China Science & Technology Forum

[JSCh]

Chinese-made ventricular assist device enters clinical testing
Source: Xinhua| 2017-12-08 18:59:24|Editor: pengying



CHONGQING, Dec. 8 (Xinhua) -- Several Chinese hospitals Friday started a clinical test for a ventricular assist device (VAD), which is believed to be the first such test conducted on the Chinese mainland.

The test will be conducted at three hospitals, namely Fuwai Hospital under the Chinese Academy of Medical Sciences, Union Hospital affiliated with Tongji Medical College at Huazhong University of Science and Technology, and Fujian Medical University Union Hospital.

It is expected to benefit hundreds of thousands of Chinese patients with severe heart failure.

The VAD was developed by Chongqing Yongrenxin Medical Devices Co. Ltd., a Sino-Japanese joint venture. The device entered a period of clinical testing in Japan in 2005.

In November, the Chongqing-based company officially obtained approval for the clinical test from the China Food and Drug Administration.

According to Hu Shengshou, president of Fuwai Hospital, heart failure caused more than 40 percent deaths due to diseases in China annually.

Hu said that China has at least 600,000 patients with severe heart failure. However, due to a severe donor shortage, the country only conducts around 300 heart transplant surgeries each year.

VAD is known globally as one of the most effective measures to treat patients with severe heart failure. Domestically-made devices are not yet ready to be put into commercial use, while foreign-made devices are often unaffordable.

The device will be put into use in 2018 after the clinical test concludes.

A VAD is an electromechanical device for assisting cardiac circulation, which is used either to partially or completely replace the function of a failing heart.

 

[JSCh]

China develops advanced PET scan technology
(People's Daily Online) 14:25, April 28, 2016

China has developed the world's first clinical all-digital positron emission tomography (PET) scan which helps significantly with the early detection of cancer.(People.cn/Photo)​

It was announced on Wednesday that Chinese scientists have developed the world's first clinical all-digital positron emission tomography (PET) scan, which is used for checking the whole human body, and also helps significantly with the early detection of cancer.

Developed by Huazhong University of Science and Technology, the new PET represents today's cutting-edge medical imaging technology. In addition to cancer prevention, the new technology will be used to diagnose cardiovascular and neurological diseases.

The all-digital PET has been granted 81 patents at home and abroad, and will be put into clinical application soon, said professor Xie Qingguo, who led the research for the project.

The machine consists of more than 300 modules that take just five minutes to scan an entire body. The resolution of its scans reaches 2.2 millimeters, which is twice as good as the capability of current imported models.

China has developed the world's first clinical all-digital positron emission tomography (PET) scan which helps significantly with the early detection of cancer.(People.cn/Photo)​

China develops world’s first digital positron emission tomography
CGTN
2017-12-13 11:59 GMT+8

The world’s first digital positron emission tomography (PET ) has been developed at China's Huazhong University of Science and Technology (HUST) in Wuhan City, central China.

The medical imaging device which helps doctors detect cancer and brain diseases is expected to better fight serious diseases at a lower cost.

In early November, Professor Xie Qingguo and his team at HUST conducted full digital PET for online proton beam monitoring in Taiwan Chang Gung Memorial Hospital, which has the largest and most advanced proton radiotherapy center in Asia.

“This is the first time in human history that we monitored how the proton produced oxygen-15 on a rat. It has proven two things about digital PET: To help the proton knife locate where to hit and where it actually hits,” said Professor Xie.

The full clinical digital PET is currently in the process of installment at the Affiliated Hospital of Zhongshan University in Guangzhou. It has begun to carry out the China Food and Drug Administration clinical trials.

The formal starting up of the first digital PET will take place in early 2018.

