Objective:To explore the online learning status of medical undergraduates in Guangzhou during the epidemic of COVID-19, so as to provide basis for improving online medical education in colleges and universities.Methods:From March 27, 2020 to April 10, 2020, a self-compiled questionnaire was used to investigate the online learning status of medical students in a medical college in Guangzhou by using snowball sampling and convenience sampling. SPSS 25.0 was used for data analysis, and frequency and percentage (%) were used to describe the enumeration data.Results:According to the survey, 63.8% of students studied for average 3-6 hours each day. Among the online learning platforms, the usage rate of MOOC was the highest (1 230, 92.9%), and 56.0% of medical students' self-assessment of online learning results are ordinary. The main factors affecting learning effect are visual fatigue (1 051, 79.4%), lack of learning atmosphere and inability to concentrate at home (960, 72.5%), and inconvenient operation due to different platforms for certain different courses (940, 71.0%). There are 32.2% of medical students who dislike the comprehensive online teaching mode. Due to the limitations of online experimental teaching, 61.0% of medical students indicated that the learning effect of experimental classes was affected.Conclusion:Comprehensive online teaching has certain limitations. Corresponding measures should be taken from the following four aspects of college teachers, teaching platforms, students themselves, and college management departments to help the development of online medical teaching.

Objective To investigate whether sodium butyrate(NaB)and sorafenib synergistically induces ferroptosis to suppress proliferation of hepatocellular carcinoma cells and the possible underlying mechanisms.Methods CCK8 assay and colony formation assay were used to assess the effects of NaB and sorafenib,alone or in combination,on proliferation of HepG2 cells,and ferroptosis of the treated cells was detected with GSH assay and C11-BODIPY 581/591 fluorescent probe.TCGA database was used to analyze differential YAP gene expression between liver cancer and normal tissues.The effects of NaB and sorafenib on YAP and p-YAP expressions in HepG2 cells were invesitigated using Western blotting.Results NaB(2 mmol/L)significantly reduced the IC50 of sorafenib in HepG2 cells,and combination index analysis confirmed the synergy between sorafenib and NaB.The ferroptosis inhibitor Fer-1 and the YAP activator(XMU)obviously reversed the growth-inhibitory effects of the combined treatment with NaB and sorafenib in HepG2 cells.The combined treatment with NaB and sorafenib,as compared with the two agents used alone,significantly inhibited colony formation of HepG2 cells,further enhanced cellular shrinkage and dispersion,and decreased intracellular GSH and lipid ROS levels,and these effects were reversed by Fer-1 and XMU.TCGA analysis revealed a higher YAP mRNA expression in liver cancer tissues than in normal liver tissues.NaB combined with sorafenib produced significantly stronger effects than the individual agents for downregulating YAP protein expression and upregulating YAP phosphorylation level in HepG2 cells.Conclusion NaB combined with sorafenib synergistically inhibit hepatocellular carcinoma cell proliferation possibly by inducing ferroptosis via inhibiting YAP expression.

Objective To investigate whether sodium butyrate(NaB)and sorafenib synergistically induces ferroptosis to suppress proliferation of hepatocellular carcinoma cells and the possible underlying mechanisms.Methods CCK8 assay and colony formation assay were used to assess the effects of NaB and sorafenib,alone or in combination,on proliferation of HepG2 cells,and ferroptosis of the treated cells was detected with GSH assay and C11-BODIPY 581/591 fluorescent probe.TCGA database was used to analyze differential YAP gene expression between liver cancer and normal tissues.The effects of NaB and sorafenib on YAP and p-YAP expressions in HepG2 cells were invesitigated using Western blotting.Results NaB(2 mmol/L)significantly reduced the IC50 of sorafenib in HepG2 cells,and combination index analysis confirmed the synergy between sorafenib and NaB.The ferroptosis inhibitor Fer-1 and the YAP activator(XMU)obviously reversed the growth-inhibitory effects of the combined treatment with NaB and sorafenib in HepG2 cells.The combined treatment with NaB and sorafenib,as compared with the two agents used alone,significantly inhibited colony formation of HepG2 cells,further enhanced cellular shrinkage and dispersion,and decreased intracellular GSH and lipid ROS levels,and these effects were reversed by Fer-1 and XMU.TCGA analysis revealed a higher YAP mRNA expression in liver cancer tissues than in normal liver tissues.NaB combined with sorafenib produced significantly stronger effects than the individual agents for downregulating YAP protein expression and upregulating YAP phosphorylation level in HepG2 cells.Conclusion NaB combined with sorafenib synergistically inhibit hepatocellular carcinoma cell proliferation possibly by inducing ferroptosis via inhibiting YAP expression.