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Vlcak P, Sepitka J, Koller J, Drahokoupil J, Tolde Z, Svoboda S. Effect of Annealing on the Surface Hardness of High-Fluence Nitrogen Ion-Implanted Titanium. Materials (Basel) 2023; 16:ma16103837. [PMID: 37241465 DOI: 10.3390/ma16103837] [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] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/10/2023] [Accepted: 05/15/2023] [Indexed: 05/28/2023]
Abstract
Commercially pure titanium grade II was kinetically nitrided by implanting nitrogen ions with a fluence in the range of (1-9)·1017 cm-2 and ion energy of 90 keV. Post-implantation annealing in the temperature stability range of TiN (up to 600 °C) shows hardness degradation for titanium implanted with high fluences above 6·1017 cm-2, leading to nitrogen oversaturation. Temperature-induced redistribution of interstitially located nitrogen in the oversaturated lattice has been found to be the predominant hardness degradation mechanism. The impact of the annealing temperature on a change in surface hardness related to the applied fluence of implanted nitrogen has been demonstrated.
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Affiliation(s)
- Petr Vlcak
- Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, 16607 Prague, Czech Republic
| | - Josef Sepitka
- Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, 16607 Prague, Czech Republic
| | - Jan Koller
- Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, 16607 Prague, Czech Republic
| | - Jan Drahokoupil
- Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, 16607 Prague, Czech Republic
| | - Zdenek Tolde
- Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, 16607 Prague, Czech Republic
| | - Simon Svoboda
- Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, 16607 Prague, Czech Republic
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Voltrova B, Jarolimova P, Hybasek V, Blahnova VH, Sepitka J, Sovkova V, Matějka R, Daniel M, Fojt J, Filova E. In vitro evaluation of a novel nanostructured Ti-36Nb-6Ta alloy for orthopedic applications. Nanomedicine (Lond) 2020; 15:1843-1859. [PMID: 32752935 DOI: 10.2217/nnm-2020-0123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: To evaluate the impact of a nanostructured surface created on β-titanium alloy, Ti-36Nb-6Ta, on the growth and differentiation of human mesenchymal stem cells. Materials & methods: The nanotubes, with average diameters 18, 36 and 46 nm, were prepared by anodic oxidation. Morphology, hydrophilicity and mechanical properties of the nanotube layers were characterized. The biocompatibility and osteogenic potential of the nanostructured surfaces were established using various in vitro assays, scanning electron microscopy and confocal microscopy. Results: The nanotubes lowered elastic modulus close to that of bone, positively influenced cell adhesion, improved ALP activity, synthesis of type I collagen and osteocalcin expression, but diminished early cell proliferation. Conclusion: Nanostructured Ti-36Nb-6Ta with nanotube diameters 36 nm was the most promising material for bone implantation.
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Affiliation(s)
- Barbora Voltrova
- Department of Tissue Engineering, Institute of Experimental Medicine of The Czech Academy of Sciences, Vídeňská 1083, 142 20, Prague, Czech Republic.,Department of Physiology, Faculty of Science, Charles University in Prague, Albertov 2038/6, 128 00, Prague, Czech Republic
| | - Petra Jarolimova
- Department of Metals & Corrosion Engineering, University of Chemistry & Technology, Technická 5, 166 29, Prague, Czech Republic
| | - Vojtech Hybasek
- Department of Metals & Corrosion Engineering, University of Chemistry & Technology, Technická 5, 166 29, Prague, Czech Republic
| | - Veronika Hefka Blahnova
- Department of Tissue Engineering, Institute of Experimental Medicine of The Czech Academy of Sciences, Vídeňská 1083, 142 20, Prague, Czech Republic.,Second Faculty of Medicine, Charles University in Prague, V Úvalu 84, 150 06, Prague, Czech Republic
| | - Josef Sepitka
- Faculty of Mechanical Engineering, Czech Technical University in Prague, Technická 4, 160 00, Prague, Czech Republic
| | - Vera Sovkova
- Department of Tissue Engineering, Institute of Experimental Medicine of The Czech Academy of Sciences, Vídeňská 1083, 142 20, Prague, Czech Republic
| | - Roman Matějka
- Faculty of Biomedical Engineering, Czech Technical University in Prague, Náměstí Sítná 3105, 272 01, Kladno, Czech Republic
| | - Matej Daniel
