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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Facile Fabrication of Meso-to-Macroscale Single-Molecule Arrays for High-Throughput Digital Assays

January 2019 (has links)
abstract: One of the single-most insightful, and visionary talks of the 20th century, “There’s plenty of room at the bottom,” by Dr. Richard Feynman, represented a first foray into the micro- and nano-worlds of biology and chemistry with the intention of direct manipulation of their individual components. Even so, for decades there has existed a gulf between the bottom-up molecular worlds of biology and chemistry, and the top-down world of nanofabrication. Creating single molecule nanoarrays at the limit of diffraction could incentivize a paradigm shift for experimental assays. However, such arrays have been nearly impossible to fabricate since current nanofabrication tools lack the resolution required for precise single-molecule spatial manipulation. What if there existed a molecule which could act as a bridge between these top-down and bottom-up worlds? At ~100-nm, a DNA origami macromolecule represents one such bridge, acting as a breadboard for the decoration of single molecules with 3-5 nm resolution. It relies on the programmed self-assembly of a long, scaffold strand into arbitrary 2D or 3D structures guided via approximately two hundred, short, staple strands. Once synthesized, this nanostructure falls in the spatial manipulation regime of a nanofabrication tool such as electron-beam lithography (EBL), facilitating its high efficiency immobilization in predetermined binding sites on an experimentally relevant substrate. This placement technology, however, is expensive and requires specialized training, thereby limiting accessibility. The work described here introduces a method for bench-top, cleanroom/lithography-free, DNA origami placement in meso-to-macro-scale grids using tunable colloidal nanosphere masks, and organosilane-based surface chemistry modification. Bench-top DNA origami placement is the first demonstration of its kind which facilitates precision placement of single molecules with high efficiency in diffraction-limited sites at a cost of $1/chip. The comprehensive characterization of this technique, and its application as a robust platform for high-throughput biophysics and digital counting of biomarkers through enzyme-free amplification are elucidated here. Furthermore, this technique can serve as a template for the bottom-up fabrication of invaluable biophysical tools such as zero mode waveguides, making them significantly cheaper and more accessible to the scientific community. This platform has the potential to democratize high-throughput single molecule experiments in laboratories worldwide. / Dissertation/Thesis / Doctoral Dissertation Biomedical Engineering 2019
192

Arranging multiple types of enzymes in defined space by modular adaptors / モジュール型アダプターを利用した複数酵素の特異的空間配置

NGUYEN, MINH THANG 25 March 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第21886号 / エネ博第387号 / 新制||エネ||75(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻 / (主査)教授 森井 孝, 教授 木下 正弘, 教授 片平 正人 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DGAM
193

Chemical Templating by AFM Tip-Directed Nano-Electrochemical Patterning

Nelson, Kyle A. 14 December 2011 (has links) (PDF)
This work has examines the creation and use of chemical templates for nanocircuit and other nanodevice fabrication. Chemical templating can be useful in attachment, orientation and wiring of molecularly templated circuits. DNA origami provides a suitable method for creating molecularly templated circuits as DNA can be folded into complex shapes and functionalized with active circuit elements, such as semiconducting nanomaterials. Surface attachment of DNA origami structures can be accomplished by hybridization of dangling single-stranded DNA (ssDNA) on the origami structures with complementary surface-bound strands. Chemical templating provides a pathway for placing the patterned surface-bound attachment points needed for surface alignment of the molecular templates. Chemical templates can also be used to connect circuit elements on the surface by selectively metallizing the templates to form local wiring. AFM tip-directed nano-oxidation was selected as the method for patterning to create chemical templates. This project demonstrates new techniques for creating, continuous metallization of, and DNA attachment to nanochemical templates. Selective-continuous metallization of nanochemical templates is needed for wiring of circuit templates. To improve the metallization density and enable the continuous nano-scale metallization of amine-coated surfaces, the treatment of amine-coated surfaces with a plating additive prior to metallization was studied. The additive treatment resulted in a 73% increase in seed material, enabling continuous nano-scale metallization. A new method was developed to create amine nanotemplates by selective attachment of a polymer to surface oxide patterns created by nano-oxidation. The treatment of the templates with the additive enabled a five-fold reduction in feasible width for continuous metallization. Nano-oxidation was also used in the nanometer-scale patterning of a thiol-coated surface. Metallization of the background thiols but not the oxidized patterns resulted in a metal film that was a negative of the patterns. The resulting metal film may be useful for nanometer-scale pattern transfer. DNA-coated gold nanoparticles (AuNPs) were selectively attached to amine templates by an ionic interaction between the template and ssDNA attached to the particles. Only the ssDNA on the bottom of the AuNPs interacted with the template, leaving the top strands free to bind with complementary ssDNA. Attempts to attach origami structures to these particles were only marginally successful, and may have been hindered by the presence of complementary ssDNA in solution but not attached to the origami, or the by the low density of DNA-AuNPs attached to the templates. The formation of patterned binding sites by direct, covalent attachment of ssDNA to chemical templates was also explored. Initial results indicated that ssDNA was chemically bound to the templates and able to selectively bind to complementary strands; however, the observed attachment density was low and further optimization is required. Methods such as these are needed to enable nano-scale, site-specific alignment of nanomaterials.
194

