61 resultados para Second harmonic generation
Resumo:
El principal problema de les teràpies actuals contra el càncer es la baixa especificitat envers les cèl•lules tumorals, cosa que comporta gran quantitat d’efectes secundaris. Per això es important el desenvolupament de nous tipus de teràpies i sistemes d’alliberament efectius per als fàrmacs ja existents al mercat. En la immunoteràpia contra el càncer es pretén estimular el sistema immunològic per a eliminar les cèl•lules canceroses de manera selectiva. En aquest projecte s’han sintetitzat derivats de l’antigen peptídic de melanoma NY-ESO1 i s’ha estudiat la seva capacitat per a estimular el sistema immunològic com a vacunes contra el càncer. També s’han encapsulat el antígens peptídics en liposomes com a adjuvants i sistemes d’alliberament. De totes les variants peptídiques la que resultà més immunogènica fou la que contenia el grup palmitoil i el fragment toxoide tetànic en la seva estructura. La utilització de liposomes com a sistema adjuvant sembla una estratègia interessant per al disseny de vacunes contra el càncer donat que l’encapsulació del pèptid en liposomes va augmentar notablement la resposta immunològica de l’antigen. Per altra banda, s’han desenvolupat dendrímers basats en polietilenglicol com a sistemes alliberadors de fàrmacs per al tractament de tumors. El polietilenglicol és àmpliament utilitzat com a sistema d’alliberament de fàrmacs degut a les seves interessants propietats, augment de la solubilitat i dels temps de residència en plasma, entre d’altres. La metodologia química descrita permet la diferenciació controlada de varies posicions en la superfície del dendrímer a més del creixement del dendrímer fins a una segona generació. S’ha sintetitzat la primera generació del dendrímer contenint el fàrmac antitumoral 5-fluorouracil i s’han realitzat estudis de citotoxicitat comprovant que l’activitat del nanoconjugat és del mateix ordre de magnitud que el 5-fluorouracil sense conjugar.
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We discuss necessary as well as sufficient conditions for the second iterated local multiplier algebra of a separable C*-algebra to agree with the first.
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The problem of waste management is causing growing concern due to increasing generation rates, the emissions into soil, water and air, the social conflicts derived from the election of disposal sites and the loss of resources and energy among others. In this work, an innovative methodology is used to enable a better understanding of the waste generation and management system in Italy. Two new waste indicators are built to complement the conventional indicators used by official statistics. Then a multi-scale analysis of the Density of Waste Disposed (DWD) is carried out to highlight the territorial diversity of waste performances and test its contribution to detect plausible risky areas. Starting from Italian regions, the scale down goes on to the provincial level and, only for the region of Campania, the municipal one. First, the analysis shows that the DWD is able to complement the information provided by the conventional waste indicators. Second, the analysis shows the limitations of using a unique institutional solution to waste management problems. In this sense the multi-scale analysis provides with a more realistic picture of Italian waste system than using a single scale.
Resumo:
The main goal of this research is explain the impact of the new trends of wine consumption, and the way these enterprises adapted to the circumstances. The hypothesis is that the Spanish companies had to start a deep and traumatic restructuring process, with the aim of surviving adequately in the changeable wine national and international markets. Heavy technological investments were made, with serious finance problems, during the eighties and nineties. We will see this from two specific cases, the Cooperatives "San Isidro" and "Rosario", located in the Region of Murcia, in the Spanish southeast.
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"Vegeu el resum a l'inici del document del fitxer adjunt."
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The Great Tohoku-Kanto earthquake and resulting tsunami has brought considerable attention to the issue of the construction of new power plants. We argue in this paper, nuclear power is not a sustainable solution to energy problems. First, we explore the stock of uranium-235 and the different schemes developed by the nuclear power industry to exploit this resource. Second, we show that these methods, fast breeder and MOX fuel reactors, are not feasible. Third, we show that the argument that nuclear energy can be used to reduce CO2 emissions is false: the emissions from the increased water evaporation from nuclear power generation must be accounted for. In the case of Japan, water from nuclear power plants is drained into the surrounding sea, raising the water temperature which has an adverse affect on the immediate ecosystem, as well as increasing CO2 emissions from increased water evaporation from the sea. Next, a short exercise is used to show that nuclear power is not even needed to meet consumer demand in Japan. Such an exercise should be performed for any country considering the construction of additional nuclear power plants. Lastly, the paper is concluded with a discussion of the implications of our findings.
