38 research outputs found
Evaporation and Vapor Formation of Graphite Suspensions Based on Water in a High-Temperature Gas Environment: an Experimental Investigation
We performed an experimental research on evaporation and vapor formation of water droplets containing large (2 mm in size) and small (0.05 mm and 0.2 mm in diameter) graphite inclusions, when heated in a high-temperature gas environment. We applied a high-speed (up to 104 fps) video recording to establish mechanisms of the processes considered. Moreover, we revealed the positive influence of addition of small graphite inclusions on intensifying the evaporation of heterogeneous suspension droplets. In addition, we made the assumption on the formation of vapor layer around the 10 and 15 ?l suspension droplets, as well as its negative influence on the lifetimes of suspension droplets ?h (increasing the times) in a high-temperature gas environment
Enhancing efficiency of using water due to explosive breakup of liquid drop
Using high-speed video recording, the experiments were performed to research quantitative characteristics of explosive breakup phenomenon of 5-15 [mu]l water droplets containing 2•2•1 mm and 2•2•2 mm solid inclusions, when heated in a tube furnace at temperatures of 1070-1370 K. Experimental results report number and size of the droplets detached during explosive breakup. We show that the fragmentation of liquid layer covering solid particles facilitates the increase the evaporation surface area 15-fold versus the initial surface area of a drop
Enhancing efficiency of using water due to explosive breakup of liquid drop
Using high-speed video recording, the experiments were performed to research quantitative characteristics of explosive breakup phenomenon of 5-15 [mu]l water droplets containing 2•2•1 mm and 2•2•2 mm solid inclusions, when heated in a tube furnace at temperatures of 1070-1370 K. Experimental results report number and size of the droplets detached during explosive breakup. We show that the fragmentation of liquid layer covering solid particles facilitates the increase the evaporation surface area 15-fold versus the initial surface area of a drop
Bastroviruses (<i>Astroviridae</i>): genetic diversity and potential impact on human and animal health
Introduction. Bastroviruses were discovered in the Netherlands in 2016 in human stool samples and show partial genetic similarities to astroviruses and hepatitis E viruses. Their association with disease onset has not yet been established.
Materials and methods. Metagenomic sequencing of fecal samples of Nyctalus noctula bats collected in the Russian Federation in 2023 was performed. Two almost complete genomes of bastroviruses were assembled. The zoonotic potential of these viruses was assessed using machine learning methods, their recombination was studied, and phylogenetic trees were constructed.
Results. A nearly complete bastrovirus genome was de novo assembled in one of the samples, and it was used to assemble another genome in another sample. The zoonotic potential of the virus from one of these samples was estimated as high. The existence of recombination between structural and non-structural polyproteins was demonstrated.
Conclusion. Two bastrovirus genomes were assembled, phylogenetic and recombination analyses were performed, and the zoonotic potential was evaluated
Comparative analysis of IgG levels in blood sera from patients with COVID-19, persons vaccinated by «Gam-COVID-Vac» and healthy donors before the pandemic
Introduction. Serum IgG measurement is used in the diagnosis and monitoring of many diseases. Therefore, it seems important to study the impact of coronavirus pandemic on IgG levels in population and the role of this parameter in COVID-19.
The aim of this study was to compare mean IgG levels in sera obtained from 31 hospitalized COVID-19 patients, 30 healthy donors before pandemic and 34 donors vaccinated with «Sputnik V» (have not had COVID-19).
Materials and methods. Total IgG was quantitated by two enzyme immunoassays (EIAs): «IgG Total-ELISA-BEST» kit certificated in Russia and homemade competitive EIA utilizing bispecific monoclonal antibodies (bsAbs) against human IgG (HIgG) and horseradish peroxidase (HRP).
Results and discussion. The groups did not show differences in IgG levels (regardless of sex) with both methods giving comparable results. However, «IgG Total-ELISA-BEST» kit revealed statistically significant differences in mean serum IgG levels in subgroups of male patients depending on the levels of antibodies to viral RBD-antigen: below and above 400 BAU/ml. In the first subgroup (10 men) the mean serum IgG content was 14.3 ± 4.1 mg/mL, while in the second (6 men) — 6.9 ± 2.7 mg/mL.
Conclusion. Sera obtained before pandemic contained the same mean IgG concentrations as sera from donors vaccinated with «Sputnik V» and COVID-19 patients. The relatively decreased mean IgG concentration was found only in COVID-19 male patients with anti-RBD antibodies levels above 400 BAU/ml. In light of literature data on association of decreased serum IgG with COVID-19 severity, it would be reasonable to further compare larger groups, taking into account clinical differences. The possibility of using bsAbs for human Ig measurements by competitive EIA was demonstrated
Plant Growth Promoting Activity and Metal Tolerance of Bacteria Isolated from Rhizosphere of the Orchid Epipactis atrorubens Growing on Serpentine Substrates of the Middle Urals
В статье представлены данные, полученные при изучении бактерий, выделенных
из ризосферы орхидеи Epipactis atrorubens (Hoffm.) Besser. Проведен сравнительный анализ
некоторых морфологических, физиологических и биохимических характеристик ризобактерий растений, произрастающих в двух биотопах на серпентинитовых породах: в естественном
лесном фитоценозе (фоновый участок) и на отвале после добычи асбеста (Свердловская
область, Средний Урал). Оценка ростстимулирующей (PGP) активности выделенных штаммов
не показала достоверных различий между исследованными участками по способности
ризобактерий к синтезу индолил‑3-уксусной кислоты (ИУК) и солюбилизации фосфатов.
