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Kamel SM, Daróczi L, Tóth LZ, Beke DL, Juárez GG, Cobo S, Salmon L, Molnár G, Bousseksou A. Acoustic emissions from spin crossover complexes. J Mater Chem C Mater 2024; 12:5757-5765. [PMID: 38680543 PMCID: PMC11044199 DOI: 10.1039/d4tc00495g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 03/19/2024] [Indexed: 05/01/2024]
Abstract
Acoustic emission from the compounds [Fe(HB(tz)3)2] and [Fe(Htrz)(trz)2]BF4 was detected during the thermally induced spin transition and is correlated with simultaneously recorded calorimetric signals. We ascribe this phenomenon to elastic waves produced by microstructural and volume changes accompanying the spin transition. Despite the perfect reversibility of the spin state switching (seen by the calorimeter), the acoustic emission activity decreases for successive thermal cycles, revealing thus irreversible microstructural evolution of the samples. The acoustic emission signal amplitude and energy probability distribution functions followed power-law behavior and the characteristic exponents were found to be similar for the two samples both on heating and cooling, indicating the universal character, which is further substantiated by the well scaled average temporal shapes of the avalanches.
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Affiliation(s)
- Sarah M Kamel
- Department of Solid State Physics, Doctoral School of Physics, University of Debrecen P.O. Box 2 H-4010 Debrecen Hungary
- Physics Department, Faculty of Science Ain Shams University, Abbassia 11566 Cairo Egypt
| | - Lajos Daróczi
- Department of Solid State Physics, Doctoral School of Physics, University of Debrecen P.O. Box 2 H-4010 Debrecen Hungary
| | - László Z Tóth
- Department of Solid State Physics, Doctoral School of Physics, University of Debrecen P.O. Box 2 H-4010 Debrecen Hungary
| | - Dezső L Beke
- Department of Solid State Physics, Doctoral School of Physics, University of Debrecen P.O. Box 2 H-4010 Debrecen Hungary
| | - Gerardo Gutiérrez Juárez
- Departamento de Ingeniería Física, División de Ciencias e Ingenierías, Universidad de Guanajuato-Campus León, Loma del Bosque 103, Loma del Campestre 37150 León Gto. Mexico
| | - Saioa Cobo
- LCC, CNRS & University of Toulouse, 205 route de Narbonne 31077 Toulouse France
| | - Lionel Salmon
- LCC, CNRS & University of Toulouse, 205 route de Narbonne 31077 Toulouse France
| | - Gábor Molnár
- LCC, CNRS & University of Toulouse, 205 route de Narbonne 31077 Toulouse France
| | - Azzedine Bousseksou
- LCC, CNRS & University of Toulouse, 205 route de Narbonne 31077 Toulouse France
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2
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Hatvani-Nagy AF, Hajdu V, Ilosvai ÁM, Muránszky G, Sikora E, Kristály F, Daróczi L, Viskolcz B, Fiser B, Vanyorek L. Bentonite as eco-friendly natural mineral support for Pd/CoFe 2O 4 catalyst applied in toluene diamine synthesis. Sci Rep 2024; 14:4193. [PMID: 38378814 PMCID: PMC10879086 DOI: 10.1038/s41598-024-54792-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Accepted: 02/16/2024] [Indexed: 02/22/2024] Open
Abstract
Toluene diamine (TDA) is a major raw material in the polyurethane industry and thus, its production is highly important. TDA is obtained through the catalytic hydrogenation of 2,4-dinitrotoluene (2,4-DNT). In this study a special hydrogenation catalyst has been developed by decomposition cobalt ferrite nanoparticles onto a natural clay-oxide nanocomposite (bentonite) surface using a microwave-assisted solvothermal method. The catalyst particles were examined by TEM and X-ray diffraction. The palladium immobilized on the bentonite crystal surface was identified using an XRD and HRTEM device. The obtained catalyst possesses the advantageous property of being easily separable due to its magnetizability on a natural mineral support largely available and obtained through low carbon- and energy footprint methods. The catalyst demonstrated outstanding performance with a 2,4-DNT conversion rate exceeding 99% along with high yields and selectivity towards 2,4-TDA and all of this achieved within a short reaction time. Furthermore, the developed catalyst exhibited excellent stability, attributed to the strong interaction between the catalytically active metal and its support. Even after four cycles of reuse, the catalytic activity remained unaffected and the Pd content of the catalyst did not change, which indicates that the palladium component remained firmly attached to the magnetic support's surface.
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Affiliation(s)
- Alpár F Hatvani-Nagy
- Higher Education and Industrial Cooperation Centre, University of Miskolc, Miskolc-Egyetemváros, 3515, Hungary
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros, 3515, Hungary
| | - Viktória Hajdu
- Higher Education and Industrial Cooperation Centre, University of Miskolc, Miskolc-Egyetemváros, 3515, Hungary
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros, 3515, Hungary
| | - Ágnes Mária Ilosvai
- Higher Education and Industrial Cooperation Centre, University of Miskolc, Miskolc-Egyetemváros, 3515, Hungary
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros, 3515, Hungary
| | - Gábor Muránszky
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros, 3515, Hungary
| | - Emőke Sikora
- Higher Education and Industrial Cooperation Centre, University of Miskolc, Miskolc-Egyetemváros, 3515, Hungary
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros, 3515, Hungary
| | - Ferenc Kristály
- Institute of Mineralogy and Geology, University of Miskolc, 3515, Miskolc-Egyetemváros, Hungary
| | - Lajos Daróczi
- Department of Solid State Physics, University of Debrecen, P.O. Box 2, Debrecen, 4010, Hungary
| | - Béla Viskolcz
- Higher Education and Industrial Cooperation Centre, University of Miskolc, Miskolc-Egyetemváros, 3515, Hungary
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros, 3515, Hungary
| | - Béla Fiser
- Higher Education and Industrial Cooperation Centre, University of Miskolc, Miskolc-Egyetemváros, 3515, Hungary.
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros, 3515, Hungary.
- Ferenc Rakoczi II Transcarpathian Hungarian College of Higher Education, Beregszász, 90200, Ukraine.
- Department of Physical Chemistry, Faculty of Chemistry, University of Lodz, 90-236, Lodz, Poland.
| | - László Vanyorek
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros, 3515, Hungary.
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Ilosvai ÁM, Forgách L, Kovács N, Heydari F, Szigeti K, Máthé D, Kristály F, Daróczi L, Kaleta Z, Viskolcz B, Nagy M, Vanyorek L. Development of Polymer-Encapsulated, Amine-Functionalized Zinc Ferrite Nanoparticles as MRI Contrast Agents. Int J Mol Sci 2023; 24:16203. [PMID: 38003394 PMCID: PMC10671131 DOI: 10.3390/ijms242216203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
The need for stable and well-defined magnetic nanoparticles is constantly increasing in biomedical applications; however, their preparation remains challenging. We used two different solvothermal methods (12 h reflux and a 4 min microwave, MW) to synthesize amine-functionalized zinc ferrite (ZnFe2O4-NH2) superparamagnetic nanoparticles. The morphological features of the two ferrite samples were the same, but the average particle size was slightly larger in the case of MW activation: 47 ± 14 nm (Refl.) vs. 63 ± 20 nm (MW). Phase identification measurements confirmed the exclusive presence of zinc ferrite with virtually the same magnetic properties. The Refl. samples had a zeta potential of -23.8 ± 4.4 mV, in contrast to the +7.6 ± 6.8 mV measured for the MW sample. To overcome stability problems in the colloidal phase, the ferrite nanoparticles were embedded in polyvinylpyrrolidone and could be easily redispersed in water. Two PVP-coated zinc ferrite samples were administered (1 mg/mL ZnFe2O4) in X BalbC mice and were compared as contrast agents in magnetic resonance imaging (MRI). After determining the r1/r2 ratio, the samples were compared to other commercially available contrast agents. Consistent with other SPION nanoparticles, our sample exhibits a concentrated presence in the hepatic region of the animals, with comparable biodistribution and pharmacokinetics suspected. Moreover, a small dose of 1.3 mg/body weight kg was found to be sufficient for effective imaging. It should also be noted that no toxic side effects were observed, making ZnFe2O4-NH2 advantageous for pharmaceutical formulations.
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Affiliation(s)
- Ágnes M. Ilosvai
- Institute of Chemistry, University of Miskolc, 3515 Miskolc, Hungary; (Á.M.I.); (B.V.); (M.N.)
- Higher Education and Industrial Cooperation Centre, University of Miskolc, 3515 Miskolc, Hungary
| | - László Forgách
- Department of Biophysics and Radiation Biology, Semmelweis University, 1094 Budapest, Hungary; (N.K.); (F.H.); (K.S.); (D.M.)
| | - Noémi Kovács
- Department of Biophysics and Radiation Biology, Semmelweis University, 1094 Budapest, Hungary; (N.K.); (F.H.); (K.S.); (D.M.)
- In Vivo Imaging Advanced Core Facility, Hungarian Center of Excellence for Molecular Medicine (HCEMM), 1094 Budapest, Hungary
| | - Fatemeh Heydari
- Department of Biophysics and Radiation Biology, Semmelweis University, 1094 Budapest, Hungary; (N.K.); (F.H.); (K.S.); (D.M.)
| | - Krisztián Szigeti
- Department of Biophysics and Radiation Biology, Semmelweis University, 1094 Budapest, Hungary; (N.K.); (F.H.); (K.S.); (D.M.)
| | - Domokos Máthé
- Department of Biophysics and Radiation Biology, Semmelweis University, 1094 Budapest, Hungary; (N.K.); (F.H.); (K.S.); (D.M.)
