China Science & Technology Forum

[JSCh]

What China’s latest five-year plan means for science
Oceanography, brain science and stem cells among research fields that look set to grow.

• David Cyranoski
• 18 March 2016

From a slowing economy to geopolitical tensions in the South China Sea, it is a testing time for China’s ruling Communist party. But its science aspirations seem unbridled. On 16 March, China approved its 13th Five-Year Plan. A draft version, as well as statements by key politicians, make it clear that innovation through science and technology is a priority. China also intends for its research expenditure to rise to 2.5% of gross domestic product by 2020, from less than 2.2% over the past five years. Reductions in energy use and the development of low-carbon energy sources feature in the latest five-year plan. Forsome of the other themes that are set to shape Chinese research over the next five years, Nature spoke to a range of scientists.

• The ocean deep
• Brain science
• Conservation
• Stem-cells
• Pollution

Continue reading -> What China’s latest five-year plan means for science : Nature News & Comment

 

[bobsm]

Second Chinese team reports gene editing in human embryos

Study used CRISPR technology to introduce HIV-resistance mutation into embryos.

Ewen Callaway
08 April 2016
Article toolsRights & Permissions

Yorgos Nikas/SPL
Early-stage human embryos have been edited by scientists.
Researchers in China have reported editing the genes of human embryos to try to make them resistant to HIV infection. Their paper1 — which used CRISPR-editing tools in non-viable embryos that were destroyed after three days — is only the second published claim of gene editing in human embryos.

Where in the world could the first CRISPR baby be born?

In April 2015, a different China-based team announced that they had modified a gene linked to a blood disease in human embryos (which were also not viable, and so could not have resulted in a live birth)2. That report — a world first — fuelled global deliberations over the ethics of modifying embryos and human reproductive cells, and led to calls for a moratorium on even such proof-of-principle research.

At the time, rumours swirled that other teams had conducted similar experiments. Sources in China told Nature’s news team that a handful of papers had been submitted for publication. The latest paper, which appeared in the Journal of Assisted Reproduction and Genetics on 6 April, might be one of these. Nature’s news team has asked the paper’s corresponding author, stem-cell scientist Yong Fan, for comment, but had not heard from him by the time of this report.

HIV resistance
In the paper, Fan, who works at Guangzhou Medical University in China, and his team say that they collected a total of 213 fertilized human eggs between April and September 2014. The fertilized eggs, donated by 87 patients, were unsuitable for implantation as part of in vitro fertility therapy, because they contained an extra set of chromosomes.

Fan’s team used CRISPR–Cas9 genome editing to introduce into some of the embryos a mutation that cripples an immune-cell gene called CCR5. Some humans naturally carry this mutation (known as CCR5Δ32) and they are resistant to HIV, because the mutation alters the CCR5 protein in a way that prevents the virus from entering the T cells it tries to infect.


CRISPR: gene editing is just the beginning
Genetic analysis showed that 4 of 26 human embryos targeted were successfully modified. But not all the embryos’ chromosomes harboured the CCR5Δ32 mutation — some contained unmodified CCR5, whereas others had acquired different mutations.

George Daley, a stem-cell biologist at Children’s Hospital Boston in Massachusetts, says that the paper’s main advance is the use of CRISPR to introduce a precise genetic modification successfully. “This paper doesn’t look like it offers much more than anecdotal evidence that it works in human embryos, which we already knew,” he says. “It’s certainly a long way from realizing the intended potential” — a human embryo with all its copies of CCR5 inactivated.

“It just emphasizes that there are still a lot of technical difficulties to doing precision editing in human embryo cells,” says Xiao-Jiang Li, a neuroscientist at Emory University in Atlanta, Georgia. He thinks that researchers should work out these kinks in non-human primates, for example, before continuing to modify the genomes of human embryos using techniques such as CRISPR.

Ethics of experiments
Tetsuya Ishii, a bioethicist at Hokkaido University in Sapporo, Japan, sees no problem with how the experiments were conducted — a local ethics committee approved them, and the egg donors gave their informed consent — but he questions their necessity. “Introducing CCR5Δ32 and trying repair, even in non-viable embryos, is just playing with human embryos,” Ishii says.


Don’t edit the human germ line
Fan's team writes in the paper that proof-of-principle experiments for human-embryo editing such as theirs are important to conduct while the ethical and legal issues of germline modification are being hashed out. “We believe that any attempt to generate genetically modified humans through the modification of early embryos needs to be strictly prohibited until we can resolve both ethical and scientific issues,” they write.

Daley sees a stark contrast between Fan’s work and research approved in February by UK fertility regulators that will allow CRISPR genome editing of human embryos. Those experiments, led by developmental biologist Kathy Niakan at the Francis Crick Institute in London, will inactivate genes involved in very early embryo development, in hopes of understanding why some pregnancies terminate. (The work will be done in viable embryos, but the researchers' licence requires that experiments be stopped within 14 days.)

Earlier this year, developmental biologist Robin Lovell-Badge, also at the Francis Crick Institute, told Nature that he thought that the carefully considered UK approval might embolden other researchers who are interested in pursuing embryo-editing research. “If they've been doing it in China, we may see several manuscripts begin to appear,” he said.

Whereas Niakan's work is answering questions intrinsic to embryology, Fan's work is establishing proof of principle for what would need to be done to generate an individual with resistance to HIV, Daley adds. “That means the science is going forward before there’s been the general consensus after deliberation that such an approach is medically warranted," he says.


