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Association between Gene Polymorphisms and SNP-SNP Interactions of the Matrix Metalloproteinase 2 Signaling Pathway and the Risk of Vascular Senescence
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作者 LIAO Zhen Yu YANG Shuo +3 位作者 HU Song LIU Jia MAO Yong Jun SUN Shu Qin 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2024年第2期146-156,共11页
Objective This study aimed to explore the association of single nucleotide polymorphisms(SNP)in the matrix metalloproteinase 2(MMP-2)signaling pathway and the risk of vascular senescence(VS).Methods In this cross-sect... Objective This study aimed to explore the association of single nucleotide polymorphisms(SNP)in the matrix metalloproteinase 2(MMP-2)signaling pathway and the risk of vascular senescence(VS).Methods In this cross-sectional study,between May and November 2022,peripheral venous blood of151 VS patients(case group)and 233 volunteers(control group)were collected.Fourteen SNPs were identified in five genes encoding the components of the MMP-2 signaling pathway,assessed through carotid-femoral pulse wave velocity(cf PWV),and analyzed using multivariate logistic regression.The multigene influence on the risk of VS was assessed using multifactor dimensionality reduction(MDR)and generalized multifactor dimensionality regression(GMDR)modeling.Results Within the multivariate logistic regression models,four SNPs were screened to have significant associations with VS:chemokine(C-C motif)ligand 2(CCL2)rs4586,MMP2 rs14070,MMP2rs7201,and MMP2 rs1053605.Carriers of the T/C genotype of MMP2 rs14070 had a 2.17-fold increased risk of developing VS compared with those of the C/C genotype,and those of the T/T genotype had a19.375-fold increased risk.CCL2 rs4586 and MMP-2 rs14070 exhibited the most significant interactions.Conclusion CCL2 rs4586,MMP-2 rs14070,MMP-2 rs7201,and MMP-2 rs1053605 polymorphisms were significantly associated with the risk of VS. 展开更多
关键词 Vascular senescence Pulse wave velocity(PWV) Single nucleotide polymorphism(SNP) matrix metalloproteinase 2(MMP-2) Extracellular matrix(ECM) Structural degradation Multifactor dimensionality reduction(MDR)
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Reinforced tissue matrix to strengthen the abdominal wall following reversal of temporary ostomies or to treat incisional hernias
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作者 Spencer P Lake Corey R Deeken Amit K Agarwal 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第3期823-832,共10页
BACKGROUND Abdominal wall deficiencies or weakness are a common complication of tem-porary ostomies,and incisional hernias frequently develop after colostomy or ileostomy takedown.The use of synthetic meshes to reinfo... BACKGROUND Abdominal wall deficiencies or weakness are a common complication of tem-porary ostomies,and incisional hernias frequently develop after colostomy or ileostomy takedown.The use of synthetic meshes to reinforce the abdominal wall has reduced hernia occurrence.Biologic meshes have also been used to enhance healing,particularly in contaminated conditions.Reinforced tissue matrices(R-TMs),which include a biologic scaffold of native extracellular matrix and a syn-thetic component for added strength/durability,are designed to take advantage of aspects of both synthetic and biologic materials.To date,RTMs have not been reported to reinforce the abdominal wall following stoma reversal.METHODS Twenty-eight patients were selected with a parastomal and/or incisional hernia who had received a temporary ileostomy or colostomy for fecal diversion after rectal cancer treatment or trauma.Following hernia repair and proximal stoma closure,RTM(OviTex®1S permanent or OviTex®LPR)was placed to reinforce the abdominal wall using a laparoscopic,robotic,or open surgical approach.Post-operative follow-up was performed at 1 month and 1 year.Hernia recurrence was determined by physical examination and,when necessary,via computed tomo-graphy scan.Secondary endpoints included length of hospital stay,time to return to work,and hospital readmissions.Evaluated complications of the wound/repair site included presence of surgical site infection,seroma,hematoma,wound dehiscence,or fistula formation.RESULTS The observational study cohort included 16 male and 12 female patients with average age of 58.5 years±16.3 years and average body mass index of 26.2 kg/m^(2)±4.1 kg/m^(2).Patients presented with a parastomal hernia(75.0%),in-cisional hernia(14.3%),or combined parastomal/incisional hernia(10.7%).Using a laparoscopic(53.6%),robotic(35.7%),or open(10.7%)technique,RTMs(OviTex®LPR:82.1%,OviTex®1S:17.9%)were placed using sublay(82.1%)or intraperitoneal onlay(IPOM;17.9%)mesh positioning.At 1-month and 1-year follow-ups,there were no hernia recurrences(0%).Average hospital stays were 2.1 d±1.2 d and return to work occurred at 8.3 post-operative days±3.0 post-operative days.Three patients(10.7%)were readmitted before the 1-month follow up due to mesh infection and/or gastrointestinal issues.Fistula and mesh infection were observed in two patients each(7.1%),leading to partial mesh removal in one patient(3.6%).There were no complications between 1 month and 1 year(0%).CONCLUSION RTMs were used successfully to treat parastomal and incisional hernias at ileostomy reversal,with no hernia recurrences and favorable outcomes after 1-month and 1-year. 展开更多
