Dissertations / Theses on the topic 'Complex substrates'
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Alhijjaji, Fariha. "Studies on the microbial degradation of complex substrates." Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/10040/.
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Microorganisms, mainly bacteria and fungi, are key agents involved in the breakdown and decomposition of plant and animal polymers in ecosystems. The aim of this research project was to study the mechanisms of degradation of four complex substrates; keratin, pectin, alginate and chitin. In this study, keratinophylic fungi were isolated from agricultural soil via a hair-baiting technique (HBT) using wool and hair as baits; additionally, keratinophylic species were isolated from contaminated feathers. The isolates from hair, wool and feathers were grown on solid media supported by keratin azure as a source of carbon and nitrogen. Keratinolytic activities were observed by the formation of a clearing zone in the medium. A study of keratinolytic assay in shaking culture was made by measuring the activity of keratinase (release keratin azure). In addition, scanning electron microscopy (SEM) studies were included in this study. Qualitative assays of pectin degradation, using apple pectin as a carbon source are reported. Pectin degradation in plates was detected using a solution of iodine-potassium iodide. Pectinase activity was determined in the supernatants by release of reducing sugars (galacturonic acid) using dinitrosalicylate reagent (DNS). Antimicrobial activities of pectin esterified potassium salt against some pathogens partically the bacteria which cause infection in wounds was determined by measuring inhibition zones around the wells. Alginolytic microorganisms were isolated from two fresh seaweeds, namely Fucus and Laminaria. The enzymatic activities were quantified by the formation of new unsaturated non-reducing ends and as reducing sugar (RS). The amount of reducing sugar formed was determined using 3, 5-dinitrosalicylic acid (DNS) methods. Crab shell chitin was hydrolysed by acid to produce colloidal chitin. Fungal and bacterial isolates were tested to determine chitinolytic properties in plates by measuring purple zones against yellow background. The supernatants derived from selected isolates were then used to determine chitinase activity by measuring reducing sugars (RS). RS calculated as glucose using Nelson and DNS methods. The fertilizer-potential of the substrates was determined by measuring nitrification and the oxidation of sulphur in soil amendment with the individual complex substrates. A variety of bacteria and fungal isolates were identified using molecular identification techniques. Finally, four enzymes were isolated and partially purified using ammonium sulphate in order to determine their molecular weight using SDS polyacrylamide gel electrophoresis (SDS-PAGE). In addition, liquid chromatography mass spectrometry (LC-MS/MS) has been used to identify three enzymes namely; keratinase, pectinases and chitinases.
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Selander, Nicklas. "Catalytic Functionalization of Allylic Substrates by Palladium Pincer Complexes." Doctoral thesis, Stockholms universitet, Institutionen för organisk kemi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-39065.
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This thesis is based on the development of novel catalytic reactions for the synthesis and application of organometallic reagents. The main focus is directed towards organoboronate derivatives. We developed an efficient procedure for converting allylic alcohols to the corresponding allylboronates using palladium pincer complexes as catalysts. The reactions were performed under mild conditions with high selectivity, allowing further one-pot transformations. Using this approach, a variety of stereodefined homoallylic alcohols and amino acid derivatives were synthesized via trapping of the in situ generated allylboronate derivatives with an appropriate electrophile. The synthetic scope of these types of multi-component reactions is broad as many different substrate allylic alcohols may be used together with various electrophiles. Several aspects of these reactions were studied, including different reagents, catalysts and electrophiles. Furthermore, we studied the possibility to use oxidizing reagents as an essential component in the functionalization of olefins. Two main strategies were utilized for these catalytic methods using palladium pincer complexes. The functional group was either transferred from the oxidizing reagent, or introduced via an oxidation-transmetallation route. We propose that both methods involve palladium(IV) intermediates thus expanding both the coordination sphere of palladium and the synthetic scope of pincer complex catalysis.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 11: In press.
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Thoresen, Mariska. "An investigation into the synergistic action of cellulose-degrading enzymes on complex substrates." Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1017915.
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Gössl, Illdiko Maria. "Supramolecular structures of dendronized polymers and DNA on solid substrates." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2003. http://dx.doi.org/10.18452/14893.
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Komplexe aus entgegengesetzt geladenen Polyelektrolyten haben sowohl in der Biologie als auch in den Materialwissenschaften eine große Bedeutung. Im Mittelpunkt des Interesses stehen besonders die Kondensation der DNA in vitro, die Struktur des Nukleosoms im Zellkern, nicht-virale Systeme zur Transfektion von DNA in Zellen oder der Vorgang der layer-by-layer Adsorption. Verschiedene Theorien befassen sich mit den treibenden Kräften solcher Komplexbildungen. Allerdings standen experimentelle Untersuchungen auf diesem Gebiet bisher noch aus. Dieser Arbeit liegt die Fragestellung zu Grunde, ob es mit Hilfe der Rasterkraftmikroskopie möglich ist, die Struktur einzelner Polyelektrolytkomplexe, bestehend aus den beiden Polyelektrolyten DNA und dendronisierten Polymer, aufzuklären und ihre Komplexbildung zu untersuchen. Die Komplexe bildeten sich in Lösung und wurden anschließend auf einer unbeschichteten oder mit positiven Polymeren beschichteten Glimmeroberfläche adsorbiert. Auf der positiv beschichteten Glimmeroberfläche hafteten DNA-dendronisierte Polymer Komplexe mit einem Ladungsverhältnis von 1:1 bis 1:0.7 (DNA:dendronisiertes Polymer). Anhand der hochaufgelösten rasterkraftmikroskopischen Aufnahmen wurde ein Modell entwickelt, das die Umwicklung der DNA um das dendronisierte Polymer beschreibt. Der DNA-DNA Abstand ergab sich zu (2.30 ± 0.27) nm für den Komplex mit DNA und zweiter Generation dendronisierter Polymere und zu (2.16 ± 0.27) nm mit vierter Generation. Die theoretische Vorhersage der Überladung der Komplexe konnte experimentell bestätigt werden. Mit Hilfe der Rasterkraftmikroskopie konnte überdies der Einfluss des Salzgehaltes der Lösung auf die Bildung der Komplexe mit DNA und zweiter Generation dendronisierter Polymere untersucht werden. Wie man anhand des Zusammenwirkens von elektrostatischen Kräften und entropischen Wechselwirkungen bei der Adsorption von Polyelektrolyten vorhersagen kann, durchlief der DNA-DNA Abstand ein Minimum bei ansteigendem Salzgehalt. Bei sehr hohem Salzgehalt (2.4 M NaCl) konnte das Ablösen der DNA von dem Komplex beobachtet werden. Die untersuchten DNA/dendroniserten Polymer Komplexe bilden ein neues Modellsystem, mit dem einzelne Polyelektrolyt-Wechselwirkungen direkt untersucht werden können. Ein Vergleich der experimentellen Daten mit den vorhandenen Theorien zeigte, dass der Prozess des Überladens weitgehend durch elektrostatische Wechselwirkung zwischen den beiden Polyelektrolyten beschrieben werden kann. Sowohl entropische Beiträge als auch die Biegeenergie der umwickelnden DNA sind vernachlässigbar. Basierend auf diesen Ergebnissen können neue Trägerstrukturen für effizientere nicht-virale DNA-Transfektionssysteme entwickelt werden.Complexes of oppositely charged polyelectrolytes play an important role in both biology and material science, for instance DNA condensation in vitro, nucleosomal structure, non-viral gene transfection systems as well as layer-by-layer adsorption. Although there are theories predicting overcharging of polyelectrolyte complexes, the driving forces are still under debate and systematic experimental studies on single polyelectrolytes remain challenging. Therefore the question arose if it is possible to analyze single polyelectrolyte complexes, using DNA and dendronized polymers, with the scanning force microscope in order to investigate the complexation in detail. For the complex analysis, the polyelectrolytes were allowed to interact in solution and then to adsorb on negatively charged mica or on mica coated with a positively charged polymer. Scanning force microscopy was used to investigate the adsorbed species. DNA/dendronized polymer complexes of charge ratio of 1/1 through 1/0.7 adsorbed on mica coated with a positively charged polymer. The analysis of high resolution molecular images indicated that DNA wraps around the dendronized polymer with an estimated pitch of (2.30 ± 0.27) nm and (2.16 ± 0.27) nm for dendronized polymers of generation two and four, respectively. In the proposed model the polyelectrolyte with the smaller linear charge density is wrapped around the more highly charged dendronized polymer, resulting in a negatively overcharged complex. This overcharging is consistent within recent theories of spontaneous overcharging of complexes of one polyelectrolyte wrapping around the other. Using the complex of DNA and dendronized polymers of second generation, the influence of monovalent salt concentration on the molecular structure was studied. By increasing the salt concentration the pitch showed a minimum as predicted by the interplay of electrostatic forces and entropic interactions of polyelectrolyte adsorption. At high salt concentration (2.4 M NaCl) the release of DNA from the complex can be observed. The results showed that the DNA/dendronized polymer system can be used as a new, high potential model system to investigate single polyelectrolyte interactions. With regard to recent theories, the experimental results indicate that the overcharging of the complex is mainly driven by electrostatic forces whereas contributions of counterion entropy and bending energy seem to be negligible. This understanding may be useful for the design of single polyelectrolyte complexes for non-viral gene delivery systems and might help to optimize the transfection efficiency based on the structure of the vector system.
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Zich, Judith. "Analysis of Mph1 kinase and its substrates in spindle checkpoint signalling." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/8253.
