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Experimental animation is developping in festivals, demonstrations and exhibitions and it is closely joined to the graphic, pictorical, musical and photographical productions. Definitively it is used as artistic expression medium. Therefore we should see animation as a new support of broadcasting the work, according to the new ways of seeing and understanding the world and the needs of the society. Analyzing this new support we discover that the techniques employed are so different and diverse like the artists self that use them, finding between them techniques like painting or engraving, both possessors of a wide range of procedures and outcomes.Focussing our attention on engraving, we discover that, for a group of experimental animators, this is the base for their produccions. Some of them influenced by the pioneers Len Lye en Norman McLaren, use the technique in its purest essence, some others use their aesthetics and characteristics as a starting point in order to develop their productions along with other techniques.Engraving offers the possibility of working with different techniques attending to his mould and printing, considering the technical procedures, the printing methodes and the manipulation and intervention of the printings as a wide range of new possibilities.

Porphyrazines have recently emerged as a useful class of tetrapyrroles suitable for photodynamic therapy of cancer (PDT) with excellent uptake and retention properties in vivo. Here we demonstrate that the photophysical properties of cyano-aryl porphyrazine pz1 are strongly viscosity dependent, i.e. the fluorescence lifetime and the quantum yield of pz1 increase as a function of solution viscosity. We have calibrated pz1 as a red-emitting fluorescent 'molecular rotor' in a large range of viscosities from 80 to ca. 5500 cP, in solutions of various solvent compositions and temperatures. On the other hand, pz1 works as an efficient PDT sensitiser, i.e. it induces apoptosis and necrosis in cells upon irradiation with red light through formation of singlet oxygen. We demonstrate that PDT in cells using pz1 is accompanied by a significant viscosity increase by monitoring the fluorescence lifetime of the rotor. We suggest that this increase could be used as a completely new type of diagnostic and dosimetry tool in a PDT treatment.

The fluorescence quenching, by a series of amino acids, of pseudopeptidic compounds acting as probes for cellular acidity has been investigated. It has been found that amino acids containing electron-rich aromatic side chains like Trp or Tyr, as well as Met quench the emission of the probes mainly via a collisional mechanism, with Stern–Volmer constants in the 7–43 M−1 range, while other amino acids such as His, Val or Phe did not cause deactivation of the fluorescence. Only a minor contribution of a static quenching due to the formation of ground-state complexes has been found for Trp and Tyr, with association constants in the 9–24 M−1 range. For these ground-state complexes, a comparison between the macrocyclic probes and an open chain analogue reveals the existence of a moderate macrocyclic effect due to the preorganization of the probes in the more rigid structure.

A series of nitric oxide (NO) sensitive polymeric hydrogels have been synthesized and their properties described. The new materials are based on a poly(2-hydroxyethyl methacrylate) matrix entrapping the DAF-FM (4-amino-5-methylamino-2′,7′-difluorofluorescein) fluorescent probe. Some of the developed materials show sensitivities in the range ca. 50–75 nM towards NO dissolved in aerated phosphate buffer (PBS), being nitrous anhydride the reactive species under such conditions. Remarkably, the sensitivity of the fluorescent polymers is not influenced by dehydroascorbic acid, a molecule of biological importance, which has been reported to be a common interfering species capable to react with well known probes for NO.

