What the scientists are saying…

Human eggs grown in lab Human eggs have been grown to maturity in a lab for the first time, a breakthrough that could lead to more effective fertility treatments. Researchers at the University of Edinburgh began by using biopsies to extract strips of ovarian tissue from ten women in their late 20s and 30s. Women are born with more than a million immature eggs, which are stored in their ovaries in structures called ovarian follicles. From puberty, eggs start to develop in these follicles (one by one) and each month a mature egg is released. The team were able to mimic this in the lab by maturing the follicles in a culture and then squeezing out their eggs. In the journal Molecular Human Reproduction, they report that they started with 385 follicles; only nine eggs made it to maturity, and it’s not clear if these were healthy. If perfected, however, the technique could be used to help preserve the fertility of young cancer patients. Prepubescent girls do not produce mature eggs that can be frozen, so some opt to have ovarian tissue removed before they undergo treatment, with a view to having it reimplanted later. But this carries a risk of reintroducing the cancer; being able to grow their eggs in the lab would be safer for those patients. It might also help some women for whom IVF has failed.

Ants take care of their wounded Ants have been seen nursing their wounded colony members after a battle – a type of behaviour never previously observed in a non-human animal. West African Matabele ants leave their colonies in groups of about 600 to hunt for termites. Their aim is to kill the termites and drag them back to their nests – but the termites fight back using their powerful mandibles and a significant proportion of the ants lose limbs in these battles. Researchers have before observed that as the ants march back, they stop to pick up the wounded. Now closer analysis has revealed that back at the base, they also examine and treat their comrades’ wounds, by licking them for extended periods. “We don’t know if they are just removing dirt from the wound or applying an antimicrobial substance to fight off an infection. But we do know that if they don’t receive the treatment, 80% die within 24 hours,” said Erik T. Frank of the University of Würzburg. By contrast, among those treated for an hour, only a tenth died. He also found that not all the wounded are rescued. On the battlefield, injured ants give off a pheromone distress signal and tuck their legs in, the better to be carried. Those too badly injured to get into the rescue position are left to die. This triage process means that the ants don’t waste their time on hopeless cases. The wood stronger than steel Wood could soon be used to make cars and skyscrapers – or even bulletproof armour. Scientists have been trying for decades to strengthen wood, and now researchers at the University of Maryland claim to have cracked the problem. Their two-step “densifying” technique, outlined in the journal Nature, involves first treating wood with caustic soda and sodium sulphite, fundamentally altering its chemical structure. The block is then compressed while simultaneously heated to 100°C. The result is a product three times as dense as untreated wood and about 12 times stronger. Because wood is so abundant, and the technique relatively uncomplicated, experts say it has the potential to create a cheaper, more environmentally friendly alternative to existing high-strength materials, such as metal alloys and carbon fibre composites.

Processed food linked to cancer Eating a diet rich in ultra-processed food has been linked to a slightly raised risk of cancer. The study in France, published in The British Medical Journal, had 100,000 volunteers (most of them women) periodically fill in questionnaires about their diets, which were compared with their health records. This showed that each 10% increase in the proportion of ultraprocessed food in the diet was associated with a 12% increase in the number of cancers detected, once other possible factors, such as alcohol intake, age and body mass index, had been accounted for. The researchers said their findings might be down to a number of factors, including the “wide range of additives” in some ultra-processed foods (those substantially altered by a factory process) and its “generally poorer nutritional quality”.