Transfer matrix eigenvalues of the anisotropic multiparametric U model

A multiparametric extension of the anisotropic U model is discussed which maintains integrability. The R-matrix solving the Yang-Baxter equation is obtained through a twisting construction applied to the underlying U-q(sl (2/1)) superalgebraic structure which introduces the additional free parameters that arise in the model. Three forms of Bethe ansatz solution for the transfer matrix eigenvalues are given which we show to be equivalent.

A note on the decomposition of the health concentration index

In recent work, the concentration index has been widely used as a measure of income-related health inequality. The purpose of this note is to illustrate two different methods for decomposing the overall health concentration index using data collected from a Short Form (SF-36) survey of the general Australian population conducted in 1995. For simplicity, we focus on the physical functioning scale of the SF-36. Firstly we examine decomposition 'by component' by separating the concentration index for the physical functioning scale into the ten items on which it is based. The results show that the items contribute differently to the overall inequality measure, i.e. two of the items contributed 13% and 5%, respectively, to the overall measure. Second, to illustrate the 'by subgroup' method we decompose the concentration index by employment status. This involves separating the population into two groups: individuals currently in employment; and individuals not currently employed. We find that the inequality between these groups is about five times greater than the inequality within each group. These methods provide insights into the nature of inequality that can be used to inform policy design to reduce income related health inequalities. Copyright (C) 2002 John Wiley Sons, Ltd.

The interaction of metal ions and Marimastat with matrix metalloproteinase 9

The effect of a range of metal ions on the ability of Marimastat to inhibit matrix metalloproteinase 9 (MMP-9) was examined in a fluorescence based proteolytic assay. Whilst none of the metals examined significantly affected the inhibitory ability of Marimastat, several metal ions did have a significant effect on MMP-9 activity itself. In the absence of Marimastat, Zn(II) and Fe(II) significantly inhibited MMP-9 activity at metal ion concentrations of 10 and 100 muM, respectively. In both the absence and presence of Marimastat, Cd(II) significantly inhibited MMP-9 at 100 muM. In contrast, 1 mM Co(II) significantly upregulated MMP-9 proteolytic activity. (C) 2003 Elsevier Science Inc. All rights reserved.

The game to play: expanding the co-opetition proposal through the strategic games matrix

Purpose - Using Brandenburger and Nalebuff`s 1995 co-opetition model as a reference, the purpose of this paper is to seek to develop a tool that, based on the tenets of classical game theory, would enable scholars and managers to identify which games may be played in response to the different conflict of interest situations faced by companies in their business environments. Design/methodology/approach - The literature on game theory and business strategy are reviewed and a conceptual model, the strategic games matrix (SGM), is developed. Two novel games are described and modeled. Findings - The co-opetition model is not sufficient to realistically represent most of the conflict of interest situations faced by companies. It seeks to address this problem through development of the SGM, which expands upon Brandenburger and Nalebuff`s model by providing a broader perspective, through incorporation of an additional dimension (power ratio between players) and three novel, respectively, (rival, individualistic, and associative). Practical implications - This proposed model, based on the concepts of game theory, should be used to train decision- and policy-makers to better understand, interpret and formulate conflict management strategies. Originality/value - A practical and original tool to use game models in conflict of interest situations is generated. Basic classical games, such as Nash, Stackelberg, Pareto, and Minimax, are mapped on the SGM to suggest in which situations they Could be useful. Two innovative games are described to fit four different types of conflict situations that so far have no corresponding game in the literature. A test application of the SGM to a classic Intel Corporation strategic management case, in the complex personal computer industry, shows that the proposed method is able to describe, to interpret, to analyze, and to prescribe optimal competitive and/or cooperative strategies for each conflict of interest situation.

Pt-RuO(2) electrodes prepared by thermal decomposition of polymeric precursors as catalysts for direct methanol fuel cell applications

The electrocatalytic activity of Pt and RuO(2) mixed electrodes of different compositions towards methanol oxidation was investigated. The catalysts were prepared by thermal decomposition of polymeric precursors and characterized by energy dispersive X-ray, scanning electronic microscopy, X-ray diffraction and cyclic voltammetry. This preparation method allowed obtaining uniform films with controlled stoichiometry and high surface area. Cyclic voltammetry experiments in the presence of methanol showed that mixed electrodes decreased the potential peak of methanol oxidation by approximately 100 mV (RHE) when compared to the electrode containing only Pt. In addition, voltammetric experiments indicated that the Pt(0.6)Ru(0.4)O(y) electrode led to higher oxidation current densities at lower potentials. Chronoamperometry experiments confirmed the contribution of RuO(2) to the catalytic activity as well as the better performance of the Pt(0.6)Ru(0.4)O(y) electrode composition. Formic acid and CO(2) were identified as being the reaction products formed in the electrolysis performed at 400 and 600 mV. The relative formation of CO(2) was favored in the electrolysis performed at 400 mV (RHE) with the Pt(0.6)Ru(0.4)O(y) electrode. The presence of RuO(2) in Pt-Ru-based electrodes is important for improving the catalytic activity towards methanol electrooxidation. Moreover, the thermal decomposition of polymeric precursors seems to be a promising route for the production of catalysts applicable to DMFC. (C) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.

