Thermal Effects in Anisotropic Porous Elastic Rods

This research is concerned with the thermoelastic deformation of a porous anisotropic right cylinder subjected to a thermal field independent of the axial coordinate. The case of a material with a plane of elastic symmetry which contains the axis of cylinder is considered. The solution of the problem is expressed in terms of solutions of some generalized plane strain problems. It is shown that the temperature field produces extension, torsion, and a plane strain. For this kind of anisotropy, an infinitesimal twist produces a variation of volume fraction field. The method is used to study the deformation of an inhomogeneous circular cylinder.     

Strong,Ductile Magnesium-Zinc Nanocomposites

Incorporated SiC nanoparticles are demonstrated to influence the solidification of magnesium-zinc alloys resulting in strong, ductile, and castable materials. By ultrasonically dispersing a small amount (less than 2 vol pct) of SiC nanoparticles, both the strength and ductility exhibit marked enhancement in the final casting. This unusual ductility enhancement is the result of the nanoparticles altering the selection of intermetallic phases. Using transmission electron microscopy (TEM), the MgZn₂ phase was discovered among SiC nanoparticle clusters in hypoeutectic compositions. Differential thermal analysis showed that the MgZn₂ formation resulted in elimination of other intermetallics in the Mg-4Zn nanocomposite and reduced their formation in Mg-6Zn and Mg-8Zn nanocomposites.     

Determination of the Synthetic Cannabinoids JWH-122, JWH-210, UR-144 in Oral Fluid of Consumers by GC-MS and Quantification of Parent Compounds and Metabolites by UHPLC-MS/MS

The consumption of synthetic cannabinoids (SCs) has significantly increased in the last decade and the analysis of SCs and their metabolites in human specimens is gaining interest in clinical and forensic toxicology. A pilot study has been carried out using a combination of an initial last generation gas chromatography-mass spectrometry (GC-MS) screening method for the determination of JWH-122, JWH-210, UR-144) in oral fluid (OF) of consumers and an ultra-high performance liquid chromatography high resolution mass spectrometry (UHPLC-HRMS) confirmatory method for the quantification of the parent compounds and their metabolites in the same biological matrix. OF samples were simply liquid-liquid extracted before injecting in both chromatographic systems. The developed methods have been successfully validated and were linear from limit of quantification (LOQ) to 50 ng/mL OF. Recovery of analytes was always higher than 70% and matrix effect always lower than 15% whereas intra-assay and inter-assay precision and accuracy were always better than 16%. After smoking 1 mg JWH-122 or UR-144 and 3 mg JWH-210, maximum concentration of 4.00–3.14 ng/mL JWH-122, 8.10–7.30 ng/mL JWH-210 ng/mL and 7.40 and 6.81 ng/mL UR-144 were measured by GC-MS and UHPLC-HRMS respectively at 20 min after inhalation. Metabolites of JWH 122 and 210 were quantified in OF by UHPLC-HRMS, while that of UR144 was only detectable in traces. Our results provide for the first time information about disposition of these SCs and their metabolites in consumers OF. Last generation GC-MS has proven useful tool to identify and quantify parent SCs whereas UHPLC-HRMS also confirmed the presence of SCs metabolites in the OF of SCs consumers.     

The Urokinase Receptor: A Multifunctional Receptor in Cancer Cell Biology. Therapeutic Implications

Proteolysis is a key event in several biological processes; proteolysis must be tightly controlled because its improper activation leads to dramatic consequences. Deregulation of proteolytic activity characterizes many pathological conditions, including cancer. The plasminogen activation (PA) system plays a key role in cancer; it includes the serine-protease urokinase-type plasminogen activator (uPA). uPA binds to a specific cellular receptor (uPAR), which concentrates proteolytic activity at the cell surface, thus supporting cell migration. However, a large body of evidence clearly showed uPAR involvement in the biology of cancer cell independently of the proteolytic activity of its ligand. In this review we will first describe this multifunctional molecule and then we will discuss how uPAR can sustain most of cancer hallmarks, which represent the biological capabilities acquired during the multistep cancer development. Finally, we will illustrate the main data available in the literature on uPAR as a cancer biomarker and a molecular target in anti-cancer therapy.     

Asymmetric hydrodimerization of styrene by a chiral zirconium complex containing a tetradentate [OSSO]-type bis(phenolato) ligand

The chiral non racemic (Λ,R,R)-[OSSO]Zr(CH₂Ph)₂ (1a) activated by methylaluminoxane (MAO) and in presence of H₂ produces the chiral hydrodimer (S)-1,3-diphenylbutane with good selectivity respect to the achiral 1,4-diphenylbutane. The absolute configuration of the chiral dimer and the effect of the hydrogen pressure on the ratio between 1,3-diphenylbutane and 1,4-diphenylbutane give useful information about the regiochemistry and stereochemistry of insertion of the styrene into the Zr–H bond.     

Concession period for PPPs: A win–win model for a fair risk sharing

Public Private Partnership (PPP) is adopted throughout the world for delivering public infrastructure. Despite the worldwide experience has shown that PPP can provide a variety of benefits to the government, to fully gain them several critical aspects related to a PPP project need to be managed, among these the determination of the concession period.     

A THEORY OF THERMOELASTIC MATERIALS WITH VOIDS WITHOUT ENERGY DISSIPATION

This article is concerned with the theory of thermoelastic materials with voids based on the concept of volume fraction [Goodman and Cowin, Arch. Rational Mech. Anal., vol. 44, pp. 249-266, 1972; Nunziato and Cowin, Arch. Rational Mech. Anal., vol. 72, pp. 175-201, 1979]. We use the results of Green and Naghdi [Proc. Roy Soc. London A, vol. 432, pp. 171-194, 1991; J. Elasticity, vol. 31, pp. 189-209, 1993] on thermomechanics of continua to derive a linear theory of thermoelastic materials with voids that does not sustain energy dissipation and permits the transmission of heat as thermal waves at finite speed. Then we establish a uniqueness result and the continuous dependence of solutions upon the initial data and body loads.     

Surgical aspects of renal transplantation in children

Incubation of the acutely dissected rat hippocampal slices in calcium-containing media resulted in spontaneous activation-translocation of classical PKC isoforms and their subsequent (especially gamma-type) proteolytic degradation. These changes were blocked by calpain inhibitor MDL 28 170 in 100 microM concentration. Rat hippocampal slices were metabolically prelabelled with 32Pi and stimulated with NMDA/glycine, depolarization or phorbol dibutyrate (PDBu) treatment. The basal phosphorylation of specific PKC substrates (MARCKS, neuromodulin and neurogranin) was significantly reduced in non-stimulated slices by MDL pretreatment. In contrast, only the slices where calpain activity was inhibited responded to further NMDA or phorbol dibutyrate stimulation by a substantial increase of PKC-dependent protein phosphorylation. It is concluded that the PKC phosphorylation system is severely affected by non-specific activation and a subsequent, calpain-dependent proteolysis in the acutely prepared hippocampal slices. Calpain inhibition by 100 microM MDL partially prevented these changes and increased stimulus-dependent phosphorylation of PKC-specific protein substrates.