| 1. |
- Ausen, Dag, et al.
(författare)
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Foresight Biomedical Sensors
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The foresight study on biomedical sensors has addressed different approaches with future use of biomedical sensors in the health care sector, like: How will biomedical sensors shape the healthcare systems of the future? How can they impact the quality and cost of healthcare and what are the business opportunities in the Nordic region?
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| 2. |
- Bryllert, Tomas, et al.
(författare)
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Designed emitter states in resonant tunneling through quantum dots
- 2002
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 80:15, s. 2681-2683
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Tidskriftsartikel (refereegranskat)abstract
- Resonant tunneling through a single layer of self-assembled quantum dots (QDs) is compared to tunneling through two layers of vertically aligned (stacked) dots. The difference can be viewed as going from a two-dimensional emitter to a zero-dimensional emitter. The temperature dependence of current peaks originating in tunneling through individual QDs and individual stacks is used to clarify this point. In addition, we show that the statistical size distribution of self-assembled quantum dots causing the inhomogeneous broadening in luminescence experiments can be analyzed in a resonant tunneling experiment. (C) 2002 American Institute of Physics.
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| 3. |
- Bryllert, Tomas, et al.
(författare)
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Resonant tunneling through coupled self-assembled quantum dots and the influence of inhomogeneous broadening
- 2002
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Ingår i: 7th International Conference on Nanometer-Scale Science and Technology and 21st European Conference on Surface Science.
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Konferensbidrag (refereegranskat)abstract
- Resonant tunneling through a single layer of self-assembled quantum dots (QDs) as well as tunneling through two layers of vertically aligned (stacked) dots is investigated. The difference between single and double layers of QDs can be viewed as going from a two-dimensional emitter to a zero-dimensional emitter. By fabricating small-area devices we are able to probe single stacks of quantum dots, revealing details of the coupling between the stacked dots. Very sharp resonances, with peak-to-valley ratios of several hundred, have been measured in the current-voltage characteristics. We also show that the statistical size distribution of self-assembled quantum dots causing the inhomogeneous broadening in luminescence experiments can be analysed in a resonant tunneling experiment
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| 4. |
- Edvinsson, Lars, et al.
(författare)
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Neuropeptides in cerebrospinal fluid of patients with Alzheimer's disease and dementia with frontotemporal lobe degeneration
- 1993
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Ingår i: Dementia (Switzerland). - 1013-7424. ; 4:3-4, s. 71-167
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Tidskriftsartikel (refereegranskat)abstract
- The two major primary degenerative dementias, dementia of Alzheimer type (DAT) and frontal lobe degeneration of non-Alzheimer type (FLD) have several clinical features in common but also many symptoms that differ. In a clinical material of 80 patients with either of the two forms of dementia (DAT = 39, FLD = 41) we have studied the levels of neuropeptides in the cerebrospinal fluid (CSF) in order to find biochemical markers for CNS affection. The dementia forms were evaluated by careful clinical analysis, psychometric testing and measurement of regional cerebral blood flow. Approximately one third of the subjects died during the completion of the study and neuropathology was performed, confirming the diagnoses. We observed reductions in the CSF levels of antidiuretic hormone and somatostatin in both DAT and FLD. A strong tendency to reduction was noted for neuropeptide Y (NPY). There was a correlation with the duration of disease demonstrating a significant reduction in NPY levels in subjects with DAT. Most notably there was a strong reduction in the levels of delta sleep inducing peptide (DSIP) in DAT cases only. The levels of DSIP in FLD were the same as in controls. The reverse was found for corticotropin releasing factor (CRF) which had a significant reduction in FLD patients but not in those with DAT. The present study indicates a difference in the CSF levels of neuropeptides, observations that these may serve as biochemical markers which differentiate DAT and FLD.
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| 5. |
- Eriksson, Staffan, 1969-
(författare)
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Falls in people with dementia
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Falls and concomitant injuries are common problems among large groups of the elderly population, leading to immobility and mortality. These problems are even more pronounced among people suffering from dementia. This thesis targets fall risk factors for people with dementia in institutions. The overall aim of this thesis was to investigate risk factors for falls, predisposing as well as related to circumstances surrounding falls, and to do this as efficiently as possible. In a prospective cohort study including residents of residential care facilities with and without dementia, the fall rate was higher for those with dementia, the crude incidence rate ratio (IRR) was 2.55 (95% CI 1.60–4.08) and the adjusted IRR was 3.79 (95% CI 1.95–7.36). In the group of people suffering from dementia, including 103 residents, a total of 197 falls resulted in 11 fractures during the 6-months follow-up period. From the same baseline measurements 26% and 55%, respectively, of the variation in falls could be explained in the group of residents with and without dementia. Fall predictors significantly and independently associated with an increased risk of falls in the group of people suffering from dementia were the category “man walking with an aid” and the use of more than four drugs. In a prospective cohort study, including 204 patients in a psychogeriatric ward, a total of 244 falls resulted in 14 fractures. Fall predictors significantly and independently associated with an increased risk of falls were male sex, failure to copy a design, use of clomethiazole, and walking difficulties. Treatment with statins was associated with a reduced risk of falls. With these fall predictors in the negative binomial regression (Nbreg) model, 48% of the variation in falls was explained. The data from the psychogeriatric ward were also analysed with the use of partial least squares regression (PLS) and regression tree to be compared with the results of the Nbreg analysis. PLS and regression tree are techniques based on combinations of variables. They both showed similar patterns, that a combination of a more severe level of dementia, behavioral complications and medication related to these complications is associated with an increased fall rate. Thirty-two percent and 38%, respectively, of the variation in fall rate were explained in the PLS and regression tree analysis. The circumstances surrounding the falls in the psychogeriatric ward were analysed. It was found that the fall rate was equally high during the night and the day. A large proportion of the falls was sustained in the patients’ own room and a small proportion of the falls was witnessed by the staff. This pattern was even more pronounced during the night. The proportion of diurnal rhythm disturbances and activity disturbances was higher for falls at night than for falls during the day. Circumstances associated with an increased risk of falls, as shown by a short time to first fall, were anxiety, darkness, not wearing any shoes and, for women, urinary tract infection. The proportion of urinary tract infection was also higher in connection to falls sustained by women than to falls sustained by men. This thesis confirms that people suffering from dementia are prone to fall. Walking difficulties, male sex and impaired visual perception are factors that should be considered in the work of reducing falls among people suffering from dementia. Furthermore, falls at night, behavioral complications and medication related to these complications should also be considered in this work, especially as the dementia disease progresses. A larger portion of the variation of the outcome variable was explained by the Nbreg model than the regression tree and PLS. However, these statistical methods, based on combinations of variables, gave a complementary perspective on how the fall predictors were related to falls.
