| 1. |
- Bergersen, L H, et al.
(författare)
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Immunogold detection of L-glutamate and D-serine in small synaptic-like microvesicles in adult hippocampal astrocytes.
- 2012
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Ingår i: Cerebral Cortex. - : Oxford University Press. - 1047-3211 .- 1460-2199. ; 22:7, s. 1690-1697
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Tidskriftsartikel (refereegranskat)abstract
- Glutamate and the N-methyl-D-aspartate receptor ligand D-serine are putative gliotransmitters. Here, we show by immunogold cytochemistry of the adult hippocampus that glutamate and D-serine accumulate in synaptic-like microvesicles (SLMVs) in the perisynaptic processes of astrocytes. The estimated concentration of fixed glutamate in the astrocytic SLMVs is comparable to that in synaptic vesicles of excitatory nerve terminals (≈ 45 and ≈ 55 mM, respectively), whereas the D-serine level is about 6 mM. The vesicles are organized in small spaced clusters located near the astrocytic plasma membrane. Endoplasmic reticulum is regularly found in close vicinity to SLMVs, suggesting that astrocytes contain functional nanodomains, where a local Ca(2+) increase can trigger release of glutamate and/or D-serine.
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| 2. |
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| 3. |
- Abu-samha, M, et al.
(författare)
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Lineshapes in carbon 1s photoelectron spectra of methanol clusters
- 2006
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Ingår i: Physical Chemistry Chemical Physics. - : Royal Society of Chemistry (RSC). - 1463-9084. ; 8:21, s. 2473-2482
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Tidskriftsartikel (refereegranskat)abstract
- A general protocol for theoretical modeling of inner-shell photoelectron spectra of molecular clusters is presented and applied to C1s spectra of oligomers and medium-sized clusters of methanol. The protocol employs molecular dynamics for obtaining cluster geometries and a polarizable force field for computing site-specific chemical shifts in ionization energy and linewidth. Comparisons to spectra computed from first-principle theories are used to establish the accuracy of the proposed force field approach. The model is used to analyze the C1s photoelectron spectrum of medium-sized clusters in terms of surface and bulk contributions. By treating the surface-to-bulk ratio as an adjustable parameter, satisfactory fits are obtained to experimental C1s spectra of a beam of methanol clusters.
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| 4. |
- Abu-samha, M, et al.
(författare)
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The local structure of small water clusters : imprints on the core-level photoelectron spectrum
- 2009
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Ingår i: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 42:5, s. 055201-
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Tidskriftsartikel (refereegranskat)abstract
- We report on an O 1s photoelectron-spectroscopy study of small neutral water clusters produced by adiabatic expansion. The photoelectron spectra were acquired under two different experimental conditions. At intermediate resolution, the cluster signal was characterized by a very broad O 1s peak with a flat top. In the second set of measurements, resolution was significantly increased at the cost of lower count rates. The cluster signal was now partly resolved into a bimodal structure. Extensive theoretical calculations were undertaken to facilitate an interpretation of the spectrum. These results suggest that the bimodal feature may be ascribed to ionization of water molecules in different hydrogen-bonding configurations, more specifically, molecules characterized by donation of either one or both hydrogen atoms in H-bonding.
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| 5. |
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| 6. |
- Bergersen, H, et al.
(författare)
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Predictors of emotional distress and well-being 2-5 years after stroke.
- 2013
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Ingår i: ISRN Stroke. - : Hindawi Limited. - 2090-9454.
