Plant thionins: structure, biological functions and potential use in biotechnology

Antimicrobial peptides (AMPs) are important components of defense system in both plants and animals. They represent an ancient mechanism of innate immunity providing rapid first line of defense against pathogens. Plant AMPs are classified into several families: thionins, defensins, nonspecific lipid-transfer proteins, hevein- and knottin-type peptides, hairpinins and macrocyclic peptides (cyclotides). The review focuses on the thionin family. Thionins comprise a plant-specific AMP family that consists of short (~5 kDA) cysteine-rich peptides containing 6 or 8 cysteine residues with antimicrobial and toxic properties. Based on similarity in amino acid sequences and the arrangement of disulphide bonds, five structural classes of thionins are discriminated. The three-dimensional structures of a number of thionins were determined. The amphipathic thionin molecule resembles the Greek letter Г, in which the long arm is formed by two antiparallel α-helices, while the short one, by two parallel β-strands. The residues responsible for the antimicrobial activity of thionins were identified. Thionins are synthesized as precursor proteins consisting of a signal peptide, the mature peptide region and the C-terminal prodomain. Thionins protect plants from pathogenic bacteria and fungi acting directly on the membranes of microorganisms at micromolar concentrations, although their precise mode of action remains unclear. In addition to plant pathogens, thionins inhibit growth of a number of human pathogens and opportunistic microorganisms, such as Candida spp., Saccharomyces cerevisiae, Fusarium solani, Staphylococcus aureus and Escherichia coli. Thionins are toxic to different types of cells including mammalian cancer cell lines. Transgenic plants expressing thionin genes display enhanced resistance to pathogens. A wide range of biological activities makes thionins promising candidates for practical application in agriculture and medicine

Measurements and modeling of optical-equivalent snow grain sizes under arctic low-sun conditions

The size and shape of snow grains directly impacts the reflection by a snowpack. In this article, different approaches to retrieve the optical-equivalent snow grain size (r$_{opt}$) or, alternatively, the specific surface area (SSA) using satellite, airborne, and ground-based observations are compared and used to evaluate ICON-ART (ICOsahedral Nonhydrostatic—Aerosols and Reactive Trace gases) simulations. The retrieval methods are based on optical measurements and rely on the r$_{opt}$-dependent absorption of solar radiation in snow. The measurement data were taken during a three-week campaign that was conducted in the North of Greenland in March/April 2018, such that the retrieval methods and radiation measurements are affected by enhanced uncertainties under these low-Sun conditions. An adjusted airborne retrieval method is applied which uses the albedo at 1700 nm wavelength and combines an atmospheric and snow radiative transfer model to account for the direct-to-global fraction of the solar radiation incident on the snow. From this approach, we achieved a significantly improved uncertainty (<25%) and a reduced effect of atmospheric masking compared to the previous method. Ground-based in situ measurements indicated an increase of r$_{opt}$ of 15 µm within a five-day period after a snowfall event which is small compared to previous observations under similar temperature regimes. ICON-ART captured the observed change of r$_{opt}$ during snowfall events, but systematically overestimated the subsequent snow grain growth by about 100%. Adjusting the growth rate factor to 0.012 µm$^{2}$ s$^{-1}$ minimized the difference between model and observations. Satellite-based and airborne retrieval methods showed higher r$_{opt}$ over sea ice (<300 µm) than over land surfaces (<100 µm) which was reduced by data filtering of surface roughness features. Moderate-Resolution Imaging Spectroradiometer (MODIS) retrievals revealed a large spread within a series of subsequent individual overpasses, indicating their limitations in observing the snow grain size evolution in early spring conditions with low Sun

Classification of Municipalities in the Republic of Buryatia by the Level of Tick-Borne Viral Encephalitis Incidence

Tick-borne viral encephalitis (TBVE) is one of the most significant natural-focal infections in the Russian Federation.The aim of the study was to analyze the current epidemiological situation on TBVE in the Buryat Republic in 2010–2020 with a subsequent differentiation of municipalities by epidemiological risk groups in order to elaborate proposals for optimization of preventive measures.Materials and methods. A retrospective analysis of the epidemiological situation on TBVE in the Buryat Republic was carried out using forms of federal statistical surveillance No. 2 “Information on infectious and parasitic diseases” over 2010–2020 and the data from the Reference Center of the Irkutsk Research Anti-Plague Institute of Siberia and Far East of the Rospotrebnadzor on the epidemiological situation and preventive measures in the municipalities of the constituent entity. Statistical processing was performed applying conventional methods of variation statistics. Based on calculated 95 % parametric confidence interval for the data on variability of the long-term average TBVE incidence in the municipalities of the Republic of Buryatia over a 10-year period, the entities were differentiated by epidemiological risk groups. QGis 2.18.28 and a set of open geodata OpenStreetMap were used for mapping.Results and discussion. All municipalities have been classified into five groups by the level of epidemiological risk: with zero TBVE incidence – 2 districts, with a low level – 4, medium – 8, high – 5, very high – 2. In addition, the administrative center has been placed into a separate group. Each individual group of municipalities is characterized by the number of TBVE cases, the level of morbidity, the frequency of seeking medical aid because of tick bites, the scope of specific and non-specific prevention measures. Recommendations for optimizing the tactics of TBVE prevention in certain municipal districts have been provided

