JSPS KAKENHI Grant Number Research Articles

Analysis of the Association of Posttransplant Donor-Specific HLA Antibody with Liver Fibrosis After Pediatric Liver Transplantation

Objectives Although the short-term outcomes of pediatric liver transplantation (LT) have improved, the long-term outcomes, which are especially important in pediatric LT, have not improved to the same extent. This is partly caused by immunological progression of liver graft fibrosis. However, liver function test results are commonly normal even among patients with liver fibrosis; therefore, the indication and timing of liver graft biopsy have not been established. The aim of this study was to identify predictive factors of immunological graft fibrosis during long-term follow-up after pediatric LT. Methods We retrospectively identified 90 patients who underwent pediatric living donor LT (LDLT) at our institution between July 1991 and October 2013. Out of 90 LDLT patients, donor-specific antibody (DSA) screening was performed for 71 patients. After the DSA screening, liver biopsies were subsequently performed and graft fibrosis plus findings of chronic rejection were evaluated for 18 patients. Patients were divided into two groups based on histological findings, and clinical characteristics among patients with immunological graft fibrosis were assessed. The degree of fibrosis was diagnosed based on the Metavir fibrosis staging, and the fibrosis group included patients with fibrosis of F2 or more and patients with F1 fibrosis plus findings of chronic rejection, especially including C4d deposition. The cut-off for a positive reaction of Single Antigen Beads assay was set at a mean fluorescence intensity (MFI) of 1,000 or more. Results Of 18 patients, seven were included in the fibrosis group. No significant between-group differences were found regarding pretransplant characteristics, including age, sex, primary disease, ABO incompatibility, and immunosuppressive regimen. Episodes of biopsy-proven acute rejection and non-adherence to immunosuppressive drugs were comparable between the two groups. The mean fluorescence intensity (MFI) for anti-DR DSAs was significantly higher in the fibrosis group than the non-fibrosis group (1655 vs. 216; p = 0.019). There were significant between-group differences regarding the positive rate of anti-DR DSAs (86% vs. 28%; p = 0.012). The MFI for anti-DQ DSA was higher among patients with liver fibrosis, although this between-group difference did not reach statistical significance. The immunosuppression minimization rate was more prevalent among patients with liver fibrosis, although this between-group difference did not reach statistical significance (71% vs. 45%; p = 0.37). Conclusion Posttransplant development of anti-DR DSA is a risk factor of liver fibrosis during long-term follow-up. This finding provides useful information for the implementation of valid histological examinations of liver grafts for patients with higher MFI, especially for anti-DR DSA, after pediatric LT. JSPS KAKENHI Grant Numbers JP17K16502. JSPS KAKENHI Grant Numbers JP26861036.

Examination of validity and reliability for prototype scale to assess achievement motive in community-dwelling healthy older adults

Long-term care prevention is an important issue, particularly given the rapidly growing aging society. For rehabilitation, an achievement motive defined as “the intention to achieve one's goals while maintaining a standard of excellence” has been used as a means of assessment and intervention. The purpose of this study was to examine the validity and the reliability for a prototype scale for achievement motive in geriatric (P-SAMG) based on a scale for achievement motive in rehabilitation. A cross-sectional study was conducted to measure the P-SAMG, which has been accepted content validity by 8 experts, classification and assessment of occupational dysfunction (CAOD) and comprehensive environmental questionnaire for the elderly (CEQ) in 238 older adults (average age: 76.1 ± 7.2) who participated in senior clubs. The factorial validity of P-SAMG was examined using exploratory structural equation modeling (ESEM) and a confirmatory factor analysis (CFA), the concurrent validity was assessed using correlative analysis, and the internal consistency reliability was assessed by calculating Cronbach's alpha coefficient. This study was approved by the Ethical Review Board of Kibi International University and written consent was obtained from all the participants. This research was supported by JSPS KAKENHI Grant Number JP17H07288. ESEM presented good factor loadings (first factor of item 1–5: 0.93–0.56, the second factor of item 6–10: 0.95–0.54) and the CFA presented adequate fit indices. Moreover, P-SAMG indicated a moderate or low correlation with CEQ (0.42–0.20) and a partially low correlation with CAOD (−0.20 to −0.29). Cronbach's alpha coefficient demonstrated a sufficient value for two factors and the whole scale (0.89–0.94). These results demonstrated that P-SAMG is useful in the assessment of achievement motives for older adults without rehabilitation service. Management of material or personal environment and appropriate occupational engagements was suggested as a valid strategy to improve motivation in this population.

Nordic walking must be a common fitness technique and one of the effective rehabilitation menu for many gait disorders on oxygen intake and muscle activity

Nordic walking (NW) has spread recently not only in European countries but in Japan as well. Although the use of NW has begun in several clinical settings, opinions remain divided on exercise load and muscle activity of the legs during walking. So subjects’ oxygen intake and leg muscle activity during NW were measured and compared with normal walking. The subjects were 14 healthy adult men (21.3 years old). Normal walking and NW were performed with a uniform walking cadence of 110 steps per minute. Subjects walked 10 m in each movement task, and oxygen intake, carbon dioxide emission and muscle activity were measured. Activities in the rectus femoris, adductor magnus, tensor fasciae latae, biceps femoris, tibialis anterior, and lateral head of the gastrocnemius muscles were measured. The obtained electromyogram waveforms were processed with a 20-500 Hz bandpass filter, after which the integrated value from full-wave rectification was obtained. The integrated value from full-wave rectification for each muscle during walking was normalized with 100% maximum voluntary contraction (%MVC). In the measurement of the exercise load, oxygen intake and carbon dioxide emission were measured for 10 minutes and compared every minute though the paired t -test ( P < 0.05). %MVC tended to increase in the rectus femoris and adductor magnus muscles during NW compared with normal walking. In contrast, %MVC tended to decrease in the tensor fasciae latae, tibialis anterior, and lateral head of the gastrocnemius muscles during NW compared with normal walking. Oxygen intake of NW were higher than normal walking after 5 minutes from the beginning of walking exercise. We discovered that NW needs more oxygen and muscle activity than Normal walking. NW must become one of the effective total exercise menu for many elderly person with knee pain and hip pain. This study was supported by JSPS KAKENHI Grant Number JP16K16473.

