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Detailed Structural Analysis (detailed + structural_analysis)
Selected AbstractsA geometric and kinematic model for double-edge propagating thrusts involving hangingwall and footwall folding.GEOLOGICAL JOURNAL, Issue 5-6 2010An example from the Jaca, Pamplona Basin (Southern Pyrenees) Abstract A new geometric and kinematic model is proposed for a particular type of fault-related folding based on the study of a natural example developed in Palaeogene carbonate rocks from the Jaca,Pamplona Basin (Southern Pyrenees). The example consists of a hangingwall anticline related to a reverse fault with variable displacement and a gentle footwall syncline. A detailed structural analysis of the structure and a cross-section, perpendicular to its axis and parallel to the transport direction, reveals that none of the previous published models of fault-related folds is able to simulate its main characteristics and reproduce its geometry. The main features of the new model are: double-edge propagating fault and folding developed in both the hangingwall and the footwall. A MATLAB-based program was created to calculate structural parameters such as shortening, structural relief and fault slip; obtain graphs of different parameters such as shortening versus slip along the fault, shortening versus fault length, and produce sections across forward models showing the different stages of fold growth. The model presented here gives an acceptable geometrical fit to the studied natural structure and provides a reasonable evolutionary history. In addition, the results obtained using the model are similar to those measured on the cross-section. As a final step the subsurface portion of the natural fold was completed following the constraints imposed by the model. Copyright © 2010 John Wiley & Sons, Ltd. [source] Changes in structure and geometric properties of human hair by agingINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 4 2010S. Nagase J. Cosmet. Sci., 60, 637,648 (November/December 2009) Synopsis To clarify hair changes by aging, the effect of age on hair properties was investigated from macro- to microscopic viewpoints. Sensory hair luster tests were performed on 230 Japanese females from 10 to 70 year of age, revealing that hair luster decreases with age. The age dependence of the hair diameter and the ellipticity of the hair cross section could not explain luster reduction by aging. It has been determined that an irregular increase in fiber curvature occurs with age and is a cause of luster reduction with aging. A detailed structural analysis by synchrotron radiation microbeam X-ray diffraction revealed that the inhomogeneity in the lateral distribution of the hair microstructure increased with age and relates to the irregular increase in curvature. Such an increase in curvature is one of the important factors that leads to a poor alignment of hairs and luster reduction, and is related to the appearance of aging hair. [source] Determination of primary bond scissions by mass spectrometric analysis of ultrasonic degradation products of poly(ethylene oxide- block -propylene oxide) copolymersJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 7 2010Takehiro Watanabe Abstract Ultrasonic degradation of poly(ethylene oxide- block -propylene oxide) copolymers consisting of a hydrophilic and a hydrophobic portion was studied with the aim to determine the location of bonds involved in the initial scission of the copolymers. LC,APCI-IT-MS and LC,APCI-orbitrap-MS were used for the detailed structural analysis of degradation products. The results indicated that initial bond scissions occurred principally at the boundary regions between backbones of polyethylene oxide (PEO) and polypropylene oxide (PPO) chains. Further structural analysis revealed the presence of oxygen adducts in the degradation products. Comparison with a thermal degradation carried out in helium atmosphere, one can conclude that the oxygen adducts are formed by radical reaction with water or dissolving oxygen molecules. The study demonstrated that chemical reactions as well as physical bond stress scissions are involved in the ultrasonic degradation of the copolymers. Copyright © 2010 John Wiley & Sons, Ltd. [source] Analysis of Campylobacter jejuni capsular loci reveals multiple mechanisms for the generation of structural diversity and the ability to form complex heptosesMOLECULAR MICROBIOLOGY, Issue 1 2005Andrey V. Karlyshev Summary We recently demonstrated that Campylobacter jejuni produces a capsular polysaccharide (CPS) that is the major antigenic component of the classical Penner serotyping system distinguishing Campylobacter into >60 groups. Although the wide variety of C. jejuni serotypes are suggestive of structural differences in CPS, the