Q63 2002010785生物样品的散射和吸收特性对双光子激发和共焦成像深度的影响=Effect of scattering and absorption prop-erties of biological tissue on two - photon excitationand confocal imaging depth[刊,中]/傅玲,骆清铭,鲁强...Q63 2002010785生物样品的散射和吸收特性对双光子激发和共焦成像深度的影响=Effect of scattering and absorption prop-erties of biological tissue on two - photon excitationand confocal imaging depth[刊,中]/傅玲,骆清铭,鲁强,曾绍群(华中科技大学生物医学光子学研究所.湖北,展开更多
Peripheral nerves are particularly vulnerable to injuries and are involved in numerous pathologies for which specific treatments are lacking. This review summarizes the pathophysiological features of the most common t...Peripheral nerves are particularly vulnerable to injuries and are involved in numerous pathologies for which specific treatments are lacking. This review summarizes the pathophysiological features of the most common traumatic nerve injury in humans and the different animal models used in nerve regeneration studies. ~Ihe current knowledge concerning Wallerian degeneration and nerve regrowth is then described. Finally, the involvement of intraneural vascularization in these processes is addressed. As intraneural vascularization has been poorly studied, histological experiments were carried out from rat sciatic nerves damaged by a glycerol injection. The results, taken together with the data from literature, suggest that revascularization plays an important role in peripheral nerve regeneration and must therefore be studied more carefully.展开更多
To describe strategies for addressing technical aspects of computational modeling of leg tissue with the finite element （FE） method, a patient＇s leg sample was selected and scanned by CT at the direction parallel t...To describe strategies for addressing technical aspects of computational modeling of leg tissue with the finite element （FE） method, a patient＇s leg sample was selected and scanned by CT at the direction parallel to the Frankfort Horizontal plane. A three-dimensional （3D） finite element model of the human leg was developed using the actual geometry of the leg skeleton and soft tissues, which were obtained from 3D reconstruction of CT images. All joints were defined as contact surfaces, which allow relative articulating movement. The major ligaments were simulated using tension-only truss elements by connecting the corresponding attachment points on the bone surfaces. The bony and ligamentous structures were embedded in a volume of soft tissues. The muscles were defined as non-linear viscoelastic material, and the skin, ligaments and tendons were defined as hyperelastic, while the bony structures were assumed to be linearly elastic. The muhilayer FEM model containing thighbone, tibia, fibula, kneecap, soft tissue was formed after meshing. Diverse forces were imposed on the FEM model. The results show that the multilayer FEM model can represent tissue deformation more accurately.展开更多
This paper presents an application of finite element method to study the thermoreg- ulatory behavior of three layers of human dermal parts with varying properties. The investigation of temperature distributions in epi...This paper presents an application of finite element method to study the thermoreg- ulatory behavior of three layers of human dermal parts with varying properties. The investigation of temperature distributions in epidermis, dermis and subcutaneous tissue together with Crank-Nicholson scheme at various atmospheric conditions was carried out. The finite element method has been applied to obtain the numerical solution of gov- erning differential equation for one-dimensional unsteady state bioheat equation using suitable values of parameters that affect the heat transfer in human body. The outer skin is assumed to be exposed to cold atmospheric temperatures and the loss of heat due to convection, radiation and evaporation has been taken into consideration. The important parameters like blood mass flow rate, metabolic heat generation rate and thermal conductivity are taken heterogeneous in each layer according to their distinct physiological and biochemical activities. The temperature profiles at various nodal points of the skin and in vivo tissues have been calculated with respect to the severe cold ambient temperatures. The conditions under which hypothermia, non-freezing and freezing injuries develop were illustrated in the graphs.展开更多
Measurement of optical properties of skin is an expanding and growing field of research.Recent studies have shown that the biological tissue,especially skin,changes the polarization state of the incident light.Using t...Measurement of optical properties of skin is an expanding and growing field of research.Recent studies have shown that the biological tissue,especially skin,changes the polarization state of the incident light.Using this property will enable the study of abnormalities and diseases that alter not only the light intensity but also its polarization state.In this paper we report an experimental study for measuring changes of polarization state of the light scattered from a phantom similar to a sample model of scattering skin.Using the notation of Stokes vector for the polarized light and Mueller matrix for the sample with its polarization properties,we have shown that some elements of the matrix were particularly sensitive to the changes of the polarization-altering physical properties of the scatterers within the phantom.展开更多
