Peptide hydrogen exchange is measured in bovine pancreatic trypsin inhibitor (BPTI) by 2D NMR in KCl solutions varying between 0.02 and 0.43 M. The effects of salt are analyzed for 16 assigned peptide groups located near the protein-solvent interface in the crystal structure. Salt effects are obtained for exchange by H+ and OH- catalysis, at pH 2.3 and 5.3, respectively. Semilogarithmic plots of rate constants vs the square root of the ionic strengths are virtually linear. The salt effects, taken as the slopes of these plots, vary both in size and sign for each catalytic process, reflecting the variation of local electrostatic field at the exchanging site. The effects are correlated with electrostatic potentials calculated by the finite differences method, taking into account both ionic and dipolar charges in the static structure. This suggests that the transition complexes between the catalyst and the protein are formed with the protein structure very similar to the crystal structure.
A series of 2,6-dihydroxy acylaromatic compounds were investigated to characterize the rotational and hydrogen bonding properties of the carbonyl group. Deuterium isotope effects on 'H and 13C chemical shifts due to deuteriation of OH groups were determined at both ambient and low temperature. In the latter case isotope effects on chemical shifts of the individual rotamers can be determined. Deuteriation of one of the OH groups may lead to isotopic perturbation of the tautomeric equilibrium of the carbonyl group and the two hydroxyl groups. The perturbation was found to be larger in ketones than in esters. Complete band shape analysis of the OH resonances of the esters and ketones in a temperature interval above and below the coalescence temperature led to AC', AHf and A S f values for various concentrations of added THF-d,. A S f was found to be strongly negative. Temperature coefficients for the shift of the OH resonances showed large variations for esters and ketones owing to the different hydrogen bond patterns. The esters have two intramolecular hydrogen bonds, one strong and an additional weaker one between the OH and OR groups. The second O H group of the ketones was shown to point primarily towards C-5. Increasing amounts of THF-I, increased the amount of this rotamer. The anisotropy of the XC=O group at C-2, C-6 was shown to lead to a low-field shift of C-2, very different from that found for C=O groups without hydrogen bonds. The anisotropy caused by OH groups can also be estimated. On the basis of the thermodynamic parameters, a model for the rotation of the ester group is suggested. The rate-determining step involves both intramolecular hydrogen bonds, which are twisted out of the ring plane to form hydrogen bonds to the solvent or other hydrogen bond acceptors.
The present article reports a study conducted to develop and validate a Danish translation of the Purpose in Life test-Short Form (PIL-SF) and examine age effects on this eudemonic measure. The study examined the reliability, unidimensionality, and construct validity of the Danish PIL-SF using a large and representative sample (N = 4,849). The results indicated that the Danish PIL-SF is a reliable and valid measure of meaning and purpose in life, positively associated with but distinct from hedonic well-being. The high degree of similarity between the measurement properties of the Danish PIL-SF, as compared with the English-language PIL-SF, supports the validity of the Danish translation. Furthermore, the unidimensional structure of the Danish measure replicates the structure of the English-language PIL-SF. Given its large and representative sample, the present study provides the current best estimate of a normative population value for the PIL-SF. Also, the present study is the first to our knowledge to explore potential relationships between age and the PIL-SF, and a small positive effect of age on the Danish PIL-SF was found. Limitations and suggestions for further research are discussed.
Abstract. Historically, the psychotherapeutic treatment of psychological problems in old people has had low priority among both clinical psychologists and researchers. Fortunately, this bleak picture is now changing, and a number of reviews and meta-analyses have documented the effect of psychotherapy with older adults suffering from psychopathology such as anxiety or depression. Yet studies on whether older adults not suffering from a psychiatric disorder benefit from psychotherapy are sparse. The objective of this study is threefold: First, we investigate the effects of individual psychotherapy on subjective well-being and symptoms of depression and anxiety of elderly care recipients. Second, we investigate whether the treatment effects continue 3 months after the final treatment session. Third, we examine whether well-being scores improve relatively more than depression and anxiety scores. We found significant positive treatment effects across all measures. Effect sizes were moderate to high. There were no significant differences between posttreatment and follow-up scores, indicating lasting treatment effects. Differences in treatment effect size for our three outcome variables indicated that the WHO-5 scores changed the most, followed by anxiety and depression symptoms. Strengths and weaknesses of the study are discussed, and future directions for research and practice are proposed.
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