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
Satellite communication plays an important role in 6G systems.However,satellite communication systems are more susceptible to intentional or unintentional interference signals than other communication systems because ...Satellite communication plays an important role in 6G systems.However,satellite communication systems are more susceptible to intentional or unintentional interference signals than other communication systems because of their working mechanism of transparent forwarding.For the purpose of eliminating the influence of interference,this paper develops an angle reciprocal interference suppression scheme based on the reconstruction of interferenceplus-noise covariance matrix(ARIS-RIN).Firstly,we utilize the reciprocity between the known beam central angle and the unknown signal arrival angle to estimate the angle of arrival(AOA)of desired signal due to the multi-beam coverage.Then,according to the priori known spatial spectrum distribution,the interferenceplus-noise covariance matrix(INCM)is reconstructed by integrating within the range except the direction of desired signal.In order to correct the estimation bias of the first two steps,the worst-case performance optimization technology is adopted in the process of solving the beamforming vector.Numerical simulation results show that the developed scheme:1)has a higher output signal-to-interference-plus-noise ratio(SINR)under arbitrary signal-to-noise ratio(SNR);2)still has good performance under small snapshots;3)is robuster and easier to be realized when comparing with minimum variance distortionless response(MVDR)and the traditional diagonal loading algorithms.展开更多
BACKGROUND Demineralized bone matrix(DBM)is a commonly utilized allogenic bone graft substitute to promote osseous union.However,little is known regarding outcomes following DBM utilization in foot and ankle surgical ...BACKGROUND Demineralized bone matrix(DBM)is a commonly utilized allogenic bone graft substitute to promote osseous union.However,little is known regarding outcomes following DBM utilization in foot and ankle surgical procedures.AIM To evaluate the clinical and radiographic outcomes following DBM as a biological adjunct in foot and ankle surgical procedures.METHODS During May 2023,the PubMed,EMBASE and Cochrane library databases were systematically reviewed to identify clinical studies examining outcomes following DBM for the management of various foot and ankle pathologies.Data regarding study characteristics,patient demographics,subjective clinical outcomes,radiological outcomes,complications,and failure rates were extracted and analyzed.In addition,the level of evidence(LOE)and quality of evidence(QOE)for each individual study was also assessed.Thirteen studies were included in this review.RESULTS In total,363 patients(397 ankles and feet)received DBM as part of their surgical procedure at a weighted mean follow-up time of 20.8±9.2 months.The most common procedure performed was ankle arthrodesis in 94 patients(25.9%).Other procedures performed included hindfoot fusion,1st metatarsophalangeal joint arthrodesis,5th metatarsal intramedullary screw fixation,hallux valgus correction,osteochondral lesion of the talus repair and unicameral talar cyst resection.The osseous union rate in the ankle and hindfoot arthrodesis cohort,base of the 5th metatarsal cohort,and calcaneal fracture cohort was 85.6%,100%,and 100%,respectively.The weighted mean visual analog scale in the osteochondral lesions of the talus cohort improved from a pre-operative score of 7.6±0.1 to a post-operative score of 0.4±0.1.The overall complication rate was 27.2%,the most common of which was non-union(8.8%).There were 43 failures(10.8%)all of which warranted a further surgical procedure.CONCLUSION This current systematic review demonstrated that the utilization of DBM in foot and ankle surgical procedures led to satisfactory osseous union rates with favorable wound complication rates.Excellent outcomes were observed in patients undergoing fracture fixation augmented with DBM,with mixed evidence supporting the routine use of DBM in fusion procedures of the ankle and hindfoot.However,the low LOE together with the low QOE and significant heterogeneity between the included studies reinforces the need for randomized control trials to be conducted to identify the optimal role of DBM in the setting of foot and ankle surgical procedures.展开更多
In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to ...In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.展开更多
Driven by advancements in mobile internet technology,images have become a crucial data medium.Ensuring the security of image information during transmission has thus emerged as an urgent challenge.This study proposes ...Driven by advancements in mobile internet technology,images have become a crucial data medium.Ensuring the security of image information during transmission has thus emerged as an urgent challenge.This study proposes a novel image encryption algorithm specifically designed for grayscale image security.This research introduces a new Cantor diagonal matrix permutation method.The proposed permutation method uses row and column index sequences to control the Cantor diagonal matrix,where the row and column index sequences are generated by a spatiotemporal chaotic system named coupled map lattice(CML).The high initial value sensitivity of the CML system makes the permutation method highly sensitive and secure.Additionally,leveraging fractal theory,this study introduces a chaotic fractal matrix and applies this matrix in the diffusion process.This chaotic fractal matrix exhibits selfsimilarity and irregularity.Using the Cantor diagonal matrix and chaotic fractal matrix,this paper introduces a fast image encryption algorithm involving two diffusion steps and one permutation step.Moreover,the algorithm achieves robust security with only a single encryption round,ensuring high operational efficiency.Experimental results show that the proposed algorithm features an expansive key space,robust security,high sensitivity,high efficiency,and superior statistical properties for the ciphered images.Thus,the proposed algorithm not only provides a practical solution for secure image transmission but also bridges fractal theory with image encryption techniques,thereby opening new research avenues in chaotic cryptography and advancing the development of information security technology.展开更多
