{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2023,8,20]],"date-time":"2023-08-20T13:53:15Z","timestamp":1692539595170},"reference-count":41,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2021,4,7]],"date-time":"2021-04-07T00:00:00Z","timestamp":1617753600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2021,4,7]],"date-time":"2021-04-07T00:00:00Z","timestamp":1617753600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Sci Rep"],"abstract":"<jats:title>Abstract<\/jats:title><jats:p>Time-of-flight secondary ion mass spectrometry fragment analysis remains a challenging task. The fragment appearance regularity (FAR) rule is particularly useful for two-element compounds such as ZnO. Ion fragments appearing in the form of Zn<jats:sub><jats:italic>x<\/jats:italic><\/jats:sub>O<jats:sub><jats:italic>y<\/jats:italic><\/jats:sub> obey the rule <jats:inline-formula><jats:alternatives><jats:tex-math>$$2x \\ge 2y + 1$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                  <mml:mrow>\n                    <mml:mn>2<\/mml:mn>\n                    <mml:mi>x<\/mml:mi>\n                    <mml:mo>\u2265<\/mml:mo>\n                    <mml:mn>2<\/mml:mn>\n                    <mml:mi>y<\/mml:mi>\n                    <mml:mo>+<\/mml:mo>\n                    <mml:mn>1<\/mml:mn>\n                  <\/mml:mrow>\n                <\/mml:math><\/jats:alternatives><\/jats:inline-formula> in the positive secondary ion spectrum and <jats:inline-formula><jats:alternatives><jats:tex-math>$$2x \\le 2y + 1$$<\/jats:tex-math><mml:math xmlns:mml=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                  <mml:mrow>\n                    <mml:mn>2<\/mml:mn>\n                    <mml:mi>x<\/mml:mi>\n                    <mml:mo>\u2264<\/mml:mo>\n                    <mml:mn>2<\/mml:mn>\n                    <mml:mi>y<\/mml:mi>\n                    <mml:mo>+<\/mml:mo>\n                    <mml:mn>1<\/mml:mn>\n                  <\/mml:mrow>\n                <\/mml:math><\/jats:alternatives><\/jats:inline-formula> in the negative spectrum where the valence of Zn is\u2009+\u20092 and that of O is \u2212\u20092. Fragment analysis in gallium-doped ZnO (GZO) films can give insights into the bonding of the elements in this important semiconductor. Fragment analysis of 1 and 7\u00a0wt% GZO films shows that only the negative ion fragments obey the FAR rule where ZnO<jats:sup>\u2012<\/jats:sup>, <jats:sup>66<\/jats:sup>ZnO<jats:sup>\u2012<\/jats:sup>, <jats:sup>68<\/jats:sup>ZnO<jats:sup>\u2012<\/jats:sup> and ZnO<jats:sub>2<\/jats:sub><jats:sup>\u2012<\/jats:sup> ion fragments appear. In the positive polarity, subdued peaks from out-of-the-rule ZnO<jats:sup>+<\/jats:sup>, <jats:sup>66<\/jats:sup>ZnO<jats:sup>+<\/jats:sup> and <jats:sup>68<\/jats:sup>ZnO<jats:sup>+<\/jats:sup> ion fragments are observed. The Ga ion peaks are present in both the positive and negative spectra. The secondary ion spectra of undoped ZnO also shows consistency with the FAR rule. This implies that Ga doping even in amounts that exceed the ZnO lattice limit of solubility does not affect the compliance with the FAR rule.