Tailored hollow mesoporous silica nanoplatforms with biological labels for colon targeted drug deliver systems

Hollow mesoporous silica nanoparticles (HMSNs) were synthesized via a new strategy. HMSNs have a high drug loading, controlled release behaviour, and specifically targeting when bioconjugated with Epidermal Growth Factor. The promising in vitro cell tests have revealed the great potential of the HMSNs to be used for cancer therapy.

Incorporating carbon footprints into seafood sustainability certification and eco-labels

The seafood industry has become increasingly interconnected at a global scale, with fish the most traded commodity worldwide. Travel to the farthest reaches of the oceans for capture is now common practice, and subsequent transport to market can require hundreds to thousands of miles of travel by sea and air. Refrigeration of seafood products is generally required at all stages of the journey from ocean to dinner plate, resulting in substantial energy expenditure. Energy input for aquaculture (including mariculture) products can also be high, namely due to the large amounts of feed required to support fish growth. As a result of these factors, the seafood industry has a substantial carbon footprint. Surprisingly, however, carbon footprints of seafood products are rarely integrated into assessments of their sustainability by eco-labels, sustainability certification, or consumer seafood sustainability guides. Suggestions are provided here for how carbon footprints could be incorporated within seafood sustainability schemes.

Structural and thermal characterization of dioctadecyldimethylammonium bromide dispersions by spin labels

Dioctadecyldimethylammonium bromide (DODAB) dispersions obtained by simply mixing the amphiphile in water, and by bath-sonication, were investigated by electron spin resonance (ESR) of stearic acids and their methyl ester derivatives, labeled at the 5th and 16th carbons of the acyl chain. The ESR spectra indicate that the non-sonicated dispersions are formed mainly by one population of DODAB vesicles, either in the gel (T < T-m) or in the liquid-crystalline (T > T-m) state. Around T-m there is a co-existence of the two phases, with a thermal hysteresis of about 3.2 degreesC. In sonicated DODAB dispersions, spin labels indicate two different environments even for temperatures far below T-m: one similar to that obtained with non-sonicated samples, a gel phase, and another one in the liquid-crystalline state. The fluid phase domain present below T-m could correspond to either the periphery of bilayer fragments, reported to be present in sonicated DODAB dispersions, or to high curvature vesicles. (C) 2001 Elsevier B.V. Ireland Ltd. All rights reserved.

Selecting candidate labels for hierarchical document clusters using association rules

One way to organize knowledge and make its search and retrieval easier is to create a structural representation divided by hierarchically related topics. Once this structure is built, it is necessary to find labels for each of the obtained clusters. In many cases the labels have to be built using only the terms in the documents of the collection. This paper presents the SeCLAR (Selecting Candidate Labels using Association Rules) method, which explores the use of association rules for the selection of good candidates for labels of hierarchical document clusters. The candidates are processed by a classical method to generate the labels. The idea of the proposed method is to process each parent-child relationship of the nodes as an antecedent-consequent relationship of association rules. The experimental results show that the proposed method can improve the precision and recall of labels obtained by classical methods. © 2010 Springer-Verlag.

Improving hierarchical document cluster labels through candidate term selection

One way to organize knowledge and make its search and retrieval easier is to create a structural representation divided by hierarchically related topics. Once this structure is built, it is necessary to find labels for each of the obtained clusters. In many cases the labels must be built using all the terms in the documents of the collection. This paper presents the SeCLAR method, which explores the use of association rules in the selection of good candidates for labels of hierarchical document clusters. The purpose of this method is to select a subset of terms by exploring the relationship among the terms of each document. Thus, these candidates can be processed by a classical method to generate the labels. An experimental study demonstrates the potential of the proposed approach to improve the precision and recall of labels obtained by classical methods only considering the terms which are potentially more discriminative. © 2012 - IOS Press and the authors. All rights reserved.