- In Vivo Imaging Advanced Core Facility, Hungarian Center of Excellence for Molecular Medicine (HCEMM), 1094 Budapest, Hungary
| | - Ferenc Kristály
- Institute of Mineralogy and Geology, University of Miskolc, 3515 Miskolc, Hungary;
| | - Lajos Daróczi
- Department of Solid State Physics, University of Debrecen, P.O. Box 2, 4010 Debrecen, Hungary;
| | - Zoltán Kaleta
- Pro-Research Laboratory, Progressio Engineering Bureau Ltd., 8000 Szekesfehervar, Hungary;
- Institute of Organic Chemistry, Semmelweis University, 1092 Budapest, Hungary
| | - Béla Viskolcz
- Institute of Chemistry, University of Miskolc, 3515 Miskolc, Hungary; (Á.M.I.); (B.V.); (M.N.)
- Higher Education and Industrial Cooperation Centre, University of Miskolc, 3515 Miskolc, Hungary
| | - Miklós Nagy
- Institute of Chemistry, University of Miskolc, 3515 Miskolc, Hungary; (Á.M.I.); (B.V.); (M.N.)
| | - László Vanyorek
- Institute of Chemistry, University of Miskolc, 3515 Miskolc, Hungary; (Á.M.I.); (B.V.); (M.N.)
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4
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Hajdu V, Prekob Á, Muránszky G, Kristály F, Daróczi L, Harasztosi L, Kaleta Z, Viskolcz B, Nagy M, Vanyorek L. Amine Functionalization Leads to Enhanced Performance for Nickel- and Cobalt-Ferrite-Supported Palladium Catalysts in Nitrobenzene Hydrogenation. Int J Mol Sci 2023; 24:13347. [PMID: 37686152 PMCID: PMC10487572 DOI: 10.3390/ijms241713347] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 08/22/2023] [Accepted: 08/26/2023] [Indexed: 09/10/2023] Open
Abstract
Easy preparation, good yield and easy recovery are the key challenges in the development of industrial catalysts. To meet all these three criteria, we have prepared intelligent, magnetizable NiFe2O4- and CoFe2O4-supported palladium catalysts that can be easily and completely recovered from the reaction medium by magnetic separation. The fast and facile preparation was achieved by a solvothermal method followed by sonochemical-assisted decomposition of the palladium nanoparticles onto the surface of the magnetic nanoparticles. The metal-support interaction was enhanced by amine functionalization of the supports using monoethanolamine. The performance and stability of the non-functionalized and amine-functionalized NiFe2O4- and CoFe2O4-supported palladium catalysts were compared in the industrially important nitrobenzene hydrogenation reaction. All catalysts showed high catalytic activity during aniline synthesis; complete nitrobenzene conversion and high aniline yield (above 97 n/n%) and selectivity (above 98 n/n%) were achieved. However, during reuse tests, the activity of the non-functionalized catalysts decreased, as the palladium was leached from the surface of the support. On the other hand, in the case of their amine-functionalized counterparts, there was no decrease in activity, and a non-significant decrease in palladium content could be measured. Based on these results, it can be concluded that amine functionalization of transition metal ferrites may result in more effective catalysts due to the enhanced metal-carrier interaction between the support and the precious metal.
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Affiliation(s)
- Viktória Hajdu
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros, 3515 Miskolc, Hungary; (V.H.); (Á.P.); (G.M.); (B.V.)
| | - Ádám Prekob
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros, 3515 Miskolc, Hungary; (V.H.); (Á.P.); (G.M.); (B.V.)
| | - Gábor Muránszky
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros, 3515 Miskolc, Hungary; (V.H.); (Á.P.); (G.M.); (B.V.)
| | - Ferenc Kristály
- Institute of Mineralogy and Geology, University of Miskolc, Miskolc-Egyetemváros, 3515 Miskolc, Hungary;
| | - Lajos Daróczi
- Department of Solid State Physics, University of Debrecen, 4010 Debrecen, Hungary; (L.D.); (L.H.)
| | - Lajos Harasztosi
- Department of Solid State Physics, University of Debrecen, 4010 Debrecen, Hungary; (L.D.); (L.H.)
| | - Zoltán Kaleta
- Pro-Research Laboratory, Progressio Engineering Bureau Ltd., 8000 Szekesfehervar, Hungary;
- Higher Education and Industrial Cooperation Centre, University of Miskolc, Miskolc-Egyetemváros, 3515 Miskolc, Hungary
- Institute of Organic Chemistry, Semmelweis University, 1092 Budapest, Hungary
| | - Béla Viskolcz
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros, 3515 Miskolc, Hungary; (V.H.); (Á.P.); (G.M.); (B.V.)
| | - Miklós Nagy
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros, 3515 Miskolc, Hungary; (V.H.); (Á.P.); (G.M.); (B.V.)
| | - László Vanyorek
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros, 3515 Miskolc, Hungary; (V.H.); (Á.P.); (G.M.); (B.V.)
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5
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Czifrák K, Lakatos C, Szabó G, Vadkerti B, Daróczi L, Zsuga M, Kéki S. Bisphenol A Diglycidyl Ether-Primary Amine Cooligomer-poly(ε-caprolactone) Networks: Synthesis and Characterization. Polymers (Basel) 2023; 15:2937. [PMID: 37447582 DOI: 10.3390/polym15132937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 06/30/2023] [Accepted: 07/02/2023] [Indexed: 07/15/2023] Open
Abstract
In this work, the preparation and systematic investigation of cross-linked polyurethane-epoxy (PU-EP) polymer systems are reported. The PU-EP polymers were prepared using a reaction of isocyanate (NCO)-terminated PU-prepolymer with diglycidyl ether of bisphenol A (DGEBA)-amine cooligomer. The oligomerization of DGEBA was carried out by adding furfurylamine (FA) or ethanolamine (EA), resulting in DGEBA-amine cooligomers. For the synthesis of NCO-terminated PU-prepolymer, poly(ε-caprolactone)diol (PCD) (Mn = 2 kg/mol) and 1,6-hexamethylene diisocyanate (HDI) were used. The cross-linking was achieved by adding DGEBA-amine cooligomer to PU-prepolymer, in which the obtained urethane bonds, due to the presence of free hydroxil groups in the activated DGEBA, served as netpoints. During cross-linking, ethanolamine provides an additional free hydroxyl group for the formation of a new urethane bond, while furfurylamine can serve as a thermoreversible coupling element (e.g., Diels-Alder adduct). The PU-EP networks were characterized using attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), dynamical mechanical analysis (DMA) and scanning electron microscopy (SEM). The DMA curves of some PU-EPs (depending on the compositions and the synthetic method) revealed a plateau-like region above the melting temperature (Tm) of PCD, confirming the presence of a cross-linked structure. This property resulted in a shape memory (SM) behavior for these samples, which can be fine-tuned in the presence of furfurylamine through the formation of additional thermoreversible bonds (e.g., Diels-Alder adduct).
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Affiliation(s)
- Katalin Czifrák
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Csilla Lakatos
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Gabriella Szabó
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Bence Vadkerti
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
- Doctoral School of Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Lajos Daróczi
- Department of Solid State Physics, University of Debrecen, Bem tér 18/b, H-4026 Debrecen, Hungary
| | - Miklós Zsuga
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Sándor Kéki
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
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Boda R, Lázár I, Keczánné-Üveges A, Bakó J, Tóth F, Trencsényi G, Kálmán-Szabó I, Béresová M, Sajtos Z, D Tóth E, Deák Á, Tóth A, Horváth D, Gaál B, Daróczi L, Dezső B, Ducza L, Hegedűs C. β-Tricalcium Phosphate-Modified Aerogel Containing PVA/Chitosan Hybrid Nanospun Scaffolds for Bone Regeneration. Int J Mol Sci 2023; 24:ijms24087562. [PMID: 37108742 PMCID: PMC10141662 DOI: 10.3390/ijms24087562] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 04/13/2023] [Accepted: 04/18/2023] [Indexed: 04/29/2023] Open
Abstract
Electrospinning has recently been recognized as a potential method for use in biomedical applications such as nanofiber-based drug delivery or tissue engineering scaffolds. The present study aimed to demonstrate the electrospinning preparation and suitability of β-tricalcium phosphate-modified aerogel containing polyvinyl alcohol/chitosan fibrous meshes (BTCP-AE-FMs) for bone regeneration under in vitro and in vivo conditions. The mesh physicochemical properties included a 147 ± 50 nm fibrous structure, in aqueous media the contact angles were 64.1 ± 1.7°, and it released Ca, P, and Si. The viability of dental pulp stem cells on the BTCP-AE-FM was proven by an alamarBlue assay and with a scanning electron microscope. Critical-size calvarial defects in rats were performed as in vivo experiments to investigate the influence of meshes on bone regeneration. PET imaging using 18F-sodium fluoride standardized uptake values (SUVs) detected 7.40 ± 1.03 using polyvinyl alcohol/chitosan fibrous meshes (FMs) while 10.72 ± 1.11 with BTCP-AE-FMs after 6 months. New bone formations were confirmed by histological analysis. Despite a slight change in the morphology of the mesh because of cross-linking, the BTCP-AE-FM basically retained its fibrous, porous structure and hydrophilic and biocompatible character. Our experiments proved that hybrid nanospun scaffold composite mesh could be a new experimental bone substitute bioactive material in future medical practice.
