CHEMISTRY

Author: NAVARRO LÓPEZ PALOMA.
Year: 2003.
University: AUTÓNOMA DE MADRID [More theses of this university] [www.uam.es].
Place of defense: INSTITUTO DE CATÁLISIS Y PETROLEOQUÍMICA.
Place of preparation: INSTITUTO DE CATÁLISIS Y PETROLEOQUÍMICA (ICP-CSIS, MADRID).

Summary: The research work has focused initially on the catalytic synthesis of materials that have a high content of carbon nanotubes and morphological characterization of them. This has been prepared iron catalysts supported on different materials, oxídicos as silica and alumina and carbonaceous as activated carbon, molecular sieve (SARAN) and graphite high superifice (HSAG), it has changed the burden and procursor cash. In addition to the more conventional impregnation techniques to incipient wetness has used the sol-gel method to obtain a catalyst with high dispersion of iron. To summarize on the catalysts prepared carbon nanotubes in a controlled fashion tested different gases and different feeding conditions. All experiments have been followed gravimetrically in a termobalanza, which has enabled a study on the speed of deposition of coal during the reaction. The gas that brings gravimetrically in a termobalanza, which has enabled a study on the speed of deposition of coal during the reaction. The gas that contributes carbon has been fed on the catalyst for a continuous (work flow continuo-) or introducing pulses (pulse method). Once obtained carbonaceous deposits has been studied their morphology using the technique of transmission electron microscopy which has identified the nature tubular products. In some cases they have used other techniques such as, scanning electron microscopy, X-ray diffraction even spectroscopy ultravioleta-Raman, which have helped product characterization. The method of pulses has allowed proposing a mechanism for the growth of carbon nanotubes. In a second part of the work has been trying to explore the potential application of these materials in the storage of hydrogen. It has developed a system volumentría high pressure. Thus, it has evaluated the adsorption capacity of the various carbonaceous materials used in this Report, nanotubes business and the formation of metal alloys using metal hydrides known.

Author: MEZCUA PERAL MILAGROS.
Year: 2003.
University: ALMERÍA [More theses of this university] [www.ual.es].
Place of defense: FACULTAD DE CIENCIAS EXPERIMENTALES.
Place of preparation: FACULTAD DE CIENCIAS EXPERIMENTALES.

Summary: The latest directives on the protection of waters speak on the preservation of aquatic ecosystems, proper use of water and preservation of water sources. Current legislation focuses on pollutants "priority" conventional, especially those that are persistent or who have a chronic toxicity or delivered are carcinogenic. But there is a large number of chemical compounds can be a risk to the environment through different routes. The risks associated with pollutants previously unknown, unrecognized as pollutants or not that might be suspected contaminants, which are not regulated by legislation, is one of the main objectives of environmental scientists. This diverse group of compounds is commonly known in the scientific world as "emerging contaminants." In recent years there has been a great interest in following up on the presence of these contaminants in thee emerging environment, in other words, there is a need to develop analytical methods that are rapid, sensitive and selective in determining such contaminants in water . This dissertation focuses on the study of three different groups of emerging contaminants such as antiseptics, some emerging contaminants that have activity endocrine disruption and additives for gasoline. The studies for each of the groups include the development of analytical methods for identifying unknown compounds in environmental samples, the development of follow-up studies and implementation and assessment processes and fotolisis photocatalyst. The analytical methods have been developed using gas chromatography with atomic emission detectors and mass spectrometry (GC-AED and GC-MS) and liquid chromatography coupled to mass spectrometry with analyzer flight time (LC- ToF-MS) . Both systems were used to scan and confirmation of unknown compounds in follow-up studies. The implementation of both systems and mainly LC-ToF-MS has contributed to the assessment of the routes to degradation processes fotolíticos and fotocatalíticos. The LC- ToF-MS is a new analytical technique and a powerful tool that provides the correct identification of the products of transformation from unknown processes fotolíticos and fotocatalíticos. The LC-MS and GC-MS techniques have offered sufficient qualitative and quantitative information needed to conduct follow-up studies of these compounds

Author: GARRIDO HERRERA FRANCISCO JAVIER.
Year: 2003.
University: ALMERÍA [More theses of this university] [www.ual.es].
Place of defense: FACULTAD DE CIENCIAS EXPERIMENTALES.
Place of preparation: FACULTAD DE CIENCIAS EXPERIMENTALES.

