Solitons in a chain of PT-invariant dimers

Dynamics of a chain of interacting parity-time invariant nonlinear dimers is investigated. A dimer is built as a pair of coupled elements with equal gain and loss. A relation between stationary soliton solutions of the model and solitons of the discrete nonlinear Schrodinger (DNLS) equation is demonstrated. Approximate solutions for solitons whose width is large in comparison to the lattice spacing are derived, using a continuum counterpart of the discrete equations. These solitons are mobile, featuring nearly elastic collisions. Stationary solutions for narrow solitons, which are immobile due to the pinning by the effective Peierls-Nabarro potential, are constructed numerically, starting from the anti-continuum limit. The solitons with the amplitude exceeding a certain critical value suffer an instability leading to blowup, which is a specific feature of the nonlinear PT-symmetric chain, making it dynamically different from DNLS lattices. A qualitative explanation of this feature is proposed. The instability threshold drops with the increase of the gain-loss coefficient, but it does not depend on the lattice coupling constant, nor on the soliton's velocity.Comment: 9 pages, 9 figure

Clinical and immunological characteristics of chronic obstructive pulmonary disease with frequent exacerbations associated with obliterating atherosclerosis of lower limb arteries

Chronic obstructive pulmonary disease (COPD) is often associated with atherosclerotic cardiovascular disease (ASCVD), of which obliterating atherosclerosis of lower limb arteries or peripheral arterial disease (PAD) is an important component. The aim of the study was to evaluate the clinical, functional and immunological characteristics of COPD with the phenotype of frequent exacerbations in combination with PAD. Materials and methods. Four groups of COPD patients were included: 20 COPD patients with infrequent exacerbations without ASCVD, 20 COPD patients with frequent exacerbations without ASCVD, 20 patients with frequent exacerbations and PAD, and 20 COPD patients with a phenotype of frequent exacerbations and PAD. Data from 20 healthy controls were analysed for comparison. Clinical and spirometric data were evaluated. General clinical laboratory data and immunological markers (interleukin 1 beta (IL1b) and tumor necrosis factor (TNF) in exhaled breath condensate (EBC) and serum were analysed. Results. Higher levels of IL1b and TNF in EBC and serum were found in patients with COPD and PAD compared to COPD patients without ASCVD (p<0.05) and healthy controls (p<0.001). The high prevalence of COPD exacerbates the clinical and immunological characteristics of disease severity both without ASCVD and with concomitant PAD. Conclusions. COPD with the phenotype of frequent exacerbations and PAD is characterized by greater severity of local and systemic inflammation, which corresponds to increased inflammatory markers in EBC and serum

The evolution of mass loaded supernova remnants: II. Temperature dependent mass injection rates

We investigate the evolution of spherically symmetric supernova remnants in which mass loading takes place due to conductively driven evaporation of embedded clouds. Numerical simulations reveal significant differences between the evolution of conductively mass loaded and the ablatively mass loaded remnants studied in Paper I. A main difference is the way in which conductive mass loading is extinguished at fairly early times, once the interior temperature of the remnant falls below ~ 107 K. Thus, at late times remnants that ablatively mass load are dominated by loaded mass and thermal energy, while those that conductively mass load are dominated by swept-up mass and kinetic energy. Simple approximations to the remnant evolution, complementary to those in Paper I, are given

Two novel approaches for photometric redshift estimation based on SDSS and 2MASS databases

We investigate two training-set methods: support vector machines (SVMs) and Kernel Regression (KR) for photometric redshift estimation with the data from the Sloan Digital Sky Survey Data Release 5 and Two Micron All Sky Survey databases. We probe the performances of SVMs and KR for different input patterns. Our experiments show that the more parameters considered, the accuracy doesn't always increase, and only when appropriate parameters chosen, the accuracy can improve. Moreover for different approaches, the best input pattern is different. With different parameters as input, the optimal bandwidth is dissimilar for KR. The rms errors of photometric redshifts based on SVM and KR methods are less than 0.03 and 0.02, respectively. Finally the strengths and weaknesses of the two approaches are summarized. Compared to other methods of estimating photometric redshifts, they show their superiorities, especially KR, in terms of accuracy.Comment: accepted for publication in ChJA

Application of magnesium drugs and their influence on the indicators of connective tissue dysplasia in patients with varicose veins

