{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T02:44:23Z","timestamp":1791945863751,"version":"4.3.4"},"reference-count":52,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2021,2,8]],"date-time":"2021-02-08T00:00:00Z","timestamp":1612742400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001711","name":"Swiss National Science Foundation","doi-asserted-by":"publisher","award":["310030_149958"],"award-info":[{"award-number":["310030_149958"]}],"id":[{"id":"10.13039\/501100001711","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Stiftung Lindenhof Bern","award":["17-15-F"],"award-info":[{"award-number":["17-15-F"]}]},{"DOI":"10.13039\/501100001824","name":"Czech Science Foundation","doi-asserted-by":"publisher","award":["20\/13017S"],"award-info":[{"award-number":["20\/13017S"]}],"id":[{"id":"10.13039\/501100001824","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Grant Agency of Charles University","award":["SVV 2020\/260414"],"award-info":[{"award-number":["SVV 2020\/260414"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Steroid hormones play a crucial role in supporting a successful pregnancy and ensuring proper fetal development. The placenta is one of the principal tissues in steroid production and metabolism, expressing a vast range of steroidogenic enzymes. Nevertheless, a comprehensive characterization of steroidogenic pathways in the human placenta and potential developmental changes occurring during gestation are poorly understood. Furthermore, the specific contribution of trophoblast cells in steroid release is largely unknown. Thus, this study aimed to (i) identify gestational age-dependent changes in the gene expression of key steroidogenic enzymes and (ii) explore the role of trophoblast cells in steroid biosynthesis and metabolism. Quantitative and Droplet Digital PCR analysis of 12 selected enzymes was carried out in the first trimester (n = 13) and term (n = 20) human placentas. Primary trophoblast cells (n = 5) isolated from human term placentas and choriocarcinoma-derived cell lines (BeWo, BeWo b30 clone, and JEG-3) were further screened for gene expression of enzymes involved in placental synthesis\/metabolism of steroids. Finally, de novo steroid synthesis by primary human trophoblasts was evaluated, highlighting the functional activity of steroidogenic enzymes in these cells. Collectively, we provide insights into the expression patterns of steroidogenic enzymes as a function of gestational age and delineate the cellular origin of steroidogenesis in the human placenta.<\/jats:p>","DOI":"10.3390\/ijms22041704","type":"journal-article","created":{"date-parts":[[2021,2,9]],"date-time":"2021-02-09T23:43:16Z","timestamp":1612914196000},"page":"1704","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":57,"title":["Revisiting Steroidogenic Pathways in the Human Placenta and Primary Human Trophoblast Cells"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1962-0288","authenticated-orcid":false,"given":"Rona","family":"Karahoda","sequence":"first","affiliation":[{"name":"Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University, Akademika Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sampada","family":"Kallol","sequence":"additional","affiliation":[{"name":"Institute of Biochemistry and Molecular Medicine, University of Bern, B\u00fchlstrasse 28, 3012 Bern, Switzerland"},{"name":"Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, 3012 Bern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6740-5980","authenticated-orcid":false,"given":"Michael","family":"Groessl","sequence":"additional","affiliation":[{"name":"Department of Nephrology and Hypertension, Department of Biomedical Research, Inselspital, University of Bern, Freiburgstrasse 15, 3010 Bern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Edgar","family":"Ontsouka","sequence":"additional","affiliation":[{"name":"Institute of Biochemistry and Molecular Medicine, University of Bern, B\u00fchlstrasse 28, 3012 Bern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pascale","family":"Anderle","sequence":"additional","affiliation":[{"name":"Sitem Center for Translational Medicine and Biomedical Entrepreneurship and Sitem-Insel AG, University of Bern, Freiburgstrasse 3, 3010 Bern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4568-5504","authenticated-orcid":false,"given":"Christa","family":"Fluck","sequence":"additional","affiliation":[{"name":"Pediatric Endocrinology, Diabetology and Metabolism, Department of Pediatrics, Department of Biomedical Research, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse 15, 3010 Bern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6712-097X","authenticated-orcid":false,"given":"Frantisek","family":"Staud","sequence":"additional","affiliation":[{"name":"Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Kralove, Charles University, Akademika Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7846-6930","authenticated-orcid":false,"given":"Christiane","family":"Albrecht","sequence":"additional","affiliation":[{"name":"Institute of Biochemistry and Molecular Medicine, University of Bern, B\u00fchlstrasse 28, 3012 Bern, Switzerland"},{"name":"Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, 3012 Bern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,2,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3479","DOI":"10.1007\/s00018-019-03104-6","article-title":"Human placenta and trophoblast development: Key molecular mechanisms and model systems","volume":"76","author":"Haider","year":"2019","journal-title":"Cell. Mol. Life Sci."