Design and Characterization of New Luminescent Sensors and Labels

The aim of this Ph.D. project has been the design and characterization of new and more efficient luminescent tools, in particular sensors and labels, for analytical chemistry, medical diagnostics and imaging. Actually both the increasing temporal and spatial resolutions that are demanded by those branches, coupled to a sensitivity that is required to reach the single molecule resolution, can be provided by the wide range of techniques based on luminescence spectroscopy. As far as the development of new chemical sensors is concerned, as chemists we were interested in the preparation of new, efficient, sensing materials. In this context, we kept developing new molecular chemosensors, by exploiting the supramolecular approach, for different classes of analytes. In particular we studied a family of luminescent tetrapodal-hosts based on aminopyridinium units with pyrenyl groups for the detection of anions. These systems exhibited noticeable changes in the photophysical properties, depending on the nature of the anion; in particular, addition of chloride resulted in a conformational change, giving an initial increase in excimeric emission. A good selectivity for dicarboxylic acid was also found. In the search for higher sensitivities, we moved our attention also to systems able to perform amplification effects. In this context we described the metal ion binding properties of three photoactive poly-(arylene ethynylene) co-polymers with different complexing units and we highlighted, for one of them, a ten-fold amplification of the response in case of addition of Zn2+, Cu2+ and Hg2+ ions. In addition, we were able to demonstrate the formation of complexes with Yb3+ an Er3+ and an efficient sensitization of their typical metal centered NIR emission upon excitation of the polymer structure, this feature being of particular interest for their possible applications in optical imaging and in optical amplification for telecommunication purposes. An amplification effect was also observed during this research in silica nanoparticles derivatized with a suitable zinc probe. In this case we were able to prove, for the first time, that nanoparticles can work as “off-on” chemosensors with signal amplification. Fluorescent silica nanoparticles can be thus seen as innovative multicomponent systems in which the organization of photophysically active units gives rise to fruitful collective effects. These precious effects can be exploited for biological imaging, medical diagnostic and therapeutics, as evidenced also by some results reported in this thesis. In particular, the observed amplification effect has been obtained thanks to a suitable organization of molecular probe units onto the surface of the nanoparticles. In the effort of reaching a deeper inside in the mechanisms which lead to the final amplification effects, we also attempted to find a correlation between the synthetic route and the final organization of the active molecules in the silica network, and thus with those mutual interactions between one another which result in the emerging, collective behavior, responsible for the desired signal amplification. In this context, we firstly investigated the process of formation of silica nanoparticles doped with pyrene derivative and we showed that the dyes are not uniformly dispersed inside the silica matrix; thus, core-shell structures can be formed spontaneously in a one step synthesis. Moreover, as far as the design of new labels is concerned, we reported a new synthetic approach to obtain a class of robust, biocompatible silica core-shell nanoparticles able to show a long-term stability. Taking advantage of this new approach we also showed the synthesis and photophysical properties of core-shell NIR absorbing and emitting materials that proved to be very valuable for in-vivo imaging. In general, the dye doped silica nanoparticles prepared in the framework of this project can conjugate unique properties, such as a very high brightness, due to the possibility to include many fluorophores per nanoparticle, high stability, because of the shielding effect of the silica matrix, and, to date, no toxicity, with a simple and low-cost preparation. All these features make these nanostructures suitable to reach the low detection limits that are nowadays required for effective clinical and environmental applications, fulfilling in this way the initial expectations of this research project.

The Law and Economics of Eco-labels

Eco-labels and certification are one of the many environmental policy tools that have been under scrutiny in recent years. This is because the damages of environmental degradation are becoming more apparent over time. Hence there is a pressure to come up with tools that help solve even small parts of the problem. Eco-labels have been around for over 30 years. However the market, the environment and eco-labels have changed drastically during this period. Moreover, in the last 5 years there has been a sudden increase in eco-labels making them more visible in the market and to the average consumer. All this has made evident that little is known about the effectiveness of eco-labels as environmental policy tools. Hence, there is a call to find answers regarding the actual effects of eco-labels on the market and on the environment. While this work cannot address whether eco-labels have an environmental impact it addresses the effects of eco-labels on the markets. Moreover, this work aimed to find the role of law in eco-labelling. In addition, it aims to find a legal solution that would improve the performance of eco-labelling and certification.

