The effect of biogel content on the some viscoelastic properties of a snail pate

Four sorts of snail pâté with different contents (0, 1, 2, 3%) of a vegetal protein (biogel) were prepared. The influence of the content of biogel on the viscoelastic characteristics of snail pâté were studied in this paper. These characteristics of snail pâté were derived from stress relaxation tests. The relaxation times and the elastic moduli, as viscoelastic characteristics, were calculated from the relaxation curves by non-linear regression. The best correspondence between experimental data and calculated curves was obtained for a mechanical model with three Maxwell elements in parallel with a lone ideal spring element. Every measurement was made in triplicate. From above viscoelastic parameters, the viscosities were calculated. Correlation between experimental relaxation curves and calculated curves were emphasized by absolute average deviation (AAD), the minimum AAD value being 0.15% and the maximum one 0.82%. The stiffest snail pâté contains 2% biogel, and the snail pâté with 3% biogel is more viscous

The effect of biogel content on the some viscoelastic properties of a snail pate

Four sorts of snail pâté with different contents (0, 1, 2, 3%) of a vegetal protein (biogel) were prepared. The influence of the content of biogel on the viscoelastic characteristics of snail pâté were studied in this paper. These characteristics of snail pâté were derived from stress relaxation tests. The relaxation times and the elastic moduli, as viscoelastic characteristics, were calculated from the relaxation curves by non-linear regression. The best correspondence between experimental data and calculated curves was obtained for a mechanical model with three Maxwell elements in parallel with a lone ideal spring element. Every measurement was made in triplicate. From above viscoelastic parameters, the viscosities were calculated. Correlation between experimental relaxation curves and calculated curves were emphasized by absolute average deviation (AAD), the minimum AAD value being 0.15% and the maximum one 0.82%. The stiffest snail pâté contains 2% biogel, and the snail pâté with 3% biogel is more viscous

Tracking antioxidant properties and color changes in low-sugar bilberry jam as effect of processing, storage and pectin concentration

<p>Abstract</p> <p>Background</p> <p>Recently, an increased interest in the identification of valuable possibilities for preserving the antioxidant properties of products obtained by thermal processing of fruits rich in bioactive compounds can be noticed. In this regard, an extensive analysis is necessary in terms of thermal processed products behavior in relation to various factors. The purpose of the present study was to assess the effect which processing and storage at 20°C has on the antioxidant properties and color quality of low-sugar bilberry jam with different low-methoxyl pectin (LMP) concentrations.</p> <p>Results</p> <p>For all measured parameters, it should be noted that thermal processing induced significant alterations reported to the values registered for fresh fruit. Most important losses due to thermal processing were recorded for total monomeric anthocyanins (TMA) (81-84%), followed by L-ascorbic acid (L-AsAc) content (53-58%), total phenolics (TP) content (42-51%) and FRAP (ferric reducing antioxidant power) values (36-47%). Moreover, depreciation of the investigated compounds occurred during storage at 20°C. Jam storage for 7 months resulted in severe losses in TMA content in the range 58-72% from the value recorded one day after processing. This coincided with marked increases in polymeric color percent of these products after 7 months of storage. Also, bilberry jam storage for 7 months resulted in a decrease in L-AsAc content of 40-53% from the value recorded one day after processing, 41-57% in TP content and 33-46% from the value recorded one day after processing for FRAP values. By decreasing of LMP concentration in the jam recipe from 1 to 0.3% there has been an increase in losses of investigated compounds.</p> <p>Conclusion</p> <p>Overall, the results indicated that bilberry jams can also represent a good source of antioxidant compounds, although compared to the fruit, important losses seem to occur. Practical application of this work is that this kind of information will be very useful in optimizing the jam processing technology and storage conditions, in order to improve the quality of these products.</p

Monitoring Black Sea environmental changes from space: New products for altimetry, ocean colour and salinity. Potentialities and requirements for a dedicated in-situ observing system

