| 11. |
|
|
| 12. |
- Nilsson, Thomas, 1965, et al.
(författare)
-
He-6 and neutron momentum distributions from He-8 in nuclear break-up reactions at 240 MeV/u
- 1996
-
Ingår i: Nuclear Physics A. - 0375-9474. ; 598:3, s. 418-434
-
Tidskriftsartikel (refereegranskat)abstract
- Neutron and He-6 momentum distributions from He-8 break-up reactions in a C target have been measured at 240 MeV/u. The two-neutron removal cross section was found to be sigma(-2n) = 0.27 +/- 0.03 b. The nature of the momentum distributions is interpreted in some simple reaction scenarios.
|
|
| 13. |
- Burghart, FJ, et al.
(författare)
-
Muons and muonium in Zn-spinels
- 1997
-
Ingår i: HYPERFINE INTERACTIONS. - : BALTZER SCI PUBL BV. - 0304-3843. ; 106:1-4, s. 187-192
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We have studied the magnetic spinel (Zn)[Fe-2]O-4 (T-N approximate to 10.5 K) and the non-magnetic spinels (Zn)[Al-2]O-4, (Zn)[Ga-2]O-4, (Zn)[ZnTi]O-4 and (Zn)[ZnSn]O-4, both with surface and decay channel muons. In (Zn)[Fe-2]O-4 the relaxation rate incre
|
|
| 14. |
- Hornyak, G. L., et al.
(författare)
-
Effective medium theory characterization of Au/Ag nanoalloy-porous alumina composites
- 1997
-
Ingår i: Nanostructured materials. - : Elsevier BV. - 0965-9773 .- 1872-9150. ; 9:1-8, s. 571-574
-
Tidskriftsartikel (refereegranskat)abstract
- The optical constants nAl and kAl of a 50/50 volume fraction Au/Ag alloy were derived synthetically by application of a Bruggeman (BG) effective medium expression. The alloy data base was then input into a Maxwell-Garnett (MG) effective medium expression to determine the absorption maximum of the nano- alloy/insulator composite (the volume fraction of the nano-alloy was equal to 5%). The absorption maximum (λmax) of the hypothetical composite was found to be 499 nm for spherical particles and was blue-shifted relative to that of a composite containing pure gold nanospheres (499 vs. 528 nm respectively). The transmission color at this wavelength was a red-orange. λmax in the range 512 to 519 nm (Au/Ag alloy between 60/40 - 70/30 volume fraction respectively) is needed to obtain the scarlet-red exhibited by the famous Lycurgus cup of 4th century Rome (1). © 1997 Acta Metallurgica Inc.
|
|
| 15. |
- Kremer, B, et al.
(författare)
-
Influence of lamotrigine on progression of early Huntington disease : a randomized clinical trial.
- 1999
-
Ingår i: Neurology. - 0028-3878 .- 1526-632X. ; 53:5, s. 1000-11
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To assess the efficacy of lamotrigine, a novel antiepileptic drug that inhibits glutamate release, to retard disease progression in Huntington disease (HD).BACKGROUND: Excitatory amino acids may cause selective neuronal death in HD, and lamotrigine may inhibit glutamate release in vivo.METHODS: A double-blinded, placebo-controlled study was conducted of 64 patients with motor signs of less than 5 years' duration who were randomly assigned to either placebo or lamotrigine and assessed at 0 (baseline), 12, 24, and 30 months. The primary response variable was total functional capacity (TFC) score. Secondary response variables included the quantified neurological examination and a set of cognitive and motor tests. Repeated fluorodeoxyglucose measurements of regional cerebral metabolism using PET also were included.RESULTS: Fifty-five patients (28 on lamotrigine, 27 on placebo) completed the study. Neither the primary response variable nor any of the secondary response variables differed significantly between the treatment groups. Both the lamotrigine and the placebo group deteriorated significantly on the TFC, in the lamotrigine group by 1.89 and the placebo group by 2.11 points. No effect of CAG size on the rate of deterioration could be detected.CONCLUSIONS: There was no clear evidence that lamotrigine retarded the progression of early Huntington disease over a period of 30 months. However, more patients on lamotrigine reported symptomatic improvement (53.6 versus 14.8%; p = 0.006), and a trend toward decreased chorea was evident in the treated group (p = 0.08). The study also identified various indices of disease progression, including motor tests and PET studies, that were sensitive to deterioration over time.
|
|
| 16. |
- Magnuson, Martin, 1965-, et al.
