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Els lagomorfs (O. Lagomorpha, Cl. Mammalia) del Pliocè i Pleistocè europeusDe Marfà Taillefer, Roger Joan 20 February 2009 (has links)
En aquest treball han estat estudiades nombroses restes de lagomorfs (O. Lagomorpha, Cl. Mammalia) de diversos jaciments del Pliocè i Pleistocè europeus, com Zújar - 11 (Granada), Casablanca 1 (Castelló), Perrier (França), Valdarno (Itàlia), Barranco León 5 i Fuente Nueva 3 (Granada), Cueva Victoria (Murcia), Sima del Elefante 9 (Atapuerca), Dmanisi (Geòrgia), Cova del Toll i El Carmel (Barcelona). S'ha prestat especial interès en la família Leporidae, que és la que presenta més problemàtiques en la sistemàtica. Abans de dur a terme l'estudi sistemàtic dels fòssils, ha estat necessari reconèixer els principals caràcters morfològics que diferencien els taxons de lepòrids actuals que viuen en la regió mediterrània occidental. Aquest estudi s'ha centrat bàsicament en l'esquelet i, especialment, en el tercer premolar inferior. Així, d'una banda, les relacions entre els paràmetres biomètrics han permès diferenciar els gèneres Oryctolagus i Lepus; d'altra banda, a partir de l'anàlisi morfomètrica del P3 que s'ha efectuat mitjançant landmarks i transformades de Fourier, també ha sigut possible discriminar entre ambdós gèneres. D'aquesta manera, a partir d'aquests dos estudis dels lepòrids actuals s'ha realitzat una assignació taxonòmica de les restes fòssils.Pel que fa als ocotònids (Fam. Ochotonidae), s'ha identificat Prolagus michauxi a Zújar (sent la resta més moderna d'aquesta espècie), Prolagus calpensis a Casablanca i Cueva Victoria, Prolagus sp. a Barranco León 5, i Ochotona sp. a Dmanisi.Respecte els lepòrids, s'ha identificat la presència d'un Leporidae indet. a Perpignan (França), tot i que probablement es tracti de Trischizolagus o Hypolagus; d'Oryctolagus sp. a Zújar 11, Casablanca, Barranco León 5, Fuente Nueva 3 i Sima del Elefante TE9; d'Oryctolagus lacosti a Perrier (França) i Valdarno (Itàlia); d'Oryctolagus giberti (nova espècie per la ciència) a Cueva Victoria i El Carmel; d'O. cuniculus a la Cova del Toll, i de Lepus sp. en el jaciment de Sima del Elefante TE9.Cap resta fòssil clarament atribuïble a O. cuniculus ha estat identificada en el Pleistocè inferior, fet que no concorda amb els resultats dels estudis moleculars. D'altra banda, la presència de veritables llebres ja en el Pleistocè inferior a Europa occidental, fins ara en discussió, queda confirmada a partir del material de Sima del Elefante TE9. / Fossil lagomorphs (Lagomorpha, Mammalia) are common in Pliocene and Pleistocene European sites but they have been understudied until now. Fossil remains are craneal and postcraneal bones, teeth being particularly abundant, but the high morphological variability of this group makes taxonomic identification difficult. To solve this main obstacle, a morphologic study of Recent and fossil lagomorphs, paying special attention to the morphometry of the third lower premolar of modern Leporids from the Western Mediterranean area has been carried out. Landmark and elliptic Fourier analyses are applied for the first time to the study of this group. So, the results allow to clearly discriminate the leporid genera Oryctolagus and Lepus, and are very useful for the determination of fossil remains.Studied material was either directly sampled in the outcrops or belongs to historical collections housed in Museums. The main considered localities are Perrier (France), Valdarno (Italy), Dmanisi (Georgia), Zújar 11, Casablanca, Barranco León and Fuente Nueva, Cueva Victoria, Sima del Elefante, Cova del Toll and El Carmel (Spain).The following taxa have been identified: Prolagus sp., Prolagus michauxi, Prolagus calpensis, and Ochotona sp. (Ochotonidae); and Oryctolagus sp., Oryctolagus lacosti, Oryctolagus giberti (new species), Oryctolagus cuniculus, and Lepus sp. (Leporidae). Oryctolagus giberti shows several intermediate characters between O. laynensis, the first known representative of the genus, and the modern European rabbit (O. cuniculus), turning it in a firm candidate to occupy a phylogenetic place between these two species. The remains of P. michauxi of Zújar (upper Pliocene) represent the most modern record of this species known until now, and the abundant fossils of Lepus sp. from Sima del Elefante confirms the early presence of this genus in the Lower Pleistocene of Europe.