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Accurate chromosome segregation is crucial as mis-segregation results in aneuploidy, which can lead to severe diseases such as cancer. The spindle checkpoint monitors sister-chromatid attachment and inhibits the onset of anaphase until all chromosomes are correctly bi-oriented on the mitotic spindle. The spindle checkpoint machinery of S.pombe is composed of many proteins, one of which is the kinase Mph1 (Mps1p-like pombe homolog). It previously has been shown that Mph1 is essential for the spindle checkpoint but not whether this is due to its kinase activity. In this study we determined the role of Mph1 kinase activity in the spindle checkpoint. To do so a kinase-dead version of Mph1, which had no detectable kinase activity, was analysed. Using this kinase-dead allele we showed that lack of Mph1 kinase activity abolished the spindle checkpoint and led to chromosome missegregation. As a result of these two defects cell viability of cells lacking Mph1 kinase activity was severely impaired. These results led to the question of how Mph1 kinase activity regulates the spindle checkpoint. Spindle checkpoint signalling is thought to mainly take place at two sites, at the kinetochore and at the anaphase promoting complex (APC). The APC is an E3 ubiquitin ligase that drives cells into anaphase by targeting the separase inhibitor securin and cyclin B for degradation by the 26 S proteasome. Upon activation of the spindle checkpoint the APC is inhibited by the mitotic checkpoint complex (MCC) composed of Slp1, Mad2 and Mad3. In this study we wanted to test whether the regulatory role of Mph1 kinase in the spindle checkpoint is via MCC binding to the APC. Using the kinase-dead version of Mph1 we showed that Mad2 and Mad3 binding to the APC is severely impaired in the absence of Mph1 kinase activity. This result led to the hypothesis that Mph1 might regulate Mad2 and Mad3 binding Using kinase assays Mad2 and Mad3 were identified as in vitro substrates of Mph1 and phosphorylation sites in Mad2 and Mad3 were determined by mass spectrometry. Phosphorylation mutants of Mad2 and Mad3 showed spindle checkpoint defects, indicating that they are important Mph1 substrates.
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Kothe, Thomas. "Reductive Binding of C‒O and Nitro Substrates at a Pyrazolate-Bridged Preorganized Dinickel Scaffold." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2020. http://hdl.handle.net/21.11130/00-1735-0000-0005-1524-B.
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Duan, Peng-Cheng. "A Dinuclear Dihydride Complex for Bimetallic Reductive Activation and Transformation of a Range of Inert Substrates." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2017. http://hdl.handle.net/11858/00-1735-0000-002E-E38C-2.
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Bakir, Ilyas. "Molecular studies of the γ-secretase complex activity and selectivity towards the two substrates APP and Notch." Thesis, Mälardalen University, School of Sustainable Development of Society and Technology, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-9622.
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Alzheimer Disease (AD) is the most common neurodegenerative disorder in the world. One of the neuropathological hallmarks of AD is the senile plaques in the brain. The plaques are mainly composed of the amyloid β (Aβ) peptide. Aβ is generated from the amyloid precursor protein, APP, when it is first cleaved by the β-secretase and subsequently the γ-secretase complex. The γ-secretase complex cleaves at different sites, called γ and ε, where the γ-cleavage site generates Aβ peptides of different lengths and ε-cleavage generates the APP intracellular domain (AICD). The two major forms of Aβ is 40 and 42 amino acids long peptides, where the latter is more prone to aggregate and is the main component in senile plaques. The γ-secretase complex is composed of four proteins; Pen-2, Aph-1, nicastrin and presenilin (PS). The PS protein harbours the catalytic site of the complex, where two aspartate residues in position 257 and 385 (Presenilin 1 numbering) are situated. Most Familial AD (FAD) mutations in the PS gene cause a change in the γ-cleavage site, leading to a shift from producing Aβ40 to the longer more toxic variant Aβ42. Frequently, this often leads to impairments of the AICD production. Another substrate for the γ-secretase complex is Notch. It is important to maintain the Notch signaling since an intracellular domain (NICD) is formed after cleavage by the γ-secretase complex in the membrane (S3-site) and this domain is involved in transcription of genes important for cell fate decisions.
It has been reported that certain APP luminal juxtamembrane mutations could drastically alter Aβ secretion, however their effect on AICD production remains unknown. In this study we want to analyse wether the juxtamembrane region is important for the AICD production. To gain more insight into the luminal juxtamembrane function for γ-secretase-dependent proteolysis, we have made a juxtamembrane chimeric construct. A four-residue sequence preceding the transmembrane domain (TMD) of APP (GSNK), was replaced by its topological counterpart from the human Notch1 receptor (PPAQ). The resulting chimeric vector C99GVP-PPAQ and the wildtype counterpart were expressed in cells lacking PS1 and PS2 (BD8) together with PS1wt. We observed that the chimeric construct did not alter production of AICD when using a cell based luciferase reporter gene assay monitoring AICD production. We also introduced a PS1 variant lacking a big portion of the large hydrophilic loop, PS1∆exon10, since our group has previously observed that this region affect Aβ production143. We found that the absence of the large hydrophilic loop in PS1 gave a 2-fold decrease in AICD-GVP formation from C99GVPwt compared to PS1wt. The activity of PS1wt and PS1Δexon10 using C99GVP-PPAQ as a substrate gave similar result as the C99GVPwt substrate, i.e. a 2-fold decrease in AICD-GVP formation when comparing PS1Δexon10 with PS1wt. From this data we therefore suggest that the four residues in the juxtramembrane domain (JMD) (GSNK) is not altering ε-cleavage of APP when changed to Notch1 counterpart, PPAQ. Furthermore, we also show that the 2-fold decrease in AICD-production by the PS1Δexon10 molecule is not changed between the two substrates C99GVPwt and C99GVP-PPAQ. This indicates that the luminal region of APP is not directly involved in the ε-site processing. If the luminal region is affecting processing in the γ-cleavage sites, remains however to be investigated.
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Cowan, James. "The development and study of chelating substrates for the separation of metal ions in complex sample matrices." Thesis, University of Plymouth, 2002. http://hdl.handle.net/10026.1/1881.
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Stefani, Nicola. "Energy from crops: experimental study and dynamic simulation of biogas production by anaerobic digestion of complex substrates." Doctoral thesis, Università degli studi di Trieste, 2011. http://hdl.handle.net/10077/4506.
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2009/2010Anaerobic digestion (AD) is a biological process which allows the removal of high organic-loading and potentially polluting substances by their transformation into biogas, a mixture of methane and carbon dioxide, prevalently. AD presents many other advantages: it has a low energy consumption and low construction costs with a relatively simple plant technology. Actually, since anaerobic bacteria work more efficiently at room temperature or higher, AD can be profitably applied in developing countries. Biogas production is a foundamental parameter of AD because it is the main index to be considered in a process economic evaluation and also because it gives a measure of its efficiency as well. Moreover, biogas production, and more frequently methane production, is often used as an index set to control the process. With the increase of energy price, the specific biogas production (SGP) of primary and residuals crops has become a goal for economic energy supply and, as a consequence, a rapid and effective method for measuring the gas produced has to be put forward, because there is not an accepted international standard yet. The effective knowledge of biogas production rate allows study of the biological process through macroscopic indicators, easily usable in industrial field, as well. The present study concerns the development and the validation of a technique for biogas production measurement and kinetic determination which adopts bench-mark laboratory-scale experiments with complex solid substrates, i.e. primary and residual energy crops. A laboratory-scale plant was designed and put up to perform this task. The equipment permits to carry out 4 contemporary tests because it is composed of 4 independent gas-lines, each of which connecting an anaerobic reactor to a gas-meter. Data from the experiments were continuously recorded by a data logger. The equipment was tested with synthetic substrate feeds of ethanol and sodium acetate. By a comparison between experimental gas production data and the theoretical ones, stoichiometrically calculated, the range of the error on methane productions resulted within ± 5%. In addition, the presence of oxygen amounts in the mixture, revealed the inconsistency of a test. These positive results allowed the implementation of different experiments to measure biogas produced from natural substrates. Apple, onion, corn straw, potato and winery wastes mixture were therefore tested in various experiments in order to calculate the SGP and SMA of the different crops. A new mathematical model for the description of complex substrate degradation was developed as well. The model was calibrated on the different biological systems and then applyed on real substrates to carry out their COD fractionation, to analyse the biological variable trends and to test the reliability of results. Finally, the reliability of a procedure for the evaluation of a two-step AD as compared to the one-step AD was tested by using apple and potato substrates.
