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All living organisms are controlled by circadian rhythms fuelled by endogenous oscillators. The molecular components of mammalian circadian clocks remain elusive. A human gene termed RIGUI, encoding a bHLH/PAS protein which is 44% homologous to Drosophila period has been isolated. The mouse homolog (m-rigui) is presented in a circadian pattern in the suprachiasmatic nucleus (SCN), the mammal circadian clock regulator. Expression patterns indicated that RIGUI is a mammalian ortholog of the Drosophila period gene.

This paper reviews the chemical composition of 12 Antarctic lakes at offshore Russian stations in the period of seasonal work 55 and 58 RAE (Russian Antarctic Expedition) in December-January 2009–2010 and 2013–2014. Results of hydrochemical analyses of lake water, as well as their classification by ion composition, organic matter content, and mineralization, are presented in this paper. Low-level content of microelements in lake waters are also presented. Enrichment factors of lake waters in relation to ocean water were calculated and direct stratification of water from the surface to the bottom of Lake Progress was identified. [ABSTRACT FROM AUTHOR]

Background. Wilson's disease (WD) is a rare inherited disorder caused by mutations in the ATP7B gene resulting in copper accumulation in different organs. However, data on ATP7B mutation spectrum in Russia and worldwide are insufficient and contradictory. The objective of the present study was estimation of the frequency of ATP7B gene mutations in the Russian population of WD patients. Materials and methods. 75 WDpatients were examined by next-generation sequencing (NGS). A targeted panel NimbleGen SeqCap EZ Choice: 151012_HG38_CysFib_EZ_HX3 (ROCHE)was designed for analysis of ATP7B gene and possible modifier genes. Retrospective assessment of a diagnostic WD score (Leipzig, 2001) was also performed. Results. 31 mutations in ATP7B gene were detected. Two most frequent mutations were c.3207C > A (51,85% of alleles) and c.3190 G > A (8,64% of alleles). Single rare mutations were detected in 29% of cases. In 96% cases mutations of both copies of the ATP7B were revealed. We also observed 3 novel potentially pathogenic variants which were not previously described (c.1870-8A > G, c.3655A > T (p.Ile1219Phe), c.3036dupC (p.Lys1013fs). For 25% of patients at the time of the manifestation the diagnosis WD could not be established using the earlier proposed diagnostic score. There was a remarkable delay in diagnosis for the majority of patients. Only 33% of patients WD was diagnosed in three months after the first symptoms, 29%patients - in 3–12 months, 30% – in 1–10 years, in 8% – more than 10 years. Generally, clinical appearance of WD may be rather variable at manifestation and genetic profiling at this step is the only way to confirm the presence of WD. [ABSTRACT FROM AUTHOR]

Peculiarities of the near-infrared and visible up-conversion spectra of nanocrystalline (Er 2 O 3) x (ZrO 2) 1-x have been studied. It is shown that for the samples with 0.026 < x < 0.143 the photoluminescence spectra of Er3+ are defined a by similar erbium environment in spite of the different symmetry of the host ZrO 2 matrix. The low temperature and room temperature emission bands in the spectral range of the 4I 13/2 → 4I 15/2 transition are measured and interpreted in terms of the multi-electron molecular orbitals cluster model developed for the case of nanocrystal structures. The role of the intra-manifold 4I 13/2 relaxation caused by the spatial confinement effects in erbium-stabilized nanocrystalline zirconia is discussed. • (Er 2 O 3) x (ZrO 2) 1-x have been optically investigated by means of photoluminescence and up-conversion technique. • Different symmetry of the host ZrO 2 matrix does not influence the erbium environment and its photoluminescence spectra. • The 4I 13/2 → 4I 15/2 optical transitions have been interpreted with an account of the calculated crystal-field splitting. • An energy-restricted relaxation (so-called phonon bottleneck) is expected due to level splitting within 4I 13/2 manifold. • The mechanism explains the appearance of the "hot PL bands" in the range of the 4I 13/2 → 4I 15/2 erbium transitions. [ABSTRACT FROM AUTHOR]

Abstract: Main objectives of the present work were to develop an internationally agreed methodology for deriving optimized remediation strategies in rural areas that are still affected by the Chernobyl accident, and to give an overview of the radiological situation in the three affected countries, Belarus, Russia and Ukraine. Study settlements were defined by having in 2004 less than 10,000 inhabitants and official dose estimates exceeding 1mSv. Data on population, current farming practices, contamination of soils and foodstuffs, and remedial actions previously applied were collected for each of such 541 study settlements. Calculations of the annual effective dose from internal radiation were validated with extensive data sets on whole body counter measurements. According to our calculations for 2004, in 290 of the study settlements the effective dose exceeded 1mSv, and the collective dose in these settlements amounted to about 66person-Sv. Six remedial actions were considered: radical improvement of grassland, application of ferrocyn to cows, feeding pigs with uncontaminated fodder before slaughter, application of mineral fertilizers for potato fields, information campaign on contaminated forest produce, and replacement of contaminated soil in populated areas by uncontaminated soil. Side effects of the remedial actions were quantified by a ‘degree of acceptability’. Results are presented for two remediation strategies, namely, Strategy 1, in which the degree of acceptability was given a priority, and Remediation Strategy 2, in which remedial actions were chosen according to lowest costs per averted dose only. Results are highly country-specific varying from preference for soil replacement in populated areas in Belarus to preference for application of ferrocyn to cows in Ukraine. Remedial actions in 2010 can avert a large collective dose of about 150person-Sv (including averted doses, which would be received in the following years). Nevertheless, the number of inhabitants in Belarusian and Russian settlements with annual doses exceeding 1mSv remains large. Compared to international values for the cost-effectiveness of actions to reduce occupational exposures, the recommended remediation strategies for rural areas affected by the Chernobyl accident are quite cost-effective (about 20k€/person-Sv). [Copyright &y& Elsevier]

