Comparative Cohort Epidemiological Study of Collective Immunity against New Coronavirus Infection among Different Groups of Military Personnel

2021 ◽  
Vol 76 (6) ◽  
pp. 661-668
Author(s):  
Evgenij V. Kryukov ◽  
Dmitrij V. Trishkin ◽  
Andrej M. Ivanov ◽  
Dmitrii V. Ovchinnikov ◽  
Aleksandr A. Kuzin ◽  
...  
Keyword(s):  
Epidemiological Study ◽  
Solid Phase ◽  
Total Sample ◽  
Blood Groups ◽  
Educational Organizations ◽  
Epidemic Process ◽  
Population Immunity ◽  
Vaccination History ◽  
Antibody Titers ◽  
First Time

Background. The need to study the population immunity to the SARS-CoV-2 virus is due to the intensive spread of COVID-19 and the implementation of immunoprophylaxis of this infection. The identification of the features of the formation of immunoresistance in organized military collectives will allow us to predict the development of the epidemic situation, including among comparable population groups. Aims the study of population immunity to the SARS-CoV-2 virus in the context of the COVID-19 pandemic against the background of specific immunoprophylaxis in organized military collectives. Methods. According to epidemiological indications, an epidemiological study of collective immunity to the SARS-CoV-2 virus was conducted against the background of vaccination among cadets of military educational organizations. The study involved 497 people, divided into groups by epidemiological and vaccination history for COVID-19, blood groups and Rh factor. The assessment of the immunity intensity was carried out by the levels of class G immunoglobulins (IgG) to SARS-CoV-2 in the blood serum by the method of solid-phase enzyme immunoassay. Results. Seroprevalence in the total sample was 92.6%. The highest rates were observed among vaccinated patients: those who were not ill and vaccinated 99.0 0.7%, those who were ill and vaccinated-100% (mean geometric antibody titers 1:2234 and 1:4399). Among the ill, unvaccinated individuals, the seroprevalence index was 84.5 3.2% (1:220). Among those who were not ill, not vaccinated 8.2 3.1% (1:113), which may indicate a hidden course of the epidemic process in the team. A negative immune response was more common (tSt = 2.01; p 0.05) in individuals A(II)Rh+ blood group. The highest proportion of maximum antibody titers (1:32001:6400) was determined in AB(IV) individuals. Rh-blood groups (tSt=2.21; p 0.05). Conclusions. For the first time, the formation of combined immunity with the highest concentrations of specific antibodies was revealed in patients who have been ill and vaccinated has been revealed, which allows us to recommend vaccination to those who have suffered from COVID-19. The emergence of post-infectious immunity in organized groups with a latent epidemic process has been established. The relationship between the intensity of immunity with blood groups and the Rh factor was found.

Optimization of thermal conductivity in composites loaded with the solid-solid phase-change materials

2018 ◽  
Vol 25 (6) ◽  
pp. 1157-1165
Author(s):  
Taoufik Mnasri ◽  
Adel Abbessi ◽  
Rached Ben Younes ◽  
Atef Mazioud
Keyword(s):  
Thermal Conductivity ◽  
Phase Change ◽  
Phase Change Materials ◽  
Solid Phase ◽  
Spherical Inclusions ◽  
First Case ◽  
The Matrix ◽  
Composite Conductivity ◽  
First Time

AbstractThis work focuses on identifying the thermal conductivity of composites loaded with phase-change materials (PCMs). Three configurations are studied: (1) the PCMs are divided into identical spherical inclusions arranged in one plane, (2) the PCMs are inserted into the matrix as a plate on the level of the same plane of arrangement, and (3) the PCMs are divided into identical spherical inclusions arranged periodically in the whole matrix. The percentage PCM/matrix is fixed for all cases. A comparison among the various situations is made for the first time, thus providing a new idea on how to insert PCMs into composite matrices. The results show that the composite conductivity is the most important consideration in the first case, precisely when the arrangement plane is parallel with the flux and diagonal to the entry face. In the present work, we are interested in exploring the solid-solid PCMs. The PCM polyurethane and a wood matrix are particularly studied.

