical communication in the infrared region. However, the photodetection performance of self-powered QD devices is still limited by their unfavorable charge carrier dynamics due to their intrinsically discrete charge carrier transport process. Herein, we strategically constructed semiconducting matrix in QD film to achieve efficient charge transfer and extraction.The p-type semiconducting CuSCN was selected as energy-aligned matrix to match the n-type colloidal PbS QDs that was used as proof-of-concept. Note that the PbS QD/CuSCN matrix not only enables efficient charge carrier separation and transfer at nano-interfaces but also provides continuous charge carrier transport pathways that are different from the hoping process in neat QD film, resulting in improved charge mobility and derived collection efficiency. As a result, the target structure delivers high specific detectivity of 4.38 × 10^(12)Jones and responsivity of 782 mA/W at 808 nm, which is superior than that of the PbS QD-only photodetector(4.66 × 10^(11)Jones and 338 mA/W). This work provides a new structure candidate for efficient colloidal QD based optoelectronic devices.展开更多
Rehabilitation training is believed to be an effectual strategy that canreduce the risk of dysfunction caused by spasticity.However,achieving visualizationrehabilitation training for patients remains clinically challe...Rehabilitation training is believed to be an effectual strategy that canreduce the risk of dysfunction caused by spasticity.However,achieving visualizationrehabilitation training for patients remains clinically challenging.Herein,wepropose visual rehabilitation training system including iontronic meta-fabrics withskin-friendly and large matrix features,as well as high-resolution image modules fordistribution of human muscle tension.Attributed to the dynamic connection and dissociationof the meta-fabric,the fabric exhibits outstanding tactile sensing properties,such as wide tactile sensing range(0~300 kPa)and high-resolution tactile perception(50 Pa or 0.058%).Meanwhile,thanks to the differential capillary effect,the meta-fabric exhibits a“hitting three birds with one stone”property(dryness wearing experience,long working time and cooling sensing).Based on this,the fabrics can be integrated with garmentsand advanced data analysis systems to manufacture a series of large matrix structure(40×40,1600 sensing units)training devices.Significantly,the tunability of piezo-ionic dynamics of the meta-fabric and the programmability of high-resolution imaging modules allowthis visualization training strategy extendable to various common disease monitoring.Therefore,we believe that our study overcomes theconstraint of standard spasticity rehabilitation training devices in terms of visual display and paves the way for future smart healthcare.展开更多
Basalt fibers/7075 aluminum matrix composites were studied to meet the demand of aluminum alloy drill pipes for material wear resistance.The composites with different basalt fiber additions were prepared by hot presse...Basalt fibers/7075 aluminum matrix composites were studied to meet the demand of aluminum alloy drill pipes for material wear resistance.The composites with different basalt fiber additions were prepared by hot pressed sintering and hot extrusion.The mechanical properties as well as friction and wear properties of the composites were studied by microstructure analysis,tensile experiments,friction and wear experiments.The results showed that basalt fibers were oriented and uniformly distributed and led to local grain refinement in the alloy matrix.The hardness and elongation of the composites were improved.The friction coefficient of the composites increased and then decreased,and the maximum wear depth and wear amount decreased,then increased,then decreased again with the growth of basalt fiber addition.Meanwhile,the inclusion of basalt fibers mitigated the uneven wear of the extruded 7075 aluminum alloy.The value of wear depth difference of 7075-0.2BF was the smallest,and that of 7075-2.0BF was close to it.The maximum wear depth and wear volume the 7075-0.2BF and 7075-2.0BF were also the smallest.The inhibition of uneven wear by basalt fibers enhanced of wear resistance for 7075 aluminum alloy,which has reference significance for improving the performance of aluminum alloy drill pipes.展开更多
This work used 5CrMnMo steel and titanium carbide(TiC)powders to fabricate particulate metal matrix composites(PMMCS).The composites’microstructure,hardness,and impact toughness were compared with four different tita...This work used 5CrMnMo steel and titanium carbide(TiC)powders to fabricate particulate metal matrix composites(PMMCS).The composites’microstructure,hardness,and impact toughness were compared with four different titanium carbide ceramic particle sizes.The phase composition and microstructure of composites were studied.Vickers hardness and Charpy impact tests were employed to analyze composites’hardness and impact ductility,respectively.The results showed that the four groups of composites are mainly composed of martensite,trace residual austenite,and titanium carbide(undissolved TiC and primary TiC particles).With the growth of the ceramic particle dimension in the composite layer,the number of primary titanium carbide ceramics gradually decreased.When the initial ceramic particle size was small,it tended to generate dendritic primary TiC,and when the particle size was large,it tended to generate polygons and ellipsoids.Furthermore,with the growth of titanium carbide ceramic particle dimension in the composites,the hardness of the composites decreased but the impact toughness of the composites rose first and then descended.When the ceramic particle size was 50-75μm,the composite had the highest hardness,and the impact energy of the composites was the highest,which is 8 J.This was because there were more undissolved titanium carbide ceramics in the composite,and there was a thicker matrix metal between the ceramic particles.展开更多