Concentrations of 137Cs and stable Cs were determined in plant, mushroom, lichen and soil samples collected at two forest sites with different contamination levels in Belarus in 1998. The concentration of 137Cs in soil was the highest in near-surface organic layers (Of and Oh horizons) and decreased with depth in the mineral layers, whereas the concentrations of stable Cs were almost constant in the soil profile. The levels of 137Cs and stable Cs in biological samples varied depending both on the species and the plant part sampled. Even though different species and parts of the same species were included, the concentration ratios of 137Cs to stable Cs were fairly constant for samples collected at the same forest site, and were in the same order of magnitude as the 137Cs to stable Cs ratios for the organic soil layers. This finding suggests that 137Cs, mainly deposited on the forest ecosystems from the Chernobyl accident in 1986, was well mixed with stable Cs within the biological cycle in the forest ecosystems by 1998. The transfer factor for each biological sample of 137Cs was almost the same as that of stable Cs, if they were calculated based on the concentrations in the Of+Oh layer. This suggests that the stable-Cs-based transfer factor could be used as equilibrium transfer factor of 137Cs for different types of biological samples in the forest. [Copyright &y& Elsevier]

Quantum well micro-Hall devices based on uniformly Si-doped Al0.3Ga0.7As/GaAs and Si-δ-doped Al0.3Ga0.7As/GaAs/In0.3Ga0.7As heterostructures are investigated as function of electric field and compared in terms of sensitivity and noise properties. The data show that at high electric fields, doped-channel quantum well devices are advantageous over high-mobility structures and that the use of pseudomorphic InGaAs results in better performance than does GaAs. A maximal signal-to-noise sensitivity (SNS) of 138 dB T−1 is achieved in a 10 μm×10 μm device at 300 K, at frequency of 100 kHz and bandwidth of 1 Hz. This performance corresponds to a lowest detection limit of 127 nT Hz−1/2, with no degradation for electric fields up to 2.4 kV cm−1; these values represent the best reported at such high electric fields. Furthermore, our results suggest that a signal-to-noise sensitivity of 160 dB T−1 and a lowest detection limit of 10 nT is achievable in doped-channel structures. [Copyright &y& Elsevier]

We present new results concerning the carrier transfer between quantum dots (QDs) in dense InAs/GaAs QD arrays with a bimodal size distribution explored by means of steady-state and time-resolved photoluminescence (PL). Interdot carrier transfer involves transitions from the ground state of small QDs into lower lying states of larger QDs, a relaxation channel that saturates at high excitation densities. A staircase-like spectral dependence of the PL decay time is observed and analyzed by taking into account the bimodal QD size distribution. We show that monitoring the spectral behavior of the ground-state PL time constants offers a new and independent tool for distinguishing between PL contributions from different dot size families. [Copyright &y& Elsevier]

• Annealing at 900 °C of Tb,Eu-ZnO/Si films causes formation of Tb oxides and silicates. • RE ion enrichment of n-ZnO/p-Si interface is explained by ion drift in electric field. • Annealing at 900 °C of Tb,Eu-ZnO/Al 2 O 3 films results in formation of Tb oxides and ZnAl 2 O 4. • Energy transfer from Tb3+ to Eu3+ is observed in Tb 2 O 3 and Tb x Eu y SiO 7 phases. • A theoretical approach for Tb3+ and Eu3+ energy spectra calculation is developed. In (Tb, Eu) co-doped ZnO films grown on p-Si and Al 2 O 3 substrates, the annealing at 900 °C was found to result in the diffusion and segregation of rare earth (RE) dopants to ZnO grain boundaries and film surface. The segregation of RE dopants to film/substrate interface was observed in the film on p-Si and explained by the drift of positively charged RE ions in the electric field of n-ZnO/p-Si junction. The annealing promoted also formation of additional crystal phases, namely Tb 2 O 3 , TbO 2 , Tb x Eu y SiO 7 , Zn 2 SiO 4 and ZnAl 2 O 4. In the photoluminescence spectra, it caused the appearance of narrow and broader Eu3+ emission lines. The broader lines emerged only for the film on p-Si substrate and were ascribed to Eu3+ in Tb x Eu y SiO 7 inclusions formed at the ZnO/p-Si interface. The narrow lines were attributed to Eu3+ ions in Tb 2 O 3 inclusions located at ZnO grain boundaries and film surface. The energy transfer from Tb3+ to Eu3+ was demonstrated in the annealed films only. A theoretical approach that allowed to describe the RE ion surrounding and to calculate the energy spectra of Tb3+ and Eu3+ in various site positions was developed. The crystal field parameters were also estimated. [ABSTRACT FROM AUTHOR]