关键词 Reinforced tissue matrix Reinforced forestomach matrix ILEOSTOMY COLOSTOMY Ostomy takedown Incisional hernia Abdominal wall
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Factors influencing Frey syndrome after parotidectomy with acellular dermal matrix
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作者 Xian-Da Chai Huan Jiang +2 位作者 Ling-Ling Tang Jing Zhang Long-Fei Yue 《World Journal of Clinical Cases》 SCIE 2024年第9期1578-1584,共7页
BACKGROUND Frey syndrome,also known as ototemporal nerve syndrome or gustatory sweating syndrome,is one of the most common complications of parotid gland surgery.This condition is characterized by abnormal sensations ... BACKGROUND Frey syndrome,also known as ototemporal nerve syndrome or gustatory sweating syndrome,is one of the most common complications of parotid gland surgery.This condition is characterized by abnormal sensations in the facial skin accompanied by episodes of flushing and sweating triggered by cognitive processes,visual stimuli,or eating.AIM To investigate the preventive effect of acellular dermal matrix(ADM)on Frey syndrome after parotid tumor resection and analyzed the effects of Frey syndrome across various surgical methods and other factors involved in parotid tumor resection.METHODS Retrospective data from 82 patients were analyzed to assess the correlation between sex,age,resection sample size,operation time,operation mode,ADM usage,and occurrence of postoperative Frey syndrome.RESULTS Among the 82 patients,the incidence of Frey syndrome was 56.1%.There were no significant differences in sex,age,or operation time between the two groups(P>0.05).However,there was a significant difference between ADM implantation and occurrence of Frey syndrome(P<0.05).ADM application could reduce the variation in the incidence of Frey syndrome across different operation modes.CONCLUSION ADM can effectively prevent Frey syndrome and delay its onset. 展开更多
关键词 Parotid gland tumor Frey syndrome Acellular dermal matrix Acellular allogenic dermal matrix
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Numerical Methods for a Class of Quadratic Matrix Equations
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作者 GUAN Jinrui WANG Zhixin SHAO Rongxia 《应用数学》 北大核心 2024年第4期962-970,共9页
Quadratic matrix equations arise in many elds of scienti c computing and engineering applications.In this paper,we consider a class of quadratic matrix equations.Under a certain condition,we rst prove the existence of... Quadratic matrix equations arise in many elds of scienti c computing and engineering applications.In this paper,we consider a class of quadratic matrix equations.Under a certain condition,we rst prove the existence of minimal nonnegative solution for this quadratic matrix equation,and then propose some numerical methods for solving it.Convergence analysis and numerical examples are given to verify the theories and the numerical methods of this paper. 展开更多
关键词 Quadratic matrix equation M-matrix Minimal nonnegative solution Newton method Bernoulli method
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Research and design of matrix operation accelerator based on reconfigurable array
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作者 邓军勇 ZHANG Pan +2 位作者 JIANG Lin XIE Xiaoyan DENG Jingwen 《High Technology Letters》 EI CAS 2024年第2期128-137,共10页
In the case of massive data,matrix operations are very computationally intensive,and the memory limitation in standalone mode leads to the system inefficiencies.At the same time,it is difficult for matrix operations t... In the case of massive data,matrix operations are very computationally intensive,and the memory limitation in standalone mode leads to the system inefficiencies.At the same time,it is difficult for matrix operations to achieve flexible switching between different requirements when implemented in hardware.To address this problem,this paper proposes a matrix operation accelerator based on reconfigurable arrays in the context of the application of recommender systems(RS).Based on the reconfigurable array processor(APR-16)with reconfiguration,a parallelized design of matrix operations on processing element(PE)array is realized with flexibility.The experimental results show that,compared with the proposed central processing unit(CPU)and graphics processing unit(GPU)hybrid implementation matrix multiplication framework,the energy efficiency ratio of the accelerator proposed in this paper is improved by about 35×.Compared with blocked alternating least squares(BALS),its the energy efficiency ratio has been accelerated by about 1×,and the switching of matrix factorization(MF)schemes suitable for different sparsity can be realized. 展开更多
