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1
Larsson, Niklas. "InP/Si Template for Photonic Application." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187046.
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In this work an epitaxial layer of Indium Phosphide (InP) has been grown on top of a silicon substrate using the Corrugated Epitaxial Lateral Overgrowth (CELOG) technique. The grown InP CELOG top layer typically has a poor surface roughness and planarity. Before this surface can be used for any processing it has to be smooth and planarized. For this purpose a two-step Chemical Mechanical Polishing (CMP) technique has been investigated and developed. In the first step commercially available Chemlox has been used to planarize the sample. In the second step Citric Acid (CA) and sodium hypochlorite (NaClO) has been mixed together to form abrasive-free polishing slurry. The second step has been developed to remove defects introduced by the first step. This surface is prepared to demonstrate that a photonic device such as a quantum well can be realized in a Photonic Integrated Circuit (PIC). A quantum well was grown on the polished CELOG InP/Si sample and measured with Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Photoluminescence (PL). The roughness was improved with CMP from 33.2 nm to 12.4 nm. However the quantum well did not give any response in the PL measurements.<br>I detta arbete har ett epitaxiellt lager indiumfosfid (InP) blivit växt på ett kiselsubstrat med hjälp av en korrugerad epitaxial lateral överväxt (CELOG) teknik. Det översta lagret av den CELOG växta ytan har ofta en väldigt ojämn yta. Innan denna yta kan användas till någon fortsatt utveckling måste den vara slät och plan. Det översta lagret har polerats med hjälp av en två-stegs kemisk mekanisk polerings (CMP) teknik. I det första steget har komersiellt tillgänglig Chemlox använts för att planarisera ytan. I det andra steget har citronsyra (CA) och natrium hypoklorit (NaClO) blandats samman för att bilda ett partikelfritt polermedel. Det andra steget har tagits fram för att ta bort defekter introducerade I det första steget. Ytan är preparerad för att demonstrera att en fotonisk enhet, t.ex. en kvantbrunn kan realiseras I en fotonisk integrerad krets (PIC). En kvantbrunn växtes fram på det polerade CELOG InP/Si provet och mattes med hjälp av atomkraftsmikroskop (AFM), scanning electron mikroskopi (SEM), röntgendiffraktion (XRD) och fotoluminisens (PL). Ytojämnheten förbättrades med hjälp av CMP från 33.2 nm till 12.4 nm. Dock så gav ej kvantbrunnen någon respons I PL-mätningarna.
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Koulikoff-Souviron, Marie. "Characteristics of reciprocal dyadic supply relationships and related people management practices : a cross-case comparison of an inter- and an intra-firm context." Thesis, Cranfield University, 2003. http://hdl.handle.net/1826/55.
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Dipsche, Patrick. "Chemo-/Biomechanische Kariesentfernung mit Biosolv." Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-106989.
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Humphrey, Andrew Joseph. "Chemo-enzymatic synthesis using transketolase." Thesis, University of Edinburgh, 1997. http://hdl.handle.net/1842/12093.
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The enzyme transketolase (TK) [E.C.2.2.1.1] catalyses the stereoselective transfer of a two-carbon ketol unit from a donor substrate such as lithium hydroxypyruvate (LiHPA, i) to an α-hydroxyaldehyde. Research into the use of TK from <I>Escherichia coli </I>as a process catalyst for asymmetric carbon-carbon bond formation has required the development of synthetic routes to novel acceptor substrates. The preparation of novel α-hydroxyaldehydes in enantiomerically pure form from chiral pool α-hydroxy-or α-amino acids, and of racemic α-hydroxy-aldehydes of utility in the synthesis of natural produce analogues, is described. Formerly, biotransformations mediated by TK involved the use of an excess of aldehyde substrate in buffered aqueous solution. An alternative protocol is presented, in which the biotransformations are performed in unbuffered medium; the natural pH change during the biotransformation is offset by use of a pH autotitrator to maintain the solution pH at the process optimum of 7.0. The synthetic utility of the chiral triols produced from TK-mediated biotransformations has been demonstrated through the development of synthetic routes to the natural product nectrisine, ii, and the <I>N-</I>hydroxypyrrolidine sugar analogue iii from the triols iv and v, available <I>via</I> TK-mediated condensation of LiHPA with the appropriate α-hydroxyaldehyde.
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STRENTA, CLAUDIO. "Chemo-embolisation des metastases hepatiques." Lyon 1, 1989. http://www.theses.fr/1989LYO1M465.
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Fröhlich, Holger. "Kernel methods in chemo- and bioinformatics." Berlin Logos-Verl, 2006. http://deposit.d-nb.de/cgi-bin/dokserv?id=2888426&prov=M&dok_var=1&dok_ext=htm.
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Dalponte, Luca. "Chemo-enzymatic modification of cyclic peptides." Thesis, University of Aberdeen, 2018. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=239393.
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Warwel, Mathias. "Untersuchungen zur chemo-enzymatischen Synthese von Sialokonjugaten." Phd thesis, [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=963625004.
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Phung, Nga. "Chemo-enzymatische asymmetrische Synthesen mit DHAP-Aldolasen." Phd thesis, [S.l.] : [s.n.], 2004. http://elib.tu-darmstadt.de/diss/000498.
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Brook, Chris Bryan A., and cbrook@phy ulaval ca. "Chemo-dynamical simulations of the Milky Way." Swinburne University of Technology, 2004. http://adt.lib.swin.edu.au./public/adt-VSWT20050323.121320.
