Sequenziamento e Analisi Molecolare di Varianti Alleliche del Gene PRB1

The aim of this work was the molecular characterization of gene PRB1 in three subjects with different salivary proteome profile. The PRB1 gene encodes a member of the heterogeneous family of Basic Proline rich Proteins (PRB), produced by the parotid gland and secreted in human saliva. The protein polymorphism resulting from post-translational modifications of the pre-protein PRB1, are further complicated by the gene allelic variants. Those variants involves the third exon of the gene, and are related to the presence or absence of a tandem repeat sequence 183 bp long. That tandem repeat may originate three different allelic forms, defined small, medium or large depending on the number of repeats inside the third exon. The information reported in the literature about the class of PRP genes, and in particular PRB1 are, from the molecular point of view, fragmentary and difficult to reconstruct. In fact, the literature on this topic covers a time span ranging from the seventies (Azen & Oppenheim, 1973), when the associated peptides have been characterized for the first time, up to the end of the nineties (Stubbs et al., 1998). Since the eighties, there have been various attempts to characterize the PRB1 allelic variants, based on the resulting peptides. This approach has greatly complicated the classification of the gene, but also of his allelic variants and the deriving proteins (Maeda et al., 1985 ; Lyons et al., 1988a, b; Azen et al., 1993). Today we know that from PRB1, considering its allelic and splicing variants, are expressed six different proteins (Marconi et al., 2015). However, amongst the three allelic variants of this gene, the only of which we have the complete nucleotide sequence is the medium. Conversely, for the small and large we have so far only partial sequences, referring only to the third exon. Among the objectives of this study, there was the reconstruction of the complete sequences of the small and large variants, of which there have been previously characterized two putative bearers from the proteomic point of view. At the same time, we also sequenced the PRB1 gene from a putative homozygotic bearer of the medium variant. While for the subject bearer of the small variant, we were able to identify and sequence the entire gene, the same was not possible for the subject bearer of the large variant. In fact, from our analysis this last subject has shown to be homozygous carrier of the medium variant. This result is incompatible with the presence in his saliva of Ps2 protein, which is characteristic of the large variant. In the absence of further mass spectrometric analysis, we cannot explain the reason for this discrepancy between genomic and proteomic data. The analysis of the complete sequences did not allow us to understand why it has not been identified to the mass spectrometer the peptide relative to the splice variant classified by Maeda with the acronym cP5 (Maeda et al., 1985), while in all the subject has been identified the peptide and the relative cP4 splice variant. Pk-o protein has so far been reported to be expressed from the large variant only, although the first classification of splice variants had been made from an individual carrying the medium variant. Since in none of the three sequenced subjects the splice acceptor site in 3' of the cP5 variant results to be altered, it is possible that the relative peptide has not been identified to the mass spectrometer. Otherwise, specific splicing factors, that recognize Splicing Regulatory Elements (SRES; Hernandez-Imaz et al., 2015) in the neighborhood of the two molecular acceptor sites, prevented the transcription of the cP5 in favor of cP4. In order to shed light on this aspect, there are some possible strategies in perspective. Recently, in fact, studies have been published in which extensive in vivo screening for the detection of SRES is coupled with RNA affinity purification and mass spectrometry, which allow also the identification of the splicing factors which bound to the SRES (Wang Y & Z Wang, 2014; Wang et al., 2013). This strategy could be effectively integrated with the analysis of minigenes (Hernandez-Imaz et al., 2015), specifically designed on the model of the third exon of PRB1, where alternative splicing takes place and where are probably placed the SRES. Molecular analysis has also enabled us to identify a set of Single Nucleotide Polymorphims (SNPs), most of which have never been described so far, localized specially inside introns and some even within exons. In particular, for two of these, we have detected a non-synonymous substitution at the amino acid level, the role of which can only be clarified by means of appropriate functional studies. Although translationally silent, even synonymous SNPs may have an important function, especially in alternative splicing. In fact, these substitutions can determine the genesis or destruction of SRES, or strengthen cryptic donor /acceptor sites. Furthermore, they can result in the alteration of the secondary structure of the mRNA, important for the exons definition and the pause sites of RNA II. This could, in turn, alter the processivity of the polymerase, with possible consequences on the choice of splicing sites. The reconstruction of the complete sequences and the comparison with the data available in the literature (Lyons et al., 1988) allowed us to produce an updated model, which allows to explain the generation of allelic variants small and large from the medium variant. Hopefully, the reconstruction also of the large allelic variation, and possibly the very large, will lay the basis for the validation of our model and possibly also its extension to other allelic variants of the PRB gene class. The genotypic characterization of allelic variants of PRB1 may be, in the future, an important predictive tool about the subjective susceptibility towards a series of oral pathogens. In fact, polymorphic variations in the PRB1 peptides can build the basis for the prediction of individual differences at the level of the oral microflora, with repercussions on the susceptibility to infections and diseases in this body part (Newman et al., 1993 and 1996; O'Sullivan et al., 2000)

