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Sunscreen
Sunscreen (also known as sunblock) is a lotion, spray or other topical product that helps protect the skin from the sun's ultraviolet (UV) radiation, and which reduces sunburn and other skin damage, ultimately leading to a lower risk of skin cancer.
The best sunscreens protect against both UVB (ultraviolet radiation with wavelength between 290 and 320 nanometres), which can cause sunburn, and UVA (between 320 and 400 nanometres), which damages the skin with more long-term effects, such as premature skin aging. Most sunscreens work by containing either an organic chemical compound that absorbs ultraviolet light (such as oxybenzone) or an opaque material that reflects light (such as titanium dioxide, zinc oxide), or a combination of both. Typically, absorptive materials are referred to as chemical blocks, whereas opaque materials are mineral or physical blocks.
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Health & Medicine News
December 19, 2025
Dec. 19, 2025 Researchers have revealed that so-called “junk DNA” contains powerful switches that help control brain cells linked to Alzheimer’s disease. By experimentally testing nearly 1,000 DNA switches ...
Dec. 19, 2025 In a rare and historic achievement, Children’s Hospital Colorado successfully completed its first dual heart and liver transplant in a pediatric patient. The life-saving surgery was performed on 11-year-old Gracie Greenlaw, whose congenital heart ...
Dec. 19, 2025 Spending a few hours a week helping others may slow the aging of the brain. Researchers found that both formal volunteering and informal acts, like helping neighbors or relatives, were linked to noticeably slower cognitive decline over time. The ...
Dec. 19, 2025 A small tweak to mitochondrial energy production led to big gains in health and longevity. Mice engineered to boost a protein that helps mitochondria work more efficiently lived longer and showed better metabolism, stronger muscles, and healthier ...
Dec. 19, 2025 After injury, the visual system can recover by growing new neural connections rather than replacing lost cells. Researchers found that surviving eye cells formed extra branches that restored communication with the brain. These new pathways worked ...
Dec. 18, 2025 Firefighter turnout gear is designed to shield first responders from extreme heat and danger, but new research suggests it may also introduce chemical exposures. A U.S. study found that brominated flame retardants are present across multiple layers ...
Dec. 18, 2025 Scientists have discovered that T cell receptors activate through a hidden spring-like motion that had never been seen before. This breakthrough may help explain why immunotherapy works for some cancers and how it could be improved for ...
Dec. 18, 2025 More than 20% of young adults say they use cannabis or alcohol to fall asleep, with cannabis leading by a wide margin. Researchers warn this strategy can backfire, disrupting sleep quality and increasing the risk of long-term sleep and substance-use ...
Dec. 17, 2025 AI tools designed to diagnose cancer from tissue samples are quietly learning more than just disease patterns. New research shows these systems can infer patient demographics from pathology slides, leading to biased results for certain groups. The ...
Dec. 17, 2025 Researchers have identified a previously overlooked protein that helps regulate appetite and energy use in the body. This “helper” protein supports a key system that decides whether the body burns energy or stores it, and when it does not ...
Dec. 17, 2025 A missing brain molecule may be disrupting neural wiring in Down syndrome, according to new research. Replacing it in adult mice rewired brain circuits and improved brain flexibility, challenging the ...
Dec. 17, 2025 A rare tick-borne allergy linked to red meat has now been confirmed as deadly for the first time. A healthy New Jersey man collapsed and died hours after eating beef, with later testing revealing a severe allergic reaction tied to alpha-gal, a sugar ...
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Dec. 17, 2025 Kimchi may do far more than add flavor to meals—it could help fine-tune the human immune system. A clinical study using advanced single-cell genetic analysis found that regular kimchi consumption ...
Dec. 17, 2025 Scientists at Northern Arizona University are developing a promising new way to detect Alzheimer’s disease earlier than ever before—by tracking how the brain uses sugar. Using tiny particles in ...
Dec. 17, 2025 Researchers used miniature human brains grown in the lab to uncover why certain genetic mutations lead to abnormally small brains. Changes in actin disrupted the orientation of early brain cell ...
Dec. 16, 2025 Cases of colorectal cancer in younger adults are climbing worldwide, driven by lifestyle changes and inherited genetic risks. Diet, obesity, and lack of early screening are playing a major role in ...
Dec. 16, 2025 Scientists are uncovering a surprising way to influence bacteria—not by killing them, but by changing how they communicate. Researchers studying oral bacteria found that disrupting chemical signals ...
Dec. 16, 2025 A new genetic mapping strategy reveals how entire networks of genes work together to cause disease, filling in the missing links left by traditional genetic studies. The technique could transform how ...
Dec. 16, 2025 A newly developed AI can predict which diseases specific genetic mutations are likely to cause, not just whether they are harmful. The breakthrough could speed up diagnoses and open new paths for ...
Dec. 15, 2025 Researchers discovered a hidden molecular “switch” that herpes viruses rely on to invade cells. By combining AI, simulations, and lab experiments, they identified and altered a single amino acid ...
Dec. 15, 2025 Researchers tracking over 63,000 adults found that high-quality, minimally processed plant foods significantly reduce cardiovascular risk. But when those plant foods are ultra-processed, the ...
Dec. 15, 2025 New research shows that your brain’s “true age” can shift dramatically depending on how you live, with optimism, restorative sleep, stress management, and strong social support acting like ...