According to modern theories, the parameters of neutral mesons such as their mass and width are closely connected with the medium in which the mesons are present. Experimental data on the study of ...mesons in a nuclear medium are in demand for development of theoretical models describing processes in the field of nonperturbative quantum chromodynamics (QCD). Masses and widths of neutral mesons produced in meson-nucleus interactions on various nuclei are measured in the Hyperon-M experiment at the U70 accelerator. The paper describes a method for precision measurement of the parameters of neutral mesons, presents the results on measurement of the mass and width of the
meson and preliminary results on the measurement of the mass and width of the
meson. The measurements indicate the absence of dependence of the quantities under study on the nuclear environment.
Studies at the Nuclotron in JINR indicate the presence of a previously unknown resonance-like structure in the two-photon mass spectrum in the region of 300–400 MeV/
c
2
, observed in nucleus–nucleus ...interactions. The goal of this work is to search for such structures in the two-photon mass spectrum in meson–nuclear interactions at a momentum of 7 GeV/
c
at the Hyperon-M experiment of the U-70 accelerator complex. An upper limit has been established on the ratio of the cross section for the formation of unknown resonance structures to the cross section for the production of
-meson
at the 95% confidence level.
The analysis of amplitude spectra from a thin polystyrene-based scintillation counter on muon-enriched and hadron beams of channel 18 of the U-70 accelerator complex in Protvino has been presented. ...On the basis of statistics of 150 million events on the Hyperon-M setup, the contribution of the
-fragmentation processes are highlighted and the cross sections of these processes on hadron and pion beams with a momentum of 7 GeV/
c
have been measured. In the future, the obtained result may be of interest for the method of analyzing the age of gas fields based on the concentration of helium in natural gas, the formation of which is possible in the reaction of
fragmentation of carbon nuclei in
interactions induced by high-energy cosmic muons.
A decrease of nonspecific body resistance, an imbalance of local and systemic immunity and a free-radical oxidation abnormality substantially contribute to the pathogenesis of community-acquired ...pneumonia (CAP). Purpose: To study the efficiency of including immunomodulators into the comprehensive treatment of nonsevere community-acquired pneumonia and assess the long-term effects of the treatment conducted. Patients (n = 55) with non-severe CAP (41 (31-48) years old, with CRB-65 score of 0.15 (0-1)) are included in the study. Group 1 (control) received only standard CAP therapy; the other two groups received immunomodulators concurrently with the standard therapy: bacterial lysate (BL) for group 2 and azoximer bromide (AzB) for group 3. TNFα and IL-6 concentration was determined on the day of visit, on day 13 and day 60 of follow-up. During 2 years, the incidence of low respiratory tract infections (LRTI) was studied in the same patients with CAP in past (n = 55). All patients (n = 55) had clinical signs of non-severe community-acquired pneumonia. The overall duration of all symptoms was lower in immunomodulators groups as compared to the control group: 12 (11-13) days in BL group (p < 0.001) and 12 (11-12) days in AzB group (p < 0.001) with no statistically significant difference between intervention groups (p = 0.36). During treatment, TNFα and IL-6 concentration decreased on day 13 and day 60 in all patients; in patients who received immunomodulators, TNFα and IL-6 were reliably lower as compared to the control. Changes of TNFα and IL-6 concentration in the groups on day 60 of the study as compared to the baseline showed a decrease in BL group by 85 (-89 – -82) % and 86 (-90 – -85) % (p < 0.001; p = 0.001 and control); in AzB group by 82 (-86 – -80) % and 86 (-88 – -84) % (p = 0.002; p = 0.007 and control). Intensity of IL-6 concentration decrease on day 60 in BL and AzB groups did not differ (p = 0.72). Gender- and age-adjusted odds ratio for the development of low respiratory tract diseases (during 2 years after CAP) in AzB group was 0.15 (0.02-0.93) (p = 0.04) suggesting its protective effect. Inclusion of immunomodulators in basic treatment of non-severe community-acquired pneumonia reduces duration of symptoms and is associated with improvement of the proinflammatory cytokine profile. In 2 years of follow-up, long-term effects of the immunomodulatory therapy showed statistically significant lower incidence of low respiratory tract infections in AzB group only.
The modification of the spectral function of vector mesons in nuclear matter is predicted in many theoretical models. However, the existing experimental results for testing these models are ...contradictory. Possible effects of the modification of the mass and width of ω mesons produced in the collisions of 7-GeV/
c
positively charged mesons with C, Be, Al, Cu, Sn, and Pb nuclear targets have been sought in the Hyperon-M experiment. The measured mass and width of ω mesons produced on the indicated nuclei are in agreement with each other with a high accuracy, which does not confirm the theoretical models predicting modification of the mass and/or width of the ω meson in nuclear matter.
