The Effect of Surface Modification of Ti13Zr13Nb Alloy on Adhesion of Antibiotic and Nanosilver-Loaded Bone Cement Coatings Dedicated for Application as Spacers - Publication - MOST Wiedzy


The Effect of Surface Modification of Ti13Zr13Nb Alloy on Adhesion of Antibiotic and Nanosilver-Loaded Bone Cement Coatings Dedicated for Application as Spacers


Spacers, in terms of instruments used in revision surgery for the local treatment of postoperative infection, are usually made of metal rod covered by antibiotic-loaded bone cement. One of the main limitations of this temporary implant is the debonding effect of metal–bone cement interface, leading to aseptic loosening. Material selection, as well as surface treatment, should be evaluated in order to minimize the risk of fraction and improve the implant-cement fixation the appropriate manufacturing. In this study, Ti13Zr13Nb alloys that were prepared by Selective Laser Melting and surface treated were coated with bone cement loaded with either gentamicin or nanosilver, and the effects of such alloy modifications were investigated. The SLM-made specimens of Ti13Zr13Nb were surface treated by sandblasting, etching, or grounding. For each treatment, Scanning Electron Microscope (SEM), contact profilometer, optical tensiometer, and nano-test technique carried out microstructure characterization and surface analysis. The three types of bone cement i.e., pure, containing gentamicin and doped with nanosilver were applied to alloy surfaces and assessed for cement cohesion and its adhesion to the surface by nanoscratch test and pull-off. Next, the inhibition of bacterial growth and cytocompatibility of specimens were investigated by the Bauer-Kirby test and MTS assay respectively. The results of each test were compared to the two control groups, consisting of commercially available Ti13Zr13Nb and untreated SLM-made specimens. The highest adhesion bone cement to the titanium alloy was obtained for specimens with high nanohardness and roughness. However, no explicit relation of adhesion strength with wettability and surface energy of alloy was observed. Sandblasting or etching were the best alloys treatments in terms of the adhesion of either pure or modified bone cements. Antibacterial additives for bone cement affected its properties. Gentamicin and nanosilver allowed for adequate anti-bacterial protection while maintaining the overall biocompatibility of obtained spacers. However, they had different effects on the cement’s adhesive capacity or its own cohesion. Furthermore, the addition of silver nanoparticles improved the nanomechanical properties of bone cements. Surface treatment and method of fabrication of titanium affected surface parameters that had a significant impact on cement-titanium fixation.


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Materials no. 12,
ISSN: 1996-1944
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Dziaduszewska M., Wekwejt M., Bartmański M., Pałubicka A., Gajowiec G., Seramak T., Osyczka A., Zieliński A.: The Effect of Surface Modification of Ti13Zr13Nb Alloy on Adhesion of Antibiotic and Nanosilver-Loaded Bone Cement Coatings Dedicated for Application as Spacers// Materials -Vol. 12,iss. 18 (2019), s.2964-
Digital Object Identifier (open in new tab) 10.3390/ma12182964
Bibliography: test
  1. Soffiatti, R. The preformed spacers: From the idea to the realization of an industrial device. In Infection and Local Treatment in Orthopedic Surgery; open in new tab
  2. Meani, E., Romano, C., Crosby, L., Hofmann, G., Calonego, G., Eds.; Springer: Berlin, Germany, 2007; pp. 112-120. open in new tab
  3. Cigada, A.; Brunella, M.F. Surface analysis of the spacer before and after the clinical use. In Infection and Local Treatment in Orthopedic Surgery; open in new tab
