Analysis of infected human mononuclear cells by atomic force microscopy

The surfaces of the human lymphoid cells of the line H9 chronically infected with the Human Immunodeficiency Virus HIV-1, and of human monocytes acutely infected in vitro with Mycobacterium Tuberculosis (MTB) were dried, fixed and imaged with atomic force microscopy (AFM). These images were compared with those of non-infected samples. Dried and fixed samples of infected cells can be distinguished from non-infected ones by AFM technology due to their different surface structures and by the presence of pathogenic (viz al or mycobacterial) agents on the cell surface

Atomic Force Microscopy of Neuron Networks

We imaged uncoated neuron networks by an atomic force microscope in the repulsive regime of contact mode. Images of granule cells and their axons have been clearly revealed with details smaller than 20 nm. The good stability of the sample and the mechanical reproducibility of the microscope allowed the imaging of a neuron culture area of several square microns. By combining tens of images, we were able to reconstruct a highly defined neuronal network. Furthermore, the images were very reproducible over repeated scanning acquisition, demonstrating the mechanical and thermal stability of the instrument-sample system

Stability Enhancement in OPV: In-Situ Studies of Plasmonic Devices

Extended Abstract Bulk heterojunction (BHJ) organic photovoltaic (OPV) devices attracted considerable research interest due to several significant characteristics, such as their flexibility, lightweight, low environmental impact and reduced cost of large-scale production. A key aspect in OPVs is improving the device long-term stability: in this contest, novel organic materials and cell architectures are developed and a significant task is played by the development of in-situ diagnostics able to detect the driving mechanisms of device degradation, considering that the optical and transport properties of the device active elements depend on the structural, morphological and interfacial characteristics. In this work we discuss our recent results on devices incorporating metallic nanoparticles (NPs) in the photoactive layer, in order to take advantage of the ability of the metallic NPs to rise the BHJ optical absorption by the excitation of Localized Surface Plasmon Resonance. Both plasmonic and reference systems are studied and a powerful approach for addressing the role of structural/morphological and interface properties of the different layers and their interfaces is used: time-resolved Energy Dispersive X-ray Reflectivity/Diffraction (EDXR/EDXD) techniques are applied jointly with in-situ atomic force microscopy (AFM). The results of such unconventional approach, based on time-resolved EDXR/AFM cross-monitoring, showed that incorporating metallic NPs allowed to control both the bulk and the interface morphological degradation pathways References [1] B. Paci, A. Generosi, V. Rossi Albertini, G.Spyropoulos, E. Stratakis, E. Kymakis, "Enhancement of photo/thermal stability of organic bulk heterojunction photovoltaic devices via gold nanoparticles doping of the active layer,&quot

Collaborative digital and wide format printing : methods and considerations for the artist and master printer

This thesis investigates the collaborative production of fine art digital prints for artists,a process which is used by many contemporary practitioners including Richard Hamilton and Damien Hirst. Digital print as a fine art process has emerged over the last twenty years, and as yet, there is no in depth evidence on the collaborative endeavour and production process which is central to the digital Master Printer’s role. The investigation first establishes the historical context and significance of the Master and Printer in traditional printmaking, and the more recent development of the digital print studio and the digital print pioneers of the 1990s. A series of seven artists’ case studies in the context of the collaborative digital print studio are then offered to demonstrate the working process. The analysis of these proposes a best practice model for Master Printers working with contemporary artists to produce high quality, fine art, wide format inkjet digital prints. The study also compares production methods at the cutting-edge digital facility of the Rijksakademie in The Netherlands, to assess the validity of the practices proposed through a facility closest to the study’s research base at the CFPR’s digital studio. The comparative study also explored the expanding digital production process and the role of the Master Printer. Evolving production processes are also considered in this study as a response to the advancement of digital print technology alongside a practical exploration of what actually constitutes a digital print in this rapidly expanding field of fine art printmaking. This study aims to reveal the inner workings of the digital collaborative process between the artist and Master Printer, and appraise the digital Master Printer’s role. It offers a set of best practice methods for the digital Master Printer developed from this research. The study also considers how the digital print, and the digital print studio may evolve in line with current and future developments in new technologies.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

New Materials and Technologies for Durability and Conservation of Building Heritage

The increase in concrete structures’ durability is a milestone to improve the sustainability of buildings and infrastructures. In order to ensure a prolonged service life, it is necessary to detect the deterioration of materials by means of monitoring systems aimed at evaluating not only the penetration of aggressive substances into concrete but also the corrosion of carbon-steel reinforcement. Therefore, proper data collection makes it possible to plan suitable restoration works which can be carried out with traditional or innovative techniques and materials. This work focuses on building heritage and it highlights the most recent findings for the conservation and restoration of reinforced concrete structures and masonry buildings

Spectroscopic infrared scanning near-field optical microscopy (IR-SNOM)

Scanning near-field optical microscopy (SNOM or NSOM) is the technique with the highest lateral optical resolution available today, while infrared (IR) spectroscopy has a high chemical specificity. Combining SNOM with a tunable IR source produces a unique tool, IR-SNOM, capable of imaging distributions of chemical species with a 100 nm spatial resolution. We present in this paper boron nitride (BN) thin film images, where IR-SNOM shows the distribution of hexagonal and cubic phases within the sample. Exciting potential applications in biophysics and medical sciences are illustrated with SNOM images of the distribution of different chemical species within cells. We present in this article images with resolutions of the order of λ/60 with SNOM working with infrared light. With our SNOM setup, we routinely get optical resolutions between 50 and 150 nm, regardless of the wavelength of the light used to illuminate the sample

Infrared near-field microscopy with the Vanderbilt free electron laser: overview and perspectives

Scanning near-field optical microscopy (SNOM) makes it routinely possible to overcome the fundamental diffraction limit of standard (far-field) microscopy. Recently, aperture-based infrared SNOM performed in the spectroscopic mode,using the Vanderbilt University free electron laser,started delivering spatially-resolved information on the distribution of chemical species and on other laterally-fluctuating properties.The practical examples presented here show the great potential of this new technique both in materials science and in life sciences