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Third Component (third + component)
Selected AbstractsChylomicron accelerates C3 tick-over by regulating the role of Factor H, leading to overproduction of acylation stimulating proteinJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 1 2007Takayuki Fujita Abstract Acylation stimulating protein (ASP) is a fragment of the third component of complement (C3) that is generated in the presence of chylomicron, and plays a role in the synthesis of triacylglycerol by transporting free fatty acids into adipocytes. However, the precise mechanism of ASP generation, especially the role of chylomicron in ASP generation, is unknown. We examined the mechanism through which chylomicron induces ASP generation. Ultracentrifugationally separated chylomicron was incubated with normal human serum (NHS) under various conditions, and the amounts of complement activation products and ASP in the incubation mixture were determined by enzyme-linked immunosorbent assay (ELISA). Upon incubation of NHS with various amounts of chylomicron for 120,min, ASP was generated in a dose-dependent manner. The time course of the production of ASP was similar to the time course of the C3 tick-over phenomenon that occurred by depletion of factor H from the serum. The complement activation induced by chylomicron was different from the usual complement activation that occurs under the regulation of factor H and factor I with respect to the time course and the amount of ASP produced. Our results indicate that chylomicron accelerates C3 tick-over by regulating the role of factor H, leading to the overproduction of ASP. J. Clin. Lab. Anal. 21:14,23, 2007. © 2007 Wiley-Liss, Inc. [source] Influence of third component on mechanical properties and thermal stability of polypropylene/(regenerated polyurethane) blendsJOURNAL OF VINYL & ADDITIVE TECHNOLOGY, Issue 2 2008Shu Ling Zhang The possibility of polypropylene (PP) modification by regenerated polyurethane (PU), obtained after partial thermochemical decomposition of waste PU, has been studied. The degradation product was a thermoplastic mixture, applicable for reuse without any purification and fractionation. It was proved that regenerated PU could be reused as an effective polymeric plasticizer for PP and that the addition of regenerated PU did not decrease the thermal stability of PP. In order to improve further the elongation at break of PP modified by regenerated PU, a third component was added to the PP/(regenerated PU) blend. The influence of the third component on the mechanical properties and thermal stability of the blends was evaluated by using a universal testing machine (UTM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The data showed that the elongations of PP/(regenerated PU) blends with styrene-ethylene-butylene-styrene polymer (SEBS) were obviously better than those of the PP/(regenerated PU) blend without the third component and with PP- g -MA or SEBS- g -MA (MA = maleic anhydride). In addition, the thermal stability of PP/(regenerated PU) blends with a third component was almost same as that of the PP/(regenerated PU) blend without a third component. J. VINYL ADDIT. TECHNOL., 2008. © 2008 Society of Plastics Engineers. [source] Immiscible Poly(L -lactide)/Poly(, -caprolactone) Blends: Influence of the Addition of a Poly(L -lactide)-Poly(oxyethylene) Block Copolymer on Thermal Behavior and MorphologyMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 7 2004Giovanni Maglio Abstract Summary: A binary blend of poly (L -lactide) (PLLA) and poly(, -caprolactone) (PCL) of composition 70:30 by weight was prepared using a twin screw miniextruder and investigated by differential scanning calorimetry (DSC), optical microscopy and scanning electron microscopy (SEM). Ternary 70:30:2 blends were also obtained by adding either a diblock copolymer of PLLA and poly(oxyethylene) (PEO) or a triblock PLLA-PCL-PLLA copolymer as a third component. Optical microscopy revealed that the domain size of dispersed PCL domains is reduced by one order of magnitude in the presence of both copolymers. SEM confirmed the strong reduction in particle size upon the addition of the copolymers, with an indication of an enhanced emulsifying effect in the case of the PLLA-PEO copolymer. These results are analyzed on the basis of solubility parameters of the blend components. Optical micrograph of M3EG2 blend melt quenched at 125,°C. [source] The role of a third component on the conductivity behavior of ternary epoxy/Ag conductive compositesPOLYMER COMPOSITES, Issue 4 2002W. Jia Conductive adhesives, based on highly filled silver particles dispersed in a liquid epoxy resin, with an aliphatic amine [diethyltriamine (DETA)] as a curing agent, were investigated. A third component was added to the epoxy/Ag system