157 research outputs found
The level of training of dental surgeons for the diagnosis and prevention of complications of dental implantation (case study)
Modern dental implants can most adequately compensate the lost teeth and the functions of a full dentition. The method of dental implantation is still fraught with a high risk of complications in each of its stages. A particularly acute problem for the early diagnosis and prevention of complications of dental implants. Unprofessional actions of a dentist, poor knowledge of the anatomy of the maxillofacial region, neglecting the necessity of full X-rays are able to neutralize any result achieved by using the most advanced technologies and materials. The article analyzes the data obtained from the survey 295 dentists on dental implants with different work experience in the field of medicine and dentistry - from 5 to 20 years. The findings of the study data indicate inadequate training of doctors, significant gaps in academic and specialized knowledge of the majority of the doctors surveyed, which gives rise to the need for correction of both academic and postgraduate education curriculu
Artistic creativity of martiros saryan as the indicator of national self-identification of the personality in a multicultural space: features of methodology of a retrospective research
In this article, the life and works of the famous Armenian artist, founder of the modern Armenian school of painting Martiros Saryan (1880-1972) are analyzed in the context of the influence of Russian and Armenian culture during the Russian period of his activity. In this retrospective analysis of the life and works of the artist, it is proposed to use the new indicator, which is Russian or the Middle East countries place names being included in the titles of works by the artist. On the basis of the analysis of Russian archival sources and the analytical research of content, it is established that, in Russia, the interest of the artist during the first period of his life and study was mainly on subjects reflecting the life of the Armenian diaspora in the south of Russia. Landscapes were mainly represented against the background in which the artist spent his childhood. During the time which he spent in Moscow, interest in Russian culture was connected with the recognition of the contribution of teachers of the School of Painting, Sculpture and Architecture in the development of the Russian art school and world culture. Saryan has shown the aspiration to seize this particular technic of painting, at the same time he had the original vision of the world. Keywords: methodology, personality, geographical indicators, Martiros Saryan, culture,regional archiv
RESEARCH OF FEATURES OF DECREASE IN RISK AND UNCERTAINTY OF INNOVATIVE ACTIVITY OF THE INDUSTRIAL ENTERPRISE
The mechanism of decrease in uncertainty and risk of innovative activity of the industrial enterprise is offered. On the basis of the established dependences of change of risk level on stages of innovative process effective management of adaptation of innovative processes can be carried out by a certain type of risk, and in that period when this type of risk poses the greatest threat to all innovative process
RESEARCH OF FEATURES OF DECREASE IN RISK AND UNCERTAINTY OF INNOVATIVE ACTIVITY OF THE INDUSTRIAL ENTERPRISE
The mechanism of decrease in uncertainty and risk of innovative activity of the industrial enterprise is offered. On the basis of the established dependences of change of risk level on stages of innovative process effective management of adaptation of innovative processes can be carried out by a certain type of risk, and in that period when this type of risk poses the greatest threat to all innovative process
Spatial Correlation of Conduction Electrons in Metal with Complicated Geometry Of The Fermi Surface
The "density-density" correlation function of conduction electrons in metal
is investigated. It is shown, that the asymptotic behaviour of the CF depends
on the shape and the local geometry of the Fermi surface. In particular, the
exponent of power law which describes the damping of Friedel oscillations at
large r (-4 for an isotropic Fermi gas) is determined by local geometry of the
FS. The applications of the obtained results to calculations of the CF in a
metal near the electron topological transition and of the RKKY exchange
integral are considered as well.Comment: 12 pages, LaTeX, 5 figures upon request (to appear in J.Phys.:CM,
1993
Itt1p, a novel protein inhibiting translation termination in Saccharomyces cerevisiae
BACKGROUND: Termination of translation in eukaryotes is controlled by two interacting polypeptide chain release factors, eRFl and eRF3. eRFl recognizes nonsense codons UAA, UAG and UGA, while eRF3 stimulates polypeptide release from the ribosome in a GTP- and eRFl – dependent manner. Recent studies has shown that proteins interacting with these release factors can modulate the efficiency of nonsense codon readthrough. RESULTS: We have isolated a nonessential yeast gene, which causes suppression of nonsense mutations, being in a multicopy state. This gene encodes a protein designated Itt1p, possessing a zinc finger domain characteristic of the TRIAD proteins of higher eukaryotes. Overexpression of Itt1p decreases the efficiency of translation termination, resulting in the readthrough of all three types of nonsense codons. Itt1p interacts in vitro with both eRFl and eRF3. Overexpression of eRFl, but not of eRF3, abolishes the nonsense suppressor effect of overexpressed Itt1p. CONCLUSIONS: The data obtained demonstrate that Itt1p can modulate the efficiency of translation termination in yeast. This protein possesses a zinc finger domain characteristic of the TRIAD proteins of higher eukaryotes, and this is a first observation of such protein being involved in translation
GTP-dependent structural rearrangement of the eRF1:eRF3 complex and eRF3 sequence motifs essential for PABP binding
