Determination of Hydrogen Diffusion Parameters of Ferritic Steel from Electrochemical Permeation Measurement under Tensile Loads

The hydrogen permeation experiment, performed with a stepwise permeation sequence involving "1st permeation-desorption-2nd permeation under loading, demonstrates that fine blister cracks are frequently observed on the steel surface in hydrogen charging side after the 2nd permeation under the load over 95% of yield strength of the steel. To accommodate the experimental phenomena under the loading conditions, a numerical model is developed for determination of hydrogen diffusion parameters of the sour-resistant ferritic steel evaluated under tensile stress in plastic ranges. To solve the modified diffusion equation, a numerical finite difference method (FDM) is employed. The diffusion parameters determined by curve-fitting with the newly proposed diffusion equation indicates that, with the transition of mechanical domain from local-plasticity to generalized-plasticity, a big increase in the crack formation rate and hydrogen capture rate per irreversible trap are observed. It suggests that the transition probability for hydrogen transport from interstitial lattice site to irreversible trap site increases with the stress level. (C) The Author(s) 2014. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. All rights reserved.1110Ysciescopu

Printing three-dimensional tissue analogues with decellularized extracellular matrix bioink

The ability to print and pattern all the components that make up a tissue (cells and matrix materials) in three dimensions to generate structures similar to tissues is an exciting prospect of bioprinting. However, the majority of the matrix materials used so far for bioprinting cannot represent the complexity of natural extracellular matrix (ECM) and thus are unable to reconstitute the intrinsic cellular morphologies and functions. Here, we develop a method for the bioprinting of cell-laden constructs with novel decellularized extracellular matrix (dECM) bioink capable of providing an optimized microenvironment conducive to the growth of three-dimensional structured tissue. We show the versatility and flexibility of the developed bioprinting process using tissue-specific dECM bioinks, including adipose, cartilage and heart tissues, capable of providing crucial cues for cells engraftment, survival and long-term function. We achieve high cell viability and functionality of the printed dECM structures using our bioprinting method.open11349353sciescopu

Post-Stenotic Recirculating Flow May Cause Hemodynamic Perforator Infarction

Background and Purpose The primary mechanism underlying paramedian pontine infarction (PPI) is atheroma obliterating the perforators. Here, we encountered a patient with PPI in the post-stenotic area of basilar artery (BA) without a plaque, shown, by high-resolution magnetic resonance imaging (HR-MRI). We performed an experiment using a 3D-printed BA model and a particle image velocimetry (PIV) to explore the hemodynamic property of the post-stenotic area and the mechanism of PPI. Methods 3D-model of a BA stenosis was reconstructed with silicone compound using a 3D printer based on the source image of HR-MRI. Working fluid seeded with fluorescence particles was used and the velocity of those particles was measured horizontally and vertically. Furthermore, microtubules were inserted into the posterior aspect of the model to measure the flow rates of perforators (pre- and post-stenotic areas). The flow rates were compared between the microtubules. Results A recirculating flow was observed from the post-stenotic area in both directions forming a spiral shape. The velocity of the flow in these regions of recirculation was about one-tenth that of the flow in other regions. The location of recirculating flow well corresponded with the area with low-signal intensity at the time-of-flight magnetic resonance angiography and the location of PPI. Finally, the flow rate through the microtubule inserted into the post-stenotic area was significantly decreased comparing to others (P<0.001). Conclusions Perforator infarction may be caused by a hemodynamic mechanism altered by stenosis that induces a recirculation flow. 3D-printed modeling and PIV are helpful understanding the hemodynamics of intracranial stenosis.114Ysciescopu

The immediate upstream region of the 5 '-UTR from the AUG start codon has a pronounced effect on the translational efficiency in Arabidopsis thaliana

The nucleotide sequence around the translational initiation site is an important cis-acting element for post-transcriptional regulation. However, it has not been fully understood how the sequence context at the 5'-untranslated region (5'-UTR) affects the translational efficiency of individual mRNAs. In this study, we provide evidence that the 5'-UTRs of Arabidopsis genes showing a great difference in the nucleotide sequence vary greatly in translational efficiency with more than a 200-fold difference. Of the four types of nucleotides, the A residue was the most favourable nucleotide from positions -1 to -21 of the 5'-UTRs in Arabidopsis genes. In particular, the A residue in the 5'-UTR from positions -1 to -5 was required for a high-level translational efficiency. In contrast, the T residue in the 5'-UTR from positions -1 to -5 was the least favourable nucleotide in translational efficiency. Furthermore, the effect of the sequence context in the -1 to -21 region of the 5'-UTR was conserved in different plant species. Based on these observations, we propose that the sequence context immediately upstream of the AUG initiation codon plays a crucial role in determining the translational efficiency of plant genes.ope

High Quality Bioreplication of Intricate nanostructures from a Fragile Gecko Skin Surface with Bactericidal Properties

published_or_final_versio

Field-induced water electrolysis switches an oxide semiconductor from an insulator to a metal