Однако доля изолятов, способных к азотфиксации, была выше в ризосфере E. atrorubens,
произрастающего на отвале, по сравнению с фоновым местообитанием. Устойчивость изолятов
к тяжелым металлам оценивали по максимальной концентрации металла (400, 600 и 1000 мг/л
соответственно для Ni, Cu и Zn), при которой отмечался рост бактерий. Показано, что
ризобактерии с отвала оказались более устойчивыми к повышенным концентрациям металлов
по сравнению с естественным лесным фитоценозом. На основе молекулярно-генетического
анализа изолятов с наиболее выраженной PGP‑активностью (ИУК >1,0 мг/л; PO4
3- >50,0 мг/л)
обнаружено сходство между изученными местообитаниями по родовой принадлежности
ризобактерий E. atrorubens: выделенные штаммы принадлежали преимущественно к родам
Buttiauxella и Pseudomonas. В модельных экспериментах протестирована ростстимулирующая
способность четырех отобранных штаммов на семенах циннии. Инокуляция семян Pseudomonas
sp. и Buttiauxella sp. не оказывала значимого влияния на их всхожесть, однако Buttiauxella sp.
способствовала увеличению длины проростков в сравнении с контролем (в среднем на 25 %).
Сделано предположение, что отобранные изоляты ризобактерий E. atrorubens, благодаря их
ростстимулирующей активности и металлоустойчивости, могут способствовать натурализации
орхидеи на техногенно нарушенной территорииThe article presents data obtained in the study of bacteria isolated from the rhizosphere of the orchid Epipactis atrorubens (Hoffm.) Besser. Analysis was carried out to compare some morphological, physiological, and biochemical characteristics of plant rhizobacteria growing on serpentine rocks in two biotopes: in the natural forest community (control habitat) and on the asbestos mine dump (the Sverdlovsk region, Middle Urals). An assessment of the plant growth promoting (PGP) activity of the isolated strains did not show significant differences in the ability of rhizobacteria to synthesize indol‑3-acetic acid (IAA) and solubilize phosphates between the study sites. However, the proportion of isolates capable of nitrogen fixation was higher in the rhizosphere of E. atrorubens growing on the dump compared to the control habitat. The tolerance of isolates to heavy metals was assessed by the maximum metal concentration (400, 600, and 1000 mg/L, respectively, for Ni, Cu, and Zn) at which bacterial growth was observed. Rhizobacteria from the dump were found to be more
resistant to elevated concentrations of metals compared to their counterparts from the natural forest
community. The molecular genetic analysis of isolates with the highest PGP‑activity (IAA >1.0 mg/L;
PO4
3- >50.0 mg/L) revealed that most of the E. atrorubens rhizobacteria in both habitats belonged to
the genera Buttiauxella and Pseudomonas. In model experiments, the PGP ability of four selected
strains was tested on zinnia seeds. Seed inoculation with Pseudomonas sp. and Buttiauxella sp. did not
have any significant effect on their germination; however, Buttiauxella sp. contributed to the increase
in the length of seedlings compared with the control (by 25 %, on average). It has been suggested that
the selected isolates of E. atrorubens rhizobacteria, due to their growth promoting activity and metal
tolerance, can facilitate naturalization of the orchid in an industrially disturbed are
The Eurasian Modern Pollen Database (EMPD), version 2
The Eurasian (née European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60 % from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019)Swiss National Science Foundation | Ref. 200021_16959
The Eurasian Modern Pollen Database (EMPD), version 2
The Eurasian (nee European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60% from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019).Peer reviewe
The Eurasian Modern Pollen Database (EMPD), version 2
Abstract. The Eurasian (née European) Modern Pollen Database (EMPD) was established in 2013 to provide a public database of high-quality modern pollen surface samples to help support studies of past climate, land cover, and land use using fossil pollen. The EMPD is part of, and complementary to, the European Pollen Database (EPD) which contains data on fossil pollen found in Late Quaternary sedimentary archives throughout the Eurasian region. The EPD is in turn part of the rapidly growing Neotoma database, which is now the primary home for global palaeoecological data. This paper describes version 2 of the EMPD in which the number of samples held in the database has been increased by 60 % from 4826 to 8134. Much of the improvement in data coverage has come from northern Asia, and the database has consequently been renamed the Eurasian Modern Pollen Database to reflect this geographical enlargement. The EMPD can be viewed online using a dedicated map-based viewer at https://empd2.github.io and downloaded in a variety of file formats at https://doi.pangaea.de/10.1594/PANGAEA.909130 (Chevalier et al., 2019).</jats:p
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