Summary: In this thesis proposes synthesis systems controlled release of pesticides isoproturon, imidacloprid and cyromazine and urea nitrogen fertilizer, as an alternative to existing conventional formulations. Based on the properties fisicoqulmicas presenting the active ingredients selected for the purpose of this study have been used biodegradable polymeric matrices as a means encapsulants, and the agents have been investigated aids features more appropriate to achieve more effective encapsulation, depending on the pesticide fertilizer or scrutinized. We have prepared three types of controlled release formulations: (1) - based systems using polymer matrix of alginate as modifiers or components filling a natural bentonite, activated charcoal and various mixtures of both adsorbents, (2) systems based on polymer matrix lignin, and (3) based systems coatings with ethylcellulose fluidized bed. Once obtained and characterized such systems controlled release has been the study of the kinetic process of release of the active ingredient in water, mostrándose a significant slowdown in the process of release of íngredientes assets with respect to products técnicoas of . Then, in order to investigate in greater depth the influence the characteristics of the systems on the kinetic process of liberation, liberation of the experimental data have been adjusted to model Ritger and Peppas, obteniéndose the parameter values characteristic of the process liberation T50 (time required for the release 50% of the active ingredient initially present in the granule), from which have been established correlations between this parameter T50 and the different properties of granules that allow us to predict the behavior kinetic System prepared. Following the experiences in water, addressed the evaluation of controlled release formulations such soil, carried out as kinetic study, mobility and balance sheets of matter. It used two types of experimental devices: columns of soil on which a dripping aqueous solution with a constant flow, and static incubation systems that mantenfan soil in a certain humidity constant. Experimental data release in soil also followed the model Ritger and Peppas. With the application of pesticides and fertilizers in the form of controlled release systems is achieved by a delay in the onset of these active ingredients in ellixiviado, and increased residence time of the same on the ground. Finally, we have developed equations that relate the rate of release of the active ingredient in water and soil, based on the kinetic studies conducted in both media. These equations allow us to predict the behavior cínético of systems developed and design an appropriate profile release of the active ingredient in each crop.

Author: Pascual Ramón Rosalia.
Year: 2003.
University: RAMÓN LLULL [More theses of this university] [www.url.edu].
Place of defense: Escuela Técnica Superior IQS.
Place of preparation: Escuela Técnica Superior IQS.

Summary: The explosion in the number of compounds that cause the introduction combinatorial chemistry in the process of drug-discovery leads to resort to computational chemistry as a useful tool to suggest the best candidates, which in this work has deepened in the study tools that enable successful this election. It has developed the program Pralins (Program for Rational Analysis of Libraries in silico), which incorporates the main criteria for selection of libraries: MaxSum, MaxMin, MaxMin averaged, DN2, CTD (based on distance), hierarchical clustering, clustering K-means, Patrick Jarvis and Optimum Binning (based classification). Pralins allows selections combinatorial type cherry picking, but also full array selections, selecting reagents depending on the properties of the products. The program has been validated through a three-step combinatorial library of partial agonists of the FXR characterized by descriptors standard computational chemistry. In addition, it has allowed, in terms of space and coating population, comparatively analyzing the goodness of the different methods for different sizes of product selection and configuration of the size in the array of reagents to select. The program, developed in UNIX environment and ANSI-C language, has also endowed a graphical interface used bookstores Xt / Motif and OpenGL capabilities of molecular visualization and editing. It has been listed and marked 3D virtual library of 125396 analogues HEPT, a reverse transcriptase inhibitor of HIV from fragments present in 180 similar published. The library has allowed explore alternative approaches to diversity, as well as analyze the readiness of the analogs tested in the total space available and contrast intuition químico-médica with combinatorial design. The values of 180 similar activity, as well as the crystalline structure pdb1rti of HIV1-RT have allowed explore the technical MM-GBSA implemented AMBER for evaluating energy union. We also have evaluated the results of docking and scoring program AUTODOCK for 180 compounds, automating the process to provide a tool for screening in silico. It has been used to test the 114,300 compounds of the virtual library obtained from commercial reagents, after filtration process, and a way of combinatorial synthesis proposal for new analogues HEPT. The compounds of the library were also evaluated using four models CSAR can compare the results of both approaches. Theoretical models have been developed for the cell receptors CXCR4 and CCR5 involved in the early stages of infection the HIV virus. In the case of CXCR4 has tried to validate the model through interaction studies with the antagonist AMD3100.

Author: LÓPEZ SOLIDADO FERNÁNDEZ ILIANA.
Year: 2003.
University: SAN PABLO CEU [More theses of this university] [www.ceu.es].
Place of preparation: FACULTAD DE CIENCIAS EXPERIMENTALES Y DE LA SALUD.

