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- A. Nojima,, et al.
(author)
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Calculational aspects of electron-phonon coupling at surfaces
- 2008
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In: J. Phys: Condens. Matter. - : IOP Publishing. - 1361-648X .- 0953-8984. ; 20
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Journal article (peer-reviewed)abstract
- We study the validity of two frequently used approximations in calculations of electron–phonon coupling at surfaces. The rigid-ion approximation is a standard approximation used for the bulk metals. On the basis of density functional theory calculations, we find that for Be this approximation is as valid for surface atoms as for bulk atoms. In addition, the slab method for calculations of a phonon induced surface state lifetime is examined. The convergence of the electron–phonon matrix element with respect to the thickness of the slab is studied for several systems. When the number of slab layers is increased, the net effect of decreasing overlap and increasing number of final states depends strongly on the decay length of the surface state wavefunction and the band structure.
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- A. Nojima,, et al.
(author)
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Model Eliashberg function for surface states
- 2008
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In: Applied Surface Science. ; 254:23
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Journal article (peer-reviewed)abstract
- We present a simplified procedure for the analysis of the phonon-induced lifetimes of surface states. The model includes information about the electron and phonon structure and is thus more reliable than procedures based on phonon Debye models. We apply the model to calculate the lifetime broadening of Cu(1 1 1) and Al(0 0 1) surface states. The obtained Eliashberg functions and lifetimes are in reasonable agreement with previous detailed studies.
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- Bexell, U., et al.
(author)
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A ToF-SIMS study of linseed oil bonded to mercapto silane treated aluminium
- 2004
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In: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 231-2, s. 362-365
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Journal article (peer-reviewed)abstract
- ToF-SIMS has been used to analyse an aluminium surface treated with a vegetable oil using a mercapto silane as a coupling agent between the aluminium substrate and the vegetable oil. The coupling between the vegetable oil and the mercapto silane was obtained through a photoinduced thiol-ene reaction using UV-radiation. The ToF-SIMS results show that the desired thiolene reaction has taken place between the unsaturated parts of the vegetable oil and the thiol groups of the mercapto silane via the thiol-ene reaction forming a surface film.
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- Carlsson, Anna K, 1966, et al.
(author)
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High-resolution photoemission from a tunable quantum well: Cu(111)/Na
- 1997
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In: Physical Review B - Condensed Matter and Materials Physics. - 2469-9950 .- 2469-9969. ; 56:3, s. 1593 - 1600
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Journal article (peer-reviewed)abstract
- High-resolution photoemission (ΔE=5 meV) at a low photon energy (3.82 eV) is used to probe discrete quantum-well-type subband states near, below, and above EF for Cu(111) covered with 2 ML or less of Na. A subband characteristic of the monolayer range shifts gradually to lower energy as the coverage is increased, extending below the Fermi level for coverages above 0.85 ML. Combined with previous observations of shifts for filled and empty states the present results show that the Na monolayer has continuously tunable quantum-well state energies. Beyond the monolayer range quantum-well states characteristic of both one and two atomic layers are observed, indicating growth of the second layer via monolayer high islands. A small downshift, by 25 meV, with increasing coverage in the second layer is ascribed to an increase of the island size. Lorentzian photoemission line shapes are observed for well-ordered samples. The linewidth varies linearly with temprature in the probed range (130–295 K) and this is ascribed to the phonon contribution to the width. Structural disorder leads to an asymmetric line, which is Lorentzian on the steeper, low-kinetic-energy side.
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- Graf, W, et al.
(author)
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The influence of early postoperative intraperitoneal chemotherapy on human wound healing.
- 1994
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In: Journal of Surgical Research. - : Elsevier BV. - 0022-4804 .- 1095-8673. ; 57:3, s. 394-400
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Journal article (peer-reviewed)abstract
- Cell ingrowth, hydroxyproline accumulation, and mRNA expression of collagen I were measured in two polytetrafluoroethylene grafts implanted subcutaneously at the time of colorectal cancer surgery to evaluate the influence of early postoperative chemotherapy on human wound healing. Eleven patients treated with intraperitoneal 5-fluorouracil and intravenous folinic acid Days 1-6 after operation were compared with 15 patients who underwent surgery alone. At 1 week, chemotherapy-treated patients had accumulated less hydroxyproline (mean 0.35 +/- 0.33 micrograms/cm) compared with untreated patients (mean 0.73 +/- 0.37 micrograms/cm, P < 0.05). By 2 weeks, the hydroxyproline content had increased sixfold in the chemotherapy group (P < 0.01) and threefold in the nonchemotherapy group (P < 0.01) and there was no difference between the groups. Cell and connective tissue ingrowth and total RNA content did not differ between the groups at any point in time, but at 1 week the mRNA expression of collagen I was higher in the chemotherapy group (P < 0.05). These results indicate that collagen accumulation in human subjects is reduced during a short course of postoperative chemotherapy and normalizes after the end of treatment.
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- Hellsing, Maja S., et al.