(författare)
-
Resonant inelastic soft X-ray scattering spectra at the nitrogen and carbon K-edges of poly(pyridine-2,5-diyl)
- 1999
-
Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - 0368-2048 .- 1873-2526. ; 101-103, s. 573-578
-
Tidskriftsartikel (refereegranskat)abstract
- Resonant inelastic scattering measurements of the conjugated polymer, poly(pyridine-2,5-diyl) have been performed at the nitrogen and carbon K-edges using synchrotron radiation. For comparison, molecular orbital calculations of the spectra have been carried out with the repeat unit as a model molecule of the polymer chain. The resonant emission spectra show depletion of the π electron bands which is consistent with symmetry selection and momentum conservation rules. The depletion is most obvious in the resonant inelastic scattering spectra of carbon while the nitrogen spectra are dominated by lone pair n orbital emission of σ symmetry and are less excitation energy dependent. By comparing the measurements to calculations an isomeric dependence of the resonant spectra is found giving preference to two of the four possible isomers in the polymer.
|
|
| 17. |
- Magnuson, Martin, 1965-, et al.
(författare)
-
The electronic structure of poly(pyridine-2,5-diyl) investigated by soft X-ray absorption and emission spectroscopies
- 1998
-
Ingår i: Chemical Physics. - 0301-0104 .- 1873-4421. ; 237:3, s. 295-304
-
Tidskriftsartikel (refereegranskat)abstract
- The electronic structure of the poly-pyridine conjugated polymer has been investigated by resonant and non-resonant inelastic X-ray scattering and X-ray absorption spectroscopies using synchrotron radiation. The measurements were made for both the carbon and nitrogen contents of the polymer. The analysis of the spectra has been carried out in comparison with molecular orbital calculations taking the repeat-unit cell as a model molecule of the polymer chain. The simulations indicate no significant differences in the absorption and in the non-resonant X-ray scattering spectra for the different isomeric geometries, while some isomeric dependence of the resonant spectra is predicted. The resonant emission spectra show depletion of the electron bands in line with symmetry selection and momentum conservation rules. The effect is most visual for the carbon spectra; the nitrogen spectra are dominated by lone pair n orbital emission of symmetry and are less frequency dependent.
|
|
| 18. |
- Marques, F. M., et al.
(författare)
-
Neutrons from the breakup of C-19
- 1996
-
Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 381:4, s. 407-412
-
Tidskriftsartikel (refereegranskat)abstract
- Neutrons arising from the breakup of a 30 MeV/nucleon C-19 beam on a tantalum target have been measured using the 98 element array DEMON. A narrow, forward peaked neutron angular distribution, with a corresponding momentum spread considerably smaller than those measured simultaneously for N-21, O-22 and F-24 was observed for charged fragments with Z
|
|
| 19. |
- Michaëlsson, E., et al.
(författare)
-
Macrophages, but not dendritic cells, present collagen to T cells
- 1995
-
Ingår i: European Journal of Immunology. - : Wiley. - 0014-2980 .- 1521-4141. ; 25:8, s. 2234-2241
-
Tidskriftsartikel (refereegranskat)abstract
- Dendritic cells, such as epidermal Langerhans cells, play a crucial role for the antigen-specific priming of T cells. We have addressed the question whether dendritic cells present collagen, a major protein component in tissues through which dendritic cells migrate, i.e. the basement membrane, dermis, and synovial tissue. Langerhans cells, spleen cells and peritoneal macrophages were compared for antigen-presenting capacity using a panel of mouse T cell hybridomas reactive with different determinants on type II collagen, myelin basic protein, ovalbumin and pepsin. Langerhans cells did not present any of the type II collagen determinants, unless the antigen was administered as a 15-mer peptide, but did present myelin basic protein, ovalbumin and pepsin. Spleen cells and peritoneal macrophages, in contrast, presented all type II collagen determinants. This biased antigen presentation was also observed when Langerhans cells were pulsed with antigen in vivo. The inability to present type II collagen is related to the collagen sequence as such, since both native type II collagen, type II collagen alpha chains, as well as a type II collagen determinant incorporated in type I collagen, were not presented by Langerhans cells. In addition, granulocyte/macrophage colony-stimulating factor-expanded blood dendritic cells displayed the same biased antigen presentation, suggesting that the inability to present collagen is not restricted to dendritic cells localized in epidermis. B cell-deficient mice could prime a type II collagen-reactive T cell response, thus excluding B cells as obligatory antigen-presenting cells for the priming of collagen-reactive T cells. We suggest that neither Langerhans cells nor B cells, but macrophages are the primary antigen-presenting cells in the immune response towards type II collagen.
|
|
