59 research outputs found
Conformal symmetry in quasifree Markovian open quantum systems
Conformal symmetry governs the behavior of closed systems near second-order phase transitions and is expected to emerge in open systems going through dissipative phase transitions. We propose a framework allowing for a manifest description of conformal symmetry in open Markovian systems. The key difference from the closed case is that both conformal algebra and the algebra of local fields are realized on the space of superoperators. We illustrate the framework by a series of examples featuring systems with quadratic Hamiltonians and linear jump operators, where the Liouvillian dynamics can be efficiently analyzed using the formalism of third quantization. We expect that our framework can be extended to interacting systems using an appropriate generalization of the conformal bootstrap.</p
Conformal symmetry in quasi-free Markovian open quantum systems
Conformal symmetry governs the behavior of closed systems near second-order
phase transitions, and is expected to emerge in open systems going through
dissipative phase transitions. We propose a framework allowing for a manifest
description of conformal symmetry in open Markovian systems. The key difference
from the closed case is that both conformal algebra and the algebra of local
fields are realized on the space of superoperators. We illustrate the framework
by a series of examples featuring systems with quadratic Hamiltonians and
linear jump operators, where the Liouvillian dynamics can be efficiently
analyzed using the formalism of third quantization. We expect that our
framework can be extended to interacting systems using an appropriate
generalization of the conformal bootstrap.Comment: 15 pages, supplementary Wolfram Mathematica notebook available at
https://github.com/idnm/third_quantization v2: minor revision (references
added, typos corrected) v2: Minor revisions done and typos correcte
Dual axis solar tracker test results in the condition of the Ural region
Работа посвящена исследованию эффективности применения технологии солнечного трекинга в климатических условиях Уральского региона. Авторами показано, что эффективность данной технологии сильно зависит от времени года. Так же в работе сделаны выводы о целесообразности применения технологии солнечного трекинга в условиях умеренно континентального климата.This article is devoted to the study of the solar tracking technology efficiency in climatic conditions of the Ural region. The authors have shown that the effectiveness of this technology is heavily dependent on the time of year. The conclusions of the feasibility of using solar tracking technology in a temperate continental climate also in this article
Heavy-meson physics and flavour violation with a single generation
We study flavour-violating processes which involve heavy B- and D-mesons and
are mediated by Kaluza-Klein modes of gauge bosons in a previously suggested
model where three generations of the Standard Model fermions originate from a
single generation in six dimensions. We find the bound on the size R of the
extra spatial dimensions 1/R>3.3 TeV, which arises from the three-body decay
B_s to K mu e. Due to the still too low statistics this bound is much less
stringent than the constraint arising from K to mu e, 1/R>64 TeV, which was
found in a previous work (Frere et al., JHEP, 2003). Nevertheless, we argue
that a clear signature of the model would be an observation of K to mu e and
B_s to K mu e decays without observations of other flavour and lepton number
changing processes at the same precision level.Comment: 15 page
RESULTS OF EXPERIMENTAL OPERATING OF ANAEROBIC TEST MODULAR BIOGAS PLANT MODEL BASED COMPOSITE MATERIALS
The paper discusses the results of the commissioning of the biogas plant. Also, a graph of the output of biogas in the period of the experiment.В работе рассматриваются результаты введения в эксплуатацию биогазовой установки. Так же приведен график выхода биогаза в период проведения эксперимента
Demonstration of a parity-time symmetry breaking phase transition using superconducting and trapped-ion qutrits
Scalable quantum computers hold the promise to solve hard computational
problems, such as prime factorization, combinatorial optimization, simulation
of many-body physics, and quantum chemistry. While being key to understanding
many real-world phenomena, simulation of non-conservative quantum dynamics
presents a challenge for unitary quantum computation. In this work, we focus on
simulating non-unitary parity-time symmetric systems, which exhibit a
distinctive symmetry-breaking phase transition as well as other unique features