Summary: In this work we wanted to achieve an experimental model of moderate diabetes (DM) in pregnant rats by administration of estreptozotocína associated with a mild hyperglycemia and glucose intolerance, comparable to that which occurs in pregnant woman who developed gestational diabetes and well explore cosecuencias short-term offspring. On day 20 of gestation fetuses of rats DEM were hiperisulinémicos, normoglucémicos and had the same body weight than controls. The birth and 21 days of age the offspring of mother DEM had a higher body weight you controls. At 70 days of age the offspring of mother DEM presented alterations in the relationship glucose / insulin. He also wanted to study the effects of maternal diabetes linked to the ingestion of a diet rich in olive oil or fish during pregnancy and lactation on the development and metabolism of offspring. At birth, infants rat diet DM allimentadas with olive weighed more than the controls, whereas this effect disappears in rats with diet food fish. The postnatal development was highly deteriorated in the offspring of rats fed a control diet of fish, compared with the olive. At 70 days of age the offspring of madro control fed diet of fish had higher insulin sensitivity that the offspring controlling oil. Therefore, the fatty acid composition of the maternal diet has an important role in the growth of programming and the relationship glucose / insulin when adult offspring.

Author: BONILLA CARMONA JULIA.
Year: 2003.
University: SEVILLA [More theses of this university] [www.us.es].
Place of defense: CENTRO DE INVESTIGACIONES CIENTÍFICAS ISLA DE LA CARTUJA.
Place of preparation: FACULTAD DE QUÍMICA.

Summary: The mechanism of insulin signaling is a complex process still unclear. The hypothesis of the second messenger, which is based this dissertation, predicts the existence of measuring type IPG (inositol fosfoglicanos), which are responsible for transmitting the signal. The structure of the same is not known and the amount of material that can isolate itself is very small, so that the synthesis becomes a suitable tool for the study of its structure. This thesis has been prepared various derivatives as potential insulinomiméticos have been studied its structure and studies were conducted activity insulinomimetica.

Author: HERNÁN PRADO MIGUEL ANGEL.
Year: 2004.
University: COMPLUTENSE DE MADRID [More theses of this university] [www.ucm.es].
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MEDICINA (U.C.M.).

Summary: OBJECTIVE: To examine the biological effect of Human Growth Hormone in arthrodesis vertebral posterolaterales experimental rabbits, through two possible routes of administration. INTRODUCTION: The arthrodesis posterolateral intertransversa is the kind of lumbar interbody fusion most commonly performed, but the failure to achieve a solid fusion still varies between 5-35% which often causes an unsatisfactory resolution of the clinical symptoms and results in an increase of medical costs and morbidity. MATERIALy METHODS: Study Groups: We used 48 rabbits in New Zealand who were randomly divided into 3 groups: I.: 16 animals where it will only be used autologous iliac crest graft; II.GHsc: 16 animals in which employment autologous graft crest, and subsequently received doses of 2 IU 112h 1sc of rhGH, until the time of slaughter; III.GHlocal: 16 animals to be used in grafting cresla mixed on each side with 2 Uide rhGH as powder . It is scheduled to sacrifice 8 animals at 2 weeks and another 8 to 4 weeks. Surgical Technique: We performed a merger intertransversa posterolateral a level L5-L6 using grafting cresla iliac corticoesponjoso. Study Methods: Studies were conducted gammagráficos the 1 and 2 weeks in animals prepared for slaughter to 2 weeks, and at 2 and 4 weeks in those who are sacrificed at the 4 week. At the time of slaughter pieces are subjected to a manual scan and radiological. Then prepare to make a densitométrico and histomorphometric analysis. RESULTS: The study gammagráfico of 2 and 4semana the indices of semicuantificación are higher in the control group compared to the groups treated with GH. The radiological assessment is similar in the 3 groups. When assessing the manual provides better control group in the middle r week, the results remain similar in the 3 groups at 4 weeks. The groups treated with GH show an increase in the parameters of bone formation that is higher in the group with GH local r week and in the group with GH were at the 4. The parameters of bone resorption are clearly higher in the group with growth hormone in 2 weeks local CONCLUSIONS: WR produces an acceleration of bone remodeling to increase the parameters of bone formation and resorption. When administered locally produces an effect greater than the initial impetus found if adminisra so sc. When GH is administered in a manner sc twice daily presents most obvious effects between 2 and 4 weeks.

Author: SANZ SANZ CRISTINA.
Year: 2004.
University: AUTÓNOMA DE MADRID [More theses of this university] [www.uam.es].
Place of defense: UNIVERSIDAD AUTÓNOMA DE MADRID.
Place of preparation: CSIS-DEPARTAMENTO QUÍMICA FÍSICA APLICADA.

