134 research outputs found
A simple model for the time evolution of the condensation sink in the atmosphere for intermediate Knudsen numbers
Transformation of the mass flux towards the particle from the kinetic regime to the continuum regime is often described by the Fuchs-Sutugin coefficient. Kinetic regime can be obtained as a limiting case when only one term of the expansion of the Fuchs-Sutugin coefficient at small 1/Kn is considered. Here we take the two first terms into account, and get a mass flux which agrees well with the full mass flux down to Kn similar to 0.5. This procedure allows an analytical solution of the condensation equation valid for the range of intermediate Knudsen numbers to be obtained. The expansion is further applied to analytically calculate the condensation sink. The formula for the condensation sink is tested against field observations. The relative contribution of different aerosol modes to the condensation sink is discussed. Furthermore, we present a simple model describing the coupled dynamics of the condensing vapour and the condensation sink. The model gives reasonable predictions of condensation sink dynamics during the periods of the aerosol modes' growth by condensation in the atmosphere.Peer reviewe
Predicted facies, sedimentary structures and potential resources of Jurassic petroleum complex in S-E Western Siberia (based on well logging data)
This paper is devoted to the current problem in petroleum geology and geophysics- prediction of facies sediments for further evaluation of productive layers. Applying the acoustic method and the characterizing sedimentary structure for each coastal-marine-delta type was determined. The summary of sedimentary structure characteristics and reservoir properties (porosity and permeability) of typical facies were described. Logging models SP, EL and GR (configuration, curve range) in interpreting geophysical data for each litho-facies were identified. According to geophysical characteristics these sediments can be classified as coastal-marine-delta. Prediction models for potential Jurassic oil-gas bearing complexes (horizon J[1]{1}) in one S-E Western Siberian deposit were conducted. Comparing forecasting to actual testing data of layer J[1]{1} showed that the prediction is about 85%
Variability of cef Genes in Toxigenic and Non-Toxigenic Vibrio cholerae O1 Strains
Objective of the investigation was a comparative bioinformatics analysis of Vibrio cholerae О1 Cef (CHO cell elongating factor) genes and proteins. Materials and methods. 36 Vibrio cholerae О1 strains from the Rostov-on-Don Research Anti-Plague Institute collection have been utilized. DNA sequencing was conducted on the MiSeq platform (Illumina); gene identification and analysis was carried out by means of BioEdit 7.2.5, BLASTN 2.2.29, BLASTP, MEGA 7, Vector NTI Advance 11 software programs. Results and conclusions. The data obtained confirmed Cef to be rather conserved in choleragenic strains (carrying cholera toxin genes ctxAB as a part of genome-integrated CTX prophage): all of them shared closely related prototype alleles cefС or cefЕ1. The Е1 allele was also revealed in ctxAB– strains carrying the pre-CTX prophage and in a single strain lacking both prophages. In the rest of CTX–/pre-CTX– V. cholerae four novel cef variants, that were not previously described, have been identified, two of which (E2 and E3), belonging to the Russian isolates, appeared to be unique, while for the two others absolute homologues were found in NCBI. In this connection several strains which caused severe cholera-like diseases in humans were placed in the group of cefЕ4 host strains. Since Cef is one of pathogenicity/persistence factors of cholera vibrios, we presume that conservation of its altered variants in the course of natural selection embodies a certain biological sense in respect of possible acquisition of qualities, significant for realization of both pathogenic and persistence potential
Analysis of the Results of Cholera Vibrios Monitoring in Environmental Objects in the Administrative Territories of the Russian Federation Using GIS “CHOLERA 1989–2014”
