In-Situ Coating of Iron with a Conducting Polymer, Polypyrrole, as a Promise for Corrosion Protection.

Iron microparticles were coated with polypyrrole in situ during the chemical oxidation of pyrrole with ammonium peroxydisulfate in aqueous medium. A series of hybrid organic/inorganic core-shell materials were prepared with 30-76 wt% iron content. Polypyrrole coating was revealed by scanning electron microscopy, and its molecular structure and completeness were proved by FTIR and Raman spectroscopies.

Senataxin RNA/DNA helicase promotes replication restart at co-transcriptional R-loops to prevent MUS81-dependent fork degradation.

Replication forks stalled at co-transcriptional R-loops can be restarted by a mechanism involving fork cleavage-religation cycles mediated by MUS81 endonuclease and DNA ligase IV (LIG4), which presumably relieve the topological barrier generated by the transcription-replication conflict (TRC) and facilitate ELL-dependent reactivation of transcription. Here, we report that the restart of R-loop-stalled replication forks via the MUS81-LIG4-ELL pathway requires senataxin (SETX), a helicase that can unwind RNA:DNA hybrids. We found that SETX promotes replication fork progression by preventing R-loop accumulation during S-phase.

Conducting and Magnetic Hybrid Polypyrrole/Nickel Composites and Their Application in Magnetorheology.

Hybrid organic/inorganic conducting and magnetic composites of core-shell type have been prepared by in-situ coating of nickel microparticles with polypyrrole. Three series of syntheses have been made. In the first, pyrrole was oxidised with ammonium peroxydisulfate in water in the presence of various amounts of nickel and the composites contained up to 83 wt% of this metal.

Carbonized Leather Waste with Deposited Polypyrrole Nanotubes: Conductivity and Dye Adsorption.

This paper reports the conversion of a waste to a conducting material, exploiting the ability to adsorb pollutant organic dyes. Leather waste was carbonized at 800 °C in an inert nitrogen atmosphere. The resulting biochar was used for in-situ deposition of polypyrrole nanotubes produced by the oxidative polymerization of pyrrole in the presence of methyl orange.

Flexible, ultrathin and light films from one-dimensional nanostructures of polypyrrole and cellulose nanofibers for high performance electromagnetic interference shielding.

Combining highly conducting one-dimensional nanostructures of polypyrrole with cellulose nanofibers (CNF) into flexible films with tailored electrical conductivity and mechanical properties presents a promising route towards the development of eco-friendly electromagnetic interference shielding devices. Herein, conducting films with a thickness of 140 μm were synthesized from polypyrrole nanotubes (PPy-NT) and CNF using two approaches, i.e.

Carbonized Leather Waste: A Review and Conductivity Outlook.

The carbonization of collagen-based leather waste to nitrogen-containing carbon is reviewed with respect to the preparation, characterization of carbonized products, and applications proposed in the literature. The resulting nitrogen-containing carbons with fibrous morphology have been used as adsorbents in water pollution treatment, in electrocatalysis, and especially in electrodes of energy-storage devices, such as supercapacitors and batteries. Although electrical conductivity has been implicitly exploited in many cases, the quantitative determination of this parameter has been addressed in the literature only marginally.

The Effect of Glass Fiber Storage Time on the Mechanical Response of Polymer Composite.

The growing demand for polymer composites and their widespread use is inevitably accompanied by the need to know their degradation behavior over a sufficiently long period of time. This study focuses on commercial glass fiber rovings, which were stored in the indoor environment for up to 11 years. Fibers with different storage times, from fresh up to the oldest, were used to produce unidirectional fiber-reinforced polyester composites that were characterized to determine their shear and flexural properties dependent on fiber storage time.

Pressure-Sensitive Conducting and Antibacterial Materials Obtained by Dispersion Coating of Macroporous Melamine Sponges with Polypyrrole.

Melamine sponges were coated with polypyrrole during the polymerization of pyrrole. The precipitation polymerization was compared with the dispersion mode, that is, with the preparation in the presence of poly(-vinylpyrrolidone) and nanosilica as colloidal stabilizers. The coating of sponges during the dispersion polymerization leads to the elimination of the undesired polypyrrole precipitate, improved conductivity, and increased specific surface area.

Simplified Testing of the Bond Strength of Adhesives Used for Bonded Anchors.

The analysis presented in this paper is focused on problems of bond strength as an overall bond quality parameter of industrial adhesives for structural anchoring. In the first part, the problem of bond strength as the most important parameter influencing the final anchor resistance to tension load is described. Further in the text, a new methodology of simplified testing of the strength parameters of adhesives is described.

One-Dimensional Nanostructures of Polypyrrole for Shielding of Electromagnetic Interference in the Microwave Region.

Polypyrrole one-dimensional nanostructures (nanotubes, nanobelts and nanofibers) were prepared using three various dyes (Methyl Orange, Methylene Blue and Eriochrome Black T). Their high electrical conductivity (from 17.1 to 60.

Meniscus transplantation-prospective assessment of clinical results in two, five and ten year follow-up.

Purpose: The authors present clinical results in patients following transplantation of deep-frozen menisci within ten years following the surgery.

Methods: A cohort of 46 patients who were transplanted altogether 49 menisci was subject to prospective study following six months, two, five and ten years after meniscus transplantation. For subjective assessment, we used KOOS, IKDC and Lysholm scores; objective assessment was based on load X-ray examination of the operated knee at two, five and ten years after the surgery, MRI examination of 34 patients in the interval of two and ten years after the operation, control arthroscopy was performed in 23 patients eight of whom suffered a new injury.

