Radiative Decay Width of Neutral non-Strange Baryons from PWA

An overview of the GW SAID and ITEP groups effort to analyze pion photoproduction on the neutron-target will be given. The disentanglement the isoscalar and isovector EM couplings of N* and Delta* resonances does require compatible data on both proton and neutron targets. The final-state interaction plays a critical role in the state-of-the-art analysis in extraction of the gamma n --> pi N data from the deuteron target experiments. It is important component of the current JLab, MAMI-C, SPring-8, ELSA, and ELPH programsComment: 7 pages, 7 figures, 1 table; Proceedings of International Conference Dark Matter, Hadron Physics and Fusion Physics, Messina, Italy, Sept. 2014; will be published in EPJ Web of Conference

ОСОБЕННОСТИ ПРОДУКЦИИ ВНЕКЛЕТОЧНЫХ ВЕЗИКУЛ КЛЕТКАМИ ЛИНИИ THP-1 ПРИ СТИМУЛЯЦИИ IN VITRO

HighlightsExtracellular vesicles (EVs) are membrane objects with inner and surface molecular cargo performing various biological functions associated with intercellular connection. Therefore, they are a promising object for diagnostic and therapeutic purposes.THP-1 is a human leukemia monocytic cell line and a classic model for monocyte/macrophage function and differentiation. Spectrum of THP-1-derived extracellular vesicles are heterogenic and are not to date totally clarified.The comparison of EVs produced by stimulated THP-1 cells is performed in the study. Aim. Quantitatively and qualitatively characterize THP-1-derived extracellular vesicles in concordance on type and dose of used stimulators.Methods. THP-1 cells were stimulated by PMA (4-phorbol 12-myristate 13-acetate), LPS (lipopolysaccharide) and TNF (tumor necrosis factor). Cell activation and viability were assessed by the expression of CD54 and DAPI (4′,6-diamidino-2-phenylindole) staining respectively. Size and quantitative characteristics were assessed using nanoparticle tracking analysis (NTA). Qualitative assessment of surface molecular markers was performed by high-sensitivity multicolor flow cytometry (hs-FCM).Results. TNF and PMA stimulation in medium and high doses led to an increase in quantity of small EVs (30–150 nm) that express tetraspanins CD9 and CD63. Low doses of TNF and PMA did not lead to a significant increase of EVs compared to control. There was a decrease in amount of small EVs (30–150 nm) in LPS-stimulated probes. However, medium and high doses of LPS stimulated selective CD63-positive EVs secretion with absence of CD9-positive events. Cell activation assessed by CD54 expression have been dose-dependent and was most prominent under PMA stimulation.Conclusion. Every type of THP-1 cell activators promotes changes in the functional activity of cells towards production of extracellular vesicles. Moreover, we demonstrate quantitative and qualitative difference in THP-1-derived vesicles under different stimulation conditions. Medium and high doses of PMA and TNF were the most relevant in stimulation of vesiculation. LPS-stimulation could be used to selectively obtain CD63-positive fraction of EV.Основные положенияВнеклеточные везикулы (ВВ) – это мембранные объекты c молекулярным грузом внутри себя и на поверхности, выполняющие разнообразные биологические функции, связанные с межклеточным взаимодействием, поэтому являются перспективным объектом для диагностических и терапевтических целей.Культура клеток острого миелоидного лейкоза человека – THP-1 – классическая модельная моноцитарно-макрофагальная система. Спектр секретируемых этой культурой ВВ гетерогенен и недостаточно охарактеризован к настоящему времени.В работе проводится сравнение продуцируемых клетками THP-1 ВВ при воздействии различных стимуляторов. Цель. Дать количественную и качественную характеристику внеклеточных везикул, продуцируемых клетками линии THP-1, в зависимости от использованного стимулятора и его дозы.Материалы и методы. В исследовании были использованы клетки культуры THP-1. Для стимуляции клеток использовались: PMA (4-форбол-12-миристат-13-ацетат) в дозах 5, 16 и 50 нг/мл, ЛПС (липополисахарид) в дозах 0,1 нг/мл, 0,3 нг/мл, 1,0 нг/мл и ФНО (фактор некроза опухоли) в дозах 5, 10 и 20 нг/мл. Активация клеток оценивалась изменением уровня экспрессии CD54, а наличие апоптоза/некроза – посредством подсчета DAPI (4′,6-диамидино-2-фенилиндол)-позитивных клеток с помощью высокочувствительной проточной цитометрии (hs-FCM). Размерность продуцируемых везикул и их количественная характеристика была дана с использованием анализа траектории наночастиц (NTA). Качественная характеристика экспрессируемых поверхностных молекулярных маркеров была дана с помощью высокочувствительной многоцветной проточной цитометрии (hs-FCM).      Результаты. Стимуляция ФНО и PMA в средних и высоких дозировках приводит к нарастанию секретируемой фракции малых (30–150 нм) внеклеточных везикул, экспрессирующих тетраспаниновые маркеры (CD9, CD63). Малые дозы ФНО и PMA не приводили к достоверному приросту количества ВВ. При использовании всех дозировок ЛПС отмечалось некоторое количественное снижение ВВ в диапазоне 30-150 нм (малые ВВ). Однако средние и высокие дозы ЛПС вызывали достоверную селективную секрецию CD63-положительных ВВ при полном отсутствии динамики изменения CD9-позитивных везикул. Активация клеток, оцениваемая по экспрессии CD54, носила дозозависимый характер и была наиболее выражена при стимуляции PMA.Заключение. Каждый вид использованной стимуляции клеток THP-1 провоцирует изменение функциональной активности клеток в отношении продуцируемых ими внеклеточных везикул. При этом может меняться не только количественный, но и качественный состав продуцируемых объектов. Наиболее предпочтительными в стимуляции везикуляции оказались средние и высокие дозы ФНО и PMA. Стимуляция ЛПС в средних и высоких дозах может быть использована для получения изолированной CD63-положительной фракции ВВ

Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires

The production of tt‾ , W+bb‾ and W+cc‾ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓν , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of $t\overline{t}$, $W+b\overline{b}$ and $W+c\overline{c}$ is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 $\pm$ 0.02 \mbox{fb}^{-1}. The $W$ bosons are reconstructed in the decays $W\rightarrow\ell\nu$, where $\ell$ denotes muon or electron, while the $b$ and $c$ quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions

Heterogenous CD8+ T Cell Maturation and ‘Polarization’ in Acute and Convalescent COVID-19 Patients

Background. The adaptive antiviral immune response requires interaction between CD8+ T cells, dendritic cells, and Th1 cells for controlling SARS-CoV-2 infection, but the data regarding the role of CD8+ T cells in the acute phase of COVID-19 and post-COVID-19 syndrome are still limited. Methods.. Peripheral blood samples collected from patients with acute COVID-19 (n = 71), convalescent subjects bearing serum SARS-CoV-2 N-protein-specific IgG antibodies (n = 51), and healthy volunteers with no detectable antibodies to any SARS-CoV-2 proteins (HC, n = 46) were analyzed using 10-color flow cytometry. Results. Patients with acute COVID-19 vs. HC and COVID-19 convalescents showed decreased absolute numbers of CD8+ T cells, whereas the frequency of CM and TEMRA CD8+ T cells in acute COVID-19 vs. HC was elevated. COVID-19 convalescents vs. HC had increased naïve and CM cells, whereas TEMRA cells were decreased compared to HC. Cell-surface CD57 was highly expressed by the majority of CD8+ T cells subsets during acute COVID-19, but convalescents had increased CD57 on ‘naïve’, CM, EM4, and pE1 2–3 months post-symptom onset. CXCR5 expression was altered in acute and convalescent COVID-19 subjects, whereas the frequencies of CXCR3+ and CCR4+ cells were decreased in both patient groups vs. HC. COVID-19 convalescents had increased CCR6-expressing CD8+ T cells. Moreover, CXCR3+CCR6- Tc1 cells were decreased in patients with acute COVID-19 and COVID-19 convalescents, whereas Tc2 and Tc17 levels were increased compared to HC. Finally, IL-27 negatively correlated with the CCR6+ cells in acute COVID-19 patients. Conclusions. We described an abnormal CD8+ T cell profile in COVID-19 convalescents, which resulted in lower frequencies of effector subsets (TEMRA and Tc1), higher senescent state (upregulated CD57 on ‘naïve’ and memory cells), and higher frequencies of CD8+ T cell subsets expressing lung tissue and mucosal tissue homing molecules (Tc2, Tc17, and Tc17.1). Thus, our data indicate that COVID-19 can impact the long-term CD8+ T cell immune response