In this study,AZ91D(Mg-9Al-Zn)alloys reinforced with 2 vol%TC4(Ti-6Al-4V)particles fabricated by semi-solid stir casting were extruded at different ratios,resulting in observed grain refinement effects.The research fi...In this study,AZ91D(Mg-9Al-Zn)alloys reinforced with 2 vol%TC4(Ti-6Al-4V)particles fabricated by semi-solid stir casting were extruded at different ratios,resulting in observed grain refinement effects.The research findings demonstrate that both TC4 andβ-Mg_(17)Al_(12) phases contribute to promoting dynamic recrystallization(DRX)nucleation.With increasing extrusion ratio,theβ-phase(Mg_(17)Al_(12))gradually fractures into smaller particles,leading to progressive grain refinement.Furthermore,the transition from〈01-10〉fiber texture to non-basal texture in theα-Mg matrix after hot extrusion is attributed to improved DRX behavior and activation of non-basal slip.As the extrusion ratio increases,the tensile strength and elongation(EL)of TC4_(p)/AZ91D composite improve significantly,reaching optimum comprehensive mechanical properties at an extrusion of 40:1 with a yield strength(YS)of 257 MPa,an ultimate tensile strength(UTS)of 357 MPa,and an EL of 9.7%.This remarkable strengthening effect is primarily attributed toβ-phase reinforcement,grain refinement strengthening,and strain hardening.展开更多
Background: Despite considerable advancements in identifying factors contributing to the development of hepatocellular carcinoma(HCC), the pathogenesis of HCC remains unclear. In many cases, HCC is a consequence of pr...Background: Despite considerable advancements in identifying factors contributing to the development of hepatocellular carcinoma(HCC), the pathogenesis of HCC remains unclear. In many cases, HCC is a consequence of prolonged liver fibrosis, resulting in the formation of an intricate premalignant microenvironment. The accumulation of extracellular matrix(ECM) is a hallmark of premalignant microenvironment. Given the critical role of different matrix components in regulating cell phenotype and function, this study aimed to elucidate the interplay between the fibrotic matrix and malignant features in HCC. Methods: Liver tissues from both control(normal) and carbon tetrachloride(CCl_(4))-induced fibrotic rats were decellularized using sodium dodecyl sulfate(SDS) and Triton X-100. The resulting hydrogel from decellularized ECM was processed into micro-particles via the water-in-oil emulsion method. Microparticles were subsequently incorporated into three-dimensional liver biomimetic micro-tissues(MTs) comprising Huh-7 cells, human umbilical vein endothelial cells(HUVECs), and LX-2 cells. The MTs were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium(MTS) assay at day 11, immunofluorescence staining, immunoblotting, and spheroid migration assay at day 14 after co-culture. Results: Fibrotic matrix from CCl4-treated rat livers significantly enhanced the growth rate of the MTs and their expression of CCND1 as compared to the normal one. Fibrotic matrix, also induced the expression of epithelial-to-mesenchymal transition(EMT)-associated genes such as TWIST1, ACTA2, MMP9, CDH2, and VIMENTIN in the MTs as compared to the normal matrix. Conversely, the expression of CDH1 and hepatic maturation genes HNF4A, ALB, CYP3A4 was decreased in the MTs when the fibrotic matrix was used. Furthermore, the fibrotic matrix increased the migration of the MTs and their secretion of alpha-fetoprotein. Conclusions: Our findings suggest a regulatory role for the fibrotic matrix in promoting cancerous phenotype, which could potentially accelerate the progression of malignancy in the liver.展开更多
A new two-state diabatic potential energy matrix(DPEM)for H3 has been constructed,based on the fun-damental invariant neural network(FI-NN)diabatization method pro-posed in our previous work[Phys.Chem.Chem.Phys.21,150...A new two-state diabatic potential energy matrix(DPEM)for H3 has been constructed,based on the fun-damental invariant neural network(FI-NN)diabatization method pro-posed in our previous work[Phys.Chem.Chem.Phys.21,15040(2019)].In that initial effort,a two-state DPEM was constructed only with a 10 eV energy threshold.The current work aims to expand the en-ergy range and improve the accura-cy of DPEM.This is achieved by the utilization of full configuration inter-action(FCI)with aug-cc-pVnZ ba-sis sets and complete basis set(CBS)extrapolation.The original dataset is augmented with additional points with higher adiabatic energies,which give rise to a total of 10985 data points.The DPEM constructed in this work now enables accurate representation of adiabatic energies up to 18 eV.Quantum dynamic calculations based on this DPEM are nearly identical to those obtained from benchmark surfaces,which makes it the most accurate DPEM for the H3 system to date,therefore facilitating detailed exploration of reaction mechanisms at higher collision energies.展开更多
