“…The first authors of the included articles were affiliated with institutes from the following countries: the USA n = 14 [1, 2, 6, 9, 10, 12, 13, 16-18, 20, 32, 34, 42] , Switzerland n = 7 [3-5, 8, 31, 37, 44] , the UK n = 5 [7,21,30,39,46] , Germany n = 5 [27,28,40,48,49] , Australia n = 5 [11,14,15,19,29] , Japan n = 4 [22][23][24][25] , Belgium n = 4 [26,33,35,36] , the Netherlands n = 1 [47] , China n = 1 [41] , Taiwan n = 1 [45] , Italy n = 1 [38] and Canada n = 1 [43] . Most authors worked together in eight research groups, and three articles were co-authored by members of separate research groups.…”