TY - JOUR AU - Nagy, Lajos AU - Üneri, Haymana Serra AU - Kordován, Marcell Árpád AU - Nagy, Tibor AU - Kuki, Ákos AU - Nyul, Dávid AU - Pál, Petra AU - Erdélyi, Zoltán AU - Zsuga, Miklós AU - Kéki, Sándor TI - Organic Solvent-Based Li–Air Batteries with Cotton and Charcoal Cathode JF - JOURNAL OF THE ELECTROCHEMICAL SOCIETY J2 - J ELECTROCHEM SOC VL - 171 PY - 2024 IS - 4 SN - 0013-4651 DO - 10.1149/1945-7111/ad3857 UR - https://m2.mtmt.hu/api/publication/34802521 ID - 34802521 AB - We report on the construction and investigation of Li–air batteries consisting of a charcoal cathode and cotton texture soaked with different organic solvents containing a lithium triflate (LiOTf) electrolyte. Charcoal was found to be an appropriate cathode for Li–air batteries. Furthermore, cycling tests showed stable operation at over 800 cycles when dimethyl sulfoxide (DMSO) and diethylene glycol dimethyl ether (DEGME) were used as solvents, whereas low electrochemical stability was observed when propylene carbonate was used. The charging, discharging, and long-term discharging steps were mathematically modeled. Electrochemical impedance spectroscopy showed Gerischer impedance, suggesting intensive oxygen transport at the surface of the charcoal cathode. Diffusion, charge transfer, and solid electrolyte interphase processes were identified using distribution of relaxation time analysis. In the polypropylene (PP) membrane soaked with LiOTf in DEGME, three different states of Li ions were identified by 7 Li-triple-quantum time proportional phase increment nuclear magnetic resonance measurements. On the basis of the latter results, a mechanism was suggested for Li-ion transport inside the PP membrane. The activity of the charcoal cathode was confirmed by Raman and cyclic voltammetry measurements. LA - English DB - MTMT ER - TY - JOUR AU - Nagy, Tibor AU - Róth, Gergő AU - Kuki, Ákos AU - Pardi-Tóth, Veronika Csilla AU - Nyul, Dávid AU - Kyzy, Zuura Kaldybek AU - Palacios, Isaac Alexander Iglesias AU - Benedek, Máté AU - Nagy, Lajos AU - Zsuga, Miklós AU - Kéki, Sándor TI - The triumvirate of effective and rapid synthesis, analysis, and artificial intelligence to explore the structure-property relationship of copolymers JF - GIANT J2 - GIANT VL - 17 PY - 2024 PG - 8 SN - 2666-5425 DO - 10.1016/j.giant.2024.100248 UR - https://m2.mtmt.hu/api/publication/34744438 ID - 34744438 AB - Understanding the structure-property relationship is of paramount importance for tailoring copolymers for specific applications. Poly(N-acryloylmorpholine)-block-poly(N-isopropylacrylamide) (PNAM-b-PNIPAM) diblock copolymers were synthesized by reversible addition?fragmentation chain transfer (RAFT) polymerization with varying Mn and composition, providing the basis for deducing structure-property relationships. The chemical structure of the copolymers was analyzed by mass spectrometry (MS). A novel and efficient mass spectrum processing methodology was developed for the detailed analysis of polymers/copolymers that greatly expands the upper mass limit of the time-of-flight (TOF) analyzers in the linear mode up to 20,000 Da. Our method "makes visible" the mass peaks of the individual copolymer species and their isotopologues providing effective and fast automatized analysis. The self-assembly property of the thermoresponsive PNAM-b-PNIPAM diblocks in aqueous solutions was investigated by dynamic light scattering (DLS) experiments, and quantified by determining the incipient temperature of the phase transition. For rapid evaluation, an artificial neural network (ANN) was created to explore the hidden relationships between the structural information obtained by