Identification of main contributions to conductivity of epitaxial InN

Complex effect of different contributions (spontaneously formed In nanoparticles, near-interface, surface and bulk layers) on electrophysical properties of InN epitaxial films is studied. Transport parameters of the surface layer are determined from the Shubnikov-de Haas oscillations measured in undoped and Mg-doped InN films at magnetic fields up to 63 T. It is shown that the In nanoparticles, near-interface and bulk layers play the dominant role in the electrical conductivity of InN, while influence of the surface layer is pronounced only in the compensated low-mobility InN:Mg films

The balance of elements in the system “Luvic Chernozems – agricultural plants” on the Plavsk upland (Tula region of Russia)

To assess the transfer of macro (K, P, S, Mg, Ca, as well as Si, Na, Fe, Al, Mn and Ti) and microelements (Zn, Ba, Cu, Sr, Mo, as well as As, Zr, Pb, Co, Ni, V and Cr) from Luvic Chernozems (Aric, Loamic, Pachic) into agricultural plants, we studied the inventories of chemical elements in three agrocenoses (wheat, soybean, Galega orientalis Lam. and Bromopsis inermis Leyss grass mixtures) from the Plavsk upland (Tula Region). This territory is subjected to intensive industrial and agricultural impacts: it is 40 km away from the town of Shchekino with a nitrogen fertilizer plant and a thermal power plant, 60 km away from Tula with large metallurgical enterprises, 70 km away from the town of Novomoskovsk with several chemical enterprises and state district power plant. In soils, the total content of elements was determined by the X-ray fluorescence spectrometry. The elemental composition of plants after autoclave decomposition with a mixture of concentrated nitric acid and hydrogen peroxide and the content of the bioavailable fraction (extracted by an ammonium acetate buffer with pH 4.8) of elements in soil were estimated by the atomic emission spectrometry with inductively coupled plasma. In topsoil (a 10-cm layer), maximal inventories are typical for total Si (40 ± 4 kg/m2), Al (7.0 ± 0.8 kg/m2) and Fe (3.4 ± 0.3 kg/m2) and for bioavailable Ca (570 ± 48 g/m2), Mg (43 ± 4 g/m2), K (22 ± 6 g/m2). In plants, the main inventories (g/m2) of K, P, S, Mg, Si, Mn, Zn, Ba, Cu, Mo occur in the above ground phytomass. The most effectively plants assimilate bioavailable fractions of K, P, Ti, Mo, As, Zr, V. Based on the resource method for soil quality assessment, the studied Chernozems are characterized by a low level of Ni contamination, a moderate supply of bioavailable K with a lack of bioavailable P

Pulsations and Long-Term Light Variability of Three Candidates to Protoplanetary Nebulae

We present new photometric data and analysis of the long-duration UBV photoelectric observations for three candidates to protoplanetary objects - F-supergiants with IR-excesses located at large galactic latitudes, IRAS 18095+2704, IRAS 19386+0155, and IRAS 19500-1709. All three stars have revealed quasiperiodic low-amplitude variabilities caused by pulsations observed against the long-term trends of brightnesses. For IRAS 18095+2704=V887 Her we have found a pulsation period of 109 days and a linear trend of brightness under the constant colours if being averaged over the year timescale. The light curve of IRAS 19386+0155=V1648 Aql over 2000-2008 can be approximated by a wave with a main period of 102 days which is modulated by close frequency, with a period of 98 days, that results in brightness oscillations with a variable amplitude. V1648 Aql has also shown synchronous reddening together with a persistent rise of brightness in the V-band. IRAS 19500-1709=V5112 Sgr experiences irregular pulsations with the periods of 39 and 47 days. The long-term component of the variability of V5112 Sgr may be related to the binary character of this star.Comment: 11 pages, 6 figures, accepted for publication in Pis'ma Astron. Z

Spectrum of mutations and their phenotypic manifestations in children and adults with long QT syndrome

Aim. To determine the spectrum of mutations in the genes responsible for the long QT syndrome (LQTS) and study their phenotypic manifestations in patients with LQTS in different age groups.Materials and methods. The study included 35 unrelated probands with a clinical diagnosis of LQTS: 23 adults (8 men) and 12 children (9 boys). There were following clinical features: syncope — 54%, positive family history for SCD — 29%, implanted cardioverter defibrillator (ICD) — 46%. All participants underwent 12-lead electrocardiography (ECG), 24-hour Holter monitoring, genealogical analysis, echocardiography and cardiac MRI. The genetic study was performed by nextgeneration sequencing (NGS) using the MiSeq system (Illumina). The quantitative comparison of two unrelated groups was carried out using the nonparametric MannWhitney U-test. The differences were considered significant at p<0,05.Results. In the examined group of 35 probands, 23 genetic variants of pathogenicity class IV and V (hereinafter referred to as) were identified. The molecular genetic variant of the disease was verified in 66% of probands. At the same time, the detection of mutations in the group with early manifestation (children) was significantly higher: 83% (10 out of 12 children) vs 57% in adults (13 out of 23). Rare genetic variants of uncertain significance (VUS, class III pathogenicity) were detected in 4 probands (11%). In the groups of children and adults with LQT1, LQT2 and LQT3, the sex distribution deviated from the 1:1 ratio. Among children, two-thirds were boys, among adults — the same proportion was represented by women. Disease manifestation time, QTc duration and adverse events risk depended on the genetic type of LQTS, intragenic localization of mutations and sex. In children, all 4 missense mutations in the KCNQ1 gene were located in transmembrane domain, and in adults, 4 mutations were in the transmembrane domain and three — in the C-terminal domain of the protein. LQT1 in boys was characterized by early manifestation, while QTc did not exceed 500 ms and there were no adverse outcomes. Two women out of 7 adults with LQT1 with mutations in the transmembrane domain had na ICD (QTc >520 ms). All patients with LQT2 (4 children, 4 adults) had QTc >500 ms. At the same time, 2 children and 3 women had an ICD. LQT3 was diagnosed only in the children subgroup (2 boys, with QTc of 510 ms and QTc of 610 ms); one of them died suddenly despite beta-blocker therapy. Four adult patients, carriers of class III pathogenicity variants, had QTc <500 ms and delayed disease manifestation (after 30 years). Three of them had episodes of clinical death with subsequent resuscitation and implantation of cardioverter defibrillator.Conclusion. The average diagnostic efficiency of mutation identification using NGS in patients with clinically manifest LQTS was 66%. At the same time, mutations were more common in the children’s group. In genotype-positive probands, the risk of adverse outcomes correlated with sex, age and the genetic variant of disease. The greatest number of adverse outcomes was observed in carriers of mutations in both KCNH2 (LQT2) and SCN5A (LQT3) genes. Variants with unknown clinical significance were identified in 4 probands (11%), which potentially allowed to confirm the diagnosis after functional tests