Efficient Sensitized Luminescence of Binuclear Ln(III) Complexes Based on a Chelating Bis-Carbacylamidophosphate.

Binuclear rare earth complexes Ln2L3phen2 (LnIII = NdIII, SmIII, EuIII, TbIII, DyIII, YbIII and YIII) with bis-CAPh type ligand - tetramethyl N,N'-(2,2,3,3,4,4-hexafluoro-1,5-dioxopentane-1,5-diyl)bis(phosphoramidate) (H2L) and 1,10-phenanthroline (phen) were synthesized and characterized by elemental analysis, IR, NMR, absorption and luminescence spectroscopy. Luminescence measurements were performed for all the complexes in solid state and for the EuIII, TbIII and YIII complexes - in solution in DMSO as well. The effective energy transfer from organic ligands to LnIII ions strongly sensitizes the LnIII ions emission and under excitation by UV light, the complexes exhibited bright characteristic emission of lanthanide metal centers. It was found that the energy level of the ligands lowest triplet state in the complexes matches better to resonance level of EuIII rather than TbIII ion. Depending on temperature the emission decay times of solid europium and terbium complexes were in the range of 1.5-2.0 ms. In solid state at room temperature the EuIII complex possess intense luminescence with very high intrinsic quantum yield 91% and decay time equal 1.88 ms.

[Persistence of antibodies specific to West Nile virus in blood of reconvalescents of Volgograd region].

AIM: Determine the duration of persistence of IgM and IgG in reconvalescents of West Nile fever (WNF) 1 year after the disease in southern regions of Russia and evaluate effectiveness of PCR method for acute infection diagnostics. MATERIALS AND METHODS: Blood sera of 87 patients with WNF diagnosis was studied for the presence of West Nile virus (WNV) RNA and IgM and IgG by PCR and EIA. Samples of the first sera were collected in 2010 at days 2 - 30 after the onset of the disease, samples of the second sera--at days 5 - 23 and third--264 - 385 days later. RESULTS: During the first 2 weeks of the disease WNV RNA was detected in more than 50% of patients. In all the first sera IgM at titers of ≥ 1:800 were detected. Seroconversion of IgG titers of 4 and more times was observedin 83% (30/36) of patients. In 2011 IgG were detected in 91% of reconvalescents (79/87), IgM--in 57% (50/87), and in 25% (22/87) IgM titers were ≥ 1:800. CONCLUSION: The results obtained give evidence on the necessity of using several diagnostic criteria simultaneously for the confirmation of WNF clinical diagnosis.

[Comparative assessment of educational conditions in various secondary educational institutions in Samara].

The educational medium in varying secondary educational establishments of Samara was comparatively analyzed in accordance with the sanitary regulations SanPiN 2.4.2.1178-02 "Hygienic requirements for teaching conditions in general educational establishments". The study demonstrated that the teaching conditions at schools primarily required that school load be rationalized and the ergonomic parameters offurniture and artificial illumination improved.

[Specific antibodies in convalescents after West Nile fever]. / Pokazateli spetsificheskikh antitel u rekonvalestsentov, perenesshikh likhoradku Zapadnogo Nila.

Blood serum samples were obtained from patients with West Nile fever (WNF) from the city of Volgograd and its region within the disease weeks 1-3 (July-October 1999), month 6-7 (May_June 2000) and month 12-18 (May-June 2001) after the disease onset. In the sera of 40 patients examined 6-7 months after the disease onset IgM-antibodies to WNF virus were absent (dilution 1:50), IgG ones were detected in 35 patients (87.5%). 18 months after the disease IgG-antibodies were identified in 23 of 26 convalescents (88.5%). The serum samples obtained in autumn 1999 and May-June 2000 contained antihemagglutinins to WNF virus for 6-7 months in all 18 patients. In May-June 2000 the sera were positive in 38 convalescents who had WNF in 1999.

[Isolation of the West Nile Fever virus from human patients during an epidemic outbreak in the Volgograd and Astrakhan regions]. / Vydelenie virusa likhoradki Zapadnogo Nila ot bol'nykh liudei v periodépidemicheskoi vspyshki v Volgogradskoi i Astrakhanskoi oblastiakh.

Two strains of West Nile virus LEIV 27889 Vig and Ast 986 were isolated from the brain of a dead subject and from the blood of a patient, respectively, during an outbreak of serous meningitis and meningoencephalitis in July-September, 1999, in the Volgograd region, Krasnodar territory, and Astrakhan region. These strains reacted with convalescent sera in hemagglutination inhibition test, which proves their etiological role in this outbreak.

Spectrofluorimetric determination of anthranilic acid derivatives based on terbium sensitized fluorescence.

Terbium sensitized fluorescence was used to develop a sensitive and simple spectrofluorimetric method for the determination of the anthranilic acid derivatives furosemide and mefenamic and tolfenamic acids. The method makes use of radiative energy transfer from anthranilates to terbium ions in alkaline methanolic solutions. Optimum conditions for the formation of the anthranilate-Tb3+ complexes were investigated. Under optimized conditions, the detection limits are 6 x 10(-9), 1.4 x 10(-8) and 9.0 x 10(-9) mol l-1 for furosemide, mefenamic acids and tolfenamic acid, respectively. The range of application is 2.5 x 10(-8)-5.0 x 10(-5) mol l-1 for all three drugs. The method was successfully applied to the determination of furosemide and mefenamic and tolfenamic acids in serum after extraction of the samples with ethyl acetate, evaporation of the organic layer under a stream of nitrogen at 40 degrees C and reconstitution of the residue with alkaline methanolic terbium solution prior to instrumental measurement. The mean recoveries from serum samples spiked with furosemide (5.0 x 10(-7), 2.0 x 10(-6) and 8.0 x 10(-6) mol l-1), mefenamic acid (3.0 x 10(-6), 9.0 x 10(-6) and 3.0 x 10(-5) mol l-1) and tolfenamic acid (3.1 x 10(-6), 12.5 x 10(-6) and 2.5 x 10(-5) mol l-1) were 96 +/- 8, 101 +/- 5 and 98 +/- 7%, respectively. The within-run precision (RSD) for the method for two serum samples of each drug varied from 2 to 8% and the day-to-day precision for two concentration levels varied from 2 to 13%.

[Biochemical markers of atherogenesis in a nephrotic form of glomerulonephritis in children]. / Biochimicheskie markery aterogeneza pri nefroticheskoi forme glomerulonefrita u detei.

A study was made of the regularities and changes in the fatty acid spectrum of total lipids of the blood serum, in interaction of carbohydrate lipid metabolism, and in the hypophyseal and thyroid system in 92 patients with the nephrotic form of acute and chronic glomerulonephritis. It has been discovered that the nephrotic form of glomerulonephritis is marked by a complex of changes in the fatty acid spectrum of the blood serum, in carbohydrate lipid metabolism at the sites of their conjunction, and in the hypophyseal and thyroid system which can be regarded as metabolic potentialities of atherosclerosis formation.