that have no counterpart in closed systems. We show that a qutrit, a
three-level quantum system, is capable of realizing this non-equilibrium phase
transition. By using two physical platforms - an array of trapped ions and a
superconducting transmon - and by controlling their three energy levels in a
digital manner, we experimentally simulate the parity-time symmetry-breaking
phase transition. Our results indicate the potential advantage of multi-level
(qudit) processors in simulating physical effects, where additional accessible
levels can play the role of a controlled environment.Comment: 14 pages, 9 figure
Прогностическое значение тропонина I после операций коронарного шунтирования (по результатам исследования AMIRI-CABG)
In 2017, the European Society of Cardiology outlined the importance of the problem of diagnosing myocardial ischemia-reperfusion injury following coronary artery bypass grafting. Myocardial injury can be accompanied by a critical decline in the cardiac index and an increase in cardiac troponin I plasma levels. The prognostic value troponin I elevation after coronary artery bypass grafting is poorly understood. Objective: to determine the prognostic value of troponin I plasma levels in relation to a fall in the cardiac index after coronary artery bypass grafting (CABG). Task: To determine the probability the cardiac index falling below 2.2 for troponin I levels in the first hours, and on days 1, 2, 3, 4 after CABG. Materials and methods. The single-center, non-randomized prospective study, running from 2016 to 2019, included 336 patients admitted for elective surgical treatment of coronary artery disease. The CABG patients were divided into three observation groups: off-pump (n = 175), on-pump (n = 128), and pump-assisted (n = 33). Troponin I levels were measured in the first hours, and on days 1, 2, 3, 4 after surgery using the Pathfast Compact immunoassay analyzer. Cardiac index was measured by invasive method. Results. In patients with a cardiac index higher than 2.2, troponin I level did not exceed 0.5 ng/mL in the off-pump group, 6 ng/mL in the on-pump group, and 3.5 ng/mL in the pump-assisted group. Patients with cardiac index lower than 2.2 have comparable troponin I levels in all groups - 21 ng/mL. Troponin I thresholds on day 1 after surgery, which, when exceeded, was associated with the likelihood of the cardiac index falling below 2.2, was 3.78 ng/mL in the off-pump group, 9.67 ng/mL in the on-pump group and 17.06 ng/mL in the pump-assisted group. Conclusion. After off-pump CABG, clinically significant myocardial injury should be expected at lower troponin I levels (3.78 ng/mL) than after on-pump CABG (9.67 ng/mL) and pump-assisted CABG (14.7 ng/mL).В 2017 году Европейское общество кардиологов обозначило важность проблемы диагностики ишемически-реперфузионного повреждения миокарда после операций коронарного шунтирования. Повреждение миокарда может сопровождаться критическим снижением сердечного индекса и повышением концентрации кардиального тропонина I в крови. Прогностическое значение повышения уровня тропонина I после операций коронарного шунтирования недостаточно изучено. Цель: определить прогностическое значение концентрации тропонина I в плазме крови в отношении снижения сердечного индекса после операций коронарного шунтирования. Задачи: определить вероятность снижения сердечного индекса менее 2,2 для концентраций тропонина I в первые часы, на 1, 2, 3, 4-е сутки после операций коронарного шунтирования. Материалы и методы. В одноцентровое нерандомизированное проспективное исследование включено 336 пациентов, поступивших для планового оперативного лечения ишемической болезни сердца с 2016-го по 2019 г. Пациенты были распределены в три группы наблюдения: коронарное шунтирование без искусственного кровообращения (n = 175), с искусственным кровообращением (n = 128) и в условиях параллельного искусственного кровообращения (n = 33). Концентрацию тропонина I определяли в первые часы, на 1, 2, 3, 4-е сутки после операции с помощью прибора Pathfast Compact immuno-analyzer. Сердечный индекс измеряли инвазивным методом. Результаты. У пациентов с сердечным индексом более 2,2 уровень тропонина I в группе коронарного шунтирования без искусственного кровообращения не превышал 0,5 нг/мл, в группе с искусственным кровообращением - 6 нг/мл, в группе коронарного шунтирования на параллельном искусственном кровообращении - 3,5 нг/мл. Концентрация тропонина I у пациентов с сердечным индексом 2,2 и менее была сопоставима в группах наблюдения и составила 21 нг/мл. Пороговая концентрация тропонина I на 1-й день после операции, превышение которой было связано с вероятностью снижения сердечного индекса менее 2,2, составила 3,78; 9,67 и 17,06 нг/мл в группах без искусственного кровообращения, с искусственным кровообращением и на параллельном искусственном кровообращении соответственно. Заключение. После операций коронарного шунтирования без искусственного кровообращения клинически значимое повреждение миокарда следует предполагать при более низких концентрациях тропонина I (3,78 нг/мл), чем после коронарного шунтирования с искусственным кровообращением (9,67 нг/мл) и в условиях параллельного искусственного кровообращения (14,7 нг/мл)