La digestione anaerobica è un processo biologico che permette la rimozione di sostanze con alto carico organico, potenzialmente inquinanti, e la trasformazione di queste in biogas, costituito prevalentemente da metano e anidride carbonica. La digestione anaerobica ha anche ulteriori vantaggi: ha un basso consumo energetico, bassi costi di costruzione degli impianti, uniti ad una tecnologia impiantistica relativamente semplice. Inoltre, poiché i batteri anaerobici lavorano meglio a temperatura ambiente o superiore, si può applicare con profitto nei paesi in via di sviluppo. La produzione di biogas è un parametro fondamentale della digestione anaerobica perché è il principale indicatore cui fare riferimento nella valutazione economica del processo e perché allo stesso tempo fornisce anche una stima della sua efficienza. Inoltre, la produzione di biogas, o ancor più frequentemente quella di metano, è spesso usata come indice cui fare riferimento per un controllo di processo. Con l'aumento del costo energetico, risulta necessario definire correttamente ed efficacemente un metodo di misura del biogas prodotto, in particolare la produzione specifica (SGP) di biogas da biomasse primarie e residuali. Ad es, il test di attività metanogenica specifica (SMA), non ha ancora uno standard internazionale riconosciuto. La conoscenza effettiva della velocità di produzione di metano, infatti, apre la strada alla possibilità di studiare il processo biologico attraverso indicatori macroscopici, facili da applicare anche in un contesto industriale. Il presente lavoro riguarda lo sviluppo e la validazione di un metodo per effettuare la misurazione del biogas e la determinazione delle cinetiche di processo con esperimenti in scala di laboratorio effettuati su substrati complessi, ovvero biomasse primarie e residuali. Per fare ciò, è stato progettato e realizzato un impianto in scala di laboratorio. L'apparecchiatura permette di effettuare 4 prove contemporanee perché è provvista di 4 linee gas indipendenti, ciascuna delle quali connette un reattore anaerobico ad un gasometro. All'impianto è stato affiancato un sistema automatico di acquisizione dati, che permette la registrazione in continuo dei dati di produzione. L'impianto è stato verificato utilizzando alimentazioni di substrati sintetici quali etanolo e acetato di sodio. A seguito del confronto tra i dati di produzione di gas sperimentale e quelli di produzione teorica, calcolata stechiometricamente, l'errore nella risposta è risultato essere contenuto tra i valori di ± 5%. In aggiunta, la verifica del contenuto in ossigeno della miscela ha permesso di scartare le prove non conformi. Questi risultati positivi hanno consentito di passare ad esperimenti condotti su substrati naturali. Sono stati così testati, con i successivi esperimenti, mela, cipolla, patata, paglia di mais e residui solidi della lavorazione del vino, al fine di calcolarne l'SGP e l'SMA. E' anche stato sviluppato un nuovo modello matematico per simulare la degradazione di un substrato complesso. Tale modello è stato dapprima calibrato sui diversi sistemi biologici e in seguito applicato su alcuni substrati reali al fine di operare un frazionamento del COD, analizzare l'andamento delle variabili biologiche e verificare la compatibilità con i risultati sperimentali. Da ultimo, è stata verificata l'affidabilità di una procedura per la valutazione della digestione anaerobica a due fasi e il confronto con quella a fase singola, condotta con campioni di mele e di patate.
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Stastny, Angela. "Stoichiometric Delivery of Halogens to Substrates and a Study of Selective Bromination of Olefins by a Pt(IV) Complex." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1523629125459729.
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Pereira, Vitor Emanuel M. Loureiro S. "Computer model to predict electron beam-physical vapour deposition (EB-PVD) and thermal barrier coating (TBC) deposition on substrates with complex geometry." Thesis, Cranfield University, 2000. http://dspace.lib.cranfield.ac.uk/handle/1826/5714.
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For many decades gas turbine engineers have investigated methods to improve engine efficiency further. These methods include advances in the composition and processing of materials, intricate cooling techniques, and the use of protective coatings. Thermal barrier coatings (TBCs) are the most promising development in superalloy coatings research in recent years with the potential to reduce metal surface temperature, or increase turbine entry temperature, by 70-200°C. In order for TBCs to be exploited to their full potential, they need to be applied to the most demanding of stationary and rotating components, such as first stage blades and vanes. Comprehensive reviews of coating processes indicate that this can only be achieved on rotating components by depositing a strain-tolerant layer applied by the electron beam-physical vapour deposition (EB-PVD) coating process. A computer program has been developed in Visual c++ based on the Knudsen cosine law and aimed at calculating the coating thickness distribution around any component, but typically turbine blades. This should permit the controlled deposition to tailor the TBC performance and durability. Various evaporation characteristics have been accommodated by developing a generalised point source evaporation model that involves real and virtual sources. Substrates with complex geometry can be modelled by generating an STL file from a CAD package with the geometric information of the component, which may include shadow-masks. Visualisation of the coated thickness distributions around components was achieved using OpenGL library functions within the computer model. This study then proceeded to verify the computer model by first measuring the coating thickness for experimental trial runs and then comparing the calculated coating thickness to that measured using a laboratory coater. Predicted thickness distributions are in good agreement even for the simplified evaporation model, but can be improved further by increasing the complexity of the source model.
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Shin, Seunghoon. "Part I. Water-soluble organometallic catalysts for asymmetric reactions in aqueous media ; Part II. Silylstannylative cyclization of unsaturated substrates catalyzed by Palladium Complex /." The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu1486474078048077.
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Kumar, Abhijeet Verfasser], Tatiana [Akademischer Betreuer] [Gambaryan-Roisman, Peter [Akademischer Betreuer] Stephan, and Klitzing Regina [Akademischer Betreuer] von. "Wetting, evaporation and deposition processes in interaction of complex liquid formulations with porous substrates / Abhijeet Kumar ; Tatiana Gambaryan-Roisman, Peter Stephan, Regina von Klitzing." Darmstadt : Universitäts- und Landesbibliothek, 2020. http://nbn-resolving.de/urn:nbn:de:tuda-tuprints-142114.
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Kumar, Abhijeet [Verfasser], Tatiana [Akademischer Betreuer] Gambaryan-Roisman, Peter [Akademischer Betreuer] Stephan, and Klitzing Regina [Akademischer Betreuer] von. "Wetting, evaporation and deposition processes in interaction of complex liquid formulations with porous substrates / Abhijeet Kumar ; Tatiana Gambaryan-Roisman, Peter Stephan, Regina von Klitzing." Darmstadt : Universitäts- und Landesbibliothek, 2020. http://d-nb.info/1222163195/34.
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Kriegel, Sébastien. "Transformation of a membrane protein from the respiratory chain into a sensor for the analysis of its interaction with substrates, inhibitors and lipids." Phd thesis, Université de Strasbourg, 2013. http://tel.archives-ouvertes.fr/tel-01017392.
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The field of bioenergetics deals with the flow and transformation of energy within and between living organisms and their environment. The work presented in this thesis report focuses on cellular respiration and more specifically on the first enzyme of the respiratory chain, NADH:ubiquinone oxidoreductase (Complex I). This was done to clarify details about its function and its implication in disease. First, the creation of a sensor involving the biomimetically immobilized enzyme is presented and probed through a combination of surface enhanced infrared absorption spectroscopy (SEIRAS) and electrochemistry. This sensor is then tested against different substrates and inhibitors. In a second part, the interaction of Complex I with lipids, inhibitors (Zn2+ and NADH-OH) and the role of a Tyrosine residue situated in the NADH binding pocket are investigated through electrochemically induced UV-Vis and FTIR difference spectroscopies. The results gathered through these experiments are then explored under a structural perspective and a coupling mechanism between quinone reduction and proton translocation by Complex I is proposed.
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Duan, Peng-Cheng [Verfasser], Franc [Akademischer Betreuer] Meyer, Franc [Gutachter] Meyer, and Sven [Gutachter] Schneider. "A Dinuclear Dihydride Complex for Bimetallic Reductive Activation and Transformation of a Range of Inert Substrates / Peng-Cheng Duan ; Gutachter: Franc Meyer, Sven Schneider ; Betreuer: Franc Meyer." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2018. http://d-nb.info/1155004418/34.
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Stitou, Bachir. "Emploi de nouveaux systemes catalytiques pour la carbonylation d'alcenes et de substrats insatures fonctionnalises." Toulouse 3, 1988. http://www.theses.fr/1988TOU30028.
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Matyskiela, Mary E. "Substrate binding by the anaphase-promoting complex." Diss., Search in ProQuest Dissertations & Theses. UC Only, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3378672.
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Pauthe, Emmanuel. "Approches cinétiques et moléculaires de la reconnaissance enzyme-substrat : application à l'étude de l'activité protéolytique de la thermolysine." Compiègne, 1998. http://www.theses.fr/1998COMP1139.
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L’accomplissement de tout acte protéolytique implique nécessairement la formation d'un complexe entre l'enzyme et son substrat. Par différentes approches cinétiques, spectroscopiques et moléculaires nous avons cherché à caractériser les phénomènes mis en jeu au cours de l'hydrolyse, par la thermolysine, de petits peptides en milieu biomimétiques. Cette étude a été conduite à l'interface entre la biochimie, la biophysique, la chimie et la physique. Dans un premier temps, nous nous sommes intéressés au comportement catalytique de la thermolysine sur des substrats modèles et en milieu modifié. Nous avons montré d'une part, que l'ajout d'additifs polyhydroxylés influence grandement l'activité de la thermolysine et d'autre part, affine les connaissances sur la spécificité et la sélectivité de cette enzyme (en particulier, mise en évidence de l'influence du résidu P'2 dans le mécanisme). Dans un deuxième temps, nous présentons des études structurales des peptides substrats en milieu modifié. Nous avons mis en évidence l'absence d'influence du micro-environnement contenant une forte proportion de glycérol sur la conformation des molécules de substrat et le rôle possible de leur structure tridimensionnelle quant à leur hydrolyse. Ces études ont été étendues à un autre modèle peptidique, de forme cyclique ou linéaire, et corrélées aux résultats cinétiques. Dans un troisième temps, par deux approches différentes, nous avons abordé l'étude des relations structure-fonction de la thermolysine. Expérimentalement, par des études cinétiques avec l'enzyme immobilisée et des déterminations de sa structure par spectroscopie laser Raman, nous montrons que l'enzyme est très peu sensible au micro-environnement. Théoriquement en analysant, par modélisation, l'interaction de la thermolysine avec un tripeptide substrat, nous avons mis en évidence des changements de conformation du substrat et/ou des mouvements du site actif enzymatique au cours de l'acte catalytique.
