Believe in science

Medical science

Nine days after the pig heart transplant, a 57-year-old American man can walk on the ground.

On January 7, a team from the University of Maryland School of Medicine said it had performed the world's first pig heart transplant on a 57-year-old man with terminal heart disease. According to China Business report, Professor Wu Zhongjun, director of the artificial organs Laboratory at the University of Maryland, revealed on January 15 that the patient had left ECMO (extracorporeal membrane oxygenation, which can provide long-term cardiopulmonary support) two days ago, and began to walk on the ground one day ago. A team of doctors at the University of Maryland said it would monitor patients' immune response and heart function and would continue to conduct controlled clinical trials.

The patient was unable to receive a mechanical heart pump and a human heart transplant because of a severe arrhythmia and a previous history of poor treatment that did not follow the doctor's advice. Considering that the patient was about to die, after obtaining FDA's permission for "compassionate use", doctors gave him a pig heart transplant provided by Revivicor. The transplant lasted eight hours, when the operation went smoothly and the heart was in good condition. Scientists at Revivicor removed four genes from the donor pig genome and added six human genes to avoid overgrowth of organs and attacks by the human immune system on the heart. The company plans to launch a new clinical pig facility by the end of 2023 to help patients in need of organ transplants through more clinical trials.

Geoscience

Why Tonga volcano eruption can trigger transoceanic tsunami

On January 15, an undersea volcano on the island of Hongha Apai in the South Pacific island of Tonga erupted violently. The eruption triggered a transoceanic tsunami, affecting the entire Pacific coast, according to the latest monitoring results from the Tsunami warning Center of China's Ministry of Natural Resources. Obvious tsunami waves were detected in countries such as Chile, Japan and New Zealand along the Pacific coast, with a maximum amplitude of 1.5 meters. As of 11:30 on January 16, the largest tsunami wave amplitude at Shipu Station in Zhejiang Province, China was about 20 cm.

Physics

Measurement of Spatio-temporal curvature by time expansion effect

The researchers say that, as Einstein's theory of relativity suggests, time slows down near massive objects. Because the higher atoms in the device are closer to the gravitational field of the tungsten wire, there is a time gap between them and the rest of the atoms. This corresponds to the atomic phase shift and shows the phase shift caused by time expansion. In addition, the experimental results show that the Aharonov-Bohm effect is also applicable to gravity, and the cylindrical container can affect the particles that do not enter the container. In the experiment, the electrons moving up and down in the atomic fountain are forced to be in a superposition state, and the magnetic field changes accordingly.

After being infected with novel coronavirus, some patients developed COVID-19 's long-term symptoms (Long COVID,LC) that lasted for more than 12 weeks, including severe recurrent fatigue, dyspnea, chest tightness, cough, brain fog (it is difficult for the brain to form clear thinking and memory) and headache. In a recent study published in Nature Immunology, Australian researchers analyzed the effects of LC on the immune system in the laboratory, providing the strongest biological evidence yet for COVID-19 's sequelae.

The researchers analyzed blood samples from 62 patients diagnosed with COVID-19 between April and July 2020, looking for immune biomarkers. The researchers found that the immune system of the subjects with LC was still active eight months after being infected with novel coronavirus, indicating persistent inflammation. In their bodies, there are persistently high levels of interferon I and III, which should no longer appear after the infection has been eliminated. And this continuous change in the immune system may occur in both mild and severe patients. Researchers have discovered where these biomarkers may be produced, laying a foundation for the diagnosis and treatment of COVID-19 's sequelae in the future.

Ecology.

The sixth mass extinction is under way.

There have been five large-scale extinction events in the history of life on earth, all due to the extreme natural environment. Many scholars believe that human activities are causing the sixth mass extinction. Recently, an article published in the Biology Review comprehensively assessed the evidence of this extinction event.

Some past studies have suggested that the current extinction rate has not yet reached the level of mass extinction events. However, the article points out that this is because these studies focus only on mammals and birds, ignoring invertebrates, the most important component of biodiversity. Using changes in the number of terrestrial molluscs such as snails and slugs, the researchers estimate that about 7.5% or 13% of the 2 million known species on Earth (that is, 150000 to 260000 creatures) have disappeared since 1500. At the same time, species on islands such as the Hawaiian Islands are under greater threat than those living on the mainland. Human beings are the only species that can consciously affect the biodiversity of the earth, and human beings need to face up to this extinction event and take more positive measures to deal with the crisis, the researchers said.

Agricultural science

The application of electric shock during crop growth may increase production.

Electrified cultivation refers to the application of electrical stimulation to growing plants, which is considered to be an effective means to increase crop production. Recently, in a study published in Natural Food, scientists significantly increased crop yields by applying electric fields to the growth of peas. The discovery may be expected to increase food supplies worldwide.