The Quest to Quit: an Exploration of the Cessation - Relapse Cycle of Cigarette Smoking

The smoker's perspective is seldom sought in cessation research. Consequently, cessation approaches may be less effective because they are not based on assumptions and interpretations shared by those who smoke. Understanding how chronic relapsing smokers interpret their predicament could enhance cessation approaches, improving the chances for complete, permanent cessation. To generate such an understanding, five participants were recruited who had attempted to quit smoking several times. Aiming for depth rather than breadth, multiple interviews were conducted with each participant, who also kept an event diary, recording current smoking, nicotine withdrawal, lapsing and relapsing. Narratology, a biographical method of symbolic interactionism drawing on thematic, structural, and dialogic analysis, was used to elicit the participants' points of view from interview and diary data. The findings show that participants make sense of their chronic relapsing through a master narrative of 'willpower versus weakness'. Meanwhile, the tobacco control domain is largely driven by 'cost', and subsidised treatments are driven by the 'addiction' master narrative. This gap between ways of making sense of smoking and relapse can cause self-stigma, reducing the likelihood that quitting will be attempted and that quit attempts will succeed. Changes are proposed to mitigate the negative effects on self-efficacy brought about through the present approach to tobacco control. Ways to improve the effectiveness of existing treatments are suggested. Finally, the value of the narrative method is highlighted, with suggestions for its use in research where elucidating the insider point of view may improve treatment outcomes

Excited States of Pt(PF₃)₄ and Their Role in Focused Electron Beam Nanofabrication

Electron induced chemistry of metal-containing precursor molecules is central in focused electron beam induced deposition (FEBID). While some elementary processes leading to precursor decomposition were quantitatively characterized, data for neutral dissociation is missing. We provide this data for the model precursor Pt­(PF₃)₄ by using the available cross sections for electronic excitation and characterizing fragmentation of the excited states theoretically by TDDFT. The potential energy curves for a number of states visible in the experimental electron energy loss spectra are dissociative, either directly or via conical intersections, indicating that the quantum yield for dissociation is close to 100%. Taking into account typical electron energy distribution at the FEBID spot reveals that the importance of neutral dissociation exceeds that of dissociative electron attachment, which has been so far considered to be the dominant decomposition process. We thus established neutral dissociation as an important, albeit often neglected, channel for FEBID using Pt­(PF₃)₄. The calculations revealed a number of other phenomena that can play a role in electron induced chemistry of this compound, e.g., a considerable increase of bond dissociation energy with sequential removal of multiple ligands

Joint Experimental and Theoretical Study on Vibrational Excitation Cross Sections for Electron Collisions with Diacetylene

We have measured and calculated differential and integral cross sections for elastic and vibrationally inelastic electron scattering by diacetylene molecules at electron energies from 0.5 to 20 eV in the whole range of scattering angles from 0 to 180°. The calculations were carried out using the discrete momentum representation method (DMR), which is based on the two-channel Lippmann–Schwinger equation in the momentum space. The interaction between the scattered electron and the target molecule is described by the exact static-exchange potential. Correlation–polarization forces are included by a local density functional theory. Energy dependences of integral and differential cross sections are presented for all nine vibrational modes. A detailed comparison of theoretical and experimental electron energy loss spectra is presented for electron energies of 1, 5.5, 10, and 20 eV. The theory assigns symmetry of resonances that could not be determined by empirical analysis alone. The theory reveals, and quantitatively describes, the switching of partial waves accompanying excitation of nontotally symmetrical vibrations. Limitations of the theory in reproducing experimental data for the narrow π* resonance below 2 eV are mentioned