Objective of the work was to compare the results of monitoring of Vibrio cholerae strains isolated in the territories of federal districts, their constituent entities and from certain water bodies between 2006–2016. Based on the methodology, using updated geoinformation system “Cholera 1989–2014”, a comparative study of the dynamics of isolation and biological properties of 586 Vibrio cholerae O1, O139 strains and R-variants, collected from the surface water bodies in the administrative territories of Russia, was carried out. Eventually it is established that Vibrio cholerae strains of various serogroups are found in the territory of all federal districts, but not in all the entities included in them. It is shown that the greatest number of isolated strains was registered in the Southern Federal District. The overwhelming number of Vibrio cholerae strains, isolated in the country, were non-toxigenic. It was noted that against the background of epidemiological welfare, the detection of single epidemiologically significant strains continued (Rostov Region).ctxA–tcpA+ strains were found in the Southern, Far Eastern and North-Western Federal Districts. It is established that until 2013 in five constituent entities strains of Vibrio cholerae O1 and O139 in water bodies were not detected. Non-toxigenic strains of Vibrio cholerae O1 El Tor Ogawa serovar prevailed in the territories of the Southern and Ural, and Inaba serovar – in the remaining Federal Districts.The most frequently isolated were non-toxigenic Vibrio cholerae O1 strains with phagotype 15, while isolates with phagotypes 4, 5, 10, 14 and 17 were traced only in the Southern Federal District. The data obtained formed the basis of the approach that contributes to a comprehensive assessment of the epidemiological situation on cholera in the territory of Russia and highlighted the prospects for using GIS to improve the effectiveness of cholera vibrio monitoring in surface water bodies
Recent achievements in CAR-T cell immunotherapy for glioblastoma treatment
Glioblastoma remains the most common and aggressive primary brain tumor today. Because of the neuroanatomical location of glioblastoma, conventional chemotherapy and radiation therapy have limited efficacy in patients with these tumors. Over the past decade, antitumor immunotherapy has become widespread among modern therapeutic approaches. The importance of immunotherapeutic methods lies in their ability to increase the effectiveness of cancer treatment and prevent relapses by enhancing the systemic and local immune response against tumor cells.One of the most promising directions in modern immunotherapy is CAR-T therapy, or adoptive cell therapy using genetically modified T-lymphocytes. The functional advantage of CAR-T therapy is its ability to genetically modify lymphocytes, leading to their activation in vitro.This review examines the key principles of CAR-T therapy and analyzes the published results of clinical trials for the treatment of glioblastoma using several modifications of CAR-T cells
The association of HIV and genital mycoplasmas in pregnant women on HAART
Mycoplasma infections are most frequently associated with disease in the urogenital or respiratory tracts and, in most cases, mycoplasmas infect the host persistently. In HIV-infected individuals the prevalence and role of genital mycoplasmas has not been well studied. This study employed polymerase chain reaction (PCR) to examine the prevalence of Mycoplasma hominis in 106 HIV/AIDS patients, and 106 healthy volunteers from endocervical swabs for women. M. hominis were detected in 63 (74,1 %), and 10 (47,6%)patients in the HIV/AIDS group. The patients who refused highly active antiretroviral therapy (HAART) had a much higher risk of Mycoplasma infection (P < 0,05).This study showed that M. hominis were significantly more prevalent in HIV/AIDS patients. Further research will be required to confirm a causal relationship and to identify risk factors for Mycoplasma infection in HIV/AIDS populations.Микоплазменная инфекция наиболее часто связана с заболеваемостью мочеполовой сферы и дыхательных путей и, в большинстве случаев, отличается устойчивым течением. У ВИН -инфицированных пациентов распространенность и роль генитальных микоплазм не были хорошо изучены. Это исследование проводилось с использованием полимеразной цепной реакции с детекцией в реальном времени (ПЦР-РВ) для оценки распространенности Mycoplasma hominis у 106 ВИЧ инфицированных беременных женщин и 106 здоровых ВИЧ-негативных пациенток. Было показано, что M.hominis значительно более распространена у пациенток с ВИЧ / СПИДом. (63 (74,1%), и 10 (47,6%) соответственно, р 0,05) Необходимы дальнейшие исследования, чтобы установить причинно-следственную связь и выявить факторы риска для инфицирования Mycoplasma spp. в группе пациентов ВИЧ / СПИДа
Considerations for the Bioanalytical Part of Equivalence Studies of Biosimilar Nadroparin Calcium
