The biggest scientific breakthroughs of 2019
Capturing a black hole
Scientists this year unveiled the first-ever image of a black hole. One of the universe's most enigmatic phenomena, a black hole is a cosmic abyss so dense with matter that not even light can escape. The picture from Messier 87, a galaxy 55 million light-years away, shows a bright ring of particles heated to billions of degrees, circling a supermassive black hole some 25 billion miles wide. To capture the image, scientists focused eight ultrapowerful radio telescopes around the world on Messier 87 for 10 days. Researchers compared the resulting images to millions of simulations of what the black hole might look like — and found a match. "We have seen what we thought was unseeable," says project leader Shep Doeleman.
Ebola could soon be classified as a curable disease, thanks to a trial of experimental treatments in Congo. An epidemic of the hemorrhagic disease has killed more than 2,200 people in the African nation; about 70 percent of those who catch Ebola die. But the death rate plummeted to 29 percent for patients on one new drug, and 34 percent for those on another. Among patients who began treatment soon after developing symptoms, rates fell to 6 percent and 11 percent, respectively. The drugs use monoclonal antibodies: Y-shaped proteins that call on immune cells to attack the Ebola virus.
The new CRISPR
Scientists have developed a gene-editing tool that could one day correct 89 percent of the genetic mutations that cause inherited diseases, such as cystic fibrosis and sickle cell anemia. The most popular existing gene-editing approach, CRISPR-Cas9, uses "molecular scissors" to locate faulty genetic code, then cuts both strands of the DNA double helix and splices in a new section of code. Though cheap and fast, this process often damages nearby code or inserts the new material in the wrong place. The new technology, known as prime editing, cuts only one strand of the double helix — minimizing the risk of unintended changes.
A quadriplegic man in France can move all four of his paralyzed limbs again, thanks to a pioneering brain-controlled bodysuit. The patient, identified only as Thibault, had two implants surgically placed over the parts of his brain that control movement. His brain signals are sent to a nearby computer, which translates them into movement instructions for the exoskeleton suit. Though years away from being publicly available, the technology could pave the way for mind-controlled wheelchairs and similar equipment. Thibault said taking his first steps felt like being "the first man on the moon."
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Blood test for Alzheimer's
Doctors could soon use a simple blood test to predict if a patient will develop Alzheimer's, years before symptoms appear. An international team of researchers found that people genetically predisposed to the disorder had distinctly higher levels of neurofilament light chain — a protein found in the brain and spinal cord — seven years before symptoms began, and noticeably faster-growing levels more than 16 years in advance. An early test could help scientists determine whether new Alzheimer's drugs are effective. Study author Mathias Jucker says the reason there is no effective treatment for the condition is "partly because current therapies start much too late."
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