Magnetic resonance butterfly coils: Design and application for hyperpolarized C studies

Hyperpolarized ¹³C magnetic resonance spectroscopy in pig models enables cardiac metabolism assessment and provides a powerful tool for heart physiology studies, although the low molar concentration of derivate metabolites gives rise to technological limitations in terms of data quality. The design of dedicated coils capable of providing large field of view with high Signal-to-Noise Ratio (SNR) data is of fundamental importance.     

Protein Folding and Aggregation into Amyloid: The Interference by Natural Phenolic Compounds

Amyloid aggregation is a hallmark of several degenerative diseases affecting the brain or peripheral tissues, whose intermediates (oligomers, protofibrils) and final mature fibrils display different toxicity. Consequently, compounds counteracting amyloid aggregation have been investigated for their ability (i) to stabilize toxic amyloid precursors; (ii) to prevent the growth of toxic oligomers or speed that of fibrils; (iii) to inhibit fibril growth and deposition; (iv) to disassemble preformed fibrils; and (v) to favor amyloid clearance. Natural phenols, a wide panel of plant molecules, are one of the most actively investigated categories of potential amyloid inhibitors. They are considered responsible for the beneficial effects of several traditional diets being present in green tea, extra virgin olive oil, red wine, spices, berries and aromatic herbs. Accordingly, it has been proposed that some natural phenols could be exploited to prevent and to treat amyloid diseases, and recent studies have provided significant information on their ability to inhibit peptide/protein aggregation in various ways and to stimulate cell defenses, leading to identify shared or specific mechanisms. In the first part of this review, we will overview the significance and mechanisms of amyloid aggregation and aggregate toxicity; then, we will summarize the recent achievements on protection against amyloid diseases by many natural phenols.     

Low-enthalpy geothermal energy: An opportunity to meet increasing energy needs and reduce CO2 and atmospheric pollutant emissions in Piemonte,Italy

The scope for diffusion of very low-enthalpy geothermal plants in the Piemonte region of Italy, using groundwater heat pumps (GWHP), was analyzed to check environmental sustainability and the benefits in terms of reducing greenhouse gas emissions from fossil fuels. GWHP implementation seemed particularly suitable to the specific characteristics of the Piemonte plain. An important thick and productive shallow aquifer is present across the entire plain beneath the major energy users and is therefore appropriate for geothermal energy development purposes. The building stock could be adapted to heat pumps in different ways, but objective-oriented policies will be required to reach the best results in terms of environmental benefits.     

Morphology and electrochemical activity of SOFC composite cathodes: II. Mathematical modelling

This paper presents a mathematical model of mass and charge transport and electrochemical reaction in porous composite cathodes for application in solid oxide fuel cells. The model describes a porous composite cathode as a continuum, and characterises charge and mass transfer and electrochemical kinetics using effective parameters (i.e. conductivity, diffusivity, exchange current) related to morphology and material properties by percolation theory. The model accounts for the distribution of morphological properties (i.e. porosity, tortuosity, density of contacts among particles) along cathode thickness, as experimentally observed on scanning electron microscope images of LSM/YSZ cathodes of varying thickness. This feature allows the model to reproduce the dependence of polarisation resistance on thickness, as determined by impedance spectroscopy on LSM/YSZ cathodes of varying thickness. Polarisation resistance in these cathodes is almost constant for thin cathodes (up to 10 μm thickness), it sharply decreases for intermediate thickness, to reach a minimum value for about 50 μm thickness, then it slightly increases in thicker cathodes.     

Er doped waveguide amplifiers written with femtosecond laser in germanate glasses

The authors report the fabrication and characterization of active waveguides in GeO₂–PbO–Ga₂O₃ glass samples doped with Er³⁺, written with a femtosecond laser delivering pulses of 150 fs duration at 1 kHz repetition rate. Permanent refractive index change was obtained and waveguides were formed under different laser pulse energies and scan velocities. The passive and active optical properties of the waveguides were investigated. The minimum value of propagation loss was of 4.8 dB/cm. Optical amplification at 1.5 μm under 980 nm excitation was observed showing a maximal internal gain of 2.7 dB/cm.     

Absolute emission quantum yield determination of self-assembled mesoporous titania films grafted with a luminescent zinc complex

A luminescent zinc complex was successfully incorporated to mesostructured porous titania films through a grafting process. The resulting films show an intense blue-emission increasing with functionalization time. The emission quantum yield of these newly synthesized films was quantitatively and accurately determined by measurements carried by an integrating sphere.     

Relaxation phenomena and structural modifications of substituted polythiophenes during the p-doping processes. An electrochemical and morphological study

Electrodes modified by polythiophenes bearing different substituents have been prepared and the behaviour of the conducting polymers has been studied with respect to the structural phenomena occurring in the correspondence to the doping and the relevant undoping processes. The effects of experimental parameters, such as undoping potential and time, have been investigated. The steric hindrance of the substituents on the polymer chain is demonstrated to play a fundamental role in determining the extent of compactness of the film, as induced by polarisation of the electrode at potentials at which the previously charged polymer is neutralised. Such a conclusion is in accordance with prediction of the electrochemical stimulated conformational relaxation model. Electrochemical AFM measurements have been performed in order to acquire a direct view of the morphological modifications of the polymer coatings during the reduction.     

WINSTODEC: a stochastic deconvolution interactive program for physiological and pharmacokinetic systems.

Deconvolution allows the reconstruction of non-accessible inputs (e.g. hormone secretion rate) from their causally-related measurable effects (e.g. hormone plasma concentration). Deconvolution is challenging under several aspects both general (e.g. determination of a suitable trade-off between data fit and solution smoothness in order to contrast ill-conditioning, assessment of the confidence intervals) as well as specific of physiological systems (e.g. non-uniform and infrequent data sampling). Recently, a stochastic regularization approach has been proposed and validated to handle these difficulties (De Nicolao et al., Automatica 33 (1997) 851-870). In this paper, an interactive program, WINSTODEC, is presented to allow the clinical investigator to easily obtain the solution of a deconvolution problem by this approach.