Self-propagating high-temperature reactions: remarks and recent results

Solid-solid and gas-solid self-propagating high temperature reactions are exploited for interesting and relatively new technological applications based on the so called Self-propagating High-temperature Synthesis (SHS) technique This paper reviews the recent results obtained, also in the framework of national and international collaborations, by Cao and coworkers in the field of self-propagating high-temperature reactions with particular emphasis on SHS fundamentals and applications. In particular, the research activity conducted so far can be divided into three main topics: Macrokinetics studies on SHS using structural statics as well as dynamics approaches; Modeling studies on SHS, with the aim of developing analytical expressions of combustion front velocity and simulating experimental techniques applied for macrokinetics investigations; Technological applications related to the synthesis of centrifugal coatings and environmental protection. The activities outlined above will be described in this review paper in separate sections as discussed next

Mechanistic investigation of electric field-activated self-propagating reactions: experimental and modeling studies

The mechanism of electric field-activated self-propagating reactions is investigated using the combustion front quenching technique. In particular, previously published experimental results obtained through the Field Assisted Combustion Synthesis (FACS) of b-SiC, TaC, Ti3Al and B4C-TiB2 are re-examined and compared. Pre-combustion and combustion stages involved during synthesis wave propagation are postulated for all systems. Subsequently, modeling results aimed at simulating the process where an electric field-activated self-propagating reaction takes place are presented. In particular, a one-dimensional model of FACS technique is developed to simulate the rapid quenching of the reaction during its progress as the applied field is turned off. A rate expression which accounts for the influence of temperature, particle size, compaction density, reactant stoichiometry, and inert content is included in the model

LivDet in Action - Fingerprint Liveness Detection Competition 2019

The International Fingerprint liveness Detection Competition (LivDet) is an open and well-acknowledged meeting point of academies and private companies that deal with the problem of distinguishing images coming from reproductions of fingerprints made of artificial materials and images relative to real fingerprints. In this edition of LivDet we invited the competitors to propose integrated algorithms with matching systems. The goal was to investigate at which extent this integration impact on the whole performance. Twelve algorithms were submitted to the competition, eight of which worked on integrated systems.Comment: Preprint version of a paper accepted at ICB 201

LivDet 2017 Fingerprint Liveness Detection Competition 2017

Fingerprint Presentation Attack Detection (FPAD) deals with distinguishing images coming from artificial replicas of the fingerprint characteristic, made up of materials like silicone, gelatine or latex, and images coming from alive fingerprints. Images are captured by modern scanners, typically relying on solid-state or optical technologies. Since from 2009, the Fingerprint Liveness Detection Competition (LivDet) aims to assess the performance of the state-of-the-art algorithms according to a rigorous experimental protocol and, at the same time, a simple overview of the basic achievements. The competition is open to all academics research centers and all companies that work in this field. The positive, increasing trend of the participants number, which supports the success of this initiative, is confirmed even this year: 17 algorithms were submitted to the competition, with a larger involvement of companies and academies. This means that the topic is relevant for both sides, and points out that a lot of work must be done in terms of fundamental and applied research.Comment: presented at ICB 201

Simultaneous spark plasma synthesis and consolidation of WC/Co composites

The single-step synthesis and densification of the WC-6Co cemented carbide starting from elemental powders was obtained by the spark plasma sintering (SPS) technique. The operating conditions that guarantee the complete conversion of the reactants to the desired full dense material have been identified. Specifically, under the application of 800 A and a mechanical pressure of 40 MPa for about 200 s, a product with relative density higher than 99%, hardness of 14.97 ± 0.35 GPa, and 12.5 ± 1.0 MPa m0.5 fracture toughness was obtained. A kinetic investigation of the SPS process was also performed. It revealed that an intermediate phase, i.e., W2C, is the first carbide formed during the carburization process. It was observed that the synthesis and sintering stages take place simultaneously. It was also found that as the applied pulsed current intensity was augmented, the synthesis/sintering time required decreased significantly

