Effect of Dust Extinction on Estimating Star Formation Rate of Galaxies: Lyman Continuum Extinction

We re-examine the effect of Lyman continuum ($\lambda \leq 912$ \AA) extinction (LCE) by dust in H {\sc ii} regions in detail and discuss how it affects the estimation of the global star formation rate (SFR) of galaxies. To clarify the first issue, we establish two independent methods for estimating a parameter of LCE ($f$), which is defined as the fraction of Lyman continuum photons contributing to hydrogen ionization in an H {\sc ii} region. One of those methods determines $f$ from the set of Lyman continuum flux, electron density and metallicity. In the framework of this method, as the metallicity and/or the Lyman photon flux increase, $f$ is found to decrease. The other method determines $f$ from the ratio of infrared flux to Lyman continuum flux. Importantly, we show that f \la 0.5 via both methods in many H {\sc ii} regions of the Galaxy. Thus, it establishes that dust in such H {\sc ii} regions absorbs significant amount of Lyman continuum photons directly. To examine the second issue, we approximate $f$ to a function of only the dust-to-gas mass ratio (i.e., metallicity), assuming a parameter fit for the Galactic H {\sc ii} regions. We find that a characteristic $\hat{f}$, which is defined as $f$ averaged over a galaxy-wide scale, is 0.3 for the nearby spiral galaxies. This relatively small $\hat{f}$ indicates that a typical increment factor due to LCE for estimating the global SFR ($1/\hat{f}$) is large ($\sim 3$) for the nearby spiral galaxies. Therefore, we conclude that the effect of LCE is not negligible relative to other uncertainties of estimating the SFR of galaxies.Comment: 18 papges, 11 figures, accepted by Ap

ISOPHOT far-infrared serendipity sky survey

The ISOPHOT Serendipity Survey utilizes the slew time between ISO's pointed observations with strip scanning measurements of the sky in the far-IR at 170 micrometers . The slews contain information about two fundamentally different types of objects, namely unresolved galactic and extragalactic far-IR sources as well as extended regions of galactic cirrus emission. Since the structure of the obtained data is almost unique, the development of dedicated software to extract astrophysically interesting parameters for the crossed sources is mandatory. Data analysis is currently in its early stages and concentrates on the detection of point sources. First results from an investigation of a high galactic latitude field near the North Galactic Pole indicate that the detection completeness with respect to previously known IRAS sources will be almost 100 percent for sources with f(subscript 100micrometers > 2 Jy, dropping below approximately equals 50 percent for f(subscript 100micrometers < 1.5 Jy. Nevertheless, even faint sources down to a level of f(subscript 170micrometers approximately equals 1 Jy can be detected. Since the majority of the detected point sources are galaxies, the Serendipity Survey will result in a large database of approximately equals 2000 galaxies

The structure of ESKAPE pathogens isolated from patients of the neonatal intensive care unit at the National Hospital of Pediatrics in Hanoi, the Socialist Republic of Vietnam

