Showing papers by "Polytechnic University of Valencia published in 2010"
TL;DR: In conclusion, MOFs as Host Matrices or Nanometric Reaction Cavities should not be considered as a source of concern in the determination of MOFs’ properties in relation to other materials.
Abstract: 2.2. MOFs with Metal Active Sites 4614 2.2.1. Early Studies 4614 2.2.2. Hydrogenation Reactions 4618 2.2.3. Oxidation of Organic Substrates 4620 2.2.4. CO Oxidation to CO2 4626 2.2.5. Phototocatalysis by MOFs 4627 2.2.6. Carbonyl Cyanosilylation 4630 2.2.7. Hydrodesulfurization 4631 2.2.8. Other Reactions 4632 2.3. MOFs with Reactive Functional Groups 4634 2.4. MOFs as Host Matrices or Nanometric Reaction Cavities 4636
3,106 citations
TL;DR: A new model for ABA action has been proposed and validated, in which the soluble PYR/PYL/RCAR receptors function at the apex of a negative regulatory pathway to directly regulate PP2C phosphatases, which in turn directly regulate SnRK2 kinases.
Abstract: Abscisic acid (ABA) regulates numerous developmental processes and adaptive stress responses in plants. Many ABA signaling components have been identified, but their interconnections and a consensus on the structure of the ABA signaling network have eluded researchers. Recently, several advances have led to the identification of ABA receptors and their three-dimensional structures, and an understanding of how key regulatory phosphatase and kinase activities are controlled by ABA. A new model for ABA action has been proposed and validated, in which the soluble PYR/PYL/RCAR receptors function at the apex of a negative regulatory pathway to directly regulate PP2C phosphatases, which in turn directly regulate SnRK2 kinases. This model unifies many previously defined signaling components and highlights the importance of future work focused on defining the direct targets of SnRK2s and PP2Cs, dissecting the mechanisms of hormone interactions (i.e., cross talk) and defining connections between this new negative regulatory pathway and other factors implicated in ABA signaling.
2,359 citations
TL;DR: This paper explored the influence of different mechanisms in lowering barriers related to the orientation of universities and to the transactions involved in working with university partners, and explored the effects of collaboration experience, breadth of interaction, and inter-organizational trust on lowering different types of barriers.
901 citations
TL;DR: In this article, the authors proposed a new method where information regarding the local image noise level is used to adjust the amount of denoising strength of the filter, which is automatically obtained from the images using a new local noise estimation method.
Abstract: PURPOSE: To adapt the so-called nonlocal means filter to deal with magnetic resonance (MR) images with spatially varying noise levels (for both Gaussian and Rician distributed noise). MATERIALS AND METHODS: Most filtering techniques assume an equal noise distribution across the image. When this assumption is not met, the resulting filtering becomes suboptimal. This is the case of MR images with spatially varying noise levels, such as those obtained by parallel imaging (sensitivity-encoded), intensity inhomogeneity-corrected images, or surface coil-based acquisitions. We propose a new method where information regarding the local image noise level is used to adjust the amount of denoising strength of the filter. Such information is automatically obtained from the images using a new local noise estimation method. RESULTS: The proposed method was validated and compared with the standard nonlocal means filter on simulated and real MRI data showing an improved performance in all cases. CONCLUSION: The new noise-adaptive method was demonstrated to outperform the standard filter when spatially varying noise is present in the images.
871 citations
TL;DR: Laser-flash photolysis has allowed detecting the photochemical generation of a long lived charge separated state whose decay is not complete 300 μs after the laser flash, and the influence of the amino group producing a bathochromic shift in the optical spectrum without altering the photochemistry shows promises for the development of more efficient MOFs for water splitting.
Abstract: The Zr-containing metal-organic frameworks (MOFs) formed by terephthalate (UiO-66) and 2-aminoterephthalate ligands [UiO-66(NH(2))] are two notably water-resistant MOFs that exhibit photocatalytic activity for hydrogen generation in methanol or water/methanol upon irradiation at wavelength longer than 300 nm. The apparent quantum yield for H(2) generation using monochromatic light at 370 nm in water/methanol 3:1 was of 3.5% for UiO-66(NH(2)). Laser-flash photolysis has allowed detecting for UiO-66 and UiO-66(NH(2)) the photochemical generation of a long lived charge separated state whose decay is not complete 300 μs after the laser flash. Our finding and particularly the influence of the amino group producing a bathochromic shift in the optical spectrum without altering the photochemistry shows promises for the development of more efficient MOFs for water splitting.