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Taxonomy, morphology and distribution of common dolphin, Delphinus delphis (short-beaked form) and Delphinus capensis (long-beaked form), in West African waters = Taxonomía, morfologia y distribución del delfín común, Delphinus delphis (delfín de morro corto) y Delphinus capensis (delfín de morro largo), en aguas del Noroeste AfricanoMorais Pinela, Ana 15 July 2015 (has links)
Distinguishing population units of small cetaceans continuously distributed in a widespread area is challenging, but critical for their conservation and management. The common dolphin (genus Delphinus) has a wide distribution range that has led to the differentiation of a number of morphotypes which, until today, remain of unclear taxonomic adscription. In many areas, two morphotypes were initially distinguished and later separated into two species: the long-beaked common dolphin, or Delphinus capensis, and the short-beaked common dolphin, or Delphinus delphis. The general aim of the present thesis is to investigate the taxonomy, morphology, distribution, and habitat use of the common dolphins (genus Delphinus) occurring in the eastern sub-tropical Atlantic Ocean (NW Africa). This area is amongst those most productive in the world. It is characterized by a quasi-permanent upwelling zone that promotes high biological productivity and a highly diverse and abundant fauna of marine mammals. It has been proposed that the short- and long-beaked forms of common dolphins occur sympatrically in this area, a scenario that provides a unique opportunity to discriminate between the two morphotypes and investigate whether differences are of taxonomic relevance. For the present thesis we investigated the local marine trophic network and the relationship between apex predators, as well as the distribution (offshore vs. inshore) and niche segregation (trophic level exploited) of the two common dolphin morphotypes. Additionally, differences in morphology and habitat use between NW Africa common dolphins and those from other areas, particularly from the northeastern and southeastern Atlantic Ocean, were investigated. Because research of intra and inter specific population variability requires a multiplicity of approaches, different methods were used, including stable isotope analyses of carbon (δ13C) and nitrogen (δ15N) in bone, and measurement-based and 'landmark'-based (geometric) morphometric analyses of the skull. The results obtained revealed that most of the marine mammal species distribute in the outer continental shelf and the upper slope, and that common dolphins are rarely distributed inshore, displaying a typical oceanic behaviour. With the exception of baleen whales, common dolphins showed the lowest trophic level of all marine mammals analyzed, despite the fact that there was large variability between individuals in the exploitation of food resources, possibly to adapt to local environmental variations. The presence of both short- and long-beaked morphotypes of common dolphins was confirmed off the coast of NW Africa, with the short-beaked form inhabiting waters closer to coast and feeding at a lower trophic level than the long-beaked form. Morphological analysis of the skull revealed that variation in relative beak length in common dolphins from NW Africa was larger than in other Delphinus populations worldwide; as opposed to other regions, relative rostrum size followed a clinal variation and intermediate ratios were found. There were significant differences between common dolphin populations and species analyzed in the size and shape components of the skull. The skull of the short-beaked morphotype from NW Africa was shorter but broader than that of the long-beaked. However, despite the differences, there is a closer morphological similarity between the short-beaked morphotype of NW Africa and Delphinus delphis, and between the long-beaked morphotype of the same region and Delphinus capensis. We conclude that taxonomic splitting of common dolphins in this area into two putative species should be postponed until further research is conducted because skull differentiation could be related to niche segregation and not to speciation. Furthermore, the above results indicate that the taxonomic model described for the Northeast Pacific should not be generally applied to other areas where the sort- and long-beaked morphotypes co-habit. / Distinguir unidades poblacionales de pequeños cetáceos distribuidos de forma continua en un área extensa es fundamental para su conservación y gestión. En el amplio rango de distribución de los delfines comunes se han establecido varios morfotipos de adscripción taxonómica incierta, identificados por la longitud relativa de su morro. En muchas áreas, dos morfotipos fueron distinguidos y más tarde separados en dos especies: el delfín común de morro largo, Delphinus capensis, y el delfín común de morro corto, Delphinus delphis. El objetivo general de la presente tesis es investigar la taxonomía, morfología, distribución, y uso del hábitat del delfín común (género Delphinus) en el este del Océano Atlántico Subtropical (NW África). Se ha propuesto que las formas de delfín común de morro corto y largo ocurren en simpatría en esta área, lo que permite una oportunidad única para discriminar entre los dos morfotipos e investigar si las diferencias son de importancia taxonómica. Los resultados han demostrado una gran variabilidad entre los individuos en la explotación de los recursos alimentarios, posiblemente para adaptarse a las variaciones ambientales locales del ecosistema. La presencia de ambos morfotipos de delfines comunes se confirmó en la costa NW de África; la forma de morro corto habita aguas más cercanas a la costa y se alimenta en un nivel trófico inferior a la de morro largo. El análisis morfológico del cráneo reveló que la variación en la longitud del morro es más grande que en otras poblaciones, con el morfotipo de morro corto presentando un cráneo más corto pero más amplio que él de morro largo. Como era previsible, existe una similitud morfológica más cercana entre el morfotipo de morro corto del NW de África y Delphinus delphis, y entre el de morro largo y Delphinus capensis. La división taxonómica de delfines comunes en dos especies, en esta área, debe posponerse hasta que se realicen más investigaciones, ya que la diferenciación craneal puede estar relacionada con la segregación de nicho y no con la especiación. Además, el modelo taxonómico descrito para el Pacífico Nordeste no debe aplicarse indiscriminadamente a otras áreas donde ambos morfotipos cohabitan.
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Síntesis de derivados del biciclo (4,3,0) Nonato-7-Espiro-CiclohexanoCamps García, Pelayo 06 April 1972 (has links)
La (+)-pulegona, I, reducida con sodio y éter-agua da, además de mentoles, productos de condensación, siendo uno de ellos un reductodímero de fórmula C(20)H(36)O(2) con los dos oxígenos en forma de hidroxilo. La oxidación demuestra que uno de ellos es de carbinol secundario, rasando el producto de partida a un cetol de fórmula C20H3402 (1a).
