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Biomedical subjects

N J Bailey

Publications and source records attributed to N J Bailey.

8 recordsLinked to original sources
PubMed1998

Directly coupled CZE-NMR and CEC-NMR spectroscopy for metabolite analysis: paracetamol metabolites in human urine.

Direct coupling of NMR spectroscopic detection with both capillary zone electrophoresis (CZE) and capillary electrochromatography (CEC) was applied to the separation of metabolites of the drug paracetamol in an extract of human urine. Continuous-flow CZE-NMR and CEC-NMR allowed the detection of the major metabolites, the glucuronide and sulfate conjugates of the drug and the endogenous material hippurate. Identification of these substances was achieved by examination of individual rows of the NMR chromatogram and this also gave estimates of the detection limits. For CEC-NMR, spectra were also obtained in the stopped-flow mode including a two-dimensional TOCSY NMR experiment which afforded confirmatory evidence for paracetamol glucuronide. Characterisation of drug metabolites using NMR spectroscopy is therefore possible with nanolitre sample volumes.

Acetaminophen↗
PubMed1976

The center of projection.

Our ability to manipulate ourselves and the objects which surround us in our object space depends upon reasonably precise localization of the perceived images of these objects in our visual space. To be functionally sensible, this premise suggests that a "center of projection" must be located somewhere on the subject's body. Two studies which were done in an effort to illuminate an earlier study in regard to the center of projection are reported. One study used an "optical gun" which forced the subject to "shoot" at a perceived target. A second study used a focused beam headlamp to indicate the perceived direction of a perceived target. The perceived direction of the targets was altered by changes in the accommodative stimulus. Since the subject was aware only of the perceived direction of the image and since, in addition, he could not see the results of his efforts to localize the target, the location of a fixed center of projection could not be demonstrated.

Feedback↗
PubMed1975

Soft contact lens identification.

Measuring procedures used for hydrogel contact lenses are sufficiently difficult to make identification of a given soft lens annoyingly time-consuming and sometimes impossible. Etching a number or letter on the lens when it is received from the laboratory allows the practitioner to tell whether the proper lens is being worn, even while the lens is still on the patient's eye. A sharp pointed tool on a dry hydrogel lens produces this identifying number.

Contact Lenses, Hydrophilic↗