11 research outputs found

    On the Correlation between Hydration of the Stratum Corneum and the Nutritional Status of Dialysis Patients

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     Stratum corneum (SC) prevents evaporation of internal moisture and maintains dermal flexibility and fluidity. Malnutrition is known to decrease SC hydration, but involvement of nutritional status in SC hydration of dialysis patients is unclear. In this study, we examined the association between SC hydration and nutritional status on dialysis patients. We studied 16 control subjects and 81 dialysis patients to examine SC hydration of the neck, upper arm and lower leg. In the 81 patients, we measured serum albumin (Alb), transferrin, geriatric nutritional risk index (GNRI) and normalized protein catabolic rate (nPCR). We then classified the dialysis patients into a 21-patients group, with both Alb ≥ 3.6 g/dl and nPCR ≥ 0.9 g/kg/ day, and a 60-patients group with either Alb <3.6 g/dl or nPCR <0.9 g/kg/day. SC hydration in the lower leg and the Alb value in the 81 patients were significantly lower than those in the control subjects. SC hydration in the upper arm and lower leg and the values of transferrin and GNRI in the 60-patients group were significantly lower than those in the 21-patients group. This study demonstrates for the first time that nutritional status is correlated with maintenance of SC hydration on dialysis patients

    Membrane Potential Generated by Ion Adsorption

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    It has been widely acknowledged that the Goldman-Hodgkin-Katz (GHK) equation fully explains membrane potential behavior. The fundamental facet of the GHK equation lies in its consideration of permeability of membrane to ions, when the membrane serves as a separator for separating two electrolytic solutions. The GHK equation describes that: variation of membrane permeability to ion in accordance with ion species results in the variation of the membrane potential. However, nonzero potential was observed even across the impermeable membrane (or separator) separating two electrolytic solutions. It gave rise to a question concerning the validity of the GHK equation for explaining the membrane potential generation. In this work, an alternative theory was proposed. It is the adsorption theory. The adsorption theory attributes the membrane potential generation to the ion adsorption onto the membrane (or separator) surface not to the ion passage through the membrane (or separator). The computationally obtained potential behavior based on the adsorption theory was in good agreement with the experimentally observed potential whether the membrane (or separator) was permeable to ions or not. It was strongly speculated that the membrane potential origin could lie primarily in the ion adsorption on the membrane (or separator) rather than the membrane permeability to ions. It might be necessary to reconsider the origin of membrane potential which has been so far believed explicable by the GHK equation

    Jet spectroscopy of buckybowl: Electronic and vibrational structures in the S0 and S1 states of triphenylene and sumanene

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    Sumanene is a typical buckybowl molecule with C3v symmetry. We observed a fluorescence excitation spectrum and a dispersed fluorescence spectrum of sumanene in a supersonic jet. Bowl effects were clarified by comparing the spectra with those of triphenylene (D3h symmetry), which is a planar prototype of nonplanar sumanene. The S1 (1)A1 ← S0 (1)A1 transition is symmetry allowed. We found the 00 (0) band in the fluorescence excitation spectrum at 357.78 nm; this band was missing in the forbidden S1 (1)A1 (') ← S0 (1)A1 (') transition of triphenylene. The transition moment was shown to be along the oblate symmetric top axis (out of plane) by the observed rotational contour. A large number of vibronic bands were observed, unlike in triphenylene. Some were considered to be out-of-plane vibrational modes, which lead to a bowl-to-bowl inversion reaction assisted by in-plane vibrations. We found that the vibronic bands were markedly weak in the high energy region of triphenylene-d12. This indicates that the fluorescence quantum yield is very low at the high vibrational levels in the S1 state due to the rapid radiationless transition. The main process is considered to be internal conversion to the S0 state. The nonplanar structural distortion may also enhance radiationless transitions. We could not, however, observe weakening of the vibronic bands in the fluorescence excitation spectrum of sumanene
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