The Influence of Semi-Flipped Biochemistry Teaching Model on Students' Academic Achievement and Self-Cognition / 中国生物化学与分子生物学报

The "student-centered" flipped classroom teaching model can improve students' academic achievement, improve cognition, and cultivate innovation ability. However, it has obvious deficiencies in the integrity and systematization of knowledge as well as education. The traditional teaching concept based on " teacher-centered" has the unique advantages of systematization of knowledge learning and education. Therefore, we integrated the merits of these two different teaching models and introduced the semi-flipped classroom teaching model into the Biochemistry teaching of 2020 stomatology, pharmacy and preventive medicine majors in Cheeloo Medical College, Shandong University, compared with the traditional teaching of 2019 same majors. The data on the improvement of students ' academic achievement and self-cognition were analyzed. The results showed that the students' achievements of the semi-flipped classroom teaching model were better than those of the traditional teaching (P<0. 01). The students' self-cognitions were significantly improved after the implementation of semi-flipped classroom teaching (P<0. 01 or P<0. 05). This study provides a reference for the related teaching and research work in medical colleges.

Study on functions of N-carbohydrate chains in human parainfluenza virus type 3 hemagglutinin-neuraminidase protein / 病毒学报

To determine the functions of N-carbohydrate chains in human parainfluenza virus type 3 hemagglutinin-neuraminidase(HN) protein, a PCR-based site-directed mutagenesis method was used to obtain N-glycan mutants. Protein electrophoresis rate, cell surface expression,receptor binding activity, neuraminidase activity and cell fusion promotion activity were determined. The HN proteins of single mutants (G1, G2, and G4) and multiple mutants (G12, G14, G24 and G124) migrated faster than the wild-type (wt) HN protein on polyacrylamide gels, while G3-mutated protein and wt HN protein migrated at the same position. There was no statistic difference in cell surface expression and neuraminidase activity between wt and each mutant HN protein (P>0.05), but receptor binding activity and cell fusion promotion activity of each mutant protein was reduced to significant extent (P<0.05). G1, G2 and G4 mutants exhibited re duced receptor binding activity, which was 83.94%, 76.45% and 55.32% of the wt level, respectively. G1, G2 and G4-mutated proteins also showed reductions in fusion promotion activity, which was 80.84%, 77.83% and 64.16%, respectively. Multiple mutants with G12-, G14-, G24- and G124- substitutions could further reduce receptor binding activities, 33.07%, 20.67%, 19.96% and 15.11% of the wt HN level, respectively. G12, G14, G24 and G124 mutants exhibited levels of fusion promotion activity that were only 46.360, 12.04%, 13.43% and 4.05% of the wt amount, respectively. As N-glycans of hPIV3 HN protein play an important role in receptor binding activity and cell fusion promotion activity of HN protein. We propose that the loss of N-glycans change the conformation or orientation of globular domain that is responsible for receptor binding and lower receptor binding activity and cell fusion promotion activi ty.

Effects of 9-cis-retinoic acid on cell cycle and expression of cyclin D1 and cdk4 in lung cancer cells / 药学学报

<p><b>AIM</b>To study the effects of 9-cis-retinoic acid (9-cis-RA) on cell cycle and expression of cyclin D1 and cdk4 in lung cancer cells.</p><p><b>METHODS</b>9-cis-RA (1 x 10(-6) mol.L-1) was used to treat lung cancer cells for 24 h; Flow cytometry (FCM) was used to detect the percent of G0/G1 phase and S phase cells of three groups including blank control, DMSO control and 9-cis-RA groups; RT-PCR was used to analyze the expression changes of cyclin D1 and cdk4 before and after treatment with 9-cis-RA in lung cancer cells.</p><p><b>RESULTS</b>The percent of G0/G1 phase cells of 9-cis-RA groups was significantly higher than that of the control groups (P < 0.01 or P < 0.05) and the percent of S phase cells of 9-cis-RA groups was lower than that of the control groups (P < 0.01 or P < 0.05); the expression of cyclin D1 of PG, SPC-A1 and L78 cells was decreased (P < 0.01) and the expression of cdk4 of PG, A549 and L78 cells was also decreased (P < 0.01) after treatment with 9-cis-RA.</p><p><b>CONCLUSION</b>Most of the proliferation and the expression of cyclin D1 and cdk4 of PG, A549, SPC-A1 and L78 were inhibited by 9-cis-RA.</p>