Federal health agencies closed their investigations into the bacterial outbreak that sickened 104 people and was linked to onions on the fast-food chain’s signature Quarter...

Cassava Sciences said that its drug did not significantly reduce cognitive decline in 1,900 people with mild to moderate Alzheimer’s disease.

The company said it would put Quarter Pounders back on the menu, without the raw onions that were considered the likely source of the bacteria.

Health officials say that recalls of onions — the suspected source of the contamination — would help lessen the risk to consumers. Other major fast-food...

Officials said the onions served atop the popular hamburger were the likely source of an E. coli outbreak that has killed one person and sickened...

The C.D.C. said that nearly 50 people had become ill and one person had died from the deadly bacteria, which the agency tied to an...

The Ames Test offered a fast and inexpensive way to identify carcinogens, leading to the banning of chemicals linked to cancer and birth defects.

The Ames Test offered a fast and inexpensive way to identify carcinogens, leading to the banning of chemicals linked to cancer and birth defects.

The S.E.C. alleged shortcomings in research said to support the drug, and its developer agreed to a $40 million settlement. Some experts wonder why clinical...

Overwhelmed by queries, physicians are turning to artificial intelligence to correspond with patients. Many have no clue that the replies are software-generated.