Total Reflection and Negative Refraction of Dipole-Exchange Spin Waves at Magnetic Interfaces: Micromagnetic Modeling Study

We demonstrated that dipole-exchange spin waves traveling in geometrically restricted magnetic thin films satisfy the same laws of reflection and refraction as light waves. Moreover, we found for the first time novel wave behaviors of dipole-exchange spin waves such as total reflection and negative refraction. The total reflection in laterally inhomogeneous thin films composed of two different magnetic materials is associated with the forbidden modes of refracted dipole-exchange spin waves. The negative refraction occurs at a 90 degree domain-wall magnetic interface that is introduced by a cubic magnetic anisotropy in the media, through the anisotropic dispersion of dipole-exchange spin waves.Comment: 13 pages, 5 figure

Escuelas promotoras de la salud: un programa multicompente para prevenir los riesgos conductuales en adolescentes (2014-2017)

DOI: 10.26439/persona2020.n023(1).4834 This article is based on the analysis of the systematization of the Health Promoting School project implemented in Lima, Peru, from 2014 to 2017 by an agreement between the International cooperation agency of South Korea and the Ministry of health in Peru. A description of the phases developed, the strategies used, and the alliances built for their implementation will be presented. For that purpose, a review of secondary sources and interviews to key players as primary sources were made. The project considered the prevention and health promotion paradigms as complementary ones.DOI: 10.26439/persona2020.n023(1).4834 Este artículo se basa en el análisis de la sistematización del Proyecto de las Escuelas Promotoras de la Salud, implementado en Lima, Perú, del 2014 al 2017, a través de un acuerdo entre la Agencia de Cooperación Internacional de Corea del Sur, y el ministerio de Salud de Perú. Se describe el desarrollo de las fases del proyecto, las estrategias que se usaron, así como las alianzas que se construyeron para la implementación del proyecto. Para el análisis se revisaron fuentes secundarias y se entrevistaron a los agentes clave, como fuentes primarias. Consideramos que los paradigmas de prevención y promoción de la salud deben ser considerados como complementarios

The Neuroprotective Effect of Methanol Extract of Gagamjungjihwan and Fructus Euodiae on Ischemia-Induced Neuronal and Cognitive Impairment in the Rat

Gagamjungjihwan (GJ), a decoction consisting of five herbs including ginseng, Acori Graminei Rhizoma, Uncariae Ramulus et Uncus, Polygalae Radic and Frustus Euodiae (FE), has been widely used as herbal treatment for ischemia. In order to investigate the neuroprotective action of this novel prescription, we examined the influence of GJ and FE on learning and memory using the Morris water maze and studied their affects on the central cholinergic system in the hippocampus with neuronal and cognitive impairment. After middle cerebral artery occlusion was applied for 2 h, rats were administered GJ (200 mg kg−1, p.o.) or FE (200 mg kg−1, p.o.) daily for 2 weeks, followed by training and performance of the Morris water maze tasks. Rats with ischemic insults showed impaired learning and memory of the tasks. Pre-treatment with GJ and FE produced improvement in the escape latency to find the platform. Pre-treatments with GJ and FE also reduced the loss of cholinergic immunoreactivity in the hippocampus. The results demonstrated that GJ and FE have a protective effect against ischemia-induced neuronal and cognitive impairment. Our results suggest that GJ and FE might be useful in the treatment of vascular dementia

Nitric oxide directly activates calcium-activated potassium channels from rat brain reconstituted into planar lipid bilayer

AbstractUsing the planar lipid bilayer technique, we tested whether NO directly activates calcium-activated potassium (Maxi-K) channels isolated from rat brain. We used streptozotocin (STZ) as NO donor, and the NO release was controlled with light. In the presence of 100–800 μM STZ, the Maxi-K channel activity increased up to 3-fold within several tens of seconds after the light was on, and reversed to the control level several minutes after shutting off the light. Similar activation was observed with other NO donors such as S-nitroso-N-acetylpenicillamine and sodium nitroprusside. The degree of activity increase was dependent upon the initial open probability (Pinit). When the Pinit was lower, the activity increase was greater. These results demonstrate that NO can directly affect the Maxi-K channel activity, and suggest that the Maxi-K channel might be one of the physiological targets of NO in brain

Lattice-patterned LC-polymer composites containing various nanoparticles as additives

