Impact of the COVID-19 pandemic on travel behavior: A case study of domestic inbound travelers in Jeju, Korea.

This study analyzes a large-scale navigation dataset that captures travel activities of domestic inbound visitors in Jeju, Korea in the first nine months of 2020. A collection of regression models are introduced to quantify the dynamic effects of local and national COVID-19 indicators on their travel behavior. Results suggest that behavior of inbound travelers was jointly affected by pandemic severity locally and remotely. The daily number of new cases in Jeju has a greater impact on reducing travel activities than the national-level daily new cases of COVID-19. The impacts of the pandemic did not diminish over time but produced heterogeneous effects on travels with different trip purposes. Our findings reveal the persistence of COVID-19's effects on travel behavior and the variability in travelers' responses across tourism activities with different levels of perceived health risks. The implications for crisis management and recovery strategies are also discussed.

Dose-response and time-response analysis of total fatty acid ethyl esters in meconium as a biomarker of prenatal alcohol exposure.

OBJECTIVES: Little is known on how the dose and timing of exposure co-influence the cumulative concentration of fatty acid ethyl esters (FAEEs) in meconium. The objective of the study was to assess the cumulative concentration of FAEEs in meconium as a biomarker of light, moderate, or heavy prenatal alcohol exposure occurring at either first, second, or third trimesters of pregnancy. METHODS: History of prenatal alcohol exposure was obtained in the 34th week of gestation from 294 pregnant women. Meconium was collected from their babies within the first 6 to 12 h after birth and examined for the presence of nine FAEEs. RESULTS: No significant differences were identified between the cumulative levels of FAEEs in the meconium from the babies born to abstainers and those born to mothers with history of light-to-moderate prenatal alcohol exposure during their pregnancy. CONCLUSIONS: Light-to-moderate prenatal alcohol exposure cannot be reliably predicted by the cumulative FAEE concentrations in meconium of exposed babies. A cumulative FAEE level of >10 nmol/g would be required to consider that prenatal alcohol exposure during the second to third trimesters occurred at risky levels in the absence of reliable maternal history of ethanol exposure.

Preterm infants fed nutrient-enriched formula until 6 months show improved growth and development.

BACKGROUND: The purpose of the present study was to determine the effect of feeding nutrient-enriched preterm formula to preterm infants until 6 months' corrected age (CA) on growth and development in the first 18 months of life. METHODS: Very low-birthweight preterm infants were fed preterm formula until term (40 weeks CA). Infants were then assigned to one of three groups and were fed term formula until 6 months' CA (group 1, n= 29); preterm formula to 3 months' CA and then term formula to 6 months' CA (group 2, n= 30); or preterm formula until 6 months' CA (group 3, n= 31). Anthropometry was performed at term, 3, 6, 9, 12, 15, and at s18 months' CA. Mental and psychomotor development were assessed using the Bayley Scales of Infant Development II at 18 months' CA. RESULTS: Although body weight, length, head circumference and z score for CA at term in group 3 were significantly lower than those of groups 1 and 2, growth rates of these parameters were significantly higher in group 3 up to 18 months CA', as compared to groups 1 and 2. The mental developmental index and psychomotor developmental index of the Bayley test were not significantly different between the three groups. CONCLUSIONS: Very low-birthweight preterm infants fed nutrient-enriched preterm formula until 6 months' CA demonstrated significantly improved growth rates for bodyweight, length and head circumference, and comparable mental and psychomotor development throughout the first 18 months of life.

Comparison of clinical efficacy of Newfactan versus Surfacten for the treatment of respiratory distress syndrome in the newborn infants.

Newfactan is a domestically developed, bovine lung-derived, semi-synthetic surfactant. The aim of this study was to compare the clinical efficacy of Newfactan with that of Surfacten in the treatment of respiratory distress syndrome (RDS). Newfactan or Surfacten was randomly allocated to 492 newborn infants who were diagnosed as RDS and required surfactant instillation in four participating hospitals. The comparisons were made individually in two subsets of infants by birth weight (<1,500 g group [n=253] and > or =1,500 g group [n=239]). Short-term responses to surfactant and acute complications, such as the total doses of surfactant instilled, response type, extubation rate, ventilator settings, changes in respiratory parameters, air leak, patent ductus arteriosus, pulmonary hemorrhage, and intraventricular hemorrhage, and mortality during the 96 hr after surfactant instillation were measured. Long-term outcome and complications, such as total duration of intubation, bronchopulmonary dysplasia and periventricular leukomalacia, and ultimate mortality were measured. There were no significant differences in demographic and perinatal variables, shortterm responses to surfactant and acute complications, and long-term outcome and complications between Newfactan and Surfacten in both birth weight groups. We concluded that Newfactan was comparable to Surfacten in the clinical efficacy in the treatment of RDS in both birth weight groups.

Effects of perfluorocarbon associated high frequency oscillatory ventilation on hemodynamics and gas exchange in the newborn piglets with respiratory distress.

We sought to know whether there is a further improvement in gas exchange when partial liquid ventilation (PLV) is added to high-frequency oscillatory ventilation (HFOV) in a piglet model of saline lavage-induced acute lung injury. Seven 7-9 day-old newborn piglets of mixed strain were treated with repeated saline lavage to achieve a uniform degree of acute lung injury. Then, HFOV were applied to the subject. Four animals received two consecutive doses (15 mL/kg) of perfluorodecalin at 30-min interval (PFC+HFOV group). The other three animals remained on HFOV alone (HFOV-only group). Repetitive lung lavage led to a significant acute aggravation in both gas exchange and hemodynamic parameters. Subsequent application of HFOV produced a significant rapid recovery in both gas exchange and hemodynamic parameters to near baseline levels. During and after perfluorodecalin dosing, there were no significant changes in gas exchange or hemodynamic parameters over time in both groups, and no significant differences in gas exchange or hemodynamic parameters between groups. We concluded that the addition of 30 mL/kg of perfluorodecalin to HFOV showed no detrimental effect on hemodynamics, but did not produce a significant improvement in gas exchange over a three-hour period.