Determination of oseltamivir in human plasma by HPLC-MS/MS

A procedure for the determination of oseltamivir in human plasma by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was proposed and validated. A rapid and easy-to-use method of liquid-liquid extraction with ethyl acetate using venlafaxine as an internal standard was used during sample preparation. The addition of benzoic acid to aqueous acetonitrile solutions of the analyte was shown to prevent its oxidative degradation. The detection limit and limit of quantitation were 0.08 and 0.30 ng/mL, respectively; the calibration range, 0.3-200 ng/mL (R2 = 0.9937); the total analysis time, 3.2 min. The within- and between-run accuracy ranged from 97 to 105%. The precision was 89%). The analyte was stable when stored in plasma samples (4 h at room temperature, 31 d at (80°C, after three freeze-thaw cycles) and extracts under autosampler storage conditions (24 h at 15°C). The procedure was successfully used for oseltamivir quantitation in actual plasma samples from healthy volunteers obtained during a bioequivalence study of the new generic drug

Gas Giants in Extreme Environments

In this thesis, I will explore three ideas that relate to giant planet formation, an incredibly dynamic process that affects not only the orbital configurations, but also the atmospheric structure and processes driven by the often extreme environments in which these planets are embedded:(1) The formation of our solar system's ice giants may have involved significant migration due to a disk dynamical instability, as well as concurrent accretion of solids and gas from the protoplanetary disk, that may have consequences for their current atmospheric composition and evolution. (2) In exoplanetary systems, gas giants have been discovered on orbits that are extremely eccentric, and in the inner regions corresponding to the traditionally rocky planet region of our own solar system. These exotic systems may have undergone a phase of giant impacts, analogous to the phase that shaped our solar system's inner planet region and resulted in the Moon-forming impact. Such a phase produces outcomes that reproduce interesting features of the population: the correlation of mass with eccentricity, and eccentricity with stellar metallicity. (3) Finally, the atmospheres of the close-in planets are bathed in stellar irradiation. Photochemical reactions occur as the upper layers of the atmospheres are irradiated, and the massive amounts of deposited energy drive hydrodynamic winds from the planets. This results in mass loss that can not only be observed in the cases of giants, but can shape the global structure of smaller planets, leaving an imprint on entire populations of these planets

Well-being management of the manufacturing enterprise personnel

Целью магистерской диссертации является изучение современной литературы по проблеме благополучия персонала организаций, проведение мониторингового исследования влияния организации на благополучие персонала и разработка практических рекомендаций по повышению уровня благополучия персонала на рабочем месте. В теоретической части работы представлены основные понятия благополучия персонала, его виды, методы оценки уровня благополучия, а также охарактеризована программа повышения уровня благополучия персонала в организации. В практической части приводится краткая характеристика исследуемого производственного предприятия и системы управления персоналом, описываются результаты анализа кадрового состава предприятия, оценки уровня физического и психологического благополучия персонала с применением инструментария социологического опроса, мониторинга самочувствия работников с использованием авторского чат-бота, а также анализа действующей на предприятии системы по поддержанию уровня благополучия персонала. На основе полученных эмпирических данных разработаны предложения по повышению уровня благополучия персонала на основе развития программы «Благополучие». В заключении подведены итоги в соответствии с поставленными задачами.The purpose of the master's thesis is to study modern literature on the well-being of personnel in organizations, conduct a monitoring study of the impact of the organization on the employee well-being and develop practical recommendations for improving the well-being at work. The theoretical part of the work presents the basic concepts of personnel well-being, its types, methods for assessing the level of well-being, and also describes a program to increase the level of well-being at work. The practical part provides a brief description of the production enterprise and the personnel management system under study, describes the results of the analysis of the personnel composition of the enterprise, assesses the level of physical and psychological well-being of personnel using the tools of a sociological survey, monitors the well-being of employees using the author's chat bot, and also analyzes the current at the enterprise systems for maintaining the level of employees' well-being. On the basis of the empirical data obtained, proposals were developed to improve the personnel well-being based on the development of the "Well-Being" program. In conclusion, the results are summarized in accordance with the tasks set

Novel aspects of taxifolin pharmacokinetics: Dose proportionality, cumulative effect, metabolism, microemulsion dosage forms

Taxifolin (TFL) is a small drug molecule with a broad therapeutic potential limited by its poor aqueous solubility and excessive metabolism. Despite comprehensive research, some aspects of the TFL pharmacokinetics, e.g., dose proportionality and possible cumulative effect, remain unexplored. In the current study, we have tried to fill this gap. Our results revealed that the TFL pharmacokinetics in rats had nonlinear character in the dose range of 10–50 mg/kg after its single oral administration (AUC). For Cmax, the data are ambiguous: linearity was confirmed via the equivalence criterion and was disproved using the power model approach. Also, the cumulative drug effect was observed on the 4th day after its multiple-dose oral administration (25 mg/kg; compared to the 1st day). Interestingly, biologically active TFL metabolites such as aromadendrin and luteolin were putatively found in plasma samples, although they were previously detected only in feces. In addition, oil-in-water and water-in-oil microemulsions were fabricated to design novel drug delivery systems. These carrier dosage forms did not improve the TFL bioavailability but significantly affected its metabolism. To support pharmacokinetic studies, the bioanalytical liquid chromatography–tandem mass spectrometry method was developed and validated in the concentration range of 1–1000 ng/mL using candesartan as an internal standard. Liquid-liquid extraction with methyl tert-butyl ether was used to isolate the analytes from plasma followed by evaporation and reconstitution of the residues in acetonitrile. Thus, the present findings broaden our understanding of the TFL behavior in vivo and provide novel ideas and reference directions for its continued use in medical practice