Observation of time-reversal symmetry breaking in the band structure of altermagnetic RuO2_2

Altermagnets are an emerging third elementary class of magnets. Unlike ferromagnets, their distinct crystal symmetries inhibit magnetization while, unlike antiferromagnets, they promote strong spin polarization in the band structure. The corresponding unconventional mechanism of timereversal symmetry breaking without magnetization in the electronic spectra has been regarded as a primary signature of altermagnetism, but has not been experimentally visualized to date. We directly observe strong time-reversal symmetry breaking in the band structure of altermagnetic RuO$_2$ by detecting magnetic circular dichroism in angle-resolved photoemission spectra. Our experimental results, supported by ab initio calculations, establish the microscopic electronic-structure basis for a family of novel phenomena and functionalities in fields ranging from topological matter to spintronics, that are based on the unconventional time-reversal symmetry breaking in altermagnets

The attitude of USMU students to vaccination against COVID-19

The aim of the study – to determine the attitude of medical students to vaccination against COVID-19 (motivation, possible problems, post-vaccination reactions).Цель исследования – определить отношение студентов-медиков к вакцинопрофилактике COVID-19 (мотивация, возможные проблемы, поствакцинальные реакции)

Pulseless disease

The article discusses a rare form of large vessel vasculitis – Takayasu arteritis, based on the literature data; the questions of epidemiological, the sequence of diagnostic procedures and treatment tactics are reflectedВ статье рассмотрена редкая форма васкулита крупных артерий - Артериит Такаясу, на основании литературных данных отражены вопросы эпидемиологии, последовательность проведения диагностических процедур и тактики лечени

Suppression of the vacuum space-charge effect in fs-photoemission by a retarding electrostatic front lens

The performance of time-resolved photoemission experiments at fs-pulsed photon sources is ultimately limited by the e–e Coulomb interaction, downgrading energy and momentum resolution. Here, we present an approach to effectively suppress space-charge artifacts in momentum microscopes and photoemission microscopes. A retarding electrostatic field generated by a special objective lens repels slow electrons, retaining the k-image of the fast photoelectrons. The suppression of space-charge effects scales with the ratio of the photoelectron velocities of fast and slow electrons. Fields in the range from −20 to −1100 V/mm for Ekin = 100 eV to 4 keV direct secondaries and pump-induced slow electrons back to the sample surface. Ray tracing simulations reveal that this happens within the first 40 to 3 μm above the sample surface for Ekin = 100 eV to 4 keV. An optimized front-lens design allows switching between the conventional accelerating and the new retarding mode. Time-resolved experiments at Ekin = 107 eV using fs extreme ultraviolet probe pulses from the free-electron laser FLASH reveal that the width of the Fermi edge increases by just 30 meV at an incident pump fluence of 22 mJ/cm2 (retarding field −21 V/mm). For an accelerating field of +2 kV/mm and a pump fluence of only 5 mJ/cm2, it increases by 0.5 eV (pump wavelength 1030 nm). At the given conditions, the suppression mode permits increasing the slow-electron yield by three to four orders of magnitude. The feasibility of the method at high energies is demonstrated without a pump beam at Ekin = 3830 eV using hard x rays from the storage ring PETRA III. The approach opens up a previously inaccessible regime of pump fluences for photoemission experiments

Time of flight photoelectron momentum microscopy with 80 500 MHz photon sources electron optical pulse picker or bandpass pre filter

The small time gaps of synchrotron radiation in conventional multi bunch mode 100 500 MHz or laser based sources with high pulse rate 80 MHz are prohibitive for time of flight ToF based photoelectron spectroscopy. Detectors with time resolution in the 100 ps range yield only 20 100 resolved time slices within the small time gap. Here we present two techniques of implementing efficient ToF recording at sources with high repetition rate. A fast electron optical beam blanking unit with GHz bandwidth, integrated in a photoelectron momentum microscope, allows electron optical pulse picking with any desired repetition period. Aberration free momentum distributions have been recorded at reduced pulse periods of 5 MHz at MAX II and 1.25 MHz at BESSY II . The approach is compared with two alternative solutions a bandpass pre filter here a hemispherical analyzer or a parasitic four bunch island orbit pulse train, coexisting with the multi bunch pattern on the main orbit. Chopping in the time domain or bandpass pre selection in the energy domain can both enable efficient ToF spectroscopy and photoelectron momentum microscopy at 100 500 MHz synchrotrons, highly repetitive lasers or cavity enhanced high harmonic sources. The high photon flux of a UV laser 80 MHz, lt;1 meV bandwidth facilitates momentum microscopy with an energy resolution of 4.2 meV and an analyzed region of interest ROI down to lt;800 nm. In this novel approach to sub m ARPES the ROI is defined by a small field aperture in an intermediate Gaussian image, regardless of the size of the photon spo

Epidemiology of bloodstream infections in the burn icu

The study included data on 80 adult patients hospitalized in the ICU of the Yekaterinburg Burn Center in 2018 - 2019, who underwent at least one bacteriological blood test. In a small observational study, bloodstream infection did not lead to an increase in mortality, but is an important factor in increasing the incidence (length of hospitalization and ICU). In 70,5% of cases, the source of bloodstream infections are P. aeruginosa and S. aureus. The duration of standing of the CVC is one of the most important criteria for the development of bloodstream infectionsВ исследование включены данные о 80 взрослых пациентах, госпитализированных в ОРИТ ожогового центра Екатеринбурга в 2018 – 2019 гг, которым было сделано по крайней мере одно бактериологическое исследование крови. В небольшом обсервационном исследовании инфекция кровотока не привела к увеличению летальности, но является важным фактором увеличивающем заболеваемость (длительность госпитализации в стационаре и ОРИТ). В 70,5% случаев источником инфекций кровотока являются P. aeruginosa и S. aureus. Длительность стояния ЦВК один из важнейших критериев, обуславливающих развитие инфекций кровотока