 

[JSCh]

Public Release: 14-Dec-2017
UMass Amherst, Peking University scientists advance knowledge of plant reproduction
Researchers identify a pair of receptors essential to male-female plant communications

University of Massachusetts at Amherst

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UMass Amherst plant molecular biologist Alice Cheung says the male plant's pollen tube transports sperm to female target cells. She and colleagues identify two new receptors essential to this communication and other molecules whose interactions regulate the process.
Credit: UMass Amherst

AMHERST, Mass. - Two groups of plant molecular biologists, at the University of Massachusetts Amherst and Peking University, China, have long studied how pollen tubes and pistils, the male and female parts of flowers, communicate to achieve fertilization in plants. Today they report in a Science early release paper that they have identified a pair of receptors essential to these communications as well as molecules that modulate the receptors' activity.

The work, in the model plant Arabidopsis, advances basic understanding of plant reproduction, say Alice Cheung and Hen-Ming Wu at UMass Amherst, with Li-Jia Qu and Hongya Gu in China. The researchers named the two new receptors Buddha Paper Seal 1 and 2 (BUPS1/2). Their paper also identifies several small peptides known as Rapid Alkalinization Factors (RALF) 4, 19 and 34 as their ligands - molecules that modulate the receptors' functions.

Further, the authors describe how BUPS1/2 and a second pair of related receptors called ANXUR 1 and 2 (ANX1/2), and RALF 4 and 19, all expressed in the pollen tube and required for male fertility, interact together to get their jobs done.

Cheung says, "Our paper describes an important elaboration of the male and female interaction network in plant reproduction. Molecules involved in the process have to work intimately together to orchestrate and support the male-female interactive events. In this process the pollen tube grows inside the pistil, often over distances hundreds or thousands of times greater than the tube's diameter, to deliver sperm to the target egg cell. The pollen tube must remain intact throughout this journey, but then must burst open at exactly the right time and place when it arrives at the target to release sperm for fertilization. Bursting too soon or failing to burst when it should are both devastating to reproduction."

The two research teams found that the receptors and RALF4 and 19 are required to maintain pollen tube integrity during the growth process. They also show that RALF34, expressed from the female, facilitates the bursting process, along with some known and other not yet identified factors. They demonstrate how these molecules interact with each other, illustrating an "intriguing communication mechanism" between male and female to produce seeds, Cheung says.

She adds, "In showing how receptors and their ligands work together to ensure reproductive success, our work illuminates one of the most mysterious processes in biology."

The plant reproduction research community has a tradition of naming important genes from ancient mythology, the biologist says. For example, a gene her group also works on, FERONIA, is named after the Roman goddess of fertility. The researchers named the new factors Buddha paper seal 1 and 2 after a Chinese tale about a naughty monkey held under a rock for 400 years by a charmed paper seal. When a kindly monk passing by broke the seal, the monkey burst out, which is what the scientists were reminded of when they saw how the pollen tube explodes to release sperm and enable fertilization.

This work continues the Cheung-Wu group's many years of plant reproduction research, especially on FERONIA, a receptor related to BUPSs and ANXURs that plays a major role in controlling plant female fertility in development and in coping with environmental stresses.

"It's actually very interesting," says Cheung. "The pollen tube transports sperm to female target cells. FERONIA is waiting there for the pollen tube to arrive. BUPSs, ANXURs, RALF 4 and 10 in the pollen tube make sure the tube does not burst too early, but wait until it gets to the target female cell. There the tube bursts abruptly, an action controlled by FERONIA and in part mediated by a different set of RALFs, releasing sperm at the right time and place."

The team used a combination of reverse genetics, biochemical and biophysical approaches for this work, in collaboration not only with the Chinese group, but also involved investigators from Brazil, Germany, the United States and Mexico. Cheung says the U.S. National Science Foundation's Research Coordination Network in Integrative Pollen Biology, of which she is the principle investigator, provided the catalyst and forum that stimulated these international interactions.

She adds, "I want to emphasize this work as a collaboration. We and the Peking University group, close colleagues with common interests, worked in parallel on some of the topics in this paper without knowing about each other's efforts. In a discussion one day we found out that we had common results, but each group had also generated unique observations and developed distinct insights, so we decided to merge our efforts and publish jointly."

