1,865 zoekresultaten voor “organic chemisch” in de Publieke website
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Design and Synthesis of Click Lipids as Tools to Study Immune Cell Metabolism
This thesis advances our understanding of lipid uptake, a vital first step in lipid metabolism, by developing innovative click chemistry-based tools to study how immune cells internalize lipids.
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Microstructural and Metabolic Alterations in the Zebrafish Brain Induced by Toll-Like Receptor 2 Deficiency
Advanced UHF MRI techniques provide powerful tools for studying the zebrafish brain, an emerging model in neurological research. In this work, various MRI and localized MRS methods are optimized and employed for UHF strength for studying the zebrafish brain.
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Substrate adaptability of β-lactamase
The research aims to explore the evolutionary adaptability of enzymes and the impact of temperature on protein evolution pathways, using M. tuberculosis β-lactamase BlaC as the object of study. Enzymes inherently embody a delicate balance between activity and stability, and the acquisition of new enzymatic…
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Evolutionary adaptability of β-lactamase: a study of inhibitor susceptibility in various model systems
β-Lactamases are enzymes that can break down β-lactam substrates, such as antibiotics, preventing the use of these antibiotics for the treatment of various infectious diseases. However, some compounds, β-lactamase inhibitors, can block these enzymes allowing for possible treatments using a combination…
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Nuclear Quantum Effects in Solid Water
Ice, the solid state of water, plays an important role on our planet as well as the entire universe.Despite the fact that an individual water molecule has a very simple structure, its chemical bonding in the solid phase can be surprisingly complex.
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Molecular and Nano-Engineering with Iron, Ruthenium and Carbon: Hybrid structures for Sensing
Metal complexes and 2D materials like graphene were combined to produce structures that can function as sensors.
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Reagent Controlled Synthesis of 1,2-cis-Oligosaccharides
This Thesis describes a strategy to synthesize 1,2-cis-oligosaccharides modulated by additives, such as dimethylformamide (DMF), triphenylphosphine oxide (Ph3P=O) and N-methyl(phenyl)formamide (MPF), using building blocks that carry solely benzyl type protecting groups and are therefore of uniform r…
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Platinum electrochemistry through a magnifying glass
In most applications, electrocatalysts exhibit a large surface area to volume ratio, for example using nanoparticles.
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Unveiling the electrolyte effects of CO2 electroreduction to CO and H2 evolution from the interfacial pH perspective
The role of the interfacial environment during electrochemical reactions has been increasingly valued, especially for those reactions involving protons or hydroxyl ions.
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Bioorthogonal chemistry to unveil antigen processing events
The research described in this thesis focused on the use of bioorthogonal antigens to investigate immunological processes in antigen presenting cells. Bioorthogonal antigens are antigenic proteins produced through recombinant expression in a methionine auxotrophic E. coli strain.
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The environmentally-regulated interplay between local three- dimensional chromatin architecture and gene expression
Nucleoid associated proteins maintain the architecture of the bacterial chromosome and regulate gene expression, hinting that their role as transcription factors may involve local three-dimensional chromosome re-modelling.
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Exploring Reactive Interfaces: Nanoplastics, Catalysts, and 2D Materials
This thesis investigates reactive interfaces in surface science across three domains: heterogeneous catalysis, environmental nanoplastics, and two-dimensional materials.
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Electrocatalytic CO2 reduction toward liquid fuels : on heterogeneous electrocatalysts and heterogenized molecular catalysts
With the energy transition toward a renewable energy supply and a CO2-neutral economy, electrification of the energy system is rising in importance, which leads to the challenge of long-term storage of renewable electricity.
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Insights into the mechanism of electrocatalytic CO2 reduction and concomitant catalyst degradation pathways
This work describes several studies into the electroreduction of carbon dioxide (CO2RR), both regarding mechanistical aspects and catalyst stability considerations. Mechanistic insights into carbon-carbon bond formation on a silver catalyst are described in Ch 2, were we find an acetaldehyde-like surface…
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Semi-empirical approach to the simulation of molecule-surface reaction dynamics
Catalysis is of extreme relevance in the production of everyday materials and plays a central role in many aspects of our life.
