Multi-armed nanorods and nanobars of semiconductor selenium were simultane- ously synthesized in the light of biomineralization process through bio-membrane bi-templates of rush at room temperature. The multi-armed na...Multi-armed nanorods and nanobars of semiconductor selenium were simultane- ously synthesized in the light of biomineralization process through bio-membrane bi-templates of rush at room temperature. The multi-armed nanorods are 60 nm in diameter and 1.5 μm in length; the nanobars are 150 nm in diameter and 1000—1100 nm in length. The XRD pattern indicates that these nanocrystals were crystallized in the hexagonal structure with lattice constants a = 0.437 nm, c = 0.495 nm. The possible formation mechanism was investigated.展开更多
The phospholipid membrane plays a key role in myriad biological processes and phenomena, and the arrangement structure of membrane determines its function. However, the molecular arrangement structure of phospholipids...The phospholipid membrane plays a key role in myriad biological processes and phenomena, and the arrangement structure of membrane determines its function. However, the molecular arrangement structure of phospholipids in cell membranes is difficult to detect experimentally. On the basis of molecular dynamic simulations both in a non-destructive way and at native environment, we observed and confirmed that the phospholipids self-assemble to a hexagonal arrangement structure under physiological conditions. The underlying mechanism was revealed to be that there are hexagonal arrangement regions with a lower free energy around each lipid molecule. The findings potentially advance the understanding of biological functions of phospholipid bilayers.展开更多
Natural composites, formed through biomineralization, have highly ordered structures which have been aptly explored for functional applications. Though the role of organic phases has been well understood in biomineral...Natural composites, formed through biomineralization, have highly ordered structures which have been aptly explored for functional applications. Though the role of organic phases has been well understood in biomineralization, not enough attention has been paid to the role of bio-membranes which are often found encapsulating the chamber in which mineralization occurs. We have used the natural protein and semi-permeable membrane of chicken eggs to grow different materials such as ceramics, semi-metals and metals to understand the role of bio-membranes in biomineralization. We here report the successful biomimetic synthesis of calcite, cadmium sulphide, and silver having homogeneous morphologies. We have found that the membrane operates like a tuned gateway, playing a significant role in controlling the morphology of the inorganic crystals formed during biomineralization.展开更多
In this paper, we study numerical approximations of a recently proposed phase field model for the vesicle membrane deformation governed by the variation of the elastic bending energy. To overcome the challenges of hig...In this paper, we study numerical approximations of a recently proposed phase field model for the vesicle membrane deformation governed by the variation of the elastic bending energy. To overcome the challenges of high order nonlinear differential systems and the nonlinear constraints associated with the problem, we present the phase field bending elasticity model in a nested saddle point formulation. A mixed finite element method is then employed to compute the equilibrium configuration of a vesicle membrane with prescribed volume and surface area. Coupling the approximation results for a related linearized problem and the general theory of Brezzi-Rappaz-Raviart, optimal order error estimates for the finite element approximations of the phase field model are obtained. Numerical results are provided to substantiate the derived estimates.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.20175013&20471042)Nano-Foundation of Shanghai in China(Grant Nos.0259 nm021,0352 nm129).
文摘Multi-armed nanorods and nanobars of semiconductor selenium were simultane- ously synthesized in the light of biomineralization process through bio-membrane bi-templates of rush at room temperature. The multi-armed nanorods are 60 nm in diameter and 1.5 μm in length; the nanobars are 150 nm in diameter and 1000—1100 nm in length. The XRD pattern indicates that these nanocrystals were crystallized in the hexagonal structure with lattice constants a = 0.437 nm, c = 0.495 nm. The possible formation mechanism was investigated.
基金Project supported by the National Natural Science Foundation of China(Grant No.11904231)the National Key R&D Program of China(Grant Nos.2018YFE0205501 and 2018YFB1801500)Shanghai Sailing Program,China(Grant No.19YF1434100)。
文摘The phospholipid membrane plays a key role in myriad biological processes and phenomena, and the arrangement structure of membrane determines its function. However, the molecular arrangement structure of phospholipids in cell membranes is difficult to detect experimentally. On the basis of molecular dynamic simulations both in a non-destructive way and at native environment, we observed and confirmed that the phospholipids self-assemble to a hexagonal arrangement structure under physiological conditions. The underlying mechanism was revealed to be that there are hexagonal arrangement regions with a lower free energy around each lipid molecule. The findings potentially advance the understanding of biological functions of phospholipid bilayers.
文摘Natural composites, formed through biomineralization, have highly ordered structures which have been aptly explored for functional applications. Though the role of organic phases has been well understood in biomineralization, not enough attention has been paid to the role of bio-membranes which are often found encapsulating the chamber in which mineralization occurs. We have used the natural protein and semi-permeable membrane of chicken eggs to grow different materials such as ceramics, semi-metals and metals to understand the role of bio-membranes in biomineralization. We here report the successful biomimetic synthesis of calcite, cadmium sulphide, and silver having homogeneous morphologies. We have found that the membrane operates like a tuned gateway, playing a significant role in controlling the morphology of the inorganic crystals formed during biomineralization.
文摘In this paper, we study numerical approximations of a recently proposed phase field model for the vesicle membrane deformation governed by the variation of the elastic bending energy. To overcome the challenges of high order nonlinear differential systems and the nonlinear constraints associated with the problem, we present the phase field bending elasticity model in a nested saddle point formulation. A mixed finite element method is then employed to compute the equilibrium configuration of a vesicle membrane with prescribed volume and surface area. Coupling the approximation results for a related linearized problem and the general theory of Brezzi-Rappaz-Raviart, optimal order error estimates for the finite element approximations of the phase field model are obtained. Numerical results are provided to substantiate the derived estimates.