scholarly journals Magnetic solid phase extraction with octahedral structured Fe3O4@SiO2@polydimethylsiloxane magnetic nanoparticles as the sorbent for determining benzene, toluene, ethylbenzene and xylenes in water samples

RSC Advances ◽  
2017 ◽  
Vol 7 (66) ◽  
pp. 41862-41868 ◽  
Author(s):  
Maosheng Zhang ◽  
Guobin Huang ◽  
Jiarong Huang ◽  
Ling Zhong ◽  
Weilan Chen
Keyword(s):  
Magnetic Nanoparticles ◽  
Solid Phase Extraction ◽  
Water Samples ◽  
Solid Phase ◽  
Magnetic Solid Phase Extraction ◽  
Phase Extraction ◽  
Benzene Toluene ◽  
Magnetic Solid ◽  
First Time

Novel octahedral structured Fe3O4@SiO2@polydimethylsiloxane magnetic nanoparticles (Fe3O4@SiO2@PDMS MNPs) have been successfully synthesized for the first time.

scholarly journals Influence of Ligand Functionalization of UiO-66-Based Metal-Organic Frameworks When Used as Sorbents in Dispersive Solid-Phase Analytical Microextraction for Different Aqueous Organic Pollutants

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2869 ◽  
Author(s):  
Iván Taima-Mancera ◽  
Priscilla Rocío-Bautista ◽  
Jorge Pasán ◽  
Juan Ayala ◽  
Catalina Ruiz-Pérez ◽  
...  
Keyword(s):  
High Performance ◽  
Solid Phase ◽  
Metal Organic Frameworks ◽  
Aqueous Sample ◽  
Optimization Study ◽  
Relative Standard ◽  
Polycyclic Aromatic ◽  
Metal Organic ◽  
Array Detection ◽  
First Time

Four metal-organic frameworks (MOFs), specifically UiO-66, UiO-66-NH2, UiO-66-NO2, and MIL-53(Al), were synthesized, characterized, and used as sorbents in a dispersive micro-solid phase extraction (D-µSPE) method for the determination of nine pollutants of different nature, including drugs, phenols, polycyclic aromatic hydrocarbons, and personal care products in environmental waters. The D-µSPE method, using these MOFs as sorbents and in combination with high-performance liquid chromatography (HPLC) and diode-array detection (DAD), was optimized. The optimization study pointed out to UiO-66-NO2 as the best MOF to use in the multi-component determination. Furthermore, the utilization of isoreticular MOFs based on UiO-66 with the same topology but different functional groups, and MIL-53(Al) to compare with, allowed us for the first time to evaluate the influence of such functionalization of the ligand with regards to the efficiency of the D-µSPE-HPLC-DAD method. Optimum conditions included: 20 mg of UiO-66-NO2 MOF in 20 mL of the aqueous sample, 3 min of agitation by vortex and 5 min of centrifugation, followed by the use of only 500 µL of acetonitrile as desorption solvent (once the MOF containing analytes was separated), 5 min of vortex and 5 min of centrifugation. The validation of the D-µSPE-HPLC-DAD method showed limits of detection down to 1.5 ng·L−1, average relative recoveries of 107% for a spiked level of 1.50 µg·L−1, and inter-day precision values with relative standard deviations lower than 14%, for the group of pollutants considered.

scholarly journals Hepatitis B antibody titers in Indonesian adolescents who received the primary hepatitis B vaccine during infancy

2013 ◽  
Vol 53 (3) ◽  
pp. 160
Author(s):  
Hartono Gunardi ◽  
Adra Firmansyah ◽  
Sri Rezeki S Harun ◽  
Sudigdo Sastroasmoro
Keyword(s):  
Hepatitis B ◽  
Booster Dose ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Blood Tests ◽  
Vaccination History ◽  
Antibody Titers ◽  
Hb Vaccine ◽  
Over Time