She adds, "In my mind, this sort of collaboration is probably the best kind of scientific interaction. As scientists, we value our own independence and creativity. Even with common results, our thinking could diverge, leading each team to further investigate in different directions, getting to end points that complement each other. This collaboration is not a matter of different expertise, but a matter of common interest and curiosity that took us in different directions that eventually came back together in a complete story."

###​

Major support for this work was from the U.S. National Science Foundation to the Cheung-Wu group, National Natural Science Foundation of China and the Peking-Tsinghua Joint Center for Life Sciences to the Qu-Gu group, and by graduate student fellowships from Brazil and Mexico for studies at UMass Amherst.



UMass Amherst, Peking University scientists advance knowledge of plant reproduction | EurekAlert! Science News

Zengxiang Ge, Tabata Bergonci, Yuling Zhao, Yanjiao Zou, Shuo Du, Ming-Che Liu, Xingju Luo, Hao Ruan, Liliana E. García-Valencia, Sheng Zhong, Saiying Hou, Qingpei Huang, Luhua Lai, Daniel S. Moura, Hongya Gu,, Juan Dong, Hen-Ming Wu, Thomas Dresselhaus, Junyu Xiao, Alice Y. Cheung, Li-Jia Qu. Arabidopsis pollen tube integrity and sperm release are regulated by RALF-mediated signaling. Science (2017). DOI: 10.1126/science.aao3642.​

 

[cirr]

Tsinghua University builds 'future lab' to promote cross-field research

2017-12-17 07:55 CGTN Editor: Gu Liping

Tsinghua University, China's top university in the QS World Rankings, has launched a "future lab" to encourage collaboration among research fields.

The lab's mission is to "explore humans' future," according to the university's official press release on Thursday.

Another lab for brain and AI research was also launched on the same day.

How to study the future?

The future seems too abstract to do research on. But the university has found its path to tap into the area.

"We'll start from the fields including subversive teaching, future living, future healthcare, computer vision, computer emotions and multichannel cognition," Xu Yingqing, head of the lab, explained during the launching ceremony.

"It's going to be a massive crossover between science, tech, society and art," Xu added.

The crossover can only be achieved in a school that has a leading position in all these fields, said the press release.

This is also a method to build a more dynamic university because the researchers have to work in both their own fields and the new labs at the same time.

Interdisciplinary research

When we study at school, the knowledge is taught in different "disciplines" or subjects, which may include math, literature, physics, history and many more.

This kind of division also happens when scientists do their research.

Even the Nobel Prize has different awards for physics, chemistry and biology studies.

But the division is under heavy question now, as more and more new subjects stand in the middle of two fields or more.

One of the most obvious examples is biochemistry. The name is obviously indicating that the study has one leg in biology and the other in chemistry.

But scientists in different fields have their own angles to view the world. It can be hard for them to fully understand each other, although they are all highly intelligent.

That's one of the main reasons why universities are promoting "interdisciplinary research" to encourage collaboration between different fields.

In the case of Tsinghua's future lab, the university didn't specify which fields are included, leaving vast space for great minds to join in.

"In this way, we hope to attract the best researchers in the world and bring the future within our reach," Xu said.

http://www.ecns.cn/2017/12-17/284788.shtml

 

[JSCh]

Chinese scientist among Nature magazine's 10 people who matter in science
Source: Xinhua| 2017-12-19 01:52:34|Editor: yan



LONDON, Dec. 18 (Xinhua) -- For his role in pushing forward the development of quantum communications, Chinese physicist Pan Jianwei has been included in Nature's 10, the annual list of ten people who mattered in science in 2017, which was released online Monday by the prestigious journal Nature.

From quantum communications and genome editing to the threat of a nuclear crisis and the dismantling of environmental protections in the United States, "this list covers the highs and lows for science and scientists in 2017," said Brendan Maher, news features editor at Nature.

