A Bio-Conjugated Fullerene as a Subcellular-Targeted and Multifaceted Phototheranostic Agent

Fullerenes are candidates for theranostic applications because of their high photodynamic activity and intrinsic multimodal imaging contrast. However, fullerenes suffer from low solubility in aqueous media, poor biocompatibility, cell toxicity, and a tendency to aggregate. C₇₀@lysozyme is introduced herein as a novel bioconjugate that is harmless to a cellular environment, yet is also photoactive and has excellent optical and optoacoustic contrast for tracking cellular uptake and intracellular localization. The formation, water-solubility, photoactivity, and unperturbed structure of C₇₀@lysozyme are confirmed using UV-visible and 2D ¹H, ¹⁵N NMR spectroscopy. The excellent imaging contrast of C₇₀@lysozyme in optoacoustic and third harmonic generation microscopy is exploited to monitor its uptake in HeLa cells and lysosomal trafficking. Last, the photoactivity of C₇₀@lysozyme and its ability to initiate cell death by means of singlet oxygen (¹O₂) production upon exposure to low levels of white light irradiation is demonstrated. This study introduces C₇₀@lysozyme and other fullerene-protein conjugates as potential candidates for theranostic applications.     

An Optimized Content-Aware Authentication Scheme for Streaming JPEG-2000 Images Over Lossy Networks

This paper proposes an optimized content-aware authentication scheme for JPEG-2000 streams over lossy networks, where a received packet is consumed only when it is both decodable and authenticated. In a JPEG-2000 codestream, some packets are more important than others in terms of coding dependency and image quality. This naturally motivates allocating more redundant authentication information for the more important packets in order to maximize their probability of authentication and thereby minimize the distortion at the receiver. Towards this goal, with the awareness of its corresponding image content, we formulate an optimization framework to compute an authentication graph to maximize the expected media quality at the receiver, given specific authentication overhead and knowledge of network loss rate. System analysis and experimental results demonstrate that the proposed scheme achieves our design goal in that the rate-distortion (R-D) curve of the authenticated image is very close to the R-D curve when no authentication is required     

The TSIMMIS Approach to Mediation: Data Models and Languages

TSIMMIS—The Stanford-IBM Manager of Multiple InformationSources—is a system for integrating information. It offers a datamodel and a common query language that are designed to support thecombining of information from many different sources. It also offerstools for generating automatically the components that are needed tobuild systems for integrating information. In this paper we shalldiscuss the principal architectural features and their rationale.     

Atheromatous plaque macrophages produce plasminogen activator inhibitor type-1 and stimulate its production by endothelial cells and vascular smooth muscle cells

The capacity of macrophages to influence directly and indirectly fibrinolytic processes in atherosclerosis was studied using macrophages isolated from atherosclerotic plaques of patients undergoing surgical repair of distal aortic and femoral arteries. These cells were characterized by their morphology, adherence, esterase positivity, and expression of CD14 antigen. Production of plasminogen activator inhibitor type-1 (PAI-1) by plaque macrophages (6.7 +/- 2.7 ng/10(5) cells/24 hours [mean +/- SEM]) was significantly greater than PAI-1 production by blood monocytes isolated simultaneously from the same patients (1.8 +/- 1.5 ng/10(5) cells/24 hours). Production of tissue type plasminogen activator and urokinase type was not augmented compared to blood monocytes. Conditioned medium from cultured plaque macrophages significantly increased production of PAI-1 by endothelial cells (85 +/- 11% above basal) and vascular smooth muscle cells (25 +/- 10%) in vitro. This response was significantly greater than the response to monocyte-conditioned medium (endothelial cells 38 +/- 11%, vascular smooth muscle cells 2.5 +/- 2.0%). Stimulation of endothelial cell PAI-1 production by macrophage-conditioned medium was partially inhibitable by a monoclonal antibody to transforming growth factor-beta. Tissue type plasminogen activator production by endothelial cells and vascular smooth muscle cells was not affected by plaque macrophage- or monocyte-conditioned medium. Urokinase type plasminogen activator production by endothelial cells and vascular smooth muscle cells was undetectable in control medium and was augmented to similar levels in response to plaque macrophage- and monocyte-conditioned media. These results demonstrate upregulation of PAI-1 production by macrophages in atheromatous plaques and the capacity of soluble products from plaque macrophages to upregulate PAI-1 production by endothelial cells and vascular smooth muscle cells in vitro. These data suggest that macrophages in atherosclerotic plaques may inhibit thrombolysis both directly and indirectly by effects of their soluble products on endothelial cells and vascular smooth muscle cells.     

