1,181 research outputs found

    РАСШИРЕНИЕ РАБОЧЕГО ДИАПАЗОНА ОПРЕДЕЛЕНИЯ ЩЕЛОЧНЫХ МЕТАЛЛОВ И КАЛЬЦИЯ МЕТОДОМ ПЛАМЕННОЙ ФОТОМЕТРИИ СО СПЕКТРОМЕТРОМ «ПАВЛИН»

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    At the Novosibirsk Chemical Concentrates Plant, the determination of alkali metals and calcium in the range of 0.1–100 mg/l is carried out using atomic emission spectra excited in an air-acetylene flame and recorded in the range of 390–860 nm. When these elements are analyzed simultaneously in a wide range of concentrations, the accumulation time of the analytical signal (exposure) is determined by the minimum concentration of calcium. However, at this exposure, the highly sensitive lines of sodium and potassium do not provide the analysis in the entire concentration range, since at large values, the analytical signal goes into saturation. Other analytical lines of potassium and sodium in the above-mentioned operating spectral range have three to four orders of magnitude lower sensitivity. As a result, there may be a gap in the range of detectable concentrations. This paper provides a way to eliminate this gap. To evaluate the degree of correction of the recorded signal, the relative intensities of the spectral lines of potassium and sodium excited in an air-acetylene flame are calculated. Then, based on the calculation results, an optimal echelette diffraction grating with a blaze angle of 300 nm is selected, and a combination of filters is installed to equalize the recorded radiation. As a result, for sodium and potassium, for which the determination is carried out along two analytical lines, the calibration dependences have an overlap that includes at least two concentration values.Keywords: Alkali metals, calcium, flame photometry, diffraction grating, light filters, dynamic range of calibration curves DOI: http://dx.doi.org/10.15826/analitika.2021.25.4.003 I.A. Zarubin1, 2, 3, A.N. Putmakov1, 3, E.A. Lukina4, D.O. Selunin1, 3, аnd I.D. Burumov1, 3 1Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, pr. AkademikaKoptyuga 1, Novosibirsk, 630090,  Russian Federation2Novosibirsk State Technical University, pr. K. Marksa  20, Novosibirsk, 630073, Russian Federation3VMK-Optoelektronika, pr. Koptyuga, 1, Novosibirsk, 630090, Russian Federation4Novosibirsk Chemical Concentrates Plant, ul. B. Khmelnitskogo,  94, Novosibirsk, 630110, Russian FederationПо атомно-эмиссионным спектрам, возбуждаемым в воздушно-ацетиленовом пламени и регистрируемым в диапазоне 390-860 нм, на Новосибирском заводе химконцентратов проводят определение 0.1-100 мг/л щелочных металлов и кальция. При их одновременном измерении в широком интервале концентраций время накопления аналитического сигнала определяется минимальной концентрацией кальция в пробе. Однако, при увеличении длительности регистрации сигнала, интенсивность высокочувствительных линий  натрия и калия уходит в насыщение, что не позволяет обеспечить возможность их определения во всем необходимом диапазоне концентраций. Другие аналитические линии калия и натрия в указанной выше рабочей спектральной области обладают на 3-4 порядка меньшей чувствительностью. В результате этого возникает разрыв в диапазоне определяемых концентраций. В работе приводится способ устранения данного разрыва. Для оценки необходимой степени коррекции регистрируемого сигнала проведен расчет относительных интенсивностей спектральных линий калия и натрия, возбуждаемых в воздушно-ацетиленовом пламени. Далее, с учетом результатов расчета, была выбрана оптимальная дифракционная решетка-эшелетт, имеющая угол блеска для 300 нм, а также подобрана комбинация светофильтров для сближения интенсивностей регистрируемого излучения спектральных линий с резко различной чувствительностью. В результате для натрия и калия, у которых определение проводится по двум аналитическим линиям различной чувствительности, градуировочные зависимости имеют область перекрытия, включающую не менее двух значений концентрации.Ключевые слова. Щелочные металлы, кальций, пламенная фотометрия, дифракционная решетка, светофильтры, динамический диапазон градуировочных графиковDOI: http://dx.doi.org/10.15826/analitika.2021.25.4.00