Translation termination in eukaryotes is governed by the concerted action of eRF1 and eRF3 factors. eRF1 recognizes the stop codon in the A site of the ribosome and promotes nascent peptide chain release, and the GTPase eRF3 facilitates this peptide release via its interaction with eRF1. In addition to its role in termination, eRF3 is involved in normal and nonsense-mediated mRNA decay through its association with cytoplasmic poly(A)-binding protein (PABP) via PAM2-1 and PAM2-2 motifs in the N-terminal domain of eRF3. We have studied complex formation between full-length eRF3 and its ligands (GDP, GTP, eRF1 and PABP) using isothermal titration calorimetry, demonstrating formation of the eRF1:eRF3:PABP:GTP complex. Analysis of the temperature dependence of eRF3 interactions with G nucleotides reveals major structural rearrangements accompanying formation of the eRF1:eRF3:GTP complex. This is in contrast to eRF1:eRF3:GDP complex formation, where no such rearrangements were detected. Thus, our results agree with the established active role of GTP in promoting translation termination. Through point mutagenesis of PAM2-1 and PAM2-2 motifs in eRF3, we demonstrate that PAM2-2, but not PAM2-1 is indispensible for eRF3:PABP complex formation
Pulmonary Vascular Thrombosis in COVID-19: Clinical and Morphological Parallels
Aim. We aimed to study the histological and thrombotic changes in lung vessels in patients who died with COVID-19, to access the correlation between anticoagulation therapy (ACT) and thrombotic events (TE), treatment results, clinical and laboratory patients' characteristics.Material and Methods. We retrospectively analyzed treatment results of patients hospitalized with COVID-19 and lung vessel samples of the deceased patients. Dynamic changes and highest levels of D-dimer and fibrinogen were studied in its correlation with the disease severity according to SOFA score, computer tomographic (CT) results, lung, renal and hepatic dysfunction. The association between different doses of ACT and treatment results, laboratory indicators and thrombotic events was accessed. The histological lung vessels examination was performed using Martius Scarlet Blue (MSB)staining.Results. 313 patients were included in the study (61 patients died). The median age of hospitalized patients was 60 years (IQR 51-66 years). The frequency of the intravitallyconfirmed TE was 4,8%. The strong statistical association was revealed between D-dimer level and 3-4 points SOFA score, patients' mortality, oxygen support requirement, CT3-CT4 pneumonia, glomerular filtration rate and TE. There was no mortality in patients with D-dimer normal references, but in cases with three times elevation reached 13%, 48,5% - in cases with 3-6 times elevation and 64,6% - in cases with more than 6 times elevation. The strong statistical association was registered between fibrinogen and SOFA score, CT 3-4 pneumonia, patients' mortality. D-dimer and fibrinogen levels demonstrated weak correlation. There was no statistical correlation between prophylactic, intermediate and therapeutic ACT and D-dimer and fibrinogen levels, CT results, patients' mortality. MSBstaining was used in 36 deceased patients tissue samples. 1394 lung vessels were analyzed. Lung vessels thrombi persisted in samples of all 36 patients (100%). Vessels with the diameter 3,5-30 mm were thrombosed in 7%, with the diameter 0,034-0,84 mm - in 48%, with the diameter 0,85-3,4 mm - in 45%. The frequency of thrombi persisted 06 hours, 6-12 hours, 12-18hours, 18-24 hours and more than 24 hours was12%, 14%, 62%, 5% and 7% respectively.Conclusion. Thrombi of different ages from fresh to organized were observed in one third of lung vessels in all deceased patients. Lung vessels thrombosis plays an important role in pathogenesis and thanatogenesis of COVID-19. The D-dimer level correlates with lung, renal dysfunction, patients' mortality and doesn't show any correlation with ACT and can be accepted as a criterion of lung vessel thrombotic progression
[PSI+] Maintenance Is Dependent on the Composition, Not Primary Sequence, of the Oligopeptide Repeat Domain
[PSI+], the prion form of the yeast Sup35 protein, results from the structural conversion of Sup35 from a soluble form into an infectious amyloid form. The infectivity of prions is thought to result from chaperone-dependent fiber cleavage that breaks large prion fibers into smaller, inheritable propagons. Like the mammalian prion protein PrP, Sup35 contains an oligopeptide repeat domain. Deletion analysis indicates that the oligopeptide repeat domain is critical for [PSI+] propagation, while a distinct region of the prion domain is responsible for prion nucleation. The PrP oligopeptide repeat domain can substitute for the Sup35 oligopeptide repeat domain in supporting [PSI+] propagation, suggesting a common role for repeats in supporting prion maintenance. However, randomizing the order of the amino acids in the Sup35 prion domain does not block prion formation or propagation, suggesting that amino acid composition is the primary determinant of Sup35's prion propensity. Thus, it is unclear what role the oligopeptide repeats play in [PSI+] propagation: the repeats could simply act as a non-specific spacer separating the prion nucleation domain from the rest of the protein; the repeats could contain specific compositional elements that promote prion propagation; or the repeats, while not essential for prion propagation, might explain some unique features of [PSI+]. Here, we test these three hypotheses and show that the ability of the Sup35 and PrP repeats to support [PSI+] propagation stems from their amino acid composition, not their primary sequences. Furthermore, we demonstrate that compositional requirements for the repeat domain are distinct from those of the nucleation domain, indicating that prion nucleation and propagation are driven by distinct compositional features
- …