21 pages, 13 figures, 2 tables, supplementary material https://www.frontiersin.org/articles/10.3389/fmars.2022.998970/full#supplementary-material.-- Data availability statement: The datasets generated for this study can be found on the web interface (http://www.eo4sibs.uliege.be/) and on Zenodo under data doi: 10.5281/zenodo.6397223 with a full documentation that include Products User Manuals (PUM) and Algorithm Theoretical Basis Document (ATBD). All these products are distributed in netCDF files Grégoire et al. (2022). SMOS SSS and CDM products are also available at https://bec.icm.csic.es/bec-ftp-service/In this paper, satellite products developed during the Earth Observation for Science and Innovation in the Black Sea (EO4SIBS) ESA project are presented. Ocean colour, sea level anomaly and sea surface salinity datasets are produced for the last decade and validated with regional in-situ observations. New data processing is tested to appropriately tackle the Black Sea’s particular configuration and geophysical characteristics. For altimetry, the full rate (20Hz) altimeter measurements from Cryosat-2 and Sentinel-3A are processed to deliver a 5Hz along-track product. This product is combined with existing 1Hz product to produce gridded datasets for the sea level anomaly, mean dynamic topography, geostrophic currents. This new set of altimetry gridded products offers a better definition of the main Black Sea current, a more accurate reconstruction and characterization of eddies structure, in particular, in coastal areas, and improves the observable wavelength by a factor of 1.6. The EO4SIBS sea surface salinity from SMOS is the first satellite product for salinity in the Black Sea. Specific data treatments are applied to remedy the issue of land-sea and radio frequency interference contamination and to adapt the dielectric constant model to the low salinity and cold waters of the Black Sea. The quality of the SMOS products is assessed and shows a significant improvement from Level-2 to Level -3 and Level-4 products. Level-4 products accuracy is 0.4-0.6 psu, a comparable value to that in the Mediterranean Sea. On average SMOS sea surface salinity is lower than salinity measured by Argo floats, with a larger error in the eastern basin. The adequacy of SMOS SSS to reproduce the spatial characteristics of the Black Sea surface salinity and, in particular, plume patterns is analyzed. For ocean colour, chlorophyll-a, turbidity and suspended particulate materials are proposed using regional calibrated algorithms and satellite data provided by OLCI sensor onboard Sentinel-3 mission. The seasonal cycle of ocean colour products is described and a water classification scheme is proposed. The development of these three types of products has suffered from important in-situ data gaps that hinder a sound calibration of the algorithms and a proper assessment of the datasets quality. We propose recommendations for improving the in-situ observing system that will support the development of satellite productsThis work has been carried out as part of the European Space Agency contract Earth Observation data For Science and Innovations in the Black Sea (EO4SIBS, ESA contract n° 4000127237/19/I-EF). MG received fundings from the Copernicus Marine Service (CMEMS), the European Union’s Horizon 2020 BRIDGE-BS project under grant agreement No. 101000240 and by the Project CE2COAST funded by ANR(FR), BELSPO (BE), FCT (PT), IZM (LV), MI (IE), MIUR (IT), Rannis (IS), and RCN (NO) through the 2019 “Joint Transnational Call on Next Generation Climate Science in Europe for Oceans” initiated by JPI Climate and JPI Oceans. The research on SMOS SSS has been also supported in part by the Spanish R&D project INTERACT (PID2020-114623RB-C31), which is funded by MCIN/AEI/10.13039/501100011033, funding from the Spanish government through the “Severo Ochoa Centre of Excellence” accreditation (CEX2019-000928-S) and the CSIC Thematic Interdisciplinary Platform TeledetectPeer reviewe

Synthetic, Spectroscopic, structural, and speciation studies in the Co(II) - N,N - Bis(phosponomethyl)glycine system

