Nitrogen-based plasma

Phospholipids. Phospholipids, components of every cell membrane, are active determinants of membrane permeabiUty. They are sources of energy, components of certain enzyme systems, and involved in Hpid transport in plasma. Because of their polar nature, phosphoUpids can act as emulsifying agents (42). The stmcture of most phosphoUpids resembles that of triglycerides except that one fatty acid radical has been replaced by a radical derived from phosphoric acid and a nitrogen base, eg, choline or serine. 

S. J. Hill, M. J. Ford, L. Ebdon, Simplex optimisation of nitrogen-argon plasmas in inductively coupled plasma mass spectrometry for the removal of chloride based interferences, J. Anal. Atom. Spectrom., 7 (1992), 719-727. 

These are complex lipids containing phosphate and a nitrogenous base. They are found in plasma lipoproteins, in biological membranes and in bile where they help to maintain cholesterol in solution. Phospholipids can be estimated by digestion of a lipid extract followed by measurement of the inorganic phosphate liberated. 

The above considerations lead to the conclusion that the liver should be capable of synthesizing plasma phospholipides in toto from its various components. This appears to be the case, for a purified enzyme preparar-tion of rat liver has been shown to form diacylphosphatidic acids from fatty acids and L-a-glycerophosphate. i The diacylphosphatidic acids need only a nitrogenous base in ester linkage with the phosphate to form lecithin (or a cephalin). The following mechanism was postulated for the synthesis of distearylphosphatidic acid from stearic acid-l-C and L-o-glycerophosphate-P (a-G-P) by the rat liver preparation ... 

G. L. Coppoc and S. J. Leger, "Effect of Nitrogen Triduoride on Plasma Concentrations of Lactate, Methemoglobin, and Selected Enzymes," ApriWune 1968, SAM-TR-70-42 (AD 711044), School of Aerospace Medicine, Brooks Air Eorce Base, Texas, July 1970. 

Despite such limitations, plasma-deposited a-C(N) H films were found to be used in a number of applications. The stress reduction induced by nitrogen incorporation [12] and consequent adhesion improvement, allowed the development of a-C(N) H antireflective coatings for Ge-based infrared detectors [13]. It was also found that N can electronically dope a-C H films, and can strongly decrease the defect density, which gives prospects on its use as a semiconductor material [14]. Nitrogen incorporation was also found to decrease the threshold electric field in electron-field emission process [15], making possible the use of a-C(N) H films as an overcoat on emission tips in flat-panel display devices [16]. 

Dean et al. [93] used a high performance liquid chromatographic method for the simultaneous determination of primaquine and carboxyprimaquine in plasma with electrochemical detection. After the addition of the internal standard, plasma was deproteinized by the addition of acetonitrile. Nitrogen-dried supernatants, resuspended in mobile phase were analyzed on a C8 reversed-phase column. Limits of detection for primaquine and carboxyprimaquine were 2 and 5 ng/mL with quantitation limits of 5 and 20 ng/mL, respectively. The assay sensitivity and specificity are sufficient to permit quantitation of the drug in plasma for pharmacokinetics following low dose (30 mg, base) oral administration of primaquine, typically used in the treatment of malaria and P. carinii pneumonia. 

A plasma torch is based on arc ignition between a thermionic tungsten cathode and a co-axial copper anode both water-cooled anode and cathode are immersed in an axial magnetic field. Nitrogen is generally chosen as the plasma gas. Air or steam can be injected into the plasma to increase the enthalpy and to produce sub-stoichiometric incineration. The torch is powered by a thyristor-controlled rectifier, which has controls to match the torch impedance. 

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