Here we demonstrate that water-infiltrated nanoporous glass electrically switches an oxide semiconductor from an insulator to metal. We fabricated the field effect transistor structure on an oxide semiconductor, SrTiO3, using 100%-water-infiltrated nanoporous glass - amorphous 12CaO*7Al2O3 - as the gate insulator. For positive gate voltage, electron accumulation, water electrolysis and electrochemical reduction occur successively on the SrTiO3 surface at room temperature, leading to the formation of a thin (~3 nm) metal layer with an extremely high electron concentration of 10^15-10^16 cm^-2, which exhibits exotic thermoelectric behaviour.Comment: 21 pages, 12 figure

Research on edge-control methods in CNC polishing

Background: We have developed edge-control for the Precessions TM process suitable for fast fabrication of large mirror segments, and other applications sensitive to edge mis-figure. This has been applied to processing of European extremely large telescope (E-ELT) prototype mirror-segments, meeting the specification on maximum edge mis-figure. However we have observed residuals that have proved impossible to correct with this approach, being in part the legacy of asymmetries in the input edge-profiles. Methods: We have therefore compared different proposed methods experimentally and theoretically and report here on a new edge-rectification step, which operates locally on edges, does not disturb the completed bulk area. Results: A new toolpath has been developed and experiments have been carried out to demonstrate that local edge rectification can be carried out. Conclusions: With this method, the residue error on edges can be removed separately and has potential to reduce total process time

Bio-implant as a novel restoration for tooth loss

published_or_final_versio

Combined effects of time spent in physical activity, sedentary behaviors and sleep on obesity and cardio-metabolic health markers: a novel compositional data analysis approach

<div><p>The associations between time spent in sleep, sedentary behaviors (SB) and physical activity with health are usually studied without taking into account that time is finite during the day, so time spent in each of these behaviors are codependent. Therefore, little is known about the combined effect of time spent in sleep, SB and physical activity, that together constitute a composite whole, on obesity and cardio-metabolic health markers. Cross-sectional analysis of NHANES 2005–6 cycle on N = 1937 adults, was undertaken using a compositional analysis paradigm, which accounts for this intrinsic codependence. Time spent in SB, light intensity (LIPA) and moderate to vigorous activity (MVPA) was determined from accelerometry and combined with self-reported sleep time to obtain the 24 hour time budget composition. The distribution of time spent in sleep, SB, LIPA and MVPA is significantly associated with BMI, waist circumference, triglycerides, plasma glucose, plasma insulin (all p<0.001), and systolic (p<0.001) and diastolic blood pressure (p<0.003), but not HDL or LDL. Within the composition, the strongest positive effect is found for the proportion of time spent in MVPA. Strikingly, the effects of MVPA replacing another behavior and of MVPA being displaced by another behavior are asymmetric. For example, re-allocating 10 minutes of SB to MVPA was associated with a lower waist circumference by 0.001% but if 10 minutes of MVPA is displaced by SB this was associated with a 0.84% higher waist circumference. The proportion of time spent in LIPA and SB were detrimentally associated with obesity and cardiovascular disease markers, but the association with SB was stronger. For diabetes risk markers, replacing SB with LIPA was associated with more favorable outcomes. Time spent in MVPA is an important target for intervention and preventing transfer of time from LIPA to SB might lessen the negative effects of physical inactivity.</p></div

The association of health literacy with adherence in older 2 adults, and its role in interventions: a systematic meta-review

Background: Low health literacy is a common problem among older adults. It is often suggested to be associated with poor adherence. This suggested association implies a need for effective adherence interventions in low health literate people. However, previous reviews show mixed results on the association between low health literacy and poor adherence. A systematic meta-review of systematic reviews was conducted to study the association between health literacy and adherence in adults above the age of 50. Evidence for the effectiveness of adherence interventions among adults in this older age group with low health literacy was also explored. Methods: Eight electronic databases (MEDLINE, ERIC, EMBASE, PsycINFO, CINAHL, DARE, the Cochrane Library, and Web of Knowledge) were searched using a variety of keywords regarding health literacy and adherence. Additionally, references of identified articles were checked. Systematic reviews were included if they assessed the association between health literacy and adherence or evaluated the effectiveness of interventions to improve adherence in adults with low health literacy. The AMSTAR tool was used to assess the quality of the included reviews. The selection procedure, data-extraction, and quality assessment were performed by two independent reviewers. Seventeen reviews were selected for inclusion. Results: Reviews varied widely in quality. Both reviews of high and low quality found only weak or mixed associations between health literacy and adherence among older adults. Reviews report on seven studies that assess the effectiveness of adherence interventions among low health literate older adults. The results suggest that some adherence interventions are effective for this group. The interventions described in the reviews focused mainly on education and on lowering the health literacy demands of adherence instructions. No conclusions could be drawn about which type of intervention could be most beneficial for this population. Conclusions: Evidence on the association between health literacy and adherence in older adults is relatively weak. Adherence interventions are potentially effective for the vulnerable population of older adults with low levels of health literacy, but the evidence on this topic is limited. Further research is needed on the association between health literacy and general health behavior, and on the effectiveness of interventions