China Science & Technology Forum

[JSCh]

China Launches Major Physics Experiment Facility in Worlds' Deepest Underground Lab
CCTV Video News Agency
Published on Jul 21, 2019

China launched the construction of a major physics experiment facility in the world's best-shielded underground lab in southwest China's Sichuan Province on Saturday.

 

[JSCh]

Researchers develop low-cost, hand-powered water disinfection system
Source: Xinhua| 2019-07-22 18:45:30|Editor: Xiang Bo

BEIJING, July 22 (Xinhua) -- An international team of researchers have developed a low-cost and hand-powered water disinfection system based on triboelectric nanogenerator technology.

In recent years, water disinfection at the point of use (POU) has become a focus of both academia and industry. Compared with traditional centralized water disinfection approaches, POU devices treat water at the point of consumption. Researchers have been trying to lessen their cost and dependence on electricity.

In 2012, the triboelectric nanogenerator (TENG) was developed as a new power-generation technology to convert various mechanical energy from the living environment into electricity, based on the coupling between the triboelectric effect and electrostatic induction.

In the new study, researchers from Tsinghua University, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences and Georgia Institute of Technology in the United States proposed the concept of TriboPump, including a water pump, a disinfection device and a disk triboelectric nanogenerator (D-TENG) as the power source.

According to the research paper published in the journal Advanced Energy Materials, a design incorporating a coaxial mechanical structure integrated into a 3D-printed support with a well-matched gear ratio enables the D-TENG and water pump to be driven by the same rotating mechanical stimuli, such as hand power, while achieving different rotating speeds.

Meanwhile, the D-TENG can adapt to different water qualities without additional power management circuits.

The researchers said the TriboPump water disinfection system can be effectively operated by hand power and cost as low as 10 U.S. dollars for a two-year service for a single family.

It provides a feasible one-stop and cost-efficient solution for POU water pumping and disinfection, and is especially suitable for rural areas or locations hit by unexpected disasters without direct access to a power supply, they said.

According to the World Health Organization's report in 2017, one out of nine people in the world have no direct access to clean water due to pathogen contamination. Access is further limited by factors including secondary contamination during water distribution, natural disasters, war and poverty.

 

[Grandy]

Science
Could a Chinese supercharged bacterium spark a superhuman revolution?

• Researchers say they created E coli strain that can draw on electrons in the environment
• Scientists’ next task is to see if technique can be applied to complex life forms

Stephen Chen
Published: 3:00am, 25 Jul, 2019

Scientists in Tianjin modified E coli to enable the germ to convert electrons into energy. Photo: Alamy

Scientists at a government laboratory in northern China say they have edited the DNA of a germ, creating a super bacterium that can use electrons as an energy source, perhaps opening the door to superpowers in humans.

The gene-edited germ uses electricity as “food”, increasing its physical performance by as much as 70 per cent, according to a team at the Chinese Academy of Sciences’ Tianjin Institute of Industrial Biotechnology. In theory, that would be like a human athlete running 100 metres (330ft) in three seconds or jumping over a bar more than four metres off the ground.

The researchers engineered the bacterium by adding an “alien” gene to the DNA of E coli, a germ common in animal intestines. The gene helped generate a protein – a compound that behaves like a worker bee or an information carrier within a cell – that can harvest free-roaming electrons from the environment and turn them into energy.

The Tianjin study was inspired by one of the biggest discoveries in biology over the last two decades, where researchers from around the world discovered a bacterium – Shewanella oneidensis – that generates small but regular electric currents using a protein that moves electrons in and out of cells.

In the future, [this technology] may even give rise to a superhuman race Professor Bi Changhao

Scientists could “cut and paste” electrically activated Shewanella oneidensis DNA into almost any living cell to give it the ability to absorb free-roaming electrons, the Tianjin researchers said in findings published in the Biochemical Engineering Journal this year.
“If the technology works on E coli, it should work on the cells of animals or human beings,” Professor Bi Changhao, lead scientist on the Tianjin project, said on Tuesday. “This will be one direction of our studies.”
Bi said human and animal cells did not use electricity – energy in the form of charged particles called electrons – directly. That is why electric shocks cause pain and, if they are strong enough, can kill.

Revolutionary implant helps paralysed patients walk again

But the ability to electrically charge a muscle might give humans great strength, or revive tired, overworked muscles, he said.
Other possible applications of the technology included biofuel production and treatment for cell-related diseases and conditions such as cancer and age-related infirmity.