We read with the great interest the study by Ababneh et al in which inducedmesenchymal stem cell-derived exosomes were shown to exhibit a stronger andmore sustained anti-proliferative effect by inducing a senescence-l...We read with the great interest the study by Ababneh et al in which inducedmesenchymal stem cell-derived exosomes were shown to exhibit a stronger andmore sustained anti-proliferative effect by inducing a senescence-like state withoutapoptosis.The results obtained by the authors highlight the features of theeffects of senescent drift induction in surrounding tissues.In the light of thesefindings,the role of the properties of extracellular matrix and cellular glycocalyxin responses of human tumors to therapy remain uninvestigated.These extracellularbarriers appear to be significant obstacles to effective cancer therapy,especiallyin relation to the use of unique properties of tumor microenvironment forthe immunotherapy-resistant cancer treatment.展开更多
Peripheral nerve injury causes severe neuroinflammation and has become a global medical challenge.Previous research has demonstrated that porcine decellularized nerve matrix hydrogel exhibits excellent biological prop...Peripheral nerve injury causes severe neuroinflammation and has become a global medical challenge.Previous research has demonstrated that porcine decellularized nerve matrix hydrogel exhibits excellent biological properties and tissue specificity,highlighting its potential as a biomedical material for the repair of severe peripheral nerve injury;however,its role in modulating neuroinflammation post-peripheral nerve injury remains unknown.Here,we aimed to characterize the anti-inflammatory properties of porcine decellularized nerve matrix hydrogel and their underlying molecular mechanisms.Using peripheral nerve injury model rats treated with porcine decellularized nerve matrix hydrogel,we evaluated structural and functional recovery,macrophage phenotype alteration,specific cytokine expression,and changes in related signaling molecules in vivo.Similar parameters were evaluated in vitro using monocyte/macrophage cell lines stimulated with lipopolysaccharide and cultured on porcine decellularized nerve matrix hydrogel-coated plates in complete medium.These comprehensive analyses revealed that porcine decellularized nerve matrix hydrogel attenuated the activation of excessive inflammation at the early stage of peripheral nerve injury and increased the proportion of the M2 subtype in monocytes/macrophages.Additionally,porcine decellularized nerve matrix hydrogel negatively regulated the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB axis both in vivo and in vitro.Our findings suggest that the efficacious anti-inflammatory properties of porcine decellularized nerve matrix hydrogel induce M2 macrophage polarization via suppression of the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB pathway,providing new insights into the therapeutic mechanism of porcine decellularized nerve matrix hydrogel in peripheral nerve injury.展开更多
Objectives:High-grade serous ovarian cancer(HGSOC),the most common subtype of epithelial ovarian cancer(EOC),exhibits a mesenchymal phenotype characterized by fibrotic stroma and poor prognosis.Human epididymis protei...Objectives:High-grade serous ovarian cancer(HGSOC),the most common subtype of epithelial ovarian cancer(EOC),exhibits a mesenchymal phenotype characterized by fibrotic stroma and poor prognosis.Human epididymis protein 4(HE4),a key diagnostic biomarker for ovarian cancer,is involved in fibrotic processes in several non-malignant diseases.Given the clinical significance of stromal fibrosis in HGSOC and the potential link between HE4 and fibrosis,this study aimed to investigate the role of HE4 in the formation of stromal fibrosis in HGSOC.Methods:A total of 126 patients with gynecological conditions were included and divided into normal,benign,and EOC groups.Tissue stiffness was quantitatively measured and analyzed for its correlation with clinicopathological features.We further investigated the correlation between tumor stiffness and the expression levels of HE4 and fibroblast activation markers(α-smooth muscle actin(α-SMA)and fibroblast activation protein(FAP))in tumor tissues from 22 HGSOC patients.In vitro,primary fibroblasts were treated with recombinant HE4(rHE4)or conditioned media from HE4-knockdown ovarian cancer cells to assess fibroblasts activation and matrix contractility(Collagen gel contraction assays).In vivo,a subcutaneous xenograft model using HE4-knockdown cells was established to evaluate the effects of HE4 suppression on tumor growth and extensive extracellular matrix(ECM)remodeling.Results:Ovarian cancer tissues showed significantly increased stiffness compared to benign/normal groups,showing positive correlation with serum HE4 levels.High-stiffness HGSOC tumors exhibited upregulated expression of HE4,α-SMA,FAP,and collagen I.rHE4 stimulated fibroblast activation and enhanced matrix contractility,whereas HE4 knockdown in cancer cells abrogated these pro-fibrotic effects.In vivo,HE4-silenced xenografts displayed restricted tumor growth accompanied by reduced stromal expression ofα-SMA,FAP,and collagen I.Conclusion:Our findings suggest that HE4 may facilitate ECM remodeling in HGSOC through promoting fibroblast activation and increasing collagen deposition.展开更多