FEATURES OF THE IMMUNE RESPONSE DURING VIRAL INFECTION

The aim of the investigation was to select using cluster analysis and comparatively characterize immune disorders types in acute and chronic viral infections. Patients with acute and chronic viral infections (n = 896) were examined: 77 patients with acute viral hepatitis B, 94 — chronic viral hepatitis B, 119 — chronic hepatitis C, 531 — recurrent herpes, 75 — human papillomavirus infection. Healthy persons (n = 466) were examined as control. The research of blood lymphocyte phenotype was performed by flow cytometry. Four-color immunophenotyping were used in the following panels: Т-lymphocytes (CD3+CD19–CD16/56–CD45+), Т-helpers (CD3+CD4+CD45+), cytotoxic Т-cells (CD3+CD8+CD45+), NKcells (CD3–CD16/56+CD45+), B-lymphocytes (CD3–CD19+CD16/56+CD45+). Absolute values were obtained on a dualplatform technology using the results of haematological analysis. The immunoglobulin concentrations were determined by ELISA. The clustering was performed by a single linkage method. The number of clusters was determined on the basis of calculating the values of the Euclidean distance between the mean group values. It was found that the parameters, characterizing the functional state of the various parts of the immune system in acute and chronic viral infections, considerable diversity values. Custer analysis allows to allocate 6 immunotypes defined different states of innate and adaptive immunity: characterized by activation of the innate (increasing the number of neutrophils and NK-cells) and adaptive immunity humoral response (increasing the concentration of IgG), characterized by hyperreaction of adaptive immunity (a significant increase in the concentration of IgG), discoordinated (multidirectional changes in the values of immunological parameters), immunodeficiency and unresponsiveness (did not differ from the control parameters) immunotypes. It is proved that in patients with viral infections most often determined by the “unresponsiveness” immunotype (40,5%), as well as humoral immunodeficiency (24,9%) and adaptive immune reaction (24,5%). A group of patients with chronic viral hepatitis B and C is allocated separately in which more than 10% of the detected adaptive immunity overreaction that is probably due to the development of chronic hepatitis. These immunotypes can be regarded as different pathogenetic variants of the course of acute and chronic viral infections. Healthy people often had unresponsiveness or immunodeficiency immunotypes, that is their immune system is out of activation. Stratification of patients with viral infections by immunotypes will increase the effectiveness of treatment and implement personalized approaches to diagnosis and treatment of functional disorders of the immune system

The study of supersaturated solid solution decomposition in magnesium-rich aluminum alloys with scandium and hafnium additions

Magnesium-rich aluminum alloys with small scandium additives are widely used in many branches of modern industry due to the high level of their mechanical properties. However, the issue of low thermal stability of Al3Sc particles, which does not allow performing deformation processing of this group of alloys at a temperature above 400 °С, continues to be relevant. Hafnium addition can become one of the ways to solve this problem as hafnium forms a shell around the Al3Sc particles and, due to the low diffusion coefficient in the aluminum matrix, reduces their coagulation rate. The paper studies the influence of addition of 0.2 % and 0.5 % Hf on the electrical conductivity and the process of supersaturated solid solution decomposition, as well as on the size and quantity of nanoparticles in the 1570 magnesium-rich aluminum alloy at its thermal treatment. The authors studied the kinetics of supersaturated solid solution decomposition in the 1570, 1570–0.2Hf, and 1570–0.5Hf alloys by the electrical conductivity measuring and constructed C-curves describing the supersaturated solid solution decomposition in the studied alloys in the temperature range of 260–440 °С. Besides, using transmission electron microscopy, the strengthening nanoparticles of the 1570 and 1570–0.5Hf alloys were studied during heating to 370 °C and 4-hour soaking. The study showed that hafnium addition significantly slows down the supersaturated solid solution decomposition in the 1570 alloy. The authors identified that in the alloys with hafnium additives, the supersaturated solid solution decomposition is the most intense at a temperature of 350 °С, and in the alloys without hafnium – at a temperature of 430 °С. The transmission microscopy data confirm that the 1570 alloy without hafnium contains 3–4.5 times more nanoparticles than the 1570–0.5Hf alloy