bluuebunny/crossref_metadata_2025_split huggingface dataset:
The human primary olfactory pathway: Fine structural and cytochemical aspects during development and in adults
Authors: Chuah Meng Inn , Zheng Da Ren 
Published: February 2005

AbstractDespite increasing knowledge about the biophysiology of the human olfactory system, understanding of the development of this pathway in humans lags considerably behind that of other vertebrates. Development studies have largely concentradted on the generation of cell types in the olfactory epithelium during the first trimester, while detailed ultrastructural observations usually describe the adult morphologh. In this review, we have shown that contrary to what has been generally assumed, the surface of the human olfactory epithelium is heterogeneous and that its olfactory nerves differ ultrastructurally from those of other vertebrates studied. The development of the human primary olfactory pathwayis discussed in terms of the appearance of olfactory bulb laminae, synaptogenesis and the expression of specific cell markers, such as the S‐100 protein and olfactory marker protein (OMP). Positive immunohistochemical staining for N‐cadherin in human fetuses suggests that growth ofolfactory axons to their target may be mediated by cell adhesion molecules. The overall data presented here indicate that this pathway develops more precociously in humans than in rodents. Whether this translates also to earlier functional maturity remains to be elecidated. © 1992 Wiley‐Liss, Inc.
Endocytic pathways in the olfactory and vomeronasal epithelia of the mouse: Ultrastructure and uptake of tracers
Authors: Bannister Lawrence H. , Dodson Hilary C. 
Published: February 2005

AbstractMammalian olfactory neurons possess a well‐developed system of endocytic vesicles, endosomes, and lysosomes in their dendrites and perikarya. Vomeronasal neurons are similar and also contain much perikaryal agranular endoplasmic reticulum (AER). Olfactory supporting cells contain endocytic vesicles and endosomes associated closely with abundant fenestrated AER, and vesicles and numerous large dense vacuoles are present basally. Vomeronasal supporting cells have little AER, and few dense vacuoles occur in their bases. In olfactory neurons, ultrastructural tracers (0.08% horseradish peroxidase, thorium dioxide, ferritin) are endocytosed by olfactory receptor endings and transported to the cell body, where their movement is halted in lysosomes. Higher concentrations (1%) of horseradish peroxidase penetrate olfactory receptor plasma membranes and intercellular junctions. In olfactory supporting cells, endocytosed tracers pass through endosomes to accumulate in dense basal vacuoles. These observations indicate that olfactory sensory membranes are rapidly cycled and that endocytosed materials are trapped within the epithelium. It is proposed that in the olfactory epithelium, endocytosis presents redundant odorants to the enzymes of the supporting cell AER to prevent their accumulation, whereas in the vomeronasal epithelium the receptor cells carry out this activity. © 1992 Wiley‐Liss, Inc.
Structures of grain boundaries in long‐chain te crystals observed by high‐resolution transmission electron microscopy
Authors: Isshiki Toshiyuki , Hirota Yoshihiro , Saijo Hiroshi , Shiojiri Makoto 
Published: February 2005

AbstractVacuum‐deposited Te crystals, composed of endless chains of the right‐handed or left‐handed spiral, have been investigated by high‐resolution electron microscopy with the aid of image simulation. A (010) grain boundary, which accompanies edge dislocations having an extra layer of the width of one Te chain, has been observed. A through‐focal series of images reveal that it is not a reflectional nor a rotational twin boundary but a small angle grain boundary in a single crystal or an inversion twin. The lattice on one side of the boundary is shifted from that on the other side by [001]c/3 + [120]a/8, and inclined at 1.1° around the c‐axis of the other side. Also found between crystallites of [100] and [011] orientation is a grain boundary which is built with the (011) facets on one side of the boundary and the (211) or (0,1,10) facets on another side. © 1992 Wiley‐Liss, Inc.
Effect of crystal and beam tilt on simulated high‐resolution TEM images of interfaces
Authors: Howe J. M. , Rozeveld S. J. 
Published: February 2005