Second Chinese team reports gene editing in human embryos : Nature News & Comment

 

[bobsm]

Chinese scientists succeed in micro-g 3D printing test
(Xinhua)
Updated: 2016-04-13 23:04

BEIJING -- Chinese scientists have successfully tested 3D printing at microgravity, the Technology and Engineering Center for Space Utilization (CSU) announced Wednesday.

The CSU team has conducted 93 parabolic test flights in France, and printed out the designed specimen with Chinese-developed equipment and processes.

The parabolic test flights, which created a microgravity environment that lasts about 22 seconds, were facilitated by the Space Administration of Germany.

Wang Gong, technical chief of the team, said 3D printing in an environment such as this would be advantageous to space probe technology as it would enable supplies to be printed during space missions.

At present, supplies must be sent to space stations via carrier rockets or cargo spacecraft, which is both costly and time-consuming, Wang added.

Earth-bound 3D printing technology, materials, equipment and operations need to be adapted to work in space, Wang said.

The experiment team has tested five materials, including fiber reinforced polymer, which has not been tested by NASA, Wang said.

The data obtained will be important to the future of space-bound 3D printing.


Chinese scientists succeed in micro-g 3D printing test - China - Chinadaily.com.cn

 

[JSCh]

Media Releases

2016.04.12
PolyU Develops Perovskite-Silicon Tandem Solar Cells with the World's Highest Power Conversion Efficiency

The Hong Kong Polytechnic University (PolyU) has successfully developed perovskite-silicon tandem solar cells with the world's highest power conversion efficiency of 25.5% recently. Perovskite solar cells first appeared in 2009 with an efficiency of just 3.8%. With the outstanding photovoltaic properties, perovskite solar cell has become a subject of vigorous research for sustainable power generation, with researchers around the world finding new ways to increase its energy conversion efficiency. It has currently established itself as one of the most promising solar cell materials. The research team in the Department of Electronic and Information Engineering led by Professor Charles Chee Surya, Clarea Au Endowed Professor in Energy, has recently made this world record with innovative means to enhance energy conversion efficiency. With this innovation, it is estimated that solar energy can be generated at cost of HK$2.73/W, compared with HK$3.9/W at present generated by existing silicon solar cells available in the market.

As there are different wavelengths for solar energy, a combination of different materials for making solar cells would work best for energy absorption. For example, methylammonium lead tri-halide perovskite and silicon solar cells can form a complementary pair. With the perovskite solar cell functioning as a top layer, it can harvest the short wavelength photons while the bottom layer coated with silicon is designed to absorb the long wavelength photons. PolyU's research team maximizes efficiency by making use of this feature with three innovative approaches. Firstly, the team discovers a chemical process - low-temperature annealing process in dry oxygen to reduce the impact made by perovskite defects. Secondly, the team fabricates a tri-layer of molybdenum trioxide / gold / molybdenum trioxide with optimized thickness of each layer, making it highly transparent for light to go into the bottom silicon layer under perovskite layer. Finally, by mimicking the surface morphology of the rose petals, a haze film, developed by Dr Zijian Zheng of PolyU Institute of Textiles and Clothing, has been applied as the top layer of the solar panel to trap more light. All three innovative approaches help enhance energy conversion efficiency. Professor Shen Hui of Sun Yat-sen University and Shun De SYSU Institute for Solar Energy, who excelled in the fabrication high-efficiency silicon cells, was responsible for the design and fabrication of the bottom silicon cell.

PolyU research team will continue to improve the power conversion efficiency as well as the performance of large-scale fabrication of perovskite-silicon solar cells.

https://www.polyu.edu.hk/web/en/media/media_releases/index_id_6208.html

 

[bobsm]

Global industry body says China at the forefront of 5G tech
By Fan Feifei (China Daily)
Updated: 2016-04-15 07:37

China has always been at the forefront of new technologies, especially now in 5G telecom technologies research and development, according to Mats Granryd, the newly installed director-general of the Global System for Mobile Communications Association.

Granryd said the organization is making great effort to provide guidance and regulation on 5G rollout worldwide.

The global industry body unites nearly 800 mobile operators with more than 250 companies in the mobile ecosystem, including handset and device makers, software companies and internet companies, as well as organizations in adjacent-industry sectors.

It also hosts industry-leading events such as the Mobile World Congress, the world's largest exhibition dedicated to the mobile telecom industry.

Granryd, who spent 15 years in a variety of roles at Sweden telecom giant Ericsson and was CEO of Tele2, one of Europe's fastest-growing telecom operators, said the telecom industry in China is developing rapidly, not only in scale, but also in innovative ways of using new technologies.

He is confident that "in a few years", 5G will be employed widely in China.

"Some operators in Asia, Europe and the United States are claiming they will launch 5G as early as 2018, which is two years before it will be fully standardized.

"China's major operators are all working on 5G and will be early adopters of the technology," said Granryd, adding that 5G's fast development in China is making a growing contribution to promoting the technology worldwide.

"In working with our members and considering how we are going to treat 5G from a government perspective, it's important for us to follow global standards and regulations," he said

China is currently working hard at gaining an edge over international competitors in 5G research and development.

The Ministry of Industry and Information Technology has said the experimental stage of 5G will last three years from 2016 to 2018, before being fully commercialized in 2020.

