At two congressional hearings, lawmakers slammed executives of major companies, saying they were failing to rein in the cost of medical care for consumers.Stephen Hemsley, chief executive of UnitedHealth Group, left, defended insurers’ practices, along with other companies’ executives, during congressional hearings on Thursday.

A planned U.S.-funded study of a hepatitis B vaccine drew widespread condemnation from researchers. Now the host country says it cannot proceed.Each year thousands of babies born in Guinea-Bissau, one of the world’s least developed countries, are exposed to hepatitis B, a virus that can cause severe liver damage and cancer.

Many of the cancellations had been known for months, but the announcement underscored the drastic change in the energy landscape under President Trump.The Energy Department canceled a partial loan guarantee to Sunnova Energy, a residential solar panel installer that was experimenting with a novel way to link home solar and battery systems.

The prohibition halts support for projects both inside and outside the N.I.H. President Biden had restored funding after an earlier ban by President Trump during his first term.Dr. Jay Bhattacharya, the N.I.H. director, said that the agency will look to make additional investments in “validated emerging technologies” that could “reduce or potentially replace reliance on human em...

The sensors used to listen for earthquakes could help protect people from the hazards created by falling spacecraft.