189 research outputs found
Modeling of Return on Pension Funds, Taking into Well-being of Older Generation
The hypothesis that the well-being of the older generation can be improved by increasing the efficiency of pension savings investments into more profitable securities is proposed.A key factor, which increases the return on investment at a constant level of risk, is to diversify risk in the preparation of the portfolio. The well-being of older generations in terms of the need for optimum use of pension savings is considered. Four types of securities with different levels of risk and return, which theoretically can be invested pension funds are taken for analysis. Opportunities for investment securities in the simple and expanded portfolios are determined on the basis of existing legislation. Portfolios with different risk levels are compared. The principle of diversification is used. The curve of return and risk of various possible investment portfolios is simulated. The study is based on statistical methods.The opportunities for investing pension savings in securities with a higher level of profitability while maintaining a constant risk is demonstrated. The study focused on the revision of legislation in the field of investments of the pension funds of the Russian Federation in the stocks and bonds of Russian companies
Phase equilibria, crystal structure and oxygen content of intermediate phases in the Y-Ba-Co-O system
The phase equilibria in the Y-Ba-Co-O system were systematically studied at 1373 K in air. The intermediate phases formed in the Y-Ba-Co-O system at 1373 K in air were: YBaCo2O5+δ, YBaCo4O 7 and BaCo1-yYyO3-δ (0.09≤y≤0.42). It was shown that YBaCo2O5+δ possesses tetragonal structure with the 3ap×3a p×2ap superstructure (sp. gr. P4/mmm). High-temperature X-ray diffraction analysis of the YBaCo2O 5+δ in the temperature range from 298 K up to 1073 K under Po2=0.21 atm has not shown any phase transformations. The value of oxygen content for the YBaCo2O5+δ at room temperature was estimated as 5.40 and at 1323 K it was equal to 5.04. Thermal expansion of sample shows a linear characteristics and the average thermal expansion coefficient (TEC) is about 13.8×10-6, K-1 in the temperature range 298-1273 K. The homogeneity range and crystal structure of the BaCo1-yYyO3-δ (0.09≤y≤0.42) solid solutions were determined by X-ray diffraction of quenched samples. All BaCo1-yYyO3-δ solid solutions were found to have cubic structure (sp. gr. Pm3m). The unit cell parameters were refined using Rietveld full-profile analysis. Oxygen nonstoichiometry of BaCo 1-yYyO3-δ solid solutions with 0.1≤y≤0.4 was measured by means of thermogravimetric technique within the temperature range 298-1373 K in air. Thermal expansion of BaCo 1-yYyO3-δ (y=0.0; 0.1; 0.2; 0.3) samples was studied within the temperature range 298-1200 K in air. The projection of isothermal-isobaric phase diagram for the Y-Ba-Co-O system to the compositional triangle of metallic components was presented. © 2013 Elsevier Inc
Endogenous amyloidogenesis in long-term rat hippocampal cell cultures
<p>Abstract</p> <p>Background</p> <p>Long-term primary neuronal cultures are a useful tool for the investigation of biochemical processes associated with neuronal senescence. Improvements in available technology make it possible to observe maturation of neural cells isolated from different regions of the rodent brain over a prolonged period <it>in vitro</it>. Existing experimental evidence suggests that cellular aging occurs in mature, long-term, primary neuronal cell cultures. However, detailed studies of neuronal development <it>in vitro </it>are needed to demonstrate the validity of long-term cell culture-based models for investigation of the biochemical mechanisms of <it>in vitro </it>neuronal development and senescence.</p> <p>Results</p> <p>In the current study, neuron-enriched hippocampal cell cultures were used to analyze the differentiation and degeneration of hippocampal neurons over a two month time period. The expression of different neuronal and astroglial biomarkers was used to determine the cytochemical characteristics of hippocampal cells in long-term cultures of varying ages. It was observed that the expression of the intermediate filament nestin was absent from cultures older than 21 days in vitro (DIV), and the expression of neuronal or astrocytic markers appeared to replace nestin. Additionally, morphological evaluations of neuronal integrity and Hoescht staining were used to assess the cellular conditions in the process of hippocampal culture development and aging. It was found that there was an increase in endogenous production of Aβ<sub>1-42 </sub>and an increase in the accumulation of Congo Red-binding amyloidal aggregates associated with the aging of neurons in primary culture. <it>In vitro </it>changes in the morphology of co-existing astrocytes and cell culture age-dependent degeneration of neurodendritic network resemble features of <it>in vivo </it>brain aging at the cellular level.</p> <p>Conclusion</p> <p>In conclusion, this study suggests that long-term primary CNS culture is a viable model for the study of basic mechanisms and effective methods to decelerate the process of neuronal senescence.</p