Backgi-ound Hepatitis B (HB) has been classified as moderate-tohighlyendemic in Indonesia. HB vaccination, the most effectivemethod to prevent HB viral transmission, induces protectiveantibodies against HB surface antigen (anti-HBs). However, theseantibodies decline in titer over time. Studies on the duration ofprotection and the prevalence of n on-responders in Indonesianadolescents have been limited.Objectives To determine anti-HBs titers in 15-17-year oldIndonesian adolescents given primary HB vaccine during infancyand the prevalence of non-responders after a HB vaccine boosterdosage.Methods This cross-sectional study was performed from Februaryto September 2008 on adolescents aged 15-17 years in threesenior high schools in Jakarta who received complete primary HBvaccines during infancy, based on parents' recall. Investigationsincluded HB vaccination history, anthropometric measurements,and blood tests for anti-HBs before and 4-6 weeks after a boosterdose ofHB vaccine.Results Of 94 subjects, 35 had protective anti-HBs and 59 hadundetectable anti-HBs. A booster dose was administered to 5 8 of then on-protected subjects, of which 33 showed anamnestic responses.However, 25 subjects failed to generate protective anti-HBs. Takinginto consideration the adolescents with protective anti-HBs beforeand after the booster dose, serologic protection was demonstratedin 73%. Non-responder prevalence was 27%. The high prevalenceof non-responders may indicate bias of parents' recall.Conclusion Protective anti-HBs is detected in less than half ofIndonesian adolescents given primary HB vaccine during infancy.Following booster dosage, anamnestic responses are n oted in onethirdof subjects. The prevalence of non-responders is 27%, butconfirmation with further study is needed.

scholarly journals THE PRODUCTION OF MONOCLONAL ANTIBODIES TO TETRASACCHARIDE - SYNTHETIC ANALOGUE OF THE CAPSULAR POLYSACCHARIDE OF STREPTOCOCCUS PNEUMONIAE OF SEROTYPE 14 AND THEIR IMMUNOCHEMICAL CHARACTERIZATION

2018 ◽  
pp. 26-31
Author(s):  
I. V. Yakovleva ◽  
E. A. Kurbatova ◽  
E. A. Akhmatova ◽  
E. V. Sukhova ◽  
D. V. Yashunsky ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Streptococcus Pneumoniae ◽  
Capsular Polysaccharide ◽  
Solid Phase ◽  
Synthetic Analogue ◽  
Immunochemical Characterization ◽  
Carbohydrate Epitopes ◽  
First Time

Aim. Production of monoclonal antibodies (mAb) to synthetic tetrasaccharide - repeating unit of the capsular polysaccharide (CP) of Streptococcus pneumoniae serotype 14 and their immunochemical characterization. Materials and methods. In order to generate the hybridoma producing mAb, mice were immunized with synthetic tetrasaccharide conjugated with bovine serum albumin (BSA) with following hybridization of B lymphocytes with mouse myeloma cells. Antibodies were obtained in vitro andin vivo. Immunochemical characterization of mAb to tetrasaccharide was carried out using a variety of ELISA options. Results. For the first time obtained mouse hybridoma, producing IgM to tetrasacchride. The IgM titer of anti-tetrasacharide antibodies in supernatants of clones and in the ascitic fluid of mice in ELISA detected by biotinylated tetrasaccharide and synthetic CP adsorbed on the solid phase was higher compared to the use of bacterial CP as well cover antigen. In the reaction of inhibition of the ELISA, the mAb recognized the corresponding carbohydrate epitopes of the bacterial CP of S. pneumoniae serotype 14 dissolved in the liquid phase better than tetrasaccharide ligand and synthetic CP. Conclusion. To detect mAb to tetrasaccharide in ELISA preferably to use synthetic analogues of the CP as solid phase antigens. The obtained mAb to tetrasaccharide can be used to determine the representation of the protective tetrasaccharide epitope of CP in the development of pneumococcal vaccines.