Dubbed "Father of Quantum" by some in China, Pan Jianwei and his team harnessed quantum laws to transmit information securely, called quantum communications.

In July, Pan and his team reported they had broken the record for quantum teleportation. In September, the team used a satellite to beam photons to Beijing and Vienna, generating quantum encryption keys that allowed teams in these cities to video chat securely, according to Nature.

More experiments have been planned by Pan and his team, and in the next five years, "many wonderful results will come, It's really a new era," Pan was quoted as saying in the Nature feature.

Renowned scientist and president of the Austrian Academy of Sciences Anton Zeilinger, seen as a pioneer in the field of quantum information and of the foundations of quantum mechanics, believes the landmark quantum-encrypted intercontinental video call between China and Austria is very important and impressive.

"I see this as a part of the goal of building a future quantum internet, where in this case China enabled a worldwide quantum-secure communication," the physicist told Xinhua earlier.

Another scientist featured in the list is David Liu. The biologist and his team at the Broad Institute in Cambridge, Massachusetts, have dedicated efforts to improving the powerful CRISPR genome-editing technique. Such tools could one day save lives, as cell-based therapies can be enhanced by the method.

"I'm deeply honored to be selected for this distinction, and I'm especially grateful to the remarkably talented and dedicated members of my research group. Their insight and hard work are what really mattered, and they are the true recipients of this recognition," Liu told Xinhua.

This year's list also includes Marica Branchesi. The astronomer is a member of the Virgo collaboration, which operates a gravitational wave detector near Pisa, Italy. Branchesi helped bring together more than 3,500 researchers who captured the collision of two neutron stars in detail, according to Nature.

Meanwhile, Khaled Toukan, a physicist who kept the Middle East's first synchrotron light source on track, is among Nature's top ten.

Nature's 10 are not just about scientists, and policy makers are also featured in the list. Lassina Zerbo, head of the Comprehensive Nuclear-Test-Ban Treaty Organization, is included for his hard work on encouraging nuclear non-proliferation.

 

[JSCh]

First CSNS Research Proposals Released
Dec 21, 2017

The China Spallation Neutron Source (CSNS) announced its first batch of research proposals in Dongguan on December 14, 2017. The proposals reflect the research needs in several cutting-edge and cross-disciplinary research fields.

The proposed experiments at CSNS will allow scientists to have a closer look at the inner structure of materials including lithium-ion battery materials, photovoltaic materials, thermoelectric materials, polymer-based nanocomposites, and super-strong steel, magnesium, and aluminum alloys.

"We have witnessed the construction of the China Spallation Neutron Source for more than a decade. We are excited to see that the facility will soon start operation and play an important role in materials science, new energy, chemical engineering, soft matter and life sciences in the near future,” Prof. WANG Yifang, Director of the Institute of High Energy Physics said.

Following its first neutron beam in late August, CSNS completed the first round of joint commissioning of the accelerator and target station spectrometer in early November. During the joint commissioning, the average power of the target beam reached 10kW, which met the design specifications. The next goal is the national acceptance test, scheduled in March next year.

The main principle of the facility is to generate neutrons by accelerating protons which then hit a tungsten target. Because neutrons are uncharged, they can penetrate materials more easily than other probing methods and thus they can help reveal the microstructure and kinetic characteristics of the material.

Since the construction of spallation neutron sources is very difficult, only the United Kingdom, the United States and Japan already have such a facility. CSNS is the first spallation neutron source in a developing country, with over 96% of the equipment produced domestically.

CSNS is designed to host twenty spectrometers. However, due to a funding shortage, only three spectrometers have been built so far - the Small Angle Neutron Scattering instrument, the Multiple Purpose Reflectometer and the General Purpose Powder Diffractometer.

