Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
      More Filters
      Clear All
      More Filters
      Source
    • Language
157 result(s) for "Sanna, Simone"
Sort by:
High proton conduction in grain-boundary-free yttrium-doped barium zirconate films grown by pulsed laser deposition
Reducing the operating temperature in the 500–750 °C range is needed for widespread use of solid oxide fuel cells (SOFCs). Proton-conducting oxides are gaining wide interest as electrolyte materials for this aim. We report the fabrication of BaZr 0.8 Y 0.2 O 3− δ (BZY) proton-conducting electrolyte thin films by pulsed laser deposition on different single-crystalline substrates. Highly textured, epitaxially oriented BZY films were obtained on (100)-oriented MgO substrates, showing the largest proton conductivity ever reported for BZY samples, being 0.11 S cm −1 at 500 °C. The excellent crystalline quality of BZY films allowed for the first time the experimental measurement of the large BZY bulk conductivity above 300 °C, expected in the absence of blocking grain boundaries. The measured proton conductivity is also significantly larger than the conductivity values of oxygen-ion conductors in the same temperature range, opening new potential for the development of miniaturized SOFCs for portable power supply. Proton conductor oxides are promising materials for their use as electrolytes for reducing the operation temperature of solid-oxide fuel cells. Epitaxially oriented yttrium-doped barium zirconate films now show unprecedented proton conductivity in the 500–700 °C range.
Genetic basis of human congenital anomalies of the kidney and urinary tract
The clinical spectrum of congenital anomalies of the kidney and urinary tract (CAKUT) encompasses a common birth defect in humans that has significant impact on long-term patient survival. Overall, data indicate that approximately 20% of patients may have a genetic disorder that is usually not detected based on standard clinical evaluation, implicating many different mutational mechanisms and pathogenic pathways. In particular, 10% to 15% of CAKUT patients harbor an unsuspected genomic disorder that increases risk of neurocognitive impairment and whose early recognition can impact clinical care. The emergence of high-throughput genomic technologies is expected to provide insight into the common and rare genetic determinants of diseases and offer opportunities for early diagnosis with genetic testing.
Evolution of Topological Surface States Following Sb Layer Adsorption on Bi2Se3
Thin antimony layers adsorbed on bismuth selenide (Bi2Se3) present an exciting topological insulator system. Much recent effort has been made to understand the synthesis and electronic properties of the heterostructure, particularly the migration of the topological surface states under adsorption. However, the intertwinement of the topological surface states of the pristine Bi2Se3 substrate with the Sb adlayer remains unclear. In this theoretical work, we apply density functional theory (DFT) to model heterostructures of single and double atomic layers of Sb on a bismuth selenide substrate. We thereby discuss established and alternative structural models, as well as the hybridization of topological surface states with the Sb states. Concerning the geometry, we reveal the possibility of structures with inverted Sb layers which are energetically close to the established ones. The formation energy differences are below 10 meV/atom. Concerning the hybridization, we trace the band structure evolution as a function of the adlayer-substrate distance. By following changes in the connection between the Kramers pairs, we extract a series of topological phase transitions. This allows us to explain the origin of the complex band structure, and ultimately complete our knowledge about this peculiar system.
Enhanced non-classical electrostriction in strained tetragonal ceria
Electrostriction is the upsurge of strain under an electric field in any dielectric material. Oxygen-defective metal oxides, such as acceptor-doped ceria, exhibit high electrostriction 10 -17 m 2 V -2 values, which can be further enhanced via interface engineering at the nanoscale. This effect in ceria is “non-classical” as it arises from an intricate relation between defect-induced polarisation and local elastic distortion in the lattice. Here, we investigate the impact of mismatch strain when epitaxial Gd-doped CeO 2 thin films are grown on various single-crystal substrates. We demonstrate that varying the compressive and tensile strain can fine-tune the electromechanical response. The electrostriction coefficients achieve a large M 11  ≈ 3.6·10 -15 m 2 V -2 in lattices of in-plane compressed films, i.e., a positive tetragonality ( c/a -1 > 0), with stress above 3 GPa at the film/substrate interface. Chemical and structural analysis suggests that the high electrostriction stems from anisotropic distortions in the local lattice strain, which lead to constructively oriented elastic dipoles and Ce 3+ electronic defects. Non-classical electrostriction in fluorites arises from defect-induced polarization and lattice distortions. This study shows that mismatch strain in Gd-doped CeO 2 thin films fine-tunes electromechanical responses, achieving high electrostriction above 10− 15 m 2 V −2 .
