Search results for "Surfaces"
showing 10 items of 2837 documents
Biopreservation of Myoglobin in Crowded Environment: A Comparison between Gelatin and Trehalose Matrixes.
2017
Biopreservation by sugar and/or polymeric matrixes is a thoroughly studied research topic with wide technological relevance. Ternary amorphous systems containing both saccharides and proteins are extensively exploited to model the in vivo biopreservation process. With the aim of disentangling the effect of saccharides and polypeptidic crowders (such as gelatin) on the preservation of a model protein, we present here a combined differential scanning calorimetry and UV-vis spectrophotometry study on samples of myoglobin embedded in amorphous gelatin and trehalose + gelatin matrixes at different hydrations, and compare them with amorphous myoglobin-only and myoglobin-Trehalose samples. The res…
Fostering the antiviral activity of green tea extract for sanitizing purposes through controlled storage conditions
2018
Food-contact surfaces is considered an important vehicle for the indirect transmission of foodborne viral diseases with enteric viruses, especially human norovirus (HuNoV) and hepatitis A virus (HAV). The aim of the present study was to evaluate the antiviral activity of green tea extract (GTE) at room temperature as a function of pH and storage time and to relate it with changes in composition as a consequence of degradation and epimerization reactions in the storage conditions. The obtained results revealed that freshly prepared GTE was very effective in inactivating murine norovirus (MNV) and HAV at neutral and alkaline pH but was ineffective at pH 5.5. Additionally, storage of the solut…
'Maleducados/Ill-mannered' during the #A28 political campaign on Twitter: A metapragmatic study of impoliteness labels and comments in Spanish
2020
AbstractThis paper approaches the study of conflict through an examination of Spanish metapragmatic labels and comments of impoliteness on Twitter. The aim is twofold. It first aims to confirm the attributed importance of the labelmaleducado/ill-mannered in the specific context of Twitter and of digital discourse more generally, on quantitative and comparative grounds; then, it investigates this label, and the metapragmatic comments where it occurred, in a contextualized corpus of tweets compiled during the political campaign of Spain’s General Elections of April 28, 2019. The study draws from fivead hoccorpora specifically compiled from Twitter, and a general corpus of Spanish digital disc…
STANCE BUNDLES IN ENGLISH-TO-POLISH TRANSLATION: A CORPUS-INFORMED STUDY
2018
In this paper, we make an attempt to improve the textual fit of English-to-Polish translation of a peculiar type of multi-word units known in corpus linguistic literature as lexical bundles (Biber et al. 1999). Inspired by a study conducted by Grabar and Lefer (2015), we used the English-Polish parallel corpus Paralela (Pezik 2016) and the National Corpus of Polish (NKJP) to extract and explore the use - in terms of frequency distributions - of the Polish equivalents of selected English lexical bundles expressing attitudinal and epistemic stance. More precisely, we used the NKJP corpus to check whether the Polish equivalents are typical of contemporary Polish as found in native texts. The r…
Direct Observation of Nanometer-Scale Pores of Melittin in Supported Lipid Monolayers
2015
Melittin is the most studied membrane-active peptide and archetype within a large and diverse group of pore formers. However, the molecular characteristics of melittin pores remain largely unknown. Herein, we show by atomic force microscopy (AFM) that lipid monolayers in the presence of melittin are decorated with numerous regularly shaped circular pores that can be distinguished from nonspecific monolayer defects. The specificity of these pores is reinforced through a statistical evaluation of depressions found in Langmuir-Blodgett monolayers in the presence and absence of melittin, which eventually allows characterization of the melittin-induced pores at a quantitative low-resolution leve…
Design of new sensitive α,β-unsaturated carbonyl 1,8-naphtalimide fluorescent probes for thiol bioimaging
2017
International audience; We report herein an efficient synthesis of news naphtalimide-based fluorescent derivatives functionalized with an a,(3-unsaturated carbonyl group. Probes were synthesized from reaction of an amino-naphtalimide precursor with maleic anhydride. Photophysical study of fluorescent probes and cells labelling were performed, and showed that the reactive derivatives exhibit rich turn on fluorescence properties in presence of different biological thiol (Glutathione and Cysteine) making these systems a very promising way for thiol bioimaging.
New fourfolds from F-theory
2015
In this paper, we apply Borcea-Voisin's construction and give new examples of fourfolds containing a del Pezzo surface of degree six, which admit an elliptic fibration on a smooth threefold. Some of these fourfolds are Calabi-Yau varieties, which are relevant for the $N=1$ compactification of Type IIB string theory known as $F$-Theory. As a by-product, we provide a new example of a Calabi--Yau threefold with Hodge numbers $h^{1,1}=h^{2,1}=10$.
Embeddings of a family of Danielewski hypersurfaces and certain \C^+-actions on \C^3
2006
International audience; We consider the family of complex polynomials in \C[x,y,z] of the form x^2y-z^2-xq(x,z). Two such polynomials P_1 and P_2 are equivalent if there is an automorphism \varphi of \C[x,y,z] such that \varphi(P_1)=P_2. We give a complete classification of the equivalence classes of these polynomials in the algebraic and analytic category.
Physico-chemical investigation of the state of cyanamide confined in AOT and lecithin reversed micelles
2004
Sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and lecithin reversed micelles containing cyanamide have been investigated by small-angle X-ray scattering, FT-IR, and 1H NMR spectroscopy at various cyanamide-to-surfactant molar ratio (X) and at fixed surfactant concentration (0.1 mol kg-1). Experimental data are consistent with a model of cyanamide molecules confined in reversed micelles, quite uniformly distributed among them and mainly located among surfactant headgroups. SAXS data analysis leads also to hypothesize a unidimensional growth of the reversed micelles with increasing the X value. Moreover, the cyanamide state and the cyanamide/cyanamide interactions in reversed micelles have bee…
Asymmetric synthesis of 3,3′-pyrrolidinyl-dispirooxindoles via a one-pot organocatalytic Mannich/deprotection/aza-Michael sequence
2016
Chemical communications 52, 2249-2252 (2016). doi:10.1039/C5CC10057G