Hyperbolic heat conduction in a circular plate from green’s function

We show the existence and uniqueness of Green’s function of the Neumann problem for the axisymmetric hyperbolic heat conduction equation in a circular plate and present its explicit and rigorous computation. As an application, we use this function in order to compute the temperature profile in a circular plate irradiated by a continuous Gaussian laser source.     

Anti-diabetic effects of a series of vanadium dipicolinate complexes in rats with streptozotocin-induced diabetes

The effects of oral treatment of rats with streptozotocin-induced diabetes with a range of vanadium dipicolinate complexes (Vdipic) and derivatives are reviewed. Structure–reactivity relationships are explored aiming to correlate properties such as stability, to their insulin-enhancing effects. Three types of modifications are investigated; first, substitutions on the aromatic ring, second, coordination of a hydroxylamido group to the vanadium, and third, changes in the oxidation state of the vanadium ion. These studies allowed us to address the importance of coordination chemistry, and redox chemistry, as modes of action. Dipicolinate was originally chosen as a ligand because the dipicolinatooxovanadium(V) complex (V5dipic), is a potent inhibitor of phosphatases. The effect of vanadium oxidation state (3, 4 or 5), on the insulin-enhancing properties was studied in both the Vdipic and VdipicCl series. Effects on blood glucose, body weight, serum lipids, alkaline phosphatase and aspartate transaminase were selectively monitored. Statistically distinct differences in activity were found, however, the trends observed were not the same in the Vdipic and VdipicCl series. Interperitoneal administration of the Vdipic series was used to compare the effect of administration mode. Correlations were observed for blood vanadium and plasma glucose levels after V5dipic treatment, but not after treatment with corresponding V4dipic and V3dipic complexes. Modifications of the aromatic ring structure with chloride, amine or hydroxyl groups had limited effects. Global gene expression was measured using Affymetrix oligonucleotide chips. All diabetic animals treated with hydroxyl substituted V5dipic (V5dipicOH) and some diabetic rats treated with vanadyl sulfate had normalized hyperlipidemia yet uncontrolled hyperglycemia and showed abnormal gene expression patterns. In contrast to the normal gene expression profiles previously reported for some diabetic rats treated with vanadyl sulfate, where both hyperlipidemia and hyperglycemia were normalized. Modification of the metal, changing the coordination chemistry to form a hydroxylamine ternary complex, had the most influence on the anti-diabetic action. Vanadium absorption into serum was determined by atomic absorption spectroscopy for selected vanadium complexes. Only diabetic rats treated with the ternary V5dipicOH hydroxylamine complex showed statistically significant increases in accumulation of vanadium into serum compared to diabetic rats treated with vanadyl sulfate. The chemistry and physical properties of the Vdipic complexes correlated with their anti-diabetic properties. Here, we propose that compound stability and ability to interact with cellular redox reactions are key components for the insulin-enhancing activity of vanadium compounds. Specifically, we found that the most overall effective anti-diabetic Vdipic compounds were obtained when the compound administered had an increased coordination number in the vanadium complex.     

Controllability Results for Nonlinear Fractional-Order Dynamical Systems

This paper establishes a set of sufficient conditions for the controllability of nonlinear fractional dynamical system of order 1<α<2 in finite dimensional spaces. The main tools are the Mittag–Leffler matrix function and the Schaefer’s fixed-point theorem. An example is provided to illustrate the theory.     

Influence of boundary structure and near neighbor crystallographic orientation on the dynamic damage evolution during shock loading

The role of crystallographic orientation on damage evolution in ductile metals during shock loading has been investigated. By utilizing large-grained copper specimens, it has been shown that the development of intragranular damage, in the form of void growth and coalescence, is influenced by the grain orientation with respect to the applied load. Additionally, strain incompatibility and the inability to promote transmission or activation of secondary dislocation slip across a grain boundary, are proposed as the likely cause for intergranular failure. Finally, the free surface velocity profiles of each grain, specifically the decay of the oscillations after the pull-back, correlated well with the amount of damage measured within the respective grain.     

Evaluation of the importance of germinative cycles for destruction of bacillus cereus spores in miniature cheeses

Our objective was to determine the effect of high pressure on inactivation of spores of Bacillus cereus ATCC 9139 inoculated into cheese made of raw cow's milk. Inoculated miniature cheeses were manufactured under controlled bacteriological conditions, vacuum packed and kept at 8 °C for 15 days after pressure treatment. Cheeses were submitted to pressures of 300, 400 or 500 MPa at 30 °C, during 15 min. Some of them were treated with a germination cycle of 60 MPa at 30 °C for 210 min. Lethality was calculated comparing surviving sample counts to control ones. Adding the germinative cycle resulted in higher efficiency, and when applied with 500 MPa, lethality reached 2.0 log cfu/mL. We saw that with both cycles initial counts of spores diminish, but all of them were not inactivated. However, considering that in raw milk mesophilic spore counts are 2.6-2.9 log cfu/mL, this treatment may be useful.     

Fractional power-law spatial dispersion in electrodynamics

Electric fields in non-local media with power-law spatial dispersion are discussed. Equations involving a fractional Laplacian in the Riesz form that describe the electric fields in such non-local media are studied. The generalizations of Coulomb’s law and Debye’s screening for power-law non-local media are characterized. We consider simple models with anomalous behavior of plasma-like media with power-law spatial dispersions. The suggested fractional differential models for these plasma-like media are discussed to describe non-local properties of power-law type.     

Justicidone, a novel p-quinone-lignan derivative from Justicia hyssopifolia

An uncommon, previously unreported p-quinone-lignan compound called justicidone (4-(1,3-benzodioxol-5-yl)-6-methoxynaphtho[2,3-c]furan-1,5,8(3H)-trione) (2), along with the known savinin (1) were isolated from Justicia hyssopifolia (Acanthaceae). Their structures were determined by spectroscopic methods.