The country's main telecom carriers have already accelerated their efforts at developing 5G technology.

China Mobile Communications Corp, the country's largest carrier, set up a 5G innovation center in February, and will launch a 5G laboratory.

It also plans to finish the testing of 5G technologies and products in 2017 and conduct trial operations in 2018, with commercial use by 2020.

Fu Liang, a telecom expert, said: "5G development in China is generally keeping pace with the world, and China's technology companies, such as Huawei Technologies Co Ltd and ZTE Corp, have a right to a say in formulating the standard of 5G globally and take a lead in promoting its commercial use."


http://www.chinadaily.com.cn/business/tech/2016-04/15/content_24557098.htm

 

[JSCh]

“The end product is what matters”
Detlef Weigel, Director at the Max Planck Institute for Developmental Biology, explains why genome editing offers a targeted way of breeding better crops
April 12, 2016

Greater resistance to pests, less sensitivity to drought, higher yields – this is just a small selection of the requirements that crops will have to fulfil in future. Humanity needs new crops that can withstand the changes arising from global warming and can meet the growing demand for food. With the help of a new method called genome editing, scientists are seeking to develop new crop varieties more efficiently than before. If no foreign genes are inserted into these plants they cannot be distinguished from plants that have been bred using traditional methods. For this reason, Detlef Weigel from the Tübingen-based Max Planck Institute for Developmental Biology, together with colleagues from the USA and China, is asking for genome-edited plant varieties of this kind not to be classified as genetically modified plants.

Mr Weigel, how are new varieties bred from crops today?
Detlef Weigel: It is important to realize that traditional breeding also aims to alter the DNA of the plants. For example, if you would like to obtain a new plant that can withstand drought and produce high yields, you can cross existing varieties which are resistant to drought or produce particularly high yields. The genes for these traits are newly mixed in the descendants’ DNA and some plants receive the genes for both traits. Chemical substances or radiation can also be used to generate mutations somewhere in the genetic code. Plants with new traits can also arise in this way. However, it is very time-consuming and complicated to seek out plants with the desired traits from thousands of mutants.

What is the difference between genome-edited and genetically modified plants?
With traditional genetic engineering, genes are often introduced into a plant’s DNA that do not arise naturally in the species, for example genes for resistance to a herbicide. Different processes exist for this: for example, the genes can be ‘shot’ into the plant cells using a kind of ‘gene gun’. With genome editing, we cut the DNA with a protein at a predefined location. The genome editing method known as CRISPR/Cas9 has become the most common method. We can then modify the DNA at the interface or insert new sections. So genome editing should be viewed as a variant of mutation breeding, with the difference that the generation of particular mutations is targeted.

The major advantage here is that these modifications can be obtained in the same way as they are made in traditional breeding and crossing experiments. For example, individual letters of the genetic code can be exchanged. This corresponds to a modification which can also arise through natural mutation. Short sections of DNA can also be inserted and, in this way, genes from a species can be replaced with genes from its other varieties or from closely related species – something that is also done in traditional cross-breeding.

The criticism regarding genetically modified plants is aroused by the aforementioned ‘foreign genes’ in particular. Do genome-edited plants also contain such foreign DNA?
The genetic information for the cutting protein is usually inserted into the plant’s DNA so that it can be formed in the plant cells. This gene does not arise naturally in plants and is, therefore, foreign DNA. Following the successful modification of the genome, however, it can be completely removed. Using the analysis methods available today, it is possible to ensure that a genome-edited plant no longer contains any foreign DNA. Genome editing can also be used to insert completely foreign genes into the genome – as is the case in traditional genetic engineering. However, this kind of genome editing should be subject to different regulations than the kind that is used to make minor modifications.

Is it possible to distinguish at all between genome-edited and traditionally bred plants?
If no foreign genes are inserted, then, no, it is not possible. A plant that has been modified using genome editing does not differ in any way from a plant whose genome was altered through breeding. At the end of the process, there is nothing to indicate how the new variety arose.

So genome-edited plants should not be treated like genetically modified plants if they do not contain any foreign DNA?
Exactly! This is why we are asking for them to be classified like traditionally bred plants. In our view, how a plant variety came into being does not make any difference; the end product alone is what matters. In my view, it does not make any sense to classify plants as different if it is not possible to say how they came into being.

Is this possible from a legal point of view or would it require a change in the law?
The German Genetic Engineering Act states that the descendants of a genetically-modified plant must also be classified as genetically modified. So the fact that genome-edited plants temporarily contained the gene for the cutting protein would make them and their descendents genetically modified plants forever – despite the fact that the foreign gene was removed without trace. This was certainly not the intention of the legislator as genome engineering did not yet exist when the Genetic Engineering Act was passed. So we suggest that the Genetic Engineering Act should not be applied to genome-edited plants.