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Affiliation(s)
- Róbert Boda
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
| | - István Lázár
- Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology, University of Debrecen, 4032 Debrecen, Hungary
| | - Andrea Keczánné-Üveges
- Department of Biomaterials and Prosthetic Dentistry, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
| | - József Bakó
- Department of Biomaterials and Prosthetic Dentistry, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
| | - Ferenc Tóth
- Department of Biomaterials and Prosthetic Dentistry, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
| | - György Trencsényi
- Division of Nuclear Medicine and Translational Imaging, Department of Medical Imaging, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Ibolya Kálmán-Szabó
- Division of Nuclear Medicine and Translational Imaging, Department of Medical Imaging, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Monika Béresová
- Department of Medical Imaging, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Zsófi Sajtos
- Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology, University of Debrecen, 4032 Debrecen, Hungary
| | - Etelka D Tóth
- Department of Dentoalveolar Surgery, University of Debrecen, 4032 Debrecen, Hungary
| | - Ádám Deák
- Department of Operative Techniques and Surgical Research, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Adrienn Tóth
- Department of Dentoalveolar Surgery, University of Debrecen, 4032 Debrecen, Hungary
| | - Dóra Horváth
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
| | - Botond Gaál
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Lajos Daróczi
- Department of Solid State Physics, University of Debrecen, 4002 Debrecen, Hungary
| | - Balázs Dezső
- Department of Oral Pathology and Microbiology, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
| | - László Ducza
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Csaba Hegedűs
- Department of Biomaterials and Prosthetic Dentistry, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
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Tóth LZ, Bronstein E, Daróczi L, Shilo D, Beke DL. Scaling of Average Avalanche Shapes for Acoustic Emission during Jerky Motion of Single Twin Boundary in Single-Crystalline Ni 2MnGa. Materials (Basel) 2023; 16:2089. [PMID: 36903204 PMCID: PMC10004433 DOI: 10.3390/ma16052089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 06/18/2023]
Abstract
Temporal average shapes of crackling noise avalanches, U(t) (U is the detected parameter proportional to the interface velocity), have self-similar behavior, and it is expected that by appropriate normalization, they can be scaled together according to a universal scaling function. There are also universal scaling relations between the avalanche parameters (amplitude, A, energy, E, size (area), S, and duration, T), which in the mean field theory (MFT) have the form E∝A3, S∝A2, S∝T2. Recently, it turned out that normalizing the theoretically predicted average U(t) function at a fixed size, U(t)=atexp-bt2 (a and b are non-universal, material-dependent constants) by A and the rising time, R, a universal function can be obtained for acoustic emission (AE) avalanches emitted during interface motions in martensitic transformations, using the relation R~A1-φ too, where φ is a mechanism-dependent constant. It was shown that φ also appears in the scaling relations E~A3-φ and S~A2-φ, in accordance with the enigma for AE, that the above exponents are close to 2 and 1, respectively (in the MFT limit, i.e., with φ= 0, they are 3 and 2, respectively). In this paper, we analyze these properties for acoustic emission measurements carried out during the jerky motion of a single twin boundary in a Ni50Mn28.5Ga21.5 single crystal during slow compression. We show that calculating from the above-mentioned relations and normalizing the time axis of the average avalanche shapes with A1-φ, and the voltage axis with A, the averaged avalanche shapes for the fixed area are well scaled together for different size ranges. These have similar universal shapes as those obtained for the intermittent motion of austenite/martensite interfaces in two different shape memory alloys. The averaged shapes for a fixed duration, although they could be acceptably scaled together, showed a strong positive asymmetry (the avalanches decelerate much slower than they accelerate) and thus did not show a shape reminiscent of an inverted parabola, predicted by the MFT. For comparison, the above scaling exponents were also calculated from simultaneously measured magnetic emission data. It was obtained that the φ values are in accordance with theoretical predictions going beyond the MFT, but the AE results for φ are characteristically different from these, supporting that the well-known enigma for AE is related to this deviation.
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Affiliation(s)
- László Z. Tóth
- Department of Solid State Physics, University of Debrecen, P.O. Box 400, H-4002 Debrecen, Hungary
| | - Emil Bronstein
- Faculty of Mechanical Engineering, Technion—Israel Institute of Technology, Haifa 3200003, Israel
| | - Lajos Daróczi
- Department of Solid State Physics, University of Debrecen, P.O. Box 400, H-4002 Debrecen, Hungary
| | - Doron Shilo
- Faculty of Mechanical Engineering, Technion—Israel Institute of Technology, Haifa 3200003, Israel
| | - Dezső L. Beke
- Department of Solid State Physics, University of Debrecen, P.O. Box 400, H-4002 Debrecen, Hungary
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Beke DL, Kamel SM, Daróczi L, Tóth LZ. Thermodynamic Analysis of Anomalous Shape of Stress-Strain Curves for Shape Memory Alloys. Materials (Basel) 2022; 15:9010. [PMID: 36556816 PMCID: PMC9785706 DOI: 10.3390/ma15249010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 12/05/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
Abstract
In some shape-memory single crystals the stress-strain (σ~ε) curves, belonging to stress induced martensitic transformations from austenite to martensite at fixed temperature, instead of being the usual slightly increasing function or horizontal, have an overall negative slope with sudden stress drops in it. We discuss this phenomenon by using a local equilibrium thermodynamic approach and analysing the sign of the second derivative of the difference of the Gibbs free energy. We show that, considering also the possible nucleation and growth of two martensite structural modifications/variants, the stress-strain loops can be unstable. This means that the overall slope of the uploading branch of the stress-strain curve can be negative for smooth transformation if the second martensite, which is more stable with larger transformation strain, is the final product. We also show that local stress-drops on the stress-strain curve can appear if the nucleation of the second martensite is difficult, and the presence of such local stress-drops alone can also result in an overall negative slope of the stress-strain curves. It is illustrated that the increase of the temperature of the thermal recovery during burst-like transition is a measure of the change of the nucleation energy: the more stable martensite has larger nucleation energy.
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Affiliation(s)
- Dezső L. Beke
- Department of Solid State Physics, University of Debrecen, P.O. Box 400, H-4002 Debrecen, Hungary
| | - Sarah M. Kamel
- Department of Solid State Physics, University of Debrecen, P.O. Box 400, H-4002 Debrecen, Hungary
- Physics Department, Faculty of Science, Ain Shams University, Cairo 11566, Egypt
| | - Lajos Daróczi
- Department of Solid State Physics, University of Debrecen, P.O. Box 400, H-4002 Debrecen, Hungary
| | - László Z. Tóth
- Department of Solid State Physics, University of Debrecen, P.O. Box 400, H-4002 Debrecen, Hungary
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9
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Tóth LZ, Daróczi L, Elrasasi TY, Beke DL. Clustering Characterization of Acoustic Emission Signals Belonging to Twinning and Dislocation Slip during Plastic Deformation of Polycrystalline Sn. Materials (Basel) 2022; 15:6696. [PMID: 36234037 PMCID: PMC9572014 DOI: 10.3390/ma15196696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/21/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
Results of acoustic emission (AE) measurements, carried out during plastic deformation of polycrystalline Sn samples, are analyzed by the adaptive sequential k-means method. The acoustic avalanches, originating from different sources, are separated on the basis of their spectral properties, that is, sorted into clusters, presented both on the so-called feature space (energy-median frequency plot) and on the power spectral density (PSD) curves. We found that one cluster in every measurement belongs to background vibrations, while the remaining ones are clearly attributed to twinning as well as dislocation slips at −30 °C and 25 °C, respectively. Interestingly, fingerprints of the well-known “ringing” of AE signals are present in different weights on the PSD curves. The energy and size distributions of the avalanches, corresponding to twinning and dislocation slips, show a bit different power-law exponents from those obtained earlier by fitting all AE signals without cluster separation. The maximum-likelihood estimation of the avalanche energy (ε) and size (τ) exponents provide ε=1.57±0.05 (at −30 °C) and ε=1.35±0.1 (at 25 °C), as well as τ=1.92±0.05 (at −30 °C) and τ= 1.55±0.1 (at 25 °C). The clustering analysis provides not only a manner to eliminate the background noise, but the characteristic avalanche shapes are also different for the two mechanisms, as it is visible on the PSD curves. Thus, we have illustrated that this clustering analysis is very useful in discriminating between different AE sources and can provide more realistic estimates, for example, for the characteristic exponents as compared to the classical hit-based approach where the exponents reflect an average value, containing hits from the low-frequency mechanical vibrations of the test machine, too.
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Affiliation(s)
- László Z. Tóth
- Department of Solid State Physics, University of Debrecen, P.O. Box 400, H-4002 Debrecen, Hungary
| | - Lajos Daróczi
- Department of Solid State Physics, University of Debrecen, P.O. Box 400, H-4002 Debrecen, Hungary
| | - Tarek Y. Elrasasi
- Department of Physics, Faculty of Science, Benha University, Benha 13518, Egypt
| | - Dezső L. Beke
- Department of Solid State Physics, University of Debrecen, P.O. Box 400, H-4002 Debrecen, Hungary
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10
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Kocsis B, Lee MK, Yu JH, Nagy T, Daróczi L, Batta G, Pócsi I, Leiter É. Functional analysis of the bZIP-type transcription factors AtfA and AtfB in Aspergillus nidulans. Front Microbiol 2022; 13:1003709. [PMID: 36204617 PMCID: PMC9530789 DOI: 10.3389/fmicb.2022.1003709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
Transcription factors (TFs) with the basic leucin zipper domain are key elements of the stress response pathways in filamentous fungi. In this study, we functionally characterized the two bZIP type TFs AtfA and AtfB by deletion (Δ) and overexpression (OE) of their encoding genes in all combination: ΔatfA, ΔatfB, ΔatfAΔatfB, ΔatfAatfBOE, ΔatfBatfAOE, atfAOE, atfBOE and atfAOEatfBOE in Aspergillus nidulans. Based on our previous studies, ΔatfA increased the sensitivity of the fungus to oxidative stress mediated by menadione sodium bisulfite (MSB) and tert-butylhydroperoxide (tBOOH), while ΔatfB was not sensitive to any oxidative stress generating agents, namely MSB, tBOOH and diamide at all. Contrarily, the ΔatfB mutant was sensitive to NaCl, but tolerant to sorbitol. Overexpression of atfB was able to compensate the MSB sensitivity of the ΔatfA mutant. Heavy metal stress elicited by CdCl2 reduced diameter of the atfBOE and atfAOEatfBOE mutant colonies to about 50% of control colony, while the cell wall stress generating agent CongoRed increased the tolerance of the ΔatfA mutant. When we tested the heat stress sensitivity of the asexual spores (conidiospores) of the mutants, we found that conidiospores of ΔatfAatfBOE and ΔatfBatfAOE showed nearly 100% tolerance to heat stress. Asexual development was negatively affected by ΔatfA, while atfAOE and atfAOE coupled with ΔatfB increased the number of conidiospores of the fungus approximately 150% compared to the control. Overexpression of atfB led to a 25% reduction in the number of conidiospores, but increased levels of abaA mRNA and size of conidiospores. Sexual fruiting body (cleistothecium) formation was diminished in the ΔatfA and the ΔatfAΔatfB mutants, while relatively elevated in the ΔatfB and the ΔatfBatfAOE mutants. Production of the mycotoxin sterigmatocystin (ST) was decreased to undetectable levels in the ΔatfA mutant, yet ST production was restored in the ΔatfAΔatfB mutant, suggesting that ΔatfB can suppress ST production defect caused by ΔatfA. Levels of ST were also significantly decreased in the ΔatfAatfBOE, ΔatfBatfAOE and atfAOEatfBOE mutants.
