human 448 Humans 355 Article 210 male 207 female 199 adult 175 article 156 controlled study 139 organization and management 136 Male 130 Female 125 organization 91 United States 87 procedures 86 major clinical study 85 middle aged 80 Organic carbon 76 Adult 74 Middle Aged 72 nonhuman 71 COVID-19 70 aged 70 China 60 Animals 57 Soils 57 human experiment 57 animal 54 Aged 52 child 51 coronavirus disease 2019 50