—
This paper examines the feasibility of improving the strength of hydroxyapatite prepared by precipitation from solution via partial substitution of fluoride ions for hydroxyl groups and the ...addition of calcium fluoride. A comparative analysis of the resultant materials is carried out using advanced physicochemical characterization techniques. Fluoride ions are shown to influence the thermal stability, sintering behavior, microstructure, and strength of ceramics produced using precipitated hydroxyapatite.
Relevance.
Staphylococci
are
one
of
the
most
common
pathogens
in
the
etiological
structure
of
nosocomial
infections.
Methicillinresistant
staphylococci
are
resistant
to
the
main
groups
of
antibiotics
...and
are
one
of
bacteria
that
pose
the
greatest
threat
to
human
health
according
to
the
World
Health
Organization.
The
introduction
of
modern
molecular
biological
methods
in
the
monitoring
o
f
m
e
thi
c
illin-r
es
i
s
tant
staphylococci is necessary for the rapid and accurate identification of microorganisms, monitoring the epidemiological situation and studying the need for anti-epidemic measures.
Aims.
Аnalysis of the results of monitoring methicillinresistant staphylococcus strains using molecular biological methods in a multidisciplinary hospital in Moscow for one year.
Materials and methods.
Single-center
observational
study
with
a one-year follow-up period (December 2016 to December 2017). The research included a molecular-biological analysis of biological material from 240 patients with signs of infection and washings samples (n=250) from the objects of the hospital environment. The whole genome sequencing was carried out for 24 samples, isolated from patients with different forms of staphylococcal infection and washings from a hospital environment. DNA detection of methicillin-resistant strains was performed using the «AmpliSens®MRSA-screen-titer-FL» reagent kit. Sequencing was performed on an Illumina HiSeq1500 instrument using the IlluminaHiSeq PE RapidClusterKit v2 and IlluminaHiSeqRapid SBS Kit v2.
Results.
DNA
of
methicillin-resistant
staphylococci
were
detected
in
6.3%
of
blood
samples
from
patients
with
signs
of
infection
and
in
42.4%
of
washings
from
the
objects
of
the
hospital
environment.
The
results
of
PCR
of
washing
samples
showed
that
DNA
of
methicillin-resistant
coagulase-negative
staphylococci
were
detected
much
more
often
than
MRSA
(p
<0.001).
DNA
of
methicillin-resistant
staphylococci
were
detected
more
often
in
the
intensive
care
and
intensive
care
units
compared
with
the
hematology
and
surgical
departments
(p
<0.001).
The
examine
samples
of
Staphylococcus
aureus
belonged
to
6 different sequence types (ST-5, ST-7, ST-8, ST-22, ST-30 and ST-5555) and 8 spatypes (t008, t021, t091, t1062, t12437, t1544, t223, t4573). As a result of monitoring, an isolate with a new allelic profile was found. Today it has been assigned the number ST5555. The predominant type of staphylococcal mec cassette was the type IV SCCmec cassette.
Conclusion.
Due
to
the
widespread
distribution
of
methicillin-resistant
strains
and
the
identification
of
epidemiologically
significant
genetic
lines
of
staphylococci,
it
is
necessary
to
conduct
regular
monitoring,
take
measures
to
limit
the
spread
of
such
strains
and
introduce
modern
molecular
biological
methods
for
quick
and
accurate
identification.
The new COVID-19 coronavirus infection caused by SARS-CoV-2 is a global health threat. Neurological disorders detected in patients with coronavirus infection have a wide range of clinical signs: ...headache, dizziness, altered level of consciousness, acute ischemic stroke, intracerebral hemorrhage, cerebral venous sinus thrombosis. Evidence suggests that patients with more severe systemic symptoms were more likely to experience neurological symptoms. The main risk factors for the development of ischemic stroke in patients with coronavirus infection are considered. It was shown that COVID-19 more often occurred in people with vascular risk factors, among which the mortality rate was higher. Various possible and not mutually exclusive mechanisms which may play a role in the development of ischemic stroke in patients with COVID-19 are described in detail, including hyper-inflammatory state («cytokine storm»), «COVID-19-associated coagulopathy», and disseminated intravascular coagulation syndrome. Stroke risk factors associated with the critical condition in these patients are presented. Stroke, the leading cause of death and disability worldwide, requires immediate treatment and decision-making as well as 24/7 availability for specialized vascular centers. The results of observation of patients with acute cerebral circulation disorder in specialized vascular centers 2 months before and 15 days after quarantine due to COVID-19 are presented. The tactics of managing patients with ischemic stroke under conditions of coronavirus infection is considered.
The article presents the data on the state of endothelial function in the normally and in various diseases and conditions. The basic functions of endothelium in modulation of vascular tone, ...atrombogenicity and thrombogenicity of the vascular wall, regulation of vascular wall adhesion, regulation of vascular growth are described. The main causes leading to the formation of endothelial dysfunction and the mechanisms underlying it are highlighted. Numerous studies on the evaluation of endothelial function in various diseases are presented. The basic methods of drug and non-drug correction of endothelial dysfunction are presented.