The π-trap approach for obtaining crystal structure data of inherently amorphous cluster compounds
Single crystal diffraction is one of the most common and powerful tools for structural elucidation. However, obtaining single crystals of adequate size and quality is not always trivial. The “crystalline sponge” method has been used for crystallizing intrinsically amorphous compounds inside a metal organic framework, 1–4 , but its application is limited by the size and stability of the pores within the networks. Here, we report the use of π–π interactions between C 60 and nanometer-sized molecules that by themselves do not form crystalline compounds. Using this “π-trap” approach, we successfully crystallized adamantane-like clusters exhibiting extreme nonlinear optical properties, which so far resisted any attempt for crystallization. C 60 ···cluster interactions enabled long-range order, so the clusters’ molecular structures could be precisely determined. Spectroscopy and quantum chemical studies showed that clusters and C 60 behave like being dissolved in each other. This method should be applicable to all kinds of amorphous compounds that undergo π–π interactions. Single crystal diffraction is one of the most common and powerful tools for structural elucidation, but obtaining single crystals of adequate size and quality is not always trivial. Here, the authors report a method to crystallize inherently non-crystalline adamantane-like organic-inorganic clusters using π-π interactions between C 60 and nano-sized molecules.
Water-Soluble Sacrificial Layer of Sr3Al2O6 for the Synthesis of Free-Standing Doped Ceria and Strontium Titanate
Epitaxial layers of water-soluble Sr3Al2O6 were fabricated as sacrificial layers on SrTiO3 (100) single-crystal substrates using the Pulsed Laser Deposition technique. This approach envisages the possibility of developing a new generation of micro-Solid Oxide Fuel Cells and micro-Solid Oxide Electrochemical Cells for portable energy conversion and storage devices. The sacrificial layer technique offers a pathway to engineering free-standing membranes of electrolytes, cathodes, and anodes with total thicknesses on the order of a few nanometers. Furthermore, the ability to etch the SAO sacrificial layer and transfer ultra-thin oxide films from single-crystal substrates to silicon-based circuits opens possibilities for creating a novel class of mixed electronic and ionic devices with unexplored potential. In this work, we report the growth mechanism and structural characterization of the SAO sacrificial layer. Epitaxial samarium-doped ceria films, grown on SrTiO3 substrates using Sr3Al2O6 as a buffer layer, were successfully transferred onto silicon wafers. This demonstration highlights the potential of the sacrificial layer method for integrating high-quality oxide thin films into advanced device architectures, bridging the gap between oxide materials and silicon-based technologies.
Selective high-temperature CO2 electrolysis enabled by oxidized carbon intermediates
High-temperature CO 2 electrolysers offer exceptionally efficient storage of renewable electricity in the form of CO and other chemical fuels, but conventional electrodes catalyse destructive carbon deposition. Ceria catalysts are known carbon inhibitors for fuel cell (oxidation) reactions; however, for more severe electrolysis (reduction) conditions, catalyst design strategies remain unclear. Here we establish the inhibition mechanism on ceria and show selective CO 2 to CO conversion well beyond the thermodynamic carbon deposition threshold. Operando X-ray photoelectron spectroscopy during CO 2 electrolysis—using thin-film model electrodes consisting of samarium-doped ceria, nickel and/or yttria-stabilized zirconia—together with density functional theory modelling, reveal the crucial role of oxidized carbon intermediates in preventing carbon build-up. Using these insights, we demonstrate stable electrochemical CO 2 reduction with a scaled-up 16 cm 2 ceria-based solid-oxide cell under conditions that rapidly destroy a nickel-based cell, leading to substantially improved device lifetime. CO 2 electrolysers store electricity as CO or other chemical fuels, but can suffer from carbon deposition at the electrodes. Skafte et al. identify a mechanistic route to inhibiting carbon build-up in ceria-based electrolysers and build a cell that operates beyond the thermodynamic carbon deposition threshold.
