Characterization and discrimination of different aged 'Aceto Balsamico Tradizionale di Modena' products by head space mass spectrometry and chemometrics.

This work can be seen as an attempt to develop an analytical procedure in the context of quality control and authenticity assessment of typical food. To this aim, head-space mass spectrometry (HS-MS) coupled with multivariate data analysis, is proposed as a fast technique for furnishing a clear visualization and a suitable interpretation of the ageing process of 'Aceto Balsamico Tradizionale di Modena' (ABTM) and, for classifying products of different age. Considering the complexity of this food matrix, due to its traditional making procedure, the obtained instrumental data have first been analysed by parallel factor analysis (PARAFAC), an extension of principal component analysis to higher order arrays, in order to visualise the 'natural' grouping of vinegar samples and to inspect producers similarity/dissimilarity.

Subject classification obtained by cluster analysis and principal component analysis applied to flow cytometric data.

Background: Polychromatic flow cytometry (PFC) allows the simultaneous determination of multiple antigens in the same cell, resulting in the generation of a high number of subsets. As a consequence, data analysis is the main difficulty with this technology. Here we show the use of cluster analysis (CA) and principal component analyses (PCA) to simplify multicolor data visualization and to allow subjects' classification.

Photophysics of an electrophosphorescent platinum (II) porphyrin in solid films.

We examine electronic processes in platinum (II) octaethyl porphyrin (PtOEP) embedded in an organic solid state matrix and in the form of vacuum-evaporated neat films in conjunction with potential applications of this compound to organic photovoltaic and electrophosphorescent devices. Absorption, photoexcitation, and luminescence spectra indicate the excitonic dimers to be dominant excited states, and their dissociation underlies the charge photogeneration process. Different charge separation distance (1.

A chemometric approach to the comparison of different sample treatments for metals determination by atomic absorption spectroscopy in aceto Balsamico tradizionale di Modena.

A comparison of different digestion procedures has been carried out for the analysis of metal concentration in samples of vinegars and Aceto Balsamico Tradizionale of Modena (ABTM) coming from an unique barrel set. In particular, classical wet, dry ashing, and closed vessel microwave digestion procedure have been utilized and compared for each investigated species. In a few cases, direct metal determination on ABTM (without treatment procedure) is proposed as possible alternative to sample manipulation.

A study of the dielectric behaviour and the liquid structure of a ternary solvent system.

The static dielectric constant of the [DMF(1) + ME(2) + DME(3)] ternary mixtures was measured as a function of temperature (25 < or = t/degrees C < or = 80) and composition, over the whole mole fraction range 0 < or = chi,chi2,chi3 < or = 1. The experimental values were processed by an empirical equation accounting for the dependence epsilon = epsilon(T, phi(i)), where phi(t) is the volume fraction of the components. A comparison between calculated and experimental data shows that this fitting relationship can be effectively employed to predict epsilon values in correspondence to experimental data gaps.

Potential vectors of West Nile virus following an equine disease outbreak in Italy.

In the late summer of 1998, an outbreak of equine encephalomyelitis due to West Nile virus (WNV) occurred in the Tuscany region of central Italy. The disease was detected in 14 race horses from nine localities in four Provinces: Firenze, Lucca, Pisa and Pistoia. The outbreak area included Fucecchio wetlands (1800 ha), the largest inland marsh in Italy, and the adjacent hilly Cerbaie woodlands with farms breeding horses.

Classification of cereal flours by chemometric analysis of MIR spectra.

Different kinds of cereal flours submitted to various technological treatments were classified on the basis of their mid-infrared spectra by pattern recognition techniques. Classification in the wavelet domain was achieved by using the wavelet packet transform for efficient pattern recognition (WPTER) algorithm, which allowed singling out the most discriminant spectral regions. Principal component analysis (PCA) on the selected features showed an effective clustering of the analyzed flours.

Fatty acids composition of plasma phospholipids and triglycerides in children with cystic fibrosis. The effect of dietary supplementation with an olive and soybean oils mixture.

Cystic fibrosis (CF) is characterized by abnormal levels of essential fatty acids (EFA) in plasma phospholipids. The reduced availability of EFA has been reported to alter patterns of circulating and tissue esterified acids and may determine profound changes in membrane fluidity and cell signaling mechanisms. In the current study, the results of a new strategy aimed at the realization of a practical, low cost integrator, for daily use in the dietary management of FC subjects, are reported.

Determination of carboxylic acids in vinegars and in Aceto Balsamico Tradizionale di Modena by HPLC and GC methods.

The presence of carboxylic acids in grape products has been investigated for a long time by researchers, from both the qualitative and quantitative points of view. Evaluation of carboxylic acids requires the study and optimization of some operative variables which are strictly related to the matrix. In particular, the determination of organic acids in real matrixes such as Aceto Balsamico Tradizionale of Modena (ABTM; a traditional balsamic vinegar made from cooked grape must) is often difficult because of the presence of numerous interferences that need to be removed by separation techniques.

Temperature and composition dependence of the refractive indices of the 2-chloroethanol + 2-methoxyethanol binary mixtures.

Measurements of the refractive index n for the binary mixtures 2-chloroethanol + 2-methoxyethanol in the 0 < or = t/degree C < or = 70 temperature range have been carried out with the purpose of checking the capability of empirical models to express physical quantity as a function of temperature and volume fraction, both separately and together, i.e., in a two independent variables expression.

Beta-functionalised polythiophenes as microelectrode modifiers in low conductive media.

