Optical coherence tomography angiography(OCTA)is a fast,non-invasive imaging modality that provides detailed information on retinal and choroidal vascular flow and macular structure.OCTA offers an accurate three-dimen...Optical coherence tomography angiography(OCTA)is a fast,non-invasive imaging modality that provides detailed information on retinal and choroidal vascular flow and macular structure.OCTA offers an accurate three-dimensional view of the individual retinal vascular plexuses and the choriocapillaris which facilitates the detection of the microvascular abnormalities in a variety of macular diseases.The perfusion indices(vessel density and flow index)are valuable parameters evaluated by OCTA that allow a quantitative interpretation of changes in the retinal vasculature that can reflect the severity of disease.Crystalline retinopathy encompasses a group of conditions whose distinctive feature is the presence of retinal crystals often located in the posterior pole.Select crystalline retinopathies also demonstrate retinal vascular abnormalities as well.Considering that the OCTA is a novel imaging modality and crystalline retinopathies are relatively rare conditions,there are currently few reports of OCTA findings associated with crystalline retinopathy.The advent of OCTA allows visualization of vascular and structural changes in crystalline retinopathies that are unique and cannot be appreciated on other imaging modalities,including fluorescein angiography(FA).This article reviews novel OCTA findings which provide new insights in the pathogenesis of crystalline retinopathies,including Bietti crystalline retinopathy,talc retinopathy,macular telangiectasia type 2,tamoxifen retinopathy,and Sjögren-Larsson Syndrome maculopathy.展开更多
Cu 5%Cr alloy bulk material with submicron grains were fabricated by mechanical alloying and subsequent hot hydrostatic extrusion. The microstructure, mechanical properties and electrical conductivity of the alloy wer...Cu 5%Cr alloy bulk material with submicron grains were fabricated by mechanical alloying and subsequent hot hydrostatic extrusion. The microstructure, mechanical properties and electrical conductivity of the alloy were experimentally investigated, and the influence of the extrusion temperature on its microstructure and properties was made clear. Also, the strengthening mechanism of the alloy was discussed. It was revealed that the microstructure of the alloy is very fine, with an average grain size being about 100～120 nm, and thus possesses significant fine grain strengthening effect, leading to very high mechanical strength of 800～1 000 MPa. Meanwhile, the alloy also possesses quite good electrical conductivity and moderate tensile elongation, with the former in the range of 55%～70%(IACS) and the latter about 5% respectively.展开更多
Warm extrusion of submicron crystalline Cu-5%Cr from 100 ℃ to 600 ℃ was investigated. The effects of different extrusion ratios and different extrusion temperatures on microstructures and properties of submicron cry...Warm extrusion of submicron crystalline Cu-5%Cr from 100 ℃ to 600 ℃ was investigated. The effects of different extrusion ratios and different extrusion temperatures on microstructures and properties of submicron crystalline Cu-5%Cr were studied. The microstructures of the extruded Cu-5%Cr were characterized by backscattered electron images(BSE) and transmission electron microscopy(TEM). The mechanical properties of the extruded Cu-5%Cr were measured by means of microhardness and tension test. The results show that, the deformation, dynamic recovery and dynamic recrystallization of the extruded Cu-5%Cr are mainly produced in Cu matrix. The higher extrusion ratio leads to more uniform microstructure and finer Cu grains. When being extruded in the range of 100?600 ℃ , dynamic recovery of Cu is the dominant process, and dynamic recrystallization of Cu occurred above 300 ℃ is far from end. The most part of microstructure of as-extruded Cu-5%Cr is subcrystallines produced by dynamic recovery, only a few recrystallines exist, and the average size of these grains is not larger than 400 nm. With extrusion temperature rising, the tensile strength and microhardness of Cu-5%Cr decrease, and elongation increases gradually.展开更多
The microstructures and properties after cold drawing and subsequent annealing of submicron crystalline Cu-5%Cr (mass fraction) alloy were investigated. The results show that, the microstructure of submicron crystalli...The microstructures and properties after cold drawing and subsequent annealing of submicron crystalline Cu-5%Cr (mass fraction) alloy were investigated. The results show that, the microstructure of submicron crystalline Cu-5%Cr can be further refined by cold drawing. After cold drawing, the grains of Cu-5%Cr alloy with grain size of 400-500 nm can be refined to be cellular structures and subgrains with size of 100-200 nm. Both strength and ductility of Cu-5%Cr alloy can be enhanced by cold drawing, and the optimal mechanical properties can be achieved with drawing deformation increasing. It is suggested that dislocation glide is still the main mechanism in plastic deformation of submicron crystalline Cu-5%Cr, but grain boundary slide and diffusion may play more and more important roles with drawing deformation increasing. When the cold drawn Cu-5%Cr wires are annealed at 550 ℃, fine recrystal grains with grain size of 200-300 nm can be obtained. Furthermore, there are lots of fine Cr particles precipitated during annealing, by which the recrystallization softening temperatures of the cold drawn Cu-5%Cr wires can be increased to 480-560 ℃. Due to the fact that Cr particles have the effect of restricting Cu grains growth, a favorable structural thermal stability of the submicron crystalline Cu-5%Cr can be achieved, and the submicron grained microstructure can be retained at high temperature annealing.展开更多
