黄河流域泥沙密度试验研究

泥沙密度是河流泥沙的主要物理特性之一。本项试验研究采集了黄河干支流２３个水文站５２６个泥沙样品，基本覆盖了黄河上、中、下游各河段及主要支流泥沙来源区，泥沙样品具有广泛的代表性。分析结果表明：泥沙密度与垂线上不同位置处的泥沙颗粒级配无关，与含沙量之间也没有明显的关系；自上游至下游，泥沙密度沿程略有变化，年际间比较稳定。最后建议泥沙密度值上游区选用２７４ｇ／ｃｍ３，中游区选用２７３ｇ／ｃｍ３，下游区选用２７１ｇ／ｃｍ３。     

Anti-Kir4.1 Antibodies in Multiple Sclerosis: Specificity and Pathogenicity

The glial cells in the central nervous system express diverse inward rectifying potassium channels (Kir). They express multiple Kir channel subtypes that are likely to have distinct functional roles related to their differences in conductance, and sensitivity to intracellular and extracellular factors. Dysfunction in a major astrocyte potassium channel, Kir4.1, appears as an early pathological event underlying neuronal phenotypes in several neurological diseases. The autoimmune effects on the potassium channel have not yet been fully described in the literature. However, several research groups have reported that the potassium channels are an immune target in patients with various neurological disorders. In 2012, Srivastava et al. reported about Kir4.1, a new immune target for autoantibodies in patients with multiple sclerosis (MS). Follow-up studies have been conducted by several research groups, but no clear conclusion has been reached. Most follow-up studies, including ours, have reported that the prevalence of Kir4.1-seropositive patients with MS was lower than that in the initial study. Therefore, we extensively review studies on the method of antibody testing, seroprevalence of MS, and other neurological diseases in patients with MS. Finally, based on the role of Kir4.1 in MS, we consider whether it could be an immune target in this disease.     

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.