scholarly journals Splayed Tetrahymena cilia. A system for analyzing sliding and axonemal spoke arrangements.

1976 ◽  
Vol 71 (2) ◽  
pp. 589-605 ◽  
Author(s):  
W S Sale ◽  
P Satir
Keyword(s):  
Structural Parameters ◽  
Three Dimensional ◽  
Tetrahymena Pyriformis ◽  
Dimensional Structure ◽  
Ciliary Movement ◽  
Dimensional Changes ◽  
Local Contraction ◽  
Critical Point Drying ◽  
Triton X ◽  
Section Analysis

This study makes use of a procedure designed to illustrate, without serial section analysis, the three-dimensional changes in the ciliary axoneme produced by microtubule sliding, and to confirm essential features of the sliding microtubule hypothesis of ciliary movement. Cilia, isolated from Tetrahymena pyriformis by the dibucaine procedure, are attached to polylysine substratum, and treated with Triton X-100. Critical point drying maintains three-dimensional structure without embedding. The detergent removes the membrane and many axonemes unroll, always in an organized fashion so that doublets follow one another in sequence, according to the enantiomorphic form of the cilium. The central pair of microtubules fall to the side as a unit. The parallel doublet microtubules retain relative longitudinal positions in part by interdoublet or nexin links. Spoke organization and tip patterns are preserved in the opened axonemes. We generalize the work of Warner and Satir (Warner, F. D., and P. Satir, 1976. J. Cell Biol. 63:35-63) to show that spoke group arrangements are maintained for all doublets in straight regions, while systematic displacements occur in bent regions. The conclusion that local contraction of microtubles is absent in the axoneme is strengthened, and direct graphic demonstrations of sliding at the ciliary tip are shown. A morphogenetic numbering scheme is presented which results in a quantitative fit of the tip images to the images predicated by the equation for doublet sliding, and which makes possible new comparisons of structural parameters between axonemes and with cilia of other organisms.

Revealing gross three-dimensional structure in the SEM

1987 ◽  
Vol 45 ◽  
pp. 656-657
Author(s):  
Sterling P. Newberry
Keyword(s):  
Freeze Drying ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Small Object ◽  
Final Solution ◽  
Dimensional Representation ◽  
X Ray ◽  
Three Dimensional Representation ◽  
Freeze Dried ◽  
Critical Point Drying

The beautiful three dimensional representation of small object surfaces by the SEM leads one to search for ways to open up the sample and look inside. Could this be the answer to a better microscopy for gross biological 3-D structure? We know from X-Ray microscope images that Freeze Drying and Critical Point Drying give promise of adequately preserving gross structure. Can we slice such preparations open for SEM inspection? In general these preparations crush more readily than they slice. Russell and Dagihlian got around the problem by “deembedding” a section before imaging. This some what defeats the advantages of direct dry preparation, thus we are reluctant to accept it as the final solution to our problem. Alternatively, consider fig 1 wherein a freeze dried onion root has a window cut in its surface by a micromanipulator during observation in the SEM.

scholarly journals Brain capillary structures of schizophrenia cases and controls show a correlation with their neuron structures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rino Saiga ◽  
Masayuki Uesugi ◽  
Akihisa Takeuchi ◽  
Kentaro Uesugi ◽  
Yoshio Suzuki ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Superior Temporal Gyrus ◽  
Anterior Cingulate ◽  
Dimensional Structure ◽  
Constant Diameter ◽  
The Mean ◽  
Cartesian Coordinate ◽  
Micrometer Scale

AbstractBrain blood vessels constitute a micrometer-scale vascular network responsible for supply of oxygen and nutrition. In this study, we analyzed cerebral tissues of the anterior cingulate cortex and superior temporal gyrus of schizophrenia cases and age/gender-matched controls by using synchrotron radiation microtomography or micro-CT in order to examine the three-dimensional structure of cerebral vessels. Over 1 m of cerebral blood vessels was traced to build Cartesian-coordinate models, which were then used for calculating structural parameters including the diameter and curvature of the vessels. The distribution of vessel outer diameters showed a peak at 7–9 μm, corresponding to the diameter of the capillaries. Mean curvatures of the capillary vessels showed a significant correlation to the mean curvatures of neurites, while the mean capillary diameter was almost constant, independent of the cases. Our previous studies indicated that the neurites of schizophrenia cases are thin and tortuous compared to controls. The curved capillaries with a constant diameter should occupy a nearly constant volume, while neurons suffering from neurite thinning should have reduced volumes, resulting in a volumetric imbalance between the neurons and the vessels. We suggest that the observed structural correlation between neurons and blood vessels is related to neurovascular abnormalities in schizophrenia.

scholarly journals Three-dimensional structure of actin filaments and of an actin gel made with actin-binding protein.

