Structures and orientational transitions in thin films of tilted hexatic smectics

We present detailed systematic studies of structural transformations in thin liquid crystal films with the smectic-C to hexatic phase transition. For the first time all possible structures reported in the literature are observed for one material (5 O.6) at the variation of temperature and thickness. In unusual modulated structures the equilibrium period of stripes is twice with respect to the domain size. We interpret these patterns in the frame work of phenomenological Landau type theory, as equilibrium phenomena produced by a natural geometric frustration in a system having spontaneous splay distortion.Comment: 7 pages, 6 figure

Обработка сигналов ЭКГ с помощью вейвлет-анализа: диагностические возможности

The problem of recognition and classification of biomedical signals is a complex problem related to the interdisciplinary field of computer science and medicine. Within the framework of the project implementation of the development of the new defibrillation equipment, it is necessary to solve the problems of analyzing biomedical signals of the electrocardiogram to obtain a diagnostic solution with the possibility of assigning a specific condition to the pathological condition of the patient. This article presents the analysis of electrocardiogram signals, considering the technical aspects of the analysis of multicomponent signals, and describes the diagnostic possibility of wavelet analysis of ECG signals. The paper considers the limited tools of analyzing the electrocardiogram signal, in particular, limitation of parametric data. Wavelet analysis may significantly expand the analysis of signals and transfer them into the time-frequency domain. Thus, the use of various basic functions of the wavelet transform leads to the determination of the additional diagnostically significant information formalized in the parameters extracted from the wavelet scalogram. Chupov A. A., Zhdanov A. E., Rakhmatullov F. K., Rakhmatullov R. F., Dolganov A. Yu. ECG Signals Processing by Using Wavelet Analysis: Diagnostic Capabilities. Ural Radio Engineering Journal. 2021;5(4):337–352. (In Russ.) DOI: 10.15826/urej.2021.5.4.001.Задача распознавания и классификации биомедицинских сигналов является комплексной задачей, относящейся к междисциплинарной области компьютерных наук и медицины. В рамках реализации проекта по разработке нового деффибрилляционного оборудования необходимо решить задачи анализа биомедицинских сигналов электрокардиограммы для получения диагностического решения с возможностью отнесения конкретного состояния к патологическому состоянию пациента. В настоящей статье представлен анализ сигналов электрокардиограммы, учитывающий технические аспекты анализа многокомпонентных сигналов, также описана диагностическая возможность вейвлет-анализа сигналов. Учитывая ограниченный инструментарий анализа сигнала электрокардиограммы с точки зрения набора параметрических данных, вейвлет-анализ позволяет значительно расширить анализ сигналов и перейти в частотно-временную область. Таким образом, использование различных базисных функций вейвлет-преобразования позволяет определить дополнительную диагностически значимую информацию, формализованную в параметрах, извлекаемых из вейвлет-скалограм. Чупов А. А., Жданов А. Е., Князев С. Т., Рахматуллов Ф. К., Рахматуллов Р. Ф., Долганов А. Ю. Обработка сигналов ЭКГ с помощью вейвлет-анализа: диагностические возможности. Ural Radio Engineering Journal. 2021;5(4):337–352. DOI: 10.15826/urej.2021.5.4.001. 

