The day she arrived at the laboratory and saw that the mice were moving again, Zaida Álvarez (Barcelona, 1984) could not help but shudder. Behind her lay more than six years of research, from Monday to Sunday, and a risky bet to outsmart evolution and repair the irreparable: the central nervous system of a mammal. "It was mind-blowing. Those animals, which had a severe spinal cord injury and were paralyzed, were walking again," she recounts, still moved, this bioengineer and researcher at the Institute for Bioengineering of Catalonia (IBEC).

A group of researchers from the Institute of Bioengineering of Catalonia (IBEC), In collaboration with Dexeus University Hospital, the team has recorded for the first time how a human embryo implants in the uterus. This is a microscopic process that occurs in the body of an adult, so it had never been observed before. "It was like a black box whose inside we were finally able to see," says Samuel Ojosnegros, director of the study.