Resumo:
This project deals with the generation of profitability and the distribution of its benefits. Inspired by Davis (1947, 1955), we define profitability as the ratio of revenue to cost. Profitability is not as popular a measure of business financial performance as profit, the difference between revenue and cost. Regardless of its popularity, however, profitability is surely a useful financial performance measure. Our primary objective in this project is to identify the factors that generate change in profitability. One set of factors, which we refer to as sources, consists of changes in quantities and prices of outputs and inputs. Individual quantity changes aggregate to the overall impact of quantity change on profitability change, which we call productivity change. Individual price changes aggregate to the overall impact of price change on profitability change, which we call price recovery change. In this framework profitability change consists exclusively of productivity change and price recovery change. A second set of factors, which we refer to as drivers, consists of phenomena such as technical change, change in the efficiency of resource allocation, and the impact of economies of scale. The ability of management to harness these factors drives productivity change, which is one component of profitability change. Thus the term sources refers to quantities and prices of individual outputs and inputs, whose changes influence productivity change or price recovery change, either of which influences profitability change. The term drivers refers to phenomena related to technology and management that influence productivity change (but not price recovery change), and hence profitability change.
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La beca concedida ha anat destinada a desenvolupar la tesi doctoral que duu per nom "Les ciutats turístiques, les noves ciutats. Anàlisi de l'evolució del model turístic en destinacions de litoral madures a partir de l'anàlisi de paràmetres urbanístics". L’àrea d’estudi comprèn els municipis de Cambrils, Salou i La Pineda (Vila-seca) que conformen la Costa Daurada central, destinació madura de litoral mediterrani, que basa el seu desenvolupament d’acord el model turístic de sol i platja. Arribats en aquest punt de finalització de la beca, cal destacar que s’ha complert amb l'objectiu d'analitzar el procés de transformació de les ciutats turístiques, tot establint com el turisme litoral mediterrani s'ha convertit en un factor de creació de ciutat. Així mateix també s'han complert els objectius específics tals com: analitzar l'evolució de les destinacions turístiques consolidades del litoral mediterrani, recopilar informació per a la creació d'índexs i eines que serveixin per l'anàlisi del procés de tranformació de les ciutats turístiques a ciutats tradicionals a partir del tractament dels plans parcials, recopilar i analitzar les polítiques de planificació que han condicionat l'area d'estudi, modelitzar el procés de construcció de l'espai turístic a partir de l'establiment d'unes unitats bàsiques en la descripció i anàlisi territorial i paisatgístic, i crear un SIG per culminar el procés d'anàlisi tot creant una base de dades i la representació dels resultats en cartogradia temàtica. Pel que fa al disseny i l’execució de la metodologia, es poden considerar dos vessants, una vessant més qualitativa i una altra més quantitativa per al tractament de la informació recopilada. Igualment la generació de cartografia específica completa el procés amb la producció de cartografia específica, tal i com es desenvolupa en la present memòria. La tesi parteix del guió que contempla: un prier capítol d'introducció, un segon dedicat al marc teòric, un tercer apartat on s'exposaran les hipòtesis de les quals es parteix, i un quart dedicat a la metodologia. Pren especial importància l'apartat dedicat a l’ànalisi, així com el dedicat a la discussió dels resultats obtinguts, que es desenvoluparà en el sisè apartat. Per últim resta destacar el setè apartat dedicat a les conclusions a les que s'ha arribat.