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Using a state of the art galaxy formation software package, GCD+, we model the formation and evolution of galaxies which resemble our own Galaxy, the Milky Way. The simulations include gravity, gas dynamics, radiative gas cooling, star formation and stellar evolution, tracing the production of several elements and the subsequent
pollution of the interstellar medium. The simulations are compared with observations
in order to unravel the details of the Milky Way's formation. Several unresolved issues regarding the Galaxy's evolution are specifically addressed. In our first study, limits are placed on the mass contribution of white dwarfs to the dark matter halo which envelopes the Milky Way. We obtain this result by comparing the abundances
of carbon and nitrogen produced by a white dwarf-progenitor-dominated halo with the abundances observed in the present day halo. Our results are inconsistent with a white dwarf component in the halo 5% (by mass), however mass fractions of
~1-2% cannot be ruled out. In combination with other studies, this result suggests that the dark matter in the Milky Way is probably non-baryonic. The second component of this thesis probes the dynamical signatures of the formation of the
stellar halo. By tracing the halo stars in our simulation, we identify a group of high-eccentricity stars that can be traced to now-disrupted satellites that were accreted by the host galaxy. By comparing the phase space distribution of these stars in our simulations to observed high-eccentricity stars in the solar neighbourhood, we find devidence that such a group of stars - a 'stellar stream' - exists locally in our own Galaxy. Our next set of simulations demonstrate the importance of strong energy feedback from supernova explosions to the regulation of star formation. Strong feedback
ensures that the building blocks of galaxy formation remain gas-rich at early epochs. We demonstrate that this process is necessary to reproduce the observed low mass and low metallicity of the stellar halo of the Milky Way. Our simulated galaxy is shown to have a thick disk component similar to that observed in the Milky Way through an abrupt discontinuity in the velocity dispersion-versus-age relation for solar neighbourhood stars. This final study suggests that the thick disk forms in a chaotic merging period during the Galaxy's formation. Our thick disk formation scenario is shown to be consistent with observed properties of the thick disk of the
Milky Way.
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Gkoutos, Georgios Vasileios. "Internet-based resource discovery in chemo-bioinformatics." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268851.
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Cater, Philip A. "Chemo-enzymatic studies using hydrolases and dehydrogenases." Thesis, University of Warwick, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340552.
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Baker, Anne. "The chemo-enzymatic synthesis of glycosidic bonds." Thesis, University of Exeter, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294484.
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Di, Leo Claudio V. "Chemo-mechanics of lithium-ion battery electrodes." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/100119.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 181-187).<br>Mechanical deformation plays a crucial role both in the normal operation of a Lithium-Ion battery, as well as in its degradation and ultimate failure. This thesis addresses the theoretical formulation, numerical implementation, and application of fully-coupled deformation-diffusion theories aimed at two different classes of electrode materials: (i) phase-separating electrodes, and (ii) amorphous Silicon electrodes, which are elaborated on next. Central to the study of phase-separating electrodes is the coupling between mechanical deformation and the Cahn-Hilliard phase-field theory. We have formulated a thermodynamically consistent theory which couples Cahn-Hilliard species diffusion with large elastic deformations of a body. Through a split-method, we have numerically implemented our theory, and using our implementation we first studied the diffusion-only problem of spinodal decomposition in the absence of mechanical deformation. Second, we studied the chemomechanically- coupled problem of lithiation of isotropic spheroidal phase-separating electrode particles. We showed that the coupling of mechanical deformation with diffusion is crucial in determining the lithiation morphology, and hence the Li distribution, within these particles. Amorphous silicon (a-Si), when fully lithiated, has a theoretical capacity ~~ 10 times larger than current-generation graphite anodes. However, the intercalation of such a large amount of Li into a-Si induces very large elastic-plastic deformations. We have formulated and numerically implemented a fully-coupled deformation-diffusion theory, which accounts for transient diffusion of lithium and accompanying large elastic-plastic deformations. We have calibrated our theory, and applied it to modeling galvanostatic charging of hollow a- Si nanotubes whose exterior walls have been oxidized to prevent outward expansion. Our predictions of the voltage vs. state-of-charge (SOC) behavior at various charging rates (Crate) are in good agreement with experiments from the literature. Through simulation, we studied how plastic deformation affects the performance of a-Si-based anodes by reducing stress, thus enabling higher realizable capacities, and introducing dissipation. Finally, in order to design a-Si-based anodes aimed at mitigating failure of the solid electrolyte interphase (SEI), we have formulated and studied a continuum theory for the growth of an SEI layer - a theory which accounts for the generation of growth stresses.<br>by Claudio V. Di Leo.<br>Ph. D.
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Perry, James David. "Chemo and Radioresistance in Brain-Related Tumors." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1397567849.
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Errera, Reagan Michelle. "Inhibition and success of prymnesium parvum invasion on plankton communities in Texas, USA and prymnesium parvum pigment dynamics." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/5985.
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Prymnesium parvum Carter, a haptophyte species capable of forming harmful algal blooms (HABs), has been identified in fresh and brackish water habitats worldwide. In Texas, P. parvum blooms have diminished local community revenues from losses to tourism, fishing, and hatchery production. In this thesis, P. parvum dynamics were studied using in-situ microcosm experiments at Lake Possum Kingdom, Texas during three seasons (fall, winter, spring) in 2004-2005. Specifically, nutrient additions were used to test the hypothesis that increased nutrient levels would not enhance P. parvum's ability to invade phytoplankton communities. In addition to full nutrient additions to levels of f/2 media, other treatments included nutrient additions deficient in either nitrogen (N) or phosphorus (P). Additionally, barley straw extract was tested as a growth inhibitor to prevent P. parvum blooms. Furthermore, P. parvum initial population density was examined to test the hypothesis that increased initial populations could promote an increase in P. parvum population densities. Findings indicated that P. parvum populations in Lake Possum Kingdom would not likely gain a selective advantage over other species when inorganic nutrients (nitrogen and phosphorus) were not limiting. P. parvum did, however, gain an advantage during both N- and P-limited conditions as indicated by toxicity, cell concentrations, and bulk phytoplankton community shifts. Furthermore, P. parvum blooms in Lake Possum Kingdom would likely not be inhibited by barley straw extract application. Initial population densities affected the final population density, but only when initial populations were low. A method to quickly and accurately detect the presence of P. parvum is needed due to P. parvum's potential to cause toxic and lethal blooms. This thesis tested whether P. parvum photopigments are conservative regardless of growth conditions and could be used to quantify the relative abundance of P. parvum in mixed community samples. If biomarker pigments are conservative, then an optimized version of CHEMTAX could be employed as an alternative diagnostic tool to microscopy for enumeration of P. parvum. However, P. parvum pigments in the Texas strain were not conservative throughout the growth cycle and therefore may not be a reliable indicator of cell abundance.
