China Science & Technology Forum

[JSCh]

Chinese scientists turn black coal by-product into white paper | South China Morning Post

• After nearly a decade of research, fly ash could reduce amount of wood pulp used in paper production

Stephen Chen
Published: 2:00am, 22 Oct, 2019

In 2010, Professor Zhang Meiyun, from the Shaanxi University of Science and Technology, and collaborators proposed to the government that coal fly ash could be used as a filler in paper. Photo: Handout

More than 2,000 years after the invention of paper in China, the country’s scientists are claiming another first – a breakthrough that replaces its key ingredient with the dirty waste from coal-fired power plants.

The result – which is almost indistinguishable from paper made from wood pulp – achieves a more than 90 per cent match to pure whiteness, despite being made with the black fly ash produced from burning coal.

The process has passed stringent tests in real production lines and is ready for mass application, with some Chinese paper mills now able to replace nearly half the wood fibres in their products with the chimney waste, according to scientists involved in the government-funded research programme.

The breakthrough has come nearly 10 years after Professor Zhang Meiyun, from the Shaanxi University of Science and Technology, and her colleagues first proposed that fly ash could be used as a filler in paper.

Professor Zhang Meiyun in 2010 when the proposal to research the use of fly ash in paper making was presented to the Chinese central government. Photo: Shaanxi University of Science and Technology.

The new product addresses two problems – the environmental impact of the global industrial demand for timber and how to dispose of millions of tonnes of fly ash each year.

Paper mills are responsible for more than 40 per cent of the timber felled globally for industrial use which “has devastating impacts on some of the world’s most ecologically important places and species”, according to the World Wide Fund for Nature (WWF).

Because most forests in China are protected, the country’s paper mills source wood pulp mainly from Canada, Russia, the United States and other countries endowed with vast forests. China has the world's largest paper industry, with paper and pulp production reaching nearly 100 million tonnes annually – more than all European countries combined.

The first sheets produced in our lab looked grey. We had a Cinderella but the paper industry wanted a Snow White.

Dr Song Shunxi, Shaanxi University of Science and Technology​

China is also the world's largest electricity producer, collecting about 700 million tonnes of fly ash each year, according to government statistics. About 70 per cent of this waste – a by-product of coal combustion composed of fine particles containing various minerals such as calcium and silicon – is used by the construction industry but the remainder has had nowhere to go, until now.

To Zhang and her colleagues, the fly ash was a promising candidate as a wood pulp substitute because its chemical and physical properties were similar to industrial additives – such as talcum powder and kaolin – already used in paper production.

Professor Zhang Meiyun (centre, seated) and her team inspect samples of paper made using fly ash, a waste product from coal-fired power stations. Photo: Shaanxi University of Science and Technology

They soon realised it was easier said than done. “The first sheets that came out in our lab looked grey,” Dr Song Shunxi, another scientist in the programme, said. “We had a Cinderella but the paper industry wanted a Snow White. It didn’t work out very well.”

China has the world's largest paper industry, with paper and pulp production reaching nearly 100 million tonnes annually – more than all European countries combined. Photo: Xinhua

The problem was the presence in the fly ash of unburnt carbon particles which reduced the paper’s brightness. Without a cost-effective method to remove these particles, the project was stuck. Datang Power, one of the largest state-owned electricity producers in China, joined the programme with a potential solution.

Many coal beds in China contain aluminium, and the chemical process to extract aluminium from fly ash was known to have a whitening effect. At an aluminium factory next to a Datang power plant in Inner Mongolia, the scientists found a suitable fly ash and brought the sample back to their lab in Xian.

The sheet turned bright, just as they had predicted, but it was too brittle and inflexible for use. According to Song, this latest problem was caused in part by the size and shape of the fly ash particles, and it took the scientists and engineers several years to fine-tune the processing of raw fly ash to achieve the perfect grains.

“Plant fibre is organic, fly ash is not. Blending them together is difficult, and there are lots of gaps to fill between the fibres,” Song said. “Nobody wants to use paper on which the ink spreads or which has dust coming off.”

There was no simple solution to this problem, the scientists found, because improving one property of the material could easily lead to the degradation of another.

It was not until 2014 that the team found an effective formula that addressed all elements in the papermaking process – from the atomic structure of the different materials, to the amount of water added to the pulp, to the brand of adhesive chemicals added to bind the different components.

The technology worked perfectly in the laboratory but no factory wanted to try it. To use it, production lines required modification and workers and engineers needed time to learn and become familiar with the process. There was also concern that if the technology failed, a plant could miss its annual production target.

“Thankfully we had the government behind us,” Song said. With financial support and liaison from the authorities at numerous levels, the scientists were able to test and improve the technology over several years at paper mills in Shaanxi, Zhejiang, Henan and Shandong provinces.

The researchers did not give details of their support from the authorities, except to say most of the funding came from the central government in Beijing, with additional help from provincial and city-level governments. Feedback was positive, with production cost savings ranging from eight to 15 per cent, according to Song.

There were still some factors limiting the application of the process across the country, including the location of some paper mills far from coal-fired power plants. The greater the distance, the higher the costs of transporting the fly ash.

The quality of the coal also varied from one location to another, so the whitening and blending formula would need to be adjusted on a case-by-case basis.

“We will continue to improve the technology until one day it can be used in every paper mill,” Song said.

A senior researcher at the State Key Laboratory of Pulp and Paper Engineering in Guangzhou, in the southern province of Guangdong, said that China had solved all the major technical problems in making paper with fly ash.

Several research teams had come up with innovative solutions using different strategies, said the researcher, who asked not to be named because of his role on a national committee which reviews these technologies.

“The cost of using fly ash is only about one tenth of importing pulp,” the scientist said.

The main competitor of fly ash, however, is not wood but other inorganic fillers such as the kaolin clay from ceramic industry.

“The technology must prove itself profitable and sustainable. It must be competitive even without the support of the government,” he said.

 

[JSCh]

The future of continuous inorganic materials
2019-10-18 Global Communications

When a cup of dense saltwater is continuously heated, there will appear small crystalized particles. The research team led by Prof. TANG Ruikang of the Zhejiang University Department of Chemistry “intercepted” a special precursor—ionic oligomers in their endeavor to “suspend” this crystallization process. Amazingly, oligomers can be cross-linked like polymer materials, thereby forming continuous and bulky inorganic materials. This means that inorganic materials are expected to be manufactured monolithically like plastic products, and that various complicated shapes can be produced.

Prof. Tang （left）with his team​

The relevant finding is published in a research article titled “Crosslinking ionic oligomers as conformable precursors to calcium carbonate” in the October 17 issue of Nature. The lead author is Dr. LIU Zhaoming. The research team also tried to repair such inorganic materials as single crystal calcite, sea-urchin spines and teeth. This method is believed to create a novel reaction system, namely “inorganic ionic polymerization”, which crosses the boundary between inorganic chemistry and polymer chemistry and presages that inorganic materials will enter human life with new structures and properties.