A study on polythiophene coated microelectrodes is reported, the goal being that of checking the capability of these electrochemical systems to work in low conductive media. The possibility of electrochemically p-doping the polymer in the presence of very low concentrations or even in the absence of supporting electrolyte in the solution is ascertained, opening the way to the use of similar systems in pure solvent media. This result is obtained in such conditions that the presence of residual charges--and corresponding counterions--trapped inside the film coating can be reasonably hypothesised.

Computer modeling of size and shape descriptors of alpha 1-adrenergic receptor antagonists and quantitative structure-affinity/selectivity relationships.

Computational chemistry and molecular modeling procedures allow us to define and compute ad hoc size and shape descriptors on the different prototropic forms assumed by drugs in biotest solutions. Together with experimental data measured on a well-identified target receptor, these descriptors are essential elements for obtaining simple, consistent, comparable, and easily interpretable theoretical quantitative structure-activity relationship (QSAR) models based on the ligand similarity-target receptor complementarity paradigm. In this context, quantitative size and shape affinity/subtype selectivity relationships have been modeled for a large set of very heterogeneous alpha 1a-, alpha 1b-, and alpha 1c-adrenergic receptor antagonists.

Alpha 1-adrenoceptor subtype selectivity: molecular modelling and theoretical quantitative structure-affinity relationships.

This study constitutes a preliminary rationalization, at the molecular level, of antagonist selectivity towards the three cloned alpha 1-adrenergic receptor (alpha 1-AR) subtypes. Molecular dynamics simulations allowed a structural/dynamics analysis of the seven alpha-helix-bundle models of the bovine alpha 1a-, hamster alpha 1b-, and rat alpha 1d-AR subtypes. The results showed that the transmembrane domains of these subtypes have different dynamic behaviours and different topographies of the binding sites, which are mainly constituted by conserved residues.

Status of malaria vectors in Italy.

About 30 yr after malaria eradication, surveys to assess the presence and abundance of anopheline vectors were carried out in central and southern Italy and in the islands of Sardinia and Sicily from 1992 to 1994. Anopheles labranchiae Falleroni was present in scattered foci in all regions, except for Tuscany, where it breeds almost exclusively in rice fields (Grosseto Province). Most common breeding sites were rivers and streams, followed by ponds and ground pools.

Effect of diets containing different amounts of precursor and derivative fatty acids on serum TXB2.

Dietary precursor and derivative polyunsaturated fatty acids influence metabolic parameters, such as eicosanoid synthesis. We have studied the effect of dietary intakes of lipids containing different amounts of precursor and derivative fatty acids (olive oil, olive-blackcurrant-fish oil mixture, blackcurrant-fish oil mixture, MCT (medium chain triglycerides)-soyabean oil mixture) on serum thromboxane B2 (TXB2) in four groups of rats. Plasma fatty acid composition showed differences related to dietary intakes.

The transfer of docosahexaenoic acid from the yolk to the tissues of the chick embryo.

Changes in the amounts of the major fatty acids present in the lipids of the yolk complex and the embryo were delineated during embryogenesis of the chicken. The rates of transfer of palmitic, oleic, linoleic, linolenic and arachidonic acids from the lipids of the yolk complex were essentially identical. In contrast, docosahexaenoic acid (DHA) was preferentially transferred from the yolk complex at a rate which was significantly higher than that exhibited by the other major fatty acids.

The effect of dietary lipid changes on the fatty acid composition and function of liver, heart and brain mitochondria in the rat at different ages.

A correlation between dietary lipids and cellular enzyme activities is a problem that has only been partially addressed by nutritionists. Therefore, changes in the fatty acid composition and the activities of some key metabolic enzymes (ubiquinol-2-cytochrome c reductase (EC 1.10.

Alpha-tocopherol absorption and polyunsaturated fatty acid metabolism in the developing chick embryo.

1. A study has been made relating alpha-tocopherol uptake from the yolk and yolk sac membrane to the polyunsaturated fatty acid status of the liver during incubation. 2.

Effect of soya and cellulose fibers on postprandial glycemic response in type II diabetic patients.

Objective: We studied the effect on serum glucose and insulin of a preprandial ingestion of 7 g of soya fibers or of an equal amount of purified cellulose on eight non-insulin-dependent (type II) diabetic patients.

Research Design And Methods: Four tests were conducted in each patient in random order. In the first study, soya or cellulose was ingested before a standard breakfast, and postprandial glucose and insulin curves were determined.

[Anopheles in Italy: distribution on rice lands in the provinces of Grosseto and Siena].

The Laboratory of Parasitology of Istituto Superiore di Sanità acts as a coordinating centre for anophelism data collection in Italy, and collaborates with the health local authorities. This specific investigation takes into consideration several areas in the provinces of Grosseto and Siena, focusing attention on the rice fields, which are today the most important anopheline breeding sites in Maremma. The records collected in collaboration with the Department of Environmental Zoology (USL 28 Grosseto), show a high density of A.

Influence of dietary fatty acids on phospholipid composition and prostaglandin E synthesis in rat kidneys.

The effects of oils with different amounts of n6 and n3 fatty acid precursors and derivatives were evaluated on phospholipid composition and PGE2 synthesis of rat kidneys. Dietary lipids were: olive oil, an olive-blackcurrant-fish oil mixture and a blackcurrant-fish oil mixture. We observed in the kidneys of rats fed the blackcurrant-fish oil mixture a significant decrease in PGE2 synthesis, while arachidonate values did not show significant variations.