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Napso, T., Yong, H.E.J., Lopez-Tello, J., and Sferruzzi-Perri, A.N. (2018). The Role of Placental Hormones in Mediating Maternal Adaptations to Support Pregnancy and Lactation. Front. Physiol., 9.","DOI":"10.3389\/fphys.2018.01091"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1016\/j.placenta.2005.01.001","article-title":"Corticosterone transfer and metabolism in the dually perfused rat placenta: Effect of 11beta-hydroxysteroid dehydrogenase type 2","volume":"27","author":"Staud","year":"2006","journal-title":"Placenta"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"640","DOI":"10.1210\/jc.2017-02140","article-title":"Transfer and Metabolism of Cortisol by the Isolated Perfused Human Placenta","volume":"103","author":"Stirrat","year":"2018","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1046\/j.1365-2265.1997.1230939.x","article-title":"Placental 11 beta-hydroxysteroid dehydrogenase: A key regulator of fetal glucocorticoid exposure","volume":"46","author":"Benediktsson","year":"1997","journal-title":"Clin. Endocrinol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1027","DOI":"10.3389\/fphar.2018.01027","article-title":"Physiology and Pathophysiology of Steroid Biosynthesis, Transport and Metabolism in the Human Placenta","volume":"9","author":"Chatuphonprasert","year":"2018","journal-title":"Front Pharm."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"376","DOI":"10.1080\/09513590.2018.1564742","article-title":"Steroid hormones and pregnancy","volume":"35","author":"Halhali","year":"2019","journal-title":"Gynecol. Endocrinol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1096","DOI":"10.1111\/j.1471-0528.2005.00633.x","article-title":"Modulation of cytokine production by dydrogesterone in lymphocytes from women with recurrent miscarriage","volume":"112","author":"Raghupathy","year":"2005","journal-title":"BJOG"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1007\/BF02820507","article-title":"Progesterone-dependent decidualization of the human endometrium is mediated by cAMP","volume":"6","author":"Brar","year":"1997","journal-title":"Endocrine"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1016\/j.mce.2011.05.034","article-title":"The effects of human chorionic gonadotrophin, progesterone and oestradiol on trophoblast function","volume":"342","author":"Chen","year":"2011","journal-title":"Mol. Cell Endocrinol."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"O\u2019Shaughnessy, P.J., Antignac, J.P., Le Bizec, B., Morvan, M.L., Svechnikov, K., S\u00f6der, O., Savchuk, I., Monteiro, A., Soffientini, U., and Johnston, Z.C. (2019). Alternative (backdoor) androgen production and masculinization in the human fetus. PLoS Biol., 17.","DOI":"10.1371\/journal.pbio.3000002"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"397","DOI":"10.1387\/ijdb.082758ea","article-title":"Estrogen regulation of placental angiogenesis and fetal ovarian development during primate pregnancy","volume":"54","author":"Albrecht","year":"2010","journal-title":"Int. J. Dev. Biol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1093\/humupd\/dmn021","article-title":"Potential significance of physiological and pharmacological glucocorticoids in early pregnancy","volume":"14","author":"Michael","year":"2008","journal-title":"Hum. Reprod. Update"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"938","DOI":"10.1016\/0140-6736(93)91224-A","article-title":"Fetal nutrition and cardiovascular disease in adult life","volume":"341","author":"Barker","year":"1993","journal-title":"Lancet"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1016\/0140-6736(93)90148-A","article-title":"Dysfunction of placental glucocorticoid barrier: Link between fetal environment and adult hypertension?","volume":"341","author":"Edwards","year":"1993","journal-title":"Lancet"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"947","DOI":"10.1210\/er.2003-0030","article-title":"Overview of steroidogenic enzymes in the pathway from cholesterol to active steroid hormones","volume":"25","author":"Payne","year":"2004","journal-title":"Endocr. Rev."},{"key":"ref_17","unstructured":"Benirschke, K., Kaufmann, P., and Baergen, R. (2016). Pathology of the Human Placenta, Springer."