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. To identify predictors of emotional distress and psychological wellbeing in stroke survivors 2–5 years after discharge from comprehensive rehabilitation. Material and Methods. The Hospital Anxiety and Depression Scale (HADS), the General Health Questionnaire (GHQ-30), and questions regarding life situations were mailed to former patients. Multiple regression analyses were performed. Results. The responses from 68 participants (37% women), of an average age of 58 years old, were used. Emotional distress (HADS > 10) was identified in 41%. Well-being (GHQ-30 < 6) was identified in 46%. Not surprisingly, there was a strongly negative association between well-being (GHQ-30 < 6) and emotional distress (HADS > 10) at follow up. Dependency in toileting during rehabilitation predicted emotional distress 2–5 years later. Finally, well-being at followup was predicted by age > 65 years, independent mobility, perceiving proxies as supportive, and being in employment. Conclusions. Dependence in the activities of daily living 3–6 months after-injury predicted emotional distress 2–5 years after-stroke. Being over 65 years, having an occupation, proxy support and being less dependent all predicted well-being. Emotional distress and well-being were clearly negatively associated. Gender, education, marital status, and type of stroke were not associated with the outcome measures.
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| 7. |
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| 8. |
- Harnes, J., et al.
(författare)
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Neutral CH3Cl and CH3Br clusters studied by X-ray photoelectron spectroscopy and modeling : Insight to intermolecular interactions and structure
- 2008
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Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 166, s. 53-64
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Tidskriftsartikel (refereegranskat)abstract
- Single-component clusters of methyl chloride and methyl bromide have been produced by adiabatic expansion and their C 1s, Cl 2p and Br 3d photoelectron spectra recorded using synchrotron radiation and a high-resolution electron analyzer. The experimentally observed cluster-to-monomer shifts in core-level ionization energies are interpreted in terms of theoretical models based on molecular dynamics (MD) in conjunction with polarizable force fields developed and validated in the course of this work. MD simulations have also been used to explore the global and local structure of the clusters, providing evidence for a predominance of anti-parallel, head-to-tail arrangement of neighboring molecules. Whereas the cluster-to-monomer shifts are strongly dominated by polarization effects, the polarization contribution is very similar for ionization of carbon and the halogen, respectively. The difference in cluster shifts between the two ionization sites within the same molecule, C vs. Cl or C vs. Br, is thus determined by permanent electrostatic moments, i.e. the magnitude and direction of the permanent dipole moment and the local alignment of dipoles.
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| 9. |
- Lindblad, A., et al.
(författare)
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Charge delocalization dynamics of ammonia in different hydrogen bonding environments : free clusters and in liquid water solution
- 2009
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 11:11, s. 1758-1764
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Tidskriftsartikel (refereegranskat)abstract
- Valence and core level photoelectron spectra and Auger electron spectra of ammonia in pure clusters have been measured. The Auger electro spectra of gas-phase ammonia, pure ammonia clusters and ammonia in aqueous solution are compared and interpreted via ab initio calculations of the Auger spectrum of the ammonia monomer and dimer. The calculations reveal that the final two-hole valence states can be delocalized over both ammonia molecules. Features at energies pertaining to delocalized states involving one, or more, hydroge bonding orbitals can be found in both the ammonia cluster Auger electron spectrum and in that of the liquid solvated molecule. The lower Coulombic repulsion between two delocalized valence final state holes gives higher kinetic energy of the Auger electrons which is also observed in the spectra. This decay path-specific to the condensed phase-is responsible for more than 5% of the total cluster Auger intensity. Moreover, this interpretation is also applicable to the solid phase since the same features have been observed, but not assigned, in the Auger spectrum of solid ammonia.
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| 10. |
- Lindblad, A, et al.
(författare)
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Postcollision interaction in noble gas clusters: Observation of differences in surface and bulk line shapes
- 2005
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 123:21
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Tidskriftsartikel (refereegranskat)abstract
- The surface and bulk components of the x-ray photoelectron spectra of free noble gas clusters are shown to display differences in the influence of postcollision interaction between the photoelectron and the Auger electron on the spectral line shape; the bulk component is observed to be less affected than the surface and atomic parts of the spectra. A model for postcollision interaction in nonmetallic solids and clusters is also provided which takes the polarization screening into account. Core-level photoelectron spectra of Ar, Kr, and Xe have been recorded to verify the dependence of the postcollision interaction effect on the polarizability of the sample.
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