Medical academic journal最新文献

{"title":"M proteins are the major pathogenicity factors of Streptococcus pyogenes","authors":"L. Burova, A. Suvorov, A. Totolian","doi":"10.17816/maj106990","DOIUrl":"https://doi.org/10.17816/maj106990","url":null,"abstract":"M proteins are the major pathogenicity factors of the widespread and potentially deadly bacterial pathogen Streptococcus pyogenes. These proteins confer to bacteria resistance against innate and adaptive immune responses. The study of the M proteins of hemolytic streptococci group A and their involvement in pathology clearly indicates that strains of streptococci, for one reason or another devoid of M proteins are unable to multiply in the macroorganism and form a focus of infection. This circumstance in itself once again underlines the leading role of M proteins in the realization of its many properties and in the development of the infectious process. The ability of M proteins to recruit plasma proteins of the macroorganism is their significant pathogenetic properties. The most important is the nonimmune binding by M proteins of human immunoglobulins, because it participates in the suppression of phagocytosis, violations of bacterial opsonization and complement activation along the classical pathway, not to mention the possible involvement of this phenomenon in the genesis of post-infectious complications of autoimmune nature. This review summarizes the current data on the structure M proteins, their functional activity, manifestations of pathogenicity, genetic regulation and methods of emm-typing.","PeriodicalId":342669,"journal":{"name":"Medical academic journal","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123850507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alphacoronaviruses detected in fecal samples of bats captured in Moscow and Rostov-on-Don in 2021","authors":"Elena V. Korneenko, A. Samoilov, I. Artyushin, A. P. Yusefovich, S. Dolotova, E. Klyuchnikova, Valeriya Sbarzaglia, A. Gladkikh, V. Dedkov, A. Speranskaya","doi":"10.17816/maj108718","DOIUrl":"https://doi.org/10.17816/maj108718","url":null,"abstract":"BACKGROUND: Bats are a reservoir of a large number of viruses, including coronaviruses. Monitoring viruses in bats is an important task. \u0000AIM: To detect viruses belonging to Coronaviridae family in bats which habitat in European part of Russia. \u0000MATERIALS AND METHODS: We used PCR amplification of viral genome fragments, followed by high-throughput sequencing. \u0000RESULTS: RdRp gene fragments of at least two different alphacoronaviruses (Bat coronavirus, Coronaviridae) were revealed in four bats of three species. \u0000CONCLUSIONS: Our results demonstrate the presence of viruses of the Alphacoronavirus genus in 4 of 17 bats. Coronavirus-positive animals were captured in 2021 in Moscow, Moscow Region and Rostov-on-Don, these four animals have been found to be carriers of different isolates of the same alphacoronavirus, which allows us to suggest the possibility of transmission of this virus between animals between different species. One animal was found as carrier of genome fragments of two different alphacoronaviruses.","PeriodicalId":342669,"journal":{"name":"Medical academic journal","volume":"26 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123499643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of purification conditions and study of antigenic properties of recombinant nucleocapsid protein of different SARS-CoV-2 strains","authors":"A. Rak, S. Donina, I. Isakova-Sivak, L. Rudenko","doi":"10.17816/maj108599","DOIUrl":"https://doi.org/10.17816/maj108599","url":null,"abstract":"BACKGROUND: In the context of the constant manifestation of new SARS-CoV-2 strains and the need to determine the immunogenicity of new variants of antiviral vaccines, it is necessary to create diagnostic test systems based on conservative viral proteins. The SARS-CoV-2 nucleocapsid protein can be considered as a candidate antigen. However, the relevance of existing test systems based on it for determining the titer of antibodies produced in response to infection by recently emerging strains is unknown. \u0000AIM: The goal is to optimize the conditions for obtaining recombinant N proteins of various SARS-CoV-2 strains and to analyze the possibility of creating ELISA test systems based on them. \u0000MATERIALS