Meaning in life among Chinese undergraduate students in the post-epidemic period: A qualitative interview study.

Background: COVID-19 epidemic has lasted for nearly 3 years, and revolutionized social life. In the study, in-depth interviews were conducted with Chinese undergraduate students to explore their understanding and experience of meaning in life. Meaning of life is interpreted from four aspects: life goals, life value, life enthusiasm, and life freedom. These four aspects are independent yet interrelated. Based on the free grasp of life, individuals explore and pursue the true meaning of life goals, acquire life value in evaluating the completion of life goals, and subsequently experience enthusiasm for life. Life enthusiasm and the perception of life value can help individuals to further understand and possess their meaning of life. Materials and methods: The present study adopts the qualitative method to understand the experience of meaning in life among Chinese undergraduate students. Semi-structured interviews were conducted, and six people participated the study. The Grounded Theory was adopted to analyze the qualitative data. Results: (1) Chinese undergraduates had clear life goals and obtained a certain sense of achievement and satisfaction when striving for these goals. (2) The life value of Chinese undergraduates was mainly to their families, but there was also a willingness to make due contributions to the country and society. (3) Chinese undergraduates' feelings about life were polarized, but they all expressed the view of "living in the moment and cherishing the present." (4) Chinese undergraduate students see life freedom as freedom of choice and generally believed that COVID-19 did not restrict their lives very much. (5) Chinese undergraduate students gained a deeper understanding of meaning in life after this major public health emergency.

[mRNA expression and methylation status of p15 promoter in mouse bone marrow cells exposed to 1,4-benzoquinone].

OBJECTIVE: To detect the expression and the CpG island methylation status of tumor suppressor gene p15 after exposure to 1,4-benzoquinone (1,4-BQ) in primary cultivated C57BL/6J mouse bone marrow cells in vitro. METHODS: The mouse bone marrow cells were isolated in vitro. The effect of 0, 0.1, 1, 5, 10, 20, and 40 µmol/L 1,4-BQ on cell viability (CKK-8) was detected. 0, 0.1, 1, 10 µmol/L 1,4-BQ were used to intoxicate the mouse bone marrow cells for 24 h; Real-time PCR was employed to analyze the mRNA expression level of p15; The bisulfite sequencing PCR (BSP) was used to look into the methylation status of CpG islands in p15 promoter region. RESULTS: 1,4-BQ exhibited dose-dependent toxicity to mouse bone marrow cells, and the LC(50) was 8.3 µmol/L (95%CI: 4.6 - 10.6 µmol/L). The mRNA expression of p15 in 10 µmol/L group was only equivalent to 43% of control group. Compared with control group, the decrease of p15 mRNA expression in1 and 10 µmol/L concentration were obvious, and the differences had statistical significance (P < 0.05 or P < 0.01). BSP sequencing results were same between the exposure groups and control group, the 56 CpG sites on CpG islands remained in the state of unmethylated. CONCLUSION: mRNA expression of p15 gene decreases after exposure to 1,4-BQ, but the CpG islands methylation status in promoter is not affected, suggesting that methylation does not participate in 1,4-BQ-mediated p15 gene expression decrease, other effect mechanisms still need to be investigated.

[Effects of fertilizer application on contents of 2-undecanone and soluble carbonhydrate in Houttuynia cordata with different fertilizers].

OBJECTIVE: To investigate the effect of five kinds of fertilizers at three application levels on the content of 2-undecanone and carbohydrate in Houttuynia cordata. METHOD: A single factor randomized block design was used to investigate the content of 2-undecanone and carbohydrate in the plant. RESULT: The results showed that the content of 2-undecanone was the highest both in aerial and underground parts of H. cordata, which was fertilized with complex fertilizers served in conventional way, having the content 18.6 microg g(-1) and 26.0 microg g(-1) respectively. In addition, 2-undecanone contents in aerial parts of H. cordata (14.9 microg g(-1)) fertilized with manure of human were also higher than that with chemical fertilizer, pig and duck manures, but no significant difference were found among the other treatments in aerial or underground parts of the plants, respectively. The results also demonstrated that fertilized with organic fertilizer might be beneficial to enhance the quality of sugar in H. cordata, mainly including the contents of total sugar, solutable sugar, fructose and reduced sugar in the plants, especially with manure of human and pig. CONCLUSION: As the result of this study and the related previous research on yield of H. cordata were considered, the fertilizing ways for increasing quality of H. cordata should take the manure of human as a main fertilizer and mix with the other organic fertilizers, complex fertilizers and chemical ones may be needed to balance the plant nutrient. In the field practice, the amount of organic fertilizer including 108,000 kg hm(-2) human mature, together with some high-efficient complex fertilizer and a small amount of quick-acting chemical fertilizer is recommended.