Introduction. The incidence of healthcare-associated infections is a major public health problem worldwide, affecting all countries regardless of their economic status. The main agents of these infections are pathogens belonging to the ESKAPE group. The aim of the study was to explore the structure, molecular and antigenic characteristics of the ESKAPE pathogens isolated from oral and anal mucosa of patients of the neonatal intensive care unit (NICU), and to assess their etiological significance in occurrence of healthcare-associated infections. Materials and methods. Samples from a total of 49 children were tested, including 40 newborns patients of NICU at the National Hospital of Pediatrics in Hanoi. Collection and processing of biomaterial (oropharyngeal swabs, rectal swabs) and isolation of bacterial cultures were performed using conventional bacteriological methods. Mass spectrometry was used for identification of isolates. Klebsiella pneumoniae strains were analyzed using the whole-genome sequencing method. Results. The group of gram-positive ESKAPE pathogens identified in oral mucosa was represented by isolates Enterococcus faecium and Staphylococcus aureus. The isolates of the family Enterobacteriaceae included K. pneumoniae, Escherichia coli, Enterobacter cloacae; the group of nonfermenting gram-negative bacteria was represented by Pseudomonas aeruginosa, Acinetobacter baumannii. The structure of ESKAPE pathogens persistent in anal mucosa was characterized by dominance of Enterococcus spp., E. coli, K. pneumoniae and P. aeruginosa bacteria. The whole-genome sequencing of K. pneumoniae isolates revealed 7 clusters and 8 sequence types. ST14 and ST1741 prevailed, accounting for 25%, respectively, of the total number of the studied strains. The molecular serotyping showed that by the O antigen, strains belonged mainly to serotypes O1v1, O1/ O2v2, O5; by the presence of the capsular antigen to serotypes KL2, KL104, KL60. Conclusion. The analysis of the structure of the ESKAPE pathogens isolated from the oral and anal mucosa of patients of NICU at the National Hospital of Pediatrics in Hanoi identified etiologically significant agents of bacterial infections: S. aureus, K. pneumoniae, E. coli, E. cloacae, P. aeruginosa, A. baumannii. The molecular and genetic analysis of K. pneumoniae strains co-circulating in mucous membranes of several patients of the unit revealed their homology, thus confirming healthcare-associated contamination of children with nosocomial strains

Антивирусная и интерферониндуцирующая активность новых соединений – производных индолхиноксалинов

Проблематика. Розробка нових препаратів з антивірусною активністю та здатністю індукувати інтерферон є актуальним завданням з огляду на стрімке поширення вірусних інфекцій, формування резистентних до існуючих антивірусних препаратів штамів вірусів, загальне зниження імунної відповіді. Мета дослідження. Визначення антивірусної та інтерфероногенної активності похідних індолохіноксалінів в умовах in vitro. Методика реалізації. У роботі в умовах in vitro на перещеплюваній культурі клітин ST вивчали антивірусну та інтерфероніндукуючу дію 18 нових новосинтезованих сполук – похідних індолохіноксалінів. Результати дослідження. Показано здатність досліджуваних речовин пригнічувати розвиток вірусного цитопатичного ефекту на моделі ST-BBC тільки при лікувальній схемі введення. На моделі перещеплюваних культур клітин ST показано, що 12 із 18 досліджених сполук у концентраціях 0,1–0,2 мкг/мл здатні до індукції ІФН. Висновки. Серед досліджених сполук – похідних індолохіноксаліну як перспективну для подальших досліджень визначено сполуку RG-61, яка проявляє низьку токсичність (порівняно зі сполуками низки похідних) і антивірусну активність у інфікованих клітинах, а також здатна до індукції ІФН.Background. The development of new drugs with antiviral activity and the ability to induce interferon is an urgent task, taking into account the rapid spread of viral infections, development of resistance the virus strains to existing antiviral drugs and the overall decline of the immune response. Objective. Determine the antiviral activity and interferon inducer actions of indolequinoxalines derivatives in terms of in vitro. Methods. The work on PST cell cultures in conditions of in vitro antiviral and interferon inducer of the 18 new indolequinoxalines derivatives was studied. Results. The ability of indolequinoxalines derivatives to inhibit the development of viral cytopathic effect on the model PST-BBC only in therapeutic regimens was shown. In the model of inoculated cell cultures PST is shown that 12 compounds are capable of inducing interferon in low concentrations. Conclusions. Among the indolequinoxalines derivatives RG-61 compound as a promising for further studies was identified, which has a low toxicity (as compared to a number of compounds derived), has antiviral activity in infected cells and is capable of inducing IFN.Проблематика. Разработка новых препаратов с антивирусной активностью и способностью индуцировать интерферон является актуальной задачей с учетом стремительного распространения вирусных инфекций, формирования резистентных к существующим антивирусным препаратам штаммов вирусов, общего снижения иммунного ответа. Цель исследования. Определение антивирусной и интерфероногенной активности производных индолохиноксалинов в условиях in vitro. Методика реализации. В работе на культурах клеток ST в условиях in vitro изучали противовирусное и интерферониндуцирующее действие 18 новых новосинтезированных соединений – производных индолохиноксалинов Результаты исследования. Показана способность исследуемых веществ подавлять развитие вирусного цитопатического эффекта на модели ST-BBC только при лечебной схеме введения. На модели перевиваемых культур клеток ST показано, что 12 из 18 исследованных соединений вызывают индукцию ИФН в достаточно низких концентрациях. Выводы. Среди исследованных соединений производных индолохиноксалина как перспективное для дальнейших исследований определено соединение RG-61, которое проявляет низкую токсичность (по сравнению с соединениями ряда производных) и антивирусную активность в инфицированных клетках, а также индуцирует ИФН