675 citations
TL;DR: A literature review on exact, heuristic and metaheuristic methods that have been proposed for the solution of the hybrid flow shop problem is presented.
647 citations
TL;DR: In this paper, a review of the use of layered and porous aluminosilicates and layered double hydroxides as catalysts for the Fenton reaction is presented, and the results reported up to late 2009 are presented.
Abstract: This review focuses on the use of layered and porous aluminosilicates and layered double hydroxides as catalysts for the Fenton reaction. In the general sections of this review we present the elementary equations leading to the generation of hydroxyl radicals from H2O2 and the subsequent reactivity of this highly aggressive species. After justifying the advantages of using insoluble solids as heterogeneous catalysts, replacing soluble iron salts, we discuss the desirable features that should have an ideal Fenton catalyst and which are the parameters to be considered when ranking the efficiency of the materials. The main part of this review is focused on presenting the results reported up to late 2009 obtained using layered and porous aluminosilicates as heterogeneous catalysts. The structure of these materials is briefly presented to highlight the benefits and advantages of each type of solid with respect to their use as catalysts. When presenting the catalytic data, special emphasis is made on the missing data that would be useful to clarify, the relative efficiency and performance of the materials. In the final concluding remarks we stress again that the present situation needs to be clarified to draw solid conclusions on the relative performance and efficiency of the tested catalysts.
572 citations
TL;DR: Analysis of the molecular mechanisms underlying AP1 function indicates that it functions first to repress vegetative identity, then to help establish floral primordia, and finally to shape the differentiation of floral parts, implying that AP1 orchestrates floral initiation by integrating growth, patterning, and hormonal pathways.
Abstract: The MADS-domain transcription factor APETALA1 (AP1) is a key regulator of Arabidopsis flower development. To understand the molecular mechanisms underlying AP1 function, we identified its target genes during floral initiation using a combination of gene expression profiling and genome-wide binding studies. Many of its targets encode transcriptional regulators, including known floral repressors. The latter genes are down-regulated by AP1, suggesting that it initiates floral development by abrogating the inhibitory effects of these genes. Although AP1 acts predominantly as a transcriptional repressor during the earliest stages of flower development, at more advanced stages it also activates regulatory genes required for floral organ formation, indicating a dynamic mode of action. Our results further imply that AP1 orchestrates floral initiation by integrating growth, patterning, and hormonal pathways.
470 citations
TL;DR: The harmonization of rabbit carcass criteria is a result of an international work as mentioned in this paper, which specifies the main traits to be consider from the birth of the animal to carcass analysis, to define these traits with enough accuracy and to propose a common terminology.
Abstract: The harmonization of rabbit carcass criteria is a result of an international work. lts task was to specify the main traits to be considerad from the birth of the animal to carcass analysis, to define these traits with enough accuracy and to propose a common terminology. Work on harmonization has been initialized by the Mediterranean Rabbit Group Conference (BLASCO, OUHAYOUN and MASOERO, 1992), completad by several research teams and, finally, discussed during a round table of the Vth World Rabbit Congress (Corvallis, 1992). The proposal described in this work concerns: 1- growth, consumption and breeding measurments, preslaughter handling and slaughter processing, 2- dressing percentage analysis, 3- measurments or prediction of commercial and reference carcass composition. The work represents an official document of the World Rabbit Science Association. A commission has been created to examine the efficiency of the proposed criteria and to modify them according to what the scientific development and the practica! experience or thei use would recommend.
442 citations
TL;DR: In this article, the authors present the current evidence in support of considering some MOFs as semiconductors, including the synthesis of semiconducting MOFs by design and development of applications.