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| 6. |
- Gustafson, Boel, et al.
(författare)
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Coupling between lateral modes in a vertical resonant tunneling structure
- 2002
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Ingår i: Physica E: Low-Dimensional Systems and Nanostructures. - 1386-9477. ; 13:2-4, s. 950-953
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Tidskriftsartikel (refereegranskat)abstract
- We present experimental results and theoretical calculations of the vertical electron transport through a laterally constricted resonant tunneling transistor. Current-voltage measurements at 4.2 K show numerous current peaks that exhibit a complex dependence on the applied gate voltage. A scattering-matrix approach combined with the Landauer formalism was used to perform quantum mechanical calculations of the electron transport through a quantum dot structure with laterally confined emitter and collector regions. The simulations qualitatively reproduce the measured data, suggesting a strong coupling between the lateral modes in the quantum dot and the collector
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| 7. |
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| 8. |
- Minthon, Lennart, et al.
(författare)
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Correlation between clinical characteristics and cerebrospinal fluid neuropeptide Y levels in dementia of the Alzheimer type and frontotemporal dementia
- 1996
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Ingår i: Alzheimer Disease and Associated Disorders. - 1546-4156. ; 10:4, s. 197-203
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Tidskriftsartikel (refereegranskat)abstract
- Neuropeptide Y (NPY) has been shown to be involved in the control of several neuroendocrine functions. Moreover, in animal models, NPY produces behavioral effects that are similar to those induced by anxiolytics. We studied NPY-like immunoreactivity (NPY-LI) in cerebrospinal fluid (CSF) in two primary degenerative dementias, Alzheimer disease (AD, n = 34) and frontotemporal dementia (FTD, n = 22) and correlated the CSF NPY-LI levels with clinical characteristics, as rated with the Organic Brain Syndrome scale. There were significant correlations between NPY-LI and such clinical items as suspiciousness, anxiousness, restlessness-agitation, and irritability in both AD and FTD. AD patients, but not FTD patients, showed a significant negative correlation between NPY-LI and duration of the disease. Thus, the study found significant correlations between CSF NPY-LI and emotional symptoms and behavior in organic dementia.
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| 9. |
- Minthon, Lennart, et al.
(författare)
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Long-term effects of tacrine on regional cerebral blood flow changes in Alzheimer's disease
- 1995
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Ingår i: Dementia and Geriatric Cognitive Disorders. - 1420-8008. ; 6:5, s. 245-251
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Tidskriftsartikel (refereegranskat)abstract
- Regional cerebral blood flow (rCBF) was studied in patients with Alzheimer's disease (AD) before and after 14 months of tacrine treatment. The treated group was compared with an identical reference group of untreated AD patients. At baseline the two groups showed an identical rCBF and mean hemispheric blood flow. After 14 months the tacrine-treated patients showed a stable rCBF level and a significant increase in rCBF in the central-parietal regions, compared to the untreated reference group, who showed typical AD reductions in rCBF in these regions. Clinical outcome: 7 of 9 patients in the tacrine group were clinically unchanged or slightly improved during the study time. In the untreated group 8 of 11 patients had deteriorated in clinical assessments and none had improved. Long-term tacrine treatment in Alzheimer's disease may delay the progression of symptoms.
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| 10. |
- Minthon, Lennart, et al.
(författare)
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Neuropeptide levels in Alzheimer's disease and dementia with frontotemporal degeneration
- 1990
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Ingår i: Journal of neural transmission. Supplementum. ; 30, s. 57-67
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Tidskriftsartikel (refereegranskat)abstract
- The CSF levels of somatostatin-LI (SLI), neuropeptide Y (NPY-LI) and Delta Sleep Inducing Peptide (DSIP-LI) have been measured in patients with dementia of Alzheimer type (DAT) and dementia with frontotemporal degeneration of non-Alzheimer type (FTD). The distribution pattern of cortical degeneration differs between these two types of dementia. DAT shows degeneration of mainly temporo-parietal and temporo-limbic structures, whereas FTD discloses its main degeneration in the frontotemporal regions (Brun, 1987). The somatostatin-LI was significantly reduced both in DAT and FTD. NPY-LI showed a significant reduction in DAT but not in FTD. A tendency to a reduction with duration of the disease was observed in DAT whereas the contrary was noted in FTD. The DSIP-LI levels were reduced in DAT and slightly increased in FTD. The study provides an evidence of neurochemical differences between the two primary degenerative dementias.
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