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M A Lantz

Publications and source records attributed to M A Lantz.

10 recordsLinked to original sources
PubMed2001

Quantitative measurement of short-range chemical bonding forces.

We report direct force measurements of the formation of a chemical bond. The experiments were performed using a low-temperature atomic force microscope, a silicon tip, and a silicon (111) 7x7 surface. The measured site-dependent attractive short-range force, which attains a maximum value of 2.1 nanonewtons, is in good agreement with first-principles calculations of an incipient covalent bond in an analogous model system. The resolution was sufficient to distinguish differences in the interaction potential between inequivalent adatoms, demonstrating the ability of atomic force microscopy to provide quantitative, atomic-scale information on surface chemical reactivity.

Journal Article↗
PubMed1977

The FTA-ABS test: a diagnostic help or hindrance?

The fluorescent treponemal antibody absorption (FTA-ABS) test, an excellent confirmatory treponemal test, has been used increasingly for syphilis screening and case detection. To evaluate its performance as an initial test, we did Venereal Disease Research Laboratory (VDRL) slide and FTA-ABS tests on 1,043 patients suspected of having syphilis. When retested in both a local and a reference laboratory, sera from 226 patients with borderline or reactive results demonstrated interlaboratory consistency for the VDRL but not the FTA-ABS. Borderline FTA-ABS results correlated poorly with the diagnosis of syphilis in both laboratories; a reactive FTA-ABS test correlated well only in the reference laboratory. Performance of the test appeared to be diminished by its use in a low-prevalence population and by seemingly minor alterations in the test procedure at the local laboratory.

Absorption↗