<\/jats:p>","DOI":"10.1038\/s41598-021-87386-6","type":"journal-article","created":{"date-parts":[[2021,4,7]],"date-time":"2021-04-07T10:12:21Z","timestamp":1617790341000},"update-policy":"http:\/\/dx.doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Time-of-flight secondary ion mass spectrometry fragment regularity in gallium-doped zinc oxide thin films"],"prefix":"10.1038","volume":"11","author":[{"given":"K. G.","family":"Saw","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"S. R.","family":"Esa","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"297","published-online":{"date-parts":[[2021,4,7]]},"reference":[{"key":"87386_CR1","doi-asserted-by":"publisher","first-page":"24247","DOI":"10.1021\/jp208035x","volume":"115","author":"S Muramoto","year":"2011","unstructured":"Muramoto, S. et al. ToF-SIMS analysis of adsorbed proteins: principal component analysis of the primary ion species effect on the protein fragmentation patterns. J. Phys. Chem. C 115, 24247\u201324255 (2011).","journal-title":"J. Phys. Chem. C"},{"key":"87386_CR2","doi-asserted-by":"publisher","first-page":"49","DOI":"10.1007\/s13758-012-0049-3","volume":"7","author":"DJ Daniel","year":"2012","unstructured":"Daniel, D. J. & Castner, D. G. Multivariate analysis of ToF-SIMS data from multicomponent systems: the why, when, and how. Biointerphases 7, 49 (2012).","journal-title":"Biointerphases"},{"key":"87386_CR3","doi-asserted-by":"publisher","first-page":"6860","DOI":"10.1016\/j.apsusc.2006.02.149","volume":"252","author":"DJ Graham","year":"2006","unstructured":"Graham, D. J., Wagner, M. S. & Castner, D. G. Information from complexity: challenges of ToF-SIMS data interpretation. Appl. Surf. Sci. 252, 6860\u20136868 (2006).","journal-title":"Appl. Surf. Sci."},{"key":"87386_CR4","doi-asserted-by":"publisher","first-page":"136","DOI":"10.1016\/S0169-4332(03)00839-0","volume":"220","author":"Z Li","year":"2003","unstructured":"Li, Z. & Hirokawa, K. Ga+ primary ion ToF-SIMS fragment pattern of inorganic compounds and metals. Appl. Surf. Sci. 220, 136\u2013153 (2003).","journal-title":"Appl. Surf. Sci."},{"key":"87386_CR5","doi-asserted-by":"publisher","first-page":"348","DOI":"10.1007\/s002160100811","volume":"370","author":"K Hirokawa","year":"2001","unstructured":"Hirokawa, K., Li, Z. & Tanaka, A. Role of electronegativity in the qualitative inference of the ToF-SIMS fragment pattern of inorganic compounds. Fresenius J. Anal Chem. 370, 348\u2013357 (2001).","journal-title":"Fresenius J. Anal Chem."},{"key":"87386_CR6","doi-asserted-by":"publisher","first-page":"359","DOI":"10.1380\/jsssj.25.359","volume":"25","author":"Z Li","year":"2004","unstructured":"Li, Z. & Hirokawa, K. Possibility of the thickness estimation of Si surface oxides using Ga+ primary ion TOF-SIMS. J. Surf. Sci. Soc. Jpn. 25, 359\u2013362 (2004).","journal-title":"J. Surf. Sci. Soc. Jpn."},{"key":"87386_CR7","doi-asserted-by":"publisher","first-page":"736","DOI":"10.1380\/jsssj.23.736","volume":"23","author":"Z Li","year":"2002","unstructured":"Li, Z. & Hirokawa, K. Observation of Ga+ primary ion TOF-SIMS fragment pattern obtained from water containing oxide surfaces. J. Surf. Sci. Soc. Jpn. 23, 736\u2013739 (2002).","journal-title":"J. Surf. Sci. Soc. Jpn."},{"key":"87386_CR8","doi-asserted-by":"publisher","first-page":"818","DOI":"10.1002\/1096-9918(200012)29:12<818::AID-SIA931>3.0.CO;2-4","volume":"29","author":"S Bukallah","year":"2000","unstructured":"Bukallah, S., Houalla, M. & Hercules, D. M. Characterization of supported Nb catalysts by ToF-SIMS. Surf. Interface Anal. 29, 818\u2013822 (2000).","journal-title":"Surf. Interface Anal."