Highly fluorescent organogels (QD-organogel), prepared by combining a pseudopeptidic macrocycle and different types of CdSe quantum dots (QDs), have been characterized using a battery of optical and microscopic techniques. The results indicate that the presence of the QDs not only does not disrupt the supramolecular organization of the internal fibrillar network of the organogel to a significant extent, but it also decreases the critical concentration of gelator needed to form stable and thermoreversible organogels. Regarding the photophysical properties of the QDs, different trends were observed depending on the presence of a ZnS inorganic shell around the CdSe core. Thus, while the core-shell QDs preserve their photophysical properties in the organogel medium, a high to moderate increase of the fluorescence intensity (up to 528%) and the average lifetime (up to 1.7), respectively, was observed for the core QDs embedded in the organogel. The results are relevant for the development of luminescent organogels based on quantum dots, which have potential applications as advanced hybrid materials in different fields. © 2012 American Chemical Society. Fil: Wadhavane, Prashant D.. Universitat Jaume I; España Fil: Galian, Raquel Eugenia. Universidad de Valencia; España Fil: Izquierdo, M. Angeles. Universitat Jaume I; España Fil: Aguilera Sigalat, Jordi. Universidad de Valencia; España Fil: Galindo, Francisco. Universitat Jaume I; España Fil: Schmidt, Luciana Carina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Valencia; España Fil: Burguete, M. Isabel. Universitat Jaume I; España Fil: Pérez Prieto, Julia. Universidad de Valencia; España Fil: Luis, Santiago V.. Universitat Jaume I; España

A new type of hybrid materials composed by core–shell (CdSe/ZnS) quantum dots adsorbed on polymethacrylate surfaces has been synthesized and characterized, specially by means of time-resolved fluorimetry. The ability of such materials to sense NO and NOx has been tested, with promising results. Fluorescence quenching measurements afford limits of detection of ca. 0.1 ppm for NO and of ca. 1.0 ppm for NOx, which opens the way for the development of new materials with analytical applications.

A new family of fluorescent anthracenic pH probes has been synthesized, chemically characterized, and their photophysical properties have been investigated by steady-state and time-resolved fluorescence spectroscopy. The ability of these compounds to monitor pH has been investigated in solution and it was found that molecules 1-12 can act as fluorescent sensors for pH in a range between 4.6 and 6.5. This range corresponds to the pH of acidic organelles in the cell (pH 4.5-6.0) for which a limited number of probes are described. The acid―base behavior of each sensor varies slightly depending on the nature of substituents close to the amines present in the molecules. Thus, the pK a of this family of compounds can be finely tuned by the appropriate selection of the synthetic building blocks at the design stage. To test the potential diagnostic applications of this family of probes, macrocyclic pseudopeptide 2 was used to monitor the phagocytosis of a culture of GFP-labelled bacteria by human monocytic cells U937 using flow cytometry as the analytical tool. It was found that the occurrence of bacterial killing was concomitant with the production of reactive oxygen species and a drop in pH, the latter monitored indirectly by macrocyclic sensor 2, which suggests its potential use for diagnostic purposes.

El objetivo del presente trabajo es doble: por un lado analizar los factores que inducen a un inversor a seleccionar un plan de pensiones concreto y por otro determinar si dichos inversores poseen habilidades de selección. Los resultados obtenidos al aplicar un análisis univariante muestran que los inversores seleccionan su plan de pensiones en función de la rentabilidad obtenida en el pasado, sin embargo, únicamente muestran capacidad de selección los partícipes más conservadores. Así mismo, los resultados obtenidos al aplicar un análisis multivariante indican que la antigüedad, el patrimonio acumulado por el plan, la rentabilidad pasada, y la naturaleza jurídica de la entidad depositaria ejercen un impacto significativo en las variaciones monetarias del plan de pensiones The aim of the present paper is two-fold: firstly, to analyse the factors that lead investors to choose a specific pension fund, and secondly, to determine whether these investors possess selection skills. The results of a univariate analysis show that investors choose their pension fund according to the returns it has obtained in the past; however, selection capabilities are shown by only the most conservative participants. Moreover, the results of a multivariate analysis indicate that the age of the fund, its accumulated assets, its past returns and the legal status of the custodian have a significant impact on monetary variations in pension funds

The synthesis of five new chiral macrocyclic peptidomimetic naphthalenophanes, together with two open-chain derivatives, is described. The cyclization step is accomplished in good yields without the use of high dilution or template techniques. The new compounds have been photophysically studied by means of steady-state fluorescence spectroscopy. It has been found that the smaller the ring size, the higher the emission quantum yield from the excited charge-transfer state (CTS, exciplex) and the lower the fluorescence from the locally excited state (LES). The occurrence of exciplex fluorescence is noteworthy as the electron-donating groups are secondary amine moieties, which do not normally form emissive exciplexes.

