| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Aleksandrov, D., et al.
(författare)
-
Invariant mass spectrum and alpha-n correlation function studied in the fragmentation of He-6 on a carbon target
- 1998
-
Ingår i: Nuclear Physics A. - 0375-9474. ; 633:2, s. 234-246
-
Tidskriftsartikel (refereegranskat)abstract
- Momentum distributions and invariant mass spectra from the breakup of He-6 ions with an energy of 240 MeV/u interacting with a carbon target have been studied. The data were used to extract information about the reaction mechanism which is influenced by the structure of He-6. It is found that the dominant reaction mechanism is a two-step process: knock out of one neutron followed by the decay of the He-5 resonance. The shape of the (alpha+n) two-body invariant mass spectrum is interpreted as mainly reflecting the 5He ground state which is a J(pi) = 3/2(-) resonance. However, no evidence for correlations between cu particles and neutrons is observed in the momentum widths of the distributions. It is demonstrated that a combined analysis of the two-body invariant mass spectrum and an appropriate correlation function may be used to determine the properties of the intermediate resonance. (C) 1998 Elsevier Science B.V.
|
|
| 5. |
- 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
|
|
| 6. |
- Karadima, G, et al.
(författare)
-
Nondisjunction studies in trisomy 8.
- 1997
-
Ingår i: CYTOGENETICS AND CELL GENETICS. - 0301-0171. ; 77:1-2, s. P105-P105
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
| 11. |
- Axelsson, L., et al.
(författare)
-
Beta decay of Ar-31
- 1998
-
Ingår i: Nuclear Physics A. - 0375-9474. ; 634:4, s. 475-496
-
Tidskriftsartikel (refereegranskat)abstract
- A complete study of Ar-31 beta decay has been made by high-resolution charged-particle and gamma-ray spectroscopy. Beta-delayed radiation was detected by an array of three charged-particle detectors and a large-volume germanium detector. Fifteen new energy levels were discovered in Cl-31. The beta-strength distribution, measured to 14.5 MeV, is compared with a shell-model calculation in the full sd space. The quenching of the Gamow-Teller strength and the isospin impurity of the IAS in Cl-31 are discussed. (C) 1998 Published by Elsevier Science B.V.
|
|
| 12. |
- Axelsson, L., et al.
(författare)
-
Two-proton emission in the decay of Ar-31
- 1998
-
Ingår i: Nuclear Physics A. - 0375-9474. ; 628:3, s. 345-362
-
Tidskriftsartikel (refereegranskat)abstract
- Several beta-delayed two-proton branches were observed in the decay of Ar-31, the most intense ones proceeding through the isobaric analogue state (IAS) in Cl-31. The mechanism of the two-proton emission is studied via the energy and angular distributions of the two protons, Simultaneous emission of the two protons fits the present data well, sequential decays might also describe them. Independent of the decay mechanism, a spin of 5/2 for the IAS is suggested, An improved limit on the direct two-proton emission fi om the ground state of Ar-31 is presented, (C) 1998 Elsevier Science B.V.
|
|
| 13. |
|
|
| 14. |
|
|
| 15. |
- Lernmark, Å, et al.
(författare)
-
Heterogeneity of islet pathology in two infants with recent onset diabetes mellitus
- 1995
-
Ingår i: Virchows Archiv. - 0945-6317. ; 425:6, s. 631-640
-
Tidskriftsartikel (refereegranskat)abstract
- The mechanisms by which the beta cells of pancreatic islets are destroyed in insulin-dependent diabetes mellitus (IDDM) are poorly understood. In this report the pancreatic histo- and immunopathology of two children, both HLA-DR 3/4, DQ 2/8 positive and who both died from cerebral oedema within a day of clinical diagnosis of IDDM, were investigated. Patient 1, a 14-month-old girl, had a 4-week history of polydipsia and polyuria. Patient 2, a 3-year-old boy, had 2 days of illness. Both patients had a similarly severe loss of insulin cells but differed markedly as to the extent of lymphocytic islet infiltration (insulitis). Apart from insulitis, marked islet macrophage infiltration was demonstrated in both patients with the HAM-56 monoclonal antibody. Neither patient showed aberrant expression of HLA class II antigens on insulin-immunoreactive cells, but allele-specific HLA-DQ8 expression was evident on endothelial cells. Glutamic acid decarboxylase immunoreactivity was detected in both insulin- and glucagon-immunoreactive cells. It is concluded that the heterogeneity of islet pathology, especially insulitis, may reflect different dynamics and extent rather than different pathomechanisms of immune destruction of islets in IDDM.
|
|
| 16. |
|
|
| 17. |
|
|
| 18. |
- Baslund, B., et al.
(författare)
-
Screening for anti-neutrophil cytoplasmic antibodies (ANCA) : Is indirect immunofluorescence the method of choice?
