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Full-Text Articles in Physics

Spectral Cross Correlation As A Supervised Approach For The Analysis Of Complex Raman Datasets: The Case Of Nanoparticles In Biological Cells, Mark Keating, Franck Bonnier, Hugh Byrne Oct 2012

Spectral Cross Correlation As A Supervised Approach For The Analysis Of Complex Raman Datasets: The Case Of Nanoparticles In Biological Cells, Mark Keating, Franck Bonnier, Hugh Byrne

Articles

Spectral Cross-correlation is introduced as a methodology to identify the presence and subcellular distribution of nanoparticles in cells. Raman microscopy is employed to spectroscopically image biological cells previously exposed to polystyrene nanoparticles, as a model for the study of nano-bio interactions. The limitations of previously deployed strategies of K-means clustering analysis and principal component analysis are discussed and a novel methodology of Spectral Cross Correlation Analysis is introduced and compared with the performance of Classical Least Squares Analysis, in both unsupervised and supervised modes. The previous study demonstrated the feasibility of using Raman spectroscopy to map cells and identify polystyrene …


Mechanistic Studies Of In Vitro Cytotoxicity Of Poly(Amidoamine) Dendrimers In Mammalian Cells, Sourav Prasanna Mukherjee, Fiona Lyng, Amaya Garcia, Maria Davoren, Hugh Byrne Aug 2010

Mechanistic Studies Of In Vitro Cytotoxicity Of Poly(Amidoamine) Dendrimers In Mammalian Cells, Sourav Prasanna Mukherjee, Fiona Lyng, Amaya Garcia, Maria Davoren, Hugh Byrne

Articles

Poly(amidoamine) (PAMAM) dendrimer nanoparticles have been demonstrated to elicit a well defined cytotoxicological response from mammalian cell lines, the response increasing systematically with dendrimer generation and number of surface amino groups. In this work, using generation G4, G5, and G6 dendrimers, this systematic response is furthermore demonstrated for the generation of reactive oxygen species, lysosomal activity, and the onset of apoptosis and levels of DNA damage. The results are consistent with a pathway of localisation of PAMAM dendrimers in the mitochondria leading to ROS production causing oxidative stress, apoptosis and DNA damage. ROS production is co-located in the mitochondria, and …


Optical Properties Of Photopolymer Layers Doped With Aluminophosphate Nanocrystals, Elsa Leite, Tzvetanka Babeva, E Ng, Vincent Toal, Svetlana Mintova, Izabela Naydenova Jan 2010

Optical Properties Of Photopolymer Layers Doped With Aluminophosphate Nanocrystals, Elsa Leite, Tzvetanka Babeva, E Ng, Vincent Toal, Svetlana Mintova, Izabela Naydenova

Articles

The optical properties of photopolymer layers consisting of an acrylamide–based matrix and microporous aluminophosphate nanocrystals of AEI- type are investigated. The compatibility of the photopolymer doped with the nanoparticles is studied. The surface and volume properties of the layers with different levels of doping with microporous nanocrystals are characterized. The effective refractive indices and absorption coefficients of the doped photopolymer layers are determined and used to calculate the refractive index and porosity of pure AEI nanoparticles used as dopants. Volume transmission gratings were recorded in the doped photopolymer layers at different spatial frequencies. By spatial monitoring of the characteristic Raman …


Swcnt Suppress Inflammatory Mediator Responses In Human Lung Epithelium In Vitro, Eva Herzog, Hugh Byrne, Maria Davoren, Anke-Gabriele Lenz, Albert Duschl, Gertie Janneke Oostingh Feb 2009

Swcnt Suppress Inflammatory Mediator Responses In Human Lung Epithelium In Vitro, Eva Herzog, Hugh Byrne, Maria Davoren, Anke-Gabriele Lenz, Albert Duschl, Gertie Janneke Oostingh

Articles

Single walled carbon nanotubes have gained enormous popularity due to a variety of potential applications which will ultimately lead to increased human and environmental exposure to these nanoparticles. This study was carried out in order to evaluate the inflammatory response of immortalised and primary human lung epithelial cells (A549 and NHBE) to single walled carbon nanotube samples (SWCNT). Special focus was placed on the mediating role of lung surfactant on particle toxicity. The toxicity of SWCNT dispersed in cell culture medium was compared to that of nanotubes dispersed in dipalmitoylphosphatidylcholine (DPPC, the main component of lung lining fluid). Exposure was …