Nonequilibrium thermodynamics and statistical physics: From rational modeling to its applications

PrefaceThe present volume contains 10 contributed papers presented at the meeting on “Nonequilibrium thermodynamics and statistical physics: From rational modeling to its applications” held during March 16 – 17, 2017 in Hakata, Japan. Each submitted contributed paper was peer-reviewed by at least one referee.The meeting was dedicated to 66th birthday of Prof. Masaru Sugiyama in Nagoya Institute of Technology. The aim of this meeting is to provide the related researchers in the fields of nonequilibrium thermodynamics and statistical physics with an opportunity to get together and to exchange their recent results. Main topics of the meeting are the following:• Rational extended thermodynamics• Nonequilibrium statistical physics• Kinetic theory of rarefied gases• Nonlinear wave propagation• Computational fluid dynamics• Numerical simulation on material scienceValuable discussions from the viewpoints of theoretical physics, chemical physics and applied mathematics were also made after the talks.This international meeting attracted 15 participants from 3 countries, namely, Japan, Italy and China. 12 oral contributions were presented at the meeting.We would like to thank all participants for their essential contributions to the success of the meeting. We are also grateful to the reviewers for their careful reading and prompt response. The meeting was partially supported by JSPS KAKENHI Grant Numbers JP16K17555 (S. T.) JP15K21452 (T.A.) and by National Institute of Technology, Kitakyushu College, Japan.Editors: Shigeru Taniguchi and Takashi Arima

Asymmetry Of Knee Extension Strength And Single-leg Landing Impact In ACL reconstructed Athletes

PURPOSE: Excessive magnitude, speed, and asymmetry of single-leg landing impacts contribute to re-injury risk in athletes after ACL reconstruction (ACLR). The limb symmetry index (LSI) of knee strength tends to decrease after ACLR even after return to sport. We analyzed relationships between the asymmetry of vertical ground reaction force (VGRF) parameters during single-leg jump landings and the knee isokinetic extension strength in athletes after ACLR. METHODS: Twenty-six participants were recruited based on the inclusion criteria: age 16-40 years at time of measurement; primary or one-sided ACL injury; >150 and <240 days since anatomical double-bundle ACLR using a hamstring tendon autograft; completed athletic rehabilitation within the same protocol; and agreement to participate in single-leg hop exercise and basic noncontact practice of jump-landings and cutting sports. The isokinetic strength of the quadriceps was tested at an angle of 60°/sec. Participants were subdivided into groups according to LSI for quadriceps strength (low quadriceps [LQ], <85% LSI, N10; high quadriceps [HQ], >90% LSI, N12). A 20-cm step was placed 60 cm from the center of a force plate. The participants stood on one leg on the step with their arms crossed, then jumped forward without any intended upward action and landed as naturally as possible on the same leg in the center of the force plate. The VGRF was collected at a sampling rate of 1000 Hz, filtered using a low-pass Butterworth filter with a cut-off frequency of 50 Hz, and normalized by body weight. Loading rate was calculated as peak VGRF (pVGRF) divided by the time from initial contact to pVGRF. The LSI of pVGRF and loading rate were compared between groups using non-paired t-tests. RESULTS: The quadriceps strength LSI of the LQ and HQ groups were 76±6.7% and 96.5±7.2%, respectively. The pVGRF LSI were 104.0±1.3% and 98.0±8.7%, respectively. Loading rate LSI were 115.9±23.6% and 98.8±21.7%, respectively. Loading rate LSI of LQ was significant larger than HQ (p=0.041). The pVGRF LSI of LQ tended to be larger than HQ (p=0.074). CONCLUSIONS: Smaller asymmetry in knee extension isokinetic strength is important for symmetrical landing impact during single-leg anterior jump-landings performed by athletes after ACLR. Supported by JSPS KAKENHI Grant number 26350606.

Blunted Sympathetic Vasomotor Outflow To Inspiratory Resistive Breathing During Exercise In Women Compared to Men

It has been reported that in young men high inspiratory muscle work at rest and during exercise reflexively increases muscle sympathetic nerve activity (MSNA), with corresponding increases in arterial blood pressure (ABP). This sympathoexcitation occurs through an inspiratory muscle-induced metaboreflex. Young women have attenuated inspiratory muscle metaboreflex-induced increases in ABP compared to age-matched men. One potential mechanism is less sympathetic vasomotor output in women compared to men. PURPOSE: We compared changes in MSNA and cardiovascular variables during leg cycle exercise with increased inspiratory muscle resistance in men and women. METHODS: Eight young women (19.5±0.2) and seven men (20.3±0.3) completed the study. The subjects performed two 10-min submaximal cycle ergometer exercises in a semirecumbent position. The first 5-min was spontaneous breathing, and latter 5-min half was voluntary hyperventilation with or without inspiratory resistive breathing. Mean arterial blood pressure (MAP) was measured using finger photoplethysmography and MSNA was recorded via microneurography of the arm at the elbow. RESULTS: During exercise with inspiratory resistive breathing, MSNA burst frequency was significantly increased accompanied by an increase (p<0.05) in MAP in both men and women. Women had significantly less of an increase in MSNA (Women: +9.6±1.0 vs. Men: +14.6±2.4 bursts/min) and MAP (Women: +22.8±5.7 vs. Men: +32.2±2.0 mmHg) as compared to men. CONCLUSION: These results suggest that lesser sympathetic vasomotor outflow partially contributes the attenuated inspiratory muscle-induced metaboreflex during exercise in young women. Supported by JSPS KAKENHI Grant Number 15H3079.

