Keel
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Laser and navigation take the top prizes in technology awards
2017-03-23 09:19
Shanghai Daily Editor: Huang Mingrui
Award winners and representatives attend the meeting for Shanghai Science and Technology Awards. (Chen Zhengbao)
Shanghai Science and Technology Awards — the city's highest awards for science and technology achievements — were handed to 265 projects and individuals yesterday.
For the first time, there were two winners of the top award, one involving a material developed for China's super laser facility, the other a new BeiDou location technology.
Hu Lili, director of the R&D Center of High Power Laser Optical Components of the Shanghai Institute of Optics and Fine Mechanics, won the top prize for developing technologies for mass production of a large-size phosphate laser glass that can amplify the energy of a laser.
Hu and his team spent 12 years developing key technologies for the full flow of mass production for "Nd-doped" phosphate glass, including continuous melting, fine annealing, cladding of the laser glass and high-accuracy testing.
The second top award winner is Yu Wenxian, professor of School of Electronic Information and Electrical Engineering of Shanghai Jiao Tong University.
He and his team have made a series of breakthroughs on location applications to produce a satellite navigation system to make tracking more accurate.
The technology developed has helped to create China's largest indoor map database, which is used by Internet companies including Tencent and the country's largest map service provider Amap.
"Most indoor map models still rely on manual data collection, which is of rather low efficiency," Yu said. "However, the demand for indoor maps is increasing, which requires making and updating the maps faster."
The international cooperation awards went to Michail Vladimirovich Ivanov from Russia and Jun Chen from the United States.
Zhang Jianhua, 45, from Shanghai University, is one of the 10 laureates of the Youth with Outstanding Science and Technology Contribution.
Cooperating with two local companies, her project on a manufacturing technique and application of the latest high resolution display technology also won the first prize of the Science and Technology Progress Awards.
The project has resolved several bottlenecks with the development of "AM OLED," a display technology used in devices including mobile phones and laptops.
"The companies need time to scale up the production and make it available for the public, while the researchers must go one step forward on the most frontier technology so that they can serve the industry at the best time," Zhang said.
Health and environmental protection projects were among the leading awards.
A physical therapy for patients with terminal pancreatic cancer through artery injection of chemo-medicine developed by Dr Li Maoquan from Shanghai No.10 People's Hospital has benefited more than 5,000 patients.
"The therapy has prolonged patients' survival period from 6.7 months to 13.8 months and improved their life quality," Li said.
http://www.ecns.cn/2017/03-23/250331.shtml
2017-03-23 09:19
Shanghai Daily Editor: Huang Mingrui
Award winners and representatives attend the meeting for Shanghai Science and Technology Awards. (Chen Zhengbao)
Shanghai Science and Technology Awards — the city's highest awards for science and technology achievements — were handed to 265 projects and individuals yesterday.
For the first time, there were two winners of the top award, one involving a material developed for China's super laser facility, the other a new BeiDou location technology.
Hu Lili, director of the R&D Center of High Power Laser Optical Components of the Shanghai Institute of Optics and Fine Mechanics, won the top prize for developing technologies for mass production of a large-size phosphate laser glass that can amplify the energy of a laser.
Hu and his team spent 12 years developing key technologies for the full flow of mass production for "Nd-doped" phosphate glass, including continuous melting, fine annealing, cladding of the laser glass and high-accuracy testing.
The second top award winner is Yu Wenxian, professor of School of Electronic Information and Electrical Engineering of Shanghai Jiao Tong University.
He and his team have made a series of breakthroughs on location applications to produce a satellite navigation system to make tracking more accurate.
The technology developed has helped to create China's largest indoor map database, which is used by Internet companies including Tencent and the country's largest map service provider Amap.
"Most indoor map models still rely on manual data collection, which is of rather low efficiency," Yu said. "However, the demand for indoor maps is increasing, which requires making and updating the maps faster."
The international cooperation awards went to Michail Vladimirovich Ivanov from Russia and Jun Chen from the United States.
Zhang Jianhua, 45, from Shanghai University, is one of the 10 laureates of the Youth with Outstanding Science and Technology Contribution.
Cooperating with two local companies, her project on a manufacturing technique and application of the latest high resolution display technology also won the first prize of the Science and Technology Progress Awards.
The project has resolved several bottlenecks with the development of "AM OLED," a display technology used in devices including mobile phones and laptops.
"The companies need time to scale up the production and make it available for the public, while the researchers must go one step forward on the most frontier technology so that they can serve the industry at the best time," Zhang said.
Health and environmental protection projects were among the leading awards.
A physical therapy for patients with terminal pancreatic cancer through artery injection of chemo-medicine developed by Dr Li Maoquan from Shanghai No.10 People's Hospital has benefited more than 5,000 patients.
"The therapy has prolonged patients' survival period from 6.7 months to 13.8 months and improved their life quality," Li said.
http://www.ecns.cn/2017/03-23/250331.shtml
JSCh
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Volume 95 Issue 13 | p. 4 | News of The Week
Issue Date: March 27, 2017 | Web Date: March 22, 2017
New process for generating hydrogen fuel
Catalyst produces hydrogen from methanol and water at relatively low temperatures
By Stu Borman
Atomically dispersed Pt on MoC particles catalyzes the “reformation” of CH3OH and H2O to form H2. Reaction intermediates shown on particle surface. H is white, C is gray, O is red, Pt is blue, and Mo is cyan.
Credit: Courtesy of Ding Ma
A sustainable, cleaner-burning alternative to gasoline could help shrink the carbon footprint of cars and trucks. One option is to use methanol by catalytically releasing hydrogen from the liquid to power a hydrogen fuel cell.
Ding Ma of Peking University, Beijing, and coworkers report a new catalyst to do so: atomically dispersed platinum over molybdenum carbide particles that drive the efficient and relatively low-temperature “reforming” of CH3OH and water to form H2 (Nature 2017, DOI: 10.1038/nature21672).
The process is about five times as efficient as the previous H2-from-methanol champ, a ruthenium-catalyzed dehydrogenation developed by Matthias Beller of the University of Rostock and coworkers (Nature 2013, DOI: 10.1038/nature11891).
The new Pt/MoC catalyst works at relatively low temperatures, 150 to 190 °C—cooler than the 200 °C or more traditionally used to reform CH3OH vapor, but considerably hotter than Beller’s process, which works at 65 to 95 °C. But the new process has advantages over the Beller technique: It avoids the use of caustic hydroxide, and the Pt/MoC catalyst is heterogeneous, which makes it cheaper and easier to recycle than the homogeneous ruthenium catalyst.