Guanine-rich oligonucleotides can fold into quadruple-stranded helical structures known as G-quadruplexes. Mounting experimental evidence has gathered suggesting that these non-canonical nucleic acid structures form in vivo and play essential biological roles. However, to date, there are no small-molecule optical probes to image G-quadruplexes in live cells. Herein, we report the design and development of a small fluorescent molecule, which can be used as an optical probe for G-quadruplexes. We demonstrate that the fluorescence lifetime of this new probe changes considerably upon interaction with different nucleic acid topologies. Specifically, longer fluorescence lifetimes are observed in vitro for G-quadruplexes than for double- and single-stranded nucleic acids. Cellular studies confirm that this molecule is cell permeable, has low cytotoxicity and localizes primarily in the cell nucleus. Furthermore, using fluorescence lifetime imaging microscopy, live-cell imaging suggests that the probe can be used to study the interaction of small molecules with G-quadruplexes in vivo., Guanine-rich oligonucleotides can fold into secondary structures known as G-quadruplexes that are proposed to have various biological roles. Here, Shivalingam et al. develop a cell-permeable, low-toxicity probe that can be used to probe interactions between G-quadruplexes and small molecules in vivo.

Two valine-derived bis(amino amides) ligands have been prepared and fully characterized. Both compounds contain additional functionalities that implement their basicity and their water solubility. Besides, compound 1 is an open chain ligand, while 2 is a macrocycle. Their protonation constants as well as their stability constants for the formation of the corresponding Cu2+ complexes have been determined potentiometrically. Important differences are associated to the macrocyclic effect and to the additional functionalities in the spacer. The presence of an additional amine group and/or the inclusion of a carboxylic side chain in this spacer increase the stabilities of the Cu2+complexes, suggesting its participation in the interaction with the metal. Thus, 2 is the first pseudopeptidic cyclophane of this family displaying the ability to form highly stable metal complexes in water. UV-Vis and ESI-MS were used for analyzing the complex species detected in the speciation diagram.

A novel perylene imide and oligo-pentaphenyl bisfluorene containing molecule is shown to undergo electron transfer to form an emissive charge transfer state in di-benzyl ether and THF. At the single molecule level in a PMMA film, fluorescence spectra characteristic of both emissive states (locally excited and charge transfer) are observed with 44% of the molecules studied showing switching between the two states. These results demonstrate that charge transfer fluorescence from single molecules can be used to report on the properties and dynamics of a molecule’s immediate surroundings or nano-environment.

A steady-state and laser flash photolysis (LFP) study of the TPPBF(4)-photosensitized oxidation of ring-methoxylated benzyl alcohols has been carried out. Direct evidence on the involvement of intermediate benzyl alcohol radical cations and benzylic cations in these reactions has been provided through LFP experiments. The reactions lead to the formation of products (benzaldehydes, dibenzyl ethers, and diphenylmethanes) whose amounts and distributions are influenced by the number and relative position of the methoxy substituents. This behavior has been rationalized in terms of the interplay between the stabilities of benzyl alcohol radical cations and benzyl cations involved in these processes. A general mechanism for the TPPBF(4)-photosensitized reactions of ring-methoxylated benzyl alcohols has been proposed, where the alpha-OH group of the parent substrate acts as the deprotonating base promoting alpha-C-H deprotonation of the benzyl alcohol radical cation (formed after electron transfer from the benzyl alcohol to TPP) to give a benzyl radical and a protonated benzyl alcohol, precursor of the benzylic cation. This hypothesis is in contrast with previous studies, where formation of the benzyl cation was suggested to occur from the neutral benzyl alcohol through the Lewis acid action of excited TPP(+) (TPP).

