Lignin peroxidase (LiP) hosted in Brij 30/cyclohexane/water nonionic reversed micelle could express its catalytic activity, but in Triton X-100/n-pentanol/cyclohexane/water nonionic reversed micelle LiP didn't show any catalytic activity. Some key factors that affected the catalytic activity of LiP in Brij 30 reversed micelle were studied at 20 degrees C. The optimum conditions were:omega0 = 8.5, pH = 2.2, [Brij30] = 600 mmol/L; under these conditions the half time of LiP was ca. 50 hours. As compared with the properties of LiP in aqueous solution, the activity of LiP hosted in Brij 30 reversed micelle dropped, but its stability improved greatly. To reveal the role of normal alcohol, which was a necessary component for forming Triton X-100 reversed micelles, the effect of n-pentanol on the catalytic activity of LiP in Brij 30 reversed micelle was investigated. Results indicated that high concentration of the alcohol deactivated LiP. So it was deduced that the phenomenon that LiP hosted in the Triton X-100 reversed micelles could not express its activity was mainly due to the alcohol co-surfactant.
Catalysis ; Cyclohexanes ; chemistry ; Enzyme Activation ; drug effects ; Micelles ; Octoxynol ; chemistry ; Pentanols ; chemistry ; Peroxidases ; metabolism ; Surface-Active Agents ; chemistry

OBJECTIVETo develop a solvent desorption gas chromatographic method for determination of n-pentanol in the workplace air.

METHODSn-Pentanol in the workplace air was collected with activated carbon tubes, desorbed with 2% 2-propanol in carbon disulfide, separated with a nitroterephthalic acid-modified FFAP capillary column, and detected with flame ionization detector.

RESULTSThe limit of detection was 0.2 mg/L; the lower limit of quantification was 0.6 mg/L; the linear range was 0.6-4072.0 mg/L. The minimum detectable mass concentration was 0.2 mg/m3 for 1.5 L of air sample. This method was highly repeatable. The relative standard deviations were 2.3%-5.4%. The average desorption efficiencies were 86.9%-94.2%. The absorption efficiencies were 100%. The breakthrough volume was above 8.0 mg in 100-mg activated carbon. The samples in activated carbon tubes could be stored for at least 14 days at room temperature.

CONCLUSIONThe method is feasible for determination of n-pentanol in the workplace air.

2-Propanol ; Air Pollutants, Occupational ; analysis ; Carbon Disulfide ; Charcoal ; Chromatography, Gas ; Limit of Detection ; Pentanols ; analysis ; Solvents ; Workplace

OBJECTIVETo explore the feasibility of functional magnetic resonance imaging (fMRI) in analysis of olfaction function with modified OEP-98C olfactometer and event-related design.

METHODSSix young right-handed men underwent olfactory fMRI with event-related design. OEP-98C olfactometer was modified to accommodate MR environment. There were 2 types of tasks in the experiment. In one task, only isoamyl acetate was used as odorant. In the other task, to avoid possible decreased olfactory attention, vanillin was given before each presentation of isoamyl acetate.

RESULTSIn both tasks, uniform activation in piriform cortex and secondary olfactory cortexes was determined. The activation of piriform cortex was not significantly different between the two tasks (P > 0.01).

CONCLUSIONSWith isoamyl acetate as odorant, modified OEP-98C olfactometer, and event-related design, olfaction fMRI can depict cortex activation at primary and secondary olfactory cortex. Applying other odorant with similar quality to avoid olfactory attention decrease can not promote depiction of activation in primary olfactory cortex.

Adult ; Evoked Potentials ; physiology ; Feasibility Studies ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Olfactory Pathways ; physiology ; Olfactory Perception ; physiology ; Pentanols

A simple and rapid method for preparation of plasmid DNA from overnight incubation was introduced. It does not require any additional reagents; the incubation mixture containing recombinant plasmid DNA was just mixed with H2O and phenol/chloroform/isoamyl alcohol in certain ratio. After vortexing and spinning of the mixture, the supernatant could be directly loaded onto agarose gel and analyzed using electrophoresis. The whole preparation requires only 3-5 minutes. So to quickly screen recombinant clones, this method is better compared with traditional methods.
Centrifugation, Density Gradient ; Chloroform ; chemistry ; Cloning, Molecular ; methods ; DNA, Bacterial ; genetics ; isolation & purification ; metabolism ; Deoxyribonuclease HindIII ; metabolism ; Electrophoresis ; Escherichia coli ; genetics ; Pentanols ; chemistry ; Phenol ; chemistry ; Plasmids ; chemistry ; genetics ; Reproducibility of Results ; Time Factors ; Water ; chemistry