Si la reducción de la (+)-pulegona se hace con amalgama de aluminio se forma directamente un cetol de la misma fórmula, pero distinto del anterior, transformable en otros y uno de ellos el citado.
La reducción con amalgama de aluminio se ha trabajado en el Laboratorio de un modo multindicativo y exhaustivo (1f), permitiéndonos transformar un 30% de la pulegona en cetoles cristalinos. Hasta el presente se han obtenido así cuatro cetoles en cantidades suficientes para trabajarlos, y también en muy pequeña cantidad un 5º cetol.
En las varias publicaciones y tesis doctorales proce-dentes del Laboratorio sobre el tema (1a-1f) se ha fijado como estructura de todos estos cetoles la representada en las fórmulas III y IV, explicándose su formación por la se¬cuencia 1.
En cuanto a la configuración, la tienen fija y R los átomos de carbono 4 y 5', por ser la de los mismos átomos en la pulegona de origen, mientras se configuran durante el proceso los átomos de carbono 1, 6 y 7, explicando que pueden ser varios, hasta 8, los cetones en cuestión.
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Synthesis and Characterization of Engineered Carbon-based Nanoparticles by Arc-discharge PlasmaSanaee, Mohammad Reza 02 July 2015 (has links)
The concept of nanotechnology is attributed to Nobel prize winner Richard Feynman who gave a very famous, visionary in 1959 (published in 1960) during one of his lectures, saying: "the principles of physic, as far as I can see, do not speak against the possibility of maneuvering things atom by atom". At the time, Feynman’s words were received as pure science fiction". Today, we have instruments that allow precisely what Feynman had predicted: creating structures by moving atoms individually.
In principle, the ultimate results of this research study leads to the synthesis of magnetic and porous carbon based nanoparticles as the material and tool for biomedical applications. Currently, we are in a battle with a dangerous and destructive diseases such as cancers, and nanotechnology is then presented as a tool that can help us win control. This work is to support medical and other applications of nanotechnology specifically aimed to prepare carbon based nanoparticles.
Magnetic nanoparticles are being of great interest because of their unique properties especially in drug delivery, hyperthermia, magnetic resonance imaging and cell separation. In many clinical situations, medication doses are oversized as a result of impaired drug absorption or tissue unspecific delivery. The ultimate goal of magnetically controlled drug delivery and drug therapy is to selectively delivering drug molecules to the diseased site without a concurrent increase in its level in healthy tissues.
Consequently, in this research study the objective is to develop an approach to control the synthesis of carbon encapsulated iron nanoparticles in the form of core@shell nanostructure. Accordingly, understanding and revealing the growth mechanism of carbon encapsulated iron nanoparticles is necessary by doing characterization.
Furthermore, engineering of suitable carbon based nanoparticles for biomedical applications has been also considered.
Common challenges for synthesis of carbon encapsulated iron nanoparticles are improving uniformity, enhancing coating protection and controlling particles compositions, shape and core/shell sizes. In addition, due to the lack of comprehensive understanding of the optimal parameters and formation mechanism most of the current fabrication process are empirical, which means a large number of experimental trials are required to optimize any given process.
Since the last two decades, arc discharge technique leads to the discovery of two important carbon based materials, nanotubes and fullerenes. However, the formation of nanomaterials by thermal plasma still remains poorly understood and need further investigation. The focus in this study is on synthesis of carbon based nanoparticles by arc discharge method, particularly carbon encapsulated iron nanoparticles in the form of Core@Shell nanostructure. An arc discharge reactor that was patented by FEMAN group was used with slight modification. The growth processes were elucidated through many experiments and characterizations. Precise control over carbon encapsulated iron nanoparticles were addressed. In addition, a new carbon encapsulated multi iron nanoparticles is introduced. The results have been lead to new elements for understanding the growth mechanism of iron core and carbon shell nanostructure. In order to improve the synthesis process, a new modified arc discharge reactor was developed and implemented. Two new materials are prepared through a new facile synthetic method; carbon nanoparticles decorated by fullerenes and spherical porous carbon microparticles. Last but not least, in this research medical application requirements have been taken into account to prepare suitable nanoparticle. / El concepto de la nanotecnología se atribuye al ganador del premio Nobel Richard Feynman, científico visionario, quien dio una muy famosa conferencia en 1959 (publicada en 1960), en la que dijo: "los principios de la física, por lo que yo puedo ver, no están en contra de la posibilidad de maniobrar los objetos átomo por átomo "(Feynman, 1960). En ese momento, se recibieron las palabras de Feynman como pura ciencia ficción, sin embargo, a día de hoy, tenemos instrumentos que permiten precisamente lo que Feynman ya había predicho: La creación de estructuras de átomos en movimiento de forma individual.
En principio, los resultados finales del presente trabajo de investigación conduce a la síntesis de nanoestructuras del tipo core@shell, consistentes en nanopartículas de hierro encapsulado en carbono, en nanopartículas de carbono decoradas con fullerenos y micropartículas de carbono porosas esféricas como material y herramienta para aplicaciones biomédicas. Actualmente, nos encontramos en un frente contra enfermedades peligrosas y destructivas como el cáncer, y la nanotecnología se presenta como una herramienta que nos puede ayudar a establecer un control de este tipo de dolencias. Este trabajo se enmarca en la Nanotecnología y tiene por objetivo el estudio y preparación de nanopartículas a base de carbono que puedan ser útiles para ciertas aplicaciones aplicaciones médicas o biomédicas y otras del ámbito de la nanotecnología más general.