},{"key":"87386_CR9","doi-asserted-by":"publisher","first-page":"4544","DOI":"10.1002\/anie.201411581","volume":"54","author":"T Lunkenbein","year":"2015","unstructured":"Lunkenbein, T., Schumann, J., Behrens, M., Schlogl, R. & Willinger, M. G. Formation of a ZnO overlayer in industrial Cu\/ZnO\/Al2O3 catalysts induced by strong metal\u2013support interactions. Angew. Chem. Int. Ed. Engl. 54, 4544\u20134548 (2015).","journal-title":"Angew. Chem. Int. Ed. Engl."},{"key":"87386_CR10","doi-asserted-by":"publisher","first-page":"3260","DOI":"10.1021\/acscatal.5b00188","volume":"5","author":"J Schumann","year":"2015","unstructured":"Schumann, J. et al. Promoting strong metal support interaction: doping ZnO for enhanced activity of Cu\/ZnO: M (M = Al, Ga, Mg) catalysts. ACS Catal. 5, 3260\u20133270 (2015).","journal-title":"ACS Catal."},{"key":"87386_CR11","doi-asserted-by":"publisher","first-page":"305201","DOI":"10.1088\/1361-6528\/ab1739","volume":"30","author":"DM Kinyua","year":"2019","unstructured":"Kinyua, D. M. et al. Gigahertz acoustic vibrations of Ga-doped ZnO nanoparticle array. Nanotechnology 30, 305201 (2019).","journal-title":"Nanotechnology"},{"key":"87386_CR12","doi-asserted-by":"publisher","first-page":"638","DOI":"10.1038\/s41598-020-57532-7","volume":"10","author":"SD Ponja","year":"2020","unstructured":"Ponja, S. D., Santhasivam, S., Parkin, I. P. & Carmalt, C. J. Highly conductive and transparent gallium doped zinc oxide thin films via chemical vapor deposition. Sci. Rep. 10, 638 (2020).","journal-title":"Sci. Rep."},{"key":"87386_CR13","first-page":"100386","volume":"14","author":"S Majumder","year":"2020","unstructured":"Majumder, S., Chatterjee, S., Basnet, P. & Mukherjee, J. ZnO based nanomaterials for photocatalytic degradation of aqueous pharmaceutical waste solutions\u2014a contemporary review. Environ. Nanotechnol. Monit. Manag. 14, 100386 (2020).","journal-title":"Environ. Nanotechnol. Monit. Manag."},{"key":"87386_CR14","doi-asserted-by":"publisher","first-page":"4131","DOI":"10.1016\/j.tsf.2011.04.067","volume":"520","author":"N Yamamoto","year":"2012","unstructured":"Yamamoto, N. et al. Development of Ga-doped ZnO transparent electrodes for liquid crystal display panels. Thin Solid Films 520, 4131\u20134138 (2012).","journal-title":"Thin Solid Films"},{"key":"87386_CR15","doi-asserted-by":"publisher","first-page":"203506","DOI":"10.1063\/1.3517506","volume":"97","author":"HW Zan","year":"2010","unstructured":"Zan, H. W. et al. Amorphous indium-gallium-zinc-oxide visible-light phototransistor with a polymeric light absorption layer. Appl. Phys. Lett. 97, 203506 (2010).","journal-title":"Appl. Phys. Lett."},{"key":"87386_CR16","doi-asserted-by":"publisher","first-page":"8591","DOI":"10.1007\/s10853-017-1084-8","volume":"52","author":"S Edinger","year":"2017","unstructured":"Edinger, S. et al. Highly transparent and conductive indium-doped zinc oxide films deposited at low substrate temperature by spray pyrolysis from water-based solutions. J. Mater. Sci. 52, 8591\u20138602 (2017).","journal-title":"J. Mater. Sci."