Gamma-radiation-induced damage of chicken myosin and actin

The single 60Co gamma radiation-induced damage of purified chicken myosin and actin in N2O saturated solution is dose dependent protein cross-linking. The differences in myosin and actin conformation and Mm do not influence the type of radiation-induced damage, but they influence the extent of radiation-induced damage, judged by the lower cross linking of fibrillar myosin compared to actin. The radiolytic behavior of myosin and actin in purified forms is different from their radiolysis in intact muscle, according to the absence of protein fragmentation in the former. The results confirm that industrially sterilized meat may contain significant amount (25- 35%) of structurally altered proteins.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

Gamma-radiation-induced damage of proteins in the thick fraction of egg white

The 60Co gamma-ray irradiation of ovomucin based protein network of the thick fraction of egg white in the absence of oxygen causes both protein cross linking and protein fragmentation. Protein fragmentation in the absence of oxygen is interpreted as a consequence of decreased diffusion of protein radicals within the protein network. Both protein cross linking and fragmentation, are dose dependent processes, with fragmentation prevailing below 10-15 kGy, and cross linking prevailing at the radiation doses >15 kGy. The radiolytic behaviour of the thick fraction of egg white, suggests that gamma irradiation of similar mucine containing structures might also result in accumulation of structurally altered and conceivably non-functional proteins in vivo.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

Sonolytic degradation of ovomucin based protein matrix of hen egg white

Sonication of ovomucin based protein matrix of the thick fraction of egg white with the therapeutic ultrasound of 23 kHz frequency and 5µm amplitude causes irreversible decrease of its viscosity down to the limit value of 2.1mPa⋅s. The ultrasound treatment does not affect structure of proteins with lower molecular mass (Mm 3 x 106 g/mol) which form the thick egg white matrix. The results suggest that in analogy with avian egg white matrix, sonication-induced changes in mammalian mucin matrix of joints and tendons may constitute the therapeutical action of ultrasound.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

Errata Corrige: Stress-Induced Phosphorylation of C-Jun-N-Terminal Kinases and Nuclear Translocation of Hsp70 in the Wistar Rat Hippocampus (Vol 61, Pg 1, 2009)

In the paper entitled: Adžić, M., Đorđević, A., Krstić-Demonacos, M., & Radojčić, M. B. (2009). Stress-induced phosphorylation of c-Jun-N-terminal kinases and nuclear translocation of Hsp70 in the Wistar rat hippocampus. Archives of Biological Sciences, 61(1), 1-8. Fig. 1, on page 4, section b, should read "Nucleus" instead of "Cytoplasm

Stress effects on the phosphorylation of c-jun-nterminal kinases and on nuclear translocation of hsp70 in rat hippocampus

Glucocorticoids have diverse effects in cellular processes in hippocampus (HIPPO) under stress. Beside genomic pathways, their effects are also mediated by direct activation of subfamily of mitogen-activated protein kinases termed, c-Jun-Nterminal kinases (JNKs). We analysed the phosphorylation status of cytoplasmic and nuclear JNK isoforms, and expression of its inhibitor Hsp70 protein in HIPPO of rats exposed to diverse types of stress. Activity of JNK1 in cytoplasm and nucleus was decreased in all types of stress, while the activity of cytoplasmic JNK2/3 was markedly higher in acute stress, and unaltered or lowered in chronic and combined stress. Hsp70 was significantly decreased in cytoplasm and increased in nucleus under all stress conditions indicating its cytoplasmic-nuclear translocation.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

Spectral and Dynamical Properties in Classes of Sparse Networks with Mesoscopic Inhomogeneities