ECG Signals Processing by Using Wavelet Analysis: Diagnostic Capabilities

The concept of this article writing started up at the conference shortly after the 2021 IEEE 22nd International Conference of Young Professionals in Electron Devices and Materials (IEEE EDM 2021). We are grateful for the assistance of JSC «PA «UOMP» represented by Aleksandr V. Koshelev, Deputy General Director in Research and Dvelopment. The article is a part of the work devoted to the implementation of the project «Creation of high-tech production of medical devices for the restoration of heart function to ensure public defibrillation».Received: 14.10.2021. Accepted: 12.12.2021.Идея написания этой статьи возникла на международной конференции 2021 IEEE 22nd International Conference of Young Professionals in Electron Devices and Materials (IEEE EDM 2021). Благодарим за содействие АО «ПО «УОМЗ», в лице заместителя генерального директора по НИОКР Кошелева Александра Викторовича. Данная статья является частью работы, посвященной реализации проекта «Создание высокотехнологичного производства медицинских изделий для восстановления функции сердца в обеспечение общедоступной дефибрилляции».Поступила: 14.10.2021. Принята в печать: 12.12.2021.Задача распознавания и классификации биомедицинских сигналов является комплексной задачей, относящейся к междисциплинарной области компьютерных наук и медицины. В рамках реализации проекта по разработке нового деффибрилляционного оборудования необходимо решить задачи анализа биомедицинских сигналов электрокардиограммы для получения диагностического решения с возможностью отнесения конкретного состояния к патологическому состоянию пациента. В настоящей статье представлен анализ сигналов электрокардиограммы, учитывающий технические аспекты анализа многокомпонентных сигналов, также описана диагностическая возможность вейвлет-анализа сигналов. Учитывая ограниченный инструментарий анализа сигнала электрокардиограммы с точки зрения набора параметрических данных, вейвлет-анализ позволяет значительно расширить анализ сигналов и перейти в частотно-временную область. Таким образом, использование различных базисных функций вейвлет-реобразования позволяет определить дополнительную диагностически значимую информацию, формализованную в параметрах, извлекаемых из вейвлет-скалограм.The problem of recognition and classification of biomedical signals is a complex problem related to the interdisciplinary field of computer science and medicine. Within the framework of the project implementation of the development of the new defibrillation equipment, it is necessary to solve the problems of analyzing biomedical signals of the electrocardiogram to obtain a diagnostic solution with the possibility of assigning a specific condition to the pathological condition of the patient. This article presents the analysis of electrocardiogram signals, considering the technical aspects of the analysis of multicomponent signals, and describes the diagnostic possibility of wavelet analysis of ECG signals. The paper considers the limited tools of analyzing the electrocardiogram signal, in particular, limitation of parametric data. Wavelet analysis may significantly expand the analysis of signals and transfer them into the time-frequency domain. Thus, the use of various basic functions of the wavelet transform leads to the determination of the additional diagnostically significant information formalized in the parameters extracted from the wavelet scalogram

Taxonomic distribution and origins of the extended LHC (light-harvesting complex) antenna protein superfamily

<p>Abstract</p> <p>Background</p> <p>The extended light-harvesting complex (LHC) protein superfamily is a centerpiece of eukaryotic photosynthesis, comprising the LHC family and several families involved in photoprotection, like the LHC-like and the photosystem II subunit S (PSBS). The evolution of this complex superfamily has long remained elusive, partially due to previously missing families.</p> <p>Results</p> <p>In this study we present a meticulous search for LHC-like sequences in public genome and expressed sequence tag databases covering twelve representative photosynthetic eukaryotes from the three primary lineages of plants (Plantae): glaucophytes, red algae and green plants (Viridiplantae). By introducing a coherent classification of the different protein families based on both, hidden Markov model analyses and structural predictions, numerous new LHC-like sequences were identified and several new families were described, including the red lineage chlorophyll <it>a/b</it>-binding-like protein (RedCAP) family from red algae and diatoms. The test of alternative topologies of sequences of the highly conserved chlorophyll-binding core structure of LHC and PSBS proteins significantly supports the independent origins of LHC and PSBS families via two unrelated internal gene duplication events. This result was confirmed by the application of cluster likelihood mapping.</p> <p>Conclusions</p> <p>The independent evolution of LHC and PSBS families is supported by strong phylogenetic evidence. In addition, a possible origin of LHC and PSBS families from different homologous members of the stress-enhanced protein subfamily, a diverse and anciently paralogous group of two-helix proteins, seems likely. The new hypothesis for the evolution of the extended LHC protein superfamily proposed here is in agreement with the character evolution analysis that incorporates the distribution of families and subfamilies across taxonomic lineages. Intriguingly, stress-enhanced proteins, which are universally found in the genomes of green plants, red algae, glaucophytes and in diatoms with complex plastids, could represent an important and previously missing link in the evolution of the extended LHC protein superfamily.</p

