Polyaniline–13X zeolite composite‐supported platinum electrocatalysts for direct methanol fuel cell applications

We successfully synthesized 13X zeolite using a hydrothermal method. Then, composites of polyaniline (PANI) with 13X zeolite and PANI–13X with platinum were prepared by chemical oxidative polymerization and chemical reduction, respectively. Field emission scanning electron microscopy, X‐ray diffraction, Raman spectroscopy and Brunauer–Emmett–Teller techniques were used to characterize the PANI–Pt and PANI–Pt–13X composites. Further, the electrocatalytic activity towards methanol oxidation of the synthesized catalysts was explored using cyclic voltammetry in 1 mol L^?1 CH₃OH + 0.5 mol L^?1 H₂SO₄ solution. From the obtained results, PANI–Pt–13X shows superior performance compared to PANI–Pt towards methanol oxidation and electrical conductivity. Hence, the 13X zeolite‐incorporated PANI–Pt composite could be an efficient catalyst for direct methanol fuel cell applications. © 2019 Society of Chemical Industry     

Comparison of PPAR Ligands as Modulators of Resolution of Inflammation,via Their Influence on Cytokines and Oxylipins Release in Astrocytes

Neuroinflammation is a key process of many neurodegenerative diseases and other brain disturbances, and astrocytes play an essential role in neuroinflammation. Therefore, the regulation of astrocyte responses for inflammatory stimuli, using small molecules, is a potential therapeutic strategy. We investigated the potency of peroxisome proliferator-activated receptor (PPAR) ligands to modulate the stimulating effect of lipopolysaccharide (LPS) in the primary rat astrocytes on (1) polyunsaturated fatty acid (PUFAs) derivative (oxylipins) synthesis; (2) cytokines TNFα and interleukin-10 (IL-10) release; (3) p38, JNK, ERK mitogen-activated protein kinase (MAPKs) phosphorylation. Astrocytes were exposed to LPS alone or in combination with the PPAR ligands: PPARα (fenofibrate, GW6471); PPARβ ({"type":"entrez-nucleotide","attrs":{"text":"GW501516","term_id":"289075981","term_text":"GW501516"}}GW501516, GSK0660); PPARγ (rosiglitazone, GW9662). We detected 28 oxylipins with mass spectrometry (UPLC-MS/MS), classified according to their metabolic pathways: cyclooxygenase (COX), cytochrome P450 monooxygenases (CYP), lipoxygenase (LOX) and PUFAs: arachidonic (AA), docosahexaenoic (DHA), eicosapentaenoic (EPA). All tested PPAR ligands decrease COX-derived oxylipins; both PPARβ ligands possessed the strongest effect. The PPARβ agonist, {"type":"entrez-nucleotide","attrs":{"text":"GW501516","term_id":"289075981","term_text":"GW501516"}}GW501516 is a strong inducer of pro-resolution substances, derivatives of DHA: 4-HDoHE, 11-HDoHE, 17-HDoHE. All tested PPAR ligands decreased the release of the proinflammatory cytokine, TNFα. The PPARβ agonist {"type":"entrez-nucleotide","attrs":{"text":"GW501516","term_id":"289075981","term_text":"GW501516"}}GW501516 and the PPARγ agonist, rosiglitazone induced the IL-10 release of the anti-inflammatory cytokine, IL-10; the cytokine index, (IL-10/TNFα) was more for {"type":"entrez-nucleotide","attrs":{"text":"GW501516","term_id":"289075981","term_text":"GW501516"}}GW501516. The PPARβ ligands, {"type":"entrez-nucleotide","attrs":{"text":"GW501516","term_id":"289075981","term_text":"GW501516"}}GW501516 and GSK0660, are also the strongest inhibitors of LPS-induced phosphorylation of p38, JNK, ERK MAPKs. Overall, our data revealed that the PPARβ ligands are a potential pro-resolution and anti-inflammatory drug for targeting glia-mediated neuroinflammation.     

Cooling capacity of contemporary hardening diffusers

The design and technological parameters of diffusers for hardening sheet glass on contemporary production lines are considered. The limiting lower level of the thickness of glass that can undergo air-jet hardening is determined. Translated from Steklo i Keramika, No. 2, pp. 10–11, February, 2000.     

