scholarly journals Microscopical characterization of the salivary glands of the carnivorous cephalaspidean Philinopsis depicta (Mollusca, Opisthobranchia)

2009 ◽  
Vol 15 (S3) ◽  
pp. 39-40
Author(s):  
A. Lobo-da-Cunha ◽  
I. Ferreira ◽  
G. Calado
Keyword(s):  
Salivary Glands ◽  
Secretory Cells ◽  
Apical Region ◽  
Ciliated Cells ◽  
Transmission Electron ◽  
Herbivorous Species ◽  
Small Clusters ◽  
The Relationship ◽  
Apical Vacuole

AbstractCephalaspideans are a group of opisthobranch gastropods comprising carnivorous and herbivorous species, allowing an investigation of the relationship between these diets and the morphofunctional features of the salivary glands.In this study, the salivary glands of the carnivorous cephalaspidean Philinopsis depicta were observed by light microscopy using semithin sections and by transmission electron microscopy. A central duct runs along the length of these thin ribbon-shaped glands dividing them in two halves, each formed by a single row of tubules perpendicularly attached to the central duct. The simple epithelium of the central duct and lateral tubes contains ciliated cells and two types of secretory cells, named granular cells and cells with apical vacuole (Fig. 1). A very thin outer layer of connective tissue covers the epithelium (Fig. 1). The ciliated cells are numerous but very thin, forming small clusters between secretory cells. The nucleus, several mitochondria and a few lysosomes are located in the apical region were the cells are wider. A very thin cytoplasmic stalk reaches the base of the epithelium and contains bundles of filaments in addition to some mitochondria.

Cephalic salivary gland ultrastructure of worker and queen eusocial bees (Hymenoptera, Apidae)

2009 ◽  
Vol 59 (3) ◽  
pp. 299-311 ◽  
Author(s):  
Carminda da Cruz-Landim ◽  
Silvana Beani Poiani
Keyword(s):  
Salivary Glands ◽  
Smooth Endoplasmic Reticulum ◽  
Secretory Cells ◽  
Apical Region ◽  
Transmission Electron ◽  
Basal Plasma ◽  
Eusocial Bees ◽  
Scaptotrigona Postica ◽  
Microscopy Techniques

AbstractEusocial bees present a pair of functional salivary glands in head, the cephalic salivary glands. These glands from workers and queens of two eusocial bee species, Apis mellifera and Scaptotrigona postica, were examined at different life stages using routine transmission electron microscopy techniques to correlate morphology and gland functions. Ultrastructural features of worker and queen glands ducts and secretory units were descriptively compared between species. The duct cells present basal plasma membrane invaginations reaching the apical region. Intercellular space and invaginations contain material of similar electron-density to the basal lamina, suggesting that substances might be directly absorbed from the hemolymph to the gland lumen. The secretory cells are rich in smooth endoplasmic reticulum, mitochondria, Golgi, and vesicles typical of lipid secretion. Secretory cells in S. postica become flattened with age in contrast to A. mellifera, where cells remained cuboidal. Mitochondria are associated with secretory vesicles and may become lipid deposits. A possible role of worker and queen secretion is discussed, taking changes in caste gland morphology and their function in the colony into account.

Scanning and Transmission Electron Microscopy of the Endometrium in Women with Ovarian Dysgenesis (Turner'S Syndrome)

1976 ◽  
Vol 34 ◽  
pp. 148-149
Author(s):  
A. González-Angulo ◽  
S. Armendares-Sagrera ◽  
I. Ruíz de Chávez ◽  
H. Marquez-Monter ◽  
R. Aznar
Keyword(s):  
Surface Epithelium ◽  
Secretory Cells ◽  
Turner's Syndrome ◽  
Ciliated Cells ◽  
Turner’S Syndrome ◽  
Exogenous Hormone ◽  
Ovarian Dysgenesis ◽  
Transmission Electron ◽  
Normal Women ◽  
Microscopy Examination