- 1995
-
Ingår i: Clinical and Experimental Immunology. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 99:3, s. 486-492
-
Tidskriftsartikel (refereegranskat)abstract
- Detection of ANCA has become an important tool for the diagnosis and monitoring of disease activity in Wegener's granulomatosis (WG). Unfortunately, a group of sera positive by the standard method for ANCA detection, indirect immunofluorescence (IIF), are negative when more specific tests with purified proteins are used. In order to examine this discrepancy we examined groups of sera selected for being (i) C-ANCA-positive by IIF; (ii) positive in proteinase 3 (PR3)-ANCA ELISA; and (iii) from 24 patients with WG. The following assays were used: IIF, PR3-ANCA ELISA and capture PR3-ANCA ELISA using MoAbs against PR3. Furthermore, since granule enzymes are released during coagulation, we also measured ANCA in complex with PR3. To test if granule enzyme release had any influence on ANCA detection, both serum and EDTA-plasma were collected from a patient with active WG. No difference, however, was found. In the IIF-positive group (n = 60) 68% of the sera were positive in PR3-ANCA ELISA, 86% in capture PR3-ANCA-ELISA and 80% were positive for the PR3/IgG-ANCA complex. In the PR3-ANCA ELISA group (n = 105) 88% of the sera were positive by IIF, 98% in capture PR3-ANCA ELISA and 53% in the PR3/IgG-ANCA assay. To evaluate the tests clinically sera from 24 patients with WG were examined. In the remission group (n = 10) two patients were positive by IIF, four in the PR3-ANCA ELISA, and five in the capture PR3-ANCA ELISA. Fourteen had active disease, and in this group 11/14 were positive by IIF, 10/14 in PR3-ANCA ELISA and 12/14 by capture-ELISA. The correlation between IIF and capture PR3-ANCA ELISA titre (r = 0.72, P = 0.0095) was better than between PR3-ANCA ELISA and IIF (r = 0.56, P = 0.043). It is concluded that the capture PR3-ANCA ELISA is more sensitive than PR3-ANCA ELISA, and that the capture ELISA can be used for screening of PR3-ANCA.
|
|
| 19. |
|
|
| 20. |
- Hansson, Oskar, et al.
(författare)
-
Transgenic mice expressing a Huntington's disease mutation are resistant to quinolinic acid-induced striatal excitotoxicity
- 1999
-
Ingår i: Proceedings of the National Academy of Sciences. - 1091-6490. ; 96:15, s. 8727-8732
-
Tidskriftsartikel (refereegranskat)abstract
- Huntington's disease (HD) is a hereditary neurodegenerative disorder presenting with chorea, dementia, and extensive striatal neuronal death. The mechanism through which the widely expressed mutant HD gene mediates a slowly progressing striatal neurotoxicity is unknown. Glutamate receptor-mediated excitotoxicity has been hypothesized to contribute to the pathogenesis of HD. Here we show that transgenic HD mice expressing exon 1 of a human HD gene with an expanded number of CAG repeats (line R6/1) are strongly protected from acute striatal excitotoxic lesions. Intrastriatal infusions of the N-methyl-D-aspartate (NMDA) receptor agonist quinolinic acid caused massive striatal neuronal death in wild-type mice, but no damage in transgenic HD littermates. The remarkable neuroprotection in transgenic HD mice occurred at a stage when they had not developed any neurological symptoms caused by the mutant HD gene. At this stage there was no change in the number of striatal neurons and astrocytes in untreated R6/1 mice, although the striatal volume was decreased by 17%. Moreover, transgenic HD mice had normal striatal levels of NMDA receptors, calbindin D28k (calcium buffer), superoxide dismutase activity (antioxidant enzyme), Bcl-2 (anti-apoptotic protein), heat shock protein 70 (stress-induced anti-apoptotic protein), and citrate synthase activity (mitochondrial enzyme). We propose that the presence of exon 1 of the mutant HD gene induces profound changes in striatal neurons that render these cells resistant to excessive NMDA receptor activation.
|
|
| 21. |
- Honkanen, A., et al.
(författare)
-
Fine structure in the beta-delayed proton decay of Ar-33
- 1996
-
Ingår i: Nuclear Physics A. - 0375-9474. ; 611:1, s. 47-55
-
Tidskriftsartikel (refereegranskat)abstract
- Low-energy beta-delayed protons from Ar-33 have been measured for the first time, The data reveal states, which, despite unfavourable barrier penetrability values, strongly decay to the first excited 2(+) state in S-32. The observation is discussed in terms of the standard shell model, A natural explanation is provided by the large spectroscopic amplitudes, involving s(1/2) and d(3/2) orbitals, as well as the l = 0 barrier penetrability, favouring the decay to the 2(+) state.
|
|
| 22. |
|
|
| 23. |
|
|
| 24. |
- Petersen, H, et al.
