Good adaptability of freshmen in medical universities under the Coronavirus 2019 pandemic: a questionnaire-based single center study in China.

Objective: To investigate the adaptability of freshmen in medical universities to the Coronavirus Disease 2019 (COVID-19) pandemic and to understand the relevant factors affecting their adaptation in medical university.

Methods: Freshmen in a medical university in Guangdong Province were selected and surveyed using a self-administered general questionnaire and a college student adjustment scale prepared by Fang Xiaoyi et al. The results were analyzed statistically.

[Purification of Taq DNA polymerase expressed in Escherichia coli].

Taq DNA polymerase is one of the most commonly thermostable DNA polymerases in molecular biological researches, which shares its basic characters with others of the family, thereby its purifying strategy could be used not only in itself production but also in the extraction of the others as a reference. At present, the protocols reported for large scale preparation of Taq DNA are high cost, so a cheaper method was described here. In this protocol, by heat denaturation, ammonium sulfate precipitation and cation exchange chromatography of 724 resin, about 18 g powder of Na form resin could recover about 27.