Strangeness dynamics in relativistic nucleus-nucleus collision

We investigate hadron production as well as transverse hadron spectra in nucleus-nucleus collisions from 2 $A\cdot$GeV to 21.3 $A\cdot$TeV within two independent transport approaches (UrQMD and HSD) that are based on quark, diquark, string and hadronic degrees of freedom. The comparison to experimental data demonstrates that both approaches agree quite well with each other and with the experimental data on hadron production. The enhancement of pion production in central Au+Au (Pb+Pb) collisions relative to scaled $pp$ collisions (the 'kink') is well described by both approaches without involving any phase transition. However, the maximum in the $K^+/\pi^+$ ratio at 20 to 30 A$\cdot$GeV (the 'horn') is missed by $\sim$ 40%. A comparison to the transverse mass spectra from $pp$ and C+C (or Si+Si) reactions shows the reliability of the transport models for light systems. For central Au+Au (Pb+Pb) collisions at bombarding energies above $\sim$ 5 A$\cdot$GeV, however, the measured $K^{\pm}$ $m_{T}$-spectra have a larger inverse slope parameter than expected from the calculations. The approximately constant slope of $K^\pm$ spectra at SPS (the 'step') is not reproduced either. Thus the pressure generated by hadronic interactions in the transport models above $\sim$ 5 A$\cdot$GeV is lower than observed in the experimental data. This finding suggests that the additional pressure - as expected from lattice QCD calculations at finite quark chemical potential and temperature - might be generated by strong interactions in the early pre-hadronic/partonic phase of central Au+Au (Pb+Pb) collisions.Comment: 10 pages, 5 figures, Invited talk presented by H. Stocker at ERICE-2003 (Sep. 2003, Erice, Italy), to be published in Prog. Part. Nucl. Phys. 52 (2004

Beam-target helicity asymmetry e in K0 Λ and K0 Σ0 photoproduction on the neutron

We report the first measurements of the E beam-target helicity asymmetry for the γ - n - →K0Λ and K0Σ0 channels in the energy range 1.70≤W≤2.34 GeV. The CLAS system at Jefferson Lab uses a circularly polarized photon beam and a target consisting of longitudinally polarized solid molecular hydrogen deuteride with low background contamination for the measurements. The multivariate analysis method boosted decision trees is used to isolate the reactions of interest. Comparisons with predictions from the KaonMAID, SAID, and Bonn-Gatchina models are presented. These results will help separate the isospin I=0 and I=1 photocoupling transition amplitudes in pseudoscalar meson photoproduction

Photon beam asymmetry Sigma for eta and eta ' photoproduction from the proton

Measurements of the linearly-polarized photon beam asymmetry $\Sigma$ for photoproduction from the proton of $\eta$ and $\eta^\prime$ mesons are reported. A linearly-polarized tagged photon beam produced by coherent bremsstrahlung was incident on a cryogenic hydrogen target within the CEBAF Large Acceptance Spectrometer. Results are presented for the $\gamma p \to \eta p$ reaction for incident photon energies from 1.070 to 1.876 GeV, and from 1.516 to 1.836 GeV for the $\gamma p \to \eta^\prime p$ reaction. For $\gamma p \to \eta p$, the data reported here considerably extend the range of measurements to higher energies, and are consistent with the few previously published measurements for this observable near threshold. For $\gamma p \to \eta^\prime p$, the results obtained are consistent with the few previously published measurements for this observable near threshold, but also greatly expand the incident photon energy coverage for that reaction. Initial analysis of the data reported here with the Bonn-Gatchina model strengthens the evidence for four nucleon resonances -- the $N(1895)1/2^-$, $N(1900)3/2^+$, $N(2100)1/2^+$ and $N(2120)3/2^-$ resonances -- which presently lack the "four-star" status in the current Particle Data Group compilation, providing examples of how these new measurements help refine models of the photoproduction process.Comment: 10 pages, 3 figure

First measurement of the polarization observable E in the p→(γ→,π⁺)n reaction up to 2.25 GeV

First results from the longitudinally polarized frozen-spin target (FROST) program are reported. The double-polarization observable E, for the reaction $\vec \gamma \vec p \to \pi^+n$, has been measured using a circularly polarized tagged-photon beam, with energies from 0.35 to 2.37 GeV. The final-state pions were detected with the CEBAF Large Acceptance Spectrometer in Hall B at the Thomas Jefferson National Accelerator Facility. These polarization data agree fairly well with previous partial-wave analyses at low photon energies. Over much of the covered energy range, however, significant deviations are observed, particularly in the high-energy region where high-L multipoles contribute. The data have been included in new multipole analyses resulting in updated nucleon resonance parameters. We report updated fits from the Bonn-Gatchina, J\"ulich, and SAID groups.Comment: 6 pages, 3 figure

