The gas–liquid phase-transition singularities in the framework of the liquid-state integral equation formalism

6 pages, 4 figures.-- PACS: 64.70.Fx; 65.20.+w; 02.30.Rz; 62.10.+sThe singularities of various liquid-state integral equations derived from the Ornstein–Zernike relation and its temperature derivatives, have been investigated in the liquid–vapor transition region. As a general feature, it has been found that the existence of a nonsolution curve on the vapor side of the phase diagram, on which both the direct and the total correlation functions become complex—with a finite isothermal compressibility—also corresponds to the locus of points where the constant-volume heat capacity diverges, in consonance with a divergence of the temperature derivative of the correlation functions. In contrast, on the liquid side of the phase diagram one finds that a true spinodal (a curve of diverging isothermal compressibilities) is reproduced by the Percus–Yevick and Martynov–Sarkisov integral equations, but now this curve corresponds to states with finite heat capacity. On the other hand, the hypernetted chain approximation exhibits a nonsolution curve with finite compressibilities and heat capacities in which, as temperature is lowered, the former tends to diverge.E.L. acknowledges financial support of the Dirección General de Investigación Científica y Técnica under Grant No. FIS2004-02954-C03-01. This work has been carried out under the auspices of the exchange agreement between the Consejo Superior de Investigaciones Científicas and the Russian Academy of Sciencies, which supported the exchange visits of E.L. and G.S. in the past two years.Peer reviewe

IL-15 modulates the effect of retinoic acid, promoting inflammation rather than oral tolerance to dietary antigens

3 páginas.-- Evaluation of: DePaolo RW, Abadie V, Tang F et al. Co-adjuvant effects of retinoic acid and IL-15 induce inflammatory immunity to dietary antigens. Nature 471(7337), 220–224 (2011).The physiological immune response in the intestine against dietary proteins and commensal flora is characterized by regulatory mechanisms (tolerance) that prevent harmful consequences. Intestinal dendritic cells (DCs) have a central role in the development of immunosuppressive regulatory T cells owing to their ability to produce TGF-b and retinoic acid (RA). However, the article under evaluation shows an unexpected effect of RA – that of promoting a proinflammatory phenotype in intestinal DCs involved in the generation of inflammatory immune responses to dietary antigens. By using a double transgenic murine model that resembles human celiac disease, it was demonstrated that RA synergizes with IL‑15 in promoting the breakdown of gluten tolerance and the development of enteropathy. The tissue microenvironment modulates DC function, and immune therapies that are based on RA aiming to restore oral tolerance should be used with caution because the presence of IL‑15 (and/or other proinflammatory cytokines) may have undesirable effects.Peer reviewe

Інвестиційна політика як один з пріорітетних шляхів розвитку економіки регіонів

В сучасних умовах спаду економічного розвитку регіонів важливу роль відіграють пошуки нових напрямів в регіональній реформі. На сучасному етапі дуже мало приділяється уваги новаторським питанням. Таким чином, розвиток інноваційної діяльності суб’єктів господарювання регіону може бути використаний як дієвий чинник економічного оздоровлення

Развитие подхода к моделированию процесса получения этилбензола

На примере процесса синтеза этилбензола предложен подход к формализации схемы превращений углеводородов, заключающийся в группировании компонентов по их реакционной способности в отношении определенной реакции. Рассчитаны значения степеней компенсации реакций как показателя реакционной способности компонентов. Разработаны кинетические модели процессов алкилирования бензола этиленом и трансалкилирования полиалкилатов