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Brennan, Meabh B. "Chemo- and stereoselective oxidation of allylic amino alcohols." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531953.
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Jones, A. B. "Studies towards combined chemo-biocatalytic reactions in water." Thesis, University College London (University of London), 2011. http://discovery.ucl.ac.uk/1317755/.
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In recent years green chemistry has been increasingly applied to industrial syntheses. One key area of growth is the use of biocatalysts to perform reactions selectively in non-organic media. However, there is currently no set development process for the discovery and evolution of enzymes to be applied in these reactions. A process has been suggested by Hailes et al, part of which is the development of chemical reactions that work in combination with the biocatalysts.1 The interface between traditional chemistry and biocatalysis has yet to be fully explored, particularly in relation to the potential degree of interaction between the two synthetic techniques. The development of a chemical reaction that can be used in one-pot with a biotransformation is explored within this thesis. The synthesis of a standard to calibrate an assay of the transketolase selectivity was performed first. This allowed the stereochemistry of the starting material of the reductive amination being developed to be determined. Next a reductive amination reaction that proceeded in water and in the presence of transketolase was discovered and then optimized using cyclohexanone as a test substrate. This reaction was developed so that it could offer an alternative to a similar transformation performed by a transaminase enzyme, specifically with respect to substrate and stereoselectivity. This optimized reaction was then applied to an intermediate (1,3-dihydroxy-pentan-2- one), synthesized both using standard organocatalytic techniques and a biotransformation using transketolase, to produce 2-benzylamino-pentane-1,3-diol. The reaction was seen to be diastereoselective and an alternative transfer hydrogenation reaction that displayed the opposite selectivity was also investigated. This complimentary pair of reactions meant that all four diastereoisomers of 2-benzylamino-pentane-1,3-diol could potentially be synthesized. This work illustrated that the development of chemical reactions towards one-pot cascade reactions with biocatalysts is possible.
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Fregapane, Giuseppe. "Chemo-enzymatic synthesis of sugar fatty acid ethers." Thesis, University of Reading, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357150.
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Bezerra, Francisco de Aquino. "Chemo-enzymatic Synthesis of (S)-Moprolol Using Lipase." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=15601.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico<br>Herein we describe the chemoenzymatic synthesis of active principle of the drug Levotensin (SimesÂ), a drug used in the therapy of patients with hypertension associated with heart disease. This substance has a stereogenic center and presents as eutomer the enantiomer with S configuration. The (S)-moprolol, also can be used in combination with other substances to form an eye drops, which is used to control intraocular pressure, being efficient as timolol in control of glaucoma. We used the enzymatic kinetic resolution to introduce chirality in the target molecule. Firstly, we conducted a screening with nine commercial enzymes [free lipases: Amano lipase from Pseudomonas fluorescens, lipase from Candida rugosa, Amano Lipase PS Burkholderia cepacia, Acylase I from Aspergillus Mellus and immobilized lipases: CAL-B, lipase Amano PS-IM immobilized on diatomaceous earth, Rhizopus oryzae immobilized on immobead 150, Lipozyme RM IM and the lipase from Thermomyces lanuginosus immobilized on immobead-150]. These lipases were used for kinetic resolution of rac-1-(chloromethyl)-2-(o-methoxyphenoxy) ethyl acetate by hydrolysis reaction. The kinetic resolution lead to the corresponding alcohol of S configuration and the remaining acetate of R configuration. Among the evaluated enzymes, two lipases showed the highest values of enantioselectivity, Amano lipase from Pseudomonas fluorescens in free form, with enantioselectivity (E) 72 and the immobilized CAL-B, with enantioselectivity (E) 60. These lipases were evaluated in enzymatic kinetic resolution of rac-1-chloro-3- (o-methoxyphenoxy) propan-2-ol in organic media via the reaction of acetylation. In this case, the resolutions occurred with high activity (conversions near 50%), but with low selectivity (enantiomeric excesses around 65%). Therefore, the introduction of chirality in the target molecule [(S)-moprolol)] was performed using as the intermediate R-1-(chloromethyl)-2-(o-methoxyphenoxy)ethyl acetate obtained by kinetic resolution of rac-1-(chloromethyl)-2-(o-methoxyphenoxy)ethyl acetate by hydrolysis reaction, mediated by CAL-B, with enantiomeric excess of 97% and close to 50% conversion.