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Affiliation(s)
- Beatrix Kocsis
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary
- Doctoral School of Pharmaceutical Sciences, University of Debrecen, Debrecen, Hungary
| | - Mi-Kyung Lee
- Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup-si, South Korea
| | - Jae-Hyuk Yu
- Department of Bacteriology, Food Research Institute, University of Wisconsin, Madison, WI, United States
- Department of Systems Biotechnology, Konkuk University, Seoul, South Korea
| | - Tibor Nagy
- Department of Applied Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Lajos Daróczi
- Department of Solid State Physics, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Gyula Batta
- Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary
| | - Éva Leiter
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary
- *Correspondence: Éva Leiter,
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11
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Kordován MÁ, Hegedűs C, Czifrák K, Lakatos C, Kálmán-Szabó I, Daróczi L, Zsuga M, Kéki S. Novel Polyurethane Scaffolds Containing Sucrose Crosslinker for Dental Application. Int J Mol Sci 2022; 23:ijms23147904. [PMID: 35887250 PMCID: PMC9319899 DOI: 10.3390/ijms23147904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 07/14/2022] [Accepted: 07/16/2022] [Indexed: 02/05/2023] Open
Abstract
In this paper, the synthesis, characterization, and properties of crosslinked poly(ε-caprolactone)-based polyurethanes as potential tissue replacement materials are reported. The polyurethane prepolymers were prepared from poly(ε-caprolactone)diol (PCD), polyethylene glycol (PEG)/polylactic acid diol (PLAD), and 1,6-hexamethylene diisocyanate (HDI). In these segmented polyurethanes, the role of PEG/PLAD was to tune the hydrophobic/hydrophilic character of the resulting polymer while sucrose served as a crosslinking agent. PLAD was synthesized by the polycondensation reaction of D,L-lactic acid and investigated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and nuclear magnetic resonance spectroscopy (NMR). The crosslinked polyurethane samples (SUPURs) obtained were characterized by attenuated total reflectance Fourier-transform infrared spectroscopy (AT-FT-IR), swelling, and mechanical (uniaxial tensile tests) experiments. The thermo and thermomechanical behavior were studied by differential scanning calorimetry (DSC) and dynamical mechanical analysis (DMA). The viability of dental pulp stem cells was investigated in the case of polyurethanes composed of fully biocompatible elements. In our studies, none of our polymers showed toxicity to stem cells (DPSCs).
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Affiliation(s)
- Marcell Árpád Kordován
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (M.Á.K.); (K.C.); (C.L.); (M.Z.)
- Doctoral School of Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Csaba Hegedűs
- Department of Prosthetic Dentistry and Biomaterials, Faculty of Dentistry, University of Debrecen, H-4012 Debrecen, Hungary; (C.H.); (I.K.-S.)
| | - Katalin Czifrák
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (M.Á.K.); (K.C.); (C.L.); (M.Z.)
| | - Csilla Lakatos
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (M.Á.K.); (K.C.); (C.L.); (M.Z.)
| | - Ibolya Kálmán-Szabó
- Department of Prosthetic Dentistry and Biomaterials, Faculty of Dentistry, University of Debrecen, H-4012 Debrecen, Hungary; (C.H.); (I.K.-S.)
| | - Lajos Daróczi
- Department of Solid State Physics, University of Debrecen, Bem tér 18/b, H-4026 Debrecen, Hungary;
| | - Miklós Zsuga
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (M.Á.K.); (K.C.); (C.L.); (M.Z.)
| | - Sándor Kéki
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (M.Á.K.); (K.C.); (C.L.); (M.Z.)
- Correspondence: ; Tel.: +36-52-512-900 (ext. 22455)
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12
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Lakatos C, Kordován MÁ, Czifrák K, Nagy L, Vadkerti B, Daróczi L, Zsuga M, Kéki S. Synthesis of Sucrose-HDI Cooligomers: New Polyols for Novel Polyurethane Networks. Int J Mol Sci 2022; 23:ijms23031444. [PMID: 35163372 PMCID: PMC8836168 DOI: 10.3390/ijms23031444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/24/2022] [Accepted: 01/25/2022] [Indexed: 02/04/2023] Open
Abstract
Sucrose-1,6-hexamethylene diisocyanate (HDI) cooligomers were synthesized and used as new polyols for poly(ε-caprolactone) (PCL)-based polyurethanes. The polyaddition reaction of sucrose and HDI was monitored by MALDI-TOF MS. It was found that by selecting appropriate reaction conditions, mostly linear oligomer chains containing 16 sucrose units could be obtained. For the synthesis of polyurethane networks, prepolymers were prepared by the reaction of poly(ε-caprolactone) (PCL, 10 kg/mol) with HDI or 4,4′-methylene diphenyl diisocyanate (MDI) and were reacted with sucrose-HDI cooligomers. The so-obtained sucrose-containing polyurethanes were characterized by means of attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FT IR), swelling, mechanical (uniaxial tensile tests) and differential scanning calorimetry (DSC).
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Affiliation(s)
- Csilla Lakatos
- Department of Applied Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (C.L.); (M.Á.K.); (K.C.); (L.N.); (B.V.); (M.Z.)
| | - Marcell Árpád Kordován
- Department of Applied Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (C.L.); (M.Á.K.); (K.C.); (L.N.); (B.V.); (M.Z.)
- Doctoral School of Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Katalin Czifrák
- Department of Applied Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (C.L.); (M.Á.K.); (K.C.); (L.N.); (B.V.); (M.Z.)
| | - Lajos Nagy
- Department of Applied Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (C.L.); (M.Á.K.); (K.C.); (L.N.); (B.V.); (M.Z.)
| | - Bence Vadkerti
- Department of Applied Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (C.L.); (M.Á.K.); (K.C.); (L.N.); (B.V.); (M.Z.)
- Doctoral School of Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Lajos Daróczi
- Department of Solid State Physics, Faculty of Science and Technology, University of Debrecen, Bem tér 18/b, H-4026 Debrecen, Hungary;
| | - Miklós Zsuga
- Department of Applied Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (C.L.); (M.Á.K.); (K.C.); (L.N.); (B.V.); (M.Z.)
| | - Sándor Kéki
- Department of Applied Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (C.L.); (M.Á.K.); (K.C.); (L.N.); (B.V.); (M.Z.)
- Correspondence: ; Tel.: +36-52-512-900 (ext. 22455)
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13
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Boczonádi I, Jakab Á, Baranyai E, Tóth CN, Daróczi L, Csernoch L, Kis G, Antal M, Pusztahelyi T, Grawunder A, Merten D, Emri T, Fábián I, Kothe E, Pócsi I. Rare earth element sequestration by Aspergillus oryzae biomass. Environ Technol 2021; 42:3725-3735. [PMID: 32134365 DOI: 10.1080/09593330.2020.1739146] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 03/02/2020] [Indexed: 06/10/2023]
Abstract
The fungus Aspergillus oryzae could be shown to be a viable alternative for biosorption of valuable metals from solution. Fungal biomass can be obtained easily in high quantities as a waste of biofermentation processes, and used in a complex, multi-phase solution mimicking naturally occurring, mining-affected water samples. With test solution formulated after natural conditions, formation of secondary Al and Fe phases co-precipitating Ce was recorded in addition to specific biosorption of rare earth elements. Remarkably, the latter were removed from the solution despite the presence of high concentrations of interfering Fe and Al. The biomass was viable even after prolonged incubation in the metal solution, and minimal inhibitory concentrations for single metals were higher than those in the test solution. While precipitation/biosorption of Ce (maximal biosorption efficiency was 58.0 ± 22.3% after 6 h of incubation) coincided with the gross removal of Fe from the metal solution, Y (81.5 ± 11.3% efficiency, 24 h incubation) and Nd (87.4 ± 9.1% efficiency, 24 h incubation) were sequestered later, similarly to Ni and Zn. The biphasic binding pattern specific to single metals could be connected to dynamically changing pH and NH4+ concentrations, which were attributed to the physiological changes taking place in starving A. oryzae biomass. The metals were found extracellularly in minerals associated with the cell wall, and intracellularly precipitated in the vacuoles. The latter process was explained with intracellular metal detoxification resulting in metal resistance.
