Roy Armstrong

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Measurements of bone lead concentrations in the tibia, wrist, sternum, and calcaneus were performed in vivo by x ray fluorescence on active and retired lead workers from two acid battery factories, office personnel in the two factories under study, and control subjects. Altogether 171 persons were included. Lead concentrations in the tibia and ulna(More)
A group of workers occupationally exposed to lead have had measurements of their tibia lead concentrations made on two occasions separated by five years; on the second occasion calcaneus lead concentrations were also measured. The results serve to confirm the reliability of the measurement technique and to illustrate the improved precision achieved through(More)
Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), known as nonmelanoma skin cancer (NMSC), are the most common cancers worldwide. Although many factors are involved in the pathogenesis of NMSC, UV radiation is an important risk factor. A fundamental question in skin cancer research is whether varying doses of total UV radiation influence key(More)
PURPOSE The purpose of the present study was to determine whether contact and immersion A-scan techniques produce comparable measures of the magnitude of eye axial length. METHOD A prospective study in which 225 consecutive patients scheduled for cataract surgery in a private day surgery setting had axial lengths measured with an Alcon Ocuscan machine(More)
An in vivo neutron activation system for measuring kidney cadmium has been redesigned, firstly to reduce ambient dose levels and, secondly, to improve the cadmium signal to neutron dose ratio by modifying the neutron spectrum from 238Pu/Be, by interposing a beryllium premoderator. The ambient dose was reduced by a factor of seven. The overall system(More)
A model simulating a spiral diaphyseal fracture with butterfly fragments and bone loss was utilized to evaluate an hydroxyapatite/tricalcium phosphate, and collagen composite bone graft substitute in twelve dogs. The resultant grafted and contralateral control femora were tested in torsion at one year. This study examines the histological response to the(More)
A method is described for the measurement of lignocaine in small samples of fetal and placental tissue. Tissue samples (ca 100 mg) are digested using a preteolytic enzyme. Lignocaine and an internal standard are extracted into methyl tert-butyl ether and analysed by high-performance liquid chromatography with electrochemical detection (+1.0 V vs Ag/AgCl).(More)
The radiance transmittance (Tr) is the ratio of the water-leaving radiance (Lw(0+)) to the sub-surface upwelling radiance (Lu(0-)), which is an important optical parameter for ocean optics and ocean color remote sensing. Historically, a constant value (~0.54) based on theoretical presumptions has been adopted for Tr and is widely used. This optical(More)