July 3, 2020 Science Journal.

!--webeditor:page title"--July 11, 2020 // --- This week with the release of a new journal of Science (June 26, 2020), what are the great studies? Let the little ones come togetherPhoto from the Journal of Science1.Science: Revealing the number of HIV-1 protytherial variants is determined by the infection stage of the infected partner: 10.1126/science.aba5443 During sexual transmission, the high genetic diversity of HIV-1 in the individual is often reduced to a starting variant (founder variant) that can trigger infectionUnderstanding the drivers of this bottleneck can help you develop effective infection control strategiesDuring this bottleneck period, little is known about the importance of the source partnerIn a new study, researchers from the London School of Hygiene and Tropical Medicine, Oxford University, the University of Edinburgh, the Zurich Institute of Technology in Switzerland and the Yale School of Public Health in the Us, put forward a hypothesis that the infectious partner affects the number of HIV-1 starter variantsTo test this hypothesis, they established a system dynamics model and calibrated it using genetic and epidemiological data from all known transmission directions and sexual partners at the stage of infection at the partner of the source of infectionThe findings were published in the July 3, 2020 issue of The Journal of Science under the title "Number of HIV-1 wvariants is sid by the recency of the source partner"Using epidemiological and genetic data from 112 pairs of sexual partners, the researchers found that individuals in the acute (early) infection phase were more likely to transmit multiple starting HIV-1 variants than individuals at the stage of chronic (late) infectionThe study provides the first direct test of the characteristics of the infected partner to explain the low frequency of multiple starting HIV-1 variants of infection2Science: Discover a reliable CRISPR/Cas13a system inhibitor doi: 10.1126/science.abb6151; doi:10.1126/science.abc8243 In the VI CRISPR-Cas antiviral response, the CRISPR RNA (crRNA)-guided Cas13 nuclease indiscriminately destroys the RNA of bacterial cells and their invaders, while preventing the growth of infected hosts and the spread of the virus, thereby protecting the bacterial population from viral infectionsThis reaction is mediated by Cas13 nuclease, which performs a large amount of RNA degradation after identifying viral transcripts that complement its wizard RNA (gRNA)However, it is not clear how the virus fights the bacteria's immune systemIn a new study, researchers from Rockefeller University, Memorial Sloan Kettering Cancer Center and Cornell University in the United States found that AcrVIA1 binds to Cas13a as an inhibitor encoded by phage, blocking gRNA and preventing the activation of the nucleaseThis suggests that AcrVIA1 can potentially act as a control switch for Cas13a nucleases202073Science,"A phage-encoded anti-CRISPR enables complete evasion of type VI-A CRISPR-Cas immunity"。 They found that AcrVIA1, a coded anti-CRISPR protein, was encoded by listeria phage (LS46) and was able to inactivate listeria's VI-A CRISPR system Using genetics, biochemistry, and structural biology, they found that AcrVIA1 interacts with the wizard exposure surface of Cas13a nuclease, preventing the entry of target RNA and the structural changes required for the activation of this nuclease 3.Science: Significant progress! First discovery of histone H3-H4 tetrapolymer is a copper reductase doi: 10.1126/science.aba8740; Doi: 10.1126/science.abc8242 In a new study, researchers from the University of California, Los Angeles, found that histone H3-H4 tetrapolymer is a copper reductase The findings were published in the July 3, 2020 issue of The histone H3-H4 tetramer is a copper reductase enzyme In this paper, they describe two experiments they conducted that showed that the histone H3-H4 quadruple was involved in the reduction of copper inside the cell Johannes Rudolph and Karolin Luger of the University of Colorado At Boulder published a view-type article in the journal Science at the same time, outlining research involving histones and presenting the research done by the researchers Histones are proteins that exist inside eukaryotic cells Previous studies have shown that their main function is to arrange THE STRUCTURE of DNA into nucleosomes Their function is to act as a spool of DNA spiral wounding so that it can adapt to the nucleus of the cell In the new study, the researchers found that histones have another function: reducing copper ions from toxic forms to a form that can be safely present in cells In their study, the researchers noted that decades ago, other scientists had discovered that pairs of histine and cysteine amino acids may bind to metal ions where two histones meet inside cells This suggests that histones may have played a role in making the body safe to use copper To test the idea, they set up and conducted two experiments involving yeast cells The first experiment involved mutations in the amino acid sequence of histones in the region they proposed in previous studies They found that cells with mutant histones had lower levels of Cu (I) ions, which are a safe form of copper They believe this is evidence that histones play a role in this reduction process In a second experiment, they tested histone H3-H4 tetrapolymers in a test tube and found that they could indeed restore Cu (II) to Cu (I) !--/ewebeditor:!--webeditor: !