关键词 matrix factorization(MF) recommender system(RS) array processor RECONFIGURABLE matrix multiplication
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基于Doehlert Matrix的全贯流泵装置定转子进出流间隙优化设计
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作者 刘健峰 奚望 +2 位作者 陆伟刚 陆雯 杨晨霞 《农业机械学报》 EI CAS CSCD 北大核心 2024年第8期170-180,共11页
全贯流泵是一种新型的机电-水泵一体式贯流泵,然而其在运行时存在定转子间隙回流,扰乱了叶轮内的流场分布,导致泵装置产生能量损失、压力波动和噪声等问题,影响泵站的正常运行。通过数值模拟和模型试验研究全贯流泵装置定转子间隙流的... 全贯流泵是一种新型的机电-水泵一体式贯流泵,然而其在运行时存在定转子间隙回流,扰乱了叶轮内的流场分布,导致泵装置产生能量损失、压力波动和噪声等问题,影响泵站的正常运行。通过数值模拟和模型试验研究全贯流泵装置定转子间隙流的水力特性,结合Doehlert Matrix设计-响应面优化法对其定转子进、出流间隙结构进行优化设计,揭示全贯流泵装置定转子进、出流间隙结构对泵装置性能的影响机理,并得到最终优化的折角式定转子进、出流间隙结构方案为:外侧延伸段长度t1为4.921r,外侧收缩段长度x1为0.624r,内侧延伸段长度t2为3.655r,内侧收缩段长度x2为1.6r(r为定转子间隙宽度),使得全贯流泵装置扬程和效率分别提升约10.3%和5.2%。 展开更多
关键词 全贯流泵 定转子间隙流 Doehlert matrix设计
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Amino-functionalized UiO-66-doped mixed matrix membranes with high permeation performance and fouling resistance 被引量:1
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作者 Yi Zhang Di Liu +6 位作者 Zhaoli Wang Junjian Yu Yanyin Cheng Wenjing Li Zhe Wang Hongzhe Ni Yuchao Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第3期68-77,共10页
For the reduction of bovine serum proteins from wastewater,a novel mixed matrix membrane was prepared by functionalizing the substrate material polyaryletherketone(PAEK),followed by carboxyl groups(C-SPAEKS),and then ... For the reduction of bovine serum proteins from wastewater,a novel mixed matrix membrane was prepared by functionalizing the substrate material polyaryletherketone(PAEK),followed by carboxyl groups(C-SPAEKS),and then adding amino-functionalized UiO-66-NH_(2)(Am-UiO-66-NH_(2)).Aminofunctionalization of UiO-66 was accomplished by melamine,followed by an amidation reaction to immobilize Am-UiO-66-NH_(2),which was immobilized on the surface of the membrane as well as in the pore channels,which enhanced the hydrophilicity of the membrane surface while increasing the negative potential of the membrane surface.This nanoparticle-loaded ultrafiltration membrane has good permeation performance,with a pure water flux of up to 482.3 L·m^(-2)·h^(-1) for C-SPAEKS/AmUiO-66-NH_(2) and a retention rate of up to 98.7%for bovine serum albumin(BSA)-contaminated solutions.Meanwhile,after several hydrophilic modifications,the flux recovery of BSA contaminants by this series of membranes increased from 56.2%to 80.55%of pure membranes.The results of ultra-filtration flux time tests performed at room temperature showed that the series of ultrafiltration membranes remained relatively stable over a test time of 300 min.Thus,the newly developed mixed matrix membrane showed potential for high efficiency and stability in wastewater treatment containing bovine serum proteins. 展开更多
关键词 ULTRAFILTRATION Mixed matrix membranes Amino functionalization Hydrophilic modification Negatively charged
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High quality repair of osteochondral defects in rats using the extracellular matrix of antler stem cells 被引量:1
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作者 Yu-Su Wang Wen-Hui Chu +4 位作者 Jing-Jie Zhai Wen-Ying Wang Zhong-Mei He Quan-Min Zhao Chun-Yi Li 《World Journal of Stem Cells》 SCIE 2024年第2期176-190,共15页
BACKGROUND Cartilage defects are some of the most common causes of arthritis.Cartilage lesions caused by inflammation,trauma or degenerative disease normally result in osteochondral defects.Previous studies have shown... BACKGROUND Cartilage defects are some of the most common causes of arthritis.Cartilage lesions caused by inflammation,trauma or degenerative disease normally result in osteochondral defects.Previous studies have shown that decellularized extracellular matrix(ECM)derived from autologous,allogenic,or xenogeneic mesenchymal stromal cells(MSCs)can effectively restore osteochondral integrity.AIM To determine whether the decellularized ECM of antler reserve mesenchymal cells(RMCs),a xenogeneic material from antler stem cells,is superior to the currently available treatments for osteochondral defects.METHODS We isolated the RMCs from a 60-d-old sika deer antler and cultured them in vitro to 70%confluence;50 mg/mL L-ascorbic acid was then added to the medium to stimulate ECM deposition.Decellularized sheets of adipocyte-derived MSCs(aMSCs)and antlerogenic periosteal cells(another type of antler stem cells)were used as the controls.Three weeks after ascorbic acid stimulation,the ECM sheets were harvested and applied to the osteochondral defects in rat knee