Reference Terms
from Wikipedia, the free encyclopedia
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.
Related Stories
1
2
Health & Medicine News
January 13, 2026
Jan. 13, 2026 A generative AI system can now analyze blood cells with greater accuracy and confidence than human experts, detecting subtle signs of diseases like leukemia. It not only spots rare abnormalities but also recognizes its own uncertainty, making it a ...
Jan. 13, 2026 Childbirth depends not just on hormones, but on the uterus’s ability to sense physical force. Scientists found that pressure and stretch sensors in uterine muscles and surrounding nerves work together to trigger coordinated contractions. When ...
Jan. 13, 2026 Scientists at Tufts have found a way to turn common glucose into a rare sugar that tastes almost exactly like table sugar—but with far fewer downsides. Using engineered bacteria as microscopic factories, the team can now produce tagatose ...
Jan. 13, 2026 MIT engineers have developed a pill that can wirelessly report when it’s been swallowed. Inside the capsule is a biodegradable antenna that sends a signal within minutes of ingestion, then safely dissolves. The system is designed to work with ...
Jan. 12, 2026 Some antibiotics stop bacteria from growing without actually killing them, allowing infections to return later. Scientists at the University of Basel created a new test that tracks individual bacteria to see which drugs truly eliminate them. When ...
Jan. 12, 2026 Researchers have discovered a brain activity pattern that can predict which people with mild cognitive impairment are likely to develop Alzheimer’s disease. Using a noninvasive brain scanning technique and a custom analysis tool, they detected ...
Jan. 12, 2026 Most U.S. adults have risk factors tied to a little-known condition called CKM syndrome, which connects heart disease, kidney problems, diabetes, and obesity into one powerful health threat. When these issues overlap, the danger rises far more than ...
Jan. 12, 2026 Weight-loss drugs like Ozempic and Wegovy are changing how Americans spend money on food. A large Cornell study found households cut grocery spending by over 5% within six months, with even bigger drops at fast-food restaurants. Snack foods and ...
Jan. 11, 2026 A new international trial has delivered striking results for people on dialysis, showing that daily fish oil supplements can sharply reduce serious heart-related events. Patients taking fish oil had ...
Jan. 11, 2026 Roasted coffee may do more than wake you up—it could help control blood sugar. Researchers discovered several new coffee compounds that inhibit α-glucosidase, a key enzyme linked to type 2 diabetes. Some of these molecules were even more potent ...
Jan. 11, 2026 KAIST researchers have developed a way to reprogram immune cells already inside tumors into cancer-killing machines. A drug injected directly into the tumor is absorbed by macrophages, prompting them to recognize and attack cancer cells while ...
Jan. 11, 2026 In a striking real-world experiment, flu patients spent days indoors with healthy volunteers, but the virus never spread. Researchers found that limited coughing and well-mixed indoor air kept virus levels low, even with close contact. Age may have ...
Latest Headlines
updated 12:56 pm ET
Jan. 10, 2026 Although the gut renews itself constantly, its stem cells accumulate age-related molecular changes that quietly alter how genes are switched on and off. Scientists found that this “epigenetic ...
Jan. 10, 2026 Sleep isn’t just about feeling rested—it may be one of the strongest predictors of how long you live. Researchers analyzing nationwide data found that insufficient sleep was more closely tied to ...
Jan. 10, 2026 New research shows that aging blood can accelerate Alzheimer’s-like changes in the brain, while younger blood may offer protection. In mouse experiments, older blood worsened memory performance and ...
Jan. 10, 2026 Pancreatic cancer is notoriously hard to treat, often resisting therapies that target its most common mutations. Researchers have now uncovered a hidden three-part loop that fuels tumor growth, ...
Jan. 9, 2026 Sugar-loving mouth bacteria create acids that damage teeth, but arginine can help fight back. In a clinical trial, arginine-treated dental plaque stayed less acidic, became structurally less harmful, ...
Jan. 9, 2026 Scientists at USC are launching a new trial to test a tiny stem cell implant that could restore vision in people with advanced dry macular degeneration. The hair-thin patch replaces damaged retinal ...
Jan. 9, 2026 A large genetic study shows that many people carry DNA sequences that slowly expand as they get older. Common genetic variants can dramatically alter how fast this expansion happens, sometimes ...
Jan. 9, 2026 Foods that rely heavily on preservatives may be doing more than extending shelf life. In a large study spanning more than a decade, people with the highest intake of preservative additives were far ...
Jan. 9, 2026 Researchers have developed a new class of antibodies that amplify the immune system’s ability to fight cancer. By clustering immune receptors that normally receive weak signals from tumors, these ...
Jan. 9, 2026 Stanford researchers have developed an AI that can predict future disease risk using data from just one night of sleep. The system analyzes detailed physiological signals, looking for hidden patterns ...