Relationships between Smartphone Usage, Sleep Patterns and Nursing Students' Learning Engagement

PURPOSE: In 2015, South Korea had the highest global smartphone penetration (88%). However, smartphone addiction can seriously disrupt daily life and have a major negative impact on academic achievement. METHODS: A structured questionnaire was completed by 250 nursing students for this descriptive study. RESULTS: Students who were older, more satisfied with their major, exercised, and used their smartphone for less than 30 minutes before sleeping had higher learning engagement than those who were younger, less satisfied, did not exercise and used their smartphone for more than three hours. Quality of sleep and smartphone addiction were negatively correlated as was quality of sleep and daytime sleepiness. Interestingly, sleep pattern did not impact learning engagement directly. CONCLUSION: Smartphone usage influences learning engagement of nursing students rather than their sleeping patterns, which suggests a need to develop self-disciplining strategies for smartphone use to enhance learning engagement.

Effects of Organizational Culture, Self-Leadership and Empowerment on Job Satisfaction and Turnover Intention in General Hospital Nurses / 간호행정학회지

PURPOSE: In this study factors affecting job satisfaction and turnover intention of nurses were explored in the context of organizational culture, self-leadership, and empowerment. METHODS: Participants were 286 nurses drawn from 3 general hospitals. Data were analyzed using t-test, one-way ANOVA, Pearson correlation, and hierarchial multiple regression with the SPSS/WIN 18.0 program. RESULTS: Significant differences in job satisfaction and turnover intention were found according to organizational culture types. Significant positive correlations were found between self-leadership, empowerment, task oriented organizational culture, relationship oriented organizational culture, innovation oriented organizational culture and job satisfaction. On the other hand, significant negative relationships were found between empowerment, relationship oriented organizational culture, innovation oriented organizational culture and turnover intention. The factors that enhance job satisfaction were found to be higher innovation-oriented organizational culture. Lower turnover intention was shown to be positively associated with relationship- or innovation oriented organization culture. CONCLUSION: Innovation oriented organizational culture is needed in order to raise job satisfaction and reduce turnover intention of nurses.

Evaluation of Luminescent P450 Analysis for Directed Evolution of Human CYP4A11

Cytochrome P450 4A11 (CYP4A11) is a fatty acid hydroxylase enzyme expressed in human liver. It catalyzes not only the hydroxylation of saturated and unsaturated fatty acids, but the conversion of arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE), a regulator of blood pressure. In this study, we performed a directed evolution analysis of CYP4A11 using the luminogenic assay system. A random mutant library of CYP4A11, in which mutations were made throughout the entire coding region, was screened with luciferase activity to detect the demethylation of luciferin-4A (2-[6-methoxyquinolin-2-yl]-4,5-dihydrothiazole-4-carboxylic acid) of CYP4A11 mutants in Escherichia coli. Consecutive rounds of random mutagenesis and screening yielded three improved CYP4A11 mutants, CP2600 (A24T/T263A), CP2601 (T263A), and CP2616 (A24T/T263A/V430E) with ~3-fold increase in whole cells and >10-fold increase in purified proteins on the luminescence assay. However, the steady state kinetic analysis for lauric acid hydroxylation showed the significant reductions in enzymatic activities in all three mutants. A mutant, CP2600, showed a 51% decrease in catalytic efficiency (k cat/K m) for lauric acid hydroxylation mainly due to an increase in K m. CP2601 and CP2616 showed much greater reductions (>75%) in the catalytic efficiency due to both a decrease in k cat and an increase in K m. These decreased catalytic activities of CP2601 and CP2616 can be partially attributed to the changes in substrate affinities. These results suggest that the enzymatic activities of CYP4A11 mutants selected from directed evolution using a luminogenic P450 substrate may not demonstrate a direct correlation with the hydroxylation activities of lauric acid.