AbstractThe effects of crystal and beam tilt on high‐resolution transmission electron microscope (HRTEM) images of planar coherent interfaces were investigated by multislice image simulations. It was found that a beam tilt of 0.5 Bragg angle (θB) was sufficient to introduce detrimental artifacts into most images of interfaces in crystals only 1/8ξ000 thick, while crystal tilt had a much smaller effect even for crystals 1ξ000 thick. Effects produced in HRTEM images of interfaces by crystal and beam tilt included the introduction of additional periodicities and loss of compositional detail across a boundary, translation of a boundary from its actual position, and apparent mismatch of atomic planes across a perfectly coherent interface. These results indicate that alignment of the electron beam parallel to the optic axis is critical for reliable HRTEM imaging of interfaces in materials. Techniques for obtaining accurate alignment are also discussed. © 1992 Wiley‐Liss, Inc.
Improved method for the preparation of TiN‐coated WC‐Co‐based samples for cross‐sectional AEM investigation
Authors: Hefter J. , Ostreicher K. , Sung C. 
Published: February 2005

AbstractAn improved method for the preparation of cross‐sectional thin foils of coated WC‐Co samples for studies by analytical electron microscopy is described. A braze alloy is used to join the sections of the sample together and the resulting sample is stable during subsequent grinding, dimpling, and milling operations. Cross‐sectional micrographs provide examples of the efficacy of this method. No microstructural alteration associated with the brazing operation was observed. © 1992 Wiley‐Liss, Inc.
Intracellular injection in fixed slices in combination with neuroanatomical tracing techniques and electron microscopy to determine multisynaptic pathways in the brain
Authors: Buhl Eberhard H. 
Published: February 2005

AbstractIntracellular Lucifer Yellow filling in fixed tissue has been recently introduced as a novel neuroanatomical approach to reveal the detailed morphology of individual neurons in isolated preparations of the central nervous system. Since dye injections are performed under visual control, the method is characterized by a high degree of inherent staining selectivity, thus circumventing the element of randomness often considered to be the crux of classical Golgi‐impregnation techniques. Moreover, the opportunity to optically monitor the injection procedure renders fixed slice preparations highly advantageous to be used in combination with retrograde fluorescent tracing. Subsequently, dye‐filled neurons may be subjected to a simple photoconversion procedure leading to the intracellular formation of a stable polymer thus obtaining permanent specimens for light microscopy purposes. Due to the osmiophilic nature of the precipitate the photoconverted material is equally suitable for correlated electron microscopy, thus enabling the analysis of neuronal microcircuitry. At the ultrastructural level, sources of afferent input to identified projection neurons may be revealed by lesion‐induced anterograde degeneration of synaptic terminals, therefore enabling the direct demonstration of multisynaptic links. Finally, morphologically identified neurons may be immunocytochemically characterized at the pre‐ and postembedding levels. It is therefore suggested that their methodological versatility and relative technical ease render intracellular fixed‐slice injections a promising complement to the catalogue of anatomical techniques. © 1993 Wiley‐Liss, Inc.
Electron microscopy of intracellularly labeled neurons in the hippocampal slice preparation
Authors: Kunkel Dennis D. , Scharfman Helen E. , Schmiege Donna L. , Schwartzkroin Philip A. 
Published: February 2005

AbstractWe have assessed the properties of three intracellular markers, horseradish peroxidase, biocytin/Neurobiotin, and Lucifer Yellow, and have compared their usefulness as neuronal markers for light and electron microscopic visualization. Neurons in the acute slice preparation of rat hippocampus were filled with one of these markers, and the marker was converted to an optical and electron‐dense reaction product. Dimethylsulfoxide (DMSO) greatly facilitated penetration of recognition reagents while preserving membrane integrity. The markers were compared with respect to injection parameters, mobility and recognition, stability and visibility, and ultrastructural clarity. Horseradish peroxidase (HRP)‐labeled neurons, recognized histochemically with diaminobenzedine (DAB), were easily visualized by the density of the DAB reaction product; however, the electron density was often so great as to obscure ultrastructural details. Biocytin (BC)‐/Neurobiotin (NB)‐labeled neurons were recognized by avidin‐HRP, followed by histochemical localization of HRP with DAB. The optically dense reaction product gave complete visualization of the soma and processes at the light microscopic level. The electron density was homogeneously distributed throughout the cell, so that ultrastructural features were easily identified. Lucifer Yellow (LY), a fluorescent marker, was converted to an optical and electron‐dense reaction product via immunocytochemical staining with a rabbit anti‐LY antibody, followed by goat anti‐rabbit IgG‐HRP and DAB histochemical localization. Similar to BC/NB, the reaction product was evenly dispersed, providing good light microscopic and ultrastructural clarity. Under our experimental conditions, BC/NB and LY were superior markers that could be used routinely to label neurons, and give excellent visualization not only at the light but also at the electron microscopic level. © 1993 Wiley‐Liss, Inc.
Molecular and cellular properties of mammalian primary olfactory axons
Authors: Mori Kensaku 
Published: February 2005

