Synthesis of shape-programmable elastomer for a bioresorbable, wireless nerve stimulator.

Materials that have the ability to manipulate shapes in response to stimuli such as heat, light, humidity and magnetism offer a means for versatile, sophisticated functions in soft robotics or biomedical implants, while such a reactive transformation has certain drawbacks including high operating temperatures, inherent rigidity and biological hazard. Herein, we introduce biodegradable, self-adhesive, shape-transformable poly (L-lactide-co-ε-caprolactone) (BSS-PLCL) that can be triggered via thermal stimulation near physiological temperature (∼38 °C). Chemical inspections confirm the fundamental properties of the synthetic materials in diverse aspects, and study on mechanical and biochemical characteristics validates exceptional stretchability up to 800 % and tunable dissolution behaviors under biological conditions. The integration of the functional polymer with a bioresorbable electronic system highlights potential for a wide range of biomedical applications.

Lactic acid bacteria starter in combination with sodium chloride controls pathogenic Escherichia coli (EPEC, ETEC, and EHEC) in kimchi.

Kimchi is one of the primary sources of high sodium content in the Korean diet. Low-sodium kimchi is commercially manufactured to minimize the health effects of high salt. We investigated the influence of lactic acid bacteria (LAB) as starter culture in combination with 1% or 2.5% salt on the survival of pathogenic Escherichia coli and physicochemical properties of kimchi during fermentation at 10 °C and 25 °C. Among ten strains of LAB isolated from kimchi, Leuconostoc mesenteroides (KCTC 13374) and Lactobacillus plantarum (KCTC 33133) exhibited antimicrobial activities against pathogenic E. coli (EPEC, ETEC, and E. coli O157:H7) and strong tolerance to low pH (2 and 3) and 0.3% bile salts. Thus, L. mesenteroides and L. plantarum were used as starter cultures for kimchi that contained 1% and 2.5% salt. All pathogenic E. coli strains survived in kimchi regardless of starter cultures or salt concentration for over 15 days at 10 °C, but they died off within 4 days at 25 °C. Survival of pathogenic E. coli was better in naturally fermented kimchi (titratable acidity:0.65%) than kimchi fermented with starter cultures (titratable acidity:1.0%). At 10 °C, the average delta value of E. coli O157:H7 (16.15 d) was smaller than those of EPEC (20.76 d) and ETEC (20.20 d) in naturally fermented kimchi. Overall, survival ability of E. coli O157:H7 was lower than EPEC and ETEC, although differences were not significant. Reduced salt concentration from 2.5% to 1% in kimchi did not affect the growth of LAB and the fermentation period. Pathogenic E. coli died at a faster rate in kimchi fermented with starter cultures and 1% salt than in naturally fermented kimchi with 2.5% salt.

Efficacy Evaluation of Control Measures on the Reduction of Staphylococcus aureus in Salad and Bacillus cereus in Fried Rice Served at Restaurants.

The objective of this study was to assess the effect of washing on Staphylococcus aureus reduction in salads and the effect of reheating on Bacillus cereus vegetative cells and spores reduction in fried rice at restaurants using the stochastic food safety objective (FSO) tool. The leaf vegetable was inoculated with S. aureus and washed with tap water, 100 ppm of NaClO, or 30 ppm of slightly acidic electrolyzed water (SAEW) for either 60 s or 5 min. The washing effect of 30 ppm SAEW was greater than that of 100 ppm NaClO. Based on the FSO concept, washing leaf vegetables with 30 ppm SAEW for 5 min was the most efficient control measure for S. aureus in salads. In addition, the salad should be consumed within 4 h at 25°C and 2 h at 35°C after 5 min of washing with 100 ppm NaClO or 30 ppm SAEW. The fried rice was first inoculated with B. cereus vegetative cells or spores and was then reheated in a frying pan at medium (internal temperature of fried rice: 69.2°C-78.8°C) or high heat (internal temperature of fried rice:103.8°C-121.4°C) or in a microwave oven (internal temperature of fried rice:86.3°C-90.6°C) for 3 or 4 min. Based on the FSO, reheating rice in a microwave oven was the most efficient control measure for B. cereus vegetative cells and spores in fried rice. The holding time for fried rice can be extended up to 6 h at 25°C, 3 h at 35°C, and 2 h at 45°C with reheating. Microbiological hazards in salads and fried rice can be controlled by washing with a sanitizer and reheating, respectively and then by controlling of holding temperature before being served at restaurants.

Effect of methylphenidate on sleep parameters in children with ADHD.

OBJECTIVE: The primary aim of this study was to investigate the acute impact of methylphenidate (MPH) on sleep parameters in attention-deficit/hyperactivity disorder (ADHD) children. The second aim was to investigate the different effects of intermediate- and longacting MPH on sleep parameters. The third aim was to test the different effects of dose and age on sleep parameters. METHODS: Ninety-three ADHD children were enrolled and randomized to two different MPH preparations. Baseline and daily sleep diaries were evaluated for four weeks after taking medication. Weekday and weekend bedtimes, wake-up times, sleep latencies and total sleep times were compared by weeks. RESULTS: After taking MPH, there was a significant delay in bedtimes and a significant reduction of total sleep time (TST) both on weekdays and at weekends. There was also a significant delay in wake-up time on weekdays. However, the difference was applied to younger age group children only. There was no difference in changes of TST between metadate-CD and OROS-MPH. There also was no difference in changes of TST with different doses of MPH. CONCLUSION: MPH had negative impacts on sleep among young ADHD children, but different preparations and doses did not affect the result.

Sleep patterns and their age-related changes in elementary-school children.

OBJECTIVES: This study aimed to evaluate children's bedtime, wake-up time, total sleep duration (TSD), sleep latency, and daytime napping by age and gender. Its secondary aim was to compare sleep duration among demographic and lifestyle factors. METHODS: We performed a cross-sectional study of 3639 children in Daegu, Korea, comparing bedtimes, wake-up times, TSDs, daytime naps, and sleep latency according to age and gender, as well as comparing sleep duration according to the children's demographic and lifestyle factors. RESULTS: Bedtime and TSD varied significantly by age. But wake-up time differences were not as large, as the differences in bedtimes and TSDs. There were no gender differences in any sleep parameters. The percentage of the children who took naps decreased until age 9 and began increasing again at age 10. Children who lived in apartments got less sleep than did those living in other types of housing. Extracurricular academic activities, duration and timing of television-watching, and computer playing were also related to the children's sleep duration. CONCLUSIONS: Older children sleep less than younger children; the main reason is late bedtimes. Late bedtimes may be due to socio-cultural factors, high levels of nighttime and recreational activities, and/or excessive academic activities.