Antimicrobial Activity of Anionic Bis(-Heterocyclic Carbene) Silver Complexes.

The antimicrobial properties of a series of anionic bis(carbene) silver complexes Na[Ag(NHC)] were investigated (- and , where NHC is a 2,2'-(imidazol-2-ylidene)dicarboxylate-type -heterocyclic carbene). The complexes were synthesized by the interaction of imidazolium dicarboxylate compounds with silver oxide in the presence of aqueous sodium hydroxide. Complexes , were characterized analytically and spectroscopically, and the ligand precursor and complexes and were structurally identified by X-ray diffraction methods.

Lateral unicompartmental knee arthroplasty: is really a good option?

Introduction: Lateral unicompartmental knee arthroplasties (LUKA) account for only < 1% of all knee arthroplasties and for only 5-10% of all unicompartmental knee replacements. This means that there is less published literature on these procedures and that the surgeon's experience with them is smaller than with medial UKA. The aim of this study was to analyze the survival and the clinical-functional outcomes of LUKA according to the type of bearing surface (all-polyethylene versus metal-backed) used.

Megaprosthesis use in Paprosky III/IV femoral defects in non-oncological patients: analysis of survival, clinical, and functional outcomes after an average follow-up of five years.

Purpose: To determine the survival and patient-reported outcomes in non-oncological patients treated with proximal femoral resection (PFR) using MEG for femoral reconstruction.

Materials And Methods: This retrospective study included 16 patients. Demographic variables and complications developed were analyzed.

Electroassisted Incorporation of Ferrocene within Sol-Gel Silica Films to Enhance Electron Transfer.

The sol-gel method is a straightforward technique that allows electrode modification with silica thin films. Furthermore, the silica pores could be functionalized to enhance the electrical conductivity and reactivity of the silica films. In this context, silica thin films were functionalized with ferrocene species.

Unicompartmental knee arthroplasties: does the type of tibial component selected influence implant survival?

Introduction: Few information has been published on the survival of unicompartmental knee arthroplasty (UKA) and fixed-bearing tibial components. The aim of this study is to analyze if UKA survival varies according to UKA model used and to analyze the possible risk factors for UKA revision.

Materials And Methods: A retrospective study analyzing 301 UKAs (ACCURIS, all-polyethylene tibial component, 152; Triathlon PKR, metal-backed tibial component, 149) was performed.

Fluorescent Nanocomposite Hydrogels Based on Conjugated Polymer Nanoparticles as Platforms for Alkaline Phosphatase Detection.

This work describes the development and characterization of fluorescent nanocomposite hydrogels, with high swelling and absorption capacity, and prepared using a green protocol. These fluorescent materials are obtained by incorporating, for the first time, polyfluorenes-based nanoparticles with different emission bands-poly[9,9-dioctylfluorenyl-2,7-diyl] (PFO) and poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(1,4-benzo-{2,1,3}-thiadiazole)] (F8BT)-into a three-dimensional polymeric network based on polyacrylamide. To this end, two strategies were explored: incorporation of the nanoparticles during the polymerization process (in situ) and embedment after the hydrogel formation (ex situ).

Disposable Electrochemical Biosensor Based on the Inhibition of Alkaline Phosphatase Encapsulated in Acrylamide Hydrogels.

The present work describes the development of an easy-to-use portable electrochemical biosensor based on alkaline phosphatase (ALP) as a recognition element, which has been immobilized in acrylamide-based hydrogels prepared through a green protocol over disposable screen-printed electrodes. To carry out the electrochemical transduction, an electroinactive substrate (hydroquinone diphosphate) was used in the presence of the enzyme and then it was hydrolyzed to an electroactive species (hydroquinone). The activity of the protein within the matrix was determined voltammetrically.

Chirality influence on the cytotoxic properties of anionic chiral bis(N-heterocyclic carbene)silver complexes.

Complexes Na[Ag(NHC)], 2a-e and 2b'-c', where NHC is a N-heterocyclic carbene of the 2,2'-(1H-2λ,3λ-imidazole-1,3-diyl)dicarboxylate type, were prepared by treatment of compounds HL, 1a-e and 1b'-c' (2-(1-(carboxyalkyl)-1H-imidazol-3-ium-3-yl)carboxylate), with silver oxide in the presence of aqueous sodium hydroxide. They were characterized by analytical, spectroscopic (infrared, IR, H and C nuclear magnetic resonance, NMR, and circular dichroism) and X-ray methods (2a). In the solid state, the anionic part of complex 2a, [Ag(NHC)], shows a linear disposition of C-Ag-C atoms and an eclipsed conformation of the two NHC ligands.

Antimicrobial Properties of Amino-Acid-Derived N-Heterocyclic Carbene Silver Complexes.