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"42941","DOI":"10.1038\/srep42941","article-title":"Cytotrophoblast, Not Syncytiotrophoblast, Dominates Glycolysis and Oxidative Phosphorylation in Human Term Placenta","volume":"7","author":"Kolahi","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"989","DOI":"10.1016\/j.placenta.2010.08.011","article-title":"Trophoblast invasion: Assessment of cellular models using gene expression signatures","volume":"31","author":"Bilban","year":"2010","journal-title":"Placenta"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"48","DOI":"10.1016\/j.placenta.2018.10.008","article-title":"Comparative expression patterns of selected membrane transporters in differentiated BeWo and human primary trophoblast cells","volume":"72","author":"Kallol","year":"2018","journal-title":"Placenta"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Karahoda, R., Abad, C., Horackova, H., Kastner, P., Zaugg, J., Cerveny, L., Kucera, R., Albrecht, C., and Staud, F. (2020). Dynamics of Tryptophan Metabolic Pathways in Human Placenta and Placental-Derived Cells: Effect of Gestation Age and Trophoblast Differentiation. Front. Cell Dev. Biol., 8.","DOI":"10.3389\/fcell.2020.574034"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1016\/j.biocel.2018.09.016","article-title":"Trophoblast: The central unit of fetal growth, protection and programming","volume":"105","author":"Staud","year":"2018","journal-title":"Int. J. Biochem. Cell Biol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1016\/j.rbmo.2015.10.005","article-title":"The endocrine function of human placenta: An overview","volume":"32","author":"Costa","year":"2016","journal-title":"Reprod. Biomed. Online"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1145","DOI":"10.1210\/jcem-63-5-1145","article-title":"Developmental expression of genes for the stereoidogenic enzymes P450scc (20,22-desmolase), P450c17 (17 alpha-hydroxylase\/17,20-lyase), and P450c21 (21-hydroxylase) in the human fetus","volume":"63","author":"Voutilainen","year":"1986","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"751","DOI":"10.1210\/jcem-26-7-751","article-title":"Placental estrogen biosynthesis during human pregnancy","volume":"26","author":"Siiteri","year":"1966","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_26","first-page":"455","article-title":"The conversion of progesterone to 17 alpha-hydroxyprogesterone by human placenta in vitro","volume":"36","author":"Little","year":"1961","journal-title":"Acta Endocrinol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1385","DOI":"10.1210\/jc.2010-2504","article-title":"The human placenta expresses CYP17 and generates androgens de novo","volume":"96","author":"Escobar","year":"2011","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_28","first-page":"1309","article-title":"P450(17 alpha) and P450SCC gene expression and regulation in the rat placenta","volume":"130","author":"Durkee","year":"1992","journal-title":"Endocrinology"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"799","DOI":"10.1210\/jcem-35-6-799","article-title":"Sources of plasma 17alpha-hydroxyprogesterone in human pregnancy","volume":"35","author":"Tulchinsky","year":"1972","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Baronio, F., Ortolano, R., Menab\u00f2, S., Cassio, A., Baldazzi, L., Di Natale, V., Tonti, G., Vestrucci, B., and Balsamo, A. (2019). 46,XX DSD due to Androgen Excess in Monogenic Disorders of Steroidogenesis: Genetic, Biochemical, and Clinical Features. Int. J. Mol. Sci., 20.","DOI":"10.3390\/ijms20184605"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1235","DOI":"10.1210\/jcem-51-6-1235","article-title":"Plasma steroid concentrations in maternal and umbilical circulation after spontaneous onset of labor","volume":"51","author":"Mathur","year":"1980","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1147","DOI":"10.1210\/mend-5-8-1147","article-title":"Structure and expression of a new complementary DNA encoding the almost exclusive 3 beta-hydroxysteroid dehydrogenase\/delta 5-delta 4-isomerase in human adrenals and gonads","volume":"5","author":"Lachance","year":"1991","journal-title":"Mol. Endocrinol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1016\/j.ajhg.2011.06.009","article-title":"Why boys will be boys: Two pathways of fetal testicular androgen biosynthesis are needed for male sexual differentiation","volume":"89","author":"Pandey","year":"2011","journal-title":"Am. J. Hum. Genet."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"3003","DOI":"10.1021\/bi00226a004","article-title":"Purification of human placental aromatase cytochrome P-450 with monoclonal antibody and its characterization","volume":"30","author":"Yoshida","year":"1991","journal-title":"Biochemistry"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"E181","DOI":"10.1073\/pnas.1617115114","article-title":"Glucocorticoid receptor in T cells mediates protection from autoimmunity in pregnancy","volume":"114","author":"Engler","year":"2017","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"3017","DOI":"10.3389\/fimmu.2019.03017","article-title":"Steroids, Pregnancy and Fetal Development","volume":"10","author":"Solano","year":"2020","journal-title":"Front. Immunol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"739","DOI":"10.1016\/S0143-4004(03)00103-6","article-title":"Alterations in human placental 11beta-hydroxysteroid dehydrogenase type 1 and 2 with gestational age and labour","volume":"24","author":"Murphy","year":"2003","journal-title":"Placenta"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1016\/j.jsbmb.2005.08.004","article-title":"Enzymes involved in the formation and transformation of steroid hormones in the fetal and placental compartments","volume":"97","author":"Pasqualini","year":"2005","journal-title":"J. Steroid. Biochem. Mol. Biol."