<br>No presente trabalho descrevemos a sÃntese quimioenzimÃtica do princÃpio ativo do fÃrmaco Levotensin (SimesÂ), que à utilizado na terapia de pacientes com hipertensÃo arterial associada a cardiopatias. Essa substÃncia possui um centro estereogÃnico e apresenta como eutÃmero o enantiÃmero com configuraÃÃo S. O (S)-moprolol, tambÃm, pode ser usado em combinaÃÃo com outras substÃncias para compor um colÃrio, sendo tÃo eficiente quanto o timolol no controle do glaucoma. Utilizamos a resoluÃÃo cinÃtica enzimÃtica para introduzir quiralidade na molÃcula alvo. Primeiramente, realizamos uma triagem com nove enzimas comerciais [lipases livres: Amano lipase de Pseudomonas fluorescens, lipase de Candida rugosa, Amano Lipase PS de Burkholderia cepacia e a Acilase I de Aspergillus mellus e lipases imobilizadas: Candida antarctica tipo B (CAL-B), Amano lipase PS-IM imobilizada em diatomaceous earth, lipase de Rhizopus oryzae imobilizada em immobead 150, lipozyme imobilizada de Mucor miehei (Lipozyme RM IM) e a lipase de Thermomyces lanuginosus imobilizada em immobead-150]. As referidas lipases foram utilizadas na resoluÃÃo cinÃtica do rac-acetato de 1-(clorometil)-2-(o-metoxifenoxi)etila via reaÃÃo de hidrÃlise. A resoluÃÃo cinÃtica levou ao correspondente Ãlcool, como produto, com configuraÃÃo S e ao acetato remanescente com configuraÃÃo R. Dentre as enzimas avaliadas, duas lipases apresentaram os maiores valores de enantiosseletividade, a Amano lipase de Pseudomonas fluorescens na forma livre, com enantiosseletividade (E) de 72 e a CAL-B imobilizada, com enantiosseletividade (E) de 60. Tais lipases foram avaliadas na resoluÃÃo cinÃtica enzimÃtica do rac-1-cloro-3-(o-metoxifenoxi)propano-2-ol em meio orgÃnico via reaÃÃo de acetilaÃÃo. Neste caso, as resoluÃÃes ocorreram com alta atividade (conversÃes prÃximas a 50%), porÃm com baixa seletividade (excessos enantiomÃricos em torno de 65%). Portanto, a introduÃÃo da quiralidade na molÃcula alvo [(S)-moprolol)] foi realizada utilizando como intermediÃrio o R-acetato de 1-(clorometil)-2-(o-metoxifenoxi)etila obtido por resoluÃÃo cinÃtica (RC) do rac-acetato de 1-(clorometil)-2-(o-metoxifenoxi)etila, via reaÃÃo de hidrÃlise, mediada por CAL-B, com excesso enantiomÃrico de 97% e conversÃo prÃxima a 50%.
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Chlubnová, Ilona. "Chemo-enzymatic synthesis of bioactive furanosyl-containing glycoconjugates." Rennes 1, 2010. http://www.theses.fr/2010REN1S196.
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Hexofuranoses are absent from mammals, but are present in numerous microorganisms, often highly pathogenic. This makes them very attractive targets for the development of new antimicrobial drugs. As an alternative to organic synthesis, the use of enzymes has been increasingly appreciated in the synthesis of glycoconjugates. Here we report the use of alpha-l-Arabinofuranosidase Araf51 for the synthesis of furanosyl-containing glycoconjugates. This enzyme was really efficient in catalysing oligomerisations of l-arabinofuranoside and d-galactofuranoside up to the formation of pentasaccharides, as well as in the synthesis of furanosides containing structurally modified d-galactofuranosides and pyrano-furano disaccharides. Many of synthesised compounds represented biologically relevant structures found in some clinically important pathogens. Biological tests proved that these neofuranosides have robust immunostimulatory properties and can become a potentially very useful new type of adjuvants<br>Les hexofuranoses sont absents chez les mammifères, mais sont présents dans de nombreux micro-organismes souvent hautement pathogènes, ce qui les rend très intéressants pour le développement de nouveaux médicaments antimicrobiens. Les enzymes sont de plus en plus souvent utilisées pour la synthèse de glycoconjugués comme une alternative à la synthèse organique. Dans ce travail, nous présentons l'utilisation d’alpha-l-Arabinofuranosidase Araf51 pour la synthèse de glycoconjugés contenant des unités furanosidiques. Cette enzyme s’est révélée très efficace pour catalyser les oligomérisations des dérivés du l-arabinofuranoside et ceux du d-galactofuranoside jusqu'à la formation de pentasaccharides, ainsi que dans la synthèse de furanosides contenant des motifs structuralement modifiés du d-galactofuranose et des disaccharides de type pyrano-furano. Un grand nombre de composés synthétisés présentent des structures d’intérêt biologique que l’on retrouve dans certains agents pathogènes. Les essais biologiques ont montré que ces néofuranosides ont de fortes propriétés immunostimulatrices et peuvent potentiellement constituer un nouveau type d’adjuvants
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Ali, Arham. "Chemo-Thermal Micromachining of Glass: An Explorative Study." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin154392221273875.
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Leichsenring, Peter, and Thomas Wallmersperger. "Time-dependent chemo-electromechanical behavior of hydrogelbased structures." SPIE, 2018. https://tud.qucosa.de/id/qucosa%3A35174.
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Charged hydrogels are ionic polymer gels and belong to the class of smart materials. These gels are multiphasic materials which consist of a solid phase, a fluid phase and an ionic phase. Due to the presence of bound charges these materials are stimuli-responsive to electrical or chemical loads. The application of electrical or chemical stimuli as well as mechanical loads lead to a viscoelastic response. On the macroscopic scale, the response is governed by a local reversible release or absorption of water which, in turn, leads to a local decrease or increase of mass and a respective volume change.
Furthermore, the chemo-electro-mechanical equilibrium of a hydrogel depends on the chemical composition of the gel and the surrounding solution bath. Due to the presence of bound charges in the hydrogel, this system can be understood as an osmotic cell where differences in the concentration of mobile ions in the gel and solution domain lead to an osmotic pressure difference.
