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Objective: To investigate the genetic diversity of coronaviruses in wild and domestic birds in the bird park and live poultry markets of Ca Mau province in Vietnam in 2020. Methods: A total of 228 samples (121 from wild birds and 107 from poultry) were collected in the territory of Ca Mau province of Vietnam in 2020. The avian samples were tested for the presence of the four genera of coronaviruses using reverse transcription and nested PCR. Molecular genetic analysis using targeted NGS sequencing of RdRp gene was performed for 29 representative samples (12 samples from wild birds and 17 from poultry). Phylogenetic analysis was performed using the neighbour joininig method with 1 000 bootstrap replications using MEGA X software. Results: Among wild birds, 21.5% samples were positive for the genetic material of coronaviruses and 38.3% samples were positive for coronaviruses among poultry. Genetic analysis of the partial sequence of RdRp gene from representative samples revealed that wild birds were carriers of gammacoronaviruses and deltacoronaviruses. Among poultry, three genotypes of infectious bronchitis virus (QX, Mass and Q1) were detected in chickens, with QX genotypes being predominant, and viruses of DCoV group were detected in domestic ducks. There was no detection of alphacoronaviruses or betacoronaviruses in the studied birds. Conclusions: Coronaviruses of genera Gammacoronavirus and Deltacoronavirus were detected in wild birds. A high percentage of infectious bronchitis virus was detected in poultry. Thus, there is a need for broader surveillance of coronaviruses in birds, which can be used for evaluation of diversity, evolution and distribution of coronaviruses in Vietnam. Continuous surveillance of coronaviruses circulation in wild and domestic animals is necessary for implementing strategic measures for poultry and domestic animal protection and for evaluation of possible risk of circulating coronaviruses to human health. [ABSTRACT FROM AUTHOR]

This paper shows how bubbling the reaction medium with CO affects the nucleation/growth of Pt nanoparticles under the synthesis using formic acid or formaldehyde as reducing agents. CO has been found to affect not only the dynamics of the Pt(IV) to Ptx 0 transformation but also the size of the formed particles (1.1–3.9 nm) deposited on the carbon support (ca. 20 wt% Pt). The dual role of CO due to combining the functions of a stabilizer and a reducing agent has been shown. The study demonstrates that the introduction of the dispersed carbon support to the reaction medium leads to the enhancement of the CO positive effect on the microstructure of Pt/C catalysts. In this case, the spatial distribution of Pt nanoparticles over the carbon support surface becomes more uniform that is conducive to increasing the electrochemical surface area. Thus, CO is a unique reagent used to control the microstructure of Pt nanoparticles during their wet synthesis. [ABSTRACT FROM AUTHOR]

In this work, Surface-enhanced Raman spectroscopy (SERS) along with machine learning algorithms (MLA) were used to detect and classify the viral particles to assess the possibility of using the spectra of inactivated influenza A viruses for MLA training and spectra database compilation for further study and diagnosis of intact forms of the virus. Viral particles inactivation was performed by formalin, ultraviolet and beta-propiolactone. Support vector method and principal component analysis allowed to classify intact and inactivated viral particles spectra with an accuracy of 80.0–96.7 %. The results obtained suggest that it is not advisable to create a spectral database and train machine learning algorithms for their further application in SERS diagnostics of intact viruses based on the spectra of the inactivated virus particles. • SERS and ML algorithms detect and classify viral particles. • Investigated inactivation of influenza A viruses for MLA training. • Achieved 80.0-96.7% accuracy using SVM and PCA. • Caution against using spectra of inactivated viruses for SERS diagnostics. [ABSTRACT FROM AUTHOR]