Arrhythmias in patients with chronic renal insufficiency

Arrhythmias in patients with chronic renal insufficiency are more frequent then in the whole adult population. Evolution of arrhythmias in this group of patients is associated with the high risk of cardiovascular complications and sudden cardiac death. Abnormalities on electrocardiogram which reflect repolarization and depolarization changes appear earlier then arrhythmias. Mostly changes of P-wave and QT interval are learned now. Reasons of arrhythmias’ appearance are not known exactly. Probably arrhythmias in patients with chronic renal insufficiency evaluate because of factors’ complex, including electrolyte disbalance, influence of uremic toxins, left ventricular hypertrophy, procedure of haemodialysis. Nowadays decrease of “dialysis-associated" arrhythmias’ evolution is urgent question.Частота развития нарушений ритма у пациентов с хронической почечной недостаточностью выше, чем в общей популяции. Возникновение аритмий у данной категории пациентов ассоциировано с повышенным риском возникновения других сердечно-сосудистых осложнений и внезапной сердечной смерти. Развитию аритмий предшествуют изменения на ЭКГ, являющиеся отражением нарушения процессов деполяризации и реполяризации в сердце. Чаще всего это касается изменений зубца Р и интервала QT. Причины развития аритмий до конца не изучены. Вероятнее всего, у пациентов с нарушенной функцией почек аритмии возникают на фоне действия комплекса факторов, включающих электролитный дисбаланс, действие на сердце уремических токсинов, гипертрофии левого желудочка сердца, проведение процедуры гемодиализа. В настоящее время активно изучается вопрос снижения частоты развития «диализ-ассоциированных» нарушений ритма

EFFICACY AND SAFETY OF SINUS RHYTHM RESTORATION WITH AMIODARONE AND PROPAFENONE IN OUTPATIENTS, ECONOMIC ASPECTS (BASED ON DATA OF N.A. SEMASHKO NORTHERN MEDICAL CLINICAL CENTER)

Aim. To study efficacy and safey of sinus rhythm restoration with amiodarone and propafenone in outpatients with recurrent atrial fibrillation (AF), and to estimate pharmacoeconomic efficiency of such cardioversion in comparison with hospital treatment.Material and methods. Patients (n=199; aged 59.2±1.36) with paroxysmal (73.9%) or persistent (26.1%) AF were included into the multicenter prospective study. Follow-up period was 13.14 months (min 1 month, max 36 months). Patients with arrhythmia relapse &lt;48 h received outpatient cardioversion with amiodarone or propafenone orally. Daily outpatient examination, including ECG and blood pressure monitoring every 30-60 min, was carried out to evaluate efficacy of cardioversion and hemodynamics. Phone contact with patients was available. Patients with unstable hemodynamics received cardioversion in hospital. Patients received propafenone in cumulative dose of 600 mg (150-300 mg every hour), and amiodarone 600-800 mg daily. The cost/effectiveness ratio (CER) was estimated. This ratio shows the cost of one unit of effect.Results. Outpatient cardioversion with amiodarone was started 24 h earlier (p=0.029) and with propafenone — 4.5 h earlier (p=0.002) than that in hospital. The average dose of amiodarone in ambulatory cardioversion was 1.3 times less (713.7±84,62 mg, p=0.345) than that in hospital cardioversion. Outpatient treatment with amiodarone restored sinus rhythm 8.7 h earlier, and with propafenone - 3.5 h earlier than the same treatments in hospital. Efficiency of hospital cardioversion with amiodarone was 70%, with propafenone - 80%, and efficiency of outpatient cardioversion — 96,1% and 98,4%, respectively. Outpatient treatment did not cause any severe side effects. Expenses for outpatient cardioversion made up 143 724.25 rubles, and for hospital cardioversion — 92 870.47 rubles. Average treatment costs for one patient in hospital was 6 times greater than for an outpatient. Outpatient cardioversion had the lowest CER (~1300 rubles%).Conclusion. Outpatient cardioversion with amiodarone or propafenone is not only effective and safe, but also economically feasible

Распространенность и клиническое значение нарушений дыхания, вызванных обструкцией верхних дыхательных путей во время сна, у пациентов с нарушениями сердечного ритма