Cobalt plays important roles in biological systems, despite its low availability in the earth's crust. The most common examples are vitamin B12 and coenzyme B12, a cofactor required for a group of enzymatic systems of central importance in biochemistry. Its involvement in (bio)chemical processes contributing to the integrity of the physiology of humans underscores its ability to promote (bio)chemistry with molecular targets of variable mass and biological properties. Given the fact that organic phosphonates are widespread substrates-ligands in biological fluids, we sought to investigate the relevant chemistry with Co(II). In an effort to unravel the aqueous chemistry of Co(II) in the presence of phosphonate ligands, two new Co(II)- N,N-bis(phosphonomethyl) glycine acid, aqueous soluble, complexes were synthesized, isolated and characterized. Aqueous reactions of Co(NO3)2 . 6H2O with N,N-bis(phosphonomethyl) glycine acid led to the isolation of complex [Co(C4H9O8NP2)2(H2O)2] . 2H2O (1) at low pH. At higher pH values 5.5-6 aqueous reactions of Co(CH3COO)2 . 6H2O with N,N-bis(phosphonomethyl) glycine acid in the presence of ammonia led to the isolation of complex (NH4)4[Co(H2O)6][Co{N(CH2COO)(CH2PO3)2}(H2O)2]2[Co(H2O)2{N(CH2COO)(CH2PO3 H)(CH2PO3)}Co(NH3)2(H2O)3]2 .10 H2O . 1.36 CH3CH2OH (2). The complexes were further characterized analytically, spectroscopicaly (FTIR, UV-vis, EPR), and electrochemically (cyclic voltammetry). Speciation studies were carried out for nitrilotriacetic acid (NTA) and its phosphonic derivatives (N-(phosphonomethyl)- iminodiacetic acid (NTAP), N,N-bis(phosphonomethyl)glycine (NTA2P) and nitrilotris( methylphosphonic acid) (NTA3P)). Such information are vital in trying to understand the interactions of soluble and bioavailable forms of Co(II) in biological interactions in human organisms

Ανάπτυξη των πολυμερικών ψηκτρών ως έξυπνα υποστρώματα για την τροποποίηση επιφανειών

