Download or read book Scanning X ray nano diffraction on eukaryotic cells written by Britta Weinhausen and published by Göttingen University Press. This book was released on 2014 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: X-rays provide an ideal probe for studying structures at the nano-scale and are routinely employed for investigating the structure and the composition of biological systems, making use of the variety of different techniques. By raster scanning the sample with a small beam, structural information obtained from individual scattering patterns in reciprocal space can be combined with positional information in real space. In this work, scanning X-ray diffraction using a nano-focused beam was applied to samples of biological cells in order to probe the structure of cytoskeletal bundles and networks of keratin intermediate filaments. Cellular samples were prepared using different methods, starting from well-established freeze-dried samples and going on to fixed-hydrated and finally living cells. In this context, the development of X-ray compatible microfluidic devices allowing for measurements on living cellular samples was an important aspect. Comparing the scattering signal from freeze-dried, fixed-hydrated and living cells, differences between the sample types at length scales of several tens of nanometers were determined. The successful application to hydrated and living cells further demonstrates the potential for structural analysis at hardly accessible length scales in native samples. Published: 2014

Download or read book Scanning X ray nano diffraction on eukaryotic cells written by Britta Weinhausen and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigating Cellular Nanoscale with X rays written by Clément Hémonnot and published by Göttingen University Press. This book was released on 2016 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: The advances and technical improvements of X-ray imaging techniques, taking advantage of X-ray focussing optics and high intensity synchrotron sources, nowadays allow for the use of X-rays to probe the cellular nanoscale. Importantly, X-rays permit thick samples to be imaged without sectioning or slicing. In this work, two macromolecules, namely keratin intermediate filament (IF) proteins and DNA, both essential components of cells, were studied by X-ray techniques. Keratin IF proteins make up an integral part of the cytoskeleton of epithelial cells and form a dense intracellular network of bundles. This network is built from monomers in a hierarchical fashion. Thus, the keratin structure formation spans a large range of length scales from a few nanometres (monomers) to micrometres (networks). Here, keratin was studied at three different scales: i) filaments, ii) bundles and iii) networks. Solution small-angle X-ray scattering revealed distinct structural and organisational characteristics of these highly charged polyelectrolyte filaments, such as increasing radius with increasing salt concentration and spatial accumulation of ions depending on the salt concentration. The results are quantified by employing advanced modelling of keratin IFs by a core cylinder fl anked with Gaussian chains. Scanning micro- diffraction was used to study keratin at the bundle scale. Very different morphologies of keratin bundles were observed at different salt conditions. At the network scale, new imaging approaches and analyses were applied to the study of whole cells. Ptychography and scanning X-ray nano-diffraction imaging were performed on the same cells, allowing for high resolution in real and reciprocal space, thereby revealing the internal structure of these networks. By using a fitting routine based on simulations of IFs packed on a hexagonal lattice, the radius of each fi lament and distance between fi laments were retrieved. In mammalian cells, each nucleus contains 2 nm-thick DNA double helices with a total length of about 2 m. The DNA strands are packed in a highly hierarchical manner into individual chromosomes. DNA was studied in intact cells by visible light microscopy and scanning X-ray nano-diffraction, unveiling the compaction und decompaction of DNA during the cell cycle. Thus, we obtained information on the aggregation state of the nuclear DNA at a real space resolution on the order of few hundreds nm. To exploit to the reciprocal space information, individual diffraction patterns were analysed according to a generalised Porod’s law at a resolution down to 10 nm. We were able to distinguish nucleoli, heterochromatin and euchromatin in the nuclei and follow the compaction and decompaction during the cell division cycle.

Download or read book Multiscale X Ray Analysis of Biological Cells and Tissues by Scanning Diffraction and Coherent Imaging written by Jan-David Nicolas and published by Göttingen University Press. This book was released on 2019 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the intricate details of muscle contraction has a long-standing tradition in biophysical research. X-ray diffraction has been one of the key techniques to resolve the nanometer-sized molecular machinery involved in force generation. Modern, powerful X-ray sources now provide billions of X-ray photons in time intervals as short as microseconds, enabling fast time-resolved experiments that shed further light on the complex relationship between muscle structure and function. Another approach harnesses this power by repeatedly performing such an experiment at different locations in a sample. With millions of repeated exposures in a single experiment, X-ray diffraction can seamlessly be turned into a raster imaging method, neatly combining real- and reciprocal space information. This thesis has focused on the advancement of this scanning scheme and its application to soft biological tissue, in particular muscle tissue. Special emphasis was placed on the extraction of meaningful, quantitative structural parameters such as the interfilament distance of the actomyosin lattice in cardiac muscle. The method was further adapted to image biological samples on a range of scales, from isolated cells to millimeter-sized tissue sections. Due to the ‘photon-hungry’ nature of the technique, its full potential is often exploited in combination with full-field imaging techniques. From the vast set of microscopic tools available, coherent full-field X-ray imaging has proven to be particularly useful. This multimodal approach allows to correlate two- and three-dimensional images of cells and tissue with diffraction maps of structure parameters. With the set of tools developed in this thesis, scanning X-ray diffraction can now be efficiently used for the structural analysis of soft biological tissues with overarching future applications in biophysical and biomedical research.