Introduction. Measles remains an urgent problem in Russian healthcare. Despite the ongoing vaccination, there is an increase in the incidence of measles. Prevention of measles is particularly ...important in high-risk groups, as well as among healthcare professionals to prevent hospital-acquired outbreaks of infection. The duration of post-vaccination immunity during the elimination of measles has not been sufficiently studied, so often people who have had measles in childhood or have 1–2 vaccinations against the disease lose their protective antibodies with age in the absence of natural boosterization.Goals and objectives. To study the intensity of specific immunity to measles in employees of the maternity unit.Material and methods. The study involved 271 employees of the maternity unit aged 21 to 93 years (262 serum samples). The level of IgG antibodies (Ab) to the measles virus in the blood serum was studied by ELISA using a standard set of reagents for the quantitative determination of IgG by «VECTOR-BEST». The result was considered negative if the concentration of IgG to the measles virus in tested sample was ≤ 0.18 IU/ml and positive – if 0.18 IU/ml. Results. The number of seronegatives ranged from 0% to 30.8% in female employees with its maximum at age of 31–35 years. The lowest proportion of seronegative and the highest proportion of seropositive women were observed among the elderly, 60 years.Discussion. There is a marked tendency for an increase of the proportion of persons with average Ab levels with age and a decrease of the proportion of persons with low Ab levels. The percentage of seronegative women among employees exceeded the recommended level, which makes it possible for an nosocomial outbreak when an infection is introduced.Conclusion. The authors recommend that serological testing for the intensity of the immune response against measles should be included in the standard of the pre-vaccination screening for adults.
Abstact
—The paper presents the upgrade project of the Hyperon-M experiment in the positive beam line of the U-70 accelerator complex in Protvino to study hadron-nuclear interaction mechanisms. It is ...proposed that the setup be upgraded to study the excited states of secondary nuclei formed by different types of primary hadron–nuclear interaction using precision nuclear gamma-ray spectroscopy. This could open a new direction of the nuclear physics at the junction with the physics of elementary particles at intermediate energies.
Introduction. The study of the intensity of humoral immunity to the measles virus (Paramyxoviridae: Morbillivirus) (MV) remains relevant due to the ongoing registration of the cluster cases of ...measles (including nosocomial cases).The aim of the study was to analyze correlation between the intensity of the humoral immunity to measles virus and the measles incidence in different age groups of the Moscow residents.Material and methods. A simple analytic study was carried out under the framework of measles prevention improvement program conducted in the subjects of the Russian Federation. The study included the analysis of the reasons for the increase in the proportion of seronegative individuals and the comparison of the results of seromonitoring with the data of age-related measles incidence. Throughout 2018, total 1,855 blood serum samples obtained from employees of a large hospital center in Moscow who were previously vaccinated against measles were tested for IgG antibodies (ABs) to MV. The subjects were divided into 11 groups according to their age. Statistical analysis of the obtained data was performed using nonparametric criteria.Results and discussion. The proportion of seronegative individuals among the staff of the medical facility decreased with age, from 38.5% in persons aged 19–23 to 0% among employees aged 64 and over. Persons aged 19–43 years were the most susceptible to measles infection, which was confirmed also by the highest incidence rate at these age groups (from 6.93 to 14.03 per 100,000 population). The age group most protected against measles was those over 64 years of age, who were all seropositive and had the lowest rates of incidence. This is probably due to the fact that by this age most of them have had a measles infection and have formed a sufficient immune response. At the same time, younger individuals living in the post-elimination era have only vaccine-induced ABs to MV, the level of which declines rapidly to non-protective values in the absence of boosterization due to the exposure to the wild-type strain of the pathogen.Conclusion. The monitoring of the MV-specific IgG- AB levels is required for employees in the medical institutions under the age of 35. Administration of the single dose of the appropriate vaccine is recommended for seronegative individuals.
Relevance. Lung transplantation is recognized as a method of treating terminal stages of lung disease when the drug therapy resource has been exhausted. In addition to the lack of material for ...transplantation, a serious problem of lung transplantation is the low graft survival rate. The main reasons are infections and primary allograft failure. Aims. To consider the current state of the use of vaccine prophylaxis in the integrated management of patients before and after lung transplantation. Conclusions The prevention of respiratory infections in adult candidates for organ transplantation and recipients is recommended and included in many clinical protocols and recommendations, however, they are based mainly on studies performed on healthy individuals, and are poorly supported by the results obtained in the study of individuals who underwent complete internal organ transplantation. Also, the effectiveness of vaccination remains unexplored, taking into account the individual characteristics of the immune system and the state of population immunity in relation to vaccine-preventable infections.
The review discusses the current state of the use of vaccine prevention in the debarment of pneumococcal infection in patients with chronic kidney disease (CKD). Clinical and immunological features ...of various groups of patients with chronic kidney disease are considered, the specifics of their immunoreactivity, the features of their immune system, due to the underlying and concomitant diseases, as well as treatment. The review analyzes data on various approaches to preventive vaccination and discusses the results of various vaccination regimens and vaccines.Based on the materials reviewed, recommendations are given for organizing the most rational vaccine prevention of pneumococcal infection in patients with chronic kidney disease.
PDF
