The ability of three model carcinogens, 1,2-dimethylhydrazine, di methylnitrosamine, and 2-amino-3,8-dimethylimidazo|4,5-/]qiiinoxaline, to induce mutation in a novel in vivo assay in mouse intestine has been examined. The assay is based on mutations at the Dlb-1 locus which determines the tissue specific pattern of expression of the binding site for the lectin Doltchos bifloras agglutinin. In ...

Introduction Previously we proposed construction of a miniaturized metabolic monitor that could be taken aboard the space station to monitor the physiological response of the body in a microgravity environment. The prototype consisted of an on airway non-dispersive infrared (NDIR) CO2 sensor and a luminescencequenching O2 sensor to measure gas concentrations, and differential pressure ports to ...

A gas sensor based on off-beam quartz enhanced photoacoustic spectroscopy was developed and optimized. Specifically, the length and diameter of the microresonator tube were optimized, and the outer tube shape is modified for enhancing the trace gas detection sensitivity. The impact of the distance between the quartz tuning fork and an acoustic microresonator on the sensor performance was experi...

In this research work, ZnO nanotubes were fabricated on a gold coated glass substrate through chemical etching by the aqueous chemical growth method. For the first time a nanostructure-based iodide ion selective electrode was developed. The ZnO nanotubes were functionalized with miconazole ion exchanger and the electromotive force (EMF) was measured by the potentiometric method. The iodide ion ...

A near-IR CO trace gas sensor based on quartz-enhanced photoacoustic spectroscopy (QEPAS) is evaluated using humidified nitrogen samples. Relaxation processes in the CO-N2-H2O system are investigated. A simple kinetic model is used to predict the sensor performance at different gas pressures. The results show that CO has a ~3 and ~5 times slower relaxation time constant than CH4 and HCN, respec...

The integration of gas sensor components into smart phones, tablets, and wrist watches will revolutionize the environmental health and safety industry by providing individuals the ability to detect harmful chemicals and pollutants in the environment using always-on hand-held devices. However, in order for this goal to be achieved the fabrication of gas sensors and, more precisely, the depositio...

copper sulfate was used as a precursor to prepare cuo nanoparticles in reverse micelles (o/w microemulsion).  this is a technique which allows the preparation of ultrafine metal oxide nanoparticles within the size ranging from 50 to 60 nm. the preparation of nano copper (ii) oxide studied was investigated in the inverse microemulsion system. therefore the nucleation of metal particles proceeds ...

A sensor has been developed for detecting 1-nonanal gas present in the breath of lung cancer patients by combining SnO2 nanosheets with SnO2 nanoparticles and noble metal catalysts. A significant change in the electrical resistance of this sensor was observed with increasing 1-nonanal gas concentration; the resistance decreased by a factor of 1.12 within the range of 1 to 10 ppm at 300 °C. The ...

A modified hydrothermal method was developed to synthesize ZnO-CuO composite nanostructures. A free-standing film made of ZnO-CuO nanostructures was assembled on the surface of the hydrothermal solution with a smooth surface on one side and a spherical surface on the other side. The structure, growth mechanism and the optical properties of the composite nanostructures were studied. Structural c...