To improve the wettability of Al metal matrix composites（Al-MMCs） by common filler metals,Al-12Si-xTi（x=0.1,0.5,1,3.0;mass fraction,%） system active ternary filler metals were prepared.It was demonstrated that alt...To improve the wettability of Al metal matrix composites（Al-MMCs） by common filler metals,Al-12Si-xTi（x=0.1,0.5,1,3.0;mass fraction,%） system active ternary filler metals were prepared.It was demonstrated that although the added Ti existed within Ti（Al1-xSix）3（0≤x≤0.15） phase,the shear strength and shear fracture surface of the developed Al-12Si-xTi brazes were quite similar to those of traditional Al-12Si braze due to the presence of similar microstructure of Al-Si eutectic microstructure with large volume fraction.So,small Ti addition（～1%） did not make the active brazes brittle and hard compared with the conventional Al-12Si braze.The measured melting range of each Al-12Si-xTi foil was very similar,i.e.,580-590 ℃,because the composition was close to that of eutectic.For wettability improvement,with increasing Ti content,the interfacial gap between the Al2O3 reinforcement and filler metal（R/M） could be eliminated,and the amount of the remainder of the active fillers on the composite substrate decreased after sessile drop test at 610 ℃ for 30 min.So,the wettability improvement became easy to observe repeatedly with increasing Ti content.Additionally,the amount and size of Ti（AlSi）3 phase were sensitive to the Ti content（before brazing） and Si content（after brazing）.展开更多
The reservoir-monolithic type of the controlled release systems is investigated currently,however,the existing kinetic model could not describe the release process well because the release kinetics is rather complicat...The reservoir-monolithic type of the controlled release systems is investigated currently,however,the existing kinetic model could not describe the release process well because the release kinetics is rather complicated.In this paper,a simplified release kinetic model for diffusion-controlled monolithic matrix coated with outer membrane systems is proposed and verified by the experimental data of mercaptopurinum release experiment.It shows that the model can well describe the release mechanism (the relative error is under 3%) when drug loading (C d) is above its solubility limit (C s).At the same time,the release characteristics of special cases (D mD f and D mD f) are discussed theoretically.When D mD f the release rate becomes constant,namely,zero order release,and the release rate is independent of the drug membrane.This result provides the theoretical basis for the system of zero order release as well as how to control the release rate and the amount of drug release.When D mD f,the release rate is dependent on the drug release coefficient in the monolithic matrix,solubility and drug loading but independent of the process in the outer membrane,and it is similar to monolithic matrix type.展开更多
A plane-based and linear camera calibration technique without considering lens distortion is proposed in a greedy and intuitive framework for the binocular camera system. Characteristic homography matrix and consisten...A plane-based and linear camera calibration technique without considering lens distortion is proposed in a greedy and intuitive framework for the binocular camera system. Characteristic homography matrix and consistency constraints in close range are employed in this calibration. First, in order to calculate the internal geometries of the cameras, total least-square fitting as a robust tool for the geometrical cost function is exploited to recover the accurate principal point of each camera from all the characteristic lines of the homography matrices for all model planes. Secondly, generic prior knowledge of the aspect ratio of pixel cells is incorporated into the system to obtain the exact principal length in each camera. Thirdly, extrinsic geometries are accurately computed for all planar patterns with respect to each monocular camera. Finally, the rigid displacement between binocular cameras can be obtained by imposing the consistency constraints in 3-space geometry. Both simulation and real image experimental results indicate that reasonably reliable results can be obtained by this technique. And the proposed method is sufficient for applications where high precision is not required and can be easily performed by common computer users who are not experts in computer vision.展开更多
Generally unitary solution to the system of martix equations over the quaternion field [X mA ns =B ns ,X nn C nt =D nt ] is considered. A necessary and sufficient condition for the existence o...Generally unitary solution to the system of martix equations over the quaternion field [X mA ns =B ns ,X nn C nt =D nt ] is considered. A necessary and sufficient condition for the existence of and the expression for the generally unitary solution of the system are derived.展开更多
Minor self conjugate (msc) and skewpositive semidefinite (ssd) solutions to the system of matrix equations over skew fields [A mn X nn =A mn ,B sn X nn =O sn ] are considered. Necessary and su...Minor self conjugate (msc) and skewpositive semidefinite (ssd) solutions to the system of matrix equations over skew fields [A mn X nn =A mn ,B sn X nn =O sn ] are considered. Necessary and sufficient conditions for the existence of and the expressions for the msc solutions and the ssd solutions are obtained for the system.展开更多