Ma calculates that a 50-L tank of CH3OH and catalyst with 6 to 10 g of Pt—about the weight of a wedding ring—could power a Toyota Mirai, a hydrogen fuel cell concept car, for about 690 km. The CH3OH would cost about $15 and the Pt about $320, but the catalyst is potentially recyclable.
Pt is relatively rare and expensive compared with other metal catalysts, but Ma points out that automobile catalytic converters now contain 1 to 4 g of recyclable noble metals, “so 8 g Pt is not a big number.”
Reaction engineer Dion Vlachos of the University of Delaware comments that the new process “has a technological edge in terms of reaction rate,” but improving long-term catalyst stability, developing means for catalyst regeneration, and finding alternatives to noble metals “are important future directions for widespread commercialization.”
Beller calls Ma’s catalyst “a major breakthrough,” noting that this type of catalyst might also be useful for other aqueous-phase reforming processes, such as those involving biowaste or ethanol.
Chemical & Engineering News
ISSN 0009-2347
Copyright © 2017 American Chemical Society
New process for generating hydrogen fuel | March 22, 2017 Issue - Vol. 95 Issue 13 | Chemical & Engineering News
Lili Lin, Wu Zhou, Rui Gao, Siyu Yao, Xiao Zhang, Wenqian Xu, Shijian Zheng, Zheng Jiang, Qiaolin Yu, Yong-Wang Li, Chuan Shi, Xiao-Dong Wen & Ding Ma. "Low-temperature hydrogen production from water and methanol using Pt/α-MoC catalysts". Nature (2017). DOI: 10.1038/nature21672
Issue Date: March 27, 2017 | Web Date: March 22, 2017
New process for generating hydrogen fuel
Catalyst produces hydrogen from methanol and water at relatively low temperatures
By Stu Borman
Credit: Courtesy of Ding Ma
A sustainable, cleaner-burning alternative to gasoline could help shrink the carbon footprint of cars and trucks. One option is to use methanol by catalytically releasing hydrogen from the liquid to power a hydrogen fuel cell.
Ding Ma of Peking University, Beijing, and coworkers report a new catalyst to do so: atomically dispersed platinum over molybdenum carbide particles that drive the efficient and relatively low-temperature “reforming” of CH3OH and water to form H2 (Nature 2017, DOI: 10.1038/nature21672).
The process is about five times as efficient as the previous H2-from-methanol champ, a ruthenium-catalyzed dehydrogenation developed by Matthias Beller of the University of Rostock and coworkers (Nature 2013, DOI: 10.1038/nature11891).
The new Pt/MoC catalyst works at relatively low temperatures, 150 to 190 °C—cooler than the 200 °C or more traditionally used to reform CH3OH vapor, but considerably hotter than Beller’s process, which works at 65 to 95 °C. But the new process has advantages over the Beller technique: It avoids the use of caustic hydroxide, and the Pt/MoC catalyst is heterogeneous, which makes it cheaper and easier to recycle than the homogeneous ruthenium catalyst.
Ma calculates that a 50-L tank of CH3OH and catalyst with 6 to 10 g of Pt—about the weight of a wedding ring—could power a Toyota Mirai, a hydrogen fuel cell concept car, for about 690 km. The CH3OH would cost about $15 and the Pt about $320, but the catalyst is potentially recyclable.
Pt is relatively rare and expensive compared with other metal catalysts, but Ma points out that automobile catalytic converters now contain 1 to 4 g of recyclable noble metals, “so 8 g Pt is not a big number.”
Reaction engineer Dion Vlachos of the University of Delaware comments that the new process “has a technological edge in terms of reaction rate,” but improving long-term catalyst stability, developing means for catalyst regeneration, and finding alternatives to noble metals “are important future directions for widespread commercialization.”
Beller calls Ma’s catalyst “a major breakthrough,” noting that this type of catalyst might also be useful for other aqueous-phase reforming processes, such as those involving biowaste or ethanol.
Chemical & Engineering News
ISSN 0009-2347
Copyright © 2017 American Chemical Society
New process for generating hydrogen fuel | March 22, 2017 Issue - Vol. 95 Issue 13 | Chemical & Engineering News
Lili Lin, Wu Zhou, Rui Gao, Siyu Yao, Xiao Zhang, Wenqian Xu, Shijian Zheng, Zheng Jiang, Qiaolin Yu, Yong-Wang Li, Chuan Shi, Xiao-Dong Wen & Ding Ma. "Low-temperature hydrogen production from water and methanol using Pt/α-MoC catalysts". Nature (2017). DOI: 10.1038/nature21672
Bussard Ramjet
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Volume 95 Issue 13 | p. 4 | News of The Week
Issue Date: March 27, 2017 | Web Date: March 22, 2017
New process for generating hydrogen fuel
Catalyst produces hydrogen from methanol and water at relatively low temperatures
By Stu Borman
Atomically dispersed Pt on MoC particles catalyzes the “reformation” of CH3OH and H2O to form H2. Reaction intermediates shown on particle surface. H is white, C is gray, O is red, Pt is blue, and Mo is cyan.
Credit: Courtesy of Ding Ma
A sustainable, cleaner-burning alternative to gasoline could help shrink the carbon footprint of cars and trucks. One option is to use methanol by catalytically releasing hydrogen from the liquid to power a hydrogen fuel cell.
Ding Ma of Peking University, Beijing, and coworkers report a new catalyst to do so: atomically dispersed platinum over molybdenum carbide particles that drive the efficient and relatively low-temperature “reforming” of CH3OH and water to form H2 (Nature 2017, DOI: 10.1038/nature21672).
The process is about five times as efficient as the previous H2-from-methanol champ, a ruthenium-catalyzed dehydrogenation developed by Matthias Beller of the University of Rostock and coworkers (Nature 2013, DOI: 10.1038/nature11891).
The new Pt/MoC catalyst works at relatively low temperatures, 150 to 190 °C—cooler than the 200 °C or more traditionally used to reform CH3OH vapor, but considerably hotter than Beller’s process, which works at 65 to 95 °C. But the new process has advantages over the Beller technique: It avoids the use of caustic hydroxide, and the Pt/MoC catalyst is heterogeneous, which makes it cheaper and easier to recycle than the homogeneous ruthenium catalyst.
Ma calculates that a 50-L tank of CH3OH and catalyst with 6 to 10 g of Pt—about the weight of a wedding ring—could power a Toyota Mirai, a hydrogen fuel cell concept car, for about 690 km. The CH3OH would cost about $15 and the Pt about $320, but the catalyst is potentially recyclable.
Pt is relatively rare and expensive compared with other metal catalysts, but Ma points out that automobile catalytic converters now contain 1 to 4 g of recyclable noble metals, “so 8 g Pt is not a big number.”