In the present work, a continuum-based numerical model is presented in order to describe the time-dependent swelling behavior of hydrogels. The numerical model is based on the Theory of Porous Media and captures the fluid-solid, fluid-ion and ion-ion interactions. As a direct consequence of the chemo-electro-mechanical equilibrium, the corresponding boundary conditions are defined following the equilibrium conditions. For the interaction of the hydrogel with surrounding mechanical structures, also respective jump condtions are formulated. Finaly, numerical results of the time-dependent behavior of a hydrogel-based chemo-sensor will be presented.
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Hajikhani, Aidin [Verfasser]. "Chemo-Mechanical Modeling of Polymeric Hydrogels / Aidin Hajikhani." Hannover : Gottfried Wilhelm Leibniz Universität, 2021. http://nbn-resolving.de/urn:nbn:de:101:1-2021080502090608988915.
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Boudet, Nadège. "Polyfunctionalizations of N-Heterocycles via Chemo- and Regioselective Metalations." Diss., lmu, 2008. http://nbn-resolving.de/urn:nbn:de:bvb:19-80314.
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Bachmann, Sven-Oliver. "Chemo- und Radioresistenzverhalten kleinzelliger Bronchialkarzinomzellinien in Adhärenz- und Suspensionskultur." [S.l.] : [s.n.], 2005. http://archiv.ub.uni-marburg.de/diss/z2005/0384/.
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Hesse, Marlen. "Chemo-enzymatische Werkzeuge zur Untersuchung von nicht-codierender RNA." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2017. http://dx.doi.org/10.18452/17740.
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Nicht-codierende RNAs sind ein bedeutender Bestandteil genregulatorischer Prozesse. Ihre Fehlregulierung wird mit zellulärer Dysfunktion und der Entstehung von Krankheiten in Zusammenhang gebracht. Ziel dieser Arbeit war die Entwicklung verschiedener Testsysteme zur Untersuchung nicht codierender RNAs mit dem Schwerpunkt microRNA (miRNA), precursor miRNA (pre-miRNA) und circular RNA (circRNA). Für eine Zyklisierung und Funktionalisierung von circRNA mittels Cu-katalysierter Click-Chemie zur Identifizierung zellulärer Interaktionspartner und zugehöriger Wirkmechanismen wurden die Termini linearer RNA-Template modifiziert. Mit Hilfe enzymatischer Techniken wie Transkription und Ligation konnte in vitro die Inkorporation Azid- und Alkin-funktionalisierter Nukleotid-Bausteine am 5‘- und 3‘-Terminus gezeigt werden. Zur Untersuchung der miRNA-Reifung in cellulo wurde die pre-miRNA-134 unter Verwendung chemo-enzymatischer Methoden mit einem Fluorophor/Quencher-Paar an den Termini ausgestattet. Durch intrazelluläre Reifung der gelabelten pre-miRNA mit einhergehender Fluoreszenzfreisetzung sollte die Visualisierung und damit die Lokalisierung des miRNA-Reifungsortes innerhalb von Neuronen realisiert werden. Zudem gelang die Entwicklung eines auf branched rolling-circle amplification (BRCA) basierenden Argonaute2(Ago2)-vermittelten Spaltungsassays. Ein Enzymkomplex aus rekombinantem, humanem Ago2 und der miRNA miR 122, genannt minimal RISC, wurde dabei zur Substrat-Spaltung eingesetzt. Zur Etablierung des BRCA-basierenden Ago2-vermittelten Spaltungsassays als Screening-Tool für die Identifizierung potentieller Inhibitoren der mRNA-Spaltung wurden exemplarisch sechs Testsubstanzen aus der Gruppe der Aminoglykoside untersucht. Der BRCA-basierende Ago2-vermittelte Spaltungsassay stellte eine einfache und zuverlässige Detektionsmethode dar, der die Untersuchung einer größeren Probenzahl mit geringem Aufwand und ohne Verwendung von fluorogen gelabeltem Substrat ermöglichte.<br>Non-coding RNAs are an important factor in gene regulation in which their deregulation is associated with cellular dysfunction and disease. Here, the development of different test systems for the investigation of non-coding RNAs, namely microRNA (miRNA), precursor miRNA (pre-miRNA), and circular RNA (circRNA), was on focus. In order to circularize and functionalize circRNA with the purpose of identifying cellular interaction partners and possible mechanisms of action, 5‘- and 3‘-terminal modifications were added to a linear RNA template. This was accomplished by using azide- and alkyne-functionalized nucleotides which were incorporated by enzymatic approaches like transcription and ligation to be followed by Cu-catalyzed click chemistry for circularization. For investigating miRNA maturation in neuronal cells, pre-miR-134 was modified by chemo-enzymatic approach with fluorophore and quencher at its 5‘ and 3‘ ends, respectively. Intracellular maturation of labeled pre-miRNA would produce a fluorescent signal upon cleavage, thus enabling visualization and localization of miRNA maturation in neuronal cells. Furthermore, the development of Ago2-mediated mRNA cleavage assay based on branched rolling-circle amplification (BRCA) was accomplished. A complex of recombinant human Ago2 and miRNA miR-122, called minimal RISC, was used for substrate cleavage. To establish this assay as adequate screening method for identifying potential inhibitors of mRNA cleavage, a group of six aminoglycosides was tested. The BRCA-based Ago2-mediated cleavage assay showed to be a simple and reliable detection method and screening tool for small molecule binders with little effort and without fluorescent labeling of substrate.
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Rickaby, Kirstie. "Investigation of the chemo-enzymatic synthesis of cyclic peptides." Thesis, University of Aberdeen, 2018. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=238613.