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De, Souza Roberto Fernando. "Etude des reactions d'oligomerisation, isomerisation et polymerisation de substrats insatures catalysees par des complexes allyle cationiques du nickel." Toulouse 3, 1987. http://www.theses.fr/1987TOU30152.
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Oligomerisation de l'ethylene. Mecanisme de l'isomerisation des olefines superieures en presence des complexes du titre. Polymerisation catalytique d'autres substrats insatures : styrene, dienes, alcynes. . . La polymerisation du phenylacetylene a ete etudiee en detail car elle conduit a des materiaux semiconducteurs a l'etat non dope
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Davis, Kelly Lawrence. "Substrate noise coupling in a complex mixed signal integrated circuit." Honors in the Major Thesis, University of Central Florida, 1998. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/30.
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This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucf.edu/Systems/DigitalInitiatives/DigitalCollections/InternetDistributionConsentAgreementForm.pdf You may also contact the project coordinator, Kerri Bottorff, at kerri.bottorff@ucf.edu for more information.Bachelors
Engineering
Electrical Engineering
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Hart, Kathryn Jacoba. "A RAPID PROTOTYPING METHOD FOR CONSTRUCTING A COMPLEX THREE-DIMENSIONAL SUBSTRATE." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/217.
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Cell culturing on three-dimensional structures has increased the possibilities in tissue engineering and bioreactor research. These structures enable cells to differentiate, proliferate, mobilize, and function in a conformation that more accurately mimics in vivo conditions. Computer generated models aid in development and rapid alteration of three-dimensional cell substrates, defining their internal structure as well as their external morphology. The rapid transition from substrate design to a viable culture is imperative to quickly advance research in biomedical and tissue engineering applications.
The aim of this thesis is to investigate the feasibility of a rapid prototyping process by selectively cross-linking and assembling biocompatible films. This investigation revealed that selectively cross-linking and layering gelatin films could produce a three-dimensional substrate with a defined structure after dissolving uncross-linked gelatin. The study also revealed that freeze-drying aided in the rapid dissolution of uncross-linked gelatin. The line width resolution obtained during tests was .5 mm using a template treatment method and was limited by the template construction resolution. Finally, alteration in treatment time, rinsing agitation, and rinsing temperature yielded stable films that better retained their size and shape compared to films produced in previous processes.
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Ramsay, Bruce A. "The use of complex toxic industrial waste as a fermentation substrate /." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75450.
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Two complex wastes were considered for biological conversion into a marketable product. One waste, peat runoff water (the waste-water that remains after the mining of peat), was found to be unsuitable for biological conversion to any product since it contained an insufficient quantity of carbon. The other waste, NVR (non-volatile residue, the major waste from the manufacture of nylon 6$ sp prime 6 sp prime$), was found to be a suitable carbon and energy source for the production of PHB (poly-$ beta$-hydroxybutyric acid) by Pseudomonas cepacia ATCC 17697. A general approach to the development of complex toxic wastes as fermentation substrates was formulated.NVR was found to be toxic to microorganisms. None grew in enrichment culture containing 2.0% NVR. P. cepacia was the most resistant microorganism found. It could grow well in up to 1.3% NVR. It also grew on butanoic, pentanoic, and hexanoic acid as well as 6-hexanolactone. These were found to be the major toxic components of NVR. P. cepacia was grown in a NVR-limited chemostat with a NVR feed concentration well in excess of the toxic NVR concentration. In nitrogen-limited, batch fermentation on fructose, P. cepacia accumulated PHB in excess of 50% of its dry weight. A 2-stage chemostat process for the production of PHB from NVR by P. cepacia was investigated with encouraging results.
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Nilsson, Håkan. "Substrate water binding to the oxygen-evolving complex in photosystem II." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-86500.
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Oxygenic photosynthesis in plants, algae and cyanobacteria converts sunlight into chemical energy. In this process electrons are transferred from water molecules to CO2 leading to the assembly of carbohydrates, the building blocks of life. A cluster of four manganese ions and one calcium ion, linked together by five oxygen bridges, constitutes the catalyst for water oxidation in photosystem II (Mn4CaO5 cluster). This cluster stores up to four oxidizing equivalents (S0,..,S4 states), which are then used in a concerted reaction to convert two substrate water molecules into molecular oxygen. The reaction mechanism of this four-electron four-proton reaction is not settled yet and several hypotheses have been put forward. The work presented in this thesis aims at clarifying several aspects of the water oxidation reaction by analyzing the mode of substrate water binding to the Mn4CaO5 cluster. Time-resolved membrane-inlet mass spectrometric detection of flash-induced O2 production after fast H218O labelling was employed to study the exchange rates between substrate waters bound to the Mn4CaO5 cluster and the surrounding bulk water. By employing this approach to dimeric photosystem II core complexes of the red alga Cyanidoschyzon merolae it was demonstrated that both substrate water molecules are already bound in the S2 state of the Mn4CaO5 cluster. This was confirmed with samples from the thermophilic cyanobacterium Thermosynechococcus elongatus. Addition of the water analogue ammonia, that is shown to bind to the Mn4CaO5 cluster by replacing the crystallographic water W1, did not significantly affect the exchange rates of the two substrate waters. Thus, these experiments exclude that W1 is a substrate water molecule. The mechanism of O-O bond formation was studied by characterizing the substrate exchange in the S3YZ● state. For this the half-life time of this transient state into S0 was extended from 1.1 ms to 45 ms by replacing the native cofactors Ca2+ and Cl- by Sr2+ and I-. The data show that both substrate waters exchange significantly slower in the S3YZ● state than in the S3 state. A detailed discussion of this finding lead to the conclusions that (i) the calcium ion in the Mn4CaO5 cluster is not a substrate binding site and (ii) O-O bond formation occurs via the direct coupling between two Mn-bound water-derived oxygens, which were assigned to be the terminal water/hydroxy ligand W2 and the central oxo-bridging O5. The driving force for the O2 producing S4→S0 transition was studied by comparing the effects of N2 and O2 pressures of about 20 bar on the flash-induced O2 production of photosystem II samples containing either the native cofactors Ca2+ and Cl- or the surrogates Sr2+ and Br-. While for the Ca/Cl-PSII samples no product inhibition was observed, a kinetic limitation of O2 production was found for the Sr/Br-PSII samples under O2 pressure. This was tentatively assigned to a significant slowdown of the O2 release in the Sr/Br-PSII samples. In addition, the equilibrium between the S0 state and the early intermediates of the S4 state family was studied under 18O2 atmosphere in photosystem II centers devoid of tyrosine YD. Water-exchange in the transiently formed early S4 states would have led to 16,18O2 release, but none was observed during a three day incubation time. Both experiments thus indicate that the S4→S0 transition has a large driving force. Thus, photosynthesis is not limited by the O2 partial pressure in the atmosphere.
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Webster, Michael William. "Mechanisms of mRNA substrate-selection by the Ccr4-Not deadenylase complex." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/267813.
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The level to which genes are expressed depends on the rate at which the mRNA is generated, and the rate at which it is utilised and destroyed. Almost all eukaryotic mRNAs contain a stretch of adenosine nucleotides known as the poly(A) tail. The removal of the polyA tail from an mRNA, a process called deadenylation, is an important mechanism of gene expression regulation. It is the first step in the decay of the transcript, and is also linked to repression of translation. Deadenylation is predominantly catalysed by a conserved multi-protein complex called Ccr4-Not. While the poly(A) tail is a feature of almost all mRNAs, cells control the rate at which each undergoes decay by the precise targeting of Ccr4-Not in both a gene-dependent and a context-dependent fashion. Substrate-selective deadenylation is therefore a central biochemical process to the control of gene expression. It plays a pivotal role in most cellular processes including differentiation, cell cycle control and adaptation to environmental change. The inflammatory response and embryogenesis are two systems in which deadenylation has been well studied. The subject of this dissertation is the biochemical mechanisms by which mRNAs are selected for deadenylation by Ccr4-Not. Despite its importance, intact Ccr4-Not has not previously been obtained in sufficient quantity and purity for rigorous biochemical and structural analysis. Here I present the purification of recombinant Ccr4-Not. An experimental system was devised to quantify the rate and pattern of the deadenylation reaction that it catalyses in vitro. Two models of Ccr4-Not regulation were characterised in detail: the recruitment of Ccr4-Not by RNA-binding adaptor proteins, and the effect of the protein Pab1, which binds to the poly(A) tail. These have yielded insight into the features of the proteins and RNA sequences that are critical to deadenylation. In addition, a structural study of the Ccr4-Not complex was performed using electron cryomicroscopy and single-particle analysis.
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Chauhan, Hitesh. "Protein-protein interaction and substrate channelling in the pyruvate dehydrogenase complex." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620982.
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Bailey, Matthew. "Deciphering the "Polarity Code": the Mechanism of Par Complex Substrate Polarization." Thesis, University of Oregon, 2017. http://hdl.handle.net/1794/22782.
