A presente tese relata o estudo conformacional e das interações eletrônicas de algumas α-feniltio-acetatos de etila para-substituídos e suas formas mono- e di-oxigenadas EtOC(O)CH2SOn-Φ-X (p) (I) e de alguns α-feniltio-tioacetatos de etila para-substituídos e sua forma mono-oxigenada EtSC(O)CH2SOn-Φ-X (p) (II), [ n =0 (a), 1 (b) e 2 (c) para (I)] e [n= 0 (a) e 1 (b) para (II)], sendo X substituintes atraentes, hidrogênio e doadores de elétrons. Este estudo foi realizado através da espectroscopia no infravermelho e cálculos ab initio HF/6-31G**. Nos α-ester-sulfetos (Ia) e α-tioester-sulfetos (IIa) as conformações gauche são fortemente estabilizadas pelas interações orbitalares π*co/ σc-s (hiperconjugativa) e π*co/ns. Nos β-ester-sulfóxidos (Ib) e β-tioester-sulfóxidos (IIb) enquanto a s conformações gauche são estabilizadas pela interação orbitalar πco/ σ*c-so, a conformação cis é estabilizada pela interação no(co)→π*SO. Nas β-ester-sulfonas (Ic) o confôrmero menos polar e mais estável gauche é fortemente estabilizado pelas interações Coulombicas e orbitalares Oδ-(CO) → Sδ+(SO2) e Oδ-(SO2) → Cδ+(CO), enquanto que o confôrmero gauche 1 é estabilizado por esta ultima interação e desestabilizado pela interação repulsiva entre os oxigênios negativamente carregados dos grupos C(O)OEt e SO2Et. / This thesis reports the conformational and electronic interaction studies of some ethyl α-phenylthio-acetates and their mono-and di-oxygenated derivatives EtOC(O)CH2SOn-Φ-X (I) [for n=0 (a), l(b), and 2 (c)] and some ethyl α-phenylthio-thioacetates and their mono-oxygenated derivatives EtSC(O)CH2SOn-Φ-X (II) [for n= 0 (a) and 1 (b)], bearing at the para position electron-attracting, hydrogen and electron-donating substituents. This study was performed by means of infrared spectroscopy and HF/6-31G** ab initio calculations. For the β-ester-sulfides (Ia) and β-thioester-sulfides (IIa) the more stable gauche conformers are strongly stabilised by the π*co/ σc-s and π*co / ns orbital interactions. As for the β-ester-sulfoxides (Ib) and β-thioester-sulfoxides (IIb) while the gauche conformers are stabilised by the πco/ σ*c-s orbital interaction, the cis conformer is stabilised by the no(co) → π∗co interaction. For the β-ester-sulfones (Ic) the least polar and most stable gauche rotamer is strongly stabilised by the crossed Oδ-(CO)→ Sδ+(SO2) and Oδ-(SO2)→ Cδ+(CO) Coulombic and orbital interactions, while the least stable gauche1 rotamer is stabilised by this latter interaction and destabilised by the repulsive interaction between the negatively charged oxygen atoms of the C(O)OEt and SO2Et groups.

En la presente tesis doctoral se desarrollan una serie de procedimientos para evaluar el estado de los diversos componentes bióticos (fitoplancton, macroalgas, invertebrados bentónicos) y abióticos (calidad fisicoquímica de las aguas) del medio marino en relación a la incidencia humana sobre el mismo. El objetivo de dichos procedimientos es dar respuesta a las exigencias establecidas en la Directiva Marco del Agua (Directiva 2000/60/CE) en lo que respecta a la evaluación del estado ecológico de las masas de agua costeras. En este sentido, además de ampliar el conocimiento existente sobre las características fisicoquímicas y biológicas de las masas de agua costeras de Cantabria, constituye una importante aportación tanto desde el punto de vista científico como desde el punto de vista de la gestión. Entre las contribuciones más destacadas de esta tesis cabría mencionar el desarrollo del Índice de Calidad de Fondos Rocosos (CFR) para la valoración de las comunidades de macroalgas costeras. / In this PhD. Thesis, several procedures are developed to assess human influence on the status of the marine environment biotic (phytoplankton, macroalgae, benthic invertebrates) and abiotic (physicochemical quality of water) components. The purpose of these approaches is to meet the requirements of the Water Framework Directive (2000/60/EC) regarding the ecological status assessment of coastal water bodies.In this sense, besides increasing the existing knowledge on the physicochemical and biological characteristics of the Cantabrian coastal water bodies, it provides an important contribution both from a scientific and a management point of view. One of the most outstanding contributions of this thesis is the development of the Quality of Rocky Bottoms Index (CFR) for the assessment of coastal macroalgae communities.

