ELECTROPHORETIC DEPOSITION OF METAL-PHTHALOCYANINE AS A HIGH- PERFORMANCE ELECTROCATALYST

Metal-phthalocyanines (MPc) has high chemical stability and high catalytic activities in electrochemical reactions such as oxygen reduction reaction (ORR), CO2 reduction, and so on. It has becoming known that the catalytic activity of MPc should depend on the crystal structures, i.e., alfa-type MPc gives higher activity than other phases. In this study, the alfa-structure controlled MPcs could successfully be prepared by an electrophoretic deposition (EPD) method on gas diffusion type carbon electrode (GDE) as an electrocatalyst. Double layered MPcs electrocatalyst prepared by EPD also gave high performance for ORR. MPc (M: Li, Mg, Mn, Fe, Co, Ni, Cu, Zn, Ag, Sn, Pb) was dissolved in dichloromethane solution with trifluoroacetic acid was used for EPD method at room temperature. GDE and Pt counter electrode were used EPD (DC: +40 - +100V, 1-10min). Crystal structures of the MPcs were investigated by XRD, UV-vis, SEM, FT-IR, etc. ORR properties were evaluated in a half-cell in 1M H2SO4 at 70°C with a potentiostat using reversible hydrogen electrode (RHE) and Pt plate as reference and counter electrodes, respectively. Most of the alfa-phase MPcs could be prepared by the EPD on GDEs using dichloromethane solution containing trifluoroacetic acid. However, MPcs (M=Li, Mg) couldn’t prepared by the same condition. Alfa-phase MPc doped GDE showed higher ORR activity than that of GDE loaded with beta-MPc. In the cathodic performance at 0.4 V vs. RHE (I0.4) and open circuit potential (Eocp) at 70ºC of gas-diffusion electrodes loaded with various alfa-MPc catalysts deposited by EPD method. The GDEs loaded with alfa-MPcs showed various open circuit potentials, depending on the central metal (M) of alfa-MPc. GDE loaded with alfa-FePc showed the highest open circuit potential among the alfa-MPcs. This indicates that alfa-FePc could produce effect on density of adsorbed oxygen in the catalytic layer in the GDE. Moreover alfa-FePc based electrode showed high activity even at lower overpotential range, in spite of its low activity at higher overpotential range. The change in the Tafel slops was observed which indicates the change in the mechanism of ORR. Tafel slope of -43mV/decade at lower overpotential range shows the oxygen reduction reaction route with the formation of peroxo species in which the hydrogenation desorption reaction is rapid. While, the higher overpotential the Tafel slope of -222mV/decade might show the route which the peroxo species are not formed, like the H2O2 formation route. On the other hand, the Tafel slope of the GDE loaded with alfa-CoPc was not changed in the wide overpotential range. Also, the alfa-CoPc could keep the catalytic activity for several cycles of measurements of cathodic polarization curves, while that of alfa-FePc changed in the cycles. The decrease in ORR cycle for alfa-FePc seems to be come from the large strength of oxygen adsorption of alfa-FePc. On the other hand, CoPc/FePc double layered electrocatalyst prepared by the EPD gave more higher performance for ORR and stability. Acknowledgment: This work was partially supported by the Grant from JST ACT-C and JSPS KAKENHI Grant Number 25410240

LSD1 defines the fiber type-selective responsiveness to environmental stress in skeletal muscle

Skeletal muscle exhibits remarkable plasticity in response to environmental cues, with stress-dependent effects on the fast-twitch and slow-twitch fibers. Although stress-induced gene expression underlies environmental adaptation, it is unclear how transcriptional and epigenetic factors regulate fiber type-specific responses in the muscle. Here, we show that flavin-dependent lysine-specific demethylase-1 (LSD1) differentially controls responses to glucocorticoid and exercise in postnatal skeletal muscle. Using skeletal muscle-specific LSD1-knockout mice and in vitro approaches, we found that LSD1 loss exacerbated glucocorticoid-induced atrophy in the fast fiber-dominant muscles, with reduced nuclear retention of Foxk1, an anti-autophagic transcription factor. Furthermore, LSD1 depletion enhanced endurance exercise-induced hypertrophy in the slow fiber-dominant muscles, by induced expression of ERRγ, a transcription factor that promotes oxidative metabolism genes. Thus, LSD1 serves as an ‘epigenetic barrier’ that optimizes fiber type-specific responses and muscle mass under the stress conditions. Our results uncover that LSD1 modulators provide emerging therapeutic and preventive strategies against stress-induced myopathies such as sarcopenia, cachexia, and disuse atrophy

Screening of Mild Cognitive Impairment Through Conversations With Humanoid Robots: Exploratory Pilot Study

BackgroundThe rising number of patients with dementia has become a serious social problem worldwide. To help detect dementia at an early stage, many studies have been conducted to detect signs of cognitive decline by prosodic and acoustic features. However, many of these methods are not suitable for everyday use as they focus on cognitive function or conversational speech during the examinations. In contrast, conversational humanoid robots are expected to be used in the care of older people to help reduce the work of care and monitoring through interaction. ObjectiveThis study focuses on early detection of mild cognitive impairment (MCI) through conversations between patients and humanoid robots without a specific examination, such as neuropsychological examination. MethodsThis was an exploratory study involving patients with MCI and cognitively normal (CN) older people. We collected the conversation data during neuropsychological examination (Mini-Mental State Examination [MMSE]) and everyday conversation between a humanoid robot and 94 participants (n=47, 50%, patients with MCI and n=47, 50%, CN older people). We extracted 17 types of prosodic and acoustic features, such as the duration of response time and jitter, from these conversations. We conducted a statistical significance test for each feature to clarify the speech features that are useful when classifying people into CN people and patients with MCI. Furthermore, we conducted an automatic classification experiment using a support vector machine (SVM) to verify whether it is possible to automatically classify these 2 groups by the features identified in the statistical significance test. ResultsWe obtained significant differences in 5 (29%) of 17 types of features obtained from the MMSE conversational speech. The duration of response time, the duration of silent periods, and the proportion of silent periods showed a significant difference (P<.001) and met the reference value r=0.1 (small) of the effect size. Additionally, filler periods (P<.01) and the proportion of fillers (P=.02) showed a significant difference; however, these did not meet the reference value of the effect size. In contrast, we obtained significant differences in 16 (94%) of 17 types of features obtained from the everyday conversations with the humanoid robot. The duration of response time, the duration of speech periods, jitter (local, relative average perturbation [rap], 5-point period perturbation quotient [ppq5], difference of difference of periods [ddp]), shimmer (local, amplitude perturbation quotient [apq]3, apq5, apq11, average absolute differences between the amplitudes of consecutive periods [dda]), and F0cov (coefficient of variation of the fundamental frequency) showed a significant difference (P<.001). In addition, the duration of response time, the duration of silent periods, the filler period, and the proportion of fillers showed significant differences (P<.05). However, only jitter (local) met the reference value r=0.1 (small) of the effect size. In the automatic classification experiment for the classification of participants into CN and MCI groups, the results showed 66.0% accuracy in the MMSE conversational speech and 68.1% accuracy in everyday conversations with the humanoid robot. ConclusionsThis study shows the possibility of early and simple screening for patients with MCI using prosodic and acoustic features from everyday conversations with a humanoid robot with the same level of accuracy as the MMSE