1983 ◽  
Vol 96 (5) ◽  
pp. 1400-1413 ◽  
Author(s):  
R Niederman ◽  
P C Amrein ◽  
J Hartwig
Keyword(s):  
Actin Filaments ◽  
Binding Protein ◽  
Three Dimensional ◽  
Actin Binding ◽  
Dimensional Structure ◽  
Molar Ratio ◽  
Computer Assisted ◽  
Three Dimensional Structure ◽  
Actin Binding Protein ◽  
Critical Point Drying

Purified muscle actin and mixtures of actin and actin-binding protein were examined in the transmission electron microscope after fixation, critical point drying, and rotary shadowing. The three-dimensional structure of the protein assemblies was analyzed by a computer-assisted graphic analysis applicable to generalized filament networks. This analysis yielded information concerning the frequency of filament intersections, the filament length between these intersections, the angle at which filaments branch at these intersections, and the concentration of filaments within a defined volume. Purified actin at a concentration of 1 mg/ml assembled into a uniform mass of long filaments which overlap at random angles between 0 degrees and 90 degrees. Actin in the presence of macrophage actin-binding protein assembled into short, straight filaments, organized in a perpendicular branching network. The distance between branch points was inversely related to the molar ratio of actin-binding protein to actin. This distance was what would be predicted if actin filaments grew at right angles off of nucleation sites on the two ends of actin-binding protein dimers, and then annealed. The results suggest that actin in combination with actin-binding protein self-assembles to form a three-dimensional network resembling the peripheral cytoskeleton of motile cells.

scholarly journals Seventeen-Armed Star Polystyrenes in Various Molecular Weights: Structural Details and Chain Characteristics

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1894
Author(s):  
Jia Chyi Wong ◽  
Li Xiang ◽  
Kuan Hoon Ngoi ◽  
Chin Hua Chia ◽  
Kyeong Sik Jin ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Star Polymers ◽  
Star Polymer ◽  
Dimensional Structure ◽  
Density Profiles ◽  
Molecular Weights ◽  
Radiation Sources ◽  
Structural Details

Star-shaped polymers are very attractive because of their potential application ability in various technological areas due to their unique molecular topology. Thus, information on the molecular structure and chain characteristics of star polymers is essential for gaining insights into their properties and finding better applications. In this study, we report molecular structure details and chain characteristics of 17-armed polystyrenes in various molecular weights: 17-Arm(2k)-PS, 17-Arm(6k)-PS, 17-Arm(10k)-PS, and 17-Arm(20k)-PS. Quantitative X-ray scattering analysis using synchrotron radiation sources was conducted for this series of star polymers in two different solvents (cyclohexane and tetrahydrofuran), providing a comprehensive set of three-dimensional structure parameters, including radial density profiles and chain characteristics. Some of the structural parameters were crosschecked by qualitative scattering analysis and dynamic light scattering. They all were found to have ellipsoidal shapes consisting of a core and a fuzzy shell; such ellipse nature is originated from the dendritic core. In particular, the fraction of the fuzzy shell part enabling to store desired chemicals or agents was confirmed to be exceptionally high in cyclohexane, ranging from 74 to 81%; higher-molecular-weight star polymer gives a larger fraction of the fuzzy shell. The largest fraction (81%) of the fuzzy shell was significantly reduced to 52% in tetrahydrofuran; in contrast, the lowest fraction (19%) of core was increased to 48%. These selective shell contraction and core expansion can be useful as a key mechanism in various applications. Overall, the 17-armed polystyrenes of this study are suitable for applications in various technological fields including smart deliveries of drugs, genes, biomedical imaging agents, and other desired chemicals.