Ένα από τα σημαντικότερα προβλήματα που προκύπτουν από την χρήση εμφυτευμάτων και ιατρικών συσκευών και που εμποδίζουν την μακροχρόνια χρήση τους είναι η εμφάνιση νοσοκομειακών σηψαιμικών επεισοδίων σχετιζόμενων με λοιμώξεις που προκαλούνται από πηκτάση αρνητικούς σταφυλόκοκκους, και κυρίως από τον S. epidermidis. Με δεδομένο ότι η εκτεταμένη χορήγηση αντιβιοτικών έχει οδηγήσει στην επικράτηση πολυανθεκτικών βακτηριακών στελεχών της φυσιολογικής χλωρίδας, η κατασκευή αντιβακτηριακών ή και βακτηριοστατικών βιοϋλικών κρίνεται επιβεβλημένη. Για το σκοπό αυτό απαραίτητη είναι η μελέτη και η κατανόηση του μηχανισμού προσκόλλησης των βακτηρίων στην επιφάνεια του βιοϋλικού. Στην κατεύθυνση αυτή διερευνήθηκε η επίδραση των φυσικοχημικών αλληλεπιδράσεων βακτηρίων-υλικών, του ρυθμού διάτμησης και της σχετικής συνεισφοράς τους στην ικανότητα των βακτηρίων να προσκολλώνται στην επιφάνεια του βιοϋλικού αλλά και να ενεργοποιούν τα γονίδια ica που είναι υπεύθυνα για την παραγωγή της εξωκυττάριας βλεννώδους ουσίας (slime) και συγκεκριμένα μιας πολυσακχαρικής φύσεως προσκολλητίνης (polysaccharide intercellular adhesin, PIA). Για τη μελέτη αυτή τροποιήθηκαν επιφανειακά με τεχνικές πλάσματος υπάρχοντα βιοϋλικά, παρασκευάστηκαν αυτό-οργανούμενα μονοστρωματικά συστήματα σε γυαλί και χαρακτηρίστηκαν φυσικοχημικά. Ελέγθηκε επίσης εάν οι θεωρίες κολλοειδών συστημάτων, και συγκεκριμένα η θερμοδυναμική, η DLVO και η εκτεταμένη DLVO μπορούν να εξηγήσουν τα πειραματικά αποτελέσματα. Τα αποτελέσματα έδειξαν ότι η βακτηριακή προσκόλληση μειώνεται με την αύξηση της επιφανειακής ενέργειας και του πολικού χαρακτήρα των υλικών, ενώ δεν επηρεάζεται σημαντικά από το μη πολικό τους χαρακτήρα. Η θερμοδυναμική θεωρία εξήγησε ικανοποιητικά τα αποτελέσματα για υψηλής ιοντικής ισχύος διαλύματα, ενώ η DLVO για χαμηλής. Η εκτεταμένη DLVO θεωρία εξήγησε ικανοποιητικά την επίδραση της φυσικοχημείας τόσο του διαλύματος όσο και της επιφάνειας στη βακτηριακή προσκόλληση. Η αύξηση του ρυθμού διάτμησης μείωσε την προσκόλληση των βακτηρίων με τρόπο που εξαρτώνταν από τις φυσικοχημικές αλληλεπιδράσεις βακτηρίων-υλικών, ενώ παράλληλα μείωσε την προβλεψιμότητα των παραπάνω θεωριών. Επομένως, η βακτηριακή προσκόλληση θεωρήθηκε ως αποτέλεσμα του συνδιασμού φυσικοχημικών αλληλεπιδράσεων και σχηματισμού μακρομοριακών δεσμών. Τα αποτελέσματα από τη μελέτη της έκφρασης των γονιδίων ica έδειξαν ότι η έκφρασή τους αυξάνεται με την μείωση της επιφανειακής ενέργειας του υλικού και την αύξηση του ρυθμού διάτμησης. / One of the major problems arising from the use of implants and medical devices and impeding their long-term use is the emergence of nosocomial septic incidents related to infections caused by Coagulase negative staphylococci, most notably by S. epidermidis. The extensive use of antibiotics has resulted in multi-resistant bacterial strains of normal flora, making the need for developing antibacterial biomaterials of great importance. For this purpose it is necessary to study and understand the mechanism of bacterial adhesion to the surface of biomaterials. In this direction, we investigated the influence of the physicochemical interactions between bacteria and materials, the shear rate and their relative contribution on the ability of bacteria to adhere to the biomaterial surface and to activate the ica genes, which are responsible for the production of extracellular polymeric (slime), and in particular for the production of polysaccharide intercellular adhesin (PIA), that mediates cell-cell interactions. For this study, the surface of existing biomaterials was modified by plasma methods, self-assembled monolayers were prepared on glass, and the materials were physicochemicaly characterized. The applicability of the colloidal theories, such