Fine structure of the bands in the low-temperature spectra of sodium uranyl acetate

Spectra in the O-H stretching region of some mono- and oligosaccharides have been obtained at low temperatures. Bands in the low-temperature spectra were found to be sharper and better resolved, and some bands were revealed which were not apparent at room temperature. Spectra have also been obtained in both the O-H and O-D stretching regions of partly deuterated samples of two glycosides and an oligosaccharide. From these it has been shown that the fine structure in the O-H stretching region of the spectra of these compounds arises from coupled vibrations rather than from separate vibrations of individual groups. This coupling is probably the underlying reason for the large widths of bands in this region of the spectrum of carbohydrates.

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Ultrastructure and Staining of Developing Elastic Tissue

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065274 ◽

1971 ◽

Vol 29 ◽

pp. 244-245

Author(s):

E. N. Albert

Keyword(s):

Fine Structure ◽

Phosphotungstic Acid ◽

Staining Method ◽

Rat Aorta ◽

Uranyl Acetate ◽

The Other ◽

Elastic Fibers ◽

Elastic Tissue ◽

Lead Citrate ◽

New Born

Silver tetraphenylporphine sulfonate (Ag-TPPS) was synthesized in this laboratory and used as an electron dense stain for elastic tissue (Fig 1). The procedures for the synthesis of tetraphenylporphine sulfonate and the staining method for mature elastic tissue have been described previously.The fine structure of developing elastic tissue was observed in fetal and new born rat aorta using tetraphenylporphine sulfonate, phosphotungstic acid, uranyl acetate and lead citrate. The newly forming elastica consisted of two morphologically distinct components. These were a central amorphous and a peripheral fibrous. The ratio of the central amorphous and the peripheral fibrillar portion changed in favor of the former with increasing age.It was also observed that the staining properties of the two components were entirely different. The peripheral fibrous component stained with uranyl acetate and/or lead citrate while the central amorphous portion demonstrated no affinity for these stains. On the other hand, the central amorphous portion of developing elastic fibers stained vigorously with silver tetraphenylporphine sulfonate, while the fibrillar part did not (compare figs 2, 3, 4). Based upon the above observations it is proposed that developing elastica consists of two components that are morphologically and chemically different.

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Fine Structure of Interdental Cells in the Mouse Cochlea

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100067698 ◽

1970 ◽

Vol 28 ◽

pp. 140-141

Author(s):

Roberta M. Bruck

Keyword(s):

Fine Structure ◽

Electron Microscope ◽

Young Adult ◽

Uranyl Acetate ◽

Ground Substance ◽

Tectorial Membrane ◽

Lead Citrate ◽

Unusual Structure ◽

Thin Sections ◽

Collagenous Fibers

An unusual structure in the cochlea is the spiral limbus; this periosteal tissue consists of stellate fibroblasts and collagenous fibers embedded in a translucent ground substance. The collagenous fibers are arranged in vertical columns (the auditory teeth of Haschke). Between the auditory teeth are interdental furrows in which the interdental cells are situated. These epithelial cells supposedly secrete the tectorial membrane.The fine structure of interdental cells in the rat was reported by Iurato (1962). Since the mouse appears to be different, a description of the fine structure of mouse interdental cells' is presented. Young adult C57BL/6J mice were perfused intervascularly with 1% paraformaldehyde/ 1.25% glutaraldehyde in .1M phosphate buffer (pH7.2-7.4). Intact cochlea were decalcified in .1M EDTA by the method of Baird (1967), postosmicated, dehydrated, and embedded in Araldite. Thin sections stained with uranyl acetate and lead citrate were examined in a Phillips EM-200 electron microscope.