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Affiliation(s)
- Imre Boczonádi
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- Juhász-Nagy Pál Doctoral School, University of Debrecen, Debrecen, Hungary
| | - Ágnes Jakab
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Edina Baranyai
- Department of Inorganic and Analytical Chemistry, Agilent Atomic Spectroscopy Partner Laboratory, University of Debrecen, Debrecen, Hungary
| | - Csilla Noémi Tóth
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary
| | - Lajos Daróczi
- Department of Solid State Physics, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - László Csernoch
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gréta Kis
- Department of Anatomy, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Miklós Antal
- Department of Anatomy, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tünde Pusztahelyi
- Central Laboratory of Agricultural and Food Products, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, Debrecen, Hungary
| | - Anja Grawunder
- Institute of Geosciences, Faculty of Chemistry and Earth Sciences, Friedrich Schiller University, Jena, Germany
| | - Dirk Merten
- Institute of Geosciences, Faculty of Chemistry and Earth Sciences, Friedrich Schiller University, Jena, Germany
| | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - István Fábián
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary
- MTA-DE Redox and Homogeneous Catalytic Reaction Mechanisms Research Group
| | - Erika Kothe
- Institute of Microbiology, Faculty for Bioscience, Friedrich Schiller University, Jena, Germany
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
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14
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Nagy F, Tóth Z, Daróczi L, Székely A, Borman AM, Majoros L, Kovács R. Farnesol increases the activity of echinocandins against Candida auris biofilms. Med Mycol 2020; 58:404-407. [PMID: 31127836 DOI: 10.1093/mmy/myz057] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 05/02/2019] [Accepted: 05/07/2019] [Indexed: 11/13/2022] Open
Abstract
Candida auris biofilms exhibit decreased susceptibility to echinocandins, which is associated with poorer clinical outcomes. Farnesol is a quorum-sensing molecule enhancing the activity of antifungals; therefore, we evaluated the in vitro effect of farnesol with anidulafungin, caspofungin, or micafungin against biofilms using fractional inhibitory concentration indexes (FICI), Bliss independence model, LIVE/DEAD-assay and scanning electron microscopy. Based on mathematical models, farnesol caused synergism in eleven out of twelve cases (FICIs range 0.133-0.507; Bliss synergy volume range 70.39-204.6 μM2%). This was confirmed by microscope images of combination-exposed biofilms. Our study showed the prominent effect of farnesol with echinocandins against C. auris biofilms.
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Affiliation(s)
- Fruzsina Nagy
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Nagyerdei krt. 98., Hungary
| | - Zoltán Tóth
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Nagyerdei krt. 98., Hungary
| | - Lajos Daróczi
- Department of Solid State Physics, Faculty of Science and Technology, University of Debrecen, Hungary
| | - Adrien Székely
- Public Health England UK National Mycology Reference Laboratory, Bristol, United Kingdom
| | - Andrew M Borman
- Public Health England UK National Mycology Reference Laboratory, Bristol, United Kingdom
| | - László Majoros
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Nagyerdei krt. 98., Hungary
| | - Renátó Kovács
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Nagyerdei krt. 98., Hungary.,Faculty of Pharmacy, University of Debrecen, Debrecen, 4032 Debrecen, Nagyerdei krt 98. Hungary
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15
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Czifrák K, Lakatos C, Árpád Kordován M, Nagy L, Daróczi L, Zsuga M, Kéki S. Block Copolymers of Poly(ω-Pentadecalactone) in Segmented Polyurethanes: Novel Biodegradable Shape Memory Polyurethanes. Polymers (Basel) 2020; 12:polym12091928. [PMID: 32859018 PMCID: PMC7563291 DOI: 10.3390/polym12091928] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/21/2020] [Accepted: 08/22/2020] [Indexed: 11/18/2022] Open
Abstract
In this report, the synthesis of poly(ω-pentadecalactone) (PPDL) (co)polymers and their incorporation into polyurethanes (PUs) are reported. Optimal conditions for the ring-opening polymerization (ROP) of ω-pentadecalactone (PDL) using dibutyltin dilaurate catalyst were established. For the synthesis of linear and crosslinked PUs, 50 kDa poly(ε-caprolactone) (PCL) and 1,6-hexamethylenediisocyanate (HDI) were used. The obtained polyurethanes were characterized by Attenuated Total Reflectance Fourier-Transform Infrared spectroscopy (AT-FTIR), differential scanning calorimetry (DSC), and dynamical mechanical analysis (DMA). The DMA of the selected sample showed a rubbery plateau on the storage modulus versus temperature curve predicting shape memory behavior. Indeed, good shape memory performances were obtained with shape fixity (Rf) and shape recovery (Rr) ratios.
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Affiliation(s)
- Katalin Czifrák
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (K.C.); (C.L.); (M.Á.K.); (L.N.); (M.Z.)
| | - Csilla Lakatos
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (K.C.); (C.L.); (M.Á.K.); (L.N.); (M.Z.)
| | - Marcell Árpád Kordován
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (K.C.); (C.L.); (M.Á.K.); (L.N.); (M.Z.)
| | - Lajos Nagy
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (K.C.); (C.L.); (M.Á.K.); (L.N.); (M.Z.)
| | - Lajos Daróczi
- Department of Solid State Physics, University of Debrecen, Bem tér 18/b, H-4026 Debrecen, Hungary;
| | - Miklós Zsuga
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (K.C.); (C.L.); (M.Á.K.); (L.N.); (M.Z.)
| | - Sándor Kéki
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (K.C.); (C.L.); (M.Á.K.); (L.N.); (M.Z.)
- Correspondence: ; Tel.: +36-52-512-900 (ext. 22455)
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16
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Tóth LZ, Daróczi L, Panchenko E, Chumlyakov Y, Beke DL. Acoustic Emission Characteristics and Change the Transformation Entropy after Stress-Induced Martensite Stabilization in Shape Memory Ni 53Mn 25Ga 22 Single Crystal. Materials (Basel) 2020; 13:E2174. [PMID: 32397316 PMCID: PMC7254387 DOI: 10.3390/ma13092174] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/24/2020] [Accepted: 05/06/2020] [Indexed: 11/16/2022]
Abstract
Measurements have been carried out to compare stress-induced martensite stabilization aged (SIM-aged) and as grown shape memory Ni53Mn25Ga22 single crystals with the means of simultaneous differential scanning calorimetry (DSC) and acoustic emission (AE). Contrary to expectations, the position of the hysteresis practically did not change, whilst the width of the hysteresis increased, and the forward and reverse transitions became sharper in the SIM-aged sample. The energy distributions of acoustic hits showed regular power law behaviour and the energy exponents were slightly different for heating and cooling; this asymmetry had different signs for the SIM-aged and as grown samples. During heating, in accordance with the sharper transitions observed in the DSC runs, two well-marked jumps could be seen on the plot of cumulative number of the acoustic emission events. Therefore, these were attributed to high sudden jumps in the phase transition during heating observed in the DSC. The effect of the SIM-aging on the transformation entropy was also investigated and it was found that it was about 36% less in the case of the SIM-aged sample.
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Affiliation(s)
- László Zoltán Tóth
- Department of Solid State Physics, University of Debrecen. P. O. Box 400, H-4002 Debrecen, Hungary; (L.Z.T.); (L.D.)
| | - Lajos Daróczi
- Department of Solid State Physics, University of Debrecen. P. O. Box 400, H-4002 Debrecen, Hungary; (L.Z.T.); (L.D.)
| | - Elena Panchenko
- Siberian Physical Technical Institute, Tomsk State University, Tomsk 634050, Russia; (E.P.); (Y.C.)
| | - Yuri Chumlyakov
- Siberian Physical Technical Institute, Tomsk State University, Tomsk 634050, Russia; (E.P.); (Y.C.)
| | - Dezső László Beke
- Department of Solid State Physics, University of Debrecen. P. O. Box 400, H-4002 Debrecen, Hungary; (L.Z.T.); (L.D.)
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Nagy F, Bozó A, Tóth Z, Daróczi L, Majoros L, Kovács R. In vitro antifungal susceptibility patterns of planktonic and sessile Candida kefyr clinical isolates. Med Mycol 2019; 56:493-500. [PMID: 28992253 DOI: 10.1093/mmy/myx062] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Accepted: 07/13/2017] [Indexed: 12/25/2022] Open
Abstract
The activity of fluconazole, amphotericin B, caspofungin and micafungin was determined using XTT-based fungal damage assays against planktonic cells, early and mature biofilms of Candida kefyr. Median MICs of planktonic cells were 0.25 mg/l, 0.25 mg/l, 0.5 mg/l, and 0.06 mg/l for fluconazole, amphotericin B, caspofungin, and micafungin, respectively. Fluconazole showed at least 50% fungal damage at ≥4 mg/l (51.5% ± 6.63% to 78.38% ± 1.44%) and at ≥128 mg/l (57.88% ± 9.2% to 67.25% ± 9.59%), while amphotericin B produced an even higher anti-biofilm effect at ≥0.5 mg/l (64.63% ± 6.79% to 79.5% ± 5.9%) and at ≥0.12 mg/l (77.63% ± 8.43% to 92.75% ± 1.89%) against early and mature biofilms, respectively. In case of micafungin, 50% fungal damage was observed at ≥0.06 mg/l (66.88% ± 10.16% to 98.63% ± 1.24%) and ≥0.25 mg/l (74.13% ± 10.77% to 99.38% ± 0.38%) for early and mature biofilms, respectively. Caspofungin-exposed cells showed an unexpected susceptibility pattern, that is, planktonic cells showed significantly decreased susceptibility at concentrations ranging from 0.015 mg/l to 1 mg/l compared to biofilms (P < .05-.01). The damage in planktonic cells and biofilms was comparable at higher concentrations. For planktonic cells and biofilms, 50% fungal damage was observed first at 0.5 mg/l (59.75% ± 3.16%) and at 0.06 mg/l (70.25% ± 10.95%), respectively. This unexpected pattern was confirmed using scanning electron microscopy. The unusual susceptibility pattern observed at lower caspofungin concentrations may explain the poorer outcome of caspofungin-treated C. kefyr infections documented in certain patient populations. As this phenomenon was markedly less apparent in case of micafungin, these data suggest that micafungin may be a more reliable option than caspofungin for the treatment of C. kefyr infections.
