SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Mathieu A) srt2:(2000-2004)"

Sökning: WFRF:(Mathieu A) > (2000-2004)

  • Resultat 1-20 av 20
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Korzhavyi, Pavel A., 1966-, et al. (författare)
  • Defect-induced magnetic structure in (Ga1-xMnx)As
  • 2002
  • Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 88:18, s. 187202-
  • Tidskriftsartikel (refereegranskat)abstract
    • We show that magnetic structures involving partial disorder of local magnetic moments on the Mn atoms in (Ga1-xMnx)As lower the total energy, compared to the case of perfect ferromagnetic ordering, when As defects on the Ga sublattice are present. Such magnetic structures are found to be stable for a range of concentrations of As antisites, and this result accounts for the observed magnetic moments and critical temperatures in (Ga1-xMnx)As . We propose an explanation for the stabilization of the partially disordered magnetic structures and conclude that the magnetization and critical temperatures should increase substantially by reducing the number of As antisite defects.
  •  
2.
  •  
3.
  •  
4.
  •  
5.
  •  
6.
  •  
7.
  • Azad, Abul Kalam, 1966, et al. (författare)
  • Synthesis, structural and magnetic characterisation of the double perovskite A(2)MnMoO(6) (A = Ba, Sr)
  • 2004
  • Ingår i: Journal of Alloys and Compounds. - 0925-8388. ; 364:1-2, s. 77-82
  • Tidskriftsartikel (refereegranskat)abstract
    • A study of the crystallographic structure and magnetic properties of the double perovskites Ba2MnMoO6 and Sr2MnMoO6 in polycrystalline form has been carried out by means of neutron powder diffraction (NPD) and magnetization measurements. The Rietveld analysis of room temperature data shows that the Mn2+ and Mo6+ ions are B-site ordered, i.e. the structure is a NaCl-type ordered double perovskite. Ba2MnMoO6 crystallizes in the cubic space group Full-size image (<1 K) (a=8.1680(1)) and Sr2MnMoO6 crystallizes in the space group P42/n (a=7.9575(5), c=7.9583(9)). Bond valence sum (BVS) calculation revealed that these compounds have the valency pair of {Mn2+(3d5;t32ge2g), Mo6+(4d0)}. The magnetic measurements suggest that these compounds transform to an antiferromagnetic state below 10 K.
  •  
8.
  •  
9.
  •  
10.
  •  
11.
  • Glisovic, Tina, et al. (författare)
  • Interplay between transcriptional and post-transcriptional regulation of Cyp2a5 expression
  • 2003
  • Ingår i: Biochemical Pharmacology. - 0006-2952 .- 1356-1839. ; 65:10, s. 1653-1661
  • Tidskriftsartikel (refereegranskat)abstract
    • The cytochrome P450 (Cyp) 2a5 gene can be upregulated transcriptionally or by mRNA stabilization. The heterogeneous nuclear ribonucleoprotein (hnRNP) A1 interacting with the CYP2A5 mRNA has been shown to be a key post-transcriptional regulator of the Cyp2a5 gene. The aim of this study was to investigate if the transcriptional and post-transcriptional steps of Cyp2a5 expression are linked. This was done by modifying the transcription rate with transcriptional inducers (phenobarbital and cyclic AMP) and inhibitors (actinomycin D and 5,6-dichloro-1-beta-d-ribofuranosylbenzimidazole) and analyzing the effects upon post-transcriptional events. We found that inhibition of transcription led to relocalization of hnRNP A1 from the nucleus to the cytoplasm, to its strongly increased binding to the cytoplasmic CYP2A5 mRNA and to CYP2A5 mRNA stabilization. In contrast, stimulated transcription resulted in increased binding of nuclear hnRNP A1 to the Cyp2a5 promoter, and overexpression of hnRNP A1 led to stimulated transcription of a Cyp2a5 promoter-driven luciferase recombinant. This strongly suggests that the transcriptional and post-transcriptional stages of Cyp2a5 expression are interrelated and that the nucleocytoplasmic shuttling hnRNP A1 may coordinate these different steps.
  •  
12.
  • Groenhof, Gerrit, et al. (författare)
  • Photoactivation of the photoactive yellow protein : why photon absorption triggers a trans-to-cis Isomerization of the chromophore in the protein.
  • 2004
  • Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 126:13, s. 4228-4233
  • Tidskriftsartikel (refereegranskat)abstract
