39 research outputs found
Особенности течения гриппа, вызванного новым вирусом А / H1N1 / CA / 2009, у больных в амбулаторной практике
Summary. Emergence of a new influenza virus А / H1N1 / CA / 2009 (IA2009) in October–December, 2009, in Russia required to investigate clinical features of the infection and effectiveness of treatment in ambulatory practice. Information from outpatient medical cards of 44 patients seeking for medical aid because of acute respiratory viral infection (ARVI) during pandemic 2009 was analyzed. All patients were examined for the presence of influenza А / H1N1 / CA / 2009 virus RNA, seasonal influenza virus RNA and influenza B virus RNA in nasopharyngeal swabs using polymerase chain reaction (PCR). According to the PCR results, patients were identified as having influenza А / H1N1 (n = 21) or other ARVI (n = 23). Signs and symptoms, complete blood count test, urine test, and chest X-ray were analyzed. Retrospective analysis found that 76.2 % of influenza А / H1N1 patients had acute respiratory diseases during previous 12 months and 19.0 % of them were healthcare workers. Leading symptoms and signs in patients with influenza А / H1N1 were cough, headache, weakness, myalgia, fever, obstruction of upper and lower airways. Mild course of disease was observed only in 23.8 % of the cases with recovery during 10 days. Complications were found in 28.6 % of the patients, 14.3 % of them were hospitalized. The most frequent changes in complete blood count tests were accelerated erythrocyte sedimentation rate, neutropenia / leucopenia, lymphocytosis, monocytosis, anisocytosis, thrombocyte aggregation. In 31.3 % cases, changes in white cell count remained after clinical recovery and resolving all respiratory symptoms. Administration of antiviral antibiotic Ingavirin in patients with influenza А / H1N1 started in the first 2 days of the disease was more effective compared with immunomodulating drug Arbidol.Резюме. Эпидемическая циркуляция нового вируса гриппа А / H1N1 / CA / 2009 в России в октябре–декабре 2009 г. потребовала изучения особенностей течения болезни и эффективности лечения больных гриппом в условиях поликлиники. Был проведен анализ данных 44 амбулаторных карт больных, обратившихся в поликлинику в период эпидемического подъема заболеваемости по поводу острой респираторной вирусной инфекции. Все больные были обследованы на наличие РНК вируса гриппа А / H1N1 / CA / 2009, сезонного гриппа А и гриппа В в мазках со слизистой носоглотки методом полимеразной цепной реакции (ПЦР) в режиме реального времени. По результату ПЦР были выделены больные гриппом А / H1N1 (n = 21) и ОРВИ (n = 23). Анализировались частота субъективных и объективных признаков болезни, показатели анализа крови, общего анализа мочи, рентгенографии грудной клетки, тактика ведения больных. Оценивались тяжесть течения и частота осложнений, данные об острых заболеваниях в последние 12 мес., а так же хронических болезнях. Ретроспективный анализ данных амбулаторных карт показал, что 76,2 % больных гриппом в течение 12 мес. до эпидемии перенесли острое заболевание органов дыхания. 19 % больных гриппом были медицинскими работниками. В течение 3 дней от начала заболевания обратились за медицинской помощью 14,3 % пациентов; ведущими субъективными симптомами были кашель, головная боль, слабость, боль в мышцах. В клинической картине для гриппа были характерны повышенная температура (100 % случаев), поражение верхних и нижних отделов дыхательных путей с признаками обструкции. В 76,2 % случаев отмечалось среднетяжелое и тяжелое течение болезни. Осложнения имели 28,6 % пациентов, в 14,3 % случаев им была необходима госпитализация. Вирус гриппа обнаруживался методом ПЦР в слизи из носоглотки до 11 дней болезни. Изменения в анализе крови при гриппе были обнаружены в 100 % случаев. Наиболее частыми были ускорение скорости оседания эритроцитов, нейтропения / лейкопения, лимфоцитоз, моноцитоз, анизоцитоз, агрегация тромбоцитов, которые сохранялись в 31,3 % случаев и при отсутствии клинических симптомов. Противовирусная терапия в первые 2 сут. от начала гриппа и ОРВИ сокращала продолжительность болезни. Назначение препарата ингавирин при гриппе было более эффективно, чем препарата арбидол
Determination of metals in natural waters by inductively coupled plasma optical emission spectroscopy after preconcentration on silica sequentially coated with layers of polyhexamethylene guanidinium and sulphonated nitrosonaphthols
A series of complexing adsorbents is prepared by coating silica particles with linear polyhexamethylene guanidinium (PHMG) chloride followed by saturation with a number of sulphonated nitrosonaphthols reagents electrostatically retained by positively charged polymer layer. PHMG coated silica is hydrolytically stable even during treatment with 6 M HCl heated up to 50 °C. The adsorption of 1-nitroso-2-naphthol-3,6-disulfonic acid (nitroso-R-salt), 2-nitroso-1-naphthol-4-sulfonic acid (nitroso-N-salt), and 2-nitroso-1-naphthol-3,6-disulfonic acid (nitroso-K-salt) on PHMG modified silica was studied. The effective immobilisation of sulphonated nitrosonaphthols was achieved in the range of pH of 3 - 8, while the adsorption of the monosulphonated reagent (nitroso-N-salt) is twice as high as the disulphonated analogues (nitroso-R-salt and nitroso-K-salt). The adsorption of Cu(II), Fe(III), Co(II), Ni(II), Al(III), Zn(II), Pb(II), Mn(II), and Cr(III) on prepared complexing adsorbents under static and dynamic conditions was studied as a function of time, pH, sample volume, and presence of interfering ions. Metal ions can be desorbed by using 1 M HCl or 1 M HNO3. The preconcentration factors of metals under optimized conditions are varied from 20 to 80. The developed method was used for the preconcentration of trace metals from natural waters followed by ICP-OES determination. The sub-ppb limits of detection of metals are achieved. © 2019 Svetlana L. Didukh-Shadrina et al
Estimate of the travelling wave speed for an integro-differential equation