“In the future, it may even give rise to a superhuman race,” Bi said.
He also said that an ability to convert electricity meant humans would need less food for energy, possibly reducing health problems such as obesity.

Scientists says the relationship between electricity and cells must be explored if humans are to benefit from their findings. Pictured is a scene from The Matrix in which humans are likened to batteries. Photo: Handou.

Professor Guo Weixiang, researcher at the Chinese Academy of Sciences’ Institute of Genetics and Development Biology in Beijing, said the Tianjin findings needed to be reviewed and thoroughly tested under laboratory conditions.
“The relationship between electricity and cells is not very well understood,” said Guo, who was not involved in the study.
He said that some patients with Parkinson’s disease had been given brain implants that used electrical charges to reduce symptoms such as tremors, but implants could not reverse cell degeneration.
“What works on a single-cell life form may not work on a complex organism,” Guo said.

Deep brain stimulation can aid Parkinson's sufferers

Bi said there was much more work to be done and scientists needed to study whether electrically energised cells died quicker than cells that were not stimulated.
For E coli, which spawns a new generation every half an hour, that was not a big problem, but a shortened lifespan for animal cells after every electric charge was.
“That will be unacceptable,” Bi said. “We are working on it.”

 

[JSCh]

Chinese researchers develop a new way to regenerate retina
Source: Xinhua| 2019-07-25 17:24:09|Editor: Shi Yinglun

BEIJING, July 25 (Xinhua) - Chinese researchers have used iPS cells to regenerate retina, which holds the potential to develop new therapies for some blinding diseases such as retinal degeneration.

The iPS cells are a type of pluripotent stem cell artificially derived from a non-pluripotent cell. It can be induced to have the same genetic information as early embryonic cells.

Researchers from China's Central South University made iPS cells from somatic cells in the patients' urine or blood and induced the iPS cells to differentiate into RPE cells, a layer of cells in the back of the eye.

According to the research published in the journal Acta Biomaterialia, the RPE cells can form an ultra-thin layer of structure similar to the retina.

In future studies, the researchers plan to transplant the structure behind the patient's retina to see if it can fix the patient's vision.

Since the iPS cells are derived from the patient's cells, immune rejection of cell transplantation is avoided.

The retinal degeneration, which may lead to permanent blindness, is one of the most common eye diseases among people over the age of 50.

 

[JSCh]

Chinese scientists develop new high-safety microbattery
Source: Xinhua| 2019-07-24 18:25:56|Editor: Li Xia

SHENYANG, July 23 (Xinhua) -- Chinese scientists have developed a new technique to make high-safety and scalable planar microbatteries.

The scientists of the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences developed a low-cost and highly efficient scalable screen printing technique that can help make the high-safety and scalable planar Zn//MnO2 microbatteries.

More and more electronic devices are becoming more lightweight, flexible and wearable, thus greatly boosting the demand for miniature energy storage devices.

Scientists have focused on the research of the safe flat microbattery for a period of time. In order to improve safety, the researchers developed high-safety aqueous electrolytes to replace flammable organic electrolytes to produce high-safety microbatteries.

Prof. Wu Zhongshuai, the chief scientist leading the research, found that the new batteries are not only more environmentally friendly and safe but more durable.

The microbattery has corrected the shortcomings of traditional batteries such as bulkiness, poor mechanical flexibility and easy separation of the interface under the bending state, said Wu.

The research result was published in the latest issue of the National Science Review.

 

[JSCh]

NEWS RELEASE 24-JUL-2019
Artificial throat could someday help mute people 'speak'
AMERICAN CHEMICAL SOCIETY

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A wearable artificial graphene throat, abbreviated here as 'WAGT,' can transform human throat movements into different sounds with training of the wearer.
CREDIT: Adapted from ACS Nano 2019, 10.1021/acsnano.9b03218

Most people take speech for granted, but it's actually a complex process that involves both motions of the mouth and vibrations of folded tissues, called vocal cords, within the throat. If the vocal cords sustain injuries or other lesions, a person can lose the ability to speak. Now, researchers reporting in ACS Nano have developed a wearable artificial throat that, when attached to the neck like a temporary tattoo, can transform throat movements into sounds.

