2,113 research outputs found
Helicobacter pylori genotypes among Belarus patients with gastroduodenal disorders and their association with clinical outcome
The aim of this study was to evaluate the prevalence of Helicobacter pylori genotypes (vacA and cagPAI) directly in gastric biopsy specimens in patients with gastric diseases in Belarus. Gastric biopsies were collected from 461 patients with different gastrointestinal disorders: superficial gastritis (287 subjects), atrophy gastritis (59 subjects), erosive gastritis (47 subjects), duodenal ulcer disease (54 subjects), and stomach ulcer (14 subjects). PCR-based genotyping was used to detect s1a, s1b, s2, m1a, m1b, m2, cagM, cagA, and cagT genes. Overall prevalence of vacA s1a allele was 60.5% followed by m2 (47.1%) and m1a (37.5%). The analysis of data showed that genotype s1a/m1a was significantly more prevalent in patients with duodenal ulcer (21.4% vs. 45.1%, OR = 3.0, 95% CI = 1.5–6.1). The cagA gene was found with a high incidence in most patients with inflammatory diseases of stomach and duodenum. There was a significant increase in the frequency of cagT in patients with duodenal ulcer as compared to superficial gastritis. A high cagM prevalence was found in patients with atrophy gastritis and duodenal ulcer disease. All three island genes of pathogenicity of cagPAI are more often detected in patients with duodenal ulcer, which increases the risk of developing duodenal ulcer by 4.5 times
On the nature of bright compact radio sources at z>4.5
High-redshift radio-loud quasars are used to, among other things, test the
predictions of cosmological models, set constraints on black hole growth in the
early universe and understand galaxy evolution. Prior to this paper, 20
extragalactic radio sources at redshifts above 4.5 have been imaged with very
long baseline interferometry (VLBI). Here we report on observations of an
additional ten z>4.5 sources at 1.7 and 5 GHz with the European VLBI Network
(EVN), thereby increasing the number of imaged sources by 50%. Combining our
newly observed sources with those from the literature, we create a substantial
sample of 30 z>4.5 VLBI sources, allowing us to study the nature of these
objects. Using spectral indices, variability and brightness temperatures, we
conclude that of the 27 sources with sufficient information to classify, the
radio emission from one source is from star formation, 13 are flat-spectrum
radio quasars and 13 are steep-spectrum sources. We also argue that the
steep-spectrum sources are off-axis (unbeamed) radio sources with rest-frame
self-absorption peaks at or below GHz frequencies and that these sources can be
classified as gigahertz peaked-spectrum (GPS) and megahertz peaked-spectrum
(MPS) sources.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical
Society, 18 pages, 1 figure, 7 table
Which oxidation state of uranium and thorium as point defects in xenotime is favorable?
Relativistic study of xenotime, YPO, containing atoms thorium and uranium
as point defects is performed in the framework of cluster model with using the
compound-tunable embedding potential (CTEP) method proposed by us recently. The
Y-(PO)-Y'-O' cluster for xenotime is considered, in
which central part, [Y-(PO)], is the main cluster, whereas
outermost 22 atoms of yttrium and 104 atoms of oxygen are treated as its
environment and compose electron-free CTEP with the total charge of . The
P and O atoms of the orthophosphate groups nearest to the central Y atom are
treated at all-electron level. The central Y, its substitutes, Th and U,
together with environmental Y atoms are described within different versions of
the generalized relativistic pseudopotential method. Correctness of our cluster
and CTEP models, constructed in the paper, is justified by comparing the Y-O
and P-O bond lengths with corresponding periodic structure values of the \ypo4
crystal, both experimental and theoretical. Using this cluster model, chemical
properties of solitary point defects, X = U, Th, in xenotime are analyzed. It
has been shown that the oxidation state is energetically more profitable
than not only for thorium but for uranium as well (
eV) despite the notably higher ionic radius of U compared to Y,
whereas ionic radii of U and Y are close. This leads to notable
local deformation of crystal geometry around the U impurity in xenotime
and contradicts to widespread opinion about favorite oxidation state of uranium
in such kind of minerals.Comment: 8 pages, 4 figures, 3 table
Genomic analyses reveal two distinct lineages of Corynebacterium ulcerans strains
Corynebacterium ulcerans is an important zoonotic pathogen which is causing diphtheria-like disease in humans, globally. In this study, the genomes of three recently isolated C. ulcerans strains, 4940, 2590 and BRAD-2649, respectively from an asymptomatic carrier, a patient with pharyngitis and a canine host were sequenced to investigate their virulence potential. A comparative analysis was performed including the published genome sequences of 16 other C. ulcerans isolates. C. ulcerans strains belong to two lineages; 13 strains grouped together in Lineage-1 and 6 strains in Lineage-2. Consistent with the zoonotic nature of C. ulcerans infections, isolates from both, the human and canine hosts clustered in both the lineages. Most of the strains possessed spaDEF and spaBC gene clusters along with the virulence genes cpp, pld, cwlH, nanH, rpfI, tspA and vsp1. The gene encoding Shiga-like toxin was only present in one strain and 11 strains carried the tox gene encoding the diphtheria-like toxin. However, none of strains 4940, 2590 and BRAD-2649 carried any toxin genes. These strains varied in the number of prophages in their genomes, which suggests these are playing an important role in introducing diversity in C. ulcerans. The pan-genomic analyses revealed a variation in the number of membrane-associated and secreted proteins that may contribute to the variation in the pathogenicity between different strains
