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PubMed1996

[Pharmacognostical studies on adiantum plants. V. Classification based on spore morphology and distributional patterns of silicon and calcium in the ultimate pinnules].

Crude drugs derived from Adiantum species are used as febrifuge, antidote, diuretic, tonic, etc. Some commercial samples of these drugs are composed of finely cut ultimate pinnules only, which have false indusia and spores. In this paper, in order to establish a classification method based on the characteristics of the ultimate pinnules and their attachments, the morphological study using stereoscope and scanning electron microscope, and X-ray microanalysis using an electron probe microanalyzer were carried out on the false indusia and spores, and the ultimate pinnules, respectively, of 19 Adiantum species. The results showed that examined all species could be distinguished from each other by the following characteristics: in the false indusium, the shape and the presence or absence of hairs; in the spore, the shape, the ornamentation, the ratio of the laesura, and the equatorial diameter; in the X-ray images of the ultimate pinnule, the distributional patterns of silicon and calcium. The distributional patterns of silicon were due to the presence of spicular cells, hairs and papillae, and calcium was present as crystals of calcium oxalate. The average content of silicon in the ultimate pinnules of Adiantum species was 1.99%.

Calcium↗
PubMed1981

[Electron probe x-ray microanalysis of human aorta with isthmus stenosis].

Aortas with isthmus stenosis (coarctation) can be regarded as a model for those changes of the vessel wall, that depend on blood pressure, as one can compare the proximal region (high pressure) with the distal one (low pressure). The Na, Mg, P, S, Cl, K, and Ca content of the vessel walls of 5 patients (age: 2 months to 34 years) were determined by electron probe microanalysis. We have used cryostat sections and measured the element concentrations from the lumen to the outer media. In this paper we discuss especially the measurements of Ca and P, as the mineral being deposited in the vessel wall, e.g. in arteriosclerosis, contains Ca and P. Up to 18 years Ca and P enrichments are found only in a subintimal band parallel to the lumen. The proximal region of the aorta of a 34 years old patient, however, demonstrated Ca and P enrichments in the whole media with a high peak in the subintimal band. The enrichments are proximally always higher than distally. Only in the distal region of the 2 months old infant no Ca or P enrichments were found, but they appeared proximally. Thus high blood pressure causes an enrichment of Ca and P in a subintimal band very rapidly and promotes the mineralization of the vessel wall. The quantitative electron probe microanalysis demonstrated these pathological alterations.

Adult↗
PubMed1979

The quantitative measurement of electrolyte elements in nuclei of maturing erythrocytes of chick embryo using electron-probe X-ray microanalysis.

Na, K and Cl measurements have been made on frozen sections of chick red blood cells throughout embryonic development, using electron-probe microanalysis. There is an apparent fluctuation in the levels of these elements during maturation, although the Na/K ratio remains fairly constant. The nuclear Na concentration resembles that of the cytoplasm, rather than that of the medium, at all stages. Inhibitor studies indicate that when cytoplasmic Na, K and Cl levels are altered, their corresponding nuclear levels are similarly affected. Additionally, the measurements in nuclei isolated in anhydrous media from lyophilized cells have shown artefactual accumulation of high Na, K, Ca and Mg.

Animals↗
PubMed1991

Spin labels as a probe of the molecular environment of covalently bound ligands in an hydrophobic and an hydrophilic polymer.

The molecular motions of spin-labelled ligands covalently bound by spacer groups to an hydrophobic and an hydrophilic polymer matrix were evaluated by ESR spectroscopy. The ligands were prepared by alkylation of 4-N-methylamino-TEMPO with the omega-bromocarboxylic esters, Br(CH2)nCOOEt, n = 1,4 and 10. The hydrolysed esters were coupled to a cross-linked aminoethylated polyacrylamide hydrogel (n = 1,4,10) and to a surface hydroxylated elastomeric polyester (n = 4). The rotational correlation times (tau c) of the nitroxide label in the hydrogels were measured in the dry state and after exposure to water at pH 4, 7.4 and 10.5. The tau c of the nitroxide label was insensitive to the length of the spacer group and to the degree of protonation of the tertiary amino group of the ligand. There was no evidence of self-association of the ligand and spacer, or more than a single phase within the polyacrylamide hydrogel. The tau c of the nitroxide labelled polyester was similarly insensitive to pH, but was sensitive to organic solvents. The low mobility of the spin label and its high concentration were consistent with the spin label being covalently bound within the hydrophobic polyester matrix to a depth of at least 5 microns.

Acrylic Resins↗
PubMed2006

TiO2 surface modification and characterization with nanosized PbS in dye-sensitized solar cells.