our novel mass analysis method and the properties as well as to predict the self-assembly behavior of the copolymers. LA - English DB - MTMT ER - TY - JOUR AU - Farkas, Vajk AU - Csókás, Dániel AU - Erdélyi, Ádám AU - Turczel, Gábor AU - Bényei, Attila Csaba AU - Nagy, Tibor AU - Kéki, Sándor AU - Pápai, Imre AU - Tuba, Róbert TI - “Inverted” Cyclic(Alkyl)(Amino)Carbene (CAAC) Ruthenium Complex Catalyzed Isomerization Metathesis (ISOMET) of Long Chain Olefins to Propylene at Low Ethylene Pressure JF - ADVANCED SCIENCE J2 - ADV SCI VL - 11 PY - 2024 IS - 12 SN - 2198-3844 DO - 10.1002/advs.202400118 UR - https://m2.mtmt.hu/api/publication/34742565 ID - 34742565 N1 - Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2, Budapest, H-1117, Hungary Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Szent Gellért tér 4, Budapest, H-1111, Hungary Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2, Budapest, H-1117, Hungary Research Centre for Biochemical, Environmental and Chemical Engineering, Department of MOL Hydrocarbon and Coal Processing, University of Pannonia, Egyetem u. 10, Veszprém, H-8210, Hungary Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen, H-4032, Hungary Department of Applied Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen, H-4032, Hungary Export Date: 22 March 2024 Correspondence Address: Tuba, R.; Institute of Materials and Environmental Chemistry, Magyar tudósok körútja 2, Hungary; email: tuba.robert@ttk.hu AB - Isomerization Metathesis (ISOMET) reaction is an emerging tool for “open loop” chemical recycling of polyethylene to propylene. Novel, latent N ‐Alkyl substituted Cyclic(Alkyl)(Amino)Carbene (CAAC)–ruthenium catalysts ( 5a‐Ru , 3b‐Ru – 6c‐Ru ) are developed rendering “inverted” chemical structure while showing enhanced ISOMET activity in combination with (RuHCl)(CO)(PPh 3 ) 3 ( RuH ) double bond isomerization co‐catalyst. Systematic investigations reveal that the steric hindrance of the substituents on nitrogen and carbon atom adjacent to carbene moiety in the CAAC ligand have significantly improved the catalytic activity and robustness. In contrast to the NHC‐Ru and CAAC‐Ru catalyst systems known so far, these systems show higher isomerization metathesis (ISOMET) activity (TON: 7400) on the model compound 1‐octadecene at as low as 3.0 bar optimized pressure, using technical grade (3.0) ethylene. The propylene content formed in the gas phase can reach up to 20% by volume. LA - English DB - MTMT ER - TY - JOUR AU - Nguyen Huu Huong, Duyen AU - Muthu, Arjun AU - El-Ramady, Hassan AU - Daróczi, Lajos AU - Nagy, Lajos AU - Kéki, Sándor AU - Béni, Áron AU - Csarnovics, István AU - Prokisch, József TI - Optimization of Extraction Conditions to Synthesize Green Carbon Nanodots from Maillard Reaction JF - MATERIALS ADVANCES J2 - MATER ADV VL - 5 PY - 2024 SP - 3499 EP - 3505 PG - 7 SN - 2633-5409 DO - 10.1039/D4MA00037D UR - https://m2.mtmt.hu/api/publication/34720754 ID - 34720754 AB - Carbon nanodots (CNDs) are a class of nanoparticles with unique optical properties with broad applications in various fields. However, synthesizing CNDs with high fluorescence intensity and small size using green... LA - English DB - MTMT ER - TY - JOUR AU - Herczeg, Mihály AU - Demeter, Fruzsina AU - Nagy, Tibor AU - Rusznyák, Ágnes AU - Hodek, Jan AU - Sipos, Éva AU - Lekli, István AU - Fenyvesi, Ferenc AU - Weber, Jan AU - Kéki, Sándor AU - Borbás, Anikó TI - Block Synthesis and Step-Growth Polymerization of C-6-Sulfonatomethyl-Containing Sulfated Malto-Oligosaccharides and Their Biological Profiling JF - INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES J2 - INT J MOL SCI VL - 25 PY - 