- Faculty of Mechanical Engineering, Czech Technical University in Prague, Technická 4, 160 00, Prague, Czech Republic
| | - Jaroslav Fojt
- Department of Metals & Corrosion Engineering, University of Chemistry & Technology, Technická 5, 166 29, Prague, Czech Republic
| | - Eva Filova
- Department of Tissue Engineering, Institute of Experimental Medicine of The Czech Academy of Sciences, Vídeňská 1083, 142 20, Prague, Czech Republic.,Second Faculty of Medicine, Charles University in Prague, V Úvalu 84, 150 06, Prague, Czech Republic
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Jezek J, Sepitka J, Daniel M, Kujal P, Blankova A, Waldauf P, Krbec M, Dousa P, Skala-Rosenbaum J, Samal F, Jirasek T. The role of vascularization on changes in ligamentum flavum mechanical properties and development of hypertrophy in patients with lumbar spinal stenosis. Spine J 2020; 20:1125-1133. [PMID: 32179155 DOI: 10.1016/j.spinee.2020.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/03/2020] [Accepted: 03/04/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND CONTEXT Ligamentum flavum (LF) induced lumbar spinal stenosis (LSS) is conditioned not only by its "gathering" but especially by hypertrophy. Previous studies have examined the pathophysiology and biochemical changes that cause the hypertrophy. Some studies have described a link between chronic LF inflammation and neovascularization but others have reported highly hypovascular LF tissue in LSS patients. Currently, there is no practical application for our knowledge of the pathophysiology of the LF hypertrophy. Considerations for future treatment include influencing this hypertrophy at the level of tissue mediators, which may slow the development of LSS. To our knowledge, there is no study of micromechanical properties of native LF to date. PURPOSE (1) To clarify the changes in vascularization, chondroid metaplasia, and the presence of inflammatory cell infiltration in LF associated with LSS. (2) To quantify changes in the micromechanical properties associated with LF degenerative processes. STUDY DESIGN/SETTING Vascular density analysis of degenerated and healthy human LF combined with measurement of micromechanical properties. METHODS The study involved 35 patients who underwent surgery between November 1, 2015 and October 1, 2016. The LSS group consisted of 20 patients and the control group consisted of 15 patients. LF samples were obtained during the operation and were used for histopathological and nanoindentation examinations. Sample vascularization was examined as microvascular density (Lv), which was morphometrically evaluated using semiautomatic detection in conjunction with NIS-Elements AR image analysis software. Samples were also histologically examined for the presence of chondroid metaplasia and inflammation. Mechanical properties of native LF samples were analyzed using the Hysitron TI 950 TriboIndenter nanomechanical testing system. RESULTS Vascular density was significantly lower in the LSS group. However, after excluding the effect of age, the difference was not significant. There was high association between Lv and age. With each increasing year of age, Lv decreased by 11.5 mm2. Vascular density decreased up to the age of 50. Over the age of 50, changes were no longer significant and Lv appeared to stabilize. No correlation was observed between Lv and the presence of inflammation or metaplasia; however, LSS patients had a significantly increased incidence of chondroid metaplasia and inflammatory signs. The mechanical properties of control group samples showed significantly higher stiffness than those samples obtained from the LSS group. CONCLUSION This study showed that Lv changes were not dependent on LSS but were age-dependent. Vascular density was found to decrease up to the age of 50. A significantly higher incidence of chondroid metaplasia and inflammation was observed in LSS patients. The mechanical property values measured by nanoindentation showed high microstructural heterogeneity of the tested ligaments. Our results showed that healthy ligaments were significantly stiffer than LSS ligaments. CLINICAL SIGNIFICANCE Prevention of the loss of LF vascularization during aging may influence stiffness of LF which in turn may slow down the LF degenerative processes and delay onset of LSS.
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Affiliation(s)
- Jakub Jezek
- Department of Orthopedics and Traumatology, Third Medical Faculty of Charles University and University Hospital Kralovske Vinohrady, Srobarova 50, Praha 10, 100 34 Prague, Czech Republic.
