Terminology for Scales of Working in Microchemical Analysis

2016 ◽  
Author(s):  
N. J. Zaluzec

The ultimate sensitivity of microchemical analysis using x-ray emission rests in selecting those experimental conditions which will maximize the measured peak-to-background (P/B) ratio. This paper presents the results of calculations aimed at determining the influence of incident beam energy, detector/specimen geometry and specimen composition on the P/B ratio for ideally thin samples (i.e., the effects of scattering and absorption are considered negligible). As such it is assumed that the complications resulting from system peaks, bremsstrahlung fluorescence, electron tails and specimen contamination have been eliminated and that one needs only to consider the physics of the generation/emission process.The number of characteristic x-ray photons (Ip) emitted from a thin foil of thickness dt into the solid angle dΩ is given by the well-known equation


1942 ◽  
Vol 76 (1) ◽  
pp. 103-108 ◽  
Author(s):  
Stuart Mudd ◽  
Thomas F. Anderson

The physical basis of contrast and image formation in electron micrography is considered in relation to the possibility of recording selective chemical effects on cell components. A technology of selective microchemical analysis, equivalent to differential staining, is suggested as practicable in electron micrography. Electron pictures of bacteria after exposure to salts of heavy metals have shown the bacterial inner protoplasm, but not the cell walls, to be selectively darkened; shrinkage, coagulation, or escape of protoplasm from the injured cells may result and be recorded in the electron micrographs. Recording of the action of germicidal agents on individual bacterial cells is indicated as one promising field of application of microchemical analysis with the aid of the electron microscope.


Author(s):  
Sarah C. Swan ◽  
John D.M. Gordon ◽  
Beatriz Morales-Nin ◽  
Tracy Shimmield ◽  
Terrie Sawyer ◽  
...  

Otoliths were obtained from Nezumia aequalis, a small macrourid that is widely distributed throughout the Atlantic and Mediterranean—two very different physical environments. Microchemical analysis of the otoliths was carried out using solution-based inductively coupled plasma mass spectrometry of whole otoliths. Significant differences between fish populations were found for concentrations of the elements Li and Sr. Only 54% of the samples were correctly classified by area using discriminant analysis. Otolith samples from the Reykjanes Ridge were most easily distinguished. The results are discussed in relation to trace element concentrations in the waters of the north-eastern Atlantic Ocean and the Mediterranean Sea.


2004 ◽  
Vol 78 (4) ◽  
pp. 1792-1799 ◽  
Author(s):  
Karin Maurer ◽  
Thomas Krey ◽  
Volker Moennig ◽  
Heinz-Jürgen Thiel ◽  
Till Rümenapf

ABSTRACT Various monoclonal antibodies (MAbs) that recognize cell surface proteins on bovine cells were previously shown to efficiently block infection with bovine viral diarrhea virus (BVDV) (C. Schelp, I. Greiser-Wilke, G. Wolf, M. Beer, V. Moennig, and B. Liess, Arch. Virol. 140:1997-2009, 1995). With one of these MAbs, a 50- to 58-kDa protein was purified from calf thymus by immunoaffinity chromatography. Microchemical analysis of two internal peptides revealed significant sequence homology to porcine and human CD46. The cDNA of bovine CD46 (CD46bov) was cloned and further characterized. Heterologously expressed CD46bov was detected by the MAb used for purification. A putative function of CD46bov as a BVDV receptor was studied with respect to virus binding and susceptibility of nonpermissive cells. While the expression of CD46bov correlated well with the binding of [3H]uridine-labeled BVDV, the susceptibility of cells nonpermissive for BVDV was not observed. However, the expression of CD46bov resulted in a significant increase in the susceptibility of porcine cells to BVDV. These results provide strong evidence that CD46bov serves as a cellular receptor for BVDV.


1983 ◽  
Vol 55 (12) ◽  
pp. 1861-1868 ◽  
Author(s):  
D. Luc Massart ◽  
Guido Hoogewijs

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