Author: CACHAPA AGOSTINHO FRANCISCO.
Year: 2004.
University: LA LAGUNA [More theses of this university] [www.ull.es].
Place of defense: FACULTAD DE FARMACIA.
Place of preparation: FACULTAD DE FARMACIA.

Summary: Since the discovery in 1987, that nitric oxide plays important roles in physiological processes, its chemical and biological has grown exponentially. Nitric oxide is a free radical, is synthesized by the action of the enzyme nitric oxide synthase (NOS), which contains different accessory molecules that work together to form the NO from the amino acid L-arginine and O2. This gas is involved in a number of important roles in agencies such as the regulation of blood pressure, facilitate the transmission in the processes of learning and memory and the activation of the immune response. The malfunction in the production or availability of NO is associated with diseases such as hypertension, erectile dysfunction, degenerative processes and dysfunction of the immune system, such as septic shock. The regulation of the production of NO is very important, because the excess or decrease in the concentration of NO can be fatal to the organism. In this context, seeking help for the regulation of nitric oxide in the agency urges the need to prepare complexes that can capture nitric oxide and then contribute positively minimization and perhaps elimination of the aforementioned pathologies back, the primary purpose of development this Doctoral Thesis. As in the human body, one of its key components is water, most of the processes occurring in this medium. Based on this, dithiocarbamates complexes of copper (II) preparations must be soluble in water, and chose those with radical hidroxílicos and / or carboxylic. So complex was prepared dithiocarbamates copper (II), which were obtained from the reaction between the ligands and the corresponding salts of copper (II) in aqueous solution. In this Doctoral Thesis, we study after prepared and characterized, in the interaction between dithiocarbamates aqueous solution of copper (II) with nitric oxide, and Acellular cellular conditions. As a result, explores its possible applications to regulate the concentration of nitric oxide in the tissues of mammals. Both the theoretical and experimental studies shows the ability of dithiocarbamates copper (II) trap nitric oxide and its potential applications to regulate the concentration of nitric oxide in the tissues of mammals. This work is therefore a project of the art research, the first to take place in Spain on the use of dithiocarbamates to regulate the content of nitric oxide in mammalian cells.

Author: Delgado de la Cruz Juan Luis.
Year: 2004.
University: CASTILLA-LA MANCHA [More theses of this university] [www.uclm.es].
Place of defense: Facultad de Ciencias del Medio Ambiente.
Place of preparation: Facultad de Ciencias Químicas.

Summary: This report describes the synthesis of new derivatives of fullerenes and carbon nanotubes as well as the study of their properties and electrochemical fotofísicas and its application in the design of functional solar cells

Author: MOLTO PEREZ EDUARDO.
Year: 2004.
University: CASTILLA-LA MANCHA [More theses of this university] [www.uclm.es].
Place of defense: FACULTAD DE CIENCIAS QUIMICAS.
Place of preparation: FACULTAD DE CIENCIAS QUIMICAS.

Summary: The metalotioneínas constitute a superfamily of proteins of low molecular weight (less than 9 kD), rich in cysteine residues, which confer a high capacity to bind metal ions. Although the first member of this big family was discovered in 1957, has not yet been able to establish the precise biological role of these proteins, and there are very few jobs that have helped to clarify their roles in invertebrates. This paper describes the characterization of a new metallothionein (MTPA) obtained through recombinant from hepatopancreas of the Caribbean lobster Panulirus argus. By semi-quantitative RT-PCR analyzed the expression of MTPA in hepatopancreas, intestine, nervous tissue and muscle; detected mRNA of MTPA in all tissues examined, but the greatest expression can be seen in the hepatopancreas. These results demonstrate for the first time the expression of mRNA of metallothionein in crustaceans, not only in digestive tissues, but also in muscle and nervous tissue. Additionally, he examines the induction of mRNA for Cd of MTPA in explants from different tissues of lobster, with the highest level of induction into nervous tissue. The amino acid sequence MTPA deduced from cDNA obtained, it has 59 amino acids and has homology with the rest of the streams metalotioneínas crustaceans known. Curiously, MTPA has a cysteine extra (19 in total) in the region for the C-terminal domain, as compared with most of the metalotioneínas shellfish, which could mean a greater ability to unite metals. However, as shown by 2 different techniques of analysis (ESI-MS and TXRF), this protein binds 6 ions Zn2 +, as well as the metalotioneínas crustaceans presenting 18 cisteínas. By homology with the structures of the C-terminal domain of MT-1 of Callinectes sapidus (1dmc) and the MT Homarus americanus (1j5l), shows a preliminary model of the three-dimensional structure of the C-terminal domain of MTPA, which extra cysteine be outward-oriented and therefore not form part of cluster Zn-S. On the other hand, MTPA-Zn2 +6 inhibits mitochondrial transport chain mail, and as a result, increasing levels intramitocondriales of ROS, while TPA has an opposite effect. Despite this, MTPA exerts a protective effect against oxidative stress, as the stimulation of the production of ROS by this protein is much lower compared to that caused by equivalent amounts of Zn2 + free. The fact that MTPA affects mitochondrial oxygen consumption in hepatopancreas of crustaceans is the first study of its kind in invertebrates, and is consistent with other outcomes described in the literature for mammals, which suggests a relationship of metalotioneínas with energy metabolism.

