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71.
Tsuyoshi Nakai Kiyofumi Yamada Hiroyuki Mizoguchi 《International journal of molecular sciences》2021,22(11)
Alzheimer’s disease (AD) is an age-related and progressive neurodegenerative disorder. It is widely accepted that AD is mainly caused by the accumulation of extracellular amyloid β (Aβ) and intracellular neurofibrillary tau tangles. Aβ begins to accumulate years before the onset of cognitive impairment, suggesting that the benefit of currently available interventions would be greater if they were initiated in the early phases of AD. To understand the mechanisms of AD pathogenesis, various transgenic mouse models with an accelerated accumulation of Aβ and tau tangles have been developed. However, none of these models exhibit all pathologies present in human AD. To overcome these undesirable phenotypes, APP knock-in mice, which were presented with touchscreen-based tasks, were developed to better evaluate the efficacy of candidate therapeutics in mouse models of early-stage AD. This review assesses several AD mouse models from the aspect of biomarkers and cognitive impairment and discusses their potential as tools to provide novel AD therapeutic approaches. 相似文献
72.
73.
Based on the discussion that there should be a micromechanism that causes a macroscopic slip of mono-crystal copper, molecular dynamics simulations with the analytical displacement feld around a crack tip have been carried out. The result of the simulation shows that macroscopic shear slip in an f.c.c. mono-crystal copper occurs as discrete time events. This is because cross-slips occur in many places in a material such that a macroscopic shear slip is blocked until some critical state of deformation. A macroscopic shear slip then occurs suddenly at the critical state in which the area of disordered atomic arrangement has stretched from one end of a crystal to the other end. The reason why macroscopic shear slips occur in the directions of the slip planes of a crystal is attributed to the fact that the areas of disordered atomic arrangement develop only along those directions. 相似文献
74.
I. Hama T. Okamoto E. Hidai K. Yamada 《Journal of the American Oil Chemists' Society》1997,74(1):19-24
For the purpose of estimating the reaction mechanism of the direct ethoxylation of a fatty ester in the presence of an Al-Mg
composite oxide catalyst, a labeled fatty methyl ester C11H23CO18OCH3 containing 18O isotope was synthesized and directly ethoxylated. The product was evaluated by gas chromatography-mass spectrometry (GC-MS).
The GC-MS spectra showed that the 18O isotope label was present only in the methoxy group at the molecular end of the ethoxylated fatty methyl ester. This supports
the reaction mechanism of coordination anionic polymerization where the bond between the acyl and methoxy groups of the fatty
methyl ester molecule was broken, caused by the bifunctional effect of the acid-base active sites; an intermediate chemisorption
species was formed; and then ethylene oxide was addition-polymerized sequentially, in parallel. 相似文献
75.
Minoru Ueno Satoshi Yamamoto Kenjiro Meguro 《Journal of the American Oil Chemists' Society》1974,51(8):373-376
Several salts of α,ω-sulfates, MO3SO(CH2)n OSO3M(n=12, 14, 16, 18, and M=Li, Na, and K) were prepared from the corresponding α,ω-alkane diols. The Krafft points of these
α,ω-sulfates with common counterion as estimated by electroconductivity measurements increased with the increase of the hydrocarbon
chain length, and the effect of the counterions on the Krafft points of the α,ω-sulfates with the same hydrocarbon chain length
was in the order : Li<Na<K. Solutions of the α,ω-sulfates, except disodium dodecanediol disulfate, showed two break points
corresponding to the first and second critical micelle concentration in each plot of the electroconductivity as a function
of the concentration. The existence of the second break point suggested that another aggregation of rearrangement of the existing
aggregates occurs in α,ω-sulfate solutions in addition to the usual micelle formation. The first and second break points of
α,ω-sulfates with sodium counterion decreased logarithmically with increasing total number of methylene groups. The relationships
were given as follows: log(first break point)=−0.138Nc−0.095; log(second break point)=−0.104Nc−0.251. The effect of the counterions
upon the break points of α,ω-sulfates with the same hydrocarbon chain length was in accordance with their positions in the
lyotropic series. 相似文献
76.