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Palladium-catalyzed carbonylative synthesis of carboxylic acid anhydrides from Alkenes
Hydrocarbonylation of alkenes with carboxylic acids in synthesis of carboxylic acid anhydrides is relatively less explored. We herein present a study and optimization of a palladium-catalyzed hydrocarbonylation reaction of alkenes using carboxylic acids as the nucleophile, by which acid anhydrides can…
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Glucocerebrosidase and glycolipids: In and beyond the lysosome
The lysosomal β-glucosidase named glucocerebrosidase (GCase) is a retaining β-glucosidase that hydrolyzes the glycosphingolipid glucosylceramide (GlcCer) to ceramide and glucose at acid pH.
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Chemical reactivity of O2, CO and CO2 on Cu surfaces
Despite the history of studies on methanol formation from CO2, the dominant elementary reaction steps that constitute the chemical mechanism for this catalyzed process are not determined.
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Discovery of BUB1 kinase inhibitors for the treatment of cancer
The spindle-assembly checkpoint (SAC) is a safety mechanism which secures accurate chromosome segregation during mitosis.
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Squaramide-based supramolecular polymers
Supramolecular polymers are class of materials that are formed by non-covalent interactions such as hydrogen bonding, π-π interactions, electrostatic interactions and the hydrophobic effect.
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Chemistry and characterization of the graphene basal plane and edge for recognition tunneling
Biopolymer sequencing with graphene edge-based tunnel junctions has the potential to overcome current limitations with the third generation of sequencing based on biological nanopores.
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Adsorption and catalysis on Pt and Pd monolayer-modified Pt single crystal electrodes
The focus throughout this thesis will be on gathering fundamental studies of the detailed structure and composition of the electrode/electrolyte interface effect on the rate and mechanism of key electrocatalytic reactions.
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Deciphering the atomic structure of the electrified metal oxide-electrolyte interface
Humanity stands at a pivotal juncture, facing the dual challenge of environmental sustainability and rapid population growth, projected to exceed 11 billion by century’s end.
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Superstructures of lipids and graphene
This thesis systematically analyzes the physical-chemistry of lipid-graphene interactions with the major objective of reconciliating the variety of results reported in the literature.
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Electrocatalysis of CO2/CO interconversion and Hydrogen Evolution in Bicarbonate Buffers
Bicarbonate buffer is largely found in nature due to its ability to regulate pH variations around neutral values. As the pH changes, so does the speciation of the buffer.
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Discovery and development of inhibitors selective for human constitutive proteasome and immunoproteasome active sites
This thesis describes the design and development of subunit‐selective inhibitors of particular catalytically active subunits of human constitutive proteasomes and immunoproteasomes.
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Development of new chemical tools to study the cannabinoid receptor type 2
The endocannabinoid receptors CB1R and CB2R are involved in a plethora of processes, and consequently are involved in many pathological conditions. Their wide distribution makes the CBRs both an interesting therapeutic target and hard to study.
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Chemical functionalization of the graphene surface for electrical and electrochemical sensing application
Advanced sensing techniques require graphene with high quality and well-controlled surface chemistry.
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Mechanistic studies of the water oxidation reaction with molecular iron catalysts
In this dissertation iron-based homogeneous catalysts were synthesized, characterized and investigated for water oxidation activity.
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Coiled-coils on lipid membranes: a new perspective on membrane fusion
Promotor: J.G.E.M. Fraaije, Co-Promotor: A. Kros
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A new method to reconstruct the structure from crystal images
Promotor: J.P. Abrahams, Co-promotor: T. Grüne
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Supramolecular polymer materials for biomedical applications and diagnostics
Self-assembly is an abundant process in nature and is vital to many processes in living organisms.
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Histone-DNA assemblies in archaea. Shaping the genome on the edge of life
All life on earth contains DNA, which is used to store biological information. Organisms compact their DNA in order for it to fit inside their cell(s).