Conducting polyaniline prepared in the solutions of formic acid: Does functionalization with carboxyl groups occur?

Polyaniline is a conducting polymer with an application potential in the field of biomedical engineering. By employing FTIR spectroscopy and conductivity measurements, it has been shown that the oxidation at stoichiometric peroxydisulfate-to-aniline mole ratio 1.25 in the solutions of formic acid in the range 0-10 M provides samples of a moderate conductivity of the orders 0.

Role of -Benzoquinone in the Synthesis of a Conducting Polymer, Polyaniline.

Polyaniline (PANI) and 2,5-dianilino--benzoquinone both are formed by oxidation of aniline in an acidic aqueous environment. The aim of this study is to understand the impact of addition of -benzoquinone on the structure of PANI prepared by the oxidation of aniline hydrochloride with ammonium peroxydisulfate and to elucidate the formation of low-molecular-weight byproducts. An increasing yield and size-exclusion chromatography, Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy, and nuclear magnetic resonance analyses of the products show that -benzoquinone does not act as a terminating agent in the synthesis of PANI and the content of 2,5-dianilino--benzoquinone increases with the increasing molar concentration of -benzoquinone in the reaction mixture, [BzQ].

Electrically Conductive, Transparent Polymeric Nanocomposites Modified by 2D TiCT (MXene).

The electrically conductive, transparent, and flexible self-standing thin nanocomposite films based on copolyamide matrix (coPA:Vestamelt X1010) modified with 2D TiCT (MXene) nanosheets were prepared by casting and their electrical, mechanical and optical properties and then, were investigated. The percolation threshold of the MXene filler within the coPA matrix was found to be 0.05 vol.

[Arthroscopic Treatment of Chronic Retrocalcaneal Bursitis - Endoscopic Calcaneoplasty].

INTRODUCTION The authors evaluate the results of endoscopic treatment and analyse the causes of persisting difficulties in retrocalcaneal bursitis unresponsive to conservative treatment. Stated as one of the causes is the possible chronic irritation of minor/partial tears of anterior parts of the distal portion of the Achilles tendon, which have no chance to heal due to continued overload and impingement syndrome of the superior prominence of the calcaneal tubercle. MATERIAL AND METHODS The authors evaluate the group of 24 patients (10 women and 14 men) diagnosed with retrocalcaneal bursitis, who reported more than 12 months of difficulties and in whom the conservative therapy options have already been exhausted.

Polypyrrole Nanotubes and Their Carbonized Analogs: Synthesis, Characterization, Gas Sensing Properties.

Polypyrrole (PPy) in globular form and as nanotubes were prepared by the oxidation of pyrrole with iron(III) chloride in the absence and presence of methyl orange, respectively. They were subsequently converted to nitrogen-containing carbons at 650 °C in an inert atmosphere. The course of carbonization was followed by thermogravimetric analysis and the accompanying changes in molecular structure by Fourier Transform Infrared and Raman spectroscopies.

Solid-state reduction of silver nitrate with polyaniline base leading to conducting materials.

The polyaniline (PANI) base was ball-milled with silver nitrate in the solid state. Samples were prepared at various mole ratios of silver nitrate to PANI constitutional units ranging from 0 to 1.5 for three processing times, 0, 5, and 10 min.

Coating of zinc ferrite particles with a conducting polymer, polyaniline.

Particles of zinc ferrite, ZnOFe2O3, were coated with polyaniline (PANI) phosphate during the in situ polymerization of aniline in an aqueous solution of phosphoric acid. The PANI-ferrite composites were characterized by FTIR spectroscopy. X-ray photoelectron spectroscopy was used to determine the degree of coating with a conducting polymer.

Poly(phenylenediamine) Dispersions.

The formation and properties of poly(phenylenediamine) colloidal dispersions were investigated. Oxidative dispersion polymerization of 1,3-phenylenediamine dihydrochloride stabilized with poly(N-vinylpyrrolidone) was taken as a reference experiment. Conductivity, temperature, and acidity of the reaction mixture were recorded during the polymerization.

[In vitro and in vivo physicochemical study of depot formation of cinchocaine in an atelocollagen matrix].

The paper presents an introductory physicochemical study dealing with the preparation of atelocollagen felt saturated with local anesthetics, with the modelling of the release of the anesthetic from the collagen matrix in vitro, and with the checking of the corresponding analytical procedures (dc-polarography and UV-VIS spectrophotometry) for the determination of cinchocaine. The study is supplemented with experiments in vivo that confirm the usability of the new material for the depot formation of local anesthetics.

[Distribution of 3H-labeled acetyl-HEMA monomer in rats].

Original method of tritiation of acetyl-HEMA and its hydrogenated product was developed. Distribution and excretion of both compounds was examined in rat for up to 70 hrs. While the distribution in the tissues examined (liver, spleen, kidney, lung, muscle, heart, and skin) was nearly uniform, the excretion of acetyl-HEMA and its hydrogenated form differed: acetyl-HEMA in the 24.

Toxicity of monomers HEMA, DEGMA and AEMA, used in synthesis of hydrogels for medical applications.

Acute toxicity parameters (lethal doses) were evaluated and calculated after i.m. and i.

Hormesis in effect of low uranium doses on organisms.

Uranium nitrate applied daily in small amounts per os (0.5-17 mg/l in drinking water) or per cuttim (0.2-0.