The regioselectivity in the oxidative electron-transfer cycloreversion (CR) of 2,3-diaryloxetanes depends on the substitution of the aryl groups and on the nature of the electron-transfer photosensitizer. The reaction occurs with fragmentation of the C2−C3 and C4−O bonds either in the presence of electron-releasing substituents in the 3-aryl groups, or when chloranil is used as photosensitizer. Thus, CR of the methoxy-substituted derivative trans,trans-3-(4-methoxyphenyl)-4-methyl-2-phenyloxetane (1b) results in the production of trans-anethole and benzaldehyde. In this case, the trans-anethole radical cation has been detected as transient intermediate by means of laser flash photolysis. Likewise, CR of 1a, photosensitized by chloranil, results in the formation of products arising from the trapping of the trans-β-methylstyrene radical cation by chloranil-derived intermediates. The reverse regioselectivity has been previously found in the ET cycloreversion of 4-methyl-2,3-diphenyloxetane (1a) using (thio)pyrylium salts as photosensitizers. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

En este trabajo se modeliza la volatilidad condicional del indice IBEX-35. Para ello s utilizan diferentes modelos de volatilidad condicional de la familia de los GARCH en los que se considera la existencia de respuestas asimetricas frente a noticias de diferente signo, y se ha incluido el volumen de negociacion, tomado como proxi de la llegada de informacion al mercado. Los resultados obtenidos muestran evidencia de una respuesta asimetrica de la volatilidad frente a noticias de diferente signo, y que la inclusion del volumen de negociacion como variable explicativa de la varianza de la rentabilidad diaria es significativa, aunque los efectos GARCH no desaparecen con su inclusion.

Cycloreversion of 2-(p-cyanophenyl)-4-methyl-3-phenyloxetane (1) is achieved using 1-methoxynaphthalene (2) as electron-transfer photosensitizer. The experimental results are consistent with the reaction taking place from the singlet excited state of the sensitizer. Ring splitting of the radical anion 1*- occurs with cleavage of O-C2 and C3-C4 bonds, leading to products (acetaldehyde and p-cyanostilbene) different from the reagents used in the Paterno-Büchi synthesis of 1. The olefin radical anion involved in the electron-transfer process has been detected by means of laser flash photolysis.

The thiapyrylium salt 1b is an efficient electron-transfer photosensitizer in the preparative irradiation of trans,-trans-2,3-diphenyl-4-methyloxetane (2a). Previously, the reaction has been assumed to occur through the triplet excited state of 1b, which has a very high intersystem crossing yield (Φ I S C = 0.97). In the present report, direct evidence for triplet quenching in the oxidative cycloreversion of the 2,3-diaryloxetanes is provided. The rate constants k q (T 1 ) and the free energy changes of the electron transfer ΔG E T (T 1 ) have been determined for the reaction between 1b and oxetanes 2a-d and 2a'. The process has been found to be exergonic in all cases except for 2d: this agrees with the fact that no photoproduct was obtained in the preparative irradiation of 1b in the presence of 2d. Good correlation between k q (T 1 ) and ΔG E T (T 1 ) was observed. confirming the involvement of the excited triplet state in the reaction mechanism.

Cycloreversion of 1,2,3,4-tetraphenylcyclobutanes 1a,b and oxetane 2 is achieved using (thia)pyrylium salts as electron-transfer photosensitizers. Radical cation intermediates involved in the electron-transfer process have been detected using laser flash photolysis. The experimental results are consistent with the reaction taking place from the triplet excited state of the sensitizer.