Creating a tissue-specific microdispersed matrix from a decellularized porcine liver

2020 ◽  
Vol 4 ◽  
pp. 41-50
Author(s):  
A.D. Kirillova ◽  
◽  
Yu.B. Basok ◽  
A.E. Lazhko ◽  
A. M. Grigoryev ◽  
...  
Keyword(s):  
Sodium Dodecyl ◽  
Genetic Material ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Porcine Liver ◽  
Tissue Specific ◽  
Main Components ◽  
Triton X ◽  
Injectable Form

The main problem with decellularization of liver tissue as a tissue-specific matrix/scaffold in liver bioengineered structures is the need to maximize the preservation of the original three-dimensional structure of the tissue and the main components of its extracellular matrix (ECM) while removing cells and genetic material. The attempts to use the existing protocols for the decellularization of other tissues and organs have been unsuccessful. The aim of the work is to develop a method for creation of tissue-specific microdispersed matrix from decellularized porcine liver (TMM DLp). The protocol for decellularization of porcine liver (Lp) fragments has been developed based on the complex application of chemical (sodium dodecyl sulfate and Triton X-100), biochemical (DNase I), and physical (supercritical CO2) methods for treatment the initial tissue. As a result of the found optimal conditions for decellularization of Lp with subsequent cryomicronization of DLp, the injectable form of the microdispersed tissue-specific matrix was obtained, which represents DLp microparticles with the size of 100-200 microns with the residual amount of DNA no more than 10±1.5 ng/mg (less than 1.0%), with the preservation of the microstructure and basic composition of the liver ECM. According to the assessment of biocompatible properties in vitro, TMM DLp samples meet the criteria of biological safety for cytotoxicity and hemolytic activity.

Yhe Compression Meso-Mechanics Theoretical Model and Experimental Verification of Polyurethane-Based Warp-Knit Spacer Fabric Composites

2021 ◽  
Vol 8 (5) ◽  
pp. 30-38
Author(s):  
Si Chen
Keyword(s):  
Theoretical Model ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Beam Theory ◽  
Theoretical Research ◽  
Dimensional Structure ◽  
Static Compression ◽  
Theoretical Simulation ◽  
Winkler Elastic Foundation ◽  
Spacer Fabric

In this research, a new type of binary material, a polyurethane-based warp-knitted spacer fabric composite (PWSF), having a unique three-dimensional structure, high strength, and a variety of surface structures was prepared. The compression meso-mechanics theoretical model based on the Winkler elastic foundation beam theory and structural parameters of PWSF were used to predict the compression performance of PWSF. To verify the validity of compression model, the compression stress-strain curves of theoretical simulation were compared with the quasi-static compression test results. The deviation between these two compression moduli was less than 7%. The compression meso-mechanics model established in this study can effectively simulate the actual compression behaviors for different PWSF specimens. A regular pattern of compression properties of this novel composite from the theoretical research on meso-mechanics perspectives can be proposed.

Three-Dimensional Structure Trajectory Guiding Scan and Points Cloud Registration

2013 ◽  
Vol 300-301 ◽  
pp. 423-426
Author(s):  
Yong Cai
Keyword(s):  
Point Cloud ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Surface Model ◽  
Visual Measurement ◽  
Local Point ◽  
Inverse Kinematics Problem ◽  
The Relationship ◽  
Measurement Approach

Three-dimensional visual scanning is an advanced non-contact measurement approach that can obtain a complete surface model of object. But, in the method, the local raster point cloud sets calculated must be registered to a whole. To reduce fluctuating errors and increase efficiency, we propose a new method that scanner can be moved around object guided by pre-planning trajectory of the robot. First, considering the structural parameters of the robot, the Inverse Kinematics Problem of each joint rotating function is derived, and the moving trajectory is simulated. Then, the relationship between the distances of controlled motion and data gotten by scanner is analyzed, a transform matrix which registered the local point cloud sets is deduced, the raster data can be normalized to the world coordinate by it. The experimental results show that error of registration is less than 0.09mm. The method is suited to measuring different targets in robot workspace. It can improve the efficiency and flexibility of visual measurement system.