to obtain composites of better conductivity, or similar conductivity but at lower silver contents, to modify the conductive adhesive properties, and also to reduce cost. Epoxy/Ag/carbon black (CB), epoxy/Ag/carbon fibrils (CF), epoxy/Ag/SiO2 and epoxy/Ag/dispersant composites were thus studied. The effect of high curing temperature on the uniformity and resulting conductivity level was also studied. The studied systems, excluding the epoxy/Ag/CB composite, exhibited enhanced conductivities. The microstructure of most of the systems was studied by scanning electron microscopy (SEM). The micrographs produced have served to establish structure-property relations for better understanding of the observed phenomena. [source] Micro- and macrorheological properties of polypropylene-polyoxymethylene-copolyamide mixture meltsPOLYMER ENGINEERING & SCIENCE, Issue 6 2001M. V. Tsebrenko The influence of polyoxymethylene (POM) additives on micro- and macrorheological properties of polypropylene-copolyamide (PP/CPA) mixture melts with the PP/CPA ratios of 40/60 and 20/80 wt% was investigated. We have shown that the microrheological processes such as deformation of dispersed polymer droplets and formation of liquid polymer streams, coalescence of these streams along the longitudinal direction, migration, and fracture of the liquid streams into droplets can be controlled by addition of a third component that may interact with CPA in a specific manner. The ternary mixture melt viscosity was greater than that of the binary mixture melt viscosity. The degree of viscosity increase depended upon the composition of the binary mixture, the value of shear stress, and POM content. This dependence may be explained by formation of hydrogen bonds between POM and CPA macromolecules. The addition of POM improved the specific PP fiber formation in the matrix of CPA. The latter is valid even for a composition (PP/CPA ratio is 40/60) close to phase inversion. POM migration toward the walls of the forming die occurred in the flow of the ternary polymer mixture melts. For the purpose of realizing the specific fiber formation during the processing of the above mentioned mixtures we recommend an addition of 5% to 10% of POM. [source] Evidence for a new late positive ERP component in an attended novelty oddball taskPSYCHOPHYSIOLOGY, Issue 5 2010Craig G. McDonald Abstract In attended novelty oddball tasks, rare nontarget stimuli can elicit two late positive ERP components: P3a and P300. In passive oddball tasks, P300 is not elicited by these stimuli. In passive tasks, however, P3a is accompanied by another positive component, termed eP3a, which may have evaded detection in attended oddball tasks because of its spatiotemporal overlap with P300. To address this, temporal-spatial principal components analysis was used to quantify ERPs recorded in attended three-tone and novelty oddball tasks. As expected, novel stimuli elicited both P3a and P300. The analysis also identified a third component, evident in novelty ERPs as an inflection on the leading edge of P3a. This component has the same antecedent conditions as P3a, but is earlier and more centrally distributed. Its spatiotemporal characteristics suggest that it may be the eP3a component recently described in passive oddball tasks. [source] Complement Independent Antibody-Mediated Endarteritis and Transplant Arteriopathy in MiceAMERICAN JOURNAL OF TRANSPLANTATION, Issue 3 2010T. Hirohashi Complement fixation, as evidenced by C4d in the microvasculature, is a widely accepted criterion of antibody-mediated rejection. Complement fixation has been shown to be essential in acute antibody-mediated rejection, but its role in chronic rejection has not been addressed. Previous studies showed that passive transfer of complement fixing monoclonal IgG2a anti-H-2Kk into B6.RAG1,/, KO recipients of B10.BR hearts led to progressive chronic transplant arteriopathy (CTA) over 14,28 days, accompanied by C4d deposition. The present studies were designed to test whether complement was required for these lesions. We report that a noncomplement fixing donor-specific alloantibody (DSA, monoclonal IgG1 anti-H-2Kk) injected into B6.RAG1 -/- KO recipients of B10.BR hearts also promotes CTA, without C4d deposition. Furthermore, a passive transfer of DSA (monoclonal IgG2a anti-H-2Kk) initiated endarteritis followed by CTA in B6.RAG1,/- mice genetically deficient in the third component of complement (RAG1,/,C3,/,). These studies indicate that antibody to class I MHC antigens can trigger chronic arterial lesions in vivo without complement participation, in contrast to acute antibody-mediated rejection. This pathway may be relevant to C4d-negative chronic rejection sometimes observed in patients with DSA, and argues that lack of C4d deposition does not exclude antibody-mediated