Mach 18 flow velocimetry with 100-kHz KTV and PLEET in AEDC Tunnel 9.

Krypton Tagging Velocimetry (KTV) and Picosecond Laser Electronic Excitation Tagging (PLEET) velocimetry at a 100-kHz rate were demonstrated in Mach 18 flow conditions at the Arnold Engineering Development Center (AEDC) Tunnel 9 employing a burst-mode laser system and a custom optical parametric oscillator (OPO). The measured freestream flow velocities from both KTV and PLEET agreed well with the theoretical calculation. The increase in repetition rate provides better capability to perform time-resolved velocimetry measurements in hypersonic flow environments.

Freestream velocity-profile measurement in a large-scale, high-enthalpy reflected-shock tunnel.

Abstract: We apply Krypton Tagging Velocimetry (KTV) to measure velocity profiles in the freestream of a large, national-scale high-enthalpy facility, the T5 Reflected-Shock Tunnel at Caltech. The KTV scheme utilizes two-photon excitation at 216.67 nm with a pulsed dye laser, followed by re-excitation at 769.

Two-photon cross-section calculations for krypton in the 190-220 nm range.

This paper presents multi-path, two-photon excitation cross-section calculations for krypton, using first-order perturbation theory. For evaluation of the two-photon-transition matrix element, this paper formulates the two-photon cross-section calculation as a matrix mechanics problem. From a finite basis of states, consisting of 4, 5, 6, 7, 5, 6, 4, 5, and 6 orbitals, electric dipole matrix elements are constructed, and a Green's function is expressed as a truncated, spectral expansion of solutions, satisfying the Schrödinger equation.

[An emulsion based on 1-bromoperfluorooctane: X-ray contrast properties and mechanisms of X-ray contrasting].

It has been shown that the emulsion of a mixture of the perfluorocarbons 1-bromoperfluorooctane and perfluoro[1-(4-methylcyclohexyl)piperidine], stabilized by egg yolk phospholipids, makes it possible to contrast rapidly (beginning with the 10th minute) and for a long time (up to 5 days) the tissues of various organs, such as liver, spleen, adrenal glands, heart, and the peritoneal part of the aorta. The roentgenograms of rat organs in in vivo experiments were evaluated by computer-assisted morphodensitometry. The contrasting of organs at early terms of the circulation of emulsion in the body is related to a high concentration of 1-bromoperfluorooctane in the blood flow, and the contrasting at later terms is related to the accumulation of emulsion particles by cells of the reticuloendothelial system.

[Effect of perfluorocarbon emulsions on function of enzyme systems responsible for generating active forms of oxygen in neutrophils].

The ability of the emulsion of perfluoroorganic compounds stabilized with proxanol 268 to affect the functions of peritoneal neutrophils was evaluated. The functional activity of neutrophils was estimated from the intensity of generation of reactive oxygen species using the method of chemiluminescent analysis. The emulsion was shown to suppress the neutrophil responses to phorbol-12-myristate-13-acetate in a dose-dependent manner.

[Sorption of plasma components on the surface of particles of fluorocarbon emulsions stabilized by proxanol 268].

It was found in the experiments in vivo and in vitro that the contact of perfluorocarbon emulsion stabilized with proxanol 268 with blood plasma leads to the sorption of various plasma proteins on the surface of emulsion particles. The profile of the proteins sorbed is complex and includes proteins with molecular weights ranging from 14 to 94 kDa. Among proteins sorbed on the emulsion particles circulating in blood, IgG was identified.

[Mechanisms of distribution and elimination of perfluorocarbons upon multiple exposures].

In clinical practice much more often one meets a necessity of repeated administration of fluorocarbon blood substitutes. The 19F(-)-NMR-spectroscopy has been used to study the kinetics of the blood and tissue fluorocarbon concentration after repeated administration of PFC emulsion. Analysis of the data suggests that redistribution of PFCs between organs and blood after their repeated administration is under control of Ostwald ripening depending on PFC physicochemical properties (water and lipid solubility), emulsion particle diameter etc and does not connect with activity of reticuloendothelial system.

[Perfluorocarbon emulsions and other corpuscular systems influence on neutrophil activity].

Influence of perfluorodecalin, perfluoromethilcyclohexylpiperidine, perfluorotributylamine emulsions on active oxygen form (AOF) generation by neutrophils has been studied. All investigated emulsions stabilized both proxanol 268 and egg yolk phospholipids inhibited PMA-stimulated neutrophil activity. Castor oil emulsion also inhibited the neutrophil activity.

[Uncoupling of the liver monooxygenase system by perfluorocarbons in vivo].

Administration of a perfluorodecalin (PFD) emulsion, the liver cytochrome P-450 II B1/B2 inducer, to experimental animals is followed by a two-fold increase of the NADPH oxidation rate in liver microsomes. This phenomenon is caused by the presence in the cytochrome P-450 active center of PFD which uncouples microsomal hydroxylation. The high rate of NADPH oxidation in liver microsomes after administration of the fluorocarbon does not decrease the level of reduced pyridine nucleotides in the liver and does not change the glucose concentration in the plasma.