Scientists have developed detectors that measure movements on human skin, such as pulse or heartbeat. However, the devices typically can't convert these motions into sounds. Recently, He Tian, Yi Yang, Tian-Ling Ren and colleagues developed a prototype artificial throat with both capabilities, but because the device needed to be taped to the skin, it wasn't comfortable enough to wear for long periods of time. So the researchers wanted to develop a thinner, skin-like artificial throat that would adhere to the neck like a temporary tattoo.

To make their artificial throat, the researchers laser-scribed graphene on a thin sheet of polyvinyl alcohol film. The flexible device measured 0.6 by 1.2 inches, or about double the size of a person's thumbnail. The researchers used water to attach the film to the skin over a volunteer's throat and connected it with electrodes to a small armband that contained a circuit board, microcomputer, power amplifier and decoder. When the volunteer noiselessly imitated the throat motions of speech, the instrument converted these movements into emitted sounds, such as the words "OK" and "No." The researchers say that, in the future, mute people could be trained to generate signals with their throats that the device would translate into speech.


Artificial throat could someday help mute people 'speak' | EurekAlert! Science News

Yuhong Wei, Yancong Qiao, Guangya Jiang, Yunfan Wang, Fangwei Wang, Mingrui Li, Yunfei Zhao, Ye Tian, Guangyang Gou, Songyao Tan, He Tian, Yi Yang, Tian-Ling Ren. A Wearable Skinlike Ultra-Sensitive Artificial Graphene Throat. ACS Nano (2019). DOI: 10.1021/acsnano.9b03218​

 

[JSCh]

SHANK3 (green) is expressed along with a neural marker (NeuN) in the mouse anterior cingulate cortex.
Image: Guoping Feng

Neuroscientists identify brain region linked to altered social interactions in autism model | MIT News
In a mouse model, restoring activity of a specific forebrain region reverses social traits associated with autism.

by Sabbi Lall | McGovern Institute for Brain Research
July 26, 2019

Although psychiatric disorders can be linked to particular genes, the brain regions and mechanisms underlying particular disorders are not well-understood. Mutations or deletions of the SHANK3 gene are strongly associated with autism spectrum disorder (ASD) and a related rare disorder called Phelan-McDermid syndrome. Mice with SHANK3 mutations also display some of the traits associated with autism, including avoidance of social interactions, but the brain regions responsible for this behavior have not been identified.

A new study by neuroscientists at MIT and colleagues in China provides clues to the neural circuits underlying social deficits associated with ASD. The paper, published in Nature Neuroscience, found that structural and functional impairments in the anterior cingulate cortex (ACC) of SHANK3 mutant mice are linked to altered social interactions.

“Neurobiological mechanisms of social deficits are very complex and involve many brain regions, even in a mouse model,” explains Guoping Feng, the James W. and Patricia T. Poitras Professor at MIT and one of the senior authors of the study. “These findings add another piece of the puzzle to mapping the neural circuits responsible for this social deficit in ASD models.”

The Nature Neuroscience paper is the result of a collaboration between Feng, who is also an investigator at MIT’s McGovern Institute and a senior scientist in the Broad Institute’s Stanley Center for Psychiatric Research, and Wenting Wang and Shengxi Wu at the Fourth Military Medical University, Xi’an, China.

A number of brain regions have been implicated in social interactions, including the prefrontal cortex (PFC) and its projections to brain regions including the nucleus accumbens and habenula, but these studies failed to definitively link the PFC to altered social interactions seen in SHANK3 knockout mice.

In the new study, the authors instead focused on the ACC, a brain region noted for its role in social functions in humans and animal models. The ACC is also known to play a role in fundamental cognitive processes, including cost-benefit calculation, motivation, and decision making.

In mice lacking SHANK3, the researchers found structural and functional disruptions at the synapses, or connections, between excitatory neurons in the ACC. The researchers went on to show that the loss of SHANK3 in excitatory ACC neurons alone was enough to disrupt communication between these neurons and led to unusually reduced activity of these neurons during behavioral tasks reflecting social interaction.

Having implicated these ACC neurons in social preferences and interactions in SHANK3 knockout mice, the authors then tested whether activating these same neurons could rescue these behaviors. Using optogenetics and specfic drugs, the researchers activated the ACC neurons and found improved social behavior in the SHANK3 mutant mice.