Comparison Between an Artificial Neural Network and Logistic Regression in Predicting Long Term Kidney Transplantation Outcome

Predicting clinical outcome following a specific treatment is a challenge that sees physicians and researchers alike sharing the dream of a crystal ball to read into the future. In Medicine, several tools have been developed for the prediction of outcomes following drug treatment and other medical interventions. The standard approach for a binary outcome is to use logistic regression (LR) [1,2] but over the past few years artificial neural networks (ANNs) have become an increasingly popular alternative to LR analysis for prognostic and diagnostic classification in clinical medicine [3]. The growing interest in ANNs has mainly been triggered by their ability to mimic the learning processes of the human brain. The network operates in a feed-forward mode from the input layer through the hidden layers to the output layer. Exactly what interactions are modeled in the hidden layers is still under study. Each layer within the network is made up of computing nodes with remarkable data processing abilities. Each node is connected to other nodes of a previous layer through adaptable inter-neuron connection strengths known as synaptic weights. ANNs are trained for specific applications through a learning process and knowledge is usually retained as a set of connection weights [4]. The backpropagation algorithm and its variants are learning algorithms that are widely used in neural networks. With backpropagation, the input data is repeatedly presented to the network. Each time, the output is compared to the desired output and an error is computed. The error is then fed back through the network and used to adjust the weights in such a way that with each iteration it gradually declines until the neural model produces the desired outpu

Novel processing route for the fabrication of bulk high-entropy metal diborides

A single high-entropy phase material with hexagonal structure is produced by a two-steps processing method. Elemental reactants are first remarkably converted by Self-propagating High-temperature Synthesis (SHS). The completion of the chemical transformation to the desired (Hf0.2Mo0.2Ta0.2Nb0.2Ti0.2)B2 phase and its concurrent consolidation up to 92.5% relative density is achieved by processing the SHS powders at 1950 °C via Spark Plasma Sintering. It is clearly evidenced that the use of the SHS technique is extremely beneficial to promote the formation of high-entropy ceramics, as compared to the time consuming ball milling treatment alternatively adopted

High-entropy transition metal diborides by reactive and non-reactive spark plasma sintering: A comparative investigation

The direct synthesis and consolidation by SPS (1950 °C, 20 min, 20 MPa) of high-entropy (Hf0.2Mo0.2Zr0.2Nb0.2Ti0.2)B2 from elemental powders resulted in a multiphase product. An increase of the heating rate determined a change of the mechanism governing the synthesis reaction from gradual solid-state diffusion to rapid combustion regime, while the final conversion degree was 67 wt.%. The sintered product displayed a non-uniform microstructure with the presence of 10–15 μm sized pores, due to volatilization phenomena occurring during the combustion synthesis reaction. In contrast, when the SPS process was preceded by powder synthesis via SHS, a homogeneous single-phase ceramic was obtained. Clear benefits are derived by the use of SHS, able to provide very shortly powders with elemental species very well intermixed, so that the obtainment of (Hf0.2Mo0.2Zr0.2Nb0.2Ti0.2)B2 during the subsequent SPS stage is strongly promoted. The resulting 92.5% dense product shows superior oxidation resistance with respect to individual borides prepared with the same method.ARCHIMEDES project sponsored by Regione Autonoma della Sardegna (Italy) - Fondo di Sviluppo e Coesione (FSC) 2014-2020 (Cod. RAS: RASSR88309, Cod. CUP: F76C18000980002). One of the authors (G.T.) performed her activity in the framework of the International PhD in Innovation Sciences and Technologies at the University of Cagliari, Italy. One of us (G.C.) acknowledges the results obtained in this manuscript as quite important for the “Ithermal” and “Generazione E” projects, sponsored by Sardegna Ricerche, Italy (Cod. CUP: F21I18000130006) and by the Italian Ministry of Education, University and Research, Italy (Cod. CUP: B96G18000560005), respectivel