Uv-visible characterization of gold exchanged in beta zeolite

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Kinetic regularities, catalyst deactivation and reactivation

Funding text 1 The research is funded from Ministry of Education and Science of the Russian Federation Program No. 075–03–2021–287/6 (Russia). Funding text 2 XPS measurements were carried out at the Central laboratories of Tomsk Polytechnic University (Analytical Center). HRTEM was carried out at the Innovation centre for Nanomaterials and Nanotechnologies of Tomsk Polytechnic University. The ICP-OES analysis was carried out using the core facilities of “Physics and Chemical methods of analysis” of Tomsk Polytechnic University. Fundação para a Ciência e a Tecnologia for Scientific Employment Stimulus Institutional Call (CEECINST/00102/2018), UIDB/50006/2020 and UIDP/50006/2020 (LAQV), UIDB/00100/2020 and UIDP/00100/2020 (Centro de Química Estrutural).Betulin, being a pentacyclic triterpene alcohol and an extractive from birch bark, along with its oxo-derivatives, has a broad range of physiological properties of interest for synthesis of pharmaceuticals. Instead of oxidizing betulin with strong and toxic oxidizing agents the present study shows a possibility of using liquid-phase oxidation of betulin with air over supported Ag NPs catalysts as an alternative method for synthesis of its oxo-derivatives. Based on catalytic studies, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy and ultraviolet-visible diffuse reflectance spectroscopy, the evolution of the surface of nanosilver catalysts during the catalysis was demonstrated, as well as under the impact of reactant gas composition. The kinetic regularities and causes of deactivation of supported Ag NPs catalysts were revealed. An approach to the regeneration of silver catalysts was proposed. Kinetic analysis with numerical data fitting was performed resulting in an adequate description of the concentration dependencies.publishersversionpublishe

Компетентностный подход и проблемы его реализации в высшей школе

Currently, the vocational education system is based on a competency-based approach, which considers the person»s ability to act productively in a professional situation rather than the amount of information learned as the result of education. The term «competency», as an indicator of the result of training, was introduced in the Russian Federation in 2009, with the introduction of the state educational standards for higher education of the first generation (Federal State Educational Standard), at the same time as the graduate students» competency model was introduced. Competence-based education implies competence-based orientation of both the content of the educational process and the methods of its implementation, as well as assessment procedures, means of assessing the quality of students» training, since the goals and the content of education, the organization of the educational process that are provided by educational standards, determine the results of education in the form of competencies. The implementation of the standards of competencies set in the Federal State Educational Standard of Higher Education in the actual learning process proved to be not so simple. Difficulties arise when relating the goals of education with the expected results, i.e., competencies. The difficulties are associated with the mismatch between the practical orientation of the competence-based approach and the existing subject-based orientation of the pedagogical practice. In the course of studying a specific discipline, the opportunity to fully form a speicfic competency, not a set of competencies specified by the Federal State Educational Standard, but also a specific competence, is small.However, the main difficulty is associated with the assessment of the level of competence formation. A competence-based approach requires measuring not only specific knowledge and skills of students, but an assessment of the qualities of the person him- or herself. However, the existing system for assessing the quality of education does not have the necessary assessment tools for this. This article discusses the issues of competence-based education in higher education, analyzes its features, and problems raleted to the assessment of the level of competence formation.В настоящее время система профессионального образования строится на компетентностном подходе, который в качестве результатов образования рассматривает не сумму усвоенной информации, а способность человека продуктивно действовать в профессиональной ситуации. Термин «компетенция», как показатель результата обучения, введен в РФ с 2009 г., с внедрением государственных образовательных стандартов высшего образования первого поколения (ФГОС), тогда же появляется компетентностная модель выпускника. Компетентностно-ориентированное образование подразумевает компетентностную ориентацию как содержания образовательного процесса и технологий его реализации, так и оценочных процедур, средств оценки качества подготовки обучающихся, поскольку цели и содержание образования, организация образовательного процесса, заданные образовательными стандартами, определяют результаты образования в форме компетенций. Переход от формулировок компетенций в ФГОС ВО к реальному процессу обучения оказался не таким простым. При соотнесении целей образования с предполагаемыми результатами - компетенциями возникают проблемы. Сложности связаны с несоответствием практической ориентированности компетентностного подхода и существующей предметной ориентацией педагогической практики. В ходе изучения конкретной дисциплины возможность сформировать в полной мере отдельную компетенцию не только набор компетенций, заданных ФГОС ВО, но и отдельную компетенцию - минимальна. Но основная сложность связана с диагностикой уровня сформированности компетенций. Компетентностный подход требует измерения не отдельных знаний, умений и навыков обучающихся, а оценки качеств самого человека. Однако существующая система оценки качества образования не имеет для этого необходимых оценочных средств. В представленной статье рассматриваются вопросы компетентностно-ориентированного образования в высшей школе, анализируются его особенности, проблемы диагностики уровня сформированности компетенций