The “pause key” in the process of crystallization

Crystallization is ubiquitous, ranging from limestone caves to kidney stones. However, it remains enigmatic as regards the transition of a solution from the ionic state to the crystal state. Many scientists have put forward some hypotheses and theories about the intermediate state in the past few years, but no direct observational evidence has been obtained.

The research team discovered a “pause key”—a small molecule called triethylamine (TEA). It can act as a capping agent to stabilize oligomers by forming a hydrogen bond with a protonated carbonate through its tertiary amine group. More importantly, it can be easily removed.

The discovery of “inorganic ionic oligomers”

With the addition of TEA, the crystallization process has become a “race”: carbonate ions in the solution can combine with both calcium and TEA. Which is faster? The moment carbonate ions form a “short chain” with calcium ions, TEA will come up to “seal” one end of the carbonate ion so that it can no longer react with the next calcium ion. As a result, the solution is teeming with “short chains” of calcium carbonate capped by TEA, which scientists call “oligomers”.

Gel-like (CaCO3)n oligomers​

Analysis using DAMMIF，a program that enables the shape of a substrate to be determined from SAXS data, shows that oligomers ((CaCO3)n, in which n represents the number of Ca2+:CO32− units) are rod-like with a length of 1.2 nm. It is the first time that inorganic ionic oligomers have been discovered.

Top left: CaCO3 made by traditional methods; Top right: (CaCO3)n oligomers made by current method;Bottom: Another four different kinds of inorganic materials made by the same approach.​

What can these oligomers do? What novel properties do they have? In what way are they scientifically significant? These questions need to be explored.

The manufacturing of inorganic materials

Oligomers are low molecular weight polymers comprising a small number of repeat units whose physical properties are significantly dependent on the length of the chain. Oligomers are essentially intermediates of the polymerization reaction that find wide, direct applications in material science. Plastics and rubber are polymers cross-linked by monomers or oligomers. “They have a continuous structure. For example, a plastic basin can be perceived as a large molecule”, says TANG Kuangrui. Plastics and rubber have played an essential role thanks to their exceptional properties.

However, the manufacturing of inorganic materials is circumscribed by classical crystallization, which often produces a colossal quantity of chaotic powders rather than monoliths with continuous structures.

The discovery of inorganic ionic oligomers betokens a hope of “transforming” inorganic materials. Once TEA is removed from a solution, the (CaCO3)n oligomers can be cross-linked into a continuous structure. The fluid-like behavior of the oligomer precursor enables it to be readily processed or molded into shapes, even for materials with structural complexity and variable morphologies. The material construction strategy that we introduce here arises from a fusion of classic inorganic and polymer chemistry, and uses the same cross-linking process for the manufacturing of the materials.

By using humidity- or water-induced crystallization under mild conditions, this method can be extended to the repair of biological hard tissues (biominerals) such as sea-urchin spines and teeth, demonstrating its potential in biological and biomedical applications. The capabilities and advantages of this method result from the properties of the oligomers and their crosslinking, and could enable the production of inorganic materials by a route analogous to that for organic polymers.

​

“We offer a novel method and see rays of hope,” says TANG Kangrui.


The future of continuous inorganic materials | Zhejiang University

Zhaoming Liu, Changyu Shao, Biao Jin, Zhisen Zhang, Yueqi Zhao, Xurong Xu, Ruikang Tang. Crosslinking ionic oligomers as conformable precursors to calcium carbonate. Nature (2019). DOI: 10.1038/s41586-019-1645-x​

 

[JSCh]

NEWS RELEASE 24-OCT-2019
Scientists uncover the process behind protein mutations that impact gut health
Study examines why a protein mutation that causes inflammatory bowel diseases is dysfunctional

ST. MICHAEL'S HOSPITAL

"Though we have discovered a lot regarding the impact of mutations of NOD 1 and NOD 2 on IBD, there hasn't been a satisfying reason as to why some variants cause inflammatory disease," said Dr. Greg Fairn, a scientist at the Keenan Research Centre for Biomedical Science of St. Michael's Hospital. CREDIT: Unity Health Toronto

A new study led by researchers at St. Michael's Hospital and the Princess Margaret Cancer Centre in Canada and Zhejiang University School of Medicine in China has uncovered why a protein mutation that causes inflammatory bowel diseases is dysfunctional.

Published today in Science, the research focused on nucleotide-binding oligomerization domain-containing protein 1 and 2. Known as NOD 1 and NOD 2, these are protein receptors encoded by the NOD genes. They recognize bacterial products and prompt the immune system to act quickly to fight infection. Some variants of NOD 1 and NOD 2 cause a lack of immune response, while others overstimulate the immune system. Differences in the NOD 2 gene are associated with many diseases, including inflammatory bowel disease (IBD).

IBD causes sections of the gastrointestinal tract to become irritated and ulcerated, causing pain and discomfort to patients. Every year, more than 10,000 Canadians are diagnosed with these types of disorders.

"Though we have discovered a lot regarding the impact of mutations of NOD 1 and NOD 2 on IBD, there hasn't been a satisfying reason as to why some variants cause inflammatory disease," said Dr. Greg Fairn, a scientist at the Keenan Research Centre for Biomedical Science of St. Michael's.

The team set out to understand the molecular process that determines how NOD 1 and NOD 2 recognize bacteria and how this impacts their ability to signal an appropriate immune response. The scientists collaborated over four years to uncover this function, and Dr. Fairn credits their success to a multidisciplinary and multinational effort that resulted in rigorous science.

They found that palmitoylation, the process by which fatty acids attach to proteins to alter the protein's location within cells, is essential to elicit immune signaling of NOD 1 and NOD 2. In particular, they identified one enzyme that helps in the attachment of fatty acids to proteins - known as ZDHHC5 - as the key to unlocking this process that alters NOD 1 and NOD 2 function.

"Our findings point to the potential importance of palmitoylation - too much or too little of this process can impact inflammation," Dr. Fairn said. "Now, the question is whether there is potential to fine tune this process to one day lead to treatment for a variety of inflammatory disorders."

The multinational research team hopes this work is a stepping stone to uncovering more about the molecular reasons behind why variants of these proteins impact gut health.

"There is more to the story - targeting NOD-based signaling is only one potential intervention of many that would be needed for a person with chronic inflammation and altered microbiome" said Dr. Fairn.

"Our striking observations bring us one step closer to a deeper understanding of the science behind diseases like Crohn's."


Scientists uncover the process behind protein mutations that impact gut health | EurekAlert! Science News

Yan Lu, Yuping Zheng, Étienne Coyaud, Chao Zhang, Apiraam Selvabaskaran, Yuyun Yu, Zizhen Xu, Xialian Weng, Ji Shun Chen, Ying Meng, Neil Warner, Xiawei Cheng, Yangyang Liu, Bingpeng Yao, Hu Hu, Zonping Xia, Aleixo M. Muise, Amira Klip, John H. Brumell, Stephen E. Girardin, Songmin Ying, Gregory D. Fairn, Brian Raught, Qiming Sun, Dante Neculai. Palmitoylation of NOD1 and NOD2 is required for bacterial sensing. Science (2019). DOI: 10.1126/science.aau6391​

 

[JSCh]

First structure of human cotransporter protein family member solved
October 28, 2019| Media Contact Deborah Wormser

​

DALLAS – Oct. 28, 2019 – In work that could someday improve treatments for epilepsy, UT Southwestern scientists have published the first three-dimensional structure of a member of a large family of human proteins that carry charged particles – ions – across the cell membrane.

