The Kirschner wire(K-wire)is widely used in orthopedic external fixation due to its versatility and clinical effectiveness.However,a significant challenge associated with its use is the potential for bacterial migrati...The Kirschner wire(K-wire)is widely used in orthopedic external fixation due to its versatility and clinical effectiveness.However,a significant challenge associated with its use is the potential for bacterial migration,subsequent infection,and dislodgement as the wire penetrates the skin and bone.This study introduces a novel bioactive material,selenium/calcium silicate(Se/β-CS),achieved by integrating selenium-an essential trace element in the human body-into bioceramic calcium silicate.This integration was accomplished using a combined chemical co-deposition method and redox reaction.Furthermore,a uniform and controllable Se/β-CS coating was applied to the K-wire's surface using the Langmuir-Blodgett technique.This coating gradually releases active components-Si,Ca,and Se-that effectively eliminate bacterial infections and promote osteointegration.The findings of this study offer promising opportunities for the use of robust and multifunctional coating materials on implantable devices,particularly within the fields of orthopedics,transplantation,and surgery.展开更多
A hypersurface x(M)in Lorentzian space R41 is called conformal homogeneous,if for any two points p,q on M,there exists,a conformal transformation of R41,such that(x(M))=x(M),(x(p))=x(q).In this paper,the authors gi...A hypersurface x(M)in Lorentzian space R41 is called conformal homogeneous,if for any two points p,q on M,there exists,a conformal transformation of R41,such that(x(M))=x(M),(x(p))=x(q).In this paper,the authors give a complete classifica-tion for regular time-like conformal homogeneous hypersurfaces in R41 with three distinct principal curvatures.展开更多
Let Q^3 be the common conformal compactification space of the Lorentzian space forms Q^31,S^31,We study the conformal geometry of space-like surfaces in Q^3,It is shown that any conformal CMC-surface in Q^3 must be co...Let Q^3 be the common conformal compactification space of the Lorentzian space forms Q^31,S^31,We study the conformal geometry of space-like surfaces in Q^3,It is shown that any conformal CMC-surface in Q^3 must be conformally equivalent to a constant mean curvature surface in R^31,or,H^31,We also show that if x:M→Q^3 is a space-like Willmore surface whose conformal metric g has constant curvature K,the either K=-1 and x is conformally equivalent to a minimal surface in R^31,or K=0 and x is conformally equivalent to the surface H^1(1/√2)×H^1(1/√2)in H^31.展开更多
Photocleavable hydrogels are of great importance in the field of controlled drug delivery,stem cell fate regulation,surface patterning,and intelligent devices.However,the development of novel photocleavable gel system...Photocleavable hydrogels are of great importance in the field of controlled drug delivery,stem cell fate regulation,surface patterning,and intelligent devices.However,the development of novel photocleavable gel systems by visible light is usually met with challenges such as the lack of efficient and tunable photocleavable groups and reactions.Herein,we reported the facile fabrication of a new type of photocleavable hydrogels by the direct gelation of 4-arm thiol-terminated polyethylene glycol with 3,6-dichloro-1,2,4,5-tetrazine via the formation of S,S-tetrazine linkages.The prepared hydrogels underwent efficient degradation upon irradiation by ultraviolet or green light,and the degradation kinetics could be significantly promoted by hydrogen peroxide.Correspondingly,the hydrogels loaded with calcium peroxide microparticles or glucose oxidase/catalase enzymes enabled the precise and efficient in vivo photocontrol of gel degradation and drug release for cancer treatment.This work offers a promising and facile strategy towards the fabrication of visible light cleavable hydrogels with tunable and ondemand drug release properties.展开更多
Submanifolds in space forms satisfy the well-known DDVV inequality. A submanifold attaining equality in this inequality pointwise is called a Wintgen ideal submanifold. As conformal invariant objects, Wintgen ideal su...Submanifolds in space forms satisfy the well-known DDVV inequality. A submanifold attaining equality in this inequality pointwise is called a Wintgen ideal submanifold. As conformal invariant objects, Wintgen ideal submanifolds are investigated in this paper using the framework of MSbius geometry. We classify Wintgen ideal submanfiolds of dimension rn ≥ 3 and arbitrary codimension when a canonically defined 2-dimensional distribution D2 is integrable. Such examples come from cones, cylinders, or rotational submanifolds over super-minimal surfaces in spheres, Euclidean spaces, or hyperbolic spaces, respectively. We conjecture that if D2 generates a k-dimensional integrable distribution Dk and k 〈 m, then similar reduction theorem holds true. This generalization when k = 3 has been proved in this paper.展开更多