“Next, we are planning to explore brain regions downstream of the ACC that modulate social behavior in normal mice and models of autism,” explains Wenting Wang, co-corresponding author on the study. “This will help us to better understand the neural mechanisms of social behavior, as well as social deficits in neurodevelopmental disorders.”

Previous clinical studies reported that anatomical structures in the ACC were altered and/or dysfunctional in people with ASD, an initial indication that the findings from SHANK3 mice may also hold true in these individuals.

The research was funded, in part, by the Natural Science Foundation of China. Guoping Feng was supported by NIMH grant no. MH097104, the Poitras Center for Psychiatric Disorders Research at the McGovern Institute at MIT, and the Hock E. Tan and K. Lisa Yang Center for Autism Research at the McGovern Institute at MIT.

 

[JSCh]

Four water droplets acting as wheels on a cargo carrier whiz along a negatively charged surface. Credit: Xu Deng/Zuankai Wang/Hans-Jürgen Butt

MATERIALS SCIENCE * 24 JULY 2019
How to make water flow uphill
Water droplets skitter across a surface ‘printed’ with patterns of negative charge.

Droplets of water can propel themselves up a vertical surface against the pull of gravity.

Water droplets will travel in a desired direction if placed on a surface with an uneven coating of water-repellent material: the most thickly-coated areas repel the droplets. But the droplets usually move slowly, and stop where the coating ends.

Xu Deng at the University of Electronic Science and Technology of China, Chengdu, and his colleagues have designed a system in which water drips from a pump onto a highly water-repellent surface. Upon impact, some of the water droplets’ negatively charged electrons are transferred to the surface.

The team varied certain factors, such as pump position, to layer an uneven distribution of electrons on the surface. Areas that were thus ‘printed’ with an extra helping of negative charge tugged on the water droplets, which whisked the droplets quickly along the surface. The technique allowed water droplets to flow uphill and climb walls.

This approach could control the flow of water, blood and other fluids in medical devices, the authors write.

Nature Mater. (2019)

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How to make water flow uphill : Research Highlights | Nature

 

[JSCh]

To feed its 1.4 billion, China bets big on genome editing of crops
By Jon Cohen
Jul. 29, 2019 , 8:00 AM

This story, the first in a series on CRISPR in China, was supported by the Pulitzer Center.

IN BEIJING AND DURHAM, NORTH CAROLINA—If Gao Caixia were a farmer, she might be spread a little thin. Down the hall from her office at a branch of the Chinese Academy of Sciences (CAS) here in Beijing, seeds from a strain of unusually soft rice and a variety of wheat with especially fat grains and resistance to a common fungus sprout in a tissue culture room. A short stroll away, wild tomato plants far hardier than domestic varieties but bearing the same sweet fruit crowd a greenhouse, along with herbicide-resistant corn and potatoes that are slow to brown when cut. In other lab rooms Gao grows new varieties of lettuce, bananas, ryegrass, and strawberries.

But Gao isn’t a farmer, and that cornucopia isn’t meant for the table—not yet, anyway. She is a plant scientist working at the leading edge of crop improvement. Every one of those diverse crops has been a target for conventional plant breeders, who have slowly and painstakingly worked to endow them with traits to make them more productive, nutritious, or hardy. But Gao is improving them at startling speeds by using the genome editor CRISPR.


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To feed its 1.4 billion, China bets big on genome editing of crops | Science | AAAS

 

[Galactic Penguin SST]

Asia’s 1st Tyrannosauripus found in China

30 July 2019 - 19:10

http://web.archive.org/web/20190730230112if_/https://img9.irna.ir/d/r2/2019/07/30/4/156513038.jpg ; https://archive.is/5rHnS/7c05a4bc219068bf5eeb8b0cddf6ea3579048851/scr.png ; https://en.irna.ir/news/83417923/Asia-s-1st-Tyrannosauripus-found-in-China
▲ 1. Tehran, July 30, IRNA/ Global Times - A tyrannosaurid footprint was found by paleontologists in East China's Jiangxi Province, the first of its kind to be found in Asia, it was announced on Tuesday.



The discovery is of great significance to the research of fauna distribution and Late Cretaceous evolution.

The track, found in Ganzhou, Jiangxi, is 58 centimeters long and 47 centimeters wide, and is one of the largest theropod tracks from China, said Xing Lida, a dinosaur footprint expert at Beijing-based China University of Geosciences.

