Current Management and Therapeutic Strategies for Cerebral Amyloid Angiopathy

Cerebral amyloid angiopathy (CAA) is characterized by accumulation of amyloid β (Aβ) in walls of leptomeningeal vessels and cortical capillaries in the brain. The loss of integrity of these vessels caused by cerebrovascular Aβ deposits results in fragile vessels and lobar intracerebral hemorrhages. CAA also manifests with progressive cognitive impairment or transient focal neurological symptoms. Although development of therapeutics for CAA is urgently needed, the pathogenesis of CAA remains to be fully elucidated. In this review, we summarize the epidemiology, pathology, clinical and radiological features, and perspectives for future research directions in CAA therapeutics. Recent advances in mass spectrometric methodology combined with vascular isolation techniques have aided understanding of the cerebrovascular proteome. In this paper, we describe several potential key CAA-associated molecules that have been identified by proteomic analyses (apolipoprotein E, clusterin, SRPX1 (sushi repeat-containing protein X-linked 1), TIMP3 (tissue inhibitor of metalloproteinases 3), and HTRA1 (HtrA serine peptidase 1)), and their pivotal roles in Aβ cytotoxicity, Aβ fibril formation, and vessel wall remodeling. Understanding the interactions between cerebrovascular Aβ deposits and molecules that accumulate with Aβ may lead to discovery of effective CAA therapeutics and to the identification of biomarkers for early diagnosis.     

Theoretical analysis on the relationship between left ventricular energetic efficiency and acute infarct size

Energetic efficiency is an important indicator of cardiac function in acute myocardial infarction. However, the relationship between cardiac energetic efficiency and infarct size is not perfectly elucidated. In this study, the relationship is analysed by means of simulation using a theoretical model of the guinea pig left ventricle. In simulation with varied ratios of infarct area, pressure–volume area (PVA), which is an index of total mechanical energy by ventricular contraction, and myocardial oxygen consumption (MVO₂) are calculated for each infarct ratio. Then, change of PVA when MVO₂ alters (PVA/MVO₂) as a well‐known index of energy conversion efficiency is evaluated. In addition, PVA/VO₂, which represents a ratio of PVA change to alteration of mean oxygen consumption of myocytes except for infarct myocytes, is introduced as an index for real energetic efficiency. In simulation results, PVA/MVO₂ increases but PVA/VO₂ decreases as infarct area expands, because with expansion of infarct area PVA decreases but VO₂ remains almost unchanged because of larger shortening of myocytes. This implies that the enlargement of shortening of noninfarcted myocyte to compensate for depression of cardiac output is a potential cause of myocardial remodelling.Inspec keywords: blood vessels, cardiology, cellular biophysics, haemodynamics, muscle, oxygen, physiological modelsOther keywords: theoretical analysis, left ventricular energetic efficiency, acute infarct size, cardiac function, acute myocardial infarction, cardiac energetic efficiency, guinea pig left ventricle, pressure‐volume area, total mechanical energy, ventricular contraction, myocardial oxygen consumption, energy conversion efficiency, myocyte mean oxygen consumption, infarct myocytes, energetic efficiency index, noninfarcted myocyte shortening enlargement, cardiac output, myocardial remodellingInspec keywords: blood vessels, cardiology, cellular biophysics, haemodynamics, muscle, oxygen, physiological modelsOther keywords: theoretical analysis, left ventricular energetic efficiency, acute infarct size, cardiac function, acute myocardial infarction, cardiac energetic efficiency, guinea pig left ventricle, pressure‐volume area, total mechanical energy, ventricular contraction, myocardial oxygen consumption, energy conversion efficiency, myocyte mean oxygen consumption, infarct myocytes, energetic efficiency index, noninfarcted myocyte shortening enlargement, cardiac output, myocardial remodelling     

Carbon-supported hafnium oxynitride as cathode catalyst for polymer electrolyte membrane fuel cells