scholarly journals Natural infection of Deroceras laeve (Mollusca: gastropoda) with metastrongylid larvae in a transmission focus of abdominal angiostrongyliasis

2002 ◽  
Vol 44 (1) ◽  
pp. 53-54 ◽  
Author(s):  
Rafael Lucyk MAURER ◽  
Carlos GRAEFF-TEIXEIRA ◽  
José Willibaldo THOMÉ ◽  
Luís Antônio CHIARADIA ◽  
Hiroko SUGAYA ◽  
...  
Keyword(s):  
Epidemiological Study ◽  
Natural Infection ◽  
Southern Brazil ◽  
Intermediate Hosts ◽  
Santa Catarina ◽  
Crop Pest ◽  
The Third ◽  
The Family ◽  
Third Stage ◽  
First Time

Angiostrongylus costaricensis is a nematode parasitic of rodents. Man may become infected by ingestion of the third stage larvae produced within the intermediate hosts, usually slugs from the family Veronicellidae. An epidemiological study carried out in a locality in southern Brazil (western Santa Catarina State) where these slugs are a crop pest and an important vector for A. costaricensis has documented for the first time the natural infection of Deroceras laeve with metastrongylid larvae. This small limacid slug is frequently found amid the folds of vegetable leaves and may be inadvertently ingested. Therefore D. laeve may have an important role in transmission of A. costaricensis to man.

scholarly journals DEVELOPMENT OF ENVIRONMENTAL VOLUNTEERING IN EDUCATIONAL ORGANIZATIONS

2021 ◽  
pp. 127-138
Author(s):  
Татьяна Николаевна Арсеньева ◽  
Игорь Владимирович Козин ◽  
Владимир Евгеньевич Менников
Keyword(s):  
Continuing Education ◽  
Educational Organizations ◽  
Empirical Basis ◽  
The Creation ◽  
Environmental Projects ◽  
Environmental Volunteering ◽  
First Time ◽  
Federal Center

Рассмотрены проблемы развития экологических добровольческих практик в общеобразовательных организациях. Обосновывается предположение, что вовлечение обучающихся в создание и реализацию социально-значимых экологических проектов способствует формированию гражданской позиции школьников и становится эффективным инструментом их социализации. Эмпирическую базу статьи составляет исследование, проведенное Федеральным центром дополнительного образования и организации отдыха и оздоровления детей. Материалы данного исследования вводятся в научный оборот впервые. This article is devoted to the problems of the development of environmental volunteer practices in educational organizations. The assumption is substantiated that the involvement of students in the creation and implementation of socially significant environmental projects contributes to the formation of the civic position of schoolchildren and becomes an effective tool for socialization. The empirical basis of the article is a study conducted by the Federal Center for Continuing Education and Organization of Recreation and Recreation of Children. The materials of this research are being introduced into scientific circulation for the first time.

Application of Wray-Agarwal turbulence model for numerical simulation of gas-solid flows in CFB risers

2021 ◽  
pp. 1-25
Author(s):  
Yali Shao ◽  
Ramesh K. Agarwal ◽  
Xudong Wang ◽  
Baosheng Jin
Keyword(s):  
Turbulence Model ◽  
Circulating Fluidized Bed ◽  
Volume Fraction ◽  
Solid Phase ◽  
Solid Volume Fraction ◽  
Turbulence Models ◽  
Two Phase ◽  
Efficient Simulation ◽  
Pressure Profiles ◽  
First Time

Abstract In recent decades, increasing attention has been focused on accurate modeling of circulating fluidized bed (CFB) risers to provide valuable guidance to design, optimization and operation of reactors. Turbulence model plays an important role in accurate prediction of complex gas-solid flows. Recently developed Wray-Agarwal (WA) model is a one-equation turbulence model with the advantages of high computational efficiency and competitive accuracy with two-equation models. In this paper for the first time, Eulerian-Eulerian approach coupled with different turbulence models including WA model, standard κ-ε model and shear stress transport (SST) κ-ω model is employed to simulate two-phase flows of gas phase and solid phase in two CFB risers, in order to assess accuracy and efficiency of WA model compared to other well-known two-equation models. Predicted gas-solid flow dynamic characteristics including the gas-solid volume fraction distributions in radial and axial directions, pressure profiles and solid mass flux distributions are compared with data obtained from experiment in detail. The results demonstrate WA model is very promising for accurate and efficient simulation of gas-solid multiphase flows.