Στην παρούσα εργασία περιγράφεται η σύνθεση πολυμερικών ψηκτρών από επίπεδες επιφάνειες με την τεχνική του ριζικού πολυμερισμού μεταφοράς ατόμου (ΑΤRP) από επιφάνεια. Τα πολυμερικά υμένια που παρασκευάστηκαν χαρακτηρίστηκαν με ελλειψομετρία, μικροσκοπία ατομικών δυνάμεων (AFM), φασματοσκοπία υπερύθρου εσωτερικής ανακλαστικότητας (ATR-FTIR) καθώς και με μετρήσεις γωνίας επαφής. Στο πρώτο μέρος της εργασίας, περιγράφεται ο εκκινούμενος από επιφάνεια χρυσού πολυμερισμός αποκρινόμενων ομοπολυμερικών και συσταδικών συμπολυμερικών ψηκτρών. Συγκεκριμένα, χρησιμοποιήθηκαν τρία ευαίσθητο- αποκρινόμενα μεθακρυλικά μονομερή, ο μεθακρυλικός 2-(διμεθυλαμινο)αιθυλεστέρας (DMAEMA), ο οποίος είναι υδρόφιλος και ιονιζόμενος, ο μεθακρυλικός 2- (διαιθυλαμινο)αιθυλεστέρας (DEAEMA), που είναι υδρόφοβος και ευαίσθητος στο pH, και το μεθακρυλικό τετραϋδροπυράνιο (THPMA), που είναι υδρόφοβος μεθακρυλικός εστέρας, ο οποίος μπορεί εύκολα να υδρολυθεί σε μεθακρυλικό οξύ (MAA), που είναι υδρόφιλο και ιονιζόμενο μονομερές. Επιπρόσθετα, συντέθηκαν πολυμερικά υμένια αποτελούμενα από ουδέτερες ομάδες, ολιγο(αιθλυλενογλυκόλη) μεθακρυλικού εστέρα (OEGMA). Σε όλα τα παραπάνω πολυμερικά υμένια πραγματοποιήθηκε μελέτη της ικανότητας διαβροχής. Επιπλέον, μελετήθηκε η pH εξαρτώμενη διόγκωση των πολυμερικών ψηκτρών του PDMAEMA. Στην συνέχεια συντέθηκαν επιτυχώς συσταδικές συμπολυμερικές ψήκτρες, γεγονός που αποδεικνύει τον ζωντανό χαρακτήρα των πολυμερισμών. Στις ψήκτρες αυτές πραγματοποιήθηκε μελέτη της ικανότητας διαβροχής σε διάφορους διαλύτες. Στο δεύτερο τμήμα της διατριβής, παρουσιάζεται η σύνθεση και ο χαρακτηρισμός πολυμερικών ψηκτρών σε τραχείες επιφάνειες πυριτίου. Συγκεκριμένα, πολυμερικές ψήκτρες ευαίσθητες σε μεταβολές του pH, αποτελούμενες από επαναλαμβανόμενες μονάδες του μονομερούς μεθακρυλικός 2-(διισοπρόπυλαμινο)αιθυλεστέρας (DPAEMA) αγκυροβολήθηκαν πάνω σε τραχείες επιφάνειες πυριτίου καθιστώντας τις επιφάνειες ικανές να μετατρέπονται αντιστρεπτά από υδρόφιλες σε χαμηλό pH, σε υπέρ-υδρόφοβες σε υψηλό pH. Οι τραχείες επιφάνειες πυριτίου παρουσιάζουν τραχύτητα σε μίκρο- και νάνο- κλίμακα, μορφολογία παρόμοια με αυτή επιφανειών που συναντώνται στην φύση και έχουν την ικανότητα να απομακρύνουν το νερό. Η ικανότητα διαβροχής των επιφανειών, στην υπέρ υδρόφοβη κατάσταση χαρακτηρίστηκε με μετρήσεις στατικής γωνίας επαφής και με μελέτες υστέρησης γωνίας επαφής. Επιπλέον διερευνήθηκε ο συντελεστής απόδοσης της ελαστικότητας της ανάκρουσης σταγόνων νερού από τις υπερυδρόφοβες επιφάνειες συναρτήσει της ταχύτητας πρόσκρουσης. Στο τελευταίο μέρος της εργασίας παρουσιάζεται η άμεση σύνθεση ομοπολυμερικών ψηκτρών υψηλής πυκνότητας σύνδεσης αποτελούμενες από παράγωγα σακχαριτών μεθακρυλικού εστέρα. Συγκεκριμένα, συντέθηκαν ομοπολυμερικες ψήκτρες βασιζόμενες στο μεθακρυλικό (γλυκοαιθυλ)αμίδιο (GAMA), που φέρει μια ομάδα γλυκόζης και στο μεθακρυλικό 2-(λακτοαιθυλ)αμίδιο (LAMA) που φέρει μια ομάδα γαλακτόζης. Σε επιφάνειες χρυσού, πυριτίου/γυαλιού παρασκευάστηκαν πολυμερικά υμένια σακχάρων διαφορετικού πάχους με αλλαγή στις συνθήκες και στον χρόνο πολυμερισμού. Τα πολυμερικά υμένια που συντέθηκαν παρουσιάζουν ισχυρή αλληλεπίδραση δέσμευσης με συγκεκριμένες λεκτίνες γεγονός που επιβεβαιώνεται με μελέτες διέγερσης επιφανειακών πλασμονίων (SPR). Επιπλέον, εξετάστηκε η αλληλεπίδραση ανθρώπινων ηπατικών κυττάρων και κυττάρων του συνδετικού ιστού από ποντίκια με τις γλυκοπολυμερικές ψήκτρες. Τέλος, μελετήθηκε η επίδραση της μοριακής δομής και του πάχους των πολυμερικών υμενίων στην εναπόθεση των κυττάρων.The synthesis of advanced functional materials with well-defined compositions, architectures and functionalities offers a route for tuning the surface properties of materials. Surface-attached polymers became increasingly attractive as reliable means for tailoring the surface properties and their study has received a lot of attention in the last decade. The “grafting from” technique in tandem with controlled surface-initiated polymerizations offers numerous possibilities in designing well-defined grafted polymer layers. This thesis describes the synthesis of polymer brushes on flat substrates by the “grafting from” technique using atom transfer radical polymerization (ATRP). This polymerization is one of the most robust controlled/“living” radical polymerizations used for the synthesis of polymer brushes as it allows the accurate control of the molecular weight or thickness of the brush while maintaining a low polydispersity. The prepared polymer films were characterized by ellipsometry, atomic force microscopy (AFM), attenuated total reflectance (ATR)-FTIR spectroscopy and contact angle measurements. The surface-initiated polymerization of responsive homopolymer and block copolymer brushes on gold substrates is described. Three stimuli-responsive methacrylate monomers were used, namely 2-(dimethylamino)ethyl methacrylate (DMAEMA), hydrophilic and ionizable, 2-(diethylamino)ethyl methacrylate (DEAEMA), hydrophobic and pH-sensitive, tetrahydropyranyl methacrylate (THPMA), a hydrophobic methacrylate ester that can be easily hydrolyzed to methacrylic acid (MAA) which is hydrophilic and ionizable. Grafted polymer films comprising of neutral oligo(ethylene glycol) methacrylate (OEGMA) moieties were also synthesized. The wettability of the prepared films and the pH dependent swelling of the PDMAEMA brushes were studied. The living character of the polymerizations was demonstrated by the successful synthesis of block copolymer brushes. The wetting properties of the block copolymer brushes upon solvent treatment were investigated. pH-responsive polymer brushes comprising of 2-(diisopropylamino)ethyl methacrylate (DPAEMA) monomer repeat units were grafted onto roughened silicon substrates to give surfaces which can reversibly switch between superhydrophilicity at low pH and superhydrophobicity at high pH. The roughened silicon substrates exhibit hierarchical micro- and nano-roughness, which mimics the morphology of natural water repellent surfaces. The water repellency of the prepared surfaces in their superhydrophobic state was characterized by static contact angle measurements and contact angle hysteresis studies. Moreover, the restitution coefficient of water droplets bouncing off the superhydrophobic surfaces as a function of their impact velocity was investigated. The direct synthesis of sugar methacrylate-based homopolymer brushes of high grafting densities based on D-gluconamidoethyl methacrylate (GAMA) carrying a glucose functionality and 2-lactobionamidoethyl methacrylate (LAMA) which possesses a galactose group is presented. Glycopolymer films with various thicknesses were prepared on gold, silicon and glass substrates by varying the reaction conditions and the polymerization time. The synthesized glycopolymer films exhibited strong binding interactions with specific lectins via the “glycocluster” effect as verified by surface plasmon resonance (SPR). The interactions of human hepatocyte and mouse fibroblast cell lines with the glycopolymer brushes were investigated and the influence of the glycopolymer molecular structure and film thickness on the cell deposition was studied

