Synthetic aperture diffraction tomography for three-dimensional imaging

2009 ◽  
Vol 465 (2109) ◽  
pp. 2877-2895 ◽  
Author(s):  
Francesco Simonetti ◽  
Lianjie Huang
Keyword(s):  
World War Ii ◽  
High Resolution ◽  
Three Dimensional ◽  
Synthetic Aperture ◽  
Sensor Technology ◽  
Dimensional Structure ◽  
Two Dimensional ◽  
Theoretical Formulation ◽  
Three Dimensional Objects ◽  
Aperture Diffraction

Tomography of complex three-dimensional objects with ultrasound or microwave has been a long-standing goal since the introduction of these technologies after World War II. While current state-of-the-art systems can provide high-resolution images of cylindrical objects characterized by a two-dimensional structure, the three-dimensional case remains an open challenge owing to current limitations of sensor technology and computer power. Here, this problem is addressed by means of a synthetic aperture technique that, while using hardware technology developed for two-dimensional problems, accounts for the complexity of three-dimensional scattering and leads to high-resolution three-dimensional reconstructions. In this paper, we present the theoretical formulation of this new approach and illustrate it by means of a numerical example.

scholarly journals Biophysical Characterisation of Human LincRNA-p21 Sense and Antisense Alu Inverted Repeats

2021 ◽  
Author(s):  
Michael H. D’Souza ◽  
Tyler Mrozowich ◽  
Maulik D. Badmalia ◽  
Mitchell Geeraert ◽  
Angela Frederickson ◽  
...  
Keyword(s):  
High Resolution ◽  
Noncoding Rna ◽  
Tertiary Structure ◽  
Analytical Ultracentrifugation ◽  
Three Dimensional ◽  
Size Exclusion ◽  
Dimensional Structure ◽  
Inverted Repeats ◽  
Two Dimensional ◽  
Low Resolution

AbstractHuman Long Intergenic Noncoding RNA-p21 (LincRNA-p21) is a regulatory noncoding RNA that plays an important role in promoting apoptosis. LincRNA-p21 is also critical in down-regulating many p53 target genes through its interaction with a p53 repressive complex. The interaction between LincRNA-p21 and the repressive complex is likely dependent on the RNA tertiary structure. Previous studies have determined the two-dimensional secondary structures of the sense and antisense human LincRNA-p21 AluSx1 IRs using SHAPE. However, there were no insights into its three-dimensional structure. Therefore, we in vitro transcribed the sense and antisense regions of LincRNA-p21 AluSx1 Inverted Repeats (IRs) and performed analytical ultracentrifugation, size exclusion chromatography, light scattering, and small angle X-ray scattering (SAXS) studies. Based on these studies, we determined low-resolution, three-dimensional structures of sense and antisense LincRNA-p21. By adapting previously known two-dimensional information, we calculated their sense and antisense high-resolution models and determined that they agree with the low-resolution structures determined using SAXS. Thus, our integrated approach provides insights into the structure of LincRNA-p21 Alu IRs. Our study also offers a viable pipeline for combining the secondary structure information with biophysical and computational studies to obtain high-resolution atomistic models for long noncoding RNAs.

High Resolution Microscopy of Multi-Layered Biological Crystals

1982 ◽  
Vol 40 ◽  
pp. 80-83
Author(s):  
H.A. Cohen ◽  
T.W. Jeng ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Low Dose ◽  
Three Dimensional ◽  
Data Interpretation ◽  
Two Dimensional ◽  
Biological Objects ◽  
Density Maps ◽  
Density Map ◽  
Complex Crystal ◽  
High Resolution Microscopy

This tutorial will discuss the methodology of low dose electron diffraction and imaging of crystalline biological objects, the problems of data interpretation for two-dimensional projected density maps of glucose embedded protein crystals, the factors to be considered in combining tilt data from three-dimensional crystals, and finally, the prospects of achieving a high resolution three-dimensional density map of a biological crystal. This methodology will be illustrated using two proteins under investigation in our laboratory, the T4 DNA helix destabilizing protein gp32*I and the crotoxin complex crystal.

