Vertical interface effect on the physical properties of epitaxial metal‐oxide films is demonstrated. Self‐assembled (BiFeO3)0.5:(Sm2O3)0.5 nanocomposite films are fabricated with three‐dimensional ...heteroepitaxy having an ordered nano‐columnar structure on a large scale. The vertical interface effect on lattice parameters, dielectric properties, and leakage currents is investigated.
Reel-to-reel tape processing capable of fabricating tens of meters of coated conductor has been set up at Los Alamos National Laboratory. These reel-to-reel facilities include electropolishing, ...IBAD-MgO texturing, buffer layer deposition, REBaCuO pulsed laser deposition and position dependent critical current and ac-loss measurement. The systems enable development of long-length coated conductors as well as high-throughput experimentation. IBAD-MgO is an extremely fast process, demonstrated at 100 meters/hour, but requires smooth surfaces over long lengths, which is achieved in our laboratory by electropolishing of metal alloy tapes. Barrier and buffer layers are optimized to minimize interdiffusion from the substrate into the superconductor and to maximize crystalline alignment. YBCO is deposited in a multi-zone heater that allows for an engineered heating power profile as the YBCO film is deposited. Currently the best critical current result on a 1 meter length for a 3 /spl mu/m thick YBCO layer is 350 A (self field, 75.5 K).
Inflammation and its resolution is a tenuous balance that is under constant contest. Though several regulatory mechanisms are employed to maintain homeostasis, disruptions in the regulation of ...inflammation can lead to detrimental effects for the host. Of note, the gut and microbial dysbiosis are implicated in the pathology of systemic chronic low-grade inflammation which has been linked to several metabolic diseases. What remains to be described is the extent to which dietary fat and concomitant changes in the gut microbiota contribute to, or arise from, the onset of metabolic disorders. The present review will highlight the role of microorganisms in host energy regulation and several mechanisms that contribute to inflammatory pathways. This review will also discuss the immunomodulatory effects of the endocannabinoid system and its link with the gut microbiota. Finally, a brief discussion arguing for improved taxonomic resolution (at the species and strain level) is needed to deepen our current knowledge of the microbiota and host inflammatory state.
We discuss our recent progress using IBAD MgO as a template for subsequent deposition of YBa
2Cu
3O
7−
δ
(YBCO) high-temperature superconductors on metallic substrate tapes. We have refined the ...process by improving substrate preparation and by using reflected high-energy electron diffraction to monitor and improve IBAD MgO films. High quality, continuously processed IBAD MgO (c-IBAD) has been deposited on moving meter-length metal tape. By incorporating these optimized processing parameters, we have been able to deposit biaxially textured MgO on metallic substrates continuously with the best in-plane mosaic spreads near 9°. The subsequent pulsed laser deposition of 1–2 μm thick YBCO films on c-IBAD has resulted in superconducting transport critical current densities>1 MA/cm
2 (75 K, SF) on small area samples. Longer 4.5 cm samples of c-IBAD tape have also been coated with a 1 cm wide sample carrying 93 A (75 K, SF) for a 1.5 μm thick YBCO.
Thick films containing ultrafine multilayer structures of two complex metal oxides are grown with a single, sectored target in conjunction with pulsed laser deposition on stationary or moving ...templates. This process is demonstrated with the high‐temperature superconductors YBa2Cu3Oy and EuBa2Cu3Oy. Multilayer periodicities (see figure) as low as 5.5 nm (approximately five unit cells) are obtained in thick films (1.84 μm ≈ 335 bilayer pairs) with improved superconducting properties.
The microstructures of continuously processed YBa/sub 2/Cu/sub 3/O/sub y/ (YBCO) coated conductors processed with three different architectures are presented. YBCO films were deposited directly on ...ion-beam-assisted deposition (IBAD) yttria-stabilized zirconia (YSZ) or on intervening layers of Y/sub 2/O/sub 3/ or CeO/sub 2/. Different interfacial reactions were observed in each case. The volume changes that occur with the interfacial reactions were calculated based on the identified reaction products. The calculated volume changes correlate with the observed microstructures and appear to be an important factor in determining an optimal buffer layer system. The interfacial reactions do not preclude the attainment of high I/sub c/ and J/sub c/ values in these coated conductors.
A composite layer has been successfully implemented in high temperature superconducting (HTS) coated conductors (CCs) based on ion beam assisted deposition (IBAD) MgO technology. This layer serves a ...dual function: a nucleation layer for the growth of high quality biaxially aligned MgO and a diffusion barrier to inhibit interdiffusion between the Ni-alloy substrate and the superconductor. The composition of the composite Y 2 O 3 -Al 2 O 3 influences the texture and superconducting properties of YBCO films grown on STO buffered MgO/Y 2 O 3 -Al 2 O 3 /Ni-alloy. Our experimental results demonstrate that the superconducting properties of YBCO grown on STO buffered MgO/Y 2 O 3 -Al 2 O 3 /Ni-alloy are comparable with those of YBCO on standard architecture. The use of a single composite Y 2 O 3 -Al 2 O 3 layer instead of individual layers of Y 2 O 3 and Al 2 O 3 for the fabrication of HTS CCs based on IBAD MgO provides advantages such as simplified architecture and potentially reduced cost due to the reduced number of fabrication steps.
We investigated the effects of gut microbes, and the mechanisms mediating the enhanced exercise performance induced by exercise training, i.e., skeletal muscle blood flow, and mitochondrial ...biogenesis and oxidative function in male mice.
All mice received a graded exercise test before (PRE) and after exercise training via forced treadmill running at 60% to 70% of maximal running capacity 5 d·wk -1 for 5 wk (POST). To examine the role of the gut microbes, the graded exercise was repeated after 7 d of access to antibiotic (ABX)-treated water, used to eliminate gut microbes. Peripheral blood flow, mitochondrial oxidative capacity, and markers of mitochondrial biogenesis were collected at each time point.
Exercise training led to increases of 60% ± 13% in maximal running distance and 63% ± 11% work to exhaustion ( P < 0.001). These increases were abolished after ABX ( P < 0.001). Exercise training increased hindlimb blood flow and markers of mitochondrial biogenesis and oxidative function, including AMP-activated protein kinase, sirtuin-1, PGC-1α citrate synthase, complex IV, and nitric oxide, all of which were also abolished by ABX treatment.
Our results support the concept that gut microbiota mediate enhanced exercise capacity after exercise training and the mechanisms responsible, i.e., hindlimb blood flow, mitochondrial biogenesis, and metabolic profile. Finally, results of this study emphasize the need to fully examine the impact of prescribing ABX to athletes during their training regimens and how this may affect their performance.
High critical current (>100 A) YBCO thick films, or coated conductors, are being developed for superconductor applications. The critical current I/sub c/ of these materials exhibits a magnetic field ...dependence that depends on the angle of the applied field. Measurement of this anisotropy is critical to the development of high temperature superconductor applications. We have developed the capability to characterize the magnetic field anisotropy of large, high critical current YBCO superconductors as a function of angle. We have measured the magnetic field anisotropy of the critical current in the H/spl perp/I orientation of three samples in fields from 0 to 7 T and at temperatures from 75 K to 64 K. The results of these measurements characterize the field dependence of these materials and reveal performance issues of importance to applications. In contrast to previous measurements on thin films, which show that I/sub c/ for the H/spl par/c orientation has the strongest field dependence, we demonstrate that the intermediate angle of /spl sim/45/spl deg/ to the normal to the tape plane shows the greatest field dependence for these coated conductors on technical substrates. The field performance, anisotropy, and temperature dependence are discussed in relation to sample quality.
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