Degradation of structure and properties of rail surface layer at long-term operation
The microstructure evolution and properties variation of the surface layer of rail steel after passed 500 and 1000 million tons of gross weight (MTGW) have been investigated. The wear rate increases to 3 and 3.4 times after passed 500 and 1000 MTGW, respectively. The corresponding friction coefficient decreases by 1.4 and 1.1 times. The cementite plates were destroyed and formed the cementite particles of around 10-50 nm in size after passed 500 MTGW. The early stage dynamical recrystallization was observed after passed 1000 MTGW. The mechanisms for these have been suggested. The large number of bend extinction contours is revealed in the surface layer. The internal stress field is evaluated
Some New Reactions and Properties of Xanthane Hydride (5-Amino-1,2,4-dithiazole-3-thione)
Aminomethylation of xanthane hydride (5-amino-1,2,4-dithiazole-3-thione) with the RNH2–HCHO system has resulted in the formation of the derivatives of new heterocyclic system (3,7-dihydro-5H-[1,2,4]-dithiazolo[4,3-a][1,3,5]triazine) in low yields. The reaction of xanthane hydride with dicyandiamide has led to thioammeline [4,6-diamino-1,3,5-triazine-2(5Н)-thione]. Some practically important properties of xanthane hydride and its derivatives have been investigated. Xanthane hydride has efficiently exhibited carbon steel corrosion in neutral aqueous media. The prepared compounds have not exhibited growth-regulating or antidote activity to herbicide 2,4-D
A Defective mRNA Cleavage and Polyadenylation Complex Facilitates Expansions of Transcribed (GAA) n Repeats Associated with Friedreich’s Ataxia
Expansions of microsatellite repeats are responsible for numerous hereditary diseases in humans, including myotonic dystrophy and Friedreich's ataxia. Whereas the length of an expandable repeat is the main factor determining disease inheritance, recent data point to genomic trans modifiers that can impact the likelihood of expansions and disease progression. Detection of these modifiers may lead to understanding and treating repeat expansion diseases. Here, we describe a method for the rapid, genome-wide identification of trans modifiers for repeat expansion in a yeast experimental system. Using this method, we found that missense mutations in the endoribonuclease subunit (Ysh1) of the mRNA cleavage and polyadenylation complex dramatically increase the rate of (GAA) n repeat expansions but only when they are actively transcribed. These expansions correlate with slower transcription elongation caused by the ysh1 mutation. These results reveal an interplay between RNA processing and repeat-mediated genome instability, confirming the validity of our approach. Keywords: genome instability; repeat expansion; RNA polyadenylation; RNA processing; transcription-replication conflicts;
Friedreich’s ataxia; DNA double-strand breaks; trans-modifiers of repeat expansions; genetic screen; whole-genome sequencin
Deformation Hardening of Steels of Different Structural Classes
Получены кривые деформационного упрочнения сталей различных структурных классов, подвергнутых пластической деформации одноосным сжатием. Установлено, что деформационное упрочнение исследуемых сталей носит многофакторный характер.The curves of strain hardening of steels of various structural classes subjected to plastic deformation by uniaxial compression are obtained. It was found that the strain hardening of the investigated steels is multifactorial
EVALUATION OF EPIDEMIOLOGICAL AND EPIZOOTIOLOGICAL SITUATION ON ANTHRAX IN 2016, THE FORECAST FOR 2017
The results of analysis of epidemiological and epizootiological situation on anthrax in the world in 2016 are presented. In the Russian Federation 36 human cases of anthrax are registered. Epizooties are noted in 3 federal districts. Anthrax in humans was detected in neighboring countries of Central Asia, in a number of Asian and African countries. Epizootic foci are identified throughout with prevalence in the countries of Africa and Asia, where anthrax cases among wild animals were also revealed. The unstable situation on anthrax is forecasted in 2017 in the Russian Federation and neighboring countries
Soy Isoflavones Genistein and Daidzein Exert Anti-Apoptotic Actions via a Selective ER-mediated Mechanism in Neurons following HIV-1 Tat1–86 Exposure