A new family of acidity sensitive fluorescent macrocycles has been synthesized and fully characterized. Their photophysical properties including emission quantum yield and fluorescence lifetime have been determined. The acid–base properties of the new molecules can be tuned by the incorporation of pendant functional groups. The nature of such functional groups (carboxylic acid or ester) influences dramatically the pKa of the probes, two compounds of which exhibit low values. Preliminary intracellular studies using confocal microscopy together with emission spectra of the probes from the cellular environment have shown that the synthesized fluorescent macrocycles mark the acidic organelles of RAW 264.7 macrophage cells. Financial support from the Spanish MINECO (CTQ2012-38543-C03-01) and UJI (project P1·1B-2012-41) are acknowledged. P.D.W. thanks the financial support from GV (Grisolia Fellowship). M.J.M. acknowledges the School of Chemistry (University of East Anglia, Norwich, UK) for a studentship. The authors are grateful to Dr Jelena Gavrilovic (School of Biological Sciences, University of East Anglia, Norwich, UK) for the kind gift of the RAW 264.7 mouse macrophage cells used in this work.

RESUMENEn este trabajo se estudia la existencia de un comportamiento diferencial del ratio de cobertura de minima varianza (RCMV) alrededor de la fecha de vencimiento del contrato de futuros sobre el indice IBEX-35; se analiza la existencia de un efecto vencimiento en el RCMV. Con la finalidad de contrastar las diferencias que pueda tener considerar diferentes horizontes temporales de inversion, el estudio se realiza para series de frecuencia diaria y semanal. La metodologia utilizada es diferente dependiendo del horizonte temporal (HTI) considerado, debido a que las caracteristicas de las series de distinta frecuencia son diferentes. Los resultados indican que para coberturas de caracter diario, el RCMV tiende a disminuir la ultima semana de vencimiento, consecuencia, tal y como se muestra en el trabajo, del incremento del riesgo de base que se produce en esas mismas fechas. En cambio para coberturas de frecuencia semanal, los resultados evidencian una tendencia, a partir de la cuarta semana antes de ven...

RESUMENEl continuo crecimiento de la industria de la inversion colectiva ha motivado el desarrollo de medidas que evaluan los resultados obtenidos por los fondos de inversion. En este trabajo se analiza desde un enfoque endogeno y multiperiodo, el rendimiento y riesgo de una muestra de Fondos de Inversion Mobiliaria de renta variable nacional. Para un conjunto de fondos, la evaluacion endogena establece la comparacion de los resultados de un fondo con respecto a los obtenidos por una combinacion lineal convexa de los propios fondos. Esta evaluacion se plantea simultaneamente en tres horizontes temporales, mediante un problema de programacion cuadratica cuya maximizacion, sujeta a las restricciones en rendimiento y varianza en cada periodo, proporciona la medida de eficiencia para cada uno de los fondos analizados. Se estudia la persistencia de los resultados obtenidos, asi como el efecto de los fondos incorporados durante el periodo muestral, y la relacion entre la eficiencia y el tainano de los FIM.

Molecular rotors have emerged as versatile probes for microscopic viscosity in live cells, however, the exclusive localisation of rotors in the plasma membrane has remained elusive. We report the synthesis, spectroscopic characterisation and live cell imaging of a new BODIPY-based molecular rotor suitable for mapping viscosity in the cell plasma membrane.

The regioselectivity of the oxidative electron-transfer cycloreversion of trans,trans-2,3-diphenyl-4-methyloxetane is photosensitiser dependent. With chloranil the reaction proceeds through the trans-beta-methylstyrene radical cation; however, in the case of pyrylium salts, the trans-stilbene radical cation is formed.

Nanoparticle doped hybrid organogels were prepared using the pseudopeptidic macrocycle 1 and CdSe/ ZnS quantum dots (QDs). The new semi-solid materials show the same thermal stability and excellent optical transparency as compared to the parent organogel in the absence of the nanoparticles, but they are fluorescent due to the presence of embedded semiconductor nanocrystals. The fluorescence lifetime of a QD–organogel composite is reported for the first time, and it was found to be similar to that of the QDs in solution in a related solvent, independent of the concentration of gelator. The chemical sensing ability of the hybrid organogels towards gaseous nitric oxide was investigated by steady-state fluorescence spectroscopy. The gels show fluorescence sensitivity towards NO ranging from 0.05 to 0.5 (vol%). The results reported herein constitute a proof of principle of the potential of the hybrid supramolecular soft materials to develop nitric oxide sensor devices of practical application, especially because the semi-solid state of the organogel is preserved after interaction with the analyte. This is remarkable since, for the vast majority of organogels with analytical capabilities reported so far, the signaling mechanism relies upon the disassembly of the supramolecular structure.