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Animal cells, as distinct as epithelia and migratory cells, have cell polarity that is defined by a common set of molecules. The Par complex polarizes the cortex of animal cells through the activity of atypical protein kinase C (aPKC). In this work, I aimed to determine the mechanism of aPKC substrate polarization and identify common characteristics of aPKC substrates that are polarized by phosphorylation. I found that several diverse Par-polarized proteins contain short highly basic and hydrophobic motifs that overlap with their aPKC phosphorylation sites. These Phospho-Regulated Basic and Hydrophobic (PRBH) motifs mediate plasma membrane localization by electrostatics-based phospholipid binding when unphosphorylated but are displaced into the cytoplasm when phosphorylated. To assess whether the Par complex polarizes other proteins by this mechanism, I developed an algorithm to identify potential PRBH motifs and score these linear motifs for basic and hydrophobic character, as well as the quality and number of aPKC phosphorylation sites. Using this algorithm, I identified numerous putative PRBH candidates in the fruit fly proteome and performed two screens of these candidates for Par-polarized proteins. The first screen focused on determining whether aPKC regulates cortical targeting of proteins that are reported to be polarized. This screen identified the Rho GAP crossveinless-c (cv-c) to be a novel aPKC substrate and found that aPKC is sufficient to polarize cv-c in a reconstituted polarity assay. The second screen characterized the localization of putative PRBH motif-containing proteins in vivo. This screen identified a previously uncharacterized protein, CG6454, to be basolateral in epithelia; however, ex vivo experiments found it to have a Ca2+-dependent and aPKC-independent membrane targeting mechanism. Overall this work identified a common mechanism for Par substrate polarization and used knowledge of this mechanism to identify a novel Par effector.
This dissertation contains previously published coauthored materials as well as unpublished materials.2019-05-08
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Dahl, Mads Ronald. "Mannan-binding lectin (MBL) associated serine protease-3 (MASP-3) : complex formation in serum and plasma, conditions required for the conversion of the zymogen form into a two-chain serin protease, and a search for substrates using recombinant material produced by stable expression in eukaryotic cell lines." Thesis, University of Leicester, 2004. http://hdl.handle.net/2381/29483.
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The complement system is part of the innate immune system and is crucial for identifying invading microorganisms. The lectin pathway of complement activation is initiated through multimeric macromolecules which recognise pathogen-associated patterns and translate binding through activation of associated serine proteases that start a cascade of proteolytic events leading to bactericidal, opsonising and proinflammatory responses. Mannan-binding lectin (MBL) is one of the macromolecules mediating binding to specific carbohydrate structures common to a range of microorganisms. Three different mannan-binding lectin associated serine proteases (MASP-1/-2/-3) and a non-enzymatic protein of 19 kDa (MApl9) have been described. MASP-2 appears to mediate all processes required for complement activation while little or no complement-related functional activity was found to be mediated by MASP-1, MASP-3 or MApl9. Functional and biophysical studies of MASP-3 relied on continuous and reliable supply of recombinant MASP-3. In this work production of recombinant MASP-3 in mammalian cells with subsequent affinity purification and characterisation of the recombinant MASP-3 was performed to obtain large quantities of homogeneous enzyme. The development of screening assays and assays for quantitative determination of MASP-3 levels were two other tools essential for the development of this thesis. As a result of this thesis MASP-3 levels in different body fluids were determined in healthy individuals using a quantitative assay. The assays were used to analyse the MASP-3 level in sample collections from patients suffering from Alzheimer disease and type-1 diabetes. The correlation of MASP-3 level and MBL genotype, H-/L-Ficolin concentration, age, BMI, acute phase and time of year were analysed. The enzymatic activity of MASP-3 was analysed on chromogenic substrates and the results permitted a study of MASP-3 inhibition. Attempts were made to affinity purify potential MASP-3 substrates and ligands using beads coupled with recombinant MASP-3 and anti- MASP-3 antibodies. The influence of calcium on MASP-3 complex formation, dissociation, activation and stability was analysed.
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Lu, Lei. "Alterations in activity and specificity of intracellular proteolysis in disease pathogenesis /." Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-397-3/.
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Burcher, Benjamin. "Novel low-oxidation state iron complexes : reactivity towards unsaturated substrates." Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAF022.
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Dans cette thèse nous avons eu pour but d’étudier la réactivité des complexes à bas degré d’oxydation du fer stabilisés par des ligands phosphines vis-à-vis des substrats insaturés. Cet objectif s’inscrit dans une démarche plus large d’accès à des systèmes catalytiques au fer capables de transformer de manière sélective l’éthylène, par la réaction d’oligomérisation, vers des alpha-oléfines linéaires courtes (butène-1, héxène-1, octène-1), ce qui n’a jamais été rapporté dans la littérature. Pour se faire, le passage par le mécanisme métallacyclique de transformation de l’éthylène est la voie privilégiée. Cependant, les propriétés électroniques et géométriques de ligand requises pour suivre un tel mécanisme, et en particulier son étape clé de couplage oxydant de deux molécules d’éthylène sur le centre métallique, ne sont pas clairement identifiées. Nous rapportons ici dans un premier temps la synthèse d’une bibliothèque de complexes de fer(II) et fer(III) à base de ligands phosphines présentant des propriétés électroniques et géométriques variées. Ces nouveaux complexes sont opportunément testés en tant que catalyseurs, d’une part pour la réaction d’oligomérisation de l’éthylène; mais également en tant qu’espèces réduites in situ en association avec des diènes (isoprène, butadiène) conduisant à leur polymérisation. Afin de nous rapprocher davantage de notre objectif d’accès aux espèces à bas degré d’oxydation du fer, l’emploi d’une voie de réduction en une étape et en conditions douces est rapportée; conduisant à l’isolement et la caractérisation de neuf complexes phosphorés de fer(0) à 18 et à 16 électrons. Bien qu’a priori inactifs vis-à-vis de l’éthylène ou des oléfines plus longues, nous montrons la capacité de ces complexes à promouvoir des réactions de couplage oxydant de substrats insaturés (alcynes) le couplage catalytique de l’éthylène et du butadiène et l’activation de divers composés tels que les silanes ou les halogénures d’alkyles, posant ainsi un premier jalon vers leur optimisation et application en tant que catalyseurs d’autres réactions, et potentiellement dans l’avenir, pour la transformation de l’éthylèneIn this thesis our aim was to study the reactivity of phosphine-based low-valent iron complexes towards unsaturated substrates. This goal is part of a wider approach of access to an iron catalytic system able to transform ethylene in a selective manner, by the reaction of oligomerization, towards short linear alpha-olefins (1-butene, 1-hexene, 1-octene), which is unreported in the literature. To achieve this, going through the metallacyclic mechanism of ethylene transformation is the most likely way. However, the electronic and geometrical features of the ligand required to follow this mechanism, and in particular the key step of the oxidative coupling of two molecules of ethylene to the metal center, are ill-defined. We thus report here in a first part the synthesis of a library of P-based iron(II) and iron(III) complexes bearing varied electronic and geometrical features. These novel complexes are opportunistically screened as catalysts for ethylene oligomerization on one hand, and as in situ reduced species in association with dienes (isoprene, butadiene) leading to the polymerization of the latter substrates, on the other hand. In order to get closer to our goal of access to low-valent iron complexes, the use of a one-pot reduction methodology under mild conditions is reported, leading to the isolation and characterization of nine 18- and 16-electron iron(0) complexes. Even though they do not show reactivity towards ethylene or longer olefins, we demonstrate the ability of these complexes to promote reactions involving the oxidative coupling elementary step of unsaturated substrates (alkynes), the catalytic coupling of ethylene and butadiene and the activation of various compounds such as silanes and organic halides, representing a first milestone towards their optimization and application as catalysts for other reactions, including potentially in the near future, for ethylene transformation
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Seeba, Marten. "Bioinspired dinuclear copper complexes for catalytic oxidation of phenolic substrates." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2017. http://hdl.handle.net/11858/00-1735-0000-002E-E4DC-8.
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Al-Salih, T. "The electrosynthesis of metal complexes from the molecular substrates, N2̲, H2̲, CO and isocyanides." Thesis, University of Sussex, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377062.
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Blons, Charlie. "Complexes organométalliques d'or(III) et de cuivre(III) et leur réactivité vis-à-vis des substrats π." Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30248/document.
