Author Index to Volume 29

Authors Index

Author Index to Volume 29     

Influence of multisensory feedback on haptic accessibility tasks

Environments of a certain nature, such as those related to maintenance tasks can benefited from haptic stimuli by performing accessibility simulation in a realistic manner. Accessibility is defined as the physical feasibility of accessing an element of a 3D model avoiding undesirable collisions. This paper studies the benefits that multisensory systems can provide in performing this kind of tasks. The research is specially focused on the improvements provided by auditory feedback to the user’s performance. We have carried out a user study where participants had to perform an accessibility task with the aid of different combinations of sensorial stimuli. A large haptic interface for aeronautic maintainability has been extended with real-time sound generation capabilities to study this issue. The results of these experiments show that auditory stimuli provide with useful cues to the users helping them to correct trajectories and hence improving their performance.     

Avidin decorated core-shell nanoparticles for biorecognition studies by elastic light scattering

In this paper, a straightforward method based on elastic light scattering is shown to provide a sensitive and reliable tool for the quantitative determination of protein-ligand interactions that occur at the surface of suitably designed core-shell nanoparticles. The assay makes use of monodisperse nanocolloids that have minimal optical contrast with the aqueous environment. By properly coating the particles with avidin and oligo(ethylene glycol)-based amphiphiles, we developed a hybrid system that combines the availability of standard ligands with the necessary bioinvisibility towards the accidental adsorption of nonspecific macromolecules. This probe was employed to detect interactions between different kinds of biotinylated proteins, and it revealed high specificity and affinities in the low nanomolar range. In particular, we obtained an efficient avidin anchorage of biotinylated protein A on the surface of the nanoparticles, which we exploited as a functional probe for the rapid, quantitative, picomolar detection of human IgG antibodies. Overall, these light-scattering-based nanosensors appear as a simple and highly informative tool for proteomics studies.     

Peptide derivatized lamellar aggregates as target-specific MRI contrast agents

The relaxivity behaviour and the structural characterization of new supramolecular aggregates (bilayer structures and micelles) obtained by combining two different amphiphilic monomers are reported. One monomer, (C18)(2)DTPAGlu-Gd, contains a very stable gadolinium complex, and the other, DSPE-PEG(2000)-CCK8, contains the bioactive CCK8 peptide. Samples that contained only DSPE-PEG(2000)-CCK8, or up to 50 % (C18)(2)DTPAGlu-Gd, aggregated as double-layer structures (lamellar aggregates) with a thickness of approximately 80-100 A, as evaluated by SANS measurement and Cryo-TEM imaging. A transition to micelle formation was observed when the amount of (C18)(2)DTPAGlu-Gd in the aggregate was increased. These were rod-like micelles approximately 40 A in radius and >200 A in length. The proton relaxivities for both lamellar aggregates and rod-like micelles were the same (17.2 mM(-1) s(-1)), although the values were the results of different combinations of local and global contributions. The in vitro target selectivity of aggregates that contained the CCK-8 peptide was demonstrated by using nuclear medicine techniques.     

Effects of stir-fry cooking with different edible oils on the phytochemical composition of broccoli

ABSTRACT:  Numerous epidemiological studies indicate that Brassica vegetables in general and broccoli in particular protect humans against cancer; they are rich sources of glucosinolates and posses a high content on flavonoids, vitamins, and mineral nutrients. The contents of total intact glucosinolates, total phenolics, vitamin C, and minerals (potassium, sodium, calcium, magnesium, iron, manganese, zinc, and copper) in the edible portions of freshly harvested broccoli (florets), which was subjected to stir-frying treatments, were evaluated. In the present work, the stir-fry cooking experiments were carried out using different edible oils from plant origin (refined olive oil, extra virgin olive oil, sunflower oil, peanut oil, soyabean oil, and safflower oil) known and used worldwide. Results showed that during stir-frying, phenolics and vitamin C were more affected than glucosinolates and minerals. Stir-fry cooking with extra virgin olive, soybean, peanut, or safflower oil did not reduce the total glucosinolate content of the cooked broccoli compared with that of the uncooked sample. The vitamin C content of broccoli stir-fried with extra virgin olive or sunflower oil was similar to that of the uncooked sample, but greater than those samples stir-fried with other oils.     