"In the first phase, the number of spectrometers is too small to carry out research on high-precision measurements and kinetics, neutron physics and neutron technology. This is not only a serious waste of neutron beam resources, but also means the facility does not yet meet the need for high-performance neutron spectrometers in the domestic neutron scattering research and applied science fields,” Prof. CHEN Hesheng, CSNS project manager and Academician of the Chinese Academy of Sciences, commented, “therefore, currently, we need to launch the second phase of construction at CSNS, which means adding more spectrometers is now a top priority for CSNS.”

On the same day, the management of CSNS also announced plans for joint construction of thirteen spectrometers with the Hong Kong University of Science and Technology, Southern University of Science and Technology, Sun Yat-Sen University, etc. It is hoped to boost the construction of national science and technology industry innovation centers in the Guangdong-Hong Kong-Macao Greater Bay Area, and promote technological innovation and industrial restructuring and upgrading in Guangdong province.

 

[cirr]

Chinese scientists develop fast-charging aluminum-graphene battery

2017-12-24 10:34

Xinhua Editor: Liang Meichen

A team of researchers from Zhejiang University have developed a new type of aluminum-graphene battery that can be charged in seconds, instead of hours.

The team, led by professor Gao Chao, from Department of Polymer Science and Engineering of Zhejiang University, designed a battery using graphene films as anode and metallic aluminum as cathode.

The battery could work well after quarter-million cycles and can be fully charged in seconds.

Experiments show that the battery retains 91 percent of its original capacity after 250,000 recharges, surpassing all the previous batteries in terms of cycle life.

In quick charge mode, the battery can be fully charged in 1.1 seconds, according to Gao. The finding was detailed in a paper recently published in Science Advances.

The assembled battery also works well in temperatures range of minus 40 to 120 degrees Celsius. It can be folded, and does not explode when exposed to fire.

However, the aluminum-ion battery cannot compete with commonly-used Li-ion batteries in terms of energy density, or the amount of power you can store in a battery in relation to the size, according to Gao.

"It is still costly to make such battery. Commercial production of the battery can only be possible until we can find cheaper electrolyte," Gao said.

http://www.ecns.cn/2017/12-24/285645.shtml

 

[cirr]

China builds first national lab for monitoring atmospheric environment

2017-12-25 15:03

Xinhua Editor: Mo Hong'e

China started building its first national engineering laboratory for atmospheric environmental monitoring on Sunday in Hefei, capital of east China's Anhui Province.

Jointly launched by the Hefei government and Hefei Institute of Physical Science under the Chinese Academy of Sciences (CAS), the lab aims to develop advanced monitoring technology and equipment for the country's environmental monitoring agencies and companies.

Liu Wenqing, director of the lab, said construction will last three years.

"The national engineering lab will research and develop advanced technology and equipment related to monitoring of fine particulate matter, gaseous pollutants, volatile organic compounds and heavy metals, as well as onboard and satellite telemetry systems," said Liu.

Yan Qing, director of the Bureau of Science and Technology for Development under the CAS, said that the new lab will put China's home-grown atmospheric environmental monitoring technology into domestic and international markets.

Tackling pollution has been listed as one of "the three tough battles" that China aims to win in the next three years, according to the Central Economic Work Conference, which concluded this month.

http://www.ecns.cn/2017/12-25/285786.shtml

 

[JSCh]

18 December 2017
A big bad bacterial killer powered by light
Harmful microbes help to transform a clump of molecules into an antibiotic.

Certain harmful bacteria help to kill themselves when exposed to a clutch of molecules paired with near-infrared light.

Molecules that produce heat when illuminated hold promise for suppressing drug-resistant microbes. Jiang-Fei Xu and Xi Zhang at Tsinghua University in Beijing and their colleagues assembled a large molecule, known as a supramolecule, from three sections. It comprised a central rod — made from carbon rings, oxygen and nitrogen — flanked by more carbon rings that formed bulky pumpkin shapes at each end.

Some kinds of bacteria, such as Escherichia coli, change these molecules into negatively charged ions. When zapped with near-infrared light, the ions absorb the light and heat their surroundings, killing the bacteria.

