Healthy mice were created from freeze-dried sperm stored for 6 years in space. Photo: Teruhiko Wakayama. A new study shows that rat sperm that was freeze-dried and stored on the International Space Station (ISS) for nearly six years didn’t suffer any DNA damage and went on to produce “mice pups” healthy”. The study was published June 11 in the journal Science Advances . According to the scientists, this discovery sheds more light on whether mammals, including humans, can reproduce in space. Combined with ground-based experiments exposing mouse sperm to X-rays, the study found that mammalian sperm cells can be preserved on the International Space Station for up to 200 years. Researchers have long thought that exposure to space radiation can damage the DNA in cells and lead to the possibility of passing mutations on to offspring. The lack of freezers on the ISS has prevented long-term research into living cells. To overcome these limitations, the researchers frozen dried sperm samples from 12 mice and sealed them in small, lightweight tubes and transported to the ISS by rocket without the need for a freezer. Mouse sperm were freeze-dried in glass tubes and stored on the ISS . Photo: Teruhiko Wakayama. Because of the complex mix of different types of radiation in space, scientists say, only simulation experiments to assess DNA damage on Earth cannot capture the reality of conditions. outside our atmosphere. Dr. Sayaka Wakayama, Yamanashi University, Japan, lead author of the study told The Independent : “There are different types of radiation flying around in space, unlike on the ground. For example, there are heavy ions, protons and electromagnetic waves from the rays of the sun.” “It’s very difficult to irradiate and reproduce all these types of radiation at once on the ground, so I think DNA damage in biological samples can only be measured in space,” he explains. . Scientists periodically test small portions of the sample. The samples returned to Earth after 9 months, 2 years 9 months, and 5 years and 10 months, respectively. Mouse embryos developed normally in the laboratory after fertilization with freeze-dried sperm and stored in space. Photo: Teruhiko Wakayama. When the researchers examined the samples using instruments that measured how much radiation they had absorbed and performed tests to assess DNA damage in the cell nuclei, they found a long stay. Long duration on the ISS did not result in DNA damage to freeze-dried sperm. Dr Wakayama said: “The total amount of space radiation absorbed by the ISS, as measured by the Japan Aerospace Exploration Agency (JAXA), is 0.41 milli Gray (mGy) per day. Meanwhile, typical radiation doses used to treat cancers such as solid epithelial tumors range from 60 to 80Gy. “The results of the ground X-ray experiment show that freeze-dried sperm can withstand up to 30 Gy and still be able to produce the next generation,” added Dr Wakayama. The freeze-drying process used in the study is “similar to instant coffee, or freeze-dried fruit,” explains Dr. Wakayama. With food, just adding water can be used “instantly”. The freeze-drying process kills sperm, but when rehydrated and injected into a mouse egg, the sperm can still fertilize the egg, then develop normally. The rehydrated sperm cells, when injected into fresh ovarian cells and transferred to female mice, resulted in the birth of “healthy pups”. Mouse sperm that has been preserved in space for years is injected into egg cells. Photo: Teruhiko Wakayama. Although there is a difference between DNA damage caused by X-rays and space radiation, it can be roughly predicted that freeze-dried sperm can be preserved on the surface of the body, the scientists wrote in the study. ISS for over 200 years”. According to the scientists, a total of 168 mice were born from sperm kept in space for six years, all of which were normal in appearance and had no abnormalities in their gene activity patterns. compared with control mice born from sperm preserved on Earth. Some of these mice were raised to adulthood and were able to produce healthy offspring. Scientists believe that more studies from similar experiments could shed more light on radiation effects and the tolerance of life forms for long periods of time in space. Scientists are also conducting research to find out whether mammalian embryos can develop in zero-gravity conditions. Proposals for this experiment were approved by NASA and JAXA in 2015. In August, frozen mouse embryos will be launched to the ISS, where astronauts will thaw and culture in zero gravity.

