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Biomedical subjects

J E Lovell

Publications and source records attributed to J E Lovell.

11 recordsLinked to original sources
PubMed1995

Subparsec-scale structure and evolution of Centaurus A (NGC5128).

We present a series of 8.4-GHz very-long-baseline radio interferometry images of the nucleus of Centaurus A (NGC5128) made with a Southern Hemisphere array, representing a 3.3-year monitoring effort. The nuclear radio jet is approximately 50 milliarcseconds in extent, or at the 3.5-megaparsec distance of NGC5128, approximately 1 parsec in length. Subluminal motion is seen and structural changes are observed on time scales shorter than 4 months. High-resolution observations at 4.8 and 8.4 GHz made in November 1992 reveal a complex morphology and allow us to unambiguously identify the self-absorbed core located at the southwestern end of the jet.

Journal Article↗
PubMed1993

The effect of aluminum hydroxide dissolution on the bleeding of aluminum lake dyes.

The effect of pH on the bleeding of FD&C yellow No. 5 aluminum lake and FD&C red No. 40 aluminum lake was investigated. The pH-bleeding profiles corresponded to the pH-solubility profile of aluminum hydroxide. The similarity of the bleeding profiles of both lake dyes and the pH-solubility profile of aluminum hydroxide indicates that pH related bleeding, other than that occurring by competition with anions, is a result of dissolution of the aluminum hydroxide substrate. This dissolution is related to the properties of the substrate rather than to the structure of adsorbed dye.

Aluminum Hydroxide↗
PubMed1979

Maternal attitudes toward circumcision.

Two hundred questionnaires were completed anonymously by mothers to determine the nature of their attitudes and knowledge of neonatal circumcision. Neonatal circumcision had been performed on 95 percent of the sons. A wide variety of reasons were given for circumcising newborns; few were medically valid. Eighty-seven percent of mothers considered circumcision to be without risk, and 80 percent of mothers stated that the risks of circumcision had not been explained to them. This retrospective study revealed a lack of maternal understanding regarding neonatal circumcision.

Adult↗
PubMed1979

Histology of the hair cycle in male beagle dogs.

A detailed histologic study of the hair follicles of male Beagle dogs was made to determine changes in microscopic structure associated with the three stages in the hair cycle. Observed changes are that the bulbs of hair follicles in anagen are more closely associated with adipose tissue than they are in telogen. This is due to the deeper penetration of the follicles into the subcutaneous tissue during anagen. The hair germ cells of telogen were presumed to arise from the stratum basale of the matrix cells rather than from the outer root sheath cells. During telogen, the dermal papilla is separated from the club hair, but remains in close proximity to it. There is no connecting stalk as is reported for other animals.

Animals↗
PubMed1977

Hair follicle cycle and shedding in male beagle dogs.

Skin biopsy samples were collected from the thoracolumbar region of 9 male Beagle dogs ranging in age from 2 weeks to 32 months. The highest percentages of anagen hair follicles were present in samples collected during the winter and the summer seasons, and highest percentages of telogen hair follicles were present in samples collected during the fall and the spring seasons. Catagen, never exceeding 7% of the follicles, was found during a brief transitory stage. Peak shedding of hairs combed from the coats of dogs occurred in the spring and fall--these peaks appearing simultaneously with peak percentages of hair follicles in the telogen phase. Dogs younger than 1 year of age had 10% fewer follicles in the telogen stage than did older dogs. In dogs 2 weeks of age, 12 to 16% of the hair follicles were in the telogen stage.

Aging↗
PubMed1975

Electrical modification of disuse osteoporosis.

Localized electrical stimulation of the immobilized hind limb of young rabbits resulted in dramatically more bone in the tuber calcis (heel bone) compared to the severe loss of bone (osteoporosis) seen in unstimulated, immobilized controls. Detailed histological evaluation using microradiography and fluorescence and polarization microscopy showed that the increase was probably due to an overall inhibition of surface cortical bone loss )endosteal resorption) and an increase in the quantity of the new immature bone. There was also evidence of increased osteonal resorption in the stimulated animals.

Animals↗
PubMed1975

Biocompatibility and state fatigue behavior of glassy carbon.

1. The normal stages of bone modeling and remodeling occur following the implantation of carbon plugs. 2. Glassy carbon bars aged in vivo for five months did not undergo statistically significant weakening. 3. Glassy carbon does undergo static fatigue when aged in a simulated biological environment. However, the conditions necessary to cause this failure are extreme. 4. Minimal tissue response was seen to the presence of the carbon.

Animals↗
PubMed1975

Two-year biocompatibility study of ORNL graphite.

A new grade of graphite-isotropic, fine-grained, and of superior strength-has been produced at the Oak Ridge National Laboratory. The possibility of using this material in orthopedic implants is under study at the University of Illinois. As part of this program, plugs 1/8 in. in diam were inserted in holes drilled in the proximal femur of 2 groups of 8-week old male rabbits. The groups were sacrificed at the end of 1 and 2 years. A single i.m. injection of achromycin was given 2 days prior to sacrifice. Thin sections of the plugs and surrounding tissue were examined by microradiography and optical microscopy (white light, polarizing, and fluorescent). All bone was normal. Minimal evidence of irritation or fibrous encapsulation appeared.

Animals↗