Stress hormone timing creates a different kind of obesity, study suggests

histology of liver tissue
Liver tissue from mice after 60 days of treatment. From left to right: control, glucocorticoid-rhythm flattening, and high-fat diet. The top row shows H&E-stained liver tissue, while red staining in the bottom row marks fat in the liver. Mice with flattened glucocorticoid rhythms on a standard diet displayed minimal liver fat compared with mice fed a high-fat diet, despite similar obesity. Scale bar, 100 µm. Credit: Teruel Lab

Obesity caused by disrupted stress-hormone rhythms is metabolically very different from obesity caused by a high-fat diet, according to a new preclinical study by Weill Cornell Medicine investigators...

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Asteroid Ryugu’s dust reveals nitrogen’s slow concentration into complex molecules

Ancient asteroid dust reveals nitrogen's slow concentration into complex molecules
Revealing nitrogen-bearing compounds in the sample returned from Ryugu. Credit: Toru Matsumoto et al.

Nitrogen is a key ingredient in the biomolecules that form the building blocks of life. Yet as an unbonded gas, it is far more likely to drift into space than to lock itself into solid compounds, making it difficult for astronomers to trace its journey to Earth in the distant past.

Through new research published in Nature Astronomy, a team led by Toru Matsumoto at Kyoto University has found some of the best evidence yet of how this journey happened, hidden inside grains of dust from the asteroid Ryugu.

Evidence across the solar system
Nitrogen-bearing compounds, particularly ammonia, have already been spotted on the dwarf planet Ceres and on several carbon-rich asteroids, hinting ...

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A single IV treatment retrains immune cells to fight autoimmune diseases in early trial

Scientists use single injection to retrain immune cells to fight auto-immune diseases from within
In 16 patients with hard-to-treat neurological autoimmune disorders, a single infusion of JY231 generated CAR T cells inside the body. Credit: Pexels.

CAR T-cell therapy is an immune-reprogramming procedure that turns a patient’s own immune cells into cancer-fighting specialists. The entire process is complex, but researchers have now found a faster way to achieve similar effects using a single intravenous (IV) drip of a harmless engineered virus.

In the standard process, clinicians extract T cells from the patient’s blood, then re-engineer them in the lab, arming each one with a chimeric antigen receptor (CAR)—engineered proteins designed to recognize specific markers on cancer cells...

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Long AI conversations reveal misinformation vulnerabilities across seven leading chatbots

chatbots
Credit: Pavel Danilyuk from Pexels

The results are in: Which AI model is the most fallible? Persuadable? Correctible? University of Arizona researchers assessed seven different generative AI large language models, or LLMs, for these three qualities during lengthy conversations. Their work, published in Nature’s Scientific Reports, reveals intrinsic limitations that might go undetected during one-off interactions.

Among the seven LLMs tested—ChatGPT (GPT-3.5, GPT-4o and GPT-4o-mini), Claude 3.5 Sonnet, Gemini 1.5 Pro, Llama-3-70B and DeepSeek-R1—they found that:

ChatGPT 3.5 was most vulnerable to reaffirming misinformation during a conversation containing repeated false statements; Claude 3.5 Sonnet was the least.
All seven were more susceptible to misinformation on obscure top...

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