Human KCC1 structure​

The potassium chloride cotransporter 1 (KCC1) structure solved in this study carries positively charged potassium ions (K+) and negatively charged chloride (Cl-) ions across cell membranes to help regulate the volume of the cell. The protein is one of a large family of cotransporters found in many of the body’s tissues, particularly in the kidneys and the brain.

Despite extensive study of cotransporters, the lack of high-resolution structures has hindered a deeper understanding of their actions. The scientists solved the structure using cryo-electron microscopy (cryo-EM) – an advanced technology in which samples are frozen at extremely low temperatures at speeds that prevent the formation of ice crystals.

Mutations in this family of cotransporters can lead to diseases such as hereditary epilepsy, including one form that starts in infancy, said Dr. Xiao-chen Bai, corresponding author of the Science study. Drugs that target cotransporters are currently used as diuretics to treat high blood pressure.

“Cryo-EM was the only way to determine the structure of an integral membrane protein such as this one. We hope this structure will facilitate the design of drugs that target this protein,” said Dr. Bai, Assistant Professor of Biophysics and Cell Biology and a Virginia Murchison Linthicum Scholar in Medical Research as well as a Cancer Prevention and Research Institute of Texas (CPRIT) Scholar.

Proteins on the cellular membrane have been particularly resistant to X-ray crystallography, formerly considered the gold standard in structural biology technology before cryo-EM.

In cryo-EM, samples are viewed using robot-assisted microscopes that can be twice as tall as a person. These microscopes containing high-tech electron detectors work with powerful computers to record multiple images and apply advanced algorithms to interpret the data. UT Southwestern’s Cryo-EM Facility operates 24 hours a day, seven days a week.

This work at UT Southwestern using cryo-EM also required advanced specimen preparation techniques that Dr. Bai is known for internationally.

Other study participants included researchers at Vanderbilt University in Nashville and from China’s Zhejiang University School of Medicine, Tianjin University, and Wuxi Biortus Biosciences Co. Ltd. One of the corresponding authors is Dr. Jingtao Guo of Zhejiang University School of Medicine, who began the project while a postdoctoral researcher in the UTSW laboratory of Dr. Youxing Jiang, Professor of Physiology and Biophysics. Dr. Jiang holds the Rosewood Corporation Chair in Biomedical Science and is a W.W. Caruth, Jr. Scholar in Biomedical Research at UT Southwestern and an Investigator of the Howard Hughes Medical Institute.

The study received funding from China’s Ministry of Science and Technology, the National Natural Science Foundation of China, Zhejiang Provincial Natural Science Foundation, the Fundamental Research Funds for the Central Universities, and Zhejiang University, and from CPRIT, The Welch Foundation, the National Institutes of Health, and the Leducq Foundation.

The authors report no competing financial interests.



First structure of human cotransporter protein family member solved: Newsroom - UT Southwestern, Dallas, TX

Si Liu, Shenghai Chang, Binming Han, Lingyi Xu, Mingfeng Zhang, Cheng Zhao, Wei Yang, Feng Wang, Jingyuan Li, Eric Delpire, Sheng Ye, Xiao-chen Bai, Jiangtao Guo. Cryo-EM structures of the human cation-chloride cotransporter KCC1. Science (2019). DOI: 10.1126/science.aay3129​

 

[Galactic Penguin SST]

Tiny raptor living 100m years ago discovered in Myanmar

October 30, 2019

An international team led by Chinese scientists has discovered a new specimen of a tiny raptor in a 100-million-year-old amber from north Myanmar.

The discovery shows the diversity of birds in the dinosaur age and has revealed the evolution of feathers.

The team led by Xing Lida, a paleontologist from China University of Geosciences in Beijing, has discovered a series of ambers that preserve enantiornithine fossils and have enriched people's knowledge of the evolution of ancient birds and enantiornithine, according to a press release Xing sent to the Global Times.

Fossils remains discovered this time preserved some skeletons and skin of a bird's foot. Its overall shape and the curvature of the preserved ungual sheath strongly suggest it was an arboreal bird, Xing told the Global Times.

The prominent plantar pads and papillose plantar surface are related to gripping substrates and prey. The combination of strongly padded, robust digits with elongated claws was most commonly found in extant raptorial birds, which may suggest the bird was a small aerial insectivore.

The ambers came from Hukawng Valley, a mountainous region of Myanmar with high rainfall and many rivers. Local language refers to it as "the place where demons live." Ambers discovered in the region, which date back 100 million years, record its unique ecosystem in ancient times.

The team had earlier discovered strange-shaped feathers that have an open central shaft. The cross-section of the shaft is in the shape of the letter C, not the letter O as extant birds. C-shaped feathers were not as good for flying as O-shaped ones because they were less sturdy, but they were lighter than O-shaped feathers and more energy-efficient.

The newly discovered fossils connect such feathers with enantiornithine as a previous discovery contained only feathers without skeletons.

Xing's team discovered the world's first raptor fossils in ambers and wings of ancient birds in 2016. They have also discovered snakes and frogs in ambers.

https://archive.is/a8il9/5fc6a8ee695df2c67a5b37d2b12646d71fc8091f.jpg ; https://archive.is/a8il9/50fd43586bea52f2c0535799718ce54afb3064f2/scr.png ; http://web.archive.org/web/20191030...e/pic/BIG/20191030/0/16563737996719262284.jpg
▲ 1. Restitute picture of the tiny raptor living 100 million years ago drawn by Han Zhixin.

https://archive.ph/5Cgek/a2e0c6225ee2e52c15b33ccbdf0423bd61ca6df1.jpg ; https://archive.ph/5Cgek/381bd65fae204826628a514a0c51847eb34f8549/scr.png ; http://web.archive.org/web/20191030...e/pic/BIG/20191030/3/14080166679519934923.jpg
▲ 2. The 100-million-year-old amber, in which a new specimen of a tiny raptor has been discovered Photo: Xing Lida

https://archive.ph/VCQZn/fcd91e23e0810610d1a9528f53ab129df2fe4dad.jpg ; https://archive.ph/VCQZn/b4e05d98f12399dd55de53ed0014f89ef5693b8b/scr.png ; http://web.archive.org/web/20191030...e/pic/BIG/20191030/81/8035343050008476705.jpg
▲ 3. Strange-shaped feathers that have an open central shaft discovered by the international team led by Chinese scientists Photo: Xing Lida

https://archive.ph/53s6j/f91cf5b9a01df542967569e49a8dc1d33698efb9.jpg ; https://archive.ph/53s6j/c78a2d7aea7c1a22c20d608158edfa4cd38a6f86/scr.png ; http://web.archive.org/web/20191030.../pic/BIG/20191030/10/16837602028000995742.jpg
▲ 4. Scanned image of the tiny raptor's foot sample Photo: Xing Lida

http://web.archive.org/web/20191030230936/http://en.people.cn/n3/2019/1030/c90000-9627701.html
http://archive.ph/0xqYu

 

[JSCh]

Atomically thin high-temperature superconductor
31 OCT 2019

Copper oxide high-temperature superconductors were first discovered in 1986 by physicists J. Georg Bednorz and K. Alex Müller. The Nobel Prize in Physics was awarded to this important breakthrough in the following year. Since then, dozens of other copper oxide superconductors have been discovered; the highest superconducting transition temperature (Tc) of this family of materials could be as high as 134 Kelven, or -139 ̊C, under ambient pressure. Although different in composition and Tc, various copper oxide superconductors share a similar layered atomic structure, i.e., the crystals can be viewed as two-dimensional, atomically thin planes that are stacked together. The two-dimensional nature of these high temperature superconductors, however, ostensibly contradicts with a conventional wisdom: long-range order such superconductivity is suppressed in two dimensions. This apparent dichotomy may be the key to understand high temperature superconductivity.

