| 1. |
- Abadei, S., et al.
(författare)
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Microwave properties of tunable capacitors basee on magnetron sputtered ferroelectric Na0.5K0.5NbO3 film on low and high resistivity silicon substrates
- 2001
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Ingår i: Integrated Ferroelectrics. - : Informa UK Limited. - 1058-4587 .- 1607-8489. ; 39:1-4, s. 359-366
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this work, small signal DC voltage dependent dielectric permittivity, loss tangent, and tuneability of magnetron sputtered epitaxial Na0.5K0.5NO3 films are studied experimentally. (100)-oriented Na0.5K0.5NbO3 films are deposited onto SiO2-buffered CMOS grade low resistivity (p = 10-20 cm) and high resistivity (p = 15-45 kcm) silicon substrates. Planar capacitors with 2 or 4 m gaps between electrodes have been fabricated on top of ferroelectric films. These devices have been characterized in the frequency range 1.0 MHz to 50 GHz at temperatures 30 - 300K. Na0.5K0.5NbO3/SiO2/Si structures on high resistivity silicon substrate exhibit C-V performances typical for Metal-Insulator- Semiconductor (MIS) capacitors. At low frequencies, f 1.0 GHz, the large tuneability and large losses are associated with the MIS structure, while at higher microwave frequencies the tuneability is mainly associated with the ferroelectric, film. At 1.0 MHz and room temperature, the tuneability of Na0.5K0.5NbO3/SiO2/Si structures more than 90%, reducing to 10-15 % at 50 GHz. The losses decrease with increasing the DC bias and frequency. A Q-factor more than 15 at 50 GHz is observed. The dielectric permittivity of the Na0.5K0.5NbO3 film is in the range 50-150 at frequencies 0.045-50 GHz. On low resistivity substrate the performance of Na0.5K0.5NbO3 films is completely screened by the high losses in silicon, and the tuneability is negligible. © 2001 Taylor and Francis.
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| 2. |
- Andréasson, Hanna, et al.
(författare)
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Mitochondrial sequence analysis for forensic identification using Pyrosequencing technology
- 2002
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Ingår i: BioTechniques. - 0736-6205 .- 1940-9818. ; 32:1, s. 124-6, 128, 130-3
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Tidskriftsartikel (refereegranskat)abstract
- Over recent years, requests for mtDNA analysis in the field of forensic medicine have notably increased, and the results of such analyses have proved to be very useful in forensic cases where nuclear DNA analysis cannot be performed. Traditionally, mtDNA has been analyzed by DNA sequencing of the two hypervariable regions, HVI and HVII, in the D-loop. DNA sequence analysis using the conventional Sanger sequencing is very robust but time consuming and labor intensive. By contrast, mtDNA analysis based on the pyrosequencing technology provides fast and accurate results from the human mtDNA present in many types of evidence materials in forensic casework. The assay has been developed to determine polymorphic sites in the mitochondrial D-loop as well as the coding region to further increase the discrimination power of mtDNA analysis. The pyrosequencing technology for analysis of mtDNA polymorphisms has been tested with regard to sensitivity, reproducibility, and success rate when applied to control samples and actual casework materials. The results show that the method is very accurate and sensitive; the results are easily interpreted and provide a high success rate on casework samples. The panel of pyrosequencing reactions for the mtDNA polymorphisms were chosen to result in an optimal discrimination power in relation to the number of bases determined.
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| 3. |
- Andréasson, H., et al.
(författare)
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Real-Time DNA Quantification of Nuclear and Mitochondrial DNA in Forensic Analysis
- 2002
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Ingår i: BioTechniques. - 0736-6205 .- 1940-9818. ; 33:2, s. 402-411
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Tidskriftsartikel (refereegranskat)abstract
- The rapid development of molecular genetic analysis tools has made it possible to analyze most biological materialfound at the scene of a crime. Evidence materials containing DNA quantities too low to be analyzed using nuclear markers can be analyzed using the highly abundant mtDNA. However, there is a shortage of sensitive nDNA and mtDNA quantification assays. In this study, an assay for the quantification of very small amounts of DNA, based on the real-time Taq-Man assay, has been developed. This analysis will provide an estimate of the total number of nDNA copies and the total number of mtDNA molecules in a particular evidence material. The quantification is easy to perform, fast, and requires a minimum of the valuable DNA extracted from the evidence materiaL The results will aid in the evaluation of whether the specific sample is suitable for nDNA or mtDNA analysis. Furthermore, the optimal amount of DNA to be used in further analysis can be estimated ensuring that the analysis is successful and that the DNA is retained for future independent analysis. This assay has significant advantages over existing techniques because of its high sensitivity, accuracy, and the combined analysis of nDNA and mtDNA. Moreover, it has the potential to provide additional information about the presence of inhibitors in forensic samples. Subsequent mitochondrial and nuclear analysis of quantified samples illustrated the potential to predict the number of DNA copies required for a successful analysis in a certain typing assay.
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| 4. |
- Andréasson, Sven, et al.