(författare)
-
Auditory Feedback Regulation of Perturbed Stance in Stroke Patients
- 1996
-
Ingår i: Scandinavian Journal of Rehabilitation Medicine. - 0036-5505. ; 28:4, s. 23-217
-
Tidskriftsartikel (refereegranskat)abstract
- The effect of auditory input on impaired postural control perturbations was evaluated in two groups of stroke patients participating in a rehabilitation programme after a recent (< 12 months) and single episode of stroke, or less recent (> 12 months), and multiple episodes of stroke. Auditory input took the form of feedback signals generated by the forces actuated by the feet on a force platform in response to the patient's postural movements. Vibratory stimuli applied to the calf muscles induced sudden perturbations which the patients had to counteract to maintain an upright stance. The effect of auditory feedback in facilitating the maintenance of stance was measured in terms of sagittal torque variance (body sway) recorded on a force platform. In the presence of auditory feedback, body torque variance in response to perturbed posture was significantly reduced in the recent stroke group, whereas in the less recent stroke group the auditory feedback did not prove effective. Moreover, learning seems essential to utilize the auditory feedback.
|
|
| 25. |
- Petersen, H, et al.
(författare)
-
Vestibular Stimulation Perturbs Human Stance also at Higher Frequencies
- 1995
-
Ingår i: Acta Oto-Laryngologica, Supplement. - 0365-5237. ; 520 Pt 2, s. 6-443
-
Tidskriftsartikel (refereegranskat)abstract
- The effect of primary vestibular disturbance on postural control was investigated in 11 normal subjects exposed to perturbation by bi-polar binaural galvanic stimulation of the vestibular nerve. The stimulus consisted of 30 s of sinusoidal galvanic stimulation at frequencies of 0.2, 0.3, 0.5, 1.0, 1.5, 2.0, 3.0 and 4.0 Hz, with a current of +/- 1 mA, the subject standing with open or closed eyes and the response evoked being recorded with a force platform. As compared with resting values, i.e. no stimuli, variance of lateral body sway was significantly greater at all frequencies tested in the closed eyes condition and at frequencies of 0.2, 0.5, 1.0, 3.0 and 4.0 Hz in the open eyes condition; using a high pass filter with a cut-off frequency of 0.1 Hz, variance of lateral body sway was significantly greater at frequencies 0.2, 0.3, 0.5, 1.0 and 2.0 Hz in the closed eyes condition and at frequencies 0.5 and 2.0 Hz in the open eyes condition. These findings suggest that in the lateral plane vestibular input affects and probably contributes to human postural control over a wider frequency range than suggested by findings in previous studies. Moreover, the visual contribution appears to enable the subject to suppress vestibular input causing lateral body sway only in the lower frequency range (here at 0.2 and 0.3 Hz). This evidence of vestibular contribution to postural control in the lateral plane is consistent with the response characteristics of the vestibulo-ocular reflex.
|
|
| 26. |
- Petersen, PH, et al.
(författare)
-
The influence of analytical bias on diagnostic misclassifications
- 1997
-
Ingår i: CLINICA CHIMICA ACTA. - : ELSEVIER SCIENCE BV. - 0009-8981. ; 260:2, s. 189-206
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Quality specifications for analytical imprecision and bias based on 'the state of the art', 'biology' and 'analysis of clinical situations' have been proposed by several scientists. Most interesting is the assessment of 'diagnostic misclassifications' bas
|
|
| 27. |
|
|
| 28. |
- Vought, Lena B. M., et al.
(författare)
-
Effect of riparian structure, temperature and channel morphometry on detritus processing in channelized and natural woodland streams in southern Sweden
- 1998
-
Ingår i: Aquatic conservation. - 1052-7613 .- 1099-0755. ; 8:2, s. 273-285
-
Tidskriftsartikel (refereegranskat)abstract
- 1. Ten south Swedish streams were selected to represent two distinct types—natural woodland streams and channelized streams. Measurements were made on leaching, decomposition and microbial respiration of the dominant riparian vegetation (European Black Alder), structure of the benthic macroinvertebrate community, macroinvertebrates inhabiting leaf material, channel morphometry, macrophyte composition, water chemistry and total accumulated degree days.2. Leaf decomposition rates were not significantly different when channelized streams were compared with natural woodland streams. In channelized streams the average decomposition rate was −0.0556±0.0337 (±S.D.) day−1 compared with −0.0457±0.0115 day−1 in natural woodland streams.3. There was significantly higher variation in leaf decomposition among the five channelized streams compared with the five natural streams (F–test, p<0.05). This was mainly due to extremely high decomposition rates in channelized streams colonized by emergent macrophytes.4. Alder decomposition rates were low in channelized streams without macrophytes (−0.0053 °day−1), intermediate in natural streams (−0.0087 °day−1), and high in channelized streams with macrophytes (−0.0136 °day−1).5. The shredder functional group ranged from 13 to 70% of the benthic community in the natural streams. Channelized streams had a more variable shredder population ranging from 0.5 to 80%. The highest values were found in channelized streams that had become colonized by macrophytes.6. There was a significant difference in total accumulated degree days between the channelized (256 °day) and natural woodland streams (209 °day). This is most likely an effect of drainage tiles contributing warmer groundwater to the channelized streams during fall.7. It is concluded that, contrary to the prevailing conceptual model of stream systems, decomposition rates and macroinvertebrate functions are not necessarily reduced in streams without riparian vegetation. The loss of the riparian canopy can stimulate emergent macrophytes which will provide autochthonous detritus for benthic communities. This will change benthic community structure and the life cycle strategies present.
|
|