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Novel light management techniques for thin film solar cells: Nanotextured substrates and transparent conducting upconvertersLluscà Jané, Marta 10 July 2015 (has links)
The objective of this work was to study two different light management approaches to enhance the efficiency of thin film Si solar cells and these were the manipulation of the light path (light trapping) and changing the incoming photon energy (upconversion).
In the first approach the light path was manipulated by creating either periodic or random textured interfaces. Periodic patterns were created at the front AZO by means of direct laser ablation. Amongst all the patterns assessed, the best result was achieved with a linear pattern of 10 lam of pitch and 360 nm of groove depth, that yielded to an Rs of 11 SI/sq and a haze of 12.7% at 600 nm. However structures in the sub-micrometer range cannot be created because the minimum period is limited by the laser spot.
By means of the Aluminum Induced Texturing method (AIT) random textures were performed on glass substrates. In this method, a thin Al film is deposited onto a glass substrate and a redox reaction between the Al and the SiO2 of the glass is induced by high temperature annealing. The reaction products are wet-etched and the result is a uniform and rough glass surface. The process parameters were varied in order to control the resultant glass roughness and it was found that the most critical was the Al deposition method. By using evaporation smooth U-shaped craters morphology and roughness up to 90 nm were created, whereas the sputtered films resulted in rough and porous textures with roughness until 145 nm. AZO grown over the U-shape crater morphology led to a double texture with haze values above 10% at 600 nm, transparency above 84%, and Rs-7 SI/sq whereas AZO over very rough glass resulted in a cauliflower-like surface with haze values >32% at 600 nm, Rs around 9.5 SI/sq and transmittance of 74%. A-Si:H solar cells were deposited on different AIT textures and an improvement of the short circuit current, as well as a reduction of the device reflectivity was achieved in all cases in comparison to the cells deposited on smooth glass textures.
The second approach was to create a transparent and conducting upconverter to be used on top of the rear reflector of a thin film Si solar cell. For that purpose, ZnO was doped with Er and Yb ions and was post-annealed under different treatments. The unique spectral properties of rare earth (RE) elements due to their electronic configuration occur as a result of their intra 4f-4f shell transitions. In the case of Er, its excitation takes places at 1500 nm and 980 nm and the upconverted photons are emitted within the Si absorption range. Moreover, codoping with Yb can enhance the Er visible emission because they cooperate together due to the matching of their energy levels for k=980 nm.
As deposited ZnO doped with rare earths (RE) was found to be transparent and conducting but not luminescent. RE ions need to be surrounded by 6 oxygen in a distorted octahedron to be optically active and REs replacing zinc in the ZnO lattice do not present this symmetry; hence, a post deposition treatment is needed. When the films were post-annealed in air, visible upconversion (UC) was seen at 660 nm under 980 nm laser excitation, however, the films become almost insulating. When the films were annealed in vacuum, lower UC luminescence was achieved, and the resistivity increased 1 order of magnitude. By using CW laser radiation, the electrical properties were maintained and high UC was observed. UC came from clusters of RE06 as well as from RE203 inside or outside the matrix. When annealing in air, in vacuum or by laser radiation, oxygen from the atmosphere bound to the RE to form RE oxides and/or RE06 complexes but just laser annealing was able to preserve the conductivity while producing optically active centers. / L'objectiu d'aquesta tesi és la millora de l'eficiència de les cèl•lules solars de silici en capa prima mitjançant l'estudi de nous mètodes per a l'aprofitament de la llum solar al dispositiu. El primer mètode consisteix en texturar el substrat de vidre per dispersar la llum incident i així incrementar l'absorció en la capa activa. El mètode emprat es la texturització induïda per alumini (AIT); que es basa en una reacció de reducció no uniforme entre el vidre i una capa prima d'alumini gràcies a un tractament tèrmic. Posteriorment els productes de la reacció s'eliminen mitjançant una solució basada en àcid i el resultat és un vidre transparent i texturat. S'ha fet un estudi de la rugositat en funció dels paràmetres del procés i s'ha aconseguit obtenir rugositats controlades i uniformes en superfícies de fins a 10x 10 cm2. Diferents textures s'han provat en cèl.lules solars de silici amorf i s'ha demostrat l'eficàcia d'aquestes en la millora del corrent respecte a les mateixes cèl•lules dipositades sobre vidre pla.
El segon mètode estudiat és el fenomen de l'up-conversion que consisteix en la conversió de fotons de baixa energia (E<Eg), que normalment són transmesos, en fotons d'alta energia (E>Eg) que podran ser absorbits en la zona activa; així doncs s'ha intentat fer una capa conductora, transparent i amb propietats d'up-conversion per utilitzar com a contacte per a cèl• lules solars. Per aquest propòsit s'han estudiat capes conductores i transparents d'òxid de zinc dopat amb erbi i iterbi dipositades per polvorització catòdica sobre vidre. Com que les terres rares han d'estar envoltades d'oxigen per actuar com a centres òptics actius, i en les capes de ZnO:Er:Yb no es dóna aquesta configuració, les capes s'han hagut de sotmetre a diferents tractaments tèrmics, com escalfament en aire, en buit o escalfament amb làser. Escalfant en aire o en buit s'aconsegueix obtenir up-conversion però la conductivitat disminueix notablement, en canvi, escalfant amb radiació làser es possible de mantenir les propietats elèctriques i a més, activar òpticament les terres rares.
