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After every meal, the intestines perform an action called peristalsis—moving food through their hollow interiors with coordinated contractions and relaxations of the smooth muscle.

For more than a century, scientists have known that nerve cells in the gut propel the colon to move, allowing the organ to perform its life-sustaining function. But exactly how these intestinal nerve cells do their job has remained elusive.

Now a new study led by researchers at Harvard Medical School and the Icahn School of Medicine at Mount Sinai has identified the mechanism behind this phenomenon, showing that the gut’s motility is altered by exercise, pressure, and inflammation.

An experimental drug appears to reduce the risk of Alzheimer’s-related dementia in people destined to develop the disease in their 30s, 40s or 50s, according to the results of a study led by the Knight Family Dominantly Inherited Alzheimer Network-Trials Unit (DIAN-TU), which is based at Washington University School of Medicine in St. Louis.

The findings suggest—for the first time in a clinical trial—that early treatment to remove amyloid plaques from the brain many years before symptoms arise can delay the onset of Alzheimer’s dementia.

The study is published in The Lancet Neurology.

This Viewpoint discusses how prerequisite comprehensive lifestyle interventions for novel antiobesity medications may disproportionately impact patients at highest risk of obesity-related complications and perpetuate disparities in care.

Alopecia is an autoimmune disorder that causes non-scarring hair loss on the scalp and body that is experienced by almost 2% of the global population at some point in their lifetime.

A team of researchers from Australia, Singapore, and China discovered that activated hair follicle stem cells (HFSCs), crucial for hair regrowth and repair, require a powerful protector protein called MCL-1 to function successfully. Without MCL-1, these cells undergo stress and eventually die, leading to hair loss, as reported in a Nature Communications study.

Hair follicles are small tunnel-like structures in the skin where hair grows. These follicles repeatedly cycle through three : anagen, the active growth phase; catagen, a transitional phase marked by slowed growth and follicle shrinkage; and telogen, a resting phase where growth ceases and shedding occurs, after which the cycle begins afresh, driven by HFSCs.

You may have heard of the fantastic-sounding “dark side of the genome.” This poorly studied fraction of DNA, known as heterochromatin, makes up around half of your genetic material, and scientists are now starting to unravel its role in your cells.

For more than 50 years, scientists have puzzled over the genetic material contained in this “dark DNA.” But there’s a growing body of evidence showing that its proper functioning is critical for maintaining cells in a healthy state. Heterochromatin contains tens of thousands of units of dangerous DNA, known as “” (or TEs). TEs remain silently “buried” in heterochromatin in normal cells—but under many pathological conditions they can “wake up” and occasionally even “jump” into our regular genetic code.

And if that change benefits a cell? How wonderful! Transposable elements have been co-opted for new purposes through evolutionary history—for instance the RAG genes in and the genes required for driving the development of the placenta and mammalian evolution have been derived from TEs.

Chewing gum releases hundreds of tiny plastic pieces straight into people’s mouths, researchers said on Tuesday, also warning of the pollution created by the rubber-based sweet.

The small study comes as researchers have increasingly been finding small shards of plastic called microplastics throughout the world, from the tops of mountains to the bottom of the ocean – and even in the air we breathe.

They have also discovered microplastics riddled throughout human bodies – including inside our lungs, blood and brains – sparking fears about the potential effect this could be having on health.

Natural biological tissues, like human skin, possess a unique combination of properties that synthetic materials struggle to replicate. Skin is strong yet flexible and, most impressively, capable of self-repair. Until now, scientists have only been able to replicate either the stiffness of biological tissues or their self-healing ability—but never both at once.

Hydrogels have many advantages, such as biocompatibility, nutrient transport, and ionic conductivity. These features make them promising materials for biomedical applications, but their mechanical limitations have kept them from reaching their full potential.

Most self-healing hydrogels are too soft, with a Young’s modulus below 100 kilopascals (kPa). Others that achieve stiffness above 100 megapascals (MPa) typically lose their ability to heal.