The nanoporous TiO2 films utilized in dye-sensitized solar cells (DSSCs) possess a large surface-to-volume ratio, which facilitates the adsorption of sensitizing dye and the recombination due to the high density of surface traps. In this paper, nanosized PbS was fabricated on the TiO2 films. The components of the modified TiO2 film were studied by X-ray diffraction (XRD) and electron probe microanalysis (EPMA), while the structure of the film was characterized with BET physisorption and high-resolution scanning electron microscopy (HRSEM). The results showed that the PbS particles were 2-3 nm and discrete on the surface of TiO2. Diffusion photovoltage (PV) spectroscopy was employed to study the charge separation and diffusion processes inside modified and unmodified TiO2 films. The diffusion PV signals revealed that the traps on the surface of TiO2 were extremely reduced due to the presence of PbS. The results of transient photovoltage and back I-V characteristics showed that the back reaction, that is, the recombination due to the reaction between an electron on TiO2 and the hole-transporting media, was retarded significantly.

Journal Article↗
PubMed1999

Silver methenamine staining for scanning electron microscopy of bone sections containing biomaterials.

Sections of tissue containing orthopedic materials are currently used to study the compatibility of those materials and to perform electron probe microanalysis at the material-tissue interface. Identification of the cells in contact with the material by Scanning electron microscopy (SEM) is of interest. We have developed a method for staining cells and tissue structures embedded in polymethyl methacrylate with silver methenamine once the sections have been obtained. Sections were prepared by grinding, and the silver methenamine was applied after oxidation with periodic acid. The procedure was carried out in a microwave oven. Backscatter SEM showed staining of the cell nucleus membrane, chromatin, the nuclear organizers, and the chromosomes of dividing cells. The cytoplasm and the cytoplasmic membrane were also stained. Collagen fibers of the extracellular matrix and the mineralized matrix of bone were labeled. Material particles in the macrophages were easily recognizable and Energy-Dispersive Spectrometer were not impaired by the presence of silver in the preparation.

Animals↗
PubMed1999

[Induction and validation of arterial calcium overload in rats].

OBJECTIVE: To induce arterial calcium overload (ACO) in rats and analyze its features. METHODS: Arterial calcium content and intracellular calcium content were determined by atomic absorption spectrometer and electron probe microanalysis, respectively. The morphological changes of endothelial cells and vascular smooth muscle cells were studied with scanning and transmission electron microscopes. DNA contents and its mass distribution were determined by DNA imaging analysis. Arterial collagen and elastin contents were determined biochemically. RESULTS: Seven days after the induction of ACO with selected regimen, massive calcium was found accumulating in the arterial wall, including the cytoplasm and mitochondrion of the medial smooth muscle cells, indicating both extracellular and intracellular calcium overload. Degeneration of aortic endothelial cells was found at the early stage of ACO under scanning and transmission electron microscope. At the late time of ACO, significant proliferation and sclerotic reactions of arteries occurred, including the proliferation of smooth muscle cells, matrix remodeling, and damage of elastic structure. The average DNA content per smooth muscle cell was elevated, and more cells entered the S phase of proliferating cycle since day 7. On the other hand, total collagen content of aorta was increased 7 days after induction of ACO, and rose continuously at day 14 (P < 0.05). Functional studies showed that arterial elasticity was significantly impaired. CONCLUSION: Our method could induce ACO/constantly in rats, and the ACO model shares the similarities with the characterization of human arteriosclerosis on many aspects.

Animals↗
PubMed1995

Human skin physiology studied by particle probe microanalysis.

Particle probe methods (electron probe and proton probe X-ray microanalysis) have been applied to investigate the distribution of elements and water over the different layers of the epidermis. For major elements, electron probe X-ray microanalysis (XRMA) provides the advantage of superior spatial resolution, but for trace element analysis the more sensitive proton probe (particle induced X-ray emission, PIXE) analysis has to be used. On a dry weight basis, the concentration of S is rather constant across the epidermis, whereas the concentrations of P, K, Cl and Na show gradients with high levels in stratum germinativum (basale) and stratum spinosum but low levels in the stratum granulosum and stratum corneum. Essentially, Fe and Zn are confined to the basal region in normal skin. The concentration of Ca, however, increased steadily from the basal region to the stratum corneum. The probe technique allows quantitative analysis of stratum-specific changes in elemental content in a variety of pathological conditions, e.g., changes induced by nickel, detergents and other chemicals, or in psoriatic skin. Of particular interest are findings of increased Fe and Zn in non-involved psoriatic skin. Since the different layers of the skin have different elemental concentrations and react differently under pathological conditions, the probe techniques are far superior to bulk chemical analysis in elucidating physiological and pathological processes in the skin.

Apoptosis↗
PubMed2000

Chemical composition of individual aerosol particles from working areas in a nickel refinery.

Individual aerosol particles (n = 1170) collected at work stations in a nickel refinery were analyzed by wavelength-dispersive electron-probe microanalysis. By placing arbitrary restrictions on the contents of sulfur and silicon, the particles could be divided into four main groups. Scanning electron images indicated that most of the particles examined were relatively small (< or = 2 microm, equivalent projected area diameter), and that their morphology suggested formation from a melt. There was an absence of well-defined phases and simple stoichiometries, indicating that exposures to pure substances such as nickel subsulfide or specific oxides appeared not to occur. Although the elemental composition of particles varied greatly, a rough association was evident with the known elemental content of the refinery intermediates. The implications of the findings for aerosol speciation measurements, toxicological studies and interpretation of adverse health effects are explored.