For an AKNS matrix system,Lie algebraic structure and its mastersymmetry are obtained by a purely algebraic approach;and by using the reduced technique,two similar algebraic structures for MKdV and KdV matrix systems ...For an AKNS matrix system,Lie algebraic structure and its mastersymmetry are obtained by a purely algebraic approach;and by using the reduced technique,two similar algebraic structures for MKdV and KdV matrix systems are given.展开更多
AIM: To investigate the relationship between matrix metalloproteinase-2 (MMP-2) mRNA expression and clinicopathologic and urokinase-type plasminogen activator (uPA) system parameter and prognosis in human gastric canc...AIM: To investigate the relationship between matrix metalloproteinase-2 (MMP-2) mRNA expression and clinicopathologic and urokinase-type plasminogen activator (uPA) system parameter and prognosis in human gastric cancer. METHODS: Expression of MMP-2 mRNA, uPA, and uPA-R mRNA in tumor tissues and ≥5 cm adjacent normal tissues from 67 cases of gastric cancer was studied using RT-PCR and Northern blot respectively.Survival analyses were done using the Kaplan-Meier method. RESULTS: The expression rates of MMP-2 mRNA,uPA and uPA-R mRNA in tumor tissues (31%,41%,and 51%, respectively) were significantly higher than those in ≥5 cm adjacent tissues (19%, 11%, and 9%; X2=4.59,43.58, and 53.24 respectively, P<0.05,0.0001,and 0.0001, respectively). Expression of MMP-2 mRNA was significantly correlated with lymph node metastasis (metastasis: 61.9%, no metastasis: 39.1%, X2= 7.61, P<0.05),Lauren's classification of diffuse/mixed types:54.2%,intestinal type: 26.3%,X2 = 4.25, P<0.05, expression of uPA and uPA-R mRNA (uPA+: 55.1%, uPA-: 22.2% and uPA-R+: 54.9%, uPA-R-: 18.8%, X2=5.72 and 6.40 respectively, P<0.05).Kaplan-Meier survival analysis of MMP-2 mRNA expression did not show significant difference in all 67 cases, but revealed an association of the expression of MMP-2 mRNA, uPA, and uPA-R mRNA with worse prognosis (P= 0.0083, 0.0160, and 0.0094, respectively). CONCLUSION: MMP-2 may play an important role in the development of invasion and metastasis of gastric cancer.展开更多
To characterize effects of plant roots on preferential flow（PF）,we measured root length density（RLD）and root biomass（RB） in Jiufeng National Forest Park,Beijing,China.Comparisons were made for RLD and RB between...To characterize effects of plant roots on preferential flow（PF）,we measured root length density（RLD）and root biomass（RB） in Jiufeng National Forest Park,Beijing,China.Comparisons were made for RLD and RB between soil preferential pathways and soil matrices.RLD and RB declined with the increasing soil depth（0–10,10–20,20–30,30–40,40–50,50–60 cm） in all experimental plots.RLD was greater in soil preferential pathways than in the surrounding soil matrix and was 69.5,75.0 and72.2 % for plant roots of diameter（d） ／1,1 ／ d ／ 3 and3 ／ d ／ 5 mm,respectively.Fine root systems had the most pivotal influence on soil preferential flow in this forest ecosystem.In all experimental plots,RB content was the sum of RB from soil preferential pathways and the soil matrix in each soil depth.With respect to 6 soil depth gradient（0–10,10–20,20–30,30–40,40–50,50–60 cm） in each plot,the number of soil depth gradient that RB content was greater in soil preferential pathways than in the soil matrix was characterized,and the proportion was68.2 % in all plots.展开更多
In this paper, we address the stabilization problem for linear periodically time-varying switched systems. Using discretization technique, we derive new conditions for the global stabilizability in terms of the soluti...In this paper, we address the stabilization problem for linear periodically time-varying switched systems. Using discretization technique, we derive new conditions for the global stabilizability in terms of the solution of matrix inequalities. An algorithm for finding stabilizing controller and switching strategy is presented.展开更多
A series of (1-x)La0.6Dy0.1Sr0.3MnO3/0.5x(Sb2O3)(x=0.15) samples were prepared by the solid-state reaction method, and the influence of sintering temperature of the matrix on low-field magnetoresistance of (1-x)La0.6D...A series of (1-x)La0.6Dy0.1Sr0.3MnO3/0.5x(Sb2O3)(x=0.15) samples were prepared by the solid-state reaction method, and the influence of sintering temperature of the matrix on low-field magnetoresistance of (1-x)La0.6Dy0.1Sr0.3MnO3/0.5x (Sb2O3) was studied through the measurements of X-ray diffraction (XRD) patterns, scanning electron microscope (SEM) image, resistivity-temperature (ρ-T) curves, and magnetoresistance-temperature (MR-T) curves. The results indicate that for the samples with low sintering temperature of the matrix, lowfield magnetoresistance effect appears on the whole temperature range and can be explained by grain boundary effect; for the sample with high sintering temperature of the matrix, intrinsic magnetoresistance peak appears on the high-temperature range, low-field magnetore-sistance effect appears on low temperature range, and the magnetoresistance in the magnetic field of 0.2 T and on the comparatively large temperature range between 280 K and 225 K hardly changes with temperature and remains at 4.8%, which can be explained by the competition between the intrinsic magnetoresistance induced by double-exchange function inside grains and the tunneling magnetoresis-tance (TMR) induced by grain boundary effect. The temperature stability of magnetoresistance is beneficial to the practical applications of MR.展开更多
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.
