244 research outputs found

    Nonequilibrium corrections in the pressure tensor due to an energy flux

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    The physical interpretation of the nonequilibrium corrections in the pressure tensor for radiation submitted to an energy flux obtained in some previous works is revisited. Such pressure tensor is shown to describe a moving equilibrium system but not a real nonequilibrium situation.Comment: 4 pages, REVTeX, Brief Report to appear in PRE Dec 9

    Information theory in the study of anisotropic radiation

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    Information theory is used to perform a thermodynamic study of non equilibrium anisotropic radiation. We limit our analysis to a second-order truncation of the moments, obtaining a distribution function which leads to a natural closure of the hierarchy of radiative transfer equations in the so-called variable Eddington factor scheme. Some Eddington factors appearing in the literature can be recovered as particular cases of our two-parameter Eddington factor. We focus our attention in the study of the thermodynamic properties of such systems and relate it to recent nonequilibrium thermodynamic theories. Finally we comment the possibility of introducing a nonequilibrium chemical potential for photons.Comment: 1 eps figure upon request by e-mail, to appear in Journal of Physics

    Local and global behaviour of nonlinear equations with natural growth terms

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    This paper concerns a study of the pointwise behaviour of positive solutions to certain quasi-linear elliptic equations with natural growth terms, under minimal regularity assumptions on the underlying coefficients. Our primary results consist of optimal pointwise estimates for positive solutions of such equations in terms of two local Wolff's potentials.Comment: In memory of Professor Nigel Kalto

    A new clinically applicable immune-metabolic signature (IMMETCOLS) reveals metabolic singularities in consensus molecular subtypes (CMS) in colorectal cancer

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    Background: In the last years, a great effort has been made to unify different independent colorectal cancer (CRC) molecular classification systems into four consensus molecular subtypes (CMS). The four subtypes are found to be associated with distinct microenvironmental features and clinical outcome, although metabolic singularities are not well established. Metabolic dysregulation has been reported as a hallmark of CMS3, but metabolic heterogeneity among other subtypes has not been investigated. Here, taking into account the increasing evidence on the importance, for determining response to therapies, of the metabolic crosstalk between cancer cells, tumor microenvironment and immune cells, we investigated the metabolic singularities in the four CMS using a genetic immune-metabolic signature (IMMETCOLS). Conclusions: IMMETCOLS signature refines CMS prognosis in CRC patients and potentially allows specific metabolic interventions in CMS subtypes

    Synthesis, characterization and biological activity of new cyclometallated platinum(IV) complexes containing a para-tolyl ligand

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    The synthesis of three new cyclometallated platinum(II) compounds containing a para-tolyl ligand and a tridentate [C,N,N'] (cm1) or a bidentate [C,N] ligand and an additional ligand such as SEt2 (cm2) or Ph3 (cm3) is reported. The X-ray molecular structure of platinum(II) compound cm3 is also presented. Intermolecular oxidative addition of methyl iodide or iodine upon cm1, cm2 and cm3 produced six novel cyclometallated platinum(IV) compounds. The cytotoxic activity against a panel of human adenocarcinoma cell lines (A-549 lung, MDA-MB-231 and MCF-7 breast, and HCT-116 colon), DNA interaction, topoisomerase I, IIα, and cathepsin B inhibition, and cell cycle arrest, apoptosis and ROS generation of the investigated complexes are presented. The best results for antiproliferative activity were obtained for platinum (IV) compounds cm1MeI and cm1I2 arising from oxidative addition of methyl iodide and iodine, respectively, to cm1. Cyclometallated platinum(IV) compounds cm1MeI and cm3MeI induce significant changes in the mobility of DNA and, in addition, cm1MeI, cm3MeI and cm1I2, showed considerable topoisomerase IIα inhibitory activity. Moreover, the compounds exhibiting the higher antiproliferative activity (cm1MeI and cm1I2) were found to generate ROS and to supress HCT-116 colon cancer cell growth by a mixture of cell cycle arrest and apoptosis induction. 1H NMR experiments carried out in a buffered aqueous medium (pH 7.40) indicate that compound cm1MeI is not reduced by common biologically relevant reducing agents such as ascorbic acid, glutathione or cysteine

    Systems biologists seek fuller integration of systems biology approaches in new cancer research programs

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    Systems biology takes an interdisciplinary approach to the systematic study of complex interactions in biological systems. This approach seeks to decipher the emergent behaviors of complex systems rather than focusing only on their constituent properties. As an increasing number of examples illustrate the value of systems biology approaches to understand the initiation, progression, and treatment of cancer, systems biologists from across Europe and the United States hope for changes in the way their field is currently perceived among cancer researchers. In a recent EU-US workshop, supported by the European Commission, the German Federal Ministry for Education and Research, and the National Cancer Institute of the NIH, the participants discussed the strengths, weaknesses, hurdles, and opportunities in cancer systems biology

    Test of Information Theory on the Boltzmann Equation

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    We examine information theory using the steady-state Boltzmann equation. In a nonequilibrium steady-state system under steady heat conduction, the thermodynamic quantities from information theory are calculated and compared with those from the steady-state Boltzmann equation. We have found that information theory is inconsistent with the steady-state Boltzmann equation.Comment: 12 page
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