BIOLOGICAL PROPERTIES AND MOLECULAR-GENETIC CHARACTERISTICS OF BACILLUS ANTHRACIS STRAINS, ISOLATED DURING THE OUTBREAK OF ANTHRAX IN THE YAMALO-NENETS AUTONOMOUS DISTRICT IN 2016

Objective of the study was to identify phenotypic properties and genetic peculiarities of Bacillus anthracis strains, isolated during the outbreak of anthrax in the territory of Yamal in 2016. Materials and methods. Investigated were the strains of anthrax agent, applying basic and subsequent identification tests and canSNP-, MLVA-genotyping methods and whole genome sequencing. Results and conclusions. The results showed the identity of the phenotypic properties, canSNPand MLVA25-genotypes, and profiles of whole genome-sequencing, regardless of the source of the strains isolation. Confirmed was a common source of human infection. Defined were phylogenetic interrelations of the tested strains and their position in global B. anthracis population. For the first time ever explored was variability of the gene pattern, associated with pathogenicity, and demonstrated – the efficiency of the proposed algorithm for genetic typing

CMR-determined scar volume: predictive for ventricular tachycardias?

The interesting data reported by Bernhardt et al. strengthen the diagnostic benefit of CMR in patients with ischemic cardiomyopathy. Consequently, the presence, location and size of the CMR-determined scar tissue may be used for better risk stratification in patients with ischemic cardiomyopathy eligible for ICD therapy

The emerging role of magnetic resonance imaging and multidetector computed tomography in the diagnosis of dilated cardiomyopathy

Magnetic resonance imaging and multidetector computed tomography are new imaging methods that have much to offer clinicians caring for patients with dilated cardiomyopathy. In this article we briefly describe the clinical, pathophysiological and histological aspects of dilated cardiomyopathy. Then we discuss in detail the use of both imaging methods for measurement of chamber size, global and regional function, for myocardial tissue characterisation, including myocardial viability assessment, and determination of arrhythmogenic substrate, and their emerging role in cardiac resynchronisation therapy

Role of Structure-Based Changes due to Somatic Mutation in Highly Homologous DNA-Binding and DNA-Hydrolyzing Autoantibodies Exemplified by A23P Substitution in the VH Domain

Anti-DNA autoantibodies are responsible for tissue injury in lupus. A subset of DNA-specific antibodies capable of DNA cleavage can be even more harmful after entering the living cells by destroying nuclear DNA. Origins of anti-DNA autoantibodies are not fully understood, and the mechanism of induction of DNA-cleaving activity remains speculative. The autoantibody BV04-01 derived from lupus-prone mouse is the only DNA-hydrolyzing immunoglobulin with known 3D structure. Identification and analysis of antibodies homologous to BV04-01 may help to understand molecular bases and origins of DNA-cleaving activity of autoantibodies. BLAST search identified murine anti-DNA autoantibody MRL-4 with sequences of variable region genes highly homologous to those of autoantibody BV04-01. Despite significant homology to BV04-01, not only MRL-4 had no DNA-cleaving activity, but also reversion of its unusual P23 mutation to the germline alanine resulted in a dramatic loss of affinity to DNA. Contrary to this effect, transfer of the P23 mutation to the BV04-01 has resulted in a significant drop in DNA binding and almost complete loss of catalytic activity. In the present paper we analyzed the properties of two homologous autoantibodies and mutants thereof and discussed the implications of unusual somatic mutations for the development of autoantibodies with DNA-binding and DNA-hydrolyzing activity