joints.RESULTS The defects were successfully repaired by applying the ECM-sheets.The highest quality of repair was achieved in the RMC-ECM group both in vitro(including cell attachment and proliferation),and in vivo(including the simultaneous regeneration of well-vascularized subchondral bone and avascular articular hyaline cartilage integrated with surrounding native tissues).Notably,the antler-stem-cell-derived ECM(xenogeneic)performed better than the aMSC-ECM(allogenic),while the ECM of the active antler stem cells was superior to that of the quiescent antler stem cells.CONCLUSION Decellularized xenogeneic ECM derived from the antler stem cell,particularly the active form(RMC-ECM),can achieve high quality repair/reconstruction of osteochondral defects,suggesting that selection of decellularized ECM for such repair should be focused more on bioactivity rather than kinship. 展开更多
关键词 Osteochondral defect repair Mesenchymal stem cells Extracellular matrix DECELLULARIZATION Antler stem cells Reserve mesenchymal cells Xenogeneic
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Stiffness-tunable biomaterials provide a good extracellular matrix environment for axon growth and regeneration
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作者 Ronglin Han Lanxin Luo +4 位作者 Caiyan Wei Yaru Qiao Jiming Xie Xianchao Pan Juan Xing 《Neural Regeneration Research》 SCIE CAS 2025年第5期1364-1376,共13页
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
关键词 ALGINATE axon growth BIOMATERIALS extracellular matrix neural repair neurons NEUROREGENERATION POLYACRYLAMIDE POLYDIMETHYLSILOXANE stiffness
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An approximate analytical model for unconventional reservoir considering variable matrix blocks and simultaneous matrix depletion
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作者 Kai-Xuan Qiu Jia Li +2 位作者 Dong Feng Shi-Ming Wei Gang Lei 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期352-365,共14页
In regard to unconventional oil reservoirs,the transient dual-porosity and triple-porosity models have been adopted to describe the fluid flow in the complex fracture network.It has been proven to cause inaccurate pro... In regard to unconventional oil reservoirs,the transient dual-porosity and triple-porosity models have been adopted to describe the fluid flow in the complex fracture network.It has been proven to cause inaccurate production evaluations because of the absence of matrix-macrofracture communication.In addition,most of the existing models are solved analytically based on Laplace transform and numerical inversion.Hence,an approximate analytical solution is derived directly in real-time space considering variable matrix blocks and simultaneous matrix depletion.To simplify the derivation,the simultaneous matrix depletion is divided into two parts:one part feeding the macrofractures and the other part feeding the microfractures.Then,a series of partial differential equations(PDEs)describing the transient flow and boundary conditions are constructed and solved analytically by integration.Finally,a relationship between oil rate and production time in real-time space is obtained.The new model is verified against classical analytical models.When the microfracture system and matrix-macrofracture communication is neglected,the result of the new model agrees with those obtained with the dual-porosity and triple-porosity model,respectively.Certainly,the new model also has an excellent agreement with the numerical model.The model is then applied to two actual tight oil wells completed in western Canada sedimentary basin.After identifying the flow regime,the solution suitably matches the field production data,and the model parameters are determined.Through these output parameters,we can accurately forecast the production and even estimate the petrophysical properties. 展开更多
关键词 Analytical solution Unconventional reservoir Variable matrix Simultaneous flow
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MgO-attached graphene nanosheet(MgO@GNS)reinforced magnesium matrix nanocomposite with superior mechanical,corrosion and biological performance
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作者 S.Abazari A.Shamsipur +3 位作者 H.R.Bakhsheshi-Rad M.S.Soheilirad F.Khorashadizade S.S.Mirhosseini 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第9期2062-2076,共15页