Background: While smokeless tobacco (ST) causes oral cancer and is associated with cardiovascular diseases, less is known about how its effects differ from other tobacco use. Biomarkers of potential harm (BOPH) can measure short-term health effects such as inflammation and oxidative stress. Methods: We compared BOPH concentrations [IL6, high-sensitivity C-reactive protein, fibrinogen, soluble intercellular adhesion molecule-1 (sICAM-1), and F2-isoprostane] across 3,460 adults in wave 1 of the Population Assessment of Tobacco and Health study (2013-2014) by tobacco use groups: primary ST users (current exclusive ST use among never smokers), secondary ST users (current exclusive ST use among former smokers), exclusive cigarette smokers, dual users of ST and cigarettes, former smokers, and never tobacco users. We estimated geometric mean ratios using never tobacco users, cigarette smokers, and former smokers as referents, adjusting for demographic and health conditions, creatinine (for F2-isoprostane), and pack-years in smoker referent models. Results: BOPH levels among primary ST users were similar to both never tobacco users and former smokers. Most BOPH levels were lower among ST users compared with current smokers. Compared with never tobacco users, dual users had significantly higher sICAM-1, IL6, and F2-isoprostane. However, compared with smokers, dual users had similar biomarker levels. Former smokers and secondary ST users had similar levels of all five biomarkers. Conclusions: ST users have lower levels of inflammatory and oxidative stress biomarkers than smokers. Impact: ST use alone and in combination with smoking may result in different levels of inflammatory and oxidative stress levels. [ABSTRACT FROM AUTHOR]

The analysis of both the mineralogical and geochemical composition and the stratigraphy of Holocene sediments of Lake Onego provided a novel interpretation of their genesis. Their mineral composition suggests that Holocene bottom sediments generally inherit the composition of terrigenous material that enters the lake with river runoff. The predominant authigenic minerals include biogenic opal from diatom skeletons, Fe-illite, and Fe-chlorite, which are the main iron mineral forms in bottom sediments of Lake Onego. Unstable suspension components (illite and chlorite) transform into their ferruginous varieties under humid climate conditions and high concentrations of iron and silicon in the lake waters. Both the presence of ferromanganese nodules in the uppermost part of bottom sediments of Lake Onego and their formation result from the location of the lake in the northern humid zone, geological composition of Fennoscandian crystalline rocks on the Lake Onego watershed, and the presence of an oxidative geochemical barrier into the lake sediment sequence. Late Holocene bottom sediments are represented by two types of sequences: 1) Fe-Mn enriched layers are formed near the sediment-water interface under oxygenated near bottom waters, and 2) such layers are not formed due to low concentrations of oxygen in water; but there are also non-laminated, homogeneous greyish-green silts, similar to those present in the lower parts of the first type of cores. Sedimentation rates (~0.10 cm y−1) were determined by 210Pb- and 137Cs geochronologies. [ABSTRACT FROM AUTHOR]

An analysis of the mineral-geochemical composition and structure of the Holocene-Pleistocene bottom sediments was performed on Lake Polevskoye, a small lake in the northern Lake Onega area in Russian Karelia, which is considered representative to describe the Late Weichselian Onega Ice Lake sediments. The analysis was accomplished using modem analytical methods, including scanning electron microscopy and ICP-MS, which allowed us to interpret their genesis in a new light. It is assumed that the distribution of rare earth elements (REE) in the bottom sediments of the recent Lake Onega and in the sediments of Onega Ice Lake will improve our understanding of the history of sedimentogenesis. It is apparent in the distribution of REE, their composition and data on the geochemical and mineral composition of the Holocene bottom sediments of Lake Onega and Lake Polevskoye (varved clays) that in their composition of terrigenous matter the material introduced from the north-western part of the catchment area is mainly composed of Archaean and Early Proterozoic crystalline complexes. However, the values of several indicator ratios of elements in the lower part of the of varved clays with shungite interlayers indicate the presence of mixing of clastic material from two sources of different geochemical origin: the north-western part of the catchment area (source of shungite rocks) and the south-eastern part of the catchment area (Phanerozoic sedimentary rocks of the Russian Platform). [ABSTRACT FROM AUTHOR]