    EFFECT OF SACUBITRIL/VALSARTAN ON NATRIURESIS, DIURESIS AND BLOOD PRESSURE IN HYPERTENSIVE PATIENTS

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    Aim. To study the effect of sacubitril/valsartan compared with valsartan on natriuresis, diuresis, blood pressure (BP) and the level of biomarkers in hypertensive patients.Material and methods. Hypertensive patients (n=16) received sacubitril/valsartan 400 mg QD or valsartan 320 mg QD for 7 days in a double-blind,-randomized, cross-over study. The change in 24-hour diuresis and natriuresis, fractional urinary sodium excretion, and BP level have been studied, as-well as soluble biomarkers: cyclic guanosine monophosphate (cGMP), plasma brain natriuretic peptide (BNP), mid-regional precursor of the atrial natriuretic-peptide (MR-proANP) and the N-terminal precursor of the brain natriuretic peptide (NT-proBNP).Results. The trend toward higher levels of 24-hour natriuresis on Day 1 (21%, p=0.068) was found in the sacubitril/valsartan group compared to-valsartan one. Fractional sodium excretion was significantly higher in the sacubitril/valsartan group on Day 1 after 6 hours (50%, p=0.004) and subsequent-samples up to 12 hours; the maximum effect was achieved 2-4 hours after taking the medication (mean value 2.08, p=0.005). Sacubitril/valsartan-therapy compared with valsartan therapy was associated with a significant increase in 24-hour diuresis on Day 1 (41%, p<0.05), but not on Day 7-(15%, p=0.134). Sacubitril/valsartan therapy, in contrast to valsartan therapy demonstrated a significant increase in 24 h cGMP urinary excretion-on Day 1 (95%, p<0.001) and Day 7 (83%, p=0.001). Sacubitril/valsartan lowered BP more effectively than valsartan [on Day 7, 12 hours after-taking the drug, the differences were13.6 mm Hg (p=0.004) for systolic and6.7 mm Hg (p=0.03) for diastolic BP. The decrease in the level of-NT-proBNP and MR-proANP in plasma and the transient increase in the level of BNP were found in the sacubitril/valsartan group. Both sacubitril/valsartan and valsartan therapies were well tolerated and safe.Conclusion. Sacubitril/valsartan therapy in hypertensive patients compared with valsartan therapy was associated with transient increase in natriuresis and diuresis, more pronounced decrease in BP and changes in biomarker levels reflecting persistent inhibition of neprilysin and decrease in myocardial wall tension

    COMPARATIVE ANALYSIS OF ARTERIAL HYPERTENSION TREATMENT IN MEN AND WOMEN BASED ON THE RESULTS OF ACCORD STUDY (ACRIDILOLE IN COMBINATION THERAPY IN PATIENTS WITH ARTERIAL HYPERTENSION AND OBESITY OR TYPE 2 DIABETES)

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    Aim. To compare the efficacy and safety of carvedilol in men and women with mild to moderate arterial hypertension, associated with obesity and/or compensated diabetes type 2. Material and methods. Hypertensive patients (n=592, 176 men and 416 women) with obesity and/or diabetes were involved into randomized comparative open-label study in parallel groups. Patients were randomized into two groups. Patients of group A (n=291: 90 men and 201 women) kept on to receive previous antihypertensive drugs except beta-blockers which were withdrawn and replaced with carvedilol (Acridilole®, PLC “Akrikhin”, Russia). Patients of control group (n=301: 86 men and 215 women) kept on to receive only previous antihypertensive drugs. Efficacy of antihypertensive therapy was assessed at every 2-week visits during 24-week observation. Biochemical parameters of glucose and lipid metabolism, 12-lead ECG were evaluated at baseline and at the end of the study. Target blood pressure (BP) achievement and safety was assessed in 24 weeks of treatment. Results. Women had more severe metabolic abnormalities compared with men. By the 24th week of treatment significant reduction in systolic BP , diastolic BP , and heart rate was found in the both groups of patients regardless of gender , intergroup differences were significant (p<0,05). By the end of the study target BP level was achieved in 96.3% of men and 96,8% of women in group A and 85.9% and 88.8%, respectively , in the control group (p<0,001). The number of hospital admissions decreased in 4.8 times in men (p<0.0001) and 12 times - in women (p<0.05) in group A, and in 2.7 and 3.3 times, respectively , — in the control group (p<0.0001). Mild to moderate side effects were observed in 32 patients: 19 and 13 patients in group A and control group, respectively (p=0.58). Adverse event rate was not distinguished significantly between men and women. Conclusion: The results show comparable high efficacy and safety of carvedilol in hypertensive men and women with concomitant diseases and high metabolic and cardiovascular risk

