China's Ministry of Science and Technology unveiled the country's top 10 scientific advances of 2020 on Saturday.
1. Chinese scientists make remarkable progress in tackling COVID-19
Chinese scientists teamed up to make a quick response to COVID-19 from the outset, making progress on various fronts while offering strong support to the nation to overcome the pandemic.
In January 2020, China's Center for Disease Control succeeded in isolating the first novel coronavirus strain and shared with the WHO information on the genomic sequence of the virus. They have revealed how the novel coronavirus infects human cells and continued probing how it is transmitted.
Combining Western methods and traditional Chinese medicine, eight editions of guidelines on diagnosis and treatment for pneumonia caused by the novel coronavirus were published successively. More prevention and control measures were proposed such as setting up makeshift hospitals, conducting mass nucleic acid tests and using big data in tracing virus carriers.
Vaccines against the virus, including the inactivated vaccines, adenovirus vector vaccines, protein subunit vaccines and RNA vaccines are in the development with their efforts.
2. Chang'e 5 probe's retrieval of lunar samples
The Chang'e 5 mission, China's most complicated space project, has achieved the Chinese space industry's first extraterrestrial sampling and return. It has achieved many major breakthroughs including China's first lunar surface sampling and sealing, first liftoff from the moon, first rendezvous and docking in lunar orbit, and first spacecraft carrying samples to re-enter the Earth's atmosphere.
The success of the Chang'e 5 mission marks a conclusion of China's three-step lunar exploration project, which includes orbiting, landing and return. It represents a great step forward for China's space industry and will contribute to deepening our understanding of how the moon formed and the evolution of solar system.
3. Deep-sea manned submersible Fendouzhe's diving record
China's new deep-sea manned submersible Fendouzhe (Striver) set off on Oct 10, 2020, for the 10,000-meter deep-sea diving operation in the Mariana Trench. During the expedition, it completed 13 dives, eight of which exceeded a depth of 10,000 meters.
It set a national record by diving to a depth of 10,909 meters in the Mariana Trench at 8:12 am on Nov 10, 2020.
Fendouzhe is the world's deepest-diving manned submersible, capable of carrying up to three passengers to conduct scientific research in the deep sea. With multiple breakthroughs in various key technologies, the Fendouzhe represents a milestone in the country's endeavor into deep-sea exploration.
4. Research on transmission of human genetic materials
The research published in Nature, led by Dr Li Guohong and Dr Zhu Mingzhao from the Institute of Biophysics of the Chinese Academy of Sciences, has demonstrated that the histone variant H2A.Z facilitates the licensing and activation of early DNA replication origins.
This study describes a novel epigenetic regulation mechanism for DNA replication origin selection and offers a new way of understanding DNA replication regulation in eukaryotes. Importantly, this regulatory pathway can potentially serve as a target for cancer treatment and regulation of T cell function during immunotherapy.
5. Transparent ferroelectric single crystals with ultrahigh piezoelectricity
Transparent piezoelectrics are highly desirable for numerous hybrid ultrasound–optical devices ranging from photoacoustic imaging transducers to transparent actuators for haptic applications.
However, it is challenging to achieve high piezoelectricity and perfect transparency simultaneously because most high-performance piezoelectrics are ferroelectrics that contain high-density light-scattering domain walls.
The research team from Xi'an Jiaotong University led by professor Xu Zhuo demonstrated a method to enhance the performance of single crystal PMN-PT.
The research, published in the journal Nature, presents a paradigm for achieving high transparency and piezoelectricity by ferroelectric domain engineering, and the transparent ferroelectric crystals are expected to provide a route to a wide range of hybrid device applications, such as medical imaging, self-energy-harvesting touch screens and invisible robotic devices.
6. Measuring the new height of Mount Qomolangma
The new height of the world's tallest mountain, Mount Qomolangma, also known as Mount Everest in the West, was measured as standing 8,848.86 meters above sea level by Chinese surveyors in May 2020.
The number is of the highest precision ever in the mountain's height measurement history.
The mission, headed by the Ministry of Natural Resources, was conducted by the first Geodetic Surveying Brigade and members of the China Mountaineering Team. It took nearly a month to complete the work.