Abstract The article investigates SNP in genes of toxin-antitoxin systems type II in Mycobacterium tuberculosis Beijing lineage strains and their possible role in the development and formation of new sublineages. We established the catalog of SNPs in 142 TA systems genes in 1349 sequenced genomes of the M. tuberculosis Beijing lineage. Based on the catalog, 15 new sublineages were identified as part of Beijing lineages by non-synonymous SNP in 21 genes of TA systems. We discovered three toxin genes with mutations specific for epidemiologically dangerous sublineages Beijing-modern (vapC37 A46G, vapC38 T143C) and Beijing-B0/W148 (vapC12 A95G). We proved the functional significance of these polymorphisms by cloning these genes wild-type and with marker mutations for the Beijing lineage vapC12 (A95G), vapC37 (A46G), vapC38 (T143C). In vitro study of their activities revealed effect of mutations on the RNase activity of toxin proteins. Mutations in vapC37 and vapC38 decreased toxin activity, and mutation in the vapC12 increased it. We cloned the toxin vapC37 gene of Mycobacterium smegmatis mc2 155 in both allelic variants: without mutation and with A46G mutation, specific for the Beijing-modern lineage. It was shown that this mutation leads to a loss of toxicity. [ABSTRACT FROM AUTHOR]

Morphology and mineralogical and geochemical compositions of freshwater ferromanganese nodules of Ol’khon Island (Sasa Formation) and Kulunda Plain (Lake Porozhnee) were studied. The study has shown rhythmic structures of the nodules, formed by macro- and microlayers with mineralized microflora. The layers are composed of either crystalline Mn mineral phases and finely dispersed Fe phases (Lake Porozhnee) or, on the contrary, crystalline goethite and X-ray amorphous Mn phases (Ol’khon Island). Separation of Mn and Fe mineral phases in the nodules proceeded during their formation and diagenesis. The freshwater nodules show both high (Lake Porozhnee) and low (Ol’khon Island) Mn/Fe ratios. The predominance of Fe phase in the Ol’khon nodules accounts for their high contents of REE, including Ce. The Porozhnee nodules grew, most likely, more rapidly, which is reflected in their low REE contents and Ce anomaly. The examined chemical and mineral compositions, textures, and structures of the nodules testify to the low-temperature hydrothermal source of their ore substance. [ABSTRACT FROM AUTHOR]

Sediments of intracontinental closed lakes are unique natural archives that store climate history records. We study Late Holocene carbonate-bearing sediments of Lake Dolgoe, a small saline lake in the Eravnoe basin on the Vitim Plateau (western Transbaikalia). Sediment samples have been analyzed by several methods: X-ray powder diffraction, infrared spectroscopy, stable isotope ( 18 O and 13 C) determination, laser diffraction particle size analysis, XRF elemental analysis, etc. The mineral phases of bottom sediments include clastic and carbonate components and hydromagnesite at the section top; carbonates are authigenic varieties of the calcite-dolomite series. Modeling of complex XRD profiles reveal Mg-calcite with various Mg contents and excess-Ca dolomites, which are mixed-structure crystals compositionally close to stoichiometric dolomite. The crystal structure and relative percentages of carbonates from the dated sedimentary section controlled by climate and lake level changes allow reconstructing the Holocene history of Lake Dolgoe. [ABSTRACT FROM AUTHOR]

Sediments of lakes located in closed basins in inland areas are an excellent archive of environmental and climatic changes. One of such archives is the Chany lake system located in the Baraba steppe of southern West Siberia and comprising three associated lakes: Bol’shie Chany, Malye Chany, and Yarkul’, connected by watercourses. We present the first data on the mineral composition of the Holocene sediments of Yarkovsky Pool of Lake Bol’shie Chany with predominantly carbonate sedimentation. The sediments were studied by X-ray diffraction (XRD), IR spectroscopy, scanning electron microscopy, 18 O and 13 C stable-isotope geochemistry, laser granulometry, elemental analysis, and radioisotope dating. Mathematical modeling of complex XRD profiles of carbonate minerals in the sediments has revealed Mg-calcites with different Mg contents, excess-Ca dolomites, and aragonite. The obtained carbonate record gives an insight into the stratigraphic distribution of chemogenic carbonates, in which the number and proportion of phases are determined by the Mg/Ca ratio, salinity, and total alkalinity of the lake water. The phase proportions change depending on climatic cycles and lake level fluctuations. Comparison of the carbonate record with the lithologic data, δ 18 O and δ 13 C values, and distribution of some geochemical indicators of sedimentary environments showed several stages of evolution of Yarkovsky Pool related to Holocene regional climatic changes. [ABSTRACT FROM AUTHOR]