Cognitive Dual-tasking Augments Age-differences In Dynamic Balance While Walking On A Narrow Beam

Beam walking is a measure of dynamic balance. We tested the idea that cognitive dual-tasking during beam walking could be an effective method to detect age-related differences in dynamic balance. PURPOSE: To determine the effects of age and cognitive dual-tasking on dynamic balance measured during narrow-beam walking. METHODS: 16 old (7M, 71.2 ±3.5 y, foot width: 9.2 ±0.5 cm, MMSE score ≥ 27) and 20 young (10M, 22.0 ±1.5 y, foot width: 9.3 ±0.8 cm) healthy volunteers participated in the study. Subjects walked on a 4-m long and 2-cm high beam with a width of 4, 8, and 12 cm, arms crossed in front of the chest. Subjects completed 3 walking trials with or without performing a calculation task. We recorded the gait trials from the subject’s right side with a digital video camera at 60 Hz, and computed walking distance, step number, and average step length. Average of 3 was used for the statistical analyses. RESULTS: There was a Group (old, young) by beam width (4, 8, 12 cm) by task (dual task, no dual task) interaction (F = 4.0, P < 0.05). In the young group, beam-walking distance decreased similarly with descending beam width while no dual-tasking (12 cm: 3.88, 8 cm: 3.62, 4 cm: 2.49 m) and dual tasking (12-cm: 3.87, 8-cm: 3.76, 4-cm: 2.59 m). In the old group, beam-walking distance decreased substantially and most in the narrowest beam width during no dual-tasking (12-cm: 3.85, 8-cm: 3.72, 4-cm: 1.46 m) but decreased extremely in both narrower widths during dual-tasking (12-cm 3.91, 8-cm: 2.63, 4-cm 0.66 m). Further, only in the old group, the distance walked was shorter while dual-tasking compared with no dual-tasking at 8 and 4 cm beam widths (both P < 0.01). Depending on beam width, step length decreased in the young while both step number and step length decreased in the old group. CONCLUSIONS: Beam width but not dual- tasking affected young adults’ dynamic balance whereas both beam width and dual-tasking affected substantially and interactively old adults’ dynamic balance as quantified by beam distance walked and stride properties. These results suggest that, if validated and cognitive performance also quantified, dual task beam walking could be a sensitive measure of dynamic balance and motor-cognitive function in aging. Supported by JSPS KAKENHI Grant Number 16K21320.

(Invited) Biological Imaging Using up-Conversion Photoluminescence of Carbon Nanotubes

Single-walled carbon nanotubes (SWNTs) have been considered as nearly ideal luminescent probes for deep-tissue bioimaging because of their photoluminescence in near-infrared range known as the second optical window of biological tissues [1]. Moreover, efficient phonon-assisted up-conversion photoluminescence (UCPL) in SWNTs, for which the excitation light wavelength can be longer than the emission one, has recently been discovered [2, 3]. The UCPL phenomena enable SWNTs excited at wavelengths longer than ~1050-1200 nm to emit PL shorter than 1000 nm in which standard Si-based detectors have finite sensitivity. The availability of the UCPL thus potentially enhances the usefulness of SWNTs as luminescent probes in their bioimaging applications. We will report our recent progress in whole-body imaging of living mice with negligible autofluorescence using UCPL of SWNTs. We will also discuss application of the UCPL phenomena of SWNTs for near-infrared optical thermometry. [1] K. Welsher, Z. Liu, S. P. Sherlock, J. T. Robinson, Z. Chen, D. Daranciang, and H. Dai, Nat. Nanotechnol. 4, 773 (2009). [2] N. Akizuki, S. Aota, S. Mouri, K. Matsuda, and Y. Miyauchi, Nat. Commun. 6, 8920 (2015). [3] S. Aota, N. Akizuki, S. Mouri, K. Matsuda, and Y. Miyauchi, Appl. Phys. Express 9, 045103 (2016). Part of this study was supported by the Research Foundation for Opto-Science and Technology, the Nakatani Foundation, and by JSPS KAKENHI Grant Number JP15H05408.

Carbon Nanotubes for Flexible Perovskite Solar Cells

Single-walled carbon nanotubes (SWNT), graphene, and fullerene (C60 and PCBM) would be very efficiently used in lead halide Perovskite solar cells. A film of SWNTs or graphene can be flexible and stretchable transparent-conductive layer. At the same time, this film can be carrier-selective layers, i.e., electron-blocking-layers or hole-blocking-layers. Based on our experiences of using nanotube films for CNT-Si solar cells and organic polymer solar cells [1,2], we have explored the application of SWNT films for organic-inorganic perovskite solar cells. We have demonstrated the replacement of ITO in inverted-type perovskite solar cells, SWNTs/PEDOT:PSS/CH3NH3PbI3/PCBM/Al [3]. The flexible application on polyethylene terephthalate (PET) is also demonstrated [3]. With the improved perovskite structure, a film of carbon nanotubes or graphene can be practical replacement of ITO for the flexible transparent electrode of inverted perovskite solar cells [4]. Replacement of electron-blocking-layer and metal electrode in normal-type perovskite solar cells is demonstrated as well. Those devices can have comparable PCE as the conventional design with organic electron-blocking layer and top metal electrode. The normal-type perovskite solar cell, composed of ITO/C60/CH3NH3PbI3/SWNTs, can achieve a PCE of 17 % with spiro-MeOTAD as dopant to SWNTs [5]. This structure with a perovskite layer sandwiched by C60 and SWNTs can lead to the solar cells without hysteresis and with much improved air-stability [5]. The effective passivation of the degradation of perovskite material by moisture can be achieved with C60 and SWNTs [5]. More recent configuration is using a film of SWNTs for both anode and cathode electrode [6]. The new physical understanding of band alignment must be discussed based on the demonstrations of efficient carrier selective layers with these dry-deposited SWNTs which are composed of metallic and semiconductor nanotubes. Part of this work was supported by JSPS KAKENHI Grant Numbers JP25107002 and JP15H05760.