Electron crystallographic determination of the 3-D structure of staurolite at atomic resolution

1991 ◽  
Vol 49 ◽  
pp. 540-541
Author(s):  
Kenneth H. Downing ◽  
Hu Meisheng ◽  
Hans-Rudolf Went ◽  
Michael A. O'Keefe
Keyword(s):  
High Resolution ◽  
Three Dimensional ◽  
High Resolution Electron Microscopy ◽  
Atomic Resolution ◽  
Dimensional Structure ◽  
Structure Information ◽  
Resolution Electron ◽  
Scattering Effects ◽  
High Resolution Images ◽  
Effects Of Radiation

With current advances in electron microscope design, high resolution electron microscopy has become routine, and point resolutions of better than 2Å have been obtained in images of many inorganic crystals. Although this resolution is sufficient to resolve interatomic spacings, interpretation generally requires comparison of experimental images with calculations. Since the images are two-dimensional representations of projections of the full three-dimensional structure, information is invariably lost in the overlapping images of atoms at various heights. The technique of electron crystallography, in which information from several views of a crystal is combined, has been developed to obtain three-dimensional information on proteins. The resolution in images of proteins is severely limited by effects of radiation damage. In principle, atomic-resolution, 3D reconstructions should be obtainable from specimens that are resistant to damage. The most serious problem would appear to be in obtaining high-resolution images from areas that are thin enough that dynamical scattering effects can be ignored.

Three-Dimensional Structure of Cloned T3 Connector Protein at 1.6nm Resolution

1990 ◽  
Vol 48 (1) ◽  
pp. 282-283
Author(s):  
José L. Carrascosa ◽  
José M. Valpuesta ◽  
Hisao Fujisawa
Keyword(s):  
Dna Sequences ◽  
Expression Vector ◽  
Three Dimensional ◽  
Deae Cellulose ◽  
Dna Packaging ◽  
Dimensional Structure ◽  
Two Dimensional ◽  
Freezing And Thawing ◽  
Three Dimensional Structure ◽  
Dimensional Reconstruction

The head to tail connector of bacteriophages plays a fundamental role in the assembly of viral heads and DNA packaging. In spite of the absence of sequence homology, the structure of connectors from different viruses (T4, Ø29, T3, P22, etc) share common morphological features, that are most clearly revealed in their three-dimensional structure. We have studied the three-dimensional reconstruction of the connector protein from phage T3 (gp 8) from tilted view of two dimensional crystals obtained from this protein after cloning and purification.DNA sequences including gene 8 from phage T3 were cloned, into Bam Hl-Eco Rl sites down stream of lambda promotor PL, in the expression vector pNT45 under the control of cI857. E R204 (pNT89) cells were incubated at 42°C for 2h, harvested and resuspended in 20 mM Tris HC1 (pH 7.4), 7mM 2 mercaptoethanol, ImM EDTA. The cells were lysed by freezing and thawing in the presence of lysozyme (lmg/ml) and ligthly sonicated. The low speed supernatant was precipitated by ammonium sulfate (60% saturated) and dissolved in the original buffer to be subjected to gel nitration through Sepharose 6B, followed by phosphocellulose colum (Pll) and DEAE cellulose colum (DE52). Purified gp8 appeared at 0.3M NaCl and formed crystals when its concentration increased above 1.5 mg/ml.

scholarly journals High-resolution three-dimensional probes of biomaterials and their interfaces

2012 ◽  
Vol 370 (1963) ◽  
pp. 1337-1351 ◽  
Author(s):  
Kathryn Grandfield ◽  
Anders Palmquist ◽  
Håkan Engqvist
Keyword(s):  
High Resolution ◽  
Electron Tomography ◽  
Three Dimensional ◽  
Controlled Drug Release ◽  
Biological Tissues ◽  
Dimensional Structure ◽  
Bone Interface ◽  
Biomaterial Interfaces ◽  
Titania Coating

Interfacial relationships between biomaterials and tissues strongly influence the success of implant materials and their long-term functionality. Owing to the inhomogeneity of biological tissues at an interface, in particular bone tissue, two-dimensional images often lack detail on the interfacial morphological complexity. Furthermore, the increasing use of nanotechnology in the design and production of biomaterials demands characterization techniques on a similar length scale. Electron tomography (ET) can meet these challenges by enabling high-resolution three-dimensional imaging of biomaterial interfaces. In this article, we review the fundamentals of ET and highlight its recent applications in probing the three-dimensional structure of bioceramics and their interfaces, with particular focus on the hydroxyapatite–bone interface, titanium dioxide–bone interface and a mesoporous titania coating for controlled drug release.

scholarly journals Tokens, Writing and (Ac)counting: A Conversation with Denise Schmandt-Besserat and Bill Maurer

2017 ◽  
Vol 5 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Denise Wilding ◽  
Clare Rowan ◽  
Bill Maurer ◽  
Denise Schmandt-Besserat ◽  
Denise Wilding ◽  
...  
Keyword(s):  
20Th Century ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Three Dimensional Objects ◽  
American Scientist