Reaction engineer Dion Vlachos of the University of Delaware comments that the new process “has a technological edge in terms of reaction rate,” but improving long-term catalyst stability, developing means for catalyst regeneration, and finding alternatives to noble metals “are important future directions for widespread commercialization.”
Beller calls Ma’s catalyst “a major breakthrough,” noting that this type of catalyst might also be useful for other aqueous-phase reforming processes, such as those involving biowaste or ethanol.
Chemical & Engineering News
ISSN 0009-2347
Copyright © 2017 American Chemical Society
New process for generating hydrogen fuel | March 22, 2017 Issue - Vol. 95 Issue 13 | Chemical & Engineering News
Lili Lin, Wu Zhou, Rui Gao, Siyu Yao, Xiao Zhang, Wenqian Xu, Shijian Zheng, Zheng Jiang, Qiaolin Yu, Yong-Wang Li, Chuan Shi, Xiao-Dong Wen & Ding Ma. "Low-temperature hydrogen production from water and methanol using Pt/α-MoC catalysts". Nature (2017). DOI: 10.1038/nature21672
I hope they focus on commercializing these catalysts.
JSCh
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Chinese 'wearable robot' could help disabled people walk again
(CNTV) 16:46, March 24, 2017
Could a "wearable robot" one day help paraplegics and disabled people walk in the same way shortsighted people simply put on a pair of glasses to correct their vision? That is the hope of one Chinese company which is designing exoskeletons that people can wear.
A commercial exoskeleton robot, Fourier X1, was recently independently developed by Chinese manufacturing company Fourier Intelligence and released in Shanghai. The promotional material for the robot, which includes a video released online, shows the robot mainly being used for patients with lower body paralysis.
The company says the "wearable robot" can help a person sit, stand, walk, and go up or down the stairs etc.
The robot is also meant to be able to "perceive" the changes in a person's posture and "think about" their intentions, with the help of 19 different sensors and 11 distributed CPU modules.
The company has also stressed the safety aspects of the device, stating that if the person's center of gravity deviates beyond the pre-set range, the robot will shut down automatically, give an alarm, and take other security measures. The person will then be kept in a fixed state , without falling down after the robot stops.
Fourier Intelligence boasts that a person wearing the exoskeleton can walk continuously for about 7 hours before needing to recharge the device.
(CNTV) 16:46, March 24, 2017
Could a "wearable robot" one day help paraplegics and disabled people walk in the same way shortsighted people simply put on a pair of glasses to correct their vision? That is the hope of one Chinese company which is designing exoskeletons that people can wear.
A commercial exoskeleton robot, Fourier X1, was recently independently developed by Chinese manufacturing company Fourier Intelligence and released in Shanghai. The promotional material for the robot, which includes a video released online, shows the robot mainly being used for patients with lower body paralysis.
The company says the "wearable robot" can help a person sit, stand, walk, and go up or down the stairs etc.
The robot is also meant to be able to "perceive" the changes in a person's posture and "think about" their intentions, with the help of 19 different sensors and 11 distributed CPU modules.
The company has also stressed the safety aspects of the device, stating that if the person's center of gravity deviates beyond the pre-set range, the robot will shut down automatically, give an alarm, and take other security measures. The person will then be kept in a fixed state , without falling down after the robot stops.
Fourier Intelligence boasts that a person wearing the exoskeleton can walk continuously for about 7 hours before needing to recharge the device.
JSCh
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Mar 23, 2017
Stable grain boundaries toughen up metallic nanograins
Conventional metals become harder with decreasing grain size but this is not the case for some nanograined metals that become softer. Researchers in China and France have now discovered that they can adjust hardness in fine nanograined metals by tailoring the stability of grain boundaries in these materials. The technique could be used to produce novel nanograined metals with extraordinary properties.
Conventional polycrystalline materials become harder with decreasing grain size, according to the classical Hall–Petch relationship – with the increase in strength being reversely proportional to the square root of the grain size. The strengthening occurs thanks to dislocation pileups at grain boundaries that then prevent the dislocations from moving. Plastic deformation therefore becomes more difficult at smaller grains as the density of the grain boundaries increases. The situation can be different in certain nanograined materials, however, and researchers have already observed softening, rather than hardening, when grain sizes are smaller than 10 to 30 nm in size.
A team of researchers, led by Ke Lu of Shenyang National Laboratory for Materials Science, the Institute of Metal Research at the Chinese Academy of Sciences and Nanjing University of Science and Technology, has now found that the mechanical behaviour and plastic deformation mechanisms can fundamentally differ in extremely-fine nanograined metals with the same grain size. Here, the nature of their grain boundaries becomes more important instead. “With more stable grain boundaries, these materials can be extremely hard (even as hard as ceramics),” explains Lu, “while for less stable grain boundaries, they can be soft thanks to grain boundary migration. This finding is important since it provides us with an alternative way to tailor the properties of nanograined metals along with grain size.”
Different plastic deformation mechanisms at play
In their previous studies on the mechanical behaviour of nanograined metals, Lu and colleagues observed grain boundary migration-induced softening in a number of samples. In their new work, they designed an experiment to stabilize grain boundaries in nanograined nickel by segregating molybdenum at the metal grain boundaries. They did this by synthesizing nanograined Ni-Mo samples using a technique called electrodeposition and then thermally annealing them to segregate the Mo into the Ni grain boundaries.
“We found a pronounced hardening effect upon annealing, and the smaller the grains, the higher the hardness increase,” Lu tells nanotechweb.org. “Thanks to detailed structural and compositional characterization of the as-deposited and as-annealed nanograined Ni-Mo samples, we discovered that there are very different plastic deformation mechanisms at play. Grain boundary migration dominates deformation in as-deposited nanograined samples while extended partial deformation with the formation of multiple through-grain stacking faults dominates in the as-annealed ones. The two samples thus have very different hardness.”
Advanced materials with novel properties and performance
“Since the stability of grain boundaries governs hardening and softening in extremely-fine nanograined samples, we could synthesize extremely hard versions of these materials by decreasing grain size and stabilizing grain boundaries,” he adds.
The team, which includes researchers from UNIROUEN in France, says that it will now exploit this technique to develop advanced materials with novel properties and performance.
The researchers detail their present work in Science doi: 10.1126/science.aal5166.