Development of novel bioanodes for ethanol biofuel cell using PAMAM dendrimers as matrix for enzyme immobilization

This paper describes the preparation and application of a novel bioanode for use in ethanol/O(2) biofuel cells based upon immobilization of alcohol dehydrogenase (ADH) and polyamidoamine (PAMAM) dendrimers onto carbon cloth platforms. The power density measurements indicated a direct relationship between the amount of anchored ADH and the anode power values, which increased upon enzyme loading. The power density values ranged from 0.04 to 0.28 mW cm(-2), and the highest power density was achieved with the bioanode prepared with 28 U of ADH, which provided a power density of 0.28 mW cm(-2) at 0.3 V. The latter power output values were the maximum observed, even for higher enzyme concentrations. Stability of the bioanodes was quite satisfactory, since there was no appreciable reduction of enzymatic activity during the measurements. The method of bioanode preparation described here has proven to be very effective. The PAMAM dendrimer represents a friendly environment for the immobilization of enzymes, and it is stable and capable of generating high power density compared to other immobilization methods. (C) 2010 Elsevier B.V. All rights reserved.

Characterization and voltammetric behavior of Pt(y)Mo(z)O(x)/C electrodes prepared by the thermal decomposition of polymeric precursors

Carbon-supported catalysts containing platinum and molybdenum oxide are prepared by thermal decomposition of polymeric precursors. The Pt(y)Mo(z)O(x)/C materials are characterized by energy dispersive X-ray spectroscopy, transmission electron microscopy, and X-ray diffraction. The catalysts present a well-controlled stoichiometry and nanometric particles. Molybdenum is present mainly as the MoO(3) orthorhombic structure, and no Pt alloys are detected. The voltammetric behavior of the electrodes is investigated; a correlation with literature results for PtMo/C catalysts prepared by other methods is established. The formation of soluble species and the aging effect are discussed. (C) 2009 Elsevier B.V. All rights reserved.

Proteoliposomes Harboring Alkaline Phosphatase and Nucleotide Pyrophosphatase as Matrix Vesicle Biomimetics

We have established a proteoliposome system as an osteoblast-derived matrix vesicle (MV) biomimetic to facilitate the study of the interplay of tissue-nonspecific alkaline phosphatase (TNAP) and NPP1 (nucleotide pyrophosphatase/phosphodiesterase-1) during catalysis of biomineralization substrates. First, we studied the incorporation of TNAP into liposomes of various lipid compositions (i.e. in pure dipalmitoyl phosphatidylcholine (DPPC), DPPC/dipalmitoyl phosphatidylserine (9:1 and 8:2), and DPPC/dioctadecyl-dimethylammonium bromide (9:1 and 8:2) mixtures. TNAP reconstitution proved virtually complete in DPPC liposomes. Next, proteoliposomes containing either recombinant TNAP, recombinant NPP1, or both together were reconstituted in DPPC, and the hydrolysis of ATP, ADP, AMP, pyridoxal-5`-phosphate (PLP), p-nitrophenyl phosphate, p-nitrophenylthymidine 5`-monophosphate, and PP(i) by these proteoliposomes was studied at physiological pH. p-Nitrophenylthymidine 5`-monophosphate and PLP were exclusively hydrolyzed by NPP1-containing and TNAP-containing proteoliposomes, respectively. In contrast, ATP, ADP, AMP, PLP, p-nitrophenyl phosphate, and PPi were hydrolyzed by TNAP-, NPP1-, and TNAP plus NPP1- containing proteoliposomes. NPP1 plus TNAP additively hydrolyzed ATP, but TNAP appeared more active in AMP formation than NPP1. Hydrolysis of PPi by TNAP-, and TNAP plus NPP1- containing proteoliposomes occurred with catalytic efficiencies and mild cooperativity, effects comparable with those manifested by murine osteoblast-derived MVs. The reconstitution of TNAP and NPP1 into proteoliposome membranes generates a phospholipid microenvironment that allows the kinetic study of phosphosubstrate catabolism in a manner that recapitulates the native MV microenvironment.

