With the accelerated urbanization process, there are growing interests in the potential impact of neighborhood built-environment on residents’ physical activity and dietary habits. In this paper, we introduced the concept of the built environment and the ways to assess the built-environment related to physical activity and dietary habits. We reviewed papers on the association of the built-environment with physical activity and dietary habits. Improvement of the built-environment is expected to reduce the health burden caused by insufficient physical activity and unhealthy dietary habits. As this field is still at its initial stage, there are many questions to be explored. We then discussed the challenges for this field and made some suggestions for future study.

Objective: To investigate the effect of caffeine citrate administering at different time on outcome and neurodevelopment of premature infants. Methods: A total of 113 preterm infants with gestational age less than 32 weeks and birth weight less than 1 500 g who were hospitalized and treated in the neonatal intensive care unit from January 2018 to June 2018 were enrolled.According to the time when caffeine citrate treatment was started, they were divided into early treatment group(≤1 days) with 53 infants and late treatment group(1 to 10 days) with 60 infants.A retrospective analysis was performed for their clinical data.The perinatal conditions, treatment process and clinical outcomes of the two groups were compared and the neurological development was followed up at 12 months old. Results: Compared with the late treatment group, the early treatment group had a significantly shorter durations of mechanical ventilation time, oxygen therapy time, hospitalization days and a significantly lower incidence of bronchopulmonary dysplasia, patent ductus arteriosusand intraventricular hemorrhage or periventricular leukomalacia, and there were significant differences between two groups(P<0.05, respectively). The neonatal behavioral neurological assessment score in the early treatment group was higher than that in the late treatment group at 40 weeks of gestational age, and there was significant difference between two groups(P<0.05). The mental developmental index at 3 months of corrected age, the mental developmental index and psychomotor developmental index at 12 months were significantly better in the early treatment group than those in the late treatment group, and there were significant differences between two groups(P<0.05, respectively). Conclusion Early use of caffeine citrate can improve the outcome of premature infants and improve the prognosis of nervous system.