【慢速听力190,191】CRISPR Gene Editing Used to Restore Eyesight

SCIENCE & TECHNOLOGY

CRISPR Gene Editing Used to Restore Eyesight

March 04, 2020

Dr. Jason Comander, inherited retinal disorder specialist at Massachusetts Eye and Ear Infirmary in Boston points to a model of an eye during an interview on Jan. 8, 2020. Comander's hospital plans to enroll patients in a gene editing treatment for blindn

Scientists say they have used the gene-editing tool CRISPR to repair a person's eyesight for the first time.

DNA is short for deoxyribonucleic acid. It is the substance that carries genetic information in the cells of living things. The CRISPR tool makes it possible to change DNA to add needed genes or take some away if they lead to problems.

A patient recently had the procedure done for an inherited form of blindness, the companies that make the treatment announced Wednesday. The operation took place at Oregon Health and Science University in Portland. The companies did not release additional details about the patient.

It may take up to a month to see if the procedure worked to repair a patient’s vision. If the first few attempts seem safe, doctors plan to test it on 18 children and adults.

“We literally have the potential to take people who are essentially blind and make them see,” said Charles Albright. He is chief scientific officer at Editas Medicine in Cambridge, Massachusetts. Editas is one of the companies developing the treatment. The other is Allergan, based in Dublin, Ireland.

Albright added, “We think it could open up a whole new set of medicines to go in and change your DNA.”

Dr. Jason Comander is an eye doctor at Massachusetts Eye and Ear in Boston. He said it marks “a new era in medicine” in which technology has made “editing DNA much easier and much more effective.”

Doctors first tried in-the-body gene editing in 2017 for a different inherited disease using a tool called zinc fingers. Many scientists believe CRISPR is a much easier tool for finding and cutting DNA at an exact spot.

The people taking part in the study have a genetic condition that keeps the body from making a protein needed to turn light into signals to the brain, which leads to sight. People with the disease are often born with little ability to see. They can lose whatever vision they are born with when they are still very young.

Scientists have found it difficult to treat the condition with usual gene therapy. So, they are aiming to edit or remove the mutation by making two cuts on either side of it. The hope is that the ends of DNA will reconnect and make the gene work as it should.

The procedure is done in an hour-long operation. Through a tube the width of a human hair, doctors put three drops of fluid containing the gene editing machinery just under the retina. That is the lining at the back of the eye that contains the light-sensing cells.

Doctors believe they need to fix one-tenth to one-third of the cells to repair vision. In animal tests, scientists were able to correct half of the cells with the treatment, Albright said.

Some independent experts were hopeful about the new study.

Dr. Kiran Musunuru is a gene-editing expert at the University of Pennsylvania. He said the treatment seems likely to work, based on tests in human tissue, mice and monkeys.

The gene editing tool stays in the eye and does not travel to other parts of the body. So, “if something goes wrong, the chance of harm is very small,” Musunuru said. “It makes for a good first step for doing gene editing in the body.”

I’m Bryan Lynn.

The Associated Press reported this story. Ashley Thompson adapted it for VOA Learning English. Hai Do was the editor.

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Words in This Story

inherit - v. to have (a characteristic, disease, etc.) because of the genes that you get from your parents when you are born

literally - adv. a way that uses the ordinary and usual meaning of a word

potential - n. capable of becoming real

essentially - adv. used to strengthen the basic nature of something

era - n. a period of time that is associated with a particular quality, event, person, etc.

mutation - n. a change in the genes of a plant or animal that causes physical characteristics that are different from what is normal

vision - n. the ability to see : sight or eyesight

 NO.191

SCIENCE & TECHNOLOGY

CN's TikTok Keeps Growing Among US Youth

March 04, 2020

In this Feb. 28, 2018 photo, Matty Nev Luby holds up her phone in front of a ring light she uses to lip-sync with the smartphone app Musical.ly, in Wethersfield, Conn.

The popularity of CNs -owned video sharing service TikTok continues to grow among young people in the United States. In 2019, experts say the service more than doubled its American user base to 37 million. TikTok is especially popular with teens and young adults.

The service lets users create and share short videos, many of which are under 15 seconds. The TikTok app offers a wide choice of sounds, brief parts of songs and special effects tools to help create a video. Some TikTok-based memes go viral. Videos often include popular songs from well-known artists and TikTok has even helped launch the careers of new music stars.

TikTok is considered a competitor to video-sharing app Snapchat, as well as Facebook’s Instagram service. Snapchat and Instagram also mainly interest young users with a wide mix of photos and videos centered largely on fashion, pop culture and humor.

In this Feb. 28, 2018 photo, Matty Nev Luby, right, and her mother Kerrylynn Mahoney pose together for a photograph in Wethersfield, Conn. The high school gymnast’s popularity on the lip-syncing app Musical.ly, which merged this summer into the CNs  vi

Last year, TikTok was the second-most downloaded app from Apple and Google stores. Only WhatsApp was downloaded more. Research company Sensor Tower estimates people have downloaded the TikTok app 1.65 billion times.

TikTok has been used by many major companies to reach young people who use little or no traditional media.

One of those companies is American-based e.l.f. Cosmetics. The makeup company’s chief marketer, Kory Marchisotto, told The Associated Press that TikTok is “where the Gen Z party is.” Gen Z is a name used to describe the generation born between the late 1990s and the early 2000s. “That’s where they’re all hanging out,” Marchisotto said.