HIV-1 viral protein Tat partially mediates the neural dysfunction and neuronal cell death associated with HIV-1 induced neurodegeneration and neurocognitive disorders. Soy isoflavones provide protection against various neurotoxic insults to maintain neuronal function and thus help preserve neurocognitive capacity.We demonstrate in primary cortical cell cultures that 17β-estradiol or isoflavones (genistein or daidzein) attenuate Tat(1-86)-induced expression of apoptotic proteins and subsequent cell death. Exposure of cultured neurons to the estrogen receptor antagonist ICI 182,780 abolished the anti-apoptotic actions of isoflavones. Use of ERα or ERβ specific antagonists determined the involvement of both ER isoforms in genistein and daidzein inhibition of caspase activity; ERβ selectively mediated downregulation of mitochondrial pro-apoptotic protein Bax. The findings suggest soy isoflavones effectively diminished HIV-1 Tat-induced apoptotic signaling.Collectively, our results suggest that soy isoflavones represent an adjunctive therapeutic option with combination anti-retroviral therapy (cART) to preserve neuronal functioning and sustain neurocognitive abilities of HIV-1 infected persons
Clinical features of osteoporosis among indigenous women of Russian and Buryat ethnicity in Trans-Baikal region
Introduction Osteoporosis (OP) is a major social and medical problem for society. The aim of research was to identify risk factors for OP and the incidence of low-energy fractures in women with OP of Russian and Buryat ethnicity in Trans-Baikal region. Materials and methods We examined 98 women with OP (50 of Russian and 48 of Buryat nationality) and 100 women without objective signs of OP, comparable by age and nationality with the main group. All women underwent a questionnaire to identify risk factors for osteoporosis and osteoporotic fractures, determination of bone mineral density (BMD) using dual-energy X-ray absorptiometry, and determination of the absolute 10-year risk of major osteoporotic fractures using the online FRAX® calculator. Results The mean age of women with OP of Russian ethnicity was 65.5 [57.0;71.0] years, of Buryat nationality – 65.3 [56.0;69.0] years. Among risk factors in female members of Russian nationality, age older than 65 years, tendency to fall and decreased creatinine clearance were found more frequently. There was an inverse association between proximal femoral BMD and risk of falls (R = -0.31, p = 0.04) and a direct correlation between family history of ОP and spinal BMD (R = 0.65, p = 0.02). Discussion Age over 65 is a significant risk factor for osteoporosis and is included in the FRAX (Fracture Risk Assessment Tool) model. Reduces creatinine clearance and a tendency to fall have been associated with the development of OP and fractures in some studies. Our findings are consistent with previous studies. Conclusion Russian women were more likely than Buryat women to have risk factors for OP, such as falls and decreased creatinine clearance. Associations were found between proximal femoral BMD and falls, spinal BMD with a family history of OP and smoking among Russian women.Введение. Остеопороз (ОП) представляет большую социальную и медицинскую проблему для общества. Цель исследования – установить факторы риска ОП и частоту встречаемости низкоэнергетических переломов у женщин с остеопорозом русской и бурятской национальностей в Забайкалье. Материалы и методы. Обследовано 98 женщин с ОП (50 русской и 48 бурятской национальностей) и 100 женщин, не имеющих объективных признаков ОП, аналогичных по возрасту и национальности основной группе. Для выявления факторов риска остеопороза и остеопоротических переломов всем женщинам было проведено анкетирование, определение минеральной плотности костной ткани (МПКТ) с помощью двухэнергетической рентгеновской абсорбциометрии, а также определение абсолютного 10-летнего риска основных остеопоротических переломов с помощью on-line калькулятора FRAX®. Результаты. Средний возраст женщин с ОП русской национальности составил 65,5 [57,0;71,0] лет, бурятской национальности – 65,3 [56,0;69,0] лет. Среди факторов риска у представительниц русской национальности чаще встречались: возраст старше 65 лет, склонность к падениям и снижение клиренса креатинина. Установлена обратная связь МПКТ проксимального отдела бедра с риском падений (R = -0,31, p = 0,04) и корреляционная связь прямой направленности между семейным анамнезом ОП и МПКТ в позвоночнике (R = 0,65, p = 0,02). Обсуждение. Возраст старше 65 лет является значимым фактором риска развития остеопороза и входит в модель FRAX (англ. Fracture Risk Assessment Tool — инструмент оценки риска переломов). Снижение клиренса креатинина и склонность к падениям, согласно данным отдельных исследований, ассоциированы с развитием ОП и возникновением переломов. Полученные нами результаты согласуются c данными проведенных ранее исследований. Заключение. У женщин русской национальности, проживающих в Забайкальском крае, чаще, чем у бурят, выявляли такие факторы риска развития ОП, как падения и снижение клиренса креатинина. Установлены связи между МПКТ в проксимальном отделе бедра и падениями, МПКТ в позвоночнике с семейным анамнезом ОП и курением среди русских женщин
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