According to the ministry, innovations in techniques and equipment included the use of the Beidou 3 Navigation Satellite System, Chinese-made surveying equipment, a gravimeter carried by plane and 3D interactive virtual reality.
During the process, the Chinese scientists' team completed the first high-precision airborne gravity survey for Mount Qomolangma and its surrounding region and it filled the gap in relevant data.
7. Ancient DNA reveals evolution and migration history of Chinese populations
Ancient DNA research on East Asians, particularly on the prehistoric people in China, is scarce in the field worldwide. Researchers from the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences reported in the journal Science that they retrieved ancient DNA from 25 ancient human remains dating back 9,500 to 4,200 years and one dating back 300 years from sites across China.
It is the first systematic ancient DNA research on China's northern ancestry and southern ancestry in the prehistoric period on large scale and with the longest time span.
Reportedly, a northern ancestry existed along the Yellow River and up into the eastern steppes of Siberia in early Neolithic East Asia from 9,500 years ago, while a southern ancestry existed along the coast of the southern Chinese mainland and islands in the Taiwan Straits from 8,400 years ago.
But the evolution of the northern ancestry and the southern ancestry is basically continuous and has not been influenced by other immigrants. The mixing largely occurred regionally between northern and southern populations in East Asia.
It also provides evidence that Austronesian speakers today originated from a population derived from southern China at least 8,400 years ago.
Austronesian refers to a family of languages spoken in the area extending from Madagascar eastward through the Malay Peninsula and Archipelago to Hawaii and Easter Island and including almost all the native languages of the Pacific islands.
8. Recreating history of over 300 million years of biodiversity changes on Earth
The origin and evolution of life is one of the world's greatest scientific puzzles. More than 99 percent of the organisms that once lived on Earth have become extinct, making recreating the history of the Earth's biodiversity through fossil records an important way to understand the current development of the Earth's biodiversity inhabited by humans today.
Fan Junxuan and Shen Shuzhong, a professor and an academician, respectively, at Nanjing University in East China's Jiangsu province, built their own database, developed artificial intelligence algorithms and used the Tianhe II supercomputer to make the breakthrough, producing the world's first high-precision curve demonstrating the change of marine biodiversity over the 300 million years of the Paleozoic Era, with a resolution 400 times higher than similar international studies.
The curve accurately portrays several major extinctions and their effects on environmental changes. The results were published in Science on Jan 17, 2020.
9. Biomarkers and potential intervention targets for organ aging in mammals
Ovarian aging may influence women's reproductive health and lead to other possible diseases such as cardiovascular diseases. However, it is difficult to accurately reveal the molecular mechanisms of human ovarian aging, which restricts the development of intervention methods for ovarian aging and related diseases.
Researchers from the Institute of Zoology under the Chinese Academy of Sciences, Peking University, Salk Institute for Biological Studies as well as other institutions used single-cell transcriptome sequencing technology and drew a comprehensive aging roadmap of cynomolgus monkey ovaries at the single-cell resolution.
Through the bioinformatic analyses of the single-cell transcriptomic data of ovarian tissues from monkeys and the experimental validation in human ovarian cells, they identified the disturbance of antioxidant signaling as a main feature of primate ovarian aging.
The research also revealed several genes that could be used as aging biomarkers.
According to Liu Guanghui, one of the researchers, the research provides therapeutic targets for ovarian aging and new biological markers for early warnings of female infertility.
It lays a theoretical foundation for formulating intervention strategies to delay ovarian aging and related diseases, Liu said.
The research was published in the journal Cell.
10. Quantum interference in chemical reactions
Quantum interference, or QI, effects play a fundamental role in the dynamics of chemical reactions, but is usually difficult to observe directly.
The scientists from the Dalian Institute of Chemical Physics under the Chinese Academy of Sciences detected unusual QI oscillations in the differential cross section measured in the recoil scattering direction of the prototypical elementary reaction H + HD → H2 + D.
Topological analysis showed that this pattern originates from the QI between a direct abstraction and previously unknown rebounding insertion pathways, which are affected by the geometric phase at energies far below the conical intersection. The QI observed between these two distinctive pathways in the three-atom system is a clear example of the quantum nature of chemical reactivity.
The research was published in the journal Science.