Studio NMR di molecole biologicamente attive nell'olio di oliva

Il crescente interesse a livello chimico e biochimico verso i composti biofenolici minori polari degli oli di oliva ci ha indotto alla applicazione di moderne tecniche NMR come la DOSY (Diffusion Ordered Spectroscopy). L'utilizzo di specifiche sequenze NMR con gradienti consente di determinare il coefficiente di diffusione delle molecole in soluzione. Recentemente queste sequenze sono state applicate allo scopo di separare le componenti di miscele che si differenziano per la diversa velocità  di diffusione

Bag of Peaks

Abstract Motivation: The analysis of high-resolution proton nuclear magnetic resonance (NMR) spectrometry can assist human experts to implicate metabolites expressed by diseased biofluids. Here, we explore an intermediate representation, between spectral trace and classifier, able to furnish a communicative interface between expert and machine. This representation permits equivalent, or better, classification accuracies than either principal component analysis (PCA) or multi-dimensional scaling (MDS). In the training phase, the peaks in each trace are detected and clustered in order to compile a common dictionary, which could be visualized and adjusted by an expert. The dictionary is used to characterize each trace with a fixed-length feature vector, termed Bag of Peaks, ready to be classified with classical supervised methods. Results: Our small-scale study, concerning Type I diabetes in Sardinian children, provides a preliminary indication of the effectiveness of the Bag of Peaks approach over standard PCA and MDS. Consistently, higher classification accuracies are obtained once a sufficient number of peaks (>10) are included in the dictionary. A large-scale simulation of noisy spectra further confirms this advantage. Finally, suggestions for metabolite-peak loci that may be implicated in the disease are obtained by applying standard feature selection techniques. Availability: Matlab code to compute the Bag of Peaks representation may be found at http://economia.uniss.it/docenti/bicego/BagOfPeaks/BagOfPeaks.zip Contact: [email protected]

Bag of Peaks: interpretation of NMR spectrometry

Motivation: The analysis of high-resolution proton nuclear magnetic resonance (NMR) spectrometry can assist human experts to implicate metabolites expressed by diseased biofluids. Here, we explore an intermediate representation, between spectral trace and classifier, able to furnish a communicative interface between expert and machine. This representation permits equivalent, or better, classification accuracies than either principal component analysis (PCA) or multi-dimensional scaling (MDS). In the training phase, the peaks in each trace are detected and clustered in order to compile a common dictionary, which could be visualized and adjusted by an expert. The dictionary is used to characterize each trace with a fixedlength feature vector, termed Bag of Peaks, ready to be classified with classical supervised methods. Results: Our small-scale study, concerning Type I diabetes in Sardinian children, provides a preliminary indication of the effectiveness of the Bag of Peaks approach over standard PCA and MDS. Consistently, higher classification accuracies are obtained once a sufficient number of peaks (>10) are included in the dictionary. A large-scale simulation of noisy spectra further confirms this advantage. Finally, suggestions for metabolite-peak loci that may be implicated in the disease are obtained by applying standard feature selection techniques

NMR investigations for a quality assessment of Italian PDO saffron (<i>Crocus sativus</i> L.)

High-resolution NMR spectroscopy was employed to analyze Italian Protected Designation of Origin (PDO) saffron from L'Aquila, S. Gimignano and Sardinia and commercial saffron samples available on the Italian market. An extensive resonance assignment of DMSO saffron extract was reported, including glucose and gentiobiose in bound and unbound form for the first time. A multivariate statistical analysis of NMR data led to a clustering of samples by performing unsupervised PCA. OPLS-DA model was successively performed to highlight the markers responsible for this discrimination. An analysis of the corresponding S-plot indicated that picrocrocin and crocins were the most relevant compounds for characterizing Italian PDO saffron. By contrast, commercial saffron barely contained these characteristic compounds, and they were primarily enriched in fatty acids

Pathogenesis, Clinical Signs and Treatment Recommendations in Brittle Nails: A Review

Nail plate brittleness (or fragility) is a common complaint affecting up to 20% of the population, especially women over 50 years of age, with fingernail fragility being more prevalent than toenail fragility. Nail brittleness is characterized by nails that split, flake and crumble, become soft and lose elasticity. The main clinical presentations are: onychoschizia, onychorrhexis, superficial granulation of keratin and worn-down nails. According to causative factors, we can distinguish 2 forms of nail fragility (NF): a primary “idiopathic or brittle nail syndrome” form and NF secondary to different causes such as inflammatory nail disorders, infections, systemic diseases and general conditions, traumas and alteration of the nail hydration. Optimal management requires treatment of the primary cause of brittle nails, when possible. In idiopathic NF oral supplementation, vitamins (especially biotin, also known as vitamin B7), trace elements and amino acids (especially cysteine) have been reported to be useful. In addition, several products, such as topical moisturizers and lacquers could be considered to restructure the affected nail plate and to reduce psychological impacts of this common problem.SCOPUS: re.jinfo:eu-repo/semantics/publishe

Pathogenesis, Clinical Signs and Treatment Recommendations in Brittle Nails: A Review

Nail plate brittleness (or fragility) is a common complaint affecting up to 20% of the population, especially women over 50 years of age, with fingernail fragility being more prevalent than toenail fragility. Nail brittleness is characterized by nails that split, flake and crumble, become soft and lose elasticity. The main clinical presentations are: onychoschizia, onychorrhexis, superficial granulation of keratin and worn-down nails. According to causative factors, we can distinguish 2 forms of nail fragility (NF): a primary "idiopathic or brittle nail syndrome" form and NF secondary to different causes such as inflammatory nail disorders, infections, systemic diseases and general conditions, traumas and alteration of the nail hydration. Optimal management requires treatment of the primary cause of brittle nails, when possible. In idiopathic NF oral supplementation, vitamins (especially biotin, also known as vitamin B7), trace elements and amino acids (especially cysteine) have been reported to be useful. In addition, several products, such as topical moisturizers and lacquers could be considered to restructure the affected nail plate and to reduce psychological impacts of this common problem

Correction to: Pathogenesis, Clinical Signs and Treatment Recommendations in Brittle Nails

Unfortunately, the co-author name was incorrectly published as “Jose L. López-Esterbaranz” instead of ‘Jose L. López-Estebaranz” in the original article. The correct version of author name is updated here. The original article has been corrected.SCOPUS: er.jinfo:eu-repo/semantics/publishe