Polar discontinuities, emergent conductivity, and critical twist-angle-dependent behaviour at wafer-bonded ferroelectric interfaces
Probing novel properties, arising from twisted interfaces, has traditionally relied on the stacking of exfoliated two-dimensional materials and the spontaneous formation of van der Waals bonds. So far, investigations involving intimate covalent or ionic bonds have not been a focus. Yet, we show here that an established technique, involving thermocompressional wafer bonding, works well for creating twisted non-van der Waals interfaces. We have successfully bonded z-cut lithium niobate single crystals to create ferroelectric oxide interfaces with strong polar discontinuities and have mapped the associated emergent interfacial conductivity. In some instances, a dramatic change in microstructure occurs, involving local dipolar switching. A twist-induced collapse in the capability of the system to effec8tively screen interfacial bound charge is implied. Importantly, this only occurs around specific moiré twist angles with sparse coincident lattices and associated short-range aperiodicity. In quasicrystals, aperiodicity is known to induce pseudo-bandgaps and we suspect a similar phenomenon here. Wafer bonding has allowed the synthesis of twisted interfaces which support polar discontinuities in ferroelectric lithium niobate. Two-dimensional sheet conductivity arises but is suppressed when twist angles lead to interfacial lattice aperiodicity.
Isolated polycystic liver disease genes define effectors of polycystin-1 function
Dominantly inherited isolated polycystic liver disease (PCLD) consists of liver cysts that are radiologically and pathologically identical to those seen in autosomal dominant polycystic kidney disease, but without clinically relevant kidney cysts. The causative genes are known for fewer than 40% of PCLD index cases. Here, we have used whole exome sequencing in a discovery cohort of 102 unrelated patients who were excluded for mutations in the 2 most common PCLD genes, PRKCSH and SEC63, to identify heterozygous loss-of-function mutations in 3 additional genes, ALG8, GANAB, and SEC61B. Similarly to PRKCSH and SEC63, these genes encode proteins that are integral to the protein biogenesis pathway in the endoplasmic reticulum. We inactivated these candidate genes in cell line models to show that loss of function of each results in defective maturation and trafficking of polycystin-1, the central determinant of cyst pathogenesis. Despite acting in a common pathway, each PCLD gene product demonstrated distinct effects on polycystin-1 biogenesis. We also found enrichment on a genome-wide basis of heterozygous mutations in the autosomal recessive polycystic kidney disease gene PKHD1, indicating that adult PKHD1 carriers can present with clinical PCLD. These findings define genetic and biochemical modulators of polycystin-1 function and provide a more complete definition of the spectrum of dominant human polycystic diseases.
Impact of diet and host genetics on the murine intestinal mycobiome
The mammalian gut is home to a diverse microbial ecosystem, whose composition affects various physiological traits of the host. Next-generation sequencing-based metagenomic approaches demonstrated how the interplay of host genetics, bacteria, and environmental factors shape complex traits and clinical outcomes. However, the role of fungi in these complex interactions remains understudied. Here, using 228 males and 363 females from an advanced-intercross mouse line, we provide evidence that fungi are regulated by host genetics. In addition, we map quantitative trait loci associated with various fungal species to single genes in mice using whole genome sequencing and genotyping. Moreover, we show that diet and its’ interaction with host genetics alter the composition of fungi in outbred mice, and identify fungal indicator species associated with different dietary regimes. Collectively, in this work, we uncover an association of the intestinal fungal community with host genetics and a regulatory role of diet in this ecological niche. In this study, 591 mice from an advanced-intercross mouse line were used to provide evidence that fungi are regulated by host genetics, while uncovering a regulatory role of diet on the composition of fungi in the murine gut.