Author: GOMEZ LARA ISABEL.
Year: 2004.
University: ROVIRA I VIRGILI [More theses of this university] [www.urv.cat].
Place of defense: FACULTAD DE QUIMICA.
Place of preparation: FACULTAD DE QUIMICA.

Summary: This thesis is nemarca dentre of work done in the Grup Quantum Chemistry of the Rovira i Virgili University, and she has dealt with the theoretical study of several photosensitive molecular systems of interest sintétivo and tecnologíco. Using methods ab inito has allowed an assessment of the nature of excited states involved, the geometries and energies of the species are formed and the mechanisms leading to its photochemical transformations, as well as to examine the effect produced in the reaction mechanism by factors the variation of substituent groups or the reaction medium. This has required the analysis of the potential energy surfaces of the excited states of lower energy in each of the systems in which they are produced by photochemical reactions studied. It is essential to identify critical points (minimum and estdos Transition), reaction paths and points of interaction between surfaces, as are conical intersections, junctions and crossings real avoided. An indispensable condition, which involves a major difficulty added, it is necessary to carry out such calculations with an accuracy similar to that of the ground state, so it is essential use of a methodology ab initio to provide an accurate description of surfaces potential energy of the excited states involved. This report is structured as follows: Chapter 2 consists of a general introduction, which includes the basic aspects to be considered in photochemical reactions, while Chapter 3 describes the theoretical methods that have been used in the study of reactions studied. Chapter 4 is devoted to the study of the mechanisms of the different photochemical transformations suffering derivatives Bicycle [3.1.0] -3-hexen-2-onas, has been compared reactions competitive and determined the electronic nature of the intermediate reaction that is generated. This chapter also contains the tautomerización cetofenólica because it is the last stage of reaction of a transposition of biciclohexenonas, yel mechanism interconversion between isomers's largest phenol. It has also evaluated the enthalpy of decoupling of the link in the OH molecule phenol and its barrier internal rotation. In chapter 5 has been studied with different groups donor-aceptor in which reactions can occur transfer intramolecular load. It has identified the mechanism by which these reactions occur, the electronic nature of the species involved and the role of the reaction medium in fenímeno of dual - fluorescence. Chapter 6 deals with the processes taking place in molecules whose properties reversibly colors can be exchanged through the use of a radiation source. In particular have been studied cis-and trans-isomers of the molecule merocianina and has established the mechanism of the photochemical reaction that leads to the formation of the molecule benzopirano. Finally, Chapter 7 presents the main conclusions drawn from the previous chapters.

Author: AMPLE NAVARRO FRANCISCO.
Year: 2004.
University: ROVIRA I VIRGILI [More theses of this university] [www.urv.cat].
Place of defense: FACULTAD DE QUIMICA.
Place of preparation: FACULTAD DE QUIMICA.

Author: VALCÁRCEL ORTÍ ANA.
Year: 2004.
University: ROVIRA I VIRGILI [More theses of this university] [www.urv.cat].
Place of defense: FACULTAD DE QUÍMICA.
Place of preparation: FACULTAD DE QUÍMICA.

Author: Ramírez Ramírez Víctor Miguel.
Year: 2004.
University: VALENCIA [More theses of this university] [www.uv.es].
Place of defense: Facultat de Química.
Place of preparation: Universidad de Valencia.