Клинические и морфологические особенности повреждения миокарда и течения фульминантного миокардита на фоне СOVID-19, диагностика и тактика лечения

In a review article based on my own clinical experience of managing patients with acute myocardial injury and fulminant myocarditis, taking into account expert recommendations on the clinical treatment of myocardial damage associated with novel coronavirus infection a National clinical geriatric medical research center, division of cardiovascular diseases, the Chinese geriatrics society, Department of cardiology, Beijing Medical Association and European clinics discusses the pathogenesis, diagnosis and treatment of myocardial damage and FM patients, infected with SARS-CoV-2 in the context of the COVID-19 pandemic. Clinical features and diagnostic criteria are presented, including screening tests of markers of myocardial damage in the form of a highly sensitive troponin test, a natriuretic peptide. The article discusses in detail the pathogenesis and mechanisms of myocardial damage, including immune mechanisms, cytokine storm, systemic inflammation with macro- and microvascular dysfunction and the development of myocardial dysfunction with acute heart failure, hypotension, cardiogenic shock and/or life-threatening heart rhythm disorders caused by hypoxia and metabolic disorders at the cellular level. Features of the clinical course of fulminant myocarditis in infected patients (SARS-CoV-2) in the conditions of the COVID-19 pandemic are presented. For the first time, a detailed histo-morphological analysis of pathological myocardial injuries and complications is presented on the basis of unique autopsy material on post-mortem diagnostics of various pathoanatomic autopsies of those who died from COVID-19 in Moscow. Based on the clinical, functional and morphological material, the Protocol of etiopathogenetic treatment is presented. The basis of standard therapy is considered antiviral drugs, immunoglobulin G, the use of monoclonal antibodies to interleukin-6, anticoagulants, glucocorticoids, depending on the clinical situation, cardioprotectors and symptomatic treatment are recommended to maintain the heart, which in combination can achieve a certain clinical effectiveness. As adjuvant cardioprotective targeted therapy, the sodium salt of phosphocreatine is considered in order to preserve the myocardium, maintain its contractility and vital activity.В обзорной статье обсуждаются вопросы патогенеза, диагностики и лечения повреждения миокарда и фульминантного миокардита у больных, инфицированных SARS-CoV-2, в условиях пандемии COVID-19. Представлены клинические особенности и диагностические критерии, включающие скрининговые тесты маркеров повреждения миокарда в виде высокочувствительного тропонинового теста, натрийуретического пептида. Детально обсуждаются вопросы патогенеза и механизмы повреждения миокарда, включающие иммунные механизмы, цитокиновый шторм, системное воспаление с макро- и микроваскулярной дисфункцией и развитием дисфункции миокарда с острой сердечной недостаточностью, гипотензией, кардиогенным шоком и/или жизнеугрожающими нарушениями ритма сердца, обусловленные гипоксией и метаболическими нарушениями на клеточном уровне. Представлены особенности клинического течения фульминантного миокардита у больных, инфицированных SARS-CoV-2, в условиях пандемии COVID-19. Впервые представлен детальный гистоморфологический анализ патологических повреждений миокарда и осложнений на основе уникального аутопсийного материала по посмертной диагностике многообразных патологоанатомических вскрытий умерших от COVID-19 в Москве. На основании клинико-функционального и морфологического материала представлен протокол этиопатогенетического лечения. В зависимости от клинической ситуации для поддержания работы сердца в качестве метаболической адъювантной кардиопротективной таргетной терапии рассматривается натриевая соль фосфокреатина с целью поддержания сократительной способности и жизнедеятельности миокарда. Для улучшения прогноза у больных с COVID-19, перенесших острое повреждение миокарда, фульминантный миокардит, в протокол лечения рекомендовано введение кардиопротективной терапии, которая в комбинации со стандартной терапией позволяет достичь клинической эффективности

Организация рабочих процессов по рекрутингу доноров и заготовке реконвалесцентной плазмы в период пандемии COVID-19