(Invited) Electrochemical Biosensors Based on CMOS LSI Chips

Electrochemical biosensors are the sensors for bio-related substances/phenomena based on electrochemical principles. While optical and colorimetric biosensors are widely used for clinical and research purposes, electrochemical biosensors offer various advantages such as compact/affordable instrumentation and high throughput. As a platform of such electrochemical biosensors, a complementary metal-oxide-semiconductor (CMOS) large-scale integrated (LSI) circuit chip can be an ideal platform for its microscale structures and electronic circuit integration. In this paper, general overview and some examples of such CMOS-based electrochemical sensing experiments/simulations are presented. The electrochemical methods can be categorized into three types, that is, (i) amperometoric and voltammetric method, (ii) potentiometric method, and (iii) impedance method. In the amperometric method, electrochemical current is measured as a function of time under constant voltage application, while voltammetric method often means that the voltage is swept and current vs. voltage is plotted. On the other hand, in potentiometric method, no voltage is applied and therefore no current will be induced. Instead, open-circuit potential of a floating electrode in contact with sample solution is measured. Finally, in impedance method, the relation between sinusoidal voltage applied to the sample solution and resulting sinusoidal current is measured as a complex valued impedance. We have been working on various CMOS-based electrochemical biosensing experiments and simulations. Experimental demonstrations of amperometric and voltammetric methods can been seen in [1, 2], where carbon-ink electrodes are formed on CMOS chip and used to measure current under constant/swept voltages. Computer simulation of amperometric measurement using CMOS on-chip electrode has also been presented in [3]. As for the potentiometric method, we have demonstrated a potentiometric glucose sensor with carbon electrode and enzyme-functionalized chromatography paper on CMOS chip [4]. Computer simulation of ion-sensitive field-effect transistors (ISFET) for DNA sensing [5, 6] and lipid bilayer (cell membrane) detection [7] have also been demonstrated. In terms of impedance measurement using CMOS, we have developed a computationally efficient three-dimensional model of electrolytic solution and living cells for finite-element method (FEM) simulation. Using this, we have demonstrated computer simulation of impedance measurement of single mammalian cell or bacterial cell using microscale electrode on CMOS chip [8, 9]. Compact formulae for equivalent circuit model of such cell/electrolyte/electrode system have demonstrated a good accuracy [9]. Our current goal is the experimental implementation of such single cell monitoring by impedance measurement using CMOS on-chip microelectrodes. In summary, we have been developing both experimental and simulation techniques of the major electrochemical biosensing methods using CMOS on-chip microelectrodes. Such effort would lead to a comprehensive understanding of multi-modal electrochemical biosensing where CMOS LSI chips are used as a platform. This work was partially supported by JSPS KAKENHI Grant Numbers 25220906 and 26289111, as well as VLSI Design and Education Center (VDEC), the University of Tokyo in collaboration with Synopsys, Cadence Design Systems, and Mentor Graphics. [1] M. Miki, S. Iwahara, and S. Uno, “A hybrid system of carbon ink electrodes and chromatography paper on a CMOS chip and its application to Enzymatic glucose sensor”, Jpn. J. Appl. Phys., vol. 53, p. 04EL06 (2014). [2] J. Eguchi, K. Yamaoka, and S. Uno, “Simultaneous Electrochemical Measurement using Paper Fluidic Channel on CMOS Chip”, TELKOMNIKA, vol. 15, no. 2, pp. 847-852 (2017). [3] J. Hasegawa, S. Uno, and K. Nakazato, “Amperometric Electrochemical Sensor Array for On-Chip Simultaneous Imaging: Circuit and Microelectrode Design Considerations”, Jpn. J. Appl. Phys., vol. 50, p. 04DL03 (2011). [4] K. Yamaoka, J. Eguchi, and S. Uno, “Potentiometric Glucose Detection by Paper-based Electrochemical Sensor on CMOS Chip”, TELKOMNIKA, vol. 15, no. 2, pp. 836-841 (2017). [5] Y. Nishio, S. Uno, and K. Nakazato, “Three-Dimensional Simulation of DNA Sensing by Ion-Sensitive Field-Effect Transistor: Optimization of DNA Position and Orientation”, Jpn. J. Appl. Phys., vol. 52, p. 04CL01 (2013). [6] S. Uno, M. Iio, H. Ozawa, and K. Nakazato, “Full Three-dimensional Simulation of ISFET Flatband Voltage Shift due to DNA Immobilization and Hybridization”, Jpn. J. Appl. Phys., vol. 49, no. 1, p. 01AG07 (2010). [7] S. Uno, “Computer simulation of lipid bilayer detection using ion-sensitive field-effect transistors” SPIE BIOS, San Francisco, USA (January 26, 2012) 8231-28. [8] S. Uno, “Simulation of Microelectrode Electrochemical Impedance Sensor for Single-cell Monitoring”, The 11th International Symposium on Electrochemical Micro & Nanosystem Technologies (EMNT2016), Brussel, Belgium (August 17-19, 2016), P-18. [9] S. Uno, and K. Nakazato “Numerical and Equivalent Circuit Analysis of Electrochemical Impedance Spectroscopy of Single Bacterial Cell Detection using CMOS LSI Chip”, 11th International Symposium on Electrochemical Impedance Analysis 2017, Camogli, Italy (November 7-11, 2017).

Synthesis and Evaluation of Iridium Oxide Nanoparticle Catalysts Supported on Nitrogen-Doped Reduced Graphene Oxides