The footprint shows sharp claw marks and steady feet; its toes are well developed, especially the second one with a slight marked inward curvature. Based on the above characteristics, it can be identified as a right footprint cast, the expert said.

Xing said the Ganzhou track is different from other large theropod tracks from China, but similar to the well-preserved Tyrannosauripus tracks from New Mexico and to Bellatoripes from British Columbia. The similarity has led Xing to tentatively label the track with Tyrannosauripus.

Xing noted that most dinosaur footprints found in China date back to the Jurassic Period or early-Cretaceous.

"A dinosaur footprint from the late-Cretaceous is very rare, not to mention a Tyrannosauripus, which is at the top of the food chain."

Xing said theropods are at least 7.5 meters long. This is similar to the estimated length of the Qianzhousaurus skeleton which was approximately 7.5 to 9 meters long.

Qianzhousaurus is a type of Tyrannosauripus previously found in Ganzhou, Jiangxi Province.

The footprint was located less than 33 kilometers from where the Qianzhousaurus was found, Xing said, noting that because it belongs to the top-level predator, it increases the possibility the track was left by a Qianzhousaurus.

Construction workers accidentally found the footprint. After realizing the track looked similar to dinosaur footprints, they gave the information to Niu Kecheng of the Yingliang Stone Nature History Museum in Nan'an, Southeast China's Fujian Province.

But Niu lost contact with the construction workers.

Two months later, Xing was informed by another person that the fossil was collected by people in Ganzhou.

"I was ecstatic when I heard the news. After seeing the picture, I knew that the goddess of luck had come to visit me," said Xing.

The findings were published by Xing, Niu, Martin G. Lockley of the University of Colorado and other researchers in Science Bulletin, a multidisciplinary academic journal supervised by the Chinese Academy of Sciences and co-sponsored by the National Natural Science Foundation of China.

In June, a joint China-US research team announced in Beijing that they had discovered four nearly 100-million-year old fossilized dinosaur footprints in East China's Jiangsu Province.

https://en.irna.ir/news/83417923/Asia-s-1st-Tyrannosauripus-found-in-China

 

[JSCh]

China’s CRISPR push in animals promises better meat, novel therapies, and pig organs for people
By Jon Cohen
Jul. 31, 2019 , 8:00 AM

This story, one in a series, was supported by the Pulitzer Center.

BEIJING, GUANGZHOU, JIANGMEN, KUNMING, AND SHANGHAI—Early one February morning, researchers harvest six eggs from a female rhesus macaque—one of 4000 monkeys chirping and clucking in a massive outdoor complex of metal cages here at the Yunnan Key Laboratory of Primate Biomedical Research. On today’s agenda at the busy facility, outside Kunming in southwest China: making monkey embryos with a gene mutated so that when the animals are born 5 months later, they will age unusually fast. The researchers first move the eggs to a laboratory bathed in red light to protect the fragile cells. Using high-powered microscopes, they examine the freshly gathered eggs and prepare to inject a single rhesus sperm into each one. If all goes well, the team will introduce the genome editor CRISPR before the resulting embryo begins to grow—early enough for the mutation for aging to show up in all cells of any offspring.


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China’s CRISPR push in animals promises better meat, novel therapies, and pig organs for people | Science | AAAS

 

[JSCh]

New approach could make HVAC heat exchangers five times better
Turbulent heat exchangers are widely used in HVAC systems around the world, and a new study demonstrates a simple modification that can improve their capability by 500%.

PROVIDENCE, RI [Brown University] — Researchers from Tsinghua University and Brown University have discovered a simple way to give a major boost to turbulent heat exchange, a method of heat transport widely used in heating, ventilation and air conditioning (HVAC) systems.

In a paper published in Nature Communications, the researchers show that adding a readily available organic solvent to common water-based turbulent heat exchange systems can boost their capacity to move heat by 500%. That’s far better than other methods aimed at increasing heat transfer, the researchers say.

“Other methods for increasing heat flux — nanoparticle additives or other techniques — have achieved at best about 50% improvement,” said Varghese Mathai, a postdoctoral researcher at Brown and co-first author of the study, who worked with Chao Sun, a professor at Tsinghua who conceived of the idea. “What we achieve here is 10 times more improvement than other methods, which is really quite exciting.”