In this study, we show the effect of various nanoparticle additives on phase separation behavior of a lattice-patterned liquid crystal [LC]-polymer composite system and on interfacial properties between the LC and polymer. Lattice-patterned LC-polymer composites were fabricated by exposing to UV light a mixture of a prepolymer, an LC, and SiO2 nanoparticles positioned under a patterned photomask. This resulted in the formation of an LC and prepolymer region through phase separation. We found that the incorporation of SiO2 nanoparticles significantly affected the electro-optical properties of the lattice-patterned LC-polymer composites. This effect is a fundamental characteristic of flexible displays. The electro-optical properties depend on the size and surface functional groups of the SiO2 nanoparticles. Compared with untreated pristine SiO2 nanoparticles, which adversely affect the performance of LC molecules surrounded by polymer walls, SiO2 nanoparticles with surface functional groups were found to improve the electro-optical properties of the lattice-patterned LC-polymer composites by increasing the quantity of SiO2 nanoparticles. The surface functional groups of the SiO2 nanoparticles were closely related to the distribution of SiO2 nanoparticles in the LC-polymer composites, and they influenced the electro-optical properties of the LC molecules. It is clear from our work that the introduction of nanoparticles into a lattice-patterned LC-polymer composite provides a method for controlling and improving the composite's electro-optical properties. This technique can be used to produce flexible substrates for various flexible electronic devices

Risk factors for post-contrast acute kidney injury in patients sequentially administered iodine- and gadolinium-based contrast media on the same visit to the emergency department: a retrospective study

Background This study compares the incidence of post-contrast acute kidney injury (PC-AKI) in patients who received a single administration of iodine-based contrast medium (ICM) with that in patients who received a sequential administration of ICM and gadolinium-based contrast agents (GBCA) in a single visit to an emergency department (ED) to determine the risk factors for PC-AKI. Methods Patients who received one or more contrast media in the ED from 2016 to 2021 were included in this retrospective study. They were divided into the ICM alone and ICM + GBCA groups, and the incidence of PC-AKI was compared between the groups. The risk factors were assessed using a multivariable analysis after propensity score matching (PSM). Results Overall, 6,318 patients were analyzed, of whom 139 were in the ICM + GBCA group. The incidence of PC-AKI was significantly higher in the ICM + GBCA group than in the ICM alone group (10.9% vs. 27.3%, p < 0.001). In the multivariable analysis, sequential administration was a risk factor for PC-AKI, and single administration was not (adjusted odds ratio [95% confidence interval] in the 1:1, 2:1, and 3:1 PSM cohorts: 2.38 [1.25–4.55], 2.13 [1.26–3.60], and 2.28 [1.39–3.72], respectively). In subgroup analyses of the ICM + GBCA group, osmolality (1.05 [1.01–1.10]) and estimated glomerular filtration rate (eGFR, 0.93 [0.88–0.98]) were associated with PC-AKI. Conclusion Compared with a single administration of ICM alone, sequential administration of ICM and GBCA during a single ED visit might be a risk factor for PC-AKI. Osmolality and eGFR might be associated with PC-AKI after sequential administration

Vascular Protective Role of Samul-Tang in HUVECs: Involvement of Nrf2/HO-1 and NO

Samul-Tang (Si-Wu-Tang, SMT), composed of four medicinal herbs, is a well-known herbal formula treating hematological disorder or gynecologic disease. However, vascular protective effects of SMT and its molecular mechanisms on the vascular endothelium, known as the central spot of vascular inflammatory process, are not reported. The aim of this study was to investigate vascular protective effects of SMT water extract in human umbilical vein endothelial cells (HUVECs). Water extract of SMT was prepared and identified by HPLC-PDA analysis. Expression of cell adhesion molecules (CAMs) and heme oxygenase-1 (HO-1) and translocation of nuclear factor-kappa B (NF-κB) and nuclear factor-erythroid 2-related factor 2 (Nrf2) were determined by western blot. Nuclear localization of NF-κB and Nrf2 was visualized by immunofluorescence and DNA binding activity of NF-κB was measured. ROS production, HL-60 monocyte adhesion, and intracellular nitric oxide (NO) were also measured using a fluorescent indicator. SMT suppressed NF-κB translocation and activation as well as expression of CAMs, monocyte adhesion, and ROS production induced by TNF-α in HUVECs. SMT treated HUVECs showed upregulation of HO-1 and NO which are responsible for vascular protective action. Our study suggests that SMT, a traditionally used herbal formula, protects the vascular endothelium from inflammation and might be used as a promising vascular protective drug

A Case of Small Bowel Obstruction Due to a Paracecal Hernia

Internal hernias are rare causes of small bowel obstruction, and one such internal hernia is the paracecal hernia. We report a case of a small bowel obstruction related to a paracecal hernia in which a preoperative diagnosis was made on computed tomography. A laparotomy was performed for definitive diagnosis and treatment. The surgery achieved a good outcome