bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrastructural studies of microtubules and microtubule organizing centers of the vertebrate olfactory neuron
Authors: Burton Paul R. 
Published: February 2005

AbstractThe olfactory neuron is specialized along its length into highly determined morphological regions. These regions include the dendritic cilia, dendritic vesicle, dendritic shaft proper, perikaryon, axon, zone of transition where the axon widens as it approaches its termination, and the axon terminal. Except for the zone of transition and the terminal, characteristic populations of microtubules occur in these compartments. In the olfactory vesicle, three discrete microtubule organizing centers (MTOCs) nucleate microtubules: the basal body, the lateral foot associated with the body, and dense masses of nearby material. Little is known about MTOCs elsewhere in the neuron, although the polarity of the axonal microtubules indicate that they originate at or near the perikaryon. An attempt is made to summarize what is known of the origin, structure, distribution, and function of microtubules in vertebrate olfactory neurons, which are useful model systems in which to study microtubules. Information about olfactory neuron microtubules may be applicable to neurons in general (e.g., the discovery that axons contain microtubules of uniform polarity was first made in the olfactory neuron) or to microtubules in other eukaryotic cells. © 1992 Wiley‐Liss, Inc.
Lectins bind differentially to cilia and microvilli of major and minor cell populations in olfactory and nasal respiratory epithelia
Authors: Menco Bert Ph.M. 
Published: February 2005

AbstractBinding of colloidal gold‐conjugated lectins was studied in cilia and microvilli of rat olfactory and respiratory epithelia. This was done in sections of rapidly frozen, freeze‐substituted specimens embedded in Lowicryl K11M or, for wheat germ agglutinin (WGA) alone, in deep‐etched replicas. Olfactory dendritic endings and cilia labeled with WGA and faintly with soybean agglutinin (SBA); olfactory supporting cell microvilli bound only Dolichos biflorus agglutinin (DBA). Microvilli of an infrequent cell bound peanut agglutinin (PNA), SBA, and WGA. These microvilli labeled more strongly with the last two lectins than the olfactory cilia. Respiratory cilia bound WGA and, somewhat more weakly, PNA; microvilli of ciliated respiratory cells bound all four lectins. Visualization of specific labeling improved after preincubation of sections with neuraminidase, except for DBA where lectin binding was abolished. PNA labeling was seen only after neuraminidase preincubation. The densities of membrane surface particles that labeled with WGA corresponded with those of fracture plane particles in a quantitative freeze‐fracture, deepetch analysis. Therefore, a considerable fraction of the WGA‐bound particles could reflect transmembrane proteins in olfactory dendritic endings and cilia and in respiratory cilia. The possible nature of these particles is discussed. © 1992 Wiley‐Liss, Inc.
Photoconversion of diaminobenzidine with different fluorescent neuronal markers into a light and electron microscopic dense reaction product
Authors: Lübke Joachim 
Published: February 2005

AbstractThis article describes methods for photoconverting diaminobenzidine (DAB) into a stable, light and electron microscopically visible dark reaction product in neurons which contain a fluorescent dye. Photoconversion of DAB has been achieved so far with the following fluorescent dyes: rhodamine labeled latex microspheres (RLM), 4,6‐diamidino‐2‐phenylindole (DAPI), 5,7‐di‐hydroxytryptamine (5,7‐DHT), Fast Blue (FB), Nuclear Yellow (NY), Diamidino Yellow (DY), Evans Blue (EB), acridine orange (AO), ethidium bromide (EBR),1,1′‐dioctadecyl‐3,3,3′,3′‐tetramethylindolcarbocyanine perchlorate, D‐282 (DiI), propidium iodide (PI), and intracellularly injected Lucifer Yellow (LY). The dye is introduced into the neurons by tinctorial staining, retrograde transport, or intracellular injection. Photoconversion is conducted by incubating the tissue with the fluorescent substance‐containing cells in a DAB solution under simultaneous strong illumination with ultraviolet (UV) light. During the formation of the reaction product, the fluorescence disappears from the cell. In all cases, photoconversion provided a stable, nonfading DAB reaction product for light microscopy. In addition, at the electron microscopic level, it appeared that the photoconversion results in a homogeneously distributed, fine granular, dark, intracellularly located reaction product. With most of the retrograde tracers tested, photoconversion led only to staining of the cell bodies and the proximal portions of primary dendrites. Following photoconversion with intracellularly LY‐filled neurons and cells labeled retrogradely with DiI, DiO, and 5,7‐DHT, the reaction product was present throughout the cells, extending from the cell bodies into dendrites and dendritic appendices, and into axons. The high selectivity and methodological simplicity of photoconversion of DAB with fluorescent dyes into a stable, light and electron microscopical dense reaction product provide a promising alternative to classical neuroanatomical techniques and a new useful application of fluorescent neuronal tracers to light and electron microscopy. © 1993 Wiley‐Liss, Inc.
Ultrastructural and functional connectivity of intracellularly stained neurones in the vertebrate retina: Correlative analyses
Authors: Djamgoz Mustafa B. A. , Kolb Helga 
Published: February 2005