Turbulent heat exchangers are fairly simple devices that use the natural movements of liquid to move heat. They consist of a hot surface, a cold surface and tank of liquid in between. Near the hot surface, the liquid heats up, becomes less dense and forms warm plumes that rise toward the cold side. There, the liquid loses its heat, becomes denser and forms cold plumes that sink back down toward the hot side. The cycling of water serves to regulate the temperatures of each surface. This type of heat exchange is a staple of modern HVAC systems widely used in home heaters and air conditioning units, the researchers say.

In 2015, Sun had the idea to use an organic component known as hydrofluoroether or HFE to speed the cycling of heat inside this kind of exchanger. HFE is sometimes used as the sole fluid in heat exchangers, but Sun suspected that it might have more interesting properties as an additive in water-based systems. Working with the study’s co-first author Ziqi Wang, Mathai and Sun experimented with adding small amounts of HFE and, after three years of work, were able to maximize its effectiveness in speeding heat exchange. The team showed that concentrations of around 1% HFE created dramatic heat flux enhancements up to 500%.

Using high-speed imaging and laser diagnostic techniques, the researchers were able to show how the HFE enhancement works. When near the hot side of the exchanger, the globules of HFE quickly boil, forming biphasic bubbles of vapor and liquid that rise rapidly toward the cold plate above. At the cold plate, the bubbles lose their heat and descend as liquid. The bubbles affect the overall heat flux in two ways, the researchers showed. The bubbles themselves carry a significant amount of heat away from the hot side, but they also increase the speed of the surrounding water plumes rising and falling.

“This basically stirs up the system and makes the plumes move faster,” Sun said. “Combined with the heat that the bubbles themselves carry, we get a dramatic improvement in heat transfer.”

That stirring action could have other applications as well, the researchers say. It could be useful in systems designed to mix two or more liquids. The extra stir makes for faster and more complete mixing.

The researchers pointed out that the specific additive they used — HFE7000 — is non-corrosive, non-flammable and ozone friendly. One limitation is that the approach only works on vertical heat exchange systems — ones that move heat from a lower plate to an upper one. It doesn’t currently work on side-to-side systems, though the researchers are considering ways to adapt the technique. Still, vertical exchangers are widely used, and this study has shown a simple way to improve them dramatically.

“This biphasic approach generates a very large increase in heat flux with minimal modifications to existing heating and cooling systems,” Mathai said. “We think this has great promise to revolutionize heat exchange in HVAC and other large-scale applications.”


New approach could make HVAC heat exchangers five times better | Brown University

Ziqi Wang, Varghese Mathai, Chao Sun. Self-sustained biphasic catalytic particle turbulence. Nature Communications (2019). DOI: 10.1038/s41467-019-11221-w​

 

[JSCh]

China’s CRISPR push in animals promises better meat, novel therapies, and pig organs for people
By Jon Cohen
Jul. 31, 2019 , 8:00 AM

This story, one in a series, was supported by the Pulitzer Center.

BEIJING, GUANGZHOU, JIANGMEN, KUNMING, AND SHANGHAI—Early one February morning, researchers harvest six eggs from a female rhesus macaque—one of 4000 monkeys chirping and clucking in a massive outdoor complex of metal cages here at the Yunnan Key Laboratory of Primate Biomedical Research. On today’s agenda at the busy facility, outside Kunming in southwest China: making monkey embryos with a gene mutated so that when the animals are born 5 months later, they will age unusually fast. The researchers first move the eggs to a laboratory bathed in red light to protect the fragile cells. Using high-powered microscopes, they examine the freshly gathered eggs and prepare to inject a single rhesus sperm into each one. If all goes well, the team will introduce the genome editor CRISPR before the resulting embryo begins to grow—early enough for the mutation for aging to show up in all cells of any offspring.


....

China’s CRISPR push in animals promises better meat, novel therapies, and pig organs for people | Science | AAAS

China's CRISPR revolution | Science
Jon Cohen

Science 02 Aug 2019:
Vol. 365, Issue 6452, pp. 420-421
DOI: 10.1126/science.365.6452.420

Editing of plant, animal, and human genomes has never been easier, as this country's scientists are rapidly demonstrating.

FOR MANY PEOPLE, CRISPR plus China equals the biophysicist He Jiankui, who infamously used the genome editor last year to alter the DNA of two human embryos that would become twin girls. Before his announcement, He was little-known within the country's CRISPR community, which has grown rapidly and is now challenging—and by some measures surpassing—the United States in its use of the powerful tool (see graphics, below).

