Specific-heat Study of Low-energy Vibrational State m Vitreous Samarium Phosphates

Measurements of specific heat in the temperature range 1.5K to 30K were made for two samples of vitreous samarium phosphates. A large contribution to the specific heat, well above what is expected from acoustic phonons (in the Debye approximation), is discussed in terms of the theoretical predictions of a phonon-fracton cross-over approach. The phonon-fracton density of states used to fit the excess specific heat gives rise to model parameters with the same magnitudes as those found previously for a wide range of glasses

Silkworm pupae as source of high-value edible proteins and of bioactive peptides

To characterize the high-value protein content and to discover new bioactive peptides, present in edible organisms, as silkworm pupae, semiquantitative analytical approach has been applied. The combination of appropriate protein extraction methods, semiquantitative high-resolution mass spectrometry analyses of peptides, in silico bioactivity and gene ontology analyses, allowed protein profiling of silkworm pupae (778 gene products) and the characterization of bioactive peptides. The semiquantitative analysis, based on the measurement of the emPAI, revealed the presence of high-abundance class of proteins, such as larval storage protein (LSP) class. This class of proteins, beside its nutrient reservoir activity, is of great pharmaceutical interest for their efficacy in cardiovascular diseases. Potential allergens were also characterized and quantified, such as arginine kinase, thiol peroxiredoxin, and Bom m 9. This powerful bioanalytical approach proved the potential industrial applications of Bombyx mori pupae, as source of high-value proteins in a green and \u201ccircular\u201d economy perspective

Development of a direct ESI-MS method for measuring the tannin precipitation effect of proline-rich peptides and in silico studies on the proline role in tannin-protein interactions

Tannins are a heterogeneous class of polyphenols that are present in several plants and foods. Their ability to interact and precipitate proline-rich proteins leads to different effects such as astringency or antidiarrheal activity. Thus, evaluation of the tannin content in plant extracts plays a key role in understanding their potential use as pharmaceuticals and nutraceuticals. Several methods have been proposed to study tannin-protein interactions but few of them are focused on quantification. The purpose of the present work is to set up a suitable and time efficient method able to quantify the extent of tannin protein precipitation. Bradykinin, chosen as a model, was incubated with increasing concentrations of 1,2,3,4,6-penta-O-galloyl-\u3b2-D-glucose and tannic acid selected as reference of tannic compounds. Bradykinin not precipitated was determined by a mass spectrometer TSQ Quantum Ultra Triple Quadrupole (direct infusion analysis). The results were expressed as PC 50 , which is the concentration able to precipitate 50% of the protein. The type of tannin-protein interaction was evaluated also after precipitate solubilisation. The involvement of proline residues in tannin-protein interactions was confirmed by repeating the experiment using a synthesized peptide (RR-9) characterized by the same bradykinin sequence, but having proline residues replaced by glycine residues: no interaction occurred between the peptide and the tannins. Moreover, modelling studies on PGG-BK and PGG-RR-9 were performed to deeply investigate the involvement of prolines: a balance of hydrophobic and H-bond contacts stabilizes the PGG-BK cluster and the proline residues exert a crucial role thus allowing the PGG molecules to elicit a sticking effect

The Cepheids of NGC1866: A Precise Benchmark for the Extragalactic Distance Scale and Stellar Evolution from Modern UBVI Photometry

We present the analysis of multiband time-series data for a sample of 24 Cepheids in the field of the Large Magellanic Cloud cluster NGC1866. Very accurate BVI VLT photometry is combined with archival UBVI data, covering a large temporal window, to obtain precise mean magnitudes and periods with typical errors of 1-2% and of 1 ppm, respectively. These results represent the first accurate and homogeneous dataset for a substantial sample of Cepheid variables belonging to a cluster and hence sharing common distance, age and original chemical composition. Comparisons of the resulting multiband Period-Luminosity and Wesenheit relations to both empirical and theoretical results for the Large Magellanic Cloud are presented and discussed to derive the distance of the cluster and to constrain the mass-luminosity relation of the Cepheids. The adopted theoretical scenario is also tested by comparison with independent calibrations of the Cepheid Wesenheit zero point based on trigonometric parallaxes and Baade-Wesselink techniques. Our analysis suggests that a mild overshooting and/or a moderate mass loss can affect intermediate-mass stellar evolution in this cluster and gives a distance modulus of 18.50 +- 0.01 mag. The obtained V,I color-magnitude diagram is also analysed and compared with both synthetic models and theoretical isochrones for a range of ages and metallicities and for different efficiencies of core overshooting. As a result, we find that the age of NGC1866 is about 140 Myr, assuming Z = 0.008 and the mild efficiency of overshooting suggested by the comparison with the pulsation models.Comment: 13 pages, 10 figures, accepted in MNRAS (2016 January 14