基金supported by the National Natural Science Foundation of China under Grants No.61671367 and 62471381the Research Foundation of Science and Technology on Communication Networks Laboratory,and the National Key Laboratory of Wireless Communications Foundation under Grant No.IFN202401.
文摘Satellite communication plays an important role in 6G systems.However,satellite communication systems are more susceptible to intentional or unintentional interference signals than other communication systems because of their working mechanism of transparent forwarding.For the purpose of eliminating the influence of interference,this paper develops an angle reciprocal interference suppression scheme based on the reconstruction of interferenceplus-noise covariance matrix(ARIS-RIN).Firstly,we utilize the reciprocity between the known beam central angle and the unknown signal arrival angle to estimate the angle of arrival(AOA)of desired signal due to the multi-beam coverage.Then,according to the priori known spatial spectrum distribution,the interferenceplus-noise covariance matrix(INCM)is reconstructed by integrating within the range except the direction of desired signal.In order to correct the estimation bias of the first two steps,the worst-case performance optimization technology is adopted in the process of solving the beamforming vector.Numerical simulation results show that the developed scheme:1)has a higher output signal-to-interference-plus-noise ratio(SINR)under arbitrary signal-to-noise ratio(SNR);2)still has good performance under small snapshots;3)is robuster and easier to be realized when comparing with minimum variance distortionless response(MVDR)and the traditional diagonal loading algorithms.
文摘BACKGROUND Demineralized bone matrix(DBM)is a commonly utilized allogenic bone graft substitute to promote osseous union.However,little is known regarding outcomes following DBM utilization in foot and ankle surgical procedures.AIM To evaluate the clinical and radiographic outcomes following DBM as a biological adjunct in foot and ankle surgical procedures.METHODS During May 2023,the PubMed,EMBASE and Cochrane library databases were systematically reviewed to identify clinical studies examining outcomes following DBM for the management of various foot and ankle pathologies.Data regarding study characteristics,patient demographics,subjective clinical outcomes,radiological outcomes,complications,and failure rates were extracted and analyzed.In addition,the level of evidence(LOE)and quality of evidence(QOE)for each individual study was also assessed.Thirteen studies were included in this review.RESULTS In total,363 patients(397 ankles and feet)received DBM as part of their surgical procedure at a weighted mean follow-up time of 20.8±9.2 months.The most common procedure performed was ankle arthrodesis in 94 patients(25.9%).Other procedures performed included hindfoot fusion,1st metatarsophalangeal joint arthrodesis,5th metatarsal intramedullary screw fixation,hallux valgus correction,osteochondral lesion of the talus repair and unicameral talar cyst resection.The osseous union rate in the ankle and hindfoot arthrodesis cohort,base of the 5th metatarsal cohort,and calcaneal fracture cohort was 85.6%,100%,and 100%,respectively.The weighted mean visual analog scale in the osteochondral lesions of the talus cohort improved from a pre-operative score of 7.6±0.1 to a post-operative score of 0.4±0.1.The overall complication rate was 27.2%,the most common of which was non-union(8.8%).There were 43 failures(10.8%)all of which warranted a further surgical procedure.CONCLUSION This current systematic review demonstrated that the utilization of DBM in foot and ankle surgical procedures led to satisfactory osseous union rates with favorable wound complication rates.Excellent outcomes were observed in patients undergoing fracture fixation augmented with DBM,with mixed evidence supporting the routine use of DBM in fusion procedures of the ankle and hindfoot.However,the low LOE together with the low QOE and significant heterogeneity between the included studies reinforces the need for randomized control trials to be conducted to identify the optimal role of DBM in the setting of foot and ankle surgical procedures.
基金Supported in part by Natural Science Foundation of Guangxi(2023GXNSFAA026246)in part by the Central Government's Guide to Local Science and Technology Development Fund(GuikeZY23055044)in part by the National Natural Science Foundation of China(62363003)。
文摘In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.
基金supported by the National Natural Science Foundation of China(62376106)The Science and Technology Development Plan of Jilin Province(20250102212JC).
文摘Driven by advancements in mobile internet technology,images have become a crucial data medium.Ensuring the security of image information during transmission has thus emerged as an urgent challenge.This study proposes a novel image encryption algorithm specifically designed for grayscale image security.This research introduces a new Cantor diagonal matrix permutation method.The proposed permutation method uses row and column index sequences to control the Cantor diagonal matrix,where the row and column index sequences are generated by a spatiotemporal chaotic system named coupled map lattice(CML).The high initial value sensitivity of the CML system makes the permutation method highly sensitive and secure.Additionally,leveraging fractal theory,this study introduces a chaotic fractal matrix and applies this matrix in the diffusion process.This chaotic fractal matrix exhibits selfsimilarity and irregularity.Using the Cantor diagonal matrix and chaotic fractal matrix,this paper introduces a fast image encryption algorithm involving two diffusion steps and one permutation step.Moreover,the algorithm achieves robust security with only a single encryption round,ensuring high operational efficiency.Experimental results show that the proposed algorithm features an expansive key space,robust security,high sensitivity,high efficiency,and superior statistical properties for the ciphered images.Thus,the proposed algorithm not only provides a practical solution for secure image transmission but also bridges fractal theory with image encryption techniques,thereby opening new research avenues in chaotic cryptography and advancing the development of information security technology.
