A vibrational circular dichroism implementation within a Slater-type-orbital based density functional framework and its application to hexa- and hepta-helicenes

We describe the implementation of the rotational strengths for vibrational circular dichroism (VCD) in the Slater-type orbital based Amsterdam Density Functional (ADF) package. We show that our implementation, which makes use of analytical derivative techniques and London atomic orbitals, yields origin independent rotational strengths. The basis set dependence in the particular case of Slater-type basis functions is also discussed. It turns out that the triple zeta STO basis sets with one set of polarization functions (TZP) are adequate for VCD calculations. The origin- dependence of the atomic axial tensors is checked by a distributed origin gauge implementation. The distributed and common origin gauge implementations yield virtually identical atomic axial tensors with the Slater-type basis sets employed here, proving that our implementation yields origin independent rotational strengths. We verify the implementation for a set of benchmark molecules, for which the dependence of the VCD spectra on the particular choice of the exchange–correlation functional is studied. The pure functionals BP86 and OLYP show a particularly good performance. Then, we apply this approach to study the VCD spectra of hexa- and hepta- helicenes. In particular we focus on relationships between the sign of the rotational strengths of the two helicenes

Improving the study of proton transfers between amino acid sidechains in solution: choosing appropriate DFT functionals and avoiding hidden pitfalls

We have studied the influence of implicit solvent models, inclusion of explicit water molecules, inclusion of vibrational effects, and density functionals on the quality of the predicted pK a of small amino acid side chain models. We found that the inclusion of vibrational effects and explicit water molecules is crucial to improve the correlation between the computed and the experimental values. In these micro-solvated systems, the best agreement between DFT-computed electronic energies and benchmark values is afforded by BHHLYP and B97-2. However, approaching experimental results requires the addition of more than three explicit water molecules, which generates new problems related to the presence of multiple minima in the potential energy surface. It thus appears that a satisfactory ab initio prediction of amino acid side chain pK a will require methods that sample the configurational space in the presence of large solvation shells, while at the same time computing vibrational contributions to the enthalpy and entropy of the system under study in all points of that surface. Pending development of efficient algorithms for those computations, we strongly suggest that whenever counterintuitive protonation states are found in a computational study (e.g., the presence of a neutral aspartate/neutral histidine dyad instead of a deprotonated aspartate/protonated histidine pair), the reaction profile should be computed under each of the different protonation micro-states by constraining the relevant N–H or O–H bonds, in order to avoid artifacts inherent to the complex nature of the factors contributing to the pK a

Sjukvårdspersonalens upplevelse i mötet med patienter med fetma

Bakgrund: Då fetma ökar i världen behöver sjukvårdspersonal vara förberedd för att möta dessa patienter ute i vården. I ett möte sker en kontinuerlig kommunikation, vilket i sin tur har en stor betydelse på relationer, då det är en ömsesidig process. Det krävs vidare forskning för att utvärdera hur patientens vikt påverkar mötet med sjukvårdspersonal. Det var därför av intresse att forska vidare inom detta område. Syfte: Att beskriva sjukvårdspersonals upplevelser i mötet med patienter med fetma Metod: Metoden var en litteraturstudie med kvalitativ metod baserad på sju vetenskapliga artiklar. Analysen genomfördes utifrån Graneheim och Lundmans tolkning av kvalitativ innehållsanalys. Resultat: Efter analysprocessen framkom tre kategorier som beskrev studiens resultat. Att känna medkänsla. Att känna frustration. Att känna oro. Slutsats: Sjukvårdspersonals upplevelse i mötet med patienter med fetma bygger till stor del på förutfattade meningar. Då fetma alltmer blir ett växande problem i världen kan detta leda till att sjukvårdspersonal i sitt arbete kommer att möta dessa patienter i större utsträckning. Det behövs därför vidare forskning för att sjukvårdspersonal ska ha en trygg grund att stå på inför mötet med patienter med fetma. Endast då kan fetma bekämpas