The heterogeneous chemistry of surface-adsorbed polycyclic aromatic hydrocarbons (PAHs) plays key roles in nanoscience, environmental science, and public health. Experimental evidence shows that the substrate can influence the heterogeneous oxidation of surface-bound PAHs, however, a mechanistic understanding of the role of the surface is still lacking. We examine the effects of the PAH-substrate interaction on the oxidation of surface-adsorbed anthracene, pyrene, and benzo[a]pyrene by ozone (O(3)) using density functional theory. We find that some O(3) oxidation mechanisms for these planar PAH molecules lead to nonplanar intermediates or products, the formation of which may necessitate partial desorption or "lift-off" from a solid substrate. The energy penalty for partial desorption of each PAH from the surface is estimated for four different substrate types on the basis of literature data and accounted for in the thermodynamic analysis of the reaction pathways. We find that the attractive PAH-substrate interaction may render oxidation pathways involving nonplanar intermediates or products thermodynamically unfavorable. The influence of the PAH-substrate interaction could contribute in part to the variations in PAH oxidation kinetics and product distributions that have been observed experimentally. Our choice of test molecules enabled us to identify trends in reactivity and product formation for four types of potentially reactive site (zigzag, armchair, bridge, and internal), allowing us to infer products and mechanisms of O(3) oxidation for PAHs of larger sizes. Implications for atmospheric chemistry and the stability of graphene in the presence of O(3) are discussed.

NY Purpose: SCD is characterized by chronic organ dysfunction and poor quality of life (QOL). Myeloablative conditioning (MAC) and AlloSCT for SCD is the only curative therapy for children who are at high risk for SCD related morbidity and mortality (Bhatia et al, BMT, 2008). MAC and alloSCT are associated with significant acute morbidity and late effects (Satwani/Cairo et al, BBMT 2005). Despite the emerging clinical benefit of RTC alloSCT in SCD (Bhatia/Cairo et al, ASBMT, 2011), little is known about its impact on the longitudinal QOL of these patients. Therefore, the objective of this study was to serially evaluate the QOL of children who received RTC alloSCT for SCD. Methods: Hierarchical linear modeling was used to explore trends in PedsQL 4.0 physical, emotional, and social functioning sub-scales and select individual items of 14 children $ 5 years of age undergoing alloSCT for SCD between 2004 and 2008 at Columbia University Medical Center. QOL was assessed once pre-alloSCT and days 100, 180, 365, and 730, post-alloSCT. Post hoc exploratory analyses were performed to further evaluate the effect of RTC and alloSCT on outcomes. Effect sizes (ES) were included to describe the magnitude of difference in scores from baseline. Results: Mean age: 9.9 years. Emotional and social functioning was stable over time. Physical functioning (PF) was estimated to improve from baseline (BL) for parent (M 5 69.54) and child selfreport (M 5 72.96) at a rate of 0.57 (p 5 0.06) and 0.43 (p 5 0.16) points per month (ppm) respectively, with a large difference estimated at 2-years post-alloSCT by parent report (ES 5 0.93 SD) and a moderate difference by child self-report (ES 5 0.70 SD). Post hoc analysis of parent reported PF items revealed statistically significant improvements from BL in running, pain, and fatigue (Table 1). A large ES difference was estimated for each of these items at 2-years post-alloSCT with running scoring 0.99 SD higher, pain improving by 1.72 SD, and fatigue by 1.31 SD. Children who received a matched related donor (MRD) transplant (M 5 69.05) significantly improved at a rate of 0.93 ppm/11.31 points per year (ppy) (t 5 3.08