Subtle changes in how blood flows through the brain and how brain tissue uses oxygen may be closely linked to Alzheimer’s disease risk, according to new research from the Mark and Mary Stevens Neuroimaging and Informatics Institute (Stevens INI) at the Keck School of Medicine of USC. Stevens INI researchers found that noninvasive measures of brain blood flow and oxygenation were associated with hallmark brain changes in older adults with and without cognitive impairment, including amyloid buildup and a smaller hippocampus, a region essential for memory. The findings suggest that vascular health of the brain may play an important role early in the disease process and could help identify individuals at risk before significant symptoms appear. The research team used two noninvasive tools that can be applied while a person rests quietly. Transcranial Doppler ultrasound measures how fast blood moves through major brain arteries, while near-infrared spectroscopy measures how well oxygen reaches brain tissue near the surface of the cortex. Advanced mathematical models were then used to summarize these signals into indicators that reflect how well the brain adjusts blood flow and oxygen delivery in response to natural changes in blood pressure and carbon dioxide levels. Higher values on these indicators, meaning brain blood vessels behaved more like those of cognitively healthy adults, were linked to lower levels of amyloid plaques and larger hippocampal volume. Both of these brain features are associated with a lower risk of Alzheimer’s disease.

Zero‑alcohol drink advertising may not be as harmless as it seems, with new research showing it could increase teenagers’ interest in drinking full‑strength alcohol.  A study of almost 400 adolescents aged 15–17 found that teens who had seen — and especially those who liked — zero‑alcohol advertisements reported significantly stronger intentions to try the alcoholic versions of those brands.

Microplastics are now widely recognized as pollutants in oceans and waterways, but a growing body of research suggests they may pose equally serious risks on land. A new review highlights how microscopic plastic particles accumulating in soils can alter microbial genes that control essential ecosystem functions, potentially affecting food production, climate processes, and environmental health.

Never-before-seen 3D reconstructions of human liver tissue have been created at a cellular level. The details capture the spatial microstructure of multiple lobes of this multitasking organ. The reconstructions show how cirrhosis rearranges this intricate architecture and thereby alter the organ's biological activities. In addition, 3D liver maps with a high degree of cellular detail are critical to someday realizing the dream of bioprinting new organs for transplantation.