It is a well documented fact that endometrial hyperplasia and adenocarcinoma may develop in women with Turner's syndrome who had received unopposed estrogen treatment (1), as well as in normal women under contraceptive medication with the sequential regime (2). The purpose of the present study was to characterize the possible changes in surface and glandular epithelium in these women who were treated with a sequential regime for a period of between three and eight years. The aim was to find organelle modifications which may lead to the understanding of the biology of an endometrium under exogenous hormone stimulation. Light microscopy examination of endometrial biopsies of nine patients disclosed a proliferative pattern; in two of these, there was focal hyperplasia. With the scanning electron microscope the surface epithelium in all biopsies showed secretory cells with microvilli alternating with non secretory ciliated cells. Regardless of the day of the cycle all biopsies disclosed a large number of secretory cells rich in microvilli (fig.l) with long and slender projections some of which were branching (fig. 2).

Regenerated Middle Ear Mucosa after Tympanoplasty. Part I. Transmission Electron Microscopy

1986 ◽  
Vol 94 (3) ◽  
pp. 339-343 ◽  
Author(s):  
Roberto Gamoletti ◽  
Paola Poggi ◽  
Mario Sanna ◽  
Carlo Zini
Keyword(s):  
Electron Microscopy ◽  
Middle Ear ◽  
Goblet Cells ◽  
Secretory Cells ◽  
Canal Wall ◽  
Ciliated Cells ◽  
Middle Ear Mucosa ◽  
Morphologic Characteristics ◽  
Transmission Electron ◽  
Ultrastructural Appearance

The ultrastructural appearance of the regenerated middle ear mucosa—found at the second operation of staged intact canal wall tympanoplasty (ICWT) with mastoidectomy—has been evaluated with the transmission electron microscope. The regenerated epithelium showed all the morphologic characteristics of the normal middle ear mucosa: ciliated cells, noncillated cells, and secretory cells. All of these (Including goblet cells) have been found in the specimens. It is concluded that a normal middle ear mucosa regenerates to cover all denuded bone surfaces after the first operation of staged ICWT with mastoidectomy, when silicone rubber sheeting has been used to prevent adhesions and maintain an air-containing middle ear space.

Histochemical and Ultrastructural Characterization of the Posterior Esophagus of Bulla striata (Mollusca, Opisthobranchia)

2010 ◽  
Vol 16 (6) ◽  
pp. 688-698 ◽  
Author(s):  
Alexandre Lobo-da-Cunha ◽  
Elsa Oliveira ◽  
Íris Ferreira ◽  
Rita Coelho ◽  
Gonçalo Calado
Keyword(s):  
Digestive System ◽  
Light And Electron Microscopy ◽  
Secretory Cells ◽  
Secretory Vesicles ◽  
Ultrastructural Characterization ◽  
Herbivorous Species ◽  
Columnar Cells ◽  
Electron Lucent ◽  
Dense Vesicles

AbstractThe posterior esophagus of Bulla striata, running from the gizzard to the stomach, was investigated with light and electron microscopy to obtain new data for a comparative analysis of the digestive system in cephalaspidean opisthobranchs. In this species, the posterior esophagus can be divided into two regions. In the first, the epithelium is formed by columnar cells with apical microvilli embedded in a cuticle. Many epithelial and subepithelial secretory cells are present in this region. In both, electron-lucent secretory vesicles containing filaments and a peripheral round mass of secretory material fill the cytoplasm. These acid mucus-secreting cells may also contain a few dense secretory vesicles. In the second part of the posterior esophagus, the cuticle is absent and the epithelium is ciliated. In this region, epithelial cells may contain larger lipid droplets and glycogen reserves. Subepithelial secretory cells are not present, and in epithelial secretory cells the number of dense vesicles increases, but most secretory cells still contain some electron-lucent vesicles. These cells secrete a mixture of proteins and acid polysaccharides and should be considered seromucous. The secretory cells of the posterior esophagus are significantly different from those previously reported in the anterior esophagus of this herbivorous species.

