Preparation of SARS-CoV-2 Polymerase Nsp12 and Optimization of Expression Conditions

he core component of transcription and replication of SARS-CoV-2 is Nsp12, a non-structural protein that function as an RNA-dependent RNA polymerase. Nsp12 is a key drug target for the development of anti-coronavirus drugs. The purpose of this study was to explore and optimize the expression conditions of Nsp12 of SARS-CoV-2 with the aim of establishing expression conditions to obtain high-purity Nsp12 protein. This study compared the “ice-water bath cooling” and “shaking table cooling” methods and explored the differences in cooling rates and protein expression and properties using the two cooling methods. The shaking table cooling method resulted in reduced amounts of ArnA protein in the Nsp12 protein samples compared with levels from the ice-water bath cooling method. The shaking table method enabled purification of high-quality Nsp12 protein and ensured stable output of the protein. These methods will enable subsequent exploration of the SARS-CoV-2 replication mechanism, the development of specific drugs and drug screening for anti-SARS-CoV-2 pneumonitis

Identify bottom contribution in non-photonic electron spectra and \vv\ from \AuAu collisions at RHIC

We present a study on the spectra and elliptic flow v2 for heavy flavor (charm and bottom) decayed electrons provided the relative contributions of charm and bottom hadrons from the PYTHIA calculations. We made a simultaneous fit to both measured non-photonic electron spectra and v2 distributions. The results suggest that the bottom contribution is not dominant for electron pt<5 GeV/c in the 200 GeV Au+Au collisions.Comment: 4 pages, 3 figures, proceedings for Hard Probe 2006, Asilomar; to be published in Nuclear Physics, Section

Porous calcium phosphate ceramics prepared by coating polyurethane foams with calcium phosphate cements

Porous calcium phosphates have important biomedical applications such as bone defect fillers, tissue engineering scaffolds, and drug delivery systems. While a number of methods to produce the porous calcium phosphate ceramics have been reported, this study aimed to develop a new fabrication method. The new method involved the use of polyurethane foams to produce highly porous calcium phosphate cements (CPCs). By firing the porous CPCs at 1200 degrees Celsius, the polyurethane foams were burnt off and the CPCs prepared at room temperature were converted into sintered porous hydroxyapatite-based calcium phosphate ceramics. The sintered porous calcium phosphate ceramics could then be coated with a layer of the CPC at room temperature, resulting in high porosity, high pore interconnectivity, and controlled pores size