B2-CuZr phase reinforced amorphous alloy matrix composites has become one of the research hotspots in the field of materials science due to the“transformation-induced plasticity”phenomenon,which makes the composites...B2-CuZr phase reinforced amorphous alloy matrix composites has become one of the research hotspots in the field of materials science due to the“transformation-induced plasticity”phenomenon,which makes the composites show better macroscopic plastic deformability and obvious work-hardening behavior compared to the conventional amorphous alloy matrix composites reinforced with ductile phases.However,the in-situ metastable B2-CuZr phase tends to undergo eutectoid decomposition during solidification,and the volume fraction,size,and distribution of B2-CuZr phase are difficult to control,which limits the development and application of these materials.To date,much efforts have been made to solve the above problems through composition optimization,casting parameter tailoring,and post-processing technique.In this study,a review was given based on relevant studies,focusing on the predictive approach,reinforcing mechanism,and microstructure tailoring methods of B2-CuZr phase reinforced amorphous alloy matrix composites.The research focus and future prospects were also given for the future development of the present composite system.展开更多
Heterogeneous composites have strong anisotropy and are prone to dynamic recrystallization during hot compression,making the me-chanical response highly nonlinear.Therefore,it is a very challenging task to intellectua...Heterogeneous composites have strong anisotropy and are prone to dynamic recrystallization during hot compression,making the me-chanical response highly nonlinear.Therefore,it is a very challenging task to intellectually judge the thermal deformation characteristics of magnesium matrix composites(MgMCs).In view of this,this paper introduces a method to accurately solve the thermoplastic deformation of composites.Firstly,a hot compression constitutive model of magnesium matrix composites based on stress softening correction was established.Secondly,the complex quasi-realistic micromechanics modeling of heterogeneous magnesium matrix composites was conducted.By introducing the recrystallization softening factor and strain parameter into the constitutive equation,the accurate prediction of the global rheological response of the composites was realized,and the accuracy of the new constitutive model was proved.Finally,the thermal pro-cessing map of magnesium matrix composites was established,and the suitable processing range was chosen.This paper has certain guiding values for the prediction of the thermodynamic response and thermal processing of magnesium matrix composites.展开更多
In this work,the microstructure evolution and mechanical behavior of extruded SiC/ZA63 Mg matrix composites are investigated via combined experimental study and three-dimensionalfinite element modelling(3D FEM)based on...In this work,the microstructure evolution and mechanical behavior of extruded SiC/ZA63 Mg matrix composites are investigated via combined experimental study and three-dimensionalfinite element modelling(3D FEM)based on the actual 3D microstructure achieved by synchrotron tomography.The results show that the average grain size of composite increases from 0.57μm of 8μm-SiC/ZA63 to 8.73μm of 50μm-SiC/ZA63.The type of texture transforms from the typicalfiber texture in 8μm-SiC/ZA63 to intense basal texture in 50μm-SiC/ZA63 composite and the intensity of texture increases sharply with increase of SiC particle size.The dynamic recrystallization(DRX)mechanism is also changed with increasing SiC particle size.Experimental and simulation results verify that the strength and elongation both decrease with increase of SiC particle size.The 8μm-SiC/ZA63 composite possesses the optimal mechanical property with yield strength(YS)of 383 MPa,ultimate tensile strength(UTS)of 424 MPa and elongation of 6.3%.The outstanding mechanical property is attributed to the ultrafine grain size,high-density precipitates and dislocation,good loading transfer effect and the interface bonding between SiC and matrix,as well as the weakened basal texture.The simulation results reveal that the micro-cracks tend to initiate at the interface between SiC and matrix,and then propagate along the interface between particle and Mg matrix or at the high strain and stress regions,and further connect with other micro-cracks.The main fracture mechanism in 8μm-SiC/ZA63 composite is ductile damage of matrix and interfacial debonding.With the increase of particle size,interface strength and particle strength decrease,and interface debonding and particle rupture become the main fracture mechanism in the 30μm-and 50μm-SiC/ZA63 composites.展开更多
基金supported by National Institute on Aging(NIH-NIA)R21 AG074152(to KMA)National Institute of Allergy and Infectious Diseases(NIAID)grant DP2 AI171150(to KMA)Department of Defense(DoD)grant AZ210089(to KMA)。
文摘The brain's extracellular matrix(ECM),which is comprised of protein and glycosaminoglycan(GAG)scaffolds,constitutes 20%-40% of the human brain and is considered one of the largest influencers on brain cell functioning(Soles et al.,2023).Synthesized by neural and glial cells,the brain's ECM regulates a myriad of homeostatic cellular processes,including neuronal plasticity and firing(Miyata et al.,2012),cation buffering(Moraws ki et al.,2015),and glia-neuron interactions(Anderson et al.,2016).Considering the diversity of functions,dynamic remodeling of the brain's ECM indicates that this understudied medium is an active participant in both normal physiology and neurological diseases.