Interview: Harald Rösch

“The end product is what matters” | Max Planck Society

 

[JSCh]

Public Release: 14-Apr-2016
A simple and efficient 3-D fabrication technique for bio-inspired hierarchical structures
Chinese scientists developed a facile approach for the rapid and maskless fabrication of bio-inspired hierarchical structures using multi-beam laser interference, demonstrating its potential in large-area, low-cost and high-volume 3-D fabrication

The Optical Society

This is a Scanning Electron Microscope (SEM) image of a moth eye.
Credit: Zuobin Wang/Changchun University of Science and Technology, China​

WASHINGTON -- Nature is no doubt the world's best biological engineer, whose simple, exquisite but powerful designs have inspired scientists and engineers to tackle the challenges of technologies for centuries. Scientists recently mimicked the surface structure of a moth's eye, a unique structure with an antireflective property, to develop a highly light-absorbent graphene material. This is breakthrough in solar cell technology. Rice leaves and butterfly wings also have unique self-cleaning surface characteristics, which inspire scientists to develop novel materials resistant to biofouling. The bio-inspired periodic multi-scale structures, called hierarchical structures, have recently caught broad attention among scientists in various applications such as solar cells, Light-emitting diodes (LEDs), biomaterials and anti-bacterial surfaces.

Although a number of techniques for fabricating bio-inspired hierarchical structures already exist, most conventional methods either involve complicated processes or are highly time-consuming and low cost-efficiency for industrial applications. Now, a team of researchers from Changchun University of Science and Technology, China, have developed a novel method for the rapid and maskless fabrication of bio-inspired hierarchical structures, using a technique called laser interference lithography.

Specifically, the researchers use the interference pattern of three-and four-beam lasers to fabricate ordered multi-scale surface structures on silicon substrates, with the pattern of hierarchical structures controllable by adjusting the parameters of incident light. In accordance with the theoretical and computer analysis, the researchers have experimentally demonstrated the novel technique's potential in large-area, low-cost and high-volume 3D fabrication of micro and nanostructures. This week in the journal Applied Optics, from The Optical Society (OSA), the researchers describe the work.

"We presented a flexible and direct method for fabricating ordered multi-scale 3D structures using three- and four-beam interference lithography," said Zuobin Wang, the primary author and a professor of International Research Centre for Nano Handling and Manufacturing of China at the Changchun University of Science and Technology, China. "Compared with other patterning technologies, our method is simple and efficient in terms of obtaining bio-inspired hierarchical structures."

Wang mentioned that for certain complicated surface structures, conventional techniques such as electron beam lithography may take several hours or a day to fabricate the pattern, while the laser interference approach only takes several minutes to generate the structure, which makes the technique suitable for high-volume industrial production.

"Laser interference lithography is a maskless patterning technique that uses the interference patterns generated from two or several coherent laser beams to fabricate micro and nanometer periodic patterns over large areas," Wang said. Different from conventional patterning techniques like electron beam lithography, the laser interference technique enables fabricating the entire substrate surface with one single exposure or one-step lithography.

For example, in Wang's experiment, the one-dimension multi-scale structure, that is, one-dimension oriented arrangement with the sinusoidal grooves covered with periodic line-like structures was fabricated by exposing the silicon substrate to three or four interfered beams for one time. The resultant surface pattern, though arranged in one direction, has three-dimension spatial structure. To obtain more complicated structures such as two-dimension oriented multi-scale structures, the researchers simply rotated the substrate by 90 degrees in the plane and applied second laser exposure to the surface.

"Laser interference lithography is capable of fabricating homogeneous micro and nanometer structured patterns over areas more than one square meter, which is either impossible or highly time or cost consuming for conventional techniques," Wang said. These features make laser interference lithography superior to other techniques in terms of efficiency and high-volume production.

According to Wang, their experimental process is simple: a high power laser beam was split into three or four equal beams, which then were directed by mirrors to generate interference patterns to fabricate the surface structures. The laser parameters such as incident angle and azimuthal angle of each beam were adjusted by beam splitters and mirror positions. Other optical devices such as quarter-wave plates and polarizers were used to select the polarization mode and control the energy of laser beams.

"The laser beam parameters are selected according to the desired surface structure and corresponding interference energy distribution calculated from theoretical simulation. In other words, the shapes or patterns of hierarchical structures in our method are controllable by adjusting the parameters of each incident beams," Wang noted.

According to Wang, the proposed technique could be used to fabricate optical or medical devices such as solar cells, antireflective coatings, self-cleaning and antibacterial surfaces and long-life artificial hip joints.

The researchers' next step is to develop functional surface structures with controllable wettability, adhesion and reflectivity properties for optical, medical and mechanical applications.

A simple and efficient 3-D fabrication technique for bio-inspired hierarchical structures | EurekAlert! Science News

 

[bobsm]

Tracheal surgery using 4D-printing technology successful in China
(Xinhua) 11:10, April 16, 2016

XI'AN, April 16 -- Doctors from northwest China's Shaanxi Province recently performed a successful and rare tracheal surgery using 4D printing technology on a woman suffering from breathing problem.

According to a press conference held in provincial capital Xi'an on Friday, doctors with Tangdu Hospital inserted a 4D-printed tracheal stent, a tubular support, outside a female patient's collapsed windpipe to keep the airway open.

The 46-year-old female patient had a severe form of tracheobronchomalacia, which causes the windpipe to regularly collapse, preventing normal breathing.

"Her collapsed trachea is inside the thorax and is 6-centimeters long. It is very risky to cut it directly. Placing a stent inside the windpipe is also impossible because the narrowest section is only three millimeters wide," said Li Xiaofei, director with Tangdu's department of thoracic surgery.

The hospital worked with several other institutions, including 3D printing research center with the Fourth Military Medical University, to produce the stent made of a biomaterial called polycaprolactone, which dissolves over time.

"4D printing technology is new," said Cao Tiesheng, director with the center. "It involves 3D printing items that are designed to change over time."

