TY - JOUR AU - Diana-Alexandra, FLOREA AU - Aurora, MOCANU AU - Lucian-Cristian, POP AU - Gheorghe, TOMOAIA AU - Cristina-Teodora, DOBROTA AU - Várhelyi, Csaba, ifj. AU - Maria, TOMOAIA-COTISEL TI - Remineralization of Tooth Enamel with Hydroxyapatite Nanoparticles: an in vitro Study JF - STUDIA UNIVERSITATIS BABES-BOLYAI CHEMIA J2 - STUD UNIV BABES-BOLYAI CHEM VL - 68 PY - 2023 IS - 2 SP - 99 EP - 113 PG - 15 SN - 1224-7154 DO - 10.24193/subbchem.2023.2.07 UR - https://m2.mtmt.hu/api/publication/34145841 ID - 34145841 AB - The use of toothpastes is the best way to combat enamel loss and degradation. When they also contain hydroxyapatite nanoparticles, HAP NPs, the tooth enamel can be restored by remineralization. In this study, we developed two types of toothpastes, one with nano sized HAP, noted P1, and the other with nano multi-substituted hydroxyapatite (ms-HAP, HAP-Mg-Zn-Si), noted P2, which were used to treat the artificially demineralized teeth enamel surface. The remineralization efficacy of the two toothpastes was determined on artificially created enamel lesions by suspending healthy enamel slices in demineralizing solution, made of orthophosphoric acid of 37.5% for 90 s. For this purpose, six extracted third molars were collected and twenty-four enamel slices were cut and arbitrarily allocated to the four groups, namely n = 6 enamel slices for each group. One group served as untreated (natural) enamel control, and another group comprised demineralized enamel and two test groups, firstly demineralized, and then, they were treated with toothpastes P1 and P2, respectively, each of them for ten days, and finally were noted P1 and P2 enamel surfaces. The surface morphology and roughness of all enamel specimens were studied by atomic force microscopy (AFM) before and after applying the treatment with the toothpastes. The toothpastes effect was evidenced by the average diameter of ceramic nanoparticles deposited within the superficial smooth layer on enamel surface having, at the completion of 10 days treatment, a low surface roughness close to that of natural enamel. This in vitro comparative study demonstrated that both toothpastes P1 and P2 can promote surface enamel repair by remineralization and the formation of a protective hydroxyapatite coating layer on the enamel surface treated with these toothpastes. LA - English DB - MTMT ER - TY - CHAP AU - Várhelyi, Csaba, ifj. AU - GYÖRGY, POKOL AU - IMRE-MIKLÓS, SZILÁGYI AU - RALUCA-ANCA, MEREU AU - JÁNOS, MADARÁSZ AU - ROLAND, SZALAY AU - JUDIT, PAPP AU - MELINDA, SIMON-VÁRHELYI AU - JUDITH, MIHÁLY TI - Thermal and Spectroscopical Analysis of Platinum(II) Complexes with Glyoximes, Schiff Bases and Thiosemicarbazones T2 - 3rd Journal of Thermal Analysis and Calorimetry Conference and 9th V4 (Joint Czech-Hungarian-Polish-Slovakian) Thermoanalytical Conference PB - Akadémiai Kiadó CY - Budapest SN - 9789634549154 PY - 2023 SP - 95 EP - 96 PG - 2 UR - https://m2.mtmt.hu/api/publication/34145735 ID - 34145735 AB - After the discovery of anticancer activity of cisplatin by Barnett Rosenberg, platinum coordination complexes became a very important class of drugs. In recent years other platinum-based drugs have entered in clinical trials, and high efforts have been made to find more active and less toxic agents for cancer treatment in humans. Many pathogenic bacteria show resistance toward antibiotics, therefore it is necessary to find new compounds to control the multidrug-resistant microorganisms. Other platinum coordination and organometallic