Simultaneous Analysis of Multiple Mycobacterium tuberculosis Knockdown Mutants In Vitro and In Vivo

Mycobacterium tuberculosis (Mtb) represents one of the most persistent bacterial threats to human health and new drugs are needed to limit its impact. Conditional knockdown mutants can help validate new drug targets, but the analysis of individual mutants is laborious and time consuming. Here, we describe quantitative DNA tags (qTags) and their use to simultaneously analyze conditional Mtb knockdown mutants that allowed silencing the glyoxylate and methylcitrate cycles (via depletion of isocitrate lyase, ICL), the serine protease Rv3671c, and the core subunits of the mycobacterial proteasome, PrcB and PrcA. The impact of gene silencing in multi-strain cultures was determined by measuring the relative abundance of mutant-specific qTags with real-time PCR. This achieved accurate quantification over a broad range of qTag abundances and depletion of ICL, Rv3671c, or PrcBA resulted in the expected impairment of growth of Mtb with butyrate as the primary carbon source, survival during oxidative stress, acid stress and starvation. The impact of depleting ICL, Rv3671c, or PrcBA in multi-strain mouse infections was analyzed with two approaches. We first measured the relative abundance of mutant-specific qTags in total chromosomal DNA isolated from bacteria that were recovered from infected lungs on agar plates. We then developed a two-step amplification procedure, which allowed us to measure the abundances of individual mutants directly in infected lung tissue. Both strategies confirmed that inactivation of Rv3671c and PrcBA severely reduced persistence of Mtb in mice. The multi-strain infections furthermore suggested that silencing ICL not only prevented growth of Mtb during acute infections but also prevented survival of Mtb during chronic infections. Analyses of the ICL knockdown mutant in single-strain infections confirmed this and demonstrated that silencing of ICL during chronic infections impaired persistence of Mtb to the extent that the pathogen was cleared from the lungs of most mice

Measurement of isotopic separation of argon with the prototype of the cryogenic distillation plant Aria for dark matter searches

The Aria cryogenic distillation plant, located in Sardinia, Italy, is a key component of the DarkSide-20k experimental program for WIMP dark matter searches at the INFN Laboratori Nazionali del Gran Sasso, Italy. Aria is designed to purify the argon, extracted from underground wells in Colorado, USA, and used as the DarkSide-20k target material, to detector-grade quality. In this paper, we report the first measurement of argon isotopic separation by distillation with the 26&nbsp;m tall Aria prototype. We discuss the measurement of the operating parameters of the column and the observation of the simultaneous separation of the three stable argon isotopes: 36Ar , 38Ar , and 40Ar . We also provide a detailed comparison of the experimental results with commercial process simulation software. This measurement of isotopic separation of argon is a significant achievement for the project, building on the success of the initial demonstration of isotopic separation of nitrogen using the same equipment in 2019

Study on cosmogenic activation above ground for the DarkSide-20k project

The activation of materials due to the exposure to cosmic rays may become an important background source for experiments investigating rare event phenomena. DarkSide-20k is a direct detection experiment for galactic dark matter particles, using a two-phase liquid argon time projection chamber filled with 49.7 tonnes (active mass) of Underground Argon (UAr) depleted in 39Ar. Here, the cosmogenic activity of relevant long-lived radioisotopes induced in the argon and other massive components of the set-up has been estimated; production of 120 t of radiopure UAr is foreseen. The expected exposure above ground and production rates, either measured or calculated, have been considered. From the simulated counting rates in the detector due to cosmogenic isotopes, it is concluded that activation in copper and stainless steel is not problematic. Activation of titanium, considered in early designs but not used in the final design, is discussed. The activity of 39Ar induced during extraction, purification and transport on surface, in baseline conditions, is evaluated to be 2.8% of the activity measured in UAr from the same source, and thus considered acceptable. Other products in the UAr such as 37Ar and 3H are shown to not be relevant due to short half-life and assumed purification methods