genetic mechanisms of such differences are unknown. In this study we sequenced biosynthetic cps regions, ranging in size from 15 to 34 kb, from selected C. jejuni strains of HS:1, HS:19, HS:23, HS:36, HS:23/36 and HS:41 serotypes. Comparison of the determined cps sequences of the HS:1, HS:19 and HS:41 strains with the sequenced strain, NCTC11168 (HS:2), provides evidence for multiple mechanisms of structural variation including exchange of capsular genes and entire clusters by horizontal transfer, gene duplication, deletion, fusion and contingency gene variation. In contrast, the HS:23, HS:36 and HS:23/36 cps sequences were highly conserved. We report the first detailed structural analysis of 81-176 (HS:23/36) and G1 (HS:1) and refine the previous structural interpretations of the HS:19, HS:23, HS:36 and HS:41 serostrains. For the first time, we demonstrate the commonality and function of a second heptose biosynthetic pathway for Campylobacter CPS independent of the pathway for lipooligosaccharide (LOS) biosynthesis and identify a novel heptosyltransferase utilized by this alternate pathway. Furthermore, we show the retention of two functional heptose isomerases in Campylobacter and the sharing of a phosphatase for both LOS and CPS heptose biosynthesis. [source] Structure of small II-VI semiconductor nanoparticles: A new approach based on powder diffractionPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 9 2007Franziska Niederdraenk Abstract In many cases of nanostructures a better understanding of the optical, electronic, and catalytic properties is hindered by a lack of detailed structural knowledge of sufficient quality. This is in particular true for very small nanoparticles (<5 nm) where quantum confinement effects play a dominant role. We introduce a novel method for the detailed structural analysis of such small nanoparticles, which includes not only the modeling of basic parameters like size, shape, and structure, but also allows to determine impurities and defects (like, e.g., stacking faults), stress and relaxation effects, etc. Distributions of basic parameters as the size distribution are also implemented by enabling ensemble averaging. Different examples obtained from CdS, ZnS and ZnO particles are presented and demonstrate the superiority of the new approach compared to simpler methods. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Purification, crystallization and preliminary X-ray analysis of human GIMAP2ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 6 2010David Schwefel GTPases of immunity-associated proteins (GIMAPs) are important regulators of T-cell death and survival. Here, the crystallization and data collection of three GIMAP2 constructs in various nucleotide-loaded states is described. Selenomethionine-substituted carboxy-terminally truncated GIMAP2 (amino-acid residues 1,260; GIMAP21,260) in the nucleotide-free form crystallized in space group P212121 and the crystals diffracted X-rays to 1.5,Å resolution. The phase problem was solved using the single anomalous dispersion (SAD) protocol. GDP-bound GIMAP221,260 and GDP-bound GIMAP21,234 crystallized in space group P212121 and the crystals diffracted X-rays to 2.9 and 1.7,Å resolution, respectively. GTP-bound GIMAP21,234 crystallized in space group C2221 and the crystals diffracted to 1.9,Å resolution. These results will allow a detailed structural analysis of GIMAP2, which will provide insight into the architecture and function of the GIMAP family. [source] Molecular structure of the outer bacterial membrane of Pseudomonas aeruginosa via classical simulationBIOPOLYMERS, Issue 6 2002Robert M. Shroll Abstract A detailed structural analysis has been performed of the outer bacterial membrane of Pseudomonas aeruginosa using a parameterized classical simulation model (R. D. Lins and T. P. Straatsma, Biophysical Journal, 2001, Vol. 81, pp. 1037,1046) with modest modifications. The structural analysis of the membrane is presented and newly discovered characteristics of the membrane are discussed. Simulations indicate that the relative contribution of different ligands to calcium ion coordination varies across the membrane, while maintaining a constant average coordination number of 6.1. Water penetrates the surface of the membrane to a depth of about 30 Å. The hydration of ions and phosphate groups is shown to depend on location within the membrane. A measure of saccharide residue orientation is defined and average orientations are presented. Saccharide residues possess varying degrees of motion with a trend of greater mobility at the membrane surface. However, their motion is limited and even in the membrane outer core region the average structure appears fairly rigid over a period of 1 ns. © 2002 Wiley Periodicals, Inc. Biopolymers 65: 395,407, 2002 [source] | ||||||||||