Brain-on-a-chip. Dazzling in green and magenta this image shows the nerve fibres (in green) produced by neural stem cells (in magenta) as they grow on a synthetic gel. Captured by a technique known as confocal microscopy, the image is part of research shedding light on how tinkering with the environment can affect the way in which nerve fibres grow. (Photo by Collin Edington and Iris Lee/Massachusetts Institute of Technology/Wellcome Images)

Bangladeshi Muslim devotees arrive in an over-crowded train to attend the final day of an Islamic congregations' first phase in Tongi, 20 kilometers (13 miles) north of Dhaka, Bangladesh, Sunday, January 10, 2016. The second phase of the annual event, one of the world's largest congregations of Muslims is scheduled to begin Friday. (Photo by A.M. Ahad/AP Photo)

A woman is detained by security forces after looting broke out during an ongoing blackout in Caracas, Venezuela, March 10, 2019. (Photo by Ivan Alvarado/Reuters)

A woman walks behind the installation “Wandering boy is forever attractive” (1985) by Tetsumi Kudo during the press preview at the exhibition “Tetsumi Kudo – Retrospective” in the Fridericianum in Kassel, Germany, Friday, September 23, 2016. The exhibition offers an in-depth, comprehensive view of works by the Japanese artist Kudo. It starts on Sept. 25, 2016 and lasts until Jan. 1, 2017. (Photo by Jens Meyer/AP Photo)

Mr. Zhong Hua, of Johns Hopkins University School of Medicine, took this image of the peripheral nerves (those outside of the brain) in an 11.5-day-old mouse embryo, magnified five times. (Photo by Zhong Hua)

The world heavyweight boxing champion Joe Frazier, before his fight with Joe Bugner. (Photo by Evening Standard/Getty Images). 18th June 1973

Camila Iachini, 8, performs with her bike during celebrations for the 400th anniversary of the founding of the neighbourhood Petare, in Caracas, Venezuela on February 17, 2021. (Photo by Leonardo Fernandez Viloria/Reuters)

People walk along the sea front at Blyth in Northumberland in North East England on Monday, May 24, 2021. (Photo by Owen Humphreys/PA Images via Getty Images)