TEM Characterization of 2º Tilt Grain Boundary in Alumina

2007 ◽  
Vol 561-565 ◽  
pp. 2427-2430 ◽  
Author(s):  
E. Tochigi ◽  
Naoya Shibata ◽  
Atsutomo Nakamura ◽  
Takahisa Yamamoto ◽  
Yuichi Ikuhara
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Boundary ◽  
Separation Distance ◽  
Stacking Fault ◽  
Tem Characterization ◽  
Transmission Electron ◽  
Tilt Grain Boundary ◽  
The Relationship

Dislocation structure of {1120}/<1100> 2º tilt grain boundary in alumina was observed by transmission electron microscopy (TEM). The grain boundary consisted of periodical array of basal dislocations, which were dissociated into pairs of 1/3<1010> and 1/3<0110> partials with {1120} stacking-fault in between. The relationship between the separation distance of partials and the stacking-fault was modeled by considering the force balances of periodical dislocations. The estimated stacking-fault energy for 2o tilt grain boundary was consistent with the previous reports.

scholarly journals Synthesis and Characterization of Molybdenum Disulfide Nanoflowers and Nanosheets: Nanotribology

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
S. V. Prabhakar Vattikuti ◽  
Chan Byon
Keyword(s):  
Electron Microscopy ◽  
Tribological Performance ◽  
Wear Scar ◽  
Engine Oil ◽  
Sulfur Source ◽  
X Ray Diffraction ◽  
Interface Surface ◽  
Transmission Electron ◽  
The Relationship

This paper reports the solvothermal synthesis of MoS2nanoflowers and nanosheets. The nanoflowers have a mean diameter of about 100 nm and were obtained using thioacetamide (C2H5NS) as a sulfur source. The few layered nanosheets were obtained using thiourea (CH4N2S) as a sulfur source. The obtained powders were characterized using powder X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The lubricating effect of MoS2nanoflowers and nanosheets were analyzed using four-ball test, the topography of the wear scar was analyzed using SEM, EDS, and 3D surface profilometry. The relationship between the tribological properties and morphology of the materials was determined. It is observed that the engine oil containing the MoS2nanomaterials penetrated more easily into the interface space, and it formed a continuous film on the interface surface. The tribological performance showed that the synthesized nanosheets had superior antiwear and friction-reducing properties as a lubrication additive compared with nanoflowers. Also, the wear scar of balls lubricated with nanoflowers revealed a larger diameter compared to nanosheets. In conclusion, nanosheets dispensed in oil have better tribological performance compared to nanoflowers oil in terms of capability to reduce friction.

scholarly journals Immuno-Ultrastructural Localization and Putative Multiplication Sites of Huanglongbing Bacterium in Asian Citrus Psyllid Diaphorina citri

Insects ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 422 ◽  
Author(s):  
El-Desouky Ammar ◽  
Diann Achor ◽  
Amit Levy
Keyword(s):  
Salivary Glands ◽  
Close Association ◽  
Ultrastructural Localization ◽  
Ultrastructural Level ◽  
Malpighian Tubules ◽  
Secretory Cells ◽  
Asian Citrus Psyllid ◽  
Bacterial Cells ◽  
Transmission Electron ◽  
Candidatus Liberibacter