Silver containing sorbents: Physicochemical and biological properties

New silver containing sorbents, based on mineral carriers, such as alumina and silica systems with a meso- and macro- porous structure, have a higher mechanical resistance and, hydrophilic and hydrophobic chemical composition of the surface. These sorbents are easy to find and relatively inexpensive, compared to their known equivalents. They are furthermore characterised by high specific surface and simple preparation, whilst the addition of silver considerably increases their antiseptic activity. The results of research of the physical, chemical and biological properties of the developed substances, as well as bio-comparability of sorbents with biological tissues, are presented in this paper. The modified material acts simultaneously as the carrier for active substances to the area of therapeutic application and as a sorbent used to remove toxic agents from such areas. This approach led us to modify the sorbent, and prolong the delivery of substances such as silver, as an effective antibacterial and antimycotic agent

Elimination of sulfates from wastewaters by natural aluminosilicate modified with uric acid

Natural aluminosilicate activated by a heat/acid treatment, followed by modification with uric acid was used to remove sulfates for treatment of wastewater effluent. Natural aluminosilicates were studied in every stage of the modification (namely activation, modification with uric acid, and after sulfates absorption) by scanning electron microscopy (SEM), spectroscopy X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), surface area (BET), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and Z potential. More than 60% of the initial concentration of sulfates (500 mg/l) was removed with the natural aluminosilicate modified with uric acid. Absorption isotherms rendered a mechanism with contributions from both Langmuir and Freundlich mechanisms. This study opens the path for the use of natural and abundant local material to remove sulfates using a modifier already present in wastewater effluents as contaminant

Effect of gold electronic state on the catalytic performance of nano gold catalysts in n-octanol oxidation

UIDB/50006/2020 project VIU-RSCBMT-65/2019 project 18-29-24037 (Russia) MINECO project CTQ2017-86170-R (Spain)This study aims to identify the role of the various electronic states of gold in the catalytic behavior of Au/MxOy/TiO2 (where MxOy are Fe2O3 or MgO) for the liquid phase oxidation of n-octanol, under mild conditions. For this purpose, Au/MxOy/TiO2 catalysts were prepared by deposition-precipitation with urea, varying the gold content (0.5 or 4 wt.%) and pretreatment conditions (H2 or O2), and characterized by low temperature nitrogen adsorption-desorption, X-ray powder diffraction (XRD), energy dispersive spectroscopy (EDX), scanning transmission electron microscopy-high angle annular dark field (STEM HAADF), diffuse reflectance Fourier transform infrared (DRIFT) spectroscopy of CO adsorption, temperature-programmable desorption (TPD) of ammonia and carbon dioxide, and X-ray photoelectron spectroscopy (XPS). Three states of gold were identified on the surface of the catalysts, Au0, Au1+ and Au3+, and their ratio determined the catalysts performance. Based on a comparison of catalytic and spectroscopic results, it may be concluded that Au+ was the active site state, while Au0 had negative effect, due to a partial blocking of Au0 by solvent. Au3+ also inhibited the oxidation process, due to the strong adsorption of the solvent and/or water formed during the reaction. Density functional theory (DFT) simulations confirmed these suggestions. The dependence of selectivity on the ratio of Brønsted acid centers to Brønsted basic centers was revealed.publishersversionpublishe

Evaluation of silver nanoparticles for the prevention of SARS-CoV-2 infection in health workers: In vitro and in vivo

14 Pág.SARS-CoV-2 infection in hospital areas is of a particular concern, since the close interaction between health care personnel and patients diagnosed with COVID-19, which allows virus to be easily spread between them and subsequently to their families and communities. Preventing SARS-CoV-2 infection among healthcare personnel is essential to reduce the frequency of infections and outbreaks during the pandemic considering that they work in high-risk areas. In this research, silver nanoparticles (AgNPs) were tested in vitro and shown to have an inhibitory effect on SARS-CoV-2 infection in cultured cells. Subsequently, we assess the effects of mouthwash and nose rinse with ARGOVIT® silver nanoparticles (AgNPs), in the prevention of SARS-CoV-2 contagion in health workers consider as high-risk group of acquiring the infection in the General Tijuana Hospital, Mexico, a hospital for the exclusive recruitment of patients diagnosed with COVID-19. We present a prospective randomized study of 231 participants that was carried out for 9 weeks (during the declaration of a pandemic). The "experimental" group was instructed to do mouthwash and nose rinse with the AgNPs solution; the "control" group was instructed to do mouthwashes and nose rinse in a conventional way. The incidence of SARS-CoV-2 infection was significantly lower in the "experimental" group (two participants of 114, 1.8%) compared to the "control" group (thirty-three participants of 117, 28.2%), with an 84.8% efficiency. We conclude that the mouth and nasal rinse with AgNPs helps in the prevention of SARS-CoV-2 infection in health personnel who are exposed to patients diagnosed with COVID-19.The authors of this study would like to thank the staff of General Tijuana Hospital for their invaluable participation in this research during the extremely difficult period of the COVID-19 pandemic. The health care personnel are under intense workout during this pandemic. The authors would also like to thank CONACyT “International Network of Bionanotechnology with an Impact on Biomedicine, Food and Biosafety” and Tomsk Polytechnic University for their important collaboration in the field of fundamental and applied research on nanomaterials in nanomedicine.Peer reviewe