AbstractA variety of intracellular recording and staining techniques has been used to establish structure‐function and, in some cases, structure‐function‐neurochemical correlations in fish, turtle, and cat retinae. Cone photoreceptor‐horizontal cell connectivity has been studied extensively in the cyprinid fish retina by intracellular staining with horseradish peroxidase (HRP) and subsequent electron microscopy. The available data suggest that horizontal cell dendrites around the ridge of the synaptic ribbon are postsynaptic, whilst finger‐like extensions (“spinules”) of lateral dendrites function as inhibitory feedback terminals. An interesting feature of this inter‐action is its plasticity: the feedback pathway is suppressed in the dark and becomes potentiated by light adaptation of the retina.Intracellular recordings and stainings of ganglion cells in both turtle and cat retinae have been possible. Prelabelling of ganglion cells by retrograde transport of rhodamine from the tectum allows ganglion cells to be stained under visual control, and their synaptic inputs determined by electron microscopy. Such studies have been extended to double labelling by using autoradiography or postembedding immunohistochemistry to identify the neurotransmitter content of the labelled cell and/or the neurotransmitter(s) converging upon it. It is envisaged that further applications of intracellular staining followed by double‐ or even triple‐labelling will continue to enhance greatly our understanding of the functional architecture of the vertebrate retina. © 1993 Wiley‐Liss, Inc.
Programmable freeze‐substitution and cryo‐embedding device
Authors: Trachtenberg Shlomo 
Published: February 2005

AbstractThe construction and performance of a modular and fully controlable freeze‐substitution device are described. The core of the device consists of a heavy brass block providing a large, stable thermal mass. The block is composed of two perforated plates and a base plate forming nine deep wells, which enable the concomitant substitution of several samples in various substitution fluids, and in large volumes. The wells are surrounded by an isometric network of tunnels through which either liquid nitrogen or hot air can flow. The isometric network enables heat transfer across short uniform distances throughout the entire block's volume, thus minimizing temperature gradients and differences. The temperature of the substitution fluid, rather than that of the metal block, is monitored by a programmable controller, enabling the presetting of any freeze‐substitution regime. © 1993 Wiley‐Liss, Inc.
Improved TEM samples of semiconductors prepared by a small‐angle cleavage technique
Authors: McCaffrey John P. 
Published: February 2005

AbstractA small‐angle cleavage technique has been developed that produces superior transmission electron microscope (TEM) samples of semiconductors and related materials. The technique involves back‐thinning the sample to approximately 100 μm, then scribing a groove on this back face at a specified small angle to a standard cleavage plane. The sample is cleaved along this scribe line followed by cleaving along the standard cleavage plane to produce a thin wedged sample. Samples prepared by this method are characterized and compared with conventional and low‐angle ion milled samples. The technique is illustrated, and the characteristic geometry of the cleaved sample is explained in terms of a simplified cleavage model. © 1993 Wiley‐Liss, Inc.
Tracing neural pathways in snail olfaction: From the tip of the tentacles to the brain and beyond
Authors: Chase Ronald , Tolloczko Barbara 
Published: February 2005

