Glucose transporter 4 (GLUT4) is responsible for insulin-stimulated glucose transporting into the insulin-sensitive fat and muscle cells. The dynamics of GLUT4 storage vesicles (GSVs) remains to be explored and it is ...Glucose transporter 4 (GLUT4) is responsible for insulin-stimulated glucose transporting into the insulin-sensitive fat and muscle cells. The dynamics of GLUT4 storage vesicles (GSVs) remains to be explored and it is unclear how GSVs are arranged based on their mobility. We examined this issue in 3T3-L1 cells via investigating the three-dimensional mobility of single GSV labeled with EGFP-fused GLUT4. A thin layer of cytosol right adjacent to the plasma membrane was illuminated and successively imaged at 5 Hz under a total internal reflection fluorescence microscope with a penetration depth of 136 nm. Employing single particle tracking, the three-dimensional subpixel displacement of single GSV was tracked at a spatial precision of 22 nm. Both the mean square displacement and the diffusion coefficient were calculated for each vesicle. Tracking results revealed that vesicles moved as if restricted within a cage that has a mean radius of 160 nm, suggesting the presence of some intracellular tethering matrix. By constructing the histogram of the diffusion coefficients of GSVs, we observed a smooth distribution instead of the existence of distinct groups. The result indicates that GSVs are dynamically retained in a continuous and wide range of mobility rather than into separate classes.展开更多
INSULIN secretion was traditionally measured with biochemical and immunological methods such as enzyme linked immunosorbant assay and radioimmunoassay. However, these methods can only tell the amount of insulin secret...INSULIN secretion was traditionally measured with biochemical and immunological methods such as enzyme linked immunosorbant assay and radioimmunoassay. However, these methods can only tell the amount of insulin secreted; they give no information about the secretion process or mechanism of exocytosis. In recent years, an imaging technique known as total internal reflection fluorescence （TIRF） microscopy has been employed to study insulin secretion.展开更多
Ultraviolet(UV)visualization has extensive applications in military and civil fields such as security monitoring,space communication,and wearable equipment for health monitoring in the internet of things(IoT).Due to t...Ultraviolet(UV)visualization has extensive applications in military and civil fields such as security monitoring,space communication,and wearable equipment for health monitoring in the internet of things(IoT).Due to their remarkable optoelectronic features,perovskite materials are regarded as promising candidates for UV light detecting and imaging.Herein,we report for the first time the excitationdependent perovskite/polymer films with dynamically tunable fluorescence ranging from green to magenta by changing the UV excitation from 260 to 380 nm.And they still render dynamic multicolor UV light imaging with different polymer matrixes,halogen ratios,and cations of perovskite materials.The mechanism of its fluorescence change is related to the chloride vacancies in perovskite materials.A patterned multi-color ultraviolet visualization pad is also demonstrated for visible conversion of the UV region.This technique may provide a universal strategy for information securities,UV visualizations,and dynamic multi-color displays in the IoT.展开更多
We investigate theoretically the electron-reflection phenomenon in a graphene n＋n junction based on electron optics, where the local potential in the left n ＋ region is higher than that in the right n region. It is ...We investigate theoretically the electron-reflection phenomenon in a graphene n＋n junction based on electron optics, where the local potential in the left n ＋ region is higher than that in the right n region. It is demonstrated numerically that electrons emitting from a point source in the n ＋ region will experience total internal reflection through the interface of the junction. The reflection becomes stronger and the transmission becomes weaker with decrease of the local potential in the right graphene ribbon. It is also found that when a nonideal interface is considered in the junction, the electron-reflection effect is enhanced due to interracial backseattering.展开更多
To evaluate the light field display system with a liquid crystal display(LCD) and a holographic functional screen(HFS),the voxel theory based on the ray tracing is used.By analyzing the voxels defined by the cases of ...To evaluate the light field display system with a liquid crystal display(LCD) and a holographic functional screen(HFS),the voxel theory based on the ray tracing is used.By analyzing the voxels defined by the cases of corresponding pixels overlapping completely and partially in the image space,the resolution characteristics of the system are discussed.The theoretical model is verified in the reconstruction experiment of a resolution target and compared with the calculation result of the presented system.Finally,we give an optimization method for the display image quality.展开更多
文摘Glucose transporter 4 (GLUT4) is responsible for insulin-stimulated glucose transporting into the insulin-sensitive fat and muscle cells. The dynamics of GLUT4 storage vesicles (GSVs) remains to be explored and it is unclear how GSVs are arranged based on their mobility. We examined this issue in 3T3-L1 cells via investigating the three-dimensional mobility of single GSV labeled with EGFP-fused GLUT4. A thin layer of cytosol right adjacent to the plasma membrane was illuminated and successively imaged at 5 Hz under a total internal reflection fluorescence microscope with a penetration depth of 136 nm. Employing single particle tracking, the three-dimensional subpixel displacement of single GSV was tracked at a spatial precision of 22 nm. Both the mean square displacement and the diffusion coefficient were calculated for each vesicle. Tracking results revealed that vesicles moved as if restricted within a cage that has a mean radius of 160 nm, suggesting the presence of some intracellular tethering matrix. By constructing the histogram of the diffusion coefficients of GSVs, we observed a smooth distribution instead of the existence of distinct groups. The result indicates that GSVs are dynamically retained in a continuous and wide range of mobility rather than into separate classes.
