Best operating conditions to produce hydroxyapatite nanoparticles by means of a spinning disc reactor

In this work, Mg²⁺ doped hydroxyapatite (Mg-HAP) nanoparticles were produced by a reactionprecipitation process by using a spinning disc reactor (SDR) at high rotational speed. The production process of these nanoparticles consisted of the neutralization reaction between two aqueous solutions of calcium chloride and ammonia orthophosphate at room temperature. By operating at pH = 10, a high purity Mg-HAP nanoparticles were obtained. In particular, they were 51 nm in average size when the two reagents were fed over the disc symmetrically at 3 cm from the disc center and a rotational speed of the disc reactor equal to 1400 r/min was adopted.     

A signature protein-based method to distinguish Mediterranean water buffalo and foreign breed milk

A novel genetic variant at the α_s1-casein locus of water buffalo (WB), 8-residue shorter than its wild-type has been found and sequenced. The internal deletion of the peptide E³⁵KVNELsT⁴² was confirmed by the isolation of the junction peptide. The 8-residue deletion mutant has a molecular weight that is 919 Da less than that of the wild-type. The novel isoform with a unique f35-42 deletion could be the result of the skipping of exon 6, generating an exon 6-deleted variant of α_s1-casein. The wild-type and its shortened α_s1-casein forms were found to co-exist in many individual milk samples. In contrast, the 8-residue, internally deleted α_s1-casein variant did not occur in water buffaloes of the Mediterranean breed reared in Italy. Wild-type α_s1-casein has 6 to 8 phosphate groups (P) while the internally deleted form 6 and 7P per molecule.     

Primary structure of water buffalo alpha-lactalbumin variants A and B

A novel electrophoretic alpha-lactalbumin (alpha-la) variant was detected in the Italian water buffalo breed. The isoelectric point of the variant, labelled A, was lower than the most frequent variant B. It presented an allelic frequency of 0.5% compared with the 97.1% of the BB allele. From Liquid Chromatography-Electrospray Ionization/Mass spectrometry, the molecular mass of the two alpha-la A and B variants were measured as 14,235.1+/-0.8 and 14,236.1+/-0.9 Da, respectively. The two proteins were sequenced and differentiated from one another by a single amino acid substitution, Asn45(B)-->Asp45(A). As this amino acid substitution altered the N-glycosylation sequence consensus Asn45-X-Ser46 it may be deduced that the protein glycosylation level of the alpha-la A would decrease.     

A Formal Model for Video Shot Segmentation and its Application via Animate Vision

The first step in a video indexing process is the segmentation of videos into meaningful parts called shots. In this paper we present a formal model of the video shot segmentation process. Starting from a mathematical characterization of the most common transition effects, a video segmentation algorithm capable to detect both abrupt and gradual transitions is proposed. The proposed algorithm is based on the computation of an arbitrary similarity measure between consecutive frames of a video. The algorithm has been tested adopting a similarity metric based on the Animate Vision theory and results have been reported.     

Peptides from water buffalo cheese whey induced senescence cell death via ceramide secretion in human colon adenocarcinoma cell line

Scope: Milk proteins are a source of bioactive peptides. Recent studies have indicated that protein‐derived peptides released in buffalo cheese acid whey exert a cytomodulatory effect in human epithelial colon cancer (CaCo2) cells. The aim of the present study was to explain the molecular mechanism involved in the response of CaCo2 cells to oxidative stress in the presence of peptide fractions of buffalo cheese whey, purified and characterized by mass spectrometry. Methods and results: We demonstrated that treatment of CaCo2 treated with H₂O₂ (H‐CaCo2) cells with a partially purified peptide sub‐fraction (f3) from buffalo cheese acid whey induced a reduction of mitochondrial superoxide anion with subsequent decrease in heat shock protein 70 and 90 expression. Moreover, we observed a 5‐fold decrease in cyclin A expression and cell cycle arrest in G1/G0 phases. These responses were associated with increased activity of alkaline phosphatase and beta‐galactosidase, markers of differentiation and senescence respectively. Conclusions: The structural characterization of the active peptide fraction and the elucidation of the effects induced by its treatment on H‐CaCo2 cells in vitro demonstrated an activity of this peptide sub‐fraction in the modulation of cell cycle, thus suggesting potential application for the development of nutraceuticals as well as health‐promoting functional foods.     

