Photochemical formation of singlet molecular oxygen (1O2) in illuminated aqueous solutions of p-aminobenzoic acid (PABA)

Evidence is presented for the photochemical formation of singlet molecular oxygen (1O2) in air-saturated buffered aqueous solutions of p-aminobenzoic acid (PABA) using sunlight-range illumination. This is significant because PABA is widely used as an active ingredient in sunscreen preparations that are applied to the surface of the skin and 1O2 is known to cause oxidative damage to cells via the formation and subsequent reactions of lipid peroxides. Furfuryl alcohol (FFA), a well known chemical trap for 1O2, was added to aqueous PABA solutions prior to illumination. The FFA was consumed when the solution was illuminated, but no loss of FFA occurred in the dark and loss by direct photolysis was negligibly slow. Further evidence for the formation of 1O2 in illuminated aqueous PABA solutions is provided by the results of experiments in which individual solutions containing PABA and FFA that were diluted with D2O exhibited an increased rate of FFA consumption due to the increased lifetime and concentration of 1O2 in this solvent.     

Differential inhibition of human prostaglandin endoperoxide synthase-1 and -2 by nonsteroidal anti-inflammatory drugs

PURPOSE: The authors determined the effect of photocoagulation of drusen on visual acuity and progression to subretinal neovascular membranes (SRNV). METHODS: One of paired eyes was randomized to photocoagulation with other eye to control in 27 patients having symmetrical maculopathy and visual acuities, aged 46 to 81 years (mean, 69.7 years); follow-up 1 to 6 years (mean, 3.2 years). RESULTS: Final visual acuity was improved in treated eye or decreased in control eye in 12 patients, equal in 13 patients, and decreased in treated eye in 2 patients (P < 0.006). Progression to SRNV was less with treatment. CONCLUSION: Laser photocoagulation of confluent soft macular drusen may improve long-term visual prognosis.     

氧化球团烟气中SO2和H2O(g)对SCR脱硝的影响

选择性催化还原(SCR)具有效率高、技术成熟的优势,但处理球团烟气需要加热才能达到SCR脱硝的反应温度,导致能耗和运行成本高.氧化球团预热Ⅱ段(PH段)烟气温度在300℃以上,满足SCR反应所需温度,但是烟气中含有的SO2和H2O(g),会对催化剂的脱硝性能产生影响.研究了 PH段烟气中SO2和H2O(g)对V/Ti催...     

Effects of nonsteroidal anti-inflammatory drugs on interleukin-1 receptor antagonist production in cultured human peripheral blood mononuclear cells

The effects of nonsteroidal anti-inflammatory drugs (NSAIDs), mofezolac, indomethacin, sodium diclofenac, and zaltoprofen, on the production of interleukin-1 receptor antagonist (IL-1ra) were examined in cultured human peripheral blood mononuclear cells (PBMC). Among the NSAIDs tested, mofezolac and sodium diclofenac were found to stimulate the mRNA expression for IL-1ra without affecting the mRNA expression for IL-1 beta. These two drugs also stimulated the secretion of IL-1ra by PBMC in the absence of bacterial lipopolysaccharide (LPS), however, the stimulatory effect of sodium diclofenac diminished in the presence of LPS. Mofezolac suppressed the mRNA expression for IL-1 beta in PBMC stimulated with exogenous IL-1 beta, indicating the secreted IL-1ra in the presence of mofezolac to be biologically active. Since IL-1ra suppresses the function of IL-1, a pro-inflammatory cytokine, the stimulatory effect of such NSAIDs as mofezolac on IL-1ra production could also be one of the mechanisms involved in its anti-inflammatory and antinociceptive actions.