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Biomedical subjects

B A Lloyd

Publications and source records attributed to B A Lloyd.

8 recordsLinked to original sources
PubMed2000

A norbornenyl derivative with through-space ketone pi-interaction.

The title compound, endo,exo-12-oxotetracyclo[6.2.1.1(3,6).0(2, 7)]dodeca-9-en-anti-11-yl p-bromobenzoate, C(19)H(17)BrO(3), consists of norbornene with an anti-p-bromobenzoate substituent at the methano bridge and an exo-fused norbornanone unit bonded to the ethano bridge. The spatially proximate ketone and alkene interact through space and the ketone C atom is substantially pyramidalized. Through-space ketone pi-interaction is probably responsible for the low solvolysis rate of the anti-11-chloride derivative.

Journal Article↗
PubMed1990

Clinical use of 24-hour gastric pH monitoring vs o-diisopropyl iminodiacetic acid (DISIDA) scanning in the diagnosis of pathologic duodenogastric reflux.

The efficacy of o-diisopropyl iminodiacetic acid (DISIDA) scanning was compared with that of computerized analysis of 24-hour gastric pH monitoring to diagnose excessive duodenogastric reflux in 22 normal volunteers and 106 consecutive patients with foregut symptoms. DISIDA scanning had a false-positive rate of 18% in the normal volunteers. Gastric pH monitoring showed an increasing prevalence of duodenogastric reflux in patients with increasing clinical evidence of this condition, which was not seen with DISIDA scanning. Both DISIDA scanning and gastric pH monitoring identified duodenogastric reflux in most patients who had had previous pyloroplasty or antrectomy. Only gastric pH monitoring, however, showed a significantly increased prevalence of duodenogastric reflux in symptomatic patients after previous cholecystectomy compared with those who had not undergone previous surgery. These data suggest that 24-hour gastric pH monitoring is superior to DISIDA scanning in identifying duodenogastric reflux as a cause of foregut symptoms.

Adolescent↗
PubMed1978

Thermal stress in teeth.

Observations of crack damage in the tooth structure from in vivo studies and in vitro experimental thermal cycling studies were combined with numerical analysis techniques to identify and isolate the influence of thermal stresses on the creation and propagation of cracks in teeth. The factors considered in this study included: (a) variations in tooth type or geometry (molar, bicuspid, etc.), (b) tooth age, (c) material properties of the tooth, (d) the magnitude of the change in the temperature of the environment surrounding the tooth, and (e) the thermal resistance between the tooth and the medium surrounding the tooth.

Adolescent↗
PubMed1978

Numerical and experimental evaluation of energy inputs, temperature gradients, and thermal stresses during restorative procedures.

Wet cutting in enamel should be used during restorative procedures. According to evidence reported here, dry cutting can induce sufficiently high thermal stresses to fracture the enamel. Temperatures resulting from dry cutting in dentin are high enough to cause biologic pulp damage if the cutting is within 1 to 2 mm of the pulp. Cracks induced in the cavity walls by dry cutting may eventually contribute to marginal failure. A hand-held syringe directing a small, high-velocity stream of water into the cutting region is a more effective cooling technique than an air-water spray.

Adult↗
PubMedDate not supplied

Effect of cooling techniques on temperature control and cutting rate for high-speed dental drills.

This paper describes a series of tests conducted to determine the effectiveness of various cooling techniques used while preparing teeth for restoration. Comparisons are presented for four cooling techniques: air stream, air-water spray, water stream from a separate hand-held syringe, and water applied through a hollow bur. The comparisons were made in two ways, temperature control and influence on cutting rate. It was demonstrated that wet cooling techniques provided better temperature control than cooling with air and also improved the rate of material removal.

Air↗
PubMedDate not supplied

A balancing act: the curriculum vitae and the interview process.

The authors believe that one possible solution to the dearth of minority nursing faculty in higher education is thorough preparation for the search process by the minority applicant. This article discusses the appointment/hiring process and provides the reader with authoritative and experiential information necessary for constructing a curriculum vitae (CV) and preparing for an interview. Armed with a proper CV and knowledge of potential interview questions, the authors believe that minority applicants will be able to maneuver their way through the maize of job interviews. In addition, suggestions are offered to those serving on promotion and tenure committees and administrators.

Black or African American↗