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Fine Structure of Carotid Body: Normal and Anoxic Cats

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100060763 ◽

1967 ◽

Vol 25 ◽

pp. 150-151

Author(s):

Fadhil Al-Lami ◽

R.G. Murray

Keyword(s):

Fine Structure ◽

Adrenal Medulla ◽

Carotid Body ◽

Uranyl Acetate ◽

Lead Citrate ◽

Glomus Cells ◽

Sustentacular Cells ◽

Carotid Bodies

Although the fine structure of the carotid body has been described in several recent reports, uncertainties remain, and the morphological effects of anoxia on the carotid body cells of the cat have never been reported. We have, therefore, studied the fine structure of the carotid body both in normal and severely anoxic cats, and to test the specificity of the effects, have compared them with the effects on adrenal medulla, kidney, and liver of the same animals. Carotid bodies of 50 normal and 15 severely anoxic cats (9% oxygen in nitrogen) were studied. Glutaraldehyde followed by OsO4 fixations, Epon 812 embedding, and uranyl acetate and lead citrate staining, were the technics employed.We have called the two types of glomus cells enclosed and enclosing cells. They correspond to those previously designated as chemoreceptor and sustentacular cells respectively (1). The enclosed cells forming the vast majority, are irregular in shape with many processes and occasional peripheral densities (Fig. 1).

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High-resolution SEM and STEM of adrenocortical endothelium: Molecular resolution of membrane complexes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100148885 ◽

1993 ◽

Vol 51 ◽

pp. 610-611

Author(s):

Robert P. Apkarian

Keyword(s):

Fine Structure ◽

Low Voltage ◽

Uranyl Acetate ◽

Correlative Microscopy ◽

Coated Pits ◽

Fine Grain ◽

Structural Identity ◽

Cellular Pathways ◽

Steroidogenic Cells ◽

Cr Film

A multitude of complex ultrastructural features are involved in endothelial cell (EC) gating and sorting of lipid through capillaries and into steroidogenic cells of the adrenal cortex. Correlative microscopy is necessary to distinguish the structural identity of features involved in specific cellular pathways. In addition to diaphragmed fenestrae that frequently appear in clusters, other 60-80 nm openings; plasmalemma vesicles (PV), channels and pockets fitted with diaphragms of the same dimension, coexist on the thin EC surface. Non-diaphragmed coated pits (CP) (100-120 nm) involved in receptor mediated endocytosis were also present on the EC membrane. The present study employed HRSEM of cryofractured and chromium coated specimens and low voltage HRSTEM of 80 nm thick LX-112 embedded sections stained with 2.0% uranyl acetate. Both preparations were imaged at 25 kV with a Topcon DS-130 FESEM equipped with in-lens stage and STEM detector.HRSEM images of the capillary lumen coated with a lnm continuous fine grain Cr film, provided the ability to scan many openings and resolve (SE-I contrast) the fine structure of diaphragm spokes and central densities (Fig. 1).

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The Microscopic Structure Of Shallow Donors In Silicon Carbide

MRS Proceedings ◽

10.1557/proc-442-619 ◽

1996 ◽

Vol 442 ◽

Author(s):

J.-M. Spaeth ◽

S. Greulich-Weber ◽

M. März ◽

E. N. Kalabukhova ◽

S. N. Lukin

Keyword(s):

High Temperature ◽

Low Temperature ◽

Temperature Dependence ◽

Double Resonance ◽

Epr Spectra ◽

Electron Nuclear Double Resonance ◽

Paramagnetic Resonance ◽

Vacancy Pair ◽

Temperature Spectra ◽

Electron Paramagnetic

AbstractThe electronic structure of nitrogen donors in 6H-, 4H- and 3C-SiC is investigated by measuring the nitrogen hyperfine (hf) interactions with electron nuclear double resonance (ENDOR) and the temperature dependence of the hf split electron paramagnetic resonance (EPR) spectra. Superhyperfine (shf) interactions with many shells of 13C and 29Si were measured in 6H-SiC. The hf and shf interactions are discussed in the framework of effective mass theory. The temperature dependence is explained with the thermal occupation of the lowest valley-orbit split A1 and E states. It is proposed that the EPR spectra of P donors observed previously in neutron transmuted 6H-SiC at low temperature (<10K) and high temperature (>60K) are all due to substitutional P donors on the two quasi-cubic and hexagonal Si sites, whereby at low temperature the E state is occupied and at high temperature the A1 state. The low temperature spectra are thus thought not to be due to P-vacancy pair defects as proposed previously.

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