A direct way to unravel such a mystery is to thin down these superconductors to their smallest structural unit—one monolayer—and see whether superconductivity changes. The result may provide important insight into the high temperature superconductivity in copper oxides. Experimentally obtaining atomically thin films of copper oxides, however, is challenging: the material is extremely unstable in air, making it difficult to handle.

A team led by Prof. Yuanbo Zhang from the Department of Physics at Fudan University now overcomes these challenges, and successfully obtained, for the first time, monolayer copper oxide superconductors with their intrinsic properties intact. They found that the high temperature superconductivity—and various other correlated phenomena associated with high temperature superconductivity—in monolayer remains exactly the same as that in bulk crystal. High temperature superconductivity in copper oxide is, therefore, essentially a 2D phenomenon.

The team focused their study on a representative copper oxide superconductor, Bi2Sr2CaCu2O8+δ (referred to as Bi-2212). They overcame the instability of the monolayers with a low temperature device fabrication technique that they have developed. In addition, they were able to tune the doping level of the monolayer over a wide range, and mapped out a large portion of the phase diagram. Surprisingly, the maximum value of Tc in these monolayers was similar to that in bulk—a direct evidence that the high temperature superconductivity of Bi-2212 in the 2D limit is the same as in the bulk.

Fig. The electronic structure of monolayer Bi-2212 on the atomic scale with scanning tunnelling microscopy

The team also probed the electronic structure of monolayer Bi-2212 on the atomic scale with scanning tunnelling microscopy. They discovered that apart from the superconductivity, various other phenomena that are closely-related to high temperature superconductivity phases persists in the monolayer Bi-2212. These phenomena include pseudo-gap, charge order and Mott state that are believed to be precursors to high temperature superconductivity.

The results from transport and scanning tunnelling microscopy experiments allow the team to conclude that all essential physics in Bi-2212 is contained in its monolayer. The discovery paved the way for further study of high temperature superconductivity with new techniques emerging from the field of two-dimensional materials.


Atomically thin high-temperature superconductor | Fudan University

Yijun Yu, Liguo Ma, Peng Cai, Ruidan Zhong, Cun Ye, Jian Shen, G. D. Gu, Xian Hui Chen & Yuanbo Zhang. High-temperature superconductivity in monolayer Bi2Sr2CaCu2O8+δ. Nature (2019); DOI: 10.1038/s41586-019-1718-x​

 

[JSCh]

NEWS RELEASE 31-OCT-2019
Unlocking the black box of embryonic development
International collaboration improves method for culturing primate embryos to learn more about human development

SALK INSTITUTE

​

Pictured is Day 17 of a cultured primate embryo; the various colors indicate markers of cellular differentiation (specialization). CREDIT: Weizhi Ji/Kunming University of Science and Technology

LA JOLLA--(October 31, 2019) Little is known about the molecular and cellular events that occur during early embryonic development in primate species. Now, an internationally renowned team of scientists in China and the United States has created a method to allow primate embryos to grow in the laboratory longer than ever before, enabling the researchers to obtain molecular details of key developmental processes for the first time. This research, while done in nonhuman primate cells, can have direct implications for early human development.

The findings, published in Science on October 31, 2019, provide valuable insight into early embryonic development and potentially can help inform approaches to advance regenerative medicine in humans.

"Our study provides a first look into this black box of early development," says Juan Carlos Izpisua Belmonte, co-corresponding author and a professor in Salk's Gene Expression Laboratory. "We can now observe how cells progress through each embryonic stage and what factors they need to develop, which will aid in creating better options for the generation of a variety of cells and tissues."

"To understand cellular and molecular mechanisms underlying primate gastrulation, we began monkey embryo culture experiments in China three years ago. Because of the team's long-standing expertise on the systematic study of nonhuman primates and well-established reproductive research systems, such as an in vitro fertilization platform, we succeeded in achieving our goals. This can help to shed light on previously unknown aspects of human post-implantation development." says Weizhi Ji, co-corresponding author, professor and dean of the Institute of Primate Translational Medicine of Kunming University of Science and Technology, in China.

The scientists wanted to study an early developmental milestone called gastrulation, which occurs when a developing embryo transforms into a multilayered structure, called the gastrula, from which all future tissues and organs will be derived. One layer will become the lungs, gastrointestinal tract and liver; another will become the heart, muscles and reproductive organs; and a third will become the skin and nervous system. Yet, scientists did not know the molecular and cellular drivers of this process in primates, largely due to limited access to early embryos.

"Our goal was to culture a primate embryo from an early timepoint in order to study the process of development," says Jun Wu, a co-author of the paper and assistant professor at University of Texas Southwestern Medical Center. "We wanted to monitor the embryos every day to observe their shape, size and migration patterns as well as how they generate different types of cells during early primate development."

To better study this critical transformation, the scientists modified a previously established embryo culture protocol to allow an early primate embryo to develop in laboratory conditions for up to twenty days; previously researchers had only been able to maintain cultured primate embryos prior to the second week of gestation. Using the new protocol, the team found that the cells within cultured embryos exhibited clear developmental trajectories towards each layer of the gastrula, and the results revealed some of the molecular details required for this growth. The data could also be used as a resource to aid in extending the cultured embryo duration past twenty days in order to better study stem- cell differentiation (specialization).

"These results illuminate some of the regulation networks and signaling pathways that are crucial to development in primates," says Izpisua Belmonte. "This system provides a foundation and resource for developing better strategies to examine early primate development in both health and disease, in the laboratory."


