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Biomedical subjects

M Bowker

Publications and source records attributed to M Bowker.

13 recordsLinked to original sources
PubMed2004

The structure and reactivity of anchored nanoparticles on a reducible support.

We have used scanning tunnelling microscopy (STM) to study the structure and reactivity of metal nanoparticles on a TiO2(110) surface. We have deposited two metals (Pt and Ru) using different techniques, metal vapour deposition (MVD) for Pt and metal organic chemical vapour deposition (MOCVD) for Ru. Pt was deposited onto a (1 x 3) reconstructed surface and is found to sinter at temperatures above 873 K, where the onset of nanoparticle mobility is expected. The effect that Pt has on the rate of re-oxidation of a more reduced titania sample with a (1 x 1) terminated surface was studied. At 673 K no preferential re-growth around the particles is observed and this has been attributed to the desorption characteristics of oxygen from Pt surfaces. The results are compared to those obtained from Pd covered TiO2 where such preferential growth has previously been observed. Ru was deposited using a carbonyl precursor, Ru3(CO)12, and is found to adsorb preferentially on the (1 x 2) rows of a surface consisting of both (1 x 1) and (1 x 2) added row structures. Upon annealing the compound is initially de-carbonylated to leave Ru nanoparticles on the surface, which can then sinter with increasing temperature. These particles have been alloyed with Pt and their re-oxidation characteristics studied. The alloy particles alter the oxygen desorption characteristics from that of the constituent elements (Pt and Ru) and consequently an enhancement in the rate of re-oxidation of a TiO2(110) surface at 673 K is observed.

Microscopy, Scanning Tunneling↗
PubMed1997

Gestational diabetes mellitus and gene mutations which affect insulin secretion.

We investigated whether genetic mutations known to impair insulin secretion and glucose tolerance are operative in a group of American women with gestational diabetes mellitus. Study groups were comprised of elderly non-diabetic controls (n = 55) with normal glucose tolerance and patients with gestational diabetes (n = 50), together with one family with maturity-onset diabetes of the young (three controls and three affected). No mutations were detected in any exon of the human glucokinase gene or the mitochondrial tRNA[Leu](UUR) gene by single strand conformational analysis and direct exon sequencing. Also, chi2 analysis showed no significant association with gestational diabetes for a polymorphism at position -30 (G --> A) of the beta-cell-specific glucokinase gene promoter. We have determined that glucokinase and mitochondrial tRNA[Leu](UUR) gene mutations, which are known to impair insulin secretion are relatively uncommon and do not constitute a large component of genetic risk for gestational diabetes in the study population.

Adult↗
PubMedDate not supplied

The health care solution: understanding the crisis and the cure.

Following is Part I of an excerpt from the soon-to-be released book, "The Health Care Solution: Understanding the Crisis and the Cure" by CAHHS CEO/President C. Duane Dauner. Dauner paves the road to reform in his book by providing a step-by-step solution to ending the nation's health care crisis.

Delivery of Health Care↗
PubMedDate not supplied

The health care solution.

Following is Part II of an excerpt from the recently published book, The Health Care Solution: Understanding the crisis and the Cure, by C. Duane Dauner. Dauner paves the road to reform in his book by providing a step-by-step solution to ending the nation's health care crisis. Part I can be found in the January/February edition of California Hospitals magazine.

Community Health Services↗