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Cette thèse porte sur la synthèse de composés d'Au(III) et de Cu(III) ainsi que sur l'étude de leur stabilité et de leur réactivité vis-à-vis de substrats p. Une approche conjointe expérimentale et théorique a été exploitée afin d'accéder à des complexes capables d'induire des processus d'insertion migratoire. Le premier chapitre aborde de manière globale la chimie organométallique de l'or et du cuivre sur le plan bibliographique. L'importance du degré d'oxydation +III est mis en évidence par la description des principaux exemples ayant contribué à la compréhension des processus associés à l'accès et la réactivité des complexes d'Au(III) et de Cu(III). Le second chapitre traite de la synthèse de deux complexes p-arènes d'Au(III) par insertion migratoire d'oléfines dans la liaison Au-C(sp)2 d'un composé (P,C) cyclométallé. Les interactions entre les systèmes aromatiques et l'or ont été mises en évidence par RMN, DFT et DRX pour un des complexes. Sur la base de cette réactivité, un processus d'arylation directe de l'éthylène a été mis en évidence. Le chapitre trois a pour objet la mise au point d'une réaction d'hydroarylation intermoléculaire d'alcynes catalysée par des complexes de type [(P,C)Au(III)(OAcF)2]. Ces derniers se sont avérés très actifs et robustes en présence d'acide trifluoroacétique. La réaction a pu être généralisée à un large panel de substrats et une étude comparative, notamment avec des complexes (N,C) cyclométallés, a mis en évidence la supériorité des complexes (P,C) pour l'hydroarylation des alcynes. Le quatrième chapitre expose la stratégie envisagée pour le développer d'un processus d'oligomérisation de l'éthylène catalysé par le cuivre. Une approche prédictive basée sur les calculs DFT a permis de mettre en évidence des insertions migratoires plus aisées dans les liaisons Cu(III)-C que dans les Cu(I)-C. Deux stratégies d'accès aux complexes de Cu(III) par addition oxydante de liaisons C-I sur des précurseurs de Cu(I) ont été évaluées théoriquement. Les calculs les plus favorables ont orienté le choix des modèles de ligands envisagés dans les chapitres cinq et six. Le cinquième chapitre aborde l'étude expérimentale associée à la première stratégie d'accès au Cu(III) : l'addition oxydante intramoléculaire dirigée par des ligands naphthylphosphine et naphthylamine peri-iodées. [...]The present work deals with the synthesis of Au(III) and Cu(III) compounds and the study of their stability and reactivity toward p substrates. An experimental and theoretical approach has been used in order to access complexes capable of undergoing migratory insertion processes. The first chapter delivers a bibliographic overview of the organometallic chemistry of gold and copper. The importance of the high oxidation state +III is highlighted by the description of important examples having contributed to the understanding of processes associated to the access and reactivity of Au(III) and Cu(III) complexes. The second chapter describes the synthesis of two p-arene Au(III) complexes by migratory insertion of olefins in the Au-C(sp)2 bond of a (P,C) cyclometallated complex. Interactions between the metallic center and the aromatic systems have been characterized by NMR, DFT and XRD for one of the complexes. Based on this insertion reactivity, a process of direct arylation of ethylene has been evidenced. The third chapter concerns the development of an intermolecular hydroarylation of alkynes process, catalyzed by [(P,C)Au(III)(OAcF)2] complexes. These have shown great activity and robustness in presence of trifluoroacetic acid. The reaction has been generalized to a broad substrate scope and a comparative study has been carried on, especially with (N,C) cyclometallated complexes, showing the superiority of (P,C) complexes for the hydroarylation of alkynes. The fourth chapter presents the envisioned strategy to develop a copper-catalyzed oligomerization of ethylene process. A predictive approach based on DFT calculations permitted to evidence easier migratory insertions in the Cu(III)-C bond than in the Cu(I)-C bond. Two strategies for the access to Cu(III) species have been theoretically evaluated. The most favourable calculations have oriented the choice of ligand models used in chapters five and six. The fifth chapter deals with the experimental study related to the first strategy of access to Cu(III) species: the directed intramolecular oxidative addition by peri-iodo napthylphosphine and naphthylamine ligands. [...]
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Batista, Denise de Souza. "Vellozia ramosissima: estrutura populacional, anatomia foliar e avalia??o nutricional em ?reas de Complexos Rupestres, sob diferentes substratos, na Serra do Espinha?o, MG." UFVJM, 2016. http://acervo.ufvjm.edu.br/jspui/handle/1/1445.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)
O objetivo deste trabalho ? entender os processos ecol?gicos que orientam a distribui??o espacial e estrutura vegetacional da esp?cie Vellozia ramosissima e tamb?m analisar a anatomia foliar, a nutri??o e a ecofisiologia, inter-relacionados com a an?lise do solo, para reconhecer a plasticidade desta esp?cie em ?reas de Complexos Rupestres Quartz?ticos (CRQs) e Ferruginosos (CRFs). A coleta de dados foi baseada na amostragem de uma parcela de 50x50m em quatro ?reas em Complexos Rupestres: duas ?reas localizadas em afloramentos quartz?ticos e duas em ferruginosos. Nas parcelas, todos os indiv?duos com altura maior ou igual a um metro foram mapeados, o padr?o de distribui??o espacial foi avaliado utilizando a fun??o K de Ripley. O m?todo de Sturges foi utilizado para defini??o do n?mero de classes diam?tricas e de altura. As an?lises de solos avaliaram: pH, teores de P, K+, Ca2+, Mg2+ e Al3+; acidez potencial (H+Al), CTC a pH 7,0 (T); CTC efetiva (t), soma de bases (SB), satura??o por bases (V%), satura??o por alum?nio (m%), areia (fina e grossa), silte, argila e equivalente de umidade (EU). Para anatomia foliar foram estimados a ?rea foliar e cortes anat?micos foliares (fotomicrografias). Para cada imagem foram mensurados os par?metros anat?micos: espessura da cut?cula, da epiderme (nas faces adaxial e abaxial), do par?nquima pali??dico e lacunoso, da extens?o da bainha voltada para o feixe vascular (hipoderme), da hipoderme voltada para fenda e altura da fenda estom?tica. O material coletado para a nutri??o foliar e de raiz foi processado e determinados os nutrientes: N; P; K+; Ca2+; Mg2+; Zn2+; Fe2+; Mn2+; Cu; C; H+ e Al3+. O fluor?metro port?til modulado MINI-PAM, foi utilizado para fazer as medi??es pontuais das vari?veis: fotorrespira??o e rendimento qu?ntico efetivo. Nas quatro ?reas foram levantadas o total de 2542 indiv?duos com a seguinte distribui??o: 158 indiv?duos na ?rea CRQ1, 682 na ?rea CRQ2, 39 em CRF1e 1663 em CRF2. A fun??o K de Ripley calculada para as quatro ?reas rejeitaram a hip?tese de completa aletoriedade espacial, demonstrando, no geral, um padr?o de distribui??o agregado. A estrutura diam?trica e de altura das quatro ?reas seguem um aumento gradativo da frequ?ncia de indiv?duos nas quatro primeiras classes, exceto para ?rea CRF1. As an?lises de solos demonstram baixa fertilidade e textura arenosa com baixa capacidade de reten??o de umidade, al?m de toxidade por metais como: Mn2+ e Al3+, para as ?reas CRF2 e CRQ2, respectivamente. H? uma similaridade na organiza??o estrutural da anatomia foliar, nas quatro popula??es, com caracter?sticas t?picas de esp?cies de ambientes xerom?rficos, como: presen?a de cut?cula espessa, fibras subepid?rmicas, hipoderme aqu?fera e sistema vascular bem desenvolvidos, al?m de fendas estom?ticas. Em termos nutricionais a esp?cie apresenta baixos n?veis de requerimentos, foram observados altos concentra??es de metais pesados (Mn2+ e Al3+) nas folhas e ra?zes da esp?cie. As vari?veis ambientais: altitude, temperatura, umidade relativa do ar e radia??o influenciam diretamente na atividade de fotoss?ntese que ? complexa e sujeita a influ?ncias regulat?rias, internas e ambientais. Foram observadas caracter?sticas funcionais como plasticidade representada pela resposta morfo-anat?mica e ecofisiol?gica nesta esp?cie.
Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016.
The objective of this work is to understand the ecological processes that guide the spatial distribution and vegetative structure of the species Vellozia ramosissima and also to analyze leaf anatomy, nutrition and ecophysiology, interrelated with soil analysis, to recognize the plasticity of this species in Areas of Quartzite Rock Complexes (CRQs) and Ferruginous Complexes (CRFs). Data collection was based on the sampling of a 50x50 m plot in four areas in Rock Complexes: two areas located in quartzitic outcrops and two in ferruginous outcrops. In the plots, all individuals with height greater than or equal to one meter were mapped, the spatial distribution pattern was evaluated using the Ripley's K function. The Sturges method was used to define the number of diametric and height classes. Soil analyzes evaluated: pH, levels of P, K+, Ca2+, Mg2+ and Al3+; Potential acidity (H + Al), CTC at pH 7.0 (T); effective CTC (t), base saturation (SB), base saturation (V%), saturation by aluminum (m%), sand (fine and coarse), silt, clay and moisture equivalent (EU). Leaf anatomy and foliar anatomical sections (photomicrographs) were estimated for leaf anatomy. For each image, the anatomical parameters were measured: cuticle thickness, epidermis (on the adaxial and abaxial sides), palisade and lacunar parenchyma, extension of the sheath facing the vascular bundle (hypodermis), hypodermis facing the Stomatal cleft. The material collected for leaf and root nutrition was processed and the nutrients determined: N; P; K+; Ca2+; Mg2+; Zn2+; Fe2+; Mn2+; Cu; C; H+ and Al3+. The portable MINI-PAM modulating fluorometer was used to make point measurements of the variables: photorespiration and effective quantum yield. In the four areas, a total of 2.542 individuals with the following distribution were surveyed: 158 individuals in the CRQ1 area, 682 in the CRQ2 area, 39 in CRF1 and 1663 in CRF2. The Ripley's K function calculated for the four areas rejected the hypothesis of complete spatial randomness, generally showing an aggregate distribution pattern. The diameter and height structure of the four areas follow a gradual increase of the frequency of individuals in the first four classes, except for CRF1 area. Soil analyzes show low fertility and sandy texture with low moisture retention capacity, as well as toxicity by metals such as: Mn2+ and Al3+, for the areas CRF2 and CRQ2, respectively. There is a similarity in the structural organization of the leaf anatomy, in the four populations, with typical characteristics of species of xeromorphic environments, such as: presence of thick cuticle, subepidermal fibers, well developed hypodermis and vascular system, and stomatal cracks. In nutritional terms, the species presented low levels of requirements, high concentrations of heavy metals (Mn2+ and Al3+) were observed in the leaves and roots of the species. The environmental variables: altitude, temperature, relative air humidity and radiation directly influence the activity of photosynthesis that is complex and subject to regulatory, internal and environmental influences. Functional characteristics were observed as plasticity represented by the morpho-anatomical and echophysiological response in this species.
