郑州眼睛轻度近视怎么矫正(郑州多少度算高度近视眼) (今日更新中)

New research suggests that antibodies the immune system makes to fight the new coronavirus may only last a few months in people with mild illness, but that doesn’t mean protection also is gone or that it won’t be possible to develop an effective vaccine.“Infection with this coronavirus does not necessarily generate lifetime immunity,” but antibodies are only part of the story, said Dr. Buddy Creech, an infectious disease specialist at Vanderbilt University. He had no role in the work, published Tuesday in the New England Journal of Medicine.The immune system remembers how to make fresh antibodies if needed and other parts of it also can mount an attack, he said.Antibodies are proteins that white blood cells called B cells make to bind to the virus and help eliminate it. The earliest ones are fairly crude but as infection goes on, the immune system becomes trained to focus its attack and to make more precise antibodies.Dr. Otto Yang and others at the University of California, Los Angeles, measured these more precise antibodies in 30 patients diagnosed with COVID-19 and four housemates presumed to have the disease. Their average age was 43 and most had mild symptoms.Researchers found that the antibodies had a half-life of 73 days, which means that half of them would be gone after that much time. It dovetails with a previous report from China also suggesting antibodies quickly fade.The results “call for caution regarding antibody-based ‘immunity passports,’ herd immunity, and perhaps vaccine durability,” the California authors write.That’s true, Creech said, but other parts of the immune system also help confer protection. Besides churning out antibodies, B cells develop a memory so they know how to do that again if needed.“They would get called into action very quickly when there’s a new exposure to the virus. It’s as if they lie dormant, just waiting,” he said.Other white blood cells called T cells also are better able to attack the virus the next time they see it, Creech said.Although circulating antibodies may not last long, what we need to know is if and how people remake antibodies if exposed to the coronavirus again and if they protect against another infection, Alison Criss, an immunologist at the University of Virginia, wrote in an email. “We also need to know if there is a protective T cell response” that reappears.Vaccines, which provoke the immune system to make antibodies, might give longer-lasting protection than natural infection because they use purified versions of what stimulates that response, she noted.Creech agreed.“This shouldn’t dissuade us from pursuing a vaccine,” he said. “Antibodies are only a part of the story.”___Marilynn Marchione can be followed on Twitter at http://twitter.com/MMarchioneAP___The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content. 2967

NEW YORK (AP) — Century 21 Stores, a destination for bargain hunters looking for fat deals on designer dresses and shoes for nearly 60 years, has filed for Chapter 11 bankruptcy.The retail chain says it’s winding down its business, including all 13 stores across New York, New Jersey, Pennsylvania and Florida.Century 21 joins more than two dozen retailers who have filed for bankruptcy since the pandemic which forced non-essential stores to temporarily close.Century 21 said that the decision followed nonpayment by the company’s insurance providers of about 5 million due under policies put in place to protect against losses stemming from business interruption.That insurance money helped it rebuild its downtown Manhattan flagship store after it was damaged by the 9/11 attacks. 794

New York City is painting the town…white! But the paint isn’t for aesthetics. The city is coating rooftops in order to reduce the internal temperature of a building by 30 percent."Painting a rooftop reflects the sun's radiant energy on the building,” explains Gregg Bishop, commissioner with NYC Small Business Services.Bishop says this reduces air conditioning costs.The initiative is called Cool Roofs. Officials say the initiative is helping to reduce the impact New York has on the climate, while lowering energy costs."Here in the city, we're facing temperatures that can be up to 22 degrees hotter than surrounding rural and suburban areas," says Jainey Bavishi, with the Mayor’s Office of Recovery and Resiliency.Since the program launched, they've covered 9 million square feet of rooftops.A similar initiative launched recently in Los Angeles, where they're testing reflective streets. The trend is growing. Academic research shows reflective surfaces do make a difference."What some of my own work has found out is that cool roofs are actually very effective at decreasing, for example, summertime temperatures, on the order of 1 to 3 degrees which is quite significant," explains Dr. Matei Georgescu, with the Global Institute of Sustainability at Arizona State University.While there are definitely benefits to making surfaces like this rooftop reflective, researchers say there may be some downsides as well."If you deploy highly reflective roofs, you're now assuming high reflectivity during the entire winter,” says Dr. Georgescu. “In other words, you're making things a lot colder than normally they would have been.”Dr. Georgescu studies reflective surfaces and says it could mean higher heating costs in the winter."We don't wanna give back 50 percent of these benefits during the winter."He says a possible solution might be reflective covers that would be removable during cold months.The city says any higher heating bills in the winter have been negligible. For now, officials have no plans to cool down the Cool Roofs program. 2067

New research shows more people 65 years old and older are filing for bankruptcy instead of retiring. The biggest cause of bankruptcies, according to a recent CNBC report, are medical bills. “Insurance, no matter what kind of insurance one has, typically only goes so far," says bankruptcy judge William J. Lafferty. "And when one has to actually start paying for those expenses, they rack up very quickly. It’s an immediate game changer for most families.”Another large factor is losing a job.  527

New York City has reached the 3% testing positivity 7-day average threshold. Unfortunately, this means public school buildings will be closed as of tomorrow, Thursday Nov. 19, out an abundance of caution. We must fight back the second wave of COVID-19.— Mayor Bill de Blasio (@NYCMayor) November 18, 2020 317

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