Unlocking the black box of embryonic development | EurekAlert! Science News

Yuyu Niu, Nianqin Sun, Chang Li, Ying Lei, Zhihao Huang, Jun Wu, Chenyang Si, Xi Dai, Chuanyu Liu, Jingkuan Wei, Longqi Liu, Su Feng, Yu Kang, Wei Si, Hong Wang, E. Zhang, Lu Zhao, Ziwei Li, Xi Luo, Guizhong Cui, Guangdun Peng, Juan Carlos Izpisúa Belmonte, Weizhi Ji, Tao Tan. Dissecting primate early post-implantation development using long-term in vitro embryo culture. Science (2019). DOI: 10.1126/science.aaw5754​

 

[JSCh]

Complex cellular machine visualized to yield new insights in cancer
October 31, 2019
Huntsman Cancer Institute

Cellular machines that control chromosome structure, such as the RSC complex, are mutated in about one-fifth of all human cancers. Now, for the first time, scientists have developed a high-resolution visual map of this multi-protein machine, elucidating how the RSC complex works and what role it has in healthy and cancer cells. The study was co-led by Bradley Cairns, PhD, cancer researcher at Huntsman Cancer Institute (HCI) and professor and chair of oncological sciences at the University of Utah, along with Ning Gao, PhD, at Peking University and Zhucheng Chen, PhD, at Tsinghua University in China. The study was published today in the journal Science.

A process known as gene expression underlies the behavior of every cell in all living organisms. Gene expression provides cells with a blueprint that orchestrates their behavior, including growth, death, and responses to changes in the cellular environment. Gene expression is necessary for living healthy and cancer cells; however, cancer cells express genes that carry a defective set of instructions that often lead to uncontrolled growth. The RSC and related complexes are crucial regulators of chromosome structure and gene expression. Once the RSC complex binds to the genome, it executes machine-like movements that expose segments of DNA in chromosomes, leading to the initiation of gene expression.

Nearly 20 years ago, Cairns discovered the RSC complex and later added to his findings by identifying many of its protein components and revealing its machine-like behavior. Now, Cairns and his colleagues have established how this complex works in conjunction with the cellular machinery. He believes these findings will yield highly significant insights into how certain cancers develop. "The RSC complex plays an important role in both healthy and cancer cells," says Cairns. "Now, we can accurately visualize a high-resolution map of the RSC complex, including all of its components. We can see how the complex interacts with, and moves, chromosomes and DNA. This provides crucial information that helps us understand how RSC-like complexes are involved in cancer."

Previous studies led to lower resolution models of the RSC complex, but many questions remained unanswered, including how the subunits of this complex assemble and interact with the chromosomal genome. Cairns and his colleagues, including lab members Cedric Clapier, PhD, and Naveen Verma built on existing knowledge using yeast cells, a classic model system to study chromosomes and gene expression. They utilized new and sophisticated microscopic techniques that allowed them to visualize chromosomal structures in high detail. Cairns and his colleagues were able to study the RSC complex in depth by developing numerous cell lines that contained both normal and mutated versions of the RSC complex. Next, their team studied yeast RSC using cryo-electron microscopy -- a technology that has only become available in recent years. This tool allows scientists to view the architecture of large, sophisticated cell components at a high-resolution molecular level.

The scientists are now using this information to understand the RSC complex and its role in cancer further. "This study has crucial implications for our ability to understand how chromosomal genes in healthy and cancer cells are exposed and expressed," said Cairns. "This type of information is a critical step in the processes that scientists use to develop new drugs and understand the genomic characteristics of a tumor."

This research was supported by the National Cancer Institute grants P30CA042014, R01CA201396, and U54 CA231652; Howard Hughes Medical Institute, Huntsman Cancer Foundation, the Ministry of Science and Technology of China, and the National Natural Science Foundation of China.

Story Source:

Materials provided by Huntsman Cancer Institute. Note: Content may be edited for style and length.​

Journal Reference:

1. Youpi Ye, Hao Wu, Kangjing Chen, Cedric R. Clapier, Naveen Verma, Wenhao Zhang, Haiteng Deng, Bradley R. Cairns, Ning Gao, Zhucheng Chen. Structure of the RSC complex bound to the nucleosome. Science, 2019 DOI: 10.1126/science.aay0033

Complex cellular machine visualized to yield new insights in cancer -- ScienceDaily

 

[JSCh]

NEWS | 31 OCTOBER 2019
Primate embryos grown in the lab for longer than ever before | Nature
The 20-day-old monkey embryos could reopen the debate about how long the human variety should be allowed to grow in a dish.

​

Two groups have grown cynomolgus monkey embryos for 20 days in the lab.Credit: Mark MacEwen/Nature Picture Library

They are the longest lived primate embryos to thrive outside the body. Two groups working in China have succeeded in growing monkey embryos in a dish for 20 days. The work sheds light on a crucial but little-understood phase of early development, and will probably reignite the debate about how long human embryos should be permitted to develop in the lab.

Researchers grow embryos to understand the earliest stages of development. In 2016, biologists in the United States successfully grew human embryos in the lab for 13 days, but then stopped the experiments because of an internationally accepted rule that restricts scientists from growing human embryos past 14 days for ethical reasons. As a closely related species, monkey embryos are a window into early human development, but scientists have previously grown them for only nine days.

The two teams in China report in Science1,2 today that lab-grown embryos from cynomolgus monkeys (Macaca fascicularis) underwent several crucial processes. This includes the process of gastrulation, which is when the basic cell types that give rise to different organs and tissues begin to emerge, around day 14.

“The best part is that there is a system to study gastrulation in vitro in a model very similar to the human,” says Magdalena Zernicka-Goetz, a developmental biologist at the California Institute of Technology in Pasadena. “This is very exciting.”

Although the studies show that early monkey development mirrors many aspects of the first two weeks of the human process, the teams report subtle differences between that species and ours. This suggests that monkey embryos might not be an adequate model for studying some advanced stages of human development, says Pierre Savatier, a stem-cell biologist at the Stem-cell and Brain Research Institute in Bron, France. He predicts that the papers will reinvigorate a push to extend the 14-day policy.

The ability to grow monkey embryos for longer than ever before could also boost research in another hot and controversial field — the generation of hybrid human–monkey embryos, known as chimaeras, with the goal of investigating how human cells differentiate into organs. This research has been held back because researchers haven’t been able to grow monkey embryos for long enough to see how the injected human cells behave. Savatier says he will use the culture technique to grow monkey embryos that will be injected with human stem cells. “This culture system is hugely important for chimaera experiments,” he says.

Embryo bonanza
Both teams grew monkey embryos on a gel matrix that supplied higher levels of oxygen than do cells in the womb. This culture technique was developed by Zernicka-Goetz’s team, which was one of two groups in the United States that succeeded in growing human embryos for 13 days, in 20163,4.

In one of the latest two papers, a team led by Juan Carlos Izpisua Belmonte, a developmental biologist at the Salk Institute for Biological Studies in La Jolla, California, and Ji Weizhi at the Yunnan Key Laboratory of Primate Biomedical Research in Kunming, China, reports that 46 of 200 monkey embryos survived to 20 days. The authors of the other paper, led by Li Lei, a developmental biologist at the Institute of Zoology, Chinese Academy of Sciences, in Beijing, say they grew three embryos that long.

A 17-day-old embryo.Credit: Y. Niu et al./Science

The teams tracked the progress of the embryos, which were created using in vitro fertilization, to check whether they grew as they would have in the womb. They examined the timing and shape of structures in the embryos and the structures that support embryonic growth, the types of protein that are expressed by cells at different stages and the primordial germ cells that go on to become eggs or sperm. Then they compared these observations with what is known about development of this species from past experiments, in which embryos were removed from pregnant monkeys at different stages up to 17 days5.

