| 1. |
- Rosen, Johanna, et al.
(author)
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Ab initio studies of adsorption and migration surface processes on an α-Al2O3 surface
- 2005
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In: Solid State Communications. - : Elsevier BV. - 0038-1098 .- 1879-2766. ; 135:1-2, s. 90-94
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Journal article (peer-reviewed)abstract
- Surface processes on α-Al2O3 (0001) have been investigated theoretically using density functional theory. Ion–surface interactions prior to collision were investigated by means of ab initio molecular dynamics simulations, showing an adsorbate trajectory towards a preferred adsorption site. Furthermore, the adsorption process at different surface sites was investigated, together with calculations of barriers for migration between these sites. Although the equilibrium (bulk) adsorption site was energetically favourable, the presence and magnitude of the migration barriers indicate that activation energy is necessary to form the equilibrium surface structure. These results are of importance for a fundamental understanding of ion–surface interactions.
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| 2. |
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| 3. |
- Nene, Vishvanath, et al.
(author)
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Genome sequence of Aedes aegypti, a major arbovirus vector.
- 2007
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In: Science (New York, N.Y.). - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 316:5832, s. 1718-23
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Journal article (peer-reviewed)abstract
- We present a draft sequence of the genome of Aedes aegypti, the primary vector for yellow fever and dengue fever, which at approximately 1376 million base pairs is about 5 times the size of the genome of the malaria vector Anopheles gambiae. Nearly 50% of the Ae. aegypti genome consists of transposable elements. These contribute to a factor of approximately 4 to 6 increase in average gene length and in sizes of intergenic regions relative to An. gambiae and Drosophila melanogaster. Nonetheless, chromosomal synteny is generally maintained among all three insects, although conservation of orthologous gene order is higher (by a factor of approximately 2) between the mosquito species than between either of them and the fruit fly. An increase in genes encoding odorant binding, cytochrome P450, and cuticle domains relative to An. gambiae suggests that members of these protein families underpin some of the biological differences between the two mosquito species.
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| 4. |
- Rosén, Johanna, et al.
(author)
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Ab initio molecular dynamics study of hydrogen removal by ion–surface interactions
- 2005
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In: Journal of Physics: Condensed Matter. ; 17, s. L137-L142
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Journal article (peer-reviewed)abstract
- The energy dependence of surface reactions has been investigated through ab initio MD simulations for collisions between Al1+ and a gibbsite surface. No change in surface composition was observed for 0 eV initial kinetic energy of Al1+. An increase in energy to 3.5 eV resulted in extended surface migration of hydrogen, subsequent H2 formation and desorption from the surface. These results may be understood based on thermodynamics and an increase in entropy upon H2 formation. They are of fundamental importance for an increased understanding of thin film growth through the correlation between ion energy and film composition. They may also indicate a pathway to affect impurity incorporation during film growth.
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| 5. |
- Rosen, Johanna, et al.
(author)
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Ab initio molecular dynamics study of ion-surface interactions
- 2005
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In: Solid State Communications. - : Elsevier BV. - 0038-1098 .- 1879-2766. ; 134, s. 333-336
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Journal article (peer-reviewed)abstract
- Ion-surface collisions have been investigated theoretically using ab initio molecular dynamics within density functional theory. The temporal evolution of the position of the bombarding ion, as well as its nearest neighbors, was studied for initial kinetic energies of 0 and 3.5 eV (0 and 5 km/s, respectively). Also investigated was the ion-surface interaction prior to collision and the following energy transfer, as indicated by changes in ion velocity. At 3.5 eV collision energy, the calculation results suggest the formation of local structural disorder within the simulation time frame studied. These results are of fundamental importance for an increased understanding of the ion-surface interaction during a collision event, with resulting changes in atomic level structure.
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| 6. |
- Rosen, Johanna, et al.
(author)
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Reducing the impurity incorporation from residual gas by ion bombardment during high vacuum magnetron sputtering
- 2006
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In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 88, s. 191905-
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Journal article (peer-reviewed)abstract
- The influence of ion energy on the hydrogen incorporation has been investigated for alumina thin films, deposited by reactive magnetron sputtering in an Ar/O2/H2O environment. Ar+ with an average kinetic energy of ~5 eV was determined to be the dominating species in the plasma. The films were analyzed with x-ray diffraction, x-ray photoelectron spectroscopy, and elastic recoil detection analysis, demonstrating evidence for amorphous films with stoichiometric O/Al ratio. As the substrate bias potential was increased from –15 V (floating potential) to –100 V, the hydrogen content decreased by ~70%, from 9.1 to 2.8 at. %. Based on ab initio calculations, these results may be understood by thermodynamic principles, where a supply of energy enables surface diffusion, H2 formation, and desorption [Rosén et al., J. Phys.: Condens. Matter 17, L137 (2005)]. These findings are of importance for the understanding of the correlation between ion energy and film composition and also show a pathway to reduce impurity incorporation during film growth in a high vacuum ambient.
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| 7. |
- Sjöberg Wester, Elisabet, et al.
(author)
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Genetic basis of the K phenotype in the Swedish population.
- 2005
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In: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 45:4, s. 545-549
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Journal article (peer-reviewed)abstract
- Abstract in Undetermined BACKGROUND: The absence of all Kell blood group antigens (K0 phenotype) is very rare. K0 persons, however, can produce clinically significant anti-Ku (K5) after transfusion and/or pregnancy and require K0 blood for transfusion. Ten alleles giving rise to the K0 phenotype have been reported: different populations were studied although none from Scandinavia. STUDY DESIGN AND METHODS: Three K0 samples were identified by blood banks in Sweden (Uppsala,Umeå, and Linköping) during a 20-year period. Kell antigen typing was performed with standard serologic techniques by the respective blood banks and K 0 status was confirmed by the International Blood GroupReference Laboratory in Bristol, England. Polymerase chain reaction and DNA sequencing of the KEL coding region (exons 1-19) was performed on genomic DNA. RESULTS:The Uppsala K0 was homozygous for a 1540C>T substitution in exon 13, leading to an immediate stop codon. The Umeå K0 was homozygous for 1023delG in exon 8 that results in a frameshift and a premature stop codon in exon 9. In the Linköping K0, a previously reported mutation g>a at +1 of intron 3 was found. CONCLUSION: Two novel and one previously reported null alleles at the KEL locus are described. The identified nonsense mutations abolish expression of the Kell glycoprotein and are thus responsible for the K0 phenotype in these Swedish families.
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