Novel thermal curing of cycloaliphatic resins by thiol–epoxy click process with several multifunctional thiols

Novel thermosets were prepared by the base‐catalysed reaction between a cycloaliphatic resin (ECC) and various thiol crosslinkers. 4‐(N,N‐Dimethylaminopyridine) (DMAP) was used as base catalyst for the thiol–epoxy reaction. A commercial tetrathiol (PETMP) and three different thiols synthesized by us, 6SH‐SQ, 3SH‐EU and 3SH‐ISO, were tested. 6SH‐SQ and 3SH‐EU were prepared from vinyl or allyl compounds from renewable resources such as squalene and eugenol, respectively. Thiol 3SH‐ISO was prepared starting from commercially available triallyl isocyanurate. A kinetic study of the mixtures was performed using differential scanning calorimetry. Stoichiometric ECC/thiol/DMAP formulations were cured at 120 °C for 1 h, at 150 °C for 1 h and post‐cured for 30 min at 200 °C. The materials were characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis and dynamic mechanical thermal analysis. The results revealed that the materials obtained from the synthesized thiols had higher thermal stability and glass transition temperatures than those obtained from the commercial PETMP. In addition, all the materials obtained exhibited very good transparency. This study proves the ability of multifunctional thiols to crosslink cycloaliphatic epoxy resins, leading to more flexible materials than those obtained by cationic homopolymerization of ECC or base‐catalysed ECC–anhydride copolymerization. © 2017 Society of Chemical Industry     

Immobilization of olfactory receptors onto gold electrodes for electrical biosensor

We investigate the immobilization of native nanovesicles containing functional olfactory receptors onto gold electrodes by means of atomic force microscopy in liquid. We show that nanovesicles can be adsorbed without disrupting them presenting sizes once immobilized ranging from 50 nm to 200 nm in diameter. The size of the nanovesicles shows no dependence on the electrode hydrophobicity being constant in a height/width ratio close to 1:3. Nevertheless, electrode hydrophobicity does affect the surface coverage, the surface coverage is five times higher in hydrophilic electrodes than on hydrophobic ones. Surface coverage is also affected by nanovesicles dimensions in suspension, the size homogenization to around 50 nm yields a further five fold increment in surface coverage achieving a coverage of about 50% close to the hard spheres jamming limit (54.7%). A single layer of nanovesicles is always formed with no particle overlap. Present results provide insights into the immobilization on electrodes of olfactory receptors for further olfactory electrical biosensor development.     

HLA class I and class II DNA typing and the origin of Basques

The SH gene of the paramyxovirus SV5 is located between the genes for the glycoproteins, fusion protein (F) and hemagglutinin-neuraminidase (HN), and the SH gene encodes a small 44-residue hydrophobic integral membrane protein (SH). The SH protein is expressed in SV5-infected cells and is oriented in membranes with its N terminus in the cytoplasm. To study the function of the SH protein in the SV5 virus life cycle, the SH gene was deleted from the infectious cDNA clone of the SV5 genome. By using the recently developed reverse genetics system for SV5, it was found that an SH-deleted SV5 (rSV5DeltaSH) could be recovered, indicating the SH protein was not essential for virus viability in tissue culture. Analysis of properties of rSV5DeltaSH indicated that lack of expression of SH protein did not alter the expression level of the other virus proteins, the subcellular localization of F and HN, or fusion competency as measured by lipid mixing assays and a new content mixing assay that did not require the use of vaccinia virus. The growth rate, infectivity, and plaque size of rSV5 and rSV5DeltaSH were found to be very similar. Although SH is shown to be a component of purified virions by immunoblotting, examination of purified rSV5DeltaSH by electron microscopy did not show an altered morphology from SV5. Thus in tissue culture cells the lack of the SV5 SH protein does not confer a recognizable phenotype.     

Tsallis entropy-based information measures for shot boundary detection and keyframe selection

Automatic shot boundary detection and keyframe selection constitute major goals in video processing. We propose two different information-theoretic approaches to detect the abrupt shot boundaries of a video sequence. These approaches are, respectively, based on two information measures, Tsallis mutual information and Jensen–Tsallis divergence, that are used to quantify the similarity between two frames. Both measures are also used to find out the most representative keyframe of each shot. The representativeness of a frame is basically given by its average similarity with respect to the other frames of the shot. Several experiments analyze the behavior of the proposed measures for different color spaces (RGB, HSV, and Lab), regular binnings, and entropic indices. In particular, the Tsallis mutual information for the HSV and Lab color spaces with only 8 regular bins for each color component and an entropic index between 1.5 and 1.8 substantially improve the performance of previously proposed methods based on mutual information and Jensen–Shannon divergence.     

