Correlation of Intracellular Calcium Measurements Using X-Ray Microanalysis and Fluorescence Microscopy Techniques

1989 ◽  
Vol 47 ◽  
pp. 898-899
Author(s):  
H.K. Hagler
Keyword(s):  
Electron Microscope ◽  
Dry Weight ◽  
Elemental Content ◽  
X Ray ◽  
Intensity Measurements ◽  
Inactive Form ◽  
Freeze Dried ◽  
Total Elemental Content ◽  
Microscopy Techniques ◽  
Irreversible Injury

It is my thought that calcium plays a major role in the development of irreversible cellular injury in the myocardium.There are two basic forms of calcium within the cell, the active, ionized calcium and the inactive form which may be bound to cell proteins or held in storage sites within the cells.The use of energy dispersive x-ray microanalysis in an analytical electron microscope permits the localization and measurement of the total elemental content of subcellular regions of cells. These measurements generally require that the cells be cryofixed , cryosectioned, cryotransfered and freeze dried in the electron microscope. The Hall method of continuum normalization is then used to convert the x-ray intensity measurements into dry weight concentrations.Because the cells have to be cryofixed, it is not possible to follow the development of elemental changes within a single cell over time, thus many cells have to be frozen at different time intervals to measure time dependent changes of irreversible injury and cell death. Thus, selected time points are identified and sampled for x-ray microanalysis.

Thickness and composition determinations from T.E.M. specimens using both x-ray and backscattered electron data

1984 ◽  
Vol 42 ◽  
pp. 576-577
Author(s):  
M.D. Ball ◽  
H. Lagace ◽  
M.C. Thornton
Keyword(s):  
Electron Microscope ◽  
Atomic Number ◽  
Transmission Electron Microscope ◽  
Convenient Method ◽  
Flow Chart ◽  
X Ray ◽  
Intensity Measurements ◽  
Transmission Electron ◽  
Electron Intensity ◽  
Backscattered Electron

The backscattered electron coefficient η for transmission electron microscope specimens depends on both the atomic number Z and the thickness t. Hence for specimens of known atomic number, the thickness can be determined from backscattered electron coefficient measurements. This work describes a simple and convenient method of estimating the thickness and the corrected composition of areas of uncertain atomic number by combining x-ray microanalysis and backscattered electron intensity measurements.The method is best described in terms of the flow chart shown In Figure 1. Having selected a feature of interest, x-ray microanalysis data is recorded and used to estimate the composition. At this stage thickness corrections for absorption and fluorescence are not performed.

Preparation of cultured astrocytes for x-ray microanalysis

1989 ◽  
Vol 47 ◽  
pp. 988-989
Author(s):  
N.K.R. Smith ◽  
K.E. Hunter ◽  
P. Mobley ◽  
L.P. Felpel
Keyword(s):  
Cultured Cells ◽  
Elemental Content ◽  
Elemental Distribution ◽  
Sprague Dawley ◽  
X Ray ◽  
Cultured Astrocytes ◽  
Freeze Dried ◽  
Ultimate Objective

Electron probe energy dispersive x-ray microanalysis (XRMA) offers a powerful tool for the determination of intracellular elemental content of biological tissue. However, preparation of the tissue specimen , particularly excitable central nervous system (CNS) tissue , for XRMA is rather difficult, as dissection of a sample from the intact organism frequently results in artefacts in elemental distribution. To circumvent the problems inherent in the in vivo preparation, we turned to an in vitro preparation of astrocytes grown in tissue culture. However, preparations of in vitro samples offer a new and unique set of problems. Generally, cultured cells, growing in monolayer, must be harvested by either mechanical or enzymatic procedures, resulting in variable degrees of damage to the cells and compromised intracel1ular elemental distribution. The ultimate objective is to process and analyze unperturbed cells. With the objective of sparing others from some of the same efforts, we are reporting the considerable difficulties we have encountered in attempting to prepare astrocytes for XRMA.Tissue cultures of astrocytes from newborn C57 mice or Sprague Dawley rats were prepared and cultured by standard techniques, usually in T25 flasks, except as noted differently on Cytodex beads or on gelatin. After different preparative procedures, all samples were frozen on brass pins in liquid propane, stored in liquid nitrogen, cryosectioned (0.1 μm), freeze dried, and microanalyzed as previously reported.

