A new life for sterile neutrino dark matter after the pandemic

We propose a novel mechanism to generate sterile neutrinos $\nu_s$ in theearly Universe, by converting ordinary neutrinos $\nu_\alpha$ in scatteringprocesses $\nu_s\nu_\alpha\to\nu_s\nu_s$. After initial production byoscillations, this leads to an exponential growth in the $\nu_s$ abundance. Weshow that such a production regime naturally occurs for self-interacting$\nu_s$, and that this opens up significant new parameter space where $\nu_s$make up all of the observed dark matter. Our results provide strong motivationto further push the sensitivity of X-ray line searches, and to improve onconstraints from structure formation.<br

A new life for sterile neutrino dark matter after the pandemic

We propose a novel mechanism to generate sterile neutrinos $\nu_s$ in the early Universe, by converting ordinary neutrinos $\nu_\alpha$ in scattering processes $\nu_s\nu_\alpha\to\nu_s\nu_s$. After initial production by oscillations, this leads to an exponential growth in the $\nu_s$ abundance. We show that such a production regime naturally occurs for self-interacting $\nu_s$, and that this opens up significant new parameter space where $\nu_s$ make up all of the observed dark matter. Our results provide strong motivation to further push the sensitivity of X-ray line searches, and to improve on constraints from structure formation

A new life for sterile neutrino dark matter after the pandemic

We propose a novel mechanism to generate sterile neutrinos $\nu_s$ in theearly Universe, by converting ordinary neutrinos $\nu_\alpha$ in scatteringprocesses $\nu_s\nu_\alpha\to\nu_s\nu_s$. After initial production byoscillations, this leads to an exponential growth in the $\nu_s$ abundance. Weshow that such a production regime naturally occurs for self-interacting$\nu_s$, and that this opens up significant new parameter space where $\nu_s$make up all of the observed dark matter. Our results provide strong motivationto further push the sensitivity of X-ray line searches, and to improve onconstraints from structure formation.<br

Объемная капнография как способ оценки эффективности альвеолярной вентиляции в клинической практике

The purpose of the study was to compare the relationship between the dead space volume and tidal volume (VD/VT) using volumetric capnography (VCap) during pressure controlled (PCV) and pressure supported (PSV) ventilation mode in the postoperative period.Materials and methods. 30 randomly assigned cardiac surgical patients undergoing CABG (coronary artery bypass grafting) using ECC (extracorporeal circuit) were included in an observational, prospective study. Patients were connected to the ventilator immediately after ICU admission. After that, monitoring VD/VT, CO2 production (VECO2) as well as ventilation parameters was carried out. The parameters during PCV and PSV mode were statistically evaluated using t-test.Results. Expiratory CO2 (ETCO2) concentration were not significantly different in both PCV or PSV (p=NS), although both VECO2 and minute ventilation (MV) increased during PSV mode (p&lt;0.01). VD/VT in PSV mode was lower than in PCV. Gas exchange represented by alveolar ventilation (VA) was better during PSV (p&lt;0.01). VA was also higher during PSV (p&lt;0.05). The calculated VD/VT ratio differed between PCV and PSV mode (p&lt;0.01).Conclusion. VCap represents a tool for monitoring of CO2 exchange effectivness. We registered a decrease in VD/VT with improved alveolar ventilation (VA) in PSV mode. VCap seems to be a suitable instrument for adjustment of protective lung ventilation.Цель исследования — сравнить взаимосвязь между объемом мертвого пространства и дыхательным объемом (VD/VT) методом объемной капнографии (VCap) в режимах искусственной вентиляции легких с управляемым давлением (PCV) и поддержкой давлением (PSV) в послеоперационном периоде.Материалы и методы. В обсервационное, проспективное исследование методом случайного выбора включили 30 пациентов из отделения сердечно-сосудистой хирургии, перенесших операцию аортокоронарного шунтирования (АКШ) с экстракорпоральным кровообращением. Пациентов подключали к системе вентиляции легких сразу при поступлении в отделение интенсивной терапии. Затем проводили мониторинг VD/VT, продукции CO2 (VECO2), а также параметров вентиляции. Параметры вентиляции в режимах с управляемым давлением (PCV) и поддержкой давлением (PSV) статистически оценивалиРезультаты. Не выявили достоверных различий концентрации CO2 во выдыхаемом воздухе (ETCO2) между режимами PCV и PSV (p=NS), хотя как VECO2, так и минутная вентиляция (MV) возрастали в режиме PSV (p&lt;0,01). Отношение VD/VT в режиме PSV было ниже, чем в режиме PCV. Газообмен, представленный альвеолярной вентиляцией (VA), был лучше в режиме PSV (p&lt;0,01). Показатель VA был также выше в режиме PSV (p&lt;0,05). Расчетное отношение VD/VT различалось между режимами PCV и PSV (p&lt;0,01).Заключение. Объемная капнография (VCap) является средством мониторинга эффективности обмена CO2. Отмечали снижение VD/VT с улучшением альвеолярной вентиляции (VA) в режиме PSV. VCap представляется подходящим методом регулирования протективной вентиляции легких

Drug interaction with T-cell receptors: T-cell receptor density determines degree of cross-reactivity

Background: Immune-mediated adverse reactions to drugs are often due to T-cell reactivity, and cross-reactivity is an important problem in pharmacotherapy. Objective: We investigated whether chemical inert drugs can stimulate T cells through their T-cell receptor (TCR) and analyzed the cross-reactivities to related compounds. Methods: We transfected human TCRs isolated from two drug-reactive T-cell clones (TCCs) by PCR into a TCR-negative mouse T-cell hybridoma. The TCCs were isolated from a patient with drug hypersensitivity to the antibacterial sulfonamide sulfamethoxazole (SMX). Results: The transfectants reacted to SMX only in the presence of antigen-presenting cells (APCs). Glutaraldehyde-fixed APCs, however, were sufficient to elicit T-cell stimulation, indicating a processing-independent direct interaction of the drug with the TCR and MHC molecule. The transfected hybridomas secreted IL-2 in a drug dose-dependent manner, whereas the degree of reactivity was dependent on the level of TCR expression. One transfectant reacted not only to SMX but also to related sulfonamide compounds. Interestingly, high TCR expression increased cross-reactivity to other structurally related compounds. In addition, SMX-specific TCR cross-reacted only with sulfonamides bearing a sulfanilamide core structure but not with sulfonamides such as celecoxib, furosemide, or glibenclamide. Conclusions: These results demonstrate that the T-cell reactivity to drugs is solely determined by the TCR. Moreover, these results show that cross-reactivity of structurally similar compounds correlates with the density of the TCR. Stably transfected T-cell hybridomas may represent a powerful screening tool for cross-reactivity of newly generated sulfonamide-containing compounds such as celecoxib