Complexes {Ag[NHC]} (R = H, ; Me, and ; Pr, ; Bu, ), were prepared by treatment of imidazolium precursor compounds [Im] (2-(3-mesityl-1-imidazol-3-ium-1-yl)acetate, , ()-2-(3-mesityl-1-imidazol-3-ium-1-yl)acetate, -, and ()-2-methyl(3-mesityl-1-imidazol-3-ium-1-yl)acetate, , with AgO under appropriate conditions. They were characterised by analytical, spectroscopic (IR, H, and C NMR and polarimetry), and X-ray methods (). In the solid state, is a one-dimensional coordination polymer, in which the silver(I) cation is bonded to the carbene ligand and to the carboxylate group of a symmetry-related Ag[NHC] moiety.

Homochiral imidazolium-based dicarboxylate silver(I) compounds: synthesis, characterisation and antimicrobial properties.

Complexes [Ag(L)], 2 (L = 2,2'-(imidazolium-1,3-diyl)di(2-acetate)), were prepared by treatment of compounds HL, 1, with AgO. They were characterised by analytical, spectroscopic (IR, H and C NMR and polarimetry) and X-ray methods (2c, 2c' and 2e). In the solid state, these compounds are novel one-dimensional or two-dimensional coordination polymers in which silver(I) cations are connected the chiral [L] anion with unprecedented coordination modes.

Improving the power performance of urine-fed microbial fuel cells using PEDOT-PSS modified anodes.

The need for improving the energy harvesting from Microbial Fuel Cells (MFCs) has boosted the design of new materials in order to increase the power performance of this technology and facilitate its practical application. According to this approach, in this work different poly(3,4-ethylenedioxythiophene)-polystyrenesulfonate (PEDOT-PSS) modified electrodes have been synthesised and evaluated as anodes in urine-fed MFCs. The electrochemical synthesis of PEDOT-PSS was performed by potentiostatic step experiments from aqueous solution at a fixed potential of 1.

Reactive Insertion of PEDOT-PSS in SWCNT@Silica Composites and its Electrochemical Performance.

Hybrid silica-modified materials were synthesized on glassy carbon (GC) electrodes by electroassisted deposition of sol-gel precursors. Single-wall carbon nanotubes (SWCNTs) were dispersed in a silica matrix (SWCNT@SiO) to enhance the electrochemical performance of an inorganic matrix. The electrochemical behavior of the composite electrodes was tested against the ferrocene redox probe.

Synthesis and structural characterization of homochiral coordination polymers with imidazole-based monocarboxylate ligands.

Chiral Na[(S)-L] (R = Me, 1a; Pr, 1b; CHPr, 1c, and (S)-Bu, 1d) and Na[(R)-L] (R = Me, 1a') compounds were synthesised following standard procedures. New compounds 1d and 1a' were analytically and spectroscopically characterised. 1a and 1c were structurally identified by single-crystal X-ray diffraction methods as homochiral 2D coordination polymers, {Na(HO)[(S)-L]} and {Na[(S)-L]}, respectively.

Affinity of Electrochemically Deposited Sol⁻Gel Silica Films towards Catecholamine Neurotransmitters.

Dopamine, norepinephrine, and epinephrine neurotransmitters can be detected by electrochemical oxidation in conventional electrodes. However, their similar chemical structure and electrochemical behavior makes a difficult selective analysis. In the present work, glassy carbon electrodes have been modified with silica layers, which were prepared by electroassisted deposition of sol⁻gel precursors.

Molybdenum-Catalyzed Enantioselective Sulfoxidation Controlled by a Nonclassical Hydrogen Bond between Coordinated Chiral Imidazolium-Based Dicarboxylate and Peroxido Ligands.

Chiral alkyl aryl sulfoxides were obtained by molybdenum-catalyzed oxidation of alkyl aryl sulfides with hydrogen peroxide as oxidant in mild conditions with high yields and moderate enantioselectivities. The asymmetry is generated by the use of imidazolium-based dicarboxylic compounds, HL. The in-situ-generated catalyst, a mixture of aqueous [Mo(O)(O₂)₂(H₂O)] with HL as chirality inductors, in the presence of [PPh₄]Br, was identified as the anionic binuclear complex [PPh₄]{[Mo(O)(O₂)₂(H₂O)]₂(μ-L)}, according to spectroscopic data and Density Functional Theory (DFT) calculations.

An Electrochemical Study on the Copolymer Formed from Piperazine and Aniline Monomers.

A study on the electrochemical oxidation of piperazine and its electrochemical copolymerization with aniline in acidic medium is presented. It was found that the homopolymerization of piperazine cannot be achieved under electrochemical conditions. A combination of electrochemistry, in situ Fourier transform infrared (FTIR), and ex situ X-ray photoelectron spectroscopy (XPS) spectroscopies was used to characterize both the chemical structure and the redox behavior of an electrochemically synthesized piperazine⁻aniline copolymer.

Oxidoperoxidomolybdenum(vi) complexes with acylpyrazolonate ligands: synthesis, structure and catalytic properties.

