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Direct reactions between CuI and isonicotinic acid (HIN) or the corresponding esters, ethyl isonicotinate (EtIN) or methyl isonicotinate (MeIN), give rise to the formation of the coordination polymers [CuI(L)]n with L=EtIN (1), MeIN (2) and HIN (3). Polymers 1-3 show similar structures based on a CuI double chain in which ethyl-, methyl isonicotinate or isonicotinic acid are coordinated as terminal ligands. Albeit, their supramolecular architecture differs considerably, affecting the distances and angles of the central CuI double chains and thereby their physical properties. Hence, the photoluminescence shows remarkable differences; 1 and 2 show a strong yellow emission, whereas 3 displays a weak emission; and 1 and 2 are semiconductors with moderate room temperature conductivities, whereas 3 has increased electrical conductivity up to 3×10(-3)  S cm(-1) . Additionally, 1 and 2 present an irreversible transition to a highly conducting phase with a conductivity almost 4 orders of magnitude higher and a quasi-metallic behaviour. Thermogravimetric analysis (TGA) coupled to a mass spectrometer and magnetic measurements point to a partial thermally induced oxidation of the carboxylate groups of the ligands with Cu(I) to Cu(0) reduction. DFT calculations have been carried out to rationalise these observations.

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This study aimed to describe the inhibitory activity of cell-free supernatants (CFS) of lactobacilli against extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae (K pneumoniae) and Pseudomonas aeruginosa (P aeruginosa). Material and Methods: Pathogenic clinical strains of K pneumoniae and P aeruginosa were isolated from urine samples and selected for investigation. Anti-bacterial activities of the CFS of lactobacilli were assessed by agar well diffusion, MTT assay, as well as time-kill tests. In addition, the antibiofilm characteristics were analyzed by the microplate method against fresh and 24 hold biofilms. The ability of CFS to interfere with bacterial invasion was analyzed by flow cytometry. Results: Although all tested strains were ESBL producers and showed a multidrug-resistant phenotype, the CFS displayed a high anti-ESBL activity with inhibition zone diameters greater than 13 mm in the agar well diffusion assays against both pathogens. The growth kinetics of K pneumoniae and P aeruginosa were dramatically decreased in the presence of the CFS. The CFS not only inhibited the biofilm formation by these pathogens but also was able to remove the 24-h formed biofilms. The invasion abilities of FITC-labelled K pneumoniae decreased from 30.3%±7 to 15.4%±5 and invasion of FITC-labelled P aeruginosa was reduced from 36.9%±7 to 25.2%±5. Conclusion: CFS of lactobacilli exhibit anti-ESBL activities, which suggests its potential application for controlling or preventing colonization of infections caused by ESBL-producing bacteria.

We present a structurally flexible copper-iodide-pyridine-based coordination polymer showing drastic variations in its electrical conductivity driven by temperature and sorption of acetic acid molecules. The dramatic effect on the electrical conductivity enables the fabrication of a simple and robust device for gas detection. X-ray diffraction studies and DFT calculations allow the rationalisation of these observations.In recent years, coordination polymers (CPs) have gained increasing attention due to their wide structural variety and interesting physico-chemical properties. 1 They are a potential source of multifunctional materials that can bring remarkable physical properties such as luminescence, 2 non-linear optics, 3 magnetism 4 and electrical conductivity. 5 CPs have the ability to produce dynamic structures due to the structural flexibility of the ligands and/or the ability of the coordination sites to exchange, release and/or re-accommodate molecules, rendering CPs as a source of stimuli-responsive materials. 6 These dynamic materials show potential applications as chemical switches, memories or molecular sensors.A limited number of CPs have shown spin-crossover transitions modulated or induced by a chemical stimulus such as gas or solvent sorption in the pores 7-11 and magnetic, physically-driven solid-state transformation. 12,13 Stimuli-responsive electrical materials, mainly centred on organic conductive polymers, 14 are currently of high interest. A recent example of a thin-film device based on the porous coordination polymer Cu 3 (BTC) 2 (BTC = benzene-1,3,5-tricarboxylic acid) has shown an electrical response to 7,7,8,8-tetracyanoquinododimethane (TCNQ) guest molecules. 15 Quasi-linear physical properties have also been reported for MX and MMX chains (M = transition metal, X = halide), some of them showing thermal Peierls transitions that affect their magnetic properties 16 and/or their electrical conductivity. 17 Additionally, we have reported that some double-stranded Cu-halide stairs present interesting physical properties. 18 Here we disclose two 1D-CP polymorphs of Cu(I) with iodide as bridging ligands and 2-amino-5-nitropyridine (C 5 H 5 N 3 O 2 , ANP) as terminal ligands. These polymorphs show very flexible structures that enable a reversible physically-driven electrical conductive transition with electrical bi-stability close to room temperature and a chemicallydriven transition that induces a dramatic enhancement of the electrical conductivity, allowing the fabrication of a simple and robust gas-detection device.The direct reactions carried out between CuI and ANP at 25 1C or under solvothermal conditions lead to the isolation of [Cu(C 5 H 5 N 3 O 2 )I] n (1) and its polymorph 1a, respectively. 1a is isostructural to the Br derivative, also prepared under solvothermal conditions. 19 Both polymorphs show a double-stranded stair motif in which the Cu(I) centres are bridged by m 3 -I. Since the electrical properties (see below) of compound 1 indicate a phase transition at ca. 267-282 K, we h...

Development and characterization of thermosensitive pluronic-based metronidazolein situgelling formulations for vaginal applicationThe purpose of this study was to develop pluronic-basedin situgelling formulations of metronidazole (MTZ) for treatment of bacterial vaginosis, aimed at prolonging the residence time, controlling drug release, enhancing efficacy, decreasing recurrence, and increasing patient compliance. Thein situgel formulations were prepared using different concentrations of pluronic F-127 (PF-127) alone and in combination with pluronic F-68 (PF-68). The prepared formulations were evaluated for their gelation temperature (Tgel),in vitrodrug release, rheological properties, mucoadhesion properties and tolerability by vaginal mucosa in tissue levels. TheTgeldecreased with increasing PF-127 concentration. TheTgelwas modulated by addition of PF-68 to be within the acceptable range of 25-37 °C. With increasing pluronic concentration, thein vitrodrug release decreased, viscosity and mucoadhesive force increased. Histopathological examination of rabbit vaginas from the control and treated groups revealed normal histology of the vagina and cervix. Based on thein vitroevaluation of prepared formulations, thein situgelling liquid formulated with PF-127/PF-68 (20/10 %,m/m) was selected for further clinical evaluation.

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