59 research outputs found

    Unveiling the electronic structure of pseudo-tetragonal WO3_3 thin films

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    WO3_3 is a binary 5d compound which has attracted remarkable attention due to the vast array of structural transitions that it undergoes in its bulk form. In the bulk, a wide range of electronic properties has been demonstrated, including metal-insulator transitions and superconductivity upon doping. In this context, the synthesis of WO3_3 thin films holds considerable promise for stabilizing targeted electronic phase diagrams and embedding them in technological applications. However, to date, the electronic structure of WO3_3 thin films is experimentally unexplored, and only characterized by numerical calculations. Underpinning such properties experimentally would be important to understand not only the collective behavior of electrons in this transition metal oxide, but also to explain and engineer both the observed optical responses to carriers' concentration and its prized catalytic activity. Here, by means of tensile strain, we stabilize WO3_3 thin films into a stable phase, which we call pseudo-tetragonal, and we unveil its electronic structure by combining photoelectron spectroscopy and density functional theory calculations. This study constitutes the experimental demonstration of the electronic structure of WO3_3 thin-films and allows us to pin down the first experimental benchmarks of the fermiology of this system

    FIB patterning of stainless steel for the development of nano-structured stent surfaces for cardiovascular applications

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    Stent implantation is a percutaneous interventional procedure that mitigates vessel stenosis, providing mechanical support within the artery and as such a very valuable tool in the fight against coronary artery disease. However, stenting causes physical damage to the arterial wall. It is well accepted that a valuable route to reduce in-stent re-stenosis can be based on promoting cell response to nano-structured stainless steel (SS) surfaces such as by patterning nano-pits in SS. In this regard patterning by focused ion beam (FIB) milling offers several advantages for flexible prototyping. On the other hand FIB patterning of polycrystalline metals is greatly influenced by channelling effects and redeposition. Correlative microscopy methods present an opportunity to study such effects comprehensively and derive structure–property understanding that is important for developing improved patterning. In this chapter we present a FIB patterning protocol for nano-structuring features (concaves) ordered in rectangular arrays on pre-polished 316L stainless steel surfaces. An investigation based on correlative microscopy approach of the size, shape and depth of the developed arrays in relation to the crystal orientation of the underlying SS domains is presented. The correlative microscopy protocol is based on cross-correlation of top-view scanning electron microscopy, electron backscattering diffraction, atomic force microscopy and cross-sectional (serial) sectioning. Various FIB tests were performed, aiming at improved productivity by preserving nano-size accuracy of the patterned process. The optimal FIB patterning conditions for achieving reasonably high throughput (patterned rate of about 0.03 mm2/h) and nano-size accuracy in dimensions and shapes of the features are discussed as well

    Polymorphisms of the TUB Gene Are Associated with Body Composition and Eating Behavior in Middle-Aged Women

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    BACKGROUND: The TUB gene, encoding an evolutionary conserved protein, is highly expressed in the hypothalamus and might act as a transcription factor. Mutations in TUB cause late-onset obesity, insulin-resistance and neurosensory deficits in mice. An association of common variants in the TUB gene with body weight in humans has been reported. METHODS/FINDINGS: The aim was to investigate the relationship of single nucleotide polymorphisms (SNPs) of the TUB gene (rs2272382, rs2272383 and rs1528133) with both anthropometry and self-reported macronutrient intake from a validated food frequency questionnaire. These associations were studied in a population-based, cross-sectional study of 1680 middle-aged Dutch women, using linear regression analysis. The minor allele C of the rs1528133 SNP was significantly associated with increased weight (+1.88 kg, P = 0.022) and BMI (+0.56 units, P = 0.05). Compared with non-carriers, both AG heterozygotes and AA homozygotes of the rs2272382 SNP derived less energy from fat (AG: -0.55+/-0.28%, P = 0.05, AA: -0.95+/-0.48%, P = 0.047). However, both genotypes were associated with an increased energy intake from carbohydrates (0.69+/-0.33%, P = 0.04 and 1.68+/-0.56%, P = 0.003, respectively), mainly because of a higher consumption of mono- and disaccharides. Both these SNPs, rs2272382 and rs1528133, were also associated with a higher glycemic load in the diet. The glycemic load was higher among those with AG and AA genotypes for the variant rs2272382 than among the wild types (+1.49 (95% CI: -0.27-3.24) and +3.89 (95% CI: 0.94-6.85) units, respectively). Carriers of the minor allele C of rs1528133 were associated with an increased glycemic load of 1.85 units compared with non-carriers. CONCLUSIONS: Genetic variation of the TUB gene was associated with both body composition and macronutrient intake, suggesting that TUB might influence eating behavior

    Surface-Initiated Polymer Brushes in the Biomedical Field: Applications in Membrane Science, Biosensing, Cell Culture, Regenerative Medicine and Antibacterial Coatings

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    Effect of volume reduction of cord blood units before storage on transplantation outcomes: a retrospective analysis of Eurocord-EBMT and Netcord

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    In this Registry study, manipulation of the CBUs aimed at volume reduction was not shown to infl uence the clinical outcome, indicating a satisfactory validation of the associated technologies across the banks. Cells viability assessment methodology varied among banks. Further eff orts to standardize the quality controls before CBU release are needed

    Unveiling the Electronic Structure of Pseudotetragonal WO3 Thin Films

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    WO3 is a 5d compound that undergoes several structural transitions in its bulk form. Its versatility is well-documented, with a wide range of applications, such as flexopiezoelectricity, electrochromism, gating-induced phase transitions, and its ability to improve the performance of Li-based batteries. The synthesis of WO3 thin films holds promise in stabilizing electronic phases for practical applications. However, despite its potential, the electronic structure of this material remains experimentally unexplored. Furthermore, its thermal instability limits its use in certain technological devices. Here, we employ tensile strain to stabilize WO3 thin films, which we call the pseudotetragonal phase, and investigate its electronic structure using a combination of photoelectron spectroscopy and density functional theory calculations. This study reveals the Fermiology of the system, notably identifying significant energy splittings between different orbital manifolds arising from atomic distortions. These splittings, along with the system’s thermal stability, offer a potential avenue for controlling inter- and intraband scattering for electronic applications

    La force dipolaire magnetique et electrique dans 54Fe

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    International audienceThe dipole strength of the N = 28 closed-shell nuclide 54 Fe was studied in photon-scattering experiments using bremsstrahlung produced with electron beams of kinetic energies of 7.5 and 13.9 MeV at the γ ELBE facility as well as using quasimonoenergetic and linearly polarized photon beams of 26 different energies within the range from 5.5 to 11.4 MeV at the HIγ S facility. About 100 J = 1 states were newly identified, out of them 19 with 1 + and 30 with 1 − assignments. The quasicontinuum of unresolved transitions was included in the analysis of the spectra and the intensities of branching transitions were estimated on the basis of simulations of statistical γ-ray cascades. As a result, the photoabsorption cross section up to the neutron-separation energy was determined and compared with predictions of the statistical reaction model. The experimental M1 strengths from resolved 1 + states are compared with results of large-scale shell-model calculations
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