Both groups report that embryos in a dish develop in the same way as those in the womb. “It’s ok to assume that the observations made are a representation of what happens in vivo,” says Izpisua Belmonte.

The teams stopped their experiments on day 20, when the embryos turned dark and some cells detached from them — signs that the structures were collapsing. Li says it’s not clear why that happened. He and Izpisua Belmonte say that culturing the cells in an extracellular matrix that better mimics the womb might help them to survive longer. Next, Ji hopes to grow embryos to the point when the primitive nervous system starts to form, around day 20.

Subtle differences
Data presented in both studies suggest there are subtle but crucial differences in the early development of monkeys and humans, so non-human primate embryos won’t replace the need for studies in human cells, says Fu Jianping, a bioengineer at the University of Michigan in Ann Arbor, who has been trying to grow synthetic human embryos. “In vitro cultured human embryos remain the irreplaceable system for us to study and understand human development,” he says.

Savatier says one difference, described in the Ji and Ispizua Belmonte paper, is the genes that are expressed in monkey cells that form the placenta are different from those in humans. But to study these processes in later stages in human embryos, regulators would need to lift the ban on growing them beyond 14 days.

In the wake of the US teams growing human embryos to 13 days in 2016, some scientists and ethicists pushed for a revision of the 14-day policy, and a poll conducted in the United Kingdom in 2017 reported strong public support for extending the limit. Savatier and others think the latest results showing the unique features of human embryonic development will strengthen arguments to change the policy. “No doubt that this work will force the ethical committees and regulatory bodies to reopen the debate over the 14-day rule,” he says.

Researchers are optimistic that the gel matrix could be used to grow human embryos to a more advanced stage if the rules change. Ji says that another group at his institute has developed a protocol specifically for human embryos that will soon be published. “This system could be suitable for human embryos to be cultured to 20 days, but we are not planning to do it,” he says.

 

[JSCh]

OCTOBER 31, 2019
Potential entry points for Huntington's disease drug discovery
by Fudan University

Prof. Yu Ding(R) and his student. Credit: Fudan University

Huntington's disease (HD) is one of the four major neurodegenerative diseases that have been most extensively studied. The clinical symptoms include uncontrolled dancing-mimicking behavior (chorea), as well as cognitive deficiency and psychiatric abnormalities. Since the biochemical activity of the mutant huntingtin protein (mHTT) that causes the disease is uncharacterized, the conventional drug discovery approach, which relied on inhibitors that block the bioactivity of the pathogenic proteins, is not applicable.

Recently, researchers at Fudan University, including Profs. Boxun Lu (School of Life Sciences), Yiyan Fei (School of Informatics Science and Engineering), and Yu Ding (School of Life Sciences), formed a multidisciplinary team to work on this problem. With joint efforts, they have worked out an innovative method of drug discovery: using the autophagosome-tethering compounds (ATTEC) to degrade pathogenic proteins and treat the disease. The team carried out a smartly designed screening featuring a small-molecule microarray and front-edge optical technologies, and managed to identify four small molecule compounds that specifically reduced the protein that causes Huntington's disease.

On October 31, the study was published online under the title "Allele-selective Lowering of Mutant HTT Protein by HTT-LC3 Linker Compounds" in Nature.

"Small molecule glue" helps autophagosomes "engulf" the disease-causing protein

Since the conventional approach is infeasible for mHTT, the team came up with a fundamentally new idea, which was to degrade mHTT by harnessing autophagy, an intracellular protein degradation process. During autophagy, the key protein LC3 is lipidated and expanded to form a double-membrane structure, which then engulfs proteins, lipids, organelles and other degradation cargoes and forms a complete autophagosome. The autophagosomes are then fused with lysosomes and the material engulfed therein is degraded.

However, if enhanced non-specifically, autophagy degrades all proteins engulfed into autophagosomes, including the normal wild-type huntingtin protein that plays a role in neuroprotection. This would be possibly self-defeating.

To identify compounds that only degrade mHTT but not wild-type HTT, the team envisioned a "small molecule glue" functioning as an "autophagosome tethering compound" (ATTEC), which could tether LC3 and mHTT together so that mHTT is engulfed into autophagosomes for degradation. Meanwhile, the ATTEC does not interact with the wild-type HTT protein, leaving it unaffected. Through screening, validation and preliminary search for structurally similar compounds, the team identified four compounds with the desired properties.

At this point, the identified compounds have the potential of tethering mHTT to autophagosomes without influencing the wild-type HTT, but whether they do function in degrading mHTT as expected needs further validation. The team found that these four compounds significantly reduced mHTT levels in HD mouse neurons, HD patient cells, and HD drosophila models at ~10 to 100 nanomolar concentrations, with little effect on wild-type HTT levels. Excitingly, at least two out of these four compounds are able to cross the blood-brain barrier, and a small dose of intraperitoneal injection would significantly reduce mHTT levels in the cortex and striatum of HD mice, without affecting wild-type HTT levels. They also significantly improved disease-related phenotypes, providing an entry point for the development of oral or injectable drugs for HD.

Such ATTECs were highly challenging to identify. Only one out of about 2000 compounds has the desired properties. Thus, finding it was a major obstacle of this project for a long time. The participation of the Professor Yiyan Fei's group made this possible. Dr. Fei's group developed a new high-throughput compound screening platform based on small molecule microarray (SMM) and oblique-incidence reflectivity difference (OI-RD) technology, which was fast, sensitive, label-free and high-throughput. It could identify the target protein-interacting compounds from a library of thousands of small molecule compounds.

The research team stamped nearly 4000 small-molecule compounds onto a chip and had the target protein flow through the chip. If a sample binds to a specific compound immobilized onto the chip, the molecular layer at the position will thicken, generating a tiny change that can be detected by a sensitive optical method (oblique incident light reflection difference). Using this cutting-edge screening approach, the team found two small molecules that could bind to both LC3 and mHTT proteins, but not to wild-type HTT. After studying a panel of small molecule compounds with similar structures, a total of four ATTECs that bind LC3 and mutant HTT were identified and validated.

Autophagosome tethering compounds may open new windows for drug discovery

The team further explored the intrinsic mechanisms by which these small molecule compounds could distinguish between mutant and wild-type HTT proteins, which were almost identical except in the glutamine repeat (polyQ) length. It turned out that these compounds were bound to excessively long polyQ stretches that only appeared in mHTT.

Based on this, the team realized that the application of these small molecule compounds may reach far beyond the potential treatment of Huntington's disease. Nine human diseases are so called polyQ diseases, because they are caused by specific mutant proteins containing excessively long polyQ. Among them, spinocerebellar ataxia type III (SCA3) is the most common in the Chinese population.

The clinical symptoms include motion discoordination, inability to maintain body posture and balance, accompanied by possible exophthalmos, hyperreflexia, facial muscle twitching, tendon and other symptoms. With SCA3 patient cells provided by Dr. Yimin Sun from Prof. Jian Wang's group at Huashan Hospital affiliated to Fudan University, the team found that these compounds could effectively reduce the level of the mutant ATXN3 protein (with a polyQ length of 74) that causes the disease, without affecting the wild-type ATXN3 (with a polyQ length of 27).

