喀什怀孕几天检测出来(喀什包皮有点长不割可以吗) (今日更新中)

LOS ANGELES, July 3 (Xinhua) -- Warming of the ocean's subsurface layers will melt underwater portions of the Greenland and Antarctic ice sheets faster than previously thought, increasing the sea level more than already projected, a new study suggests.The subsurface ocean layers surrounding the polar ice sheets will warm substantially as global warming progresses, according to the study led by researchers from the University of Arizona (UA).In addition to being exposed to warming air, underwater portions of the polar ice sheets and glaciers will be bathed in warming seawater, said the study appearing on the website of the American Association for the Advancement of Science (AAAS) on Sunday.The research, based on 19 state-of-the-art climate models, proposes a new mechanism by which global warming will accelerate the melting of the great ice sheets during this century and the next."To my knowledge, this study is the first to quantify and compare future ocean warming around the Greenland and the Antarctic ice sheets using an ensemble of models," said lead author Jianjun Yin, a UA assistant professor of geosciences.According to the study, the subsurface ocean along the Greenland coast could increase as much as 3.6 F (2 C) by 2100.Most previous research has focused on how increases in atmospheric temperatures would affect the ice sheets, he said."Ocean warming is very important compared to atmospheric warming because water has a much larger heat capacity than air," Yin said. "If you put an ice cube in a warm room, it will melt in several hours. But if you put an ice cube in a cup of warm water, it will disappear in just minutes."Given a mid-level increase in greenhouse gases, the researchers found the ocean layer about 650 to 1,650 feet (200 to 500 meters) below the surface would warm, on average, about 1.8 F (1 C) by 2100. Along the Greenland coast, that layer would warm twice as much, but along Antarctica would warm less, only 0.9 F (0.5 C)."No one has noticed this discrepancy before -- that the subsurface oceans surrounding Greenland and Antarctica warm very differently," Yin said.Part of the warming in the North comes from the Gulf Stream carrying warm subtropical waters north. By contrast, the Antarctic Circumpolar Current blocks some of the subtropical warmth from entering the Antarctic's coastal waters.Even so, the Antarctic ice sheet will be bathed in warming waters, according to the study.This paper adds to the evidence that sea level would rise by the end of this century by around one meter and a good deal more in succeeding centuries, the study noted.The study, "Different Magnitudes of Projected Subsurface Ocean Warming Around Greenland and Antarctica," is scheduled for the upcoming edition of Nature Geoscience later this month.

WASHINGTON, July 12 (Xinhua) -- Two U.S. astronauts stepped out the International Space Station on Tuesday to retrieve a failed ammonia pump, which is the last spacewalk of the shuttle era, NASA announced.Space station astronauts Mike Fossum and Ron Garan completed the six-hour, 31-minute spacewalk at 3:53 p.m. EDT (1953 GMT). The duo retrieved a pump module from an external stowage platform on station and store it in shuttle Atlantis' cargo bay for return to Earth.The pump module failed in 2010, shutting down half of the space station's cooling system. Engineers will evaluate the module to determine the cause of the failure and plan to refurbish it for use as a spare.The astronauts also attached a Robotic Refueling Module experiment to the space station, which aims to test technologies for repairing and refueling satellites in space.It was the 249th spacewalk by U.S. astronauts and the 160th spacewalk in support of space station assembly and maintenance, totaling 1009 hours, nine minutes.Atlantis lifted off on Friday morning from Kennedy Space Center in Florida, on the 135th and final flight in NASA's shuttle program. Its return to the earth later this month will mark the end of the 30-year shuttle program.

BEIJING, Aug. 22 (Xinhuanet) -- Researchers have discovered how a human egg captures an incoming sperm for fertilization, paving the way to help couples suffering from infertility, according to media reports on Monday.An international team of researchers found that a sugar chain known as the sialyl-lewis-x sequence (SLeX) makes the outer coat of the egg “sticky,” which has proven to be helpful in binding the egg and the sperm.As a result, this observation has filled in a huge gap in the understanding of fertility and provides hope for ultimately helping couples who currently cannot conceive.Scientists and doctors know that a sperm identifies an egg when proteins on the head of the sperm match and bind to a series of specific sugars in the egg’s outer coating. With a successful match of proteins, the outside surfaces of the sperm and egg then bind together before merging, which is then followed by delivery of sperm’s DNA into egg.To identify this molecules, the researchers used ultra-sensitive mass-spectrometric imaging technology to observe and identify which molecules are most likely to be key in the binding process.They experimented with a range of synthesised sugars in the laboratory and found that it is SLeX that specifically binds sperm to an egg.According to the World Health Organisation, infertility affects about 15 percent of reproductive-aged couples around the world and almost one in every seven couples in Britain has problems conceiving a child for various reasons.