Using the one atom theory, the electronic structures of pure Cr, Mo and W with bcc structure were determined respectively as: [Ar] (3d c) 3.32 (3d n) 2.26 (4s c) 0.25 (4s f) 0.17 , [Kr] (4d c) 4.23 (4d n) 1.48 (5s c) ...Using the one atom theory, the electronic structures of pure Cr, Mo and W with bcc structure were determined respectively as: [Ar] (3d c) 3.32 (3d n) 2.26 (4s c) 0.25 (4s f) 0.17 , [Kr] (4d c) 4.23 (4d n) 1.48 (5s c) 0.02 (5s f) 0.27 and [Xe](5d c) 5.16 (6s c) 0.25 (6s f) 0.59 .The electronic structures of these metals with hcp and fcc structures and liquid state were also studied. According to their electronic structures, the relationship between the electronic structure and crystalline structure was explained qualitatively and the relationship between the difference of mechanical properties and transport properties of pure Cr, Mo and W with bcc structure and their electronic structures was also explained qualitatively; the lattice constants, binding energy, potential curves, elasticities and the temperature dependence of the linear thermal expansion coefficient of bcc Cr, bcc Mo and bcc W were calculated quantitatively.展开更多
AIMTo examine phosphorylation of alphaB-crystallin (p-αBC), a vascular endothelial growth factor (VEGF) chaperone, and immunohistochemically investigate relationship between p-αBC, VEGF and pho...AIMTo examine phosphorylation of alphaB-crystallin (p-αBC), a vascular endothelial growth factor (VEGF) chaperone, and immunohistochemically investigate relationship between p-αBC, VEGF and phosphorylated p38-mitogen-activated protein kinase (p-p38 MAPK) in the epiretinal membrane of human proliferative diabetic retinopathy (PDR).METHODSEleven epiretinal membranes of PDR surgically excised were included in this study. Two normal retinas were also collected from enucleation tissues due to choroidal melanoma. Paraformaldehyde-fixed, paraffin-embedded tissue sections were processed for immunohistochemistry with anti-p-αBC, VEGF, CD31, and p-p38 MAPK antibodies.RESULTSImmunoreactivity for p-αBC was observed in all of the epiretinal membranes examined, where phosphorylation on serine (Ser) 59 showed strongest immunoreactivity in over 70% of the membranes. The immunolocalization of p-αBC was detected in the CD31-positive endothelial cells, and co-localized with VEGF and p-p38 MAPK in PDR membranes. Immunoreactivity for p-αBC, however, was undetectable in endothelial cells of the normal retinas, where p-p38 MAPK immunoreactivity was less marked than PDR membranes.CONCLUSIONPhosphorylation of αBC, in particular, phosphorylation on Ser59 by p-p38 MAPK may play a potential role as a molecular chaperon for VEGF in the pathogenesis of epiretinal membranes in PDR.展开更多
A new technique-series electro-pulse discharge (SEPD)-was developed as a sur-face coating process. In this technique, both positive and negative poles of a pulse power were used as the depositing electrodes with the s...A new technique-series electro-pulse discharge (SEPD)-was developed as a sur-face coating process. In this technique, both positive and negative poles of a pulse power were used as the depositing electrodes with the substrate alloy as an induction electrode. Fe-Cr and Fe-Cr-Y2O3 micro-crystalline coatings were deposited on stain-less steel (Fe-18Cr-8Ni) surfaces. Oxidation at 950℃ in ambient air showed that the coatings greatly improved the oxidation resistance of the steel. The addition of dis-persed Y2O3 nano-particles into the alloy coatings was found to further reduce the scaling rate and enhance the adhesion of oxide scales.展开更多
Prpose: To observe different features of indocyanine green angiography(ICGA) andtifocal electroretinography (ERG) in the diffuse and regional type of Bieti′sc stalline retinopathy (BCR). Thods: ICGA and the multifoca...Prpose: To observe different features of indocyanine green angiography(ICGA) andtifocal electroretinography (ERG) in the diffuse and regional type of Bieti′sc stalline retinopathy (BCR). Thods: ICGA and the multifocal ERG were performed in two cases of the diffuse andregional type of BCR respectively. These data were compared with fluoresceinangiography (FA), standard Ganzfeld ERG, and visual field testing. Results: In the regional case, ICGA revealed reduced perfusion of the choroidalcirculation in the early phase and multiple hypofluorescent spots in the posterior pole in the late phase, due to choriocapillaris filling defect; the extent of choroiocapillaris losswas shown in early phase of ICGA and there were multifocal hyperfluorescent dotssurrounding hypofluorescent spots in late phase in the diffuse case. The multifocal ERGshowed that the central responses were markedly depressed, corresponding to the visualfield defects, while the findings of Ganzfeld ERG were normal in the regional BCR;however, both the multifocal ERG and Ganzfeld ERG were severely subnormal in thediffuse case.Conclusions: The features of ICGA and multifocal ERG are different between the diffuseand regional BCR. In the meantime, the two tools are also useful to differentiate the typeand assess the extentof evolution in BCR.展开更多
