| 1. |
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| 2. |
- Frati, G., et al.
(författare)
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Human iPSC-based models highlight defective glial and neuronal differentiation from neural progenitor cells in metachromatic leukodystrophy
- 2018
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Ingår i: Cell Death & Disease. - : Springer Science and Business Media LLC. - 2041-4889. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- The pathological cascade leading from primary storage to neural cell dysfunction and death in metachromatic leukodystrophy (MLD) has been poorly elucidated in human-derived neural cell systems. In the present study, we have modeled the progression of pathological events during the differentiation of patient-specific iPSCs to neuroepithelial progenitor cells (iPSC-NPCs) and mature neurons, astrocytes, and oligodendrocytes at the morphological, molecular, and biochemical level. We showed significant sulfatide accumulation and altered sulfatide composition during the differentiation of MLD iPSC-NPCs into neuronal and glial cells. Changes in sulfatide levels and composition were accompanied by the expansion of the lysosomal compartment, oxidative stress, and apoptosis. The neuronal and glial differentiation capacity of MLD iPSC-NPCs was significantly impaired. We showed delayed appearance and/or reduced levels of oligodendroglial and astroglial markers as well as reduced number of neurons and disorganized neuronal network. Restoration of a functional Arylsulfatase A (ARSA) enzyme in MLD cells using lentiviral-mediated gene transfer normalized sulfatide levels and composition, globally rescuing the pathological phenotype. Our study points to MLD iPSC-derived neural progeny as a useful in vitro model to assess the impact of ARSA deficiency along NPC differentiation into neurons and glial cells. In addition, iPSC-derived neural cultures allowed testing the impact of ARSA reconstitution/overexpression on disease correction and, importantly, on the biology and functional features of human NPCs, with important therapeutic implications.
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| 3. |
- Avoni, G., et al.
(författare)
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The new LUCID-2 detector for luminosity measurement and monitoring in ATLAS
- 2018
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 13:7
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Tidskriftsartikel (refereegranskat)abstract
- The ATLAS luminosity monitor, LUCID (LUminosity Cherenkov Integrating Detector), had to be upgraded for the second run of the LHC accelerator that started in spring 2015. The increased energy of the proton beams and the higher luminosity required a redesign of LUCID to cope with the more demanding conditions. The novelty of the LUCID-2 detector is that it uses the thin quartz windows of photomultipliers as Cherenkov medium and a small amounts of radioactive 207Bi sources deposited on to these windows to monitor the gain stability of the photomultipliers. The result is a fast and accurate luminosity determination that can be kept stable during many months of data taking. LUCID-2 can also measure the luminosity accurately online for each of the up to 2808 colliding bunch pairs in the LHC . These bunch pairs are separated by only 25 ns and new electronics has been built that can count not only the number of pulses above threshold but also integrate the pulses.
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| 4. |
- Nag, Abhishek, et al.
(författare)
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Origin of the Spin-Orbital Liquid State in a Nearly J=0 Iridate Ba3ZnIr2O9
- 2016
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Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 116:9
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Tidskriftsartikel (refereegranskat)abstract
- We show using detailed magnetic and thermodynamic studies and theoretical calculations that the ground state of Ba3ZnIr2O9 is a realization of a novel spin-orbital liquid state. Our results reveal that Ba3ZnIr2O9 with Ir5+ (5d(4)) ions and strong spin-orbit coupling (SOC) arrives very close to the elusive J = 0 state but each Ir ion still possesses a weak moment. Ab initio density functional calculations indicate that this moment is developed due to superexchange, mediated by a strong intradimer hopping mechanism. While the Ir spins within the structural Ir2O9 dimer are expected to form a spin-orbit singlet state (SOS) with no resultant moment, substantial frustration arising from interdimer exchange interactions induce quantum fluctuations in these possible SOS states favoring a spin-orbital liquid phase down to at least 100 mK.
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| 5. |
- Torchio, R., et al.
