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Physics

The latest LHAASO experiment verifies the correctness of space-time symmetry in Einstein's theory of relativity.

But there are very high-energy processes in celestial activity. When the high-altitude large cosmic ray experiment LHAASO in Daocheng, Sichuan Province was not fully completed in 2021, it detected the gamma ray photons with the highest energy known to mankind, with an energy of 1.4 × 10 GeV. The LHAASO team used its observed high-energy gamma-ray cases to test the Lorentz symmetry. The experimental results increase the breaking energy scale of Lorentz symmetry by about 10 times, which is the strictest test of this kind of Lorentz symmetry, and once again verifies the correctness of Einstein's relativistic space-time symmetry. The relevant results are published in the latest issue of physical Review KuaiBao. (Institute of High Energy, Chinese Academy of Sciences)

Astronomy

A new planet was found around Proxima.

Astronomers had previously discovered that Proxima had two planets on the European Southern Observatory (ESO) telescope: a planet about the mass of Earth called Proxima b, which orbits the star every 11 days, and Proxima c, which orbits the star in a longer five-year orbit. Recently, a study published in the journal Astronomy and Astrophysics reported another candidate planet orbiting Proxima every five days.

New technology

Mechanical-biological hybrid fish driven by human cardiomyocytes

Scientists mimic the shape and swimming pattern of zebrafish and combine materials such as myocardial tissue, cardboard and gelatin to make a hybrid fish with a layer of myocardial tissue differentiated from human stem cells on each side of its caudal fin. When one side of the muscle contracts, the other side is elongated and the mechanically sensitive channel is activated, thus causing the elongated side to contract, thus forming a feedback loop. The scientists also designed automatic pacing nodes that can control the contraction frequency and rhythm, so that the caudal fin can swing spontaneously, continuously and harmoniously. Through such a system, the mixed fish in the experiment can swim continuously for more than 100 days, and its swimming speed and efficiency are similar to those of zebrafish in nature. The researchers say this result is still a far cry from a fully functioning artificial heart, and in the future they plan to use human heart cells to build more complex biological hybrid devices.

Astronomy

The moment when planetary debris hit the surface of a white dwarf star was observed for the first time

When planetary debris hits the surface of a white dwarf, it produces plasmas at temperatures as high as 100000 to 1 million Kelvin, which emit X-rays as they cool. With the ultra-high angular resolution of the Chandra X-ray Observatory, astronomers identified X-rays from a single white dwarf star for the first time, and observed this phenomenon on the white dwarf star G29-39. The direct detection results are consistent with the results inferred indirectly by the previous white dwarf atmospheric model.

Botany

The second National Survey of key protected Wild Plant Resources completed

The results of the survey as of December 31, 2018 showed that among the 54 species of very small wild plants comparable to the first survey (1997-2003), 36 species of wild plants in the field increased steadily, accounting for 67%. However, the number of field populations of 98 surveyed species is lower than the stable survival limit, 115 investigated species have a community area of less than 1 square kilometer, and 108 investigated species face habitat degradation and fragmentation caused by human disturbance. there are 69 surveyed species whose field populations are not included in in-situ protection or less than 10%, and there is a protection gap. This investigation provides an important scientific basis for revising the list of National key protected Wild plants and carrying out wild plant protection work in the future.

Medical science

AI looks at "face" to assist in the diagnosis of rare diseases

Many rare genetic diseases can lead to some changes in facial morphology, and if these facial changes are recognized and associated with specific diseases, it may promote the early diagnosis of rare diseases. Recently, researchers at the University of Bonn and other institutions in Germany have developed an AI system called "GestaltMatcher", which can effectively identify rare diseases by patients' facial morphological features.

The researchers constructed facial phenotypic data sets using photos of 17,560 patients with a total of 1115 rare diseases. Using the deep convolution neural network algorithm, the AI system can calculate the similarity between facial features of different people and match patients with the same genetic disease, and the system can identify and classify patients even if they have not been clinically diagnosed or even have genetic diseases that are not included in the training data set. In addition, the training data set required by the system is smaller than that of existing similar systems, which means that the system can be used to assist in the diagnosis of extremely rare diseases where it is difficult to find enough patients. This system can not only provide auxiliary advice on disease assessment, but also help identify new symptoms. The results have been published in Nature Genetics.