One of the most widely used drugs in the world isn't really a drug, at least not in the usual sense.

It's more like a dye.

Physicians call this drug "contrast," shorthand for contrast agent.

Contrast agents are chemical compounds that doctors use to improve the quality of an imaging test. In the emergency room, where I work, contrast is most commonly given intravenously during a CT scan.

As Democratic presidential hopefuls seek to grow the small-donor juggernaut that fueled the party's takeover of the House of Representatives last year, the Democratic National Committee is giving them a firm shove, offering slots in the presidential primary debates to candidates who build a broad fundraising base.

"I really believe that we're at our best when we're connecting with people," DNC chair Tom Perez told MSNBC recently. "That's how we won in 2018, and frankly that's how Barack Obama won in 2008. And that's exactly what I think this will incentivize."

After nearly two years of waiting, special counsel Robert Mueller's report into Russia's attack on the 2016 presidential election is finally done. And there's growing bipartisan pressure on Attorney General William Barr to make it public.

Robert Mueller may have completed his report, but other investigations into President Trump are expected to carry on for months.

There are, broadly, two kinds: those being undertaken from within the executive branch and those being run by members of Congress — mostly Democrats in control of major committees in the House.

About five years since the war in eastern Ukraine between government forces and Russian-backed separatists began, triggering a surge in propaganda and disinformation, some students in four cities across the country are learning how to better assess what they're reading, seeing and hearing.

A report released Friday by global education organization IREX says that students in 8th and 9th grades were better able to identify false information and hate speech after teachers integrated the organization's media literacy techniques into their lessons.