文摘We read with the great interest the study by Ababneh et al in which inducedmesenchymal stem cell-derived exosomes were shown to exhibit a stronger andmore sustained anti-proliferative effect by inducing a senescence-like state withoutapoptosis.The results obtained by the authors highlight the features of theeffects of senescent drift induction in surrounding tissues.In the light of thesefindings,the role of the properties of extracellular matrix and cellular glycocalyxin responses of human tumors to therapy remain uninvestigated.These extracellularbarriers appear to be significant obstacles to effective cancer therapy,especiallyin relation to the use of unique properties of tumor microenvironment forthe immunotherapy-resistant cancer treatment.
基金supported by the Shenzhen Hong Kong Joint Funding Project,No.SGDX20230116093645007(to LY)the Shenzhen Science and Technology Innovation Committee International Cooperation Project,No.GJHZ20200731095608025(to LY)+7 种基金Shenzhen Development and Reform Commission’s Intelligent Diagnosis,Treatment and Prevention of Adolescent Spinal Health Public Service Platform,No.S2002Q84500835(to LY)Shenzhen Medical Research Fund,No.B2303005(to LY)Team-based Medical Science Research Program,No.2024YZZ02(to LY)Zhejiang Provincial Natural Science Foundation of China,No.LWQ20H170001(to RL)Basic Research Project of Shenzhen Science and Technology from Shenzhen Science and Technology Innovation Commission,No.JCYJ20210324103010029(to BY)Shenzhen Second People’s Hospital Clinical Research Fund of Guangdong Province High-level Hospital Construction Project,Nos.2023yjlcyj029(to BY),2023yjlcyj021(to LL)Guangdong Basic and Applied Basic Research Foundation,No.2022A1515110679(to LL)China Postdoctoral Science Foundation,No.2022M722203(to GL).
文摘Peripheral nerve injury causes severe neuroinflammation and has become a global medical challenge.Previous research has demonstrated that porcine decellularized nerve matrix hydrogel exhibits excellent biological properties and tissue specificity,highlighting its potential as a biomedical material for the repair of severe peripheral nerve injury;however,its role in modulating neuroinflammation post-peripheral nerve injury remains unknown.Here,we aimed to characterize the anti-inflammatory properties of porcine decellularized nerve matrix hydrogel and their underlying molecular mechanisms.Using peripheral nerve injury model rats treated with porcine decellularized nerve matrix hydrogel,we evaluated structural and functional recovery,macrophage phenotype alteration,specific cytokine expression,and changes in related signaling molecules in vivo.Similar parameters were evaluated in vitro using monocyte/macrophage cell lines stimulated with lipopolysaccharide and cultured on porcine decellularized nerve matrix hydrogel-coated plates in complete medium.These comprehensive analyses revealed that porcine decellularized nerve matrix hydrogel attenuated the activation of excessive inflammation at the early stage of peripheral nerve injury and increased the proportion of the M2 subtype in monocytes/macrophages.Additionally,porcine decellularized nerve matrix hydrogel negatively regulated the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB axis both in vivo and in vitro.Our findings suggest that the efficacious anti-inflammatory properties of porcine decellularized nerve matrix hydrogel induce M2 macrophage polarization via suppression of the Toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-κB pathway,providing new insights into the therapeutic mechanism of porcine decellularized nerve matrix hydrogel in peripheral nerve injury.