Yutaka Nakajima Takaharu Goto Kazuo Yamada 《Journal of the American Ceramic Society》2005,88(4):850-857
The performance of poly-β-naphthalene sulfonate condensate superplasticizer (BNS) as a dispersant for cement in concrete is affected severely by slight differences in the characteristics of the cement. In order to be able to predict these effects, a model for estimating the fluidity of cement paste containing BNS is proposed. This model is based on an assumption that the fluidity of cement paste is proportional to the BNS adsorption amount per surface area of hydrated cement (Ad/Hy). BNS is known to show two types of sorption on hydrated cement: one is the bulk absorption into initial hydrates and the other one is the superficial adsorption onto hydrates. Only the superficially adsorbed BNS is expected to work as a dispersant. By assuming a competitive Langmuir-type adsorption on hydrates between BNS and SO4 2− , a simple method to estimate Ad/Hy is developed, with the concentrations of BNS and SO4 2− as the only two independent parameters. The resulting estimates of Ad/Hy show a good correlation with paste flow and its change with elapsed time for a broad range of cements. The SO4 2− concentration in the aqueous phase of the cement paste just after the beginning of the mixing is known to affect the performance of BNS as a dispersant. By using the proposed model to discriminate between the superficial adsorption and bulk absorption of BNS, this phenomenon is explained quantitatively. 相似文献
77.
Koki Murano Tomoyoshi Shimobaba Atsushi Sugiyama Naoki Takada Takashi Kakue Minoru Oikawa Tomoyoshi Ito 《Computer Physics Communications》2014
We report fast computation of computer-generated holograms (CGHs) using Xeon Phi coprocessors, which have massively x86-based processors on one chip, recently released by Intel. CGHs can generate arbitrary light wavefronts, and therefore, are promising technology for many applications: for example, three-dimensional displays, diffractive optical elements, and the generation of arbitrary beams. CGHs incur enormous computational cost. In this paper, we describe the implementations of several CGH generating algorithms on the Xeon Phi, and the comparisons in terms of the performance and the ease of programming between the Xeon Phi, a CPU and graphics processing unit (GPU). 相似文献
78.
Polystyrene (PS)/poly(ethylene oxide) (PEO) prototype brushes were prepared by alternating free‐radical copolymerization of methacryloyl‐terminated PS and α‐vinylbenzyl‐ω‐hydroxy or α‐vinylbenzyl‐ω‐perfluoroalkyl (Rf) PEO macromonomers with the addition of Lewis acid (SnCl4). It was found from their dilute‐solution properties that PS/PEO end‐capped with Rf (PBRf), and PS/PEO having OH groups at terminal ends (PBOH) prototype brushes formed a single molecule in benzene and aggregates in chloroform, respectively. However, the brush PBOH formed a single molecule in N,N‐dimethylformamide. Such aggregation behaviors seemed to be caused by the interaction between hydroxy groups of PEO chain ends. The brush PBOH was also converted into PBRf‐type brush by chemical modification, using corresponding acid chloride. The substitution of Rf groups was ~70% due to slipping of terminal hydroxy groups into PEO internal domains. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 772–778, 2006 相似文献
79.
Shin'ichiro Asai Ueki Saruta Masayuki Tobita Minoru Takano Yasuo Miyashita 《应用聚合物科学杂志》1995,56(7):769-777
A thermoset type anisotropic conductive adhesive film (ACAF), which electrically connects an ITO glass and a flex circuit both having conducting pattersn of less than 100 μm in pitch, has been developed. In this development, bisphenol A and bisphenol F epoxy resins were tested to formulate an ACAF with easy-to-handle tackiness, flexibility, and strenght. A curing agent that gives fast cure and long shelf-life properties to the epoxy resin was also selected. The tensile stress–strain responses of obtained adhesive films were successfully used for determining the formulation. Good aftercure physical properties (electrical and mechanical) were obtained. Durability against high temperature and high humidity were also tested to confirm long-term stability of the conduction of this ACAF. © 1995 John Wiley & Sons, Inc. 相似文献
80.
New polylactide/layered silicate nanocomposites. 5. Designing of materials with desired properties 总被引:2,自引:0,他引:2
Suprakas Sinha RayKazunobu Yamada Masami Okamoto Youhei FujimotoAkinobu Ogami Kazue Ueda 《Polymer》2003,44(21):6633-6646
Understanding the structure/property relationship in polymer/layered silicate nanocomposites is of great importance in designing materials with desired properties. In order to understand these relations, a series of polylactide (PLA)/organically modified layered silicate (OMLS) nanocomposites have been prepared using a simple melt extrusion technique. Four different types of OMLS have been used for the preparation of nanocomposites, three were modified with functionalized ammonium salts while fourth one was a phosphonium salt modified OMLS. The structure of the nanocomposites in the nanometer scale was characterized by using wide-angle X-ray diffraction and transmission electron microscopic observations. Using four different types of layered silicates modified with four different types of surfactants, the effect of OMLS in nanocomposites was investigated by focusing on four major aspects: structural analysis, thermal properties and spherulite morphology, materials properties, and biodegradability. Finally, we draw conclusions about the structure/property relationship in the case of PLA/OMLS nanocomposites. 相似文献