complexes have demonstrated applications in homogeneous catalysis, such as the oxidation of ethanol to acetic acid or acetaldehyde, the oxidation of sulfur dioxide to sulfuric acid and, furthermore, in catalytic combustion, hydrogenation reactions. In our research project new Pt(II) complexes were synthesized from the reaction between azomethine derivatives (glyoximes, Schiff bases and thiosemicarbazones) and PtCl2 salt, in suitable solvent. After presenting a short historical survey, classification, and possible application fields of these compounds, we report the study of their thermoanalytical behaviour (TG-DTG-DTA), spectroscopic features (such as FTIR, NMR, UV-VIS, Raman spectroscopy, mass spectrometry) as well as their powder XRD and AFM or SEM investigations. The biological activity of complexes, especially their antibacterial activity, will also be discussed. LA - English DB - MTMT ER - TY - JOUR AU - Várhelyi, Csaba, ifj. AU - Szőke, Á. AU - Sziráki, Laura AU - Tomoaia-Cotișel, M. AU - Homonnay, Zoltán AU - Szalay, Roland AU - Simon-Várhelyi, M. AU - Mereu, R.-A. AU - Pokol, György AU - Szilágyi, Imre Miklós AU - Papp, J. AU - Mihály, Judith AU - Kuzmann, Ernő TI - Fe spin states and redox processes in Schiff base type complexes JF - JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY J2 - J RADIOANAL NUCL CHEM VL - 332 PY - 2023 IS - 10 SP - 4125 EP - 4139 PG - 15 SN - 0236-5731 DO - 10.1007/s10967-023-09095-w UR - https://m2.mtmt.hu/api/publication/34107401 ID - 34107401 N1 - Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University, Arany János 11, Cluj-Napoca, 400028, Romania Institute of Chemistry, Eötvös Loránd University, Pázmány Péter 1/a, Budapest, 1117, Hungary Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Műegyetem Rkp. 3, Budapest, 1111, Hungary Faculty of Biology and Geology, Babeş-Bolyai University, Gheorghe Bilaşcu 44, Cluj-Napoca, 400015, Romania Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, Budapest, 1117, Hungary Export Date: 29 January 2024 CODEN: JRNCD Correspondence Address: Várhelyi, C.; Faculty of Chemistry and Chemical Engineering, Arany János 11, Romania; email: csaba.varhelyi@ubbcluj.ro LA - English DB - MTMT ER - TY - CONF AU - Várhelyi, Csaba, ifj. AU - Pokol, György AU - Szalay, Roland AU - MEREU, RALUCA-ANCA AU - Simon-Várhelyi, Melinda AU - Tötös, Róbert AU - Madarász, János AU - PAPP, JUDIT AU - Mihály, Judith TI - Szemi- és tioszemikarbazonokkal képzett platina- és nikkel-komplexek előállítása, valamint fizikai-kémiai és biológiai vizsgálatuk (Pt- and Ni-complexes Syntheses with Semi- and Thiosemicarbazones, and their Physical-Chemical and Biological Study) T2 - A Magyar Tudomány Napja Erdélyben 2022: Tudomány: út a világ megismeréséhez PY - 2022 SP - 28 EP - 30 PG - 3 UR - https://m2.mtmt.hu/api/publication/33646163 ID - 33646163 N1 - EME – Természettudományi szakosztály LA - Hungarian DB - MTMT ER - TY - CHAP AU - Várhelyi, Csaba, ifj. AU - Szalay, Roland AU - Pokol, György AU - Madarász, János AU - Szilágyi, Imre Miklós AU - Huszthy, Péter AU - Simon-Várhelyi, Melinda AU - Tötös, Róbert AU - RALUCA-ANCA, MEREU AU - ALEXANDRA, AVRAM AU - Korecz, László AU - May, Nóra Veronika AU - Mihály, Judith ED - Alapi, Tünde ED - Berkecz, Róbert ED - Ilisz, István TI - Novel Copper Complexes with Glyoximes, Amines, Schiff Bases, Semi- and Thiosemicarbazones; Synthesis and Physico-Chemical Analysis T2 - Proceedings of the 28th International Symposium on Analytical and Environmental Problems PB - University of Szeged CY - Szeged SN - 9789633069042 