Recently, progress toward sustainable societies with renewable energies is a critical issue to overcome environmental and social problems, for example, global warming and depletion of fossil fuels. To utilize effectively renewable energies such as solar and wind energy, conversion of renewable energies to hydrogen via water electrolysis is one of the most attractive approaches for energy storage. However, for the practical application of water electrolysis systems, its activity, durability, and catalysts cost are insufficient due to high over-potential and low kinetics of electrode reactions, especially, oxygen evolution reaction (OER) at the anode [1,2] for polymer electrolyte water electrolyzer (PEWE). As anode catalysts, iridium oxide (IrO2) particles have been used because of its high activity and durability for OER. However, iridium is one of the platinum group metals and reducing loading amount of iridium is required to reduce catalyst cost. Recently, we have successfully synthesized novel catalysts, IrO2 nanoparticle catalysts supported on nanocarbon materials with improved specific surface area, surface area per weight, of anode catalysts for PEWE. In this study, we focus on modification of IrO2 catalysts by doping of hetero atom (N) on supporting materials and characterization its electronic state condition and catalytic activity for OER. Novel catalyst of IrO2 nanoparticles supported on nitrogen-doped reduced graphene oxide (N-rGO) was prepared by hydrothermal synthesis. Graphene oxide (GO) prepared by modified Hummers method [3] was mixed with urea and hydrothermally treated at 180 ˚C for 12 h to synthesize N-rGO. For the synthesis of IrO2 / N-rGO catalysts, mixture of H2IrCl6 complex and N-rGO dispersed in ethanol/water mixture solution was stirred at 80 ˚C for 6 h in a flask to attach iridium oxide colloid to N-rGO and heated at 150 ˚C for 4 h in a hydrothermal autoclave to form IrO2 nanoparticles. The IrO2 / N-rGO catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersed X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), and electrochemical methods. The OER activity of the IrO2/ N-rGO was examined in sulfuric acid solution using rotating disk electrode system. Figure 1 shows TEM image of synthesized IrO2 / N-rGO catalysts. The IrO2 nanoparticles with an average particle size of 1.2 nm are uniformly dispersed on surface of the N-rGO substrate. The loading amount of the IrO2 nanoparticles and doping weight of nitrogen atom of the IrO2 / N-rGO catalysts are approximately 9 and 7 wt%, respectively, which was estimated from EDX measurements. Figure 2 shows the results of XPS investigation on GO, N-rGO, and IrO2 / N-rGO. The XPS data reveal nitrogen doping on GO by hydrothermal synthesis of GO with urea. After the reaction between Ir complexes and N-rGO, Ir 4f peak appeared on the spectrum and intensity of O 1s was decreased due to reduction of GO during the hydrothermal reaction. Deconvolution analysis of the N 1s peak of N-rGO indicates doped nitrogen has three different types, pyridinic, pyrrolic, and graphitic type. The binding energy of the Ir 4f peak was shifted to a lower energy state. In addition, XRD pattern of the IrO2 / N-rGO catalyst suggests that the interlayer distance of graphene sheets decreased during hydrothermal reaction because of reduction of GO. The XRD data suppot the results of the XPS measurement.Figure 3 shows linear sweep voltammogram of the IrO2 / N-rGO catalyst obtained in 0.5 M H2SO4 solution. Electrochemical measurement reveals high activity of the IrO2 / N-rGO catalyst for OER, onset potential of the reaction is ca. 1.43 V and mass activity at 1.60 V is ca. 1000 A g-1. The overvoltage of the IrO2 / N-rGO catalysts is 70 mV lower than that of conventional IrO2 powder catalysts. High activity of the IrO2 / N-rGO catalyst indicates that the IrO2 / N-rGO catalyst is a promising candidate of anode material for PEWE. Acknowledgements This work was supported by JSPS KAKENHI Grant number 17K05969. Reference[1] M. Carmo, D. L. Fritz, J. Mergel, D. Stolten, Int. J. Hydrogen Energy 38 (2013) 4901.[2] E. Antolini, ACS Catal. 4 (2014) 1426.[3] W. S. Hummers, R. E. Offeman, J. Am. Chem. Soc. 80 (1958) 1339. Figure 1

(Invited) Digital-Coded Isotope Labeling on Individual Single-Walled Carbon Nanotubes Grown on Crystal Quartz

Single-walled carbon nanotubes (SWNTs) are promising building blocks for next-generation high-performance electronics, e.g. field-effect transistors (FET). For the application, many properties, such as chirality, orientation, density and length, have to be well controlled. Despite significant progresses in controlling the SWNT chirality and density in recent years, further breakthroughs are desirable to make the SWNT-based electronics reality. Detailed understanding on the growth process of individual SWNTs with a practical form (quality, length, and alignment) will accelerate the development of application-oriented growth. In this study, we developed an isotope labeling technique with digital coding for the ex situ monitoring of individual and long (>100 μm) SWNTs. Owing to the nature of ex situ measurement, an enormous number of SWNTs can be characterized on a single substrate. In addition, digital-coding of the isotope labels enables identification of time evolution of SWNT growth with high accuracy. Horizontally aligned configuration were used for the tracing of individual SWNTs and for the breakdown of SWNT quantity into population and length [1]. Aligned SWNTs were grown on r-cut quartz substrates from iron catalysts patterned in stripes with 300-μm separation. Normal 12C ethanol was used for most parts of the growth, but pure 13C ethanol was periodically mixed in various ratios (33, 67, 100 %) to embed digital-coded isotope labels in SWNTs. For the standard growth, 5-sccm ethanol was introduced together with 50-sccm Ar/H2 buffer gas into the reactor with total pressure of ~1.5 kPa. After the growth, position of each isotope label and the SWNT properties were identified by Raman mapping. The sequence of the isotope labels clearly indicated that all the SWNTs that we observed grew in the root growth mode [2], where the catalysts stayed at the original position and SWNTs pushed forward. We obtained the time evolution of SWNT lengths, and found that the SWNTs started to grow after certain lengths of incubation time. For most cases, growth rate was constant until the abrupt termination of the growth. This suggests that the catalytic activity of metal particles did not gradually change with time under the current growth condition. Two different SWNTs with the same chirality (radial breathing mode (RBM) frequency of 190 cm-1 with 532 nm excitation laser) had different growth rates (~8 and ~15 μm/min), indicating the dependence of the growth rate on catalyst sizes or some other properties. For the extraction of intrinsic chirality dependence of the growth rate, we focused on spontaneously formed intramolecular junctions. For example, an intramolecular junction changed the RBM frequencies of an SWNT from 139 to 144 cm-1. Interestingly, the growth rate changed from ~10 to ~8 μm/min along with the chirality change. Since the growth behavior can be traced along individual SWNTs, the dependence on growth conditions, such as temperature and pressure of carbon feedstocks, was also investigated by changing the conditions during the growth. First, ethanol flow rate, which is nearly proportional to the partial pressure, was increased from 3 to 9 sccm in 2 sccm steps every four minutes. Most SWNTs grew faster as the flow rate increased; however, some SWNTs stopped growing for one or two minutes when the flow rate was suddenly increased. We also observed temperature-dependent growth rate, which provides insights into the growth dynamics of individual SWNTs. Part of this work was supported by JSPS KAKENHI Grant Numbers JP25107002, JP15H05760, JP17K06187 and JP17K14601. K.O. was financially supported by a JSPS Fellowship (JP15J07857).