chronic rejection. [source] Development of a New Pharmacophore Model That Discriminates Active Compstatin AnalogsCHEMICAL BIOLOGY & DRUG DESIGN, Issue 4 2008Ting-Lan Chiu Compstatin and its active peptide analogs can potentially be used for therapeutic purposes because their binding to the third component of complement prohibits its conversion into the proteolytically activated form of the third component of complement, thus inhibiting complement cascades in all three complement pathways. Mallik and Morikis built three quasi-dynamic pharmacophore models for compstatin peptide analogs before, but only nine compstatin peptide analogs were incorporated in their study and the most active compstatin analog had only medium inhibitory activity. Since then, many more compstatin analogs have been synthesized and their inhibitory activities tested. Furthermore, the X-ray structure of AcCompNH2-V4W-H9A bound to the third component of complement has become available (PDB ID: 2QKI). In this paper, we utilized all the new information and built a new pharmacophore model using a distinct approach. Our model demonstrated good performance in a separate test set of 82 compstatin analogs: it accurately identified 70% of the analogs of medium or high inhibitory activities and misclassified only 8.5% of the analogs of low or no inhibitory activities. The results proved our pharmacophore model to be a filter of great sensitivity and specificity. [source] Molecular recognition in solid-state crystallization: Colored chiral adduct formations of 1,1,-Bi-2-naphthol derivatives and benzoquinone with a third componentCHIRALITY, Issue 7 2002Yoshitane Imai Abstract Molecular recognition in solid-state crystallization involving derivatives of 1,1,-bi-2-naphthol and benzoquinone was studied. No adduct crystal was formed when crystals of biphenyl were further added as a third component to a grinding mixture of crystals of chiral 1,1,-bi-2-naphthol and benzoquinone, which by itself did not form an adduct. This contrasts with the case in which further addition of naphthalene crystals to the same mixture produced a new red crystal. Adduct formations using chiral 6,6,-dibromo-1,1,-bi-2-naphthol in place of 1,1,-bi-2-naphthol were also studied. In this case, adducts were produced either with or without biphenyl as a third compound, but the colors of the adducts differed significantly in the two cases: red and bluish-black. The same three-component adduct crystals were produced from solid-grinding and solution crystallization and the structure was determined by X-ray diffractometry. Based on the crystal structures, theoretical calculations were carried out to compare the mechanism of colorations in the binary and the ternary complexes. Chirality 14:604,609, 2002. © 2002 Wiley-Liss, Inc. [source] Environmental links to reduced tropical cyclogenesis over the south-east CaribbeanINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 8 2007Alexandros P. Georgiadis Abstract Tropical cyclone formation over the Caribbean is not evenly distributed across the basin. Previous work identified the south-western sector as the area that dominates the hurricane activity of the whole basin. The south-eastern sector, in contrast, exhibits a distinct suppression in cyclogenesis. This study seeks to identify the restricting factors that differentiate the cyclogenesis climatology in the south-east Caribbean. It is based on statistical analysis of eight environmental variables using principal component analysis. The first three components are examined in detail. The first component, accounting for 31.7% of the variance within the data, differentiates the Caribbean from the rest of the subtropical Atlantic, primarily in terms of an increased thermodynamic potential for cyclogenesis and enhanced atmospheric humidity in the boundary layer. The second component, accounting for 31% of the variance, marks the south-west Caribbean as the only sub-region within the area of analysis where the easterlies curve southwards and the relative vorticity is cyclonic. The third component, accounting for 20.3% of the variance, differentiates the South Caribbean from the rest of the Atlantic, indicating it to be a region of increased spatial variation in the intensity of the easterlies and in absolute vorticity. The variance of cyclogenesis within the Caribbean is greatest along the second and third components. Thus, the genesis pattern in the basin is likely associated with the low-level wind-field and absolute vorticity. The divergence of the flow, when combined with the vorticity of the wind-field over the Caribbean, renders the background conditions of the eastern sector less prone to developing disturbances than is the case in the western Caribbean. Copyright © 2006 Royal Meteorological Society [source] | |||||||||||||