STOCKHOLM - Japanese scientists Shimon Sakaguchi and Susumu Kitagawa on Wednesday received Nobel prizes in Stockholm for their respective achievements in medicine and chemistry.

Sweden's King Carl XVI Gustaf presented gold medals and diplomas to Sakaguchi, a 74-year-old distinguished professor at Osaka University, and Kitagawa, a 74-year-old distinguished professor at Kyoto University, at an award ceremony at Stockholm Concert Hall.

The two laureates received their awards to loud applause from an audience of more than 1,500 that included family members and fellow researchers.

It marks the first time in 10 years that Japanese recipients were awarded Nobel prizes in two different fields in the same year.

Sakaguchi, who received the Nobel Prize in physiology or medicine, was recognized for discovering regulatory T cells, or Tregs, which prevent other T cells from attacking the body's own healthy cells and have paved the way for new treatments for autoimmune diseases, cancer and other illnesses.

Kitagawa, meanwhile, received the Nobel Prize in chemistry for developing porous materials known as metal-organic frameworks, capable of storing and releasing gases such as methane and nitrogen.

"This is truly an honor, and I think it will be a special day in my life," Sakaguchi told reporters after the ceremony. "The medal is actually quite heavy."

Each Nobel prize carries an award of 11 million kronor ($1.2 million). Both shared the prize with two other researchers in their respective fields.

Japan has now produced 31 Nobel laureates, including Nihon Hidankyo, Japan's leading group of atomic bomb survivors, who won the Nobel Peace Prize last year.