Room-Temperature Atomic Layer Deposition of Aluminum Silicate for Molecule Sorption

A room-temperature atomic layer deposition (RT-ALD) of aluminum silicate for molecule sorption is developed using trimethylaluminum (TMA) and trismethylaminosilane (TDMAS) using a plasma excited humidified argon. The aluminum-silicate is a main material of zeolites that is used for cation sorption. If we achieved the aluminum silicate deposition on flexible films, we could expect the film used as a regenerable ion exchange filter. The schematic of ALD system is shown in Fig.1. TMA and TDMAS were introduced with mass flow controllers. A remote plasma system generating excited humidified argon was installed to the ALD chamber. The source gas for the oxidizing gas is a mixture of water vapor and argon. The plasma was generated in a glass tube with an induction coil with a frequency of 13.56 MHz and a RF power of 100 W. For the deposition, we repeated the cycle of TDMAS and TMA saturation and oxidizing gas treatment at RT. To control the aluminum to Si atomic ratio in the aluminum silicate, we adjusted the initial exposure of TDMAS. To confirm the Na sorption ability of the aluminum silicate film deposited by the present technology, we immersed the aluminum silicate coated Si sample in a 100 mM NaCl solution for 3h. The dried sample was evaluated by X-ray photoelectron spectroscopy. As shown in Fig. 2, the enhanced Na adsorption is confirmed. In the conference, we discuss the mechanism of Na sorption on the RT deposited aluminum silicate. Acknowledgements This work was partly supported by JSPS KAKENHI Grant Numbers 15H03536. It was also partly supported by JST-CREST Grant Number JPMJCR14F3, Japan. Figure 1

Suppression of Sulfur Desorption of High-Temperature Sputtered MoS2 Film By Applying DC Bias

As the research field of 2D layered materials expands and progresses, especially for the transition metal dichalcogenaides (TMD), the demand for high quality thin films is also rising. There have been many techniques proposed to fabricate TMD films [1-2]. Among the fabrication techniques, RF magnetron sputtering is expected to realize MoS2 device operating in normally-off mode due to large-area uniformity and suppression of impurity [3]. On the other hand, during sputtering deposition using compound MoS2 target, it is known that the film suffers from sulfur desorption especially when the substrate is heated to obtain sufficient crystallization of the film. We have reported the 2-step technique with the post-deposition sulfurization (PDS) to achieve the S implementation [4-5], however the crystallization is still insufficient due to the lack of migration of Mo atoms. Therefore prevention of sulfur desorption with 1-step method is desired in order to fabricate high quality MoS2 thin film. In this study, we proposed applying positive DC bias to the substrate during high-temperature sputter deposition in order to prevent sulfur desorption and obtain superior crystallinity by the enhanced Mo migration. MoS2 was deposited on SiO2 substrate by RF sputtering. The substrate temperature was varied from 250°C to 600°C. Ar partial pressure was also varied from 0.09 to 1.0 Pa with RF power of 50 to 225 W. The sputtering duration was fixed to 600 s. In order to investigate the effect of the sputtering parameters, the sputter-deposited MoS2 flms were evaluated with X-ray electron spectroscopy (XPS) to confirm Mo-S bond formation. The S/Mo ratio of the film was calculated from the ratio of Mo 3d and S 2p spectra. The samples with elevated deposition temperature were evaluated with Raman spectroscopy and compared to the as-depo. sample and the PDS sample [4]. As a result of applying bias voltage, higher positive bias voltage yielded films with higher S/Mo. Stoichiometric S/Mo ratio of 2.0 was achieved by applying positive bias voltage even with high-temperature sputtering. This is considered to be the attracting effect of S2- to the substrate due to the positive bias. When the Ar partial pressure was increased, the S/Mo ratio decreased. This result shows that the mean free path of the sputtered particles have large effect on the amount of S2- reaching the substrate determining S/Mo ratio of the film. As the sputter RF power was increased S/Mo also increased, which may also provide larger Mo migration energy, therefore result in the better crystallinity. By optimizing each sputtering parameters, S/Mo of 2.0 was achieved at 400-600°C. This work was partly supported by JST CREST Number JPMJCR16F4, Japan. This work was also partly supported by JSPS KAKENHI Grant Number 16J11377. REFERENCE D. Sarkar, X. Xie, W. Liu, W. Cao, J. Kang, Y. Gong, S. Kraemer, P. M. Ajayan, K. Banerjee, Nature 526, 91 (2015)S. Larentis, B. Fallahazad, E. Tutuc, Appl. Phys. Lett. 101, 223104 (2012)T. Ohashi, K. Suda, S. Ishihara, N. Sawamoto, S. Yamaguchi, K. Matsuura, K. Kakushima, N. Sugii, A. Nishiyama, Y. Kataoka, K. Natroi, K. Tsutsui, H. Iwai, A. Ogura, and H. Wakabayashi, Jpn. J. Appl. Phys. 54, 04DN08 (2015)S. Ishihara, Y. Hibino, N. Sawamoto, K. Suda, T. Ohashi, K. Matsuura, H. Machida, M. Ishikawa, H. Sudoh, H. Wakabayashi and A. Ogura, Jpn. J. Appl. Phys. 55,04EJ07 (2016)S. Ishihara, Y. Hibino, N. Sawamoto, K. Suda, T. Ohashi, K. Matsuura, H. Machida, M. Ishikawa, H. Sudoh, H. Wakabayashi and A. Ogura, Jpn. J. Appl. Phys. 55,06GF01 (2016) Figure 1

Creatine enhances the duration of sperm capacitation: a novel factor for improving in vitro fertilization with small numbers of sperm.