Analysis of the results of studies in a low-viscosity model medium of high-speed ball bearings, racers and rolling elements made of corrosion-resistant 95H18Sh steel with a massive bronze separator on a special multipurpose installation was carried out. Water was used as the low-viscosity model medium in accordance with GOST 2874-82. The dynamics of damage formations on bearing working surfaces, depending on the level of load-velocity parameters and on the pumping rate of lubricoolant water medium, was demonstrated. A limit level of contact stresses was established, above which damages of working surfaces have a pitting character; while under contact stresses not exceeding this limit, working surfaces are exposed only to mechanochemical wear. Recommendations for developers of bearing assemblies on the ascertainment of permissible load levels on bearings in the design of rolling contact bearings were given. [ABSTRACT FROM AUTHOR]

• Decrease in the particle size leads to the diffusion mechanism change as VD-GBD-SD. • Change in diffusion mechanism is due to the increase in contacts between particles. • Increase in the fraction of surface ions leads to the activation of the SD mechanism. • SD leads to the frame structure formation and slowdown the convergence of particles. The effect of particle size on the dominant densification mechanism at the initial stage of sintering of tetragonal zirconia nanoparticles was investigated. It has been found that a decrease in the particle size of zirconia leads to a change in the diffusion mechanism. The volume diffusion mechanism identified by the value of densification parameter n = 0.5 was dominant in zirconia nanoparticles with the average particle size 32 and 26.2 nm. The grain-boundary diffusion mechanism (n = 0.3) dominated during the sintering zirconia nanoparticles with the average particle size 21.7 nm. It was established that the change in densification parameter n from 0.5 to 0.3 caused by the increase in the value of particle surface to volume ratio due to the particles size decrease from 32 to 21 nm. A further decrease in the particle size to 17–12 nm led to a decrease in the densification parameter n to 0.17–0.11, respectively. This may be due to an increase in the influence of the particle surface on the sintering process (large values of particle surface to volume ratio) and, accordingly, the action of the surface diffusion mechanism. [ABSTRACT FROM AUTHOR]

Summary Resistance to pyrazinamide (PZA) may impact clinical outcome of anti-tuberculosis chemotherapy. PZA susceptibility testing using MGIT 960 is not reliable and little information is available on the prevalence of PZA resistance in Russia. A collection of 64 clinical isolates of Mycobacterium tuberculosis , including 35 multidrug resistant and extensively drug-resistant (MDR/XDR), was analyzed for PZA resistance using MGIT 960, Wayne test, and sequencing of PZA resistance genes pncA , rpsA and panD . In addition, we analyzed 519 MDR-TB strains for susceptibility to PZA by MGIT 960. Sequencing of pncA revealed 17 of 25 (68%) MDR strains and all 10 XDR strains harboring pncA mutations. A correlation of φ = 0.81 between MGIT 960 and pncA sequencing was observed. Mutations in rpsA and panD not associated with PZA resistance as defined by MGIT 960 were identified. We found 1 PZA-resistant strain without mutations in known PZA resistance genes. Almost 73% of MDR-TB strains isolated in Moscow, Russia, were PZA-resistant by MGIT 960 testing of 519 MDR-TB clinical isolates. Further studies are needed to determine the role of rpsA and panD mutations in possible low-level PZA resistance and to identify the molecular basis of new PZA resistance in the isolate without known PZA resistance mutations. [ABSTRACT FROM AUTHOR]

This paper presents the experimental results of wear tests in rolling bearings. During the researches, measurements of vibration overloads were made which were subsequently analyzed depending on emergence of damages on parts of the bearings. An interrelation was established between the vibration intensity and the condition of working surfaces of parts of rolling bearings. The chalking of bearing raceways and rolling bodies lead to significant changes in the vibrational characteristics of the machine. [ABSTRACT FROM AUTHOR]

This paper presents the experimental results of wear tests in rolling bearings. During the researches, measurements of vibration overloads were made which were subsequently analyzed depending on emergence of damages on parts of the bearings. An interrelation was established between the vibration intensity and the condition of working surfaces of parts of rolling bearings. The chalking of bearing raceways and rolling bodies lead to significant changes in the vibrational characteristics of the machine. [ABSTRACT FROM AUTHOR]

