Attenuation of guanine oxidation via DNA-mediated electron transfer in a crowded environment using small cosolutes

Guanine oxidation induced by photoirradiation on a pyrene-modified oligonucleotide was investigated under molecular crowding using small cosolutes such as glycerol. The efficiency of guanine photooxidation was suppressed in accordance with the increase in the concentration of glycerol. The results of photooxidation experiments using fully matched and mismatched DNA showed that guanine decomposition was mainly caused by DNA-mediated electron transfer (ET) in glycerol mixed solutions, as well as in diluted aqueous buffer solutions. Multiple factors can contribute to the suppression of guanine oxidation in crowded environments. However, our experimental results indicated that the attenuation of the DNA-mediated ET process suppressed guanine oxidation. On the other hand, experiments using ethylene glycol showed that guanine decomposition efficiency varies depending on the surrounding solvent. These results suggested that changes in the characteristics of the surrounding medium affect the DNA fluctuation, dominating DNA-mediated ET

Light Higgs boson scenario in the SUSY seesaw model

It is demonstrated that the light Higgs boson scenario, which the lightest Higgs mass is less than the LEP bound, mh > 114.4 GeV, is consistent with the SUSY seesaw model. With the assumptions of the universal right-handed neutrino mass and the hierarchical mass spectrum of the ordinary neutrinos, the bounds for the right-handed neutrino mass is investigated in terms of lepton flavor violating charged lepton decays. We also discuss the effect of the modification of renormalization group equations by the right-handed neutrinos on the b to s gamma process and the relic abundance of dark matter in the light Higgs boson scenario.Comment: 17 pages, 5 figure

実験的腸管潰瘍に対する食餌の影響 : 肉眼所見と組織ロイコトリエンの検討

Made available in DSpace on 2012-09-04T05:10:10Z (GMT). No. of bitstreams: 1 matsumoto.pdf: 2786218 bytes, checksum: 8279296574c5fe871ce353b9a45fd937 (MD5) Previous issue date: 1995-05-3

Charge–Discharge Performance of Copper Metal Positive Electrodes in Fluorohydrogenate Ionic Liquids for Fluoride-Shuttle Batteries

In search of room-temperature electrolytes for fluoride-shuttle batteries, fluorohydrogenate ionic liquids (FHILs) have emerged, showing high ionic conductivities and better operational practicality. To enhance the performance of these electrolytes, the charge–discharge behavior of copper metal as positive electrodes in FHILs was investigated in this study. In the [C₂C₁im][(FH)₂.₃F] (C₂C₁im = 1-ethyl-3-methylimidazolium) FHIL electrolyte, although the 1st discharge capacity of 599 mAh (g-Cu)⁻¹ included the reductive reaction of surface oxide films, the 2nd discharge capacity of 444 mAh (g-Cu)⁻¹ that corresponds to 53% of the theoretical capacity was achieved. However, the capacity declines to 167 mAh (g-Cu)⁻¹ at the 20th cycle, indicating low capacity retention. In contrast, the adoption of [C₂C₁pyrr][(FH)₂.₃F] (C₂C₁pyrr = N-ethyl-N-methylpyrrolidinium) electrolyte confers improved cycleability across the cycles with a higher discharge capacity of 210 mAh (g-Cu)⁻¹ at the 20th cycle. Scanning electron microscopy and energy-dispersive X-ray spectroscopy performed on the electrode surfaces confirm reduced electrode degradation characterized by suppressed aggregation of copper particles in [C₂C₁pyrr][(FH)₂.₃F] due to its low CuF₂ solubility compared with [C₂C₁im][(FH)₂.₃F]. Herein, we demonstrate the use of FHILs with low CuF₂ solubilities as a strategy for improving the charge–discharge performance of copper metal positive electrodes in fluoride-shuttle batteries

The Role of Uridine Adenosine Tetraphosphate in the Vascular System

The endothelium plays a pivotal role in vascular homeostasis, and endothelial dysfunction is a major feature of cardiovascular diseases, such as arterial hypertension, atherosclerosis, and diabetes. Recently, uridine adenosine tetraphosphate (Up4A) has been identified as a novel and potent endothelium-derived contracting factor (EDCF). Up4A structurally contains both purine and pyrimidine moieties, which activate purinergic receptors. There is an accumulating body of evidence to show that Up4A modulates vascular function by actions on endothelial and smooth muscle cells. In this paper, we discuss the effects of Up4A on vascular function and a potential role for Up4A in cardiovascular diseases