204 research outputs found
米の栄養価のラマン分子フィンガープリント
京都大学新制・論文博士博士(農学)乙第13520号論農博第2908号新制||農||1096(附属図書館)学位論文||R4||N5420(農学部図書室)京都府立医科大学(主査)教授 中﨑 鉄也, 教授 土井 元章, 教授 及川 彰, 准教授 田中 朋之学位規則第4条第2項該当Doctor of Agricultural ScienceKyoto UniversityDGA
Visualization of highly graded oxygen vacancy profiles in lead-zirconate-titanate by spectrally resolved cathodoluminescence spectroscopy
The ultraviolet and visible cathodoluminescence (CL) emitted at room temperature from bulk hard lead-zirconate-titanate polycrystalline perovskite has been systematically collected before and after an annealing cycle conducted in a reducing atmosphere. Spectroscopic assessments have been made of the in-depth stoichiometric profile developed upon annealing from the sample surface toward the subsurface. Trapping of electronic charge and local atomic scale distortions in the perovskite oxygen octahedron influences the variation observed in visible CL emission, while lattice distortions upon annealing directly arise from the formation of oxygen vacancies
ラマン分光法を用いたインフルエンザウイルス感染細胞の代謝機構の解析
京都府立医科大学令和2年
The fourfold way to Gaussianity. Physical Interactions, distributional models and monadic transformations
The Central Limit Theorem stands as a milestone in probability theory and statistical physics, as the privileged, if not the unique, universal route to normal distributions. This article addresses and describes several other alternative routes to Gaussianity, stemming from physical interactions, related to particle-particle and radiative particle–photon elementary processes. The concept of conservative mixing transformations of random ensembles is addressed, as it represents the other main universal distributional route to Gaussianity in classical low-energy physics. Monadic ensemble transformations are introduced, accounting for radiative particle–photon interactions, and are intimately connected with the theory of random Iterated Function Systems. For Monadic transformations, possessing a thermodynamic constraint, Gaussianity represents the equilibrium condition in two limiting cases: in the low radiative-friction limit in any space dimension, and in the high radiative-friction limit, when the dimension of the physical space tends to infinity
Raman piezospectroscopic evaluation of intergrowth ferroelectric polycrystalline ceramic in biaxial bending configuration
The piezospectroscopic (PS) effect was studied in an intergrowth bismuth layer-structure ferroelectricceramicBi₅TiNbWO₁₅ according to a micro-Raman spectroscopic evaluation. By using a ball-on-ring flexure configuration, a biaxial stress was generated in a Bi₅TiNbWO₁₅ plate-like specimen and in situ collected Raman spectra were acquired and analyzed under several loading conditions. As the observed spectral line contained signals arising from the whole illuminated in-depth region, the laser probe information was deconvoluted (by means of an in-depth probe response function obtained according to the defocusing method) in order to deduce biaxial PS coefficients for the three Raman bands of Bi₅TiNbWO₁₅ located at 763, 857, and 886 cm−1, respectively. The biaxial PS coefficients of these bands were derived to be −1.74±0.16, −2.51±0.16, and −2.64±0.31 cm⁻¹/GPa, respectively, and should be referred to the c axis of the Bi5TiNbWO15 crystal
Raman Molecular Fingerprints of Rice Nutritional Quality and the Concept of Raman Barcode
The nutritional quality of rice is contingent on a wide spectrum of biochemical characteristics, which essentially depend on rice genome, but are also greatly affected by growing/environmental conditions and aging during storage. The genetic basis and related identification of genes have widely been studied and rationally linked to accumulation of micronutrients in grains. However, genetic classifications cannot catch quality fluctuations arising from interannual, environmental, and storage conditions. Here, we propose a quantitative spectroscopic approach to analyze rice nutritional quality based on Raman spectroscopy, and disclose analytical algorithms for the determination of: (i) amylopectin and amylose concentrations, (ii) aromatic amino acids, (iii) protein content and structure, and (iv) chemical residues. The proposed Raman algorithms directly link to the molecular composition of grains and allow fast/non-destructive determination of key nutritional parameters with minimal sample preparation. Building upon spectroscopic information at the molecular level, we newly propose to represent the nutritional quality of labeled rice products with a barcode specially tailored on the Raman spectrum. The Raman barcode, which can be stored in databases promptly consultable with barcode scanners, could be linked to diet applications (apps) to enable a rapid, factual, and unequivocal product identification based on direct molecular screening
