99 research outputs found
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.Π Π°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°ΡΡΡΡ Π²ΠΎΠΏΡΠΎΡΡ ΡΠΏΡΠ°Π²Π»Π΅Π½ΠΈΡ ΠΊΠ°Π΄ΡΠΎΠ²ΡΠΌ ΠΏΠΎΡΠ΅Π½ΡΠΈΠ°Π»ΠΎΠΌ Π²ΡΡΡΠ΅ΠΉ ΡΠΊΠΎΠ»Ρ Π² ΡΠ²ΡΠ·ΠΈ Ρ ΠΎΠ±Π½ΠΎΠ²Π»Π΅Π½ΠΈΠ΅ΠΌ Π½ΠΎΡΠΌΠ°ΡΠΈΠ²Π½ΡΡ
ΠΏΡΠ°Π²ΠΎΠ²ΡΡ
Π°ΠΊΡΠΎΠ² Π² ΡΡΠ΅ΡΠ΅ ΡΡΡΠ΄Π°, ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΡ ΠΈ Π½Π°ΡΠΊΠΈ. ΠΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Ρ Π½Π΅ΠΊΠΎΡΠΎΡΡΠ΅ ΠΏΡΠΎΠ±Π»Π΅ΠΌΡ Π² ΡΡΠ΅ΡΠ΅ ΡΠΏΡΠ°Π²Π»Π΅Π½ΠΈΡ ΠΊΠ°Π΄ΡΠΎΠ²ΡΠΌΠΈ ΡΠ΅ΡΡΡΡΠ°ΠΌΠΈ ΠΈ ΡΠ΅Π³ΡΠ»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΡΡΡΠ΄Π° ΠΏΠ΅Π΄Π°Π³ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ°Π±ΠΎΡΠ½ΠΈΠΊΠΎΠ² Π² ΡΠΈΡΡΠ΅ΠΌΠ΅ Π²ΡΡΡΠ΅Π³ΠΎ ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΡ. ΠΠ±ΠΎΠ·Π½Π°ΡΠ΅Π½Ρ ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²Ρ Π²Π½Π΅Π΄ΡΠ΅Π½ΠΈΡ ΡΡΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎΠ³ΠΎ ΠΊΠΎΠ½ΡΡΠ°ΠΊΡΠ° ΠΈ ΠΏΡΠΈΡΠΈΠ½Ρ, ΠΏΡΠ΅ΠΏΡΡΡΡΠ²ΡΡΡΠΈΠ΅ Π΅Π³ΠΎ Π²Π½Π΅Π΄ΡΠ΅Π½ΠΈΡ
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 <sup>137</sup>Cs in alluvial soils of the Lokna River floodplain (Tula oblast) long after the Chernobyl accident and its simulation
Β© 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 erosionβaccumulation 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 CiΓͺncia 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 PNTsβ 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 (400β250 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. Β© 2023 by the authors.Fundação para a CiΓͺncia e a Tecnologia, FCT; Russian Foundation for Basic Research, Π Π€Π€Π: 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 FCTβFundação para a CiΓͺncia 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)βbranch 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