},{"key":"87386_CR17","doi-asserted-by":"publisher","first-page":"198","DOI":"10.1016\/j.vacuum.2014.11.007","volume":"114","author":"NA Vorobyeva","year":"2015","unstructured":"Vorobyeva, N. A. et al. Doping effects on electrical and optical properties of spin-coated ZnO thin films. Vacuum 114, 198\u2013204 (2015).","journal-title":"Vacuum"},{"key":"87386_CR18","doi-asserted-by":"publisher","first-page":"10820","DOI":"10.1039\/C6TC04366F","volume":"4","author":"J Wang","year":"2016","unstructured":"Wang, J. et al. High-efficiency polymer solar cells employing solution-processible and thickness-independent gallium-doped zinc oxide nanoparticles as cathode buffer layers. J. Mater. Chem. C 4, 10820\u201310826 (2016).","journal-title":"J. Mater. Chem. C"},{"key":"87386_CR19","doi-asserted-by":"publisher","first-page":"6867","DOI":"10.1038\/s41598-018-25106-3","volume":"8","author":"BMM Faustino","year":"2018","unstructured":"Faustino, B. M. M. et al. CuI p-type thin films for highly transparent thermoelectric p\u2013n modules. Sci. Rep. 8, 6867 (2018).","journal-title":"Sci. Rep."},{"key":"87386_CR20","doi-asserted-by":"crossref","unstructured":"Jung, Cho et al. Enhancement of photoluminescence and electrical of Ga-doped ZnO thin film grown on \u03b1-Al2O3(0001) single crystal substrate by rf magnetron sputtering through rapid thermal annealing. Jpn. J. Appl. Phys. 40, L1040 (2001).","DOI":"10.1143\/JJAP.40.L1040"},{"key":"87386_CR21","doi-asserted-by":"publisher","first-page":"6245","DOI":"10.1016\/j.tsf.2010.02.068","volume":"518","author":"E Nam","year":"2010","unstructured":"Nam, E., Kang, Y. H., Jung, D. & Kim, Y. S. Anode material properties of Ga-doped ZnO thin films by pulsed dc magnetron sputtering method for organic light emitting diode. Thin Solid Films 518, 6245\u20136248 (2010).","journal-title":"Thin Solid Films"},{"key":"87386_CR22","doi-asserted-by":"publisher","first-page":"184","DOI":"10.1016\/j.tsf.2018.09.004","volume":"665","author":"FC Correira","year":"2018","unstructured":"Correira, F. C. et al. Combined in-depth X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectroscopy study of the effect of deposition pressure and substrate bias on the electrical properties and composition of Ga-doped ZnO thin films grown by magnetron sputtering. Thin Solid Films 665, 184\u2013192 (2018).","journal-title":"Thin Solid Films"},{"key":"87386_CR23","doi-asserted-by":"publisher","first-page":"64","DOI":"10.1016\/j.jcrysgro.2007.01.037","volume":"304","author":"QB Ma","year":"2007","unstructured":"Ma, Q. B. et al. Structural, electrical, and optical properties of transparent conductive ZnO: Ga films prepared by dc reactive magnetron sputtering. J. Crys. Growth 304, 64\u201368 (2007).","journal-title":"J. Crys. Growth"},{"key":"87386_CR24","doi-asserted-by":"publisher","first-page":"10066","DOI":"10.1016\/j.ceramint.2016.03.110","volume":"42","author":"E Muchuweni","year":"2016","unstructured":"Muchuweni, E., Sathiaraj, T. S. & Nyakotyo, H. Effect of gallium doping on the structural, optical and electrical properties of zinc oxide thin films prepared by spray pyrolysis. Ceram. Int. 42, 10066\u201310070 (2016).","journal-title":"Ceram. Int."},{"key":"87386_CR25","doi-asserted-by":"publisher","first-page":"10603","DOI":"10.1016\/j.ceramint.2020.01.064","volume":"46","author":"J Kang","year":"2020","unstructured":"Kang, J. & Koh, J. H. The effect of Ga doping on ZnO thin films subjected to CO2 laser annealing. Ceram. Int. 46, 10603\u201310609 (2020).","journal-title":"Ceram. Int."},{"key":"87386_CR26","first-page":"13865","volume":"5","author":"S Santibenchakul","year":"2018","unstructured":"Santibenchakul, S., Sirijaturaporn, P., Mekprasart, W. & Pechrapa, W. Ga-doped ZnO nanoparticles synthesized by sonochemical-assisted process. Mater. Today: Proc. 5, 13865\u201313869 (2018).","journal-title":"Mater. Today: Proc."