Cao pointed out that for this operation, doctors set the dissolving time of the printed stent beforehand. It will be gradually absorbed by the patient in two or three years. "The patient does not need to undergo another operation to remove the stent."

The patient has recovered and will be discharged from the hospital soon.

"The long-term effects will be observed. But this successful operation will bring changes to other operations," said Li Xiaofei.


http://en.people.cn/n3/2016/0416/c202936-9045468.html

 

[JSCh]

Water: now we see it, see more
APR, 16 2016

Peking University, Apr. 15, 2016: The mystery of water mainly arises from the intermolecular hydrogen-bonding interaction. It is well known that hydrogen bonds have a strong classic component coming from electrostatics. However, its quantum component can be exceptionally prominent due to the zero-point motion of light hydrogen nuclei (proton), which is a natural result of the Heisenberg uncertainty principle. Therefore, the assessment of nuclear quantum effects has been a key issue for understanding the structure, dynamics, and macroscopic properties of water. Despite enormous scientific efforts in past decades, it still remains an open question to what extent the quantum motion of the hydrogen nuclei can affect the hydrogen bond.

Now, the teams led by Prof. Jiang Ying and Prof. Wang Enge of International Center for Quantum Materials (ICQM) of Peking University provide a smoking gun for this important question. As published in Science on Apr. 15, 2016 (Science DOI: 10.1126/science.aaf2042), the researchers unravel quantitatively, for the first time, the quantum component of a single hydrogen bond at a water-solid interface, through a combined study using a scanning tunneling microscope (STM) and density functional theory (DFT) calculations.

"The main difficulty of extracting the quantum component of hydrogen bond lies in that the quantum states of hydrogen nuclei are extremely sensitive to the coupling with local environments, leading to significant broadening and averaging effects when conventional spectroscopic or diffraction techniques are used," says Jiang. Therefore, the ability to probe water with single bond precision is crucial.

To this end, the researchers succeeded to push the limit of vibrational spectroscopy of water down to the single-bond level using a novel technique called tip-enhanced inelastic electron tunneling spectroscopy (IETS) based on STM, which combines sub-ångström spatial resolution and single-bond vibrational sensitivity. The signal-to-noise ratios of the tip-enhanced IETS are enhanced by orders of magnitude over the conventional STM-IETS, which was pioneered by Prof. Wilson Ho's group of UC Irvine 18 years ago.

"The conventional IETS signals of water are extraordinarily weak since the frontier orbitals of water are located far away from the Fermi level. The key to defeat this limitation is gating the frontier orbitals of water towards the Fermi level with a chlorine-terminated STM tip to resonantly enhance the electron-vibration coupling," explains Jiang. With such a tip-enhanced IETS, the hydrogen-bonding strength can be determined with unprecedentedly high accuracy from the redshift in the O-H stretching frequency of water.

By conducting isotopic substitution experiments (replacing hydrogen atom with heavier deuterium atom), the researchers could extract the quantum component of the hydrogen bond, which accounts for up to 14% of the bond strength. Surprisingly, the quantum contribution is much greater than the thermal energy contribution, even at room temperature. In-depth investigation combined with ab initio path integral molecular dynamics (PIMD) simulations reveal that the anharmonic quantum fluctuations of hydrogen nuclei weaken the weak hydrogen bonds and strengthen the strong ones. However, this trend can be completely reversed when the hydrogen bond is strongly coupled to the polar atomic sites of the surface.

"This joint experimental and theoretical work yields a cohesive picture for the nuclear quantum effects of hydrogen bonds," adds Wang, "Those findings may completely renovate our understanding of water and provide answers to many weirdness of water from a quantum mechanical view. It would be very interesting to further explore the quantum effects on the cooperativity of correlated H-bonds beyond the single hydrogen bond."

This work received supports from Ministry of Science and Technology of China, National Natural Science Foundation of China, Ministry of Education of China, National Program for Support of Eminent Professionals, and Collaborative Innovation Center of Quantum Matter, China.

Figure caption: Left is the schematic of STM experimental setup. The hydrogen atoms of water show prominent zero-point motion thanks to the Heisenberg uncertainty principle. Right is the tip-enhanced IETS of a single water molecule, in which stretching, bending and rotational modes are identified. Those vibrational modes can be used as sensitive probes to sense the influence of quantum motion of hydrogen nuclei on the hydrogen bond. (Design: Liang Mingcheng)

Edited by: Zhang Jiang
Source: School of Physics

Water: now we see it, see more_Peking University

#####
​

Article link: Nuclear quantum effects of hydrogen bonds probed by tip-enhanced inelastic electron tunneling | Science

Quantum effects in single hydrogen bonds
Hydrogen bonds are a combination of electrostatics with a nuclear quantum contribution arising from the light mass of hydrogen nuclei. However, the quantum states of hydrogen nuclei are extremely sensitive to coupling with local environments, and these effects are broadened and averaged with conventional spectroscopic or diffraction techniques. Guo et al. show that quantum effects change the strength of individual hydrogen bonds in water layers adsorbed on a salt surface. These effects are revealed in inelastic tunneling spectra obtained with a chlorine-terminated scanning tunneling microscope tip.

