中山大便会出血是什么原因(中山市医院治疗痔疮) (今日更新中)

NEW YORK (AP) — Uber shares sunk even further after its disappointing stock market debut as doubts lingered over the company's ability to turn a profit and trade tensions dragged down the overall market.The ride-hailing giant's stock fell 10% and hovered around Monday afternoon on Uber's first full day of trading.The mounting losses followed Uber's disappointing initial public offering. On Friday, it took a 7 million hit — the largest loss on the first day of trading by a U.S.-based company in recent history, according to Renaissance Capital.Uber's earliest investors are still making money off the IPO, but "for late-round investors, it's possible by the time they exit they will end up with a loss," said Jay Ritter, finance professor at the University of South Florida.Among the recent big investors — and perhaps losers — is PayPal, which had disclosed plans to buy 0 million in Uber stock at the IPO price of .Uber has had no trouble convincing venture capitalists to pour money into its earlier funding rounds, but with its unclear path to profitability, it's having a more difficult time with Wall Street investors."It's clearly a high-risk, high-reward scenario. You're betting on something that may happen 10 years down the road," said Matt Kennedy, senior IPO market strategist at Renaissance Capital, a manager of IPO exchange traded funds. "Public investors are looking at profits and not seeing any, and the company's growth in the last quarter was relatively strong, but I don't think it blew anyone away."Uber's main U.S. rival, Lyft, is in a similar spiral. Its stock was trading below on Friday, down 33% from its IPO price of .It's rare to see shares in a tech company hit so hard upon going public. Over the past five years, just 10% of similar companies finished their first day of trading below their IPO price, Kennedy said.Uber's revenue last year surged 42% to .3 billion, but the company admits it could be years before it turns a profit. 2000

Netflix CEO Reed Hastings and his wife, Patty Quillin, are donating 0 million toward student scholarships at historically black colleges and universities. The couple is giving million to each of three institutions: the United Negro College Fund, Spelman College and Morehouse College. The organizations said it is the largest individual gift in support of student scholarships at HBCUs. Hastings has a history of supporting educational causes, including charter schools. He launched a 0 million education fund in 2016, beginning with money toward college scholarships for black and Latino students.Business leaders have pledged solidarity with the black community amid ongoing protests over police brutality. 726

NEW YORK – Wall Street clawed back the last of the historic, frenzied losses unleashed by the coronavirus, as the S&P 500 closed at an all-time high Tuesday.The benchmark index notched a modest 0.2% gain to beat its previous record high set on Feb. 19, before the pandemic shut down businesses around the world and knocked economies into their worst recessions in decades.The S&P 500′s milestone caps a furious 51.5% rally that began in late March.Tremendous amounts of aid from the Federal Reserve and Congress helped launch the rally, which built momentum on signs of budding growth in the economy. 616

North Korea appeared to destroy at least three nuclear tunnels, observation buildings, a metal foundry and living quarters at its Punggye-ri nuclear test site on Thursday, in a process observed by invited international journalists.A CNN crew at the remote mountain site in the country's north witnessed explosions at nuclear tunnels 2, 3 and 4, from observation decks about 500 meters away.They were among two dozen journalists invited into the country to observe the apparent destruction of the site, which comes just weeks before a planned meeting between North Korean leader Kim Jong Un and US President Donald Trump.The journalists spent about 10 hours on the ground at the nuclear test site before leaving by train for the 12-hour journey back to the North Korean coastal city of Wonsan.North Korea announced on April 20 that the country had "realized nuclear weaponization," and would no longer need to test nuclear weapons. To demonstrate its commitment, it said it would destroy the nuclear test site.North Korea said inviting international media to the event would "ensure transparency of discontinuance of the nuclear test."Before the explosions, the journalists said they were invited to look inside three of the four tunnels, which appeared to be rigged with explosives, before moving a safe distance away to witness their detonation.The amount and type of explosives used were not described by the regime. The CNN journalists present described seeing "soccer ball" sized and shaped explosives, rigged alongside one another, visible for a distance of around 35 meters inside the tunnels.The journalists watched a succession of explosions, and when they were finished were allowed closer to inspect the damage. Each tunnel was caved in, with rubble blocking the entrance.There were no international experts in the invited group and no one was present who was able to assess the explosions in order to tell if they were deep enough to destroy the tunnels.North Korea has conducted six nuclear tests at the site, which lies more than 200 miles (370 kilometers) north of Pyongyang, the most recent and powerful of which was in September 2017.There are four tunnels at the site, although journalists only witnessed the destruction of three. A fourth tunnel used for one nuclear test in 2006 had already been shut down, North Korean officials said. The journalists were also shown two additional tunnels that the North Korean officials said had never been used before.Before Thursday's explosions, experts had warned that the tunnels' destruction could destroy valuable evidence of the state of North Korea's weapons program. They told CNN they would want to take samples, as well as radiation counters to assess the levels in the atmosphere.Journalists who attempted to take radiation measuring equipment into North Korea said it had been confiscated.Tom Cheshire, a correspondent with Britain's Sky News, said his team's satellite phone and radiation dosimeter -- a device to measure nuclear radiation -- was taken away by security at Wonsan airport. Chinese journalists also had equipment confiscated.?The-CNN-Wire 3131

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

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