According to current regulatory views, a comparative study of the pharmacodynamics (PD) of low molecular weight heparin (LMWH) products and confirmation of their equivalence require comparing three PD markers: the anti-Xa activity, the anti-IIa activity, and the tissue factor pathway inhibitor (TFPI) concentration. The aim of this study was to analyse the features specific to the bioanalytical part of an equivalence study of a nadroparin calcium biosimilar after single subcutaneous administration. Material and methods: the anti-Xa and anti-IIa activity values and TFPI content were determined in human plasma samples obtained after single subcutaneous administration of the test and the reference product in the same dose, using commercially available reagent kits and pre-validated assays. The authors calculated the main PD parameters (surrogate pharmacokinetic markers), namely the maximum activity or concentration (Amax or Cmax), time to maximum activity or concentration (Tmax), area under the activity–time (or concentration–time) curve (AUC ), and half-life period (T1/2), by means of model-independent statistical moment analysis and carried out further statistical testing of the parameters. Results: the anti-Xa activity and TFPI concentration results provided for the possibility of calculating and comparing the PD parameters (Amax or Cmax, AUC0-24, AUC0-∞, Tmax, T1/2) and estimating the confidence intervals that are necessary to confirm the bioequivalence of the studied products. The anti-IIa activity data had a characteristic pattern of slight fluctuations around one level, which prevented the calculation and comparison of PD parameters. Conclusion: the study identified specific features to consider when planning comparative PD studies of nadroparin calcium products. Firstly, it is feasible to divide samples into two test aliquots (one for anti-Xa and anti-IIa activity determination, the other for TFPI analysis) at the moment of collection in order to perform the analytical step correctly. Secondly, there is no need in full validation for the bioanalytical assays of the anti-Xa and anti-II activity and TFPI content in human plasma validated in the concentration ranges of 0.024–0.182 IU/mL, 0.0069–0.052 IU/mL and 1.56–100 ng/mL, respectively; a confirmation that the active ingredient does not interfere with the analytical procedure is adequate for the purpose. Finally, the data obtained may not allow for calculating PD parameters and comparing confidence intervals for all three markers. The listed considerations may be relevant for other LMWH products as well
Infective endocarditis and COVID-19: the impact of SARS-CoV-2 infection on diagnostics, course, and prognosis
Aim. To study the impact of coronavirus disease 2019 (COVID-19) pandemic on hospitalization rates, diagnosis, and outcomes of infective endocarditis (IE) with a subanalysis of IE course in combination with COVID-19.Material and methods. This prospective cohort study included 168 patients with definite or probable IE (DUKE 2015) hospitalized in the V.V. Vinogradov City Clinical Hospital from July 2017 to July 2022. All patients underwent a conventional examination in accordance with current clinical guidelines. We studied clinical, paraclinical and etiological parameters, as well as outcomes.Two clinical observations of the combination of IE and COVID-19 are presented.Results. When assessing the local registry of patients with IE, a trend towards an increase in hospitalizations rate of IE in 2021-2022 was shown, with a decrease during the period of long-term lockdowns in Moscow and a subsequent surge after their cancellation. Patients with IE during the COVID-19 pandemic had a more favorable clinical profile, a 2-fold increase in IE diagnosis (due to late hospitalization), frequent detection of Staphylococcus aureus MSSA (32,6%), and frequent surgical treatment (up to 87,6% with a combination of IE and COVID-19), as well as high in-hospital mortality, but without a tendency to increase (30,4%). Clinical observations of IE and COVID-19 combination are presented, which demonstrates the contribution of COVID-19 as the only risk factor for native tricuspid valve IE in a patient without predisposing causes, as well as a factor in the unfavorable prognosis for native aortic valve IE after the addition of COVID-19, which led to lethal outcome.Conclusion. The present study demonstrates the profile of patients with IE and COVID-19 depending on the epidemiological situation of COVID-19 and the association with SARS-CoV-2 infection. The data obtained make it possible to discuss the potential relationship between COVID-19 and IE. The "endocarditis team" determines the timely implementation of surgery and the absence of an increase in inhospital mortality, regardless of the epidemiological situation
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