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Full-Text Articles in Physical Sciences and Mathematics
Ac-Mode Atomic Force Microscope Imaging In Air And Solutions With A Thermally Driven Bimetallic Cantilever Probe, Andrew C. Hillier, Allen J. Bard
Ac-Mode Atomic Force Microscope Imaging In Air And Solutions With A Thermally Driven Bimetallic Cantilever Probe, Andrew C. Hillier, Allen J. Bard
Andrew C. Hillier
An ac imaging mode for atomic force microscopy ~AFM! has been developed that employs a thermally driven bimetallic cantilever to sense surface topography. Oscillations are induced in a composite cantilever, comprising a Si3N4 layer and Au overcoat, by local heating with a resistive wire heater placed in close proximity to the cantilever. Cantilever bending occurs upon heating due to the difference in thermal expansion coefficients of the Si3N4 and Au layers. The magnitude of this bending is a function of the heat input, the cantilever geometry, the frequency of the excitation, and the thermal properties of the surrounding medium. A …
Complexes Between Nascent Polypeptides And Their Molecular Chaperones In The Cytosol Of Mammalian Cells, Daryl K. Eggers, W. J. Welch, W. J. Hansen
Complexes Between Nascent Polypeptides And Their Molecular Chaperones In The Cytosol Of Mammalian Cells, Daryl K. Eggers, W. J. Welch, W. J. Hansen
Daryl K. Eggers
Folding of newly synthesized proteins in vivo is believed to be facilitated by the cooperative interaction of a defined group of proteins known as molecular chaperones. We investigated the direct interaction of chaperones with nascent polypeptides in the cytosol of mammalian cells by multiple methods. A new approach using a polyclonal antibody to puromycin allowed us to tag and capture a population of truncated nascent polypeptides with no bias as to the identity of the bound chaperones. In addition, antibodies that recognize the cytosolic chaperones hsp70, CCT (TRiC), hsp40, p48 (Hip), and hsp90 were compared on the basis of their …
Direct Measurement Of Diffuse Double-Layer Forces At The Semiconductor/Electrolyte Interface Using An Atomic Force Microscope, Kai Hu, Fu-Ren F. Fan, Allen J. Bard, Andrew C. Hillier
Direct Measurement Of Diffuse Double-Layer Forces At The Semiconductor/Electrolyte Interface Using An Atomic Force Microscope, Kai Hu, Fu-Ren F. Fan, Allen J. Bard, Andrew C. Hillier
Andrew C. Hillier
The forces between a silica probe and an n-type TiO2 single-crystal electrode were measured using an atomic force microscope in an aqueous electrolyte solution. These interactions were a strong function of the solution pH, the presence of specifically adsorbed anions, and the TiO2 electrode potential. For a series of pH values, a strong electrostatic repulsion was seen at high pH and decreased as the pH was reduced. At pH values below 5.5, the interaction became attractive. A series of force measurements between SiO2 and n-type TiO2 showed a repulsive interaction when TiO2 was held at negative electrode potentials, which transformed …