Download or read book Coherent X ray diffractive imaging on the single cell level of microbial samples written by Robin Niklas Wilke and published by Göttingen University Press. This book was released on 2015 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its first experimental demonstration in 1999, Coherent X-Ray Diffractive Imaging has become one of the most promising high resolution X-Ray imaging techniques using coherent radiation produced by brilliant synchrotron storage rings. The ability to directly invert diffraction data with the help of advanced algorithms has paved the way for microscopic investigations and wave-field analyses on the spatial scale of nanometres without the need for inefficient imaging lenses. X-Ray phase contrast which is a measure of the electron density is an important contrast mode of soft biological specimens. For the case of many dominant elements of soft biological matter, the electron density can be converted into an effective mass density offering a unique quantitative information channel which may shed light on important questions such as DNA compaction in the bacterial nucleoid through ‚weighing with light‘. In this work X-Ray phase contrast maps have been obtained from different biological samples by exploring different methods. In particular, the techniques Ptychography and Waveguide-Holographic-Imaging have been used to obtain twodimensional and three-dimensional mass density maps on the single-cell-level of freeze-dried cells of the bacteria Deinococcus radiodurans, Bacillus subtilis and Bacillus thuringiensis allowing, for instance, to estimate the dry weight of the bacterial genome in a near native state. On top of this, reciprocal space information from coherent small angle X-Ray scattering (cellular Nano-Diffraction) of the fine structure of the bacterial cells has been recorded in a synergistic manner and has been analysed down to a resolution of about 2.3/nm exceeding current limits of direct imaging approaches. Furthermore, the dynamic range of present detector technology being one of the major limiting factors of ptychographic phasing of farfield diffraction data has been significantly increased. Overcoming this problem for the case of the very intense X-Ray beam produced by Kirkpatrick-Baez mirrors has been explored by using semi-transparent central stops.

Download or read book Nanoscale Photonic Imaging written by Tim Salditt and published by Springer Nature. This book was released on 2020-06-09 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book, edited and authored by a team of world-leading researchers, provides a broad overview of advanced photonic methods for nanoscale visualization, as well as describing a range of fascinating in-depth studies. Introductory chapters cover the most relevant physics and basic methods that young researchers need to master in order to work effectively in the field of nanoscale photonic imaging, from physical first principles, to instrumentation, to mathematical foundations of imaging and data analysis. Subsequent chapters demonstrate how these cutting edge methods are applied to a variety of systems, including complex fluids and biomolecular systems, for visualizing their structure and dynamics, in space and on timescales extending over many orders of magnitude down to the femtosecond range. Progress in nanoscale photonic imaging in Göttingen has been the sum total of more than a decade of work by a wide range of scientists and mathematicians across disciplines, working together in a vibrant collaboration of a kind rarely matched. This volume presents the highlights of their research achievements and serves as a record of the unique and remarkable constellation of contributors, as well as looking ahead at the future prospects in this field. It will serve not only as a useful reference for experienced researchers but also as a valuable point of entry for newcomers.

Download or read book X ray Micro and Nano diffraction Imaging on Human Mesenchymal Stem Cells and Differentiated Cells written by Marten Bernhardt and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in hard x-ray optics, instrumentation and detection have made it possible to probe biological samples by combining diffraction with raster scanning, using step sizes on the order of cellular organelle dimensions and below. The data obtained from such experiments encode the local electron density in a 2D-diffraction pattern for each scan position and provide information down to molecular scales. In this way, scanning transmission x-ray microscopy (with full diffraction data) complements very well the repertoire of high resolution imaging techniques. However, the challenge is ...

