ANTIMETABOLITES

Author: PEÑUELAS PRIETO SILVIA NURIA.
Year: 2004.
University: BARCELONA [www.ub.es].
Place of defense: FACULTAD DE FARMÁCIA.

Author: ZINE NADIA.
Year: 2004.
University: AUTÓNOMA DE BARCELONA [www.uab.es].
Place of defense: CENTRO NACIONAL DE MICROELECTRÓNICA.
Place of preparation: ESCUELA DE POSTGRADO.

Summary: Work done to the thesis has been focused on the development and study of multi-chemical-based silicon for biomedical applications. This work is divided into three parts: The first part has been manufactured sensors based on silicon field effect transistors sensitive to ions (ISFET). The device comes in the form of needle and includes two sensors ISFETs a pseudo-electrodo reference platinum and a temperature sensor based on a platinum resistance. The ISFETs have caracaterizado electrically and chemically MOSFET transistors as sensors as pH, with satisfactory results, which has demonstrated the feasibility of manufacturing technologies. We have developed MEMFETs selective in potassium ion depositing on the ISFET a PVC polymer membrane containing the valinomicina as ionóforo. Sensors showed a response of 50 mV / decade or so, in the range of activity of K + ion ranging from 10 -4M until 10 -1M. Because of its huge size, the standard reference electrode is not practical to work with ISFETs. Thus has been studied conducting using differential measures in addition to the MEMFET potassium, a ISFET reference (REFET) and the pseudo platinum electrode embedded in the device allowing the substitution of reference electrode. THE REFET was fabricated by depositing a membrane polymer PVC inert. To improve the adhesion of the membrane to the surface of REFET there has been a process silanización the surface, consisting of chemically modifying the surface of the dielectric, so as to create links through which the membrane is well attached to the device. It also marked the temperature sensor based on a platinum resistance integrated into the needle. The results obtained are very linear and repetitive, with a value of the temperature coefficient of resistance CRT 3687 + -3 ppm / C. In the second part of the thesis, have developed solid state microelectrodos sensitive to hydrogen ion in the form of needle silicon-based polymeric membranes, using as ionophores the Chromoionoforo I (ETH 5294) and Tri-n-dodecilamino (TDDA ). It has been deposited on the platinum microelectrodos a new polymeric materials driver; polipirrol doped with anion cobaltabisdicarballuro [3.3 '-Co (1,2-C2B9H11) 2] - through technique electropolimerización. This polymer acts as a layer between the membrane and platinum. The use of this intermediate stage significantly increases the adhesion of PVC membrane on the surface of the transducer and thus the lifetime. The response characteristics of genetic microelectrodos are very satisfactory. The devices have a sensitivity nernstiana in a wide range of response (pH 3.5-11.0). The coefficients of selectivity poenciometricos obtained showed good selectivity of microelectrodos alión hydrogen in the presence of ions such as potassium, sodium and lithium. The last part of this work has been aimed at finding solutions to difficulties that have been encountered in using chemistry of MEMFETs sensitive K + ion. In this regard, it has studied the modification of silicon oxide used at the door of the ISFET to vary its selectivity to specific ions. This has been fabricated structures capacitive-sensitive potassium ion using inorganic membranes based on the technique of ion implantation ion aluminum and postasio in the silicon oxide. The structures have been characterized using the technique capacidad-tensión (CV) of high frequency. The characteristics of both response and 8 n obtained as 339 to selectivity and sensitivity have been acceptable and comparable to those found in the literature.

Author: HERNÁNDEZ DE ROJAS ALMA.
Year: 2004.
University: OVIEDO [www.uniovi.es].
Place of defense: FACULTAD DE BIOLOGÍA.
Place of preparation: FACULTAD DE MEDICINA UNIVERSIDAD DE VALLADOLID.

Summary: Lactococina 972 is a bacteriocina strain produced by Lactococcus lactis subsp.lactis IPLA 972. The genetic determinants necessary for the production of the bacteriocina and immunity to the same lie in the plasmid pBL1 (10.9 Kb). It is flanked by two regions differ sequences insertion ISS1. This suggests that the plasmid could be a mosaic created from the merger of two replicones different. One of the regions harbors genes replication, and the other genes responsible for the biosynthesis / immunity. The latter form a single operán consisting of the gene structural lclA, whose product is a polypeptide of 91 amino acid peptide which includes the signal, and genes lclB and lclC whose products peptídicos have the characteristics of an ABC transporter and are involved in immunity compared to the bacteriocina. Among the bacteriocins produced by lactic acid bacteria, lactococina 972 has a unique mode of action and to inhibit the formation of the septum division, similar to the effect exerted by certain antibiotics beta-lactámicos. The detection of penicillin-binding proteins (PBPs) in Lactococcus lactis, a species sensitive to bacteriocina allowed to reveal that the white that binds the bacteriocina is PBP4, protein of 55 kDa. This protein is similar structurally (functionally? Do you) PBP3 of E.coli, which is a transpèptidasa whose inhibition prevents the formation of the septum, which translates into a filamentation of crops. Also, as beta-lactámicos certain antibiotics that bind exclusively to PBP3 of E.coli induce the SOS response, lactococina 972 induces this response L.lactis. As a result of it, there is induction and profago in strain lisogénica L.lactis MG1614, which is further evidence of the action of bacteriocina on functional counterpart in L.lactis of PBP3. The synthesis of lactococina 972 shows a very kinetics of metabolism associated with growth, evolving in parallel with biomass during the exponential phase of growth in the producer strain. In continuous cultivation (quimiostato), the synthesis of a bacteriocina occurs primarily in rates close to delay the umax, confirming its metabolites associated with growth.

Author: DE LOS SANTOS APARICIO MARIO.
Year: 2004.
University: ZARAGOZA [www.unizar.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: CENTRO POLITECNICO SUPERIOR.

Summary: THE THESIS DOCTORAL VERSA ON THE DEVELOPMENT OF ANALYTICAL METHODOLOGY FOR THE DETERMINATION OF VARIOUS ANALYTES ON PAPER. ANALYTES INCLUDE THESE AGENTS BLANQUEANTES, THE AZO DYES AND AMINAS AROMATICAS. METHODS OF ANALYSIS IS DEVELOP THROUGH THE DETERMINATION OF LIQUID CHROMATOGRAPHY HIGH RESOLUTION ACOPLADA A DIFFERENT TECHNIQUES FOR SCREENING (ESPECTROMETRIA OF MASSES, OR FLUORESCENCIA ABSORPTION UTRAVIOLETA) BY OTHER SIDE, HAS BEEN OPTIMIZADO A METHOD FOR REMOVAL OF ANALYTES PAST THE MATRIX CELULOSICA THROUGH THE USE OF ULTRASONIC AND USE OF WATER PRESURIZADA A HIGH TEMPERATURE. METHODS OF GENERAL HAS COMPARATIVE OFFICIAL WITH DIFFERENT METHODS AND VALIDADO PARTLY.