基金supported by the Natio`nal Natural Science Foundation of China,No. 81801241a grant from Sichuan Science and Technology Program,No. 2023NSFSC1578Scientific Research Projects of Southwest Medical University,No. 2022ZD002 (all to JX)。
文摘Neuronal growth, extension, branching, and formation of neural networks are markedly influenced by the extracellular matrix—a complex network composed of proteins and carbohydrates secreted by cells. In addition to providing physical support for cells, the extracellular matrix also conveys critical mechanical stiffness cues. During the development of the nervous system, extracellular matrix stiffness plays a central role in guiding neuronal growth, particularly in the context of axonal extension, which is crucial for the formation of neural networks. In neural tissue engineering, manipulation of biomaterial stiffness is a promising strategy to provide a permissive environment for the repair and regeneration of injured nervous tissue. Recent research has fine-tuned synthetic biomaterials to fabricate scaffolds that closely replicate the stiffness profiles observed in the nervous system. In this review, we highlight the molecular mechanisms by which extracellular matrix stiffness regulates axonal growth and regeneration. We highlight the progress made in the development of stiffness-tunable biomaterials to emulate in vivo extracellular matrix environments, with an emphasis on their application in neural repair and regeneration, along with a discussion of the current limitations and future prospects. The exploration and optimization of the stiffness-tunable biomaterials has the potential to markedly advance the development of neural tissue engineering.
基金Supported by Natural Science Foundation of HuBei Province(2022CFB299).
文摘This paper studies the problem of the spectral radius of the uniform hypergraph determined by the signless Laplacian matrix.The upper bound of the spectral radius of a uniform hypergraph is obtained by using Rayleigh principle and the perturbation of the spectral radius under moving the edge operation,and the extremal hypergraphs are characterized for both supertree and unicyclic hypergraphs.The spectral radius of the graph is generalized.
文摘An in-depth description of an apparently forgotten matrix operation, the reversal operator, is developed. The properties of such an operation are also given, resulting in a new vector-matrix operation resembling the well-known ones of conjugation, transposition, and inversion. The reversal operator operates by ordering the object components where applied. Reversal is easy to perform as it is distributive regarding the vector sum and matrix product. Supplementary descriptions of matrix regions not often used in linear algebra, like the anti-diagonal concept, are also discussed. Some practical problems are given.
基金financial support from the National Natural Science Foundation of China(Nos.22108258 and 52003251)Program for Science&Technology Innovation Talents in Universities of Henan Province(24HASTIT004)+1 种基金Outstanding Youth Fund of Henan Scientific Committee(222300420085)Science and Technology Joint Project of Henan Province(222301420041)。
文摘Mixed matrix membranes(MMMs)have demonstrated significant promise in energy-intensive gas separations by amalgamating the unique properties of fillers with the facile processability of polymers.However,achieving a simultaneous enhancement of permeability and selectivity remains a formidable challenge,due to the difficulty of achieving an optimal match between polymers and fillers.In this study,we incorporate a porous carbon-based zinc oxide composite(C@ZnO)into high-permeability polymers of intrinsic microporosity(PIMs)to fabricate MMMs.The dipole–dipole interaction between C@ZnO and PIMs ensures their exceptional compatibility,mitigating the formation of non-selective voids in the resulting MMMs.Concurrently,C@ZnO with abundant interconnected pores can provide additional low-resistance pathways for gas transport in MMMs.As a result,the CO_(2) permeability of the optimized C@ZnO/PIM-1 MMMs is elevated to 13,215 barrer,while the CO_(2)/N_(2) and CO_(2)/CH_(4) selectivity reached 21.5 and 14.4,respectively,substantially surpassing the 2008 Robeson upper bound.Additionally,molecular simulation results further corroborate that the augmented membrane gas selectivity is attributed to the superior CO_(2) affinity of C@ZnO.In summary,we believe that this work not only expands the application of MMMs for gas separation but also heralds a paradigm shift in the application of porous carbon materials.
文摘Capacitive voltage transformers (CVTs) are essential in high-voltage systems. An accurate error assessment is crucial for precise energy metering. However, tracking real-time quantitative changes in capacitive voltage transformer errors, particularly minor variations in multi-channel setups, remains challenging. This paper proposes a method for online error tracking of multi-channel capacitive voltage transformers using a Co-Prediction Matrix. The approach leverages the strong correlation between in-phase channels, particularly the invariance of the signal proportions among them. By establishing a co-prediction matrix based on these proportional relationships, The influence of voltage changes on the primary measurements is mitigated. Analyzing the relationships between the co-prediction matrices over time allows for inferring true measurement errors. Experimental validation with real-world data confirms the effectiveness of the method, demonstrating its capability to continuously track capacitive voltage transformer measurement errors online with precision over extended durations.
