Exposing living tissue to subfreezing temperatures for long can cause permanent damage. Microscopic ice crystals (结晶体) cut cells and seize moisture (潮气), making donor organs unsuitable for transplantation. Thus, organs can be made cold for only a few hours ahead of a procedure. But a set of lasting new antifreeze compounds (化合物)—similar to those found in particularly hardy (耐寒的) animals—could lengthen organs' shelf life.

    Scientists at the University of Warwick in England were inspired by proteins in some species of Arctic fish, wood frogs and other organisms that prevent blood from freezing, allowing them to flourish in extreme cold. Previous research had shown these natural antifreeze molecules (分子) could preserve rat hearts at -1.3 degrees Celsius for up to 24 hours. But these proteins are expensive to extract (提取) and highly poisonous to some species. “For a long time everyone assumed you had to make synthetic (人造的) alternatives that looked exactly like antifreeze proteins to solve this problem, ”says Matthew Gibson, a chemist at Warwick who co-authored the new research. “But we found that you can design new molecules that function like antifreeze proteins but do not necessarily look like them.”

    Most natural antifreeze molecules have a mixture of regions that either attract or repel water. Scientists do not know exactly how this process prevents ice crystal formation, but Gibson thinks it might throw water molecules into push-pull chaos that prevents them from tuning into ice. To copy this mechanism, he and his colleagues synthesized spiral-shaped molecules that were mostly water-repellent—but had iron atoms at their centers that made them hydrophilic, or water-loving. The resulting compounds were surprisingly effective at stopping ice crystals from forming. Some were also harmless to the roundworm Caenorhabditis elegans, indicating they might be safe for other animals.

    “These compounds are really cool because they are not proteins—they are other types of molecules that nonetheless can do at least part of what natural antifreeze proteins do, ”says Clara do Amaral, a biologist at Mount St. Joseph University, who was not involved in the research. Gibson's antifreeze compounds will still need to be tested in humans, however, and may be only part of a solution. “We don't have the whole picture yet,”do Amaral adds. “It's not just one magical compound that helps freeze-tolerant organisms survive. It's a whole suite of adaptations.

    Lately a popular eight-floor bookstore in Hefei,Anhui province,has risen to fame because it becomes the world's first shared bookstore,in a move meant to encourage more reading among Chinese citizens.

    It comes to people's attention as more than 200,000 visitors flooded the store on its first day as a shared bookstore on July 16 this year,a record high since it was reopened to the public in 2013.Some 4,000 books were brought home on the first day,Thepaper.cn reported.

    Customers are allowed to borrow up to two books valued under 150 yuan per visit after registering with an app and paying the 99 yuan deposit fee（押金）.

    All books on sale in the bookstore are available for sharing.Returned books that are damaged are sold at a discount.The bookstore also provides a bonus for bookworms.People who finish reading 12 books in three months receive eight percent of their deposit back,and members can be rewarded one yuan for every book read.

    "We want to bring down the cost of reading so people could read more books,"Xu Xinwei,who helps run the bookstore,told Thepaper.cn.

    Some parents buy a lot of books for their children,but they usually end up collecting dust as their children grow up.Similarly,some popular novels for young people also fall out of fashion,according to Xu."Books are more effectively circulated when they're shared."

    Teachers' Day is, interestingly, not celebrated on the same day all over the world. In some countries it is marked by a holiday; in others it is a working day.

    International Teachers' Day is celebrated on October 5. Being held ever since 1994, it is in honor of teachers' organizations worldwide. Its aim is to encourage supports for teachers and to meet the needs of students.

China — In 1939, Teachers' Day was set for August 27, Confucius' birthday. In 1951, the celebration was stopped. However, it was founded again in 1985, and the day was changed to September 10.

India — Teachers' Day is celebrated on September 5 in honor of Dr. Sarvepalli Radhakrishnan, the second president of India, whose birthday falls on that day.

    Russia — In Russia, Teachers' Day was celebrated on the first Sunday of October between 1965 and 1994. Since 1994, the day is observed on October 5, just the same day as World Teachers' Day.

    The US - In the US, Teachers' Day is non-official holiday. It is celebrated on the Tuesday of the first full week of May. A number of activities are organized in schools to honor teachers. The celebrations can continue for the whole week of May.

Thailand — In Thailand, National Teachers' Day is celebrated every year on January 16. The first Teachers' Day was held in 1957. The day is a holiday in schools.