The authors hope that the molecule could be used to selectively kill dangerous microbes, and could have uses in treatments such as restoring microbial balance in the gut.

Angew. Chem. Int. Edn (2017)



A big bad bacterial killer powered by light : Research Highlights | Nature

 

[cirr]

CNNC breaks foreign monopoly in containers for spent nuclear fuel

2017-12-26 10:23 Global Times Editor: Li Yan

China has attained the ability to mass produce spent nuclear fuel shipping containers thanks to recent achievements by China National Nuclear Corp (CNNC), according to media reports.

The milestone was marked by the prototype unit of "Longzhou-CNSC" shipping containers of spent nuclear fuel, a national-level major scientific and technological project led and researched by CNNC.

The containers have passed the initial tests and can begin mass production on Wednesday, according to a post on the website of CNNC.

CNNC's success fills a technology gap in China and breaks the foreign monopoly in this area, the Beijing-based Science and Technology Daily newspaper reported on Sunday.

The CNNC project can carry 21 sets of spent nuclear fuel assemblies, and Xi'an Nuclear Equipment Co is the manufacturer, the report said.

According to transport regulations and provisions developed by the International Atomic Energy Agency, shipping containers have to be tested under hypothetical accidental conditions.

CNNC has built a testing platform for digital simulation and experimental verification, an industry insider told the Science and Technology Daily.

"The workload in the design stage was immense. For instance, one of the simulations required 24-hour nonstop calculations for one week," Wang Qing, project manager in the research and development team, was quoted saying in the report.

The development and manufacturing project for the shipping containers involves a series of sub-projects, including containers for new fuel and spent nuclear fuel.

These containers cover all fuel models related to transportable experimental reactors and pressurized water reactors and other new types of nuclear fuel, the report noted.

Under China's long-term nuclear development plan, by 2020, installed nuclear power capacity is expected to reach 58 million kilowatts, with spent nuclear fuel standing at more than 7,000 tons. The amount of spent fuel is expected to double by 2025, according to the report.

The project was launched in 2009 and contracted to CNNC in December 2010 by the National Energy Administration.

http://www.ecns.cn/business/2017/12-26/285881.shtml

 

[JSCh]

Chinese Scientists Develop 27.2 T All-superconducting Magnet
Dec 25, 2017

Superconducting magnets are widely used in MRI machines in hospitals, and in scientific equipment such as NMR spectrometers, mass spectrometers, fusion reactors and particle accelerators.

Through high-temperature insert magnet technology, Prof. WANG Qiuliang’s group from the Institute of Electrical Engineering (IEE) of the Chinese Academy of Sciences developed a 27.2 T all-superconducting magnet with a REBCO insert composed of 15 Double Pancake (DP) coils, currently the second highest magnetic field with steady operation.

It is the third-highest magnetic field ever achieved by all superconducting magnets. The highest now is 32 T, obtained at NHMFL on December 8, 2017 and the second-highest is 27.6 T, obtained at RIKEN in January 10, 2016.

REBCO (consisting of Rare Earth, Ba, Cu, and O) superconductor is suitable for winding high field superconducting magnet due to its high tensile strength and current-carrying features under high magnetic field.

However, with layered structure of REBCO strip, delamination may occur due to stress concentration in very high field, which would result in premature quench and prevent steady operation.

To solve this problem, the group adopted special binding device to protect the outer conductor of the magnet, adjusted the layered structure of the insert magnet coil to reduce the stress on REBCO conductor, and used grading design to increase safety margin as well as operation margin of insert magnet.

The 27.2 T all-superconducting magnet lays foundation for subsequent development of the 30 T high-field scientific device and the spectrometer magnet at the GHz level.

WANG’s group developed a 25.7 T all-superconducting magnet this May 11, making China the fourth country in the world to achieve an all-superconducting magnet above 25 T.

