An international team of researchers has captured the first image of Sagittarius A*, the supermassive black hole at the centre of the Milky Way. The results are published today in a special issue of The Astrophysical Journal Letters.

After many decades of study and thanks to the use of very precise techniques, we know more and more about these mysterious and huge bodies in the cosmos. Astronomers around the world are networking with powerful telescopes to better understand them.

Cerebrospinal fluid provides nutrients and other elements to brain cells. Scientists now show that by obtaining it from young mice and injecting it into the brains of old mice, the latter recover their memory. The effect is attributed to a protein, Fgf17, presented today in Nature as a possible brain rejuvenation factor. 

A study published today in the journal Nature Communications analyses the genomic variability of the influenza virus responsible for the 1918 pandemic and how it gave rise to the subsequent seasonal H1N1 influenza.

"The level of alcohol consumption that does not harm health is zero," says a review of dozens of studies conducted in recent years on the effect of light drinking. The 20 or so authors of the paper, and other experts, insist that "alcohol is carcinogenic from the first drink". In their view, this message should be conveyed more clearly to the public.

Studies have shown that the coronavirus has caused life expectancy to fall in many parts of the world in recent years, although differences between countries and regions are considerable. The latest WHO estimates are close to 15 million deaths worldwide between 2020 and 2021.

Caloric restriction (substantially reducing food intake in a controlled way) prolongs longevity in many animal species. A new result in mice, published in Science, finds that this effect is greater if the animals only eat during the body's natural active phase.

A review of studies in rodents and humans examines the relationship between exposure to perfluoroalkyl substances (PFAS) and liver damage.

On 27 April, the WHO reported 151 cases of salmonellosis in 11 countries, caused by the consumption of 'kinder eggs' or other contaminated products of the same brand. In Spain, two cases have been confirmed.

Climate change will lead to at least 15,000 new cross-species virus transmissions by 2070, as habitat shifts on a 2°C warmer planet will bring previously distant animals closer together. This result, published in Nature, points to increased exposure of humans to pathogens from wild animals.