  4. Meani, E., Romano, C., Crosby, L., Hofmann, G., Calonego, G., Eds.; Springer: Berlin, Germany, 2007; pp. 136-147. open in new tab
  5. Magnan, B.; Regis, D.; Costa, A.; Bartolozzi, P. Two-stage revision of infected total hip replacement using a preformed, antibiotic-loaded acrylic cement spacer. In Infection and Local Treatment in Orthopedic Surgery; open in new tab
  6. Meani, E., Romano, C., Crosby, L., Hofmann, G., Calonego, G., Eds.; Springer: Berlin, Germany, 2007; pp. 205-213. open in new tab
  7. Ginebra, M.; Montufar, E.B. Cements as bone repair materials. In Bone Repair Biomaterials, 2nd ed.; Pawelec, K.M., Planell, J.A., Eds.; Woodhead Publishing: Sawston/Cambridge, UK, 2019; pp. 233-271. open in new tab
  8. Burnett, R.S.J.; Clohisy, J.C.; Barrack, R.L. Antibiotic cement spacers in total hip and total knee arthroplasty: Problems, pitfalls, and avoiding complications. In Bone Repair Biomaterials, 2nd ed.; Pawelec, K.M., Planell, J.A., Eds.; Woodhead Publishing: Sawston/Cambridge, UK, 2019; pp. 92-111. Materials 2019, 12, 2964 open in new tab
  9. Jones, C.W.; Selemon, N.; Nocon, A.; Bostrom, M.; Westrich, G.; Sculco, P.K. The Influence of spacer design on the rate of complications in two-Stage revision hip arthroplasty. J. Arthroplasty 2019, 34, 1201-1206. [CrossRef] [PubMed] open in new tab
  10. Jeffers, J.R.T.; Browne, M.; Lennon, A.B.; Prendergast, P.J.; Taylor, M. Cement mantle fatigue failure in total hip replacement: Experimental and computational testing. J. Biomech. 2007, 40, 1525-1533. [CrossRef] [PubMed] open in new tab
  11. Gravius, S.; Wirtz, D.C.; Siebert, C.H.; Andereya, S.; Mueller-Rath, R.; Maus, U.; Mumme, T. In vitro interface and cement mantle analysis of different femur stem designs. J. Biomech. 2008, 41, 2021-2028. [CrossRef] [PubMed] open in new tab
  12. Khandaker, M.; Riahinezhad, S.; Sultana, F.; Morris, T.; Knight, J.; Vaughan, M. Peen treatment on a titanium implant: Effect of roughness, osteoblast cell functions, and bonding with bone cement. Int. J. Nanomed. 2016, 11, 585-594. [CrossRef] [PubMed] open in new tab
  13. Marx, B.; Marx, C.; Marx, R.; Reisgen, U.; Wirtz, D.C. Bone cement adhesion on ceramic surfaces-Surface activation of retention surfaces of knee endoprostheses by atmospheric pressure plasma vs. thermal surface treatment. J. Adv. Ceram. 2016, 5, 137-144. [CrossRef] open in new tab
  14. Ohashi, K.L.; Romero, A.C.; McGowan, P.D.; Maloney, W.J.; Dauskardt, R.H. Adhesion and reliability of interfaces in cemented total joint arthroplasties. J. Orthop. Res. 1998, 16, 705-714. [CrossRef] [PubMed] open in new tab
  15. Singh, G. Surface treatment of dental implants: A review. J. Dent. Med. Sci. 2018, 17, 49-53. [CrossRef] open in new tab
  16. Devgan, S.; Sidhu, S.S. Evolution of surface modification trends in bone related biomaterials: A review. Mater. Chem. Phys. 2019, 233, 68-78. [CrossRef] open in new tab
  17. Szmukler-Moncler, S.; Perrin, D.; Ahossi, V.; Magnin, G.; Bernard, J.P. Biological properties of acid etched titanium implants: Effect of sandblasting on bone anchorage. J. Biomed. Mater. Res. B 2004, 68, 149-159. [CrossRef] open in new tab
  18. Ma, T.; Ge, X.; Zhang, Y.; Lin, Y. Effect of titanium surface modifications of dental implants on rapid osseointegration. In Interface Oral Health Science 2016; open in new tab
  19. Sasaki, K., Suzuki, O., Takahashi, N., Eds.; Springer: Singapore, 2016; pp. 247-256. open in new tab
  20. Ho, B.J.; Tsoi, J.K.H.; Liu, D.; Lung, C.Y.K.; Wong, H.M.; Matinlinna, J.P. Effects of sandblasting distance and angles on resin cement bonding to zirconia and titanium. Int. J. Adhes. Adhes. 2015, 62, 25-31. [CrossRef] open in new tab