Resumo:
Los hablantes bilingües tienen un acceso al léxico más lento y menos robusto que los monolingües, incluso cuando hablan en su lengua materna y dominante. Este fenómeno, comúnmente llamado “la desventaja bilingüe” también se observa en hablantes de una segunda lengua en comparación con hablantes de una primera lengua. Una causa que posiblemente contribuya a estas desventajas es el uso de control inhibitorio durante la producción del lenguaje: la inhibición de palabras coactivadas de la lengua actualmente no en uso puede prevenir intrusiones de dicha lengua, pero al mismo tiempo ralentizar la producción del lenguaje. El primer objetivo de los estudios descritos en este informe era testear esta hipótesis mediante diferentes predicciones generadas por teorías de control inhibitorio del lenguaje. Un segundo objetivo era investigar la extensión de la desventaja bilingüe dentro y fuera de la producción de palabras aisladas, así como avanzar en el conocimiento de las variables que la modulan. En lo atingente al primer objetivo, la evidencia obtenida es incompatible con un control inhibitorio global, desafiando la idea de mecanismos específicos en el hablante bilingüe utilizados para la selección léxica. Esto implica que una explicación común para el control de lenguaje y la desventaja bilingüe en el acceso al léxico es poco plausible. En cuanto al segundo objetivo, los resultados muestran que (a) la desventaja bilingüe no tiene un impacto al acceso a la memoria; (b) la desventaja bilingüe extiende a la producción del habla conectada; y (c) similitudes entre lenguas a diferentes niveles de representación así como la frecuencia de uso son factores que modulan la desventaja bilingüe.
Resumo:
The H∞ synchronization problem of the master and slave structure of a second-order neutral master-slave systems with time-varying delays is presented in this paper. Delay-dependent sufficient conditions for the design of a delayed output-feedback control are given by Lyapunov-Krasovskii method in terms of a linear matrix inequality (LMI). A controller, which guarantees H∞ synchronization of the master and slave structure using some free weighting matrices, is then developed. A numerical example has been given to show the effectiveness of the method
Resumo:
A kinetic model is derived to study the successive movements of particles, described by a Poisson process, as well as their generation. The irreversible thermodynamics of this system is also studied from the kinetic model. This makes it possible to evaluate the differences between thermodynamical quantities computed exactly and up to second-order. Such differences determine the range of validity of the second-order approximation to extended irreversible thermodynamics
Resumo:
A new practical method to generate a subspace of active coordinates for quantum dynamics calculations is presented. These reduced coordinates are obtained as the normal modes of an analytical quadratic representation of the energy difference between excited and ground states within the complete active space self-consistent field method. At the Franck-Condon point, the largest negative eigenvalues of this Hessian correspond to the photoactive modes: those that reduce the energy difference and lead to the conical intersection; eigenvalues close to 0 correspond to bath modes, while modes with large positive eigenvalues are photoinactive vibrations, which increase the energy difference. The efficacy of quantum dynamics run in the subspace of the photoactive modes is illustrated with the photochemistry of benzene, where theoretical simulations are designed to assist optimal control experiments
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Our new simple method for calculating accurate Franck-Condon factors including nondiagonal (i.e., mode-mode) anharmonic coupling is used to simulate the C2H4+X2B 3u←C2H4X̃1 Ag band in the photoelectron spectrum. An improved vibrational basis set truncation algorithm, which permits very efficient computations, is employed. Because the torsional mode is highly anharmonic it is separated from the other modes and treated exactly. All other modes are treated through the second-order perturbation theory. The perturbation-theory corrections are significant and lead to a good agreement with experiment, although the separability assumption for torsion causes the C2 D4 results to be not as good as those for C2 H4. A variational formulation to overcome this circumstance, and deal with large anharmonicities in general, is suggested
Resumo:
We present a method for analyzing the curvature (second derivatives) of the conical intersection hyperline at an optimized critical point. Our method uses the projected Hessians of the degenerate states after elimination of the two branching space coordinates, and is equivalent to a frequency calculation on a single Born-Oppenheimer potential-energy surface. Based on the projected Hessians, we develop an equation for the energy as a function of a set of curvilinear coordinates where the degeneracy is preserved to second order (i.e., the conical intersection hyperline). The curvature of the potential-energy surface in these coordinates is the curvature of the conical intersection hyperline itself, and thus determines whether one has a minimum or saddle point on the hyperline. The equation used to classify optimized conical intersection points depends in a simple way on the first- and second-order degeneracy splittings calculated at these points. As an example, for fulvene, we show that the two optimized conical intersection points of C2v symmetry are saddle points on the intersection hyperline. Accordingly, there are further intersection points of lower energy, and one of C2 symmetry - presented here for the first time - is found to be the global minimum in the intersection space