基金supported by the Natural Science Foundation of Shandong Province,No.ZR2023MC168the National Natural Science Foundation of China,No.31670989the Key R&D Program of Shandong Province,No.2019GSF107037(all to CS).
文摘Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug delivery often results in a burst release of the drug,leading to transient retention(inefficacy)and undesirable diffusion(toxicity)in vivo.Therefore,a drug delivery system that responds to changes in the microenvironment of tissue regeneration and controls vascular endothelial growth factor release is crucial to improve the treatment of ischemic stroke.Matrix metalloproteinase-2(MMP-2)is gradually upregulated after cerebral ischemia.Herein,vascular endothelial growth factor mimic peptide QK was self-assembled with MMP-2-cleaved peptide PLGLAG(TIMP)and customizable peptide amphiphilic(PA)molecules to construct nanofiber hydrogel PA-TIMP-QK.PA-TIMP-QK was found to control the delivery of QK by MMP-2 upregulation after cerebral ischemia/reperfusion and had a similar biological activity with vascular endothelial growth factor in vitro.The results indicated that PA-TIMP-QK promoted neuronal survival,restored local blood circulation,reduced blood-brain barrier permeability,and restored motor function.These findings suggest that the self-assembling nanofiber hydrogel PA-TIMP-QK may provide an intelligent drug delivery system that responds to the microenvironment and promotes regeneration and repair after cerebral ischemia/reperfusion injury.
文摘Flexible X-ray detectors have garnered considerable attention owing to their extensive applications in three-dimensional (3D) image reconstruction, disease diagnosis and nondestructive testing^([1-3]). Conventional X-ray detectors typically employ active-matrix backplanes fabricated on rigid glass substrates, which integrate switching transistors and photodetectors^([4, 5]).
文摘BACKGROUND One of the main characteristics of oral squamous cell carcinoma(OSCC)is that it metastasizes to cervical lymph nodes frequently with a high degree of local invasiveness.A primary feature of malignant tumors is their penetration of neighboring tissues,such as lymphatic and blood arteries,due to the tumor cells'capacity to break down the extracellular matrix(ECM).Matrix metalloproteinases(MMPs)constitute a family of proteolytic enzymes that facilitate tissue remodeling and the degradation of the ECM.MMP-9 and MMP-13 belong to the group of extracellular matrix degrading enzymes and their expression has been studied in OSCC because of their specific functions.MMP-13,a collagenase family member,is thought to play an essential role in the MMP activation cascade by breaking down the fibrillar collagens,whereas MMP-9 is thought to accelerate the growth of tumors.Elevated MMP-13 expression has been associated with tumor behavior and patient prognosis in a number of malignant cases.AIM To assess the immunohistochemical expression of MMP-9 and MMP-13 in OSCC.METHODS A total of 40 cases with histologically confirmed OSCC by incisional biopsy were included in this cross-sectional retrospective study.The protocols for both MMP-9 and MMP-13 immunohistochemical staining were performed according to the manufacturer’s recommendations along with the normal gingival epithelium as a positive control.All the observations were recorded and Pearson’sχ²test with Fisher exact test was used for statistical analysis.RESULTS Our study showed no significant correlation between MMP-9 and MMP-13 staining intensity and tumor size.The majority of the patients were in advanced TNM stages(III and IV),and showed intense expression of MMP-9 and MMP-13.CONCLUSION The present study suggests that both MMP-9 and MMP-13 play an important and independent role in OSCC progression and invasiveness.Intense expression of MMP-9 and MMP-13,irrespective of histological grade of OSCC,correlates well with TNM stage.Consequently,it is evident that MMP-9 and MMP-13 are important for the invasiveness and progression of tumors.The findings may facilitate the development of new approaches for evaluating lymph node metastases and interventional therapy techniques,hence enhancing the prognosis of patients diagnosed with OSCC.
基金supported by the National Natural Science Foundation of China (No. 62204079)the Science and Technology Development Project of Henan Province (Nos.202300410048, 202300410057)+2 种基金the China Postdoctoral Science Foundation (No. 2022M711037)the Intelligence Introduction Plan of Henan Province in 2021 (No. CXJD2021008)Henan University Fund。
文摘Quantum dot(QD)-based infrared photodetector is a promising technology that can implement current monitoring,imaging and optical communication in the infrared region. However, the photodetection performance of self-powered QD devices is still limited by their unfavorable charge carrier dynamics due to their intrinsically discrete charge carrier transport process. Herein, we strategically constructed semiconducting matrix in QD film to achieve efficient charge transfer and extraction.The p-type semiconducting CuSCN was selected as energy-aligned matrix to match the n-type colloidal PbS QDs that was used as proof-of-concept. Note that the PbS QD/CuSCN matrix not only enables efficient charge carrier separation and transfer at nano-interfaces but also provides continuous charge carrier transport pathways that are different from the hoping process in neat QD film, resulting in improved charge mobility and derived collection efficiency. As a result, the target structure delivers high specific detectivity of 4.38 × 10^(12)Jones and responsivity of 782 mA/W at 808 nm, which is superior than that of the PbS QD-only photodetector(4.66 × 10^(11)Jones and 338 mA/W). This work provides a new structure candidate for efficient colloidal QD based optoelectronic devices.