Synthesis, optical and morphological characterization of soluble main chain 1,3,4-oxadiazole copolyarylethers—potential candidates for solar cells applications as electron acceptors

New copoly(arylether)s containing substituted terphenyl, quinquephenyl, fluorene and anthracene moieties with aromatic 1,3,4-oxadiazole units were prepared and the resulting copolymers are soluble in common organic solvents. Investigation of their optical properties revealed that they emit blue and yellow light. Moreover, their photovoltaic response was studied in blends with poly(3-hexylthiophene) (P3HT) as the electron donor. Despite the low power conversion efficiencies it was shown that photo-induced electron transfer does take place and the performances are higher than a single layer P3HT device. In addition, an anthracene-fluorene-oxadiazole main chain copolymer (PAFOXD) was also examined in a single layer photovoltaic device and gave one of the highest reported open-circuit voltage (V_oc) values in the literature (0.89 V). Finally, a detailed morphological study of the blends and the PAFOXD surface using the atomic force microscopy (AFM) technique, revealed the effect of solvent selection to the preparation of thin films exhibiting the desired performance characteristics.     

Mechanical Properties of Reinforcing Steel and Fatigue Behavior in Corrosive Environment

Corrosion of reinforcing steel has a great impact on the mass reduction and high- and low-cycle fatigue. An experimental study showed that the mass loss, the fatigue limit and the life expectancy were reduced by approximately 1.50-3.00%, 20-40%, and 55-75%, respectively, according to the level of corrosion. Low-cycle strain controlled fatigue testing under ±1% and ±2.5% constant amplitude strain, indicated that the corroded steel bars exhibit gradual reduction in available energy, number of cycles to failure and the load-bearing ability. Formation of pits and notches took place on the corroded steel surface and stress concentration points were developed which are highly localized at imperfections and especially at the rib bases. The fatigue limit was reduced considerably since the existence of ribs and the formation of pits and notches combined with the mass loss led to reduction of the exterior hard layer of martensite and drastic drop in the energy density of the corroded specimens. Antiseismic design that does not take into account the maximum and cumulative plastic deformation demands and the strain history that a structure will suffer under severe ground motion could lead to unpredictable performance.     

Dependability and performance stochastic modelling of a two-unit repairable production system with preventive maintenance

In this paper, a two-unit multistate repairable production system is considered in which preventive maintenance (PM) is implemented in order to improve its dependability and performance. A general model is provided for the production system using a semi-Markov process, for examining system’s limiting behaviour. Apart from combining redundancy with PM, we introduce scenarios like imperfect and failed maintenance which are usually met in real life production systems. For the proposed model, we calculate the availability, the mean time to failure and the total operational cost and we formulate optimisation problems settled with respect to the system’s inspection times. The main aim of our work is to determine the optimal inspection times and consequently the optimal PM policies to be adopted in order to optimise system’s dependability and performance.     

Simulating pavement structural condition using artificial neural networks

This article aims to investigate the feasibility of incorporating of an artificial neural network (ANN) as an innovative technique for modelling the pavement structural condition, into pavement management systems. For the development of the ANN, strain assessment criteria are set in order to characterise the structural condition of flexible asphalt pavements with regards to fatigue failure. This initial task is directly followed with the development of an ANN model for the prediction of strains primarily based on in situ field gathered data and not through the usage of synthetic databases. For this purpose, falling weight deflectometer (FWD) measurements were systematically conducted on a highway network, with ground-penetrating radar providing the required pavement thickness data. The FWD data (i.e. deflections) were back-analysed in order to assess strains that would be utilised as output data in the process of developing the ANN model. A paper exercise demonstrates how the developed ANN model combined with the suggested conceptual approach for characterising pavement structural condition with regard to strain assessment could make provisions for pavement management activities, categorising network pavement sections according to the need for maintenance or rehabilitation. Preliminary results indicate that the ANN technique could help assist policy decision makers in deriving optimum strategies for the planning of pavement infrastructure maintenance.