as the thermodynamic, the DLVO and the extended DLVO, for the prediction of bacterial adhesion was examined as well. The results showed that the increase in material surface energy and its polar component reduced bacterial adhesion, whereas adhesion was not significantly influenced by the non-polar character of the material surface. The thermodynamic theory explained satisfactorily the results for high ionic strength solutions, while DLVO for solutions with low ionic strength. The extended DLVO theory explained well the effects of both the solution and material surface properties to bacterial adhesion. The increase in shear rate reduced the number of adherent bacteria in a manner that depended on the bacteria-material physicochemical interactions, but not in the way that the above theories predicted. Therefore, bacterial adhesion considered as the result of a combination of the physicochemical and hydrodynamic interactions, and the formation of macromolecular bonds. The investigation of ica genes expression showed that the expression enhanced by the decrease in the material surface energy the increase in shear rate.

A presente tese relata o estudo conformacional e das interações eletrônicas de algumas α-feniltio-acetatos de etila para-substituídos e suas formas mono- e di-oxigenadas EtOC(O)CH2SOn-Φ-X (p) (I) e de alguns α-feniltio-tioacetatos de etila para-substituídos e sua forma mono-oxigenada EtSC(O)CH2SOn-Φ-X (p) (II), [ n =0 (a), 1 (b) e 2 (c) para (I)] e [n= 0 (a) e 1 (b) para (II)], sendo X substituintes atraentes, hidrogênio e doadores de elétrons. Este estudo foi realizado através da espectroscopia no infravermelho e cálculos ab initio HF/6-31G**. Nos α-ester-sulfetos (Ia) e α-tioester-sulfetos (IIa) as conformações gauche são fortemente estabilizadas pelas interações orbitalares π*co/ σc-s (hiperconjugativa) e π*co/ns. Nos β-ester-sulfóxidos (Ib) e β-tioester-sulfóxidos (IIb) enquanto a s conformações gauche são estabilizadas pela interação orbitalar πco/ σ*c-so, a conformação cis é estabilizada pela interação no(co)→π*SO. Nas β-ester-sulfonas (Ic) o confôrmero menos polar e mais estável gauche é fortemente estabilizado pelas interações Coulombicas e orbitalares Oδ-(CO) → Sδ+(SO2) e Oδ-(SO2) → Cδ+(CO), enquanto que o confôrmero gauche 1 é estabilizado por esta ultima interação e desestabilizado pela interação repulsiva entre os oxigênios negativamente carregados dos grupos C(O)OEt e SO2Et. / This thesis reports the conformational and electronic interaction studies of some ethyl α-phenylthio-acetates and their mono-and di-oxygenated derivatives EtOC(O)CH2SOn-Φ-X (I) [for n=0 (a), l(b), and 2 (c)] and some ethyl α-phenylthio-thioacetates and their mono-oxygenated derivatives EtSC(O)CH2SOn-Φ-X (II) [for n= 0 (a) and 1 (b)], bearing at the para position electron-attracting, hydrogen and electron-donating substituents. This study was performed by means of infrared spectroscopy and HF/6-31G** ab initio calculations. For the β-ester-sulfides (Ia) and β-thioester-sulfides (IIa) the more stable gauche conformers are strongly stabilised by the π*co/ σc-s and π*co / ns orbital interactions. As for the β-ester-sulfoxides (Ib) and β-thioester-sulfoxides (IIb) while the gauche conformers are stabilised by the πco/ σ*c-s orbital interaction, the cis conformer is stabilised by the no(co) → π∗co interaction. For the β-ester-sulfones (Ic) the least polar and most stable gauche rotamer is strongly stabilised by the crossed Oδ-(CO)→ Sδ+(SO2) and Oδ-(SO2)→ Cδ+(CO) Coulombic and orbital interactions, while the least stable gauche1 rotamer is stabilised by this latter interaction and destabilised by the repulsive interaction between the negatively charged oxygen atoms of the C(O)OEt and SO2Et groups.