基金supported by the National Key Research and Development Program(2022YFB3805800)National Natural Science Foundation of China(52473307,22208178,62301290)+9 种基金Taishan Scholar Program of Shandong Province in China(tsqn202211116)Shandong Provincial Universities Youth Innovation Technology Plan Team(2023KJ223)Natural Science Foundation of Shandong Province of China(ZR2023YQ037,ZR2020QE074,ZR2023QE043,ZR2022QE174)Shandong Province Science and Technology Small and Medium sized Enterprise Innovation Ability Enhancement Project(2023TSGC0344,2023TSGC1006)Natural Science Foundation of Qingdao(23-2-1-249-zyyd-jch,24-4-4-zrjj-56-jch)Anhui Province Postdoctoral Researcher Research Activity Funding Project(2023B706)Qingdao Key Technology Research and Industrialization Demonstration Projects(23-1-7-zdfn-2-hz)Qingdao Shinan District Science and Technology Plan Project(2022-3-005-DZ)Suqian Key Research and Development Plan(H202310)Jinan City-School Integration Development Strategy Project for the Year 2023 under Grant(JNSX2023088).
文摘Rehabilitation training is believed to be an effectual strategy that canreduce the risk of dysfunction caused by spasticity.However,achieving visualizationrehabilitation training for patients remains clinically challenging.Herein,wepropose visual rehabilitation training system including iontronic meta-fabrics withskin-friendly and large matrix features,as well as high-resolution image modules fordistribution of human muscle tension.Attributed to the dynamic connection and dissociationof the meta-fabric,the fabric exhibits outstanding tactile sensing properties,such as wide tactile sensing range(0~300 kPa)and high-resolution tactile perception(50 Pa or 0.058%).Meanwhile,thanks to the differential capillary effect,the meta-fabric exhibits a“hitting three birds with one stone”property(dryness wearing experience,long working time and cooling sensing).Based on this,the fabrics can be integrated with garmentsand advanced data analysis systems to manufacture a series of large matrix structure(40×40,1600 sensing units)training devices.Significantly,the tunability of piezo-ionic dynamics of the meta-fabric and the programmability of high-resolution imaging modules allowthis visualization training strategy extendable to various common disease monitoring.Therefore,we believe that our study overcomes theconstraint of standard spasticity rehabilitation training devices in terms of visual display and paves the way for future smart healthcare.
基金Project(2021YFC2900200)supported by the National Key Research and Development Project of ChinaProject(20230203114SF)supported by the Key Research and Development Project of Jilin Province,China。
文摘Basalt fibers/7075 aluminum matrix composites were studied to meet the demand of aluminum alloy drill pipes for material wear resistance.The composites with different basalt fiber additions were prepared by hot pressed sintering and hot extrusion.The mechanical properties as well as friction and wear properties of the composites were studied by microstructure analysis,tensile experiments,friction and wear experiments.The results showed that basalt fibers were oriented and uniformly distributed and led to local grain refinement in the alloy matrix.The hardness and elongation of the composites were improved.The friction coefficient of the composites increased and then decreased,and the maximum wear depth and wear amount decreased,then increased,then decreased again with the growth of basalt fiber addition.Meanwhile,the inclusion of basalt fibers mitigated the uneven wear of the extruded 7075 aluminum alloy.The value of wear depth difference of 7075-0.2BF was the smallest,and that of 7075-2.0BF was close to it.The maximum wear depth and wear volume the 7075-0.2BF and 7075-2.0BF were also the smallest.The inhibition of uneven wear by basalt fibers enhanced of wear resistance for 7075 aluminum alloy,which has reference significance for improving the performance of aluminum alloy drill pipes.
基金supported by the Equipment Pre-research and Sharing Technology(41423030503)provided funding for this workThe Equipment Pre-research and Sharing Technology(41423030503)funded this work.
文摘This work used 5CrMnMo steel and titanium carbide(TiC)powders to fabricate particulate metal matrix composites(PMMCS).The composites’microstructure,hardness,and impact toughness were compared with four different titanium carbide ceramic particle sizes.The phase composition and microstructure of composites were studied.Vickers hardness and Charpy impact tests were employed to analyze composites’hardness and impact ductility,respectively.The results showed that the four groups of composites are mainly composed of martensite,trace residual austenite,and titanium carbide(undissolved TiC and primary TiC particles).With the growth of the ceramic particle dimension in the composite layer,the number of primary titanium carbide ceramics gradually decreased.When the initial ceramic particle size was small,it tended to generate dendritic primary TiC,and when the particle size was large,it tended to generate polygons and ellipsoids.Furthermore,with the growth of titanium carbide ceramic particle dimension in the composites,the hardness of the composites decreased but the impact toughness of the composites rose first and then descended.When the ceramic particle size was 50-75μm,the composite had the highest hardness,and the impact energy of the composites was the highest,which is 8 J.This was because there were more undissolved titanium carbide ceramics in the composite,and there was a thicker matrix metal between the ceramic particles.