Summary: During the enjoyment of the Fellowship Predoctoral Training Staff Researcher of the Generalitat Valenciana Fellow D. Victor Miguel Ramirez Ramirez has worked on the draft Doctoral Thesis for the theoretical study of mechanisms of oxidation of interest in atmospheric chemistry, particularly the reactions of oxidation terpenos, isoprene, and related compounds. The terpenos studied have been the a-pineno, b-pineno and d-limoneno. It has elucidated the mechanism of degradation a-pineno initiated by the OH radical, analyzing the possible reaction pathways, and with particular emphasis on the initial reaction of radical oxidative attack. We have used the methods of calculation AM1 (to conduct preliminary exploration of the potential energy hypersurface), and functional B3LYP. In addition, calculations have been performed HF and UMP2 to study the initial reaction of OH addition of abstraction or H on this monoterpeno. For b-pineno and d-limoneno has conducted a detailed study of the initial reaction of OH addition to all the carbon atoms, through all possible sides of the double bonds that exist in these molecules. The methodology has been the method UMP2 to perform optimization geometries, and calculations off QCISD (T) on the structures optimized UMP2, for the refinement of the potential energy. Terpenos addition to the above, a study has been made of the mechanism of oxidation of isoprene, initiated by the OH radical in the same way as for a-pineno. After a preliminary exploration of the potential energy hypersurface using the semi-AM1, have studied the reactions of training concerning some of the major degradation products, such as metilvinilcetona, formaldehyde and some of the compounds hidroxicarbonílicos identified experimentally. On the metilvinilcetona, has studied the reaction of formation of the two isomers of the molecule through calculations B3LYP and BHandHLYP, and the method UMP2. It also shows the reaction of interconversion of the two isomers, locating the corresponding state of transition, not described so far. The formation of formaldehyde has been studied from the reaction of radical CH2OH with O2. Our results show the presence of a state of transition for the addition initial O2 not seen to date for this reaction. We have optimized the stationary points of the potential energy hypersurface with methods UMP2 and QCISD. In addition, calculations have been performed off QCISD (T) on the geometries optimized QCISD, to refine the values of potential energy. For the state of transition TS1 has been made extra calculations at CCSD for the optimization, and calculations off CCSD (T) on the structure optimized QCISD. In addition, calculations have been performed Restricted Active Space SCF (RASSCF), with the help of the program MOLCAS. Finally, we have studied the evolution of two radiclaes dihidroxialquilo, originated as degradation products of isoprene by the intermediate radical OH, resulting in the formation of two hidroxicarbonilos identified experimentally. The geometry optimization has been carried out with the method UMP2, while it has used the method QCISD (T) on the geometries UMP2 to refine the values of potential energy. In addition to these works, the scholar D. Victor Miguel Ramirez Ramirez has worked actively with other members of the research group, the study of the reaction between HCO radical and O2, and the reaction between compound H2NO and O3.

Author: MERINO MEROÑO BEATRIZ.
Year: 2004.
University: MURCIA [More theses of this university] [www.um.es].
Place of defense: FACULTAD DE BIOLOGIA.
Place of preparation: FACULTAD DE QUÍMICA.

Summary: Studies in this report are grouped into two parts. Part One deals with the Especiación arsenic and Tin hybridization using chromatography Líquida-Generación of Hidruros-Espectroscopía of Atomic Absorption (LC-HG-AAS) in different types of food and has been divided into two chapters. In Chapter I is a procedure for optimizing speciation five arsenic compounds, As (III), As (V), acid monometilarsónico acid dimetilarsínico and arsenobetaína by coupling LC-HG-AAS. The hybridization of both techniques is specific and sensitive detection limits are adequate to determine arsenic compounds and their speciation in the quality control of baby food and fish used in its preparation. Subsequently, deepened stability in the levels of arsenobetaína in baby food during its manufacture and aging. In Chapter II proposes the implementation of the coupling LC-HG-AAS to speciation six tin forms: inorganic tin, tributyltin, dibutilestaño, monobutilestaño, difenilestaño and monofenilestaño. The method has been applied to the speciation of organotin compounds in mussels. Part Two has been distributed into three chapters dealing with the Especiación Selenium, and Antimony Tellurium using hybridization Chromatography Líquida-Generación of Hidruros-Espectroscopía of Atomic Fluorescence (LC-HG-AFS) in different types of foods and environmental samples. In Chapter III optimizes the speciation of different forms of selenium. It has been optimized technique coupled LC-UV-HG-AFS for determining online Se (IV), Se (VI), selenocistina and selenomethionine. The separation takes place acoplando series two columns of ion exchange and reversed phase. The procedure for the speciation of selenium has been applied to different samples of infant formula and nutritional supplements and validation of the method was carried out using a certified reference material. Chapter IV contains a procedure for the speciation of three species of antimony. We studied the speciation of Sb (III) Sb (V) and trimetilantimonio using coupling LC-HG-AFS and LC using anion exchange with complexing agents in the mobile phase. The procedure was applied to the analysis of different samples of water and soil certificates. Finally, Chapter V deals with the speciation of tellurium. Conducted speciation Te Te (IV) and (VI) using LC-HG-AFS with an anion-exchange column and complexing agents, EDTA and anion phthalate, in the mobile phase. The procedure was applied to different water samples. In all chapters are optimized carefully chromatographic separations, the variation of the factors holding of the various forms of chemical elements in the composition of the mobile phase and, if necessary, the use of technical by gradient elution to get separate all compounds in a time of proper analysis and with good resolution. Then, the system is optimized hydride generation, studying the influence of the concentration of the various variables in order to achieve the maximum sensitivity, also selects the optimal experimental conditions detection system and assesses calibration and repetitiveness of the methods . Then apply the procedures developed to the analysis of different types of foods and environmental samples, and finally to validate the methods developed using certified reference materials when you can have them.

