AIM:To propose a novel classification system for late postoperative capsular block syndrome(CBS)based on the turbidity of intracapsular fluid,and to investigate the imaging and refractive changes before and after Nd:Y...AIM:To propose a novel classification system for late postoperative capsular block syndrome(CBS)based on the turbidity of intracapsular fluid,and to investigate the imaging and refractive changes before and after Nd:YAG laser posterior capsulotomy for each subtype.METHODS:A retrospective analysis was performed on 5 eyes from 5 patients with late postoperative CBS.Patients were categorized into turbid(3 eyes)or clear(2 eyes)types based on the turbidity of intracapsular fluid.Uncorrected visual acuity(UCVA),best-corrected visual acuity(BCVA),refractive status,slit-lamp images,Pentacam Scheimpflug data,and ultrasound biomicroscopy(UBM)images were evaluated before and 1mo after successful Nd:YAG laser posterior capsulotomy.RESULTS:Nd:YAG laser posterior capsulotomy significantly improved UCVA and BCVA in all 5 late CBS eyes.Pentacam imaging:turbid intracapsular fluid showed hyperreflection between posterior capsule and intraocular lens(IOL);clear fluid showed hyporeflection.UBM:posterior capsule was clear in turbid type but poorly defined in clear type.Capsulotomy increased aqueous depth only in clear type.Refractive changes:turbid fluid induced myopic shift.Clear type myopic shift was due to anterior IOL displacement and clear fluid-induced concave lens effect.CONCLUSION:Nd:YAG laser posterior capsulotomy is effective for late CBS.Turbid and clear late CBS types differ in imaging(Pentacam/UBM)and refractive mechanisms,supporting the proposed classification’s clinical value.展开更多
The combination of dual-main-phase(DMP)(Nd,Ce)-Fe-B magnets and grain boundary diffusion process(GBDP)is currently a research topic for obtaining high-cost performance materials in rare earth permanent magnet fields.T...The combination of dual-main-phase(DMP)(Nd,Ce)-Fe-B magnets and grain boundary diffusion process(GBDP)is currently a research topic for obtaining high-cost performance materials in rare earth permanent magnet fields.The novel structural features of GBDP(Nd,Ce)-Fe-B magnets give a version of different domain reversal processes from those of non-diffused magnets.In this work,the in-situ magnetic domain evolution of the DMP magnets was observed at elevated temperatures,and the temperature demagnetization and coercivity mechanism of the GBDP dual-main-phase(Nd,Ce)-Fe-B magnets are discussed.The results show that the shell composition of different types of grains in DMP magnets is similar,while the magnetic microstructure results indicate the Ce-rich grains tend to demagnetize first.Dy-rich shell with a high anisotropic field caused by GBDP leads to an increase in the nucleation field,which enhances the coercivity.It is found that much more grains exhibit single domain characteristics in the remanent state for GBDP dual-main-phase(Nd,Ce)-Fe-B magnets.In addition,the grains that undergo demagnetization first are Ce-rich or Nd-rich grains,which is different from that of non-diffused magnets.These results were not found in previous studies but can be intuitively characterized from the perspective of magnetic domains in this work,providing a new perspective and understanding of the performance improvement of magnetic materials.展开更多
The microstructure of(Nd,Ce)-Fe-B sintered magnets with different diffusion depths was characterized by a magnetic force microscope,and the relationship between the magnetic properties and the local structure of grain...The microstructure of(Nd,Ce)-Fe-B sintered magnets with different diffusion depths was characterized by a magnetic force microscope,and the relationship between the magnetic properties and the local structure of grain boundary diffused magnets is discussed.The domains perpendicular to the c-axis(easy magnetization direction)show a typical maze-like pattern,while those parallel to the c-axis show the characte ristics of plate domains.The significant gradient change is shown in the concentration of Dy with the direction of diffusion from the surface to the interior.Dy diffuses along grain boundaries and(Dy,Nd)_(2)Fe_(14)B layer with a high anisotropy field formed around the grains.Through in-situ electron probe micro-analysis/magnetic force microscopy(EPMA/MFM),it is found that the average domain width decreases,and the proportion of single domain grains increases as diffusion depth increases.This is caused by both the change of concentration and distribution of Dy.The grain boundary diffusion process changes the microstructure and microchemistry inside the magnet,and these local magnetism differences can be reflected by the configuration of the magnetic domain structure.展开更多