Amplification of Ehrlichial DNA from Dogs 34 Months after Infection with Ehrlichia canis

1998 ◽  
Vol 36 (1) ◽  
pp. 73-76 ◽  
Author(s):  
Shimon Harrus ◽  
Trevor Waner ◽  
Itzhak Aizenberg ◽  
Janet E. Foley ◽  
Amy M. Poland ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Carrier State ◽  
Ehrlichia Canis ◽  
Beagle Dogs ◽  
Three Samples ◽  
Canine Monocytic Ehrlichiosis ◽  
Antibody Titers ◽  
Healthy Dogs ◽  
First Time ◽  
Indirect Immunofluorescent

In order to determine whether dogs in the subclinical phase of canine monocytic ehrlichiosis (CME) are carriers of Ehrlichia canis and to determine the significance of persistent indirect immunofluorescent anti-E. canis antibody titers during this phase, PCR was performed with blood, bone marrow, and splenic aspirates collected 34 months postinoculation from six clinically healthy beagle dogs experimentally infected with E. canis. At least one of the three samples (spleen, bone marrow, and blood) from four of the six dogs was PCR positive. The spleens of all four of these dogs were PCR positive, and the bone marrow and blood of two of the four dogs were PCR positive. Indirect immunofluorescent-antibody titers increased progressively during the first 5 months postinfection, remained high for an additional period of more than 11 months, and declined thereafter, suggesting that the dogs were recovering from the disease. Five of the dogs remained seropositive 34 months postinfection. The data obtained in this study demonstrate for the first time that clinically healthy dogs in the subclinical phase of CME are carriers of the rickettsia. It was shown that dogs can harbor E. canisfor years without developing the chronic clinical disease and that dogs can eliminate the parasite and recover from CME without medical treatment. Our findings suggest that the spleen is the organ most likely to harbor E. canis parasites during the subclinical phase and the last organ to accommodate the parasite before elimination. It was concluded that PCR of DNA extracted from splenic aspirates is a reliable method for determining the carrier state of CME.

Modelling Semi-Solid Behaviour and Brittle Temperature Range

2019 ◽  
Vol 285 ◽  
pp. 361-366 ◽  
Author(s):  
Khalil Traidi ◽  
Véronique Favier ◽  
Philippe Lestriez ◽  
Karl Debray ◽  
Laurent Langlois ◽  
...  
Keyword(s):  
Solid State ◽  
Material Properties ◽  
Solid Phase ◽  
Thermal Conditions ◽  
Tensile Tests ◽  
Internal Variable ◽  
Temperature Dependent ◽  
Brittle Transition ◽  
Semi Solid ◽  
First Time

In this paper, a new elastic viscoplastic micromechanical modelling is proposed to represent the semi-solid behaviour and predict the ductile-brittle transition of the C38LTT near the solidus. It is based on a viscoplastic modelling previously presented in [1]. The originality of the new model comes from three main enhancements: the transition between the solid state and the semi-solid state was included meaning that the material properties were taken temperature-dependent, the elastic properties was taken into account similarly as [2] and the evolution of the internal variable describing the degree of agglomeration of the solid phase was enhanced. The model was implemented in the commercial software FORGE©. Tensile tests representing the experimental thermal conditions and obtained using a GLEEBLE© machine were simulated. The comparison of the predicted and experimental results shows that, for the first time to our knowledge, the three steps of the load-displacement response and ductile-brittle transition were successfully described.

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