Optimization of elastic nonlinear behavior measurements of ceramic piezoelectric resonators with burst excitation

A system of nonlinear measurement and nonlinear elastic characterization of resonators is presented, which increases the possibilities and characteristics of the other classic nonlinear characterization methods. This characterization has been necessary due to the use of resonators in power devices, where their behavior departs from the linear characteristics. The use of burst signals and a system of acquisition and data processing is proposed instead of impedance analyzers, thus avoiding the thermal effects associated with the high-signal measures, which are necessary for this characterization. The measures are repeated for different amplitudes and at the same frequency near the resonance by a single amplitude sweep, which is simpler and faster to carry out than the multiple frequency sweepings used in other methods. As a last resort, a variation on the proposed method, closer to the classical measures, is put forward, in which the resonance is ensured in all the measures. Special emphasis is placed on obtaining nonlinear characterization of the piezoceramic material in order to increase its optimization in the transducers in terms of both its use and its composition and structure.     

Mesoscopic concentration fluctuations in a fluidic nanocavity detected by redox cycling

We show that a nanofluidic device consisting of a solution-filled cavity bounded by two closely spaced parallel electrodes can amplify the electrical current from redox molecules inside the cavity by a factor of approximately 400 through redox cycling. The noise spectral density of this signal agrees quantitatively with the calculated fluctuations in the number of molecules inside the cavity due to their diffusive motion. We demonstrate sensitivity to fluctuations of as few as approximately 70 molecules.     

Preparation,Surface Characterization and Anticorrosive Behavior of Polyaniline and Poly(3,4-ethylenedioxythiophene) Deposited on Aluminum Alloy AA2024-T3

This work is focused on studying the preparation and characterization of two different conducting polymers, polyaniline and poly(3,4-ethylenedioxythiophene), on aluminum alloy AA2024-T3. In addition to the direct electrochemical deposition of the conducting polymers onto an untreated aluminum substrate, the alloy surface pre-treatments based on single chemical acid pickling or chemical acid pickling followed by application of self-assembled monolayers have been also considered before the coating application. Coatings electrochemically deposited onto both untreated and pre-treated substrates have been characterized by physicochemical and electrochemical techniques, whereas their protective performance has been evaluated by means of polarization electrochemical techniques and accelerated corrosion tests. Although conducting polymers are widely used as protective coatings for steel substrates, the results obtained in this work indicate that their protective effect is not improved when deposited onto aluminum.     

Influence of fines content on liquefaction from a critical state framework: the Christchurch earthquake case study

Bulletin of Engineering Geology and the Environment - In earthquake engineering practice, the liquefaction potential of soils is commonly evaluated through simplified procedures. These approaches...     

Role of Pharmacogenetics in Hematopoietic Stem Cell Transplantation Outcome in Children

Hematopoietic stem cell transplantation (HSCT) is an established therapeutic procedure for several congenital and acquired disorders, both malignant and nonmalignant. Despite the great improvements in HSCT clinical practices over the last few decades, complications, such as graft vs. host disease (GVHD) and sinusoidal obstructive syndrome (SOS), are still largely unpredictable and remain the major causes of morbidity and mortality. Both donor and patient genetic background might influence the success of bone marrow transplantation and could at least partially explain the inter-individual variability in HSCT outcome. This review summarizes some of the recent studies on candidate gene polymorphisms in HSCT, with particular reference to pediatric cohorts. The interest is especially focused on pharmacogenetic variants affecting myeloablative and immunosuppressive drugs, although genetic traits involved in SOS susceptibility and transplant-related mortality are also reviewed.