Science, this issue p. 321​

 

[bobsm]

Xinhua Insight: Chinese scientists develop mammal embryos in space for first time
2016-04-17 12:58:39 GMT2016-04-17 20:58:39(Beijing Time) Xinhua English

BEIJING, April 17, 2016 (Xinhua) -- Duan Enkui, researcher of the Institute of Zoology, Chinese Academy of Sciences, and also the leader of the project, introduces the development of the mammal embryos in space in Ulanqab City, north China's Inner Mongolia Autonomous Region, April 17, 2016. Over 6,000 early-stage mouse embryos carried by China's retrievable scientific research satellite have developed in space, making it the world's first-ever successful test on mammal embryo development. (Xinhua/Wang Quanchao)

BEIJING， April 17 (Xinhua) -- Chinese scientists on Sunday said they have successfully developed early-stage mouse embryos in space for the first time on a retrievable microgravity satellite set to return to Earth sometime next week.

The SJ-10 research probe， launched on April 6， carried over 6，000 mouse embryos in a self-sufficient chamber the size of a microwave oven， according to Duan Enkui， a researcher with the Chinese Academy of Sciences (CAS).
Among them， 600 embryos were put under a high-resolution camera， which took pictures every four hours for four days and sent them back to Earth.

The pictures showed that the embryos developed from the 2-cell stage, an early-on embryonic cleavage stage, to blastocyst, the stage where noticeable cell differentiation occurs, around 72 hours after SJ-10's launch, Duan said. The timing was largely in line with mbryonic development on Earth, he added.

The rest of the embryos loaded on the satellite were injected with fixatives at 72 hours after the launch for studies on the effects of space environment on embryonic development， according to Duan.

This is the first reported successful development in mammalian embryos in space in human history.

Scientists will compare the retrieved embryos with samples on Earth and perform further analyses on the profiles of early embryo development in space， once SJ-10 returns home.

SJ-10 is expected to land in a designated spot in Siziwang Banner in Inner Mongolia sometime next week. Earlier reports said the probe as a whole had a designed life of just 15 days.

The bullet-shaped probe is said to be housing a total of 19 experiments involving microgravity fluid physics， microgravity combustion， space material， space radiation effects， microgravity biological effects and space bio-technology.

These include one studying how space radiation affects the genetic stability of fruit flies and rat cells， and a combustion experiment which will test how materials used in spacecraft burn in space to find ways of making safer capsules for future manned missions.

An experiment being run in partnership between the National Space Science Center under the CAS and the European Space Agency will investigate the behavior of crude oil under high pressure， and also on board is equipment to test coal combustion and pollutant formation under microgravity.

The former experiment is aimed at improving scientists' understanding of oil reservoirs buried deep underground， while the latter is expected to help enhance energy efficiency and cut emissions on Earth.

In a separate development， retrievers for the SJ-10 satellite on Sunday said they will deploy four helicopters to aid ground vehicles in the search for the satellite after its landing next week


http://english.sina.com/news/2016-04-17/doc-ifxrizpp1534441.shtml

 

[JSCh]

China's bird flu warrior gets global award
Updated: 2016-04-15 07:42
By Liu Zhihua(China Daily)

Chen Hualan wins the 2016 L'Oreal-UNESCO for Women in Science International Awards for her research of the bird flu virus. [Photo provided to China Daily]​

Chinese women scientists have started to make their mark on the world stage more consistently.

For the second year in a row, a scientist from the Chinese mainland has won the L'Oreal-UNESCO for Women in Science International Award this year.

Chen Hualan, the head of Harbin Veterinary Research Institute, an affiliate of the Chinese Academy of Agricultural Sciences, received the award in Paris on March 24.

Created in 1998, the awards program－jointly funded by the French cosmetics maker and the United Nations' agency－identifies and supports female scientists globally.

Chen, 47, is the second Chinese scientist to win the award－after chemist Xie Yi in 2015－due to her outstanding research of the virus that causes avian influenza or bird flu.

Her work led to the development of an effective vaccine. In 2013, she had played a major role in China's action against the bird flu strain H7N9.

That year, Chen and her team from the Harbin institute in the country's northeast found out the routes of H7N9 transmission from birds or other animals to humans, lending crucial support to overall government efforts to control the spread of the disease.

Within 48 hours of the first cases being reported in Shanghai and Anhui province in the country's east, Chen and her team collected hundreds of soil, water and poultry samples from the affected areas.

Tests revealed the presence of H7N9 in some 20 samples gathered from live poultry in a Shanghai market.

[Photo provided to China Daily]​

Thanks to their findings, authorities managed to quickly shut down poultry markets in cities where the cases were reported.

Chen's contributions in quelling the outbreak in China, as well as her general studies of the bird flu virus, including experiments creating virus hybrids to illustrate the threats posed by new strains, put her on Nature magazine's list of "10 people who mattered" in 2013.

Chen says that it wasn't until she became a PhD scholar in 1994 and began working on influenza that she understood her life's goal.

"I realized that through my research I could help solve major problems and make a difference," she says.

The highly pathogenic avian influenza virus can result in large-scale killing of poultry, but it was earlier thought that vaccines would be ineffective on poultry.

When Chen was a PhD student, she generated several vaccines using both traditional and modern methods, and found that the vaccines could provide protection against bird flu.

The experience also told her that perceptions aren't always correct and that's the point of science－to dig.

In China, it is even more important to develop vaccines against avian influenza, Chen says. The country has a tradition of raising ducks and raises about 75 percent of the world's free-range duck population. The ducks here come in contact with wild birds－a situation that poses a challenge to the country's efforts to prevent and control the flu.