When it came to the future development and applications of this study, Boxun Lu says, "These compounds may not only be effective in the treatment of Huntington's disease, but also applicable to other polyQ diseases. The new concept of drug development using autophagosome-binding compounds (ATTEC) may also be applied to other pathogenic proteins that are undruggable, or even to pathogenic substances that are not proteins, such as organelles or lipids."

More information: Zhaoyang Li et al. Allele-selective lowering of mutant HTT protein by HTT–LC3 linker compounds, Nature (2019). DOI: 10.1038/s41586-019-1722-1​

https://medicalxpress.com/news/2019-10-potential-entry-huntington-disease-drug.html

 

[JSCh]

23 October 2019
Building blocks of all life gain new understanding

New research on an enzyme that is essential for photosynthesis and all life on earth has uncovered a key finding in its structure which reveals how light can interact with matter to make an essential pigment for life.

The work gives a structural understanding of how a light activated enzyme involved in chlorophyll synthesis works. Light activated enzymes are rare in nature, with only three known. This enzyme in particular, called protochlorophyllide oxidoreductase or ‘POR’, is responsible for making the pigment vital for chlorophyll in plants. Without chlorophyll, there is no photosynthesis and no plant life.

Understanding the structure of the POR enzyme gives a rare glimpse of how a natural light-activated enzyme works. Chemists and bio-scientists alike have been fascinated by light activation of biological catalysis for many years and understanding how light can drive enzyme reactions has been a major challenge.

The revealed structure shows how the architecture of the enzyme allows one of the reactants to capture light and channel it to drive a crucial biological reaction involved in chlorophyll synthesis. Understanding these fundamental concepts should have major implications for the design of new light-activated chemical and biochemical catalysts which are increasingly important in the use of enzymes in chemical manufacture.

“The crystal structure of this important light-activated enzyme has proven to be elusive for many years. Our current work provides the crucial missing link between protein structure and reaction chemistry and paves the way for detailed computational studies of the reaction in the future.„
Dr Derren Heyes​

The research led by The University of Manchester, together with colleagues in China (Chinese Academy of Agricultural Sciences, Shanghai Jiao Tong University, Zhejiang University of Technology and Qi Institute), is published today in the journal Nature. Professor Nigel Scrutton said of the new discovery: “These studies reveal how the POR enzyme brings about light-driven reduction of the pigment Pchlide. Our studies provide a structural basis for harnessing light energy to drive catalysis in this important chlorophyll biosynthetic enzyme, which is crucial for light-to-chemical energy conversion and energy flow in the biosphere.”

Dr Derren Heyes ran several of the experiments for the new research, he said: “The crystal structure of this important light-activated enzyme has proven to be elusive for many years. Our current work provides the crucial missing link between protein structure and reaction chemistry and paves the way for detailed computational studies of the reaction in the future.”

Demonstrating such a fundamental aspect of biological life for the first time tells us how the process within the cells is carried out in order to allow photosynthesis to occur. The team discovered that light energy activates one of its substrates, protochlorophyllide, a precursor of chlorophyll, within the enzyme to drive ‘downstream’ bond breaking and making reactions.

This new discovery shows we are still unravelling the core building blocks of life which pre-date humans by billions of years. This major scientific breakthrough provides a unique structural and physical insight into a fundamental reaction in nature. This could open the door to the possibility of bioengineering artificial light-activated enzymes in the future.



Building blocks of all life gain new understanding | The University of Manchester

Shaowei Zhang, Derren J. Heyes, Lingling Feng, Wenli Sun, Linus O. Johannissen, Huanting Liu, Colin W. Levy, Xuemei Li, Ji Yang, Xiaolan Yu, Min Lin, Samantha J. O. Hardman, Robin Hoeven, Michiyo Sakuma, Sam Hay, David Leys, Zihe Rao, Aiwu Zhou, Qi Cheng, Nigel S. Scrutton. Structural basis for enzymatic photocatalysis in chlorophyll biosynthesis. Nature (2019). DOI: 10.1038/s41586-019-1685-2​

 

[JSCh]

NEWS AND VIEWS | 06 NOVEMBER 2019
A rule from bacteria to balance growth and expansion
Bacteria move along gradients of chemical attractants. Two studies find that, in nutrient-rich environments, bacteria can grow rapidly by following a non-nutritious attractant — but expanding too fast leaves them vulnerable.

Bacteria can sense chemical attractants and use that information to navigate towards resources or away from harm — a process called chemotaxis. But why bacteria chase signals that often do not have much nutritional value has been a long-standing puzzle. Writing in Nature, Cremer et al.1 show that bacterial populations can use non-nutritious attractants as cues for rapidly expanding through nutrient-rich areas, ensuring that plentiful nutrients are available for their future growth. In a second paper, Liu et al.2 build on this work to reveal an unanticipated rule of bacterial evolution: the safest way for a bacterial population to colonize a habitat is not necessarily to expand as fast as possible, because rapid expansion can leave the population vulnerable to invasion by competitors.


...

A rule from bacteria to balance growth and expansion | Nature

 

[JSCh]

Study reveals how Tibetan people adapt to high altitude
Source: Xinhua| 2019-11-06 17:30:53|Editor: huaxia

Residents attend a spring plowing ceremony in Shannan City, southwest China's Tibet Autonomous Region, March 16, 2019. (Xinhua/Li Xin)

Chinese researchers have released the first high-quality genome of Tibetan people, revealing the genetic mechanism that may play an important role in human adaption to extreme environments such as high altitude.

BEIJING, Nov. 6 (Xinhua) -- Chinese researchers have released the first high-quality genome of Tibetan people, revealing the genetic mechanism that may play an important role in human adaption to extreme environments such as high altitude.

Researchers from the Kunming Institute of Zoology, Chinese Academy of Sciences, Tibet University and other Chinese research institutions assembled Tibetan genome ZF1 with new approaches like long-reading sequencing.

Genome sequencing involves cutting DNA into pieces, reading the fragments and then using a computer to patch the sequence together.

Villager Dainzin Quzhen (front) holds a traditional rite with family members before moving into her new house in Lhozhag Town of Lhozhag County, Shannan City, southwest China's Tibet Autonomous Region, Sept. 21, 2019. (Xinhua/Jigme Dorje)

Short-read sequencing technologies cut DNA into "words" that are about 100 base-pairs long. Long-read sequencing, by comparison, cuts DNA into words that are thousands of letters long, revealing parts of the genome like never before.

Structure variants (SVs) refer to the variation in the structure of an orgasm's chromosome. The researchers reported in the journal National Science Review that in the genome, they detected 17,900 SVs in ZF1, among which 6,505 are different from other East Asian SVs. The analysis found these SVs are related to the activation of molecular pathways in low-oxygen environments.

