| dc.contributor.author | Xu, Wei. | en_US |
| dc.date.accessioned | 2014-10-21T12:35:16Z | |
| dc.date.available | 1995 | |
| dc.date.issued | 1995 | en_US |
| dc.identifier.other | AAINN05244 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55051 | |
| dc.description | The present study focuses on development of techniques of STM and SFM for biological applications and is divided into two parts: investigation of metal-coating techniques for STM imaging of biological materials; and development of a new SFM technique for the measurement of the elastic properties of biological materials. | en_US |
| dc.description | We used Pt/Ir coatings prepared by a simple procedure and obtained $\sim$1 nm resolution on S-layer sheath of Methanospirillum hungatei (Mh). The 3 nm x 3 nm 2-D lattice structure of sheath was observed for the first time by STM. The surface characteristics of cell plugs of Mh was resolved, and the register alignment of the plug layers was identified for the first time. Effects of film grain size, tip convolution, and tip-sample interaction on the imaging resolution and interpretation are discussed. | en_US |
| dc.description | A new technique was developed which measures elastic properties by bending or stretching biological material suspended on grooves etched in a GaAs substrate. We measured the Young's modulus of $\beta$-chitin fibres with cross sections less than 40 nm x 20 nm to be (0.5-1.5) $\times\ 10\sp $ N/m$\sp2$. In the case of Mh sheath, a homogeneous approximation gave a Young's modulus of (2-5) $\times\ 10\sp $ N/m$\sp2$, while an inhomogeneous hoop model provided information about the molecular bonding of the sheath. By testing the sheath to its breaking strength we estimated the maximum internal pressure as well as the maximum extension the sheath can sustain, which gave insight into possible biological mechanisms. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1995. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Engineering, Biomedical. | en_US |
| dc.subject | Physics, Condensed Matter. | en_US |
| dc.title | Biological applications of scanning tunneling microscopy and scanning force microscopy. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