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Affiliation(s)
- Fruzsina Nagy
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Hungary
| | - Aliz Bozó
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Hungary
| | - Zoltán Tóth
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Hungary
| | - Lajos Daróczi
- Department of Solid State Physics, Faculty of Science and Technology, University of Debrecen, Hungary
| | - László Majoros
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Hungary
| | - Renátó Kovács
- Department of Medical Microbiology, Faculty of Medicine, University of Debrecen, Hungary.,Faculty of Pharmacy, University of Debrecen, Hungary
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18
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Fazekas L, Ghimessy Á, Gieszer B, Radeczky P, Mészáros L, Török K, Bogyó L, Hartyánszky I, Pólos M, Daróczi L, Agócs L, Kocsis Á, Bartók T, Dancs T, Tóth KK, Schönauer N, Madurka I, Elek J, Döme B, Rényi-Vámos F, Lang G, Farkas A. Lung Transplantation in Hungary From Cardiac Surgeons' Perspective. Transplant Proc 2019; 51:1263-1267. [DOI: 10.1016/j.transproceed.2019.04.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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19
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Kiss A, Naár Z, Daróczi L, Kukovics S, Kukovics F, Mirmazloum I, Némedi E. Changes of free fatty acid composition and number of lactic acid bacteria in three functional goat and sheep milk products fortified with inulin or fish oil. CyTA - Journal of Food 2019. [DOI: 10.1080/19476337.2018.1551936] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Attila Kiss
- Food Science Innovation Centre, Kaposvár University, Kaposvár, Hungary
| | - Zoltán Naár
- National Agricultural Research and Innovation Centre, Food Science Research Institute, Budapest, Hungary
| | | | - Sándor Kukovics
- Hungarian Sheep and Goat Dairying Public Utility Association, Herceghalom, Hungary
| | - Ferenc Kukovics
- Hungarian Sheep and Goat Dairying Public Utility Association, Herceghalom, Hungary
| | - Iman Mirmazloum
- Food Science Innovation Centre, Kaposvár University, Kaposvár, Hungary
- Department of Plant Physiology and Plant Biochemistry, Szent István University, Budapest, Hungary
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20
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Józsa G, Szegeczki V, Pálfi A, Kiss T, Helyes Z, Fülöp B, Cserháti C, Daróczi L, Tamás A, Zákány R, Reglődi D, Juhász T. Signalling Alterations in Bones of Pituitary Adenylate Cyclase Activating Polypeptide (PACAP) Gene Deficient Mice. Int J Mol Sci 2018; 19:ijms19092538. [PMID: 30150589 PMCID: PMC6163297 DOI: 10.3390/ijms19092538] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/10/2018] [Accepted: 08/24/2018] [Indexed: 12/15/2022] Open
Abstract
Pituitary adenylate cyclase activating polypeptide (PACAP) is a neuropeptide with diverse developmental roles, including differentiation of skeletal elements. It is a positive regulatory factor of chondrogenesis and osteogenic differentiation in vitro, but little is known about its in vivo role in bone formation. In our experiments, diaphyses of long bones from hind limbs of PACAP gene-deficient mice showed changes in thickness and increased staining intensity. Our main goal was to perform a detailed morphological and molecular biological analysis of femurs from PACAP knockout (KO) and wild type (WT) mice. Transverse diameter and anterior cortical bone thickness of KO femurs showed significant alterations with disturbed Ca2+ accumulation and collagen type I expression. Higher expression and activity of alkaline phosphatase were also observed, accompanied by increased fragility PACAP KO femurs. Increased expression of the elements of bone morphogenic protein (BMP) and hedgehog signalling was also observed, and are possibly responsible for the compensation mechanism accounting for the slight morphological changes. In summary, our results show that lack of PACAP influences molecular and biomechanical properties of bone matrix, activating various signalling cascade changes in a compensatory fashion. The increased fragility of PACAP KO femur further supports the role of endogenous PACAP in in vivo bone formation.
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Affiliation(s)
- Gergő Józsa
- Department of Anatomy, MTA-PTE PACAP Research Team, University of Pécs Medical School, Szigeti út 12, H-7624 Pécs, Hungary.
| | - Vince Szegeczki
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdeikrt. 98, H-4032 Debrecen, Hungary.
| | - Andrea Pálfi
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdeikrt. 98, H-4032 Debrecen, Hungary.
| | - Tamás Kiss
- Department of Pharmacology and Pharmacotherapy, University of Pécs Medical School, Szigeti út 12, H-7624 Pécs, Hungary.
| | - Zsuzsanna Helyes
- Department of Pharmacology and Pharmacotherapy, University of Pécs Medical School, Szigeti út 12, H-7624 Pécs, Hungary.
| | - Balázs Fülöp
- Department of Anatomy, MTA-PTE PACAP Research Team, University of Pécs Medical School, Szigeti út 12, H-7624 Pécs, Hungary.
| | - Csaba Cserháti
- Department of Solid State Physics, University of Debrecen, Bem tér 18/b, H-4026 Debrecen, Hungary.
| | - Lajos Daróczi
- Department of Solid State Physics, University of Debrecen, Bem tér 18/b, H-4026 Debrecen, Hungary.
| | - Andrea Tamás
- Department of Anatomy, MTA-PTE PACAP Research Team, University of Pécs Medical School, Szigeti út 12, H-7624 Pécs, Hungary.
| | - Róza Zákány
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdeikrt. 98, H-4032 Debrecen, Hungary.
| | - Dóra Reglődi
- Department of Anatomy, MTA-PTE PACAP Research Team, University of Pécs Medical School, Szigeti út 12, H-7624 Pécs, Hungary.
| | - Tamás Juhász
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Nagyerdeikrt. 98, H-4032 Debrecen, Hungary.
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21
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Czifrák K, Lakatos C, Karger-Kocsis J, Daróczi L, Zsuga M, Kéki S. One-Pot Synthesis and Characterization of Novel Shape-Memory Poly(ε-Caprolactone) Based Polyurethane-Epoxy Co-networks with Diels⁻Alder Couplings. Polymers (Basel) 2018; 10:E504. [PMID: 30966538 PMCID: PMC6415404 DOI: 10.3390/polym10050504] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Revised: 05/02/2018] [Accepted: 05/03/2018] [Indexed: 12/02/2022] Open
Abstract
The present work aimed at the preparation and investigation of different epoxy-polyurethane (EP-PU) co-networks. The EP-PU co-networks were obtained by applying two different synthetic strategies, in which the coupling element, the Diels⁻Alder (DA) adduct, was prepared previously or formed "in situ" in the reaction between furan functionalized polyurethane and furfuryl amine-diglycidyl ether bisphenol-A oligomers (FA_DGEBA). For the synthesis of these EP-PU networks, poly(ε-caprolactone)-diol (PCD, Mn = 2 kg/mol) and poly(ε-caprolactone) (PCL) with different molecular weights (Mn = 10, 25 and 50 kg/mol) and 1,6-hexamethylenediisocyanate (HDI) were used. The EP-PU co-networks were characterized by Attenuated Total Reflectance Fourier-Transform Infrared spectroscopy (AT-FT-IR), differential scanning calorimetry (DSC) and dynamical mechanical analysis (DMA). Scanning electron microscopy (SEM) was applied to assess the morphology of the EP-PU samples. It was demonstrated that the stress⁻strain curves for the EP-PUs could be interpreted based on the Standard Linear Solid (SLS) model. The DMA traces of some EP-PUs (depending on the composition and the synthetic method) revealed a plateau-like region above the melting temperature (Tm) of PCL confirming the presence of cross-linked structure. This feature predicted shape memory (SM) behavior for these EP-PU samples. Indeed, very good shape fixity and moderate shape recovery were obtained. The shape recovery processes of these EP-PU samples were described using double exponential decay functions.
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Affiliation(s)
- Katalin Czifrák
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary.
| | - Csilla Lakatos
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary.
| | - József Karger-Kocsis
- Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3, H-1111 Budapest, Hungary.
- MTA⁻BME Research Group for Composite Science and Technology, Műegyetem rkp. 3, H-1111 Budapest, Hungary.
| | - Lajos Daróczi
- Department of Solid State Physics, University of Debrecen, Bem tér 18/b, H-4026 Debrecen, Hungary.
| | - Miklós Zsuga
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary.
| | - Sándor Kéki
- Department of Applied Chemistry, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary.