AltitudeOmics: Red Blood Cell metabolic adaptation to high altitude hypoxia
Red blood cells (RBCs) are key players in systemic oxygen transport. RBCs respond to in vitro hypoxia through the so-called oxygen-dependent metabolic regulation, which involves the competitive binding of deoxyhemoglobin and glycolytic enzymes to the N-terminal cytosolic domain of band 3. This mechanism promotes the accumulation of 2,3-DPG, stabilizing the deoxygenated state of hemoglobin, and cytosol acidification, triggering oxygen off-loading through the Bohr effect. Despite in vitro studies, in vivo adaptations to hypoxia have not yet been completely elucidated. Within the framework of the AltitudeOmics study, erythrocytes were collected from 21 healthy volunteers at sea level, after exposure to high altitude (5260m) for 1, 7 and 16days, and following reascent after 7days at 1525m. UHPLC-MS metabolomics results were correlated to physiological and athletic performance parameters. Immediate metabolic adaptations were noted as early as a few hours from ascending to >5000m, and maintained for 16 days at high altitude. Consistent with the mechanisms elucidated in vitro, hypoxia promoted glycolysis and deregulated the pentose phosphate pathway, as well purine catabolism, glutathione homeostasis, arginine/nitric oxide and sulphur/H2S metabolism. Metabolic adaptations were preserved one week after descent, consistently with improved physical performances in comparison to the first ascendance, suggesting a mechanism of metabolic memory
Organization of providing service to epileptologlcal patients in Tyumen city and in the South of Tyumen region
Opening of Epiieptologicai Center and interterritorial epileptological rooms will improve the quality and availability of epileptological service to the population of Tyumen and South of the Tyumen region.Открытие эпилептологического центра и межтерриториальных эпилептологических кабинетов улучшит качество и доступность оказания специализированной эпилептологической помощи населению г.Тюмени и юга Тюменской области
Development and validation of an ultra?performance liquid chromatography quadrupole time of flight mass spectrometry method for rapid quantification of free amino acids in human urine
An ultra-performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-qTOFMS)method using hydrophilic interaction liquid chromatography was developed and validated for simultaneous quantification of 18 free amino acids in urine with a total acquisition time including the column re-equilibration of less than 18 min per sample. This method involves simple sample preparation steps which consisted of 15 times dilution with acetonitrile to give a final composition of 25 % aqueous and 75 % acetonitrile without the need of any derivatization. The dynamic range for our calibration curve is approximately two orders of magnitude (120-fold from the lowest calibration curve point) with good linearity (r2 ? 0.995 for all amino acids). Good separation of all amino acids as well as good intra- and inter-day accuracy (<15 %) and precision (<15 %) were observed using three quality control samples at a concentration of low, medium and high range of the calibration curve. The limits of detection (LOD) and lower limit of quantification of our method were ranging from approximately 1–300 nM and 0.01–0.5 µM, respectively. The stability of amino acids in the prepared urine samples was found to be stable for 72 h at 4 °C, after one freeze thaw cycle and for up to 4 weeks at ?80 °C. We have applied this method to quantify the content of 18 free amino acids in 646 urine samples from a dietary intervention study. We were able to quantify all 18 free amino acids in these urine samples, if they were present at a level above the LOD. We found our method to be reproducible (accuracy and precision were typically <10 % for QCL, QCM and QCH) and the relatively high sample throughput nature of this method potentially makes it a suitable alternative for the analysis of urine samples in clinical setting
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