Metallization of DNA and DNA Origami Using a Pd Seeding Method

Geng, Yanli 15 January 2013 (has links) (PDF)
In this dissertation, I developed a Pd seeding method in association with electroless plating, to successfully metallize both lambda DNA and DNA origami templates on different surfaces. On mica surfaces, this method offered a fast, simple process, and the ability to obtain a relatively high yield of metallized DNA nanostructures. When using lambda DNA as the templates, I studied the effect of Pd(II) activation time on the seed height and density, and an optimal activation time between 10 and 30 min was obtained. Based on the Pd seeds formed on DNA, as well as a Pd electroless plating solution, continuous Pd nanowires that had an average diameter of ~28 nm were formed with good selectivity on lambda DNA. The selected Pd activation time was also applied to metallize "T"-shape DNA origami, and Au coated branched nanostructures with a length between 200-250 nm, and wire diameters of ~40 nm were also fabricated. In addition, I found that the addition of Mg2+ ion into the reducing agent and electroless plating solution could benefit the surface retention of Pd seeded DNA and Au plated DNA structures. This work indicated that DNA molecules were promising templates to fabricate metal nanostructures; moreover, the formation of Au metallized branched nanostructures showed progress towards nanodevice fabrication using DNA origami. Silicon surfaces were also used as the substrates for DNA metallization. More complex circular circuit DNA origami templates were used. To obtain high enough seed density, multiple Pd seeding steps were applied which showed good selectivity and the seeded DNA origami remained on the surface after seeding steps. I used distribution analysis of seed height to study the effect of seeding steps on both average height and the uniformity of the Pd seeds. Four-repeated palladium seedings were confirmed to be optimal by the AFM images, seed height distribution analysis, and Au electroless plating results. Both Au and Cu metallized circular circuit design DNA origami were successfully obtained with high yield and good selectivity. The structures were maintained well after metallization, and the average diameters of Au and Cu samples were ~32 nm and 40 nm, respectively. Electrical conductivity measurements were done on these Au and Cu samples, both of which showed ohmic behavior. This is the first work to demonstrate the conductivity of Cu metallized DNA templates. In addition, the resistivities were calculated based on the measured resistance and the size of the metallized structures. My work shows promising progress with metallized DNA and DNA origami templates. The resulting metal nanostructures may find use as conducting interconnects for nanoscale objects as well as in surface enhanced Raman scattering analysis.
195

