143 research outputs found

    1 H and 19 F FFC-NMR of catalyst layer materials for polymer electrolyte membrane fuel cells

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    1H and 19F spin lattice relaxation rates of catalyst layer materials (CLM) of polymer electrolyte membrane fuel cells were measured by the fast field cycling (FFC) method. In contrast to ionomer membranes, 1H relaxation rates of adsorbed water in both platinum-Ketjen black (Pt-KB) catalyst powder and CLM were strongly dependent on Larmor frequency approximated by a power law due to the strong surface interaction of adsorbed water. The difference in the frequency dependence in the Pt-KB and the CLM was attributed to higher acidity of the CLM

    Time-dependent diffusion coefficient of proton in polymer electrolyte membrane

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    We investigated the time-dependent self-diffusion coefficients of water, D(T eff), in polymer electrolyte membranes at 278 K. TheD(T eff) was measured from T eff=0.7 to 100 ms by field gradient NMR techniques. The results showed that the self-diffusion coefficients of water were dependent on T eff less than 2 ms due to restricted diffusion, and were constant beyond 3 ms. The tortuosity and surface-to-volume ratio related to water diffusion were also estimated from D(T eff). The obtained values revealed the existence of large-scale restricted geometry compared with well-known nanometer-sized domain in polymer electrolyte membranes

    Comparisons of Therapeutic Effects of Allopurinol and Febuxostat in Chronic Hemodialysis Patients

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    More than few patients on maintenance hemodialysis present with hyperuricemia, and the control of serum uric acid level is an important issue in the long-term management. In addition to allopurinol, febuxostat can be used as a xanthine oxidase inhibitor in hemodialysis patients. In this study, the clinical effects of febuxostat were compared with allopurinol in chronic hemodialysis patients. Eligible hemodialysis patients taking allopurinol were randomly assigned to take 100 mg allopurinol(n=26)or 20 mg febuxostat(n=23)for 12 weeks. Serum uric acid was markedly lowered in the febuxostat group(0-week 6.7 mg/dL, 12-week 4.3 mg/dL, p<0.001)as compared with the allopurinol group(0-week 6.0 mg/dL, 12-week 5.8 mg/dL)and systolic blood pressure was lowered by 5 mmHg(p=0.036)at 4-week in the febuxostat group while blood pressure was not significantly changed in the allopurinol group throughout the study period. In addition, the dose of erythropoiesis stimulating agent was reduced(0-week 22.2 μg/wk, 12-week, 17.1 μg/wk, p=0.012)and serum phosphate level was lowered(0-week 5.9 mg/dL, 12-week 5.1 mg/dL, p=0.027)in the febuxostat group but not in the allopurinol group. It is concluded that febuxostat is more effective in lowering serum uric acid than allopurinol in hemodialysis patients. In addition, it is suggested that febuxostat has an advantage in the management of renal anemia and hyperphosphatemia as well as hyperuricemia

    Comparisons of Increasing Calcium Channel Blocker dose and Adding Thiazide Diuretic in Hypertensive Patients Given Medium-dose Angiotensin II Receptor Blocker and Amlodipine

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    We compared the efficacies of 2 prescriptions, one of a medium-dose angiotensin II receptor blocker (ARB) with high-dose of calcium channel blocker (CCB) and another of medium-dose of ARB with medium-dose of CCB and a thiazide diuretic in 22 hypertensive patients who did not achieve the target blood pressure level with the combination of medium-dose of ARB and medium-dose of CCB. A randomized crossover study was performed giving a fixed combination of 100 mg irbesartan with 10 mg amlodipine or a fixed-dose combination of 100 mg irbesartan with 5 mg amlodipine added by 1 mg trichlormethiazide for 12-16 weeks each. The blood pressure measured in hospital was comparable between the high-dose CCB period (130/77 mmHg) and the thiazide period (130/79 mmHg). The morning and the evening blood pressures measured at home were also comparable in the high-dose of CCB and the thiazide periods, while the evening heart rate was higher in the thiazide period than in the high-dose CCB period. As for the laboratory data, hemoglobin A1c (+0.2%, p=0.013), serum nonHDL cholesterol (+12 mg/dL, p=0.047) and serum uric acid (+0.8 mg/dL, p=0.001) were significantly higher in the thiazide period than in the high-dose CCB period. On the other hand, urinary albumin excretion (-28.8%,p=0.026) and estimated glomerular filtration rate (-5.8%,p=0.012) were significantly lower in the thiazide period than in the high-dose CCB period. In the combination drug therapy of hypertension, the increase of CCB dose is preferable in preserving renal function and in avoiding adverse effects on metabolisms of glucose, lipid and uric acid

