Matrix Isolation Spectroscopy and Nuclear Spin Conversion of Propyne Suspended in Solid Parahydrogen

Parahydrogen (pH₂) quantum solids are excellent matrix isolation hosts for studying the rovibrational dynamics and nuclear spin conversion (NSC) kinetics of molecules containing indistinguishable nuclei with nonzero spin. The relatively slow NSC kinetics of propyne (CH₃CCH) isolated in solid pH₂ is employed as a tool to assign the rovibrational spectrum of propyne in the 600-7000 cm^-1 region. Detailed analyses of a variety of parallel (ΔK = 0) and perpendicular (ΔK=±1) bands of propyne indicate that the end-over-end rotation of propyne is quenched, but K rotation of the methyl group around the C₃ symmetry axis still persists. However, this single-axis K rotation is significantly hindered for propyne trapped in solid pH₂ such that the energies of the K rotational states do not obey simple energy-level expressions. The NSC kinetics of propyne follows first-order reversible kinetics with a 287(7) min effective time constant at 1.7 K. Intensity-intensity correlation plots are used to determine the relative line strengths of individual ortho- and para-propyne rovibrational transitions, enabling an independent estimation of the ground vibrational state effective A″ constant of propyne.

A HElium NanoDroplet Isolation (HENDI) investigation of the weak hydrogen bonding in the propyne dimer (CH3CCH)2

A HElium Nanodroplet Isolation (HENDI) experiment was performed to explore the absorption spectra of the propyne monomer (CH₃CCH), dimer and (CH₃CCH)_≥3 multimers in the vicinity of the CH stretch region ν₁ of the monomer.

Randomised controlled trial of a guided self-help treatment on the Internet for binge eating disorder

Binge eating disorder (BED) is a common and under-treated condition with major health implications. Cognitive behavioural therapy (CBT) self-help manuals have proved to be efficient in BED treatment. Increasing evidence also support the use of new technology to improve treatment access and dissemination. This is the first randomised controlled study to evaluate the efficacy of an Internet guided self-help treatment programme, based on CBT, for adults with threshold and subthreshold BED. Seventy-four women were randomised into two groups. The first group received the six-month online programme with a six-month follow-up. The second group was placed in a six-month waiting list before participating in the six-month intervention. Guidance consisted of a regular e-mail contact with a coach during the whole intervention. Binge eating behaviour, drive for thinness, body dissatisfaction and interoceptive awareness significantly improved after the Internet self-help treatment intervention. The number of objective binge episodes, overall eating disorder symptoms score and perceived hunger also decreased. Improvements were maintained at six-month follow-up. Dropouts exhibited more shape concern and a higher drive for thinness. Overall, a transfer of CBT-based self-help techniques to the Internet was well accepted by patients, and showed positive results for eating disorders psychopathology.

[New technologies for obesity treatment: on-line supported self-treatment program]

Obesity treatment effects are difficult to maintain on a long course, especially when patients also suffer from an eating disorder. Confronted with this statement, authors were interested in the use of new technologies to enhance the treatment palette at disposal. A self-treatment for bulimia nervosa on the Internet as well as a system of relapse prevention using Telephone-Linked Care (TLC) technology for obese patients after a weightloss have already been evaluated with success. A new self-treatment program for people suffering from compulsive eating disorders was developed and implemented on the Internet. It contains eleven steps based on cognitive and behavioural therapy and has to be done under a psychologist's supervision.

Influence of a weak hydrogen bond on vibrational coherence probed by photon echoes in DCl dimer trapped in solid nitrogen

The dynamics in the ground electronic state of the two intramolecular D-Cl stretching modes of (DCl)2 in nitrogen solid has been probed by degenerate four wave mixing experiments. Accumulated photon echoes on the "free" nu1 and "bonded" nu2 modes have been performed by means of the free electron laser of Orsay (CLIO). The analysis of the time-resolved signals provides information on the various processes responsible for the loss of vibrational coherence, in particular intra- and intermolecular vibrational energy transfer and pure dephasing. The influence of the weak hydrogen bond is clearly observed on the coherence times of the two stretching modes. Whatever the temperature, the homogeneous width of nu2 lines is almost twice that of nu1 lines. Contrary to the case of isolated DCl trapped in solid nitrogen, no obvious effect of the nitrogen lattice can be extracted from the temperature dependence of the coherence times.