About the author
Belle Dumé is contributing editor at nanotechweb.org
Stable grain boundaries toughen up metallic nanograins - nanotechweb.org
J. Hu, Y. N. Shi, X. Sauvage, G. Sha, K. Lu. "Grain boundary stability governs hardening and softening in extremely fine nanograined metals". Science (2017). DOI: 10.1126/science.aal5166
Stable grain boundaries toughen up metallic nanograins
Conventional metals become harder with decreasing grain size but this is not the case for some nanograined metals that become softer. Researchers in China and France have now discovered that they can adjust hardness in fine nanograined metals by tailoring the stability of grain boundaries in these materials. The technique could be used to produce novel nanograined metals with extraordinary properties.
Conventional polycrystalline materials become harder with decreasing grain size, according to the classical Hall–Petch relationship – with the increase in strength being reversely proportional to the square root of the grain size. The strengthening occurs thanks to dislocation pileups at grain boundaries that then prevent the dislocations from moving. Plastic deformation therefore becomes more difficult at smaller grains as the density of the grain boundaries increases. The situation can be different in certain nanograined materials, however, and researchers have already observed softening, rather than hardening, when grain sizes are smaller than 10 to 30 nm in size.
A team of researchers, led by Ke Lu of Shenyang National Laboratory for Materials Science, the Institute of Metal Research at the Chinese Academy of Sciences and Nanjing University of Science and Technology, has now found that the mechanical behaviour and plastic deformation mechanisms can fundamentally differ in extremely-fine nanograined metals with the same grain size. Here, the nature of their grain boundaries becomes more important instead. “With more stable grain boundaries, these materials can be extremely hard (even as hard as ceramics),” explains Lu, “while for less stable grain boundaries, they can be soft thanks to grain boundary migration. This finding is important since it provides us with an alternative way to tailor the properties of nanograined metals along with grain size.”
Different plastic deformation mechanisms at play
In their previous studies on the mechanical behaviour of nanograined metals, Lu and colleagues observed grain boundary migration-induced softening in a number of samples. In their new work, they designed an experiment to stabilize grain boundaries in nanograined nickel by segregating molybdenum at the metal grain boundaries. They did this by synthesizing nanograined Ni-Mo samples using a technique called electrodeposition and then thermally annealing them to segregate the Mo into the Ni grain boundaries.
“We found a pronounced hardening effect upon annealing, and the smaller the grains, the higher the hardness increase,” Lu tells nanotechweb.org. “Thanks to detailed structural and compositional characterization of the as-deposited and as-annealed nanograined Ni-Mo samples, we discovered that there are very different plastic deformation mechanisms at play. Grain boundary migration dominates deformation in as-deposited nanograined samples while extended partial deformation with the formation of multiple through-grain stacking faults dominates in the as-annealed ones. The two samples thus have very different hardness.”
Advanced materials with novel properties and performance
“Since the stability of grain boundaries governs hardening and softening in extremely-fine nanograined samples, we could synthesize extremely hard versions of these materials by decreasing grain size and stabilizing grain boundaries,” he adds.
The team, which includes researchers from UNIROUEN in France, says that it will now exploit this technique to develop advanced materials with novel properties and performance.
The researchers detail their present work in Science doi: 10.1126/science.aal5166.
About the author
Belle Dumé is contributing editor at nanotechweb.org
Stable grain boundaries toughen up metallic nanograins - nanotechweb.org
J. Hu, Y. N. Shi, X. Sauvage, G. Sha, K. Lu. "Grain boundary stability governs hardening and softening in extremely fine nanograined metals". Science (2017). DOI: 10.1126/science.aal5166
Nanograined metals avoid going soft
The Hall-Petch relationship links a metal's increasing hardness with decreasing grain size, but it breaks down when grains become very small. This is unfortunate because nanograined metals could otherwise be extremely hard. Hu et al. found a way to circumvent this problem in a set of nickel-molybdenum alloys. They altered the molybdenum composition and annealed the samples at just the right temperature, which stabilized the grain boundaries in their nanograined samples. This allowed hardness to keep increasing with decreasing grain size, which could provide a route for designing superhard coatings.
Science, this issue p. 1292
Abstract
Conventional metals become harder with decreasing grain sizes, following the classical Hall-Petch relationship. However, this relationship fails and softening occurs at some grain sizes in the nanometer regime for some alloys. In this study, we discovered that plastic deformation mechanism of extremely fine nanograined metals and their hardness are adjustable through tailoring grain boundary (GB) stability. The electrodeposited nanograined nickel-molybdenum (Ni–Mo) samples become softened for grain sizes below 10 nanometers because of GB-mediated processes. With GB stabilization through relaxation and Mo segregation, ultrahigh hardness is achieved in the nanograined samples with a plastic deformation mechanism dominated by generation of extended partial dislocations. Grain boundary stability provides an alternative dimension, in addition to grain size, for producing novel nanograined metals with extraordinary properties.
The Hall-Petch relationship links a metal's increasing hardness with decreasing grain size, but it breaks down when grains become very small. This is unfortunate because nanograined metals could otherwise be extremely hard. Hu et al. found a way to circumvent this problem in a set of nickel-molybdenum alloys. They altered the molybdenum composition and annealed the samples at just the right temperature, which stabilized the grain boundaries in their nanograined samples. This allowed hardness to keep increasing with decreasing grain size, which could provide a route for designing superhard coatings.
Science, this issue p. 1292
Abstract
Conventional metals become harder with decreasing grain sizes, following the classical Hall-Petch relationship. However, this relationship fails and softening occurs at some grain sizes in the nanometer regime for some alloys. In this study, we discovered that plastic deformation mechanism of extremely fine nanograined metals and their hardness are adjustable through tailoring grain boundary (GB) stability. The electrodeposited nanograined nickel-molybdenum (Ni–Mo) samples become softened for grain sizes below 10 nanometers because of GB-mediated processes. With GB stabilization through relaxation and Mo segregation, ultrahigh hardness is achieved in the nanograined samples with a plastic deformation mechanism dominated by generation of extended partial dislocations. Grain boundary stability provides an alternative dimension, in addition to grain size, for producing novel nanograined metals with extraordinary properties.
JSCh
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China building world's largest multifunctional nano research facility
(Xinhua) 13:04, March 28, 2017
NANJING, March 28 -- Chinese scientists are building the world's largest multifunctional research platform for nano-science and nano-technology that could help develop more powerful computers and more intelligent robots.
The Vacuum Interconnected Nano-X Research Facility in Suzhou, Jiangsu Province, integrates the state-of-art capabilities of material growth, device fabrication and testing in one ultra-high vacuum environment, said Ding Sunan, deputy director of the project.
"We are exploring a new technology route of nano-scale devices production on the platform, which simulates the ultra-high vacuum environment of space," said Ding, a researcher at the Suzhou Institute of Nano-Tech and Nano-Bionics under the Chinese Academy of Sciences.
