Invited; An atomistic understanding of the oxygen vacancies in Pt/TiO2/Ti resistive random access memory: Ab initio study

Resistive random access memory (ReRAM) is a promising next-generation device. However, the mechanism of the resistive switching is still under debate. In the resistive switching metal oxides, it has been generally known that oxygen vacancies are the mobile species and that the conducting filaments (CFs) are composed of the concentrated oxygen vacancies. The atomistic behavior of these concentrated oxygen vacancies is expected to be different from that of an isolated oxygen vacancy, but it has not been intensively considered in most studies. Therefore, we performed ab initio calculations on a model system of Pt/TiO2/Ti device to elucidate the characteristics of the oxygen vacancies, such as the cohesive energy, oxidation number, and diffusion barrier energy, according to the concentration and configuration of the oxygen vacancies. Please click Download on the upper right corner to see the full abstract

Sudden unilateral visual loss after autologous fat injection into the nasolabial fold

A 27-year-old female presented with sudden visual loss of her right eye after receiving an autologous fat injection into the right nasolabial fold. Fundus examination of the right eye showed multiple whitish patchy lesions with macular edema. Fluorescein angiogram showed deterioration of choroidal circulation with patchy choroidal filling and arm-to-retina circulation time and retinal arteriovenous passage time were delayed to 30 seconds and 20 seconds, respectively. There was no response in flash visual evoked potential (VEP). High dose steroid therapy (methylprednisolone 1 g/day/i.v.) was done and about 2 weeks later, the disc edema subsided and retinal arteriovenous passage time of fluorescein angiogram was normalized but there was no improvement in visual acuity. Absence of a cherry red spot, deterioration of choroidal circulation with patchy choroidal fillings seen in fluorescein angiogram, and no response in flash VEP suggests multiple choroidal infarction due to perfusion defect of the short posterior ciliary artery. The autologous fat injected is thought to have entered the dorsal nasal artery and the retrograde migration of the emboli to the ophthalmic artery might have caused the multiple occlusions of the short posterior ciliary artery

Metal/graphene sheets as p-type transparent conducting electrodes in GaN light emitting diodes

We demonstrate the use of graphene based transparent sheets as a p-type current spreading layer in GaN light emitting diodes (LEDs). Very thin Ni/Au was inserted between graphene and p-type GaN to reduce contact resistance, which reduced contact resistance from similar to 5.5 to similar to 0.6 Omega/ cm(2), with no critical optical loss. As a result, LEDs with metal-graphene provided current spreading and injection into the p-type GaN layer, enabling three times enhanced electroluminescent intensity compared with those with graphene alone. We confirmed very strong blue light emission in a large area of the metal-graphene layer by analyzing image brightness.open281

Characterization of Fabry mice treated with recombinant adeno-associated virus 2/8-mediated gene transfer

<p>Abstract</p> <p>Background</p> <p>Enzyme replacement therapy (ERT) with α-galactosidase A (α-Gal A) is currently the most effective therapeutic strategy for patients with Fabry disease, a lysosomal storage disease. However, ERT has limitations of a short half-life, requirement for frequent administration, and limited efficacy for patients with renal failure. Therefore, we investigated the efficacy of recombinant adeno-associated virus (rAAV) vector-mediated gene therapy for a Fabry disease mouse model and compared it with that of ERT.</p> <p>Methods</p> <p>A pseudotyped rAAV2/8 vector encoding α-Gal A cDNA (rAAV2/8-hAGA) was prepared and injected into 18-week-old male Fabry mice through the tail vein. The α-Gal A expression level and globotriaosylceramide (Gb3) levels in the Fabry mice were examined and compared with Fabry mice with ERT. Immunohistochemical and ultrastructural studies were conducted.</p> <p>Results</p> <p>Treatment of Fabry mice with rAAV2/8-hAGA resulted in the clearance of accumulated Gb3 in tissues such as liver, spleen, kidney, heart, and brain with concomitant elevation of α-Gal A enzyme activity. Enzyme activity was elevated for up to 60 weeks. In addition, expression of the α-Gal A protein was identified in the presence of rAAV2/8-hAGA at 6, 12, and 24 weeks after treatment. α-Gal A activity was significantly higher in the mice treated with rAAV2/8-hAGA than in Fabry mice that received ERT. Along with higher α-Gal A activity in the kidney of the Fabry mice treated with gene therapy, immunohistochemical studies showed more α-Gal A expression in the proximal tubules and glomerulus, and less Gb3 deposition in Fabry mice treated with this gene therapy than in mice given ERT. The α-gal A gene transfer significantly reduced the accumulation of Gb3 in the tubules and podocytes of the kidney. Electron microscopic analysis of the kidneys of Fabry mice also showed that gene therapy was more effective than ERT.</p> <p>Conclusions</p> <p>The rAAV2/8-hAGA mediated α-Gal A gene therapy provided improved efficiency over ERT in the Fabry disease mouse model. Furthermore, rAAV2/8-hAGA-mediated expression showed a greater effect in the kidney than ERT.</p

Associations among elder abuse, depression and PTSD in South Korean older adults

Increasing attention is being placed on the prevalence of elder abuse and its impact on mental health. This study conducted a survey of 172 elderly people in South Korea to determine the prevalence of elder abuse and the relationships involving elder abuse, depression and posttraumatic stress disorder (PTSD). Participants completed a battery of self-report questionnaires, which included the Korean Geriatric Depression Screening Scale (KGDS) and Impact of Event Scale-Revised Korean version (IES-R-K). Descriptive analyses were conducted to examine the frequency of specific forms of abuse. Logistic regression models were estimated to identify the factors that contributed to risk of abuse exposure and the relationship between exposure and PTSD or depression. The results indicated around 22% of the participants reported abuse exposure, which most commonly included being refused physical contact, verbal threats, and/or being excluded from decision-making about personal issues. Low education and being unmarried, separated or divorced was associated with an increased risk of abuse exposure. There were strong associations between elder abuse and PTSD symptoms, while comparable relationships with depression were weaker and were not robust to the inclusion of control variables. The findings provided empirical support for the relationship between abuse experiences of the elderly and poor mental health and raise important issues for the mental health care of the elderly