Abstract: The aim of the present feature article is to present the current evidence in support of considering some MOFs as semiconductors. While MOFs and zeolites share common structural properties derived from the microporous crystal structure, zeolites are insulating materials and most of the attempts to exploit them in optoelectronics have met with failure. In contrast, some MOFs may have interesting photochemical properties that derive from the fundamental event of charge separation in electrons and holes upon light absorption. Photoinduced charge separation is the hallmark of a semiconductor that can behave simultaneously as an oxidizing or reducing agent. Considering the novelty of this field, most of the available data about MOFs as semiconductor have been obtained from MOF-5, a case that is complicated due to its low structural stability. Therefore, we point out that further studies showing the semiconducting properties of other MOFs are still welcome. The purpose of this feature article is to trigger intense research in this area including the synthesis of semiconducting MOFs by design and development of applications.
429 citations
TL;DR: An attempt has been made to rationalize the synthesis of extra-large-pore zeolites in terms of the synthesis mechanism, the directing effect of the organic structure directing agent (OSDA), the framework atoms, and the gel concentration.
Abstract: The conditions required to produce zeolites with low framework density and extra-large pores are discussed. Correlations between framework stability and geometrical and topological descriptors are presented. An attempt has been made to rationalize the synthesis of extra-large-pore zeolites in terms of the synthesis mechanism, the directing effect of the organic structure directing agent (OSDA), the framework atoms, and the gel concentration. Extra-large-pore zeolites, including the recently discovered chiral mesoporous ITQ-37, are described and their catalytic and adsorption properties discussed. Finally, strategies are presented for the preparation of extra-large-pore zeolites with different pore topologies that can fulfill pre-established catalytic and adsorption targets.
TL;DR: The pros and cons of molecular techniques for the detection and quantification of pathogens in water are discussed and further refinement is required in order to be standardized and applicable to a diversity of matrices.
TL;DR: A taxonomy framework based on supply chain structure, decision level, modeling approach, purpose, shared information, limitations, novelty and application is proposed to provide readers with a starting point for mathematical modeling problems in supply chain production and transport planning.
TL;DR: In this paper, the authors showed that balanced bifunctional acid-base catalysts where the Lewis acid activates the carbonyl of the urea and the conjugated basic site activates the hydroxyl group of the glycerol were the most active and selective catalysts.
TL;DR: This paper describes and compares a series of predictive models for forecasting water demand obtained using time series data from water consumption in an urban area of a city in south-eastern Spain, and proposes a simple model based on the weighted demand profile resulting from the exploratory analysis of the data.
TL;DR: In this article, the authors present some recent advances for the maintenance of fresh-cut fruit quality with respect to the use of chemical compounds, including plant natural antimicrobials and antioxidants, as well as calcium salts for maintaining texture.
TL;DR: In this article, the authors present the use of terrestrial laser scanning (TLS) in order to effectively produce, prior to intervention, accurate and high-resolution 3D models of a cave with engravings dating back to the Upper Palaeolithic era.
Proceedings Article•
23 Aug 2010TL;DR: Empirical evidence is given that the construction of tailored training corpora for plagiarism detection can be automated, and hence be done on a large scale.
Abstract: We present an evaluation framework for plagiarism detection. The framework provides performance measures that address the specifics of plagiarism detection, and the PAN-PC-10 corpus, which contains 64 558 artificial and 4 000 simulated plagiarism cases, the latter generated via Amazon's Mechanical Turk. We discuss the construction principles behind the measures and the corpus, and we compare the quality of our corpus to existing corpora. Our analysis gives empirical evidence that the construction of tailored training corpora for plagiarism detection can be automated, and hence be done on a large scale.
TL;DR: An augmented book called AR-Dehaes has been designed to provide 3D virtual models that help students to perform visualization tasks to promote the development of their spatial ability during a short remedial course.
TL;DR: The lowest limits of detection were achieved using microbiological inhibition tests and immunoassays with time-resolved fluorometry detection, so antibiotic residues at levels lower than the maximum residue limits established by legislation were detected.
