No abstract

Recently, we developed a new method to measure the resting level of superoxide anion in whole blood using an ultrasensitive chemiluminescence analyzer and lucigenin amplification. The advantage of this method is that the assay system can be performed in the absence of leukocyte isolation and stimulant administration. In this study, we applied this method to measure the blood resting levels of superoxide anion in 104 uremic patients on chronic hemodialysis (CHD) and 98 sex- and age-matched healthy controls to clarify the influence of HD on blood levels of superoxide anion. Simultaneously, the plasma levels of copper, zinc superoxide dismutase (Cu,Zn-SOD), glutathion peroxidase (GPX), myeloperoxidase (MPO) and lactoferrin (Lacto-F) were measured. The results showed that the basal blood levels of superoxide anion, Cu,Zn-SOD, and MPO in CHD patients were significantly greater than those of healthy controls. However, there was no difference in the basal plasma levels of Lacto-F and GPX between CHD patients and healthy controls. One session of HD further increased the blood levels of superoxide anion, MPO, Lacto-F and Cu,Zn-SOD but not GPX. These results suggest that the blood levels of superoxide anion are higher in CHD patients and further increase after one session of HD. This mechanism should be studied further.

No abstract

No abstract

Poly(vinylidene fluoride) (PVDF) membranes were prepared by the isothermal immersion and precipitation of PVDF/N-methyl-2-pyrollidone dope solutions in either harsh or soft nonsolvent baths. Low-voltage field emission scanning electron microscopy imaging of the formed membranes at high magnifications (e.g., 300,000ϫ) revealed their nanoscale fine structures, particularly dendrites observed on the surfaces of the macrovoids, cellular pores, and the membrane skin, which have never been successfully presented in the literature. Evidence of crystallization was also demonstrated by X-ray diffraction and differential scanning calorimetry measurements. The phase diagram at 25°C, including a binodal, tie lines, and a crystallization-induced gelation line, was determined both experimentally and theoretically. These results were further used in mass-transfer calculations to obtain diffusion trajectories and concentration profiles for the membrane region, which were useful for elucidating the relationship between the membrane preparation conditions and the obtained membrane morphologies.