Diagnostics, plasma

O. Auciello, D.L. Flamm, Plasma Diagnostics, Plasma-Materials Interaction Series, Academic Press, San Diego, 1989. 

Kennedy, C. R., J. T. Allen, A. H. Fensom, S. J. Steinberg, and R. Wilson. 1994. X-linked adreno-leukodystrophy with non-diagnostic plasma very long chain fatty acids. J Neurol Neurosurg Psychiatry 57 759-761. 

Diagnostic techniques that involve natural emissions are appHcable to plasmas of all sizes and temperatures and clearly do not perturb the plasma conditions. These are especially useful for the small, high temperature plasmas employed in inertial fusion energy research, but are also finding increased use in understanding the glow discharges so widely used commercially. 

Fig. 4. Examples of emission spectrometry as a diagnostic monitoring tool for plasma processing, (a) The removal of chlorine contamination from copper diode leads using a hydrogen—nitrogen plasma. Emissions are added together from several wavelengths, (b) The etching and eventual removal of a 50-p.m thick polyimide layer from an aluminum substrate, where (x ) and (° ) correspond to wavelengths (519.82 and 561.02 nm, respectively) for molecular CO2...

W. Lochte-Holtgreven, ed.. Plasma Diagnostics, North-HoUand, Amsterdam, the Nethedands, 1968. 

Various plasma diagnostic techniques have been used to study the SiH discharges and results have helped in the understanding of the growth kinetics. These processes can be categorized as r-f discharge electron kinetics, plasma chemistry including transport, and surface deposition kinetics. 

Plasma also contains numerous other enzymes that perform no known physiologic function in blood. These apparently nonfunctional plasma enzymes arise from the routine normal destruction of erythrocytes, leukocytes, and other cells. Tissue damage or necrosis resulting from injury or disease is generally accompanied by increases in the levels of several nonfunctional plasma enzymes. Table 7-2 lists several enzymes used in diagnostic enzymology. 

The fundamental role of blood in the maintenance of homeostasis and the ease with which blood can be obtained have meant that the study of its constituents has been of central importance in the development of biochemistry and clinical biochemistry. The basic properties of a number of plasma proteins, including the immunoglobulins (antibodies), are described in this chapter. Changes in the amounts of various plasma proteins and immunoglobulins occur in many diseases and can be monitored by electrophoresis or other suitable procedures. As indicated in an earlier chapter, alterations of the activities of certain enzymes found in plasma are of diagnostic use in a number of pathologic conditions. 

This reaction helps transfer certain amino acids across the plasma membrane, the amino acid being subse-quendy hydrolyzed from its complex with GSH and the GSH being resynthesized from cysteinylglycine. The enzyme catalyzing the above reaction is 7-glu-tamyltransferase (GGT). It is present in the plasma membrane of renal mbular cells and bile ducmle cells, and in the endoplasmic reticulum of hepatocytes. The enzyme has diagnostic value because it is released into the blood from hepatic cells in various hepatobihary diseases. 

L. Schott, in Plasma Diagnostics (W. Lochte-Holtgreven, Ed.). North-Holland, Amsterdam, 1968. 

In order to relate material properties with plasma properties, several plasma diagnostic techniques are used. The main techniques for the characterization of silane-hydrogen deposition plasmas are optical spectroscopy, electrostatic probes, mass spectrometry, and ellipsometry [117, 286]. Optical emission spectroscopy (OES) is a noninvasive technique and has been developed for identification of Si, SiH, Si+, and species in the plasma. Active spectroscopy, such as laser induced fluorescence (LIF), also allows for the detection of radicals in the plasma. Mass spectrometry enables the study of ion and radical chemistry in the discharge, either ex situ or in situ. The Langmuir probe technique is simple and very suitable for measuring plasma characteristics in nonreactive plasmas. In case of silane plasma it can be used, but it is difficult. Ellipsometry is used to follow the deposition process in situ. 

Knowledge on the plasma species can be obtained by the use of plasma diagnostics techniques, such as optical emission spectroscopy (OES) and mass spectroscopy (MS). Both techniques are able to probe atomic and molecular, neutral or ionized species present in plasmas. OES is based on measuring the light emission spectrum that arises from the relaxation of plasma species in excited energy states. MS, on the other hand, is generally based on the measurement of mass spectra of ground state species. 

Diagnostic procedures include dark-field microscopy12, non-treponemal exams10 (i.e., the Venereal Disease Laboratory and the rapid plasma reagin test), and treponemal exams (i.e., enzyme immunoassay, the T. pallidum hemagglutination test, the fluorescent treponemal antibody test, and the enzyme-linked immunosorbent assay). 

Release of markers bound to the endothelial cell such as thrombomodulin is indicative of vascular damage. Increased levels of soluble thrombomodulin in plasma are diagnostic (93). Other endothelium-derived markers such as 6-keto-prostaglandin F a, which is a metabolite of prostacyclin, are useful in the assessment of endothelial function, with lower levels indicative of inability to synthesize this marker due to defective or damaged endothelium through plaque formation (93). 

---