It is known that many soil fungí synthesize brown, large aromatic polymers (fungal melanins), chemically related to soil humic acids (Martin and Haider, 1971; Schnitzer and Neyroud, 1975). Since the chemical constituents (or at least, their degradation products) and the physicochemical properties of fungal melanins are comparable to those of humic acids, it is possible that fungal metabolism ma...

Mesoporous silica-carbon composites functionalized with acidic oxygen groups were prepared by oxidation of a layer of carbon deposited inside the silica pores. The synthesis procedure involved the following steps: a) removal of the silica surfactant, b) impregnation of the silica pores with a carbon precursor, c) carbonization and d) oxidation with ammonium persulfate. The resulting silica-carb...

Methods for quantifying total dissolved phosphorus (TDP) were reevaluated. High-temperature ashing/hydrolysis (Ash/Hydrol.) and Acid Persulfate methods were examined for their ability to quantitatively convert a range of organic-P compounds to orthophosphate. The Ash/Hydrol. method recovered on average 99% of organic-P compounds tested, including phosphonates (compounds with C-P bonds). Contrar...

OBJECTIVE Persulfate salts are among the most frequently implicated causes of occupational asthma. The aim of this study was to describe the course of bronchial hyperresponsiveness and immunologic test results in patients with occupational asthma due to persulfate salts. PATIENTS AND METHODS Ten patients with occupational asthma due to persulfate salts were studied. Diagnosis was based on spe...

Dielectric barrier discharge (DBD) plasma in advanced oxidation technology can degrade organic pollutants water under mild conditions. It has the advantages of universality, simple reaction conditions, and no secondary pollution. However, light, electrons, low-reactive substances generated during process cannot be fully utilized, which limits further application DBD plasma. Therefore, system co...