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Cyclic peptides constitute an attractive class of compounds for drug development, however the numerous problems associated with their synthesis have limited their applicability. The cyclisation step itself is particularly problematic, with solution phase cyclisations being required to be conducted under very high dilution to promote cyclisation over unwanted side reactions such as oligomerisation. In addition, epimerisation, leading to the loss of chiral integrity at the terminal residues is a major concern. Attention is now turning to biochemical cyclisation strategies, such as SICLOPPS and sortase mediated ligation, although these also come with their own inherent disadvantages, for example, in the case of sortase mediated ligation, there is significant “scarring” of the target due to the presence of a four amino acid long recognition sequence. Cyclisation using ribosomally synthesised post translationally modified enzymes is also gaining popularity. One such family of enzymes is the patellamides. PatGmac is capable of performing cyclisations on linear peptide substrates with minimal scarring compared to the aforementioned alternatives and, importantly, with no epimerisation and could constitute a greener and more facile route to cyclic peptides. The work herein details some of the investigations designed to define the range of synthetic utility and test the flexibility of the enzymes. This was done qualitatively, by designing a variety of linear peptide analogues of the natural product, homophymine A, featuring unique structural moieties and evaluating their compatibility with the enzyme. It was also done quantitatively, using an LCMS based semi-quantitative strategy, to assess differences between similar, but different, enzymes and to assess whether there were differences in how different substrates are processed by the same enzyme. In addition to this, a variety of these substrates were also assessed for their proclivity to cyclise under standard chemical conditions for comparison. Lastly, with the increasing appearance cyclic peptides and non-peptidic macrocycles in the libraries of compounds being considered for clinical trials, there is now a growing need for computational modelling of these structures. Herein, a 3D v structure for the natural product callipetin N is proposed for the first time, determined using a combination of computational and NMR techniques.
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Dupps, William J. Jr. "Chemo-mechanical modification of the corneal response to photokeratectomy." The Ohio State University, 1998. http://rave.ohiolink.edu/etdc/view?acc_num=osu1314731272.
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Bista, Hemanta. "Modeling Hydro-Bio-Chemo-Mechanical Mechanisms in Granular Soils." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1399587419.
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Dupps, William J. "Chemo-mechanical modification of the corneal response to photokeratectomy /." The Ohio State University, 1998. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487953204279746.
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Mess, Francis McCarthy. "Wear model for chemo-mechanical polishing of single crystal silicon." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/15984.
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Chandra, Richard P. "Chemo-enzymatic modification of high-kappa kraft pulps with laccase." Diss., Available online, Georgia Institute of Technology, 2005, 2003. http://etd.gatech.edu/theses/available/ipstetd-1011/.
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Xin, Yan. "Suramin as a chemo- and radio-sensitizer preclinical translational studies /." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1144958112.
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Cox, Philip Brian. "Novel chemo-enzymatic approaches to natural and unnatural product synthesis." Thesis, University of Exeter, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277096.
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Thomas, Sanju. "Towards a cell-based chemo receiver for artificial insect olfaction." Thesis, University of Warwick, 2017. http://wrap.warwick.ac.uk/103098/.
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Infochemical communication is ubiquitous amongst all living organisms, and particularly important in insects. Because smell being the most common basic means of chemical communication, infochemical blends must be constantly decoded in order to proclaim their readiness to mate, to mark out territorial boundaries, to warn off intruders and predators or, in some cases, to locate food or predators with millisecond precision. The central challenge of the thesis was to mimic nature in both cellular and molecular levels on to a technological platform that aids in the development of a new class of technology employing chemicals alone to communicate over space and time. This thesis describes a body of work conducted in the development of a miniaturised, smart and label-free cell-based chemoreceiver for artificial insect olfaction, as part of the development of a novel biomimetic infochemical communication system. A surface acoustic wave based microsensor has been utilized to engineer and develop a chemoreceiver system that mimics the cellular and molecular mechanisms occurring during infochemical detection and decoding in insects. Successful recovery of ratiometric information with the aid of polymer-based gas-phase measurements, established the concept of chemical communication. Thus, small scale, high-throughput infochemical communication has been realized by a combination of precise spatiotemporal signal generation using fruit volatiles and insect sex pheromones with highly sensitive detection and signal processing. This was followed by the investigation of the feasibility of using the prototype cell-based biosensor system in a static mode for artificial insect olfaction applications, mimicking the cellular detection in the receptor/antenna apparatus of insects. Finally, as part of the development of a compact and low-power portable chemoreceiver system, the discrete sensor drive and interface circuitry was deployed in an analogue VLSI chip, thereby overcoming the associated measurement complexity and equipment cost, in addition to extending the reach and functionality of point of use technologies.
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Shinkwin, Anne Elizabeth. "Bioreductively targeted inhibitors of DNA repair : radiosensitisers and chemo-sensitisers." Thesis, University of Bath, 1997. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338411.
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Pradeep, Kumar Anjali. "Chemo-Thermo Cure of Viscoelastic Materials for Semiconductor Packaging Applications." PDXScholar, 2018. https://pdxscholar.library.pdx.edu/open_access_etds/4537.
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Viscoelastic polymer materials are being actively considered as a novel material for semiconductor packaging applications as a result of their ability to develop strong adhesive bonds at lower temperatures. Viscoelastic thermoset materials are impacted by the stresses generated during the curing process, which is also accompanied by a dissipation of thermal energy. There is a need to develop a generic modeling formulation that is applicable to any material of interest in order to enable the study of different bonding materials and develop optimized curing cycles. This study reports a numerical formulation to evaluate the stress generated and energy dissipated during the cure of viscoelastic polymers. A generalized method to define the transient variation of degree of cure was developed using a 4th order Runge Kutta approximation. The mathematical formulation was implemented using a novel evaluation methodology that helped reduce the computational power requirement. The commercially-available 3501-6 resin was simulated as a characteristic material in this study. The numerical model was validated against analytically derived solutions for both a single Maxwell model, and a Generalized Maxwell Model (GMM) for cases of constant-strain inputs, and subsequently for sinusoidal strain inputs, wherein, material properties were considered to be constant or varying linearly with degree of cure. A good agreement was obtained between the present model and analytical solutions.