  21. Tęczar, P.; Majkowska-Marzec, B.; Bartmański, M. The influence of laser alloying of Ti13Nb13Zr on surface topography and properties. Adv. Mater. Sci. 2019, 19, 44-57. [CrossRef] open in new tab
  22. Chen, A.F.; Parvizi, J. Antibiotic-loaded bone cement and periprosthetic joint infection. J. Long Term Eff. Med. Implants 2014, 24, 89-97. [CrossRef] open in new tab
  23. Geetha, M.; Singh, A.K.; Asokamani, R.; Gogia, A.K. Ti based biomaterials, the ultimate choice for orthopaedic implants-A review. Prog. Mater. Sci. 2009, 54, 397-425. [CrossRef] open in new tab
  24. Zhang, B.; Pei, X.; Zhou, C.; Fan, Y.; Jiang, Q.; Ronca, A.; D'Amora, U.; Chen, Y.; Li, H.; Sun, Y.; et al. The biomimetic design and 3D printing of customized mechanical properties porous Ti6Al4V scaffold for load-bearing bone reconstruction. Mater. Des. 2018, 152, 30-39. [CrossRef] open in new tab
  25. Koutiri, I.; Pessard, E.; Peyre, P.; Amlou, O.; De Terris, T. Influence of SLM process parameters on the surface finish, porosity rate and fatigue behavior of as-built Inconel 625 parts. J. Mater. Process. Technol. 2018, 255, 536-546. [CrossRef] open in new tab
  26. Sallica-Leva, E.; Jardini, A.L.; Fogagnolo, J.B. Microstructure and mechanical behavior of porous Ti-6Al-4V parts obtained by selective laser melting. J. Mech. Behav. Biomed. Mater. 2013, 26, 98-108. [CrossRef] open in new tab
  27. Armstrong, S.R.; Boyer, D.B.; Keller, J.C. Microtensile bond strength testing and failure analysis of two dentin adhesives. Dent. Mater. 1998, 14, 44-50. [CrossRef] open in new tab
  28. Liu, D.; Kit, J.; Tsoi, H.; Matinlinna, J.P.; Wong, H.M. Effects of some chemical surface modifications on resin zirconia adhesion. J. Mech. Behav. Biomed. Mater. 2015, 46, 23-30. [CrossRef] open in new tab
  29. International Standard ISO 5833. Implants for Surgery-Acrylic Resin Cements; International Standard ISO: Geneva, Switzerland, 2002. open in new tab
  30. Wekwejt, M.; Michno, A.; Truchan, K.; Pałubicka, A.;Świeczko-Żurek, B.; Osyczka, A.M.; Zieliński, A. Antibacterial activity and cytocompatibility of bone cement enriched with antibiotic, nanosilver, and nanocopper for bone regeneration. Nanomaterials 2019, 9, 1114. [CrossRef] open in new tab
  31. Wekwejt, M.; Moritz, M.;Świeczko-Żurek, B.; Pałubicka, A. Biomechanical testing of bioactive bone cements-A comparison of the impact of modifiers: Antibiotics and nanometals. Polym. Test. 2018, 70, 234-243. [CrossRef] open in new tab
  32. Wekwejt, M.; Pałubicka, A. Antibacterial evaluation of bioactive modifiers of bone cements: Antibiotics, nanometals and chitosan. Eur. J. Med. Technol. 2018, 3, 6-10. open in new tab
  33. International Standard ISO 4287-1997. Geometrical Product Specifications (GPS)-Surface Texture: Profile Method-Terms, Definitions and Surface Texture Parameters; International Standard ISO 4287-1997: Geneva, Switzerland, 1997. open in new tab
  34. Kaelble, D.H. Dispersion-polar surface tension properties of organic solids. J. Adhes. 1970, 2, 66-81. [CrossRef] open in new tab
  35. Owens, D.; Wendt, R. Estimation of the surface free energy of polymers. J. Appl. Polym. Sci. 1969, 13, 1741-1747. [CrossRef] open in new tab
  36. Rabel, W. Einige Aspekte der Benetzungstheorie und ihre Anwendung auf die Untersuchung und Veränderung der Oberflächeneigenschaften von Polymeren. In Farbe und Lack; Habenicht, G., Ed.; Springer: Berlin, Germany, 1971; pp. 997-1005.
  37. Oliver, W.C.; Pharr, G.M. An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiment. J. Mater. Res. 1992, 7, 1564-1583. [CrossRef] open in new tab
  38. Tannant, D.D.; Ozturk, H. Evaluation of test methods for measuring adhesion between a liner and rock. In Proceedings of the 3rd International Seminar on Surface Support Linears, Quebec City, QC, Canada, 25-26 August 2003.
  39. Bauer, A.W.; Kirby, W.M.M.; Sherris, J.C.; Tuck, M. Antibiotic susceptibility testing by a standardized single disk method. Am. J. Clin. Pathol. 1966, 45, 493-496. [CrossRef] open in new tab
  40. Fousová, M.; Vojtěch, D.; Kubásek, J.; Jablonská, E.; Fojt, J. Promising characteristics of gradient porosity Ti-6Al-4V alloy prepared by SLM process. J. Mech. Behav. Biomed. Mater. 2017, 69, 368-376. [CrossRef] open in new tab
  41. Vayssette, B.; Saintier, N.; Brugger, C.; Elmay, M.; Pessard, E. Surface roughness of Ti-6Al-4V parts obtained by SLM and EBM: Effect on the high cycle fatigue life. Procedia 2018, 213, 89-97. [CrossRef] open in new tab
  42. Vaithilingam, J.; Goodridge, R.D.; Christie, S.D.; Edmondson, S.; Hague, R.J.M. Surface modification of selective melted structures using self-assembled monolayers for biomedical applications. In Proceedings of the 23rd International Symposium on Solid Freeform Fabrication, Austin, TX, USA, 12-14 August 2012. open in new tab
  43. Xu, R.; Hu, X.; Yu, X.; Wan, S.; Wu, F.; Ouyang, J.; Deng, F. Micro-/nano-topography of selective laser melting titanium enhances adhesion and proliferation and regulates adhesion-related gene expressions of human gingival fibroblasts and human gingival epithelial cells. Int. J. Nanomed. 2018, 13, 5045-5057. [CrossRef] open in new tab
  44. Al-Radha, A.S.D. The impact of different acids etch on sandblasted titanium dental implant surfaces topography. J. Dent. Med. Sci. 2016, 15, 83-86. [CrossRef] open in new tab
  45. Hatamleh, M.M.; Wu, X.; Alnazzawi, A.; Watson, J.; Watts, D. Surface characteristics and biocompatibility of cranioplasty titanium implants following different surface treatments. Dent. Mater. 2018, 34, 676-683. [CrossRef] open in new tab
  46. Aparicio, C.; Padrós, A.; Gil, F.J. In vivo evaluation of micro-rough and bioactive titanium dental implants using histometry and pull-out tests. J. Mech. Behav. Biomed. Mater. 2011, 4, 1672-1682. [CrossRef] open in new tab
  47. Manjaiah, M.; Laubscher, R.F. A review of the surface modifications of titanium alloys for biomedical applications. Mater. Technol. 2017, 51, 181-190. [CrossRef] open in new tab
  48. Boyan, B.D.; Hummert, T.W.; Dean, D.D.; Schwartz, Z. Role of material surfaces in regulating bone and cartilage cell response. Biomaterials 1996, 17, 137-146. [CrossRef] open in new tab
  49. Le Guéhennec, L.; Soueidan, A.; Layrolle, P.; Amouriq, Y. Surface treatments of titanium dental implants for rapid osseointegration. Dent. Mater. 2007, 23, 844-854. [CrossRef] open in new tab
  50. Comyn, J. Contact angles and adhesive bonding. Int. Adhes. Adhes. 1992, 12, 145-149. [CrossRef] open in new tab
  51. Rudowska, A. Assessment of Surface Preparation for the Bonding/Adhesive Technology; Academic Press: Cambridge, MA, USA, 2019. open in new tab
  52. Tao, Z.; Yaoyao, S.; Laakso, S.; Jinming, Z. Investigation of the effect of grinding parameters on surface quality in grinding of TC4 titanium alloy. Procedia Manuf. 2017, 11, 2131-2138. [CrossRef] open in new tab
  53. Radtke, A.; Ehlert, M.; Jędrzejewski, T.; Bartmański, M. The morphology, structure, mechanical properties and biocompatibility of nanotubular titania coatings before and after autoclaving process. J. Clin. Med. 2019, 8, 272. [CrossRef] Materials 2019, 12, 2964 20 of 21 open in new tab
  54. Araghi, A.; Hadianfard, M.J. Fabrication and characterization of functionally graded hydroxyapatite/TiO 2 multilayer coating on Ti-6Al-4V titanium alloy for biomedical applications. Ceram. Int. 2015, 41, 12668-12679. [CrossRef] open in new tab
  55. He, Y.H.; Zhang, Y.Q.; Jiang, Y.H.; Zhou, R. Microstructure evolution and enhanced bioactivity of Ti-Nb-Zr alloy by bioactive hydroxyapatite fabricated: Via spark plasma sintering. RSC Adv. 2016, 6, 100939-100953. [CrossRef] open in new tab
  56. Kulkarni, M.; Mazare, A.; Schmuki, P.; Iglič, A. Biomaterial surface modification of titanium and titanium alloys for medical applications. In Nanomedicine; open in new tab