Magnesium(Mg)alloys are gaining great consideration as body implant materials due to their high biodegradability and biocompatibility.However,they suffer from low corrosion resistance and antibacterial activity.In thi... Magnesium(Mg)alloys are gaining great consideration as body implant materials due to their high biodegradability and biocompatibility.However,they suffer from low corrosion resistance and antibacterial activity.In this research,semi-powder metallurgy followed by hot extrusion was utilized to produce the magnesium oxide@graphene nanosheets/magnesium(MgO@GNS/Mg)composite to improve mechanical,corrosion and cytocompatibility characteristics.Investigations have revealed that the incorporation of MgO@GNS nanohybrids into Mg-based composite enhanced microhardness and compressive strength.In vitro,osteoblast cell culture tests show that using MgO@GNS nanohybrid fillers enhances osteoblast adhesion and apatite mineralization.The presence of MgO@GNS nanoparticles in the composites decreased the opening defects,micro-cracks and micro-pores of the composites thus preventing the penetration of the corrosive solution into the matrix.Studies demonstrated that the MgO@GNS/Mg composite possesses excellent antibacterial properties because of the combination of the release of MgO and physical damage to bacterium membranes caused by the sharp edges of graphene nanosheets that can effectively damage the cell wall thereby facilitating penetration into the bacterial lipid bilayer.Therefore,the MgO@GNS/Mg composite with high mechanical strength,antibacterial activity and corrosion resistance is considered to be a promising material for load-bearing implant applications. 展开更多
关键词 metal matrix composites MgO@GNS nanohybrid strengthening mechanisms antibacterial activity BIOCOMPATIBILITY
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Biofabrication of nanocomposite-based scaffolds containing human bone extracellularmatrix for the differentiation of skeletal stem and progenitor cells
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作者 Yang-Hee Kim Janos M.Kanczler +6 位作者 Stuart Lanham Andrew Rawlings Marta Roldo Gianluca Tozzi Jonathan I.Dawson Gianluca Cidonio Richard O.C.Oreffo 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第2期121-136,共16页
Autograft or metal implants are routinely used in skeletal repair.However,they fail to provide long-term clinical resolution,necessitating a functional biomimetic tissue engineering alternative.The use of native human... Autograft or metal implants are routinely used in skeletal repair.However,they fail to provide long-term clinical resolution,necessitating a functional biomimetic tissue engineering alternative.The use of native human bone tissue for synthesizing a biomimeticmaterial inkfor three-dimensional(3D)bioprintingof skeletal tissueis anattractivestrategyfor tissueregeneration.Thus,human bone extracellular matrix(bone-ECM)offers an exciting potential for the development of an appropriate microenvironment for human bone marrow stromal cells(HBMSCs)to proliferate and differentiate along the osteogenic lineage.In this study,we engineered a novel material ink(LAB)by blending human bone-ECM(B)with nanoclay(L,Laponite®)and alginate(A)polymers using extrusion-based deposition.The inclusion of the nanofiller and polymeric material increased the rheology,printability,and drug retention properties and,critically,the preservation of HBMSCs viability upon printing.The composite of human bone-ECM-based 3D constructs containing vascular endothelial growth factor(VEGF)enhanced vascularization after implantation in an ex vivo chick chorioallantoic membrane(CAM)model.The inclusion of bone morphogenetic protein-2(BMP-2)with the HBMSCs further enhanced vascularization and mineralization after only seven days.This study demonstrates the synergistic combination of nanoclay with biomimetic materials(alginate and bone-ECM)to support the formation of osteogenic tissue both in vitro and ex vivo and offers a promising novel 3D bioprinting approach to personalized skeletal tissue repair. 展开更多
关键词 Extracellular matrix NANOCLAY Bone 3D bioprinting
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Maillard reaction affecting immunobinding activity and digestibility of tropomyosin in Alectryonella plicatula food matrix
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作者 Chenchen Yu Xinrong He +7 位作者 Nairu Ji Shuai Kang Dongxiao Li Huilin Zhang Yang Yang Dong Lai Qingmei Liu Guangming Liu 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第5期2959-2969,共11页
In recent years,the allergy rate of oysters has surged,and daily food processing methods make it hard to reduce heat resistance and digestive allergy such as tropomyosin(TM).In this study,the Maillard reaction with xy... In recent years,the allergy rate of oysters has surged,and daily food processing methods make it hard to reduce heat resistance and digestive allergy such as tropomyosin(TM).In this study,the Maillard reaction with xylose significantly reduced the IgE binding capacity of Alectryonella plicatula food matrix(AFM),that reduced by(77.81±2.68)%.The study found the Maillard reaction changes the structure of the AFM,in which the content ofα-helix decreased by(24.64±1.46)%.Structural transformation further explains why the Maillard reaction alters the immunobinding activity of AFM.In addition,the Maillard reaction reduces the digestive stability of the AFM and makes TM in the A.plicatula food matrix Maillard reaction products(AFM-MRPs)more easily digested.Based on the above research,10 amino acids on the 7 IgE epitopes of TM were modified.This result indicates that the Maillard reaction reduces the immunobinding activity of the AFM by changing the structure and modifying the amino acids on the epitope. 展开更多