Background. The pandemic of the new coronavirus infection has challenged the medical community for quickly finding and implementing effective methods of treatment. In the absence of a vaccine or specific therapy with proven effectiveness, the usage of convalescent plasma can be the one of perspective methods. An important aspect of this technology is the efficient and safe preparation of convalescent plasma. To date, in the world literature there are practically no publications about donor recruitment and the specifics of the preparation of convalescent plasma. Purpose of the research. Presentation of the experience of organizing a workflow for recruiting donors and stockpiling of convalescent plasma with a high titer of virus-neutralizing antibodies to SARS-CoV-2. Methods. The analysis of the work of the Blood Service of the Moscow Department of Health for stockpiling of COVID-19 convalescent plasma has been executed. In total it has been stockpiled 1240 doses. The normative documentation has been developed by a working group on the basis of the current federal legislation of Russian federation and been approved by the Moscow Department of Health. The titer of neutralizing antibodies (VNA) has been determined as the basic method for assessing the immunological viability of convalescent plasma. The main characteristics of donors, the characteristics of the disease course, the results of preliminary testing for the presence of specific antibodies by ELISA and CLIA methods has been compared with VNA titers in the stockpiled convalescent plasma. Results. Due to a Moscow Health Departments order No. 325 dated 01.04.2020 (a basic local regulatory document) it has been developed a regulation for the stockpiling, examination, storage, safety and transfering of fresh frozen pathogen-reduced plasma of COVID-19 convalescent donors to medical organizations of the Moscow Health Department. For arranging an interaction with donors it has been created a call-center. For effective preliminary selection, it has been formed a donor characteristics list, which has been combined with screening of specific antibodies by ELISA and CLIA methods. Conclusions. Developed a system of recruiting donors and procurement process of convalescent plasma for treatment СOVID-19, which includes the necessary regulations, algorithms for the selection and recruitment of donors, the registry of donors and recipients, algorithms, efficiency and safety of convalescent plasma.Обоснование. Пандемия новой коронавирусной инфекции поставила перед медицинским сообществом задачу быстрого поиска и внедрения эффективных методик лечения. В условиях отсутствия вакцины и средств специфической терапии с доказанной эффективностью в качестве одной из перспективных методик рассматривается трансфузия реконвалесцентной плазмы (РП). Важным аспектом данной технологии является заготовка эффективного и безопасного компонента. На сегодняшний день публикации по рекрутингу доноров и особенностях заготовки РП в мировой литературе практически отсутствуют. Цель исследования Анализ опыта организации рабочего процесса по привлечению доноров и заготовке РП с высоким титром вируснейтрализующих антител к SARS-CoV-2. Методы. Проведен анализ работы Службы крови Департамента здравоохранения г. Москвы (ДЗМ) по заготовке РП COVID-19. Всего заготовлено 1240 доз. Нормативная документация разработана рабочей группой на основании действующего федерального законодательства и утверждена ДЗМ. Как базовая методика оценки иммунологической состоятельности РП, определен титр вируснейтрализующих антител (ВНА). Проведено сопоставление основных характеристик доноров, особенностей течения заболевания, результатов предварительного тестирования на наличие специфических антител методами ИФА и ИХЛА с титрами ВНА заготовленной РП. Результаты. Работа по заготовке, обследованию, хранению, обеспечению безопасности и передаче в медицинские организации ДМЗ свежезамороженной патогенредуцированной плазмы доноров-реконвалесцентов COVID-19 была организована на основании приказа ДЗМ от 01.04.2020 № 325 как базового локального нормативного документа. Для оптимальной коммуникации с состоявшимися донорами и привлечения реконвалесцентов использовались ресурсы колл-центра. Для эффективного предварительного отбора доноров применялись анализ характеристик донора (плазма с наибольшими значениями титра ВНА ожидаема от доноров-мужчин, переболевших с признаками явной вирусной пневмонии) и результаты скрининга специфических антител методами ИФА и ИХЛА. Заключение. Разработана система обеспечения рекрутинга доноров и процесса заготовки РП для лечения СOVID-19, включающая необходимые нормативные документы, алгоритмы отбора и привлечения доноров, реестр доноров и реципиентов, алгоритмы обеспечения эффективности и безопасности РП

Double polarisation observable G for single pion photoproduction from the proton

We report measurements of and meson photoproduction from longitudinally spin-polarised protons by an energy tagged (0.73-2.3 GeV) and linearly polarised photon beam. A close to complete solid angle coverage for the reaction products was provided by the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The double-polarisation observable is extracted from Maximum Likelihood fits to the data, enabling the first accurate determination for the reaction , while also significantly extending the kinematic coverage for . This large data set provides an important constraint on the properties and spectrum of excited nucleon states decaying to Nπ in the mass range from 1.4 to 2.2 GeV, as well as for background (non-resonant) photoproduction processes. The considerable improvement achieved in the description of the observable within the SAID and Bonn-Gatchina approaches after implementation of our data, illustrates that the partial-wave analyses now significantly extend the knowledge on Nπ photoproduction amplitudes at GeV. A partial-wave analysis using the new high-precision data set has a large impact on the extracted properties of high-spin nucleon excited states