Optimization of Extraction Process for Total Flavonoids from Penthorum chinense Pursh and Comparison of Their Contents from Different Parts

[Objectives]This study was conducted to optimize the extraction process of total flavonoids from Penthorum chinense Pursh and compare their contents from different parts.[Methods]Single factor and orthogonal experiments were designed to optimize the extraction process of total flavonoids from P.chinense Pursh with the volume fraction of ethanol,the ratio of material to liquid,heating reflux extraction time and extraction times as factors,and the content of total flavonoids as the index.A verification test was carried out.The optimized extraction process was adopted to compare the contents of total flavonoids from different parts of P.chinense Pursh.[Results]The best extraction process was extracting the powder of P.chinense Pursh for 2.0 h with 20 times of 55%ethanol by reflux twice.Under this condition,the contents of total flavonoids were 3.63%,8.90%,11.28%,and 4.36%from stems,leaves,flowers and whole grass of P.chinense Pursh,respectively.[Conclusions]The process is reasonable,feasible and stable,and can effectively extract total flavonoids from P.chinense Pursh.The contents of total flavonoids from different parts of P.chinense Pursh were quite different,and the value was higher in the leaves and flowers,so the proportions of leaves and flowers should be paid attention to in the industrial processing of P.chinense Pursh.

Research on Acute Toxicity of Penthorum chinense Pursh. Total Flavonoids and Therapeutic Effect on AFL Rats

[Objectives]To study the acute toxicity of total flavonoids in Penthorum chinense Pursh. and the therapeutic effect on AFL( Alcoholic Fatty Liver). [Methods] The liquid of total flavonoids in P. chinense Pursh. was intragastrically administered to the test group rats in the maximum concentration and the maximum administration volume,an equal volume of solvent was given to the control group,and it was observed continuously for 14 d; 1. 5% ferrous sulfate feed was used for feeding,the alcohol intragastric administration method was used to copy the AFL rats model,and the therapeutic effect of total flavonoids in P. chinense Pursh. on the fatty liver rats was observed. [Results]No rat died in the medication administration group and the control group,there was no acute toxicity reaction,and the maximum tolerance dose of total flavonoids in P. chinense Pursh. for the rats by intragastric administration was 33. 6 g/kg; rats suffered AFL 6 weeks after the alcohol intragastric administration. For the 800 mg/kg P. chinense Pursh. total flavonoids and 2 000 mg/kg P. chinense Pursh. extract with the same dose as that of the P. chinense Pursh. crude drug,P. chinense Pursh. total flavonoids played a more significant role than P. chinense Pursh. extract in lowering oil red O staining area in AFL rats' liver tissue and reducing the ALT,AST,TC,TG content in AFL rats' serum. [Conclusions]The P. chinense Pursh. total flavonoids had low acute toxicity,and had a greater therapeutic effect on the AFL rats than the P. chinense Pursh.extract.

Science with the 2.5-meter Wide Field Survey Telescope(WFST)

The Wide Field Survey Telescope(WFST) is a dedicated photometric surveying facility being built jointly by University of Science and Technology of China(USTC) and the Purple Mountain Observatory(PMO). It is equipped with a 2.5-meter diameter primary mirror, an active optics system, and a mosaic CCD camera with 0.73 gigapixels on the primary focal plane for highquality image capture over a 6.5-square-degree field of view. The installation of WFST near the summit of Saishiteng mountain in the Lenghu region is scheduled in summer of 2023, and the operation is planned to start three months later. WFST will scan the northern sky in four optical bands(u, g, r and i) at cadences from hourly/daily in the deep high-cadence survey(DHS) program, to semi-weekly in the wide field survey(WFS) program. During a photometric night, a nominal 30 s exposure in the WFS program will reach a depth of 22.27, 23.32, 22.84, and 22.31(AB magnitudes) in these four bands, respectively, allowing for the detection of a tremendous amount of transients in the low-z universe and a systematic investigation of the variability of Galactic and extragalactic objects. In the DHS program, intranight 90 s exposures as deep as 23(u) and 24 mag(g), in combination with target of opportunity follow-ups, will provide a unique opportunity to explore energetic transients in demand for high sensitivities, including the electromagnetic counterparts of gravitational wave events, supernovae within a few hours of their explosions,tidal disruption events and fast, luminous optical transients even beyond redshift of unity. In addition, the final 6-year co-added images, anticipated to reach g■25.8 mag in WFS or 1.5 mags deeper in DHS, will be of fundamental importance to general Galactic and extragalactic science. The highly uniform legacy surveys of WFST will serve as an indispensable complement to those of the Vera C. Rubin Observatory's Legacy Survey of Space and Time(LSST) that monitors the southern sky.

事件视界望远镜对近邻星系M87中心超大质量黑洞的成像观测

2019年4月10日21时,天文学家公布了人类首次拍摄到的近邻椭圆星系M87中心黑洞在1.3mm波段的成像观测结果,看到黑洞视界的阴影,直接证明了黑洞的存在.黑洞是广义相对论关于时空和引力理论的伟大理论预言.直接证明黑洞的存在,不仅可以检验广义相对论的正确性,而且可以研究黑洞强引力场中的物理过程,解释相应的天文现象.

Accretion in strong field gravity with eXTP

In this paper we describe the potential of the enhanced X-ray Timing and Polarimetry(eXTP) mission for studies related to accretion flows in the strong field gravity regime around both stellar-mass and supermassive black-holes. eXTP has the unique capability of using advanced "spectral-timing-polarimetry" techniques to analyze the rapid variations with three orthogonal diagnostics of the flow and its geometry, yielding unprecedented insight into the inner accreting regions, the effects of strong field gravity on the material within them and the powerful outflows which are driven by the accretion process.