Can CPAP be an option for treating tinnitus patients with obstructive sleep apnea syndrome? Review

Tinnitus is the perception of phantom sound in the absence of an external source. Its influence on quality of life varies from minimal to severe. Tinnitus has considerable heterogeneity, thus no single mechanism explains it. There is neither effective drug treatment for the vast majority of patients nor standard rehabilitation management. Keeping that in mind, any reliable option for treatment, even for a minor group, is worth investigating.The possible relationship between obstructive sleep apnea syndrome and tinnitus, and the effect of continuous positive airway pressure on organ of hearing are discussed.We have reviewed scientific literature using Medline, PubMed, Google, and conducted a manual search of reference lists of any incorporated paper. The key terms used were: “tinnitus”, “obstructive sleep apnea syndrome,” and “CPAP”.The following investigation can clarify the tinnitus prevalence in patients suffering from OSAS, specify whether tinnitus is the result of OSAS or its comorbid condition or just a coincidence, and assess the efficacy and indications of this approach to tinnitus treatment

Energy Sector of the Russian Federation in the Context of Macroeconomic Instability

Electric power is one of the leading industries in the modern economy: it has a direct impact on all vital systems of the society per se, as well as on the formation of the social climate and on the economic development of any state. The current economic crisis and sanctions on behalf the US and the EU have significantly complicated the activities of Russian energy enterprises, thus, the government plays a key role in combating the crisis in this industry. Based on official statistical data, the article presents the results of complex analysis of the industry and defines the basic tendencies of its development. According to the results of the conducted research, it is revealed that in the past three years the performance indicators for electricity and heat production have deteriorated, the manageability of the functioning of energy systems has decreased, and the need for new technologies has increased. Keywords: state regulation, market failure, macroeconomic indicators, energy, sanctions, crisis, electricity, state support JEL Classifications: O25; Q43; Q4

The Iron Sulfides Crystal Growth from the Halide Melts

<div><p>A new approach to a single crystals growth of the iron sulfide phases of definite structure and nonstoichiometry is developed and applied. This approach is based on the method of crystal growing from solution melts. This approach is based on the crystallization or recrystallization of iron sulfides from iron sulfide solutions in iron dihalide melts under fixed sulfur vapor pressure in the closed system in non-isothermal (two-temperature) conditions. It allows to regulate the composition and structure of the resulting iron sulphide. In particular, at a relatively low pressure (<0.4 atm), pyrrhotite with a trigonal 3T structure is synthesized. At higher pressure pyrite β-FeS2 is grown. Reaction scheme for the formation of iron sulphides based on the reversible oxidation of sulfur by iron dihalide is proposed and substantiated. On the base of the {pyrite + marcasite} - mixture annealing under the melts of the deepest eutectic compositions of KCl - FeCl2 and NaCl - KCl - FeCl2 systems, the instability of the marcasite phase regarding the pyrite one (at least, for T ≥ 340°C) was shown.</p></div

Direct determination of hydrazine, methylhydrazine, and 1,1-dimethylhydrazine by zwitterionic hydrophilic interaction liquid chromatography with amperometric detection

<p>A promising alternative to ion-chromatographic methods currently used for the direct determination of hydrazines is provided by hydrophilic interaction liquid chromatography (HILIC). In this work, we propose a method for the simultaneous determination of hydrazine, methylhydrazine and 1,1-dimethylhydrazine in natural waters and soils based on a combination of chromatographic separation on a zwitterionic sulfobetaine stationary phase (Nucleodur HILIC) in the HILIC mode with amperometric detection.</p> <p>Effects of different factors on the retention of analytes were studied and the optimum conditions of analysis were found. We recommend a mixture of acetonitrile with an aqueous phosphate buffer solution of pH 2.5 (78:22 v/v) with an ionic strength of 20 mM as a mobile phase. Detection in the direct current mode was performed at a working electrode potential of 1.1 V.</p> <p>The advantages of the method are the high efficiency of separation, rapidity, high sensitivity and a wide dynamic range of analyte concentrations, covering four orders of magnitude. The attained LOD values for analytes lie in the range 0.07–0.13 μg L^–1, which is two orders of magnitude lower than those in currently used methods of ion chromatography with electrochemical and mass spectrometric detection.</p> <p>The method was validated on samples of natural waters of different origin using the added–found technique. It was found that the error of analysis did not exceed 10% for river and ground waters and increased to 20–30% for peat bog surface waters.</p> <p>The possibility of application of the developed method to the analysis of soils was shown on samples of peat bog soils selected at places of impact of the first steps of carrier rockets and polluted by rocket fuel based on 1,1-dimethylhydrazine.</p

Comparative sequence analyses of rhodopsin and RPE65 reveal patterns of selective constraint across hereditary retinal disease mutations

Retinitis pigmentosa (RP) comprises several heritable diseases that involve photoreceptor, and ultimately retinal, degeneration. Currently, mutations in over 50 genes have known links to RP. Despite advances in clinical characterization, molecular characterization of RP remains challenging due to the heterogeneous nature of causal genes, mutations, and clinical phenotypes. In this study, we compiled large datasets of two important visual genes associated with RP: rhodopsin, which initiates the phototransduction cascade, and the retinoid isomerase RPE65, which regenerates the visual cycle. We used a comparative evolutionary approach to investigate the relationship between interspecific sequence variation and pathogenic mutations that lead to degenerative retinal disease. Using codon-based likelihood methods, we estimated evolutionary rates (d N/d S) across both genes in a phylogenetic context to investigate differences between pathogenic and nonpathogenic amino acid sites. In both genes, disease-associated sites showed significantly lower evolutionary rates compared to nondisease sites, and were more likely to occur in functionally critical areas of the proteins. The nature of the dataset (e.g., vertebrate or mammalian sequences), as well as selection of pathogenic sites, affected the differences observed between pathogenic and nonpathogenic sites. Our results illustrate that these methods can serve as an intermediate step in understanding protein structure and function in a clinical context, particularly in predicting the relative pathogenicity (i.e., functional impact) of point mutations and their downstream phenotypic effects. Extensions of this approach may also contribute to current methods for predicting the deleterious effects of candidate mutations and to the identification of protein regions under strong constraint where we expect pathogenic mutations to occur.This work was supported by an NSERC Discovery Grant and a Foundation for Fighting Blindness seed grant to BSWC, Vision Science Research Fellowships to FEH, RKS, GMC, and AVN, and Ontario Graduate Fellowships to FEH and RKS. Amir Sabouhanian provided valuable feedback on the statistical analyses