| 1. |
- Adam, A, et al.
(författare)
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Abstracts from Hydrocephalus 2016.
- 2017
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Ingår i: Fluids and Barriers of the CNS. - : Springer Science and Business Media LLC. - 2045-8118. ; 14:Suppl 1
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Choudhury, Debraj, et al.
(författare)
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Tuning of dielectric properties and magnetism of SrTiO3 by site-specific doping of Mn
- 2011
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 84:12, s. 125124-
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Tidskriftsartikel (refereegranskat)abstract
- Combining experiments with first-principles calculations, we show that site-specific doping of Mn into SrTiO(3) has a decisive influence on the dielectric properties of these doped systems. We find that phonon contributions to the dielectric constant invariably decrease sharply on doping at any site. However, a sizable, random dipolar contribution only for Mn at the Sr site arises from a strong off-centric displacement of Mn in spite of Mn being in a non-d(0) state; this leads to a large dielectric constant at higher temperatures and gives rise to a relaxor ferroelectric behavior at lower temperatures. We also investigate magnetic properties in detail and critically reevaluate the possibility of a true multiglass state in such systems.
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| 3. |
- Coleman, V. A., et al.
(författare)
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Defect Formation In Graphene Nanosheets By Acid Treatment : An X-Ray Absorption Spectroscopy And Density Functional Theory Study
- 2008
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Ingår i: Journal of Physics D. - : IOP Publishing. - 0022-3727 .- 1361-6463. ; 41:6, s. 062001-4
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Tidskriftsartikel (refereegranskat)abstract
- In-plane defects have been introduced into graphene nanosheets by treatment with hydrochloric acid. Acid treatment induces bond cleavage in the C–C network via electrophilic attack. These resultant vacancy sites will then undergo further reactions with the surrounding ambient to produce C–O and C–H bonds. A σ* resonance at 287 eV in the carbon K-edge x-ray absorption spectra is observed with acid treatment and is assigned to C–O states. Theoretical modelling of a di-vacancy in a graphene bilayer reproduces all essential features of this resonance and in addition predicts a metallic conductivity of states around this vacancy. The possibility of engineering the properties of graphene via the routes explored here is an important step towards establishing strategies for building devices based on this material.
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| 4. |
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| 5. |
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| 6. |
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| 7. |
- Niarchos, D., et al.
(författare)
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Toward Rare-Earth-Free Permanent Magnets : A Combinatorial Approach Exploiting the Possibilities of Modeling, Shape Anisotropy in Elongated Nanoparticles, and Combinatorial Thin-Film Approach
- 2015
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Ingår i: JOM. - : Springer Science and Business Media LLC. - 1047-4838 .- 1543-1851. ; 67:6, s. 1318-1328
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the rare-earth free permanent magnets (REFREEPM) project is to develop a new generation of high-performance permanent magnets (PMs) without rare earths. Our approach is based on modeling using a combinatorial approach together with micromagnetic modeling and the realization of the modeled systems (I) by using a novel production of high-aspect-ratio (> 5) nanostructrures (nanowires, nanorods, and nanoflakes) by exploiting the magnetic shape anisotropy of the constituents that can be produced via chemical nanosynthesis polyol process or electrodeposition, which can be consolidated with novel processes for a new generation of rare-earth free PMs with energy product in the range of 60 kJ/m(3) < (BH)max < 160 kJ/m(3) at room temperature, and (II) by using a high-throughput thin-film synthesis and high-throughput characterization approach to identify promising candidate materials that can be stabilized in a tetragonal or hexagonal structure by epitaxial growth on selected substrates, under various conditions of pressure, stoichiometry, and temperature. In this article, we report the progress so far in selected phases.
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| 8. |
- Sanyal, S., et al.
(författare)
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Polymorphisms in DNA repair and metabolic genes in bladder cancer
- 2004
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Ingår i: Carcinogenesis. - 0143-3334. ; 25:5, s. 729-34
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the association of urinary bladder cancer with genetic polymorphisms in the xeroderma pigmentosum complementation group C (XPC), group D (XPD) and group G (XPG), X-ray repair cross-complementing group 1 (XRCC1) and group 3 (XRCC3), Nijmegen breakage syndrome 1 (NBS1), cyclin D1, methylene-tetrahydrofolate reductase (MTHFR), NAD(P)H dehydrogenase quinone 1 (NQO1), H-ras and glutathione S-transferase theta 1 (GSTT1) genes. Bladder cancer patients from the different hospitals in Stockholm County Council area and matching controls were genotyped for different polymorphisms. The frequency of the variant allele for A/C polymorphism in exon 15 of the XPC gene was significantly higher in the bladder cancer cases than in the controls (OR 1.49, 95% CI 1.16-1.92, P = 0.001). The variant allele homozygote genotype for the T/C polymorphism in exon 1 of the H-ras gene was associated with a decreased risk for bladder cancer (OR 0.12, 95% CI 0.02-0.67, P = 0.006). The variant allele genotypes for the single nucleotide polymorphisms (SNPs) in DNA repair genes, XPG and NBS1, showed a marginal association with the occurrence of bladder cancer (OR 0.38, 95% CI 0.15-0.94, P = 0.03 and OR 1.64, 95% CI 0.92-2.90, P = 0.09, respectively). We also report a positive correlation between the null homozygote of GSTT1 with the risk of bladder cancer (OR 2.54, 95% CI 1.32-4.98, P = 0.003). For other polymorphisms included in this study, NBS1 Glu185Gln, XPD Lys751Gln, XPG Asp1104His, XRCC1 Arg399Gln, XRCC3 Thr241Met, cyclin D1 Pro242Pro, MTHFR Ala222Val and Glu429Ala, NQO1 Arg139Trp and Pro187Ser, no significant differences for genotype distributions and allele frequencies between the bladder cancer cases and the controls were observed in the present study.
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| 9. |
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| 10. |
- Strömberg, F., et al.
(författare)
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Textured growth of the high moment material Gd(0001)/Cr(001)/Fe(001)
- 2011
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Ingår i: Journal of Physics D. - : IOP Publishing. - 0022-3727 .- 1361-6463. ; 44:26, s. 265004-
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Tidskriftsartikel (refereegranskat)abstract
- By magnetic coupling of Fe and Gd via Cr interlayers, the large local moment of Gd can be combined with the high Curie temperature of Fe. The textured growth of a Gd film is studied here by preparing trilayer systems of Fe/Cr/Gd on MgO(1 0 0) substrates by molecular-beam epitaxy (MBE). The thickness of the Cr interlayer was varied between 3 and 5 monolayers. The structural quality of the samples was confirmed by in situ RHEED and ex situ XRD measurements. Epitaxial Cr(0 0 1)/Fe(0 0 1) growth was observed, as expected. By use of Fe-57-CEMS (conversion electron Mossbauer spectroscopy) in combination with the Fe-57 tracer layer method the Fe/Cr interface could be examined on an atomic scale and well separated Fe/Gd layers for all Cr thicknesses were confirmed. The unusual Gd/Cr crystallographic relationship of Gd(0 0 0 1)parallel to Cr(0 0 1), with domains of the hexagonal Gd basal planes randomly oriented in the sample plane and not in registry with the underlying Cr(0 0 1) lattice, was found from combined RHEED and x-ray measurements. Annealing of the samples resulted in a remarkable improvement of the crystalline structure of the Gd layers. On the other hand, the appearance of a single line in the CEM spectrum leads to the conclusion that during annealing a small amount of Fe diffuses into the Cr layer. The electronic structure and magnetism of this system are investigated by first-principles theory.
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