Travelling waves for nonlocal reaction–diffusion equations are studied. The minimax representation of the wave speed is obtained. It is used to obtain analytical estimates and asymptotic values of the speed. Two regimes of wave propagation are identified. One of them is dominated by diffusion and another one by the nonlocal interaction. © 2018 Elsevier Lt
Dynamics of periodicwaves in a neural field model
Periodic traveling waves are observed in various brain activities, including visual, motor, language, sleep, and so on. There are several neural field models describing periodic waves assuming nonlocal interaction, and possibly, inhibition, time delay or some other properties. In this work we study the influences of asymmetric connectivity functions and of time delay for symmetric connectivity functions on the emergence of periodic waves and their properties. Nonlinear wave dynamics are studied, including modulated and aperiodic waves. Multiplicity of waves for the same values of parameters is observed. External stimulation in order to restore wave propagation in a damaged tissue is discussed. © 2020 by the authors
Cortical waves and post-stroke brain stimulation
A neural field model with different activation and inhibition connectivity and response functions is considered. Stability analysis of a homogeneous in space solution determines the conditions of the emergence of stationary periodic solutions and of periodic travelling waves. Various regimes of wave propagation are illustrated in numerical simulations. The influence of external stimulation on the wave properties is investigated. © 2019 John Wiley & Sons, Ltd
Free and nonsteady-state oscillations of elastic fluid-filled systems situated on an elastic base
Modelling the dynamics of virus infection and immune response in space and time
International audienceSpreading of viral infection in the tissues such as lymph nodes or spleendepends on virus multiplication in the host cells, their transport andon the immune response. Reaction–diffusion systems of equations withdelays in proliferation and death terms of the immune cells represent anappropriate model to study this process. The properties of the immuneresponse and the initial viral load determine the regimes of infectionspreading. In the proposed model, the proliferation rate of the immunecells is represented by a bell-shaped function of the virus concentrationwhich increases for small concentrations and decreases if the concentrationis sufficiently high. Here we use such a model system to show that aninfection can be completely eliminated or it can remain present togetherwith a decreased concentration of immune cells. Finally, immune cellscan be completely exhausted leading to a high virus concentration in thetissue. In addition, we predicted two novel regimes of infection dynamicsnot observed before. Infection propagation in the tissue can occur asa superposition of two travelling waves: first wave propagates as a lowlevel infection front followed by a high level infection front with a smallerspeed of propagation. Both of the travelling waves can have a positive or anegative speed corresponding to infection advancement or retreat. Theseregimes can be accompanied by instabilities and the emergence of complexspatiotemporal patterns
Preconcentration and Determination of Nickel ions using Silica with Functional Groups of Sulfonic Derivatives of Nitroso Naphthols
Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.Silica based adsorbents modified with polyhexamethylene guanidine and sulfonic derivatives of nitroso naphthols
- nitroso-N salt (NNS) and nitroso-R salt (NRS), have been proposed for preconcentration and solid-phase
photometric determination of Ni(II) in industrial solutions. Adsorbents with the surface concentration of the reagents
of 1.5 and 3 μmol/g have been studied. Adsorbents with NNS functional groups quantitatively extract Ni(II) at pH
5.5-7.5, while with NRS functional groups – at pH 5.5-7.0, giving complex compounds with the composition
Ni(II) : Reagent = 1 : 3. After Ni(II) adsorption the adsorbents became orange (λ = 510 нм) or brown (λ = 490 нм)
for NNS and NRS respectively. The pH range of maximum color intensity coincides with the pH range of the
quantitative extraction of Ni(II). The procedure of solid-phase photometric determination of Ni(II) in form of diffuse
reflectance spectroscopy has been developed. The analytical range of the procedure is 0.1 – 3.0 μg of Ni(II)
per 0.1 g of the adsorbent with the surface concentration of the reagent of 1.5 μmol/g and 0.15 – 6 μg of Ni(II)
per 0.1g of the adsorbent with the surface concentration of the reagent of 3 μmol/g. The procedure was used
for determination of Ni(II) in the rinsing and waste waters of galvanic manufactory. The results accuracy was
confirmed by ICP-OES analysis
Interplay between reaction and diffusion processes in governing the dynamics of virus infections
Spreading of viral infection in the tissues such as lymph nodes or spleen depends on virus multiplication in the host cells, their transport and on the immune response. Reaction-diffusion systems of equations with delays in cell proliferation and death by apoptosis represent an appropriate model to study this process. The properties of the cells of the immune system and the initial viral load determine the spatiotemporal regimes of infection spreading. Infection can be completely eliminated or it can persist at some level together with a certain chronic immune response in a spatially uniform or oscillatory mode. Finally, the immune cells can be completely exhausted leading to a high viral load persistence in the tissue. It has been found experimentally, that virus proteins can affect the immune cell migration. Our study shows that both the motility of immune cells and the virus infection spreading represented by the diffusion rate coefficients are relevant control parameters determining the fate of virus-host interaction. © 2018 Elsevier Lt