Birch and eucalyptus kraft pulps were treated with sulfite solutions in neutral conditions (pH 7) at 170 °C for 60 min and at 190 °C for 180 min. The pulps were analyzed for kappa number, viscosity, carbohydrate composition, and optical properties. Additionally, UV resonance Raman (UVRR) spectroscopy was applied to collect information on the contents of hexenuronic acid (HexA), lignin, and its ...

Media and an analytical scheme have been developed which allow both a qualitative and quantitative estimation of the formation of pyocyanine, related phenazines, pyorubrin, and a blue and a yellow-green fluorescent pigment by Pseudomonas aeruginosa. Use of the defined pyocyanine medium of Frank and DeMoss with sulfate or various organic sulfur sources allowed formation of pyocyanine, related ph...

Background Sodium sulfite (Na2SO3) is a product of sulfur dioxide (SO2). Inhaled sulfur dioxide can be easily hydrated to yield sodium sulfite in the respiratory tract. Sulfur dioxide is one of the most important air pollutants that can adversely affect the respiratory system. Rhinovirus (RV) is a major cause of common cold and is a major risk factor responsible for the exacerbation of asthma a...

Recently great advances have been made in the preparation of pure myoglobin by the introduction of ion exchange cellulose column chromatography (1, 2). Myoglobin, however, shows a strong tendency to be oxidized to metmyoglobin during isolation procedures. For this reason all myoglobin preparations reported earlier were obtained in the form of metmyoglobin. Therefore, oxymyoglobin has usually be...

The molybdenum centre of spinach (Spinacia oleracea) nitrate reductase has been investigated by e.p.r. spectroscopy of molybdenum(V) in reduced forms of the enzyme. The resting enzyme gives no signals attributable to Mo(V). However, on reduction with NADH, Mo(V) signals appeared at relatively short reaction times but decreased again on prolonged exposure to excess of the substrate as the enzyme...

In this work, an antimicrobial guanidine polymer (PHGH) was grafted onto starch as a carrier to form branched or grafted chains along the starch backbone. This grafting improved the antimicrobial properties and the adsorption of the starch on recycled cellulose fibers. Similar work was also conducted on bleached sulfite fibers for comparison. The results showed that the starch, grafted with 12 ...

A wastewater treatment and reclamation facility in north-east Spain was monitored over 1 year to determine the occurrence and concentrations of different microbial indicators (Escherichia coli, fecal enterococci, somatic bacteriophages and spores of sulfite-reducing clostridia). The removal of the indicators and its relationships through the wastewater treatment and reclamation trains were eval...

A simple and highly sensitive spectrophotometric method for the determination of biologically active thiols based on the fading of eosin-silver(I)-adenine ternary complex was established. In the determination of 6-mercaptopurine (MP), Beer's law was obeyed in the range 0.02-0.30 microg ml(-1), with an effective molar absorptivity at 562 nm and the relative standard deviation being 3.5 x 10(5) d...

All pH-oscillators reported to date function only under open (flow reactor) conditions. We describe an approach to generating pH-oscillations in a closed system by starting from an open system pH-oscillator, finding semibatch conditions under which it oscillates with an inflow of a single reactant to an otherwise closed reactor containing the remaining components, and replacing this inflow with...

Polyphenol oxidase (PPO) was purified from fresh ginseng roots using acetone precipitation, carboxymethyl (CM)-Sepharose chromatography, and phenyl-Sepharose chromatography. Two isoenzymes (PPO 1 and PPO 2) were separated using an ion-exchange column with CM-Sepharose. PPO 1 was purified up to 13.2-fold with a 22.6% yield. PPO 2 bound to CM-Sepharose, eluted with NaCl, and was purified up to 22...