AbstractThe anatomical organization of the olfactory system of terrestrial snails and slugs is described in this paper, primarily on the basis of experiments using the African snail Achatina fulica. Behavioral studies demonstrate the functional competence of olfaction in mediating food finding, conspecific attraction, and homing. The neural substrate for olfaction is characterized by an extraordinarily large number of neurons relative to the rest of the nervous system, and by the fact that many of them are unusually small. There exist multiple serial and parallel pathways connecting the olfactory organ, located at the tip of the tentacle, with integrative centers in the central nervous system. Our methods of studying these pathways have relied on the selective neural labels horseradish peroxidase and hexamminecobaltous chloride. One afferent pathway contains synaptic glomeruli whose ultrastructure is similar to that of the glomeruli seen in the mammalian olfactory bulb and the insect olfactory lobe. All of the olfactory neuropils, but especially the tentacle ganglion, contain large numbers of morphologically symmetrical chemical synapses. The procerebrum is a unique region of the snail brain that possesses further features analogous with olfactory areas in other animal groups. Olfactory axons from the tentacle terminate in the procerebrum, but the intrinsic neurons do not project outside of it. An output pathway from the procerebrum to the pedal ganglion has been identified and found to consist of inter‐ganglionic dendrites. The major challenge for future studies is to elucidate the pattern of connectivity within, rather than between, the various olfactory neuropils. © 1993 Wiley‐Liss, Inc.
Synaptic organization and development of the antennal lobe in insects
Authors: Boeckh J. , Tolbert L. P. 
Published: February 2005

AbstractMany insects possess a highly developed sense of smell. This paper summarizes the cellular and synaptic organization of the antennal (olfactory) lobe of the insect brain and then reviews morphological and fine‐structural aspects of the development of the lobe. Visualization of synapses between classes of neurons identified by physiological, morphological, or transmitter‐cytochemical properties has provided insights into arrangements of contacts and their possible roles in information processing. Studies of development have revealed the requirement for afferent axons from the antenna for the formation of olfactory glomeruli, where virtually all of the synapses in the lobe occur, and have suggested the possibility that glial cells play a role in the instructive influence of the axons on their target neurons in the lobe. The findings reviewed in this paper are primarily from one representative hemimetabolous insect, the American cockroach, and one representative holometabolous insect, a hawkmoth, and comparisons are made with vertebrate systems when appropriate. © 1993 Wiley‐Liss, Inc.
Microscopy in solid state science
Authors: McGibbon A. J. , Brown L. M. , Bleloch A. L. , Browning N. D. , Cadete Santos Aires F. , Fallon P. J. , Gaskell P. H. , Gilkes K. W. R. , Hansen P. L. , Howie A. , Maynard A. D. , McComb D. W. , McMullan D. , Müllejans H. , Murooka Y. , Paterson J. H. , Perovic D. D. , Pike W. T. , Rauf I. A. , Rodenburg J. M. , Saeed A. , Stelmashenko N. , Tu K. N. , Walls M. G. , Walsh C. A. , Yuan J. , Zhao J. 
Published: February 2005

AbstractThe Microstructural Physics group at the Cavendish Laboratory is actively involved in a considerable number of research projects which cover a broad range of materials science. In this paper, we describe briefly several such projects, with particular emphasis given to the application of parallel‐detection electron energy loss spectroscopy (PEELS) on a scanning transmission electron microscope (STEM) to the analysis of materials such as stainless steels, catalysts, and high temperature superconductors. In addition, we describe a number of related projects that are currently being carried out in the group, particularly those which utilise and develop novel STEM imaging and analytical techniques. © 1993 Wiley‐Liss, Inc.
Instrumentation, techniques, and applications of electron microscopy in the solid state physics group at Glasgow university
Authors: Craven A. J. , McVitie S. , Chapman J. N. 
Published: February 2005

