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Same Properties (same + property)
Selected AbstractsChronic nicotine treatment changes the axonal distribution of 68 kDa neurofilaments in the rat ventral tegmental areaEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 5 2002Andrea Sbarbati Abstract Region-specific decreases of neurofilament proteins (NF) were described in the ventral tegmental area (VTA) of rats treated chronically with morphine, cocaine or alcohol. In a previous study, we demonstrated that NF levels were also changed in the VTA after chronic treatment with nicotine. The aim of this study was to clarify the submicroscopic basis of decreased immunoreactivity for NF-68, NF-160 and NF-200, as determined by using NR4, BF10 and RT97 antibodies, respectively. Microdensitometric analysis of brain sections showed that immunoreactivity for all NF was reduced in the VTA of animals exposed chronically to nicotine (0.4 mg/kg per day, 6 days of treatment), when compared to rats exposed to saline. Reduction in immunoreactivity was significant for NF-68 (P < 0.05), NF-160 (P < 0.01) and NF-200 (P < 0.05), showing a relative reduction of 34%, 42% and 38%, respectively, when compared to saline-treated rats. No difference was observed for any of the NF under study when immunoreactivity measurements in the substantia nigra were compared. Ultrastructural analysis was applied to evaluate changes in NF-68, NF-160 and NF-200 immunoreactivity in regions of the VTA that contain dopaminergic neurons following chronic nicotine treatment. At the electron microscopic level, no degenerative changes were found in neurons or glial cells of the VTA. With ultrastructural immunohistochemistry, evaluation of the homogeneity parameter of NF distribution showed a loss of homogeneity for NF-68 linked to the nicotine treatment. In areas in which NF organization appeared well preserved, analysis of the numerical density of NF revealed no significant difference for NF-68 (897/µm2 vs. 990/µm2), NF-160 (970/µm2 vs. 820/µm2) and NF-200 (1107/µm2 vs. 905/µm2) in nicotine-treated rats when compared to saline-treated rats. These results confirm that nicotine shares the same properties with cocaine and morphine in reducing NF in the VTA, a key brain structure of the rewards system, and that chronic nicotine treatment changes the axonal distribution of 68 kDa neurofilaments in the rat VTA. [source] The effect of disinfectants on the properties of dental gypsum, part 2: Surface propertiesJOURNAL OF PROSTHODONTICS, Issue 4 2002Khalid M. Abdelaziz PhD Purpose This study is part of an ongoing investigation to evaluate the surface properties of dental stones mixed with disinfection solutions, and to determine the effect of adding gum arabic and calcium hydroxide on the same properties. Materials and Methods Aqueous solutions of 2 chemical disinfectants were used in mixing 2 types of dental stones (type III and type V). These dental stones were modified further by adding 1% gum arabic and 0.132% calcium hydroxide to their hemihydrate powders before mixing. Five specimens prepared from each type of dental stone were classified into 7 groups according to the hemihydrate powder modification and mixing liquid/powder ratio. Surface roughness was tested by 2-dimensional profilometery and scanning electron microscopy (SEM). Knoop hardness testing was carried out, and detail reproduction was assessed using ADA specification 25 in addition to SEM and 3-dimensional profilometer studies. Results Dental stones mixed with chemical disinfectants showed higher average roughness (Ra) values than those of the controls. However, adding gum arabic and calcium hydroxide to the hemihydrate powders before mixing restored values to the level of the control. The additives seemed to have a role in the improvement of surface hardness. There was no significant difference between the experimental and the control group in the terms of detail reproduction. Conclusions Using SEM, 3-dimensional profilometry, and ADA testing methods, we found that the surface roughness of stone casts was adversely affected by using the disinfectant solutions as mixing water substitutes. Gum arabic and calcium hydroxide additives can yield a harder stone surface without compromising other surface properties. [source] Chiroptical Properties of Terthiophene Chromophores Dispersed in Oriented and Unoriented Polyethylene FilmsMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 6 2004Andrea Pucci Abstract Summary: Two new chiral terthiophene chromophores II and III were prepared with 99% enantiomeric excess. Chiroptical properties of these dyes dispersed in ultra high molecular weight polyethylene (UHMWPE) films were determined and compared with the same properties in solution. In the solid state, the optical activity strongly depends on the interaction mechanisms within small crystalline aggregates of chromophores. The film morphology and chromophore dispersion were also investigated by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The good correlation between chromophore aggregation and chiroptical activity of the binary films promotes circular dichroism (CD) as an effective technique for monitoring the phase dispersion behaviour of dichroic dyes into polymer matrices. By mechanical stretching of the film a linearly dichroic orientation of the chromophores is obtained which results in a high