AbstractHow are the axonal projections of olfactory and vomeronasal receptor neurons to the olfactory bulb formed during development? How are the primary olfactory axonal connections functionally organized? With progress in molecular biological techniques and histochemical methods, it became possible to study cellular strategies and molecular mechanisms which guide the primary olfactory axons of the main and accessory olfactory systems to the target glomeruli in the bulb. In addition, new methodologies have begun to elucidate various subsets of the primary olfactory axons with distinctive central connections. The aim of the present paper is to review (1) the characteristic organization of the projection of the primary olfactory axons, (2) projection patterns of histochemically defined subsets of primary olfactory axons, and (3) information on molecules expressed by the surface membrane of the primary olfactory axons. This knowledge gives insight into the functional organization of the primary olfactory axon projection, which is indispensable for understanding signal processing in the olfactory system. This knowledge also underscores the notion that the primary olfactory axon projection provides an excellent model system in which to study axonal guidance and the formation of specific synaptic connections. © 1993 Wiley‐Liss, Inc.
Characterization of the suprachiasmatic nucleus in organotypic slice explant cultures
Authors: Wray S. , Castel M. , Gainer H. 
Published: February 2005

AbstractSuprachiasmatic nuclei (SCN) from hypothalami of postnatal rats were maintained for 18–39 days in vitro as organotypic slice explants. Neuronal subtypes containing vasopressin (VP), vasoactive intestinal polypeptide (VIP), gastrin releasing hormone (GRP), and GABA were immunocytochemically identifiable in these cultures. In situ hybridization histochemistry was compatible with these SCN slice explant cultures, and mRNA encoding for VP was detected bilaterally within these nuclei. After 18 days in vitro, both VP mRNA and VP immunoreactivity increased from levels present on postnatal days 4 (the earliest age from which the explanted tissue was derived) to levels typical of adult SCNs. In contrast, the GRP expression remained low, characteristic of early postnatal animals and far lower than adult levels. This suggests that the developmental cues or programs necessary for enhanced VP expression are maintained in these cultures, while those affecting GRP expression are absent or inhibited. VIP‐containing neurons were numerous in the cultures. Culture slices appeared healthy, and similar numbers and distributions of identifiable neurons within the SCN were observed, whether or not the slices were grown in the presence of serum. EM analysis revealed that the SCN in vitro is composed of tightly packed neurons, processes, and abundant synapses containing both clear and dense core vesicles, closely resembling the SCN in vivo. Vasopressinergic neuronal somata contained extensive Golgi systems and labeled secretory granules, the latter organelle being present also within processes and synaptic terminals. GABA‐immunopositive processes and synaptic profiles were abundant, with labeling occurring particularly over secretory vesicles and mitochondria. This slice culture system effectively maintained much of the intrinsic organization and cellular components of the SCN for long periods in vitro and should be an excellent model system for studying the intrinsic molecular mechanisms and extrinsic cues which regulate neuronal phenotype in this circadian pacemaker. Published 1993 Wiley‐Liss, Inc.
Granulated metrial gland cells: A natural killer cell subset of the pregnant murine uterus
Authors: Croy B. Anne , Kiso Yasuo 
Published: February 2005