文摘Objectives:High-grade serous ovarian cancer(HGSOC),the most common subtype of epithelial ovarian cancer(EOC),exhibits a mesenchymal phenotype characterized by fibrotic stroma and poor prognosis.Human epididymis protein 4(HE4),a key diagnostic biomarker for ovarian cancer,is involved in fibrotic processes in several non-malignant diseases.Given the clinical significance of stromal fibrosis in HGSOC and the potential link between HE4 and fibrosis,this study aimed to investigate the role of HE4 in the formation of stromal fibrosis in HGSOC.Methods:A total of 126 patients with gynecological conditions were included and divided into normal,benign,and EOC groups.Tissue stiffness was quantitatively measured and analyzed for its correlation with clinicopathological features.We further investigated the correlation between tumor stiffness and the expression levels of HE4 and fibroblast activation markers(α-smooth muscle actin(α-SMA)and fibroblast activation protein(FAP))in tumor tissues from 22 HGSOC patients.In vitro,primary fibroblasts were treated with recombinant HE4(rHE4)or conditioned media from HE4-knockdown ovarian cancer cells to assess fibroblasts activation and matrix contractility(Collagen gel contraction assays).In vivo,a subcutaneous xenograft model using HE4-knockdown cells was established to evaluate the effects of HE4 suppression on tumor growth and extensive extracellular matrix(ECM)remodeling.Results:Ovarian cancer tissues showed significantly increased stiffness compared to benign/normal groups,showing positive correlation with serum HE4 levels.High-stiffness HGSOC tumors exhibited upregulated expression of HE4,α-SMA,FAP,and collagen I.rHE4 stimulated fibroblast activation and enhanced matrix contractility,whereas HE4 knockdown in cancer cells abrogated these pro-fibrotic effects.In vivo,HE4-silenced xenografts displayed restricted tumor growth accompanied by reduced stromal expression ofα-SMA,FAP,and collagen I.Conclusion:Our findings suggest that HE4 may facilitate ECM remodeling in HGSOC through promoting fibroblast activation and increasing collagen deposition.
基金Project(50875199) supported by the National Natural Science Foundation of ChinaProject supported by State Key Laboratory of Advanced Welding and Joining,China
文摘To improve the wettability of Al metal matrix composites（Al-MMCs） by common filler metals,Al-12Si-xTi（x=0.1,0.5,1,3.0;mass fraction,%） system active ternary filler metals were prepared.It was demonstrated that although the added Ti existed within Ti（Al1-xSix）3（0≤x≤0.15） phase,the shear strength and shear fracture surface of the developed Al-12Si-xTi brazes were quite similar to those of traditional Al-12Si braze due to the presence of similar microstructure of Al-Si eutectic microstructure with large volume fraction.So,small Ti addition（～1%） did not make the active brazes brittle and hard compared with the conventional Al-12Si braze.The measured melting range of each Al-12Si-xTi foil was very similar,i.e.,580-590 ℃,because the composition was close to that of eutectic.For wettability improvement,with increasing Ti content,the interfacial gap between the Al2O3 reinforcement and filler metal（R/M） could be eliminated,and the amount of the remainder of the active fillers on the composite substrate decreased after sessile drop test at 610 ℃ for 30 min.So,the wettability improvement became easy to observe repeatedly with increasing Ti content.Additionally,the amount and size of Ti（AlSi）3 phase were sensitive to the Ti content（before brazing） and Si content（after brazing）.
文摘The reservoir-monolithic type of the controlled release systems is investigated currently,however,the existing kinetic model could not describe the release process well because the release kinetics is rather complicated.In this paper,a simplified release kinetic model for diffusion-controlled monolithic matrix coated with outer membrane systems is proposed and verified by the experimental data of mercaptopurinum release experiment.It shows that the model can well describe the release mechanism (the relative error is under 3%) when drug loading (C d) is above its solubility limit (C s).At the same time,the release characteristics of special cases (D mD f and D mD f) are discussed theoretically.When D mD f the release rate becomes constant,namely,zero order release,and the release rate is independent of the drug membrane.This result provides the theoretical basis for the system of zero order release as well as how to control the release rate and the amount of drug release.When D mD f,the release rate is dependent on the drug release coefficient in the monolithic matrix,solubility and drug loading but independent of the process in the outer membrane,and it is similar to monolithic matrix type.
文摘A plane-based and linear camera calibration technique without considering lens distortion is proposed in a greedy and intuitive framework for the binocular camera system. Characteristic homography matrix and consistency constraints in close range are employed in this calibration. First, in order to calculate the internal geometries of the cameras, total least-square fitting as a robust tool for the geometrical cost function is exploited to recover the accurate principal point of each camera from all the characteristic lines of the homography matrices for all model planes. Secondly, generic prior knowledge of the aspect ratio of pixel cells is incorporated into the system to obtain the exact principal length in each camera. Thirdly, extrinsic geometries are accurately computed for all planar patterns with respect to each monocular camera. Finally, the rigid displacement between binocular cameras can be obtained by imposing the consistency constraints in 3-space geometry. Both simulation and real image experimental results indicate that reasonably reliable results can be obtained by this technique. And the proposed method is sufficient for applications where high precision is not required and can be easily performed by common computer users who are not experts in computer vision.
文摘Generally unitary solution to the system of martix equations over the quaternion field [X mA ns =B ns ,X nn C nt =D nt ] is considered. A necessary and sufficient condition for the existence of and the expression for the generally unitary solution of the system are derived.
文摘Minor self conjugate (msc) and skewpositive semidefinite (ssd) solutions to the system of matrix equations over skew fields [A mn X nn =A mn ,B sn X nn =O sn ] are considered. Necessary and sufficient conditions for the existence of and the expressions for the msc solutions and the ssd solutions are obtained for the system.
基金This project is supported by the National Education Foundation of China
文摘For an AKNS matrix system,Lie algebraic structure and its mastersymmetry are obtained by a purely algebraic approach;and by using the reduced technique,two similar algebraic structures for MKdV and KdV matrix systems are given.