In 2009, Chen and her team started to work on vaccines against influenza in waterfowl. Three years later, they succeeded.

Talking about issues of gender, she jokes that women in science also have to balance work and home while men don't usually have to worry about the laundry or child care.

 

[JSCh]

Indigenous snake-shaped robot ready to dive for underwater pipelines
2016-04-18 11:36

(ECNS) -- A home-grown snake-shaped robot is ready to check on submarine oil and gas pipelines this year after a world-class performance in practical tests.

The robot was produced by the No.35 research institute of the Third Academy of the China Aerospace Science and Industry Corporation (CASIC), one of the nation's largest defense contractors.

The robot can crawl through eight-inch pipelines to precisely detect and locate potential problems, such as erosion or leaks both inside and outside the pipelines.

The submarine oil and gas pipeline inspection services in China have long been monopolized by overseas providers, who charge high fees while offering incomplete data, according to experts.

The robot has broken up the technical monopoly and will be put into use on offshore oil lines this year.

Robots compatible for 10-, 12- and 14-inch underwater pipelines are also being researched, it was added.

Song Yubin, director of the industrial development department of the institute, said China will form a comprehensive home-grown oil and gas pipeline inspection service in the 13th Five-Year Plan (2016-2020).

#####
​

Pictures from another report of the testing:

​

 

[JSCh]

April 18, 2016
Stanford researchers create super stretchy, self-healing material that could lead to artificial muscle

A new, extremely stretchable polymer film created by Stanford researchers can repair itself when punctured, a feature that is important in a material that has potential applications in artificial muscle. (Image credit: Bao Research Group)​

Researchers show how jolting this material with an electrical field causes it to twitch or pulse in a muscle-like fashion. This polymer can also stretch to 100 times its original length, and even repair itself if punctured.

By Carrie Kirby and Tom Abate

If there’s such a thing as an experiment that goes too well, a recent effort in the lab of Stanford chemical engineering Professor Zhenan Bao might fit the bill.

One of her team members, Cheng-Hui Li, wanted to test the stretchiness of a rubberlike type of plastic known as an elastomer that he had just synthesized. Such materials can normally be stretched two or three times their original length and spring back to original size. One common stress test involves stretching an elastomer beyond this point until it snaps.

But Li, a visiting scholar from China, hit a snag: The clamping machine typically used to measure elasticity could only stretch about 45 inches. To find the breaking point of their one-inch sample, Li and another lab member had to hold opposing ends in their hands, standing further and further apart, eventually stretching a 1-inch polymer film to more than 100 inches.

Bao was stunned.

“I said, ‘How can that be possible? Are you sure?'” she recalled.

Today in Nature Chemistry, the researchers explain how they made this super-stretchy substance. They also showed that they could make this new elastomer twitch by exposing it to an electric field, causing it to expand and contract, making it potentially useful as an artificial muscle.

A flexible fishnet
Artificial muscles currently have applications in some consumer technology and robotics, but they have shortcomings compared to a real bicep, Bao said. Small holes or defects in the materials currently used to make artificial muscle can rob them of their resilience. Nor are they able to self-repair if punctured or scratched.

But this new material, in addition to being extraordinarily stretchy, has remarkable self-healing characteristics. Damaged polymers typically require a solvent or heat treatment to restore their properties, but the new material showed a remarkable ability to heal itself at room temperature, even if the damaged pieces are aged for days. Indeed, researchers found that it could self-repair at temperatures as low as negative 4 degrees Fahrenheit (-20 C), or about as cold as a commercial walk-in freezer.

The team attributes the extreme stretching and self-healing ability of their new material to some critical improvements to a type of chemical bonding process known as crosslinking. This process, which involves connecting linear chains of linked molecules in a sort of fishnet pattern, has previously yielded a tenfold stretch in polymers.

First they designed special organic molecules to attach to the short polymer strands in their crosslink to create a series of structure called ligands. These ligands joined together to form longer polymer chains – spring-like coils with inherent stretchiness.

Then they added to the material metal ions, which have a chemical affinity for the ligands. When this combined material is strained, the knots loosen and allow the ligands to separate. But when relaxed, the affinity between the metal ions and the ligands pulls the fishnet taut. The result is a strong, stretchable and self-repairing elastomer.

“Basically the polymers become linked together like a big net through the metal ions and the ligands,” Bao explained. “Each metal ion binds to at least two ligands, so if one ligand breaks away on one side, the metal ion may still be connected to a ligand on the other side. And when the stress is released, the ion can readily reconnect with another ligand if it is close enough.”

Advancing artificial muscle and skin
The team found that they could tune the polymer to be stretchier or heal faster by varying the amount or type of metal ion included. The version that exceeded the measuring machine’s limits, for example, was created by decreasing the ratio of iron atoms to the polymers and organic molecules in the material.

The researchers also showed that this new polymer with the metal additives would twitch in response to an electric field. They have to do more work to increase the degree to which the material expands and contracts and control it more precisely. But this observation opens the door to promising applications. (View video.)

In addition to its long-term potential for use as artificial muscle, this research dovetails with Bao’s efforts to create artificial skin that might be used to restore some sensory capabilities to people with prosthetic limbs. In previous studies her team has created flexible but fragile polymers, studded with pressure sensors to detect the difference between a handshake and a butterfly landing. This new, durable material could form part of the physical structure of a fully developed artificial skin.