Why are many sperm required for successful fertilization of oocytes in vitro, even though fertilization occurs in vivo when only a few sperm reach the oocyte? Creatine produced in the ovary promotes efficient fertilization in vivo; however, in vitro, creatine is not contained in the in vitro fertilization (IVF) medium. The IVF medium enables capacitation of sperm. However, the IVF medium does not fully mimic the in vivo environment during fertilization. Consequently, fertilization in vitro is more inefficient than in the oviduct. Follicular and oviductal fluids were collected and then analyzed for creatine and glucose levels. To determine the physiological functions of creatine, the creatine antagonist 3-guanidinopropionic acid (GPA) was injected into hormonally primed mice. Using conventional IVF protocols, sperm were pre-incubated in IVF medium with creatine and then co-cultured with 10 ovulated cumulus-oocyte complexes (1-1000 per oocyte) in 50 μl medium droplets. Glucose and creatine levels were measured using commercial enzymatic assay kits. The effect of creatine in vivo was assessed by mating experiments using mice treated with or without GPA just before ovulation. To assess the functions of sperm incubated in IVF medium containing creatine, we analyzed (1) the motility of sperm using computer-assisted sperm assay, (2) the capacitation level of sperm by western blot analyses, and (3) the condition of sperm acrosomes by peanut agglutinin lectin-FITC staining. Oviductal creatine levels were significantly increased following ovulation. Injecting mice with GPA just before ovulation significantly reduced the number of fertilized oocytes. The addition of creatine to IVF medium enhanced sperm capacitation by increasing ATP levels. Successful fertilization was achieved with as few as five sperm/oocyte in the creatine group, and the number of fertilized oocytes was significantly higher than in the control without creatine (P < 0.01). In the present study, a pharmacological approach, creatine antagonist (GPA) treatment, but not a knockout mouse model, was used to understand the role of creatine in vivo. The role of creatine in fertilization processes can only be shown in a mouse model. A modified IVF technique using creatine-containing medium was developed and shown to markedly improve fertilization with small numbers of sperm. This approach has the potential to be highly beneficial for human assisted reproductive technologies, especially for patients with a limited number of good quality sperm. This work was supported in part by JSPS KAKENHI Grant numbers JP24688028, JP16H05017 (to M.S.), and JP15J05331 (to T.U.), the Japan Agency for Medical Research and Development (AMED) (16gk0110015h0001 to M.S.), and National Institutes of Health (NIH-HD-076980 to J.S.R). The authors have nothing to disclose.

Identification of a new splice variant of large‐conductance Ca2+‐activated K+ (BK) channel α subunit from human chondrocyte

Changes in intracellular calcium concentration ([Ca2+]i) modulate chondrogenesis, proliferation, cell death and baseline anabolic and catabolic activities in chondrocytes. Under pathophysiological conditions, like osteoarthritis (OA), histamine release from resident mast cells enhances the production of pro‐inflammatory mediators and the activities of matrix degrading enzymes. Specific patterns of [Ca2+]i changes are considered as essential components initiating and/or progressing the disease. In an established model cell‐line of the human chondrocyte, OUMS‐27 cells, large‐conductance Ca2+‐activated K+ (BK) channels are involved in the enhancement of histamine‐induced Ca2+ influx by the activation of Ca2+ release‐activated Ca2+ (CRAC) channels consisting of Orai1‐Orai2 heteromers and STIM1 via the modulation of membrane potential. We have identified a novel BKα splice variant (BKαΔe2) in OUMS‐27 cells. Although BKαΔe2 lacks exon2 that codes the intracellular S0–S1 linker (Glu127‐Leu180), significant expression was detected in several human tissues including chondrocytes of OA patients and in mouse tissues as well. BKαΔe2 channels are not expressed on plasma membrane (PM), but can traffic to PM after forming hetero‐tetramer units with wild‐type BKα (BKαWT). These hetero‐tetramers of BKα have a smaller single channel conductance and exhibit lower trafficking efficiency than BKαWT homo‐tetramers in a stoichiometry‐dependent manner. BKαΔe2 knockdown in OUMS‐27 chondrocytes increased BK current density, and augmented the responsiveness to histamine assayed as cyclooxygenase‐2 gene expression. These findings provide significant new evidence that BKαΔe2 can modulate cellular responses to physiological stimuli in human chondrocyte and contribute under pathophysiological conditions, such as OA.Support or Funding InformationThis work was supported by JSPS KAKENHI Grant Numbers, 26293021 and 15H01408 to Y.I., 26860059, 16H06215 and 16K15127 to Y.S., 16K08278 to H.Y. This work was also supported by a Grant‐in‐Aid from Takeda Science Foundation (to Y.S.) and Salt Science Research Foundation [Grant 1637] (to Y.S.). W.G. holds an Alberta Innovates‐Health Solutions Scientist Award, and CIHR funding.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Excessive shear stress sensing on the arterial endothelium initiates cerebral aneurysm formation

Although rupture of cerebral aneurysms is a major cause of life‐threatening subarachnoid hemorrhage, there are no effective therapeutic drugs for the treatment of aneurysms, partly because the pathogenesis of the aneurysm remains unresolved. We hypothesize that shear stress‐related hemodynamics initiates cerebral aneurysm formation. To test this hypothesis, we examined here whether disruption or inhibition of the endothelial shear stress sensor, P2X4 purinoceptor, has any influence on expressions of known contributors to aneurysm formation or not.P2X4 purinoceptor deficient (P2X4 KO) mice and Sprague‐Dawley rats were subjected to cerebral aneurysm‐generating surgery with ligation of unilateral common carotid artery and renal hypertension. P2X4 purinoceptor inhibitor, paroxetine (8 mg/kg/day) was administered to rats after the surgery. The incidence of aneurysm formation was examined with light microscopy, and expressions of contributors to aneurysm formation using a quantitative real‐time PCR analysis and immunohistochemical examinations.The frequency of aneurysm induction in P2X4 KO mice was significantly lower than wild‐type mice (p=0.018). In addition, paroxetine significantly attenuated the incidence of induced aneurysms in rats after aneurysm‐generating surgery (p=0.031). Expression levels of inflammatory contributors to aneurysm formation, COX‐2, TNFα, MCP‐1, IL1β, and iNOS, were significantly increased in rats after aneurysm‐inducing surgery than control non‐operated animals by a quantitative real‐time PCR analysis. Paroxetine significantly reduced the expression levels of all the contributors.These data suggest that shear sensing on the arterial endothelium initiates chronic inflammation in the arterial wall during cerebral aneurysm formation. Because paroxetine has been used for human as an antidepressant, clinical use of this P2X4 purinoceptor inhibitor is expected as a novel therapy for cerebral aneurysms.Support or Funding InformationThis work is supported by Japan Agency for Medical Research and development, AMED and JSPS KAKENHI Grant Number JP15K10323.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effects of heat stress treatment and leucine supplementation on age‐related muscle loss in mice

Acute heat stress treatment activates mammalian target of rapamycin (mTOR) signaling in skeletal muscle, leading to increase skeletal muscle protein synthesis and skeletal muscle mass. Leucine intake also activates mTOR signaling and stimulates protein synthesis. This study investigated the effects of heat stress treatment and leucine supplementation on sarcopenia (muscle loss with aging) in mice. C57BL/6J male mice (14 or 98 weeks old) were assigned randomly to young control (YC, N=6), old control (OC, n=9), heat stress (OH, n=7), leucine supplementation (OL, n=7), and heat stress and leucine supplementation (OLH) groups. Mice in OH and OLH groups were exposed to hot environment chamber (41ºC) for 40 min twice per week. Mice in OL and OLH groups were given ad libitum access to leucine‐supplemented water (114mM leucine). After 12‐week intervention, there were no differences in body weight and grip strength among groups. Body fat percentage in OLH group was significantly lower than that in OC group (29.0 ± 6.4 % vs. 39.1 ± 8.5 %, p &lt; 0.05). The vastus lateralis muscle weight was significantly lower in OC, OH and OL groups compared with that of YC group, but the muscle weight in OLH group was significantly greater than that in OC group (191.9 ± 12.8 mg vs. 167.1 ± 10.1 mg, p &lt; 0.05). Heat stress treatment induced the expression of heat shock protein 72 (HSP72) in muscle of OH and OLH groups (~5 fold, p &lt; 0.05). There were no differences in the muscle mTOR signaling (the phosphorylation of mTOR, p70s6k, S6 and 4E‐BP1) between groups under overnight fasting condition. On the other hand, the expression of L‐type amino acid transporter 1 (LAT1) of muscle was significantly increased in OC, OH and OL groups compared with YC group (~3 fold, p &lt; 0.05), but there were no difference between YC and OLH group. Our current observations show that the combination of heat stress treatment and leucine supplementation appears to be clinically beneficial for age‐related muscle loss. In addition, normal expression of LAT1 in muscle might contribute to suppression of muscle loss.Support or Funding InformationThis work was supported by JSPS KAKENHI Grant Number JP16K16565.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Interorganellar Phosphatidylserine Transfer by Sec14 Family Protein Sfh1 in Saccharomyces cerevisiae

Interorganellar phospholipid transfer is critical for the generation and maintenance of uneven distribution of phospholipids in membranes and for the phospholipid synthesis through CDP‐DAG pathway in the yeast Saccharomyces cerevisiae. While involvement of lipid transfer proteins (LTPs) in directional lipid transport has been actively discussed, the precise mechanisms of interorganellar phospholipid transfer remain unsolved. We carried out a screening to identify genes involved in aminophospholipid transfer in Psd2 branch of the CDP‐DAG pathway and obtained SFH1, a SEC14 homolog. Overexpression of SFH1 recovered the growth of psd1Δ on non‐fermenting carbon sources without ethanolamine supplementation, and partially restored the mitochondrial and cellular PE levels. Sfh1 was able to transfer fluorescence‐labeled phosphatidylserine (PS) between liposomes in vitro. In addition, binding of Sfh1 to PS in vivo was suggested by the analysis of phospholipid species copurified with Sfh1 from yeast cells by ESI‐MS/MS. Subcellular fractionation suggested that a portion of Sfh1 is localized in the endosome and the Golgi where Psd2 is reported to be localized. Together with the results that overexpression of SFH1 did not affect the protein abundance of Pss1 and Psd2, or the in vitro Psd2 activity, it is conceivable that Sfh1 enhance PE synthesis by PS transfer from the endoplasmic reticulum to the endosome. Our findings propose a novel function for Sec14‐family proteins in yeast.Support or Funding InformationThis work was partly supported by JSPS KAKENHI Grant Number 17K07710 and 15J10871.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Severe iron deficiency and manganese concentrations in the rat cerebrum

Severe iron deficiency is known to increase brain manganese concentration in rats. We studied whether severe iron deficiency affects dose‐effect relationship between dietary manganese and brain manganese in rats. Forty‐eight weaning male Wistar rats were equally divided into 8 groups and fed on respective experimental diets for 7 weeks. Four diets were iron‐deficient diet containing graded levels of manganese: one times, 3 times, 6 times and 9 times the National Research Council manganese requirement. The other four diets were iron‐adequate diet containing the graded levels of manganese as same as the above. After dietary regimen and 16 hour starvation, rat cerebrum was separated into striate, hippocampus and cortex (i.e., remaining parts). Samples were decomposed by wet ashing using nitric acid followed by hydrogen peroxide. Manganese concentration was measured by inductively coupled plasma‐mass spectrometry. Data were analyzed by simple linear regression, general linear model and nonlinear regression. The model that gave the highest Akaike information criterion was selected. Except for hippocampal manganese concentration in iron‐adequate rats, manganese concentrations in the measured brain regions were significantly and positively correlated with dietary manganese level. For hippocampus and striate, a general linear model was selected. Iron deficiency and dietary manganese independently and significantly increased manganese level in striate. In hippocampus, iron deficiency significantly increased manganese concentration. Effect of dietary manganese was significant when animals were iron‐deficient. Exponential saturation model regarding dietary manganese was selected for cortex. Effect of dietary manganese was significant and iron deficiency increased the curve span approximately by two‐fold. These results suggest that severe iron deficiency augments increments of manganese level by dietary manganese in the rat brain region.Support or Funding InformationThis work was supported by JSPS KAKENHI Grant Numbers JP17K00877 and JP 25350137.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.