    Parameter-Independent Strategies for pMDPs via POMDPs

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    Markov Decision Processes (MDPs) are a popular class of models suitable for solving control decision problems in probabilistic reactive systems. We consider parametric MDPs (pMDPs) that include parameters in some of the transition probabilities to account for stochastic uncertainties of the environment such as noise or input disturbances. We study pMDPs with reachability objectives where the parameter values are unknown and impossible to measure directly during execution, but there is a probability distribution known over the parameter values. We study for the first time computing parameter-independent strategies that are expectation optimal, i.e., optimize the expected reachability probability under the probability distribution over the parameters. We present an encoding of our problem to partially observable MDPs (POMDPs), i.e., a reduction of our problem to computing optimal strategies in POMDPs. We evaluate our method experimentally on several benchmarks: a motivating (repeated) learner model; a series of benchmarks of varying configurations of a robot moving on a grid; and a consensus protocol.Comment: Extended version of a QEST 2018 pape

    Anatomical and morphological features of Pinus sylvestris growing on the dumps of the mining industry in the middle urals

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    The results of the study of anatomical and morphological parameters of Pinus sylvestris L., growing on the serpentine dumps of Anatol'sko-Shilovsky Mining, are presented. Adaptive morphological and anatomical changes that contribute to the survival of the species in extreme environmental conditions have been identified. A significant decrease in P. sylvestris morphometic parameters (tree height, the annual growth of the tree, and the branches) under dump conditions were established. Under the influence of unfavorable factors on the dumps (lack of nutrients and water, high rockiness of the substrate), the length and the cross-sectional area of the needles decreased. Of the anatomical features, it is important to note a decrease in the number of resin ducts with a tendency to increase their diameter. © 2021 Author(s)

    Exploring the patient journey to diagnosis of Gaucher disease from the perspective of 212 patients with Gaucher disease and 16 Gaucher expert physicians

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    Gaucher disease (GD) is a rare hereditary disorder caused by a deficiency of the lysosomal enzyme β-glucocerebrosidase. Diagnosis is challenging owing to a wide variability in clinical manifestations and severity of symptoms. Many patients may experience marked delays in obtaining a definitive diagnosis. The two surveys reported herein aimed to explore the patient journey to diagnosis of GD from the perspectives of Gaucher expert physicians and patients. Findings from the surveys revealed that many patients experienced diagnostic delays and misdiagnoses, with nearly 1 in 6 patients stating that they were not diagnosed with GD for 7years or more after first consulting a doctor. Physicians and patients both reported multiple referrals to different specialties before a diagnosis of GD was obtained, with primary care, haematology/haematology-oncology and paediatrics the main specialties to which patients first presented. Splenomegaly, thrombocytopenia, anaemia and bone pain were reported as the most common medical problems at first presentation in both surveys. These findings support a clear need for straightforward and easy-to-follow guidance designed to assist non-specialists to identify earlier patients who are at risk of GD

    Limits on the effective quark radius from inclusive epep scattering at HERA

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    The high-precision HERA data allows searches up to TeV scales for Beyond the Standard Model contributions to electron-quark scattering. Combined measurements of the inclusive deep inelastic cross sections in neutral and charged current epep scattering corresponding to a luminosity of around 1 fb1^{-1} have been used in this analysis. A new approach to the beyond the Standard Model analysis of the inclusive epep data is presented; simultaneous fits of parton distribution functions together with contributions of "new physics" processes were performed. Results are presented considering a finite radius of quarks within the quark form-factor model. The resulting 95% C.L. upper limit on the effective quark radius is 0.4310160.43\cdot 10^{-16} cm.Comment: 10 pages, 4 figures, accepted by Phys. Lett.

