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Biomedical subjects

R Emerson

Publications and source records attributed to R Emerson.

At least 37 records · Page 2Linked to original sources
PubMed1987

Narrow polarized components in the OH 1612-MHz maser emission from supergiant OH-IR sources.

High-resolution OH 1612-MHz spectra are presented of the supergiant OH-IR sources VY CMa, VX Sgr, IRC 10420 and NML Cyg. The spectra have a resolution of 300 Hz. Narrow components in the spectra have linewidths as small as 550 Hz (0.1 km s-1) but there is no evidence for components narrower than this. These results are in accord with present understanding of maser line-narrowing and of the physical conditions in the OH maser regions. Many of the narrow components have an appreciable degree of circular polarization which is not apparent at the lower frequency resolutions usually employed. The circular polarization indicates the presence of magnetic fields of approximately 1 mG in the circumstellar envelopes, at distances of approximately 3x10(16) cm from the central stars. These fields are strong enough to influence the outflow from the stars, and may help to explain some of the asymmetries which are seen in their circumstellar envelopes.

Astronomical Phenomena↗
PubMed1984

Biochemical, cytological, and histological alterations in rat lung following acute beryllium aerosol exposure.

Fischer 344 rats were exposed for 1 hr to an aerosol of BeO generated at a temperature of 560 degrees C. An initial lung burden of 500 +/- 4.1 ng Be was achieved. Animals were killed at 2.5 hr, and 2, 12, and 21 days postexposure. Bronchopulmonary lavage fluids were analyzed biochemically for enzymes, protein, lipids, and sialic acid, and cytologically to determine the composition of the free alveolar cell population. Nonspecific phagocytosis of yeast was measured in adherent macrophages. There were increases in all the biochemical parameters by 2 days postexposure, which peaked by Day 5 and then began to return to control levels. The cytological response on Days 2 and 5 was characterized by polymorphonuclear leucocyte infiltration and a depression in macrophage number and phagocytic activity. By Day 12, increased numbers of newly recruited macrophages with supranormal phagocytic activity populated the lung. During the same period, there was a reduction in lavage protein and lipid levels, perhaps due to a restoration of normal clearance mechanisms. Tissue morphological changes correlated well with the cytological and biochemical alterations.

Aerosols↗
PubMed1982

The kinematic rotating hinge: biomechanics and clinical application.

The Kinematic rotating hinge offers a solution as a salvage procedure for severely deformed and unstable "end-stage" knees. Excellent short-term results in terms of pain relief can be achieved, and motion up to 130 degrees is possible, depending on the condition of the quadriceps mechanism and the extent of scarring from previous operations. Care must be taken to avoid cortical penetration, especially in cases of hinge revisions, osteoporosis, thin-walled bones, and the presence of old cement. As with any total knee arthroplasty, care must be taken to achieve optimal rotatory alignment of the tibia beneath the femur to guarantee good patellar tracking.

Adult↗
PubMed1981

Stopping medication in children with epilepsy: predictors of outcome.

Anticonvulsant therapy was discontinued in 68 children with epilepsy who had had no seizures for four years, in an attempt to find the risk of relapse and the factors predictive of recurrence. In this population the probability of remaining free of seizures for four years after discontinuation of medication was 69 per cent. Children were more likely to have recurrent seizures if they were mentally retarded, if their seizures had begun before two years of age, if they had had many generalized seizures before control, or if they had had a definitely abnormal electroencephalogram before medication was discontinued. Multivariate analysis showed that the best predictors of outcome were the electroencephalogram taken at cessation of medication and the number of seizures before control. We conclude that in the normal child who has not had many seizures and whose electroencephalogram is normal or mildly abnormal, the risks of discontinuing medication after four seizure-free years are acceptable.

Adolescent↗