Potentiometric sensors with plastized poly(vinyl chloride) membranes selective to penicillin antibiotics: Properties and applications

Potentiometric sensors with plasticized poly(vinyl chloride) membranes based on β-lactam–tetraalkylammonium ion associates sensitive to penicillin antibiotics are proposed. The physicochemical characteristics (solubility product constants and dissociation constants) of active membrane components and the electrode, transport, and selective properties of the membranes of liquidand solid-contact sensors have been studied. The quantitative characteristics of membrane transport (penetrability, ion flux, and transport rate) have been evaluated. The main charge carriers in the membranes and at the membrane/solution interface have been determined from the membrane transport characteristics. The potentiometric sensors are shown to be applicable to the determination of penicillin antibiotics in biological fluids (blood serum and oral fluid) from patients with urinary tract infection.     

Antitubercular activity of lomefloxacin in an experiment

The effect of lomefloxacin was studied on mice with experimental infection due to Mycobacterium tuberculosis. The antibiotic was administered in doses of 100 and 200 mg/kg. It was shown that the use of lomefloxacin for a month provided a lower death rate of the animals with progressing acute generalized tuberculosis, a lower level of the lesions in the internal organs and a lower number of the Mycobacterium isolates from them. The efficacy of the treatment depended on the drug dose. When lomefloxacin was used in a dose of 200 mg/kg, the survival rate was much higher and the number of the epithelial unicellular granulomas in the tissue of the lung and spleen was markedly decreased while with the lower dose the indices did not differ from those in the control.     

Mechanoluminescent pulse pressure sensors. Processing of output optical signal

The process of mechanoluminescence transformation of a pulse pressure sensor is considered. The process consists in excitation of emission under the action of mechanical loading. An algorithm for use in processing the output optical signal of the sensor that makes it possible to determine an input shock pulse is presented. __________ Translated from Izmeritel’naya Tekhnika, No. 10, pp. 28–31, October, 2007.     

Formation and investigation of epoxy intumescent compositions modified by active additives

Results are reported of research on intumescent composites based on epoxy resin cross‐linked with polyethylene polyamine and containing ammonium polyphosphate and such modifying additives as calcium borate, manganese dioxide, nickel, and chromium, containing tubulenes as gas‐formers and carbonization stimulators. The changes in composition and physicochemical properties of modified compositions under conditions of heat and fire were investigated by X‐ray photo‐electron spectroscopy, atomic force microscopy, and local force spectroscopy. Ammonium polyphosphate mainly stimulates carbonization processes on the inner surface of a bubble being formed during foam coke formation. The introduction of metal‐containing tubulenes leads to the formation of fire‐retardant and low flammability‐compositions with high coke and carbon structures content. The use of calcium borate in the compositions considerably increases the strength of foam coke being formed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1477–1483, 2002     

Effect of sulfuric acid treatment on the physicomechanical properties of polyphenyleneoxadiazole fibres

Conclusions By treatment of undried polyphenyleneoxadiazole yarns with concentrated sulfuric acid under isometric conditions, it is possible to raise their strength by 20–30% and their elongation at break 40–50%.The improvement in physicomechanical properties of the yarns which have been treated with acid is caused by a reduction in internal stresses, an improvement in the interlayer packing of the macromolecules fragments, and an increase in the degree of orientation of the macromolecules.Translated from Khimicheskie Volokna, No. 6, pp. 33–35, November–December, 1985.     

Surface behavior of blends of siloxane and siloxane-containing copolymers in poly(vinyl chloride)

X-ray photoelectron spectroscopy is used to reveal surface/bulk compositional relationships in blends of polydimethylsiloxane (PDMS) and PDMS/polycarbonate block copolymers in poly(vinyl chloride) (PVC). It is shown that the surface of PVC can be enriched in siloxane up to 60 at. % PDMS without visible indications of phase separation.     

Human gamma-interferon expression in the mammary gland of transgenic mice

Transgenic mice carrying a hybrid gene consisting of ovine beta-lactoglobulin gene sequences and human gamma-interferon (hIFN-g) cDNA were produced. hIFN-g expression in the mammary gland of two lactating transgenic founder females was found. The concentration of active hIFN-g in the milk was estimated as being ca. 1800 IU/ml. The hIFN-g ability to express in the mammary gland was found in the progeny of transgenic founder male.     

The course and outcome of viral hepatitis B in drug-addicted patients

In this paper, characterization is given of clinical and biochemical features of VH B course against the background of narcomania. Recordable in such patient populations are high percentage of delta hepatitis (14.2%), unusual severity of the intoxication syndrome, protracted course with exacerbations (12.2%) and recurrences (8%), outcome being a chronic hepatitis (14.2%), slower normalization of biochemical indicators, persistently low ratio of AIAT activity in diluted and whole blood sera. The persistence of viral markers in drug addicts discharged from the hospital (68%) is fraught with danger of spreading viral hepatitis of prophylactic measures are not strictly observed.     

First results of ground-based Fourier Transform Infrared measurements of the H2O total column in the atmosphere over West Siberia

The first results of the water vapour total column (WVTC) Fourier Transform Infrared (FTIR) measurements carried out over West Siberia (near Tomsk) in the framework of the combined experiment (22 May 2012) are presented. Direct solar radiation spectra with high spectral resolution were recorded by ground-based FTIR spectrometer Bruker IFS-125M. New spectral intervals (the advantage of this spectral band is that observations could be performed without cooling the interferometer’s detector) were tested and then used to retrieve the H₂O total columns in the atmosphere by SFIT2 v3.92. Ground-based measurements of the WVTC and aerosol optical thickness in the atmosphere were carried out by means of the automated sun photometers (SP series). Sun photometer and FTIR observations were performed under clear-sky conditions. During this study, we compared data obtained from ground-based remote sensing systems to the results of infrared atmospheric sounding interferometer (IASI) MetOP-A satellite measurements and airborne measurements with the use of the Tu-134 aircraft laboratory. Comparison shows that FTIR observations could give reasonable agreements with sun photometer data within 1%. This value is less than the combined error (1.2%) of both techniques. The average values of total H₂O obtained for three measurement systems were as follows: 1.50 and 1.49 g cm^–2 for the Fourier spectrometer and sun photometer, respectively, and 1.84 g cm^–2 for IASI.