Interaction of Carbon Dioxide with Transition-Metal-Substituted Heteropolyanions in Nonpolar Solvents. Spectroscopic Evidence for Complex Formation.

Tetraheptylammonium salts of various transition-metal-substituted heteropolyanions with alpha-Keggin ([XW(11)O(39)M](n)()(-)), alpha-Wells-Dawson ([P(2)W(17)O(61)M](m)(-)), and Weakley and Finke structures ([P(2)W(18)O(68)Co(4)](10)(-)) were investigated with respect to their reactivity with CO(2) in nonpolar solvents. It was found that copper(II)- and manganese(III)-substituted heteropolyanions do not react with CO(2). Germano- and silicotungstates with the alpha-Keggin structure do form complexes with CO(2) when substituted with Co(II), Ni(II), and Mn(II). In contrast, boro- and phosphotungstates substituted with Co(II), Ni(II), and Mn(II) are unreactive. The alpha(2) isomers of Wells-Dawson phosphotungstates show reactivity similar to that of alpha-Keggin silicotungstates-i.e., Co(II), Ni(II), and Mn(II) derivatives do react with CO(2). On the other hand, the alpha(1) isomer of the Co(II)-substituted Wells-Dawson anion does not react with CO(2), and neither does the Weakley and Finke cobaltotungstate. When reactions do occur, they are completely reversible. An excess of water decomposes the complexes. Traces of water are, however, necessary for the reactions to take place. The CO(2) adducts were characterized by UV/vis, IR, and (13)C NMR. The IR data could be explained as originating either from CO(2) complexes with a direct eta(1) metal-carbon bond or from bicarbonato complexes. IR spectra with isotopically enriched (13)CO(2) and C(18)O(2) support the presence of a eta(1) metal-carbon bond. The (13)C NMR spectra indicate the presence of two different kinds of paramagnetic CO(2) complexes after the reaction of alpha-[SiW(11)O(39)Co](6)(-) with CO(2) (chemical shifts 792 and 596 ppm at 26 degrees C). The variable-temperature experiments are consistent with the chemical exchange between these two species. UV/vis, IR, and NMR studies in the presence of controlled amounts of water or ethanol suggest the existence of H-bonding in the CO(2) complexes, similar to that reported in the past for complexes between heteropolyanions and dioxygen.

A pragmatic randomised controlled trial in primary care of the Camden Weight Loss (CAMWEL) programme.

OBJECTIVES: To evaluate effectiveness of a structured one-to-one behaviour change programme on weight loss in obese and overweight individuals. DESIGN: Randomised controlled trial. SETTING: 23 general practices in Camden, London. PARTICIPANTS: 381 adults with body mass index ≥25 kg/m(2) randomly assigned to intervention (n=191) or control (n=190) group. INTERVENTIONS: A structured one-to-one programme, delivered over 14 visits during 12 months by trained advisors in three primary care centres compared with usual care in general practice. OUTCOME MEASURES: Changes in weight, per cent body fat, waist circumference, blood pressure and heart rate between baseline and 12 months. RESULTS: 217/381 (57.0%) participants were assessed at 12 months: missing values were imputed. The difference in mean weight change between the intervention and control groups was not statistically significant (0.70 kg (0.67 to 2.17, p=0.35)), although a higher proportion of the intervention group (32.7%) than the control group (20.4%) lost 5% or more of their baseline weight (OR: 1.80 (1.02 to 3.18, p=0.04)). The intervention group achieved a lower mean heart rate (mean difference 3.68 beats per minute (0.31 to 7.04, p=0.03)) than the control group. Participants in the intervention group reported higher satisfaction and more positive experiences of their care compared with the control group. CONCLUSIONS: Although there is no significant difference in mean weight loss between the intervention and control groups, trained non-specialist advisors can deliver a structured programme and achieve clinically beneficial weight loss in some patients in primary care. The intervention group also reported a higher level of satisfaction with the support received. Primary care interventions are unlikely to be sufficient to tackle the obesity epidemic and effective population-wide measures are also necessary. CLINICAL TRIAL REGISTRATION NUMBER: Trial registrationClincaltrials.gov NCT00891943.

5-HTTLPR genotype, stressful life events and late-life depression: no evidence of interaction in a French population.

Modification of the effect of life events on risk of depression by a polymorphism in the serotonin transporter gene promoter (5-HTTLPR) has been reported in child, adolescent, adult and elderly populations. Replication attempted on data collected from 1421 individuals aged 65 and over from a French community study provided no evidence of a similar modifying effect. In the only analysis known to the authors to be carried out in an exclusively elderly, European population, this null finding remained consistent after restriction of analysis to prevalent or incident cases.