A three dimensional Lorentzian hypersurface x : M_1~3→ R_1~4 is called conformally flat if its induced metric is conformal to the flat Lorentzian metric, and this property is preserved under the conformal transformat...A three dimensional Lorentzian hypersurface x : M_1~3→ R_1~4 is called conformally flat if its induced metric is conformal to the flat Lorentzian metric, and this property is preserved under the conformal transformation of R_1~4. Using the projective light-cone model, for those whose shape operators have three distinct real eigenvalues, we calculate the integrability conditions by constructing a scalar conformal invariant and a canonical moving frame in this paper. Similar to the Riemannian case, these hypersurfaces can be determined by the solutions to some system of partial differential equations.展开更多
Tang and Zhang(2020)and Choe and Hoppe(2018)showed independently that one can produce minimal submanifolds in spheres via the Clifford type minimal product of minimal submanifolds.In this paper,we show that the minima...Tang and Zhang(2020)and Choe and Hoppe(2018)showed independently that one can produce minimal submanifolds in spheres via the Clifford type minimal product of minimal submanifolds.In this paper,we show that the minimal product is immersed by its first eigenfunctions(of its Laplacian)if and only if the two beginning minimal submanifolds are immersed by their first eigenfunctions.Moreover,we give the estimates of the Morse index and the nullity of the minimal product.In particular,we show that the Clifford minimal submanifold(√n1/nS^(n1).....,√nk/nS^(nk)■S^(n+k-1))has the index(k-1)(n+k+1)and the nullity(k-1)∑_(1≤i<j≤k)(n_(i)+1)(nj+1)(with n=∑n_(j)).展开更多
基金financially supported by the foundation of the NMPA Key Laboratory for Quality Evaluation of Medical Protective and Implant Devices,the Shandong Provincial Natural Science Foundation(ZR2021MB096)to Huali Niethe Science and Technology Research Project of Shanghai Songjiang District Science and Technology Committee(No.2023SJKWGG063)+4 种基金the Medical Engineering Cross Research Project of Shanghai Jiaotong University(No.YG2022QN074)to Changping Wangthe National Nature Science Foundation of China(No.32371383)the Shanghai 2023“Science and Technology Innovation Action Plan”Biomedical Science and Technology Support Special Project(No.23S31900100)the Foundation of National Center for Translational Medicine(Shanghai)SHU Branch(No.SUITM-202411)to Siyu Nithe Research Center for the Industries of the Future at Westlake University and the Zhejiang Provincial Natural Science Foundation of China(No.2022XHSJJ003)for support.
文摘The Kirschner wire(K-wire)is widely used in orthopedic external fixation due to its versatility and clinical effectiveness.However,a significant challenge associated with its use is the potential for bacterial migration,subsequent infection,and dislodgement as the wire penetrates the skin and bone.This study introduces a novel bioactive material,selenium/calcium silicate(Se/β-CS),achieved by integrating selenium-an essential trace element in the human body-into bioceramic calcium silicate.This integration was accomplished using a combined chemical co-deposition method and redox reaction.Furthermore,a uniform and controllable Se/β-CS coating was applied to the K-wire's surface using the Langmuir-Blodgett technique.This coating gradually releases active components-Si,Ca,and Se-that effectively eliminate bacterial infections and promote osteointegration.The findings of this study offer promising opportunities for the use of robust and multifunctional coating materials on implantable devices,particularly within the fields of orthopedics,transplantation,and surgery.
基金supported by the Principal’s Fund(No.KJ2020002)the second is supported by the National Natural Science Foundation of China(Nos.11671330 and 11871405)the third is supported by the National Natural Science Foundation of China(Nos.11831005,1196131001).
文摘A hypersurface x(M)in Lorentzian space R41 is called conformal homogeneous,if for any two points p,q on M,there exists,a conformal transformation of R41,such that(x(M))=x(M),(x(p))=x(q).In this paper,the authors give a complete classifica-tion for regular time-like conformal homogeneous hypersurfaces in R41 with three distinct principal curvatures.
基金the National Natural Science Foundation of China(No.10125105)the Research Fund for the Doctoral Program of Higher Education.