Cardiac arrhythmias and respiratory disorders caused by upper airway obstruction during sleep are quite common pathologies. Fifty two patients with paroxysmal atrial fibrillation and frequent ventricular extrasystoles were examined in order to evaluate the spreading of sleep respiratory disorders and their role for arrhythmias pathogenesis.The obtained results revealed the high frequency of respiratory disorders in arrhithmias patients and the relationship between circadian arrhithmias character and the intensity of sleep respiratory disorders. Comparative analyse of the SPAP-therapy and the anti-arrhithmic medication effect on SOAHS showed more high efficacy of the first one.Аритмии сердца и нарушения дыхания, вызванные обструкцией верхних дыхательных путей во время сна, являются весьма распространенным патологическим состоянием. С целью оценки распространенности нарушений дыхания во время сна и их роли в патогенезе аритмий были исследованы 52 пациента с пароксизмальной мерцательной аритмией и частой желудочковой экстрасистолией.По результатам исследования выявлена высокая распространенность нарушений дыхания в группе больных с аритмиями, а также наличие определенной взаимосвязи циркадного характера аритмий с выраженностью нарушений дыхания во время сна. Сравнительный анализ антиаритмического эффекта медикаментозной терапии СОАГС и СРАР-терапии показал более высокую эффективность последней

Satellite observations for detecting and forecasting sea-ice conditions: A summary of advances made in the SPICES Project by the EU's Horizon 2020 Programme

The detection, monitoring, and forecasting of sea-ice conditions, including their extremes, is very important for ship navigation and offshore activities, and for monitoring of sea-ice processes and trends. We summarize here recent advances in the monitoring of sea-ice conditions and their extremes from satellite data as well as the development of sea-ice seasonal forecasting capabilities. Our results are the outcome of the three-year (2015-2018) SPICES (Space-borne Observations for Detecting and Forecasting Sea-Ice Cover Extremes) project funded by the EU's Horizon 2020 programme. New SPICES sea-ice products include pancake ice thickness and degree of ice ridging based on synthetic aperture radar imagery, Arctic sea-ice volume and export derived from multisensor satellite data, and melt pond fraction and sea-ice concentration using Soil Moisture and Ocean Salinity (SMOS) radiometer data. Forecasts of July sea-ice conditions from initial conditions in May showed substantial improvement in some Arctic regions after adding sea-ice thickness (SIT) data to the model initialization. The SIT initialization also improved seasonal forecasts for years with extremely low summer sea-ice extent. New SPICES sea-ice products have a demonstrable level of maturity, and with a reasonable amount of further work they can be integrated into various operational sea-ice services

Characteristics of organs and tissues of the oral cavity in patients of older age groups with iron deficiency anemia

The article analyzes the characteristics of the oral mucosa of patients with iron deficiency anemia (IDA), aged 48 to 62 years. A study of their prevalence showed that in this group of patients diseases of the organs and tissues of the oral cavity prevail, an increase in the intensity of dental caries is revealed,В статье проведен анализ особенностей состояния слизистой оболочки полости ртау пациентов с железодефицитной анемией (ЖДА), в возрасте от 48 до 62 лет. Изучение их распространенности показало, что у данного контингента пациентов превалируют заболевания органов и тканей полости рта, выявлено увеличение интенсивности поражения зубов кариесом, преобладают заболевания тканей пародонта. В ходе исследования установлено наличие при ЖДА атрофического глоссита у пациентов, сопровождающегося парестезией (100%). В 88,24% случаев диагностируется ксеростомия второй степени, что подтверждают значения МПРЖ (минерализующий потенциал ротовой жидкости). Своевременный скрининг таких пациентов на приеме у врача – стоматолога способствует ранней адекватной коррекционной терапии, направленной на нормализацию показателей гемоглобина крови, положительно изменяя качество жизни больны

Characterising patterns of engagement of different participants in a public STEM-based analysis project

An analysis project undertaken in the context of a historic visitor site is described. The project offered different types of opportunity for scientific working, and involved four distinct groups of participants. Two distinguishing features of the different groups of participants were their primary motivation for engagement with the activity, and their level of previous engagement with formal science education. Participants in different parts of the project were assessed as to their level of science capital (Archer et al., 2015). Drawing upon engagement theory, the observable behaviours were used as an indicator of engagement and then categorised according to Pearson's (2010) taxonomy. The analysis showed that learner engagement was exhibited at different levels by the different categories of participants, with higher levels of engagement exhibited by participants with a higher level of science capital. Although there was general correlation between the level of science capital and the proportion of higher engagement learning behaviours, one group of participants deviated from this trend. The findings indicate that the level of science capital is a key determinant of engagement and associated learning behaviours, but did not completely account for participants’ engagement in the science outreach activity

Chromatin compaction in terminally differentiated avian blood cells: the role of linker histone H5 and non-histone protein MENT

Chromatin has a tendency to shift from a relatively decondensed (active) to condensed (inactive) state during cell differentiation due to interactions of specific architectural and/or regulatory proteins with DNA. A promotion of chromatin folding in terminally differentiated avian blood cells requires the presence of either histone H5 in erythrocytes or non-histone protein, myeloid and erythroid nuclear termination stage-specific protein (MENT), in white blood cells (lymphocytes and granulocytes). These highly abundant proteins assist in folding of nucleosome arrays and self-association of chromatin fibers into compacted chromatin structures. Here, we briefly review structural aspects and molecular mode of action by which these unrelated proteins can spread condensed chromatin to form inactivated regions in the genome