Highly stable carbon-supported hafnium oxynitride (HfO_xN_y-C) was synthesized by heating carbon-supported hafnium oxide, prepared using an impregnation method, under NH₃ gas in various conditions. X-ray diffraction patterns, X-ray photoelectron spectra, and field-emission transmission electron microscope images confirmed that HfO_xN_y nanoparticles were dispersed onto commercial carbon black, Vulcan XC-72. The stability of HfO_xN_y-C in 0.1 mol dm⁻³ H₂SO₄ at 303 K was evaluated by measuring the mass ratio of dissolved hafnium to immersed HfO_xN_y-C using inductively coupled plasma atomic emission spectroscopy. It saturated at a low level of 0.8–4.0 mg g⁻¹ with increasing immersion time up to ∼24 h. The oxygen reduction reaction (ORR) activity and rate were evaluated by obtaining cyclic voltammograms and rotating disk electrode voltammograms, respectively. The HfO_xN_y-C exhibited higher ORR activity and a lower Tafel slope than NH₃-treated C under identical conditions, demonstrating that HfO_xN_y is active toward ORR. The ORR activity most depended on the heating temperature. The ORR rate increased with increasing the heating time at 1223 K which could be due to the increased y in HfO_xN_y-C. The maximum onset potential for ORR was 0.78 V vs. standard hydrogen electrode, which is 0.18 V lower than that of carbon-supported platinum.     

Transformable device that can switch between rigid body and soft body

The materials for transformable robots can roughly be categorized into two types, that is, rigid body and soft body. They have different features, and have merits and demerits, respectively. Robots with rigid body have high stiffness, and are suitable for carrying and holding objects. However, they may injure users if they make contact. Robots with soft body have high flexibility and can make contact safely. However, they have difficulty in retaining particular shapes and are fragile against external force. In this letter, we propose some devices that can switch between rigid body and soft body using phase change of low melting alloy to resolve the problems. We also provide some experimental results with the device to clarify the applicability of the developed devices. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

A new catechin oxidation product and polymeric polyphenols of post-fermented tea

A new epicatechin oxidation product with a 3,6-dihydro-6-oxo-2H-pyran-2-carboxylic acid moiety was isolated from a commercially available post-fermented tea that is produced by microbial fermentation of green tea. The structure of this product was determined by spectroscopic methods. A production mechanism that includes the oxygenative cleavage of the catechol B-ring of (−)−epicatechin is proposed. In addition, polymeric polyphenols were separated from the post-fermented tea and partially characterised by ¹³C NMR spectroscopy and gel-permeation chromatography. The polymers appear to be primarily composed of epigalloacetechin-3-O-gallate and the molecular weight (Mn) of the acetylated form was estimated to be ∼3500.     

Large-Scale Experiments on Nonlinear Behavior of Shallow Foundations Subjected to Strong Earthquakes

We conducted a series of 1G large-scale shake table tests and cyclic eccentric loading tests of a shallow foundation model. The experimental parameters were the difference in loading methods (i.e., dynamic and static), input seismic motions (i.e., intensity and number of cycles), soil densities (i.e., dense and medium dense), and the ratio of horizontal and overturning moment loads. The experimental data set contains the accelerations and displacements of the soil and foundation as well as the distributions of normal and shear reaction forces at the foundation base. The experimental results provide crucial data to model the coupling effect among vertical, horizontal, and overturning loads, the accumulation of irreversible displacement, and the foundation uplift, and so is one of the most complete benchmark data sets for the development and validation of numerical models for the nonlinear response of shallow foundations to strong earthquakes.     

Analysis of surges measured at 550 kV substations

An automatic measuring system was developed for measuring overvoltages, and it was applied to 550 kV power stations and substations in service. This system has been in operation since June 1987, and 176 records have been successfully obtained. Induced-lightning surges, back-flashover surges due to lightning, circuit-breaker-closing surges, and gas-insulated-substation (GIS)-disconnector-switching surges were recorded. Using simple EMTP analysis, the authors were able to reproduce the fundamental characteristics of the measured waveforms. The authors report on such measured data and on the results of data analysis