Li Bai (701-762) was one of the most famous poets of the Tang Dynasty in China. He is not only known as a great poet, he is also known as “Zu Trung Tien” because of his rare wine-loving style. In particular, in his poems, there was once a cup of wine that could not be exhausted no matter how he drank it: “The ladle of the falcon, the cup of the parrot, one hundred five thirty-six thousand days, one day should be inclined three hundred cups.” (Tuong Duong ca). The cup of wine “drinking forever” really exists in history. Photo: Sina Archaeologists have always been very interested in the “parrot cup” or “parrot cup” that Li Bai refers to, but such artifacts have never been excavated. It was not until the discovery of an ancient Jin Dynasty (317 – 420) tomb in 1965 that archaeologists found the strange wine glass described in these poems. Invention ahead of its time In 1965, archaeologists discovered a family tomb in Xiangshan, Nanjing. Based on the stele unearthed, the archaeological team judged that the owner of the tomb belonged to the Vuong family, one of the four largest clans of the Eastern Jin Dynasty. Here, in addition to finding a large number of burial items, which are of great value to the study of family culture and funeral customs of the Wei and Jin dynasties, scientists were also very surprised. when unearthed a large snail shell in the grave . The cup was unearthed. Photo: Sina The appearance of the Anh Vu snail caused a lot of controversy in the professional world, because this was the first time they unearthed a strange artifact. Through research, the experts eventually discovered: It turns out that this is the famous “parrot cup” in history, this cup is originally made from Anh Vu snail shell. Perhaps, the owner of the tomb is also a person with a passion for wine like poet Ly Bach, so he decided to bring this cup to his final resting place. This is the first time people have unearthed a parrot cup, so experts are very interested and want to study why the parrot cup can contain such a large amount of alcohol, because from the outside, this is really a normal Anh Vu snail shell, nothing special. The secret inside To find out the answer to this problem, experts decided to take an X-ray of the cup, it turned out that the image of “300 cup tilting day” in Li Bai’s poetry was not a product of pompous tricks, it’s true. Inside the parrot cup there are lots of naturally created nets that occupy the dense interior of the prison and, all hidden nets are connected by small holes. When the ancients poured wine into the parrot cup, the wine would gradually seep into the net through small holes. In this way, when the ancients poured wine from a parrot cup, the wine inside would not be poured out all at once, but flowed out little by little under the influence of air pressure.In this way, it gives the illusion that the alcohol in it never runs out. Recreate the image inside the parrot cup. Photo: Sina After the experts learned this secret, they felt great admiration for the wisdom of the ancients. The working principle of the parrot cup is very similar to today’s activated carbon, it uses the spatial structure inside the object to achieve the purpose of slowing down the flow. Drinking with a small glass of wine with such a long pouring power is very elegant and rich in emotion, so the parrot cup is always sought after by antique wine lovers. The parrot cup is so popular, but why has it disappeared from history? Experts believe that the cause is due to the main material of the cup – the Anh Vu snail, which has a very small number. This animal lives on the seabed several hundred meters deep in the tropics and subtropics, so it is not easy to find.

Using computational tools, researchers can virtually open a complicated folded letter from 1697. These are complex techniques to help recipients detect if a message has been tampered with. To date, scientists say letters over 300 years old can be read without opening. Read letters using algorithm During research at the Vatican Secret Archives, conservator Janaa Dambrogio at the MIT Library (Massachusetts Institute of Technology in America) unearthed Renaissance letters with strange cuts and angles. . She found these were signs that they were initially locked with a sliding paper slot and sealed with wax. Such letters cannot be opened without tearing the letter – which helps the recipient to see if the letter has been read or not. After studying 250,000 ancient letters, Dambrogio and her colleagues invented the first system for classifying key-lettering techniques. This is a type of periodic table based on how to crease pages. “Mail lock is 10 thousand years old technology and since people try to secure their mail, gradually they have come to know the key features of mail lock” – Ms. Dambrogio said. Until now, scientists have only read these letters by cutting them out and often corrupting the letters. Although such work naturally focuses on the content of the letter, it is also important to research the letter lock. Dambrogio and her colleagues have devised a way to both read the locked letter’s text without opening it, while at the same time reconstructing the intricate folds and gaps used to fix it. “This is an interesting and pretty big contribution over the decades to the search for artifacts that have barely been opened yet,” said computer scientist Brent Seales at the University of Kentucky. He is not involved in this study. The scientists investigated the Brienne Collection – a postmaster’s chest containing more than 3,000 unsent letters, of which 577 were never opened. Letters sent from all over Europe to the Dutch city of The Hague between 1680 and 1706, the era when Salem witch trials unfold, Newton revealed his law of motion and gravity. King Louis XIV moved the court to Versailles. First, the researchers analyzed four envelopes by scanning high-resolution X-rays to create 3D models of the letter. They then use a new algorithm to identify and separate different layers of folded letters and recognize the written text. In the end, the algorithm virtually unfolds the letters, not only making the handwriting visible, but also records the crease patterns so that the researchers can re-create the step-by-step letter locking process. Scientists use technology to read locked letters dating back centuries. Open up many research directions Scientists have found a way to read the letter without breaking its seal or opening it in any way. Using highly sensitive X-ray scanners and computer algorithms, researchers can read these sealed letters. The new strategy above helps scientists read the text in unopened messages for the first time. For example, an unopened letter is from a man named Jacques Sennacques, dated 31/7/1679 to his cousin Pierre Le Pers – a French businessman in The Hague. Perhaps this letter was intended to obtain a certified copy of the death certificate of a relative, Dainel Le Pers, regarding the inheritance issue. The scientists detailed their findings in the recent Nature Communications journal. This new technique will also work for other collections of unsent mail around the world. For example, “there are so many old origami art pieces that the way they were created has never been recorded,” said study co-author Erik Demaine, a computer scientist at MIT – “The idea of ​​scanning them so they can replicate the way they are folded is really interesting.” The historian Howard Hotson at the University of St Anne in Oxford, UK was not involved in the study, however he stressed that future research on locked letters could shed light on cultural patterns and patterns. global technology exchange “because sophisticated mail locking techniques have been transferred from one country, sector or continent to the respective places over the long period in which it is used”. Scientists are making their technology and open source available for others to use and possibly improve. “We see this as the starting point for many future research directions,” said co-author of the study, algorithm engineer Amanda Ghasaei at Adobe Research in San Francisco.