    Acceleration of Age-Related Changes in the Retina in ␣-Tocopherol Transfer Protein Null Mice Fed a Vitamin E-Deficient Diet

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    PURPOSE. To assess the role of vitamin E (VE) in age-related changes in the retinal tissues by using a mouse model of severe VE deficiency. METHODS. Pups of ␣-tocopherol transfer protein null (a-TTP Ϫ/Ϫ ) mice were fed a VE-deficient diet for 4 or 18 months (VE (Ϫ) group). Wild-type C57BL/6 mice were fed a 0.002% ␣-tocopherol-supplemented diet (VE (ϩ) group). In various ocular tissues, the VE levels were measured by high-performance liquid chromatography; the fatty acid composition by gas chromatography (GC); and the hydroxyoctadecadienoic acid and 8-iso-prostaglandin F 2␣ levels, which are biomarkers for lipid peroxidation, by GC-mass spectrometry. The retinal structure was assessed by light, electron, and fluorescence microscopy. RESULTS. The ␣-tocopherol level in the retinas obtained from 4-month-old VE (Ϫ) animals was 71-fold lower than that in the retinas obtained from the VE (ϩ) group. In addition, ␥-tocopherol was not detected; thus, the VE (Ϫ) group demonstrated a more severe VE deficiency than ever reported. In this group, the concentration of n-3 polyunsaturated fatty acids decreased (0.3-to 0.9-fold), whereas that of other classes of fatty acids was unchanged or increased. At 18 months of age, the number of the outer nuclear layer (ONL) nuclei was observed to be 17% lower in the VE (Ϫ) than in the VE (ϩ) group (P Ͻ 0.05). Electron microscopy revealed larger amounts of matrix between the ONL nuclei indicating the Müller cell hypertrophy, greatly expanded rod outer segment discs, and a larger number of inclusion bodies in the retinal pigment epithelium (RPE; P Ͻ 0.05) in the VE (Ϫ) group. Fluorescence microscopy revealed that the autofluorescence signal was increased in the RPE layer in this group. When the observations of the 18-month-old animals were compared to those of the 4-month-old animals, the hydroxyoctadecadienoic acid and 8-iso-prostaglandin F 2␣ levels were found to be increased in the retina and RPE obtained from both the VE (Ϫ) and VE (ϩ) groups; however, the age-related increases were more remarkable in the VE (Ϫ) group (2.6-to 43.5-fold) than in the VE (ϩ) group (0.8-to 8.7-fold). CONCLUSIONS. The combined use of a-TTP Ϫ/Ϫ mice and a VEdeficient diet leads to a severe deficiency of VE, enhances lipid peroxidation in the retina, and accelerates degenerative damage of the retina with age. (Invest Ophthalmol Vis Sci. 2007; 48:396 -404

    PETREL for Astrophysics and Carbon Business

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    A multi-purpose 50kg class microsatellite hosting astrophysical mission and earth remote sensing, PETREL , will be launched in 2023. In the night side, PETREL observe the ultra-violet sky with a wide-field telescope covering 50 deg^2 for surveying transient objects related to supernovae, tidal disruption events, and gravitational wave events. Our UV telescope can detect the early phase UV emission from a neutron star merger occurred within 150 Mpc. In addition to the satellite observation, PETREL sends a detection alert including the coordinate and brightness of the UV transient to the ground via the real time communication network within several minutes after detection to conduct follow-up observations with the collaborating ground based observatories over the world. In the day side, PETREL observes the surface of the earth by using the tunable multi-spectral cameras and a ultra-compact hyperspectral camera. Our potential targets are the tropical forests (Green Carbon) and coastal zones (Blue Carbon) in the tropical areas to evaluating the global biological carbon strages. For this purpose PETREL will conduct multiple scale mapping collaborating with drones and small aircraft not only satellite. The obtained data will be used for academical research and for business applications. The technical difficulty of this satellite is that carries out multi-purpose with different requirements, such as astronomical observations which requires a quite high attitude stability and the earth observations requiring a high pointing accuracy, with limited resources. If it is possible, a novel small satellite system or a business style can be realized that can share the payload with academia and industry. PETREL has been adopted as Innovative Satellite Technology Demonstration Program No.3 led by JAXA, and development is underway with the aim of launching in FY2023

    The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

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    「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection
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