[Ru(bipy)(3)](2+) and [Os(bipy)(3)](2+) chromophores as sensitisers for near-infrared luminescence from Yb(iii) and Nd(iii) in d/f dyads: contributions from Forster, Dexter, and redox-based energy-transfer mechanisms.

The complexes and contain [M(bipy)(3)](2+) chromophores with a pendant aza-18-crown-6 macrocycle for binding of lanthanide(iii) ions. The photophysical properties of the adducts . and ., prepared by addition of excess Ln(NO(3))(3) (Ln = Nd, Yb) to solutions of and in MeCN, were examined using time-resolved and steady-state luminescence methods. Whereas does not act as an energy-donor to Yb(iii), it will transfer energy to (and generate sensitised near-infrared luminescence from) Nd(iii) with a Ru(ii)-->Nd(iii) energy-transfer rate constant of 6.8 x 10(6) s(-1). In contrast, is quenched by both Yb(iii) and Nd(iii), but with faster energy-transfer to Yb(iii) (2.6 x 10(7) s(-1)) than to Nd(iii) (1.4 x 10(7) s(-1)). Thus d --> f energy transfer is in both cases faster for Os(ii) than for Ru(ii), but the relative ability of Nd(iii) and Yb(iii) to act as energy-acceptors is inverted from . to .. Reasons for this are discussed with reference to contributions from the Förster and Dexter mechanism for energy-transfer in . and ., using calculated spectroscopic overlap integrals coupled with molecular modelling to estimate inter-chromophore separations. The particular effectiveness of Os(ii) --> Yb(iii) energy-transfer in . is explained in terms of the Horrocks redox mechanism involving an initial *Os(ii) --> Yb(iii) photoinduced electron transfer step generating an Os(iii)/Yb(ii) state, which is shown to be marginally favourable for ., but not for . in which the [Ru(bipy)(3)](2+) unit is a poorer excited-state electron-donor by about 0.1 eV

Forest experience and psychological health benefits: the state of the art and future prospect in Korea

The aims of this study were twofold: to examine the empirical evidence supporting the positive contribution that a forest environment can make on human psychological health and well-being and to describe the theoretical framework within which the forest environment has this effect. Our review of the literature provides empirical evidence that a forest experience can contribute to improved emotional and cognitive health.This experience can be through a forest activity program and by experiencing the social and physical conditions of the forest environment and the therapeutic elements of the forest. Visiting or viewing a forest scene has been documented to have a positive effect on psychological healing and well-being in terms of recovering from stress, improving concentration and productivity, improving the psychological state, particularly for people from urban environments. Wilderness and related studies clearly demonstrate that being in a forest environment has a positive effect on people, while results from other studies indicate that contacts with forest environments provide multiple positive physiological and psychological effects on human health that included decreasing the blood pressure and heart rate and reducing anxiety and stress. There are several theories explaining the healing effects of the forest on human beings. Most hypothesize that restorative environments are settings in which recovery is associated with the reduction of stress and that the benefits of contact with natures include a wide range of positive physiological and psychological responses. These theories are based on an evolutionary perspective and share a number of similarities and differences. This article summarizes a number of these theories of restorative environments as well as addresses the current status of forest therapy and the challenges and opportunities for therapeutic effects of the forest in Korea