Caffeine, the most commonly used medication in Neonatal Intensive Care Units, has calciuric and osteoclastogenic effects. To examine the association between the cumulative dose and duration of therapy of caffeine and osteopenia of prematurity, a retrospective cohort study was conducted including premature infants less than 31 weeks and birth weight less than 1500 g. Osteopenia of prematurity was evaluated using chest X-rays on a biweekly basis over 12 weeks of hospitalization. The cohort included 109 infants. 51% had osteopenia of prematurity and 8% had spontaneous rib fractures. Using the generalized linear mixed model, caffeine dose and duration of caffeine therapy showed a strong association with osteopenia of prematurity. Steroids and vitamin D were also significantly correlated with osteopenia of prematurity while diuretic use did not show a statistically significant effect. The cumulative dose and duration of therapy of caffeine, as well as steroid are associated with osteopenia of prematurity in this cohort. Future studies are needed to confirm these findings and determine the lowest dose of caffeine needed to treat effectively apnea of prematurity.

Construction workers are at risk of noise-induced hearing loss (NIHL) but often have no periodic audiometric testing.

Objective: To describe quality of life trajectories of older men over a 10-year time frame in mental and physical health domains, and to determine if these trajectories predict death over a subsequent 9-year period. Method: A cohort study of Royal Canadian Air Force aircrew veterans. We used Short Form–36 (SF-36) measures of mental and physical functioning collected prospectively at six time points between 1996 to 2006 (734 men with a mean age of 85.5 [SD 3.0] years in 2006) to determine trajectories. Continued contact with the cohort from 2006 to 2015 determined subsequent mortality. Results: Men were more likely to maintain high levels of mental functioning than physical functioning. Thirty-seven percent of participants maintained a high level of both mental and physical functioning. Declining function in either mental or physical function was associated with lower survival. Conclusion: Men who maintain physical and mental functioning have a lower mortality rate.

The foreign exchange market comprises the largest global volume, so the pricing of foreign exchange options has always been a hot issue in the foreign exchange market. This paper treats the exchange rate as an uncertain process that is described by an uncertain fractional differential equation, and establishes a new uncertain fractional currency model. The uncertain process is driven by Liu process, and, with the application of the Mittag-Leffler function, the solution of the fractional differential equation in a Caputo sense is presented. Then, according to the uncertain fractional currency model, the pricing formulas of European and American currency options are given. Lastly, the two numerical examples of European and American currency options are given; the price of the currency option increased when p changed from 1.0 to 1.1, and prices with different p were all decreasing functions of exercise price K.