scholarly journals THE BI-SUBSTITUTED HYDROXYAPATITE AS RADIO-OPAQUE MATERIAL

2016 ◽  
Author(s):  
Gabriela Ciobanu ◽  
Ana Maria Bargan ◽  
Constantin Luca ◽  
Octavian Ciobanu
Keyword(s):  
Opaque Material

scholarly journals EFFECT OF THE RUBY LASER MICROBEAM ON MITOCHONDRIA OF KB CELLS SUPRAVITALLY STAINED BY PINACYANOL

1969 ◽  
Vol 41 (2) ◽  
pp. 424-430 ◽  
Author(s):  
Yasukazu Tanaka
Keyword(s):  
Laser Beam ◽  
Ruby Laser ◽  
Focal Length ◽  
Direct Interaction ◽  
Experimental System ◽  
Spot Size ◽  
Kb Cells ◽  
Focal Spot Size ◽  
Laser Microbeam ◽  
Opaque Material

With pinacyanol as the supravital stain, a preferential effect on mitochondria of KB cells was achieved by the irradiation with the ruby laser beam. The observation confirmed the results of other workers using janus green B in the same experimental system. The preferential effect on mitochondria was noted in the area extending 8–10 µ beyond the nonpreferential damage of 4–5 µ in diameter. The opaque material associated with mitochondria possibly represented coagulated protein. The effect involved cristae mitochondriales without severe disarrangement of their structure. The opaque material could be interpreted as the result of direct interaction between mitochondria and the laser beam, even though the mitochondria were noted outside of the previously estimated focal spot size of about 3 µ Within the thickness of 2–4 µ of monolayered cells, larger areas of damage can be accounted for by divergence of the beam which is focused by a microscope objective of very short focal length. A threshold of biologic effectiveness is probably also involved.

scholarly journals Some Points in the Diagnosis of Stone by X-Rays

1935 ◽  
Vol 28 (7) ◽  
pp. 909-923
Author(s):  
C. A. Wells
Keyword(s):  
Urinary Tract ◽  
Surgical Treatment ◽  
X Rays ◽  
Characteristic Shape ◽  
Positive Diagnosis ◽  
Opaque Material ◽  
Operative Removal ◽  
And Function

The investigation of cases suspected of stone is concerned with (1) those in which a shadow is visible and (2) those in which X-rays throw no shadow. In the former group the nature of the shadow must be determined. If a stone, it must be accurately placed in the urinary tract and the anatomy and function of the affected and unaffected parts of the tract must be determined. A stone may be recognized by the characteristic shape to which it grows in the pelvis, in a calyx or in the ureter. In the earlier stages, or when the shape of the shadow is not characteristic, radiograms may be made on inspiration and expiration. In orthopædic and other cases immobilized for long periods interesting calculi may form and may subsequently be disintegrated and passed, or may require surgical treatment. For stones in the kidney and upper ureter pyelography by the descending route is ideal. For infected stones the retrograde route is preferable. For small ureteric stones an opaque catheter is best. Non-opaque stones are of real surgical significance. It is essential to make a positive diagnosis in a case of suspected stone, even if operation is not required. Furthermore, non-opaque stones are sometimes sufficiently large to demand operative removal. The presence of these stones can be inferred from descending pyelograms, and the stones themselves can be displayed by means of the opaque material they pick up in the course of a descending pyelography.

scholarly journals Ultrastructure of the Infection of Sorghum bicolor by Colletotrichum sublineolum

2001 ◽  
Vol 91 (2) ◽  
pp. 149-158 ◽  
Author(s):  
P. S. Wharton ◽  
A. M. Julian ◽  
R. J. O'Connell
Keyword(s):  
Cell Wall ◽  
Sorghum Bicolor ◽  
Epidermal Cells ◽  
Host Cells ◽  
Wall Thickening ◽  
Fungal Cell ◽  
Resistant Cultivars ◽  
Ultrastructural Studies ◽  
Opaque Material ◽  
Colletotrichum Sublineolum

Ultrastructural studies of the infection of susceptible and resistant cultivars of Sorghum bicolor by Colletotrichum sublineolum were conducted. Initial penetration events were the same on both susceptible and resistant cultivars. Germ tubes originating from germinated conidia formed globose, melanized appressoria, that penetrated host epidermal cells directly. Appressoria did not produce appressorial cones, but each penetration pore was surrounded by an annular wall thickening. Inward deformation of the cuticle and localized changes in staining properties of the host cell wall around the infection peg suggests that penetration involves both mechanical force and enzymic dissolution. In compatible interactions, penetration was followed by formation of biotrophic globular infection vesicles in epidermal cells. Filamentous primary hyphae developed from the vesicles and went on to colonize many other host cells as an intracellular mycelium. Host cells initially survived penetration. The host plasma membrane invaginated around infection vesicles and primary hyphae and was appressed tightly to the fungal cell wall, with no detectable matrix layer at the interface. Necrotrophic secondary hyphae appeared after 66 h and ramified through host tissue both intercellularly and intracellularly, forming hypostromatic acervuli by 114 h. Production of secondary hyphae was accompanied by the appearance of electron-opaque material within infected cells. This was thought to represent the host phytoalexin response. In incompatible interactions, infection vesicles and primary hyphae were formed in epidermal cells by 42 h. However, they were encrusted with electron-opaque material and appeared dead. These observations are discussed in relation to the infection processes of other Colletotrichum spp. and the host phytoalexin response.