AbstractThe metrial gland develops in the uterus of many rodent species during normal pregnancy. It is a maternally‐derived tissue that contains stromal and vascular elements plus a population of large cells, striking in their light microscopic appearance due to the presence of numerous cytoplasmic granules. These cells, which have become known in mice and rats as granulated metrial gland (GMG) cells, are derived from bone marrow precursors and recent work suggests they are a subset of lymphocytes belonging to the natural killer (NK) cell lineage. The functions of GMG cells during normal gestation have not been clearly defined. In vitro, GMG cells have been shown to produce cytokines and their cytokine profile is altered upon addition of medium containing the T cell growth factor interleukin‐2 (IL‐2). GMG cell granules contain the cytolytic protein perforin but GMG cells have a very limited capacity to kill in vitro unless they have been stimulated by IL‐2 or interferon‐gamma. Histological study of GMG cells has suggested they preferentially associate with fetal trophoblast. Since trophoblast appears resistant to immune lysis, except by IL‐2‐activated effector lymphocytes, and because resorbing murine embryos become infiltrated by lytic cells of the NK cell lineage, it is important to establish whether GMG cells are activated by pregnancy‐associated events to play a major lytic role in vivo. © 1993 Wiley‐Liss, Inc.
Controlled‐Depth and cross‐section preparation techniques for transmission electron microscopy subsurface studies in metals
Authors: Garcia‐Borquez A. , Kesternich W. 
Published: February 2005

AbstractThin film specimen preparation from bulk material at a controlled depth below the surface and cross‐section thin film preparation for transmission electron microscope investigations of electrically conducting materials are described. Both techniques are illustrated by austenitic stainless steel, where they have been used complementary to each other for microstructural studies of subsurface ion irradiation damage. The advantages and limitations of both techniques are discussed. © 1993 Wiley‐Liss, Inc.
Subcellular calcium localization in Toxoplasma gondii by electron microscopy and by X‐ray and electron energy loss spectroscopies
Authors: Bonhomme A. , Pingret L. , Bonhomme P. , Michel J. , Balossier G. , Lhotel M. , Pluot M. , Pinon J. M. 
Published: February 2005

AbstractThe localization of calcium in Toxoplasma gondii tachyzoites was studied at the ultrastructural level, with a cytochemical pyroantimonate precipitation method (PA) and controlled by EGTA chelating and EDX and EELS microanalyses. Appropriate conditions for material preparation, fixation and embedding, were defined. The proportion of precipitates that were either free or inside vacuoles and their distribution inside Toxoplasma appeared to be PA dose‐dependent. Precipitation mainly occurred in the anterior pole of the Epon‐embedded tachyzoites. EDX and EELS analyses showed that out of 30 PA precipitates inside tachyzoites, 78% contained Ca. In Melamine sections, 96% of the tachyzoites had intracellular precipitates and the membrane complex was stained; 25% of the tachyzoites inside host cells contained PA‐Ca precipitates, but most of them were retained in the reticular network of the parasitophorous vacuole. Melamine embedding appeared to improve the preservation of calcium pyroantimonate precipitates. © 1993 Wiley‐Liss, Inc.
High‐resolution transmission electron microscopy of hexagonal and rhombohedral molybdenum disulfide crystals
Authors: Isshiki Toshiyuki , Nishio Koji , Saijo Hiroshi , Shiojiri Makoto , Yabuuchi Yasufumi , Takahashi Noboru 
Published: February 2005

AbstractNatural (molybdenite) and synthesized molybdenum disulfide crystals have been studied by high‐resolution transmission electron microscopy. The image simulation demonstrates that the [0001] and [0110] HRTEM images of hexagonal and rhombohedral MoS2 crystals hardly disclose their stacking sequences, and that the [2110] images can distinguish the Mo and S columns along the incident electron beam and enable one to determine not only the crystal structure but also the fault structure. Observed [0001] images of cleaved molybdenite and synthesized MoS2 crystals, however, reveal the strain field around partial dislocations limiting an extended dislocation. A cross‐sectional image of a single molecular (S‐Mo‐S) layer cleaved from molybdenite has been observed. Synthesized MoS2 flakes which were prepared by grinding have been found to be rhombohedral crystals containing many stacking faults caused by glides between S/S layers. © 1993 Wiley‐Liss, Inc.
Effects of four different processing techniques on the microstructure of potatoes: Comparison with fresh samples in the ESEM
Authors: Uwins Philippa J. R. , Murray Margaret , Gould Robert J. 
Published: February 2005