Third-Order Intermodulation Distortion and Harmonic Generation in Mismatched Weakly Nonlinear Transmission Lines

This paper describes a procedure to obtain analytical expressions for the spurious signals generated in nonlinear transmission lines with impedance mismatch when they are subject to small-signals. Using these expressions one can rapidly extract the nonlinear parameters describing the nonlinear effects due to the conductor, L(i) and R(i) , such as in superconductors, and/or the nonlinear parameters due to the dielectric, C(v) and G(v) , such as in ferroelectrics. The resulting closed-form expressions have been validated by equivalent circuit simulations. Spurious signal measurements on several coplanar waveguide superconducting and ferroelectric transmission lines have been explained by the use of the resulting closed-form expressions.     

Effect of germinated seeds extract on the respiratory activity of human skin fibroblasts and sheep liver mitochondria. Influence on cell viability and proliferation and their uselfulness as active cosmetic ingredient

The present work studies the ability of a germinated seeds extract (alfalfa, radish, wheat, soy) to influence cell respiration of skin fibroblasts and the respiratory activity of sheep liver isolated mitochondria, and the cytotoxicity of the product on cultured skin fibroblasts. The content of free and total amino acids present in this extract was determined. Aspartic acid represented 37.52% of free amino acids in the extract, but 48.07% glutamic acid was found when total amino acids obtained by acid hydrolysis were quantified. The extract contains more than 6.5% free serine, glutamic acid and alanine. Arginine, serine, aspartic acid and threonine are the other amino acids that represent more than 4.5% total amino acids. Respiration of sheep liver mitochondria and human skin fibroblasts (Foreskin ATCC CRL-1635) was checked polarographically. The results obtained show the ability of this extract to stimulate cellular respiration of both in vitro models, but the effect is more marked on cell cultured fibroblasts, and its dose dependency. The role of acidic amino acids, aspartic and glutamic acids, on the increase of oxygen consumption by mitochonria is suggested. Cytotoxicity of the germinated seeds extract was tested by the assessment of the viability, the morphological changes and the proliferation of cell cultured human skin fibroblasts. It has been shown that germinated seeds extract are non-toxic to cell cultures at doses of up to 10 mg mL(-1); neither morphological changes nor membrane integrity alterations or changes in cell proliferation were observed.     

Model comparison and selection for stationary space-time models

An intensive simulation study to compare the spatio-temporal prediction performances among various space-time models is presented. The models having separable spatio-temporal covariance functions and nonseparable ones, under various scenarios, are also considered. The computational performance among the various selected models are compared. The issue of how to select an appropriate space-time model by accounting for the tradeoff between goodness-of-fit and model complexity is addressed. Performances of the two commonly used model-selection criteria, Akaike information criterion and Bayesian information criterion are examined. Furthermore, a practical application based on the statistical analysis of surface shortwave radiation budget (SSRB) data is presented.     

Anti-unification for Unranked Terms and Hedges

We study anti-unification for unranked terms and hedges that may contain term and hedge variables. The anti-unification problem of two hedges ${\tilde{s}}_1$ and ${\tilde{s}}_2$ is concerned with finding their generalization, a hedge ${\tilde{q}}$ such that both ${\tilde{s}}_1$ and ${\tilde{s}}_2$ are instances of ${\tilde{q}}$ under some substitutions. Hedge variables help to fill in gaps in generalizations, while term variables abstract single (sub)terms with different top function symbols. First, we design a complete and minimal algorithm to compute least general generalizations. Then, we improve the efficiency of the algorithm by restricting possible alternatives permitted in the generalizations. The restrictions are imposed with the help of a rigidity function, which is a parameter in the improved algorithm and selects certain common subsequences from the hedges to be generalized. The obtained rigid anti-unification algorithm is further made more precise by permitting combination of hedge and term variables in generalizations. Finally, we indicate a possible application of the algorithm in software engineering.