    • Atomistic QM/MM simulations have been carried out on the complete photocycle of Photoactive Yellow Protein, a bacterial photoreceptor, in which blue light triggers isomerization of a covalently bound chromophore. The "chemical role" of the protein cavity in the control of the photoisomerization step has been elucidated. Isomerization is facilitated due to preferential electrostatic stabilization of the chromophore's excited state by the guanidium group of Arg52, located just above the negatively charged chromophore ring. In vacuo isomerization does not occur. Isomerization of the double bond is enhanced relative to isomerization of a single bond due to the steric interactions between the phenyl ring of the chromophore and the side chains of Arg52 and Phe62. In the isomerized configuration (ground-state cis), a proton transfer from Glu46 to the chromophore is far more probable than in the initial configuration (ground-state trans). It is this proton transfer that initiates the conformational changes within the protein, which are believed to lead to signaling.
  •  
13.
  • Hariz, Marwan I, et al. (författare)
  • A quick and universal method for stereotactic visualization of the subthalamic nucleus before and after implantation of deep brain stimulation electrodes
  • 2003
  • Ingår i: Stereotactic and Functional Neurosurgery. - : S. Karger AG. - 1011-6125 .- 1423-0372. ; 80:1-4, s. 96-101
  • Tidskriftsartikel (refereegranskat)abstract
    • For deep brain stimulation (DBS) of the subthalamic nucleus (STN), it would be an advantage if the STN could be visualized with fast acquisition of MR images, allowing direct and individual targeting. We present a protocol for T2-weighted, nonvolumetric fast-acquisition MRI, implemented at 8 centers in 6 countries. Acquisition time varied between 3 min 5 s and 7 min 48 s according to the center, and imaging often provided visualization of the STN on axial and coronal scans. Postoperatively, the same imaging protocol permitted visualization of the target area and DBS electrodes with minimum artifacts. This imaging technique may contribute to a decrease in the number of electrode passes at surgery.
  •  
14.
  •  
15.
  •  
16.
  •  
17.
  • Nordblad, Per, et al. (författare)
  • Fe/V and Fe/Co(001) superlattices: growth, anisotropy, magnetisation and magnetoresistance
  • 2003
  • Ingår i: PHYSICA B-CONDENSED MATTER. - 0921-4526. ; 327:2-4, s. 344-
  • Tidskriftsartikel (refereegranskat)abstract
    • Some physical properties of BCC Fe/V and Fe/Co (0 0 1) superlattices are reviewed. The dependence of the magnetic anisotropy on the in-plane strain introduced by the lattice mismatch between Fe and V is measured and compared to a theoretical derivation. The dependence of the magnetic anisotropy (and saturation magnetisation) on the layer thickness ratio Fe/Co is measured and a value for the anisotropy of BCC Co is derived from extrapolation. The interlayer exchange coupling of Fe/V superlattices is studied as a function of the V layer thickness (constant Fe thickness) and layer thickness of Fe (constant V thickness). A region of antiferromagnetic coupling and GMR is found for V thicknesses 12-14 monolayers. However, surprisingly, a 'cutoff' of the antiferromagnetic coupling and GMR is found when the iron layer thickness exceeds about 10 monolayers.
  •  
18.
  • Ohrwall, G, et al. (författare)
  • Observation of elastic scattering effects on photoelectron angular distributions in free Xe clusters
  • 2003
  • Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 36:19, s. 3937-3949
  • Tidskriftsartikel (refereegranskat)abstract
    • We report an observation of substantial deviations in the photoelectron angular distribution for photoionization of atoms in free Xe clusters compared to the case of photoionization of free atoms. The cross section, however, seems not to vary between the cluster and free atoms. This observation was made in the vicinity of the Xe 4d Cooper minimum, where the atomic angular distribution is known to vary dramatically. The angular distribution of electrons emitted from atoms in the clusters is more isotropic than that of free atoms over the entire kinetic energy range studied. Furthermore, the angular distribution is more isotropic for atoms in the interior of the clusters than for atoms at the surface. We attribute this deviation to elastic scattering of the outgoing photoelectrons. We have investigated two average cluster sizes, (N) approximate to 4000 and 1000 and found no significant differences between these two cases.
  •  
19.
  •  
20.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-20 av 20

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy