Graphite-Conjugated Pyrazines as Molecularly Tunable Heterogeneous Electrocatalysts

Condensation of ortho-phenylenediamine derivatives with ortho-quinone moieties at edge planes of graphitic carbon generates graphite-conjugated pyrazines (GCPs) that are active for oxygen reduction electrocatalysis in alkaline aqueous electrolyte. Catalytic rates of oxygen reduction are positively correlated with the electrophilicity of the active site pyrazine unit and can be tuned by over 70-fold by appending electron-withdrawing substituents to the phenylenediamine precursors. Discrete molecular analogs containing pyrazine moieties display no activity above background under identical conditions. This simple bottom up method for constructing molecularly well-defined active sites on ubiquitous graphitic solids enables the rational design of tunable heterogeneous catalysts.Japan Society for the Promotion of Science (Postdoctoral Fellowship)United States. Dept. of Energy. Office of Basic Energy Sciences (Award number DE-SC0014176)Massachusetts Institute of Technology. Department of Chemistry (Junior Faculty Funds

Electrochemical oxygen reduction catalysed by Ni3(hexaiminotriphenylene)2

Control over the architectural and electronic properties of heterogeneous catalysts poses a major obstacle in the targeted design of active and stable non-platinum group metal electrocatalysts for the oxygen reduction reaction. Here we introduce Ni[SUBSCRIPT 3](HITP)[SUBSCRIPT 2] (HITP=2, 3, 6, 7, 10, 11-hexaiminotriphenylene) as an intrinsically conductive metal-organic framework which functions as a well-defined, tunable oxygen reduction electrocatalyst in alkaline solution. Ni[SUBSCRIPT 3](HITP)[SUBSCRIPT 2] exhibits oxygen reduction activity competitive with the most active non-platinum group metal electrocatalysts and stability during extended polarization. The square planar Ni-N[SUBSCRIPT 4] sites are structurally reminiscent of the highly active and widely studied non-platinum group metal electrocatalysts containing M-N[SUBSCRIPT 4] units. Ni[SUBSCRIPT 3](HITP)[SUBSCRIPT 2] and analogues thereof combine the high crystallinity of metal-organic frameworks, the physical durability and electrical conductivity of graphitic materials, and the diverse yet well-controlled synthetic accessibility of molecular species. Such properties may enable the targeted synthesis and systematic optimization of oxygen reduction electrocatalysts as components of fuel cells and electrolysers for renewable energy applications.United States. Department of Energy. Office of Basic Energy Sciences (Award DESC0006937

EXAMINATION OF THE ORIGINAL AWAODORI GUIDANCE WITH THE LAPTOP COMPUTER

The purposes of this study were 1) to introduce the original AWAODORI guidance computer software with the laptop computer to beginner college students and 2) to examine its effect on their motivation. AWAODORI is one of the most famous regional dances in Japan. It is a humorous dance and remains a traditional event of Tokushima, Japan. The reason why we designed the software was to pass this dance from generation to generation using some of the advantages of the modern laptop computer. 16 healthy college students participated in this study and they were divided into two groups. One group using AWAODORI software, the other the AWAODORI guidance video and other supplementary materials. In this study, there was no statistical difference to be found between the two groups indicating that the software may be as equally effective as conventional methods of guidance

Elevated Levels of VE-Cadherin-Positive Endothelial Microparticles in Patients With Type 2 Diabetes Mellitus and Coronary Artery Disease

ObjectivesThe purpose of this study was to examine whether CD144-EMP (endothelium-derived microparticles) is useful as a specific marker of endothelial cell (EC) dysfunction and to determine whether plasma levels of circulating CD144-EMP predicted coronary artery disease (CAD) in patients with type 2 diabetes mellitus (DM).BackgroundEndothelial cell dysfunction is involved in atherogenesis; however, the quantitative assessment of EC dysfunction has yet to be established clinically. Endothelium-derived microparticles are small, membrane-shed vesicles that are generated from the EC surface in response to cellular dysfunction and/or injury. Diabetes mellitus is known to be associated with EC dysfunction and accelerated atherosclerosis.MethodsWe characterized EMP using anti-CD144 (VE-Cadherin) antibody in various atherosclerosis-related cells and investigated the association between the levels of CD144-positive microparticles and hydrogen-peroxide-induced EC injury and acetylcholine-induced coronary vasomotion. Furthermore, we evaluated plasma CD144-EMP levels in patients with and without DM.ResultsWe demonstrated that CD144-positive microparticles were derived selectively from human EC. The levels of CD144-EMP reflected the degree of in vitro hydrogen-peroxide-induced EC injury and impairment of in vivo endothelium-dependent coronary vasodilation (p < 0.01). Plasma CD144-EMP levels were increased significantly in DM patients compared with patients without DM (p < 0.001). In DM patients, the elevated levels of CD144-EMP were the most significant risk factor for CAD relative to all other traditional risk factors (odds ratio [OR] 3.5, 95% confidence interval [CI] 1.8 to 6.9, p < 0.001). Notably, plasma CD144-EMP identified a subpopulation of established CAD patients in DM subjects without typical anginal symptoms (OR 10.6, 95% CI 3.9 to 29.5, p < 0.001).ConclusionsThe CD144-positive EMP exist in human plasma, and plasma CD144-EMP levels can be a clinically specific and quantitative marker of EC dysfunction and/or injury. Measurement of CD144-EMP, by providing a quantitative assessment of EC dysfunction, may be useful for identifying DM patients with increased risk of CAD

Factors explaining the yearly changes in minimum bottom dissolved oxygen concentrations in Lake Biwa, a warm monomictic lake

Vertical profiles of dissolved oxygen (DO) and water temperature (WT) measured bi-monthly for 36 years (1980–2015) near the deepest part of a warm monomictic lake were analyzed with special reference to yearly minimum DO at bottom (DOmin). DOmin changed yearly (3.0 ± 1.2 mg l−1) and significant differences in DOmin were not observed between Period I (1980–1993; cooler and worse in water quality) and Period II (1994–2015; warmer and better in water quality). This unclear trend in DOmin was probably due to the offsetting influences between warming induced by global warming and oligotrophication attempted by local governments etc. for the study period. DOmin was positively correlated with disturbance time (timing of last cold water intrusion observed from Mar to Aug), which could be related to the start of DO depletion at bottom. Thus, the linear model using this parameter could predict yearly DOmin fairly well for the entire study period (r2 = 0.60). In addition, DOmin and time of disturbance were correlated negatively with water density at bottom in Jan and positively with water density equilibrated to air temperature (AT) in Mar. Higher lake water density after full depth mixing advances the disturbance time. In contrast, lower AT in Mar and/or higher density of influent water after Mar delays the time likely due to the larger amount of snowfall in the watershed. Further, DOmin was positively correlated with maximum wind velocity in Sep which probably induced the recovery of DO. Multiple-regression models to predict DOmin using these meteorological and water quality parameters were developed (r2 ≥ 0.38, worse performances than the model using disturbance time) to forecast future trends of DOmin through global warming and/or climate change. Significant influences of water or sediment oxygen demands on DOmin were not detected. We also discuss the applicability of the proposed models

An open-label continuation trial of tocilizumab for familial Mediterranean fever with colchicine ineffective or intolerance

Background:Colchicine is the first-line treatment for familial Mediterranean fever (FMF), but secondary amyloidosis resulting from persistent inflammation is a concern in patients with colchicine-resistant or colchicine-intolerant FMF. Although tocilizumab (TCZ), which is a recombinant, humanized, anti-human interleukin 6 receptor monoclonal antibody, has been reported to prevent FMF attacks, the long-term safety and efficacy of TCZ on individuals with colchicine-resistant or colchicine-intolerant FMF have not been evaluated.Methods/design:In this investigator-initiated, multicenter, open-label trial, the long-term safety of TCZ will be evaluated in patients participating in a placebo-controlled, randomized, double-blind, parallel-group trial on colchicine-resistant or colchicine-intolerant FMF. The study will be conducted in 9 centers in Japan. After the evaluation and examination for 24 weeks in the preceding study, this trial will be started promptly. The trial will be completed by the time the drug is approved for FMF treatment in Japan. The primary endpoint is the incidence of adverse events, and the secondary endpoints include the number of FMF attacks, number of occurrences of accompanying symptoms during attacks, serum C-reactive protein and amyloid A levels, general evaluation by a physician (100mm visual analog scale [VAS]), general evaluation by a patient (100mm VAS), and body temperature.Discussion:The study is expected to obtain evidence regarding the long-term safety of TCZ as a potential new therapeutic agent for patients with colchicine-resistant or colchicine-intolerant FMF.Trial registration:This study was registered with the University Hospital Medical Information Network Clinical Trials Registry (https://upload.umin.ac.jp/cgi-open-bin/ctr-e/ctr-view.cgi?recptno=R000037116) as UMIN000032557 on May 30 2018

Molecular-Level Insights into Oxygen Reduction Catalysis by Graphite-Conjugated Active Sites

Using a combination of experimental and computational investigations, we assemble a consistent mechanistic model for the oxygen reduction reaction (ORR) at molecularly well-defined graphite-conjugated catalyst (GCC) active sites featuring aryl-pyridinium moieties $(N^+-GCC)$. ORR catalysis at glassy carbon surfaces modified with $N^+-GCC$ fragments displays near-first-order dependence in $O_2$ partial pressure and near-zero-order dependence on electrolyte pH. Tafel analysis suggests an equilibrium one-electron transfer process followed by a rate-limiting chemical step at modest overpotentials that transitions to a rate-limiting electron transfer sequence at higher overpotentials. Finite-cluster computational modeling of the $N^+-GCC$ active site reveals preferential $O_2$ adsorption at electrophilic carbons alpha to the pyridinium moiety. Together, the experimental and computational data indicate that ORR proceeds via a proton-decoupled $O_2$ activation sequence involving either concerted or stepwise electron transfer and adsorption of $O_2$, which is then followed by a series of electron/proton transfer steps to generate water and turn over the catalytic cycle. The proposed mechanistic model serves as a roadmap for the bottom-up synthesis of highly active N-doped carbon ORR catalysts