},{"key":"ref_39","first-page":"300","article-title":"Differential expression of 11 beta-hydroxysteroid dehydrogenase types 1 and 2 in human placenta and fetal membranes","volume":"82","author":"Sun","year":"1997","journal-title":"J. Clin. Endocrinol. Metab."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"425","DOI":"10.1530\/rep.0.1260425","article-title":"Glucocorticoid metabolism and reproduction: A tale of two enzymes","volume":"126","author":"Michael","year":"2003","journal-title":"Reproduction"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1002\/ajmg.a.33140","article-title":"Hypospadias in males with intrauterine growth restriction due to placental insufficiency: The placental role in the embryogenesis of male external genitalia","volume":"152a","author":"Yinon","year":"2010","journal-title":"Am. J. Med. Genet. A"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1210\/en.2016-1801","article-title":"Gestational Hyperandrogenism in Developmental Programming","volume":"158","author":"Hakim","year":"2017","journal-title":"Endocrinology"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"657","DOI":"10.3109\/09513590.2013.788623","article-title":"Glucocorticoid synthesis-related genes: HSD11B1 and HSD11B2 in hypertensive disorders in pregnancy","volume":"29","author":"Shimodaira","year":"2013","journal-title":"Gynecol. Endocrinol."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"700","DOI":"10.1007\/s12020-012-9699-7","article-title":"Estrogen synthesis genes CYP19A1, HSD3B1, and HSD3B2 in hypertensive disorders of pregnancy","volume":"42","author":"Shimodaira","year":"2012","journal-title":"Endocrine"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1567","DOI":"10.1210\/endo-118-4-1567","article-title":"Purification, characterization, and in vitro differentiation of cytotrophoblasts from human term placentae","volume":"118","author":"Kliman","year":"1986","journal-title":"Endocrinology"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1016\/j.jim.2003.03.001","article-title":"Evaluation of Cytokeratin 7 as an accurate intracellular marker with which to assess the purity of human placental villous trophoblast cells by flow cytometry","volume":"286","author":"Menu","year":"2004","journal-title":"J. Immunol. Methods"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1186\/s12958-015-0070-8","article-title":"Isolation, purification and in vitro differentiation of cytotrophoblast cells from human term placenta","volume":"13","author":"Li","year":"2015","journal-title":"Reprod. Biol. Endocrinol."},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Xie, F., Xiao, P., Chen, D., Xu, L., and Zhang, B. (2012). miRDeepFinder: A miRNA analysis tool for deep sequencing of plant small RNAs. Plant Mol. Biol.","DOI":"10.1007\/s11103-012-9885-2"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"research0034.0031","DOI":"10.1186\/gb-2002-3-7-research0034","article-title":"Accurate normalization of real-time quantitative RT-PCR data by geometric averaging of multiple internal control genes","volume":"3","author":"Vandesompele","year":"2002","journal-title":"Genome Biol."},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Karahoda, R., Horackova, H., Kastner, P., Matthios, A., Cerveny, L., Kucera, R., Kacerovsky, M., Tebbens, J.D., Bonnin, A., and Abad, C. (2020). Serotonin homeostasis in the materno-fetal interface at term: Role of transporters (SERT\/SLC6A4 and OCT3\/SLC22A3) and monoamine oxidase A (MAO-A) in uptake and degradation of serotonin by human and rat term placenta. Acta Physiol.","DOI":"10.1111\/apha.13478"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1016\/j.jsbmb.2014.10.006","article-title":"An LC-MS\/MS method for steroid profiling during adrenal venous sampling for investigation of primary aldosteronism","volume":"145","author":"Peitzsch","year":"2015","journal-title":"J. Steroid. Biochem. Mol. Biol."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"W147","DOI":"10.1093\/nar\/gkw419","article-title":"Heatmapper: Web-enabled heat mapping for all","volume":"44","author":"Babicki","year":"2016","journal-title":"Nucleic Acids Res."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/22\/4\/1704\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:21:29Z","timestamp":1760160089000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/22\/4\/1704"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,2,8]]},"references-count":52,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2021,2]]}},"alternative-id":["ijms22041704"],"URL":"https:\/\/doi.org\/10.3390\/ijms22041704","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,2,8]]}}}