Die Entwicklung der Versicherungswirtschaft in Russland

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Degradation of polymer solutions in a turbulent flow in a cylindrical channel

Water- and oil-soluble polymers capable to reduce the turbulent flow drag were studied. The cause of a decrease in the Toms effect under various conditions was determined. Recommendations were formulated for optimum use of the polymers in pipeline transport technologies

An investigation into the spectral parameters of ultra-low-frequency (ULF) waves in the polar caps and magnetotail

The present case study is focused on fluctuations at ∼ 1.5 mHz observed on open field lines in both of the polar caps in ground-based geomagnetic data and in the electron concentration in the Northern Hemisphere ionosphere. Coherent pulsations with a relatively narrow narrowband-like spectra and a higher fraction of transversal components in the total spectral power are also observed by the Cluster satellites in the magnetotail magnetic field. Interestingly, the pulsations in the magnetotail started after pulsations over a similar frequency range observed in the solar wind dynamic pressure and interplanetary magnetic field (IMF) had been switched off. This suggests evidence of an internal resonant magnetotail mode which is normally masked by a higher-amplitude broadband ultra-low-frequency (ULF) “noise” of extra-magnetospheric origin.publishedVersio

Non-triggered auroral substorms and long-period (1–4 mHz) geomagnetic and auroral luminosity pulsations in the polar cap

A study is undertaken into parameters of the polar auroral and geomagnetic pulsations in the frequency range 1–4 mHz (Pc5∕Pi3) during quiet geomagnetic intervals preceding auroral substorms and non-substorm background variations. Special attention is paid to substorms that occur under parameters of the interplanetary magnetic field (IMF) conditions typical for undisturbed days (“non-triggered substorms”). The spectral parameters of pulsations observed in auroral luminosity as measured by a meridian scanning photometer (Svalbard) in the polar cap and near the polar boundary of the auroral oval are studied and compared with those for the geomagnetic pulsations measured by the magnetometer network IMAGE in the same frequency range. It is found that Pc5∕Pi3 power spectral density (PSD) is higher during pre-substorm time intervals than for non-substorm days and that specific variations of pulsation parameters (“substorm precursors”) occur during the last 2–4 pre-substorm hours

Corticospinal excitability after 5-day Dry Immersion in women

In light of the development of manned astronautics and the increasing participation of women in space flights, the question of female body adaptation to microgravity conditions becomes relevant. Currently, one of the important directions in this issue is to study the effects of support withdrawal as a factor of weightlessness on the human sensorimotor system. Dry Immersion is one of the well-known ground-based models, which adequately reproduces the main physiological effects of space flight. The aim of this study was to evaluate the changes in motor evoked potentials of the lower leg gravity-dependent muscles in women after a 5-day Dry Immersion. We analyzed evoked responses to transcranial and trans-spinal magnetic stimulation. In this method, areas of interest (the motor cortex and lumbosacral thickening of the spinal cord) are stimulated with an electromagnetic stimulus. The experiment was conducted with the participation of 16 healthy female volunteers with a natural menstrual cycle. The thresholds, amplitudes, and latencies of motor potentials evoked by magnetic stimulation were assessed. We showed that 5-day exposure to support withdrawal leads to a decrease in motor-evoked potential thresholds and central motor conduction time, although changes in motor response amplitudes were ambiguous. The data obtained correspond to the results of previous research on Dry Immersion effects on the sensorimotor system in men

Structure-function relationships at the human spinal disc-vertebra interface.

Damage at the intervertebral disc-vertebra interface associates with back pain and disc herniation. However, the structural and biomechanical properties of the disc-vertebra interface remain underexplored. We sought to measure mechanical properties and failure mechanisms, quantify architectural features, and assess structure-function relationships at this vulnerable location. Vertebra-disc-vertebra specimens from human cadaver thoracic spines were scanned with micro-computed tomography (μCT), surface speckle-coated, and loaded to failure in uniaxial tension. Digital image correlation (DIC) was used to calculate local surface strains. Failure surfaces were scanned using scanning electron microscopy (SEM), and adjacent sagittal slices were analyzed with histology and SEM. Seventy-one percent of specimens failed initially at the cartilage endplate-bone interface of the inner annulus region. Histology and SEM both indicated a lack of structural integration between the cartilage endplate (CEP) and bone. The interface failure strength was increased in samples with higher trabecular bone volume fraction in the vertebral endplates. Furthermore, failure strength decreased with degeneration, and in discs with thicker CEPs. Our findings indicate that poor structural connectivity between the CEP and vertebra may explain the structural weakness at this region, and provide insight into structural features that may contribute to risk for disc-vertebra interface injury. The disc-vertebra interface is the site of failure in the majority of herniation injuries. Here we show new structure-function relationships at this interface that may motivate the development of diagnostics, prevention strategies, and treatments to improve the prognosis for many low back pain patients with disc-vertebra interface injuries. © 2017 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 36:192-201, 2018