(author)
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Structure of a large colloidal crystal : controlling orientation and three-dimensional order
- 2012
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In: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 2:18, s. 7091-7098
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Journal article (peer-reviewed)abstract
- The three-dimensional crystal structure of charge stabilised polystyrene latex in deionised water was investigated by small-angle neutron diffraction. Crystallisation with a grain size of approximately 1 x 1 cm(2) was observed when the sample was flowed gently in to a 2 mm path cell. Bragg scattering peaks arising from the structure were observed under rotation about three perpendicular axes of the sample. The diffraction patterns indicate clearly that there is a cubic close packed structure with a 110 axis perpendicular to the cell wall. Rotations in small steps show large changes and indicate that the crystal is well oriented and has three-dimensional order. The crystal orientation was controlled by the meniscus and direction of flow when filling the cell.
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- Lindqvist, Ulla, et al.
(author)
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A hyaluronan-loading test applied to patients with liver and joint diseases
- 1992
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In: Clinica Chimica Acta. - 0009-8981 .- 1873-3492. ; 210:1-2, s. 119-132
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Journal article (peer-reviewed)abstract
- The serum hyaluronan disappearance data, after an intravenous bolus injection of hyaluronan, were evaluated in terms of model-based parameters. The loading test was performed in 10 healthy persons (basal serum hyaluronan concentration, C0, 24.9 +/- 8.9 micrograms/l [mean +/- S.D.]), 6 patients with joint disease (62.3 +/- 41.1 micrograms/l) and 19 patients with liver disease (206 +/- 214 micrograms/l). The highest maximum Michaelis-Menten elimination rate (Vmax = 287 +/- 86 micrograms/min) was found in patients with joint disease, significantly higher than in healthy persons (Vmax = 179 +/- 16, P = 0.0015) and in patients with liver disease (Vmax = 149 +/- 59, P = 0.0002). C0 and Vmax were evaluated as discriminants for assessment of residual liver function. In patients with liver disease C0 correlated with liver function score (r = 0.875, P < 0.0001) and serum albumin concentration (r = -0.813, P < 0.0001). The Vmax parameter did not correlate with conventional liver function tests or with the liver score but a significantly negative correlation of Vmax with C0 was found in patients with liver disease. A combination of the C0 level and the Vmax parameter was found to discriminate between healthy persons, patients with joint disease and patients with liver disease and should be of benefit in separating patients, with or without elevated serum hyaluronan levels, into groups having increased influx or reduced elimination, respectively, of circulating hyaluronan.
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- Lindstedt, Göran, 1937, et al.
(author)
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[How reliable is the laboratory? Increased needs of patient-related quality assurance]. : Kan man lita på laboratoriet? Okat behov av patientrelaterad kvalitetssäkring. Expertgruppen för endokrinologi inom EQUALIS.
- 1999
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In: Läkartidningen. - 0023-7205. ; 96:38, s. 4028-31
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Journal article (peer-reviewed)abstract
- Recent developments in medical care and research involve the increased use of immunochemical assays for hormones, tumour markers, vitamins and drugs. External quality assurance programmes using pooled human sera usually fail to detect analytical interference due to substances (e.g. anti-immunoglobulin or anti-ligand antibodies) present in individual serum specimens. The article reports on experience gained during a three-year period when specimens from individual patients attending a thyroid unit were distributed to hospital laboratories in Sweden for analysis. Specimen selection criteria were based on contradictory findings at the initial clinical or laboratory evaluation. The programme has given rise to the formation of a network of the laboratories involved, under the co-ordination of EQUALIS (External quality assurance in laboratory medicine in Sweden).
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- Nouhi, Shirin, et al.
(author)
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Interactions of perfluoroalkyl substances with a phospholipid bilayer studied by neutron reflectometry
- 2018
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In: Journal of Colloid and Interface Science. - : Elsevier. - 0021-9797 .- 1095-7103. ; 511, s. 474-481
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Journal article (peer-reviewed)abstract
- The interactions between perfluoroalkyl substances (PFASs) and a phospholipid bilayer (1,2-dimyristoyl-sn-glycero-3-phosphocholine) were investigated at the molecular level using neutron reflectometry. Representative PFASs with different chain length and functional groups were selected in this study including: perfluorobutane sulfonate (PFBS), perfluorohexanoate (PFHxA), perfluorohexane sulfonate (PFHxS), perfluorononanoate (PFNA), perfluorooctane sulfonate (PFOS), and perfluorooctane sulfonamide (FOSA). All PFASs were found to interact with the bilayer by incorporation, indicating PFAS ability to accumulate once ingested or taken up by organisms. The interactions were observed to increase with chain length and vary with the functional group as SO2NH2" role="presentation">(FOSA) > SO2O−" role="presentation">(PFOS) > COO−(PFNA). The PFAS hydrophobicity, which is strongly correlated with perfluorocarbon chain length, was found to strongly influence the interactions. Longer chain PFASs showed higher tendency to penetrate into the bilayer compared to the short-chain compounds. The incorporated PFASs could for all substances but one (PFNA) be removed from the lipid membrane by gentle rinsing with water (2 mL min−1). Although short-chain PFASs have been suggested to be the potentially less bioaccumulative alternative, we found that in high enough concentrations they can also disturb the bilayer. The roughness and disorder of the bilayer was observed to increase as the concentration of PFASs increased (in particular for the high concentrations of short-chain substances i.e. PFHxA and PFBS), which can be an indication of aggregation of PFASs in the bilayer.
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