    Emily Temple-Wood was 12 years old the first time she was bullied(欺凌) online. They left ugly comments on her Wikipedia and Facebook pages about her looks “that would make my mother's hair curl.” says Temple-Wood, now 22 and in medical school. The reason? “I was a woman on the Internet,” she said.

    Over the years, she considered how she might take revenge(复仇). Then, as a freshman in college, it hit her: “What do misogynists (men who hate women) hate most?” she asked herself. “Women who are productive!” Her solution: For every rude comment she received, Temple-Wood would post a biography(传记) of a woman scientist, and thus, in 2012, Wiki Project Women Scientists was born. She wrote about her heroes, like Barbara McClintock, who received the 1983 Nobel Prize in Physiology or Medicine, and Caroline Still Anderson, one of the first African American women to become a doctor in the United States, in the late 1800s. With help from other women, many of them scientists who have also been bullied online, Temple-Wood has published hundreds of these biographies and women of all ages have taken notice.

    “When I was a kid, I could count the number of women scientists I knew about on one hand,” wrote Siko Bouterse, who used to work for the Wikimedia Foundation. “But our daughters have the chance to get much more knowledge about scientists who look like them because of Emily.

    The ugly comments still come, says Temple-Wood. Being a strong woman online is not easy. “We all have days when we break down and need to have a glass of wine,” she says. “I tell people who are being bullied that it's OK to be sad. But now you need to find a productive way to take revenge.”

    Being able to land safely is a critically important skill for all flying animals. Whereas terrestrial animals face no particular challenge when they need to stop running or crawling, flying animals move at much higher speeds, and they must be careful about how they land. Hitting the ground, or even water, at full flight speed would be quite dangerous. Before touching down, they must decrease their speed in order to land safely. Both bats and birds have mastered the skill of landing, but these two types of flyers go about it quite differently.

    In the past it was believed that, in terms of flying mechanics, there was little difference between bats and birds. This belief was based only on assumption, however, because for years nobody had actually studied in detail how bats move their wings. In recent years, though, researchers have discovered a number of interesting facts about bat flight. Bats are built differently from birds, and their wings incorporate(结合) both their front and hind limbs (后肢). This makes their limbs working together more difficult for bats and, as a result, they are not very good at flying over longer distances. However, a bat can quickly change its direction of flight or completely reverse it, something a bird cannot easily do.

    Another interesting characteristic of bat flight is the way in which bats land—upside down! Unlike birds, which touch down on the ground or on tree branches, bats can be observed flying around and then suddenly hanging upside down from an object overhead. How do they do it? A group of researchers recently used video cameras to film bats landing on nets suspended from the ceiling of their laboratory and studied the recordings in slow motion. They painted spots on the bats' wings to see in detail what happens to the wings in flight and during touchdown. It turns out that the bats flew in a straight line up to the net and then quickly flipped over and attached themselves to it upside down. One disadvantage to this landing routine is that the bats often slam into their landing spot with some force, which probably causes pain. However, not all bats hit their landing spots with the same speed and force; these will vary depending on the area where a bat species makes its home. For example, a cave bat, which regularly rests on a hard stone ceiling, is more careful about its landing preparation than a bat more accustomed to landing in leafy treetops.

    If you ask most people what water tastes like, they'll probably tell you that water has no taste and they may give you a funny look. But if you were a fruit fly, asking another fruit fly, that question might have a different answer.

    To a fruit fly, water has a taste. Scientists want to know how the fruit fly knows water because this information may help in learning how other animals — or even individual cells — manage to use water in the right way. Water is vital to life, but too much or too little can be deadly to a living creature. So by understanding how the fruit fly tastes water, researchers may learn more about other living things.

    According to the new study, a protein(蛋白质) called PPK28 makes it possible for a fly to taste water. Proteins build cells and tissues, fight disease and carry messages between cells. It's not surprising that a protein is responsible for the fruit fly's ability to taste water.

    The PPK28 protein is part of a larger family of similar proteins. One of these related proteins is used by mammals (including humans) to taste salt. Scientists have not found a protein that enables humans to "taste" water.

    In the experiment, Cameron and his team compared normal fruit flies with fruit flies whose taste cells had been disabled. The fruit flies were given a special chemical that would glow(发光) when the fly used the PPK28 protein. Then the scientists led the flies to water. When the normal flies tasted the water, the PPK28 protein lit up — showing that it was in use.

    The fruit fly in particular is so interesting that some scientists are hard at work creating a complete map of the fruit fly brain. This map will show all of a fly's neurons and help scientists understand how the neurons work together.