Poliuretana (PUR) é uma classe de polímeros que possui grupos uretânicos [-O-C(=O)-NH-] em sua estrutura e encontra diversas aplicações, inclusive na área biomédica. Esta versatilidade é devida ao uso de diferentes monômeros em sua síntese. O uso de isocianatos cicloalifáticos, um dos monômeros da PUR, é mais vantajoso em aplicações que requeiram uma maior estabilidade térmica e à radiação ultravioleta e maior resistência à hidrólise. Quando processadas inapropriadamente, as PUR baseadas em isocianatos aromáticos produzem compostos carcinogênicos, fato não observado para as PUR com isocianatos cicloalifáticos. Visando a aplicação biomédica, a PUR tem sido modificada através da incorporação de grupos iônicos à cadeia polimérica, formando ionômeros. A esterilização de materiais de uso biomédico é feita pelo emprego de óxido de etileno ou da radiação gama. Neste trabalho, visou-se a síntese e caracterização da PUR e do ionômero sultanado desta, baseadas em isocianato cicloalifático, além do estudo do efeito da radiação gama nos polímeros. Foi observado através da espectroscopia vibracional e análise elementar que se formam ligações de alofanato, uma ramificação da PUR linear. Comparando-se a PUR sintetizada com uma amostra comercial de PUR linear de uso biomédico, amorfa, verificou-se que a primeira apresentava cristalinidade. O estudo da cinética de decomposição térmica da PUR permitiu estabelecer o mecanismo com o qual acontece a decomposição. A estabilidade térmica e cristalinidade da PUR sulfonada são maiores que para a PUR, devendo estar relacionadas à contribuição dos grupos sulfonato. A PUR sulfonada tem um maior tempo de vida estimado que a PUR, nas temperaturas estudadas. A irradiação das amostras permitiu a verificação da oxidação do segmento do poliol e/ou extensor de cadeia, por meio da diminuição de intensidade das bandas relacionadas a este segmento nos espectros vibracionais e diminuição da cristalinidade por DSC. / Polyurethane (PUR) is a class of polymers that possesses urethane groups [O-C(=O)-NH-] in its structure and that find many applications, including biomedical ones. This variety is due to the use of different monomers in its synthesis. The use of aliphatic isocyanates, one of PUR monomers, is more valuable in applications that demand stability to UV radiation, resistance to hydrolysis, and a greater thermal stability. The aromatic isocyanate-based PUR produces, when processed incorrectly, carcinogenic compounds, a fact that is not observed in the cycloaliphatic isocyanate-based PUR. The PUR modification to use it in biomedical artifacts has been made, among some procedures, through the incorporation of ionic groups into the polymer chain, forming ionomers. The biomedical materials sterilization is made employing ethylene oxide or gamma radiation. The objectives of this work are the synthesis and characterization of PUR and its sulfonated ionomer, both based on a cycloaliphatic isocyanate, as well as the study of the effect of gamma radiation in the polymers. It has been observed the formation of allophanate linkages through the analysis of vibrational spectra and elemental analysis data. Comparing the synthesized PUR and a commercial, amorphous, linear PUR used in biomedical artifacts, it has been noted that the former has crystallinity. The kinetic study of thermal decomposition of PUR allowed to establish the decomposition mechanism of PUR. The thermal stability and crystallinity of sulfonated PUR are greater than of PUR, probably due to the contribution of sulfonic groups. The lifetime of sulfonated PUR is greater than that of PUR, in the temperature range studied. The samples irradiation has permitted the observation of poliol and/or chain extender oxidation, by means of the decreasing of the intensity of the vibrational bands related to these groups and the decreasing of crystallinity in DSC.