On mappings of bounded variation

We present the properties of mappings of bounded variation defined on a subset of the real line with values in metric and normed spaces and show that major aspects of the theory of realvalued functions of bounded variation remains valid in this case. In particular, we prove the structure theorem and obtain the continuity properties of these mappings as well as jump formulas for the variation. We establish the existence of Lipschitz continuous geodesic paths and prove an analog of the well-known Helly selection principle. For normed space-valued smooth mappings we obtain the usual integral formula for the variation without the completeness assumption on the space of values. As an application of our theory we show that compact set-valued mappings (=multifunctions) of bounded variation admit regular selections of bounded variation. Partially supported by the Russian Foundation for Fundamental Research, Grant No. 96-01-00278.     

Kinetic description of rapeseed oil conversion into aromatic hydrocarbons on promoted MFI zeolite

An approach to the construction of a kinetic model for the reactions of rapeseed oil hydroconversion to aromatic hydrocarbons has been proposed, which is based on analysis of experimental data obtained using a MFI zeolite promoted with zinc and chromium ions. An empirical mathematical model describing the dynamic behavior of the main products of the decomposition reaction of rapeseed oil as a model feedstock has been developed. It has been shown that an increase in the space time and temperature in the examined range of reaction conditions increase the yield of aromatic hydrocarbons. The influence of hydrogen pressure on the yield of aromatics is nonmonotonic in character, passing through a maximum, with the optimum yield being in the middle of the hydrogen pressure range of 10–20 atm.     

Mappings of Bounded Φ-Variation with Arbitrary Function Φ

We develop the general theory of mappings of bounded -variation in the sense of L. C. Young that are defined on a subset of the real line and take values in metric or normed spaces. We single out the characterizing properties for these mappings, prove the structural theorem for them, and study their continuity properties. We obtain the existence of a geodesic path of bounded -variation between two points of a compact set with certain regularity of its modulus of continuity. The classical Helly selection principle from the theory of functions of bounded variation is generalized for mappings of bounded -variation. Under natural restrictions on the function , we show that the space of all normed space-valued mappings under consideration can be endowed with a metric. Finally, we consider the problem of existence of selections of a continuous set-valued mapping Fof bounded -variation with respect to the Hausdorff distance. We show that if (0) is finite> 0, then Fhas a continuous selection of bounded -variation; if (0) = , then Fis a constant mapping; and if (0) = 0, then, under additional assumptions on , we give examples of mappings Fwith no continuous selection and with no selection of bounded -variation.     

Controllability of Linear Algebraic Differential Systems

A controllable linear system of ordinary differential equations not solvable for the derivative of the vector state function of the system is investigated. The coefficient matrix at the derivative of the vector state function is assumed to be degenerate at all points of the domain of definition. Controllability criteria for systems with constant and variable coefficient matrices are formulated in terms of input data.     

Thermogravimetry in the analysis of results of a calorimetric experiment

A method based on a refined measurement equation is proposed for enhancing the accuracy of measurements of the specific heat of solids. The equation uses calorimetric and gravimetric output signals along with analytical representation of the output and baseline signals. Translated from Izmeritel'naya Tekhnika, No. 9, pp. 26–28, September, 1998.     

Stable expression of manganese superoxide dismutase (MnSOD) in insulinoma cells prevents IL-1beta- induced cytotoxicity and reduces nitric oxide production

The fact that insulin-producing islet beta-cells are susceptible to the cytotoxic effects of inflammatory cytokines represents a potential hinderance to the use of such cells for transplantation therapy of insulin-dependent diabetes mellitus (IDDM). In the current study, we show that IL-1beta induces destruction of INS-1 insulinoma cells, while having no effect on a second insulinoma cell line RIN1046-38 and its engineered derivatives, and that this difference is correlated with a higher level of expression of manganese superoxide dismutase (MnSOD) in the latter cells. Stable overexpression of MnSOD in INS-1 cells provides complete protection against IL-1beta-mediated cytotoxicity, and also results in markedly reduced killing when such cells are exposed to conditioned media from activated human or rat PBMC. Further, overexpression of MnSOD in either RIN- or INS-1-derived lines results in a sharp reduction in IL-1beta-induced nitric oxide (NO) production, a finding that correlates with reduced levels of the inducible form of nitric oxide synthase (iNOS). Treatment of INS-1 cells with L-NMMA, an inhibitor of iNOS, provides the same degree of protection against IL-1beta or supernatants from LPS-activated rat PBMC as MnSOD overexpression, supporting the idea that MnSOD protects INS-1 cells by interfering with the normal IL-1beta-mediated increase in iNOS. Because NO and its derivatives have been implicated as critical mediators of beta-cell destruction in IDDM, we conclude that well regulated insulinoma cell lines engineered for MnSOD overexpression may be an attractive alternative to isolated islets as vehicles for insulin replacement in autoimmune diabetes.