Characterization and Analysis of Highly Hydrated, Three Dimensional Cell-Matrix Constructs

1999 ◽  
Vol 5 (S2) ◽  
pp. 388-389
Author(s):  
Ravi V. Bellamkonda ◽  
Amit Balgude ◽  
Xiaojun Yu
Keyword(s):  
Electron Microscopy ◽  
Confocal Microscopy ◽  
Three Dimensional ◽  
Neural Tissue ◽  
Dimensional Structure ◽  
Surface Rendering ◽  
Image Reconstruction Techniques ◽  
Neurite Extension ◽  
Critical Point Drying

Neural Tissue Engineering involves the use of three-dimensional biomaterial scaffolds for transplantation of neural tissue or for induction of regeneration of severed peripheral or central nerves. There is a paucity of information regarding the optimization parameters for the design of 3D constructs from the mechanical, morphological, or charge perspective such that neurite extension is maximized. In addition, cytoskeletal organization and response of neurons in 3D matrices to various stimuli is not well understood. Our laboratory has been using a combination of electron, force, light, video and confocal microscopy to address these issues. Custom surface rendering image reconstruction techniques were used to reconstruct the three-dimensional structure of neurons extending processes in 3D as visualized by confocal microscopy. We have previously reported that low concentration gels of hydroxyethylated agarose are capable of supported neurite extension from a variety of neural cells in vitro.Agarose hydrogels were fabricated in concentrations ranging from 0.75%-3.0% (w/v). These highly hydrated gels were prepared for electron microscopy using a variety of sample preparation protocols including freeze drying, and critical point drying and their morphological structure and pore radius was computed using scanning electron microscopy.

Use of Confocal Imaging for Arthropod Morphological Studies

2000 ◽  
Vol 6 (S2) ◽  
pp. 822-823
Author(s):  
Angela V. Klaus ◽  
Varuni L. Kulasekera ◽  
Norman Platnick
Keyword(s):  
Light Microscopy ◽  
Laser Scanning ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Confocal Imaging ◽  
Laser Scanning Microscopy ◽  
Dimensional Structure ◽  
Confocal Laser ◽  
Morphological Studies ◽  
Critical Point Drying

Morphological studies in spider and insect groups (Phylum Arthropoda) have historically relied upon traditional imaging techniques such as light microscopy (LM) and scanning electron microscopy (SEM). It has often been difficult, however, to examine some structural details of certain specimens due to limitations of the techniques. Light microscopy does not always provide adequate depth of focus for visualizing the true three-dimensional structure of a specimen, and out-of-focus light in the image can obscure detail. SEM is not applicable if the specimen is too delicate to undergo critical point drying. Additionally, SEM is a surface technique and does not provide any information about internal structure.If a specimen is transparent to light, information about the morphology of internal structures, and connections between structures, can easily be obtained using confocal microscopy without the problems associated with traditional LM. In this study, we used confocal laser scanning microscopy (CLSM) to study the morphology of chitinous arthropod structures by taking advantage of their autofluorescent properties.

Building Two and Three-dimensional Structures of Colloidal Particles on Surfaces using Optical Tweezers and Critical Point Drying

2001 ◽  
Vol 705 ◽  
Author(s):  
Dirk L. J. Vossen ◽  
Jacob P. Hoogenboom ◽  
Karin Overgaag ◽  
Alfons van Blaaderen
Keyword(s):  
Critical Point ◽  
Optical Tweezers ◽  
Colloidal Particles ◽  
Three Dimensional ◽  
Silica Shell ◽  
Dimensional Structure ◽  
Layer By Layer ◽  
Two Dimensional ◽  
Critical Point Drying ◽  
Shell Particles

AbstractWe describe a method for patterning substrates with colloidal particles in any designed two-dimensional structure. By using optical tweezers particles are brought from a reservoir to a surface that carries a surface charge opposite to that of the particles. Using this technique large, two-dimensional patterns can be created, where the pattern can be manipulated on a single particle level. We show that these structures can be dried using critical point drying thus preventing distortions due to surface tension forces. After drying patterned surfaces can be used for further processing, which includes repeating the procedure of patterning. We show some first results of three-dimensional structures created using this layer-by-layer method. The method is generally applicable and has been demonstrated for a variety of (core-shell) colloidal particles including particles that are interesting for photonic applications like high-refractive index (ZnS)-core – silica shell particles, metallodielectric (gold)-core – silica-shell particles, fluorescently labeled particles and small (several nanometers large) gold particles. Particle sizes used range from a few nanometers to several micrometers.

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