AbstractThis review discusses some of the work performed by the Solid State Physics Group at Glasgow University. A major aim of the group is to obtain quantitative information with high spatial resolution and to do this reliably requires a thorough understanding of both the instrumentation and the interactions between the electron beam and the specimen. Thus the first part of the review discusses those aspects of instrumentation and techniques that the group has considered in detail while the final part deals with applications which involve the study of a wide range of materials covering metallurgical, semiconductor, organic, and magnetic systems. In all these applications, the results from a range of techniques have been required to provide as complete a picture of the material as possible. © 1993 Wiley‐Liss, Inc.
Microanalysis near particles and voids at grain boundaries
Authors: Tatlock G. J. , Partridge A. , Beahan P. G. 
Published: February 2005

AbstractSome of the problems of using high spatial resolution microanalysis in the vicinity of particles and voids in metal grain boundaries are discussed. New analytical results are presented for nickel based alloys, which suggest that elemental distributions in the region immediately adjacent to growing grain boundary particles and voids are often anisotropic. © 1993 Wiley‐Liss, Inc.
Ultrastructure of early chick embryo tissues after high pressure freezing and freeze substitution
Authors: Allenspach Allan 
Published: February 2005

AbstractEarly chick embryos (stages 11–29), or parts thereof, were frozen by the high pressure technique and subjected to a variety of freeze substitution protocols. In addition to hexadecene, unincubated albumen was used as a cryoprotectant to surround the specimens during the freezing event. The quality of freeze ranged from poor to very good in these highly aqueous specimens; very good freeze quality was observed minimally to depths of 30–40 μ. Freeze substitution was carried out with a custom‐made aluminum chamber, automatic freeze substitution machine, or a combination of the two, in acetone containing (1) uranyl acetate; (2) acrolein and/or tannic acid; or (3) a sequence of (2), osmium, and glutaraldehyde. Excellent quality of morphology was cryopreserved with all solutions, given optimally cryoimmobilized tissue. Mitotic and pericentriolar microtubules and cytoskeletal elements were cryopreserved with all methods; membranous organelles were better preserved with osmium. Outstanding preservation of morphology of the ground substance of very hydrated embryonic cells, though limited in depth, was accomplished by high pressure cryoimmobilization and cryopreservation, demonstrating that the technique can be successfully applied to highly aqueous tissues. © 1993 Wiley‐Liss, Inc.
Impact of freeze substitution on biological electron microscopy
Authors: Hippe‐Sanwald Sigrun 
Published: February 2005

AbstractConsidering the increasing necessity for improved preparation techniques in biological electron microscopy as a basis for the identification and localization of cellular substances within the compartments of the cell, this review is focussed on the method of freeze substitution as an important link between the cryofixation (ultrarapid freezing) and resin embedding of biological specimens. The theory and practice of freeze substitution is summarized with particular interest in the physical and thermodynamic as well as in the chemical basis of this technique. A survey of practical aspects of the technical process of freeze substitution concerning the equipment and various protocols successfully applied in biological systems is also given. The main advantage of freeze substitution versus conventional chemical fixation is seen in the maintenance of the hydration shell of molecules and macromolecular structures. This results in an improved fine structural preservation, superior retention of the antigenicity of proteins and decreased loss of unbound, diffusible cellular components. Examples of excellent visualization of the ultrastructure of macro‐molecular complexes (nucleic acids, extracellular material, membranes etc.), small organisms (bacteria, algae, cyanobacteria and fungi) and large biological samples such as plant and animal tissue as well as the plant‐pathogen (fungus) interface and infection structures are presented. Recent data on the molecular characterization of freeze‐substituted biological tissue are exemplified with special emphasis on the subcellular detection of soluble components (elements, lipids, proteins and drugs) and the inter‐/intracellular localization of proteins including foreign proteins in transgenic plants. The molecular analysis of freeze‐substituted specimens is achieved by the combination of low temperature preparation techniques in biological electron microscopy with various detection methods such as X‐ray microanalysis, immunocytochemistry and high resolution autoradiography. © 1993 Wiley‐Liss, Inc.
Sequential observations followed by acid etching on the enamel surfaces of human teeth under scanning electron microscopy at low vacuum
Authors: Kodaka Tetsuo , Mori Ryoichi , Miyakawa Michiyo 
Published: February 2005