AND METHODS: Bacterial strains producing N proteins were obtained by amplifying the corresponding genes and ligating them into the pETDuet-1 expression vector. Expression was induced at 20 or 37C for 1, 2, 4, or 20 h using inducer (IPTG) concentrations of 0.1 mM or 0.5 mM with or without the addition of 3% ethanol. Proteins were purified from biomass by metal affinity chromatography and used as antigens for the detection of antiviral antibodies by ELISA. \u0000RESULTS: It was found that the concentration of the inductor sufficient for the expression of recombinant proteins is 0.1 mM, the induction time is 1 h, and the required temperature is 37 C. The influence of the presence of ethanol as an expression-stimulating reagent was not revealed. When determining the titers of antiviral antibodies using the obtained proteins, cross-reactivity of serums of COVID-19 convalescents was established regarding to antigens of various SARS-CoV-2 strains. \u0000CONCLUSIONS: The possibility of effective induction of protein synthesis at a minimum concentration of the inducer and cultivation time indicates the economy of its production, and antigen recognition by antiviral antibodies indicates a native structure. Cross-reactivity of the blood sera of convalescents indicates the slow character of the evolution of the antigenic properties of the SARS-CoV-2 N protein. Thus, the purified proteins can be used as a basis for development of diagnostic test systems.","PeriodicalId":342669,"journal":{"name":"Medical academic journal","volume":"125 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125767880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Generation and characterization of SARS-CoV-2 pseudoviruses","authors":"N. Rudometova, D. Shcherbakov, L. Karpenko","doi":"10.17816/maj108600","DOIUrl":"https://doi.org/10.17816/maj108600","url":null,"abstract":"BACKGROUND: Pseudovirus technology is a versatile and valuable tool for both fundamental and applied virological research. Pseudotyped viruses provide the same cell entry mechanism as SARS-CoV-2 and are widely used to investigate the virus entry mechanism, cell tropism, and virus neutralization assays. \u0000AIM: The aim of the work is to obtain pseudotyped SARS-CoV-2 viruses and evaluate their transducing activity. \u0000MATERIALS AND METHODS: Using genetic engineering methods, a genetic construct carrying the SARS-CoV-2 glycoprotein S gene was obtained, as well as the pLenti-Luc-GFP reporter plasmid encoding the green fluorescent protein (GFP) and firefly luciferase genes. Pseudovirus particles were generated by transfection of eukaryotic cells. The transducing activity of pseudoviral particles displaying SARS-CoV-2 glycoprotein S on their surface was studied using HEK293, HEK293-hACE2, and HEK293-hACE2-TMPRSS2 (t) cell cultures. \u0000RESULTS: Based on the second-generation lentiviral platform, pseudoviruses were obtained that exhibit SARS-CoV-2 S glycoprotein on their surface. It was found that the pseudoviruses penetrate more efficiently into HEK293-hACE2-TMPRSS2 cells than into HEK293-hACE2. Pseudoviruses have been shown to be sensitive to neutralization by recombinant monoclonal antibodies that interact with the receptor-binding domain (RBD) of the SARS-CoV-2 S glycoprotein. \u0000CONCLUSIONS: The pseudoviruses can be used both to search for antiviral drugs that would be able to block the penetration of SARS-CoV-2 into the target cell, and to evaluate the effectiveness of the developed monoclonal antibodies and vaccines against SARS-CoV-2.","PeriodicalId":342669,"journal":{"name":"Medical academic journal","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126917177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of SARS-CoV-2 peptides on activation of NK cells","authors":"M. O. Ustiuzhanina, O. Britanova, E. Kovalenko","doi":"10.17816/maj108517","DOIUrl":"https://doi.org/10.17816/maj108517","url":null,"abstract":"BACKGROUND: NK cells, alone with T lymphocytes, have a high antiviral activity. Exploring the contribution of NK cells in fighting SARS-CoV-2 infection may promote the development of appropriate treatments for COVID-19. Previously, NK cell response was considered nonspecific, provided by a combination of signals from activating and inhibitory receptors. Currently, the existence of certain subpopulations of antigen-specific, or