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Biomedical subjects

D J Bishop

Publications and source records attributed to D J Bishop.

8 recordsLinked to original sources
PubMed2005

Effect of swimming intensity on subsequent cycling and overall triathlon performance.

OBJECTIVES: To investigate the effects of different swimming intensities on subsequent cycling and overall triathlon performance. METHODS: Nine highly trained, male triathletes completed five separate laboratory sessions comprising one graded exercise test, a swim time trial (STT), and three sprint distance triathlons (TRI). The swimming velocities of the three TRI sessions were 80-85% (S80), 90-95% (S90), and 98-102% (S100) of the STT velocity. Subsequent cycling and running were performed at a perceived maximal intensity. Swimming stroke mechanics were measured during the swim. Plasma lactate concentration and ratings of perceived exertion were recorded at the conclusion of the swim and over the course of subsequent cycling and running. Oxygen consumption was recorded during the cycle. RESULTS: The S80 and S90 cycle times were faster than the S100 cycle time (p<0.05). The overall triathlon time of S80 was faster than that of S100 (p<0.05). The S100 swim was characterised by a greater stroke rate than S80 and S90 (p<0.05) and a greater plasma lactate concentration than S80 (p<0.01). CONCLUSION: A swimming intensity below that of a time trial effort significantly improves subsequent cycling and overall triathlon performance.

Adult↗
PubMed2001

Nonlinear micromechanical Casimir oscillator.

The Casimir force between uncharged metallic surfaces originates from quantum-mechanical zero-point fluctuations of the electromagnetic field. We demonstrate that this quantum electrodynamical effect has a profound influence on the oscillatory behavior of microstructures when surfaces are in close proximity (< or =100 nm). Frequency shifts, hysteretic behavior, and bistability caused by the Casimir force are observed in the frequency response of a periodically driven micromachined torsional oscillator.

Journal Article↗
PubMed2001

Quantum mechanical actuation of microelectromechanical systems by the Casimir force.

The Casimir force is the attraction between uncharged metallic surfaces as a result of quantum mechanical vacuum fluctuations of the electromagnetic field. We demonstrate the Casimir effect in microelectromechanical systems using a micromachined torsional device. Attraction between a polysilicon plate and a spherical metallic surface results in a torque that rotates the plate about two thin torsional rods. The dependence of the rotation angle on the separation between the surfaces is in agreement with calculations of the Casimir force. Our results show that quantum electrodynamical effects play a significant role in such microelectromechanical systems when the separation between components is in the nanometer range.

Journal Article↗
PubMed2001

Flux line lattice reorientation in the borocarbide superconductors with H parallel a.

Small angle neutron scattering studies of the flux line lattice in LuNi2B2C and ErNi2B2C induced by a field parallel to the a axis reveal a first order flux line lattice reorientation transition. Below the transition the flux line lattice nearest neighbor direction is parallel to the b axis, and above the transition it is parallel to the c axis. This transition cannot be explained using nonlocal corrections to the London model. In addition, the anisotropy of the penetration depth lambda and the coherence length xi change at the transition.

Journal Article↗
PubMedDate not supplied

Lansoprazole compared with histamine2-receptor antagonists in healing gastric ulcers: a meta-analysis.

To compare the gastric ulcer healing rates of lansoprazole with histamine2-receptor antagonists (H2RAs) (ranitidine, famotidine, cimetidine, and roxatidine), a meta-analysis was performed using data from five published and eight unpublished randomized controlled trials. Analyses were performed using (1) both evaluable patients (n = 1527) and all randomized patients (n = 1655) (assuming that patients lost to follow-up were treatment failures); (2) all studies and a subset of studies that received high methodologic quality scores; and (3) fixed-effects, random-effects, and Bayesian statistical models. In all cases, lansoprazole was associated with a significantly higher rate of endoscopic healing at both 4 and 8 weeks compared with the H2RAs. When the most conservative Bayesian statistical model and intent-to-treat analysis were used, lansoprazole was associated with a 33% higher healing rate at 4 weeks (risk ratio = 1.33; 95% confidence interval [CI] = 1.19 to 1.49) and a 12% higher healing rate at 8 weeks (risk ratio = 1.12; 95% CI = 1.06 to 1.19) than were the H2RA agents. Similar results were obtained when the meta-analysis was performed on evaluable rather than all randomized patients and using the three different analytical techniques noted above. Slightly lower, though still highly significant, improvement in ulcer healing rates was obtained when the meta-analysis was performed using a subset of six studies that received high methodologic quality scores. These results support the conclusion that lansoprazole heals ulcers more quickly than do the H2RAs and also achieves higher overall rates of healing. The eradication of Helicobacter pylori associated with gastric ulcers was not assessed in individual studies.

2-Pyridinylmethylsulfinylbenzimidazoles↗