PH-dependent syntheses, structural and spectroscopic characterization, and chemical transformations of aqueous Co(II)-Quinate complexes: An effort to delve into the structural speciation of the binary Co(II)-Quinic acid system

Cobalt(II) is an essential metal ion, which can react with biologically relevant substrates in aqueous media, affording discrete soluble forms. D-( - )-quinic acid is a representative metal ion binder, capable of promoting reactions with Co(II) under pH-specific conditions, leading to the isolation of the new species K[Co(C 7H 11O 6) 3]·3CH 3CH 2OH (1), Na[Co(C 7H 11O 6) 3]·3CH 3CH 2OH·2.25H 2O (2), and [Co(C 7H 11O 6) 2(H 2O) 2]·3H 2O (3). Compounds 1 - 3 were characterized by elemental analysis, spectroscopic techniques (Fourier-transform infrared, UV - visible, electron paramagnetic resonance (EPR), electrospray ionization mass spectrometry), magnetic studies, and X-ray crystallography. Compound 1 crystallizes in the cubic space group P2 13, with a = 15.3148(19) Å, V = 3592.0(8) Å 3, and Z= 4. Compound 2 crystallizes in the orthorhombic space group P2 12 12 1, with a = 14.9414(8) Å, b= 15.9918(9) Å, c= 16.0381(9) Å, V= 3832.1(4) Å 3, and Z= 4. Compound 3 crystallizes in the monoclinic space group P2 1/m, with a = 13.2198(10) Å, b=5.8004(6)Å, c=15.3470(12) Å, β = 108.430(7), V= 1116.45(17) Å 3, and Z= 4. The lattices in 1-3 reveal the presence of mononuclear Co(II) units bound exclusively to quinate (1 and 2) or quinate and water ligands (3), thus projecting the unique chemical reactivity in each investigated system and suggesting that 3 is an intermediate in the synthetic pathway leading to 1 and 2. The octahedral sites of Co(II) are occupied by oxygens, thereby reflecting the nature of interactions between the divalent metal ion and quinic acid. The magnetic and EPR data on 1 and 3 support the presence of a high-spin octahedral Co(II) in an oxygen environment, having a ground state with an effective spin of S= 1/2. The significance of 3 is further reflected into the aqueous speciation of the binary Co(II) - quinic acid system, in which 3 appears as a competent participant linked to the solid state species 1. The physicochemical profiles of 1 -3, in the solid state and in solution, earmark the importance of aqueous structural speciation, which projects chemical reactivity pathways in the binary Co(II) - quinate system, involving soluble Co(II) forms emerging through interactions with low molecular mass O-containing physiological substrates, such as quinic aci