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Rossi, Marco, Thomas Wallmersperger, Jorge Alejandro Ramirez, and Paola Nardinocchi. "jz Thermodynamically consistent electro-chemo-mechanical model for polymer membranes." SPIE, 2018. https://tud.qucosa.de/id/qucosa%3A35160.
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Nafion membranes, are polymeric thin films widely employed in micro-batteries and fuel cells. These devices are expected to play a key role in the next generation energy systems for use in vehicles as a replacement to combustion engines. In fact, a minimum environmental impact is guaranteed by reduced carbon dioxide emissions. It is usually complicated to investigate the behavior of thin membranes through experiments. Therefore, numerical simulations are carried out in order to enable a better understanding of the phenomena and of the multi-field couplings occurring in polymeric membranes.
A continuum-based, three-dimensional and electro-chemo-mechanical (ECM) model for a hydrated polymer membrane is presented. Different effects are taken into account: (i) mechanics, (ii) water uptake, (iii) ion transport, and (iv) electrostatics. The dissipation inequality drives the choice of the suitable constitutive equations of the multi-physics theory. In the mechanical field, an additive decomposition of the deformation gradient in (i) a distortion part, related to the ion motion, and (ii) an elastic part, is assumed. The multi-field model is numerically solved within the finite element framework. Time-dependent simulations are performed by using the commercial tool COMSOL Multiphysics. Furthermore, two closed form solutions are obtained by using (i) a one-dimensional reduced model and (ii) an approach based on the bar theory with an electro-chemical distortion field.
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Chen, Xiaohui. "Unsaturated hydro-chemo-mechanical modelling based on modified mixture theory." Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/unsaturated-hydrochemomechanical-modelling-based-on-modified-mixture-theory(64ec76bb-1379-4e87-b9a7-562fa9267404).html.
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New unsaturated coupled models have been developed for fluid transport in deformable rock by using modified mixture theory rather than a fully mechanics-based approach. These models include the following: an unsaturated hydro-mechanical coupled model for both non-swelling and swelling materials, in which a new coupled formulation for hydration swelling rock has been included; and an unsaturated hydro-mechanical-chemo coupled model, incorporating a new coupled formulation including osmosis flow and an unsaturated version of Darcy's law which has been extended by including osmosis effects.Modified mixture theory is mainly based on non-equilibrium thermodynamics. Helmholtz free energy is used to give the energy relationship between the fluids and solid and, by using the Gibbs-Duhem equation, the interactions between different fluids such as gas, water and chemical can be obtained. In this research, general coupled formulations for both large small and deformations have been obtained. For swelling rocks, the water between the clay platelets can be modeled by including the difference between the free energy of whole domain and that of the pore water plus the solid skeleton. By assuming small deformations, the final equations can be compared with those derived using the mechanics approach.The new coupled models have been tested by carrying out simple benchmark numerical simulations using finite elements. Problems analyzed include: (1) the consolidation of saturated swelling rocks in which the hydration swelling effects on consolidation have been analysed in detail; (2) the desaturation and resaturation of seasonally affected rocks around tunnels; (3) the desaturation stage for swelling rocks used in the containment of nuclear waste disposal; (4) chemical transport in very low permeability rock used for nuclear waste disposal, in which particular attention has been focused on osmosis flow and chemical consolidation. In summary, this thesis extends modified mixture theory and develops new coupled formulations which can be applied to deep nuclear waste disposal, including tunnelling, drilling and chemical transport in low permeability host rock.
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Brady, Sarah Catherine. "Chemo-enzymatic approaches to morphine-6-glucuronide and selected analogues." Thesis, University of Edinburgh, 1998. http://hdl.handle.net/1842/15258.
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Morphine 1 is metabolised in the liver into its active form, morphine-6-glucuronide (M6G) 2. When M6G 2 is administered directly to patients it has greater analgesic potency than morphine 1 and this stimulated interest in the synthesis of M6G 2 as a novel analgesic. We have examined several synthetic routes to the precursor morphine-6-glucoside 4 with selective oxidation to M6G 2 as the final step. (Fig. 10917A). The coupling of a glucose residue to morphine 1 was investigated using both chemical and enzymatic approaches. However, selective oxidation at the C6' position of morphine-6-glucoside 4 did not yield the desired metabolite M6G 2. The replacement of the glucose reside in scheme 1 by galactose and arabinose gave morphine-6-glucoside analogues which are potentially an alternative source of analgesics. (Fig. 10917B).
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AlKhayer, Majd AlArab. "Aktueller Stand der chemo-mechanischen Wurzelkanalaufbereitung in den zahnärztlichen Praxen Bayerns." Diss., lmu, 2006. http://nbn-resolving.de/urn:nbn:de:bvb:19-63257.
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Bangert, Falko. "Gekoppelte chemo-mechanische Modellierung und numerische Simulation langzeitiger Degradation von Betonstrukturen." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972079246.
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Patterson, Joanne Margaret. "Swallowing in head and neck cancer patients treated by (chemo) radiotherapy." Thesis, University of Newcastle Upon Tyne, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.545765.
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Bhatt, Surbhi. "Chemo-Enzymatic Route to Synthesis of Biodegradable Polymers and Glycolipid Analogs." Scholar Commons, 2006. http://scholarcommons.usf.edu/etd/3779.