 

[JSCh]

China launches world's largest human genome research project
By Deng Xiaoci Source:Global Times Published: 2017/12/28 22:28:40

Researchers plan to probe causes of sickness

The world's largest human genome research project of 100,000 people was launched by China on Thursday to document their genetic makeup for a study that aims to help generate the precision medicines of the future.

It is the country's first large project detecting the genetic links between health and sickness and will involve 100,000 people from different ethnic backgrounds and regions, China Central Television (CCTV) reported on Thursday.

The project will collect the genetic data of Han ethnic majority people from all over the country and nine other ethnic minority groups with a population of more than 5 million including the Zhuang and Hui peoples.

There are about 25,000 human genes and the project aims to decode the hereditary information contained in each, according to the CCTV report.

The project includes four stages - collecting, sequencing gene samples, gathering the data and sharing the findings, one of the project's founders told the Global Times.

Currently it's the first stage, said Yu Jun, former deputy head of the Beijing Institute of Genomics under the Chinese Academy of Sciences (CAS).

Researchers will create a "health contrast" pool, he said, gathering genetic information from those who suffer a variety of diseases.

In this way, they hope to dig deeper into the links between specific genes and particular diseases such as diabetes, he said.

The project's chief scientist Wang Yadong was quoted as saying by CCTV that the major research aim is to study what makes Chinese people get sick, "providing references for China's medical research, clinical diagnoses and treatments."

The project will help all Chinese people, including Han majority and ethnic minorities, Zhao Guoping, a CAS academician and director of the Chinese National Human Genome Center in Shanghai, told CCTV.

The project will conclude all its gene sequencing and analysis within four years, which will also make it the fastest genome engineering project in the world, the report said. It did not disclose the budget.

Yu revealed that the project was funded by the Ministry of Science and Technology, which has been working on promoting precision medicine for years. He declined to disclose the budget.

The key stage of the project was the sharing phase which remained unclear at the moment, Yu said, as China does not have a national gene database.

China has listed genomics as a key strategic field in its 13th Five-Year Plan (2016-20) for the country's economic and social development.

 

[JSCh]

Public Release: 3-Jan-2018
Glucagon receptor structure offers new opportunities for type 2 diabetes drug discovery
Complex structure of a class B GPCR bound to an analogue of its endogenous ligand ignites new excitement in GPCR research

Chinese Academy of Sciences Headquarters

This is the The Crystal Structure of the Full-Length Human Glucagon Receptor (GCGR)crystal structure of the full-length human glucagon receptor (GCGR): orange (extracellular domain), blue (transmembrane domain), green (stalk), magenta (the first extracellular loop), red (NNC1702), yellow (NNC0640) and cyan (mAb1)
Credit: Dr. WU Beili

Class B G protein-coupled receptors (GPCRs) exert essential action in hormonal homeostasis and are important therapeutic targets for a variety of diseases including metabolic disorders such as type 2 diabetes. These receptors consist of an extracellular domain (ECD) and a transmembrane domain (TMD), both of which are required to interact with their cognate peptide ligands and to regulate downstream signal transduction. Due to difficulties in high-quality protein preparation, determination of the structure of full-length class B GPCRs remains a challenge, thus limiting the understanding of molecular mechanisms of receptor action.

Activation of the human glucagon receptor (GCGR) by its endogenous ligand glucagon triggers the release of glucose from the liver during fasting, making it a potential drug target for type 2 diabetes. Last year, a group of scientists at the Shanghai Institute of Materia Medica (SIMM) of the Chinese Academy of Sciences determined the crystal structure of the full-length GCGR bound to a negative allosteric modulator NNC0640 and an inhibitory antibody mAb1, thus providing for the first time a clear picture of a full-length class B GPCR at high resolution.

Recently, scientists at SIMM determined the crystal structure of GCGR in complex with a glucagon analogue and partial agonist NNC1702. This structure reveals, for the first time, the molecular details of a class B GPCR binding to its peptide ligand at high resolution and unexpectedly discloses the structural complexity that governs receptor activation, thereby greatly expanding the understanding of class B GPCR signal transduction. The study was published in Nature.

