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The present study investigated the chemical constituents from the aerial parts of Glycyrrhiza uralensis. The ethanol extract of the aerial parts of G. uralensis was separated and purified by different column chromatographies such as macroporous resin, silica gel, and Sephadex LH-20, and through preparative HPLC and recrystallization. Thirteen compounds were isolated and identified as(2S)-6-[(Z)-3-hydroxymethyl-2-butenyl]-5,7,3'-trihydroxy-4'-methoxy-dihydroflavanone(1),(2S)-8-[(E)-3-hydroxymethyl-2-butenyl]-5,7,3',5'-tetrahydroxy-dihydroflavanone(2), α,α'-dihydro-5,4'-dihydroxy-3-acetoxy-2-isopentenylstilbene(3), 6-prenylquercetin(4), 6-prenylquercetin-3-methyl ether(5), formononetin(6), 3,3'-dimethylquercetin(7), chrysoeriol(8), diosmetin(9),(10E,12Z,14E)-9,16-dioxooctadec-10,12,14-trienoic acid(10), 5,7,3',4'-tetrahydroxy-6-prenyl-dihydroflavanone(11), naringenin(12), dibutylphthalate(13). Compounds 1-3 are new compounds, and compounds 10 and 13 are isolated from aerial parts of this plant for the first time.

Chemical constituents from aerial parts of Glycyrrhiza uralensis were analyzed and identified using ultra-high performance liquid chromatography coupled with hybrid quadrupole-orbitrap mass spectrometry(UPLC-Q-Exactive Orbitrap-MS). The chromatographic column of Waters Acquity UPLC BEH-C_(18)(2.1 mm×100 mm, 1.7 μm) was adopted, with acetonitrile-water(0.5% formic acid) as mobile phase at a flow rate of 0.2 mL·min~(-1). Data was collected in positive and negative modes of electrospray ionization(ESI). A total of 55 compounds, including 42 flavonoids, 9 stilbenes, 2 coumarins, 1 lignin and 1 phenolic acid, which were characterized in the aerial parts of G. uralensis based on accurate molecular mass information of molecular and product ions provided by UPLC-Q-Exactive Orbitrap-MS based on comparison with standard substances and references. It is an effective and accurate method to provide chemical information of constituents in aerial parts of G. uralensis, and can provide a reference for further study on pharmacodynamic material basis and resources development and utilization.

To analyze the development of coronavirus disease 2019(COVID-19), this study systematically retrieved relevant Chinese and English literatures from both CNKI and Web of Science database platforms by bibliometric research method and CiteSpace 5.5.R2 software to obtain information and visualize relevant literatures. A total of 695 Chinese and 446 English literatures were included in this paper. Statistics showed that China had published most of the literatures and established close cooperation with the United States and the United Kingdom. Through the analysis, Tongji Medical College of Huazhong University of Science and Technology and its affiliated hospitals published the largest number of the publications. Moreover, the highly productive journals including Journal of Traditional Chinese Medicine and The Lancet covered eight major fields, such as medicine, medical virology, radiation medicine, infectious disease, and traditional Chinese medicine. Besides, a total of 35 special COVID-19 funds were recently established to subsidize these studies. The key words and themes analysis indicated that protein structure of COVID-19, receptor targets and mechanisms of action, integration of traditional Chinese and Western medicine, screening and development of antiviral drugs from traditional Chinese medicine and Western medicine, vaccine research as well as epidemiological characteristics and prediction are current study hotspots. This study provides a reference for researchers to rapidly master main study directions of COVID-19 and screen out relevant literatures.

The clinical throat swab specimen of an imported suspected case of influenza A (H1N1) was detec ted with real-time PCR, RT-PCR and subsequently confirmed by gene sequencing. The presence of influ enza A (H1N1) virus confirmed the first case with A (H1N1) infection in Mainland China.

The interaction of cupric ions with supercoiled DNA was investigated by agarose gel electrophoresis. Experimental results indicate that cupric ions could convert DNA structure from supercoiled to relaxed forms outside the cells in distilled water medium. At the levels of 10(-3) mol/L and 10(-4) mol/L copper, supercoiled DNA was totally converted into other forms of DNA after 24 hours. At a lower cupric level of 10(-6) mol/L, 52% supercoiled DNA was converted to other forms after 24 h and the relaxed form increased by 17% at 48h. Supercoiled form of DNA relaxed and gradually disappeared with the increase of incubation period of copper ions with the plasmid DNA. Supercoiled DNA degraded into other forms more rapidly at higher copper concentration. The percentages of different forms of DNA were related to copper concentration and incubation time. These results suggested that changes in supercoiled DNA structure may provide a rapid and sensitive method to assess the harmfulness of copper in aquatic environment.

Aim: To construct human phage antibody library against SARS virus., Methods: Human Fab genes were amplified by RT-PCR from lymphocytes of a convalescent SARS patient and cloned into vector pComb3 to construct phage antibody library. Antibodies against SARS virus were screened by biopanning with immobilized virus antigen. The binding specificity of phage antibody to SARS virus was detected by ELISA., Results: 13 Ig genes were obtained by PCR. A human phage antibody library consisting of 1.3 x 10(6) clones was constructed by electrotransformation and 60 percent of the clones contained Fab genes. After three rounds of panning with SARS virus antigen, phage antibodies against SARS virus were specifically enriched. ELISA detection verified 10 positive phage antibodies that were highly specific for SARS virus., Conclusion: Human phage antibody library against SARS virus has been constructed successfully, from which 10 anti-SARS virus antibodies were obtained.