How Do Relationship Labels Affect Partner Treatment And Relationship Status Perceptions?

The present research examined which terms are most used by college students to define relationships, and how these various terms prime or affect partner treatment and relationship status perceptions. Once primed with the labels ¿hooking-up,¿ ¿exclusive¿ or ¿boyfriend/girlfriend,¿ it was hypothesized that public displays of affection, commitment, jealousy and sociosexuality would influence partner treatment. The results indicate that being primed with various relationship labels does influence public displays of affection. This priming does not influence jealousy, and it influences commitment on some occasions. The data collected can further our understanding of relationship dynamics among college students by differentiating between various terms.

Assessing Commonality and Differentiation for Packaging-Family Planning with Application to Medication Labels

This thesis presents a metric for assessing the commonality and differentiation of packaging-family planning with application to medical labels along with supporting background research and findings. Consumable products such as medications rely on the package or label to represent the contents. Package confusion has been widely recognized as a major problem for both over-the-counter and pharmacy-dispensed medications with potentially lethal consequences. It is critical to identify a medication as a member of a product family and differentiate its contributing elements based on visual features on the package or label to avoid consumer confusion and reduce dispensing errors. Indices that indicate degrees of commonality and differentiation of features in consumer products such as batteries, light bulbs, handles, etc for platforms have been shown to benefit development of engineered product families [6]. It is possible to take a similar approach for visual features in packaging such as typography, shape/form, imagery and color to benefit packaging-family development. This thesis establishes a commonality differentiation index for prominence of visual features on over-the-counter and pharmacy-dispensed medications based on occurrence, size, and location of features. It provides a quantitative measure to assist package designers in evaluating alternatives to satisfy strategic goals and improve safety. The index is demonstrated with several medications that have been identified by the Institute for Safe Medication Practice as commonly confused.

Simultaneous two-photon excitation of distinct labels for dual-color fluorescence crosscorrelation analysis

Confocal fluorescence correlation spectroscopy as a time-averaging fluctuation analysis combining maximum sensitivity with high statistical confidence has proved to be a very versatile and powerful tool for detection and temporal investigation of biomolecules at ultralow concentrations on surfaces, in solutions, and in living cells. To probe the interaction of different molecular species for a detailed understanding of biologically relevant mechanisms, crosscorrelation studies on dual or multiple fluorophore assays with spectrally distinct excitation and emission are particularly promising. Despite the considerable improvement of detection specificity provided by fluorescence crosscorrelation analysis, few applications have so far been reported, presumably because of the practical challenges of properly aligning and controlling the stability of the experimental setup. In this work, we demonstrate that two-photon excitation combined with dual-color fluorescence correlation spectroscopy can be the key to simplifying simultaneous investigations of multiple fluorescent species significantly on a single-molecule scale. Two-photon excitation allows accession of common fluorophores of largely distinct emission by the same excitation wavelength, because differences in selection rules and vibronic coupling can induce considerable shifts between the one-photon and two-photon excitation spectra. The concept of dual-color two-photon fluorescence crosscorrelation analysis is introduced and experimentally demonstrated with an established assay probing the selective cleavage of dual-labeled DNA substrates by restriction endonuclease EcoRI.

Determination of the distance between two spin labels attached to a macromolecule.

An EPR "spectroscopic ruler" was developed using a series of alpha-helical polypeptides, each modified with two nitroxide spin labels. The EPR line broadening due to electron-electron dipolar interactions in the frozen state was determined using the Fourier deconvolution method. These dipolar spectra were then used to estimate the distances between the two nitroxides separated by 8-25 A. Results agreed well with a simple alpha-helical model. The standard deviation from the model system was 0.9 A in the range of 8-25 A. This technique is applicable to complex systems such as membrane receptors and channels, which are difficult to access with high-resolution NMR or x-ray crystallography, and is expected to be particularly useful for systems for which optical methods are hampered by the presence of light-interfering membranes or chromophores.

Labels : suggestions for the shipper who is seeking to give his pack a worthy and effective mark of identification.

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