文摘Q63 2002010785生物样品的散射和吸收特性对双光子激发和共焦成像深度的影响=Effect of scattering and absorption prop-erties of biological tissue on two - photon excitationand confocal imaging depth[刊,中]/傅玲,骆清铭,鲁强,曾绍群(华中科技大学生物医学光子学研究所.湖北,
基金supported by a doctoral fellowship from the ‘Conseil Régional du Limousin’ to MC
文摘Peripheral nerves are particularly vulnerable to injuries and are involved in numerous pathologies for which specific treatments are lacking. This review summarizes the pathophysiological features of the most common traumatic nerve injury in humans and the different animal models used in nerve regeneration studies. ~Ihe current knowledge concerning Wallerian degeneration and nerve regrowth is then described. Finally, the involvement of intraneural vascularization in these processes is addressed. As intraneural vascularization has been poorly studied, histological experiments were carried out from rat sciatic nerves damaged by a glycerol injection. The results, taken together with the data from literature, suggest that revascularization plays an important role in peripheral nerve regeneration and must therefore be studied more carefully.
基金Sponsored by the Natural Science Foundation of Heilongjiang Province of China(Grant No.200815)the Research Foundation for Talented Scholars ofHarbin (Grant No.2008RFQXS061)
文摘To describe strategies for addressing technical aspects of computational modeling of leg tissue with the finite element （FE） method, a patient＇s leg sample was selected and scanned by CT at the direction parallel to the Frankfort Horizontal plane. A three-dimensional （3D） finite element model of the human leg was developed using the actual geometry of the leg skeleton and soft tissues, which were obtained from 3D reconstruction of CT images. All joints were defined as contact surfaces, which allow relative articulating movement. The major ligaments were simulated using tension-only truss elements by connecting the corresponding attachment points on the bone surfaces. The bony and ligamentous structures were embedded in a volume of soft tissues. The muscles were defined as non-linear viscoelastic material, and the skin, ligaments and tendons were defined as hyperelastic, while the bony structures were assumed to be linearly elastic. The muhilayer FEM model containing thighbone, tibia, fibula, kneecap, soft tissue was formed after meshing. Diverse forces were imposed on the FEM model. The results show that the multilayer FEM model can represent tissue deformation more accurately.
文摘This paper presents an application of finite element method to study the thermoreg- ulatory behavior of three layers of human dermal parts with varying properties. The investigation of temperature distributions in epidermis, dermis and subcutaneous tissue together with Crank-Nicholson scheme at various atmospheric conditions was carried out. The finite element method has been applied to obtain the numerical solution of gov- erning differential equation for one-dimensional unsteady state bioheat equation using suitable values of parameters that affect the heat transfer in human body. The outer skin is assumed to be exposed to cold atmospheric temperatures and the loss of heat due to convection, radiation and evaporation has been taken into consideration. The important parameters like blood mass flow rate, metabolic heat generation rate and thermal conductivity are taken heterogeneous in each layer according to their distinct physiological and biochemical activities. The temperature profiles at various nodal points of the skin and in vivo tissues have been calculated with respect to the severe cold ambient temperatures. The conditions under which hypothermia, non-freezing and freezing injuries develop were illustrated in the graphs.
文摘Measurement of optical properties of skin is an expanding and growing field of research.Recent studies have shown that the biological tissue,especially skin,changes the polarization state of the incident light.Using this property will enable the study of abnormalities and diseases that alter not only the light intensity but also its polarization state.In this paper we report an experimental study for measuring changes of polarization state of the light scattered from a phantom similar to a sample model of scattering skin.Using the notation of Stokes vector for the polarized light and Mueller matrix for the sample with its polarization properties,we have shown that some elements of the matrix were particularly sensitive to the changes of the polarization-altering physical properties of the scatterers within the phantom.