AbstractA scanning electron microscope equipped with a low vacuum specimen chamber and a Robinson's backscattered electron detector was employed to observe the natural surfaces of human buccal enamel before and after 30 percent phosphoric acid etching sequentially up to 90 sec at the same sites with no coatings. Furthermore, successive etching patterns were compared between deciduous and permanent teeth. On the imbrication lines of young permanent teeth, prismend pits surrounded with a “prismless” structure occasionally disappeared after acid etching and became a prismless enamel. Sequential etching caused the prismless areas and the areas of a type 1 etching pattern to decrease, and a cone‐shaped prism structure and a complex type of the type 1 and type 2 etching pattern (type 1–2) to appear. The former was a transitional type between the prismless enamel and type 2 prisms. These etched surfaces show type 2 prisms after deeper etching. Small dome‐shaped structures, slightly elevated on the attrited enamel surfaces, were found only in deciduous teeth. After acid etching, such areas which retained the prismless enamel rose to the underlying surfaces of cone‐shaped prisms. © 1993 Wiley‐Liss, Inc.
Cross‐sectional AEM preparation technique for ceramic‐coated WC‐Co cutting tools
Authors: Ostreicher Kim , Sung Changmo 
Published: February 2005

AbstractThe preparation of cross‐sectional specimens for AEM studies of materials such as ceramic coated tungsten carbide presents some unique problems. Pieces joined by the use of epoxies often separate at the interface between the WC and ceramic coating during the initial mechanical grinding and subsequent thinning process as a result of the vibration and physical strain placed on the sample. These problems have been overcome through the use of a preparation process which essentially encapsulates the sample within the confines of an epoxy filled quartz tube. This preparation process has allowed for facile AEM cross‐sectional analysis of TiN/TiCN coatings on WC‐Co substrates, and has revealed two distinct grain morphologies within the TiCN coating. © 1993 Wiley‐Liss, Inc.
Discrepancies in kinematic calculations of HOLZ lines
Authors: Eades J. A. , Moore S. , Pfullmann T. , Hangas Jon 
Published: February 2005

AbstractWe have found significant differences between the results of computer simulations of HOLZ line patterns. The computations in question are made in the kinematical approximation. After trivial errors are eliminated the programs fall into two groups. There is a discrepancy between the two that increases with distance from the zone axis. The difference is small but not negligible at the level of precision used in determining lattice parameters or strain.We show which of the two is correct in the kinematic approximation and that the discrepancy between the two groups is of the order of the error introduced by dynamical interaction. © 1993 Wiley‐Liss, Inc.
Quantitative analysis and cartography in scanning electron microscopy: Application to the study of bacterial adhesion to respiratory epithelium
Authors: Colliot G. , De Bentzmann S. , Plotkowski M. C. , Lebonvallet S. , Puchelle E. , Bonnet N. 
Published: February 2005

AbstractThis paper describes the coupling between a scanning electron microscope (SEM) and an image analysis workstation. The system was designed in order to drive the SEM and to analyse any sample. It allows automatic (edge detection) or semiautomatic (pointing, marking, drawing) object detection. Two types of data can be obtained: (1) topographical information, such as the location of the object within a region of interest drawn at any magnification of the microscope, or (2) quantitative data, such as morphometric characteristics of objects. In addition, high resolution maps of the section, regions of interest, and objects can be obtained with a laser printer. This software was first applied to quantitate the adhesion of the bacteria Pseudomonas aeruginosa to human respiratory epithelial cells in culture. P. aeruginosa was shown associated with ciliated cells. The second application concerned the study of the distribution of specific carbohydrate residues at the surface of the respiratory cells. The gal residues were revealed using the lectin Ricinas communis agglutinin II, adsorbed to colloidal gold particles. A relationship between the presence of adherent bacteria and labelling was shown. © 1993 Wiley‐Liss, Inc.