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Bailey, Alan James. "Oxidation of organic substrates catalysed by ruthenium complexes and related species." Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283294.
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Carpenter, Ian. "Developments in the hydrogenation of challenging substrates utilising transition metal complexes." Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/6533.
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This thesis describes the developments of new protocols for the hydrogenation of challenging substrates. Three specific substrates were highlighted for study after an initial review of the literature; benzofurans, esters and bulky ketones. Chapter 1 details a review of the hydrogenation of challenging unsaturated substrates, highlighting areas where development is still required. Chapter 2 describes studies on the hydrogenation of 2,3-benzofuran. While a benzofuran hydrogenation catalysts was optimised, severe conditions were required to facilitate the reaction, and not found to be applicable for more elaborate substrates. We therefore considered an alternative process of enantioselective hydrogenation of benzofuranyl ketones followed by heterogeneous hydrogenation. A good process for transfer hydrogenation of a range of these hitherto unstudied substrates was developed along with greater understanding. The hydrogenation of esters is another challenge in the catalytic reduction field, so was also selected for study, with the results described in Chapter 3. After screening a range of catalysts of types [RuCl₂ (diphosphine)(diamine)] and [RuCl₂ (PNX)(DMSO)], good catalysts were identified. Successful hydrogenation of a range of esters, under mild conditions was achieved using [RuCl₂ (1,3-bisdiphenylphosphinepropane)(2-aminomethylpyridine)] using high concentrations of base co-catalyst. [RuCl₂ ((2-(diphenylphosphanylbenzyl)ethane-1,2-diamine)(DMSO)] combined with 15-25 mol% of a basic co-catalyst have been shown to be active at near ambient conditions in the hydrogenation of aromatic esters. Chapter 4 related to studies where the activity of Ru, Ir and Rh complexes of the same tridentate ligand were tested in the hydrogenation of ketones that would be regarded as sluggish substrates. Highly active and selective catalysts for the hydrogenation of bulky acetophenone derivatives were found using iridium complexes of PNX ligands (formed in situ). The highest selectivity was obtained with acetophenone substrates containing iso-propyl and cyclohexyl substituents, or medicinally important piperdinyl groups. In the best cases over 90% e.e. was observed with high conversions and with only 0.1 mol% of catalyst.
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Rainford, Christopher Charles. "Early transition metal complexes supported by silanol and crown ether substrates." Thesis, University of Bath, 1997. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338405.
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Jones, Darran Dafydd. "Protein-domain interactions and substrate channelling in multienzyme complexes." Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621518.
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Schroeder, Ewald. "Structural studies of #mu#-calpain, a novel calpain substrate, and a papain-leupeptin complex." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386677.
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Borba, André Duarte. "Transporte de partículas com autopropulsão em substratos 2d ordenados." reponame:Repositório Institucional da UFC, 2015. http://www.repositorio.ufc.br/handle/riufc/11280.
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BORBA, André Duarte. Transporte de partículas com autopropulsão em substratos 2d ordenados. 2015. 49 f. Dissertação (Mestrado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2015.Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-04-09T18:58:31Z No. of bitstreams: 1 2015_dis_adborba.pdf: 22709509 bytes, checksum: b11a2f9b1be5d06c74560942dff7858b (MD5)
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Self-propelled particles are those that use their internal energy to generate movement. The term is originally associated with the model introduced by T. Vicsek et al.[Phys. Rev. Lett. 75, 1226 (1995)] that identifies a dynamic transition associated to the collective movement of "individuals" of the same species. Examples of SPP occur in natural systems such as microorganisms (bacteria, viruses, and protozoa) or artificially as in the case of colloidal particles suitably prepared. The study of SPP is important in many fields such as materials engineering, medicine and basic sciences (physics and chemistry). In general, the collective motion reveals a dramatically different behavior as compared to the characteristics motion of individual components of a given system. That is, the action of a given individual is dominated by the presence of the other components as a result of the interaction between them. Thus, it is important to understand the collective behavior of SPP. In this dissertation, we study a two-dimensional SPP system subject to an external force and in the presence of rigid obstacles with anisotropic geometry (semi-circle) orderly distributed in the form of a square lattice. In addition to the interaction between particles and between particles and obstacles, the individual movement of each SPP is influenced by a white noise. The objective is to characterize the transport of SPP in a 2D substrate in the absenceand in the presence of a driving external force. We present a systematic study of the collective motion of the SPP as a function of noise intensity, which defines the erratic movement of the SPP, the size of the obstacles, the SPP density and separation between the obstacles. Due to the presence of anisotropic obstacles, there is a spontaneous collective movement and ordered in a given preferential direction, characterized by the non-zero average velocity of SPP in the absence of the external force. The basic conditions for the spontaneous ordered collective movement are: low-intensity noise ( << 1 ) and SPP density greater than a given critical value.
Partículas com autopropulsão, ou do inglês Self Propelled Particles (SPP), são aquelas que utilizam sua energia interna para gerar movimento. O termo está originalmente associado ao modelo introduzido por T. Vicsek et al. [Phys. Rev. Lett.75, 1226 (1995)] que identifica uma transição dinâmica associada ao movimento coletivo de "indivíduos" de uma mesma espécie. Exemplos de SPP ocorrem em sistemas naturais, como microorganismos (bactérias, vírus e protozoários), ou, artificialmente, como no caso de partículas coloidais adequadamente preparadas. O estudo de SPP é importante em diversas áreas do conhecimento tais como engenharia de materiais, medicina e ciências básicas (física e química). Em geral, o movimento coletivo revela características drasticamente distintas do movimento individual dos constituintes de um dado sistema. Ou seja, a ação de um dado indivíduo é dominada pela presença de outros constituintes do sistema como resultado da interação entre eles. Desta forma, é importante o entendimento do comportamento coletivo das SPP. Em particular nesta dissertação, estudamos um sistema bidimensional de SPP sujeitas a uma força externa e na presença de obstáculos rígidos com geometria anisotrópica (semi-círculos) distribuídos ordenadamente na forma de uma rede quadrada. Além da interação entre partículas e entre partículas e obstáculos, o movimento individual de cada SPP sofre influência de um ruído branco. O objetivo é caracterizar o transporte de SPP através do substrato 2D, na ausência ou não de uma força externa propulsora. Apresentamos um estudo sistemático do movimento coletivo das SPP em função da intensidade do ruído, que define o movimento errático das SPP, do tamanho dos obstáculos, da densidade de SPP e da separação entre os obstáculos. Devido a presença de obstáculos anisotrópicos, existe um movimento coletivo espontâneo e ordenado em uma dada direção preferencial, caracterizado por velocidade média das SPP não-nula na ausência de força externa. As condições básicas para o movimento coletivo ordenado espontâneo são: ruído de baixa intensidade (<<1) e densidade de SPP maior que um dado valor crítico.
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Shaffer, Justin P., Jana M. U'Ren, Rachel E. Gallery, David A. Baltrus, and A. Elizabeth Arnold. "An Endohyphal Bacterium (Chitinophaga, Bacteroidetes) Alters Carbon Source Use by Fusarium keratoplasticum (F. solani Species Complex, Nectriaceae)." FRONTIERS MEDIA SA, 2017. http://hdl.handle.net/10150/623193.
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Bacterial endosymbionts occur in diverse fungi, including members of many lineages of Ascomycota that inhabit living plants. These endosymbiotic bacteria (endohyphal bacteria, EHB) often can be removed from living fungi by antibiotic treatment, providing an opportunity to assess their effects on functional traits of their fungal hosts. We examined the effects of an endohyphal bacterium (Chitinophaga sp., Bacteroidetes) on substrate use by its host, a seed-associated strain of the fungus Fusarium keratoplasticum, by comparing growth between naturally infected and cured fungal strains across 95 carbon sources with a Biolog((R)) phenotypic microarray. Across the majority of substrates (62%), the strain harboring the bacterium significantly outperformed the cured strain as measured by respiration and hyphal density. These substrates included many that are important for plant-and seed fungus interactions, such as D-trehalose, myoinositol, and sucrose, highlighting the potential influence of EHB on the breadth and efficiency of substrate use by an important Fusariurn species. Cases in which the cured strain outperformed the strain harboring the bacterium were observed in only 5% of substrates. We propose that additive or synergistic substrate use by the fungus bacterium pair enhances fungal growth in this association. More generally, alteration of the breadth or efficiency of substrate use by dispensable EHB may change fungal niches in short timeframes, potentially shaping fungal ecology and the outcomes of fungal-host interactions.
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Madduma-Liyanage, Kumudu C. "Reactions of Pt(IV) and Pd(IV) Complexes with Multi-Electron Substrates." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1416570506.
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Ortiz, Karpf Andrea Lucia. "Bathymetric and substrate controls on submarine mass-transport emplacement processes and channel-levee complex evolution." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/15305/.
