Liquid Chromatography – High Resolution Mass Spectrometry Method for Monitoring of 17 Mycotoxins in Human Plasma for Exposure Studies

Mycotoxins are secondary metabolites produced by filamentous fungi. Primary route of human exposure to mycotoxins is the intake of the contaminated food. Minimizing mycotoxin exposure is important for population health, as their chronic toxic effects have been associated with kidney and liver diseases, some types of cancer and immunosuppression. The objective of this work was to develop and validate a multi-class mycotoxin method suitable for exposure monitoring of mycotoxins in human plasma. A sensitive liquid chromatography – mass spectrometry method was developed for 17 mycotoxins: nivalenol (NIV), deoxynivalenol, fusarenon X, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, T-2 toxin, HT-2 toxin, aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, zearalenone, α-zearalenol (α-ZOL), β-zearalenol, zearalanone, α-zeranoland, and β-zeranol. The method relies on three-step liquid-liquid extraction with ethyl acetate to eliminate the need for immunoaffinity extraction and minimize ionization matrix effects. Chromatographic separation of mycotoxins, including all isomers, was achieved with pentafluorophenyl column and water/methanol mobile phase. Mycotoxin detection and quantitation were performed using high-resolution mass spectrometry on LTQ Velos Orbitrap, in both positive and negative electrospray ionization (ESI(+) and (ESI(−)). The use of 0.02% acetic acid as mobile phase additive for ESI(−) resulted in significant increase in ionization efficiency ranging from 1.7 to 26 times for mycotoxins that ionize better in ESI(−). The optimized method was validated according to FDA guidance procedures. LOQs of all mycotoxins ranged from 0.1 to 0.5 ng/ml, except NIV which resulted in LOQ of 3 ng/ml because of low extraction recovery of this highly polar mycotoxin. Mean intra-day accuracy ranged from 85.8% to 116.4%, and intra-day precision (n = 6) ranged from 1.6% to 12.5% RSD for all mycotoxins except α-ZOL where mean accuracy ranged from 72.9% to 97.2%. Inter-day accuracy and precision were 85.6% to 111.5% and 2.7 to 15.6% RSD respectively, showing good analytical performance of the method for biomonitoring

Analysis of the pedagogical means of general endurance

The article describes the general pedagogical approaches to the concept of endurance, the basic definition of consideration given definition. Described and analyzed the methods of general endurance. Recommendations are given for their introduction in the educational processВ статье рассмотрены общие педагогические подходы к понятию выносливость, дано основное определение рассматриваемой дефиниции. Описаны и проанализированы методы развития общей выносливости. Даны рекомендации по их внедрению в образовательный процес

Multi-Class Liquid Chromatography-High Resolution Mass Spectrometry Methods for Monitoring of Mycotoxins and Metabolites in Human Plasma for Exposure Studies