文摘Let Q^3 be the common conformal compactification space of the Lorentzian space forms Q^31,S^31,We study the conformal geometry of space-like surfaces in Q^3,It is shown that any conformal CMC-surface in Q^3 must be conformally equivalent to a constant mean curvature surface in R^31,or,H^31,We also show that if x:M→Q^3 is a space-like Willmore surface whose conformal metric g has constant curvature K,the either K=-1 and x is conformally equivalent to a minimal surface in R^31,or K=0 and x is conformally equivalent to the surface H^1(1/√2)×H^1(1/√2)in H^31.
基金This study was supported by the National Key R&D Program of China,Synthetic Biology Research(No.2019YFA0904500)the National Natural Science Foundation of China(21725402 and 21774079)+1 种基金the Shanghai Municipal Science and Technology Commission(188014580)the Guangdong Innovative and Entrepreneurial Research Team Program(2016ZT06C322).
文摘Photocleavable hydrogels are of great importance in the field of controlled drug delivery,stem cell fate regulation,surface patterning,and intelligent devices.However,the development of novel photocleavable gel systems by visible light is usually met with challenges such as the lack of efficient and tunable photocleavable groups and reactions.Herein,we reported the facile fabrication of a new type of photocleavable hydrogels by the direct gelation of 4-arm thiol-terminated polyethylene glycol with 3,6-dichloro-1,2,4,5-tetrazine via the formation of S,S-tetrazine linkages.The prepared hydrogels underwent efficient degradation upon irradiation by ultraviolet or green light,and the degradation kinetics could be significantly promoted by hydrogen peroxide.Correspondingly,the hydrogels loaded with calcium peroxide microparticles or glucose oxidase/catalase enzymes enabled the precise and efficient in vivo photocontrol of gel degradation and drug release for cancer treatment.This work offers a promising and facile strategy towards the fabrication of visible light cleavable hydrogels with tunable and ondemand drug release properties.
基金The authors thank Dr. Zhenxiao Xie for helpful discussion which deepen the understanding of the main results, and they are grateful to the referees for their critical viewpoints and suggestions, which improve the exposition and correct many errors. This work was supported by the National Natural Science Foundation of China （Grant No. 11171004） Xiang Ma was partially supported by the National Natural Science Foundation of China （Grant No. 10901006） and Changping Wang was partially supported by the National Natural Science Foundation of China （Grant No. 11331002）.
文摘Submanifolds in space forms satisfy the well-known DDVV inequality. A submanifold attaining equality in this inequality pointwise is called a Wintgen ideal submanifold. As conformal invariant objects, Wintgen ideal submanifolds are investigated in this paper using the framework of MSbius geometry. We classify Wintgen ideal submanfiolds of dimension rn ≥ 3 and arbitrary codimension when a canonically defined 2-dimensional distribution D2 is integrable. Such examples come from cones, cylinders, or rotational submanifolds over super-minimal surfaces in spheres, Euclidean spaces, or hyperbolic spaces, respectively. We conjecture that if D2 generates a k-dimensional integrable distribution Dk and k 〈 m, then similar reduction theorem holds true. This generalization when k = 3 has been proved in this paper.
基金supported by National Natural Science Foundation of China (Grant Nos. 11331002, 11471021 and 11601513)the Fundamental Research Funds for Central Universitiesthe Project of Fujian Provincial Department of Education (Grant No. JA15123)
文摘A three dimensional Lorentzian hypersurface x : M_1~3→ R_1~4 is called conformally flat if its induced metric is conformal to the flat Lorentzian metric, and this property is preserved under the conformal transformation of R_1~4. Using the projective light-cone model, for those whose shape operators have three distinct real eigenvalues, we calculate the integrability conditions by constructing a scalar conformal invariant and a canonical moving frame in this paper. Similar to the Riemannian case, these hypersurfaces can be determined by the solutions to some system of partial differential equations.
基金supported by National Natural Science Foundation of China(Grant No.11831005)supported by National Natural Science Foundation of China(Grant No.11971107)。
文摘Tang and Zhang(2020)and Choe and Hoppe(2018)showed independently that one can produce minimal submanifolds in spheres via the Clifford type minimal product of minimal submanifolds.In this paper,we show that the minimal product is immersed by its first eigenfunctions(of its Laplacian)if and only if the two beginning minimal submanifolds are immersed by their first eigenfunctions.Moreover,we give the estimates of the Morse index and the nullity of the minimal product.In particular,we show that the Clifford minimal submanifold(√n1/nS^(n1).....,√nk/nS^(nk)■S^(n+k-1))has the index(k-1)(n+k+1)and the nullity(k-1)∑_(1≤i<j≤k)(n_(i)+1)(nj+1)(with n=∑n_(j)).