Failure Analysis of Killer Defects and Yield Enhancement of Flat ROM Devices in Wafer Fabrication

2000 ◽  
Author(s):  
Y. N. Hua ◽  
Z. R. Guo ◽  
L. H. An ◽  
Shailesh Redkar
Keyword(s):  
Electron Microscope ◽  
Failure Analysis ◽  
Fault Isolation ◽  
Yield Enhancement ◽  
Wafer Fabrication ◽  
X Ray ◽  
Particle Contamination ◽  
Emission Microscopy ◽  
Microscopy Techniques ◽  
Scanning Electron

Abstract In this paper, some low yield cases in Flat ROM device (0.45 and 0.6 µm) were investigated. To find killer defects and particle contamination, KLA, bitmap and emission microscopy techniques were used in fault isolation. Reactive ion etching (RIE) and chemical delayering, 155 Wright Etch, BN+ Etch and scanning electron microscope (SEM) were used for identification and inspection of defects. In addition, energy-dispersive X-ray microanalysis (EDX) was used to determine the composition of the particle or contamination. During failure analysis, seven kinds of killer defects and three killer particles were found in Flat ROM devices. The possible root causes, mechanisms and elimination solutions of these killer defects/particles were also discussed.

Elemental content of mast cell granules measured by X-ray microanalysis of rat thymic tissue sections

1986 ◽  
Vol 83 (1) ◽  
pp. 77-87 ◽  
Author(s):  
M.D. Kendall ◽  
A. Warley
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Elemental Content ◽  
Thymic Tissue ◽  
X Ray ◽  
Tissue Sections ◽  
Freeze Dried ◽  
The Mean ◽  
Highly Correlated ◽  
The Individual

Mast cell granules were examined by fully quantitative X-ray microanalysis of 20 cells in freeze-dried cryosections. The mast cells were situated mainly in the connective tissue of the thymic capsule of five adult male Carworth Sprague Europe rats. In addition 30 red blood cells were analysed from the same sections. Nineteen of the mast cells had granules rich in S and K. One cell had smaller granules, and in this cell the granules contained high [Ca] and [P] instead of high [S] and [K]. In the majority of cells (13) the S:K ratio was highly correlated and less than 2.2, whereas in the remaining six cells the individual granule ratios were very variable in any one cell and much higher. The mean granule [K] (994 +/− 57 mmol kg-1 dry wt) was about four times the mean cytoplasmic level of 227 +/− 81 mmol kg-1 dry wt. The existence of this difference in concentration between the granules and the cytoplasm suggests that the K in the granules must be bound. The relationship between the [K] and [S] is discussed with regard to the possible binding of heparin and amines in the granules.

Preparation and characteristics of sepiolite-waterborne polyurethane composites

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Tong Xu ◽  
Hong Xu ◽  
Yi Zhong ◽  
Linping Zhang ◽  
Di Qian ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Waterborne Polyurethane ◽  
Elemental Content ◽  
Layer By Layer ◽  
Silane Coupling Agents ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Organically Modified ◽  
Polyurethane Composites

Abstract A kind of organic/inorganic composite material composed of waterborne polyurethane and sepiolite was prepared in this work. Sepiolite was organically modified by three kinds of silane coupling agents, and then compounded with waterborne polyurethane through layer-by-layer method in order to prepare composite materials. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) show the crystal and chemistry structure of sepiolite samples, and confirmed the preparation of organic sepiolite. Scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS) showed the surface microstructure and elemental content of sepiolite and organic sepiolite, and was consistent with the XRD results. Transmission electron microscope (TEM) examination of waterborne polyurethane composites surfaces showed that sepiolite particles were regularly dispersed in the waterborne polyurethane matrix. Thermal resistance of waterborne polyurethane composites was determined by thermogravimetry analyzer (TG) and derivative thermogravimetry analyzer (DTG), differential scanning calorimetry (DSC), gas chromatography (GC), and mass chromatography (MS). Mechanical behavior was examined by tensile strength tester, showed higher break strength than that of the control waterborne polyurethane. Therefore, organically modified sepiolite was considered to be a kind of wonderful inorganic material that could be used to improve the thermal stability and mechanical property of polymer.

scholarly journals A rapid method of cryofixation of tissues in situ for ultracryomicrotomy.

1980 ◽  
Vol 28 (1) ◽  
pp. 47-51 ◽  
Author(s):  
S H Chang ◽  
W J Mergner ◽  
R E Pendergrass ◽  
R E Bulger ◽  
I K Berezesky ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Punch Biopsy ◽  
Sampling Device ◽  
X Ray ◽  
Cell Compartments ◽  
Specimen Holder ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Tissue Specimens

A device is described for the rapid freezing of tissue in situ by a punch biopsy approach using a specially designed cryogun with a highly thermal conductive specimen holder. The cryogun consists of a sampling device using a double, spring-loaded gun mechanism and a system of cryochambers. Ultrathin freeze-dried sections cut from samples obtained with this cryogun are relatively free of artifacts and have few ice crystals. Organelles are seen by natural contrast when cryosections of approximately 1000 A are observed with a transmission electron microscope or in the transmission mode of a scanning electron microscope. The construction of the cryogun is described along with a method of obtaining improved, ultrafast cryofixation of tissue specimens. The reliability of obtaining x-ray microanalysis measurements of diffusible ions where movement within cell compartments has been retained is discussed.