Mycotoxins are secondary metabolites produced by fungi that can pose a serious threat to human and animal health due to their toxicity. The assessment of human chronic exposure to mycotoxins requires reliable and highly sensitive multi-analyte assay(s) enabling simultaneous measurements of common toxicologically important mycotoxins and their metabolites in human plasma. The first goal of the thesis was to develop sensitive liquid chromatography – high-resolution mass spectrometry (LC-HRMS) multi-mycotoxin method(s) for the detection and quantification of common toxicologically important mycotoxins frequently occurring in Canada and emerging mycotoxins of interest. Based on the results of extraction recoveries and chromatographic separation, two LC-HRMS methods were required to cover the full mycotoxin panel of interest. The first method combined liquid-liquid extraction with pentafluorophenyl reversed-phase LC-HRMS for the quantification of 17 mycotoxins, aflatoxins B1, B2, G1 and G2, zearalenone, 7-α-hydroxy-zearalenol (α-ZOL), 7-β-hydroxy-zearalenol, zearalanone, 7-α-hydroxy-zearalanol, 7-β-hydroxy-zearalanol, T-2 toxin, HT-2 toxin, deoxynivalenol, nivalenol, 15-acetyldeoxynivalenol, 3-acetyldeoxynivalenol and fusarenon X. The method was validated using procedures described in the Food and Drug Administration (FDA) guidance for Industry Bioanalytical Method Validation. Lower limits of quantification (LLOQs) ranged from 0.1 to 0.5 ng/ml, except for nivalenol (3 ng/ml). The method (intra-day and inter-day) accuracy and precision ranged from 85.6% to 116.4% and from 1.6% to 15.6% RSD, respectively, excluding α-ZOL for which an accuracy of 72.9 % to 97.2% was observed. The second method covered ten mycotoxins, fumonisin B1, fumonisin B2, ochratoxin α (OTα), citrinin, ochratoxin A, beauvericin, enniatin A, enniatin A1 (ENNA1), enniatin B (ENNB) and enniatin B1, and combined methanol protein precipitation with C18 reversed-phase chromatography and polarity-switching LC-HRMS. LLOQs ranged from 1.25 to 4 ng/ml. Absolute recovery ranged from 86.6% to 127.7% in individual plasma samples. Significant matrix effects were observed for OTα (77.5%) in one out of ten individual plasma samples and fumonisins (134.8% to 167.8%), ENNB (69.7% to 79.4%) and ENNA (69.3% to 79.2%) in all individual plasma samples. The rest of the mycotoxins showed negligible matrix effects ranging from 87.2% to 112.2% in all lots of plasma tested. Excellent LLOQs, negligible matrix effects and accurate quantitation capability of the first method coupled with the lower cost of analysis per sample make the method suitable for large-scale analysis of human plasma samples. The second method is also simple and low cost but requires additional modification to further improve LLOQs and reduce the matrix effect before full validation and implementation. Both methods are versatile and can be applied for retrospective analysis and other applications such as metabolism studies due to the use of HRMS and superior chromatographic separation. To show this capability, the first method was successfully applied for the in-depth metabolism studies of 17 mycotoxins. The method showed excellent suitability and advantages for the detection of various mycotoxin metabolites from Phase I metabolism and glucuronidation obtained from human microsomal incubations. Two ppm mass accuracy with internal mass calibration reduced the number of possible elemental formulas for a measured m/z value. Data-dependent acquisition in combination with collision-induced dissociation or higher energy collisional dissociation was used to ensure adequate fragmentation and to study the structure of the mycotoxin metabolites. The Compound Discoverer 2.1 software, which contains extensive libraries of common metabolic pathways and mass spectral libraries, was used to streamline the identification and the characterization of the metabolites. In total, 188 mycotoxin metabolites were generated, characterized and used to build an extensive in-house library of human mycotoxin metabolites. One hundred metabolites were reported for the first time, showing the power and sensitivity of the approach. For these 17 mycotoxins, 92 metabolites were previously described in literature, and among these known metabolites only four could not be generated using our approach. Currently, this is the most comprehensive LC-MS library of human mycotoxin metabolites. In conclusion, both LC-MS methods and the in-house mycotoxin metabolite library will allow the monitoring of 27 mycotoxins and their 188 metabolites in large-scale biomonitoring studies. In the long-term, this will help to prioritize metabolites that should be routinely included during exposure monitoring studies and will provide important new data on mycotoxin exposure of the Canadian population

Содержание конституционно-правовой модели свободных выборов в России

The subject. At the present stage, the real ideal of legal democracy is ensuring the right of citizens to participate in the management of state affairs, in particular, to elect and be elected to public authorities and to elected public office. The fundamental basis of democracy in a democratic state is free elections. In this regard, the substantive content of the constitutional-legal model of free elections in Russia is considered.The purpose of the paper. Recently, it is impossible not to note the tendency to narrow the legal understanding of free elections to «the absence of coercion to vote in elections». At the same time, the real understanding of free elections as a democratic value is much broader. Ensuring the constitutional principle of democracy, the improvement of domestic legislation and electoral law determine the study of the substantive content of the domestic constitutional legal model of free elections.The methodology of the study. The achievement of this goal was promoted by the use of both general scientific and special methods of cognition of social and legal phenomena (comparative legal method, method of legal modeling).The main results and scope of their application. The position of the author indicated in the work is based on the regulatory legal acts in the field of elections, judicial practice, as well as on the opinions of representatives of legal science in the framework of the problems of real meaningful content of free elections. As a result of the study, a three-part substantive content of the domestic constitutional legal model of free elections is substantiated.Conclusions. It is concluded that the free formation of their political behavior by participants in the electoral process (voters, candidates, electoral associations) is an integral element of the meaningful content of free elections and in combination with free and voluntary participation in elections, the free will represents a ternary component rather than a binary component.Рассматривается содержательное наполнение отечественной конституционно-правовой модели свободных выборов. Обосновывается, что свободное формирование своего политического поведения участниками избирательного процесса также является неотъемлемым элементом содержательного наполнения данной модели наряду со свободным и добровольным участием в выборах, свободным волеизъявлением