},{"key":"87386_CR27","doi-asserted-by":"publisher","first-page":"90","DOI":"10.1016\/j.tsf.2006.01.051","volume":"513","author":"SM Park","year":"2006","unstructured":"Park, S. M., Ikegami, T. & Ebihara, K. Effects of substrate temperature on the properties of Ga-doped ZnO by pulsed laser deposition. Thin Solid Films 513, 90\u201394 (2006).","journal-title":"Thin Solid Films"},{"key":"87386_CR28","doi-asserted-by":"publisher","first-page":"272","DOI":"10.1016\/j.spmi.2005.08.004","volume":"38","author":"AR Kaul","year":"2005","unstructured":"Kaul, A. R., Gorbenko, O. Y., Botev, A. N. & Burova, L. I. MOCVD of pure and Ga-doped epitaxial ZnO. Superlatt. Microstruct. 38, 272\u2013282 (2005).","journal-title":"Superlatt. Microstruct."},{"key":"87386_CR29","doi-asserted-by":"publisher","first-page":"H909","DOI":"10.1149\/1.2976885","volume":"155","author":"YS Choi","year":"2008","unstructured":"Choi, Y. S. et al. Growth and characterization of gallium-doped ZnO films for \u03b1-particle scintillators. J. Electrochem. Soc. 155, H909\u2013H911 (2008).","journal-title":"J. Electrochem. Soc."},{"key":"87386_CR30","doi-asserted-by":"publisher","first-page":"13","DOI":"10.1016\/j.tsf.2015.04.036","volume":"586","author":"MV Castro","year":"2015","unstructured":"Castro, M. V. & Tavares, C. J. Dependence of Ga-doped ZnO thin film properties on different sputtering process parameters: substrate temperature, sputtering pressure and bias voltage. Thin Solid Films 586, 13\u201321 (2015).","journal-title":"Thin Solid Films"},{"key":"87386_CR31","doi-asserted-by":"publisher","first-page":"416","DOI":"10.3938\/jkps.53.416","volume":"53","author":"JC Lee","year":"2008","unstructured":"Lee, J. C. et al. Characteristic of Ga-doped ZnO films deposited by DC magnetron sputtering with a sintered ceramic ZnO: Ga target. J. Korean Phys. Soc. 53, 416\u2013420 (2008).","journal-title":"J. Korean Phys. Soc."},{"key":"87386_CR32","doi-asserted-by":"publisher","first-page":"2879","DOI":"10.1016\/j.tsf.2006.08.047","volume":"515","author":"KG Saw","year":"2007","unstructured":"Saw, K. G., Ibrahim, K., Lim, Y. T. & Chai, M. K. Self-compensation in ZnO thin films: an insight from x-ray photoelectron spectroscopy, Raman spectroscopy and time-of-flight secondary ion mass spectroscopy analyses. Thin Solid Films 515, 2879\u20132884 (2007).","journal-title":"Thin Solid Films"},{"key":"87386_CR33","doi-asserted-by":"publisher","first-page":"859","DOI":"10.1016\/S0032-0633(01)00037-X","volume":"49","author":"T Stephan","year":"2001","unstructured":"Stephan, T. TOF-SIMS in cosmochemistry. Planet Space Sci. 49, 859 (2001).","journal-title":"Planet Space Sci."},{"key":"87386_CR34","doi-asserted-by":"crossref","unstructured":"Zhu, Y., Olson, N. & Beer, T. P. Surface chemical characterization of 2.5-\u03bcm particulates (PM2.5) from air pollution in Salt Lake City using TOF-SIMS, XPS, and FTIR. Environ. Sci. Technol. 35, 3113 (2001).","DOI":"10.1021\/es0019530"},{"key":"87386_CR35","doi-asserted-by":"publisher","first-page":"71","DOI":"10.1016\/j.jes.2016.01.025","volume":"47","author":"Z Zhang","year":"2016","unstructured":"Zhang, Z. et al. A preliminary analysis of the surface chemistry of atmospheric aerosol particles in a typical urban area of Beijing. J. Environ. Sci. 47, 71 (2016).","journal-title":"J. Environ. Sci."