Broadband velocity modulation spectroscopy of HfF^+: towards a measurement of the electron electric dipole moment
Precision spectroscopy of trapped HfF^+ will be used in a search for the
permanent electric dipole moment of the electron (eEDM). While this dipole
moment has yet to be observed, various extensions to the standard model of
particle physics (such as supersymmetry) predict values that are close to the
current limit. We present extensive survey spectroscopy of 19 bands covering
nearly 5000 cm^(-1) using both frequency-comb and single-frequency laser
velocity-modulation spectroscopy. We obtain high-precision rovibrational
constants for eight electronic states including those that will be necessary
for state preparation and readout in an actual eEDM experiment.Comment: 13 pages, 7 figures, 3 table
Prevention and control of meningococcal disease: Updates from the Global Meningococcal Initiative in Eastern Europe
Authors would like to thank Dr Olivier Ronveaux (Infectious Hazard Management, World Health Organization, Geneva, Switzerland) for his contributions during this GMI Roundtable Meeting and for providing permission to use his presentation content in this manuscript. The authors were assisted in the preparation of the manuscript by Hannah Birchby, a professional medical writer at CircleScience, an Ashfield Company, part of UDG Healthcare plc. Medical writing support was funded by Sanofi Pasteur.The Global Meningococcal Initiative (GMI) aims to prevent invasive meningococcal disease (IMD) worldwide through education, research and cooperation. In March 2019, a GMI meeting was held with a multidisciplinary group of experts and representatives from countries within Eastern Europe. Across the countries represented, IMD surveillance is largely in place, with incidence declining in recent decades and now generally at <1 case per 100,000 persons per year. Predominating serogroups are B and C, followed by A, and cases attributable to serogroups W, X and Y are emerging. Available vaccines differ between countries, are generally not included in immunization programs and provided to high-risk groups only. Available vaccines include both conjugate and polysaccharide vaccines; however, current data and GMI recommendations advocate the use of conjugate vaccines, where possible, due to the ability to interrupt the acquisition of carriage. Ongoing carriage studies are expected to inform vaccine effectiveness and immunization schedules. Additionally, IMD prevention and control should be guided by monitoring outbreak progression and the emergence and international spread of strains and antibiotic resistance through use of genomic analyses and implementation of World Health Organization initiatives. Protection of high-risk groups (such as those with complement deficiencies, laboratory workers, migrants and refugees) is recommended.S
Prevention and control of meningococcal disease: Updates from the Global Meningococcal Initiative in Eastern Europe
Authors would like to thank Dr Olivier Ronveaux (Infectious Hazard Management, World Health Organization, Geneva, Switzerland) for his contributions during this GMI Roundtable Meeting and for providing permission to use his presentation content in this manuscript. The authors were assisted in the preparation of the manuscript by Hannah Birchby, a professional medical writer at CircleScience, an Ashfield Company, part of UDG Healthcare plc. Medical writing support was funded by Sanofi Pasteur.The Global Meningococcal Initiative (GMI) aims to prevent invasive meningococcal disease (IMD) worldwide through education, research and cooperation. In March 2019, a GMI meeting was held with a multidisciplinary group of experts and representatives from countries within Eastern Europe. Across the countries represented, IMD surveillance is largely in place, with incidence declining in recent decades and now generally at <1 case per 100,000 persons per year. Predominating serogroups are B and C, followed by A, and cases attributable to serogroups W, X and Y are emerging. Available vaccines differ between countries, are generally not included in immunization programs and provided to high-risk groups only. Available vaccines include both conjugate and polysaccharide vaccines; however, current data and GMI recommendations advocate the use of conjugate vaccines, where possible, due to the ability to interrupt the acquisition of carriage. Ongoing carriage studies are expected to inform vaccine effectiveness and immunization schedules. Additionally, IMD prevention and control should be guided by monitoring outbreak progression and the emergence and international spread of strains and antibiotic resistance through use of genomic analyses and implementation of World Health Organization initiatives. Protection of high-risk groups (such as those with complement deficiencies, laboratory workers, migrants and refugees) is recommended.S
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