Abstract
Despite remarkable progress, mainly due to the development of LCP and ‘bicelle’ crystallization, lack of structural information remains a bottleneck in membrane protein (MP) research. A ...major reason is the absence of complete understanding of the mechanism of crystallization. Here we present small-angle scattering studies of the evolution of the “bicelle” crystallization matrix in the course of MP crystal growth. Initially, the matrix corresponds to liquid-like bicelle state. However, after adding the precipitant, the crystallization matrix transforms to jelly-like state. The data suggest that this final phase is composed of interconnected ribbon-like bilayers, where crystals grow. A small amount of multilamellar phase appears, and its volume increases concomitantly with the volume of growing crystals. We suggest that the lamellar phase surrounds the crystals and is critical for crystal growth, which is also common for LCP crystallization. The study discloses mechanisms of “bicelle” MP crystallization and will support rational design of crystallization.
The article is devoted to the analysis of the mythopoetic structure of the documentary drama “The Sun Rises” related to the genre of verbatim and staged at the Moscow Art Theater (author M. ...Durnenkov, director V. Ryzhakov) for the 150th anniversary of M. Gorky. The relevance of the study is due to the need for further research on the social and aesthetic function of the verbatim - a play created on the basis of editing written documentary sources. A significant difference between the object of study and other forms of the “new drama” is that the verbatim text uses sources from the end of the nineteenth to the beginning of the twentieth centuries. The modern reception of M. Gorky’s personality and work is not represented in it, there are no interviews with the participants of the performance and the audience, which, in general, complicates its perception, but at the same time increases its emotional component. The novelty of the study lies in the fact that for the first time it is indicated on the plot-compositional unity of the text of the play created by editing various documentary sources. The conceptual content of the verbatim “The Sun Rises” is revealed: the formation of the myth of M. Gorky and the artist, who was born in the public mind at the intersection of the writer’s conflicting opinions about himself and his work with assessments of his creative personality by contemporaries and descendants. The object of study was the transcript of the text of the play, which used various types of documentary sources: the correspondence of M. Gorky with correspondents, literary and critical reviews of his works, reflecting the state of literary criticism of a certain historical period, memoirs of contemporaries in which real facts from the life of the writer are included by memoirist in the historical context, as well as fragments of the dramatic works of M. Gorky and his journalism.
The article is devoted to the characteristics of the voice-over text functions as a way to embody the film discourse of a documentary film that recreates the image of M. Gorky during the last ten ...years of his life. The material of the study was the correspondence of M. Gorky in 1924–1927 with writers, where his attitude to the transformations in the Soviet Union and work on the story “The Life of Klim Samgin” were discussed. In order to restore the amount of material underlying the script, work was carried out to decipher the sounding voice-over text, the addressees of the letters, the dating of the correspondence were established, and the fragments included in the voice-over text were compared with the full text of the letters. As a result of the study, it was proved that the voice-over text, considered in the history of documentary cinema as an auxiliary element of the video sequence, in the film by S. Aranovich and B. Dobrodeev acts as the main semantic element of the narrative, built on the principle of editing fragments of the epistolary, arranging them according to the problem-thematic principle with a violation of the chronology of correspondence. The most important feature of the documentary discourse of the film is the combination within one episode of fragments of quotations from M. Gorky’s letters to different addressees, which is dictated by the author’s concept of the image of the writer as a tragic personality who turned out to be a hostage of the myth created about him as a proletarian writer, a defender of the Bolshevik ideology.
The modeling of high energy photons production in collisions of antiproton beam having
E
beam
= 15 GeV with the proton target
pp
→ γ + {ptX} is done using the event sample simulated by PYTHIA6 ...generator. Such energy is high enough to consider this collision as a relativistic one and being caused by parton-parton scattering. The distribution of the set of kinematic variables and cuts which can be useful for getting the information about proton structure in the available kinematic region is obtained. The contributions of fake photons which can appear from the hadron decays as well as of the background caused by the minimum bias events and other QCD processes are estimated. The set of cuts which can be useful for separation of signal events containing the direct photons from background events is proposed.
Objective To determine the effect of combined repetitive transcranial magnetic stimulation (rTMS) and repetitive peripheral magnetic stimulation (rPMS) on cortical excitability in stroke patients. ...Methods 77 patients (mean age – 63.02 ± 1.21 years) with ischemic stroke were randomized to receive 1 Hz real or sham rTMS and rPMS for 10 consecutive days. Motor function was evaluated by the Motor Club Assessment Scale (MCAS). Motor evoked potential (MEP) and resting motor threshold (RMT) of the affected abductor digiti minimi and abductor hallucis were measured as parameters of cortical excitability with single-pulse TMS methods. Results The improvement of motor function was greater in the real stimulation group (40.4% in MCAS) when compared to the sham group (17.1% in MCAS). The MEPs in the real stimulation group became shorter in latency and higher in amplitude and area after intervention in comparison with the sham group. The RMT in the real stimulation group became lower after treatment in comparison with the sham group. Conclusion Combined rTMS and rPMS improved motor functions and increased cortical excitability of the affected hemisphere in stroke patients. Key message Combined rTMS and rPMS may potentiate cerebral adaptive processes that facilitate motor recovery after stroke.
PDF
