Micropulse transscelral cyclophotocoagulation is a safe procedure for pediatric as well as adult glaucoma patients. Its effect seems to be short lived in pediatric patients and the rate of reoperation was high.
Electrical detection of topological magnetic textures such as skyrmions is currently limited to conducting materials. While magnetic insulators offer key advantages for skyrmion technologies with high speed and low loss, they have not yet been explored electrically. Here, we report a prominent topological Hall effect in Pt/Tm 3 Fe 5 O 12 bilayers, where the pristine Tm 3 Fe 5 O 12 epitaxial films down to 1.25 unit cell thickness allow for tuning of topological Hall stability over a broad range from 200 to 465 K through atomic-scale thickness control. Although Tm 3 Fe 5 O 12 is insulating, we demonstrate the detection of topological magnetic textures through a novel phenomenon: "spin-Hall topological Hall effect" (SH-THE), where the interfacial spin-orbit torques allow spin-Hall-effect generated spins in Pt to experience the unique topology of the underlying skyrmions in Tm 3 Fe 5 O 12 . This novel electrical detection phenomenon paves a new path for utilizing a large family of magnetic insulators in future skyrmion technologies.
Low-damping magnetic materials have been widely used in microwave and spintronic applications because of their low energy loss and high sensitivity. While the Gilbert damping constant can reach 10−4 to 10−5 in some insulating ferromagnets, metallic ferromagnets generally have larger damping due to magnon scattering by conduction electrons. Meanwhile, low-damping metallic ferromagnets are desired for charge-based spintronic devices. Here, we report the growth of Co25Fe75 epitaxial films with excellent crystalline quality evident by the clear Laue oscillations and exceptionally narrow rocking curve in the X-ray diffraction scans as well as from scanning transmission electron microscopy. Remarkably, the Co25Fe75 epitaxial films exhibit a damping constant <1.4 × 10−3, which is comparable to the values for some high-quality Y3Fe5O12 films. This record low damping for metallic ferromagnets offers new opportunities for charge-based applications such as spin-transfer-torque-induced switching and magnetic oscillations.
Interfacial Dzyaloshinskii-Moriya interaction (DMI) is responsible for the emergence of topological spin textures such as skyrmions in layered structures based on metallic and insulating ferromagnetic films. However, there is active debate on where the interfacial DMI resides in magnetic insulator systems. We investigate the topological Hall effect, which is an indication of spin textures, in Tm 3 Fe 5 O 12 films capped with various metals. The results reveal that Pt, W, and Au induce strong interfacial DMI and topological Hall effect, while Ta and Ti cannot. This study also provides insights into the mechanism of electrical detection of spin textures in magnetic insulator heterostructures.
Wide and ultra-wide band gap semiconductors can provide excellent performance due to their high energy band gap, which leads to breakdown electric fields that are more than an order of magnitude higher than conventional silicon electronics. In materials where p-type doping is not available, achieving this high breakdown field in a vertical diode or transistor is very challenging.We propose and demonstrate the use of dielectric heterojunctions that use extreme permittivity materials to achieve high breakdown field in a unipolar device. We demonstrate the integration of a high permittivity material BaTiO3 with n-type β-Ga2O3 to enable 5.7 MV/cm average electric field and 7 MV/cm peak electric field at the device edge, while maintaining forward conduction with relatively low on-resistance and voltage loss. The proposed dielectric heterojunction could enable new design strategies to achieve theoretical device performance limits in wide and ultrawide band gap semiconductors where bipolar doping is challenging.
To compare the macroscopic and microscopic histologic changes in eyes treated with micropulse transscleral cyclophotocoagulation (MP-TCP) versus continuous wave transscleral cyclophotocoagulation (CW-TCP). Methods: Twelve halves of globes from three pairs of adult cadaveric eyes were randomly assigned to nontreated control, CW-TCP, single MP-TCP treatment, or double MP-TCP treatments, and then sectioned for histologic analysis. Presence or absence of the following four unique histologic changes was recorded: splitting within the ciliary process epithelium (splitting), separation of the pigmented ciliary process epithelium from the stroma (separation), coagulation of collagen and destruction of ciliary process stroma (coagulation), and full-thickness destruction of ciliary process epithelium (destruction). Results: A total of 498 slides were analyzed, and laser scars in all treated specimens were located in the pars plana. Logistic regression analysis showed that compared with controls, CW-TCP-treated specimens were significantly more likely to experience separation (odds ratio [OR] = 11.1, P = 0.02), coagulation (OR = 24.3, P = 0.002), and destruction (OR = 11.1, P = 0.03). Destruction of the ciliary process epithelium was observed exclusively in CW-TCP-treated sections. No significant differences in histologic features were observed between controls and MP-TCP. Conclusions: MP-TCP does not produce significant histologic changes in cadaveric eyes, whereas CW-TCP treatment does. Translational Relevance: These findings improve understanding of the mechanism of MP-TCP, help explain the increased rates of adverse effects following CW-TCP treatment compared with MP-TCP, and describe effects of MP-TCP at various doses.
Purpose: To understand the distribution of trabeculectomies, glaucoma drainage implants (GDI) and micro-invasive glaucoma surgeries (MIGS) performed in the United States through geospatial mapping. Methods: We performed an observational cohort study to evaluate glaucoma surgeries in patients age ≥65. The most recently released data from Centers for Medicare Part B Carrier Summary Files were queried to determine the number of glaucoma surgeries performed per state during the year of 2017. We created choropleth maps, titled "GlaucoMap", to characterize the rates of various surgeries performed across the United States, defined as the number of procedures performed per 10,000 individuals. A chi-squared analysis was further used to evaluate differences in surgical preferences across geographic region. Standardized residuals (SR) were calculated to determine regional influences on surgical distribution. Results: There were 174,788 glaucoma surgeries performed: 22,862 trabeculectomies (13.1%), 19,991 GDI (11.4%) and 131,935 (75.5%) MIGS. The Northeast had the highest trabeculectomy rate, GDI was highest in the Southeast and MIGS were highest in the Southwest. There was a statistically significant difference in proportional use of conventional surgeries versus MIGS across various regions in the United States (p < 0.0001). Given the high trabeculectomy and GDI rates and relatively low MIGS adoption in the Southeast, we observed a +7.03 SR for conventional surgeries and −4.01 SR for MIGS. The Southwest and Western states had the highest MIGS rate and contributed +3.29 and +3.24 SR toward disproportional MIGS preference, respectively. The preference for conventional surgeries in the Northeast (SR = +2.93) and MIGS in the Midwest (SR = +0.99) also contribute to the overall differences in glaucoma surgeries across the United States. Conclusion: GlaucoMap is useful for visualizing the distribution of glaucoma surgeries in the United States. The heterogeneity in surgical preferences points to regional differences in glaucoma management.
Metallic ferromagnets with ultra-low damping are highly desirable for charge-based spintronic applications. Here, we systematically investigate the magnetic dynamics of Co25Fe75 epitaxial films with a Gilbert damping constant as low as 7.1 × 10−4. The in-plane angular dependence of ferromagnetic resonance (FMR) was measured on various thicknesses of Co25Fe75 films grown on MgO and MgAl2O4, from which the mechanisms for FMR linewidth broadening can be distinguished and quantified. The thickness dependencies of the magnetic anisotropy and inhomogeneous broadening of the linewidth are good indicators of crystal quality and magnetic uniformity. Additionally, it is shown that anisotropic two-magnon scattering is induced by defects at the surfaces.
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