Nano-X has received initial funding of 320 million yuan (about 46.5 million U.S. dollars), and will eventually have a budget of 1.5 billion yuan.
Construction on the first stage began in 2014 and is expected to be completed in 2018. It comprises 100-meter-long ultra-high vacuum pipelines connecting 30 pieces of equipment. Ultimately the facility will have ultra-high vacuum pipelines of about 500 meters, connecting more than 100 large pieces of equipment, Ding said.
Nano-X is designed as a complete system for materials growth, device fabrication and testing. All samples can be transferred accurately, quickly and smoothly among all tools in an ultra-high vacuum environment.
The facility can prevent surface contamination from the air, keeping a material's intrinsic properties unchanged and realizing quantum manipulation and control, said Ding.
Experts say it will help make breakthroughs in common and critical problems in materials science and device technology, and develop new manufacturing technologies of nano-materials and core devices in the fields of energy and information.
Nano-X is expected to be incorporated into China's national research infrastructure system, and become a world-class open platform for research and development in nano-science and nano-technology, providing advanced technical support for the national strategy of high technologies.
(Xinhua) 13:04, March 28, 2017
NANJING, March 28 -- Chinese scientists are building the world's largest multifunctional research platform for nano-science and nano-technology that could help develop more powerful computers and more intelligent robots.
The Vacuum Interconnected Nano-X Research Facility in Suzhou, Jiangsu Province, integrates the state-of-art capabilities of material growth, device fabrication and testing in one ultra-high vacuum environment, said Ding Sunan, deputy director of the project.
"We are exploring a new technology route of nano-scale devices production on the platform, which simulates the ultra-high vacuum environment of space," said Ding, a researcher at the Suzhou Institute of Nano-Tech and Nano-Bionics under the Chinese Academy of Sciences.
Nano-X has received initial funding of 320 million yuan (about 46.5 million U.S. dollars), and will eventually have a budget of 1.5 billion yuan.
Construction on the first stage began in 2014 and is expected to be completed in 2018. It comprises 100-meter-long ultra-high vacuum pipelines connecting 30 pieces of equipment. Ultimately the facility will have ultra-high vacuum pipelines of about 500 meters, connecting more than 100 large pieces of equipment, Ding said.
Nano-X is designed as a complete system for materials growth, device fabrication and testing. All samples can be transferred accurately, quickly and smoothly among all tools in an ultra-high vacuum environment.
The facility can prevent surface contamination from the air, keeping a material's intrinsic properties unchanged and realizing quantum manipulation and control, said Ding.
Experts say it will help make breakthroughs in common and critical problems in materials science and device technology, and develop new manufacturing technologies of nano-materials and core devices in the fields of energy and information.
Nano-X is expected to be incorporated into China's national research infrastructure system, and become a world-class open platform for research and development in nano-science and nano-technology, providing advanced technical support for the national strategy of high technologies.
خره مينه لګته وي
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Chinese tech giant Tencent signs $4.65 billion loan deal
Logo of Tencent is displayed at a news conference in Hong Kong, China March 22, 2017. REUTERS/Tyrone Siu
By Carol Zhong and Sijia Jiang | HONG KONG
Chinese tech giant Tencent Holdings has signed a $4.65 billion loan deal, Basis Point reported, amid a flurry of fund-raising by China's internet giants.
Tencent, which had an original target of about $2 billion for the loan, inked the deal on March 24 following commitments from a dozen banks, Thomson Reuters publication Basis Point reported, citing sources.
The loans for general corporate purposes comprise a $2.79 billion term loan and a $1.86 billion revolving credit. Citigroup was the coordinator, mandated lead arranger and bookrunner of the facility.
Tencent, best known for its WeChat mobile app, has been on an investment drive in a wide array of sectors such as gaming, entertainment, cloud computing and online financing.
It reported net profit of 41.1 billion yuan ($5.97 billion) last year on Wednesday, up 43 percent, on revenue that rose 48 percent to 151.94 billion yuan.
Tencent raised $7.94 billion in two syndicated loans in the past nine months, including $3.5 billion in October to back a deal for a majority stake in Finnish mobile game developer Supercell Oy.
Tencent did not immediately respond to requests for comment when contacted by Reuters.
(Reporting by Carol Zhong and Sijia Jiang; Writing by Sijia Jiang; Editing by Stephen Coates)
http://www.reuters.com
Logo of Tencent is displayed at a news conference in Hong Kong, China March 22, 2017. REUTERS/Tyrone Siu
By Carol Zhong and Sijia Jiang | HONG KONG
Chinese tech giant Tencent Holdings has signed a $4.65 billion loan deal, Basis Point reported, amid a flurry of fund-raising by China's internet giants.
Tencent, which had an original target of about $2 billion for the loan, inked the deal on March 24 following commitments from a dozen banks, Thomson Reuters publication Basis Point reported, citing sources.
The loans for general corporate purposes comprise a $2.79 billion term loan and a $1.86 billion revolving credit. Citigroup was the coordinator, mandated lead arranger and bookrunner of the facility.
Tencent, best known for its WeChat mobile app, has been on an investment drive in a wide array of sectors such as gaming, entertainment, cloud computing and online financing.
It reported net profit of 41.1 billion yuan ($5.97 billion) last year on Wednesday, up 43 percent, on revenue that rose 48 percent to 151.94 billion yuan.
Tencent raised $7.94 billion in two syndicated loans in the past nine months, including $3.5 billion in October to back a deal for a majority stake in Finnish mobile game developer Supercell Oy.
Tencent did not immediately respond to requests for comment when contacted by Reuters.
(Reporting by Carol Zhong and Sijia Jiang; Writing by Sijia Jiang; Editing by Stephen Coates)
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JSCh
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New method heats up ultrasonic approach to treating tumors
Researchers apply new modeling tools to improve acoustic simulations and design a new focusing method for potential clinical treatments
Date:
--> New method heats up ultrasonic approach to treating tumors: Researchers apply new modeling tools to improve acoustic simulations and design a new focusing method for potential clinical treatments -- ScienceDaily
Researchers apply new modeling tools to improve acoustic simulations and design a new focusing method for potential clinical treatments
Date:
March 28, 2017
Source:
American Institute of Physics
Summary:
High-intensity focused ultrasound (HIFU) is a breakthrough therapeutic technique used to treat tumors. The principle of this noninvasive, targeted treatment is much like that of focusing sunlight through a lens, using an ultrasonic transducer like a convex lens to concentrate ultrasound into a small focal region. Researchers have now designed a transducer for potential application in HIFU that can generate a steady, standing-wave field with a subwavelength-scale focal region and extremely high ultrasound intensity.