Poliuretana (PUR) é uma classe de polímeros que possui grupos uretânicos [-O-C(=O)-NH-] em sua estrutura e encontra diversas aplicações, inclusive na área biomédica. Esta versatilidade é devida ao uso de diferentes monômeros em sua síntese. O uso de isocianatos cicloalifáticos, um dos monômeros da PUR, é mais vantajoso em aplicações que requeiram uma maior estabilidade térmica e à radiação ultravioleta e maior resistência à hidrólise. Quando processadas inapropriadamente, as PUR baseadas em isocianatos aromáticos produzem compostos carcinogênicos, fato não observado para as PUR com isocianatos cicloalifáticos. Visando a aplicação biomédica, a PUR tem sido modificada através da incorporação de grupos iônicos à cadeia polimérica, formando ionômeros. A esterilização de materiais de uso biomédico é feita pelo emprego de óxido de etileno ou da radiação gama. Neste trabalho, visou-se a síntese e caracterização da PUR e do ionômero sultanado desta, baseadas em isocianato cicloalifático, além do estudo do efeito da radiação gama nos polímeros. Foi observado através da espectroscopia vibracional e análise elementar que se formam ligações de alofanato, uma ramificação da PUR linear. Comparando-se a PUR sintetizada com uma amostra comercial de PUR linear de uso biomédico, amorfa, verificou-se que a primeira apresentava cristalinidade. O estudo da cinética de decomposição térmica da PUR permitiu estabelecer o mecanismo com o qual acontece a decomposição. A estabilidade térmica e cristalinidade da PUR sulfonada são maiores que para a PUR, devendo estar relacionadas à contribuição dos grupos sulfonato. A PUR sulfonada tem um maior tempo de vida estimado que a PUR, nas temperaturas estudadas. A irradiação das amostras permitiu a verificação da oxidação do segmento do poliol e/ou extensor de cadeia, por meio da diminuição de intensidade das bandas relacionadas a este segmento nos espectros vibracionais e diminuição da cristalinidade por DSC. / Polyurethane (PUR) is a class of polymers that possesses urethane groups [O-C(=O)-NH-] in its structure and that find many applications, including biomedical ones. This variety is due to the use of different monomers in its synthesis. The use of aliphatic isocyanates, one of PUR monomers, is more valuable in applications that demand stability to UV radiation, resistance to hydrolysis, and a greater thermal stability. The aromatic isocyanate-based PUR produces, when processed incorrectly, carcinogenic compounds, a fact that is not observed in the cycloaliphatic isocyanate-based PUR. The PUR modification to use it in biomedical artifacts has been made, among some procedures, through the incorporation of ionic groups into the polymer chain, forming ionomers. The biomedical materials sterilization is made employing ethylene oxide or gamma radiation. The objectives of this work are the synthesis and characterization of PUR and its sulfonated ionomer, both based on a cycloaliphatic isocyanate, as well as the study of the effect of gamma radiation in the polymers. It has been observed the formation of allophanate linkages through the analysis of vibrational spectra and elemental analysis data. Comparing the synthesized PUR and a commercial, amorphous, linear PUR used in biomedical artifacts, it has been noted that the former has crystallinity. The kinetic study of thermal decomposition of PUR allowed to establish the decomposition mechanism of PUR. The thermal stability and crystallinity of sulfonated PUR are greater than of PUR, probably due to the contribution of sulfonic groups. The lifetime of sulfonated PUR is greater than that of PUR, in the temperature range studied. The samples irradiation has permitted the observation of poliol and/or chain extender oxidation, by means of the decreasing of the intensity of the vibrational bands related to these groups and the decreasing of crystallinity in DSC.