1,721,001 research outputs found
Self-assembled three-dimensional chiral colloidal architecture
No full textAlthough stereochemistry has been a central focus of the molecular sciences since Pasteur, its province has previously been restricted to the nanometric scale. We have programmed the self-assembly of micron-sized colloidal clusters with structural information stemming from a nanometric arrangement. This was done by combining DNA nanotechnology with colloidal science. Using the functional flexibility of DNA origami in conjunction with the structural rigidity of colloidal particles, we demonstrate the parallel self-assembly of three-dimensional microconstructs, evincing highly specific geometry that includes control over position, dihedral angles, and cluster chiralit
Structural DNA nanotechnology
No full textWritten by the founder of the field, this is the first text of its kind, providing a definitive introduction to structural DNA nanotechnology. Readers will learn everything there is to know about the subject from the unique perspective of the leading expert in the field. Topics covered range from origins and history, to design, experimental techniques, DNA nanomechanics devices, computing, and the uses of DNA nanotechnology in organising other materials. Clearly written, and benefiting from over 200 full colour illustrations, readers will find this an accessible and easy to follow text that is essential reading for anyone who wants to enter this rapidly growing field. Ideal for advanced undergraduate and graduate students, as well as researchers in a range of disciplines including nanotechnology, materials science, physics, biology, chemistry, computational science and engineering
At the Crossroads of Chemistry, Biology, and Materials Structural DNA Nanotechnology
No full textAbstractStructural DNA nanotechnology consists of combining unusual DNA motifs by specific structurally well-defined cohesive interactions (primarily sticky ends) to produce target materials with predictable 3D structures. This effort has generated DNA polyhedral catenanes, robust nanomechanical devices, and a variety of periodic arrays in two dimensions. The system has been used to produce specific patterns on the mesoscale through designing and combining specific DNA strands, which are then examined by atomic force microscopy. The combination of these constructions with other chemical components is expected to contribute to the development of nanoelectronics, nanorobotics, and smart materials. The organizational capabilities of structural DNA nanotechnology are just beginning to be explored, and the field is expected ultimately to be able to organize a variety of species that will lead to exciting and possibly revolutionary materials
Stabilisation of self-assembled DNA crystals by triplex-directed photo-cross-linking
Get PDFThe tensegrity triangle is a robust DNA motif that can self-assemble to generate macroscopic three-dimensional crystals. However, the stability of these crystals is dependent on the high ionic conditions used for crystal growth. Here we demonstrate that a triplex-forming oligonucleotide can be used to direct the specific intercalation, and subsequent photo-cross-linking, of 4,5?,8-trimethylpsoralen to single or multiple loci within or between the tiles of the crystal. Cross-linking between the tiles of the crystal improves their thermal stability. Such an approach is likely to facilitate the removal of crystals from their mother liquor and may prove useful for applications that require greater crystal stability
Functionalizing designer DNA crystals with a triple-helical veneer
Get PDFDNA is a very useful molecule for the programmed self-assembly of 2D and 3D nanoscale objects.1 The design of these structures exploits Watson–Crick hybridization and strand exchange to stitch linear duplexes into finite assemblies.2–4 The dimensions of these complexes can be increased by over five orders of magnitude through self-assembly of cohesive single-stranded segments (sticky ends).5,?6 Methods that exploit the sequence addressability of DNA nanostructures will enable the programmable positioning of components in 2D and 3D space, offering applications such as the organization of nanoelectronics,7 the direction of biological cascades,8 and the structure determination of periodically positioned molecules by X-ray diffraction.9 To this end we present a macroscopic 3D crystal based on the 3-fold rotationally symmetric tensegrity triangle3,?6 that can be functionalized by a triplex-forming oligonucleotide on each of its helical edges.<br/
A Topological Rubber Glove Obtained from a Synthetic Single-Stranded DNA Molecule
No full textA ‘figure-of-eight’ knot synthesized from single-stranded DNA is shown to have the properties of a topological rubber glove
Nanotecnología basada en ADN
Get PDFDesde el descubrimiento de su estructura por Watson y Crick hace unos 50 años atrás, el ADN ha venido a llenar nuestras vidas en muchas áreas; desde el reconocimiento paterno por ADN, hasta el reconocimiento forense, desde el genoma humano hasta las terapias genéticas. Estas, y otras maneras en que el ADN afecta las actividades humanas, están relacionadas a su función como material genético, no solo nuestro material genético, sino el de todos los organismos vivos. En este artículo, vamos a ignorar el papel biológico del ADN; en cambio, vamos a discutir como las propiedades que lo hacen exitoso en su rol como material genético, también lo hacen conveniente para su uso como nuevo material de construcción en la escala nanométrica: sin duda, un papel novedoso y prometedor del ADN en la emergente área de la nanotecnología
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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