Author: Aguinaga Pardo Nerea.
Year: 2004.
University: MURCIA [More theses of this university] [www.um.es].
Place of defense: Sala de Grados de la Facultad de Biología.
Place of preparation: Facultad de Química.

Summary: This Doctoral Thesis deals with the determination of toxic organic compounds and organometallic samples mediambientales and food by gas chromatography with detection by atomic emission. The thesis is divided into two main blocs. The first focuses on the identification of toxic organic compounds and is in turn divided into four chapters, corresponidentes the determination of pesticides, volatile halogenated organic compounds, chlorophenols and tricloroanisol. The determination of pesticides, volatile organic compounds and halogenated chlorophenol was applied to the analysis of water and soil, expanding in the case of volatile halogenated organic compounds its scope to beer and fruit juices. Determining tricloroanisol was applied to samples of wine and cork, being primarily responsible for the "old flavor in the wine, defect associated with the corks used in their embotallamiento. The second block of the thesis focuses on the speciation of metals and is divided into two chapters, for the determination of organic tin compounds and selenium respectively. The determination of tin compounds are applied again to the analysis of water and soil and in the case of selenium compounds analysis was performed to plant and water samples. In each of the chapters have been optimized parameters for the chromatographic separation, the detection system and method for preconcentration. He then has been carried out calibration and statistical study. The siguinte step has been optimizing the extraction procedure of the analytes from the sample as well as studies of recovery. Lastly, each method was applied to the analysis of real samples above. In every chapter except Chapter I, determination of pesticides, was used as a system preconcentration purge and trap that gave excellent results achieved in all cases detection limits satisfactory. It is also important to emphasize the use in the treatment of solid samples of an ultrasonic probe that will allow them to achieve recoveries of the various analytes excellent in a time much less than with conventional treatments. In summary, the procedures set up in this Doctoral Thesis allow the determination of toxic organic and organometallic compounds in samples of water, soil and food through the technique of gas chromatography with atomic emission detector routinely, with minimal treatment and fast the samples, giving percentages of recovery and detection limits highly acceptable.

Author: IBAÑEZ LLANO ANA.
Year: 2004.
University: AUTÓNOMA DE MADRID [More theses of this university] [www.uam.es].
Place of defense: UNIVERSIDAD AUTÓNOMA DE MADRID.
Place of preparation: UNIVERSIDAD AUTÓNOMA DE MADRID.

Summary: The electroplating of metals, base industry galvanotécnica is an area of great interest from a technological point of view, especially as regards the production of coatings with particular properties. One of the areas in which the electroplating technique is generating a lot of interest in recent years, is the production of materials nanocristalinos (ie those with grain sizes in the range naometros) which are gaining great importance technological and offering interesting properties that can not be obtained from conventional crystalline solids. The morphological characteristics, structural, etc.. In metallic films obtained electroquímicamente have been widely studied in relation to the parameters used in the electroplating. In contrast, and surprisingly, have estudiGldo much less their properties mecánias though an important factor in quality control of the industry. In recent decades are witnessing the rise of the electrochemical synthesis of other coatings such as polymer drivers. These materials possess unique characteristics that make up the physical properties and chemical properties of the polymers with the ability to conduct electricity. As in the case of metallic coatings, their mechanical properties have not been explored to the same extent that has been studied a number of other properties, such as its ability to protect against corrosion or electrical properties. In assessing the mechanical resistance of a material should take into account both its hardness as its elasticity. Until relatively recently, the methods of assessing only allowed indentation hardness. The recent development of methods sensitive to the depth also allows for information on the elasticity, which allows a better mechanical characterization of materials. The main objective of the work of the thesis is to establish correlations between variables electroplating and the mechanical properties submitting deposits, hardness and module Young. The evaluation of these relationships will allow "prediseñar" coatings with special features specific to post specific applications. The work has focused on the study of: a) electrodepósitos copper b) electrodepósitos nickel and c) a poly mere driver, polipirrol.