Download or read book Multiscale X Ray Analysis of Biological Cells and Tissues by Scanning Diffraction and Coherent Imaging written by Jan-David Nicolas and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The past 70 years of muscle research have profoundly shaped our current understanding of the structure and function of muscle. X-ray diffraction became a key method in its structural analysis and yielded valuable insights into the molecular arrangement of the contraction apparatus. This work employs an extension of the X-ray diffraction methodology, scanning X-ray diffraction, for structural imaging of biological cells and tissue. With this technique periodicites in a structure on the order of several nanometers can be detected and, by raster scanning of the X-ray beam over the sample, imag...

Download or read book X ray Microscopy written by Chris Jacobsen and published by Cambridge University Press. This book was released on 2019-12-19 with total page 595 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by a pioneer in the field, this text provides a complete introduction to X-ray microscopy, providing all of the technical background required to use, understand and even develop X-ray microscopes. Starting from the basics of X-ray physics and focusing optics, it goes on to cover imaging theory, tomography, chemical and elemental analysis, lensless imaging, computational methods, instrumentation, radiation damage, and cryomicroscopy, and includes a survey of recent scientific applications. Designed as a 'one-stop' text, it provides a unified notation, and shows how computational methods in different areas are linked with one another. Including numerous derivations, and illustrated with dozens of examples throughout, this is an essential text for academics and practitioners across engineering, the physical sciences and the life sciences who use X-ray microscopy to analyze their specimens, as well as those taking courses in X-ray microscopy.

Download or read book Scanning X Ray Nanodiffraction on Dictyostelium Discoideum written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the recent years, novel focussing optics for synchrotron radiation sources became available, which now allow focussing the x-radiation down to 100\,nm (FWHM). Thus, the typically poor spatial resolution of Small Angle X-ray Scattering (SAXS) has been overcome and enables "Scanning X-ray Nanodiffraction", where a sample is scanned in a linewise motion, while recording a far-field diffraction pattern at every scanning position. In this work, Scanning Nanodiffraction was applied to single cells of the amoeba \textit{Dictyostelium discoideum}, which is a model system for amoeboid migration, ...

Download or read book Luminescence Basic Concepts And Emerging New Applications written by Ahmed Maghraby and published by BoD – Books on Demand. This book was released on 2024-09-11 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: Luminescence, or “cold light,” is observed in everyday life through various forms such as television displays, lighting, mobile devices, and more. Although luminescence has been known since ancient civilizations and documented historically, nowadays it encompasses several types with distinct characteristics and applications. The applications of luminescence continue to expand and play a crucial role in many modern technological advances, making it an appealing field for ongoing development and innovation. This book provides a comprehensive overview of luminescence, discussing the theory, production, and real-life applications of luminescence and luminescent materials.

Download or read book Cryogenic Super Resolved Fluorescence Microscopy written by Siegfried Weisenburger and published by Logos Verlag Berlin GmbH. This book was released on 2016-11-16 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: The significance of super-resolved fluorescence microscopy beyond the diffraction barrier was recognized by the Nobel Prize in Chemistry in 2014. At room temperature, these techniques typically achieve a resolution on the order of twenty nanometers. They already allowed for resolving subcellular structures and organelles, and are starting to enable discoveries in neuroscience, molecular biology and other life sciences. One can dream about increasing the optical resolution by another two orders of magnitude in order to directly resolve sub-molecular structures such as constituents of molecular complexes or even protein structure itself. The aim of the present work is to accomplish exactly that. In this PhD thesis, a novel microscopy technique is presented that exploits cryogenic measurements to push optical resolution to the Angstrom level. The near atomic resolution is made possible by the substantial improvement of the molecular photostability at liquid helium temperature. This method allows one to gain structural information of proteins or other molecular complexes that might not be accessible by existing analytical methods such as X-ray crystallography, cryogenic electron microscopy or magnetic resonance spectroscopy. These results mark record optical resolution and demonstrate that optical resolution can be pushed beyond the diffraction limit by nearly one thousand times.

Download or read book Soft X Ray Diffraction Microscopy of a Frozen Hydrated Yeast Cell written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the first image of an intact, frozen hydrated eukaryotic cell using x-ray diffraction microscopy, or coherent x-ray diffraction imaging. By plunge freezing the specimen in liquid ethane and maintaining it below -170 °C, artifacts due to dehydration, ice crystallization, and radiation damage are greatly reduced. In this example, coherent diffraction data using 520 eV x rays were recorded and reconstructed to reveal a budding yeast cell at a resolution better than 25 nm. This demonstration represents an important step towards high resolution imaging of cells in their natural, hydrated state, without limitations imposed by x-ray optics.