ВАРИКОЗНОЕ РАСШИРЕНИЕ ВЕН /ЛЕК ТЕРФАРМАКОТЕРАПИЯМАГНИЙМАТРИКСА МЕТАЛЛОПРОТЕИНАЗЫКОЛЛАГЕНАЗА ИНТЕРСТИЦИАЛЬНАЯЖЕЛАТИНАЗА BДИСПЛАЗИЯ СОЕДИНИТЕЛЬНОЙ ТКАНИЦель. Изучение влияния приема препаратов магния на концентрацию матриксных металлопротеиназ и ионов магния у пациентов с варикозной болезнью вен нижних конечностей. Материал и методы. В исследование включено 124 пациента с варикозной болезнью вен нижних конечностей (ВБВНК) классов С2-С6, которых разделили на 4 группы. В I-й группе проводили оперативное лечение с последующим назначением стандартного консервативного лечения (32 человека); во II-й группе после операции в дополнение к консервативному лечению назначали препараты магния (32 человека); в III-й группе проводили консервативное лечение без операции (30 человек); в IV-й группе пациенты получали стандартное консервативное лечение и препараты магния (30 человек). V-ю контрольную группу составили 20 здоровых добровольцев, не страдающих варикозной болезнью. Пациентам II-й и IV-й групп назначали магния оротат 500 мг 2 табл. 3 раза в день в течение 3 мес. Содержание в сыворотке крови матриксной металлопротеиназы-1 (ММП-1), матриксной металлопротеиназы-9 (ММП-9), тканевого ингибитора матриксной металлопротеиназы-1 (ТИМП-1) определяли методом количественного твердофазного иммуноферментного анализа. Концентрацию ионов магния определяли колориметрическим методом. Результаты. У пациентов с ВБВНК отмечался достоверно меньший уровень магния по сравнению с условно здоровыми добровольцами, не страдающими варикозной болезнью: 35,5% среди страдающих варикозной болезнью имели дефицит магния, в то время как всего 15% имели снижение данного показателя среди здоровых добровольцев. На фоне проводимой дополнительной терапии препаратами магния, отмечалось уменьшение количества пациентов с дефицитом магния в группах с ВБВНК, снижение концентрации ММП-9 и повышение активности ТИМП-1. Заключение. Исследование подтвердило эффективность применения препаратов магния, которые обладают выраженным влиянием на процессы деградации коллагена и внеклеточного матрикса, снижают активность ММП-9, повышают концентрацию ТИМП-1, тем самым влияя на баланс ММП/ТИМП у пациентов с ВБВНК.Objective. To study the effect of magnesium drugs on the concentration of matrix metalloproteinases and magnesium ions in patients with varicose veins of the lower extremities. Methods. The study included 124 patients with varicose veins of the lower extremities, C2-C6, which were divided into 4 groups. In the 1st group, surgical treatment followed with the administering the standard conservative treatment (32 patient); in the 2nd group after the operation in addition to conservative treatment, magnesium drugs (32 patient) were prescribed; in the 3rd group, conservative treatment without surgery (30 patient) was performed; in the 4th group patients received standard conservative treatment and magnesium drugs (30 patient). The 5th control group consisted of 20 healthy volunteers who did not suffer from varicose veins disease. Patients of groups 2 and 4 were given magnesium orotate 500 mg 2 tablets 3 times a day for 3 months. The content of serum matrix metalloproteinase-1 (MMP-1), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) was determined by quantitative solid-phase enzyme immunoassay. The magnesium ion concentration was determined by colorimetric method. Results. In patients with varicose veins of lower extremities a significantly lower level of magnesium was registered compared to healthy volunteers not suffering from varicose veins: 35.5% of those with varicose veins had a magnesium deficiency, while only 15% had a decrease in this indicator among healthy volunteers. Against the background of additional therapy with magnesium drugs, there was a decrease in the number of patients with magnesium deficiency in groups with varicose veins of lower extremities, a decrease in MMP-9 concentration and an increase in TIMP-1 activity was also established. Conclusions. This study has confirmed the efficacy of magnesium drugs which have a pronounced effect on collagen degradation processes and extracellular matrix, reduce the activity of MMP-9, increase the concentration of TIMP-1, thereby affecting the MMP/TIMP balance in patients with varicose veins of lower extremities

