Quality of life and well-being of carers of people with dementia: are there differences between working and nonworking carers? Results from the IDEAL program

The aim of this study was to identify the differences in quality of life (QoL) and well-being between working and nonworking dementia carers and the relative contribution of psychological characteristics, caregiving experience, and social support. Multiple regressions modeled the contribution of working status, caregiver experiences, and psychological and social resources to carer QoL (EQ-5D) and well-being (WHO-5). After controlling for age, gender, carer–dyad relationship, and severity of dementia, working status contributed significant variance to EQ-5D (2%) but not to WHO-5 scores. Independent of working status, higher self-esteem and reduced stress contributed to variance in both models. Self-efficacy, social support, and positive perceptions of caregiving additionally contributed to higher WHO-5 scores. Working status associated with higher EQ-5D QoL; this may reflect the sustained sense of independence associated with supported work opportunities for carers. Outside of working status, the findings support the importance of psychological and social factors as targets to improved mental health for dementia carers

Measuring transient reaction rates from nonstationary catalysts

Up to now, methods for measuring rates of reactions on catalysts required long measurement times involving signal averaging over many experiments. This imposed a requirement that the catalyst return to its original state at the end of each experiment—a complete reversibility requirement. For real catalysts, fulfilling the reversibility requirement is often impossible—catalysts under reaction conditions may change their chemical composition and structure as they become activated or while they are being poisoned through use. It is therefore desirable to develop high-speed methods where transient rates can be quickly measured while catalysts are changing. In this work, we present velocity-resolved kinetics using high-repetition-rate pulsed laser ionization and high-speed ion imaging detection. The reaction is initiated by a single molecular beam pulse incident at the surface, and the product formation rate is observed by a sequence of pulses produced by a high-repetition-rate laser. Ion imaging provides the desorbing product flux (reaction rate) as a function of reaction time for each laser pulse. We demonstrate the principle of this approach by rate measurements on two simple reactions: CO desorption from and CO oxidation on the 332 facet of Pd. This approach overcomes the time-consuming scanning of the delay between CO and laser pulses needed in past experiments and delivers a data acquisition rate that is 10–1000 times higher. We are able to record kinetic traces of CO2 formation while a CO beam titrates oxygen atoms from an O-saturated surface. This approach also allows measurements of reaction rates under diffusion-controlled conditions

Spin-forbidden carbon–carbon bond formation in vibrationally excited α-CO

Fourier transform infrared spectroscopy of laser-irradiated cryogenic crystals shows that vibrational excitation of CO leads to the production of equal amounts of CO2 and C3O2. The reaction mechanism is explored using electronic structure calculations, demonstrating that the lowest-energy pathway involves a spin-forbidden reaction of (CO)2 yielding C(3P) + CO2. C(3P) then undergoes barrierless recombination with two other CO molecules forming C3O2. Calculated intersystem crossing rates support the spin-forbidden mechanism, showing subpicosecond spin-flipping time scales for a (CO)2 geometry that is energetically consistent with states accessed through vibrational energy pooling. This spin-flip occurs with an estimated ∼4% efficiency; on the singlet surface, (CO)2 reconverts back to CO monomers, releasing heat which induces CO desorption. The discovery that vibrational excitation of condensed-phase CO leads to spin-forbidden C−C bond formation may be important to the development of accurate models of interstellar chemistry

NO binding energies to and diffusion barrier on Pd obtained with velocity-resolved kinetics

We report nitric oxide (NO) desorption rates from Pd(111) and Pd(332) surfaces measured with velocity-resolved kinetics. The desorption rates at the surface temperatures from 620 to 800 K span more than 3 orders of magnitude, and competing processes, like dissociation, are absent. Applying transition state theory (TST) to model experimental data leads to the NO binding energy E0 = 1.766 ± 0.024 eV and diffusion barrier DT = 0.29 ± 0.11 eV on the (111) terrace and the stabilization energy for (110)-steps ΔEST = 0.060–0.030+0.015 eV. These parameters provide valuable benchmarks for theory