Abstract: Antibiotic residues in edible animal products are of great concern to regulatory agencies and consumers, so reliable screening methods for rapid, selective and sensitive detection of these residues are necessary to ensure food safety. In recent years, great efforts have been made to simplify the treatment of solid food samples and also to introduce high-throughput methods, so different screening methods have been developed. This review presents a general overview on the progress of the three most important screening approaches to detect antibiotic residues in food samples (i.e. immunoassays, microbiological tests and biosensors). Their main advantages are short analysis time, high sensitivity and selectivity for immunoassays, simplicity and low cost for microbiological tests, and automation and the possibility of in situ analysis for biosensors. Moreover, it is important to note a great increase in the number of commercial kits. Regarding the detection mode employed, the lowest limits of detection were achieved using microbiological inhibition tests and immunoassays with time-resolved fluorometry detection, so antibiotic residues at levels lower than the maximum residue limits established by legislation were detected.
TL;DR: Improved knowledge on particle morphology, primarily size, composition, levels, and the factors influencing these can be useful to identify and quantify sources of PM more accurately, to evaluate their effects, and to propose adequate abatement strategies in livestock houses.
TL;DR: In this paper, the effect of the incorporation of bergamot essential oil (BO) into the chitosan matrix, water vapour permeability (WVP), mechanical and optical properties of the dry films were evaluated and the antifungal effectiveness of CH-BO composite films against Penicillium italicum was studied.
TL;DR: In this paper, the mesoporous silica nanoparticles S1, S2, and S3 containing the grafted starch derivatives Glucidex 47, Gludicex 39, and Glucides 29 were synthesized.
Abstract: The synthesis of new capped silica mesoporous nanoparticles for on-command delivery applications is described. The gate-like functional hybrid systems consisted of nanoscopic MCM-41-based materials functionalized on the pore outlets with different “saccharide” derivatives and a dye contained in the mesopores. A series of hydrolyzed starch products as saccharides were selected. The mesoporous silica nanoparticles S1, S2, and S3 containing the grafted starch derivatives Glucidex 47, Gludicex 39, and Glucidex 29 were synthesized. Additionally, for comparative purposes solid S4 containing lactose was prepared. Delivery studies in pure water in the presence of pancreatin or β-d-galactosidase were carried out for S1−S3 and S4, respectively. S1, S2, and especially S3 showed very low release in the absence of enzyme, but displayed cargo delivery in the presence of the corresponding enzyme. Moreover, nanoparticles of S1 were used to study the controlled release of the dye in intracellular media. Cell viability ass...
12 Aug 2010
TL;DR: This paper details a framework that enables remote GPU acceleration in HPC clusters, thus allowing a reduction in the number of accelerators installed in the cluster, which leads to energy, acquisition, maintenance, and space savings.
Abstract: The increasing computing requirements for GPUs (Graphics Processing Units) have favoured the design and marketing of commodity devices that nowadays can also be used to accelerate general purpose computing. Therefore, future high performance clusters intended for HPC (High Performance Computing) will likely include such devices. However, high-end GPU-based accelerators used in HPC feature a considerable energy consumption, so that attaching a GPU to every node of a cluster has a strong impact on its overall power consumption. In this paper we detail a framework that enables remote GPU acceleration in HPC clusters, thus allowing a reduction in the number of accelerators installed in the cluster. This leads to energy, acquisition, maintenance, and space savings.
TL;DR: The design, fabrication, and characterisation of an array of optical slot-waveguide ring resonator sensors, integrated with microfluidic sample handling in a compact cartridge, for multiplexed real-time label-free biosensing is presented.
Abstract: We present the design, fabrication, and characterisation of an array of optical slot-waveguide ring resonator sensors, integrated with microfluidic sample handling in a compact cartridge, for multiplexed real-time label-free biosensing. Multiplexing not only enables high throughput, but also provides reference channels for drift compensation and control experiments. Our use of alignment tolerant surface gratings to couple light into the optical chip enables quick replacement of cartridges in the read-out instrument. Furthermore, our novel use of a dual surface-energy adhesive film to bond a hard plastic shell directly to the PDMS microfluidic network allows for fast and leak-tight assembly of compact cartridges with tightly spaced fluidic interconnects. The high sensitivity of the slot-waveguide resonators, combined with on-chip referencing and physical modelling, yields a volume refractive index detection limit of 5 × 10−6 refractive index units (RIUs) and a surface mass density detection limit of 0.9 pg mm−2, to our knowledge the best reported values for integrated planar ring resonators.
