9. PERFORMING OR5ANIZATION hAM4E AND ADDRESS 10. PPO.:FRAb ELEMENT PROJECT. TASK National Bureau of StandardsARAO. NTNUES Washington, DC 20234 _____________________________________N/ml -O NTRCLING DEFICE NA ME AND ADDRESS 12. REPORT DATE S. A=..r. ?search :ffice 1?182 _______ 0.?x 121 13. NUMBER OF PAGES searc:. 'ra.1 277C,: 1_____1_____ ONITORN. AGENCY NAME &ADDRESSrtl dif!@twnt from, ContriIn...

Derivative spectroscopy has often been used in n.m.r. and optical-absorption spectroscopy as a means of resolving narrow features obscured by broad lineshapes. E.p.r. spectra are normally presented as the first-harmonic (first derivative) form, but higher harmonics can readily be generated by modulating the magnetic field at a subharmonic frequency and operating the phase-sensitive detector at ...

Tobacco (Nicotiana tabacum L. cv. Xanthi XHFD8) possesses four nitrite reductase (NiR) genes: nii1, nii2, nii3, and nii4. Their differential expression in leaves and roots was investigated by quantitative competitive RT-PCR using gene-specific primer pairs. These results appear to contradict existing views on the expression of these NiR genes: (i) the mRNA of each of the four NiR genes was dist...

The method by which sodium nitrite may act to prevent germination or outgrowth, or both, of heat-injured spores in canned cured meats was investigated by using Clostridium perfringens spores. Four possible mechanisms were tested: (i) prevention of germination of the heat-injured spores, (ii) prior combination with a component in a complex medium to prevent germination of heat-injured spores, (i...

By JOHN D. HARLEY AND HELEN ROBIN T HE CHANGES which result when intact erythrocytes are exposed to the nitrite ion have been studied for almost a century.’6 Such exposure has been found to cause the oxidation of oxyhemoglobin to methemoglobin,26 and of reduced glutathione ( GSH ) to oxidized glutathione ( GSSG ) . .6 In addition, erythrocytes treated with nitrite have been widely used to inves...

By JOHN D. HARLEY AND HELEN ROBIN T HE CHANGES which result when intact erythrocytes are exposed to the nitrite ion have been studied for almost a century.’6 Such exposure has been found to cause the oxidation of oxyhemoglobin to methemoglobin,26 and of reduced glutathione ( GSH ) to oxidized glutathione ( GSSG ) . .6 In addition, erythrocytes treated with nitrite have been widely used to inves...

The 204- and 229-nm excited UV resonance Raman spectra of wastewater solutions containing sodium nitrite and nitrate were measured in the concentration range 7 microM to 3.5 mM (0.1-50 ppm nitrogen). The other chemical species present in wastewater do not interfere with Raman measurements of NO2-/NO3- bands. We observe detection limits of < 14 microM (< 200 ppb) for both NO2- and NO3-. UV reson...