A better representative of CRISPR in China is plant biologist Li Jiayang of the Institute of Genetics and Developmental Biology in Beijing. Li left the country in 1985 for his graduate education, as have many of China's best and brightest young scientists over the past few decades, and then returned home in 1995 to focus on manipulating plant DNA. Li, who recently ended a stint as head of the Chinese Academy of Agricultural Sciences, says he struggled for years to make pinpoint genome edits. CRISPR gave him a simple, fast way to do just that, turbocharging his efforts to modify rice. “Now, suddenly, the dreams come true,” says Li, whose lab is humming at 9 p.m. on a Wednesday with two dozen members of his team running experiments.

A technician in Gao Caixia's lab selects immature wheat embryos for CRISPR editing.
PHOTO: STEFEN CHOW

The lights are burning late at CRISPR labs around the world. In 2012, the year researchers transformed a bacterial immune system into the fast and versatile tool for genome engineering, scientific publications mentioning CRISPR totaled 127. Since then there have been more than 14,000. Although the United States has had the most CRISPR publications—and continues to have the most cited papers—China is now a close second and is pouring money into CRISPR's uses.

With support from the Pulitzer Center, Science visited scientists in five Chinese cities who are harnessing CRISPR in a wide range of disciplines. China's biggest push is in agriculture (see p. 422) but researchers there are also applying the editor on a large scale in animals (see p. 426), with pig organs for human transplants the most provocative goal. And China is aggressively exploring genome editing in medicine, having launched far more clinical trials using CRISPR, mainly for cancer, than any country (Science, 6 October 2017, p. 20).

CREDITS: (GRAPHICS) N. DESAI/SCIENCE; (DATA) GEOFFREY SIWO/UNIVERSITY OF NOTRE DAME; J. MARTIN-LAFFON ET AL., NATURE BIOTECHNOLOGY, VOL. 37, JUNE 2019, 601–621; A. RICROCH ET AL., EMERGING TOPICS IN LIFE SCIENCES (2017) 1 169–182

Although He's work lies far outside the mainstream, his actions haunt China (see p. 436). So does another, largely untold aspect of his rise and fall: the role that others, in China and abroad, played in the runup to his experiment. He shared his plans widely, and although several confidants tried to dissuade him, some were more encouraging (see p. 430).

Geneticist Wei Wensheng of Peking University in Beijing says the Chinese scientific culture has to look hard at how it creates researchers like He by overemphasizing firsts. “What I don't understand is why do you want to be named the first of something horrible or bad. What's the point?” Wei asks.

Yang Hui of the Institute of Neuroscience in Shanghai, one of the most successful young CRISPR researchers in the country, hopes China can move past He and up its game. Yes, Chinese researchers publish many CRISPR studies, he says, but “very few” do respected work that breaks new ground. “Our generation should publish more innovative papers,” Yang says.

But Yang stresses that he has seen the quality increase “very fast” over the past 2 years or so. As China plants its flag at this scientific frontier, overseas sojourns like Li's and his own may soon be the exception. “Now, many good students will choose to stay here because of the good opportunities,” Yang says. “And we have many good students working hard.”

 

[JSCh]

Structure of a Photosystem II Supercomplex from Diatom Unravels the Energy-harvesting, Transfer and Dissipation Mechanisms

Diatoms stem from red algae and account up to 40% of the net primary production in the ocean. The high photosynthesis capacity of diatoms are contributed largely by their light-harvesting antenna proteins, which are fucoxanthin (Fx) chlorophyll (Chl) a/c-binding proteins (FCPs) that can efficiently absorb blue-green light available underwater and also have strong nonphotochemical quenching (NPQ) abilities important for the highly fluctuating light environment in the surface of the ocean.

A large number of FCP subunits are associated with the PSII (Photosystem II) core, forming a PSII-FCPII supercomplex. However, the exact composition and organization of FCPs associated with the PSII core are still unknown, which restricts our understanding of the light-harvesting, energy transfer and dissipation processes in the PSII-FCPII supercomplex of diatoms.
Researchers from Institute of Botany of the Chinese Academy of Sciences and Tsinghua University cooperated to determine the structure of the PSII-FCP supercomplex from a centric diatom Chaetoceros gracilis by cryo-electron microscopy at a novel resolution.

The research entitled "The pigment-protein network of a diatom photosystem II–light harvesting antenna supercomplex" is published in Science.