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Effects of alternative dietary lipid sources on lipid metabolism and regulation of food intake in larvae and juvenile senegalese sole (Solea senegalensis)Bonacic, Kruno 26 February 2016 (has links)
The main objective of this thesis was to evaluate the potential impacts of alternative VO–based feed formulations on the regulation of appetite and food intake in a commercial marine aquaculture species (Senegalese sole) by uncovering some of the possible physiological regulatory mechanisms behind these processes in early developmental, as well as juvenile stages. Effects of dietary lipid level and FA composition on lipid absorption, metabolism and sensing, as well as gastrointestinal and central appetite-related peptides were analyzed, both pre– and post–prandially. Apart from gene expression, supporting morphometric, biometric, biochemical, histological and enzymatic data was also collected. During development of molecular tools, numerous transcripts were identified for several genes, most notably for the anorexigenic neuropeptide cart, for which a total of 7 transcripts—more than has been recorded in any vertebrate to date—were characterized.
In juvenile sole, hepatic lipid metabolism was affected more by dietary lipid level than source, especially at fasting, where high dietary lipids promoted catabolic and suppressed anabolic pathways. On the other hand, a lower food intake was also observed in fish fed high lipid levels, but only when the lipid source was FO, which may have indicated a higher satiating effect of FO than similar amounts of VO. This could not be related to basal and post–prandial (6 h) expression of anorexigenic gastrointestinal peptides which was only affected by lipid level and lower in fish fed high–lipid diets. The expression of central appetite–regulating genes in the brain was not affected at basal levels by the diets. However, most central neuropeptides (cart1b, cart4, pomca, cckl, npy, agrp2) responded to feeding and showed changes in expression during the post–prandial phase, with only slight differences in relation to lipid level. A system for hypothalamic sensing of circulating FA was discribed in juveniles, for the first time in a marine fish. Results confirmed its sensitivity to oleic acid, previously established in trout, but also, for the first time in a vertebrate, provided evidence of activation by an n-3 PUFA (ALA).
A method for quantifying live prey intake in larval fish was developed for this thesis, using fluorescent microspheres as markers. The method also enabled experiments of prey selectivity, by using different coloured microshperes to label prey from different treatmetns. While results showed that no preferance of diet was exhibited when fish were offered a choice, larvae previously grown on Artemia enriched with cod–liver oil (CLO) ingested more of their respective diet (per g body weight) compared to those fed linseed (LSO), soybean or olive oil–based diets. Larvae fed CLO also showed improved growth and survival, faster onset of metamorphosis and maturation of the intestine. Gene expression profiles of both larvae and post–larvae fed CLO stood out most from the other treatments with decreased transcript levels of genes involved in anabolic pathways, and increased of those related to phospholipid metabolism, lipoprotein secretion, lipid transport and hydrolysis. Fish fed CLO were closely followed by those fed LSO, almost catching up in terms of growth by the end of the experiment, and were closely grouped in terms of gene expression to those fed CLO, corroborating the possitive effects of enhanced phospholipid metabolism and apolipoprotein synthesis on larval performance. Peripheral peptides in larvae and post–larvae generally did not mirror their putative function or explain lower food intake in fish fed the VO diets, but fish fed CLO tended to show the most dissimilar pattern of central appetite–regulating gene expression, compared to the other dietary treatments.
While this thesis provides generally more descriptive results, it can serve as a basis for future, mechanistic studies.
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Synthesis, kinetic control and properties engineering of cerium oxide nanoparticles for biomedical applicationsYudina, Tetyana 17 June 2016 (has links)
La presente Tesis Doctoral es un fruto de colaboración entre el Instituto Catalán de Nanociencia y Nanotecnología (ICN2) y el Hospital Clínic de Barcelona, implicados en el proyecto “Marató TV3 2012”, con el objetivo de utilizar las nanopartículas de óxido de Cerio (CeO2 Nps o “nanoceria”) como una nueva herramienta terapéutica en la regeneración del tejido hepático en las enfermedades del hígado.
CeO2NPs son un material inorgánico fascinante, con una gran variedad de aplicaciones y muchas más por llegar. Lo que las hace tan interesantes es su alta capacidad de hacer de buffer de electrones en un entorno oxidante/reductor, gracias a su estructura electrónica incompleta en la capa 4f. Ésto hace posible que presente una habilidad de ser oxidada o reducida, seguida de captura o liberación de oxígeno o especies reactivas de oxígeno (ROS y los radicales libres, tales como OH·). Como consecuencia, nanoceria se comporta como una esponga natural de electrones libres. El desequilibrio de ROS tiene lugar en un gran número de enfermedades humanas. También, la sobreproducción de ROS es crítica en la neurodegeneración. A pesar de la atractiva capacidad antioxidante de CeO2 NPs, una controversia importante, en cuanto a su función biológica, fue descrita en la literatura actual.
A lo largo de ésta Tesis, los métodos existentes de síntesis de nanoceria han sido analizados en detalle, cómo también la calidad de los productos obtenidos y los aspectos toxicológicos de ámbos (los procesos y los productos).