文摘Optical coherence tomography angiography(OCTA)is a fast,non-invasive imaging modality that provides detailed information on retinal and choroidal vascular flow and macular structure.OCTA offers an accurate three-dimensional view of the individual retinal vascular plexuses and the choriocapillaris which facilitates the detection of the microvascular abnormalities in a variety of macular diseases.The perfusion indices(vessel density and flow index)are valuable parameters evaluated by OCTA that allow a quantitative interpretation of changes in the retinal vasculature that can reflect the severity of disease.Crystalline retinopathy encompasses a group of conditions whose distinctive feature is the presence of retinal crystals often located in the posterior pole.Select crystalline retinopathies also demonstrate retinal vascular abnormalities as well.Considering that the OCTA is a novel imaging modality and crystalline retinopathies are relatively rare conditions,there are currently few reports of OCTA findings associated with crystalline retinopathy.The advent of OCTA allows visualization of vascular and structural changes in crystalline retinopathies that are unique and cannot be appreciated on other imaging modalities,including fluorescein angiography(FA).This article reviews novel OCTA findings which provide new insights in the pathogenesis of crystalline retinopathies,including Bietti crystalline retinopathy,talc retinopathy,macular telangiectasia type 2,tamoxifen retinopathy,and Sjögren-Larsson Syndrome maculopathy.
文摘Cu 5%Cr alloy bulk material with submicron grains were fabricated by mechanical alloying and subsequent hot hydrostatic extrusion. The microstructure, mechanical properties and electrical conductivity of the alloy were experimentally investigated, and the influence of the extrusion temperature on its microstructure and properties was made clear. Also, the strengthening mechanism of the alloy was discussed. It was revealed that the microstructure of the alloy is very fine, with an average grain size being about 100～120 nm, and thus possesses significant fine grain strengthening effect, leading to very high mechanical strength of 800～1 000 MPa. Meanwhile, the alloy also possesses quite good electrical conductivity and moderate tensile elongation, with the former in the range of 55%～70%(IACS) and the latter about 5% respectively.
文摘Warm extrusion of submicron crystalline Cu-5%Cr from 100 ℃ to 600 ℃ was investigated. The effects of different extrusion ratios and different extrusion temperatures on microstructures and properties of submicron crystalline Cu-5%Cr were studied. The microstructures of the extruded Cu-5%Cr were characterized by backscattered electron images(BSE) and transmission electron microscopy(TEM). The mechanical properties of the extruded Cu-5%Cr were measured by means of microhardness and tension test. The results show that, the deformation, dynamic recovery and dynamic recrystallization of the extruded Cu-5%Cr are mainly produced in Cu matrix. The higher extrusion ratio leads to more uniform microstructure and finer Cu grains. When being extruded in the range of 100?600 ℃ , dynamic recovery of Cu is the dominant process, and dynamic recrystallization of Cu occurred above 300 ℃ is far from end. The most part of microstructure of as-extruded Cu-5%Cr is subcrystallines produced by dynamic recovery, only a few recrystallines exist, and the average size of these grains is not larger than 400 nm. With extrusion temperature rising, the tensile strength and microhardness of Cu-5%Cr decrease, and elongation increases gradually.
文摘The microstructures and properties after cold drawing and subsequent annealing of submicron crystalline Cu-5%Cr (mass fraction) alloy were investigated. The results show that, the microstructure of submicron crystalline Cu-5%Cr can be further refined by cold drawing. After cold drawing, the grains of Cu-5%Cr alloy with grain size of 400-500 nm can be refined to be cellular structures and subgrains with size of 100-200 nm. Both strength and ductility of Cu-5%Cr alloy can be enhanced by cold drawing, and the optimal mechanical properties can be achieved with drawing deformation increasing. It is suggested that dislocation glide is still the main mechanism in plastic deformation of submicron crystalline Cu-5%Cr, but grain boundary slide and diffusion may play more and more important roles with drawing deformation increasing. When the cold drawn Cu-5%Cr wires are annealed at 550 ℃, fine recrystal grains with grain size of 200-300 nm can be obtained. Furthermore, there are lots of fine Cr particles precipitated during annealing, by which the recrystallization softening temperatures of the cold drawn Cu-5%Cr wires can be increased to 480-560 ℃. Due to the fact that Cr particles have the effect of restricting Cu grains growth, a favorable structural thermal stability of the submicron crystalline Cu-5%Cr can be achieved, and the submicron grained microstructure can be retained at high temperature annealing.