Determination of ovine casein heterogeneity using gel electrophoresis and immunochemical techniques.

Discontinuous PAGE at alkaline and acid pH, polyacrylamide gel isoelectric focusing, two dimensional electrophoresis and immunoblotting have been used to study the heterogeneity of sheep caseins. Three main phenotypes were selected either because of mobility at alkaline and acid pH of the individual alpha s components or because of their relative intensity. On electrophoresis at alkaline pH, one phenotype showed two distinct bands of lower electrophoretic mobility than beta 1- and beta 2-caseins. A detailed study of these components using immunospecific detection with beta-casein antiserum showed that these minor components of ovine casein may have a polypeptide chain similar to that of beta 1- and beta 2-caseins. Complete electrophoretic patterns of the casein components in some individual milks are also presented.     

FINES DESTRUCTION DURING BATCH CRYSTALLIZATION

An analysis of the use of fines destruction during batch crystallization based on the population (number) balance is presented. The effects of operating policy and fines crystal cut size and destruction rate are examined in detail for two cases viz. natural and controlled cooling respectively. It is predicted that use of fines destruction has the potential as a control aid to significantly improve the product crystal size distribution from batch crystallizers and is supported by experimental data on the programmed cooling crystallization of potassium sulphate solutions.     

Identification of free and bound volatile compounds as typicalness and authenticity markers of non-aromatic grapes and wines through a combined use of mass spectrometric techniques

Molecular approaches by means of a combined use of mass spectrometric techniques can be important in order to open new possibilities in the differentiation and defense of typical products; in this study, a possible approach to the analysis of varietal volatile compounds and some precursors of a non-aromatic grape variety (Falanghina cv., Vitis vinifera L.) was traced through a combined use of techniques based on mass spectrometry (GC/MS, LC/ESI-MS, MALDI-TOF-MS). Dominant terpene compounds (limonene, cis-furanlinalool oxide, geraniol, 4-carene, myrcene, linalool, -terpineol), terpene-derivatives (bornyl acetate, menthol), terpene glycosides (glucosides, arabinosylglucosides and rhamnosylglucosides of linalool and geraniol), and norisoprenoids (β-damascenone) were identified in grapes and monovarietal wines, overcoming the analytical difficulties deriving from the low concentration of these compounds strictly related to the variety. The potential release of varietal volatile compounds from the grapes was also explored by enzyme hydrolysis.     

Flat roof integration of a-Si triple junction modules laminated together with flexible polyolefin membranes

In BIPV design (Building Integrated PV) with crystalline silicon (c-Si) solar cells, ventilation is important in order to keep cells as cool as possible. To allow good ventilation it is therefore generally preferable to mount the modules separated from the existing roof. In the case of sloped roofs, the modules are superimposed onto the existing roof and for flat roofs separated tilted mounting structures designed to withstand wind loads are used instead, but both are not real building integrations.In this paper we analyse the behaviour and the energy yield of a 15.36 kWp PV system based on flexible triple junction amorphous silicon modules laminated together with a single ply roofing system.The PV plant has been integrated on a flat roof of a professional school located south of Switzerland. A significant part of the data analysis is done in comparison with three small open-rack plants (reference plants) installed near the integrated plant.An important result was that the thermally insulated nearly horizontal modules showed temperatures higher than for modules mounted on an open-rack structure, especially for sunny days. This created higher power losses due to negative temperature coefficients. On the other hand, the higher temperature reached the level where the main degradation mechanism of a-Si modules could be reversed and better thermal annealing could be observed. This conclusion was arrived at after a direct performance comparison of the thermally insulated plant and the open-rack a-Si reference plant, which has the same module and orientation as the main plant.In order to better understand the thermally insulated nearly horizontal plant behaviour, we analysed and quantified the irradiation difference and optical losses with respect to a 20° tilted open-rack c-Si power plant. Optical losses for nearly horizontal modules were significant during the winter, partially affecting their low performance.As a main result, the final energy yield of the thermally insulated a-Si plant was almost comparable to a 20° tilted open-rack c-Si power plant, despite the lower irradiance and higher reflection losses with respect to the latter.Accordingly, compared to c-Si modules, the a-Si technology represents a better choice for thermal insulated BIPV.