Анализ гелеобразных дезинфицирующих композиций, содержащих триклозан и тинозан

Variants of tinosan and triclosan extraction from jellous disinfectants followed by UVdetermination is considered. The best extractant is hexane in a neutral (weakly acidic) solution or under acidification in case of studying alkaline disinfectants. The correct determination of the title compounds is possible in the analysis of their 2-propanol solutions by reversed-phase HPLC, both individually and as mixtures with other phenolic disinfectants. Spectrophotometric determination may be made only for the individual title compounds (extraction with hexane).Рассмотрены варианты экстракционного извлечения тинозана и триклозана из гелеобразных дезинфицирующих средств с последующим определением спектрофотометрией в УФ-области. Экстракцию предпочтительнее осуществлять гексаном в нейтральных (слабокислых условиях) или при подкислении, в случае исследования средств с щелочной реакцией. Влияние микропримесей в зависимости от характера поглощения может быть скомпенсировано или делает проводение спектрофотометрического определения невозможным. Корректное определение титульных соединений возможно при анализе изопропанольных растворов средств методом ОФ ВЭЖХ как индивидуально, так и в смесях с другими дезинфицирующими субстанциями фенольного ряда. Спектрофотометрическое определение возможно осуществить только для индивидуальных титульных веществ (экстрагирование гексаном)

Анализ дифенакума в родентицидных композициях, содержащих производные куматетралила

The possibility of simultaneous determination of the title compounds and coumatetralyl derivatives (coumatetralyl, flocumaphen and brodifacoum) in rodenticide means was considered. The conditions of direct analytical determination and stages of preparation were adapted, which will provide determination of the isomeric composition of difenacoum in rodenticide compositions. Using less polar mobile phases on the basis of acetonitrile is preferable as compared to mixtures on the basis of methanol. Conditions allowing the separation of enantiomers with the limit of sensitivity of the method for difenacoum level 0.0002% were found, which allows to monitor the content of more active trans isomers of the title compound both in the original rodenticide substances and in the end poisoned baits. Implementation of the analytical stage of the determination of the isomeric composition of difenacoum involves the use of simpler equipment due to the implementation of the isocratic mode afterwards.Рассмотрены возможности одновременного определения в родентицидных средствах титульного соединения и производных куматетралина (куматетралил, флокумафен и бродифакум). Адаптированы условия проведения непосредственно аналитического определения и стадии пробоподготовки, обеспечивающие определение изомерного состава дифенакума в родентицидных композициях. Использование менее полярных подвижных фаз на основе ацетонитрила предпочтительнее смесей на основе метанола. Подобраны условия, при которых достигается разделение энантиомеров при пределе чувствительности метода для дифенакума на уровне 0.0002%, что позволяет осуществлять мониторинг содержания более активных транс- изомеров для титульного соединения как в исходных родентицидных субстанциях, так и в конечных отравленных приманках. Реализация аналитической стадии определения изомерного состава дифенакума сопряжена с использованием аппаратурно более простого оборудавания оборудования за счет реализации изократического режима элюировани

Оценка возможностей определения методом ОФ ВЭЖХ содержания природных масел в репеллентных композициях

Considered the possibility of determining the content of natural multicomponent oils in repellent means from insects and rodents. For the analysis of finished products on the basis of Lavandin oil and a blend of essential oils containing as a main component citral, the method RP HPLC with UV detection as an alternative to more expensive options with mass-selective detection. Proposed methods of group content evaluation components of the oils with reference to a specific substance (citral), or without it. For the development and validation of the final analysis it is necessary to apply a differentiated approach in the evaluation of formulations of active substances containing multicomponent natural mixture. Perhaps the correct procedure of the analysis is to identify not only the main component (for example, citral), and minor/s components, the definition of which will more accurately indicate the actual content in the media compositions of active ingredients of disinfectants.Рассмотрены подходы к определению содержания природных многокомпонентных масел в репеллентных средствах от насекомых и грызунов. Для анализа готовых препаратов рассмотрен метод ОФ ВЭЖХ с УФ-детектированием в качестве альтернативы более дорогостоящим вариантам с масс-селективным детектированием. Предложены методы групповой оценки содержания компонентов масел с привязкой к определенному веществу или без таковой. Для разработки и валидации конечных методик анализа необходимо применять дифференцированный подход в оценке составов действующих веществ, содержащих многокомпонентные природные смеси. Возможно, корректная процедура анализа будет включать определение не только основного компонента (например, цитраля), но и минорного/ых компонентов, определение которых будет более точно свидетельствовать о реальном содержании в средствах композиций действующих веществ дезинфекционных средств