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New catalytic synthetic methods in organic chemistry that satisfy increasingly stringent environmental constraints are in great demand by the pharmaceutical and chemical industries. Studies over last 15 years have revealed that activity of enzymes can be increased in organic solvents rather than their natural aqueous environment. Because of their ease of use, high selectivity and environment friendliness, enzymes are enjoying increasing popularity in today's synthesis world.
Chapter 1 describes chemo-enzymatic synthesis of various glycolipid analogs. A highly regioselective macrolactonization was achieved using lipase from Candida antarctica as a catalyst. It also describes evaluation of lipases from different source and their efficiency in catalyzing the macrolactonization reaction. These analogs were synthesized using commercially available agriculture based disaccharides (maltose, lactose, cellobiose, melibiose). These glycolipid analogues have potential applications in the cosmetic industry, formulation, food production, and pharmaceutical industry.In Chapter 2, ring opening polymerization of epsilon-caprolactone in ionic liquid, [bmim][PF6] was investigated. A comparative study of ROP in different solvents (toluene, Ionic liquid, and bulk condition) was conducted. Effect of time and enzyme concentration on molecular weight and % yield was investigated. It was concluded that enzymatic ring opening polymerization of epsilon-caprolactone in ionic liquid, [bmim][PF6 ] is a very competitive and environmental friendly way of synthesizing high molecular weight polyesters.
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Kim, Seunghee. "CO₂ geological storage: hydro-chemo-mechanically coupled phenomena and engineered injection." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/50110.
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Global energy consumption will increase in the next decades and it is expected to largely rely on fossil fuels. The use of fossil fuels is intimately related to CO₂ emissions and the potential for global warming. Geological CO₂ storage aims to mitigate the global warming problem by sequestering CO₂ underground. Coupled hydro-chemo-mechanical phenomena determine the successful operation and long term stability of CO₂ geological storage. This research explores various coupled phenomena, identifies different zones in the storage reservoir, and investigates their implications in CO₂ geological storage. Spatial patterns in mineral dissolution and precipitation are examined based on a comprehensive mass balance formulation. CO₂-dissolved fluid flow is modeled using a novel technique that couples laminar flow, advective and diffusive mass transport of species, mineral dissolution, and consequent pore changes to study the reactive fluid transport at the scale of a single rock fracture. The methodology is extended to the scale of a porous medium using pore network simulations to study both CO₂ reservoirs and caprocks. The two-phase flow problem between immiscible CO₂ and the formation fluid (water or brine) is investigated experimentally. Plug tests on shale and cement specimens are used to investigate CO₂ breakthrough pressure. Sealing strategies are explored to plug existing cracks and increase the CO₂ breakthrough pressure. Finally, CO₂-water-surfactant mixtures are evaluated to reduce the CO₂-water interfacial tension in view of enhanced sweep efficiency. Results can be used to identify optimal CO₂ injection and remediation strategies to maximize the efficiency of CO₂ injection and to attain long-term storage.
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Pallanca, Jane Emma. "The chemo-enzymic synthesis of GDP-mannose and GDP-mannose analogues." Thesis, University of Exeter, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294003.
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Meng, Zhiyong. "Self-assembly and chemo-ligation strategies for polymeric multi-responsive microgels." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29743.
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Thesis (Ph.D)--Chemistry and Biochemistry, Georgia Institute of Technology, 2009.<br>Committee Chair: Lyon, Louis; Committee Member: Breedveld, Victor; Committee Member: Bunz, Uwe; Committee Member: Collard, David; Committee Member: Srinivasarao, Mohan. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Bailey, Victoria Clare. "Chemo-enzymatic synthesis of mimics of cyclic adenosine 5'-diphosphate ribose." Thesis, University of Bath, 1997. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338406.
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Gao, Yifan. "Chemo-mechanics of alloy-based electrode materials for Li-ion batteries." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49027.
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Lithium alloys with metallic or semi-metallic elements are attractive candidate materials for the next-generation rechargeable Li-ion battery anodes, thanks to their large specific and volumetric capacities. The key challenge, however, has been the large volume changes, and the associated stress buildup and failure during cycling. The chemo-mechanics of alloy-based electrode materials entail interactions among diffusion, chemical reactions, plastic flow, and material property evolutions.
In this study, a continuum theory of two-way coupling between diffusion and deformation is formulated and numerically implemented. Analyses based on this framework reveal three major conclusions. First, the stress-to-diffusion coupling in Li/Si is much stronger than what has been known in other electrode materials. Practically, since the beneficial effect of stress-enhanced diffusion is more pronounced at intermediate or higher concentrations, lower charging rates should be used during the initial stages of charging. Second, when plastic deformation and lithiation-induced softening take place, the effect of stress-enhanced diffusion is neutralized. Because the mechanical driving forces tend to retard diffusion when constraints are strong, even in terms of operational charging rate alone, Li/Si nano-particles are superior to Li/Si thin films or bulk materials. Third, the diffusion of the host atoms can lead to significant stress relaxation even when the stress levels are below the yield threshold of the material, a beneficial effect that can be leveraged to reduce stresses because the host diffusivity in Li/Si can be non-negligible at higher Li concentrations.
A theory of coupled chemo-mechanical fracture driving forces is formulated in order to capture the effect of deformation-diffusion coupling and lithiation-induced softening on fracture. It is shown that under tensile loading, Li accumulates in front of crack tips, leading to an anti-shielding effect on the energy release rate. For a pre-cracked Li/Si thin-film electrode, it is found that the driving force for fracture is significantly lower when the electrode is operated at higher Li concentrations -- a result of more effective stress relaxation via global yielding. The results indicate that operation at higher concentrations is an effective means to minimize failure of thin-film Li/Si alloy electrodes.