Exploring the potential of chitosan from royal shrimp waste for elaboration of chitosan/bioglass biocomposite: Characterization and "in vitro" bioactivity.

Exploiting royal shrimp waste to produce value-added biocomposites offers environmental and therapeutic benefits. This study proposes biocomposites based on chitosan and bioglass, using shrimp waste as the chitosan source. Chitin extraction and chitosan preparation were characterized using various analytical techniques.

Exploring the potential of chitosan/aragonite biocomposite derived from cuttlebone waste: Elaboration, physicochemical properties and in vitro bioactivity.

Cuttlefish bone biowaste is a potential source of a composite matrix based on chitin and aragonite. In the present work, we propose for the first time the elaboration of biocomposites based on chitosan and aragonite through the valorization of bone waste. The composition of the ventral and dorsal surfaces of bone is well studied by ICP-OES.

Single-Molecule Magnet Properties in 34 Heterobimetallic Iron and Dysprosium Complexes Involving Hydrazone Ligand.

The reaction between the (()-'-(2-hydroxy-3-methoxybenzylidene)pyrazine-2-carbohydrazide) (Hopch) ligand and the metallo-precursor [Dy(hfac)]·2HO led to the formation of an homometallic coordination complex with the formula [Dy(hfac)(HO)(Hopch)][Dy(hfac)] (). In presence of both [Dy(hfac)] 2HO and the Fe(II) salt, the heterobimetallic tetranuclear [FeDy(hfac)(HO)(opch)] () was isolated, while the addition of the co-ligand 1,2-Bis(2-hydroxy-3-methoxybenzylidene) hydrazine (Hbmh) led to the formation of two heterobimetallic tetranuclear complexes with the formula [FeDy(hfac)(opch)(Hbmh)] CH () and [FeDy(hfac)(opch)(Hbmh)] 0.5CH () .

Investigation on Akis granulifera (Coleoptera, Sahlberg, 1823) as a potential source of chitin and chitosan: Extraction, characterization and hydrogel formation.

The majority of studies have focused on the industrial exploitation of marine fisheries waste through the production of natural bioactive bioploymeres such as chitin and chitosan. However, in recent years, beetles are increasingly attracting the interest of scientists as a source of chitin and chitosan for the preparation of hydrogels for sustainable engineering development. In the present work, we focus on the study for the first time a new Moroccan species of beetle (Akis granulifera Sahlberg, 1823), for the extraction of chitin and the elaboration of chitosan.

Bulky anion effect on the architecture of chiral dysprosium single-molecule magnets.

The interest for chiral tris(β-diketonato)lanthanide complexes in coordination chemistry is huge due to its Lewis acid character, optical activity, and the control of the final compound architecture. The reaction of equimolar quantities of [Dy((-)/(+)hfc) (H O)] (hfc  = 3-(heptafluoropropylhydroxymethylene)-(+/-)-camphorate) and L led to the formation of a pair of enantiomers for dinuclear complexes [Dy((-)/(+)hfc) (L)] ⋅C H ([(-)/(+)1]⋅C H ) (L = 4'-(4'''-pyridyl-N-oxide)-1,2':6'1''-bis-(pyrazolyl)pyridine]). Starting from the previous experimental protocol with the addition of bulky BArF anions, a partial dissociation of the chiral [Dy((-)/(+)hfc) (H O)] was observed leading to the isolation of a mono-dimensional cationic chiral polymer {[Dy((-)/(+)hfc) (L)][BarF]} ⋅nCH NO ([(-)/(+)2] ⋅nCH NO ).

Modulation of the magnetic and photophysical properties in 3d-4f and 4f-4f' heterobimetallic complexes involving a tetrathiafulvalene-based ligand.

The reaction between the 2-(1-(2,6-di(pyrazol-1-yl)-4-methylpyridyl)-4,5-(4,5-bis(propylthio)-tetrathiafulvalenyl)-1-benzimidazol-2-yl)-pyridine ligand (L), 1 equivalent of Ln(hfac)·2HO/Dy(tta)·2HO (hfac = 1,1,1,5,5,5-hexafluoroacetylacetonate, tta = 2-thenoyltrifluoroacetonate) and M(hfac)·2HO leads to the formation of heteroleptic 3d-4f dinuclear complexes of formula [MLn(hfac)(L)] (M(II) = Cd, Zn, Co, Mn, Ni and Ln(III) = Dy, Yb, Nd) and [ZnDy(tta)(hfac)(L)]·(CHCl). Their X-ray structures reveal that the two coordination sites are occupied by one Ln(III) ion and one M(II) transition metal respectively. The M(II) ions are coordinated to the benzoimidazolylpyridine (bzip) moiety in a NO coordination sphere, while the Ln(III) ions are coordinated to the 2,6-di(pyrazol-1-yl)-4-pyridine (dpp) moiety in a NO surrounding.

Circularly polarized luminescence of Eu(III) complexes with chiral 1,1'-bi-2-naphtol-derived bisphosphate ligands.

The interest for lanthanide circularly polarized luminescence (CPL) has been quickly growing for 10 years. However, very few of these studies have involved correlation between the dissymmetry factor (g ) and the chemical modifications in a series of chiral ligands. Four polymeric compounds of Eu(III) were prepared by using a series of binaphtyl derivatives for which the size of the π system as well as the number of stereogenic elements (i.

Study of the influence of nuclear spin and dilution over the slow relaxation in a 3d4f heterobimetallic single-molecule magnet.

The effects of isotopic enrichment and magnetic dilution have been investigated in a heterobimetallic complex of formula [ZnLDyCl]·2HO (DyZn) (A = 162 and 163) presenting slow relaxation of the magnetization. Isotopic substitution for Dy (I = 0) and Dy (I = 5/2) leads to a shift in the relaxation times depending on the suppression or enhancement of the hyperfine interactions. The release of the dipolar interactions through magnetic dilution in a Y(iii)-based matrix enhances the slow relaxation of the magnetization and the visibility of the nuclear spin effect.

Effect of nanoparticles on spontaneous Ouzo emulsification.

Particles stabilize fluid interfaces. In particular, oil/water Pickering emulsions undergo limited coalescence, yielding droplets of smaller size as the amount of particles is increased. Herein, we studied the effect of hydrophobic nanoparticles (<10 nm, alkyl-coated) on submicronic droplets (ca 100 nm) formed in an Ouzo system.

Formulation and characterization of hydroxyapatite-based composite with enhanced compressive strength and controlled antibiotic release.

A composite based on hydroxyapatite (HA) and chitosan (CS) combined with ciprofloxacin (CIP) was formulated by the solid-liquid mixing method. The optimization of the solid to the liquid ratio and the use of chitosan in a small amount (≤5 wt%) promoted the preparation of stable and rigid monoliths. A synergistic effect of CS and CIP contents on the compressive strength of the CIP-loaded composite was evidenced.

Solid-State Near-Infrared Circularly Polarized Luminescence from Chiral Yb -Single-Molecule Magnet.

A field-induced chiral Yb Single-Molecule Magnet (SMM) displayed an unprecedented near-infrared circularly polarized luminescence (NIR-CPL) in the solid-state. The bridging bis(1,10-phenantro[5,6b])tetrathiafulvalene triad (L) allowed an efficient sensitization of the NIR F → F emission while the NIR-CPL is associated to the f-f transitions of the Yb ion bearing chiral β-diketonate derived-camphorate ancillary ligands.

Development of hybrid scaffold: Bioactive glass nanoparticles/chitosan for tissue engineering applications.

Bone tissue engineering is gaining popularity as an alternative method for the treatment of osseous defects. A number of biodegradable polymers have been explored for tissue engineering purposes. A new family of biodegradable polymer/bioactive glass composite materials has been designed to be used in bone regeneration approaches.

Sub-chronic exposure to Kalach 360 SL, Glyphosate-based Herbicide, induced bone rarefaction in female Wistar rats.

We investigated the effects of Kalach 360 SL (KL), Glyphosate (G)-based herbicide, on bone tissue in different groups of female Wistar rats. Group 1 (n = 6) received a standard diet and served as a control, groups 2 and 3 (n = 6 each) received 0.07 ml (D1: 126 mg/Kg) and 0.

Redox-Modulations of Photophysical and Single-molecule Magnet Properties in Ytterbium Complexes Involving Extended-TTF Triads.

The reaction between the 2,2'-benzene-1,4-diylbis(6-hydroxy-4,7-di--butyl-1,3-benzodithiol-2-ylium-5-olate triad () and the metallo-precursor [Yb(hfac)]2HO led to the formation of a dinuclear coordination complex of formula [Yb(hfac)()]0.5CHCl (). After chemical oxidation of in 2,2'-cyclohexa-2,5-diene-1,4-diylidenebis(4,7-di--butyl-1,3-benzodithiole-5,6-dione (), the latter triad reacted with the [Yb(hfac)]2HO precursor to give the dinuclear complex of formula [Yb(hfac)()] ().

Field-Induced Dysprosium Single-Molecule Magnet Based on a Redox-Active Fused 1,10-Phenanthroline-Tetrathiafulvalene-1,10-Phenanthroline Bridging Triad.

Tetrathiafulvalene and 1,10-phenanthroline moieties present, respectively remarkable redox-active and complexation activities. In this work, we investigated the coordination reaction between the bis(1,10-phenanthro[5,6-b])tetrathiafulvalene triad () and the Dy(hfac)·2HO metallo precursor. The resulting {[Dy(hfac)()]·CHCl·CH} () dinuclear complex showed a crystal structure in which the triad bridged two terminal Dy(hfac) units and the supramolecular co-planar arrangement of the triads is driven by donor-acceptor interactions.

Extreme strontium concentrations reveal specific biomineralization pathways in certain coccolithophores with implications for the Sr/Ca paleoproductivity proxy.

The formation of the coccolith biominerals by a group of marine algae (the Coccolithophores) offers fascinating research avenues both from the biological and geological sides. It is surprising how biomineralisation by a key phytoplanktonic group remains underconstrained, yet is influential on ocean alkalinity and responsible for the built up of our paleoclimatic archive over the last 200 Myrs. Here, we report two close relative coccolith taxa exhibiting substantial bioaccumulation of strontium: Scyphosphaera and Pontosphaera grown in the laboratory or retrieved from Pliocene sediments.

Isotopically enriched polymorphs of dysprosium single molecule magnets.

A triclinic polymorph Dy(t) and a monoclinic polymorph Dy(m) of [Dy(tta)(L)] with L = 4-[6-(1,3-benzothiazol-2-yl)pyridin-3-yl]-4',5'-bis(methylthio)tetrathiafulvene behave as Single-Molecule Magnets with hysteresis loops opened at zero field. Magnetic properties were enhanced through magnetic dilution and Dy isotopic enrichment which definitively support the importance of isotopes for the control of quantum magnets.

Antioxidative/oxidative effects and retarding osteoconductivity of ciprofloxacin-loaded porous polyvinyl alcohol/bioactive glass hybrid.

This study investigated the effect of bioglass (melting)-polyvinyl alcohol (BG (M)-PVA) and bioglass (melting)-polyvinyl alcohol-20 %ciprofloxacin (BG(M)-PVA-20Cip) in improving antioxidant activity and regenerating bone capacity. These composites were implanted in femoral condyles of ovariectomized Wistar rats and compared to that of controls groups. After the different period of implantation (15, 30, 60 and 90 days), the treatment of ovariectomized rats with BG(M)-PVA-20Cip showed a significantly higher malondialdehyde concentration when compared to that of BG(M)-PVA group.

New method of synthesis and in vitro studies of a porous biomaterial.

Biomaterials for bone reconstruction represent a widely studied area. In this paper, a new method of synthesis of a porous glass-ceramic obtained by thermal treatment is presented. The prepared biomaterial was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and induced couple plasma-optical emission spectroscopy (ICP-OES), mercury porosimetry and by the Archimedes method.

Rational Design of a Lanthanide-Based Complex Featuring Different Single-Molecule Magnets.

The rational synthesis of the 2-{1-methylpyridine-N-oxide-4,5-[4,5-bis(propylthio)tetrathiafulvalenyl]-1H-benzimidazol-2-yl}pyridine ligand (L) is described. It led to the tetranuclear complex [Dy4(tta)12(L)2] (Dy-Dy2-Dy) after coordination reaction with the precursor Dy(tta)3⋅2 H2O (tta(-) = 2-thenoyltrifluoroacetonate). The X-ray structure of Dy-Dy2-Dy can be described as two terminal mononuclear units bridged by a central antiferromagnetically coupled dinuclear complex.

Multiple single-molecule magnet behaviors in dysprosium dinuclear complexes involving a multiple functionalized tetrathiafulvalene-based ligand.

The reaction between the 2-(1-(2,6-di(pyrazol-1-yl)-4-methylpyridyl)-4,5-(4,5-bis(propylthio)-tetrathiafulvalenyl)-1H-benzimidazol-2-yl)-pyridine ligand (L) and 2 equiv of Dy(hfac)3·2H2O (hfac(-) = 1,1,1,5,5,5-hexafluoroacetylacetonate) and 1 equiv each of Dy(hfac)3·2H2O and Dy(tta)3·2H2O (tta(-) = 2-thenoyltrifluoroacetonate) metallic precursors leads to two dinuclear complexes, [Dy2(hfac)6(L)]·(CH2Cl2)2·C6H14 (1) and [Dy2(hfac)3(tta)3(L)] (2), respectively. Their X-ray structures reveal that the two coordination sites are occupied by one Dy(III) ion. The Dy(III) ion coordinated to the benzoimidazolylpyridine (bzip) moiety adopts a D4d coordination sphere, while the Dy(III) ion coordinated to the 2,6-di(pyrazol-1-yl)-4-pyridine (dpp) moiety is in a D3h surrounding.