ЭЛЕМЕНТНЫЙ АНАЛИЗ ПЕНТАКАРБОНИЛА ЖЕЛЕЗА МЕТОДОМ МАСС-СПЕКТРОМЕТРИИ С ИНДУКТИВНО СВЯЗАННОЙ ПЛАЗМОЙ

A technique for the quantitative elemental analysis of iron pentacarbonyl by high-resolution mass spectrometry with inductively coupled plasma has been developed. Samples of Fe(CO)5 were transferred to a nitrate solution for the analysis. To account for the matrix noise and the drift of the sensitivity of the mass spectrometer during the analysis, three internal standards (9Be, 59Co, 181Ta) for the various mass ranges were used. The normalization of the measured intensities of analyte signals to the intensities of the corresponding internal standards made it possible to significantly improve the accuracy of determining the concentrations of impurities using the external calibration according to the pure standards. Using the developed technique, the concentrations of 28 elements’ impurities were determined. The behavior of impurities of elements forming their own carbonyl compounds in the process of fractional distillation of iron pentacarbonyl was studied. The analysis of iron pentacarbonyl fractions showed that the impurities of B, Ni and Ti were concentrated in the light fractions, and the impurities of Cr, Co, Cd, Mo and W in the heavy ones. The detection limits of iron in pentacarbonyl for widespread impurities such as Mg, Al, P, Cr, Ni were 10–6–10–5 wt. %, and for less common impurities of Bi, Cd, Co, Pt, Re, Tl, W, U - 10-8 ÷ 10-7 wt. % respectively.Keywords: iron pentacarbonyl, impurities determination, high resolution ICP-MS(Russian)DOI: http://dx.doi.org/10.15826/analitika.2019.23.1.014M.O. Steshin1, 2, A.M. Potapov1, A.D. Bulanov1, 2, Yu.S. Belozerov1, A.I. Suchkov11G.G. Devyatykh Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences (IChHPS RAS), 49 Tropinina St., Nizhny Novgorod, 603951, Russian Federation2National Research Lobachevsky State University of Nizhny Novgorod, pr. Gagarina 23, Nizhny Novgorod, 603950, Russian FederationРазработана методика количественного элементного анализа пентакарбонила железа методом масс-спектрометрии высокого разрешения с индуктивно связанной плазмой. Пробы Fe(CO)5 предварительно переводили в азотнокислый раствор. Для учета матричных помех и дрейфа чувствительности масс-спектрометра в процессе анализа в различных диапазонах масс применяли три внутренних стандарта (9Be, 59Co, 181Ta). Нормировка измеренных интенсивностей сигналов аналитов на интенсивности соответствующих внутренних стандартов позволила значительно повысить точность определения концентраций примесей при использовании внешней градуировки по чистым стандартам. С применением разработанной методики определено содержание примесей 29 элементов. Изучено поведение примесей элементов, образующих собственные карбонилы в процессе фракционной разгонки пентакарбонила железа. Анализ фракций пентакарбонила железа, показал, что примеси B, Ni и Ti концентрируются в легких фракциях, а примеси Cr, Co, Cd, Mo и W ‒ в тяжелых. Пределы обнаружения в пентакарбониле железа для распространенных примесей Mg, Al, P, Cr, Ni составили 10-6 ÷ 10-5 % мас., для нераспространенных примесей Bi, Cd, Co, Pt, Re, Tl, W, U ‒ 10-8 ÷ 10-7 % мас.Ключевые слова: пентакарбонил железа, элементный анализ, масс-спектрометрия с индуктивно связанной плазмой высокого разрешенияDOI: http://dx.doi.org/10.15826/analitika.2019.23.1.01

Dark Matter Search Perspectives with GAMMA-400

GAMMA-400 is a future high-energy gamma-ray telescope, designed to measure the fluxes of gamma-rays and cosmic-ray electrons + positrons, which can be produced by annihilation or decay of dark matter particles, and to survey the celestial sphere in order to study point and extended sources of gamma-rays, measure energy spectra of Galactic and extragalactic diffuse gamma-ray emission, gamma-ray bursts, and gamma-ray emission from the Sun. GAMMA-400 covers the energy range from 100 MeV to ~3000 GeV. Its angular resolution is ~0.01 deg(Eg > 100 GeV), and the energy resolution ~1% (Eg > 10 GeV). GAMMA-400 is planned to be launched on the Russian space platform Navigator in 2019. The GAMMA-400 perspectives in the search for dark matter in various scenarios are presented in this paperComment: 4 pages, 4 figures, submitted to the Proceedings of the International Cosmic-Ray Conference 2013, Brazil, Rio de Janeir