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Structural Formation (structural + formation)
Selected AbstractsStructural formation of hybrid siloxane-based polymer monolith in confined spacesJOURNAL OF SEPARATION SCIENCE, JSS, Issue 10-11 2004Kazuyoshi Kanamori Abstract Structural deformation of phase-separated methylsiloxane gel under the influence of a surface has been studied. Competitive wetting of siloxane gel phase on a surface during phase formation is found to significantly affect the final morphology in a confined space. When the spinodal wavelength is sufficiently shorter than the size of the available space, a uniform bicontinuous structure forms in confined geometry. However, gel skeletons in the vicinity of a surface are elongated with decreasing size of the space, and finally when the size of the space becomes shorter than the spinodal wavelength, all the gel phase wets on a surface, showing a "wetting transition". Homogeneous bicontinuous methylsiloxane gels were successfully prepared, avoiding such structural deformation, in a long cylindrical fused silica capillary and used for capillary HPLC. The capillary gels exhibited excellent separation efficiency of nitrobenzenes and it was found that the surface character can be altered by incorporating surfactants, which will enable more advanced and extended control of surface character, depending on the analytes. [source] Effects of segment substitution on the structure and stability of immunoglobulin G binding domain of streptococcal protein GBIOPOLYMERS, Issue 1 2005Hai-Ning Du Abstract Structural formation of segments plays pivotal roles in protein folding and stability, but how the segment influences the structural ensemble remains elusive. We engineered two hybrid proteins by replacing the central helical segment of immunoglobulin G binding domain of streptococcal protein G with an ,-helix or ,2 -strand element of a structural homologue, the immunoglobulin G binding domain of streptococcal protein L. The results show that substitution by the ,-helical sequence retains a folded structure predominantly with a three-stranded ,-sheet but slightly destabilizes the compact ensemble, while substitution by the ,2 -strand sequence completely destroys the structural formation. The finding implies that the local segment may influence the tertiary structure and overall stability, and the tertiary interactions may modulate structural formation of the segment, which might be considered when studying protein folding, prediction, design, and engineering. © 2005 Wiley Periodicals, Inc. Biopolymers 79: 9,17, 2005 This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] Temperature and pressure effects on structural formations in a ternary microemulsionJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 3-1 2000M. Nagao Small angle neutron scattering experiments were conducted on a temperature-induced phase transition in a ternary microemulsion composed of AOT (dioctyl sulfosuccinate sodium salt), D2 O and n -decane and the results were compared with those of pressure-induced one. Although the static features of both the temperature- and the pressure-induced phase behaviour were similar, a temperature dependence of its characteristic repeat distance at high temperature was quite different from a pressure dependence of that at high pressure. Neutron spin echo experiments were also performed on both the phase transitions. The dynamics of the high temperature phase was different from that of the high pressure phase. These results indicated that the effect of pressure on the structural formation was different from that of temperature. [source] Secondary structural formation of ,-synuclein amyloids as revealed by g -factor of solid-state circular dichroismBIOPOLYMERS, Issue 3 2006Xiao-Jing Lin Abstract ,-Synuclein (,-Syn) has been identified as a component of intracellular fibrillar deposits in Parkinson's disease. Though the real pathogenesis is still unknown, many investigations have revealed that conformational alteration and fibril formation of ,-Syn protein have an important role in causing the disease. In this work, we introduced the g -factor spectra of solid-state circular dichroism to estimate the secondary structure contents of ,-Syn fragments in amyloids. Fourier-transform infrared (FTIR) was also applied to confirm the structural formation. The results suggest that the central hydrophobic region is critical for ,-sheet formation and the conformational alteration is the foundation of protein abnormal aggregation. The research provides a practical approach to estimate the secondary structure contents of protein amyloids and further insight into the relevance of structural transformation and amyloidogenesis. © 2006 Wiley Periodicals, Inc. Biopolymers 83: 226,232, 2006 This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] Effects of segment substitution on the structure and stability of immunoglobulin G binding domain of streptococcal protein GBIOPOLYMERS, Issue 1 2005Hai-Ning Du Abstract Structural formation of segments plays pivotal roles in protein folding and stability, but how the segment influences the structural ensemble remains elusive. We engineered two hybrid proteins by replacing the central helical segment of immunoglobulin G binding domain of streptococcal protein G with an ,-helix or ,2 -strand element of a structural homologue, the immunoglobulin G binding domain of streptococcal protein L. The results show that substitution by the ,-helical sequence retains a folded structure predominantly with a three-stranded ,-sheet but slightly destabilizes the compact ensemble, while substitution by the ,2 -strand sequence completely destroys the structural