Π£ΠΏΠ΅ΡΡΠ΅ ΠΏΠΎΠΊΠ°Π·Π°Π½ΠΎ Π°Π½ΡΠΈΠΏΡΠΎΠ»ΡΡΠ΅ΡΠ°ΡΠΈΠ²Π½Ρ Π°ΠΊΡΠΈΠ²Π½ΡΡΡΡ ΡΠ΅Π½ΡΠΉ-ΠΏΠ»Π°ΡΠΈΠ½ΠΎΠ²ΠΎΡ ΡΠΈΡΡΠ΅ΠΌΠΈ Π½Π° ΠΊΠ»ΡΡΠΈΠ½Π°Ρ
ΡΠ°ΠΊΡ ΠΊΡΠΎΠ²Ρ Π»ΡΠ΄ΠΈΠ½ΠΈ Π‘ΠΠ-Π’4. ΠΠ°ΠΉΠ΅ΡΠ΅ΠΊΡΠΈΠ²Π½ΡΡΠΈΠΌΠΈ Π²ΠΈΡΠ²ΠΈΠ»ΠΈΡΡ Π΅ΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠΈ, Π΄Π΅ Π²ΠΈΠΊΠΎΡΠΈΡΡΠΎΠ²ΡΠ²Π°Π»ΠΈΡΡ ΠΎΠ±ΠΈΠ΄Π²Π° ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΠΈ ΡΠΈΡΡΠ΅ΠΌΠΈ. ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ ΡΠ°ΠΊΠΎΠΆ ΠΏΠ΅ΡΠ΅Π²Π°Π³Ρ Π»ΡΠΏΠΎΡΠΎΠΌΠ½ΠΈΡ
ΡΠΎΡΠΌ ΠΏΠΎΡΡΠ²Π½ΡΠ½ΠΎ Π· ΡΠΎΠ·ΡΠΈΠ½Π°ΠΌΠΈ ΠΏΡΠ΅ΠΏΠ°ΡΠ°ΡΡΠ² ΡΠ° ΠΏΠ΅ΡΠ΅Π²Π°ΠΆΠ½ΠΈΠΉ Π°ΠΏΠΎΠΏΡΠΎΡΠΈΡΠ½ΠΈΠΉ ΠΌΠ΅Ρ
Π°Π½ΡΠ·ΠΌ Π·Π°Π³ΠΈΠ±Π΅Π»Ρ ΠΊΠ»ΡΡΠΈΠ½ ΠΏΡΠ΄ Π΄ΡΡΡ ΡΠΈΡΡΠ΅ΠΌΠΈ.ΠΠΏΠ΅ΡΠ²ΡΠ΅ ΠΏΠΎΠΊΠ°Π·Π°Π½Π° Π°Π½ΡΠΈΠΏΡΠΎΠ»ΠΈΡΠ΅ΡΠ°ΡΠΈΠ²Π½Π°Ρ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ ΡΠ΅Π½ΠΈΠΉ-ΠΏΠ»Π°ΡΠΈΠ½ΠΎΠ²ΠΎΠΉ ΡΠΈΡΡΠ΅ΠΌΡ Π½Π° ΠΊΠ»Π΅ΡΠΊΠ°Ρ
ΡΠ°ΠΊΠ° ΠΊΡΠΎΠ²ΠΈ ΡΠ΅Π»ΠΎΠ²Π΅ΠΊΠ° Π‘ΠΠ-Π’4. ΠΠ°ΠΈΠ±ΠΎΠ»Π΅Π΅ ΡΡΡΠ΅ΠΊΡΠΈΠ²Π½ΡΠΌΠΈ ΠΎΠΊΠ°Π·Π°Π»ΠΈΡΡ ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΡ, Π³Π΄Π΅ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π»ΠΈΡΡ ΠΎΠ±Π° ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΠ° ΡΠΈΡΡΠ΅ΠΌΡ. ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ ΡΠ°ΠΊΠΆΠ΅ ΠΏΡΠ΅ΠΈΠΌΡΡΠ΅ΡΡΠ²ΠΎ Π»ΠΈΠΏΠΎΡΠΎΠΌΠ½ΡΡ
ΡΠΎΡΠΌ Π² ΡΡΠ°Π²Π½Π΅Π½ΠΈΠΈ Ρ ΡΠ°ΡΡΠ²ΠΎΡΠ°ΠΌΠΈ ΠΏΡΠ΅ΠΏΠ°ΡΠ°ΡΠΎΠ² ΠΈ ΠΏΡΠ΅ΠΈΠΌΡΡΠ΅ΡΡΠ²Π΅Π½Π½ΡΠΉ Π°ΠΏΠΎΠΏΡΠΎΡΠΈΡΠ΅ΡΠΊΠΈΠΉ ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌ Π³ΠΈΠ±Π΅Π»ΠΈ ΠΊΠ»Π΅ΡΠΎΠΊ ΠΏΠΎΠ΄ Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ΠΌ ΡΠΈΡΡΠ΅ΠΌΡ.First the antiproliferative activity of the antitumor system rhenium-platinum on the human blood cancer cells Π‘ΠΠ-Π’4 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
- β¦