  57. Seifalian, A., de Mel, A., Kalaskar, D.M., Eds.; One Central Press: Cheshire, UK, 2014; pp. 111-136.
  58. Masanta, M.; Shariff, S.M.; Choudhury, A.R. Evaluation of modulus of elasticity, nano-hardness and fracture toughness of TiB 2 -TiC-Al 2 O 3 composite coating developed by SHS and laser cladding. Mater. Sci. Eng. A 2011, 528, 5327-5335. [CrossRef] open in new tab
  59. Hynowska, A.; Pellicer, E.; Fornell, J.; Gonzalez, S.; van Steenberge, N.; Surinach, S.; Gebert, A.; Calin, M.; Eckert, J.; Baro, M.D.; et al. Nanostructured β-phase Ti-31.0Fe-9.0Sn and sub-µm structured Ti-39.3Nb-13.3Zr-10.7Ta alloys for biomedical applications: Microstructure benefits on the mechanical and corrosion performances. Mater. Sci. Eng. C 2012, 32, 2418-2425. [CrossRef] open in new tab
  60. Fornell, J.; van Steenberge, N.; Varea, A.; Rossinyol, E.; Pellicer, E.; Surinach, S.; Baro, M.D.; Sort, J. Enhanced mechanical properties and in vitro corrosion behavior of amorphous and devitrified Ti 40 Zr 10 Cu 38 Pd 12 metallic glass. J. Mech. Behav. Biomed. Mater. 2011, 4, 1709-1717. [CrossRef] open in new tab
  61. Russo, T.; Gloria, A.; De Santis, R.; D'Amora, U.; Balato, G.; Vollaro, A.; Oliviero, O.; Improta, G.; Triassi, M.; Ambrosio, L. Bioactive materials preliminary focus on the mechanical and antibacterial activity of a PMMA-based bone cement loaded with gold nanoparticles. Bioact. Mater. 2017, 2, 156-161. [CrossRef] open in new tab
  62. Russo, T.; Gloria, A.; D'Anto, V.; D'Amora, U.; Ametrano, G.; Bollino, F.; De Santis, R.; Ausanio, G.; Catauro, M.; Rengo, S.; et al. Poly (ε-caprolactone) reinforced with sol-gel synthesized organic-inorganic hybrid fillers as composite substrates for tissue engineering. J. Appl. Biomater. Biomech. 2010, 8, 146-152. [CrossRef] open in new tab
  63. Dunne, N.J.; Leonard, D.; Daly, C.; Buchanan, F.J.; Orr, J.F. Validation of the small-punch test as a technique for characterizing the mechanical properties of acrylic bone cement. Proc. Inst. Mech. Eng. H 2006, 220, 11-21. [CrossRef] open in new tab
  64. Rossi De Aguiar, K.M.F.; Specht, U.; Maass, J.F.; Picon, C.A.; Noeske, P.L.M.; Rischka, K.; Rodrigues-Filho, U.P. Surface modification by physical treatments on biomedical grade metals to improve adhesion for bonding hybrid non-isocyanate urethanes. RSC Adv. 2016, 6, 47203-47211. [CrossRef] open in new tab
  65. Júlio, E.N.B.S.; Branco, F.A.B.; Silva, V.D. Concrete-to-concrete bond strength. Influence of the roughness of the substrate surface. Constr. Build. Mater. 2004, 18, 675-681. [CrossRef] open in new tab
  66. Fonseca, R.G.; Haneda, I.G.; De Almeida-Júnior, A.A.; De Oliveira Abi-Rached, F.; Adabo, G.L. Efficacy of air-abrasion technique and additional surface treatment at titanium/resin cement interface. J. Adhes. Dent. 2012, 14, 453-459.