Objective: We sought to evaluate the impact of the 1997 American Diabetes Association gestational diabetes mellitus screening guidelines applied to a universally screened population.Study Design: A retrospective analysis of 18,504 women universally screened for gestational diabetes mellitus at Mayo Clinic, Rochester, between January 1, 1986, and December 31, 1997, was performed. Diabetic screening consisted of plasma glucose determination 1 hour after a 50-g oral glucose challenge. Diagnosis of gestational diabetes mellitus was based on National Diabetes Data Group criteria.Results: Of 564 cases of gestational diabetes mellitus diagnosed during the study period, 17 (3.0%) would have been missed under the 1997 American Diabetes Association selective screening guidelines while exempting only 10% of this predominantly white population from screening. Screening only women >/=25 years old would have detected 90.4% of gestational diabetes mellitus cases, whereas the addition of the remaining 3 screening criteria combined would have detected only an additional 6.6% of cases.Conclusions: The proportion of patients with gestational diabetes mellitus that would remain undiagnosed under the 1997 American Diabetes Association screening guidelines would be relatively small in our population. However, implementation of these guidelines would decrease the number of screens by only 10% while adding significant complexity to the screening process. Youth appears to be the most significant protective factor for gestational diabetes mellitus in our population. [ABSTRACT FROM AUTHOR]

Objective: Prior studies have suggested that macrosomia is the only morbid condition associated with gestational diabetes and that this association is the result of confounding by maternal obesity rather than a result of gestational diabetes itself. We sought to determine whether unrecognized gestational diabetes is an independent predictor of macrosomia and other perinatal morbid conditions after controlling for confounding variables.Study Design: A retrospective analysis of 472 consecutive cases of gestational diabetes diagnosed between 24 and 30 weeks' gestation was undertaken including 16 prospectively identified but clinically unrecognized cases, 297 cases treated with diet alone, and 76 treated with diet plus insulin. Unrecognized cases were matched to 64 nondiabetic controls for race, age, body mass index, parity, pregnancy weight gain, and gestational age at delivery.Results: In the unrecognized gestational diabetes group versus the nondiabetic control versus gestational diabetes diet groups rates of large for gestational age infants (44% vs 5% vs 9%, p < 0.0005), macrosomia (44% vs 8% vs 15%, p < 0.01), shoulder dystocia (19% vs 3% vs 3%, p < 0.05), and birth trauma (25% vs 0% vs 0.3%, p < 0.001) were all significantly increased. These differences remained significant after controlling for maternal age, race, parity, body mass index, pregnancy weight gain, and gestational age at delivery.Conclusions: This study suggests that unrecognized gestational diabetes increases risks of large for gestational age infants, macrosomia, shoulder dystocia, and birth trauma independent of maternal obesity and other confounding variables. Clinical recognition and dietary control of gestational diabetes are associated with a reduction in these perinatal morbid conditions. [ABSTRACT FROM AUTHOR]

A comparative analysis of the chemical composition of the hemp fibers and stalks with cotton and representatives of hardwood and softwood was performed. The possibility of obtaining microcrystalline cellulose from hemp fibers by alkaline sulfite-alcohol delignification with preliminary acid and alkaline hydrolysis was investigated. It was found that carrying out an acid and an alkali pre-hydrolysis reduces the mineral content and partly of residual lignin in the plant material. The various bleaching schemes of organosolvent pulp with using environmentally friendly reagent -- hydrogen peroxide were analyzed. It is recommended to perform the process of bleaching organosolvent hemp pulp by scheme Q-P1-P2- A with the total consumption of hydrogen peroxide up to 12 % by weight of the cellulose with the addition of NaOH solution instead of conventional Na2SiO3, NaOH и MgSO4. It is shown that the performing of the acid pre-hydrolysis of bleached organosolvent hemp pulp by 2,5 N hydrochloric acid allows reducing the degree of polymerization and to obtains microcrystalline cellulose with quality indexes that meet the requirements of the standard. [ABSTRACT FROM AUTHOR]