Electroplasma coatings based on silicon-containing hydroxyapatite: Technology and properties

IR analysis and the plasma deposition of silicon-containing hydroxyapatite powder have been carried out. It has been shown that the coating exhibits developed morphology and consists of molten powder (including nanosize) particles uniformly distributed over the entire surface. The adhesion characteristics have been calculated and scanning electron microscope images of the resultant coating have been analyzed.     

Temperature–Frequency Dependence of the Dielectric Response in LuFe2O4 Multiferroics

Physics of the Solid State - The temperature–frequency spectra of the complex dielectric permittivity of the LuFe2O4 multiferroics have been studied in the temperature range 100–400 K...     

Solvability of the problem of taking the discrete logarithm

It is proved that consideration of the solvability problem for taking the discrete logarithm in a residue ring modulo composite M can be reduced to consideration of a similar problem in residue rings modulo pq, where p and q are prime divisors of M. For moduli of form pq, necessary and sufficient conditions for solvability checking are obtained in some cases. In addition, the problem of raising a solution of an exponential comparison in a residue ring modulo p ^α is solved.     

In Vivo Justification of Using Endobiliary Stents Made of Polyhydroxyalkanoates

Treatment of patients with mechanical jaundice (MJ) has been one of the topical problems of current medicine. The fraction of patients having MJ of oncologic character that can undergo radical surgery does not exceed 25–30%. A way out of such situation is to use minimally invasive endobiliary interventions, the main type of which is endoprosthesis replacement of bile duct lumens. The aim of the work was to study the biological properties of the experimental models of polymer stents made of PHA for endobiliary prosthetics and to investigate the biological properties of PHA suture material for forming of biliary-enteric anastomoses (cholecystoduodenostomy). Experiments were performed on 20 adult mongrel dogs, weighing 10–12 kg. The animals were divided to three groups: the negative control group (intact animals); the positive control group (the animals with implanted endobiliary silicon stents); and the experimental group (the animals with the PHA stents). The animals were monitored for 100 days. The clinical blood analysis was made before the operation, on day 7, 30, 60 and 100 days. During autopsy the presence of exudate, commissural process in the free abdominal cavity and subhepatic spatium, the appearance of choledoch where the prosthesis was located, as well as the appearance of cholecystoenterostomy, liver and duodenum. We did not found any signs of inflammation, cicatrical changes were estimated in the free abdominal cavity and subhepatic spatium. All implanted PHA stents were at their initial places of implantation. After the end of the experiment inflammatory reaction and anastomositis were absent. Macroscopic changes of liver and duodenum were also not detected. Liver function did not have any pathological deviations. These positive results give grounds to conclude that application of PHA as endobiliary stents in reconstructive surgery of bile passages and as suture material is a promising technology.     

Extraction of the 131Cs from neutron irradiated barium oxide under microwave radiation

In this work, the solubility dependence of radioactive baric samples under influence of microwave radiation (MWR) has been investigated at various concentrations of HCl after irradiation of BaO target at a flux of thermal neutrons. It is established that the use of MWR for dissolution of a sparingly-soluble barium oxide will accelerate a dissolution process at almost an order of magnitude in comparison with usual heating. Each time after separation of the ¹³¹Cs from radioactive barium solution analyses on radionuclide purity of the ¹³¹Cs product solutions were carried out.     

Synthesis and van Alphen–Hüttel rearrangement of substituted 3<Emphasis Type="Italic">H</Emphasis>-pyrazoles,adducts of 1,3-dipolar cycloaddition of 9-diazofluorene and diphenyldiazomethane to trimethyl(tosylethynyl)silane

Trimethyl(tosylethynyl)silane reacted in ethyl ether at 20°С with diphenyldiazomethane affording 3Н-pyrazole, a product of 1,3-dipolar cycloaddition against Auwers rule. The reaction with 9-diazofluorene is less selective, but its regioselectivity is also governed by the steric effect of the bulky trimethylsilyl substituent at the triple bond С≡С. The adduct with diphenyldiazomethane at boiling in methanol or keeping in glacial acetic acid in the presence of a catalytic quantity of conc. H₂SO₄ undergoes the Van Alphen–Hüttel rearrangement by the migration of the phenyl substituent to the atom N² in the 1Н-pyrazole. The same 1Н-pyrazole together with a product of nitrogen elimination, trimethylsilyl substituted cyclopropane, is formed in the 2: 1 ratio at boiling in benzene. A similar behavior is observed in the glacial acetic acid for the anti-Auwers adduct of 9-diazofluorene. It suffers nitrogen elimination at boiling in benzene converting in spirocyclic cyclopropene. The Auwers adduct of 9-diazofluorene at boiling in methanol transforms due to the van Alphen–Hüttel rearrangement into the corresponding 4Н-pyrazole that undergoes a hydrodesilylation to give a derivative of 1Н-pyrazole, 3-tosyl-1(2)H-dibenzo[e,g]indazole.     

Exploring Peptaibol’s Profile,Antifungal, and Antitumor Activity of Emericellipsin A of Emericellopsis Species from Soda and Saline Soils

Features of the biochemical adaptations of alkaliphilic fungi to exist in extreme environments could promote the production of active antibiotic compounds with the potential to control microorganisms, causing infections associated with health care. Thirty-eight alkaliphilic and alkalitolerant Emericellopsis strains (E. alkalina, E. cf. maritima, E. cf. terricola, Emericellopsis sp.) isolated from different saline soda soils and belonging to marine, terrestrial, and soda soil ecological clades were investigated for emericellipsin A (EmiA) biosynthesis, an antifungal peptaibol previously described for Emericellopsis alkalina. The analysis of the Emericellopsis sp. strains belonging to marine and terrestrial clades from chloride soils revealed another novel form with a mass of 1032.7 Da, defined by MALDI-TOF Ms/Ms spectrometers, as the EmiA lacked a hydroxyl (dEmiA). EmiA displayed strong inhibitory effects on cell proliferation and viability of HCT 116 cells in a dose- and time-dependent manners and induced apoptosis.