Henriksdalskolan / Henriksdalschool

Alsayigh, Nejwan January 2018 (has links)
Skolan är för 400 barn i årskursen F-6 och beläget i området Henriksdal i närhet till Franzén parken, vattnet, reningsverket och bostadsområden. Skolans arkitektoniska gestaltning är tänkt att återspegla barnens lekfulla natur på ett spännande och nyfiket vis. Skolans fotavtryck är utformad efter tomtens form, tillgångar och utmaningar där komplexets ambition är att skapa bättre förutsättningar till en lugnare skolgård där huskroppen skärmar av den bullriga vägen och öppnar upp mot parken. Konstruktionen av trä har hållbarhet i fokus och är stark inspirerad av origami-konsten som är både vacker och arkitektonisk i sin elegans och simpelhet. De vinklade triangulära fasaderna och taklandskapet skapar rytmisk rörelse utvändigt och spännande rum invändigt på ett balanserat sätt.  Exteriören av ljusgrå puts, glas mörkrädda takplåt och fackverk av stål skapar en harmonisk samspel av materialitet. Planritningens grundidé bottnar i funktionalitet genom att delas in i olika sektioner som kan nyttjas för olika funktioner utöver skolans verksamhet. T.ex kan idrottshallen, matsal och aula hyras ut utan tillgång till resterande lokaler i skolan då de har egna sektioner som även fungerar som brandceller och ljudisolering. / Henriksdal School Henriksdal School it for 400 children from pre-school till 6th grade. Located in Henriksdal Stockholm, in a lot enclosed by a heavy trafficked road by one side and a park on the other. Other significant factors to the area is the sewage plant and residential buildings nearby. The schools architectural concept is to reflect the children’s playful nature and enhance their curiosity with exciting architectural element that could contribute to enhanced learning capacity. The buildings footprint takes form according to the sites outline, resources and Challenges. The body of the building creates a semi enclosed schoolyard that protects from the roads noise as it opens up towards the park as an extended schoolyard. The wood based construction makes the project sustainable and energy efficient with great thermal and acoustic insulation. The structor is inspired by the art or origami witch it both beautiful and structural. The slanted triangular shapes in the facades and roof landscape creates a diverse and exciting interaction between the school and the city. The simplicity of the materials in the facades shape a harmonious and balanced visual content. The floor plans conceptual idea roots in functionality by dividing the complex in sections that could be used for other activities than Education. The nodes containing the sports hall, the foodcourt and the theatre can all be rented out without having access to other areas by those sections that also work as fire safety cells, and acoustic insulation.
196

Developing Origami-Based Approaches to Realize Novel Architectures and Behaviors for Deployable Space Arrays

Pehrson, Nathan Alan 01 October 2019 (has links)
Origami-based approaches for the folding of thick materials for specific application to large deployable space arrays is explored in this work. The folding approaches presented utilize strain energy, spatial kinematics, membranes, compliant mechanisms, and or in combination together to fold finite-thickness materials viewed through the lens of origami-based engineering. Novel architectures and behaviors of mechanisms are developed to achieve packaging efficiency, deployment, and self-stiffening. A method for the folding of monolithic thick-sheet materials is developed by incorporating compliant mechanisms into the material itself to strategically add degrees of freedom. The design and characterization of the compliant mechanisms with consideration to stress, material selection, and stiffness is given. Other folding approaches developed include a bistable vertex and a double-membrane method.The folding approaches derived are applied to larger tessellations and folding patterns. The fold patterns developed and used lend themselves well to large reconfiguration and the combination of the folding approaches with the patterns create opportunities to fabricate products out of thick, functional materials. Of specific interest is the application of these approaches and patterns to the field of deployable space arrays. Spatial kinematics, computational dynamics, physical tests, and systems engineering are used to develop an array architecture that is self-deployable, self-stiffening, and retractable. This architecture is shown to open the design space of large deployable arrays by increasing packaging efficiency and mass.The method, approaches, and architectures developed by this dissertation contribute to the fields origami-based engineering and deployable space arrays. While a focus of this work is the advancement of space technologies, the depth of the analyses provided are transferable to other origami-based and compliant-mechanism disciplines.
197

Control of Dynamic DNA Origami Mechanisms Using Integrated Functional Components

Miller, Carl A. 20 May 2015 (has links)
No description available.
198

FOLDING DYNAMICS OF G-QUADRUPLEXES DURING TRANSCRIPTION AND IN A NANO-CONFINEMENT

Shrestha, Prakash 02 January 2018 (has links)
No description available.
199

Nucleosome Regulation of Transcription Factor Binding Dynamics: a Single-molecule Study

Luo, Yi January 2015 (has links)
No description available.
200

DNA Origami Breadboard: A Platform for Cell Activation and Cell Membrane Functionalization

Mollica, Molly Y. 30 August 2016 (has links)
No description available.

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