32 research outputs found
Psychosocial Treatment of Children in Foster Care: A Review
A substantial number of children in foster care exhibit psychiatric difficulties. Recent epidemiologi-cal and historical trends in foster care, clinical findings about the adjustment of children in foster care, and adult outcomes are reviewed, followed by a description of current approaches to treatment and extant empirical support. Available interventions for these children can be categorized as either symptom-focused or systemic, with empirical support for specific methods ranging from scant to substantial. Even with treatment, behavioral and emotional problems often persist into adulthood, resulting in poor functional outcomes. We suggest that self-regulation may be an important mediat-ing factor in the appearance of emotional and behavioral disturbance in these children
The gas-phase basicity and proton affinity of 1,3,5-cycloheptatriene - energetics, structure and interconversion of dihydrotropylium ions
Salpin J-Y, Mormann M, Tortajada J, Nguyen M-T, Kuck D. The gas-phase basicity and proton affinity of 1,3,5-cycloheptatriene - energetics, structure and interconversion of dihydrotropylium ions. EUROPEAN JOURNAL OF MASS SPECTROMETRY. 2003;9(1):361-376.The hitherto unknown gas-phase basicity and proton affinity of 1,3,5-cycloheptatriene (CHT) have been determined by Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. Several independent techniques were used in order to exclude ambiguities due to proton-induced isomerisation of the conjugate cyclic C7H9+ ions, [CHT + H](+). The gas-phase basicity obtained by the thermokinetic method, GB(CHT) = 799 +/- 4 kJ mol(-1), was found to be identical, within the limits of experimental error, with the values measured by the equilibrium method starting with protonated reference bases, and with the values resulting from the measurements of the individual forward and reverse rate constants, when corrections were made for the isomerised fraction of the C7H9+ population. The experimentally determined gas-phase basicity leads to the proton affinity of cycloheptatriene, PA(CHT) = 833 +/- 4 kJ mol(-1), and the heat of formation of the cyclo-C7H9+ ion, DeltaH(r)(0)([CHT + H](+)) = 884 +/- 4 kJ mol(-1). Ab initio calculations are in agreement with these experimental values if the 1,2-dihydrotropylium tautomer, [CHT + H-(1)](+), generated by protonation of CHT at C-1, is assumed to be the conjugate acid, resulting in PA(CHT) = 825 +/- 2 kJ mol(-1) and DeltaH(f 300)degrees([CHT + H-(1)](+)) = 892 +/- 2 kJ mol(-1). However, the calculations indicate that protonation of cycloheptatriene at C-2 gives rise to transannular C-C bond formation, generating protonated norcaradiene [NCD + H](+), a valence tautomer being 19 kJ mol(-1) more stable than [CHT + H-(1)](+). The 1,4-dihydrotropylium ion, [CHT + H-(3)](+), generated by protonation of CHT at C-3, is 17 kJ mol(-1) less stable than [CHT + H-(2)](+). The bicyclic isomer [NCD + H](+) is separated by relatively high barriers, 70 and 66 kJ mol(-1) from the monocyclic isomers, [CHT + H-(1)](+) and [CHT + H-(3)](+), respectively. Therefore, the initially formed 1,2-dihydrotropylium ion [CHT + H-(1)](+) does not rearrange to the bicyclic isomer [NCD + H](+) under mild protonation conditions