A large quantity of pigments is assigned in the supercomplex, which include 230 Chls a, 58 Chls c, 124 Fxs, and 2 Diadoxanthins (Ddx). Among these pigments, Chl c and Fxs are important for their ability to harvest blue-green light under water. One Ddx is confirmed in a monomeric FCP mediating the energy transfer towards the core, which render this Ddx as an ideal site for possible energy dissipation.

"The results provide a structural basis for the efficient excitation energy transfer and quenching mechanisms in the PSII-FCPII supercomplex and also the evolutionary changes of the extrinsic proteins involved in the OEC", said Prof. SHEN Jianren, one of the corresponding authors of this study.

The paper was accompanied by a perspective written by Professor Claudia Büchel, one of the pioneers in the studies of diatom photosynthesis: "How diatoms harvest light". In this perspective, Prof. Claudia Büchel said: "The FCP structures solved by SHEN's group are milestones on the way to understanding the high flexibility of LHC/FCP proteins, where the same purpose is served by similar proteins in a very different manner."

Fig.1. Model of a diatom PSII-FCPII supercomplex embedded in the thylakoid membrane (Image by IBCAS)



Structure of a Photosystem II Supercomplex from Diatom Unravels the Energy-harvesting, Transfer and Dissipation Mechanisms---Chinese Academy of Sciences

Xiong Pi, Songhao Zhao, Wenda Wang, Desheng Liu, Caizhe Xu, Guangye Han, Tingyun Kuang, Sen-Fang Sui, Jian-Ren Shen. The pigment-protein network of a diatom photosystem II–light-harvesting antenna supercomplex. Science (2019). DOI: 10.1126/science.aax4406​

 

[JSCh]

Shanghai scientists make new discovery
By ZHOU WENTING in Shanghai | chinadaily.com.cn | Updated: 2019-08-08 18:43

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Shanghai scientists have made new discoveries regarding the spatial and temporal developmental trajectory of cells in early embryos, paving ways for more efficient methods to obtain stem cells for certain human organs. This may in turn promote the development of stem cell-related regenerative medicine.

Stem cell-related therapies, which are mainly targeted at diseases, including those in the immune and nervous systems of which no drugs are available so far, have been publicly recognized to bring prospective medical breakthroughs in the next one or two decades.

However, several factors, including low efficiency in cell differentiation, a shortage of functional cells, immaturity of differentiated cells and low purity of cells hinder the application of stem cells. The unsolved mysteries underlying the lineage regarding stem cells in the early stage of life may be the root cause, experts said.

A research group consisting of scientists from the Shanghai Institute of Biochemistry and Cell Biology, CAS-MPG Partner Institute for Computational Biology and Guangzhou Institutes of Biomedicine and Health, all of which are affiliated with the Chinese Academy of Sciences, conducted a comprehensive analysis with high-resolution spatial and temporal information retained on the developmental stages of early mouse embryo. The study established a three-dimensional molecular map for the expressed genes in the early embryos, providing a paradigm for the elucidation of lineage trajectory in primary germ layers and hence enabling the tracking of the "ancestors" of cells in different location.

Within one week, a fertilized egg will develop into a blastula – a hollow sphere of cells – before forming three layers: ectoderm, mesoderm, and entoderm. The ectoderm eventually develops into the body's nerve system and skin tissues; the mesoderm develops into tissues including heart, blood, muscles and bones; the endoderm develops into organs, such as lung, liver, pancreas and intestines.

"On the basis of our results, we revealed the fine developmental trajectory of progenitor cells that have not been observed by traditional approach. For example, some cells in mesoderm and ectoderm that used to be believed to derive separately may have common progenitors," said Jing Naihe, a leading researcher on the team.

"Such findings may help scientists develop new methods to obtain stem cells for livers, pancreas and spinal cord, and contribute to related disease researches and stem cell-related regenerative medicine," he said.

A paper about the study was published on the website of the United Kingdom-based journal Nature on Thursday.

Guangdun Peng, Shengbao Suo, Guizhong Cui, Fang Yu, Ran Wang, Jun Chen, Shirui Chen, Zhiwen Liu, Guoyu Chen, Yun Qian, Patrick P. L. Tam, Jing-Dong J. Han & Naihe Jing. Molecular architecture of lineage allocation and tissue organization in early mouse embryo. Nature (2019). DOI: 10.1038/s41586-019-1469-8​