scholarly journals IDENTIFICATION OF CYTOCHEMICAL REACTION PRODUCTS BY SCANNING X-RAY EMISSION MICROANALYSIS

1962 ◽  
Vol 15 (3) ◽  
pp. 427-435 ◽  
Author(s):  
Arthur J. Hale

The primary, secondary, and final reaction products of the cytochemical staining method for alkaline phosphatase have been demonstrated by x-ray emission microanalysis. The advantages and limitations of the technique in measuring reaction products are discussed. Scanning x-ray emission analysis provides a rapid way of detecting and measuring the amounts of individual elements in cytochemical reaction products. It has a resolution of 1 µ and a sensitivity of 0.01 per cent (w/v). It will provide information on the elementary composition of the products in situ and will permit study of the efficiency of conversion of one product to another. It will also yield information on the diffusion of reaction products in the tissue.

2005 ◽  
Vol 475-479 ◽  
pp. 2551-2554 ◽  
Author(s):  
Si Young Sung ◽  
Keun Chang Park ◽  
Myoung Gyun Kim ◽  
Young Jig Kim

The aim of the present work is to investigate the possibility of in-situ synthesis and net-shape of the titanium matrix composites (TMCs) using a casting route. From the scanning electron microscopy (SEM), electron probe micro-analyzer (EPMA), X-ray diffraction (XRD) and thermodynamic calculations, the spherical TiC and needle like TiB reinforced hybrid TMCs could be obtained by the conventional casting route between titanium and B4C. No melts-mold reaction could be possible between (TiC+TiB) hybrid TMCs and the SKKU mold, since the mold is composed of interstitial and substitutional reaction products. Not only the sound in-situ synthesis but also the economic net-shape of TMCs could be possible by conventional casting route.


1986 ◽  
Vol 75 ◽  
Author(s):  
Masataka Hirose ◽  
Tsuyoshi Ogura

AbstractA silicon surface exposed to NF3 gas was irradiated with an ArF excimer laser beam. The reaction products on the surface and their chemical bonding features were studied by in-situ x-ray photoelectron spectroscopy at each step of the photochemical etching. It was found that SiFX (1≤X≤4) units and molecular fluorine exist in the reacting surface region. The surface Si-Si bonds attacked with fluorine are progressively fluorinated and the final surface products are mainly SiF4 and SiF3. A possible mechanism of fluorine etching is discussed on the basis of a valence electron transfer (VET) model.


1990 ◽  
Vol 38 (3) ◽  
pp. 325-329 ◽  
Author(s):  
W van den Brink ◽  
C van der Loos ◽  
H Volkers ◽  
R Lauwen ◽  
F van den Berg ◽  
...  

A combination of beta-galactosidase enzyme and the immunogold/silver staining method was studied for evaluation of double-staining experiments. Applications are shown for immunohistochemical double staining using two monoclonal antibodies and for combined immunohistochemistry and DNA in situ hybridization in one tissue section. The following advantages for the present double-staining method were evaluated: superior sensitivity of the immunogold/silver staining method for at least one epitope, which also allows detection of biotinylated DNA probes. The structure of the indolyl precipitate after revelation of beta-galactosidase activity did not show a concealing effect during a sequential double-staining method, as compared with the visualization of peroxidase with diaminobenzidine. These factors, and the sharply contrasting colored reaction products of beta-galactosidase (blue-green) and the immunogold/silver staining method including silver enhancement (brown-black), allow clear distinction of mixed-stained cell constituents.


Author(s):  
J. Wood

Specific cytochemical reactions have been instrumental in the illucidation of compounds within tissues, whether these compounds are hormones, enzymes, or molecules, such as certain nerve transmitter agents. Many cytochemical reaction products depend upon some complex, which is an electron dense deposit. Several types of cytochemical procedures can be used to visualize agents related to synaptic transmission at the junctional complex. One method which has been used with considerable success has been the cytochemical localization of biogenic amines (BAs), i.e., norepinephrine (NE) and dopamine (DA). For the past few years, a chrome complex formed with certain BAs and glutaraldehyde has been utilized to localize BAs at the electron microscopic level and the specificity of the reaction has been verified biochemically.


1989 ◽  
Vol 167 ◽  
Author(s):  
M. Grant Norton ◽  
Jacek M. Kajda ◽  
Brian C. H. Steele

AbstractA technique for brazing aluminum nitride (AIN) using conventional (non-active) brazing alloys has been investigated. The process involves the in-situ decomposition of a metal hydride. This process alters the surface chemistry of the substrate and improves the wettability of the molten braze. The development of high strength bonding between braze and ceramic results. The ceramic-braze interface was studied using scanning electron microscopy (SEM). The nature of the interfacial reactions and the reaction products have been identified using x-ray diffraction (XRD). The progress of the reaction has been followed using differential thermal analysis (DTA).The experimental results have been correlated with thermodynamic predictions of the reaction process. In addition to joining ceramic to ceramic, braze joints of AIN to a low expansion iron-nickel lead frame alloy were made.


2008 ◽  
Vol 23 (9) ◽  
pp. 2366-2372 ◽  
Author(s):  
Yongjun Li ◽  
Sicheng Li ◽  
Ran Lv ◽  
Jiaqian Qin ◽  
Jian Zhang ◽  
...  

Cubic boron nitride (cBN) composites starting with cBN–Al mixtures were sintered on WC-16 wt% Co substrates under static high pressure of 5.0 GPa and at temperatures of 800–1400 °C for 30 min. Vickers hardness of the sintered samples increased with increasing cBN content, and the highest hardness of 32.7 GPa was achieved for the cBN–5 wt% Al specimens sintered at 1400 °C. The reactions between cBN and Al started to occur at about 900 °C, and the reaction products strongly depended on the Al content, sintering temperature, and Co diffusion from the substrates according to the x-ray diffraction (XRD) observations. The high pressure and high temperature in situ resistance measurement indicated that the reactions between cBN and Al could be completed in about 90 s when the temperature was higher than ∼1200 °C at high pressure. The cBN composite sintered at 1200 °C from a cBN–15 wt% Al mixture showed the best cutting performance.


2008 ◽  
Vol 587-588 ◽  
pp. 921-925 ◽  
Author(s):  
Sofia F. Marques ◽  
Raquel A. Silva ◽  
Jose Brito Correia ◽  
Nobumitsu Shohoji ◽  
Carmen M. Rangel

FeTi intermetallic powders are very promising media for reversible hydrogen storage. However, difficult activation treatments including annealing at elevated temperatures in high pressure H2 gas atmosphere are mandatory. In the present work nanostructured FeTi powders were produced and activated in situ at room temperature using mechanical alloying/milling (MA/MM) of pure metallic constituents, Fe and Ti, added with sodium borohydride. The resultant powders, FeTiHx, already H2 pre-charged, absorbed a significant amount of H2 but require optimization for reversible absorption/desorption. This system has one of the highest volumetric storage capacities and can be produced at low cost. Several parameters of the as-milled powders were controlled. The phase constitution of the reaction products was characterized by X-ray diffraction and scanning electron microscopy and the absorption isotherms of the activated powders were determined.


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