Characterization of Phase I and Glucuronide Phase II Metabolites of 17 Mycotoxins Using Liquid Chromatography—High-Resolution Mass Spectrometry

Routine mycotoxin biomonitoring methods do not include many mycotoxin phase I and phase II metabolites, which may significantly underestimate mycotoxin exposure especially for heavily metabolized mycotoxins. Additional research efforts are also needed to measure metabolites in vivo after exposure and to establish which mycotoxin metabolites should be prioritized for the inclusion during large-scale biomonitoring efforts. The objective of this study was to perform human in vitro microsomal incubations of 17 mycotoxins and systematically characterize all resulting metabolites using liquid chromatography–high-resolution mass spectrometry (LC-HRMS). The results obtained were then used to build a comprehensive LC-MS library and expand a validated 17-mycotoxin method for exposure monitoring to screening of additional 188 metabolites, including 100 metabolites reported for the first time. The final method represents one of the most comprehensive LC-HRMS methods for mycotoxin biomonitoring or metabolism/fate studies

Study of the structure of 1-nitro-3,3,3-trifluoro- and 1-nitro-3,3,3-tribromopropenes by the methods of dipole moments and quantum chemistry

© 2014 Pleiades Publishing, Ltd. Method of dipole moments and quantum-chemical calculations allowed establishing that 1-nitro-3,3,3-trifluoro- and 1-nitro-3,3,3-tribromopropenes have the E-configuration (the nitro group and the trihalomethyl substituent are in the trans-position); the obtained characteristics were compared with the corresponding data for the trichloromethyl-containing analog

Modern problems of organizing mass sports and health-improving events (2021)

In this scientific work, the author raises the main modern problems, in view of which the organization of mass sports and health-improving events is either difficult or not completely possible. "Modernity should be understood as the outgoing year 2021." The list of such problems is not exhaustive. All of the following is nothing more than "a manifestation of freedom of thought and speech (part 1 of Article 29 of the Constitution of the Russian Federation)."В данной научной работе автором поднимаются основные современные проблемы, в виду которых организация спортивно – массовых и оздоровительных мероприятий либо затруднительна, либо невозможна полностью. «Под современностью следует понимать уходящий 2021 год». Перечень таких проблем является не исчерпывающим. Все нижесказанное является не больше, чем «проявлением свободы мысли и слова (часть 1 статьи 29 Конституции Российской Федерации)»

Physical culture as a mean for prophylaxis and traetment deseases

This article examines features of physical culture’s impacts on the human organism and represented information about reasons of passive relationship between physical culture and human organismВ данной статье рассмотрены особенности влияния физических нагрузок на организм человека и представлены данные о причинах пассивного отношения к занятиям физической культурой и положительном влиянии физической культуры на здоровье человек

Metabolism and pharmacokinetics of a potent N -acylindole antagonist of the OXE receptor for the eosinophil chemoattractant 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE) in rats and monkeys

We previously identified the indole 264 as a potent in vitro antagonist of the human OXE receptor that mediates the actions of the powerful eosinophil chemoattractant 5-oxo-ETE. No antagonists of this receptor are currently commercially available or are being tested in clinical studies. The lack of a rodent ortholog of the OXE receptor has hampered progress in this area because of the unavailability of commonly used mouse or rat animal models. In the present study, we examined the feasibility of using the cynomolgus monkey as an animal model to investigate the efficacy of orally administered 264 in future in vivo studies. We first confirmed that 264 is active in monkeys by showing that it is a potent inhibitor of 5-oxo-ETE-induced actin polymerization and chemotaxis in granulocytes. The major microsomal metabolites of 264 were identified by cochromatography with authentic chemically synthesized standards and LC-MS/MS as its ω2-hydroxy and ω2-oxo derivatives, formed by ω2-oxidation of its hexyl side chain. Small amounts of ω1-oxidation products were also identified. None of these metabolites have substantial antagonist potency. High levels of 264 appeared rapidly in the blood following oral administration to both rats and monkeys, and declined to low levels by 24 h. As with microsomes, its major plasma metabolites in monkeys were ω2-oxidation products. We conclude that the monkey is a suitable animal model to investigate potential therapeutic effects of 264. This, or a related compound with diminished susceptibility to ω2-oxidation, could be a useful therapeutic agent in eosinophilic disorders such as asthma