A milestone in the field of neuroscience has been reached: A new study showcases a technique that allows the cryopreservation and thawing of brain organoids and tissues without damaging cells. This method, developed by researchers at Fudan University, has successfully revived organoids to function properly after being cryogenically stored for 18 months. The technique, named MEDY, is composed of a series of chemicals, including methylcellulose, ethylene glycol, dimethyl sulfoxide (DMSO), and Y27632. MEDY could significantly advance the progress in brain development and disease research while also providing the possibility for long-term and reliable storage of neural organ tissue and living brain tissue, promoting the development of medical applications and drug screening.

In the health field, scientists continue to explore how obesity and high-fat diets influence the development of cancer. A recent study found that a high-fat diet may promote tumor growth by increasing the number of desulfovibrio in the gut. These findings come from an analysis of tissue and fecal samples from 61 breast cancer patients, revealing higher content of desulfovibrio in obese women. Experiments in mice showed that a high-fat diet is associated with an increase in desulfovibrio, higher levels of blood leucine, and a greater number of myeloid-derived suppressor cells (MDSCs), thereby suppressing the immune system and accelerating tumor growth. These findings could pave new ways for cancer treatment, although the results need further research to confirm their broad applicability across different geographical and dietary backgrounds.

Additionally, long-term and continuous ketogenic diets may lead to organ aging problems. The ketogenic diet is a high-fat, very low-carbohydrate diet that is widely used for rapid weight loss, and some studies have shown that it may have specific health benefits.

The latest research suggests that sustained long-term ketogenic diets may promote the aging of normal tissue cells, particularly negatively impacting the heart and kidney functions, though the effects may be reversible. This experiment observed mice of different ages that were fed with two types of ketogenic diets based mainly on fats from hydrogenated vegetable shortening and cocoa butter. The results show an increase in biomarkers related to aging in heart and kidney tissues, including levels and phosphorylation of the transcription factor p53, which plays a central role in the cell aging process. However, when their diet was switched back to normal for three weeks, the levels of aging cells in their bodies almost returned to normal. Moreover, the study found that intermittent ketogenic diet strategies (4 days of ketogenic diet followed by 7 days of normal diet) did not result in accumulated aging cells in mice.

In the field of marine biology, a sea otter named Enhydra lutris nereis typically chooses easy-to-obtain and softer-shelled foods like sea urchins and abalone to protect their teeth, but will turn to harder-shelled prey when food competition is fierce. Long-term predation on hard-shelled organisms like mussels may cause long-term damage to sea otters. A study that lasted for over a decade tracking hundreds of tagged sea otters found that using tools such as rocks to open hard-shelled food allows them to obtain larger prey and also means they expend more energy. Interestingly, sea otters that use tools to hunt have relatively less tooth damage, and females use tools more frequently than males, which may have certain advantages for their survival and reproduction.

In the field of astronomy, scientists have long been curious about the origins and rapid growth mechanisms of supermassive black holes. Supermassive black holes, with masses ranging from millions to billions of solar masses, exert profound influences on the formation and evolution of their host galaxies. These colossal celestial bodies formed within the first billion years after the Big Bang, revealing their astonishingly rapid growth rates. Now, with the help of the Webb Space Telescope, astronomers have gained new clues about the growth of black holes in the early universe, hoping to understand this mysterious process.

An exciting astronomical discovery, published in the prestigious journal Royal Astronomical Society Monthly Notices, has become the focus of scientific attention. Astronomers used the cutting-edge Webb Space Telescope to conduct an in-depth exploration of the early history of the universe. They revealed direct evidence of two galaxies and their contained massive black holes undergoing a merging process approximately 740 million years after the birth of the universe.

Researchers took advantage of the Webb Telescope's exceptional imaging quality to successfully distinguish between the two merging black holes, a feat that was very difficult to achieve in previous observations. They observed that one of the black holes has a massive weight of 50 million solar masses, while the second black hole may be of similar mass. However, the latter is obscured by dense gas, posing a significant challenge for precise measurement.

This finding is of great significance for understanding the mechanisms behind the rapid growth of black holes. The study suggests that even in the universe's youthful years, merging activities of black holes were still a key pathway for their rapid growth. Furthermore, as these two black holes merge, they are expected to generate gravitational waves, and the future gravitational wave observatories are more likely to capture these subtle vibrations of the cosmos.