Éste trabajo de investigación fue enfocado en sobrepasar las problemáticas existentes de la toxicidad de nanoceria (debida a la agregación de nanopartículas, la toxicidad del surfactante o el solvente, o a la contaminación de las muestras con endtoxina) y en diseño de soluciones útiles, con el objetivo de sacar el provecho máximo de las propiedades antioxidantes de CeO2NPs en recerca y aplicaciones biomédicos. Asimismo, el presente trabajo fue centrado en el estudio de las propiedades físico-químicas y bio-quimicas de nanoceria, para optimizar su preparación y tamaño (Capitulo 2), evaluar su reactividad (Capitulo 3), biodistribución (Capitulo 4) y no-toxicidad (Capitulo 2, Anexo 2). Finalmente, la biodistribución de nanoceria y sus efectos sobre los mediadores fibrogénicos e inflamatorios fueron evaluados a nivel molecular y celular, demostrando que la administración de CeO2NPs podría ser de interés terapéutico en enfermedades del hígado (Anexo 3). / The current Doctoral Thesis is the fruit of collaboration between the Catalan Institute of Nanoscience and Nanotechnology (ICN2) and the Hospital Clinic of Barcelona, involved in the project “Marató TV3 2012”, with the objective to apply Cerium oxide nanoparticles (CeO2 NPs) as a new therapeutic tool for tissue regeneration in liver diseases.
CeO2NPs is a fascinating inorganic material with many applications and more to come. What makes nanoceria very appealing is its high capacity to buffer electrons from an oxidant/reducing environment due to the unfilled 4f electronic structure. This is due to its easy ability of being oxidized and reduced, followed by the capture or release of oxygen or reactive oxygen species (ROS and free radicals as OH·). As a result, nanoceria behaves as a natural electron sponge.
Note that ROS disbalance takes place in an enormous number of human diseases. Also, the overproduction of ROS is critical in neurodegeneration.
Despite the appealing redox catalytic capacity of CeO2 NPs, an important controversy upon biological effects of CeO2 has been numerously reported. During this Thesis, the existent methods of nanoceria preparation have been analyzed in detail, as well as the quality of the obtained products and the toxicological aspects of both (the processes and the products).
This Doctoral research has been focused in overtaking the existent problematics of the nanoceria toxicity (due to aggregation of NPs, toxic surfactant or solvent, or contamination with endotoxin) and offering suitable solutions, in order to take full advantage of the antioxidant CeO2NPs properties in biomedical research and applications.
Thus, the current work has been focused on the study of physicochemical and biochemical properties of CeO2 NPs, to optimize the preparation methods and the obtained product, in an environmentally-friendly way (Chapter 2, Annex 2). The optimization of the NPs size and monodispersity (Chapter 2); as well as the evaluation of the correspondent antioxidant activity (Chapter 3) were also performed. Finally, the in-vivo biodistribution study of CeO2 NPs, as well as their effects on inflammatory and fibrogenic mediators were evaluated at molecular and cellular level, demonstrating that administration of CeO2 NPs could be of therapeutic value in liver diseases (Annex 3).
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Economics of ocean acidification and sea warming in the mediterraneande Campos e Rodrigues, Luís Miguel 17 June 2016 (has links)
Esta tesis analiza los efectos socio-económicos de la acidificación oceánica y del calentamiento del Mediterráneo. Estas presiones ambientales vienen provocadas por el incremento de las emisiones de CO2 desde la Revolución Industrial. La combinación de estas presiones puede tener consecuencias negativas sobre hábitats y especies (p.e., coralígeno, bivalvos y gorgonias) junto con pérdidas económicas para la acuicultura y el turismo.
Esta tesis ha investigado dichas pérdidas, desarrollando las siguientes actividades: 1) desarrollo del marco conceptual para el estudio del impacto socio-económico de la acidificación en el Mediterráneo; 2) diagnóstico de la vulnerabilidad potencial de la acuicultura de moluscos del Mediterráneo respecto a varias presiones ambientales, según las percepciones del sector; 3) valoración del impacto de la acidificación y calentamiento del mar sobre los beneficios recreativos del buceo en zonas marinas protegidas (ZMP) del Mediterráneo compuestas por el coralígeno y gorgonias; y 4) transferencia de valores ambientales, en concreto, costes en términos de bienestar y pérdidas de ingresos turísticos a causa de estas presiones, utilizando un modelo ecológico para varias ZMP de la región Euro-Mediterránea.
Las principales conclusiones son cinco: primero, la acidificación y el calentamiento del mar son perceptibles en el Mediterráneo y pueden verse acentuados durante el presente siglo. Hábitats coralígenos, arrecifes de vermétidos y praderas de Posidonia, y otras especies (p.e., especies planctónicas, bivalvos, gorgonias) son vulnerables respecto a ambas presiones. Los servicios ecosistémicos potencialmente afectados incluyen la provisión de alimentos, el soporte de actividades recreativas, la protección costera y la captura de carbono. Los sectores amenazados incluyen la pesca, la acuicultura o el turismo.
Segundo, los cuestionarios a productores y ZMP indican que la acidificación es un fenómeno poco conocido y que existe una alta incertidumbre sobre sus consecuencias futuras. Muchos de los encuestados la consideran como una amenaza menor en comparación con olas de calor, el incremento gradual de la temperatura del mar o los brotes de algas tóxicas. Las olas de calor constituyen una importante preocupación para el sector acuícola, debido a experiencias recientes.