关键词 Alectryonella plicatula Food matrix Immunobinding activity Maillard reaction TROPOMYOSIN
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Effect of matrix thermal properties on laser-induced plasma
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作者 Yuheng Shan An Li +4 位作者 Xinyu Zhang Wen Yi Ying Zhang Xiaodong Liu Ruibin Liu 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期331-336,共6页
The matrix thermal properties have an important impact on laser-induced plasma,as the thermal effect dominates the interaction between ns-pulsed laser and matter,especially in metals.We used a series of pure metals an... The matrix thermal properties have an important impact on laser-induced plasma,as the thermal effect dominates the interaction between ns-pulsed laser and matter,especially in metals.We used a series of pure metals and aluminum alloys to measure plasma temperature and electron density through laser-induced breakdown spectroscopy,in order to investigate the effect of matrix thermal properties on laser-induced plasma.In pure metals,a significant negative linear correlation was observed between the matrix thermal storage coefficient and plasma temperature,while a weak correlation was observed with electron density.The results indicate that metals with low thermal conductivity or specific heat capacity require less laser energy for thermal diffusion or melting and evaporation,resulting in higher ablation rates and higher plasma temperatures.However,considering ionization energy,thermal effects may be a secondary factor affecting electron density.The experiment of aluminum alloy further confirms the influence of thermal conductivity on plasma temperature and its mechanism explanation. 展开更多
关键词 laser-induced plasma thermal properties matrix effect thermal storage coefficient plasma temperature
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先锋女性主义者的建筑实验--英国Matrix的女性主义建筑观念与实践研究
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作者 杨宇环 张卫 《世界建筑》 2024年第2期18-25,共8页
英国的Matrix是西方第一个明确以女性主义为主张的女性建筑事务所。在特定的时代背景下,她们试图挑战父权制下的建筑体系并发展一种女性主义的设计方法,是西方将女性主义理论运用到建筑空间实践中的先锋者。本文回溯了Matrix组建时的政... 英国的Matrix是西方第一个明确以女性主义为主张的女性建筑事务所。在特定的时代背景下,她们试图挑战父权制下的建筑体系并发展一种女性主义的设计方法,是西方将女性主义理论运用到建筑空间实践中的先锋者。本文回溯了Matrix组建时的政治与社会背景,分析她们以建筑师的身份采取集体合作工作模式、以女性为主体的参与式机制、以技能培训为辅助的女性建筑教育介入的方法来促进女性解放并重构建筑的空间生产。基于女性主义社会建构论的观念,解读Matrix是如何以性别批判的视角来看待和认知城市空间与女性主义建筑,并结合具体建筑案例分析女性视角下的包容性建筑设计。最后本文探讨了以Matrix为代表的女性建筑师及其女性主义建筑观念与实践对于当下建筑学科研究的价值与意义。 展开更多
关键词 matrix 女性主义 女性建筑师 参与式设计 女性主义建筑设计
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Damping properties and mechanism of aluminum matrix composites reinforced with glass cenospheres
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作者 Kai SUN Lin WANG +5 位作者 Hang SU Jia-yi GENG Qiang ZHANG Bo MENG Zeng-yan WEI Gao-hui WU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第9期2743-2755,共13页
The damping properties were improved by preparing Al matrix composites reinforced with glass cenospheres through the pressure infiltration method.Transmission electron microscopy and scanning electron microscopy were ... The damping properties were improved by preparing Al matrix composites reinforced with glass cenospheres through the pressure infiltration method.Transmission electron microscopy and scanning electron microscopy were employed to characterize the microstructure of the composites.The low-frequency damping properties were examined by using a dynamic mechanical thermal analyzer,aiming at exploring the changing trend of damping capacity with strain,temperature,and frequency.The findings demonstrated that the damping value rose as temperature and strain increased,with a maximum value of 0.15.Additionally,the damping value decreased when the frequency increased.Dislocation damping under strain and interfacial damping under temperature served as the two primary damping mechanisms.The increase in the density of dislocation strong pinning points following heat treatment reduced the damping value,which was attributed to the heat treatment enhancement of the interfacial bonding force of the composites. 展开更多
关键词 glass cenospheres Al matrix composites MICROSTRUCTURE low-frequency damping properties
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High-performance grinding of ceramic matrix composites
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作者 Jingfei Yin Jiuhua Xu Honghua Su 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2024年第3期45-55,共11页