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22
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Kovács R, Tóth Z, Nagy F, Daróczi L, Bozó A, Majoros L. Activity of exogenous tyrosol in combination with caspofungin and micafungin against Candida parapsilosis
sessile cells. J Appl Microbiol 2017; 122:1529-1536. [DOI: 10.1111/jam.13452] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 01/30/2017] [Accepted: 03/15/2017] [Indexed: 12/11/2022]
Affiliation(s)
- R. Kovács
- Department of Medical Microbiology; Faculty of Medicine; University of Debrecen; Debrecen Hungary
| | - Z. Tóth
- Department of Medical Microbiology; Faculty of Medicine; University of Debrecen; Debrecen Hungary
| | - F. Nagy
- Department of Medical Microbiology; Faculty of Medicine; University of Debrecen; Debrecen Hungary
| | - L. Daróczi
- Department of Solid State Physics; Faculty of Science and Technology; University of Debrecen; Debrecen Hungary
| | - A. Bozó
- Department of Medical Microbiology; Faculty of Medicine; University of Debrecen; Debrecen Hungary
| | - L. Majoros
- Department of Medical Microbiology; Faculty of Medicine; University of Debrecen; Debrecen Hungary
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23
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Hunyadi M, Gácsi Z, Csarnovics I, Csige L, Csik A, Daróczi L, Huszánk R, Szűcs Z. Enhanced growth of tellurium nanowires under conditions of macromolecular crowding. Phys Chem Chem Phys 2017; 19:16477-16484. [DOI: 10.1039/c7cp01011g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The time-evolution of the mean excitonic wavelength demonstrating the enhanced ripening and growth rates of tellurium nanowires at increasing concentrations of the PVP crowder.
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Affiliation(s)
- Mátyás Hunyadi
- Institute for Nuclear Research
- Hungarian Academy of Sciences
- 4026 Debrecen
- Hungary
| | - Zoltán Gácsi
- Institute for Nuclear Research
- Hungarian Academy of Sciences
- 4026 Debrecen
- Hungary
| | - István Csarnovics
- Department of Experimental Physics
- Debrecen University
- 4026 Debrecen
- Hungary
| | - Lóránt Csige
- Institute for Nuclear Research
- Hungarian Academy of Sciences
- 4026 Debrecen
- Hungary
| | - Attila Csik
- Institute for Nuclear Research
- Hungarian Academy of Sciences
- 4026 Debrecen
- Hungary
| | - Lajos Daróczi
- Department of Solid State Physics
- Debrecen University
- 4026 Debrecen
- Hungary
| | - Róbert Huszánk
- Institute for Nuclear Research
- Hungarian Academy of Sciences
- 4026 Debrecen
- Hungary
| | - Zoltán Szűcs
- Institute for Nuclear Research
- Hungarian Academy of Sciences
- 4026 Debrecen
- Hungary
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24
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Lakatos C, Czifrák K, Karger-Kocsis J, Daróczi L, Zsuga M, Kéki S. Shape memory crosslinked polyurethanes containing thermoreversible Diels-Alder couplings. J Appl Polym Sci 2016. [DOI: 10.1002/app.44145] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Csilla Lakatos
- Department of Applied Chemistry; University of Debrecen; Egyetem tér 1 H-4032 Debrecen Hungary
| | - Katalin Czifrák
- Department of Applied Chemistry; University of Debrecen; Egyetem tér 1 H-4032 Debrecen Hungary
| | - József Karger-Kocsis
- Department of Polymer Engineering; Budapest University of Technology and Economics; Műegyetem rkp. 3 H-1111 Budapest Hungary
| | - Lajos Daróczi
- Department of Solid State Physics; University of Debrecen; Bem tér 18/b H-4026 Debrecen Hungary
| | - Miklós Zsuga
- Department of Applied Chemistry; University of Debrecen; Egyetem tér 1 H-4032 Debrecen Hungary
| | - Sándor Kéki
- Department of Applied Chemistry; University of Debrecen; Egyetem tér 1 H-4032 Debrecen Hungary
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25
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Czifrák K, Karger-Kocsis J, Daróczi L, Zsuga M, Kéki S. Poly(ε-caprolactone) and Pluronic Diol-Containing Segmented Polyurethanes for Shape Memory Performance. MACROMOL CHEM PHYS 2014. [DOI: 10.1002/macp.201400237] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Katalin Czifrák
- Department of Applied Chemistry; University of Debrecen; Egyetem tér1 H-4032 Debrecen Hungary
| | - József Karger-Kocsis
- Department of Polymer Engineering; Budapest University of Technology and Economics; Mu˝egyetem rkp. 3 H-1111 Budapest Hungary
| | - Lajos Daróczi
- Department of Solid State Physics; University of Debrecen; Bem tér 18/b H-4026 Debrecen Hungary
| | - Miklós Zsuga
- Department of Applied Chemistry; University of Debrecen; Egyetem tér1 H-4032 Debrecen Hungary
| | - Sándor Kéki
- Department of Applied Chemistry; University of Debrecen; Egyetem tér1 H-4032 Debrecen Hungary
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26
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Katona B, Daróczi L, Jenei A, Bakó J, Hegedus C. [Comperative study of implant surface characteristics]. Fogorv Sz 2013; 106:135-143. [PMID: 24551957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The osseointegration between the implant and its' bone environment is very important. The implants shall meet the following requirements: biocompatibility, rigidity, resistance against corrosion and technical producibility. In our present study surface morphology and material characteristics of different implants (Denti Bone Level, Denti Zirconium C, Bionika CorticaL, Straumann SLA, Straumann SLA Active, Dentsply Ankylos and Biotech Kontact implant) were investigated with scanning electron microscopy and energy-dispersive X-ray spectroscopy. The possible surface alterations caused by the manufacturing technology were also investigated. During grit-blasting the implants' surface is blasted with hard ceramic particles (titanium oxide, alumina, calcium phosphate). Properties of blasting material are critical because the osseointegration of dental implants should not be hampered. The physical and chemical features of blasting particles could importantly affect the produced surfaces of implants. Titanium surfaces with micro pits are created after immersion in mixtures of strong acids. On surfaces after dual acid-etching procedures the crosslinking between fibrin and osteogenetic cells could be enhanced therefore bone formation could be directly facilitated on the surface of the implant. Nowadays there are a number of surface modification techniques available. These can be used as a single method or in combination with each other. The effect of the two most commonly used surface modifications (acid-etching and grit-blasting) on different implants are demonstrated in our investigation.
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Affiliation(s)
- Bernadett Katona
- Debreceni Egyetem Orvos- és Egészségtudományi Centrum, Fogorvostudomanyi Kar Fogpótlástani Tanszék
| | | | - Attila Jenei
- Debreceni Egyetem Biofizika- és Sejtbiológia Intézet
| | - József Bakó
- Debreceni Egyetem Orvos- és Egészségtudományi Centrum, Fogorvostudomanyi Kar Fogpótlástani Tanszék
| | - Csaba Hegedus
- Debreceni Egyetem Orvos- és Egészségtudományi Centrum, Fogorvostudomanyi Kar Fogpótlástani Tanszék
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27
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Tollas S, Bereczki I, Sipos A, Rőth E, Batta G, Daróczi L, Kéki S, Ostorházi E, Rozgonyi F, Herczegh P. Nano-sized clusters of a teicoplanin ψ-aglycon-fullerene conjugate. Synthesis, antibacterial activity and aggregation studies. Eur J Med Chem 2012; 54:943-8. [DOI: 10.1016/j.ejmech.2012.06.054] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 06/15/2012] [Accepted: 06/27/2012] [Indexed: 10/28/2022]
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28
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Szoboszlai Z, Kertész Z, Szikszai Z, Angyal A, Furu E, Török Z, Daróczi L, Kiss AZ. Identification and chemical characterization of particulate matter from wave soldering processes at a printed circuit board manufacturing company. J Hazard Mater 2012; 203-204:308-16. [PMID: 22226723 DOI: 10.1016/j.jhazmat.2011.12.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 11/25/2011] [Accepted: 12/10/2011] [Indexed: 05/22/2023]
Abstract
In this case study, the elemental composition and mass size distribution of indoor aerosol particles were determined in a working environment where soldering of printed circuit boards (PCB) took place. Single particle analysis using ion and electron microscopy was carried out to obtain more detailed and reliable data about the origin of these particles. As a result, outdoor and indoor aerosol sources such as wave soldering, fluxing processes, workers' activity, mineral dust, biomass burning, fertilizing and other anthropogenic sources could be separated. With the help of scanning electron microscopy, characteristic particle types were identified. On the basis of the mass size distribution data, a stochastic lung deposition model was used to calculate the total and regional deposition efficiencies of the different types of particles within the human respiratory system. The information presented in this study aims to give insights into the detailed characteristics and the health impact of aerosol particles in a working environment where different kinds of soldering activity take place.
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Affiliation(s)
- Z Szoboszlai
- Institute of Nuclear Research of Hungarian Academy of Sciences (ATOMKI), H-4001 Debrecen, P.O. Box 51, Hungary.
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Nagy M, Rácz D, Daróczi L, Lukács B, Jóna I, Zsuga M, Kéki S. Synthesis and Characterization of an Amphiphilic Blue-Light-Emitting Glycosylated Poly(naphthalene/phenylene) Copolymer. MACROMOL CHEM PHYS 2011. [DOI: 10.1002/macp.201100091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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30
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Szarvas M, Oparaugo P, Udvardy ML, Tóth J, Szántó T, Daróczi L, Vereb G, Hársfalvi J. Differential platelet deposition onto collagen in cone-and-plate and parallel plate flow chambers. Platelets 2009; 17:185-90. [PMID: 16702046 DOI: 10.1080/09537100500437638] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
To routinely test the formation of thrombi and the effect of drugs modifying it, proper test systems are needed. Their design should rely on the laws of rheology and the physiology of laminar flow. To best model physiological or pathological shear conditions, parallel/linear and rotational type flow chambers are developed. We have compared the initial phase of platelet thrombus formation in a parallel plate flow chamber (PPC) and a cone-and-plate chamber (CPC) under von Willebrand dependent shear conditions. Blood was allowed to flow through human collagen type III surfaces at a shear rate of 1000 s(-1) for 150 s. Thrombus deposition was characterized by surface coverage, average area and height of thrombi. VWF distribution within thrombi was analyzed with confocal laser scanning microscopy. Reduced surface-specific platelet adhesion and aggregation (surface coverage and average thrombus size) were observed in CPC along with a significant increase in single platelet disappearance from the circulating blood. Our data suggest that the higher rate of platelet consumption in this device, as opposed to PPC, is limiting the adhesion to the surface. Consequently, surface-specific processes and aggregation in the flowing blood are both assessed using CPC, while comprehensive evaluation of surface-specific processes is best achieved with PPC. Therefore, the choice of chamber type as a diagnostic tool is purpose-dependent.