EXPRESSION OF MEMBRANE TYPE 1 MATRIX METALLOPROTEINASE IN MEDULLARY THYROID CARCINOMA: PROGNOSTIC IMPLICATIONS

Background. Clinical and pathologic examinations cannot always provide a prognosis for patients with medullary thyroid carcinoma. Membrane type 1 matrix metalloproteinase (MT1-MMP) can act directly on carcinogenesis and takes part in 1 of the processes of metalloproteinase 2 activation, an enzyme related to prognostic impairment of patients with such tumor. Methods. Thirty-five patients who were submitted to surgery were followed up for an average of 74 months, Postoperative and final medical conditions were characterized for comparison with MT1-MMP immunostainings, performed in surgical paraffin blocks. A value of p < .05 was considered statistically significant. Results. Proposed index (association of proportion and intensity of immunostaining) and proportion of immunostained cells in primary specimens were correlated with cure or persistence after initial operations (p = .0216 and p = .0098, respectively). Conclusion. MT1-MMP immunostaining in primary tumor specimens is a new and complementary prognostic predictor in patients with medullary thyroid carcinomas. (C) 2009 Wiley Periodicals, Inc. Head Neck 32: 58-67, 2010

Effects of chronic L-NAME treatment lung tissue mechanics, eosinophilic and extracellular matrix responses induced by chronic pulmonary inflammation

The importance of lung tissue in asthma pathophysiology has been recently recognized. Although nitric oxide mediates smooth muscle tonus control in airways, its effects on lung tissue responsiveness have not been investigated previously. We hypothesized that chronic nitric oxide synthase (NOS) inhibition by N-omega-nitro-L-arginine methyl ester (L-NAME) may modulate lung tissue mechanics and eosinophil and extracellular matrix remodeling in guinea pigs with chronic pulmonary inflammation. Animals were submitted to seven saline or ovalbumin exposures with increasing doses (1 similar to 5 mg/ml for 4 wk) and treated or not with L-NAME in drinking water. After the seventh inhalation (72 h), animals were anesthetized and exsanguinated, and oscillatory mechanics of lung tissue strips were performed in baseline condition and after ovalbumin challenge (0.1%). Using morphometry, we assessed the density of eosinophils, neuronal NOS (nNOS)- and inducible NOS (iNOS)-positive distal lung cells, smooth muscle cells, as well as collagen and elastic fibers in lung tissue. Ovalbumin-exposed animals had an increase in baseline and maximal tissue resistance and elastance, eosinophil density, nNOS- and iNOS-positive cells, the amount of collagen and elastic fibers, and isoprostane-8-PGF(2 alpha) expression in the alveolar septa compared with controls (P < 0.05). L-NAME treatment in ovalbumin-exposed animals attenuated lung tissue mechanical responses (P < 0.01), nNOS- and iNOS-positive cells, elastic fiber content (P < 0.001), and isoprostane-8-PGF(2 alpha) in the alveolar septa (P < 0.001). However, this treatment did not affect the total number of eosinophils and collagen deposition. These data suggest that NO contributes to distal lung parenchyma constriction and to elastic fiber deposition in this model. One possibility may be related to the effects of NO activating the oxidative stress pathway.

Twisted quantum affine superalgebra U-q[sl(2/2)((2))], U-q[osp(2/2)] invariant R-matrices and a new integrable electronic model

We describe the twisted affine superalgebra sl(2\2)((2)) and its quantized version U-q[sl(2\2)((2))]. We investigate the tensor product representation of the four-dimensional grade star representation for the fixed-point sub superalgebra U-q[osp(2\2)]. We work out the tensor product decomposition explicitly and find that the decomposition is not completely reducible. Associated with this four-dimensional grade star representation we derive two U-q[osp(2\2)] invariant R-matrices: one of them corresponds to U-q [sl(2\2)(2)] and the other to U-q [osp(2\2)((1))]. Using the R-matrix for U-q[sl(2\2)((2))], we construct a new U-q[osp(2\2)] invariant strongly correlated electronic model, which is integrable in one dimension. Interestingly this model reduces in the q = 1 limit, to the one proposed by Essler et al which has a larger sl(2\2) symmetry.

Finite element analysis of mechanical properties in discontinuously reinforced metal matrix composites with ultrafine microstructure

This investigation focused on the finite element analyses of elastic and plastic properties of aluminium/alumina composite materials with ultrafine microstructure. The commonly used unit cell model was used to predict the elastic properties. By combining the unit cell model with an indentation model, coupled with experimental indentation measurements, the plastic properties of the composites and the associated strengthening mechanism within the metal matrix material were investigated. The grain size of the matrix material was found to be an important factor influencing the mechanical properties of the composites studied. (C) 1997 Elsevier Science S.A.