Activity

The thin-film rotating disk electrode (TF-RDE) is a well-developed, conventional ex situ electrochemical method that is limited by poor mass transport in the dissolved phase and hence can only measure the kinetic response for Pt-based catalysts in a narrow overpotential range. Thus, the applicability of TF-RDE results in assessing how catalysts perform in fuel cells has been questioned. To address this problem, we use the floating electrode (FE) technique, which can facilitate high-mass transport to a catalyst layer composed of an ultralow loading of catalyst (1-15 μgPt cmgeo-2) at the gas/electrolyte interface. In this paper, the aspects that have critical effects on the performance of the FE system are measured and parametrized. We find that, in order to obtain reproducible results with high performance, the following factors need to be taken into account system cleanliness, break-in procedure, hydrophobic agent, ionomer type, and the measurements of catalyst surface area and loading. For some of these parameters, we examined a range of different approaches/materials and determined the optimum configuration. We find that the gas permeability of the hydrophobic agent is an important factor for improving the hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) performance. We provide evidence that the suppression of the HOR and ORR introduced by the Nafion ionomers is more than a local mass transport barrier but that a mechanism involving the adsorption of the sulfonate on Pt also plays a significant role. The work provides intriguing insights into how to manufacture and optimize electrocatalyst systems that must function at the gas/electrolyte interface.

To identify the difference of quantitative radiologic stenosis between a normal latency group and an abnormal latency group, and to investigate the association of dermatomal somatosensory-evoked potential (DSEP) with magnetic resonance imaging (MRI) findings of narrowing in patients with lumbar spinal stenosis (LSS).

We retrospectively reviewed the clinical records and P40 latencies of L5 DSEP of 40 patients with unilateral symptoms of LSS at the L4-5 disc level. Quantitative assessments of stenosis in lumbar spine MRI were performed with measurements of the anteroposterior diameter (APD), cross-sectional area (CSA) of the dural sac, ligamentous interfacet distance (LID), CSA of the neural foramen (CSA-NF), and subarticular zone width. Analyses were conducted through comparisons of radiologic severity between the normal and abnormal latency groups and correlation between radiologic severity of stenosis and latency of DSEP in absolute (APD <10 mm) and relative (APD <13 mm) stenosis.

The radiologic severities of lumbar stenosis were not significantly different between the normal and abnormal latency groups. In absolute and relative stenosis, latency showed a significant negative correlation with APD (r=-0.539, r=-0.426) and LID (r=-0.459, r=-0.494). In patients with relative stenosis, a weak significant positive correlation was found between latency and CSA-NF (r=0.371, p=0.048). LID was the only significant factor for latency (β=-0.930, p=0.011).

The normal and abnormal DSEP groups showed no significant differences inradiologic severity. see more The latency of DSEP had a negative correlation with the severity of central stenosis, and LID was an influencing factor.

The normal and abnormal DSEP groups showed no significant differences inradiologic severity. The latency of DSEP had a negative correlation with the severity of central stenosis, and LID was an influencing factor.

To compare the relationship of the Bayley Scales of Infant and Toddler Development 3rd Edition (K-BSID-III) language score and the Sequenced Language Scale for Infant (SELSI) score and evaluate the sensitivity and specificity of K-BSID-III language score and optimal cutoff value with receiver operator characteristic (ROC) curve analysis in infants and toddlers with delayed language development.

A total of 104 children with suspected language developmental delay were included in this retrospective study. Subjects were tested using the K-BSID-III and SELSI and subdivided into several groups according to the severity of language scores. ROC curve analysis was performed to assess K-BSID-III for delayed language development.

Receptive and expressive language subscales of the K-BSID-III showed markedly significant correlation with the SELSI scores (p<0.001). ROC analysis showed an area under the curve of 0.877 (p<0.001) in SELSI receptive score and 0.935 (p<0.001) in SELSI expressive score. The optimal cutoff value where sensitivity of 85% and specificity of 81% were achieved with the K-BSID-III receptive score was 1.50 (between average and low average) in the SELSI receptive score. The optimal cutoff value where sensitivity of 96% and specificity of 82% were achieved with the K-BSID-III expressive score was also 1.50 in the SELSI expressive score.

In this study, the correlations between K-BSID-III and SELSI language scores were statistically significant. However, the interpretation should be considered carefully in low average group due to tendency of underestimation of delayed language development.

In this study, the correlations between K-BSID-III and SELSI language scores were statistically significant. However, the interpretation should be considered carefully in low average group due to tendency of underestimation of delayed language development.

To investigate the glial cell and AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptor activity after surgery for disc herniation pain model.

In total, 83 Sprague-Dawley rats were randomly assigned to the following groups control (n=16), sham-operated (n=4), rats for pain behavior evaluation (n=3), nucleus pulposus-exposed groups for AMPA receptors (n=30), and glial cell (n=30). The rats were tested for mechanical allodynia; immunohistochemical staining for AMPA receptors (GluA1 and GluA2) and glial cells (OX-42 and glial fibrillary acid protein [GFAP]) in the spinal dorsal horn was performed on postoperative days 3, 7, and 14.

Mechanical withdrawal thresholds decreased after surgery, and this effect was maintained for up to 14 days. Immunohistochemical expression of GluA1 and GluA2 in the spinal dorsal horn had increased quantitatively on postoperative days 3 and 7 (p<0.05) to levels similar to that of the controls on postoperative day 14. Moreover, immunohistochemical expression of OX-42 and GFAP showed similar changes to AMPA receptors after surgery.