adaptive, NK cells has been shown. \u0000AIM: To evaluate the functional response of NK cells induced by SARS-CoV-2 peptides. \u0000MATERIALS AND METHODS: The functional response of NK cells to SARS-CoV-2 peptides was determined by their degranulation (surface CD107a expression) and IFN production levels, and by the activation degree (HLA-DR expression level). Volunteers who recovered from COVID-19 participated in the study, and immune cells from a healthy volunteer without SARS-CoV-2-specific antibodies were used as controls. \u0000RESULTS: NK cells from individuals who had recovered from COVID-19, in contrast to a donor who had not been infected, showed a higher level of IFN production in response to SARS-CoV-2 peptides, compared with control samples. The level of degranulation of NK cells from donors previously infected with SARS-CoV-2 was higher than in the corresponding control. The proportion of activated NK cells obtained from recovered donors was also higher in samples stimulated with SARS-CoV-2 peptides. \u0000CONCLUSIONS: We have demonstrated the activation of NK cells obtained from people who had previously recovered from COVID-19 in response to SARS-CoV-2 peptide antigens in cultures of peripheral mononuclear cells in vitro. This study reveals the possibility for further investigation of antigen-specific NK cells in COVID-19 disease. The use of such cells could help develop treatments for SARS-CoV-2 infection.","PeriodicalId":342669,"journal":{"name":"Medical academic journal","volume":"150 12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130891833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of immunoglobulins specific to SARS-CoV-2 virus S-protein in mixed saliva","authors":"M. A. Lizunkova, Polina Kudar, I. Koroleva, Y. Desheva","doi":"10.17816/maj108961","DOIUrl":"https://doi.org/10.17816/maj108961","url":null,"abstract":"BACKGROUND: Since the beginning of the COVID-19 pandemic, scientists have been concerned about finding an effective alternative to blood-based diagnostics of antibodies to SARS-CoV-2. According to the results of numerous studies by domestic and foreign authors, saliva is a valuable diagnostic material. Mixed saliva implies the possibility of painless and non-invasive sampling and opens up great opportunities for diagnosing COVID-19 in vulnerable populations, such as children. \u0000AIM: Development of a method for detecting immunoglobulins specific to the SARS-CoV-2 virus in saliva after infection with COVID-19 and vaccination. \u0000MATERIALS AND METHODS: The study involved 43 people aged 20 to 67 years, divided into 3 groups: recovered from COVID-19; those who believe they have not had COVID-19; vaccinated with various drugs against COVID-19. Samples of unstimulated mixed saliva and capillary blood from a finger were obtained from each subject, which were subsequently examined by methods of qualitative and quantitative enzyme immunoassay. \u0000RESULTS: A high level of correlation between the content of local IgG and IgA in saliva was demonstrated, while the relationship between the content of IgA in blood and saliva was shown to be of medium strength. A higher number of seropositive patients was demonstrated in the group vaccinated with vaccines against SARS-CoV-2, compared with those who recovered from COVID-19, which is consistent with the anamnesis data. \u0000CONCLUSIONS: This work demonstrates and confirms that saliva in the oral fluid is a valuable diagnostic material for the study of local antibodies. The data obtained will allow the development of unique test systems for studying humoral immunity to the SARS-CoV-2 virus, which can become an alternative replacement for the usual determination of virus-specific immunoglobulins in the blood.","PeriodicalId":342669,"journal":{"name":"Medical academic journal","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130424774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mathematical model of the spread of COVID-19 in the rostov region for 2020–2022","authors":"V. Denisenko, A. Aleshukina","doi":"10.17816/maj108663","DOIUrl":"https://doi.org/10.17816/maj108663","url":null,"abstract":"BACKGROUND: In the context of the COVID-19 epidemic, there is a need for forecasting tools that enables us to predict the possible epidemic consequences and evaluate the effectiveness of epidemic control. Mathematical