scholarly journals Quick Analysis of Organic Amendments via Portable X-ray Fluorescence Spectrometry

2019 ◽  
Vol 16 (22) ◽  
pp. 4317 ◽  
Author(s):  
Rafael López-Núñez ◽  
Fátima Ajmal-Poley ◽  
José A. González-Pérez ◽  
Miguel Angel Bello-López ◽  
Pilar Burgos-Doménech
Keyword(s):  
Organic Matter Content ◽  
Organic Amendments ◽  
Analytical Techniques ◽  
Matter Content ◽  
Field Analysis ◽  
Elemental Content ◽  
Aqua Regia ◽  
X Ray ◽  
Total Elemental Content

The determination of heavy metals in soils and organic amendments, such as compost, manure, biofertilizer, and sludge, generally involves the digestion of samples with aqua regia, and the determination of those in the solution using various techniques. Portable X-ray fluorescence (PXRF) has many advantages in relation to traditional analytical techniques. However, PXRF determines the total elemental content and, until now, its use for the analysis of organic amendments has been limited. The objective of this work is the calibration of a PXRF instrument to determine the aqua regia-soluble elemental contents directly in solid samples of organic amendments. Our proposal will avoid the digestion step and the use of other laboratory techniques. Using a training set of samples, calibration functions were obtained that allow the determination of the aqua regia-soluble contents from the PXRF readings of total contents. The calibration functions (obtained by multiple linear regression) allowed the quantitative determination of the aqua regia-soluble contents of Fe, K, P, S, Zn, Cu, Pb, Sr, Cr, and Mn, as well as the organic matter content and a semi-quantitative assessment of Al, Ca, V, Ba, Ni, and As contents. The readings of Si, Fe, Al, Ca, K, or S were used as correction factors, indicating that the calibrations functions found are truly based on the chemical composition of the sample matrix. This study will allow a fast, cheap, and reliable field analysis of organic amendments and of other biomass-based materials.

X-ray microanalysis of mineralized deposits in a variety of pathological conditions in the brain

1995 ◽  
Vol 53 ◽  
pp. 866-867
Author(s):  
C. A. Ackerley ◽  
L. E. Becker
Keyword(s):  
Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
Small Degree ◽  
X Ray ◽  
Transmission Electron ◽  
Formalin Fixed Paraffin ◽  
Freeze Dried ◽  
Scanning Transmission ◽  
Formalin Fixed Paraffin Embedded ◽  
The Brain

Although a small degree of mineralization can be a common occurrence without associated pathological symptoms, certain diseases of the brain do however exhibit distinct increases in mineralization with characteristic distributions l>2. In this study, tissues from a number of these disorders were prepared for x-ray microanalysis in several ways. Where possible, material was slam frozen on a liquid nitrogen cooled polished copper block, cryosections prepared and freeze dried in the scanning transmission electron microscope (STEM) using a cold stage prior to analysis by energy dispersive x-ray spectrometry (EDS). In addition, samples were freeze substituted for several days, embedded in LR white and cut on dry knives before analysis. Where only formalin fixed paraffin embedded materials were available, .5μ.m sections were cut and mounted on carbon planchets. The specimens were then deparaffinized with xylene and viewed with the backscatter electron detector (BEI) in the scanning electron microscope (SEM) and analyzed by EDS.

Ion localization in Cells by Electron Probe X-Ray Microanalysis (Epxma) Depends on Cryopreparation

1990 ◽  
Vol 48 (2) ◽  
pp. 322-323
Author(s):  
Karl Zierold
Keyword(s):  
Detection Limit ◽  
Scanning Transmission Electron Microscopy ◽  
Dry Weight ◽  
Section Thickness ◽  
X Ray ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Transmission ◽  
Absolute Detection Limit ◽  
Analytical Resolution

Elements in biological cells can be localized by EPXMA. The most attractive approach of this method with respect to detection limit and spatial resolution is scanning transmission electron microscopy combined with energy dispersive x ray microanalysis of ultrathin (approximately 100 nm thick) freeze-dried cryosections. The detection limit, here determined by scanning an electron beam of 1.3 nA for 2 min over freeze-dried cryosections from frozen standard solutions was found to be about 10 mMol/kg dry weight for all elements with the atomic number Z higher than 12. Due to the Be window in the x ray detector the detection limit was 20 mMol/kg dry weight for Mg (Z = 12) and 30 mMol/kg dry weight for Na (Z = 11). The lateral analytical resolution was less than 50 nm, limited by section thickness. In most cells 10 mMol/kg dry weight correspond to an absolute detection limit of .500 atoms within a volume of 100×50×50 nm3.

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