scholarly journals Microfossils from the Lower Devonian Rhynie Chert with suggested affinities to the peronosporomycetes

2012 ◽  
Vol 86 (2) ◽  
pp. 358-367 ◽  
Author(s):  
Michael Krings ◽  
Thomas N. Taylor ◽  
Edith L. Taylor ◽  
Hans Kerp ◽  
Hagen Hass ◽  
...  
Keyword(s):  
Lower Devonian ◽  
Microbial Mats ◽  
Plant Litter ◽  
Microbial Life ◽  
Opaque Material ◽  
New Information ◽  
Single Form ◽  
Rhynie Chert ◽  
Thin Walled ◽  
Size And Morphology

A conspicuous silicified microfossil, Frankbaronia polyspora n. gen. n. sp., occurs in plant litter and as an inhabitant of microbial mats from the Lower Devonian Rhynie chert, Aberdeenshire, Scotland. Specimens are elongate-cylindrical, oval, or spherical, thin-walled, and may possess conical or column-like surface projections. Most specimens occur isolated, some are arranged in pairs or short chains. Each specimen contains several small spheres, each in turn with a (sub)centric opaque inclusion. Immature specimens indicate that ontogenesis in this fossil includes the formation of a single centric body of opaque material that subsequently is apportioned among the developing small spheres. Frankbaronia polyspora is quite similar in size and morphology to the oogonia containing oospores seen in certain extant members of the Peronosporomycetes. The Rhynie chert is known to contain the oldest fossil evidence of the Peronosporomycetes but only a single form (Hassiella monospora) has previously been documented. The discovery of a second putative representative of this group of organisms proves that this paleoecosystem is still an important source of new information on the paleodiversity of microbial life.

scholarly journals GIANT CENTRIOLE FORMATION IN SCIARA

1967 ◽  
Vol 33 (1) ◽  
pp. 73-92 ◽  
Author(s):  
David M. Phillips
Keyword(s):  
Mitotic Spindle ◽  
Daughter Cell ◽  
Germ Line ◽  
Tissue Type ◽  
Characteristic Morphology ◽  
Opaque Material ◽  
Stage Of Development ◽  
Spindle Axis ◽  
Somatic Tissues ◽  
Daughter Centriole

Although somatic tissues of Sciara contain 9-membered centrioles, germ line tissues develop giant centrioles with 60–90 singlet tubules disposed in an oval array. Some 9-membered centrioles still may be seen in second instar spermatogonia. Each of these centrioles is associated with a larger "daughter" or secondary centriole at right angles to it. Most centrioles of second instar spermatogonia consist of 20–50 singlet tubules arranged in an oval, sometimes associated with an even larger secondary centriole. The more recently formed centriole of a pair is distinguishable from its partner by a concentric band of electron-opaque material inside its tubules. If a pair of centrioles at right angles to each other is pictured as a "T" formed by two cylinders, the secondary centriole is always the stem of the T; the primary centriole is the top. The two centrioles are oriented at the pole of the mitotic spindle so that the tubules of the primary centriole are parallel to the spindle axis. Each daughter cell receives a pair of centrioles and, during interphase, each of these centrioles gives rise to a new daughter centriole. A Golgi area of characteristic morphology is found in association with centrioles shortly after two new ones have formed. We conclude that in Sciara a centriole may give rise to a daughter morphologically different from itself. Whether the daughter is a 9-membered or giant centriole depends on the tissue type and stage of development.

scholarly journals Searching for minor absorptions on D-type asteroids

2009 ◽  
Vol 5 (S263) ◽  
pp. 231-236
Author(s):  
Thais Mothé-Diniz
Keyword(s):  
Heliocentric Distance ◽  
Asteroid Belt ◽  
Main Belt ◽  
Origin And Evolution ◽  
Opaque Material ◽  
Visible Spectra ◽  
Surface Mineralogy

AbstractPreferably located in the outer main belt, D-type asteroids experienced less heating and represent an important population for studies on the origin and evolution of the asteroid belt, as well as the relations between asteroidal and cometary bodies. Their surface mineralogy is currently related to a mixture of organics, anhydrous silicates, opaque material and ice. However, like other taxonomic classes, a large spectral diversity can be seen among D-type objects. We use the Visible spectra of 100 D-type objects available in the literature to search for minor absorptions in those objects. The presence of minor absorptions around 0.6 and 0.8 microns is reported for a large number of objects in the sample. The presence of such bands is not related to the heliocentric distance of the objects, since the absorptions can be seen in the whole main belt, up to the the Trojans region.

scholarly journals Indefinite article + possessive + noun in Spanish: A case of refunctionalization?

Languages ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 44
Author(s):  
Enrique Pato
Keyword(s):  
Central American ◽  
Indefinite Article ◽  
Opaque Material ◽  
Grammatical Construction ◽  
American Spanish ◽  
Grammatical Change

The phenomenon under discussion is an example of a grammatical change that can be explained by refunctionalization, and as such, can be understood as the acquisition of a new meaning by an ‘endangered’ grammatical construction, which is reassigned to express another value. Refunctionalization involves the development of a new function (in this case a syntactic-semantic one). When an item loses its function, or is marginal within a system, it can be lost (as happens with the construction under study in Standard Spanish), it can be ‘saved’ as a marginal element (as in some areas of American Spanish varieties) or it can be reused for other purposes (as in the Central American Spanish varieties). The latter case presents new discursive values. Hence, this construction should be understood as an example of reusing grammatical functionally opaque material for new purposes.

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