基金the Guangdong Major Project of Basic and Applied Basic Research(2020B0301030006)the Guangdong Provincial Academy of Sciences Fund(2020GDASYL-20200101001)the Natural Science Foundation of Hubei Province,China(2023AFB1033).
文摘In this study,AZ91D(Mg-9Al-Zn)alloys reinforced with 2 vol%TC4(Ti-6Al-4V)particles fabricated by semi-solid stir casting were extruded at different ratios,resulting in observed grain refinement effects.The research findings demonstrate that both TC4 andβ-Mg_(17)Al_(12) phases contribute to promoting dynamic recrystallization(DRX)nucleation.With increasing extrusion ratio,theβ-phase(Mg_(17)Al_(12))gradually fractures into smaller particles,leading to progressive grain refinement.Furthermore,the transition from〈01-10〉fiber texture to non-basal texture in theα-Mg matrix after hot extrusion is attributed to improved DRX behavior and activation of non-basal slip.As the extrusion ratio increases,the tensile strength and elongation(EL)of TC4_(p)/AZ91D composite improve significantly,reaching optimum comprehensive mechanical properties at an extrusion of 40:1 with a yield strength(YS)of 257 MPa,an ultimate tensile strength(UTS)of 357 MPa,and an EL of 9.7%.This remarkable strengthening effect is primarily attributed toβ-phase reinforcement,grain refinement strengthening,and strain hardening.
基金financially supported by grants from Royan In-stitute(grant No.400000200)Bahar Tashkhis Teb Co.(BTT,9703,9809,and 9903)。
文摘Background: Despite considerable advancements in identifying factors contributing to the development of hepatocellular carcinoma(HCC), the pathogenesis of HCC remains unclear. In many cases, HCC is a consequence of prolonged liver fibrosis, resulting in the formation of an intricate premalignant microenvironment. The accumulation of extracellular matrix(ECM) is a hallmark of premalignant microenvironment. Given the critical role of different matrix components in regulating cell phenotype and function, this study aimed to elucidate the interplay between the fibrotic matrix and malignant features in HCC. Methods: Liver tissues from both control(normal) and carbon tetrachloride(CCl_(4))-induced fibrotic rats were decellularized using sodium dodecyl sulfate(SDS) and Triton X-100. The resulting hydrogel from decellularized ECM was processed into micro-particles via the water-in-oil emulsion method. Microparticles were subsequently incorporated into three-dimensional liver biomimetic micro-tissues(MTs) comprising Huh-7 cells, human umbilical vein endothelial cells(HUVECs), and LX-2 cells. The MTs were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium(MTS) assay at day 11, immunofluorescence staining, immunoblotting, and spheroid migration assay at day 14 after co-culture. Results: Fibrotic matrix from CCl4-treated rat livers significantly enhanced the growth rate of the MTs and their expression of CCND1 as compared to the normal one. Fibrotic matrix, also induced the expression of epithelial-to-mesenchymal transition(EMT)-associated genes such as TWIST1, ACTA2, MMP9, CDH2, and VIMENTIN in the MTs as compared to the normal matrix. Conversely, the expression of CDH1 and hepatic maturation genes HNF4A, ALB, CYP3A4 was decreased in the MTs when the fibrotic matrix was used. Furthermore, the fibrotic matrix increased the migration of the MTs and their secretion of alpha-fetoprotein. Conclusions: Our findings suggest a regulatory role for the fibrotic matrix in promoting cancerous phenotype, which could potentially accelerate the progression of malignancy in the liver.
基金supported by the National Natural Science Foundation of China(No.22288201)the Inno-vation Program for Quantum Science and Technology(No.2021ZD0303305)the Dalian Innovation Sup-port Program(No.2021RD05).
文摘A new two-state diabatic potential energy matrix(DPEM)for H3 has been constructed,based on the fun-damental invariant neural network(FI-NN)diabatization method pro-posed in our previous work[Phys.Chem.Chem.Phys.21,15040(2019)].In that initial effort,a two-state DPEM was constructed only with a 10 eV energy threshold.The current work aims to expand the en-ergy range and improve the accura-cy of DPEM.This is achieved by the utilization of full configuration inter-action(FCI)with aug-cc-pVnZ ba-sis sets and complete basis set(CBS)extrapolation.The original dataset is augmented with additional points with higher adiabatic energies,which give rise to a total of 10985 data points.The DPEM constructed in this work now enables accurate representation of adiabatic energies up to 18 eV.Quantum dynamic calculations based on this DPEM are nearly identical to those obtained from benchmark surfaces,which makes it the most accurate DPEM for the H3 system to date,therefore facilitating detailed exploration of reaction mechanisms at higher collision energies.
