Potential cancerostatic benfluron is metabolized by peroxidase: in vitro biotransformation of benfluron by horseradish peroxidase

Monocyte chemoattractant protein-1 (MCP-1) is a member of the chemokine family of cytokines. The principal function of MCP-1 is thought to be the stimulation of monocyte recruitment. Monocyte products are potential regulators of bone cell activity. Growth factors produced by monocytes may stimulate bone formation, while cytokines such as IL-1 and IL-6 can induce bone resorption. To determine whether MCP-1 enhances recruitment of monocytes during bone healing, studies were carried out in which MCP-1 was applied to osseous sites in vivo. Changes in monocyte number were determined by immunohistochemistry using the antibody ED-1 specific for peripheral monocytic cells. The effect of MCP-1 on osteoblast number was determined by counting the number of alkaline phosphatase positive cells in close proximity to bone. For comparison, osteoblast number was also determined following stimulation with platelet-derived growth factor (PDGF)-BB plus IGF-1 in vivo. Results indicate that MCP-1 stimulated a large increase in monocyte recruitment compared to vehicle alone. An increase in monocytes induced by MCP-1 was associated with an increase in the number of osteoblasts lining the bone surface, although not to the same magnitude as a positive control, PDGF-BB, and IGF-1. These results indicate that MCP-1 induces the recruitment of monocytes to bone and suggest that the recruitment is associated with an increase in osteoblast number. This is likely to occur via indirect mechanisms, because MCP-1 did not directly enhance DNA synthesis in osteoblastic cells in vitro. Thus, activated mononuclear phagocytes may play an important role in osseous wound healing by stimulating proliferation of osteoblastic cells, presumably through the elaboration of growth factors.     

Radiofrequency catheter ablation of supraventricular tachycardia in an adult with corrected tetralogy of Fallot

An 18 year old female with Fallot's tetralogy had undergone complete repair at thirteen years of age. Two years later she first presented a wide complex right bundle branch block tachycardia at a rate of 220 beats/min which could not be controlled on intravenous verapamil. Electrical shock successfully converted tachycardia to sinus rhythm, which showed typical Wolff-Parkinson-White syndrome. On electrophysiological study, the ortodromic tachycardia was found to be due to left lateral atrioventricular accessory pathway, which was ablated by radiofrequency catheter ablation. One year later she was symptom-free without antiarrhythmic medication.     

Synthesis and electrocatalytic activity of platinum nanoparticle/carbon nanotube composites

Pt/CNT nanocomposite materials with an average platinum particle size of 3–5 nm and platinum content of 13–28 wt % have been prepared by reducing chloroplatinic acid, H₂PtCl₆, in the presence of conical carbon nanotubes. The effect of synthesis conditions on the average platinum particle size, total platinum content, and surface composition of the nanocomposites has been studied using X-ray photoelectron spectroscopy, IR spectroscopy, electron microscopy, X-ray diffraction, and thermogravimetry. The materials have been tested as catalysts for hydrogen oxidation and oxygen reduction. Their performance has been assessed by cyclic and steady-state voltammetric techniques. The structure and composition effects on the electrocatalytic properties of the nanocomposites are discussed.     

Determination of Neomycin in Aquatic Products Using an Immunoaffinity Column Coupled to High-Performance Liquid Chromatography

Neomycin is widely used in veterinary medicine, while the confirmatory analysis of neomycin residues in aquatic samples has not been well identified. Here, in this study, an immunoaffinity chromatography (IAC) for determination of neomycin residues in aquatic sample was developed and optimized. The average maximum reserved content of neomycin (MRC) was calculated as 1611 ng, and by the simple regeneration with phosphate buffer saline, the recovery value maintained above 75 % even at the 32nd reusage (at the loading amount of 1200 ng). With the combination of IAC and high-performance liquid chromatography (HPLC), a new strategy for the analysis of neomycin was proposed and validated with different aquatic products. With the spiking concentration from 400 to 1200 ng/Kg, the recovery value was observed in the range of 75.58–117.80 %, and the CV was lower than 11 %. All these results suggested that the IAC-HPLC is a new and promising technique for the routine monitoring of neomycin residue in aquatic products.     

Features of the Preparation and Study of Electrophysical Characteristics (BeO+TiO2)-Ceramics by Impedance Spectroscopy

Refractories and Industrial Ceramics - An electrically conducting two-component BeO-ceramic with the addition of micro- and nano-crystalline TiO2 powder is prepared that can be used as a material...     

Refractory Materials Based on Secondary Resources and Phosphate Compounds

Refractories and Industrial Ceramics - Results are provided for refractory materials developed on basis of both secondary resources (broken chamotte refractory, mullite-containing waste, and...     

Phase Formation in the Synthesis of Ti2AlN by Spark Plasma Sintering in the Ti/AlN System

Refractories and Industrial Ceramics - The synthesis of a Ti2AlN-based material by mechanical activation (MA) of a Ti–AlN powder mixture in a planetary ball mill followed by vacuum spark...     

Evaluation of the Crack Resistance of Reactive Sintered Composite Boron Carbide-Based Materials

Refractories and Industrial Ceramics - The results of studying the crack resistance of reaction-sintered B4C–SiC composite materials impregnated with liquid silicon with identification and...     

Physicochemical Transformations During Low-Temperature Synthesis of Zirconium Carbide

Refractories and Industrial Ceramics - Joint reduction of zirconium dioxide and sodium carbonate to form zirconium carbide was studied. Magnesiothermic reduction of ZrO2 was shown to occur at 600...