(författare)
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Behandling av alkohol- och narkotikaproblem : En evidensbaserad kunskapssammanställning
- 2001
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Utvärderingens syfteMissbruk och beroende av alkohol är ett av de största folkhälsoproblemen. Narkotikamissbruk är mindre vanligt men har stora medicinska konsekvenser för de berörda. De sociala och juridiska aspekterna är betydande. En kritisk genomgång av litteraturen vad avser behandling av abstinens, protraherad abstinens, behandling i syfte att förhindra återfall, psykologiska och sociala behandlingar för att minska återfallsrisken, behandlingsprogram och institutionsvårdens roll, samt behandling av missbruk under graviditet. Dessutom en granskning av mini-intervention i primärvård och annan vård vars syfte är att minska konsumtionen hos högkonsumenter av alkohol. Nyligen gjorda meta-analyser inom området värderas och särskild vikt fästs vid interventioner som finns eller lätt kan introduceras i den svenska vårdorganisationen. Behandlingsprogram för patienter med samtidig annan psykisk störning värderas.Så kallat lågdosberoende av bensodiazepiner och andra lugnande medel eller sömnmedel behandlas inte. Inte heller belyses effekten av behandlingar vars primära mål är kroppsliga komplikationer av missbruket, och inte heller granskas metoder att minska tillgänglighet.TillvägagångssättStrukturerad översikt, kostnadsanalyser.Insamling av primärdataSystematisk sökning i relevanta databaser, litteraturlistor i påträffade studier samt i aktuella monografier. Ingen bakre tidsbegränsning och sökning i databaser till och med februari 1999.Utgångspunkt för urval av dataHuvudsakligen randomiserade, kontrollerade, dubbelblinda studier, samt metaanalyser som baseras på sådana studier. Vad gäller långtidsförlopp och ekonomiska analyser även kohortstudier och andra naturalistiska studier.Genomgång av publikationenSamtliga studier värderas med hjälp av en i gruppen utarbetad, och med övriga psykiatriprojekt gemensam, kvalitetsmall. Alla centrala studier läses av minst två i gruppen.Färdiga manuskript värderas av styrelse, expertgrupp samt externa granskare.
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| 5. |
- Eksandh, Louise, et al.
(författare)
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Different clinical expressions in two families with Stargardt's macular dystrophy (STGD1)
- 2001
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Ingår i: Acta Ophthalmologica Scandinavica. - : Wiley. - 1395-3907. ; 79:5, s. 524-530
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To describe the clinical expressions, with emphasis on electrophysiological examinations, in two Swedish families with Stargardt's macular dystrophy (STGD1). Methods. Two pairs of siblings with STGD1, for whom diagnosis had been confirmed by genetic linkage to the ABCA4 gene region, were examined regarding visual acuity, kinetic perimetry, fundus photography, full-field ERG and multifocal ERG (MERG). Possible disease-causing mutations were screened for by DNA sequencing of selected regions of the ABCA4 gene. Results. All STGD1 patients, had visual acuity 0.07-0.1. The two families presented different fundus appearances, MERGs and implicit times on. 30 Hz flicker white light full-field ERGs. Genetic analysis revealed one unique sequence variation in exon 19 of the ABCA4 gene, in one allele from the patients of one of the families. This point mutation causes the amino acid substitution T972N in the ABCR protein. Conclusion. Two pairs of siblings with STGD1 presented two different expressions of the disease regarding the distribution of the retinal dysfunction. One possible molecular explanation to the different clinical expressions may be the T972N substitution present in the ABCR protein in one of the STGD1 families investigated.
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| 6. |
- Kugler, Veronika Mozhdeh, et al.
(författare)
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Low temperature growth and characterization of (Na,K)NbOx thin films
- 2003
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Ingår i: Journal of Crystal Growth. - 0022-0248 .- 1873-5002. ; 254:3-4, s. 400-404
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Tidskriftsartikel (refereegranskat)abstract
- Thin (Na,K)NbOx perovskite films (NKN) have been deposited on SiO2/Si(0 0 1) substrates at low temperatures, from 350°C to 550°C, by RF magnetron sputtering. The effects of substrate temperature on microstructure, electrical-, and mechanical properties of the NKN films have been studied. X-ray diffraction analysis revealed that films deposited at temperatures in the range of 450-550°C were crystalline, growing as a single phase, with a preferred orientation of (0 0 1). Films deposited at 350°C, were shown to be amorphous. The growth temperature had a strong influence on the electrical properties of the NKN films and the relative dielectric constants of the obtained films were in between 38 and 78. Variations of the mechanical properties of the NKN films were observed for different substrate temperatures: The elastic moduli and the hardness values ranged from 205±26 to 93±29 GPa, and from 12±2 to around 2 GPa, for films deposited at 550°C and 450°C, respectively.
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| 7. |
- Kugler, Veronika Mozhdeh, et al.
(författare)
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Microstructure/dielectric property relationship of low temperature synthesised (Na,K)NbOx thin films
- 2004
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Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248 .- 1873-5002. ; 262:1-4, s. 322-326
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Tidskriftsartikel (refereegranskat)abstract
- Thin films of (Na,K)NbOx (NKN) were grown by reactive RF magnetron sputtering on polycrystalline Pt80Ir20 substrates, at relatively low growth temperatures between 300°C and 450°C. The results show that the electrical performance and the microstructure of the films are a strong function of the substrate temperature. X-ray diffraction of films grown up to 400°C revealed the formation of only one crystalline NKN-phase with a preferred (0 0 2)-orientation. However, a mixed orientation together with a secondary, paraelectric potassium niobate phase, were observed for NKN films deposited at 450°C. The differences in the microstructure explains the variations in the dielectric constants and losses: The single phase NKN films displayed a dielectric constant and a dielectric loss of 506 and 0.011, respectively, while the films with mixed phases exhibited values of 475 and 0.022, respectively. The possibility of fabricating NKN films with relatively high dielectric properties at low growth temperatures, as demonstrated here, is of high technological importance.
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