AbstractFour common scanning electron microscope (SEM) processing techniques involving freeze‐substitution and chemical fixation were compared with fresh unprocessed samples imaged in an environmental scanning electron microscope (ESEM) using small pieces of potato tubers as test specimens. Potato tubers were chosen for this investigation because of their high moisture content and, consequently, the common need for extensive processing for conventional, high vacuum SEM imaging. ESEM results showed that the fresh unprocessed specimens were essentially unaltered, showing clear potato cell structure, morphology, and cell content. However, processed samples showed strong differences to the fresh samples: freeze‐substituted specimens showed fine networks of material stretching across the surface of cells. These structures may represent fibrillar material or may be artifact caused during processing. Chemical fixation almost entirely destroyed the microstructure of these potato samples. © 1993 Wiley‐Liss, Inc.
Using ESEM and SEM to compare the performance of dentin conditioners
Authors: Gilbert Lynn C. , Doherty Robert E. 
Published: February 2005

AbstractA comparison of four dentinal conditioners was performed utilizing a traditional scanning electron microscope (SEM) and a new technology, the ElectroScan™ environmental scanning electron microscope (ESEM). Both ESEM and SEM analysis verified current theorized mechanisms of adhesion to dentin surfaces. ESEM images appeared to more closely approximate what one would expect cut and treated dentin surfaces look like. Increases in information from the “surfaces” of uncoated specimens and the reduction in specimen preparation time were associated with ESEM analysis. © 1993 Wiley‐Liss, Inc.
Application of environmental scanning electron microscopy in the development of detergents and personal products
Authors: Hoyberg Karen , Kruza Kenneth G. 
Published: February 2005

AbstractEnvironmental scanning electron microscopy enables the observation of samples in their natural state with no preparation. Unilever Research employs this technology in the research and development of detergents and personal products with much success. The results presented are from various studies which demonstrate the versatility and utility of the technique. Vacuum sensitive samples such as microcapsules were successfully characterized, the efficacy of dental products was shown by monitoring an enamel surface before and after treatment, and the performance of an adhesive was assessed by dynamic experimentation. © 1993 Wiley‐Liss, Inc.
Imaging fluid/solid interactions in hydrocarbon reservoir rocks
Authors: Uwins Philippa J. R. , Baker Julian C. , Mackinnon Ian D. R. 
Published: February 2005

AbstractThe environmental scanning electron microscope (ESEM) has been used to image liquid hydrocarbons in sandstones and oil shales. Additionally, the fluid sensitivity of selected clay minerals in hydrocarbon reservoirs was assessed via three case studies: HCl acid sensitivity of authigenic chlorite in sandstone reservoirs, freshwater sensitivity of authigenic illite/smectite in sandstone reservoirs, and bleach sensitivity of a volcanic reservoir containing abundant secondary chlorite/corrensite. The results showed the suitability of using ESEM for imaging liquid hydrocarbon films in hydrocarbon reservoirs and the importance of simulating in situ fluid‐rock interactions for hydrocarbon production programmes. In each case, results of the ESEM studies greatly enhanced prediction of reservoir/borehole reactions and, in some cases, contradicted conventional wisdom regarding the outcome of potential engineering solutions. © 1993 Wiley‐Liss, Inc.
Environmental scanning electron microscopy for dynamic corrosion studies of stainless steel piping used in UHP gas distribution systems
Authors: Gerristead W. R. , Link L. F. , Paciej R. C. , Damiani P. , Li H. 
Published: February 2005

AbstractAn ElectroScan ESEM was used for in situ corrosion studies on cold drawn electropolished 316L stainless steel tube surfaces in the as‐received and passivated conditions. Corrosion product was removed as it formed and the tube surface was viewed before, during, and after corrosive attack. The corrosion process was followed in situ, and the sample features most susceptible to corrosion (draw lines, inclusions, etc.) were identified. In addition, X‐ray photoelectron spectroscopy (XPS) was used to study the changes in surface chemistry after corrosive attack. This information provided clear evidence of relevant corrosion mechanisms and relative corrosion susceptibility. © 1993 Wiley‐Liss, Inc.