Companies appearing on TikTok can make money through advertising. Often, the companies create user “challenges” as part of their ad campaigns. In challenges, users are invited to publish their own videos in which they perform similar dance moves. One campaign by e.l.f. Cosmetics, for example, asked people to wink and move their lips while following a song. TikTok users created 3 million videos that received more than 4 billion views.

While TikTok has continued to grow since its U.S. launch in 2017, it has also received media attention for being the first CNs -owned social-media service to rise to major success in the U.S.

U.S. lawmakers have raised concerns about TikTok’s collection of user data and the possibility that the company could be sharing information with the CNs government. In addition, the lawmakers said the app presents national security risks and could be used to censor material for users in the U.S.

In this Feb. 28, 2018 photo, Matty Nev Luby holds her phone and logs into the lip-sync smartphone app Musical.ly, now known as TikTok, in Wethersfield, Conn. (AP Photo/Jessica Hill, File)

TikTok has said it does not share information with the CNs government and denies the app carries national security risks or is used to censor information.

Still, the concerns led the U.S. government to launch a national security investigation into TikTok. Also, the U.S. Department of Defense warned last December of possible security risks linked to the use of TikTok. The agency urged employees not to use the app. The warning led several military services to ban the use of TikTok on government devices.

In addition, some groups and parents have expressed concerns about videos appearing on TikTok that might be harmful for young users.

Nonprofit privacy group Common Sense Media has issued guidance for parents. The group notes on its website that many videos appearing on TikTok include offensive language and sexual subjects. For these reasons, the group urges parents to supervise what their children watch on TikTok and suggests that the service is best for those over age 16.

In this Feb. 28, 2018 photo, Matty Nev Luby poses for a photograph in front of a ring light she uses for her internet posts in Wethersfield, Conn. The high school gymnast’s popularity on the lip-syncing app Musical.ly, which merged this summer into the Ch

TikTok’s head of creator partnerships, Kudzi Chikumbu, told the AP the company is working hard to make sure the app is a “safe and positive environment.”

Last year, the company agreed to pay the U.S. government a $5.7 million fine for collecting personal information from children under age 13. Since then, TikTok created a separate part of the app that restricts possibly offensive material. The app requires users to be 13 years old, although it does not confirm users’ ages. TikTok says it does remove what it calls “wrongly created” accounts if they are reported by other users.

I’m Bryan Lynn.

Bryan Lynn wrote this story for VOA Learning English, based on reports from The Associated Press and Reuters, and information from Common Sense Media. Caty Weaver was the editor.

We want to hear from you. Write to us in the Comments section, and visit our Facebook page.

Words in This Story

meme – n. usually, an image with a caption, which is spread from person to person on the internet

fashion – n. the most popular style of clothes, appearance or behavior at a particular time

hang out – v. to spend time in a particular place with a particular group of people

challenge – n. a difficult task that tests a person’s abilities

wink – v. to shut one eye briefly as a signal or in teasing

censor – v. to examine books, movies, letters, etc., in order to remove things that are considered to be offensive, immoral, harmful to society, etc.

positive – adj. marked by or indicating acceptance, approval or affirmation

【NBA视频集锦】【H022】 公牛108-115森林狼

BULLS at TIMBERWOLVES | FULL GAME HIGHLIGHTS | March 4, 2020 Malik Beasley led the Minnesota Timberwolves with 24 PTS in their 115-108 win over the Chicago Bulls. D'Angelo Russell added 19 PTS, while Naz Reid went for 16 PTS and 11 REB. Coby White led CHI with 26 PTS. Catch Thursday's action on TNT: L.A. Clippers at Houston Rockets, 8:00 pm/et & Toronto Raptors at Golden State Warriors, 10:30 pm/et

【H023】鹈鹕123-127独行侠（OT）

PELICANS at MAVERICKS | FULL GAME HIGHLIGHTS | March 4, 2020 Kristaps Porzingis (34 PTS, 12 REB, 5 BLK) and Luka Doncic (30 PTS, 17 REB, 10 AST) both erupted in the Dallas Mavericks 127-123 win over the New Orleans Pelicans. Lonzo Ball (25 PTS, 11 REB) hit 7 3s for the Pelicans. Catch Thursday's action on TNT: L.A. Clippers at Houston Rockets, 8:00 pm/et & Toronto Raptors at Golden State Warriors, 10:30 pm/et

北京时间3月5日，NBA常规赛再战一场，独行侠主场通过加时127-123险胜鹈鹕，送给对手三连败。独行侠队东契奇砍下30分17篮板10助攻，得到职业生涯第22个三双，成为独行侠队史三双王。波尔津吉斯34分13篮板5封盖，库里21分；鹈鹕方面英格拉姆得到27分5篮板，鲍尔25分11篮板6助攻，威廉姆森21分6篮板。

【H024】 奇才105-125开拓者

WIZARDS at TRAIL BLAZERS | FULL GAME HIGHLIGHTS | March 4, 2020 Four Portland Trail Blazers scored 22+ PTS in the team's 125-104 victory over the Washington Wizards. Carmelo Anthony led the way with 25 PTS, Hassan Whiteside posted 24 PTS, 16 REB and 4 BLK, and CJ McCollum and Damian Lillard went for 22 PTS each. Washington's Bradley Beal (29 PTS) reached 25+ PTS for the 20th straight game. Catch Thursday's action on TNT: L.A. Clippers at Houston Rockets, 8:00 pm/et & Toronto Raptors at Golden State Warriors, 10:30 pm/et

沙鸥与沙暖微信公众号NBA频道（视频总目录 ）

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【NBA视频】【H014】国王133-126奇才  【H015】费城107-120湖人