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Portland State University

Nanostructured materials

Physical Sciences and Mathematics

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Full-Text Articles in Nanoscience and Nanotechnology

Synthesis And Assessment Of Radiotherapy-Enhancing Nanoparticles, Hayden Winter Aug 2020

Synthesis And Assessment Of Radiotherapy-Enhancing Nanoparticles, Hayden Winter

Dissertations and Theses

Radiation Therapy (RT) is a common treatment for cancerous lesions that acts by ionizing matter in the affected tissue, causing cell death. The disadvantage of RT is that it is most often delivered via an external beam of radiation which must pass through healthy tissues to reach the target site, ionizing matter within healthy tissues as well. To address this drawback, techniques are being developed for increasing RT-induced cell death in a target tissue while minimizing cell death in surrounding tissues. This effect is known as radiation dose enhancement or RT enhancement.

The approach to RT enhancement studied in this …


Expanding The Versatility Of Nano Assembled Capsules As Platform Of Potential High Payload Mri Contrast Agents, Annah Farashishiko Jul 2016

Expanding The Versatility Of Nano Assembled Capsules As Platform Of Potential High Payload Mri Contrast Agents, Annah Farashishiko

Dissertations and Theses

Magnetic resonance imaging (MRI) has become a powerful clinical modality in diagnostic medicine. It is non-invasive and offers high spatial and temporal resolution. The goal of molecular imaging is to reveal the pathophysiology underlying the observed anatomy and diagnose diseases. The detection of pathological biomarkers can lead to early recognition of diseases and improved monitoring for recurrence. Clinically available contrast agents are limited in their discrimination of contrast between tissues and they tend to have very high detection limits. Because biomarkers are very low in concentration there is a need for high payload deposition of contrast agent (CA) and targeted …


Structural Identification Of Cubic Iron-Oxide Nanocrystal Mixtures: X-Ray Powder Diffraction Versus Quasi-Kinematic Transmission Electron Microscopy, Peter Moeck Mar 2008

Structural Identification Of Cubic Iron-Oxide Nanocrystal Mixtures: X-Ray Powder Diffraction Versus Quasi-Kinematic Transmission Electron Microscopy, Peter Moeck

Physics Faculty Publications and Presentations

Two novel (and proprietary) strategies for the structural identification of a nanocrystal from either a single high-resolution (HR) transmission electron microscopy (TEM) image or a single precession electron diffraction pattern are proposed and their advantages discussed in comparison to structural fingerprinting from powder X-ray diffraction patterns. Simulations for cubic magnetite and maghemite nanocrystals are used as examples.


Transmission Electron Goniometry And Its Relation To Electron Tomography For Materials Science Apoplications, Peter Moeck, P. Fraundorf Nov 2006

Transmission Electron Goniometry And Its Relation To Electron Tomography For Materials Science Apoplications, Peter Moeck, P. Fraundorf

Physics Faculty Publications and Presentations

Aspects of transmission electron goniometry are discussed. Combined with high resolution phase contrast transmission electron microscopy (HRTEM) and atomic resolution scanning TEM (STEM) in the atomic number contrast (Z-STEM) or the phase contrast bright field mode, transmission electron goniometry offers the opportunity to develop dedicated methods for the crystallographic characterization of nanocrystals in three dimensions. The relationship between transmission electron goniometry and electron tomography for materials science applications is briefly discussed. Internet based java applets that facilitate the application of transmission electron goniometry for cubic crystals with calibrated tilt-rotation and double-tilt specimen holders/goniometers are mentioned. The so called cubic-minimalistic tilt …


Making Sense Of Nanocrystal Lattice Fringes, P. Fraundorf, Wentao Qin, Peter Moeck, Eric Mandell Jan 2005

Making Sense Of Nanocrystal Lattice Fringes, P. Fraundorf, Wentao Qin, Peter Moeck, Eric Mandell

Physics Faculty Publications and Presentations

The orientation dependence of thin-crystal lattice fringes can be gracefully quantified using fringe-visibility maps, a direct-space analog of Kikuchi maps [Nishikawa and Kikuchi, Nature (London) 121, 1019 (1928)]. As in navigation of reciprocal space with the aid of Kikuchi lines, fringe-visibility maps facilitate acquisition of crystallographic information from lattice images. In particular, these maps can help researchers to determine the three-dimensional lattice of individual nanocrystals, to 'fringe-fingerprint' collections of randomly oriented particles, and to measure local specimen thickness with only a modest tilt. Since the number of fringes in an image increases with maximum spatial-frequency squared, these strategies (with help …