Download or read book Correlative Light and Electron Microscopy II written by and published by Academic Press. This book was released on 2014-09-30 with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new volume of Methods in Cell Biology looks at methods for analyzing correlative light and electron microscopy (CLEM). With CLEM, people try to combine the advantages of both worlds, i.e. the dynamics information obtained by light microscopy and the ultrastructure as provided by electron microscopy. This volume contains the latest techniques on correlative microscopy showing that combining two imaging modalities provides more than each technique alone. Most importantly it includes the essential protocols, including tips, tricks and images for you to repeat these exciting techniques in your own lab. With cutting-edge material, this comprehensive collection is intended to guide researchers for years to come. Covers sections on model systems and functional studies, imaging-based approaches and emerging studies Chapters are written by experts in the field Cutting-edge material Second of two volumes dedicated to Correlative Light and Electron microscopy (CLEM)

Download or read book Toxicology of Nanomaterials written by Yuliang Zhao and published by John Wiley & Sons. This book was released on 2016-09-08 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides the reader with a comprehensive view of analytical methods for nanotoxicology studies. After an introduction to nanomaterials and toxicological studies, the book discusses various characterization methods of nanomaterials and continues with the detection of nanoparticles in vivo as well as in vitro. A variety of techniques in molecular toxicology of nanomaterials is presented, followed by a detailed explanation of interaction between nanoparticles and biomacromolecules, including the structure-toxicity relationships of nanomaterials. Finally, the book concludes with the advantages and challenges of the analytical methods for nanotoxicology.

Download or read book X Ray Diffraction Imaging of Biological Cells written by Masayoshi Nakasako and published by Springer. This book was released on 2018-03-29 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, the author describes the development of the experimental diffraction setup and structural analysis of non-crystalline particles from material science and biology. Recent advances in X-ray free electron laser (XFEL)-coherent X-ray diffraction imaging (CXDI) experiments allow for the structural analysis of non-crystalline particles to a resolution of 7 nm, and to a resolution of 20 nm for biological materials. Now XFEL-CXDI marks the dawn of a new era in structural analys of non-crystalline particles with dimensions larger than 100 nm, which was quite impossible in the 20th century. To conduct CXDI experiments in both synchrotron and XFEL facilities, the author has developed apparatuses, named KOTOBUKI-1 and TAKASAGO-6 for cryogenic diffraction experiments on frozen-hydrated non-crystalline particles at around 66 K. At the synchrotron facility, cryogenic diffraction experiments dramatically reduce radiation damage of specimen particles and allow tomography CXDI experiments. In addition, in XFEL experiments, non-crystalline particles scattered on thin support membranes and flash-cooled can be used to efficiently increase the rate of XFEL pulses. The rate, which depends on the number density of scattered particles and the size of X-ray beams, is currently 20-90%, probably the world record in XFEL-CXDI experiments. The experiment setups and results are introduced in this book. The author has also developed software suitable for efficiently processing of diffraction patterns and retrieving electron density maps of specimen particles based on the diffraction theory used in CXDI.

Download or read book Developments in Surface Contamination and Cleaning Volume 12 written by Rajiv Kohli and published by Elsevier. This book was released on 2019-06-08 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developments in Surface Contamination and Cleaning: Methods for Assessment and Verification of Cleanliness of Surfaces and Characterization of Surface Contaminants, Volume Twelve, the latest release in the Developments in Surface Contamination and Cleaning series, provides best practices on determining surface cleanliness. Chapters include an introduction to the nature and size of particles, a discussion of cleanliness levels, detailed coverage of measurement methods, characterization methods and analytical methods for evaluating surfaces, and an overview of analysis methods for various contaminants. As a whole, the series creates a unique and comprehensive knowledge base for those in research and development in a variety of industries. Manufacturing, quality control and procurement specification professionals in the aerospace, automotive, biomedical, defense, energy, manufacturing, microelectronics, optics and xerography industries will find this book to be very helpful. In addition, researchers in an academic setting will also find these volumes excellent source books. Includes an extensive listing, with a description of available methods for the assessment of surface cleanliness Provides a single source of information on methods for verification of surface cleanliness Serves as a guide to the selection, assessment and verification of methods for specific applications