},{"key":"87386_CR36","doi-asserted-by":"publisher","first-page":"899","DOI":"10.1016\/S1352-2310(01)00436-8","volume":"36","author":"VH Rita","year":"2002","unstructured":"Rita, V. H. et al. Static secondary ion mass spectrometry as a new analytical tool for measuring atmospheric particles on insulating substrates. Atmos. Environ. 36, 899\u2013909 (2002).","journal-title":"Atmos. Environ."},{"key":"87386_CR37","doi-asserted-by":"publisher","first-page":"413002","DOI":"10.1088\/0022-3727\/49\/41\/413002","volume":"49","author":"K Ellmer","year":"2016","unstructured":"Ellmer, K. & Bikowski, A. Intrinsic and extrinsic doping of ZnO and ZnO alloys. J. Phys. D. Appl. Phys. 49, 413002 (2016).","journal-title":"J. Phys. D. Appl. Phys."},{"key":"87386_CR38","doi-asserted-by":"publisher","first-page":"435","DOI":"10.1524\/rcpr.2011.0079","volume":"1","author":"W Sato","year":"2011","unstructured":"Sato, W. et al. Electric field gradient at the 111Cd(\u2190\u2009111In) site in Ga-doped ZnO. Proc. Radiochim. Acta. 1, 435\u2013438 (2011).","journal-title":"Proc. Radiochim. Acta."},{"key":"87386_CR39","doi-asserted-by":"publisher","first-page":"1365","DOI":"10.4028\/www.scientific.net\/MSF.258-263.1365","volume":"258\u2013263","author":"WW Warren","year":"1997","unstructured":"Warren, W. W., Roberts, N., Wang, R. P. & Sleight, A. W. NMR Study of carrier states and trapping complexes in the transparent conductor ZnO:MIII. Mater. Sci. Forum 258\u2013263, 1365\u20131370 (1997).","journal-title":"Mater. Sci. Forum"},{"key":"87386_CR40","doi-asserted-by":"publisher","first-page":"125","DOI":"10.1016\/j.apsusc.2014.01.096","volume":"297","author":"H Jung","year":"2014","unstructured":"Jung, H., Kim, D. & Kim, H. The electrical properties of low pressure chemical vapor deposition Ga doped ZnO thin films depending on chemical bonding configuration. Appl. Surf. Sci. 297, 125\u2013129 (2014).","journal-title":"Appl. Surf. Sci."},{"key":"87386_CR41","doi-asserted-by":"crossref","unstructured":"Choi, B. H., Im, H. B., Song, J. S. & Yoon, K. H. Optical and electrical properties of Ga2O3-doped ZnO films prepared by r.f. sputtering. Thin Solid Films 193\/194, 712\u2013720 (1990).","DOI":"10.1016\/0040-6090(90)90223-Z"}],"container-title":["Scientific Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.nature.com\/articles\/s41598-021-87386-6.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-021-87386-6","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-021-87386-6.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,12,3]],"date-time":"2022-12-03T06:20:08Z","timestamp":1670048408000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.nature.com\/articles\/s41598-021-87386-6"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,4,7]]},"references-count":41,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2021,12]]}},"alternative-id":["87386"],"URL":"https:\/\/doi.org\/10.1038\/s41598-021-87386-6","relation":{},"ISSN":["2045-2322"],"issn-type":[{"value":"2045-2322","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,4,7]]},"assertion":[{"value":"7 August 2020","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"26 March 2021","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"7 April 2021","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"The authors declare no competing interests.","order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"7644"}}