Tercero, la acidificación y el calentamiento del mar pueden perjudicar zonas de buceo del Mediterráneo con hábitat coralígeno. Los resultados de un experimento basado en la elección de alternativas, realizado en la ZMP de las Islas Medes (España), indican posibles pérdidas en términos de bienestar de los buceadores para los escenarios de reducción de 50% y 100% de las gorgonias (p.e., coral rojo, gorgonia roja), de -17€ y -60€/inmersión, respectivamente. Además, el análisis de las probabilidades de selección (o rechazo) de experiencias de buceo según escenarios climáticos indica la posible pérdida de ingresos turísticos, hecho que puede perjudicar las economías locales y la financiación de las ZMP.
Cuarto, estos resultados fueron extrapolados para otras ZMP similares del espacio Euro-Mediterráneo. El análisis mediante transferencia de valores ambientales se llevó a cabo junto al uso de costes en términos de bienestar y pérdidas de ingresos turísticos a partir de los resultados de un modelo ecológico para el hábitat coralígeno. Dicho modelo indica que las condiciones para la presencia del hábitat coralígeno serán probablemente menos favorables en el futuro. Las estimaciones de los costes en términos de bienestar y pérdidas de ingresos asociados alcanzarían máximos de 36,6 y 20,780 millones de euros, respectivamente.
Por último, el análisis de los efectos socio-económicos de la acidificación y calentamiento del mar se enfrenta a varios desafíos. Entre otros, la incertidumbre de sus efectos sobre especies, hábitats y procesos ecológicos, y la consecuente dificultad para traducirlo a términos económicos; el desconocimiento de las sinergias con otras presiones ambientales; y la falta de conocimiento sobre el potencial de adaptación de los ecosistemas y sectores económicos. / This thesis has assessed the socio-economic effects of ocean acidification (OA) and sea warming in the Mediterranean Sea. These pressures share a common driver, namely the increase in anthropogenic emissions of CO2 since the Industrial Revolution. Their combination can be detrimental to endemic habitats and species, inter alia, coralligenous, bivalve molluscs and gorgonians. This, in turn, represents potential economic losses for bivalve mollusc aquaculture and scuba diving tourism sectors.
This thesis has investigated such losses. To this end, the following tasks were undertaken: 1) development of a framework for studying the socio-economic impacts of OA in the Mediterranean Sea; 2) assessment of the potential vulnerability of Mediterranean bivalve mollusc aquaculture to climatic and non-climatic pressures by addressing the perceptions of the sector; 3) valuation of the impact of OA and sea warming on recreational benefits associated with diving in Mediterranean Marine Protected Areas (MPAs), featuring coralligenous habitat and gorgonians species; and 4) value transfer of welfare costs and tourism revenue losses due to both pressures by using an ecological model for various EU-Mediterranean MPAs.
The main conclusions cover five insights. First, OA and sea warming are already perceivable in the Mediterranean Sea, and can become more pronounced throughout the century. Unique habitats like coralligenous, vermetid reefs and Posidonia oceanica meadows, and various groups of species (e.g., planktonic species, bivalve molluscs, gorgonians) are found to be vulnerable to both pressures. Likely ecosystem services to be affected include provision of food, the support of recreation activities, coastal protection, and carbon sequestration. Sea-based market activities such as fisheries (capture and aquaculture) and tourism, are sensitive to both pressures.
Second, the results obtained from the questionnaires distributed among bivalve mollusc producers and representatives of Mediterranean MPAs show that OA is still poorly known, and that there is a high uncertainty about what it might imply in the future. Many respondents consider OA a low threat in comparison with other stressors, such as summer heat waves, a gradual increase in sea surface temperatures, or harmful algal blooms. Summer heat waves is a matter of great concern to the bivalve mollusc aquaculture sector, as it has already experienced various extreme events of this kind in the past years.
A third insight is that OA and sea warming could affect the recreational value of Mediterranean diving areas with coralligenous. Results from a choice experiment for the MPA of Medes Islands (Spain) show potential welfare losses of scuba divers for scenarios involving a decrease of 50% and 100% in gorgonians (e.g., red coral, red gorgonian, white gorgonian) to equal -€17 and -€60/dive, respectively. In addition, the analysis of choice probabilities for selecting (or rejecting) dive experiences under various climatic scenarios indicate potential losses in tourism revenues, which in turn may affect local economies and funding of the MPA.
Fourth, the previous results were extrapolated to other, similar EU-Mediterranean MPAs. This value transfer analysis combined information about welfare costs and tourism revenue losses with estimates generated by an ecological model of habitat suitability. The results show a likely decrease in the suitability of the coralligenous in the majority of the studied areas. Estimates for total welfare costs and tourism revenue losses were up to €36.6 and €20.780 million, respectively.
Finally, assessment of the socio-economic effects of OA and sea warming presents various challenges associated with, inter alia, the uncertainty about the effects of these pressure on species, habitats and ecological processes, and the consequent difficulty to translate these into economic effects; the lack of understanding about the synergetic effects between multiple environmental pressures; and the uncertainty about the potential adaptation of ecosystems and economic sectors to future ocean conditions.