2024 IS - 1 SN - 1661-6596 DO - 10.3390/ijms25010677 UR - https://m2.mtmt.hu/api/publication/34502650 ID - 34502650 AB - Highly sulfated malto-oligomers, similar to heparin and heparan-sulfate, have good antiviral, antimetastatic, anti-inflammatory and cell growth inhibitory effects. Due to their broad biological activities and simple structure, sulfated malto-oligomer derivatives have a great therapeutic potential, therefore, the development of efficient synthesis methods for their production is of utmost importance. In this work, preparation of α-(1→4)-linked oligoglucosides containing a sulfonatomethyl moiety at position C-6 of each glucose unit was studied by different approaches. Malto-oligomeric sulfonic acid derivatives up to dodecasaccharides were prepared by polymerization using different protecting groups, and the composition of the product mixtures was analyzed by MALDI-MS methods and size-exclusion chromatography. Synthesis of lower oligomers was also accomplished by stepwise and block synthetic methods, and then the oligosaccharide products were persulfated. The antiviral, anti-inflammatory and cell growth inhibitory activity of the fully sulfated malto-oligosaccharide sulfonic acids were determined by in vitro tests. Four tested di- and trisaccharide sulfonic acids effectively inhibited the activation of the TNF-α-mediated inflammatory pathway without showing cytotoxicity. LA - English DB - MTMT ER - TY - CONF AU - Kocsis, Beatrix AU - Mi-Kyung, Lee AU - Jae-Hyuk, Yu AU - Nagy, Tibor AU - Daróczi, Lajos AU - Batta, Gyula Gábor (Ifj.) AU - Pócsi, István AU - Leiter, Éva Juliánna TI - Comprehensive functional analyses of the bzip transciption factors AtfA and AtfB in Aspergillus Nidulans T2 - 16th European Conference on Fungal Genetics: Programme & Abstracts PB - Universität Innsbruck C1 - Innsbruck PY - 2023 SP - 705 EP - 706 PG - 2 UR - https://m2.mtmt.hu/api/publication/34453415 ID - 34453415 LA - English DB - MTMT ER - TY - JOUR AU - Kocsis, Beatrix AU - Imre, Boldizsár AU - Gábor, M. Kovács AU - Nagy, Tibor AU - Gyémánt, Gyöngyi AU - Gáspár, Attila AU - Csillag, Kinga Karola AU - Pócsi, István AU - Leiter, Éva Juliánna TI - Functional analysis of the deletion and overexpression mutants of the transcription factor (an7872) regulating the an7884 secondary metabolite gene cluster JF - ACTA MICROBIOLOGICA ET IMMUNOLOGICA HUNGARICA J2 - ACTA MICROBIOL IMMUNOL HUNG VL - 70 PY - 2023 IS - Supplement 1 SP - 68 SN - 1217-8950 UR - https://m2.mtmt.hu/api/publication/34448544 ID - 34448544 LA - English DB - MTMT ER - TY - JOUR AU - Lőrincz, Eszter Boglárka AU - Herczeg, Mihály AU - Houser, Josef AU - Rievajová, Martina AU - Kuki, Ákos AU - Malinovská, Lenka AU - Naesens, Lieve AU - Wimmerová, Michaela AU - Borbás, Anikó AU - Herczegh, Pál AU - Bakai-Bereczki, Ilona TI - Amphiphilic Sialic Acid Derivatives as Potential Dual-Specific Inhibitors of Influenza Hemagglutinin and Neuraminidase JF - INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES J2 - INT J MOL SCI VL - 24 PY - 2023 IS - 24 PG - 23 SN - 1661-6596 DO - 10.3390/ijms242417268 UR - https://m2.mtmt.hu/api/publication/34427826 ID - 34427826 AB - In the shadow of SARS-CoV-2, influenza seems to be an innocent virus, although new zoonotic influenza viruses evolved by mutations may lead to severe pandemics. According to WHO, there is an urgent need for better antiviral drugs. Blocking viral hemagglutinin with multivalent N-acetylneuraminic acid derivatives is a promising approach to prevent influenza infection. Moreover, dual inhibition of both hemagglutinin and neuraminidase may result in a more powerful effect. Since both viral glycoproteins can bind