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The electrode-electrolyte interface in CO2 reduction and H2 evolution: a multiscale approach
Electrocatalysis allows for storing electricity or converting it into chemical bonds, producing chemical building blocks and fuels using renewable resources.
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Evolvability and epistasis studied through the lens of an antibiotic resistance enzyme
Enzymes are innately sensitive to changes in the amino acid sequence, which largely constrains their evolutionary potential, i.e., evolvability. This evolutionary burden can be alleviated in the presence of stabilizing mutations, which increase the buffering capacity of enzymes to tolerate mutations…
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The dynamic organization of prokaryotic genomes: DNA bridging and wrapping proteins across the tree of life
Every organisms in the tree of life faces the same challenge: the length of its DNA exceeds the volume of the cell it needs to fit in. Several strategies have evolved to solve this problem, one of them being the expression of proteins that bind and organize the DNA.
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Understanding protein complex formation: The role of charge distribution in the encounter complex
Protein–protein complexes are formed via transient states called encounter complexes that greatly influence the formation of the stereospecific complex.
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Structure dependence of molecular reactions on surfaces
The research presented in this thesis makes use of small molecules (as H2 , D2 and O2 ) on well-defined single crystal surfaces (flat Pt(111), flat Cu(211) and curved Pt(111)) to elucidate the role of surface structure and degrees of freedom in the reactant in specific surface reactions.
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Making the invisible visible: paramagnetic NMR and the transient protein complex
Promotor: Prof.dr. M. Ubbink
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Anthracycline biosynthesis in Streptomyces: engineering, resistance and antimicrobial activity
Actinobacteria are well known for the production of bioactive natural products, many of which have applications in the fields of human, animal and plant health. Subject of this thesis are the anthracyclines, glycosylated aromatic polyketides with potent anticancer activity.
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Giant unilamellar vesicles: An efficient membrane biophysical tool and its application in drug delivery studies
Promotor: A. Kros
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Ruthenium-peptide conjugates for targeted phototherapy
As leading cause of death worldwide, cancer is responsible for nearly 10 million deaths in 2020 according to World Health Organization (WHO). Cisplatin and its derivatives are commonly used chemotherapy agents for current cancer treatment in the clinics.
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Gorlaeus GebouwEinsteinweg 55, Leiden
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Molecular sensors for calcium ion detection via triplet-triplet annihilation upconversion
Cardiovascular diseases (CVDs) are the leading global cause of mortality. Endothelial dysfunction, an early reversible stage of CVD development, is marked by decreased nitric oxide production linked to Ca2+ influx in endothelial cells.
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Unconventional fabrication of 2D nanostructures and graphene edges
In this work, we illustrate unconventional approaches towards the fabrication of edge functionalized graphene nanostructures and bidimensional architectures in polymeric and metallic supports, with an outlook towards molecular sensing devices.
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The architects of crenarchaeal chromatin: A biophysical characterization of chromatin proteins from Sulfolobus solfataricus
Promotor: Jaap Brouwer, Co-promotor: Remus Th. Dame
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Towards near-infrared light-activated combination chemotherapy
The goal of the research presented in this thesis was to explore the chemical space of ruthenium(II) photocages, investigate their ability to host potent chemotherapy drugs, and to red shift the activation wavelength of the most promising PACT candidates to conduct biological studies.
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Applications of paramagnetic NMR spectroscopy for protein research
The aim of the research presented in this thesis was to develop new methods forchallenging systems in liquid-state NMR using paramagnetic effects generated by thetwo-armed probe CLaNP-5.
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Atomic Insights into Hydrodesulfurization
Hydrodesulfurization (HDS) is an ubiquitous part of oil refining that ensures that fuels are cleaned of impurities and environment release of pollutants such as SOx and NOx gasses are minimized.
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The electrochemical reduction of dioxygen and hydrogen peroxide by molecular copper catalysts
The electrochemical oxygen reduction reaction (ORR) is an essential half-reaction for the utilization of hydrogen as a sustainable fuel, via the conversion of hydrogen to electrons and protons facilitated by the ORR. In the most common fuel cells, the ORR is requires high loadings of non-abundant platinum…