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Mass-transport complexes (MTCs) can significantly modify the seascape by eroding the substrate and depositing thick hetherolithic packages that can behave as hydrocarbon seals or reservoirs. MTC erosion can affect the integrity of underlying reservoir units, and affect subsequent sediment dispersal. Moreover, the irregular seabed profiles resulting from MTC erosion and emplacement can affect the distribution and architecture of subsequent sediments. This study uses a 1900 km2 3D seismic volume from the southern Magdalena Fan, offshore Colombia to investigate: i) the relationship between changes in the size, distribution and provenance of the MTCs and the evolution of tectonic structures; ii) the relationship between and the distribution of MTCs, the geometries of their basal erosion surfaces and their internal characteristics, with the morphology and composition of the seabed, and iii) the effects of MTC-related bathymetric irregularities on the architecture and development of channel-levee complex sets and avulsion lobes. The size, distribution and provenance of MTCs changed through time with the oldest MTCs being smaller (9-100 km2 in area) and sourced and from local collapse of the growing anticlines. Younger MTCs are larger (more than 200-300 km2) and sourced from the shelf, postdating the main phase of folding and faulting in the study area. These changes were used to propose a model of the tectono-stratigraphic evolution of the study area, demonstrating that MTCs can be used to constrain the timing and style of tectonic deformation in time and space. Additionally, the local morphology of the MTC basal surfaces reflects compositional changes in the underlying units, with deeper erosion occurring above channel axes deposits and more subtle slope changes across different levee units. MTC dispersal was influenced by a combination of structural and depositional relief: channel-levee complex sets channelized, diverted or blocked the subsequent mass-flows depending on the orientation of the channel-levee complex sets with respect to the direction of the flow, and the height of the levees with respect to flow thickness. Within the largest MTC, the distribution of the seismic facies was influenced by the underlying bathymetry, with internal contraction occurring updip of bathymetric highs, erosion and bypass above higher gradient slopes, and increased disaggregation towards the margins. Moreover, MTC erosion left behind an erosional remnant ridge upon which a younger channel-levee complex-set developed irregular levee geometries that led to levee collapse and channel avulsion. Map-view geometries and seismic-amplitude extractions suggest that the initial avulsion lobes were mud-prone and evolved to form sand-prone lobes. The distribution, morphology and evolution of the avulsion lobe complexes were influenced by megaclasts protruding on the MTC top surface. This study demonstrates that: i) the architecture, geometries and distribution of MTCs, channel-levee complex sets and avulsion lobes are strongly influenced by bathymetric irregularities on the seabed at various scales; ii) flow-pathways, geometries, distribution and internal characteristics of MTCs can be affected by the properties of the substrate; iii) the stratigraphic evolution of the Magdalena Fan is characterised by the interaction between MTCs and channel-levee complex sets. The learnings from this study can be applied to deeper intervals that are less well imaged and to other margins dominated by MTCs and channel-levee complex sets.
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Lima, Jaceline Maria de Negreiros. "Produção do complexo quitosana-polifosfato em Rhizopus oryzae UCP 1506 utilizando substratos agroindustriais." Universidade Católica de Pernambuco, 2013. http://www.unicap.br/tede//tde_busca/arquivo.php?codArquivo=864.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorA quitosana é um polissacarídeo natural originado da deacetilação da quitina. É solúvel em ácido devido à presença de grupos amino, livres ao longo da cadeia do polímero. Os fungos de classe Zygomycetes, em especial Rhizopus oryzae, apresenta em suas paredes celulares quitina e quitosana, podendo as mesmas estar ligadas através de proteínas e polifosfato ou outros componentes, respectivamente. O polifosfato é um biopolímero de ampla aplicabilidade na biotecnologia ambiental. A manipueira é o resultado do processo da mandioca prensada para produção de farinha e utilizada como fonte de carbono nos processos fermentativos. A milhocina é um subproduto da produção de amido de milho e considerada como fonte de nitrogênio. Investigações foram realizadas com Rhizopus oryzae em fermentação submersa para produção de biomassa e do complexo quitosana-polifosfato, através do cultivo em rejeito agroindustrial, manipueira suplementado com milhocina, utilizando um planejamento fatorial completo 23 sobre agitação de 150rpm por 96h. O ensaio com a maior quantidade de biomassa e quitosana foi selecionado para realizar uma cinética de crescimento para avaliar a produção de biomassa e do complexo quitosanapolifosfato. Neste sentido, foi utilizado frascos de Erlenmyers de 500mL de capacidade, contendo 100mL do meio formulado, sendo inoculados em 1mL da suspensão de 107 esporos por mL, incubados sob agitação orbital de 150rpm. As amostras foram coletadas a cada 12 horas até o período de 120h. Os resultados obtidos demonstraram um aumento máximo de biomassa com 48h de cultivo em pH 7,3, com produção máxima da quitosana por R. oryzae de 116mg/g de biomassa em 36h de cultivo. O polifosfato complexado à quitosana apresentou maior rendimento em 36h correspondendo a 13mg/mg de quitosana. Devido os resultados obtidos na produção de biomassa e o complexo de quitosanapolifosfato por Rhizopus oryzae, tornaram-se economicamente viáveis devido à utilização de rejeitos industriais para obtenção desses polímeros.
Chitosan is a natural polysaccharide originated from the deacetylation of chitin. It is soluble in acid because of the presence of amino groups, free along the polymer chain. The fungal class Zygomycetes, in particular Rhizopus oryzae, presents in its cell wall chitin and chitosan, and they may be linked through the polyphosphate or proteins and other components, respectively. The polyphosphate is a biopolymer with wide applicability in environmental biotechnology. Manipueira is the result of the process for production of pressed cassava flour and used as carbon source in fermentation processes. The corn steep liquor is a by-product of corn starch and regarded as nitrogen source. Investigations were carried out with Rhizopus oryzae in submerged fermentation for production of biomass and chitosan-polyphosphate complex, through cultivation in agro waste, cassava supplemented with corn steep liquor, using a full factorial design on 23 agitation at 150 rpm for 96h. The test with the greatest amount of biomass and chitosan was selected to perform a growth kinetics to evaluate the production of biomass and chitosan-polyphosphate complex. In this sense, was used bottles of 500ml capacity Erlenmyers containing 100mL of medium formulated being inoculated in 1-ml suspension of 107 spores per ml, incubated under orbital agitation at 150 rpm. Samples were collected every 12 hours until the period of 120h. The results showed a maximum increase of biomass with 48 hours of cultivation at pH 7.3, with maximum production of chitosan by R. oryzae 116mg / g biomass at 36h of cultivation. The polyphosphate complexed to chitosan had the highest yield in 36 h corresponding to 13mg/mg chitosan. Because the results in the production of biomass and chitosan-polyphosphate complex from Rhizopus oryzae, have become economically viable due to the use of industrial wastes to obtain these polymers.
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鄧煒堂 and Wai-tong Tang. "Homogeneous oxidation of organic substrates by ruthenium, iron and manganese tertiary amine complexes." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1989. http://hub.hku.hk/bib/B31231706.
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Kamp, Norbert W. J. "The catalytic oxidation of phenolic substrates using manganese triazacyclononane complexes and hydrogen peroxide." Thesis, University of York, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265366.
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Tang, Wai-tong. "Homogeneous oxidation of organic substrates by ruthenium, iron and manganese tertiary amine complexes /." [Hong Kong : University of Hong Kong], 1989. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12355203.
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BELTRANI, MICHELA. "Oxidative Carbonylation of Unsaturated Substrates Promoted by Aryl [Alfa]-Diimine Pd(II) Complexes." Doctoral thesis, Urbino, 2015. http://hdl.handle.net/11576/2628805.
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Bassard, David. "Méthodologie de prédiction et d’optimisation du potentiel méthane de mélanges complexes en co-digestion." Thesis, Compiègne, 2015. http://www.theses.fr/2015COMP2175/document.
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La co-digestion anaérobie (CoDA) des substrats agro-industriels s’inscrit pleinement dans les objectifs sociétaux d’une gestion optimisée des agroressources, d’une réduction des impacts anthropogéniques, ainsi que d’un développement des énergies renouvelables. Toutefois, en considérant les verrous industriels et scientifiques, il est apparu que la problématique méthodologique, relative à l’étude et à l’optimisation, était primordiale dans l’amélioration des performances méthanogènes en CoDA. En cela, il s’est avéré que le principal actionneur pour l’optimisation de la CoDA soit la formulation du mélange en substrats et co-substrats constituant l’intrant du digesteur. Ainsi, les travaux de thèse étaient inscrits dans un double objectif, industriel et scientifique, dont les résultats ont permis de (i) mettre en œuvre des méthodes simples, peu chronophages et surtout peu coûteuses, pour la caractérisation des intrants et le suivi de la CoDA, (ii) déterminer la relation fondamentale entre la formulation du mélange de substrats et son potentiel biométhanogène, (iii) développer des outils de prédiction du potentiel biométhanogène des mélanges de substrats, ainsi que des biodégradabilités globales et spécifiques de ces derniers, (iv) améliorer la compréhension des interactions entre les substrats codigérés et le consortium microbien de digestion, ainsi que la capacité de ce dernier à s’adapter aux diverses charges organiques qui lui sont appliquées (capacité homéostasique)The co-digestion of agro-industrial substrates in anaerobic conditions falls within the objectives of an optimized management of agricultural resources along with reduction of anthropogenic impacts and development of renewable energies. Considering scientific and industrial bottlenecks from literature review, it could be identified that a methodological approach was the key to an enhanced understanding of anaerobic co-digestion. Ultimately, formulation of the substrate and co-substrates (digestor’s inputs) appeared to be the main actuator to optimize anaerobic co-digestion. Conciliating both scientific and industrial issues, this thesis led to the following findings : (i) an implementation of simple and cost-saving methods to characterize the inputs of digestor and biogas production, (ii) a determination of fundamental relationship between substrate blend and his biomethane potential, (iii) a development of predictive tools for biomethane potential of substrate blends as well as global and specific biodegradability of substrates, (iv) an enhanced comprehension of first, interactions between codigested substrates and the microbial consortium and second, the adaptation capacity of the microbial consortium to various organic loading (homeostatic capacity)