  67. Wang, H.; Feng, Q.; Li, N.; Xu, S. Evaluation of metal-ceramic bond characteristics of three dental Co-Cr alloys prepared with different fabrication techniques. J. Prosthet. Dent. 2016, 116, 916-923. [CrossRef] open in new tab
  68. Xiang, N.; Xin, X.Z.; Chen, J.; Wei, B. Metal-ceramic bond strength of Co-Cr alloy fabricated by selective laser melting. J. Dent. 2012, 40, 453-457. [CrossRef] open in new tab
  69. Wu, L.; Zhu, H.; Gai, X.; Wang, Y. Evaluation of the mechanical properties and porcelain bond strength of cobalt-chromium dental alloy fabricated by selective laser melting. J. Prosthet. Dent. 2014, 111, 51-55. [CrossRef] open in new tab
  70. Frutos, G.; Pastorr, J.Y.; Martinez, N.; Virto, M.R.; Torrado, S. Influence of lactose addition to gentamicin-loaded acrylic bone cement on the kinetics of release of the antibiotic and the cement properties. Acta Biomater. 2010, 6, 804-811. [CrossRef] open in new tab
  71. Miola, M.; Bistolfi, A.; Valsania, M.C.; Bianco, C.; Fucale, G.; Verné, E. Antibiotic-loaded acrylic bone cements: An in vitro study on the release mechanism and its efficacy. Mater. Sci. Eng. C 2013, 33, 3025-3032. [CrossRef] open in new tab
  72. Prokopovich, P.; Köbrick, M.; Brousseau, E.; Perni, S. Potent antimicrobial activity of bone cement encapsulating silver nanoparticles capped with oleic acid. J. Biomed. Mater. Res. Part B Appl. Biomater. 2015, 103, 273-281. [CrossRef] open in new tab
  73. Materials 2019, 12, 2964 21 of 21 open in new tab
  74. Alt, V.; Bechert, T.; Steinrücke, P.; Wagener, M.; Seidel, P.; Dingeldein, E.; Domann, E.; Schnettler, R. An in vitro assessment of the antibacterial properties and cytotoxicity of nanoparticulate silver bone cement. Biomaterials 2004, 25, 4383-4391. [CrossRef] open in new tab
  75. Slane, J.; Vivanco, J.; Rose, W.; Ploeg, H.L.; Squire, M. Mechanical, material, and antimicrobial properties of acrylic bone cement impregnated with silver nanoparticles. Mater. Sci. Eng. C 2015, 48, 188-196. [CrossRef] open in new tab
  76. Moojen, D.J.F.; Vogely, H.C.; Fleer, A.; Verbout, A.J.; Castelein, R.M.; Dhert, W.J.A. No efficacy of silver bone cement in the prevention of methicillin-sensitive Staphylococcal infections in a rabbit contaminated implant bed model. J. Orthop. Res. 2009, 27, 1002-1007. [CrossRef] open in new tab
  77. Pauksch, L.; Hartmann, S.; Szalay, G.; Alt, V.; Lips, K.S. In vitro assessment of nanosilver-functionalized PMMA bone cement on primary human mesenchymal stem cells and osteoblasts. PLoS ONE 2014, 9, e114740. [CrossRef] open in new tab
  78. Matos, A.C.; Goncalves, L.M.; Rijo, P.; Vaz, M.A.; Almeida, A.J.; Bettencourt, A.F. A novel modified acrylic bone cement matrix. A step forward on antibiotic delivery against multiresistant bacteria responsible for prosthetic joint infections. Mater. Sci. Eng. C 2014, 38, 218-226. [CrossRef] open in new tab
  79. Paz, E.; Sanz-Ruiz, P.; Abenojar, J.; Vaquero-Martín, J.; Forriol, F.; Del Real, J.C. Evaluation of elution and mechanical properties of high-dose antibiotic-loaded bone cement: Comparative "In Vitro" study of the influence of vancomycin and cefazolin. J. Arhroplast. 2015, 30, 1423-1429. [CrossRef] open in new tab
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