基金Supported by the Research and Development Program of Shaanxi Province(No.2021SF-161)the Medical Research Project of Xi’an Science and Technology Action Plan[No.2019114613YX001SF041(1)]。
文摘AIM:To propose a novel classification system for late postoperative capsular block syndrome(CBS)based on the turbidity of intracapsular fluid,and to investigate the imaging and refractive changes before and after Nd:YAG laser posterior capsulotomy for each subtype.METHODS:A retrospective analysis was performed on 5 eyes from 5 patients with late postoperative CBS.Patients were categorized into turbid(3 eyes)or clear(2 eyes)types based on the turbidity of intracapsular fluid.Uncorrected visual acuity(UCVA),best-corrected visual acuity(BCVA),refractive status,slit-lamp images,Pentacam Scheimpflug data,and ultrasound biomicroscopy(UBM)images were evaluated before and 1mo after successful Nd:YAG laser posterior capsulotomy.RESULTS:Nd:YAG laser posterior capsulotomy significantly improved UCVA and BCVA in all 5 late CBS eyes.Pentacam imaging:turbid intracapsular fluid showed hyperreflection between posterior capsule and intraocular lens(IOL);clear fluid showed hyporeflection.UBM:posterior capsule was clear in turbid type but poorly defined in clear type.Capsulotomy increased aqueous depth only in clear type.Refractive changes:turbid fluid induced myopic shift.Clear type myopic shift was due to anterior IOL displacement and clear fluid-induced concave lens effect.CONCLUSION:Nd:YAG laser posterior capsulotomy is effective for late CBS.Turbid and clear late CBS types differ in imaging(Pentacam/UBM)and refractive mechanisms,supporting the proposed classification’s clinical value.
基金supported by the National Key Research and Development Program of China(Nos.2021YFB3503003,2021YFB3503100,and 2022YFB3505401).
文摘The combination of dual-main-phase(DMP)(Nd,Ce)-Fe-B magnets and grain boundary diffusion process(GBDP)is currently a research topic for obtaining high-cost performance materials in rare earth permanent magnet fields.The novel structural features of GBDP(Nd,Ce)-Fe-B magnets give a version of different domain reversal processes from those of non-diffused magnets.In this work,the in-situ magnetic domain evolution of the DMP magnets was observed at elevated temperatures,and the temperature demagnetization and coercivity mechanism of the GBDP dual-main-phase(Nd,Ce)-Fe-B magnets are discussed.The results show that the shell composition of different types of grains in DMP magnets is similar,while the magnetic microstructure results indicate the Ce-rich grains tend to demagnetize first.Dy-rich shell with a high anisotropic field caused by GBDP leads to an increase in the nucleation field,which enhances the coercivity.It is found that much more grains exhibit single domain characteristics in the remanent state for GBDP dual-main-phase(Nd,Ce)-Fe-B magnets.In addition,the grains that undergo demagnetization first are Ce-rich or Nd-rich grains,which is different from that of non-diffused magnets.These results were not found in previous studies but can be intuitively characterized from the perspective of magnetic domains in this work,providing a new perspective and understanding of the performance improvement of magnetic materials.
基金Project supported by the National Key Research and Development Program of China(2021YFB3503003,2021YFB3503100,2022YFB3505401)。
文摘The microstructure of(Nd,Ce)-Fe-B sintered magnets with different diffusion depths was characterized by a magnetic force microscope,and the relationship between the magnetic properties and the local structure of grain boundary diffused magnets is discussed.The domains perpendicular to the c-axis(easy magnetization direction)show a typical maze-like pattern,while those parallel to the c-axis show the characte ristics of plate domains.The significant gradient change is shown in the concentration of Dy with the direction of diffusion from the surface to the interior.Dy diffuses along grain boundaries and(Dy,Nd)_(2)Fe_(14)B layer with a high anisotropy field formed around the grains.Through in-situ electron probe micro-analysis/magnetic force microscopy(EPMA/MFM),it is found that the average domain width decreases,and the proportion of single domain grains increases as diffusion depth increases.This is caused by both the change of concentration and distribution of Dy.The grain boundary diffusion process changes the microstructure and microchemistry inside the magnet,and these local magnetism differences can be reflected by the configuration of the magnetic domain structure.