We study structure, eigenvalue spectra and diffusion dynamics in a wide class of networks with subgraphs (modules) at mesoscopic scale. The networks are grown within the model with three parameters controlling the number of modules, their internal structure as scale-free and correlated subgraphs, and the topology of connecting network. Within the exhaustive spectral analysis for both the adjacency matrix and the normalized Laplacian matrix we identify the spectral properties which characterize the mesoscopic structure of sparse cyclic graphs and trees. The minimally connected nodes, clustering, and the average connectivity affect the central part of the spectrum. The number of distinct modules leads to an extra peak at the lower part of the Laplacian spectrum in cyclic graphs. Such a peak does not occur in the case of topologically distinct tree-subgraphs connected on a tree. Whereas the associated eigenvectors remain localized on the subgraphs both in trees and cyclic graphs. We also find a characteristic pattern of periodic localization along the chains on the tree for the eigenvector components associated with the largest eigenvalue equal 2 of the Laplacian. We corroborate the results with simulations of the random walk on several types of networks. Our results for the distribution of return-time of the walk to the origin (autocorrelator) agree well with recent analytical solution for trees, and it appear to be independent on their mesoscopic and global structure. For the cyclic graphs we find new results with twice larger stretching exponent of the tail of the distribution, which is virtually independent on the size of cycles. The modularity and clustering contribute to a power-law decay at short return times

Catalytic Steam Reforming Of Ethanol For Hydrogen Production: Brief Status

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Hydrogen represents a promising fuel since it is considered as a dean energy carrier and also because during its combustion only water is emitted. It can be produced from different kinds of renewable feedstocks, such as ethanol. In this sense, hydrogen could be treated as biofuel. Three chemical reactions can be used to achieve this purpose: steam reforming (SR), partial oxidation (PDX), and autothermal reforming (ATR). In this study, the catalysts implemented in steam reforming of ethanol were reviewed. A wide variety of elements can be used as catalysts for this reaction, such as base metals (Ni; Cu and Co) or noble metals (Rh, Pt and Ru), usually deposited on a support material that increases surface area and improves catalytic function. The use of Rh, Ni and Pt supported or promoted with CeO2, and/or La2O3 shows excellent performance in ethanol SR catalytic process. The ratio of water to ethanol, reaction temperatures, catalysts loadings, selectivity and activity are also discussed, as they are extremely important for high hydrogen yields.224327332Sao Paulo Research Foundation - FAPESP [2014/14754-0]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Walnut Consumption Induces Tissue-Specific Omega-6/Omega-3 Decrease in High-Fructose-Fed Wistar Rats

Increased dietary, blood, and tissue n-6/n-3 fatty acid ratios are associated with obesity and metabolic syndrome. Due to Westernized dietary patterns, the increasing n-6/n-3 ratio is of growing concern worldwide, and dietary strategies aimed at its lowering are of public health importance. Walnuts are rich in dietary fats, and their consumption promotes cardiometabolic health. This study aimed to examine the effect of 6-week walnut consumption on tissue-specific n-6/n-3 ratio and fatty acid metabolic conversion in fructose-fed rats with a cluster of metabolic disorders. Male Wistar rats were fed a standard diet with or without 10% fructose in drinking water for 9 weeks. Diets of half of the animals were then supplemented with walnuts (2.4 g/day) for 6 weeks, upon which fatty acid profiles were determined in plasma, liver, adipose tissue, and kidney total lipids. Results showed that walnuts induced significant decreases in the n-6/n-3 content of total lipid pool in plasma and examined tissues, irrespective of metabolic burden. Walnut intervention decreased plasma and liver palmitoleic/palmitic, arachidonic/linoleic, and docosahexaenoic/alpha-linolenic acid ratios. It also modulated individual fatty acid levels by reducing arachidonic and palmitic acid and increasing alpha-linolenic, eicosapentaenoic, and docosapentaenoic acid in plasma and most tissues. Our study demonstrated that 6-week consumption of walnuts favorably modulated n-6/n-3 plasma and tissue ratio in male Wistar rats regardless of high-fructose feeding, underscoring the promising potential of walnuts in both prevention and treatment of the metabolic syndrome