| | - Josef Sepitka
- Division of Biomechanics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Czech Republic
| | - Matej Daniel
- Division of Biomechanics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Czech Republic
| | - Petr Kujal
- Department of Pathology, Third Medical Faculty of Charles University and University Hospital Kralovske Vinohrady, Prague, Czech Republic
| | - Alzbeta Blankova
- Department of Forensic Medicine, Regional Hospital Liberec, Czech Republic
| | - Petr Waldauf
- Department of Anesthesiology and Intensive Care Medicine, Third Medical Faculty of Charles University and University Hospital Kralovske Vinohrady, Prague, Czech Republic
| | - Martin Krbec
- Department of Orthopedics and Traumatology, Third Medical Faculty of Charles University and University Hospital Kralovske Vinohrady, Srobarova 50, Praha 10, 100 34 Prague, Czech Republic
| | - Pavel Dousa
- Department of Orthopedics and Traumatology, Third Medical Faculty of Charles University and University Hospital Kralovske Vinohrady, Srobarova 50, Praha 10, 100 34 Prague, Czech Republic
| | - Jiri Skala-Rosenbaum
- Department of Orthopedics and Traumatology, Third Medical Faculty of Charles University and University Hospital Kralovske Vinohrady, Srobarova 50, Praha 10, 100 34 Prague, Czech Republic
| | - Filip Samal
- Department of Neurosurgery, Third Medical Faculty of Charles University and University Hospital Kralovske Vinohrady, Prague, Czech Republic
| | - Tomas Jirasek
- Centrum Patos, Regional Hospital Liberec, Czech Republic
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Vakkipurath Kodakkadan YN, Idzakovicova K, Sepitka J, Ten Napel D, Safai E, Cigler P, Štěpánek F, Rehor I. Arbitrarily-shaped microgels composed of chemically unmodified biopolymers. Biomater Sci 2020; 8:3044-3051. [PMID: 32307470 DOI: 10.1039/c9bm02056j] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Biohydrogels, composed of naturally occurring biopolymers are typically preferred over their synthetic analogues in bioapplications thanks to their biocompatibility, bioactivity, mechanical or degradation properties. Shaping biohydrogels on the single-cell length scales (micrometers) is a key ability needed to create bioequivalent artificial cell/tissue constructs and cannot be achieved with current methods. This work introduces a method for photolithographic synthesis of arbitrarily shaped microgels composed purely of a biopolymer of choice. The biopolymer is mixed with a sacrificial photocrosslinkable polymer, and the mixture is photocrosslinked in a lithographic process, yielding anisotropic microgels with the biopolymer entrapped in the network. Subsequent ionic or covalent biopolymer crosslinking followed by template cleavage yields a microgel composed purely of a biopolymer with the 3D shape dictated by the photocrosslinking process. Method feasibility is demonstrated with two model polysaccharide biopolymers (alginate, chitosan) using suitable crosslinking methods. Next, alginate microgels were used as microtaggants on a pharmaceutical oral solid dose formulation to prevent its counterfeiting. Since the alginate is approved as an additive in the food and pharmaceutical industries, the presented tagging system can be implemented in practical use much easier than systems comprising synthetic polymers.
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Affiliation(s)
- Yadu N Vakkipurath Kodakkadan
- University of Chemistry and Technology, Department of Chemical Engineering, Technicka 5, 16628, Prague, Czech Republic.
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Voltrova B, Hybasek V, Blahnova V, Sepitka J, Lukasova V, Vocetkova K, Sovkova V, Matejka R, Fojt J, Joska L, Daniel M, Filova E. Different diameters of titanium dioxide nanotubes modulate Saos-2 osteoblast-like cell adhesion and osteogenic differentiation and nanomechanical properties of the surface. RSC Adv 2019; 9:11341-11355. [PMID: 35520235 PMCID: PMC9062999 DOI: 10.1039/c9ra00761j] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [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: 01/28/2019] [Accepted: 03/28/2019] [Indexed: 01/09/2023] Open
Abstract
Nanostructured cpTi surfaces affected Saos-2 cell adhesion, proliferation, and osteogenic differentiation as well as the nanomechanical properties of the surface.
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Korsa R, Lukes J, Sepitka J, Mares T. Elastic Properties of Human Osteon and Osteonal Lamella Computed by a Bidirectional Micromechanical Model and Validated by Nanoindentation. J Biomech Eng 2015; 137:081002. [DOI: 10.1115/1.4030407] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Indexed: 11/08/2022]
Abstract
Knowledge of the anisotropic elastic properties of osteon and osteonal lamellae provides a better understanding of various pathophysiological conditions, such as aging, osteoporosis, osteoarthritis, and other degenerative diseases. For this reason, it is important to investigate and understand the elasticity of cortical bone. We created a bidirectional micromechanical model based on inverse homogenization for predicting the elastic properties of osteon and osteonal lamellae of cortical bone. The shape, the dimensions, and the curvature of osteon and osteonal lamellae are described by appropriately chosen curvilinear coordinate systems, so that the model operates close to the real morphology of these bone components. The model was used to calculate nine orthotropic elastic constants of osteonal lamellae. The input values have the elastic properties of a single osteon. We also expressed the dependence of the elastic properties of the lamellae on the angle of orientation. To validate the model, we performed nanoindentation tests on several osteonal lamellae. We compared the experimental results with the calculated results, and there was good agreement between them. The inverted model was used to calculate the elastic properties of a single osteon, where the input values are the elastic constants of osteonal lamellae. These calculations reveal that the model can be used in both directions of homogenization, i.e., direct homogenization and also inverse homogenization. The model described here can provide either the unknown elastic properties of a single lamella from the known elastic properties at the level of a single osteon, or the unknown elastic properties of a single osteon from the known elastic properties at the level of a single lamella.
