Gold nanoshell bioconjugates for molecular imaging in living cells

Advances in scattering-based optical imaging technologies offer a new approach to noninvasive point-of-care detection, diagnosis, and monitoring of cancer. Emerging photonics technologies provide a cost-effective means to image tissue in vivo with high resolution in real time. Advancing the clinical potential of these imaging strategies requires the development of optical contrast agents targeted to specific molecular signatures of disease. We describe the use of a novel class of contrast agents based on nanoshell bioconjugates for molecular imaging in living cells. Nanoshells offer significant advantages over conventional imaging probes including continuous and broad wavelength tunability, far greater scattering and absorption coefficients, increased chemical stability, and improved biocompatibility. We show that nanoshell bioconjugates can be used to effectively target and image human epidermal growth factor receptor 2 (HER2), a clinically relevant biomarker, in live human breast carcinoma cells.     

Utilizing inverse micelles to synthesize calcium phosphate nanoparticles as nano-carriers

The aim of this study was to investigate the feasibility of the inverse micelles (IM) technique in producing protein-loaded calcium phosphate nanoparticles (CaP NPs), and to compare this technique with the conventional co-precipitation (co-ppt) technique. In this study, bovine serum albumin and lysozyme were used as model proteins. The results show that CaP NPs produced by IM were shown to be spherical and homogenous in size of ~50 nm. Protein loading efficiency of the IM technique was shown to be much higher than CaP NPs synthesized through co-ppt technique. X-ray photoelectron spectroscopy shows that proteins were not adsorbed onto the surface of IM-synthesized CaP NPs, which suggested that the proteins were entrapped within the particle matrix. Release studies show that protein release was more rapid at lower pH conditions (pH 5 and 6) than at physiological pH of 7.4. A burst release was observed for co-ppt CaP NPs, while a continuous release of protein was observed for IM-produced CaP NPs. This study shows the superiority of the IM technique in preparing pH responsive CaP NPs as nano-carriers.     

Low temperature Si homo-epitaxy by reduced pressure chemical vapor deposition using dichlorosilane,silane and trisilane

Dichlorosilane (DCS), silane and trisilane have been investigated as Si precursors for low temperature (<700 °C) Si reduced pressure chemical vapor deposition. DCS and silane are limited to growth temperatures higher than 600–650 and 500 °C, respectively. At lower temperatures, absence of either Cl or H desorption from the surface impedes Si growth with acceptable growth rate (>5 Å/min). Trisilane permits the growth of Si at lower temperatures below 350 °C due to a specific growth mechanism enhancing H desorption. Layers grown at temperatures lower than 500 °C are defective, irrespective of the carrier gas, pressure and precursor flow used.     

Combined electric field and near-field scanning optical microscopy: modification of silicon surfaces

Received: 3 July 1998     

A multi-objective genetic algorithm for robust flight scheduling using simulation

Traditional methods of developing flight schedules generally do not take into consideration disruptions that may arise during actual operations. Potential irregularities in airline operations such as equipment failure are not adequately considered during the planning stage of a flight schedule. As such, flight schedules cannot be met as planned and their performance is compromised, which may eventually lead to huge losses in revenue for airlines. In this paper, we seek to improve the robustness of a flight schedule by re-timing its departure times. The problem is modeled as a multi-objective optimization problem, and a multi-objective genetic algorithm (MOGA) is developed to solve the problem. To evaluate flight schedules, SIMAIR 2.0, a simulation model which simulates airline operations under operational irregularities, has been employed. The simulation results indicate that we are able to develop schedules with better operation costs and on-time performance through the application of MOGA.