文摘Using the one atom theory, the electronic structures of pure Cr, Mo and W with bcc structure were determined respectively as: [Ar] (3d c) 3.32 (3d n) 2.26 (4s c) 0.25 (4s f) 0.17 , [Kr] (4d c) 4.23 (4d n) 1.48 (5s c) 0.02 (5s f) 0.27 and [Xe](5d c) 5.16 (6s c) 0.25 (6s f) 0.59 .The electronic structures of these metals with hcp and fcc structures and liquid state were also studied. According to their electronic structures, the relationship between the electronic structure and crystalline structure was explained qualitatively and the relationship between the difference of mechanical properties and transport properties of pure Cr, Mo and W with bcc structure and their electronic structures was also explained qualitatively; the lattice constants, binding energy, potential curves, elasticities and the temperature dependence of the linear thermal expansion coefficient of bcc Cr, bcc Mo and bcc W were calculated quantitatively.
基金Supported by the Research foundation of the Japan Society for the Promotion of Science(JSPS)(No.15K10856)Scientific Research from The Ministry of Education,Culture,Sports,Science,and Technology(MEXT)
文摘AIMTo examine phosphorylation of alphaB-crystallin (p-αBC), a vascular endothelial growth factor (VEGF) chaperone, and immunohistochemically investigate relationship between p-αBC, VEGF and phosphorylated p38-mitogen-activated protein kinase (p-p38 MAPK) in the epiretinal membrane of human proliferative diabetic retinopathy (PDR).METHODSEleven epiretinal membranes of PDR surgically excised were included in this study. Two normal retinas were also collected from enucleation tissues due to choroidal melanoma. Paraformaldehyde-fixed, paraffin-embedded tissue sections were processed for immunohistochemistry with anti-p-αBC, VEGF, CD31, and p-p38 MAPK antibodies.RESULTSImmunoreactivity for p-αBC was observed in all of the epiretinal membranes examined, where phosphorylation on serine (Ser) 59 showed strongest immunoreactivity in over 70% of the membranes. The immunolocalization of p-αBC was detected in the CD31-positive endothelial cells, and co-localized with VEGF and p-p38 MAPK in PDR membranes. Immunoreactivity for p-αBC, however, was undetectable in endothelial cells of the normal retinas, where p-p38 MAPK immunoreactivity was less marked than PDR membranes.CONCLUSIONPhosphorylation of αBC, in particular, phosphorylation on Ser59 by p-p38 MAPK may play a potential role as a molecular chaperon for VEGF in the pathogenesis of epiretinal membranes in PDR.
基金This project was supported by The National Natural Science Foundation of China (Grant No. 59801002).
文摘A new technique-series electro-pulse discharge (SEPD)-was developed as a sur-face coating process. In this technique, both positive and negative poles of a pulse power were used as the depositing electrodes with the substrate alloy as an induction electrode. Fe-Cr and Fe-Cr-Y2O3 micro-crystalline coatings were deposited on stain-less steel (Fe-18Cr-8Ni) surfaces. Oxidation at 950℃ in ambient air showed that the coatings greatly improved the oxidation resistance of the steel. The addition of dis-persed Y2O3 nano-particles into the alloy coatings was found to further reduce the scaling rate and enhance the adhesion of oxide scales.
文摘Prpose: To observe different features of indocyanine green angiography(ICGA) andtifocal electroretinography (ERG) in the diffuse and regional type of Bieti′sc stalline retinopathy (BCR). Thods: ICGA and the multifocal ERG were performed in two cases of the diffuse andregional type of BCR respectively. These data were compared with fluoresceinangiography (FA), standard Ganzfeld ERG, and visual field testing. Results: In the regional case, ICGA revealed reduced perfusion of the choroidalcirculation in the early phase and multiple hypofluorescent spots in the posterior pole in the late phase, due to choriocapillaris filling defect; the extent of choroiocapillaris losswas shown in early phase of ICGA and there were multifocal hyperfluorescent dotssurrounding hypofluorescent spots in late phase in the diffuse case. The multifocal ERGshowed that the central responses were markedly depressed, corresponding to the visualfield defects, while the findings of Ganzfeld ERG were normal in the regional BCR;however, both the multifocal ERG and Ganzfeld ERG were severely subnormal in thediffuse case.Conclusions: The features of ICGA and multifocal ERG are different between the diffuseand regional BCR. In the meantime, the two tools are also useful to differentiate the typeand assess the extentof evolution in BCR.