--> New method heats up ultrasonic approach to treating tumors: Researchers apply new modeling tools to improve acoustic simulations and design a new focusing method for potential clinical treatments -- ScienceDaily
Keel
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In the midst of the loan deal, Tencent keeps surging, closing @HKD 226/share today
HK$228/share at today's closing
Keep going Tencent!
JSCh
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Soil restoration projects proposed
By Zhang Zhihao and Zheng Jinran | China Daily | Updated: 2017-03-30 07:34
A researcher adjusts a sediment collection vessel in Changsha, Hunan province, in June, as part of efforts to monitor and restore the cadmium-tainted soil.[Photo/Xinhua]
Contamination called 'alarming' for endangering food security
China's leading scientific institute will invest 20 million yuan ($2.9 million) over the next 18 months in projects that tackle heavy metal pollution in soil, as part of efforts to safeguard food and water security, the Chinese Academy of Sciences said on Wednesday.
The soil restoration projects, spearheaded by the academy's Institute of Soil Science in Nanjing, Jiangsu province, will establish regional standards for cadmium, nickel, arsenic and other toxic heavy metals.
Two pollution control demonstration zones - one focused on mercury and the other on cadmium - will be built in Tongren, Guizhou province, and the Changsha-Zhuzhou-Xiangtan area in Hunan province respectively.
Moreover, there will be a national research network for technologies such as extracting heavy metal using plants and making heavy metals less toxic.
The institute will also build a regional surveillance platform and industrialization park to monitor and recycle heavy metals during soil restoration projects, said Yan Qing, head of the academy's bureau of science and technology for development.
A 2014 survey by the ministries of environmental protection, and land and resources found that 36.3 percent of soil samples were polluted. China will conduct thorough surveys of soil pollution to get a clearer picture, Chen Jining, minister of environmental protection, said earlier this month.
China has 122 million hectares of arable land, but is losing 400,000 hectares of mostly fertile land each year to construction, pollution and natural disasters, said Shen Renfang, director of the Institute of Soil Sciences.
Soil pollution is "a very alarming matter" because "food security is unsustainable if we keep losing arable land to pollution, and polluted crops, like rice laced with cadmium, could undermine consumer trust and public health," Shen said.
In May, the State Councill, China's Cabinet, issued a national plan to improve the prevention and control of soil pollution, including strictly prohibiting the setting up of industries and farms that fail to meet standards.
"Local officials will now think twice when establishing an economically rewarding, but polluting, industry," said Zhou Dongmei, a researcher at the institute. "Sadly, there is no quick solution to cleaning up soil pollution on a large, cost-effective scale."
The short-term goals should focus on risk control and ensuring the safety of agricultural goods, as well as researching new solutions, Zhou said. "But the hardest part is balancing economic growth with ecological protection, especially at the local level."
The soil restoration projects are one of 11 major science programs planned this year. The programs, costing a total of 190 million yuan, aim to promote economic and social growth, Yan said.
"Previous pollution control projects were often on a case-by-case basis, because each area has its own complex geographical makeup and causes of pollution," Yan said. "The new projects will tackle the issue in a more wide-ranging, systematic manner, so the emerging standards and solutions are more universally applicable and effective on a greater scale."
By Zhang Zhihao and Zheng Jinran | China Daily | Updated: 2017-03-30 07:34
Contamination called 'alarming' for endangering food security
China's leading scientific institute will invest 20 million yuan ($2.9 million) over the next 18 months in projects that tackle heavy metal pollution in soil, as part of efforts to safeguard food and water security, the Chinese Academy of Sciences said on Wednesday.
The soil restoration projects, spearheaded by the academy's Institute of Soil Science in Nanjing, Jiangsu province, will establish regional standards for cadmium, nickel, arsenic and other toxic heavy metals.
Two pollution control demonstration zones - one focused on mercury and the other on cadmium - will be built in Tongren, Guizhou province, and the Changsha-Zhuzhou-Xiangtan area in Hunan province respectively.
Moreover, there will be a national research network for technologies such as extracting heavy metal using plants and making heavy metals less toxic.
The institute will also build a regional surveillance platform and industrialization park to monitor and recycle heavy metals during soil restoration projects, said Yan Qing, head of the academy's bureau of science and technology for development.
A 2014 survey by the ministries of environmental protection, and land and resources found that 36.3 percent of soil samples were polluted. China will conduct thorough surveys of soil pollution to get a clearer picture, Chen Jining, minister of environmental protection, said earlier this month.
China has 122 million hectares of arable land, but is losing 400,000 hectares of mostly fertile land each year to construction, pollution and natural disasters, said Shen Renfang, director of the Institute of Soil Sciences.
Soil pollution is "a very alarming matter" because "food security is unsustainable if we keep losing arable land to pollution, and polluted crops, like rice laced with cadmium, could undermine consumer trust and public health," Shen said.
In May, the State Councill, China's Cabinet, issued a national plan to improve the prevention and control of soil pollution, including strictly prohibiting the setting up of industries and farms that fail to meet standards.
"Local officials will now think twice when establishing an economically rewarding, but polluting, industry," said Zhou Dongmei, a researcher at the institute. "Sadly, there is no quick solution to cleaning up soil pollution on a large, cost-effective scale."
The short-term goals should focus on risk control and ensuring the safety of agricultural goods, as well as researching new solutions, Zhou said. "But the hardest part is balancing economic growth with ecological protection, especially at the local level."
The soil restoration projects are one of 11 major science programs planned this year. The programs, costing a total of 190 million yuan, aim to promote economic and social growth, Yan said.
"Previous pollution control projects were often on a case-by-case basis, because each area has its own complex geographical makeup and causes of pollution," Yan said. "The new projects will tackle the issue in a more wide-ranging, systematic manner, so the emerging standards and solutions are more universally applicable and effective on a greater scale."
JSCh
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Chinese science academy to invest 190 mln yuan in major programs
Source: Xinhua 2017-03-29 18:35:25
BEIJING, March 29 (Xinhua)-- The Chinese Academy of Sciences (CAS) said Wednesday it would fund 11 major programs in various fields including agricultural science, technology and biotechnology this year, with a total investment of 190 million yuan (about 27.6 million U.S. dollars).
CAS hopes that the programs will boost the transformation and upgrading of related industries and generate direct economic and social benefits.
The move includes a program on the prevention and control of biological invasion at the the country's borders, including the establishment of a system to rapidly inspect, quarantine and identify species. A total of 10 million yuan will be invested in the program over an 18 month period.
The funds will also cover environmental and hi-tech programs, including one on natural disaster risk assessment and disaster reduction solutions in the China-Pakistan Economic Corridor, and another on the fifth-generation chips for the latest generation of mobile telecommunications.