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Affiliation(s)
- Radim Korsa
- Department of Mechanics, Biomechanics and Mechatronics, Czech Technical University in Prague, Technicka 4, Prague 166 07, Czech Republic e-mail:
| | - Jaroslav Lukes
- Department of Mechanics, Biomechanics and Mechatronics, Czech Technical University in Prague, Technicka 4, Prague 166 07, Czech Republic e-mail:
| | - Josef Sepitka
- Department of Mechanics, Biomechanics and Mechatronics, Czech Technical University in Prague, Technicka 4, Prague 166 07, Czech Republic e-mail:
| | - Tomas Mares
- Department of Mechanics, Biomechanics and Mechatronics, Czech Technical University in Prague, Technicka 4, Prague 166 07, Czech Republic e-mail:
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Prauzner-Bechcicki S, Raczkowska J, Madej E, Pabijan J, Lukes J, Sepitka J, Rysz J, Awsiuk K, Bernasik A, Budkowski A, Lekka M. PDMS substrate stiffness affects the morphology and growth profiles of cancerous prostate and melanoma cells. J Mech Behav Biomed Mater 2014; 41:13-22. [PMID: 25460399 DOI: 10.1016/j.jmbbm.2014.09.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [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: 07/11/2014] [Revised: 09/19/2014] [Accepted: 09/22/2014] [Indexed: 11/28/2022]
Abstract
A deep understanding of the interaction between cancerous cells and surfaces is particularly important for the design of lab-on-chip devices involving the use of polydimethylsiloxane (PDMS). In our studies, the effect of PDMS substrate stiffness on mechanical properties of cancerous cells was investigated in conditions where the PDMS substrate is not covered with any of extracellular matrix proteins. Two human prostate cancer (Du145 and PC-3) and two melanoma (WM115 and WM266-4) cell lines were cultured on two groups of PDMS substrates that were characterized by distinct stiffness, i.e. 0.75 ± 0.06 MPa and 2.92 ± 0.12 MPa. The results showed the strong effect on cellular behavior and morphology. The detailed analysis of chemical and physical properties of substrates revealed that cellular behavior occurs only due to substrate elasticity.
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Affiliation(s)
- Szymon Prauzner-Bechcicki
- The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland
| | - Joanna Raczkowska
- The Marian Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków, Poland
| | - Ewelina Madej
- The Marian Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków, Poland
| | - Joanna Pabijan
- The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland
| | - Jaroslav Lukes
- Czech Technical University in Prague, Faculty of Mechanical Engineering, Technicka 4, 16607 Prague, Czech Republic
| | - Josef Sepitka
- Czech Technical University in Prague, Faculty of Mechanical Engineering, Technicka 4, 16607 Prague, Czech Republic
| | - Jakub Rysz
- The Marian Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków, Poland
| | - Kamil Awsiuk
- The Marian Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków, Poland
| | - Andrzej Bernasik
- Faculty of Physics and Applied Computer Science & Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, Reymonta 19, 30-049 Kraków, Poland
| | - Andrzej Budkowski
- The Marian Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków, Poland
| | - Małgorzata Lekka
- The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland.
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Korsa R, Lukes J, Sepitka J, Kytyr D, Mares T. Mathematical model of human osteon and its validation by nanomechanical testing of bone lamella. Comput Methods Biomech Biomed Engin 2014; 17 Suppl 1:24-5. [PMID: 25074146 DOI: 10.1080/10255842.2014.931078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- R Korsa
- a Faculty of Mechanical Engineering, Czech Technical University in Prague, Technická 4, 16607 , Prague , Czech Republic
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Sepitka J, Grzanova P, Fuzik T, Lukes J. Compression tests of a living cell: a contact detection problem. Comput Methods Biomech Biomed Engin 2014; 17 Suppl 1:40-1. [PMID: 25074154 DOI: 10.1080/10255842.2014.931093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- J Sepitka
- a Czech Technical University in Prague, Faculty of Mechanical Engineering, Technicka 4 , 16607 , Prague , Czech Republic
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Hrabánková I, Frýda J, Sepitka J, Sasaki T, Frýdová B, Lukeš J. Mechanical properties of deep-sea molluscan shell. Comput Methods Biomech Biomed Engin 2014; 16 Suppl 1:287-9. [PMID: 23923945 DOI: 10.1080/10255842.2013.815873] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- I Hrabánková
- Faculty of Environmental Sciences, Czech University of Life Sciences, Kamýcká 129, Praha, Czech Republic.
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Sedláček R, Suchý T, Sucharda Z, Balík K, Sochor M, Sepitka J, Lukeš J. The influence of sterilisation processes on the micromechanical properties of polyamide fibre-reinforced PDMS composites for orthopaedic applications. Comput Methods Biomech Biomed Engin 2012; 15 Suppl 1:91-2. [PMID: 23009437 DOI: 10.1080/10255842.2012.713642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- R Sedláček
- Department of Mechanics, Biomechanics and Mechatronics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technická 4, 166 07, Prague 6, Czech Republic
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