文摘INSULIN secretion was traditionally measured with biochemical and immunological methods such as enzyme linked immunosorbant assay and radioimmunoassay. However, these methods can only tell the amount of insulin secreted; they give no information about the secretion process or mechanism of exocytosis. In recent years, an imaging technique known as total internal reflection fluorescence （TIRF） microscopy has been employed to study insulin secretion.
基金supported by the National Natural Science Foundation of China(52125205,11974317,11674290,U20A20166,U1704138,52192614,61805015,and 61804011)the National Key R&D Program of China(2021YFB3200302 and 2021YFB3200304)+5 种基金Natural Science Foundation of Beijing Municipality(Z180011 and 2222088)Shenzhen Science and Technology Program(KQTD20170810105439418)the Fundamental Research Funds for the Central UniversitiesHenan Science Fund for Distinguished Young Scholars(212300410020)Key Project of Henan Higher Education(21A140001)the Zhengzhou University Physics Discipline Improvement Program。
文摘Ultraviolet(UV)visualization has extensive applications in military and civil fields such as security monitoring,space communication,and wearable equipment for health monitoring in the internet of things(IoT).Due to their remarkable optoelectronic features,perovskite materials are regarded as promising candidates for UV light detecting and imaging.Herein,we report for the first time the excitationdependent perovskite/polymer films with dynamically tunable fluorescence ranging from green to magenta by changing the UV excitation from 260 to 380 nm.And they still render dynamic multicolor UV light imaging with different polymer matrixes,halogen ratios,and cations of perovskite materials.The mechanism of its fluorescence change is related to the chloride vacancies in perovskite materials.A patterned multi-color ultraviolet visualization pad is also demonstrated for visible conversion of the UV region.This technique may provide a universal strategy for information securities,UV visualizations,and dynamic multi-color displays in the IoT.
基金Supported by the Science Research&Train Program of(SRTP)Southeast University for Undergraduates
文摘We investigate theoretically the electron-reflection phenomenon in a graphene n＋n junction based on electron optics, where the local potential in the left n ＋ region is higher than that in the right n region. It is demonstrated numerically that electrons emitting from a point source in the n ＋ region will experience total internal reflection through the interface of the junction. The reflection becomes stronger and the transmission becomes weaker with decrease of the local potential in the right graphene ribbon. It is also found that when a nonideal interface is considered in the junction, the electron-reflection effect is enhanced due to interracial backseattering.
基金supported by the National High Technology Research and Development Program of China(Nos.2012AA011902 and 2015AA015902)the National Natural Science Foundation of China(No.61177018)+1 种基金the State Key Laboratory of Information Photonics and Optical Communicationsthe Program of Beijng Science and Technology Plan(No.D121100004812001)
文摘To evaluate the light field display system with a liquid crystal display(LCD) and a holographic functional screen(HFS),the voxel theory based on the ray tracing is used.By analyzing the voxels defined by the cases of corresponding pixels overlapping completely and partially in the image space,the resolution characteristics of the system are discussed.The theoretical model is verified in the reconstruction experiment of a resolution target and compared with the calculation result of the presented system.Finally,we give an optimization method for the display image quality.