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Affiliation(s)
- Mariann Szarvas
- Clinical Research Center, University of Debrecen, Debrecen, Hungary
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Bodnár M, Daróczi L, Batta G, Bakó J, Hartmann JF, Borbély J. Preparation and characterization of cross-linked hyaluronan nanoparticles. Colloid Polym Sci 2009. [DOI: 10.1007/s00396-009-2061-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Chobola R, Chobola R, Mell P, Mell P, Daróczi L, Daróczi L, Vincze A, Vincze A. Rapid determination of radiostrontium isotopes in samples of NPP origin. J Radioanal Nucl Chem 2006. [DOI: 10.1007/s10967-006-0044-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Hegedus C, Lampé I, Vitályos G, Daróczi L, Beke D. [Applicability of titanium in preparing dental prostheses for allergic patients]. Fogorv Sz 2004; 97:239-45. [PMID: 15690915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Owing to its excellent biocompatibility, titanium has been used in health care, including dental care, for a long time. The unalloyed light metal is a non-allergic one, it resists corrosion, has low heat conducting ability, it tastes neutral and is relatively cheap to apply. Titanium's biocompatibility may be associated with its fast oxidizing capacity, which can inhibit its binding with proteins. Due to titanium's oxidizing capacity, its applicability in dentistry is difficult, because such prostheses are not easy to cover with ceramics, which is essential for aesthetic reasons. The bond between the ceramic, developed specially for titanium, and the metal surface is weaker than in the case of NiCr alloys or alloys of noble alloys. The strength of the bond, however, meets ISO requirements, and, according to the latest literature, it can be further strengthened by surface treatment techniques and new bond systems. These solutions are aimed at stopping cavity formation on the titanium surface and in the oxide phase (which would lead to the disjunction of the oxide phase at the interface). Comparative studies have mentioned problems with right marginal closure and precision of fitting, still they have found titanium-based prostheses acceptable. According to data in the literature the ceramic fused to titanium, and removed partial dentures are artificial dental structures which may offer an inexpensive, still aesthetically and functionally acceptable solution for certain patients suffering from metal allergy.
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Affiliation(s)
- Csaba Hegedus
- Debreceni Egyetem, Orvos es Egészségtudományi Centrum Fogorvostudományi Kar, Fogpótlástani Tanszék
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Dobó NC, Fejérdy P, Angyal J, Harasztosi L, Daróczi L, Beke D, Wesselink PR. [Measurement of periapical pressure created by occlusal loading]. Fogorv Sz 2004; 97:81-4. [PMID: 15164676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
The aim of this study was to develop an in vitro model in which the pressure in the periapical tissues can be measured during loading. Extracted human maxillary central incisors were embedded into resin blocks that had physical characteristics similar to bone and periodontal ligament. Each tooth was loaded with 20, 40, 50, 60, 75, 85, 100, 200, 300 and 450 N vertical forces from the incisal edge of the crown; this procedure was carried out three consecutive times. A minute resistor embedded in the periapical space was used to detect apical pressure changes during occlusal loading. The ratio of apical pressure changes (delta P) to the loading force changes (delta F) was calculated. The periapical pressure detected was in direct proportion to the loading force. The mean value of delta P/delta F was 5.994 kPa/N (SD = 2.04). Direct proportionality was found between the coronal loading and the apical hydrostatic pressure. The (delta P)/(delta F) ratio determined in this study makes it easier to estimate the apical hydrostatic pressure values during occlusal loading of single rooted teeth. In this study the apical pressure generated under occlusal loading was of the same magnitude as that estimated with the finite element method.
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Hegedüs C, Daróczi L, Deák G, Beke D. [Comparison of interfaces between a NiCr alloy and various dental ceramics using transmission electron microscopy (TEM) and 3-point bending test]. Fogorv Sz 2003; 96:269-72. [PMID: 14971264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Several methods (e.g. tensile strength, shear bond strength) have been used in testing metal-ceramic bonds. However, in the interface, structural and analytical investigations can be applied in determining the chemical and phase structure of substances making up the bond. The aim of the present study is to assess the interface between Wiron 99 (Bego) alloy and Vision (Wohlwend) VITA VMK68 (Vita), Carat (Dentsply/DeTrey) ceramic using transmission electron microscopy (TEM) and 3-point bending test. In the case of NiCr alloys, morphologically similar but structurally varying phases developed in all of the ceramics. In each case, a Cr2O3 layer consisting of small crystals (10-20 nm) was noticed with a series of underlying bubble-like amorphous inclusions. The exact three dimensional (3D) location of these structures and their relation to the glass-phase of the ceramic, as well as its role in the nanomechanical anchoring of the ceramic are still to be clarified. The values of debonding stress were 41.67 +/- 5.01 MPa, 52.89 +/- 8.06 MPa and 56.58 +/- 10.21 MPa for Carat, VITA VMK68 ceramic and Vision, respectively. These parameters do not present significant difference at p > or = 0.05 among the three types of ceramics. Based on our measurements it is highly likely that the micromorphology of interface is basically determined by the composition of the alloy while in the chemical composition of the newly developed phases the ceramic and the parameters of firing (temperature, magnitude of vacuum and firing time) play an important role. Values of cracking and morphological resemblance suggest that the superficial micromorphological and nanomorphological structures, acting as mechanical anchoring elements, play an important role in fixing the ceramic.
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Affiliation(s)
- Csaba Hegedüs
- Debreceni Egyetem, Orvos és Egészségtudományi Centrum Fogorvostudományi Kar, Fogpótlástani Tanszék
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Abstract
AIM To develop an in vitro model in which the pressure in the periapical tissues can be measured during loading. METHODOLOGY Extracted human maxillary central incisors were embedded in resin blocks that had physical characteristics similar to those of bone and periodontal ligament. Each tooth was loaded with 20, 40, 50, 60, 75, 85, 100, 200, 300 and 450 N vertical forces from the incisal edge of the crown on three consecutive occasions. A minute resistor embedded in the periapical space was used to detect apical pressure changes during occlusal loading. The ratio of apical pressure changes (DeltaP) to the loading force changes (DeltaF) was calculated. RESULTS The periapical pressure detected was in direct proportion to the loading force. The mean value of DeltaP/DeltaF was 5.994 kPa N-1 (SD = 2.04). CONCLUSIONS Direct proportionality was found between the coronal loading and the apical hydrostatic pressure. The DeltaP/DeltaF ratio determined in this study makes it easier to estimate the apical hydrostatic pressure values during occlusal loading of single-rooted teeth. In this study, the apical pressure generated under occlusal loading was the same magnitude as that estimated with the finite element method.
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Affiliation(s)
- C Dobó-Nagy
- Semmelweis University, Faculty of Dentistry, Budapest, Hungary.
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Hegedus C, Daróczi L, Kökényesi V, Beke DL. Comparative microstructural study of the diffusion zone between NiCr alloy and different dental ceramics. J Dent Res 2002; 81:334-7. [PMID: 12097447 DOI: 10.1177/154405910208100509] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Our knowledge on the bonding mechanisms between the metal and ceramic parts of dental systems is very limited. This work tested the hypothesis that the details of the interface processes can be described in the framework of a chemical diffusion model. The development of interfacial phases was investigated by cross-sectional analytical transmission electron microscopy between a NiCr (Wiron 99) alloy and three different dental ceramics (Carat, Vita VMK 95, and Vision). All systems were investigated at normal firing conditions (suggested by the manufacturer) and at increased firing times as well. The conclusions are based on the results that the formation of a nanocrystalline Cr(2)O(3) layer and amorphous silicon oxide inclusions were detected in the early stage of the firing process in all investigated systems, and that, in the case of Carat and Vision ceramics, formation of complex NiCr and NiCrTi oxides was also observed at longer annealing times.
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Affiliation(s)
- C Hegedus
- Medical and Health Science Center, Institute of Dental Science, Department of Prosthetic Dentistry, University of Debrecen, Debrecen, Hungary Nagyerdei krt. 98, H-4012, Hungary.
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Kövér L, Tougaard S, Tóth J, Daróczi L, Szabó I, Langer G, Menyhárd M. Determination of overlayer thickness by QUASES analysis of photon-excited KLL Auger spectra of Ni and Cu films. SURF INTERFACE ANAL 2001. [DOI: 10.1002/sia.988] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
The photochemical synthesis of Ag(0) nanoparticles in the presence of amino- and carboxylate-terminated PAMAM dendrimers is reported. The formation of Ag(0) nanoparticles was followed spectrophotometrically and by transmission electron microscopy (TEM). According to TEM investigations Ag(0) nanoparticles with the average size of about 7 nm in diameter were produced. Based on the present investigation a possible mechanism for the Ag(0) nanoparticles formation is proposed. Copyright 2000 Academic Press.
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Affiliation(s)
- S Kéki
- Department of Applied Chemistry, University of Debrecen, Debrecen, H-4010, Hungary
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Kéki S, Deák G, Daróczi L, Kuki Á, Zsuga M. Star-shaped nanomicelles of polyisobutylene-polystyrene diblock copolymers. New stabilizer for living dispersion polymerization of styrene. ACTA ACUST UNITED AC 2000. [DOI: 10.1002/1521-3900(200007)157:1<217::aid-masy217>3.0.co;2-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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