Source: Xinhua 2017-03-29 18:35:25
BEIJING, March 29 (Xinhua)-- The Chinese Academy of Sciences (CAS) said Wednesday it would fund 11 major programs in various fields including agricultural science, technology and biotechnology this year, with a total investment of 190 million yuan (about 27.6 million U.S. dollars).
CAS hopes that the programs will boost the transformation and upgrading of related industries and generate direct economic and social benefits.
The move includes a program on the prevention and control of biological invasion at the the country's borders, including the establishment of a system to rapidly inspect, quarantine and identify species. A total of 10 million yuan will be invested in the program over an 18 month period.
The funds will also cover environmental and hi-tech programs, including one on natural disaster risk assessment and disaster reduction solutions in the China-Pakistan Economic Corridor, and another on the fifth-generation chips for the latest generation of mobile telecommunications.
JSCh
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Chinese scientists explore all-weather solar cells
(Xinhua) 09:54, April 03, 2017
A photovoltaic revolution is taking place with the emergence of all-weather solar cells, according to a Chinese scientist.
"Solar cell research is mainly focused on elevating photoelectric conversion efficiency upon direct sunlight until new light has been shed on persistent high-efficiency power generation in poor light conditions such as rain, fog, haze and night," said Tang Qunwei, a professor with Ocean University of China.
Tang's team and one led by Yang Peizhi, a professor with Yunnan Normal University, developed a solar cell using a crucial material called long persistent phosphor (LPP), which can store sunlight energy in the day and harvest it in darkness.
"Only partially visible light can be absorbed by light absorbers and then converted into electricity. But solar energy from unabsorbed visible and near-infrared light can be stored in LPP, releasing monochromatic visible light at night,' Tang said. "The released light is re-absorbed by light absorbers to convert it into electricity, realizing persistent power generation in the day and in the dark."
The work of Tang and Yang was recently published in an academic journal published by the American Chemistry Society, ACS Nano, and the publication Nano Energy.
Tang has published in Chemistry - A European Journal, where he wrote that the physical proof of all-weather solar cells would open the door for an upcoming photovoltaic revolution.
"All-weather solar cells could indicate that the global solar industry will bring down the cost of energy harvesting," Tang said.
(Xinhua) 09:54, April 03, 2017
A photovoltaic revolution is taking place with the emergence of all-weather solar cells, according to a Chinese scientist.
"Solar cell research is mainly focused on elevating photoelectric conversion efficiency upon direct sunlight until new light has been shed on persistent high-efficiency power generation in poor light conditions such as rain, fog, haze and night," said Tang Qunwei, a professor with Ocean University of China.
Tang's team and one led by Yang Peizhi, a professor with Yunnan Normal University, developed a solar cell using a crucial material called long persistent phosphor (LPP), which can store sunlight energy in the day and harvest it in darkness.
"Only partially visible light can be absorbed by light absorbers and then converted into electricity. But solar energy from unabsorbed visible and near-infrared light can be stored in LPP, releasing monochromatic visible light at night,' Tang said. "The released light is re-absorbed by light absorbers to convert it into electricity, realizing persistent power generation in the day and in the dark."
The work of Tang and Yang was recently published in an academic journal published by the American Chemistry Society, ACS Nano, and the publication Nano Energy.
Tang has published in Chemistry - A European Journal, where he wrote that the physical proof of all-weather solar cells would open the door for an upcoming photovoltaic revolution.
"All-weather solar cells could indicate that the global solar industry will bring down the cost of energy harvesting," Tang said.
JSCh
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Mutations may reveal how Tibetans can live on world’s highest plateau
Scientists have long known how the people of the Tibetan Plateau, including Nepal’s famous mountain-climbing Sherpa, deal with oxygen levels up to 40% less than those at sea level. Unlike most mountain climbers, whose bodies acclimatize to higher elevations by temporarily boosting hemoglobin—a blood protein that carries oxygen throughout the body—Tibetans have evolved a suite of other biochemical adaptations that let their bodies use oxygen extremely efficiently. That’s good news for the Tibetans, because too much hemoglobin makes the blood harder to pump and likelier to clot, increasing the chances of stroke and heart disease.
But the details of Tibetans’ adaptations have been a mystery. Previous studies have suggested that two genes, EPAS1 (inherited from ancient hominins known as Denisovans) and ELGN1, play roles in reducing hemoglobin and boosting oxygen use. To find out whether other genes are involved, a team of scientists led by Jian Yang at the University of Queensland in Brisbane, Australia, and Zi-Bing Jin at Wenzhou Medical University in China compared the genomes of 3008 Tibetans and 7287 non-Tibetans.
The team looked for common variants among the Tibetan genomes; they then computed whether those variants likely spread throughout the population by chance or by natural selection. EPAS1 and ELGN1 predictably popped out as strong candidates for evolutionary adaptations, they report today in the Proceedings of the National Academy of Sciences. So did seven additional genes: MTHFR, RAP1A, NEK7, ADH7, FGF10, HLA-DQB1, and HCAR2.
In Tibetans, the ADH7 gene variant is associated with higher weight and BMI scores, which could help the body store energy during particularly lean times on the hardscrabble plateau. The MTHFR variant also helps with nutrient deficiency: It boosts production of the vitamin folate, important for pregnancy and fertility. Folate breaks down when exposed to high levels of UV radiation, so high folate levels would compensate for their increased UV exposure. And HLA-DQB1 belongs to a family of genes that regulates proteins critical to the immune system, particularly important given that extreme living conditions like malnutrition can make people more susceptible to disease, Yang says. What the other four gene variants do is less clear, but they could be an evolutionary response to selective pressures besides high altitude.
The team also used its analysis to pin down a likely date for the split between Tibetans and the closely related Han Chinese population: approximately 4725 years ago, or some 189 generations back. That’s about 2000 years earlier than suggested by previous studies focusing on a different, more selective set of genes known as the exome, but it’s in line with recent archaeological findings that point to distinctly Tibetan permanent settlements appearing between 3600 and 5200 years ago, Yang says.
Lynn Jorde, a geneticist at the University of Utah in Salt Lake City who also studies high-altitude genetics, says the study’s large size lends credence to the findings. Such a large data set would help researchers detect more significant variants and weed out false positives. It could also explain why previous studies, including several by Jorde’s team, haven’t noticed these genes before.
But it will take more than just genomic studies to convince him and others in the field that any particular gene really is an evolutionary adaptation, he says. “I think statistical results, while very important, will only take us so far in searching for signatures of natural selection,” Jorde says. “We need to follow up with functional studies, such as in animal models or at least in vitro systems, to pinpoint and validate the biological basis for selection.”