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Síntesi de nous lligands P-estereogènics. Aplicacions a la reacció de Pauson-Khand i a la hidrogenació asimètriquesOrgué Gassol, Sílvia 16 July 2015 (has links)
Tesi realitzada a l'Institut de Recerca Biomèdica de Barcelona (IRBB) / Els compostos de fòsfor han mostrat propietats úniques com a lligands per a la catàlisi asimètrica. El nostre grup de recerca ha estat dedicat a la síntesi de compostos P-estereogènics durant els darrers 5 anys. La present tesi doctoral ha estat dedicada al disseny i la síntesi de nous lligands P-estereogènics i a la seva aplicació en catàlisi asimètrica.
S’ha sintetitzat una nova família de difosfines amb quiralitat a l’àtom de fòsfor anomenades ThaxPHOS. Aquests lligands han estat complexats a cobalt i s’ha estudiat les propietats dels catalitzadors obtinguts per a la reacció de Pauson-Khand asimètrica i catalítica entre norbornadiè i alquins terminals. Com a resultat d’aquest estudi s’ha obtingut les enones corresponents amb resultats sense precedents fins al moment.
Seguidament s’ha desenvolupat una metodologia versàtil per a la síntesi de nous lligands P-estereogènics a partir d’aminofosfines òpticament pures. Mitjançant la hidròlisi àcida d’aminofosfines s’ha obtingut els àcids fosfinosos coresponents els quals han estat subjectes a la substitució nucleòfila a l’àtom de fòsfor. Mitjançant aquesta metodologia s’ha sintetitzat una nova família de lligands P-estereogènics.
Per tal de mostrar la utilitat de la nova metodologia desenvolupada s’ha sintetitzat una nova família de lligands fosfino-oxazolina, 5, els quals han estat emprats per a la hidrogenació asimètrica catalitzada per iridi. Els catalitzadors obtinguts han mostrat una elevada activitat per a aquest tipus de reacció, donant els productes hidrogenats amb elevada selectivitat en alguns casos.
Publicacions:
- S. Orgué, T. León, A. Riera, X. Verdaguer, Org. Lett. 2015, 17, 250–253.
- A. Flores-Gaspar, S. Orgué, A. Grabulosa, A. Riera, X. Verdaguer, Chem. Commun. 2015, 51, 1941–1944. / Phosphorus compounds have demonstrated unique properties as ligands for asymmetric catalysis. Our group has been devoted to the synthesis of P-stereogenic ligands in the last 5 years. The present doctoral thesis is devoted to the design and synthesis of new P-stereogenic ligands and its application in asymmetric catalysis.
We synthesized a new family of P-stereogenic diphosphines called ThaxPHOS. These ligands were complexed to cobalt and the resulting catalysts have been studied for the catalytic and asymmetric Pauson-Khand reaction between norbornadiene and different terminal alkynes. As a result of this study the corresponding enones were obtained with unprecedented results so far.
Next, we have developed a versatile method for the synthesis of new P-stereogenic ligands from optically pure aminophosphines. The acidic hydrolisis of aminophosphines was performed giving rise to phosphinous acid boranes. This compounds were used as electrophiles for nucleophilic substitutions at the P centre. Using this methodology it was synthesized a new family of P estereogenic ligands.
In order to show the usefulness of the new methodology developed, it was synthesized a new family of phosphine-oxazoline ligands, 5, which have been used for iridium catalysed asymmetric hydrogenation. The catalysts obtained showed high activity for this type of reaction, giving rise to the hydrogenated products with high selectivity in some cases.
Publications ;
- S. Orgué, T. León, A. Riera, X. Verdaguer, Org. Lett. 2015, 17, 250–253.
- A. Flores-Gaspar, S. Orgué, A. Grabulosa, A. Riera, X. Verdaguer, Chem. Commun. 2015, 51, 1941–1944.
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Discurso sobre la teoria general del movimiento en las máquinas : desarrollado por D. Lauro Clariana en el ejercicio del doctorado correspondiente a la sección de Ciencias exactasClariana Ricart, Lauro, 1842-1916 01 January 1873 (has links)
Reproducció digital de l'original manuscrit, en fulls solts, dipositat a l'Arxiu Històric d'aquesta Universitat / Lauro Clariana Ricart (Barcelona, 1842-1916) fue un matemático e ingeniero industrial español.
Obtuvo en 1873 la cátedra de matemáticas del Instituto de Tarragona. Ese mismo año se graduó de doctor en Ciencias Exactas. Fue nombrado en 1881 catedrático numerario de Cálculo Infinitesimal de la Universidad de Barcelona. De 1902 a 1907 desempeñó interinamente la cátedra de Cálculo Integral y Mecánica Racional de la Escuela de Ingenieros Industriales de esta ciudad, y desde 1909 desempeñó la de Cálculo Infinitesimal, de cuya nueva asignatura fue el iniciador.
Perteneció a la Real Academia de Ciencias y Artes de Barcelona y a la de Ciencias Exactas, Físicas y Naturales de Madrid. Colaboró en diversas revistas científicas. En la Academia de Barcelona dio conferencias sobra matemáticas superiores referentes a Funciones elípticas. Ha figurado dignamente en los congresos de París, Bruselas, Múnich y Friburgo, en los que presentó numerosos trabajos sobre distintas materias.
(Fuente: Wikipedia.org)
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