formation. The finding implies that the local segment may influence the tertiary structure and overall stability, and the tertiary interactions may modulate structural formation of the segment, which might be considered when studying protein folding, prediction, design, and engineering. © 2005 Wiley Periodicals, Inc. Biopolymers 79: 9,17, 2005 This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] Temperature and pressure effects on structural formations in a ternary microemulsionJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 3-1 2000M. Nagao Small angle neutron scattering experiments were conducted on a temperature-induced phase transition in a ternary microemulsion composed of AOT (dioctyl sulfosuccinate sodium salt), D2 O and n -decane and the results were compared with those of pressure-induced one. Although the static features of both the temperature- and the pressure-induced phase behaviour were similar, a temperature dependence of its characteristic repeat distance at high temperature was quite different from a pressure dependence of that at high pressure. Neutron spin echo experiments were also performed on both the phase transitions. The dynamics of the high temperature phase was different from that of the high pressure phase. These results indicated that the effect of pressure on the structural formation was different from that of temperature. [source] Integrated geophysical and topographical investigation in the territory of Ancient Tarquinia (Viterbo, central Italy)ARCHAEOLOGICAL PROSPECTION, Issue 3 2007S. Piro Abstract This paper presents the results of an ongoing study of the territory of Ancient Tarquinia (Viterbo, central Italy). The work is part of the University of Milano's ,Tarquinia Project', which studies the monumental area of this territory with particular emphasis on the ,Ara della Regina' temple site. To enhance the knowledge of this territory, a scientific collaboration between the University of Milano (Department of Science of Antiquity) and the Institute of Technologies Applied to Cultural Heritage (ITABC-C.N.R.) was initiated in 2000 and is still in progress. The primary objective of the study was to determine the location and degree of conservation of unknown buried structures below the sites studied, using the integration of topographical surveys, three-dimensional laser scanner surveys of the temple and ground-based remote sensing surveys. The remote sensing surveys were carried out using the ground-penetrating radar (GPR). The analysis of the GPR time-slice maps indicates that some structural formations and walls of the buildings are still present below the surface. The results presented and discussed in this paper demonstrate the potential of both the topographical survey combined with the three-dimensional laser scanner survey of the monument and the remote sensing technique for understanding of the presence and the extent of buried buildings with respect to the temple area. Copyright © 2007 John Wiley & Sons, Ltd. [source] Vegetation structure and biodiversity along the eucalypt forest to rainforest continuum on the serpentinite soil catena in a subhumid area of Central Queensland, AustraliaAUSTRAL ECOLOGY, Issue 3 2006RAY L. SPECHT Abstract The deep lateritic earths that cap the serpentinite outcrop in the Rockhampton , Marlborough area on the Tropic of Capricorn in Central Queensland have been eroded to expose the underlying ultramafic rock. Water-holding capacity of these nutrient-poor soils increases in a gradient from the skeletal soils to the deep lateritic earths and results in a continuum of structural formations from open-woodland to woodland to open-forest. A couple of closed-forest (rainforest) stands have developed where seepage into Marlborough Creek occurs throughout the year. Aerodynamic fluxes (frictional, thermal and evaporative) in the atmosphere as it flows over and through the vegetation influence the annual foliage growth in all strata in the continuum from skeletal soils to deep lateritic earths. The lateral growth of each plant is abraded so that the sum of the foliage projective covers of overstorey (FPCo) and understorey (FPCu) strata , that is ,(FPCo + FPCu) , remains constant throughout the serpentinite soil catena. As more water becomes available in the soil catena, the mineral nutrient levels in overstorey leaves increase, making developing leaves more vulnerable to insect attack. Although the number of leaves produced annually on each vertical foliage shoot in the overstorey increases along the soil-water gradient, ,(FPCo + FPCu) remains constant in all stands. The carbon isotope ratios (a measure of stomatal resistance) and leaf specific weights (LSWs) (a measure of the proportion of structural to cytoplasmic content in a leaf) of overstorey and understorey strata, however, are constant throughout the continuum. The well-watered rainforest pockets , where seepage occurs , form the end point of this serpentinite continuum. LSWs and carbon isotope ratios of the canopy trees are similar to those in the sheltered understorey in the eucalypt communities. A gradient of foliage attributes is observed from evergreen canopy trees (12 m) to subshrubs (2 m) in the sunlit life forms that compose the complex structure of the rainforest stands in the humid to subhumid climate of Central Queensland. As alpha diversity (number of species per hectare) is correlated with annual shoot growth per hectare, species richness along the serpentinite continuum is almost half that of nearby plant communities on medium-nutrient soils. The one to two eucalypt species per hectare are about a tenth of the number recorded on adjacent medium-nutrient soils. [source] | ||||||||||