(författare)
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Structure and magnetism of cobalt at high pressure and low temperature
- 2016
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Ingår i: PHYSICAL REVIEW B. - 2469-9950. ; 94:2
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Tidskriftsartikel (refereegranskat)abstract
- The magnetic and structural properties of cobalt were investigated under high pressure (160 GPa) and low temperature (50 K), by synchrotron K-edge x-ray magnetic circular dichroism and x-ray diffraction. A quasihydrostatic equation of state was measured up to 160 GPa. We found that uniaxial stress plays a role in the hexagonal close packed-face centered cubic (hcp-fcc) structural transition pressure. Also, our data provide the first experimental evidence that changes of the c/a ratio pressure derivative are related to the magnetic behavior. The complete extinction of ferromagnetism is observed above 130 GPa in a mixed hcp-fcc phase with no recovery upon cooling to 50 K, indicating that cobalt at 150 GPa is very likely nonmagnetic, i.e., characterized by zero local spin polarization. Density functional theory calculations point out that the K-edge x-ray magnetic circular dichroism (XMCD) signal is related to the 4p orbital moment rather than to the total spin moment and allow us to get a deeper insight into the K-edge XMCD measurements interpretation. The combination of novel theoretical results and experimental outputs provides a detailed scenario of the structural and magnetic properties of cobalt at these extreme conditions answering some previously unsolved issues.
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| 6. |
- Carlomagno, I., et al.
(författare)
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Co film stretching induced by lattice mismatch and annealing : The role of Graphene
- 2018
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Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332. ; 432, s. 22-26
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Tidskriftsartikel (refereegranskat)abstract
- Thin Co films intercalated between a Graphene capping layer and the Ir(111) surface are of interest for spintronics applications due to their peculiar magnetic properties and to their chemical stability. The structure, and then the magnetic properties, of the Co films depend on the intercalation process which is strongly influenced by the temperature, total amount of Cobalt and quality of the capping Graphene layer. In order to identify and disentangle the effects of these contributions, we report on the structural characterisation of four Co films as a function of thickness, annealing temperature, and Graphene capping. From the structural point of view, the deposition of Co on a hot Ir substrate mimics quite well the intercalation process proving the validity of the colander model describing the Graphene role during the process.
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| 7. |
- Imam, N. G., et al.
(författare)
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Probing the local atomic structure in CoLa0.15Fe1.85O4 as a function of the synthesis method by multi edge XAFS
- 2019
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Ingår i: Materials Research Express. - : IOP Publishing. - 2053-1591. ; 6:11
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Tidskriftsartikel (refereegranskat)abstract
- We combined x-ray powder diffraction (XRD) and x-ray absorption fine structure spectroscopy (XAFS) to characterize the crystallographic and local atomic structure of nanosized La3+ substituted CoFe2O4 spinel ferrite of composition CoLa0.15Fe1.85O4 synthesized by different synthesis routes: standard ceramic technique, citric acid (citrate) precursor and urea assisted flash auto-combustion process. Rietveld refinement of XRD patterns allowed to describe the long-range atomic structure that was used as structural model for quantitative analysis of XAFS spectra collected at the Fe-K, Co-K and La-L3 and refined via a multi-edge approach, which provided details about local atomic structure and coordination chemistry around the absorbers. Combining the complementary information from XRD and XAFS it was possible to reliably describe the cation distribution over the two spinel sublattices (tetrahedral and octahedral) as a function of the synthesis routes. We demonstrated that the inversion parameter, the cation distribution, and the local atomic structure depend strongly on the synthesis method which in particular affects the La3+ lattice-site and vacancies. In particular the citrate synthesis appears to provide a pure single pure phase with highest coordination number of La and lowest inversion parameter.
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| 8. |
- Vora, J, et al.
(författare)
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Clinical use of insulin degludec
- 2015
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Ingår i: Diabetes research and clinical practice. - : Elsevier BV. - 1872-8227 .- 0168-8227. ; 109:1, s. 19-31
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Tidskriftsartikel (refereegranskat)
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