Oxidoperoxido-molybdenum(vi) complexes containing acylpyrazolonate ligands were obtained by reaction of [Mo(O)(O)(HO)] with the corresponding acylpyrazolone compounds HQ. Complexes PhP[Mo(O)(O)(Q)] (R = neopentyl, 1; perfluoroethyl, 2; hexyl, 3; phenyl, 4; naphthyl, 5; methyl, 6; cyclohexyl, 7; ethylcyclopentyl, 8) were obtained if the reaction was carried out with one equivalent of HQ in the presence of PhPCl. Alternatively, neutral complexes [Mo(O)(O)(Q)] (R = neopentyl, 9; hexyl, 10; cyclohexyl, 11) were formed when two equivalents of HQ were used in the reaction.

Synthesis and structural characterization of homochiral 2D coordination polymers of zinc and copper with conformationally flexible ditopic imidazolium-based dicarboxylate ligands.

Different novel coordination polymers containing zinc, 1-4, and copper, 5-8, metals, connected via chiral imidazolium-based dicarboxylate ligands, [L], were isolated by reaction between zinc acetate or copper acetate and enantiomerically pure HL compounds. They were characterised and structurally identified by X-ray diffraction methods (single crystal and powder). These compounds are two-dimensional homochiral coordination polymers, [M(L)], in which the metal ions are coordinated by the two carboxylate groups of [L] anions in a general bridging monodentate μ-κ-O,κ-O fashion that afforded tetrahedral metal coordination environments for zinc, 1-4, and square planar for copper, 5-8, complexes.

Enhanced removal of 8-quinolinecarboxylic acid in an activated carbon cloth by electroadsorption in aqueous solution.

The effect of the electrochemical treatment (potentiostatic treatment in a filter-press electrochemical cell) on the adsorption capacity of an activated carbon cloth (ACC) was analyzed in relation with the removal of 8-quinolinecarboxylic acid pollutant from water. The adsorption capacity of an ACC is quantitatively improved in the presence of an electric field (electroadsorption process) reaching values of 96% in comparison to 55% in absence of applied potential. In addition, the cathodic treatment results in higher removal efficiencies than the anodic treatment.

Synthesis, characterization and structure of nickel and copper compounds containing ligands derived from keto-enehydrazines and their catalytic application for aerobic oxidation of alcohols.

Ligand precursors HL(R,Ph) (R = Me, Ph) were synthesised by condensation of acetylacetone and the corresponding N,N-substituted hydrazines and were characterised spectroscopically and structurally. Both in the solid state and in solution they behave as (Z)-keto-enehydrazines and this was confirmed by DFT calculations which showed that this form was the most stable of their possible tautomers. The reaction of HL(R,Ph) compounds with copper acetate and nickel acetate in EtOH afforded the corresponding complexes [M(L(R,Ph))2] (M = Cu, Ni; R = Me, Ph).

Modulation of the silica sol-gel composition for the promotion of direct electron transfer to encapsulated cytochrome c.

The direct electron transfer between indium-tin oxide electrodes (ITO) and cytochrome c encapsulated in different sol-gel silica networks was studied. Cyt c@silica modified electrodes were synthesized by a two-step encapsulation method mixing a phosphate buffer solution with dissolved cytochrome c and a silica sol prepared by the alcohol-free sol-gel route. These modified electrodes were characterized by cyclic voltammetry, UV-vis spectroscopy, and in situ UV-vis spectroelectrochemistry.

Experimental and theoretical insights into the oxodiperoxomolybdenum-catalysed sulphide oxidation using hydrogen peroxide in ionic liquids.

The oxidation of organic sulphides with aqueous hydrogen peroxide in ionic liquids (ILs) catalysed by oxodiperoxomolybdenum complexes was investigated. The selective formation of several sulfones was achieved using the 1 : 3 ratio of sulphide : H2O2 in [C4mim][PF6] (C4mim = 1-butyl-3-methylimidazolium) in a reaction catalysed by the [Mo(O)(O2)2(H2O)n] complex. Conversely, sulfoxides were produced with good selectivities using a 1 : 1 ratio in the same solvent in a 1 h reaction with [Mo(O)(O2)2(Mepz)2] (Mepz = methylpyrazol).

Interaction between monomers of two surfactants derived from the [Ru(2,2'-bpy)(3)](2+) complex and α, β and γ-cyclodextrins: formation of [2]- and [3]-pseudorotaxanes.

Two new surfactants derived from the tris(2,2'-bipyridine) ruthenium(II) complex, [Ru(2,2'-bpy)(3)](2+), were synthesized and characterized: the double-tailed [Ru(2,2'-bipy)2(4,4'-(C(11)H(23))(2)-2,2'-bipy)](2+) surfactant (RuC11) and the mono-tailed [Ru(2,2'-bipy)(2)(4-(CH(3))-4'-(C(13)H(27))-2,2'-bipy)](2+) surfactant (RuC13). The main characteristic of these species is the presence of an inorganic complex as the polar head of the surfactant with interesting luminescence properties, which were used to study the interaction of these cationic surfactants with α-, β- and γ-cyclodextrins (CD). The results showed the formation of [2]- and [3]-pseudorotaxanes.