Coffee-Derived Phenolic Compounds Activate Nrf2 Antioxidant Pathway in I/R Injury In Vitro Model: A Nutritional Approach Preventing Age Related-Damages

Age-related injuries are often connected to alterations in redox homeostasis. The imbalance between free radical oxygen species and endogenous antioxidants defenses could be associated with a growing risk of transient ischemic attack and stroke. In this context, a daily supply of dietary antioxidants could counteract oxidative stress occurring during ischemia/reperfusion injury (I/R), preventing brain damage. Here we investigated the potential antioxidant properties of coffee-derived circulating metabolites and a coffee pulp phytoextract, testing their efficacy as ROS scavengers in an in vitro model of ischemia. Indeed, the coffee fruit is an important source of phenolic compounds, such as chlorogenic acids, present both in the brewed seed and in the discarded pulp. Therefore, rat brain endothelial cells, subjected to oxygen and glucose deprivation (OGD) and recovery (ogR) to mimic reperfusion, were pretreated or not with coffee by-products. The results indicate that, under OGD/ogR, the ROS accumulation was reduced by coffee by-product. Additionally, the coffee extract activated the Nrf2 antioxidant pathway via Erk and Akt kinases phosphorylation, as shown by increased Nrf2 and HO-1 protein levels. The data indicate that the daily intake of coffee by-products as a dietary food supplement represents a potential nutritional strategy to counteract aging.     

Status of PRESS-MAG-O: The experimental apparatus to probe materials and phenomena under extreme conditions at Frascati

In this contribution we up-to-date the status of the PRESS-MAG-O device, a new instrument under commissioning at the INFN designed to perform magnetic and spectroscopic experiments on samples under extreme conditions. The system has been designed to work at SINBAD, the IR synchrotron radiation beamline operational at DAΦNE. The instrument, that is the result of a significant R&D, will allow performing concurrent high harmonic ac magnetic susceptibility measurements and magneto-optic experiments on a sample under high pressure, with a variable DC magnetic field in a wide temperature range. The vacuum vessel has been designed with four crossing windows to allow optical measurements in the transmission geometry on the sample loaded inside a Diamond Anvil Cell. A new superconducting miniaturized micro-SQUID gradiometer has been also developed to detect the low magnetic signal of the sample and a customized optical system has also been designed to perform IR synchrotron radiation experiments.     

Inverse compton scattering on laser beam and monochromatic isotropic radiation

Most of the known literature on inverse compton scattering (ICS) is based on earliest theoretical attempts and later approximations led by F.C. Jones and J.B. Blumenthal. We found an independent and more general analytical procedure which provide both relativistic and ultrarelativistic limits for ICS. These new analytical expressions can be derived in a straightforward way and they contain the previously reminded Jones’ results. Our detailed solutions may be probed by already existing as well future ICS experiments.     

A FPTAS for a class of linear multiplicative problems

In this paper we consider the problem of minimizing the product of two affine functions over a polyhedral set. An approximation algorithm is proposed and it is proved that it is a Fully Polynomial Time Approximation Scheme. We will also present and computationally investigate an exact version of the algorithm.     

Cross‐linked resins functionalized with triorganotin carboxylates: synthesis,characterization and preliminary catalytic screening in transesterification

Cross‐linked polymers containing triorganotin carboxylate functionalities were synthesized from ionic exchange resins bearing carboxylic groups. The organic tin substituents selected were methyl and butyl in order to ensure different accessibility at the metal centre. The functionalization degree depends on the different substituents and strongly affects the thermal stability of the final product. Catalytic screenings were performed in order to assess the activity of the above resins in transesterification reactions, using ethyl acetate as a substrate, together with differently hindered alcohols. The results obtained point to a negligible role of the bulkiness of tin substituents with a small contribution of the metal atom Lewis acidity in the conversion of the primary alcohol, whereas with secondary and tertiary alcohols the steric hindrance of the reagent strongly affects the conversion of the reacting alcohol. The transesterification process takes place at the liquid–solid interface, so that the catalyst grafted to an insoluble solid support can be completely removed by simple filtration. Copyright © 2005 John Wiley & Sons, Ltd.     

A practical entry to C18-constrained-E-ring analogues of methyllycaconitine (MLA): a concise new stereoselective approach to 8-oxa-decahydroisoquinolines accompanied by a simple microwaves-assisted synthesis of the succinimidobenzoate appendage of MLA

A Mannich-type intramolecular cyclization afforded access to a 8-oxa-decahydroisoquinoline heterocyclic system. Good stereoselectivity was observed. A promising microwave-assisted synthesis of the methylsuccinimidobenzoate moiety of methyllycaconitine has also been carried out.     

Synthesis and characterization of new polystyrenes containing tributyltin moieties linked to the aromatic ring through a methylenic spacer

Novel polymeric derivatives bearing tributyltin carboxylate moieties in the side chain were synthesized. The coordination at tin in solution and in the solid state was investigated by both Sn‐NMR and FT‐IR: the metal atom appears completely tetracoordinated in chloroform solution, while in the solid state all polymeric products exhibit both tetra‐ and pentacoordination at tin, the latter increasing with the amount of tin containing units. No evidence of tin leaching by hydrolysis of the organometallic ester was observed for these materials. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5372–5383, 2004     

Existence and qualitative properties of concentrating solutions for the sinh-Poisson equation

We prove the existence of nodal solutions for – u = sinhu with Dirichlet boundary conditions in bounded, 2D, smoothand non-smooth domains. Indeed, for positive and small enough,we show that there exist at least two pairs of solutions, whichchange sign exactly once, whose nodal lines intersect the boundary.