[Interaction of perfluoroctylbromide with liver microsomal monooxygenase].

Perfluorooctylbromide (PFOB), a constituent component of gas-transporting fluorocarbon emulsions, liberates bromide ions when PFOB undergoes NADPH-dependent metabolism by liver microsomal monooxygenase. The PFOB emulsion injected to rats decreases the liver microsomal cytochrome P-450 level down to 80% of control. Induction of the "phenobarbital" isoforms of cytochrome P-450 (cytochrome P-450 II B1/B2) after administration of PFOB is much weaker than that after administration of the perfluorodecalin emulsion.

[Mechanism of inhibiting the cytochrome P-450-dependent monooxygenase system in liver with fluorocarbons].

The inducer of the liver monooxygenase system perfluorodecalin added to microsomes as a submicron emulsion forms an enzyme-substrate complex with cytochrome P-450. The K(app) values for the perfluorodecalin binding to cytochrome P-450 in microsomes isolated from the livers of control and phenobarbital-treated rats are 5 x 10(-5) M and 2.3 x 10(-6) M, respectively.

Effect of perfluorodecalin on activities of hepatic phase II xenobiotic biotransformation enzymes.

The activity of the hepatic phase II enzymes of xenobiotic biotransformation after intravenous administration of perfluorodecalin emulsion to rats was measured. Perfluorodecalin was found to increase the microsomal glutathione S-transferase and UDP-glucuronosyltransferase activities 1.4- and 2.

[The effect of perfluordecaline on the activity of phase III xenobiotic transformation enzymes].

Injection of perfluorodecaline to rats caused an increase of the phase II xenobiotic biotransformation enzyme activities followed by cytochrome P-450 induction. The activities of liver microsomal UDP-glucuronosyl transferase and glutathione transferase increased by 130 and 40%, respectively, against the control level. The increase of the cytosolic glutathione transferase activity was insignificant In contrast, the activity of sulfotransferase decreased about 2-fold.

The phenobarbital-type induction of rat liver microsomal monooxygenases by perfluorodecalin.

Induction of perfluorodecalin (PFD) of the liver microsomal system of metabolism of xenobiotics has been studied and compared with the inductions by phenobarbital (PB) and 3-methylcholanthrene (MC). It has been shown that PFD increases the content of cytochrome P-450, NADPH-cytochrome c reductase activity. Like PB, PFD induces the activities of benzphetamine-N-demethylase, aldrine-epoxidase, 16 beta-androstendion-hydroxylase.

[Perfluorocarbons do not induce cytochrome P-448 in the rat liver].

Cytochrome P-450 forms appearing in the liver after injection of methylcholanthrene, polychlorinated biphenyls and perfluorochemical emulsion to rats were studied. Activities of marker enzymes, benzpyrenehydroxylase and 7-ethoxyresorufin-O-deethylase, as well as the interaction of liver microsomal membranes with antibodies against different cytochrome forms were investigated. It was shown that fluorocarbon emulsion containing perfluorodecalin did not induce cytochrome P-448 in the rat liver.

[Analysis of the physico-chemical properties of fluorocarbon inducers of cytochrome P-450 in membranes of liver endoplasmic reticulum].

Cytochrome P-450 induction in rat liver microsomes after intravenous injections of submicrone emulsions of nine perfluorochemicals (2 g of PFC per kg of body weight) was investigated. A comparison of physico-chemical properties of the fluorocarbons revealed that their activity as cytochrome P-450 inducers is determined by their solubility in H2O and lipids as well as by the pressure of their saturated vapours at 37 degrees C. The fluorocarbons capable of inducing cytochrome P-450 have a molecular mass of 400-550 Da.

[Phenobarbital-type induction of cytochrome P-450 in liver microsomes by perfluorodecalin].

Cytochrome P-450 induction in hepatic microsomes after injections of rats with a fluorocarbon emulsion containing perfluorodecalin was studied in comparison with phenobarbital and methylcholanthrene type inductions. It was shown that perfluorodecalin injection as well as the phenobarbital one cause an increase in the cytochrome P-450 content, NADPH-cytochrome c reductase activity, the rates of benzphetamine N-demethylation and aldrin epoxidation in the microsomes. Using the Ouchterlony double immunodiffusion test with antibodies against cytochrome P-450b, an immunological identity of cytochrome P-450 isoforms during perfluorodecalin and phenobarbital inductions was shown.

[Induction of microsomal cytochromes in the rat liver after intravenous administration of emulsions of perfluoro-organic compounds].

Intravenous injections of perfluoroorganic emulsions to rats in a dose of 3 ml/kg led to changes in the composition and activity of enzymes of the liver microsomal membrane monooxygenase system. At the peak of induction, i. e.