基金supported by the National Natural Science Foundation of China(No.52101138,No.52201075)the Natural Science Foundation of Hubei Province(No.2023AFB798,No.2022CFB614)+3 种基金the Shenzhen Science and Technology Program(No.JCYJ20220530160813032)the State Key Laboratory of Solidification Processing in NWPU(No.SKLSP202309,No.SKLSP202308)the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515011227)the State Key Laboratory of Powder Metallurgy of Central South University(No.SklpmKF-05)。
文摘B2-CuZr phase reinforced amorphous alloy matrix composites has become one of the research hotspots in the field of materials science due to the“transformation-induced plasticity”phenomenon,which makes the composites show better macroscopic plastic deformability and obvious work-hardening behavior compared to the conventional amorphous alloy matrix composites reinforced with ductile phases.However,the in-situ metastable B2-CuZr phase tends to undergo eutectoid decomposition during solidification,and the volume fraction,size,and distribution of B2-CuZr phase are difficult to control,which limits the development and application of these materials.To date,much efforts have been made to solve the above problems through composition optimization,casting parameter tailoring,and post-processing technique.In this study,a review was given based on relevant studies,focusing on the predictive approach,reinforcing mechanism,and microstructure tailoring methods of B2-CuZr phase reinforced amorphous alloy matrix composites.The research focus and future prospects were also given for the future development of the present composite system.
基金supported by the National Natural Science Foundation of China with the project of No.52305158Youth Innovation Team of Shaanxi Universities(2024),Shaanxi Province Qin Chuangyuan“Scientist+Engineer”Team construction of No.2024QCY-KXJ-112,Funding from Aero Engine Cooperation of China(No.ZZCX-2022-020)the industry-university-research cooperation of Eighth Research Institute of China Aerospace Science and Technology Corporation with the project of No.USCAST2021-1.
文摘Heterogeneous composites have strong anisotropy and are prone to dynamic recrystallization during hot compression,making the me-chanical response highly nonlinear.Therefore,it is a very challenging task to intellectually judge the thermal deformation characteristics of magnesium matrix composites(MgMCs).In view of this,this paper introduces a method to accurately solve the thermoplastic deformation of composites.Firstly,a hot compression constitutive model of magnesium matrix composites based on stress softening correction was established.Secondly,the complex quasi-realistic micromechanics modeling of heterogeneous magnesium matrix composites was conducted.By introducing the recrystallization softening factor and strain parameter into the constitutive equation,the accurate prediction of the global rheological response of the composites was realized,and the accuracy of the new constitutive model was proved.Finally,the thermal pro-cessing map of magnesium matrix composites was established,and the suitable processing range was chosen.This paper has certain guiding values for the prediction of the thermodynamic response and thermal processing of magnesium matrix composites.
基金supported by the National Natural Science Foundation of China[51974058,52371005,52022017,51927801]the Fundamental Research Funds for the Central Universities(DUT23YG104).
文摘In this work,the microstructure evolution and mechanical behavior of extruded SiC/ZA63 Mg matrix composites are investigated via combined experimental study and three-dimensionalfinite element modelling(3D FEM)based on the actual 3D microstructure achieved by synchrotron tomography.The results show that the average grain size of composite increases from 0.57μm of 8μm-SiC/ZA63 to 8.73μm of 50μm-SiC/ZA63.The type of texture transforms from the typicalfiber texture in 8μm-SiC/ZA63 to intense basal texture in 50μm-SiC/ZA63 composite and the intensity of texture increases sharply with increase of SiC particle size.The dynamic recrystallization(DRX)mechanism is also changed with increasing SiC particle size.Experimental and simulation results verify that the strength and elongation both decrease with increase of SiC particle size.The 8μm-SiC/ZA63 composite possesses the optimal mechanical property with yield strength(YS)of 383 MPa,ultimate tensile strength(UTS)of 424 MPa and elongation of 6.3%.The outstanding mechanical property is attributed to the ultrafine grain size,high-density precipitates and dislocation,good loading transfer effect and the interface bonding between SiC and matrix,as well as the weakened basal texture.The simulation results reveal that the micro-cracks tend to initiate at the interface between SiC and matrix,and then propagate along the interface between particle and Mg matrix or at the high strain and stress regions,and further connect with other micro-cracks.The main fracture mechanism in 8μm-SiC/ZA63 composite is ductile damage of matrix and interfacial debonding.With the increase of particle size,interface strength and particle strength decrease,and interface debonding and particle rupture become the main fracture mechanism in the 30μm-and 50μm-SiC/ZA63 composites.