This study offers some valuable insights into the activation mechanism of GCGR. The most exciting finding is that the linker region connecting the ECD and TMD of the receptor, termed the "stalk," and the first extracellular loop undergo significant conformational changes in their secondary structures in the peptide-bound GCGR structure compared to the previously determined non-peptide-bound structure. This leads to a marked change in the relative orientation between the ECD and TMD of the receptor to accommodate peptide binding and initiate receptor activation.

Furthermore, the stalk may modulate receptor activity by facilitating conformational movements of the receptor TMD. "It is amazing to observe how the stalk region plays such an important role in regulating receptor function, although it only contains 12 amino acids," said SIMM professor Dr. ZHAO Qiang. "This has never been observed in previously solved GPCR structural studies. It significantly deepens the knowledge about class B GPCR signaling mechanisms."

Based on the structure of GCGR-NNC1702 complex, the researchers performed a series of functional studies using techniques such as competitive ligand binding, cell signaling, molecular dynamics simulations and double electron-electron resonance spectroscopy. The results support the GCGR structure and confirm the conformational alterations of the receptor in different functional states.

"The newly solved GCGR structure provides the most accurate template to date for drug design targeting GCGR, which offers new opportunities in drug discovery for treating type 2 diabetes," said team leader and SIMM professor Dr. WU Beili.

###​

This study was a collaboration work conducted by researchers from SIMM, Fudan University, the iHuman Institute of ShanghaiTech University, Novo Nordisk, University of Toronto, and GPCR Consortium.



Glucagon receptor structure offers new opportunities for type 2 diabetes drug discovery | EurekAlert! Science News

Haonan Zhang, Anna Qiao, Linlin Yang, Ned Van Eps, Klaus S. Frederiksen, Dehua Yang, Antao Dai, Xiaoqing Cai, Hui Zhang, Cuiying Yi, Can Cao, Lingli He, Huaiyu Yang, Jesper Lau, Oliver P. Ernst, Michael A. Hanson, Raymond C. Stevens, Ming-Wei Wang, Steffen Reedtz-Runge, Hualiang Jiang, Qiang Zhao & Beili Wu. Structure of the glucagon receptor in complex with a glucagon analogue. Nature 553, 106–110 (04 January 2018). DOI:10.1038/nature25153​

 

[JSCh]

China's first bio-safety level 4 lab put into operation
Source: Xinhua| 2018-01-04 19:49:18|Editor: Xiang Bo



BEIJING, Jan. 4 (Xinhua) -- China has opened its first bio-safety level four laboratory, capable of conducting experiments with highly pathogenic microorganisms, according to the national health authority on Thursday.

Wuhan national bio-safety level four lab of the Chinese Academy of Sciences (Wuhan P4 lab) is part of Sino-French cooperation in prevention and control of emerging infectious diseases, said the Department of Health Science, Technology and Education with the National Health and Family Planning Commission.

Level four is the highest bio-safety level, used for diagnostic work and research on easily transmitted pathogens which can cause fatal disease, including Ebola virus.

The Wuhan P4 lab will conduct research in anti-virus drugs and vaccines.

 

[JSCh]

Chinese researchers make breakthrough in study of nuclear technology: report
Source: Xinhua| 2018-01-06 17:34:05|Editor: ZD



BEIJING, Jan. 6 (Xinhua) -- Chinese researchers have developed the world's top high intensity neutron generator, a breakthrough in the study of nuclear technology, the Science and Technology Daily reported.

The generator, developed by researchers at the Hefei Institutes of Physical Science, is a vital platform for studying the application of nuclear power and nuclear technology, according to the report.

The achievement has been published by the International Journal of Energy Research, the report said.

The neutron energy spectrum generated by the equipment can faithfully reproduce the complex neutron environment in advanced nuclear power systems, the report said.

The generator is therefore important for studying neutron physics and advanced nuclear technology, as well as developing new nuclear power systems, according to the report.

​