| 11. |
- Pettersson, L. G. M., et al.
(författare)
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Electronic structure effects from hydrogen bonding in the liquid phase and in chemisorption : an integrated theory and experimental effort
- 2001
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Ingår i: Journal of Synchrotron Radiation. - 0909-0495 .- 1600-5775. ; 8, s. 136-140
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Tidskriftsartikel (refereegranskat)abstract
- A closely integrated theoretical and experimental effort to understand chemical bonding using X-ray spectroscopic probes is presented. Theoretical techniques to simulate XAS (X-ray absorption spectroscopy), XES (X-ray emission spectroscopy), RIXS (resonant inelastic X-ray scattering) and XPS (X-ray photoelectron spectroscopy) spectra have been developed and implemented within a density functional theory (DFT) framework. In combination with new experimental techniques, such as high-resolution XAS on liquid water under ambient conditions and XES on complicated surface adsorbates, new insight into e.g. hydrogen-bonded systems is obtained. For the (3 x 2) overlayer structure of glycine/Cu(110), earlier work has been extended to include adsorbate-adsorbate interactions. Structures are optimized for large cluster models and for periodic boundary conditions. It is found that specific features in the spectra arise from hydrogen-bonding interactions, which thus have important effects at the molecular-orbital level. XAS on liquid water shows a pronounced pre-edge feature with significant intensity, while the spectrum of ice shows only little intensity in this region. Theoretical spectrum calculations, based on instantaneous structures obtained from molecular-dynamics (MD) simulations, show that the pre-edge feature in the liquid is caused by water molecules with unsaturated hydrogen bonding. Some aspects of the theoretical simulations will be briefly discussed.
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| 12. |
- Plashkevych, O., et al.
(författare)
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Calculations of valence electron binding energies using Kohn-Sham theory and transition potentials
- 2000
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Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - 0368-2048 .- 1873-2526. ; 106:1, s. 51-63
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Tidskriftsartikel (refereegranskat)abstract
- Motivated by the success in computing X-ray photoelectron binding energies and chemical shifts in the core region we apply the Kohn-Sham density functional and transition potential methodology to calculations of binding energies in the valence electron region. Accurate predictions of binding energies over a large energy interval are obtained for a set of molecules for which the quasi-particle approximation holds, but which still have been considered notoriously difficult. The accuracy is found to be a few tenths of an eV in the outermost valence region, slightly poorer in the intermediate region, and seems to be maintained with increasing size of the system.
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| 13. |
- Thevenin, P. O., et al.
(författare)
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Catalytic combustion of methane over cerium-doped palladium catalysts
- 2003
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Ingår i: Journal of Catalysis. - : Elsevier BV. - 0021-9517 .- 1090-2694. ; 215:1, s. 78-86
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Tidskriftsartikel (refereegranskat)abstract
- Various Pd-supported catalysts have been prepared using three different types of alumina as support material: (a) gamma-alumina, (b) Ba-stabilized alumina, and
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| 14. |
- Triguero, L., et al.
(författare)
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Direct experimental measurement of donation/back-donation in unsaturated hydrocarbon bonding to metals
- 2000
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 122:49, s. 12310-12316
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Tidskriftsartikel (refereegranskat)abstract
- Using resonant and off-resonant X-ray emission spectroscopy, in combination with ground-state density functional calculations, we examine the electronic structure of chemisarbed ethylene and benzene on thr Cu(110) surface to investigate the suitability of the donation/back-donation bonding model given by Dewar(1) and Chart and Duncanson(2) (DCD) for the interaction of unsaturated hydrocarbons with metal surfaces. We give an experimental verification of the DCD model and find donation/back-donation to be twice as large for ethylene as for benzene. In particular, the degree of sigma-pi mixing (rehybridization) is found to correspond to the amount of donation/back-donation, which is put in relation to the aromatic and nonaromatic pi characters of benzene and ethylene, respectively.
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| 15. |
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| 16. |
- Öström, Henrik, et al.
(författare)
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Bonding of Saturated Hydrocarbons to Metal Surfaces
- 2003
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Ingår i: Physical Review Letters. - : The American Physical Society. - 0031-9007. ; 91:4, s. 046102-
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Tidskriftsartikel (refereegranskat)abstract
- The adsorption of octane on Cu(110) was studied by x-ray absorption and x-ray emission spectroscopy, in combination with spectrum calculations in the framework of density functional theory, as a model system for alkane adsorption on transition metals. Significant electron sharing between the adsorbate and metal surface and involvement of both bonding and antibonding C-H molecular orbitals in the molecule-metal bond was found. The calculations were extended to the case of octane adsorbed on Ni(110), and the position of the metal d band was found to be important for the bonding. The results were generalized to show that this is important for the efficiency as an alkane dehydrogenation catalyst.
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| 17. |
- Andersson, J, et al.
(författare)
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A population-based study on the first forty-eight breast cancer patients receiving trastuzumab (Herceptin (R)) on a named patient basis in Sweden
- 2002
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Ingår i: Acta Oncologica. - : Informa UK Limited. - 1651-226X .- 0284-186X. ; 41:3, s. 276-281
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Tidskriftsartikel (refereegranskat)abstract
- Several studies have presented data on the efficacy and tolerability of trastuzumab within clinical trials. As a minority of patients is included in these trials, we undertook this retrospective study to describe trastuzumab therapy in clinical routine and its tolerability. We reviewed the medical records of the first 48 patients in Sweden who received treatment with trastuzumab on a named patient basis with (n = 29) and without (n = 19) chemotherapy. Forty-six patients had metastatic disease and had failed to respond to several prior regimens before starting antibody treatment. Two patients had locally advanced breast cancer failing on given neoadjuvant therapy. Patients with breast cancers with strong (3+) c-erbB-2 overexpression tended to have an improved survival from start of trastuzumab treatment versus those with a moderate (2+) overexpression (p=0.09). Adverse events were registered in 22 patients (46%). The most common and acute side effects were fever and chills (7 patients, 15%). The toxicity seemed reasonable but two patients (4%) suffered serious cardiac events, both of them having received previous treatment with antracyclines.
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| 18. |
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| 19. |
- Brena, Barbara, et al.
(författare)
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Ultrafast Molecular Dissociation of Water in Ice
- 2004
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Ingår i: Physical Review Letters. - : The American Physical Society. - 1079-7114 .- 0031-9007. ; 93, s. 148302-148305
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Tidskriftsartikel (refereegranskat)abstract
- Using x-ray emission and photoemission spectroscopies to measure the occupied valence levels in a thin crystalline ice film, we resolve the ionization-induced dissociation of water in ice on a femtosecond time scale. Isotope substitution confirms proton transfer during the core-hole lifetime in spite of the nonresonant excitation. Through ab initio molecular dynamics on the core-ionized state, the dissociation and spectrum evolution are followed at femtosecond intervals. The theoretical simulations confirm the experimental analysis and allow for a detailed study of the dissociative reaction path.
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| 20. |
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