Ceramic matrix composites(CMCs)are highly promising materials for the next generation of aero-engines.However,machining of CMCs suffers from low efficiency and poor surfacefinish,which presents an obstacle to their wide... Ceramic matrix composites(CMCs)are highly promising materials for the next generation of aero-engines.However,machining of CMCs suffers from low efficiency and poor surfacefinish,which presents an obstacle to their wider application.To overcome these problems,this study investigates high-efficiency deep grinding of CMCs,focusing on the effects of grinding depth.The results show that both the sur-face roughness and the depth of subsurface damage(SSD)are insensitive to grinding depth.The material removal rate can be increased sixfold by increasing the grinding depth,while the surface roughness and SSD depth increase by only about 10%.Moreover,it is found that the behavior of material removal is strongly dependent on grinding depth.As the grinding depth is increased,fibers are removed in smaller sizes,with thefiber length in chips being reduced by about 34%.However,too large a grinding depth will result in blockage by chip powder,which leads to a dramatic increase in the ratio of tangential to normal grinding forces.This study demonstrates that increasing the depth of cut is an effective approach to improve the machining efficiency of CMCs,while maintaining a good surfacefin-ish.It provides the basis for the further development of high-performance grinding methods for CMCs,which should facilitate their wider application. 展开更多
关键词 Ceramic matrix composite GRINDING Surfacefinish Subsurface damage Fiber breakage
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Working condition recognition of sucker rod pumping system based on 4-segment time-frequency signature matrix and deep learning
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作者 Yun-Peng He Hai-Bo Cheng +4 位作者 Peng Zeng Chuan-Zhi Zang Qing-Wei Dong Guang-Xi Wan Xiao-Ting Dong 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期641-653,共13页
High-precision and real-time diagnosis of sucker rod pumping system(SRPS)is important for quickly mastering oil well operations.Deep learning-based method for classifying the dynamometer card(DC)of oil wells is an eff... High-precision and real-time diagnosis of sucker rod pumping system(SRPS)is important for quickly mastering oil well operations.Deep learning-based method for classifying the dynamometer card(DC)of oil wells is an efficient diagnosis method.However,the input of the DC as a two-dimensional image into the deep learning framework suffers from low feature utilization and high computational effort.Additionally,different SRPSs in an oil field have various system parameters,and the same SRPS generates different DCs at different moments.Thus,there is heterogeneity in field data,which can dramatically impair the diagnostic accuracy.To solve the above problems,a working condition recognition method based on 4-segment time-frequency signature matrix(4S-TFSM)and deep learning is presented in this paper.First,the 4-segment time-frequency signature(4S-TFS)method that can reduce the computing power requirements is proposed for feature extraction of DC data.Subsequently,the 4S-TFSM is constructed by relative normalization and matrix calculation to synthesize the features of multiple data and solve the problem of data heterogeneity.Finally,a convolutional neural network(CNN),one of the deep learning frameworks,is used to determine the functioning conditions based on the 4S-TFSM.Experiments on field data verify that the proposed diagnostic method based on 4S-TFSM and CNN(4S-TFSM-CNN)can significantly improve the accuracy of working condition recognition with lower computational cost.To the best of our knowledge,this is the first work to discuss the effect of data heterogeneity on the working condition recognition performance of SRPS. 展开更多
关键词 Sucker-rod pumping system Dynamometer card Working condition recognition Deep learning Time-frequency signature Time-frequency signature matrix
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Ecosystem service multifunctionality of mixed conifer-broad-leaved forests under climate change and forest management based on matrix growth modelling
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作者 Xue Du Xiangdong Lei +3 位作者 Xiao He Jie Lan Hong Guo Qigang Xu 《Forest Ecosystems》 SCIE CSCD 2024年第5期743-757,共15页