Aerosols↗
PubMed1999

Logarithmic 3-Band Color Encoding: Robust Method for Display and Comparison of Compositional Maps in Electron Probe X-ray Microanalysis.

: Electron-excited X-ray maps recorded with the scanning electron microscope (SEM)/electron probe X-ray microanalyzer (EPMA) are a major method of presenting compositional information. Digitally recorded maps are processed in a variety of ways to improve the visibility of features. Scaling of the recorded signal to match the 8-bit gray-scale intensity range of a typical computer display system is almost always necessary. Inherent limitations of gray-scale displays have led to other intensity-encoding methods for X-ray maps, including clipping, histogram normalization, and pseudocolor scales. While feature visibility is improved by applying these scales, comparisons among image sets are difficult. Quantitative comparisons must be based on standardized intensities corrected for background to produce intensity ratio (k-value) maps. We have developed a new logarithmic, multiband color-encoding method to view these k-value maps more effectively. Three color bands are defined, starting with a dark primary color and grading to a bright pastel: blue = trace (0.001 to 0.01); green = minor (0.01 to 0.1); and red = major (0.1 to 1.0). Within each band, the color is assigned according to a logarithmic scale that depends on intensity ratio or compositional measurements. Logarithmic multiband color encoding permits direct comparisons of maps, such as maps of different elements in the same field of view or maps of the same element in different areas, because the color scale is identical for all maps.

Journal Article↗
PubMed1989

Bacillus-shaped deposits composed of hexahedrally based crystals in human dental calculus.

In human supra- and subgingival calculus, bacillus-shaped deposits showing various rocky-pile forms composed of hexahedrally based crystals were observed by scanning electron microscopy. The crystal size measured approximately 0.1-1.5 microns. The electron probe microanalysis always detected calcium, phosphorous, and magnesium. Their molar ratios resembled those of magnesium-containing whitlockite and moreover the crystals also gave the electron diffraction pattern of whitlockite. The bacillus-shaped deposits happened to coexist with the intracellular calcifying microorganisms, furthermore, oral microorganisms partially replaced by the hexahedrally based crystals were found. The crystal deposits were never seen in the surface layers of calculus exposed to the oral cavity, but occurred in the innermost layers and intra-spaces of supragingival and ledge-type subgingival calculus and in the outer layers of deep subgingival calculus.

Bacillus↗
PubMed1996

Pathobiology of copper-induced injury in Bedlington terriers: ultrastructural and microanalytical studies.

The pathogenesis of copper (Cu)-induced liver injury has been investigated in Bedlington terriers with familial Cu toxicosis using ultrastructural and microanalytical techniques. Livers from 3 affected and 1 non-affected Bedlington terrier were fixed in 4% paraformaldehyde and 2% glutaraldehyde for transmission electron microscopy and X-ray electron probe microanalysis. Cu analysis was performed on formalin fixed liver by atomic absorption spectrophotometry. In the dog with liver Cu concentration < 2000 micrograms/g, Cu was located only in electron dense lysosomes with minimal cytoplasmic change. With increasing concentrations of liver Cu, the metal became apparent in the nucleus with early signs of nuclear disturbance. In the dog with highest liver Cu content > 7000 micrograms/g X-ray microanalysis identified Cu peaks in lysosomes, nucleus and cytoplasm in descending order with profound cellular changes. The hepatocytes were shrunken with compacted electron dense organelles and the nuclei were contracted, misshapen with chromatin condensation and fragmentation. Apoptotic bodies were identified in sinusoids. It was concluded that excess Cu is initially sequestered in lysosomes but following increasing saturation of this compartment nuclear accumulation of Cu occurs with DNA damage. Apoptosis follows probably by induction of p53 protein.

Animals↗
PubMed1982

Selenium and kidney deposits in experimental argyria. Electron microscopy and microanalysis.

The conjugate effects of selenium and silver salts were studied in experimental renal argyria. Microanalysis has led to the localization of products of chemical reactions to Se and Ag in tissue sections. After prolonged treatment with Ag salts alone, there was Ag and S deposits in basal membranes. When Se and Ag were used together, the formation of these deposits in glomerular basal membranes was accelerated spectacularly. Electron probe microanalysis has shown that Se replaces S in silver deposits. Compared to its effect on other metals, Se was shown to have a complex action, characterized primarily by its toxic effect, favoring the appearance of symptoms of argyria.

Animals↗
PubMed1978

Electron probe X-ray microanalysis of human skeletal muscle involved in rheumatoid arthritis.

Electron probe X-ray microanalysis in the scanning microscope was used to determine the elemental composition of muscle fibres from patients with rheumatoid arthritis (RA). Quantitative data concerning phosphorus, sulphur, chlorine and potassium were correlated to the fibre type by a routine method based on serial cryosectioning and histochemical staining of adjacent sections. Significantly lowered sulphur values were found in type II A and II B muscle fibres of RA patients as compared to those of healthy controls. Traces of gold were detected in muscles of two patients treated with gold salts. The basis and mechanism for the decreased sulphur content in RA muscles are so far unknown, but may depend on the decreased amount of sulphur-rich potein(s).

Adult↗