2,290 research outputs found
Effect of high oxygen pressure annealing on superconducting Nd1.85Ce0.15CuO4 thin films by pulsed laser deposition from Cu-enriched targets
We show that the quality of Nd1.85Ce0.15CuO4 films grown by pulsed laser
deposition can be enhanced by using a non-stoichiometric target with extra
copper added to suppress the formation of a parasitic (Nd, Ce)2O3 phase. The
properties of these films are less dependent on the exact annealing procedure
after deposition as compared to films grown from a stoichiometric target. Film
growth can be followed by a 1 bar oxygen annealing, after an initial vacuum
annealing, while retaining the superconducting properties and quality. This
enables the integration of electron-doped cuprates with their hole-doped
counterparts on a single chip, to create, for example, superconducting
pn-junctions.Comment: This is an author-created, un-copyedited version of an article
accepted for publication in Superconductor Science and Technology. The
publisher is not responsible for any errors or omissions in this version of
the manuscript or any version derived from it. The Version of Record is
available online at http://dx.doi.org/10.1088/0953-2048/27/4/04401
Comparison study of iron preparations using a human intestinal model
Iron deficiency and related iron deficiency anaemia (IDA) are the most prevalent nutritional disorders worldwide. The standard treatment involves supple-mentation with solid or liquid iron supplement preparations, usually based on a ferrous salt such as ferrous sulphate, ferrous fumarate, or ferrous gluconate. In the present study, we compared iron uptake and absorption from various solid and liquid iron supplement preparations currently available in the United Kingdom using the well-characterised human epithelial adenocarcinoma cell line Caco-2. Intracellular ferritin protein formation by the Caco-2 cell was considered an indicator of cellular iron uptake and absorption. We investigated the effects of formulation ingredients at a defined pH on iron uptake and absorption, and designed a novel two-stage dissolution-absorption protocol that mimicked physiological conditions. Our experiments revealed wide variations in the rate of dissolution between the various solid iron preparations. Conventional-release ferrous iron tablets dissolved rapidly (48 ± 4 mins to 64 ± 4 mins), whereas modified-released tablets and capsules took significantly longer to undergo complete dissolution (274 ± 8 to 256 ± 8 mins). Among the solid iron preparations, ferrous sulphate conventional-release tablets demon-strated the highest iron absorption, whereas modified-release ferrous prepa-rations demonstrated uniformly low iron absorption, as compared to the control (P < 0.05). Taken together, our results demonstrate that there are wide-ranging variations in dissolution times and iron uptake from oral iron preparations, with the physical characteristics of the preparation as well as the form of iron playing a key role
Acute Administration of Bioavailable Curcumin Alongside Ferrous Sulphate Supplements Does Not Impair Iron Absorption in Healthy Adults in a Randomised Trial.
Ferrous sulphate (FS) is a cost effective, readily available iron supplement for iron deficiency (ID). The pro-oxidant effect of oral ferrous iron is known to induce inflammation, causing gastric side-effects and resulting in poor compliance. Curcumin is a potent antioxidant and has also been shown to exhibit iron chelation in-vitro, although it is not established whether these effects are retained in-vivo. The aim of this study was therefore to assess the influence of a formulated bioavailable form of curcumin (HydroCurc ; 500 mg) on acute iron absorption and status in a double blind, placebo-controlled randomized trial recruiting 155 healthy participants (79 males; 26.42 years ± 0.55 and 76 females; 25.82 years ± 0.54). Participants were randomly allocated to five different treatment groups: iron and curcumin placebo (FS0_Plac), low dose (18 mg) iron and curcumin placebo (FS18_Plac), low dose iron and curcumin (FS18_Curc), high dose (65 mg) iron and curcumin placebo (FS65_Plac), and high dose iron and curcumin (FS65_Curc). Participants were provided with the supplements according to their relevant treatment groups at baseline (0 min), and blood collection was carried out at 0 min and at 180 min following supplementation. In the treatment groups, significant difference was observed in mean serum iron between baseline (0 min) and at end-point (180 min) (F (1, 144) = 331.9, < 0.0001) with statistically significant intra-group increases after 180 min ( < 0.0001) in the FS18_Plac (8.79 ”mol/L), FS18_Curc (11.41 ”mol/L), FS65_Plac (19.09 ”mol/L), and FS65_Curc (16.39 ”mol/L) groups. A significant difference was also observed between the two time points in serum TIBC levels and in whole blood haemoglobin (HGB) in the treatment groups, with a significant increase (1.55%/2.04 g/L) in HGB levels from baseline to end-point observed in the FS65_Curc group ( < 0.05). All groups receiving iron demonstrated an increase in transferrin saturation (TS%) in a dose-related manner, demonstrating that increases in serum iron are translated into increases in physiological iron transportation. This study demonstrates, for the first time, that regardless of ferrous dose, formulated curcumin in the form of HydroCurc⹠does not negatively influence acute iron absorption in healthy humans
Toward a Viable Strategy for Estimating Vibrothermographic Probability of Detection
Vibrothermography is a technique for finding cracks and delaminations through infrared imaging of vibrationâinduced heating. While vibrothermography has shown remarkable promise, it has been plagued by persistent questions about its reproducibility and reliability. Fundamentally, the crack heating is caused by the vibration, and therefore to understand the heating process we must first understand the vibration process. We lay out the problem and begin the first steps toward relating detectability to the local motion around a crack as well as the crack size. A particular mode, the thirdâorder freeâfree flexural resonance, turns out to be particularly insensitive to the presence of clamping and transducer contact. When this mode is excited in a simple bar geometry the motions of the part follow theoretical calculations quite closely, and a single point laser vibrometer measurement is sufficient to evaluate the motion everywhere. Simple calculations estimate stress and strain anywhere in the bar, and these can then be related to observed crack heating
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