文摘AIM: To investigate the relationship between matrix metalloproteinase-2 (MMP-2) mRNA expression and clinicopathologic and urokinase-type plasminogen activator (uPA) system parameter and prognosis in human gastric cancer. METHODS: Expression of MMP-2 mRNA, uPA, and uPA-R mRNA in tumor tissues and ≥5 cm adjacent normal tissues from 67 cases of gastric cancer was studied using RT-PCR and Northern blot respectively.Survival analyses were done using the Kaplan-Meier method. RESULTS: The expression rates of MMP-2 mRNA,uPA and uPA-R mRNA in tumor tissues (31%,41%,and 51%, respectively) were significantly higher than those in ≥5 cm adjacent tissues (19%, 11%, and 9%; X2=4.59,43.58, and 53.24 respectively, P<0.05,0.0001,and 0.0001, respectively). Expression of MMP-2 mRNA was significantly correlated with lymph node metastasis (metastasis: 61.9%, no metastasis: 39.1%, X2= 7.61, P<0.05),Lauren's classification of diffuse/mixed types:54.2%,intestinal type: 26.3%,X2 = 4.25, P<0.05, expression of uPA and uPA-R mRNA (uPA+: 55.1%, uPA-: 22.2% and uPA-R+: 54.9%, uPA-R-: 18.8%, X2=5.72 and 6.40 respectively, P<0.05).Kaplan-Meier survival analysis of MMP-2 mRNA expression did not show significant difference in all 67 cases, but revealed an association of the expression of MMP-2 mRNA, uPA, and uPA-R mRNA with worse prognosis (P= 0.0083, 0.0160, and 0.0094, respectively). CONCLUSION: MMP-2 may play an important role in the development of invasion and metastasis of gastric cancer.
基金supported by a grant from the Natural Science Foundation of China(41271044)
文摘To characterize effects of plant roots on preferential flow（PF）,we measured root length density（RLD）and root biomass（RB） in Jiufeng National Forest Park,Beijing,China.Comparisons were made for RLD and RB between soil preferential pathways and soil matrices.RLD and RB declined with the increasing soil depth（0–10,10–20,20–30,30–40,40–50,50–60 cm） in all experimental plots.RLD was greater in soil preferential pathways than in the surrounding soil matrix and was 69.5,75.0 and72.2 % for plant roots of diameter（d） ／1,1 ／ d ／ 3 and3 ／ d ／ 5 mm,respectively.Fine root systems had the most pivotal influence on soil preferential flow in this forest ecosystem.In all experimental plots,RB content was the sum of RB from soil preferential pathways and the soil matrix in each soil depth.With respect to 6 soil depth gradient（0–10,10–20,20–30,30–40,40–50,50–60 cm） in each plot,the number of soil depth gradient that RB content was greater in soil preferential pathways than in the soil matrix was characterized,and the proportion was68.2 % in all plots.
基金This work was supported by the Basic Program in Natural Sciences, Vietnam and Thai Research Fund Grant, Thailand
文摘In this paper, we address the stabilization problem for linear periodically time-varying switched systems. Using discretization technique, we derive new conditions for the global stabilizability in terms of the solution of matrix inequalities. An algorithm for finding stabilizing controller and switching strategy is presented.
基金supported by the National Natural Foundation of China (No. 19934003) the Natural Science Research Key Program of Anhui Educational Committee (No. KJ2011A259)+3 种基金the Opening Program of Cultivating Base of Anhui Key Laboratory of Spintronics and Nanomaterials (Nos. 2010YKF04 2011YKF05)the Professors’and Doctors’Research Startup Foundation of Suzhou University (Nos. 2011jb01 2011jb02)
文摘A series of (1-x)La0.6Dy0.1Sr0.3MnO3/0.5x(Sb2O3)(x=0.15) samples were prepared by the solid-state reaction method, and the influence of sintering temperature of the matrix on low-field magnetoresistance of (1-x)La0.6Dy0.1Sr0.3MnO3/0.5x (Sb2O3) was studied through the measurements of X-ray diffraction (XRD) patterns, scanning electron microscope (SEM) image, resistivity-temperature (ρ-T) curves, and magnetoresistance-temperature (MR-T) curves. The results indicate that for the samples with low sintering temperature of the matrix, lowfield magnetoresistance effect appears on the whole temperature range and can be explained by grain boundary effect; for the sample with high sintering temperature of the matrix, intrinsic magnetoresistance peak appears on the high-temperature range, low-field magnetore-sistance effect appears on low temperature range, and the magnetoresistance in the magnetic field of 0.2 T and on the comparatively large temperature range between 280 K and 225 K hardly changes with temperature and remains at 4.8%, which can be explained by the competition between the intrinsic magnetoresistance induced by double-exchange function inside grains and the tunneling magnetoresis-tance (TMR) induced by grain boundary effect. The temperature stability of magnetoresistance is beneficial to the practical applications of MR.