Author: CORRAL PÉREZ INÉS.
Year: 2004.
University: AUTÓNOMA DE MADRID [More theses of this university] [www.uam.es].
Place of defense: FACULTAD DE CIENCIAS UNIVERSIDAD AUTÓNOMA DE MADRID.
Place of preparation: FACULTAD DE CIENCIAS UNIVERSIDAD AUTÓNOMA DE MADRID.

Summary: This thesis seeks to deepen the understanding and study of the link and reactivity systems cation molecule biochemical and industrial interest. This study has ranged from systems where interactions are essentially electrostatic nature, namely complex alkali metals and alcalino-térreos up systems where the covalent character is not negligible as in those complexes involved in the transition metals. In the case of systems essentially covalent nature, we have focused on the study of the complex formed between metal cations of the first series of transition, as Cu + Ni + Co + with neutral presenting an important polarity X (delta +) - H (delta-), which favors the emergence of interactions type agóstico, including certain derivatives saturated and unsaturated methane and silane German, as well as hydrides of the groups 1, 2 and 13. The importance of these complex at the possible implications that this type of interaction can take link activation processes, catalysis and the semiconductor industry. The activation of links Si-Hy Ge-H of silanos and Germans is the basis for the production of hydrogenated amorphous films of sílicio and germanium, materials used in the construction of solar cells, thin film transistors (TFTs), detectors, photoreceptors , and diodes emísores light (LED). These interactions agósticas can be considered as links to three centers No electrons as a result of the donation from orbital enlazantes (sigma) XH the orbital base to empty the metal cation transition followed by a retrodonación from orbital filled with the metal cation until orbital ( sigma) 'XH of the base. As a result, these interactions lead to the weakening of the links XH involved, the increase of such distances liaison, the decrease in density in the critical points liaison and redshift of frequencies voltage of these links. These effects are all the more important as it descends into a group and when you move from right to left at any time, a fact directly associated with the decline in electronegatividacl of heteroátomo and 01 concomitant increase in the polarity X (delta +) H (delta -). The topological analysis of the density of Bader, the analysis of populations NBO alongside the experimental spectra of InfraRojo are extremely versatile tools for the detection and characterization of these interactions agósticas. Moreover, the importance of metals of the groups 1 and 2 in biological contexts has led us to study their reactivity compared to molecules such as glycine and urea, simple prototype peptides and nucleotides. It is important to stress that this is the first time you get isolate dicationes [Urea-Ca] 2 + and [Glicina-Ca] 2 +, and therefore, the first time it was carried out jointly a theoretical and experimental study of these species. Despite the similarity between the two systems, substantial differences were found in their reactividades. In the case of system Urea-Ca2 +, processes nimoleculares associated with the loss of neutral fragments (NH3 and HNCQ) competing processes coulombianos leading to the monocationes CaNH2 + H2NCO + NCOCa + and NH4 +. By contrast, in the case of system Glicina-Ca2 + products are observed experimentally: CaCO2H + CH2NH2 + + CaOH and COCH2NH2.f are caused exclusively on processes explosion coulombiana. Aúnque for the case of Glycine also noted the formation of Carbon monoxide is a by-product of decomposition unimolecular other monocationes "primary generated through explosions coulombianas above. These differences are justified through particular features of the potential energy surfaces of both systems. system Urea-Ca2 + For the most explosions coulombianas are preceded by a series of processes that involve the transfer of Hidrógenos and barriers involving similar reaction, or is greater than those that lead to 8 the pérd 3dc leg fragments neutr (Js. In the case of system Glicina-Ca2 +, in contrast, processes explosion coulombiana have their origin in adducts formed directly from the interaction between dicatión and neutral and besides some of them occur through barriers much lower than those involved in the isomerization of these complexes. methodology utilizadá in the thesis is based on the theory of functional density while in relevant cases has conducted a validation the methodology OFT through the use of methods of high-level ab initio.

Author: MARTÍNEZ SÁNCHEZ JESÚS MARÍA.
Year: 2004.
University: SANTIAGO DE COMPOSTELA [More theses of this university] [www.usc.es].
Place of defense: FACULTAD DE QUÍMICA.
Place of preparation: FACULTAD DE QUÍMICA (CAMPUS SUR).

Summary: This dissertation deals with the synthesis and characterization of metal complexes with ligands macrocíclicos and a ligand compartment prepared from previously precursor synthesized in our laboratory. Once prepared the ligands are carried out complexation reactions with various metal salts of alkali metals, alkaline, transitional, post-transicionales and lantánidos. All ligands and complex obtained were characterized by different techniques among which diffraction and nuclear magnetic resonance of rayox X. These techniques give us information about the structure in solution and solid state of the compounds obtained.