“Artificial skin is not just made of one material,” said Franziska Lissel, a postdoctoral fellow in Bao’s lab and member of the research team. “We want to create a very complex system.”

Even before artificial muscle and artificial skin become practical, this work in the development of strong, flexible, electronically active polymers could spawn a new generation of wearable electronics, or medical implants that would last a long time without being repaired or replaced.

This latest discovery is the result of two years of collaboration, overseen by Bao, involving visiting scholar Cheng-Hui Li, a Chinese organo-metallic chemist who designed the metal ligand bonding scheme; polymer chemist Chao Wang, now an assistant professor of chemistry at the University of California, Riverside, who had made previous iterations of self-healing elastomers; and artificial muscle expert Christoph Keplinger, now an assistant professor of mechanical engineering at the University of Colorado, Boulder. Other contributors to the study, “A highly stretchable autonomous self-healing elastomer,” include Jing-Lin Zuo, Lihua Jin, Yang Sun, Peng Zheng, Yi Cao, Christian Linder and Xiao-Zeng You.

The work at Stanford was supported by the Air Force Office of Scientific Research, Samsung Electronics and the Major State Basic Research Development Program of China.

Stanford researchers' stretchy material has muscular future | Stanford News

 

[bobsm]

Chinese scientists figure out Zika virus NS1 protein structure
(CRI)Updated: 2016-04-20 10:11

This photo shows that the distribution of Zika virus NS1 protein's electric charges is entirely different from other members of the favivirus genus. [Photo/Institute of Microbiology of the Chinese Academy of Sciences]


Chinese scientists say they have worked out the structure of the Zika virus NS1 protein.

The discovery could help researchers develop a vaccine for the virus which is transmitted by the Aedes aegypti mosquito.

Associate research fellow from the Institute of Microbiology of the Chinese Academy of Sciences, Shi Yi, says the protein, which also exists in other viruses of the flavivirus genus, has two functions.

"First, it can help eliminate the virus from human body. Second, it can be used as a target for vaccines to locate the virus, because some antibodies will be generated by its stimulation resulting in some autoimmune diseases."

According to Shi Yi, they have not only worked out the protein's molecular structure, but also how it interacts with the host during the infection process.

Shi Yi added that this kind of research can help global prevention of the Zika virus, but said more research was needed.

"The main objective of our research is to inform people that there is a Zika virus NS1 protein that can be used as an important virus locator in the future. We can use the NS1 protein to develop vaccines and provide relevant diagnosis."

Zika virus outbreaks in over 30 countries have been blamed for a steep increase in the birth of babies with abnormally small heads, or microcephaly, as well as cases of Guillain-Barre syndrome, a kind of muscle weakness disease.

http://www.chinadaily.com.cn/china/2016-04/20/content_24688830.htm

 

[JSCh]

Cheap, efficient and flexible solar cells: New world record for fullerene-free polymer solar cells -- ScienceDaily

Date: April 19, 2016
Source: Linköping University

Summary:

Polymer solar cells can be even cheaper and more reliable thanks to a new breakthrough. This work is about avoiding costly and unstable fullerenes.​

Polymer solar cells manufactured using low-cost roll-to-roll printing technology, demonstrated here by professors Olle Inganäs (right) and Shimelis Admassie.
Credit: Stefan Jerrevång/Linkoping university​

Polymer solar cells can be even cheaper and more reliable thanks to a breakthrough by scientists at Linköping University and the Chinese Academy of Sciences (CAS). This work is about avoiding costly and unstable fullerenes.

Polymer solar cells have in recent years emerged as a low cost alternative to silicon solar cells. In order to obtain high efficiency, fullerenes are usually required in polymer solar cells to separate charge carriers. However, fullerenes are unstable under illumination, and form large crystals at high temperatures.

Now, a team of chemists led by Professor Jianhui Hou at the CAS set a new world record for fullerene-free polymer solar cells by developing a unique combination of a polymer called PBDB-T and a small molecule called ITIC. With this combination, the sun's energy is converted with an efficiency of 11%, a value that strikes most solar cells with fullerenes, and all without fullerenes.

Feng Gao, together with his colleagues Olle Inganäs and Deping Qian at Linköping University, have characterized the loss spectroscopy of photovoltage (Voc), a key figure for solar cells, and proposed approaches to further improving the device performance.

The two research groups are now presenting their results in the high-profile journal Advanced Materials.

-We have demonstrated that it is possible to achieve a high efficiency without using fullerene, and that such solar cells are also highly stable to heat. Because solar cells are working under constant solar radiation, good thermal stability is very important, said Feng Gao, a physicist at the Department of Physics, Chemistry and Biology, Linköping University.

-The combination of high efficiency and good thermal stability suggest that polymer solar cells, which can be easily manufactured using low-cost roll-to-roll printing technology, now come a step closer to commercialization, said Feng Gao.


Story Source:

The above post is reprinted from materials provided by Linköping University. Note: Materials may be edited for content and length.

Journal Reference:

1. Wenchao Zhao, Deping Qian, Shaoqing Zhang, Sunsun Li, Olle Inganäs, Feng Gao, Jianhui Hou. Fullerene-Free Polymer Solar Cells with over 11% Efficiency and Excellent Thermal Stability. Advanced Materials, 2016; DOI: 10.1002/adma.201600281