degree of linear dichroism. The influence of the uniaxial orientation of terthiophene molecules along the drawing direction of UHMWPE on the chiroptical properties of the films, and the possible application of the oriented devices as linear polarizers are discussed. Absorption and CD spectra of unoriented UHMWPEII film at different rotation angles ,. [source] Development of a new production method for a polypropylene-clay nanocompositePOLYMER ENGINEERING & SCIENCE, Issue 7 2004Makoto Kato A new production method for polypropylene-clay nanocomposites has been successfully developed. This method did not require the pretreatment of the clay mineral with an organo-cation. In this method we focused our attention on the nature of the clay mineral, which was exfoliated in water. Water was injected into a complex of melted polypropylene and a clay mineral in a twin-screw extruder. By controlling the pressure of the water vapor, the exfoliation of the clay mineral was achieved in the twin-screw extruder. Compatibilizers were added to the mixture of the clay mineral and the polypropylene to prevent aggregation, and we successfully prepared a polypropylene nanocomposite. The silicate layers of the clay mineral in this polypropylene nanocomposite were exfoliated and dispersed uniformly in the polypropylene matrix. This new type of polypropylene nanocomposite had almost the same properties as a conventionally prepared polypropylene-clay nanocomposite. Polym. Eng. Sci. 44:1205,1211, 2004. © 2004 Society of Plastics Engineers. [source] Mouse × pig chimeric antibodies expressed in Baculovirus retain the same properties of their parent antibodiesBIOTECHNOLOGY PROGRESS, Issue 2 2009Ana M. Jar Abstract The development of hybridoma and recombinant DNA technologies has made it possible to use antibodies against cancer, autoimmune disorders, and infectious diseases in humans. These advances in therapy, as well as immunoprophylaxis, could also make it possible to use these technologies in agricultural species of economic importance such as pigs. Porcine reproductive and respiratory syndrome virus (PRRSV) is an arterivirus causing very important economic losses to the industry. Passive transfer of antibodies obtained by biotechnology could be used in the future to complement or replace vaccination against this and other pig pathogens. To this end, we constructed and studied the properties of chimeric mouse × pig anti-PRRSV antibodies. We cloned the constant regions of gamma-1 and gamma-2 heavy chains and the lambda light chain of pig antibodies in frame with the variable regions of heavy and light chains of mouse monoclonal antibody ISU25C1, which has neutralizing activity against PRRSV. The coding regions for chimeric IgG1 and IgG2 were expressed in a baculovirus expression system. Both chimeric antibodies recognized PRRSV in ELISA as well as in a Western-blot format and, more importantly, were able to neutralize PRRSV in the same fashion as the parent mouse monoclonal antibody ISU25C1. In addition, we show that both pig IgG1 and IgG2 antibodies could bind complement component C1q, with IgG2 being more efficient than IgG1 in binding C1q. Expressing chimeric pig antibodies with protective capabilities offers a new alternative strategy for infectious disease control in domestic pigs. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] Intermediate Preferences and Behavioral Conformity in Large GamesJOURNAL OF PUBLIC ECONOMIC THEORY, Issue 1 2009GUILHERME CARMONA Motivated by Wooders, Cartwright, and Selten (2006), we consider games with a continuum of players and intermediate preferences. We show that any such game has a Nash equilibrium that induces a partition of the set of attributes into a bounded number of convex sets with the following property: all players with an attribute in the interior of the same element of the partition play the same action. We then use this result to show that all sufficiently large, equicontinuous games with intermediate preferences have an approximate equilibrium with the same property. Our result on behavior conformity for large finite game generalizes Theorem 3 of Wooders et al. (2006) by allowing both a wider class of preferences and a more general attribute space. [source] Geometrical and algebraic approach to central molecular chirality: A chirality index and an Aufbau description of tetrahedral moleculesCHIRALITY, Issue 7 2006Salvatore Capozziello Abstract On the basis of empirical Fischer projections, we develop an algebraic approach to the central molecular chirality of tetrahedral molecules. The elements of such an algebra are obtained from the 24 projections which a single chiral tetrahedron can generate in S and R absolute configurations. They constitute a matrix representation of the O(4) orthogonal group. According to this representation, given a molecule with n chiral centres, it is possible to define an "index of chirality , , {n, p}", where n is the number of stereogenic centres of the molecule and p the number of permutations observed under rotations and superimpositions of the tetrahedral molecule to its mirror image. The chirality index not only assigns the global chirality of a given tetrahedral chain, but indicates also a way to predict the same property for new compounds, which can be built up consistently. Chirality 18:462,468, 2006. © 2006 Wiley-Liss, Inc. [source] | |||||||||||||