Climate change and forest management are recognized as pivotal factors influencing forest ecosystem services and thus multifunctionality.However,the magnitude and the relative importance of climate change and forest m... Climate change and forest management are recognized as pivotal factors influencing forest ecosystem services and thus multifunctionality.However,the magnitude and the relative importance of climate change and forest management effects on the multifunctionality remain unclear,especially for natural mixed forests.In this study,our objective is to address this gap by utilizing simulations of climate-sensitive transition matrix growth models based on national forest inventory plot data.We evaluated the effects of seven management scenarios(combinations of various cutting methods and intensities)on the future provision of ecosystem services and multifunctionality in mixed conifer-broad-leaved forests in northeastern China,under four climate scenarios(SSP1-2.6,SSP2-4.5,SSP5-8.5,and constant climate).Provisioning,regulating,cultural,and supporting services were described by timber production,carbon storage,carbon sequestration,tree species diversity,deadwood volume,and the number of large living trees.Our findings indicated that timber production was significantly influenced by management scenarios,while tree species diversity,deadwood volume,and large living trees were impacted by both climate and management separately.Carbon storage and sequestration were notably influenced by both management and the interaction of climate and management.These findings emphasized the profound impact of forest management on ecosystem services,outweighing that of climate scenarios alone.We found no single management scenario maximized all six ecosystem service indicators.The upper story thinning by 5%intensity with 5-year interval(UST5)management strategy emerged with the highest multifunctionality,surpassing the lowest values by more than 20%across all climate scenarios.In conclusion,our results underlined the potential of climate-sensitive transition matrix growth models as a decision support tool and provided recommendations for long-term strategies for multifunctional forest management under future climate change context.Ecosystem services and multifunctionality of forests could be enhanced by implementing appropriate management measures amidst a changing climate. 展开更多
关键词 Multifunctional forest management THINNING Transition matrix growth model Carbon sink Timber production
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Research progress in friction stir processing of magnesium alloys and their metal matrix surface composites: Evolution in the 21^(st )century
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作者 Roshan Vijay Marode Tamiru Alemu Lemma +3 位作者 Nabihah Sallih Srinivasa Rao Pedapati Mokhtar Awang Adeel Hassan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第6期2091-2146,共56页
Rising concerns about climate change drive the demand for lightweight components.Magnesium(Mg)alloys are highly valued for their low weight,making them increasingly important in various industries.Researchers focusing... Rising concerns about climate change drive the demand for lightweight components.Magnesium(Mg)alloys are highly valued for their low weight,making them increasingly important in various industries.Researchers focusing on enhancing the characteristics of Mg alloys and developing their Metal Matrix Composites(MMCs)have gained significant attention worldwide over the past decade,driven by the global shift towards lightweight materials.Friction Stir Processing(FSP)has emerged as a promising technique to enhance the properties of Mg alloys and produce Mg-MMCs.Initially,FSP adapted to refine grain size from the micro to the nano level and accelerated the development of MMCs due to its solid-state nature and the synergistic effects of microstructure refinement and reinforcement,improving strength,hardness,ductility,wear resistance,corrosion resistance,and fatigue strength.However,producing defect-free and sound FSPed Mg and Mg-MMCs requires addressing several variables and their interdependencies,which opens up a broad range of practical applications.Despite existing reviews on individual FSP of Mg,its alloys,and MMCs,an attempt has been made to analyze the latest research on these three aspects collectively to enhance the understanding,application,and effectiveness of FSP for Mg and its derivatives.This review article discusses the literature,classifies the importance of Mg alloys,provides a historical background,and explores developments and potential applications of FSPed Mg alloys.It focuses on novel fabrication methods,reinforcement strategies,machine and tool design parameters,material characterization,and integration with other methods for enhanced properties.The influence of process parameters and the emergence of defects are examined,along with specific applications in mono and hybrid composites and their microstructure evolution.The study identifies promising reinforcement materials and highlights research gaps in FSP for Mg alloys and MMCs production.It concludes with significant recommendations for further exploration,reflecting ongoing advancements in this field. 展开更多
关键词 Magnesium alloys Friction stir processing Metal matrix composites LIGHTWEIGHT Surface modification
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