Bacterial Cellulose/Alginate Nanocomposite for Antimicrobial Wound Dressing

Development of novel wound dressing has attracted more and more attentions in recent years. Bacterial cellulose is a biopolymer of great potentials, which features a distinctive three-dimensional structure consisting of an ultrafine network of cellulos nanofibers. In the present study, nanocomposite bacterial cellulose films modified in situ by the addition of alginate during the static cultivation of Gluconacetobacter sucrofermentans B-11267 were produced and then enriching the polymer with an antimicrobial agent tetracycline hydrochloride. The structure of bacterial cellulose and nanocomposite was analyzed by AFM and FTIR. The FTIR spectra displayed the specified interaction between the hydroxyl group of cellulose and the carboxyl group of alginate. The produced bacterial cellulose and nanocomposite were analyzed to determine tensile modulus. The antibacterial activity of nanocomposites were investigated by disk diffusion method. The resulting nanocomposite have high antibiotic activity against Staphylococcus aureus and can be used in medicine as a wound dressing. Keywords: bacterial cellulose, Gluconacetobacter sucrofermentans, alginate, nanocomposite, antibacterial activity, wound dressin

Control of the enlisted potential of the higher school: problems and the prospects

In the article the problems of control of the enlisted potential of higher school in connection with the renovation of normative lawful reports in the sphere of labor, formation and science are examined. Some problems in the sphere of control of cadreresources and the regulation of the labor of pedagogical workers in the system of higher education are determined. Are designated the prospects of introducing the effective contract and the reasons, which impede its introduction.Рассматриваются вопросы управления кадровым потенциалом высшей школы в связи с обновлением нормативных правовых актов в сфере труда, образования и науки. Определены некоторые проблемы в сфере управления кадровыми ресурсами и регулирования труда педагогических работников в системе высшего образования. Обозначены перспективы внедрения эффективного контракта и причины, препятствующие его внедрению

Development of Internet communication and social networking in modern conditions: institutional and legal aspects

The development of the Internet, which has been active over the past two decades, is leading to the formation of new forms of human interaction on the World Wide Web. One of such forms is actually social networks, which from the beginning of their activity are used mainly as a way to ensure human communication. However, such a big number of consumers with the usual ways of buying goods and services, lead to the search for new platforms for companies to do business, which in turn provokes the transition of social networks to a fundamentally new level of activity

Vertical distribution of ¹³⁷Cs in alluvial soils of the Lokna River floodplain (Tula oblast) long after the Chernobyl accident and its simulation

© 2016, Pleiades Publishing, Ltd.Profiles of vertical 137Cs distribution in alluvial meadow soils on the low and medium levels of the Lokna River floodplain (central part of the Plavsk radioactive spot in Tula oblast) 28 years after the Chernobyl fallout have been studied. A significant increase in the 137Cs pool is revealed on the low floodplain areas compared to the soils of interfluves due to the accumulation of alluvium, which hampers the reduction of the total radionuclide pool in alluvial soils because of radioactive decay. The rate of alluvium accumulation in the soil on the medium floodplain level is lower by three times on average. An imitation prognostic model has been developed, which considers the flooding and climatic conditions in the region under study. Numerical experiments have quantitatively confirmed the deciding role of low-mobile forms in the migration of maximum 137Cs content along the soil profile in the absence of manifested erosion–accumulation processes

Ferroelectric nanocomposites based on polymer ferroelectrics and graphene/oxide graphene: Computer modeling and SPFM experiments

The authors are thankful to the Russian Science Foundation (RSF grant # 16-19-10112) and to the Russian Foundation for Basic Researches (RFBR grants # 16-51-53917) for support. Prof. Xiang-Jian Meng expresses his gratitude to the National Natural Science Foundation of China (NNSFC) for support of the project: "The study on the new type of infrared detector based on ferroelectric tunnel junction"

Piezoelectric, ferroelectric, optoelectronic and photo-catalytic phenomena from defect levels in hydroxyapatite by first-principles

The authors thank the Russian Foundation for Basic Researches (RFBR grant 19-01-00519 A) and to the Fundação para a Ciência e a Tecnologia (FCT) through project UID/CTM/50025/2013

Photoelectronic Properties of Chiral Self-Assembled Diphenylalanine Nanotubes: A Computational Study

Peptide nanotubes (PNT) of diphenylalanine (FF) have attracted considerable attention from researchers in the last decades. The chirality of FF monomers determines the kinetics of PNTs’ self-assembly and their morphology. The helical symmetry of PNTs causes significant intrinsic polarization and endows them with a unique combination of mechanical, electronic, and optical properties, as well as a strong piezoelectric effect useful for various applications. In this work, we used a combination of computer modeling and quantum chemical calculations to study the photoelectronic properties of FF PNTs of different chiralities. Using semiempirical methods implemented in the HyperChem and MOPAC packages, we calculated HOMO and LUMO energy levels and a band gap and their variations under the action of external and internal electric fields. We demonstrated that the photoelectronic properties of l- and d-FF PNTs are slightly different and may be related to the intrinsic electric field arising due to the internal polarization. The band gap of FF PNTs is within the ultraviolet range (400–250 nm) and can be tuned by an external electric field. These results open a way to create FF PNT-based solar-blind ultraviolet photodetectors and other electro-optic and electronic devices. © 2023 by the authors.Fundação para a Ciência e a Tecnologia, FCT; Russian Foundation for Basic Research, РФФИ: 19-01-00519_A, 20-51-53014_GFEN_AThe authors are grateful to the Russian Foundation for Basic Research, RFBR (grants 19-01-00519_A and 20-51-53014_GFEN_A). This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020, and LA/P/0006/2020, supported through the FCT/MEC (PIDDAC). Part of this work was supported by national funds (OE), through FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of article 23, of the Decree-Law 57/2016, of 29 August, changed by Law 57/2017, of 19 July. The computational parts of the study were completed within the framework of the noncommercial agreement on scientific and technical cooperation between the Institute of Mathematical Problems of Biology (IMPB)—branch of KIAM RAS, Russia and the Department of Physics of the University of Aveiro, Portugal. The authors are grateful for the opportunity to perform calculations using the computer cluster of IMPB RAS and the K-60 hybrid supercomputer installed at the KIAM RAS Shared Use Center

Influence of liposome forms of rhenium-platinum anti-tumor system on the proliferative activity of cancer cells

Уперше показано антипроліферативну активність реній-платинової системи на клітинах раку крові людини СЕМ-Т4. Найефективнішими виявилися експерименти, де використовувались обидва компоненти системи. Показано також перевагу ліпосомних форм порівняно з розчинами препаратів та переважний апоптотичний механізм загибелі клітин під дією системи.Впервые показана антипролиферативная активность рений-платиновой системы на клетках рака крови человека СЕМ-Т4. Наиболее эффективными оказались эксперименты, где использовались оба компонента системы. Показано также преимущество липосомных форм в сравнении с растворами препаратов и преимущественный апоптотический механизм гибели клеток под действием системы.First the antiproliferative activity of the antitumor system rhenium-platinum on the human blood cancer cells СЕМ-Т4 was shown. Experimental administration of both components of the system showed the most effectiveness. The advantages of liposomic forms in comparison with preparations solutions and dominating apoptotic mechanism of the cancer cells death under the treatment by the system were shown