modeling can serve as such a tool. \u0000AIM: The Aim is to present a mathematical model of the spread of COVID-19 in the Rostov Region for 20202022. To be more precise, the aim is to forecast how the number of people infected, recovered, hospitalized and died from the epidemic of the new coronovirus will change over this period of time. \u0000MATERIALS AND METHODS: The modeling of the epidemics was based on the extended SEIR model proposed by R. Neyer et al. for forecasting the COVID-19 epidemic and implemented as a freely available web application. \u0000RESULTS: The model under consideration made it possible to forecast the volume of hospitalization and the number of deaths in the course of COVID-19 epidemic in the Rostov region for 20202022. \u0000CONCLUSIONS: The performed simulations demonstrated the capabilities the considered SEIR model for forecasting the COVID-19 epidemic. It was found that the number of hospitalized patients for the entire period covered by the model does not exceed the capabilities of the health care system of the Rostov Region.","PeriodicalId":342669,"journal":{"name":"Medical academic journal","volume":"158 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129495438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of heat inactivation of ferrets serum samples on the detection of SARS-CoV-2-specific IgG antibodies in elisa","authors":"A. Goshina, V. Matyushenko, S. Donina, I. Sychev, I. Isakova-Sivak, A. Katelnikova, L. Rudenko","doi":"10.17816/maj108844","DOIUrl":"https://doi.org/10.17816/maj108844","url":null,"abstract":"BACKGROUND: Determination of serum antibody levels to the novel coronavirus SARS-CoV-2 is a necessary tool for assessing humoral immunity in COVID-19 patients or individuals vaccinated with specific vaccines, as well as for studying the immune responses to the viral antigens in animal models. Serum specimens of infected humans and animals are considered potentially infectious material, and therefore heat inactivation of samples at 56 C for 1 hour is recommended to reduce the risk of infection of personnel during serological studies. However, this procedure may affect the detection of virus-specific IgG and IgM antibodies, making interpretation of the results difficult. \u0000AIM: The goal is to evaluate the effect of heat inactivation of ferret serum samples on the binding of IgG antibodies to the SARS-CoV-2 antigens. \u0000MATERIALS AND METHODS: Serum samples of SARS-CoV-2 naive and immune ferrets were analyzed in three variants: (1) native sera, (2) serum samples than were heated at 56C for 1 hour, and (3) serum samples that were treated with receptor-degrading enzyme (RDE). The samples were studied in enzyme-linked immunosorbent assay (ELISA) using recombinant RBD protein (receptor-binding domain of SARS-CoV-2 S-protein) as a substrate, followed by determination of specific antibody levels before and after treatments. \u0000RESULTS: It has been shown that heat inactivation of the ferrets naive serum samples can lead to false-positive results, while RDE treatment can neutralize the effect of non-specific binding of IgG antibodies to the RBD domain of the SARS-CoV-2 S protein. \u0000CONCLUSIONS: Structural rearrangement of SARS-CoV-2-specific IgG antibodies and the formation of immunoglobulin complexes during heat inactivation of serum samples can affect the avidity of the antigen-antibody complex and lead to false-positive results when performing enzyme immunoassay. One of the possible methods to reduce the risk of artifacts is the treatment of blood sera with RDE, which eliminates the effect of heat inactivation.","PeriodicalId":342669,"journal":{"name":"Medical academic journal","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124871463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Method for the prevention of hospital infection in Saint Petersburg","authors":"Alexander V. Orlov, A. Pashkevich, V. Matveev, Liudmila B. Vainer, Tatiana A. Nachinkina, L. Kraeva, F. P. Romanyuk, T. A. Shutova, Mariya V. Kuropatenko, L. Zhelenina","doi":"10.17816/maj108748","DOIUrl":"https://doi.org/10.17816/maj108748","url":null,"abstract":"BACKGROUND: Cystic fibrosis is one of the most frequent monogenic diseases, in which, in addition to medical measures, measures for the prevention of the infectious process in the lungs are of great