Tests of monolithic active pixel sensors at national synchrotron light source

The paper discusses basic characterization of Monolithic Active Pixel Sensors (MAPS) carried out at the X12A beam-line at National Synchrotron Light Source (NSLS), Upton, NY, USA. The tested device was a MIMOSA V (MV) chip, back-thinned down to the epitaxial layer. This 1M pixels device features a pixel size of 17X17µm^2 and was designed in a 0,6µm CMOS process. The X-ray beam energies used range from 5 to 12 keV. Examples of direct X-ray imaging capabilities are presented

Advanced quantitative proteomics to evaluate molecular effects of low-molecular-weight hyaluronic acid in human dermal fibroblasts

Hyaluronic acid (HA) is physiologically synthesized by several human cells types but it is also a widespread ingredient of commercial products, from pharmaceuticals to cosmetics. Despite its extended use, the precise intra- and extra-cellular effects of HA at low-molecular-weight (LWM-HA) are currently unclear. At this regard, the aim of this study is to in-depth identify and quantify proteome's changes in normal human dermal fibroblasts after 24 h treatment with 0.125, 0.25 and 0.50 % LMW-HA (20 1250 kDa) respectively, vs controls. To do this, a label-free quantitative proteomic approach based on high-resolution mass spectrometry was used. Overall, 2328 proteins were identified of which 39 significantly altered by 0.125 %, 149 by 0.25 % and 496 by 0.50 % LMW-HA. Protein networking studies indicated that the biological effects involve the enhancement of intracellular activity at all concentrations, as well as the extracellular matrix reorganization, proteoglycans and collagen biosynthesis. Moreover, the cell's wellness was confirmed, although mild inflammatory and immune responses were induced at the highest concentration. The more complete comprehension of intra- and extra-cellular effects of LMW-HA here provided by an advanced analytical approach and protein networking will be useful to further exploit its features and improve current formulations

Extracellular vesicles derived from gut microbiota in inflammatory bowel disease and colorectal cancer

The human gut microbiome encompasses inter alia, the myriad bacterial species that create the optimal host-micro-organism balance essential for normal metabolic and immune function. Various lines of evidence suggest that dys-regulation of the microbiota-host interaction is linked to pathologies such as inflammatory bowel disease (IBD) and colorectal cancer (CRC). Extracellular vesicles (EVs), found in virtually all body fluids and produced by both eukaryotic cells and bacteria are involved in cell-cell communication and crosstalk mechanisms, such as the immune response, barrier function and intestinal flora. This review highlights advancements in knowledge of the functional role that EVs may have in IBD and CRC, and discusses the possible use of EVs derived from intestinal microbiota in therapeutic strategies for treating these conditions

EXTRACELLULAR VESCICLES DERIVED FROM GUT MICROBIOTA IN INFLAMMATORY BOWEL DISEASE AND COLORECTAL CANCER

The human gut microbiome encompasses inter alia, the myriad bacterial species that create the optimal host-microrganism balance essential for normal metabolic and immune function. Various lineas of evidence suggest that dysregulation of the microbiota-host interaction is linked to pathologies such as inflammatory bowel disease (IBD) and colorectal cancer (CRC). Extracellular vescicles (EVs), found in virtually all body fluids and produced by both eukaryotic cells and bacteria are involved in cell-cell communication and crosstalk mechanism, such as the immune resèponse, barrier function and intestinal flora. This review highlligts advancements in knbowledge of the functional role that Evs may have in IBD and CRC, and discusses the possible use of EVs derived from intestinal microbiota in therapeutic strategies for treating these conditions