PY - 2022 SP - 46 EP - 50 PG - 5 UR - https://m2.mtmt.hu/api/publication/33645223 ID - 33645223 LA - English DB - MTMT ER - TY - CONF AU - Várhelyi, Csaba, ifj. AU - Szalay, Roland AU - Kuzmann, Ernő AU - Homonnay, Zoltán AU - Pokol, György AU - Madarász, János AU - PAPP, JUDIT AU - MEREU, RALUCA-ANCA AU - Huszthy, Péter AU - Simon-Várhelyi, Melinda AU - AVRAM, ALEXANDRA AU - Mihály, Judith ED - Majdik, Cornelia TI - Glioximokkal, aminokkal, bórsav-észterekkel és Schiff-bázisokkal képzett új vas(II)-komplexek fizikai-kémiai elemzése, és biológiai tulajdonságainak vizsgálata (Novel Iron(II) Complexes with Glyoximes, Amines, Borate Esters and Schiff-Bases, their Physico-Chemical Analysis and Biological Properties Study) T2 - XXVIII. Nemzetközi Vegyészkonferencia = 28th International Conference on Chemistry PB - Erdélyi Magyar Műszaki Tudományos Társaság (EMT) C1 - Kolozsvár T3 - Nemzetközi Vegyészkonferencia, ISSN 1843-6293 PY - 2022 SP - 44 EP - 44 PG - 1 UR - https://m2.mtmt.hu/api/publication/33645214 ID - 33645214 N1 - EMT, XXVIII. Nemzetközi Vegyészkonferencia, 2022. okt. 27 – 29., Nagyvárad LA - Hungarian DB - MTMT ER - TY - JOUR AU - Várhelyi, Csaba, ifj. AU - Szalay, Roland AU - Pokol, György AU - Madarász, János AU - Marincaș , Laura AU - MEREU, Raluca-Anca AU - Mihály, Judith AU - PAPP, Judit AU - Simon-Várhelyi, Melinda AU - Tötös, Róbert AU - TOMOAIA- COTIŞEL, Maria TI - Synthesis of Pt(II)-complexes with symmetrical and unsymmetrical glyoximes, their physical-chemical and biological study JF - STUDIA UNIVERSITATIS BABES-BOLYAI CHEMIA J2 - STUD UNIV BABES-BOLYAI CHEM VL - 67 PY - 2022 IS - 4 SP - 315 EP - 335 PG - 21 SN - 1224-7154 DO - 10.24193/subbchem.2022.4.21 UR - https://m2.mtmt.hu/api/publication/33645156 ID - 33645156 N1 - Funding Agency and Grant Number: "Domus Hungarica Foundation" of Hungary Funding text: The authors wish to express their thankfulness to the "Domus Hungarica Foundation" of Hungary for the several fellowships provided to Csaba Varhelyi jr. LA - English DB - MTMT ER - TY - JOUR AU - M., FISCHER AU - Várhelyi, Csaba, ifj. TI - Réz(II)-komplexek szintézise Schiff-bázisokkal és alfa-dioximokkal valamint ezek fizikai-kémiai vizsgálata (Synthesis of copper(II)-complexes with Schiff bases and alpha-dioximes, and their physical-chemical study) JF - MŰSZAKI SZEMLE (EMT) J2 - MŰSZAKI SZEMLE (EMT) VL - 4 PY - 2022 IS - - SP - 1 EP - 7 PG - 7 SN - 1454-0746 UR - https://m2.mtmt.hu/api/publication/33645082 ID - 33645082 LA - Hungarian DB - MTMT ER - TY - JOUR AU - B., SZÁSZ AU - Várhelyi, Csaba, ifj. TI - Fe(II)-komplexek szintézise alfa-dioximokkal, alkalmazhatósági lehetőségeik, valamint fizikai-kémiai és biológiai vizsgálatuk (Synthesis of Fe(II) complexes with alpha-dioximes, their applicability and their physicochemical and biological investigation) JF - MŰSZAKI SZEMLE (EMT) J2 - MŰSZAKI SZEMLE (EMT) VL - 3 PY - 2022 IS - - SP - 28 EP - 34 PG - 7 SN - 1454-0746 UR - https://m2.mtmt.hu/api/publication/33645073 ID - 33645073 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Á., GERE AU - Várhelyi, Csaba, ifj. TI - Co(III)-komplexek előállítása α-dioximokkal és azidokkal, valamint fizikai-kémiai és biológiai tulajdonságainak vizsgálata (The synthesis of Co(III) complexes with α-dioximes and azides. The study of physical-chemical and biological properties) JF - MŰSZAKI SZEMLE (EMT) J2 - MŰSZAKI SZEMLE (EMT) VL - 3 PY - 2022 IS - - SP - 17 EP - 21 PG - 5 SN - 1454-0746 UR - https://m2.mtmt.hu/api/publication/33645059 ID - 33645059 LA - Hungarian DB - MTMT ER -