Raman tensor analysis of ultra-high molecular weight polyethylene and its application to study retrieved hip joint components
The angular dependences of the polarized Raman intensity of A(g), B-1g, B-2g, and B-3g modes have been preliminary investigated on a model fiber sample of ultra-high molecular weight polyethylene (UHMWPE) in order to retrieve the Raman tensor elements, i.e. the intrinsic parameters governing the vibrational behavior of the orthorhombic structure of polyethylene. Based on this Raman analysis, a method is proposed for determining unknown crystallographic orientation patterns in UHMWPE biomedical components concurrently with the orientation distribution functions for orthorhombic lamellae. An application of the method is shown, in which we quantitatively examined the molecular orientation patterns developed on the surface of four in vivo exposed UHMWPE acetabular cups vs. an unused cup. Interesting findings were: (i) a clear bimodal distribution of orientation angles was observed on worn surfaces; and (ii) a definite and systematic increase in both molecular orientation and crystallinity in main wear zones vs. non-wear zones was found in all retrieved acetabular cups. The present crystallographic analysis is an extension of our previous Raman studies of UHMWPE acetabular cups related to assessments of oxidation and residual strain and suggests a viable path to track back wear-history information from the surface of UHMWPE, thus unfolding the in vivo kinematics of the bearing surfaces in hip joints on the microscopic scale. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved
Structural modifications induced by compressive plastic deformation in single-step and sequentially irradiated UHMWPE for hip joint components
Structural modifications were studied at the molecular scale in two highly crosslinked UHMWPE materials for hip-joint acetabular components, as induced upon application of (uniaxial) compressive strain to the as-manufactured microstructures. The two materials, quite different in their starting resins and belonging to different manufacturing generations, were a single-step irradiated and a sequentially irradiated polyethylene. The latter material represents the most recently launched gamma-ray-irradiated polyethylene material in the global hip implant market. Confocal/polarized Raman spectroscopy was systematically applied to characterize the initial microstructures and the microstructural response of the materials to plastic deformation. Crystallinity fractions and preferential orientation of molecular chains have been followed up during in vitro deformation tests on unused cups and correlated to plastic strain magnitude and to the recovery capacity of the material. Moreover, analyses of the in vim deformation behavior of two short-term retrieved hip cups are also presented. Trends of preferential orientation of molecular chains as a function of residual strain were similar for both materials, but distinctly different in their extents. The sequentially irradiated material was more resistant to plastic deformation and, for the same magnitude of residual plastic strain, possessed a higher capacity of recovery as compared to the single-step irradiated one. (C) 2013 Elsevier Ltd. All rights reserved
Structural profile of ultra-high molecular weight polyethylene in acetabular cups worn on hip simulators characterized by confocal Raman spectroscopy
We applied a Raman confocal spectroscopic technique to quantitatively assess the structural features of two kinds of acetabular cups made of ultra-high molecular weight polyethylene. We wanted to know whether polyethylene cups belonging to different generations, and thus manufactured by different procedures, possess different molecular structures and how those differences affected their wear resistance. Emphasis was placed on oxidation profiles developed along the cross-sectional depth of the cups in the main wear zone developed during testing in a hip simulator. The micrometric lateral resolution of the laser beam, focused at surface or sub-surface sectional planes, enabled the visualization of highly resolved microstructural property profiles, including crystalline and amorphous phase fractions. Oxidation profiles retrieved from polyethylene cups belonging to different generations greatly differed after wear testing. The highly cross-linked polyethylene showed a lower degree of crystallinity and oxidation at an appreciably slower rate as compared to that belonging to an earlier generation. (C) 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:893-899, 201
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