[reaction: see text] Cycloreversion of oxetane 1 is achieved using (thia)pyrylium salts as photosensitizers. RadicaI cation intermediates involved in the electron-transfer process have been detected using laser flash photolysis. The experimental results are consistent with the reaction taking place from the triplet excited state of the sensitizer.

A series of crosslinked poly(2-hydroxyethyl methacrylate) films containing 1,2-diaminoantraquinone (DAQ) have been synthesized and characterized spectroscopically by FT-IR and UV-vis. Their response towards nitrite anion in acidic medium has been evaluated by means of time-resolved UV-vis spectroscopy. This kinetic analysis has provided a tool for the dynamic characterization of nitrite-sensitive films which could have application in biomedical analysis (nitrite monitoring of biological fluids) and environmental science (control of nitrite levels in drinking water). © 2009 Elsevier Ltd. All rights reserved.

Different polymeric materials have been prepared from the organogels formed by a polymerizable methacrylic mixture (methyl methacrylate/ethylene glycol dimethacrylate, 1:1, w/w) and the macrocyclic pseudopeptide 1. The use of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide as a very efficient radical initiator allows polymeric materials in which the structure of the fibrils formed by self-assembly of the organogelator 1 is truly preserved to be obtained. Removal of the pseudopeptidic molecule provides materials with a porous structure reflecting that of the original self-assembled fibrils. The use of fluorescent probes such as rhodamine B and pyrene greatly facilitate the study of the porous structures formed and, accordingly, that of the morphology of the original fibrils. Those studies reveal the presence of a permanent porosity and the organization of the substructures as a porous network. This confirms the existence of a nucleation and growth mechanism for the generation of the fibrils, giving rise to the formation of spherulitic structures. Those spherulites are additionally linked by connections of variable size. A series of diffusion experiments allowed establishment of a direct dependence of the inner porosity of the materials on the amount of self-organizing template used for their preparation.

The molecular mechanism for the cycloreversion of oxetane radical cations has been studied at the UB3LYP/ 6-31G* level. Calculations support that the cycloreversion takes place via a concerted but asynchronous process, where C-C bond breaking at the transition state is more advanced than O-C breaking. This allows a favorable rearrangement of the spin electron density from the oxetane radical cation (with the spin density located mainly on the oxygen atom) to the alkene radical cation which is one of the final products. Inclusion of solvent effects does not modify the gas-phase results.

Electron transfer cycloreversion of the methoxy substituted oxetane 1b results in the production of trans-anethole and benzaldehyde through C2–C3 bond cleavage. trans-Anethole radical cation has been detected as transient intermediate by laser flash photolysis.

2,4,6-Triaryl(thia)pyrylium salts have been used as electron-transfer photosensitizers for the cycloreversion of the oxetane ring system. The radical cation of 2,3-diphenyl-4-hydroxymethyloxetane (1) undergoes stepwise splitting via initial O-C2 cleavage. Spin and charge in the resulting intermediate are located in the oxygen and carbon atoms, respectively. Subsequent intramolecular nucleophilic attack produces 2,3-diphenyl-4-hydroxytetrahydrofuran (4a). Formation of this product occurs in the submicrosecond time scale, competing with C3-C4 cleavage to the detectable (lambdamax = 470 nm) trans-stilbene radical cation.

The use of pseudopeptidic gemini surfactants as stabilizers of hydrophobic quantum dots in water is discussed. Compound 1a acts as an intercalator with hydrophobic ligands of QDs transferring them from toluene to pure water yielding a fluorescent nanoparticle resistant to quenching by chloride anion (up to 0.1 M).