Huanglongbing, the most destructive citrus disease worldwide, is caused by the bacterium ‘Candidatus Liberibacter asiaticus’ (CLas) and is vectored by the Asian citrus psyllid (ACP). Very little is known about the form and distribution of CLas in infected psyllids, especially at the ultrastructural level. Here, we examined these aspects by transmission electron microscopy, combined with immunogold labeling. In CLas-exposed ACP adults, the CLas bacterial cells were found to be pleomorphic taking tubular, spherical, or flask-shaped forms, some of which seemed to divide further. Small or large aggregates of CLas were found in vacuolated cytoplasmic pockets of most ACP organs and tissues examined, including the midgut, filter chamber, hindgut, Malpighian tubules, and secretory cells of the salivary glands, in addition to fat tissues, epidermis, muscle, hemocytes, neural tissues, bacteriome, and walls of the female spermatheca and oviduct. Large aggregates of CLas were found outside the midgut within the filter chamber and between the sublayers of the basal lamina of the hindgut and Malpighian tubules. Novel intracytoplasmic structures that we hypothesized as ‘putative CLas multiplication sites’ were found in the cells of the midgut, salivary glands, and other tissues in CLas-exposed ACP. These structures, characterized by containing a granular matrix and closely packed bacterial cells, were unbound by membranes and were frequently associated with rough endoplasmic reticulum. Our results point to the close association between CLas and its psyllid vector, and provide support for a circulative-propagative mode of transmission.

Characterization of the parameters relating adjacent grains using transmission electron microscopy

2010 ◽  
Vol 43 (6) ◽  
pp. 1495-1501 ◽  
Author(s):  
H. W. Jeong ◽  
S. M. Seo ◽  
H. U. Hong ◽  
Y. S. Yoo
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Coincident Site Lattice ◽  
Cubic Crystal ◽  
Kikuchi Pattern ◽  
Orthogonal Relationship ◽  
Transmission Electron ◽  
Angle Of Deviation ◽  
The Relationship

A simple technique is presented for characterizing parameters such as the misorientation angle and the axis of rotation between two adjacent grains using transmission electron microscopy (TEM), without the need for an image of the Kikuchi pattern. The technique described makes use of the orthogonal relationship between the tilt axes used in TEM and the axes of the cubic crystal. The relationship was established using the well known triangulation method, in which the direction of the crystal parallel to the beam direction is determined from the measured tilt angles of the three zone axes. The error in measuring the tilt angles of the three zone axes can be evaluated by comparing the measured and crystallographic angles. The angle of deviation from the coincident site lattice (CSL) that results from the measurement error could be reduced by establishing the modified orthogonal relationship between the tilt and crystal axes. The use of this method could provide accurate measurement in real time for indexing a CSL boundary using TEM.

Defects in High Tc Cuprate Superconductors

MRS Bulletin ◽  
1991 ◽  
Vol 16 (11) ◽  
pp. 54-59 ◽  
Author(s):  
Yimei Zhu ◽  
J. Tafto ◽  
M. Suenaga
Keyword(s):  
Cuprate Superconductors ◽  
Oxide Superconductors ◽  
Layered Oxides ◽  
High Tc ◽  
Transmission Electron ◽  
Microstructural Defects ◽  
Current Densities ◽  
The Many ◽  
The Relationship

Characterization of microstructural defects in high critical temperature oxide superconductors has been very valuable in gaining an understanding of their phase transformations and insight into the relationship between defects and some superconducting properties such as critical current densities Jc. For this purpose, transmission electron microscopy (TEM) techniques have been proved powerful. In this article we will briefly summarize typical defects in the perovskite-based layered oxides, i.e., [La(1−x)(Ba,Sr)x]2CuO4, YBa2Cu3O7−δ, and (Bi,Pb)2Sr2Can−1Cun−O4+2n+δ. Then we will discuss the nature of defects in YBa2Cu3O7−δ in detail since this oxide has been most extensively studied. Among the many varieties of microstructural defects in YBa2Cu3O7−δ, we will emphasize only those we consider most important. An account of the field before 1990 is given in an excellent review by Beyers and Shaw and a more recent review of the structure of the grain boundaries in YBa2Cu3O7−δ by Babcock.Since the types and the nature of the defects depend greatly on the crystal structure of the materials, the basic structures of the three oxides are shown in Figures la to 1c: (a) [La1−x(Sr,Ba)x]2CuO4, (2:1:4), (b) YBa2Cu3O7 (1:2:3:), and (c) Bi2Sr2CaCu2O8 (2:2:1:2). (The structure of Tl cuprates are very similar to the Bicuprate and will not be discussed here.)

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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