--." -- 4.Science Full-text Compilation: The World's First! The Chinese team released the results of the new Crown Vaccine Animal Experiment doi: 10.1126/science.abc1932 In order to build a pre-in vitro and challenge model for the development of SARS-CoV-2 candidate vaccine, in a new study, from the Institute of Medical Experimental Animals of the Chinese Academy of Medical Sciences, the Zhejiang Center for Disease Control and Prevention, Kexing Holding Biotechnology Co., Ltd., the Institute of Biophysics of the Chinese Academy of Sciences, Researchers from research institutes such as the China Food and Drug Administration Institute and the Center for Disease Control and Prevention's Institute for Infectious Disease Prevention and Control isolated THE SARS-CoV-2 strain from 11 hospitalized patients , including 5 in-patients --- , including five from Italy , one from Switzerland , one from the United Kingdom and one from a Spanish --- These patients contracted SARS-CoV-2 during the recent outbreak The 11 samples contained SARS-CoV-2 strains that were widely distributed on the development tree of the system built using all available sequences, representing, to some extent, the transmitted SARS-CoV-2 strain The findings were published online May 6, 2020 in the journal Science, under the title "Rapid development of the project of an in-in-candidatefor SARS-CoV-2" The current high prevalence of COVID19 and the dramatic increase in global deaths have made it urgent to develop a SARS-CoV-2 vaccine Safety and efficacy are critical in the development of vaccines in both stages of preclinical research and clinical trials While it is too early to determine the best animal model for SARS-CoV-2 infection, rhesus monkeys with COVID-19-like symptoms after SARS-CoV-2 infection appear to be promising animal models for studying the disease In this new study, the researchers provided evidence for the safety of the PiCoVacc vaccine in rhesus monkeys, and no increased infection or immune pathology was observed in the study The data also demonstrate that the PiCoVacc vaccine, which is 6?g per dose in rhesus monkeys, has a complete protective effect on the subsequent SARS-CoV-2 challenge In summary, these findings provide a way for the clinical development of the SARS-CoV-2 vaccine Phase i, II and III clinical trials of the PiCoVacc vaccine and other SARS-CoV-2 candidate sass are expected to begin later this year 5.Science: Blood tests help detect cancer before symptoms appear: 10.1126/science.abb9601 In a new study, researchers from research institutes such as Johns Hopkins University School of Medicine in the United States found for the first time that blood tests help detect multiple cancers in thousands of people without a history or symptoms The blood test is still experimental Even its supporters say it needs improvements, and the results are not ideal However, they show what benefits and disadvantages these gene-based tests (called liquid biopsies) can bring in conventional care--- in which case PET scans are used to identify or exclude suspicious tumors The findings were published online April 28, 2020 in the journal Science, with the headline "Expertility of the Blood Testing with PET-CT to screen for cancer and guide intervention" "We think it's feasible," said Nickolas Papadopoulos, co-author of the paper and a researcher at Johns Hopkins University who helped develop the test method In the new study, he said, using it with standard screening methods would "double the number of cancers found." But the test missed far more cancer cases than was found, and alerted them to errors, leading to unnecessary follow-up procedures It is only studied among women aged 65 to 75, and also needs to be studied in men, other age groups and more diverse populations 6.Science: New Discovery! SARS-CoV-2 may infect and reproduce host intestinal cells! doi:10.1126/science.abc1669 In a recent study published in the international journal Science, scientists from the Hublert Institute and others found that the new coronavirus SARS-CoV-2 may infect intestinal cells and replicate in intestinal cells In the article, researchers used advanced human intestinal culture models to successfully reproduce the SARS-CoV-2 virus in vitro, while monitoring the cell's response to the virus, which may provide a new cell culture model for the study of COVID-19, which may explain the findings that about one-third of COVID-19 patients experience gastrointestinal symptoms such as diarrhea, and that researchers can detect viruses in fecal samples Although there are big differences between the respiratory tract and gastrointestinal organs, there are some key similarities, one of the most interesting ones being the presence of the ACE2 receptor, which is key to the virus's entry into the host cell, and the intestinal tract is full of ACE2 receptors, but until now, researchers have not been clear whether enterocells are actually infected and produce viral particles In the study, the researchers asked whether SARS-CoV-2 could directly infect cells in the gut, and if so, it could replicate in intestinal cells, and then study them using human intestinal organs, tiny versions of the human gut that can grow in the lab, which contain human intestinal wall cells, making them one of the most competitive models for investigating SARS-CoV-2 infections !--/ewebeditor--!--webeditor: !--webeditor: page title" -- When researchers add viruses to organ-like organs, SARS-CoV-2 can quickly infect organ-like organs, and viruses enter subgroup cells of intestinal organs, and continue over time The number of infected cells will also increase, using a technique called electron microscopy,which allows observation and imaging of different components in cells, and the researchers found that viral particles exist inside and outside organ cells, and that researchers remotely studied and analyzed virtual slices of infected organ at home because of the outbreak blockade The researchers then used RNA sequencing to investigate the response of intestinal cells to viruses, and the results showed that so-called interferon-stimulating genes were activated, known to fight viral infections, and in later studies the researchers focused on analyzing these genes, which they hope will develop with the results of the study In addition, the researchers cultured organ-like organs in different conditions that caused ACE2 receptors in cells to be at higher and lower levels, and to their surprise, they found that at higher and lower levels of ACE2, viruses can infect intestinal cells, and the results may help develop new ways to block the virus from entering host cells 7.Science: Heat bottlenecks in the life cycle determine the climate vulnerability of fish: 10.1126/science.aaz3658; Doi:10.1126/science.abd1272 More and more studies have revealed how organisms adapt or adapt to changing climates Learn about the life of a species.