Upconversion nanoparticles -- new types of luminescent nanomaterials that release high-energy photons after laser light stimulation -- can penetrate deeper into tissue and are more photochemically stable than conventional bioimaging agents, such as quantum dots and organic dyes. Luminescent nanocrystals doped or impregnated with small amounts of rare-earth ytterbium (Yb) ions are particularly effective...
The craft of opposition research—finding information that might put an opponent in a negative light—has long been a staple of political campaigns. This year, independent groups are taking a leading role....
Cynthia Quarterman, a top U.S. safety regulator tasked with handling the U.S. government's response to a string of oil-train crashes in recent years, is stepping down....
The Los Angeles City Council has approved one of the nation's highest minimum wages for workers at the city's large hotels....
The U.S. government will pay the Navajo Nation $554 million to settle long-standing claims that it mismanaged funds and natural resources on the tribe's reservation for years....
Connecticut gubernatorial candidate Joe Visconti opposes the state's new gun restrictions, and he has an online commercial that shows him riding in a 1974 Pontiac convertible with rifles fixed to the rear fenders. ...
The U.S. and Arab allies launched a second major wave of airstrikes in Syria targeting mobile oil refineries controlled by Islamic State, the Pentagon said....