LOS ANGELES, June 5 (Xinhua) -- U.S. researchers have developed two new drugs that can prolong the lives of patients with advanced melanoma, it was announced on Sunday.Research on both drugs was presented at the on-going annual meeting of the American Society of Clinical Oncology in Chicago, according to HealthDay News.This is the first big news in years for treatment of melanoma, one of the deadliest forms of skin cancer and one that is notoriously difficult to treat, let alone cure, the report said.The first treatment, vemurafenib, inhibits a gene mutation harbored in half of all melanoma patients, but is not yet approved by the U.S. Food and Drug Administration.The other drug, Yervoy (ipilumumab), is an immune system therapy that won approval in March."The March FDA approval of ipilumumab (Yervoy) was the first new drug approval for melanoma in 13 years," said Tim Turnham, executive director of the Melanoma Research Foundation.The two drugs were developed by researchers at Memorial Sloan- Kettering Cancer Center in New York City, the report said."This is really a huge step toward personalized care in melanoma," Dr. Paul Chapman, lead author of the first study and the attending physician in the melanoma/sarcoma service at Memorial Sloan-Kettering, said in a statement. "This (vemurafenib) is the first successful melanoma treatment tailored to patients who carry a specific gene mutation in their tumor, and could eventually become one of only two drugs available that improves overall survival in advanced cancers.""Having two trials that show a benefit in survival in patients with melanoma, both of these in first-line settings -- we weren't here just a few years ago," said Dr. Stephen Hodi, director of the Melanoma Center at Dana Farber Cancer Institute in Boston. "These are huge, paradigm-shifting results for the field."In the vemurafenib trial, sponsored by the drug's makers, researchers randomly assigned 675 patients with advanced, inoperable melanoma to receive either the chemotherapy drug dacarbazine or vemurafenib. Vemurafenib targets the V600E mutation in the BRAF gene.At the three-month mark, patients taking vemurafenib were 63 percent less likely to die and 74 percent less likely to die or see their cancer return, compared to patients taking dacarbazine alone.Few patients had side effects in the vemurafenib group, although some did develop squamous cell carcinoma, a less dangerous form of skin cancer.This is the first drug that has been proven superior to chemotherapy in this group of hard-to-treat patients, the researchers said."There was such a substantial benefit that we recommended that patients cross over," Chapman said at a Sunday news briefing. "It' s unprecedented to report a trial this early. The median follow-up time was three months." Yet the differences between the two groups became evident almost immediately.Dr. Lynn Schuchter, co-moderator of the briefing and division chief of hematology-oncology at Abramson Cancer Center of the University of Pennsylvania in Philadelphia, said symptoms subsided in some patients almost immediately, enabling them to cut back on pain medication in just 72 hours."The median time to progression with dacarbazine was 1.6 months versus three months with vemurafenib, which is a huge difference," said Chapman.In the second study, about 500 patients were randomly picked to receive Yervoy plus dacarbazine or dacarbazine alone.Those taking both drugs lived a median of 11.2 months compared to 9.1 months for those taking dacarbazine alone. Time to recurrence of disease was about the same for both groups: 2.8 months and 2.6 months, respectively.Almost half of those taking the combination therapy were alive after one year, compared to 36.3 percent in the other group. After two years, the rates were 28.5 percent and 17.9 percent, respectively.By three years out, 20.8 percent of those in the combination group were alive compared with 12.2 percent of those taking chemotherapy alone.This is the first study to combine chemotherapy and immunotherapy both safely and effectively.A study to test vemurafenib in combination with Yervoy has already begun, according to HealthDay News.

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