Mutations may reveal how Tibetans can live on world’s highest plateau | Science | AAAS
Jian Yang et al. Genetic signatures of high-altitude adaptation in Tibetans, Proceedings of the National Academy of Sciences (2017). DOI: 10.1073/pnas.1617042114
- By Michael Price
- Apr. 3, 2017 , 3:00 PM
Scientists have long known how the people of the Tibetan Plateau, including Nepal’s famous mountain-climbing Sherpa, deal with oxygen levels up to 40% less than those at sea level. Unlike most mountain climbers, whose bodies acclimatize to higher elevations by temporarily boosting hemoglobin—a blood protein that carries oxygen throughout the body—Tibetans have evolved a suite of other biochemical adaptations that let their bodies use oxygen extremely efficiently. That’s good news for the Tibetans, because too much hemoglobin makes the blood harder to pump and likelier to clot, increasing the chances of stroke and heart disease.
But the details of Tibetans’ adaptations have been a mystery. Previous studies have suggested that two genes, EPAS1 (inherited from ancient hominins known as Denisovans) and ELGN1, play roles in reducing hemoglobin and boosting oxygen use. To find out whether other genes are involved, a team of scientists led by Jian Yang at the University of Queensland in Brisbane, Australia, and Zi-Bing Jin at Wenzhou Medical University in China compared the genomes of 3008 Tibetans and 7287 non-Tibetans.
The team looked for common variants among the Tibetan genomes; they then computed whether those variants likely spread throughout the population by chance or by natural selection. EPAS1 and ELGN1 predictably popped out as strong candidates for evolutionary adaptations, they report today in the Proceedings of the National Academy of Sciences. So did seven additional genes: MTHFR, RAP1A, NEK7, ADH7, FGF10, HLA-DQB1, and HCAR2.
In Tibetans, the ADH7 gene variant is associated with higher weight and BMI scores, which could help the body store energy during particularly lean times on the hardscrabble plateau. The MTHFR variant also helps with nutrient deficiency: It boosts production of the vitamin folate, important for pregnancy and fertility. Folate breaks down when exposed to high levels of UV radiation, so high folate levels would compensate for their increased UV exposure. And HLA-DQB1 belongs to a family of genes that regulates proteins critical to the immune system, particularly important given that extreme living conditions like malnutrition can make people more susceptible to disease, Yang says. What the other four gene variants do is less clear, but they could be an evolutionary response to selective pressures besides high altitude.
The team also used its analysis to pin down a likely date for the split between Tibetans and the closely related Han Chinese population: approximately 4725 years ago, or some 189 generations back. That’s about 2000 years earlier than suggested by previous studies focusing on a different, more selective set of genes known as the exome, but it’s in line with recent archaeological findings that point to distinctly Tibetan permanent settlements appearing between 3600 and 5200 years ago, Yang says.
Lynn Jorde, a geneticist at the University of Utah in Salt Lake City who also studies high-altitude genetics, says the study’s large size lends credence to the findings. Such a large data set would help researchers detect more significant variants and weed out false positives. It could also explain why previous studies, including several by Jorde’s team, haven’t noticed these genes before.
But it will take more than just genomic studies to convince him and others in the field that any particular gene really is an evolutionary adaptation, he says. “I think statistical results, while very important, will only take us so far in searching for signatures of natural selection,” Jorde says. “We need to follow up with functional studies, such as in animal models or at least in vitro systems, to pinpoint and validate the biological basis for selection.”
Mutations may reveal how Tibetans can live on world’s highest plateau | Science | AAAS
Jian Yang et al. Genetic signatures of high-altitude adaptation in Tibetans, Proceedings of the National Academy of Sciences (2017). DOI: 10.1073/pnas.1617042114
Significance
The origin of Tibetans and the mechanism of how they adapted to the high-altitude environment remain mostly unknown. We conduct the largest genome-wide study in Tibetans to date. We detect signatures of natural selection at nine gene loci, two of which are strongly associated with blood phenotypes in present day Tibetans. We further show the genetic relatedness of Tibetans with other ethnic groups in China and estimate the divergence time between Tibetans and Han. These findings provide important knowledge to understand the genetic ancestry of Tibetans and the genetic basis of high-altitude adaptation.
Abstract
Indigenous Tibetan people have lived on the Tibetan Plateau for millennia. There is a long-standing question about the genetic basis of high-altitude adaptation in Tibetans. We conduct a genome-wide study of 7.3 million genotyped and imputed SNPs of 3,008 Tibetans and 7,287 non-Tibetan individuals of Eastern Asian ancestry. Using this large dataset, we detect signals of high-altitude adaptation at nine genomic loci, of which seven are unique. The alleles under natural selection at two of these loci [methylenetetrahydrofolate reductase (MTHFR) and EPAS1] are strongly associated with blood-related phenotypes, such as hemoglobin, homocysteine, and folate in Tibetans. The folate-increasing allele of rs1801133 at the MTHFR locus has an increased frequency in Tibetans more than expected under a drift model, which is probably a consequence of adaptation to high UV radiation. These findings provide important insights into understanding the genomic consequences of high-altitude adaptation in Tibetans.
The origin of Tibetans and the mechanism of how they adapted to the high-altitude environment remain mostly unknown. We conduct the largest genome-wide study in Tibetans to date. We detect signatures of natural selection at nine gene loci, two of which are strongly associated with blood phenotypes in present day Tibetans. We further show the genetic relatedness of Tibetans with other ethnic groups in China and estimate the divergence time between Tibetans and Han. These findings provide important knowledge to understand the genetic ancestry of Tibetans and the genetic basis of high-altitude adaptation.
Abstract
Indigenous Tibetan people have lived on the Tibetan Plateau for millennia. There is a long-standing question about the genetic basis of high-altitude adaptation in Tibetans. We conduct a genome-wide study of 7.3 million genotyped and imputed SNPs of 3,008 Tibetans and 7,287 non-Tibetan individuals of Eastern Asian ancestry. Using this large dataset, we detect signals of high-altitude adaptation at nine genomic loci, of which seven are unique. The alleles under natural selection at two of these loci [methylenetetrahydrofolate reductase (MTHFR) and EPAS1] are strongly associated with blood-related phenotypes, such as hemoglobin, homocysteine, and folate in Tibetans. The folate-increasing allele of rs1801133 at the MTHFR locus has an increased frequency in Tibetans more than expected under a drift model, which is probably a consequence of adaptation to high UV radiation. These findings provide important insights into understanding the genomic consequences of high-altitude adaptation in Tibetans.
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