In her foundational study of Neolithic clay tokens, the renowned archaeologist Denise Schmandt-Besserat identified that different token shapes represented different goods and were used in accounting and distribution. When these tokens came to be stored in sealed clay envelopes (likely representing a debt), each token was impressed on the outside of the envelope before being placed inside (thus allowing people to see quickly what was within). Three-dimensional objects were thus reduced to two-dimensional representations, the first form of writing (and contributing to cuneiform script). These clay envelopes in turn developed into pictographic tablets; here each token did not have to be impressed into the clay in a 'one, one, one' system, but instead quantity was indicated by a numerical symbol - abstract number was born. Much of Schmandt-Besserat’s work can be found online at https://sites.utexas.edu/dsb/. Her book ‘How Writing Came About’ was listed by American Scientist magazine as one of the 100 books that shaped science in the 20th century, and she remains an active expert on all things ‘token’.

scholarly journals A system for generating virtual seeds

1998 ◽  
Vol 55 (spe) ◽  
pp. 39-45 ◽  
Author(s):  
Y. Sako ◽  
K. Fujimura ◽  
M.B. McDonald ◽  
D. James
Keyword(s):  
Three Dimensional ◽  
Promising Method ◽  
Two Dimensional ◽  
Dimensional Representation ◽  
Accurate Identification ◽  
Computer Screen ◽  
Three Dimensional Objects ◽  
Three Dimensional Representation ◽  
Quicktime Vr

Seed analysts need to identify seeds, and seed catalogs are used as a reference to accomplish this task. Conventional seed catalogs supply two-dimensional photographs and hand-drawn diagrams. In this study, a new, three-dimensional representation of seeds is developed to supplement these traditional photographs and drawings. QuickTime VR is a promising method for viewing three-dimensional objects on a computer screen. It permits manipulation of an object by rotating and viewing it from any pre-specified angle at an interactive speed, allowing the viewer the sense of examining a hand-held object. In this study, QuickTime VR object movies of seeds were created as interactive "movies" of seeds that can be rotated and scaled to give the viewer the sensation of examining actual seeds. This approach allows the examination of virtual seeds from any angle, permitting more accurate identification of seeds by seed analysts.

scholarly journals Addition of Illuminator Fiber Optic to Produce 3 Dimension Effects in Micrographic Observation Using Upright Microscope

2020 ◽  
Vol 3 ◽  
pp. 493-496
Author(s):  
Sutriyono ◽  
Widodo ◽  
Retno Suryandari
Keyword(s):  
Optical Fiber ◽  
Experimental Method ◽  
Daphnia Magna ◽  
High Intensity ◽  
Fiber Optic ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Three Dimensional Objects ◽  
Stereo Microscope ◽  
Total Magnification

Microscope is one of the tools used in practicums with high intensity. The use of a microscope adjusts to the object to be observed in order to obtain optimal micrographic results. Stereo microscopes are used to observe three-dimensional objects. Upright microscopes are used to observe two-dimensional objects. This study aims to combine the two advantages of stereo microscopy that can produce three-dimensional micrography with the advantages of an upright microscope that has a high total magnification. The method used in this study is an experimental method by adding an optical fiber illuminator in the use of an upright microscope and then applying it in various observations. The conclusion of this research is the addition of an optical fiber illuminator in observations using an upright microscope can replace the function of a stereo microscope; can produce three-dimensional effects and increase magnification in Daphnia magna micrographic observations.

scholarly journals Mechanochemical Synthesis of a Mercury(II) Metal-Organic Framework Reveals a Two-Dimensional Polymorph Stabilized by Weak Interactions

2019 ◽  
Author(s):  
Isaiah R. Speight ◽  
Igor Huskić ◽  
Mihails Arhangelskis ◽  
Hatem M. Titi ◽  
Robin Stein ◽  
...  
Keyword(s):  
Density Functional ◽  
Weak Interactions ◽  
Metal Organic Framework ◽  
Three Dimensional ◽  
Density Functional Theory Calculations ◽  
Dimensional Structure ◽  
Reaction Monitoring ◽  
Two Dimensional ◽  
Functional Theory ◽  
Metal Organic

Solid-state mechanochemistry revealed a novel polymorph of the mercury(II) imidazolate framework, based on square-grid (sql) topology layers. Reaction monitoring and periodic density functional theory calculations show that the sql-structure is of higher stability than the previously reported three-dimensional structure, with the unexpected stabilization of a lower dimensionality structure explained by contributions of weak interactions, which include short C-H···Hg contacts.

Sign in / Sign up

Export Citation Format

Share Document