to neuraminic acid, we have prepared three series of amphiphilic self-assembling 2-thio-neuraminic acid derivatives constituting aggregates in aqueous medium to take advantage of their multivalent effect. One of the series was prepared by the azide-alkyne click reaction, and the other two by the thio-click reaction to yield neuraminic acid derivatives containing lipophilic tails of different sizes and an enzymatically stable thioglycosidic bond. Two of the three bis-octyl derivatives produced proved to be active against influenza viruses, while all three octyl derivatives bound to hemagglutinin and neuraminidase from H1N1 and H3N2 influenza types. LA - English DB - MTMT ER - TY - JOUR AU - Bodnár, Magdolna AU - Fazekas, Erika AU - Nagy, Tibor AU - Miltner, Noémi AU - Kalló, Gergő AU - Kerekes, Krisztina AU - Prépost, Eszter AU - Mótyán, János András TI - Synthesis of Galacto-oligosaccharides in Milk by Using Bifidobacterium bifidum β-galactosidases (Saphera 2600L and Nola Fit 5500) Immobilized on Chitosan Beads JF - FOOD AND BIOPROCESS TECHNOLOGY J2 - FOOD BIOPROCESS TECH PY - 2023 SP - 1 EP - 20 PG - 20 SN - 1935-5130 DO - 10.1007/s11947-023-03222-x UR - https://m2.mtmt.hu/api/publication/34391882 ID - 34391882 AB - The lactose intolerance—as a limiting factor for dairy milk consumption—has a high prevalence worldwide. Dairy milk and milk-derived products are major sources of multiple inorganic compounds and nutrients and thus are considered to be functional foods. β-galactosidases are able to hydrolyze lactose and are therefore widely applied for the production of lactose-free products. In addition, they are capable of the synthesis of galacto-oligosaccharides (GOSs); thus, the dairy industry has a special interest in applying them for the enrichment of dairy products with prebiotic GOSs. In this work, we studied two commercially available β-galactosidase products: Saphera 2600L and Nola Fit 5500. Both enzyme solutions contain a recombinant β-galactosidase of Bifidobacterium bifidum and have already been authorized for food industrial application, but the information about their hydrolytic and/or synthetic activities is only limited. After immobilization on chitosan beads, the enzymes were used for lactose hydrolysis and simultaneous synthesis of GOSs, by performing the reactions in pasteurized milk (skim milk). Both immobilized β-galactosidase exhibited elevated lactose hydrolysis (v max increased from ~ 1 to ~ 4 mM/min) and GOS synthesis as compared to the free enzymes. The enzyme-coated beads were efficiently re-used at least 15 cycles; the residual lactose concentration was < 2 mg/ml after each cycle. After treatment, GOSs were present in ≤ 9% of the total sugar content, indicating that the prepared low-lactose milks were enriched in prebiotic GOSs. The application of immobilized Saphera 2600L and Nola Fit 5500 β-galactosidases may be implemented for the large-scale production of GOS-enriched low-lactose milk. LA - English DB - MTMT ER - TY - CONF AU - Vadkerti, Bence AU - Lakatos, Csilla AU - Üneri, Haymana Serra AU - Rágyanszki, Anita AU - Farkas, Ödön AU - Juhász, Anett AU - Zsuga, Miklós AU - Kéki, Sándor AU - Nagy, Lajos ED - Majdik, Cornelia TI - Alifás diizocianátok és butan-1-ol reakcióinak kinetikai vizsgálata =$bKinetic study of the reactions between aliphatic diisocyanates and butan-1-ol T2 - XXIX. Nemzetközi Vegyészkonferencia / 29th International Conference on Chemistry PB - Erdélyi Magyar Műszaki Tudományos Társaság (EMT) C1 - Kolozsvár T3 - Nemzetközi Vegyészkonferencia, ISSN 1843-6293 PY - 2023 SP - 61 UR - https://m2.mtmt.hu/api/publication/34274180 ID - 34274180 LA - English DB - MTMT ER -