TL;DR: The components of an e-tongue (automatic sampler, array of chemical sensors, and data processing system) and their most important applications in food analysis in this new century are described.
TL;DR: The results showed that the serious virtual world does not present statistically significant differences with the traditional type of class, however, students from the virtual group reported enjoying the class more, being more engaged, and having greater intentions to participate thanStudents from the traditional group.
Abstract: The objective of this study is to present and to evaluate the E-Junior application: a serious virtual world (SVW) for teaching children natural science and ecology. E-Junior was designed according to pedagogical theories and curricular objectives to help children learn about the Mediterranean Sea and its environmental issues while playing. In this study, we present data about the E-Junior evaluation. A class in a serious virtual world (virtual group) was compared with a traditional type of class (traditional group) that contained identical learning objectives and contents but lacked a gaming aspect. Data collection consisted of quantitative and qualitative measures on a sample of 48 children. With regards to learning effectiveness, the results showed that the serious virtual world does not present statistically significant differences with the traditional type of class. However, students from the virtual group reported enjoying the class more, being more engaged, and having greater intentions to participate than students from the traditional group. The plausible explanation for this can be found in the qualitative data. The implications of these results and improvement proposals are also discussed in this work.
TL;DR: This work describes for the first time the integration of layer-by-layer polyelectrolyte assemblies into single conical nanopores in order to study and explore the functional features arising from the creation of charged supramolecular assemblies within the constrained geometry of the nanofluidic device.
Abstract: Molecular design of ionic current rectifiers created on the basis of single conical nanopores is receiving increasing attention by the scientific community. Part of the appeal of this topic relies on the interest in sensors and fluidic nanoactuators based on the transport of ions and molecules through nanopore architectures that can readily be integrated into functional systems. The chemical modification of the pore walls controls not only the diameter of these nanoarchitectures but also their selectivity and transport properties. In order to confer selectivity to solid-state nanopores, it is necessary to develop and explore new methods for functionalizing the pore walls. Hence, the creation of functional nanopores capable of acting as selective ion channels or smart nanofluidic sensors depends critically on our ability to assemble and build up molecular architectures in a predictable manner within confined geometries with dimensions comparable to the size of the building blocks themselves. In this context, layer-by-layer deposition of polyelectrolytes offers a straightforward process for creating nanoscopic supramolecular assemblies displaying a wide variety of functional features. In this work, we describe for the first time the integration of layer-by-layer polyelectrolyte assemblies into single conical nanopores in order to study and explore the functional features arising from the creation of charged supramolecular assemblies within the constrained geometry of the nanofluidic device. To address this challenging topic, we used a combined experimental and theoretical approach to elucidate and quantify the electrostatic changes taking place inside the nanopore during the supramolecular assembly process. The multilayered films were built up through consecutive layer-by-layer adsorption of poly(allylamine hydrochloride) (PAH) and poly(styrenesulfonate) (PSS) on the pore surface. Our results show that the charge transport properties of single conical nanopores functionalized with PAH/PSS assemblies are highly dependent on the number of layers assembled on the pore wall. In contrast to what happens with PAH/PSS films deposited on planar surfaces (quantitative charge reversal), the surface charge of the pore walls decreases dramatically with the number of PAH/PSS layers assembled into the nanopore. This behavior was attributed to the nanoconfinement-induced structural reorganization of the polyelectrolyte layers, leading to the efficient formation of ion pairs and promoting a marked decrease in the net fixed charges on the nanopore walls. We consider that these results are of paramount relevance for the modification of nanopores, nanopipets, and nanoelectrodes using charged supramolecular assemblies, as well as of importance in "soft nanotechnology" provided that structural complexity, induced by nanoconfinement, can define the functional properties of self-assembled polymeric nanostructures.
TL;DR: A new upsampling method is proposed to recover some of this high frequency information by using a data-adaptive patch-based reconstruction in combination with a subsampling coherence constraint to outperform classical interpolation methods in terms of quantitative measures and visual observation.
TL;DR: In this article, the antimicrobial effectiveness of chitosan composite films against Listeria monocytogenes and Penicillium italicum was studied. And the properties of the films were related with their microstructure, which was observed by SEM.