    Combined QCD and electroweak analysis of HERA data

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    A simultaneous fit of parton distribution functions (PDFs) and electroweak parameters to HERA data on deep inelastic scattering is presented. The input data are the neutral current and charged current inclusive cross sections which were previously used in the QCD analysis leading to the HERAPDF2.0 PDFs. In addition, the polarisation of the electron beam was taken into account for the ZEUS data recorded between 2004 and 2007. Results on the vector and axial-vector couplings of the Z boson to u- and d-type quarks, on the value of the electroweak mixing angle and the mass of the W boson are presented. The values obtained for the electroweak parameters are in agreement with Standard Model predictions.Comment: 32 pages, 10 figures, accepted by Phys. Rev. D. Small corrections from proofing process and small change to Fig. 12 and Table

    Measurement of the cross-section ratio sigma_{psi(2S)}/sigma_{J/psi(1S)} in deep inelastic exclusive ep scattering at HERA

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    The exclusive deep inelastic electroproduction of ψ(2S)\psi(2S) and J/ψ(1S)J/\psi(1S) at an epep centre-of-mass energy of 317 GeV has been studied with the ZEUS detector at HERA in the kinematic range 2<Q2<802 < Q^2 < 80 GeV2^2, 30<W<21030 < W < 210 GeV and t<1|t| < 1 GeV2^2, where Q2Q^2 is the photon virtuality, WW is the photon-proton centre-of-mass energy and tt is the squared four-momentum transfer at the proton vertex. The data for 2<Q2<52 < Q^2 < 5 GeV2^2 were taken in the HERA I running period and correspond to an integrated luminosity of 114 pb1^{-1}. The data for 5<Q2<805 < Q^2 < 80 GeV2^2 are from both HERA I and HERA II periods and correspond to an integrated luminosity of 468 pb1^{-1}. The decay modes analysed were μ+μ\mu^+\mu^- and J/ψ(1S)π+πJ/\psi(1S) \,\pi^+\pi^- for the ψ(2S)\psi(2S) and μ+μ\mu^+\mu^- for the J/ψ(1S)J/\psi(1S). The cross-section ratio σψ(2S)/σJ/ψ(1S)\sigma_{\psi(2S)}/\sigma_{J/\psi(1S)} has been measured as a function of Q2,WQ^2, W and tt. The results are compared to predictions of QCD-inspired models of exclusive vector-meson production.Comment: 24 pages, 8 figure

    Search for a narrow baryonic state decaying to pKS0{pK^0_S} and pˉKS0{\bar{p}K^0_S} in deep inelastic scattering at HERA

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    A search for a narrow baryonic state in the pKS0pK^0_S and pˉKS0\bar{p}K^0_S system has been performed in epep collisions at HERA with the ZEUS detector using an integrated luminosity of 358 pb1^{-1} taken in 2003-2007. The search was performed with deep inelastic scattering events at an epep centre-of-mass energy of 318 GeV for exchanged photon virtuality, Q2Q^2, between 20 and 100 GeV2\rm{} GeV^{2}. Contrary to evidence presented for such a state around 1.52 GeV in a previous ZEUS analysis using a sample of 121 pb1^{-1} taken in 1996-2000, no resonance peak was found in the p(pˉ)KS0p(\bar{p})K^0_S invariant-mass distribution in the range 1.45-1.7 GeV. Upper limits on the production cross section are set.Comment: 16 pages, 4 figures, accepted by Phys. Lett. B. Minor changes from journal reviewing process, including a small correction to figure
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