importance, which is provided by a clear organization of the work of any medical institution where patients are observed and where medical and rehabilitation measures are carried out. \u0000AIM: The article describes the experience of the childrens Center in St. Petersburg to prevent cross-infection of patients with cystic fibrosis who have the different luge microbiome. \u0000MATERIALS AND METHODS: The measures taken included a system for monitoring and dynamic control of the seeded pathogenic microflora with a strict separation of patients with cystic fibrosis, who had the isolation and carriage of various pathogens. The system provided for the separation of flows of patients with cystic fibrosis and the prevention of cross-infection, as well as a number of activities related to the disinfection of equipment. \u0000RESULTS: The methods adopted and put into practice have ensured the prevention of cross-infection of patients with cystic fibrosis, excreting various pathogenic bacteria from sputum. The patient management system made it possible to halve the number of hospitalizations of patients with Pseudomonas aeruginosa infection per CF patient per year: from 1.3 in 2001 to 0.6 in 2021, reduce the risk of cross-infection, reduce the number of relapses, hospitalizations and the average length of stay of a patient in a hospital. \u0000CONCLUSIONS: The developed system of assistance has shown its effectiveness and can be implemented in one form or another in the work of cystic fibrosis treatment centers in the Russian Federation.","PeriodicalId":342669,"journal":{"name":"Medical academic journal","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129312135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface expression of SARS-CoV-2 epitopes in Enterococcus faecium L3 for live oral vaccine against new coronavirus infection","authors":"O. Kopteva, Y. Desheva, A. Ivanova, Maxim G. Vorobyov, G. Leontieva, T. Gupalova, E. Bormotova, A. Suvorov","doi":"10.17816/maj108671","DOIUrl":"https://doi.org/10.17816/maj108671","url":null,"abstract":"BACKGROUND: Probiotic microorganisms are currently considered as a promising platform for the development of recombinant vaccines expressing viral or bacterial antigens. Probiotic-based mucosal vaccines are easy to produce in large quantities, they have a low cost, provide a fairly long T-cell memory. \u0000AIM: The aim was to study expression of mRNA fragment of S1 SARS-CoV-2 gene in Enterococcus faecium L3 culture and to confirm the insertion of S1 SARS-CoV-2 protein fragment into the pili of this bacterial strain by immunoelectron microscopy of original (E. faecium L3) and genetically modified strain (L3-SARS) with human sera obtained from patients with SARS-CoV-2. \u0000MATERIALS AND METHODS: mRNA expression was studied by real-time PCR with reverse transcription using primers specific to S1 protein. Immunoelectron microscopy was aimed to study the structure of E. faecium L3 pili with the expression of viral protein SARS-CoV-2. Bacteria were washed three times in PBS by centrifugation at 3500 rpm for 20 min and suspended in 0.1 M NaCl. A 10-fold bacterial concentrate was used. The source of the primary antibodies was a set of polyclonal human sera containing IgG. Labeling was performed using goat IgG conjugated with 18 nm gold particles. \u0000RESULTS: A sharp increase in mRNA amplification of inserted genetic sequence of S1 SARS-CoV-2 gene fragment relatively to the control was demonstrated. These results confirmed that DNA of S1 gene in E. faecium L3 genome is transcribed together with the target pili gene in E. faecium genome. Specific antigens of SARS-CoV-2 on the surface of L3-SARS were determined using electron microscopy, which demonstrated the correct assembly of chimeric molecules of pili on the surface of bacteria. \u0000CONCLUSIONS: Evaluation in expression of SARS-CoV-2 S1 protein after introduction of the corresponding genetic elements into genome of probiotic strain E. faecium L3 allows us to conclude that selected DNA fragments of SARS-CoV-2 were able to direct the synthesis of immunogenic protein S1 that was expressed by the strain E. faecium L3-SARS.","PeriodicalId":342669,"journal":{"name":"Medical academic journal","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125084468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}