Photographic study of propellant outflow from a cylindrical tank during weightlessness

Photographic study of liquid propellant behavior in pumping from cylindrical tank during weightlessnes

Expression of the Aldo-Ketoreductases AKR1B1 and AKR1B10 in Human Cancers

The American Cancer Society estimates that there will be more than 1.5 million new cases of cancer in 2011, underscoring the need for identification of new therapeutic targets and development of novel cancer therapies. Previous studies have implicated the human aldo-ketoreductases AKR1B1 and AKR1B10 in cancer, and therefore we examined AKR1B1 and AKR1B10 expression across all major human cancer types using the Oncomine cancer gene expression database (Compendia Biosciences, www.oncomine.com). Using this database, we found that expression of AKR1B1 and AKR1B10 varies greatly by cancer type and tissue of origin, including agreement with previous reports that AKR1B10 is significantly over-expressed in cancers of the lungs and liver. AKR1B1 is more broadly over-expressed in human cancers than AKR1B10, albeit at a generally lower magnitude. AKR1B1 over-expression was found to be associated with shortened patient survival in acute myelogenous leukemias and multiple myelomas. High AKR1B10 expression tends to predict less aggressive clinical course generally, notably within lung cancers, where it tends to be highly over-expressed compared to normal tissue. These findings suggest that AKR1B1 inhibitors in particular hold great potential as novel cancer therapeutics

Disruption of aldo-keto reductase genes leads to elevated markers of oxidative stress and inositol auxotrophy in Saccharomyces cerevisiae

AbstractA large family of aldo-keto reductases with similar kinetic and structural properties but unknown physiological roles is expressed in the yeast Saccharomyces cerevisiae. Strains with one or two AKR genes disrupted have apparently normal phenotypes, but disruption of at least three AKR genes results in a heat shock phenotype and slow growth in inositol-deficient culture medium (Ino−). The present study was carried out to identify metabolic or signaling defects that may underlie phenotypes that emerge in AKR deficient strains. Here we demonstrate that pretreatment of a pentuple AKR null mutant with the anti-oxidative agent N-acetyl-cysteine rescues the heat shock phenotype. This indicates that AKR gene disruption may be associated with defects in oxidative stress response. We observed additional markers of oxidative stress in AKR-deficient strains, including reduced glutathione levels, constitutive nuclear localization of the oxidation-sensitive transcription factor Yap1 and upregulation of a set of Yap1 target genes whose function as a group is primarily involved in response to oxidative stress and redox balance. Genetic analysis of the Ino− phenotype of the null mutants showed that defects in transcriptional regulation of the INO1, which encodes for inositol-1-phosphate synthase, can be rescued through ectopic expression of a functional INO1. Taken together, these results suggest potential roles for AKRs in oxidative defense and transcriptional regulation

Results and status of the NASA aircraft engine emission reduction technology programs

The results of an aircraft engine emission reduction study are reviewed in detail. The capability of combustor concepts to produce significantly lower levels of exhaust emissions than present production combustors was evaluated. The development status of each combustor concept is discussed relative to its potential for implementation in aircraft engines. Also, the ability of these combustor concepts to achieve proposed NME and NCE EPA standards is discussed

Component Performance Investigation of J71 Type II Turbines: III - Overall Performance of J71 Type IIA Turbine

The over-all component performance characteristics of the J71 Type IIA three-stage turbine were experimentally determined over a range of speed and over-all turbine total-pressure ratio at inlet-air conditions af 35 inches of mercury absolute and 700 deg. R. The results are compared with those obtained for the J71 Type IIF turbine, which was previously investigated, the two turbines being designed for the same engine application. Geometrically the two turbines were much alike, having the same variation of annular flow area and the same number of blades for corresponding stator and rotor rows. However, the blade throat areas downstream of the first stator of the IIA turbine were smaller than those of the IIF; and the IIA blade profiles were curve-backed, whereas those of the IIF were straight-backed. The IIA turbine passed the equivalent design weight flow and had a brake internal efficiency of 0.880 at design equivalent speed and work output. A maximum efficiency of 0.896 occurred at 130 percent of design equivalent speed and a pressure ratio of 4.0. The turbine had a wide range of efficient operation. The IIA turbine had slightly higher efficiencies than the IIF turbine at comparable operating conditions. The fact that the IIA turbine obtained the design equivalent weight flow at the design equivalent operating point was probably a result of the decrease in the blading throat areas downstream of the first stator from those of the IIF turbine, which passed 105 percent of design weight flow at the corresponding operating point. The third stator row of blades of the IIA turbine choked at the design equivalent speed and at an over-all pressure ratio of 4.2; the third rotor choked at a pressure ratio of approximately 4.

Biophysical characteristics of human milk proteins for enhancing tear stability in dry eye

Purpose : Dry eye disease affects millions of people worldwide and is prevalent in older people, females, contact lens wearers, and increasingly in the general population due to excessive use of visual display devices. Tear instability is the characteristic pathophysiology of the disease due to the inability of tears to form a stable film on the ocular surface, which leads to drying of the ocular surface. Enhancing tear stability is known to relieve symptoms of dry eye. Human breast milk (HBM) has been shown to contain proteins that enhance ocular surface healing following injury. In healthy tears, tear proteins increase tear stability by showing surface-active properties. The aim of this project was to study the biophysical characteristics of HBM proteins and compare them with the proteins found in tears as a first step to explore the use of HBM constituents for treatment of dry eye. Methods : HBM samples were fresh frozen, then thawed, centrifuged, and aqueous recovered for lyophilisation. The aqueous containing proteins was used in the experiments. Pressure-area profiles and rheology of surface films of HBM proteins and tear proteins, namely, lysozyme and lactoferrin were studied using Langmuir trough technology on an artificial tear solution at the physiological pH and temperature of tears. Results : Pressure-area profiles indicated that HBM proteins formed a highly compressible, non-collapsible surface film with a maximum surface pressure of 32mN/m. The surface films of lysozyme and lactoferrin were also compressible with the maximum surface pressures of 23mN/m and 17mN/m, respectively. Hysteresis was observed in all proteins with smallest in lactoferrin and highest in lysozyme. Conclusions : HBM proteins are surface active and capable of reducing surface tension to increase the film stability. They are effective in smaller amounts, show higher surface pressure, and wider surface coverage than tear proteins lysozyme and lactoferrin. Overall, the biophysical experiments indicate that HBM proteins in smaller amounts would provide better protection to the tear film than the natural proteins of the tear film and can be effective in enhancing tear stability in dry eye

Investigation of Turbines Suitable for Use in a Turbojet Engine with High Compressor Pressure Ratio and Low Compressor-tip Speed VII : Experimental Performance of Modified Two-stage Turbine

Modifying the original turbine by closing down the first-rotor throat area and shrouding the first and second rotors resulted in an over-all increase in in efficiency of 3.5 percentage points. At equivalent design work and speed the rating and aerodynamic efficiences of the modified turbine were 0.825 and 0.846, respectively. The maximum rating and erodynamic efficiencies were 0.875 and 0.906, respectively. A radial survey indicated improved firstively. A radial survey indicated improved first and second-stage efficiencies but showed that the effective throat areas of the second stator and rotor were too large