Artists from Lhozhag County perform Tibetan Opera during a cultural festival in Shannan, southwest China's Tibet Autonomous Region, Aug. 17, 2019. (Xinhua/Zhang Rufeng)

They also found that a gene named MKL1 shows large divergence between highland Tibetans and lowland Han Chinese. The difference is associated with lower systolic pulmonary arterial pressure, one of the key adaptive physiological traits in Tibetans.

Compared to other East Asian genomes, the researchers found that the Tibetan genome has more shared gene sequences with archaic humans like Neanderthal and Denisovan, noting that the unique genomic composition is associated with better lung function in Tibetans.

The researchers said that the ZF1 Tibetan genome and the identified SVs may provide valuable resources for future evolutionary and medical studies.

 

[JSCh]

Scientists retrieve genetic materials from 1.9-mln-yr-old giant ape fossil
Source: Xinhua| 2019-11-14 14:19:08|Editor: huaxia

NANNING, Nov. 14 (Xinhua) -- Chinese and Danish scientists have successfully retrieved genetic materials from a 1.9-million-year-old fossil of Gigantopithecus blacki, a species of great ape.

The finding, published in a paper on the journal Nature on Wednesday, marks the first time that such ancient protein evidence from fossils in the subtropics was retrieved. Scientists said it sheds new light on the origins and evolution of the long-extinct great ape species.

With the evidence, scientists are able to demonstrate that Gigantopithecus is a sister clade to orangutans with a common ancestor about 12 million to 10 million years ago, implying that the divergence of Gigantopithecus from Pongo forms part of the Miocene radiation of great apes, according to the paper.

Presumed to be more than two meters tall and weigh over 300 kg, giant apes are the largest primates known to have lived on earth. Their fossils date from two million to 300,000 years ago.

The genetic materials -- dental enamel proteome sequences -- were retrieved in 2018 from a 1.9-million-year-old Gigantopithecus blacki molar found in a cave in southern China's Guangxi Zhuang Autonomous Region, said Liao Wei, a researcher with the Anthropology Museum of Guangxi and a co-author of the paper.

Wang Wei, a professor at Shandong University, said the thick and hard enamel of the great ape and the fact that the fossil was found in a cave with a relatively stable temperature and humidity were both favorable factors for the preservation of the fossil.

"The two factors combined have helped researchers retrieve genetic materials from the enamel of the great ape fossil and make a breakthrough in the research," said Wang, whose team unearthed the fossil in 2008.

It was the first time such ancient genetic materials had been found in a warm and humid environment, said Frido Welker of the University of Copenhagen, the paper's lead author, adding that the finding is groundbreaking in the field of evolutionary biology.

 

[JSCh]

NEWS RELEASE 14-NOV-2019
Storing energy in hydrogen 20 times more effective using platinum-nickel catalyst
EINDHOVEN UNIVERSITY OF TECHNOLOGY

Catalysts accelerate chemical reactions, but the widely used metal platinum is scarce and expensive. Researchers at Eindhoven University of Technology (TU/e), together with Chinese, Singaporean and Japanese researchers, have now developed an alternative with a 20x higher activity: a catalyst with hollow nanocages of an alloy of nickel and platinum. TU/e researcher Emiel Hensen wants to use this new catalyst to develop a refrigerator-size electrolyzer of about 10 megawatts in the future. The results will be published on November 15th in the journal Science.

By 2050, the national government aims to get almost all of the Netherlands' energy requirements from sustainable sources, such as the sun or the wind. Because these energy sources are not available at all times, it is important to be able to store the generated energy. Given their low energy density, batteries are not suitable for storing very large amounts of energy. A better solution is chemical bonds, with hydrogen as the most obvious choice of gas. Using water, an electrolyzer converts (an excess of) electrical energy into hydrogen, which can be stored. At a later stage, a fuel cell does the opposite, converting the stored hydrogen back into electrical energy. Both technologies require a catalyst to drive the process.

The catalyst that helps with these conversions is - due to its high activity - mostly made of platinum. But platinum is very expensive and relatively scarce; a problem if we want to use electrolyzers and fuel cells on a large scale. TU/e catalysis professor, Emiel Hensen: "Fellow researchers from China therefore developed an alloy of platinum and nickel, which reduces costs and increases activity." An effective catalyst has a high activity; it converts more water molecules into hydrogen every second. Hensen continues: "At TU/e, we investigated the influence of nickel on the key reaction steps and to this end we developed a computer model based on images from an electron microscope. With quantum chemical calculations we were able to predict the activity of the new alloy, and we could understand why this new catalyst is so effective."

Successfully tested in a fuel cell

In addition to the other choice of metal, the researchers were also able to make significant changes to the morphology. The atoms in the catalyst have to bond with the water and/or oxygen molecules to be able to convert them. More binding sites will therefore lead to a higher activity. Hensen: "You want to make as much metal surface available as possible. The developed hollow nanocages can be accessed from the outside as well as from the inside. This creates a large surface area, allowing more material to react at the same time." In addition, Hensen has demonstrated with quantum chemical calculations that the specific surface structures of the nanocages increase the activity even further.

After calculations in Hensen's model, it turns out that the activity of both solutions combined is 20 times higher than that of the current platinum catalysts. The researchers have also found this result in experimental tests in a fuel cell. "An important criticism of a lot of fundamental work is that it does its thing in the lab, but when someone puts it in a real device, it often doesn't work. We have shown that this new catalysts works in a real application." The stability of a catalyst must be such that it can continue to work in a hydrogen car or house for years to come. The researchers therefore tested the catalyst for 50,000 'laps' in the fuel cell, and saw a negligible decrease in activity.

Electrolyzer in every district

The possibilities for this new catalyst are manifold. Both in the form of the fuel cell and the reverse reaction in an electrolyzer. For example, fuel cells are used in hydrogen-powered cars while some hospitals already have emergency generators with hydrogen-powered fuel cells. An electrolyzer can be used, for example, on wind farms at sea or perhaps even next to every single wind turbine. Transporting hydrogen is much cheaper than transporting electricity.

Hensen's dream goes further: "I hope that we will soon be able to install an electrolyzer in every neighborhood. This refrigerator-sized device stores all the energy from the solar panels on the roofs in the neighborhood during the daytime as hydrogen. The underground gas pipelines will transport hydrogen in future, and the domestic central heating boiler will be replaced by a fuel cell, the latter converting the stored hydrogen back into electricity. That's how we can make the most of the sun."

But for this to happen, the electrolyzer still needs to undergo considerable development. Together with other TU/e researchers and industrial partners from the Brabant region, Hensen is therefore involved in the start-up of the energy institute of TU Eindhoven. The aim is to scale up the current commercial electrolyzers to a refrigerator-size electrolyzer of about 10 megawatts.



Storing energy in hydrogen 20 times more effective using platinum-nickel catalyst | EurekAlert! Science News

Xinlong Tian, Xiao Zhao, Ya-Qiong Su, Lijuan Wang, Hongming Wang, Dai Dang, Bin Chi, Hongfang Liu, Emiel J.M. Hensen, Xiong Wen (David) Lou, Bao Yu Xia. Engineering bunched Pt-Ni alloy nanocages for efficient oxygen reduction in practical fuel cells. Science (2019). DOI: 10.1126/science.aaw7493​