J. M. T. McKee

Research Triangle Park Foundation

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B. J. Mulholland

University of Nottingham

Mark Higuchi

Research Triangle Park Foundation

Gary E. Hatch

Research Triangle Park Foundation

W. E. Finch-Savage

University of Warwick

Philip J. Bushnell

Research Triangle Park Foundation

Tatiana V. Morozova

A.V. Zhirmunsky National Scientific Center of Marine Biology Far Eastern Branch of the Russian Academy of Sciences

Wendy M. Oshiro

Research Triangle Park Foundation

W.H. Caplinger

C. C. Hole

University of Warwick

Ralph Slade

Research Triangle Park Foundation

Cooperative Institutions

Environmental Protection Agency

Research Triangle Park Foundation

University of North Carolina at Chapel Hill

University of Warwick

Triangle

University of Nottingham

National Institutes of Health

National Institute of Environmental Health Sciences

Australian National University

Duke University

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EVALUATION OF CARBON ACTIVITY SOURCES IN SODIUM.

J. M. T. McKee W.H. Caplinger

Carbon fibers

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Oxygen Effects in a Type-316 Stainless-Steel, Nb-1% Zr, Liquid Potassium System

Nuclear Applications (1969)

K. Goldmann J. M. T. McKee

Liquid potassium was circulated between 1200 and 1600°F in 31 Type-316 stainless-steel thermal convection loops and one forced circulation loop. Each loop contained a string of niobium-1% zirconium (Nb-1% Zr) alloy and stainless-steel test specimens positioned along the entire heated leg. To follow corrosion as a function of time and temperature, the test specimens were examined at 500 to 2500 h intervals. Controlled additions of interstitial impurities to the potassium were made in some thermal convection loops at the start of the test. Oxygen additions to the potassium sharply accelerated the initial rate of Nb-1% Zr surface removal but produced no identifiable oxide film or microstructural changes. The initially high weight-loss rates, observed in oxygen addition loops, decayed rapidly with time, returning essentially to normal rates (in the absence of further oxygen additions) after 2500 h. Oxygen additions produced very little effect on the stainless-steel corrosion rates, presumably due to rapid gettering of the added oxygen by the Nb-1% Zr.Similar tests in a forced circulation loop, with potassium velocities past the test specimens 18 times higher than in the thermal convection loops, showed that any effects of velocity on the Nb-1% Zr corrosion rate were far overshadowed by effects that are assumed to be related to oxygen in the potassium.

Getter

Forced convection

Zirconium alloy

10.13182/nt69-a28340

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Progress in Assessing Air Pollutant Risks from In Vitro Exposures: Matching Ozone Dose and Effect in Human Airway Cells

Toxicological Sciences (2014)

Gary E. Hatch Kelly Duncan David Díaz-Sánchez Michael T. Schmitt Andrew J. Ghio

In vitro exposures to air pollutants could, in theory, facilitate a rapid and detailed assessment of molecular mechanisms of toxicity. However, it is difficult to ensure that the dose of a gaseous pollutant to cells in tissue culture is similar to that of the same cells during in vivo exposure of a living person. The goal of the present study was to compare the dose and effect of O3 in airway cells of humans exposed in vivo to that of human cells exposed in vitro. Ten subjects breathed labeled O3 ((18)O3, 0.3 ppm, 2 h) while exercising intermittently. Bronchial brush biopsies and lung lavage fluids were collected 1 h post exposure for in vivo data whereas in vitro data were obtained from primary cultures of human bronchial epithelial cells exposed to 0.25-1.0 ppm (18)O3 for 2 h. The O3 dose to the cells was defined as the level of (18)O incorporation and the O3 effect as the fold increase in expression of inflammatory marker genes (IL-8 and COX-2). Dose and effect in cells removed from in vivo exposed subjects were lower than in cells exposed to the same (18)O3 concentration in vitro suggesting upper airway O3 scrubbing in vivo. Cells collected by lavage as well as previous studies in monkeys show that cells deeper in the lung receive a higher O3 dose than cells in the bronchus. We conclude that the methods used herein show promise for replicating and comparing the in vivo dose and effect of O3 in an in vitro system.

10.1093/toxsci/kfu115

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Inhibition of vascular endothelial growth factor by highbush blueberry fruit (Vaccinium corymbosum v bluecrop) in Eahy 926 and U937 cell lines

Planta Medica (2008)

Ara Der Marderosian Radhika Kota JR Porter Diane W. Morel J. M. T. McKee

Previous studies have shown that Blueberries possess anti-angiogenic, anti-infective, anti-inflammatory, anti-carcinogenic, and anti-Alzheimer's properties (Bagchi et al. 2004, Joseph et al. 2003). Whole Blueberry Extract (WBE) was prepared from Vaccinium corymbosum L Bluecrop, by macerating the whole crushed blueberries in 80% acetone/water. The above WBE fraction was lyophilized and tested using the Enzyme Linked Immuno-Sorbent Assay (ELISA) for Vascular Endothelial Growth Factor (VEGF) in U937 and Eahy926 cell lines. The WBE fraction of Vaccinium corymbosum L bluecrop was found to inhibit VEGF in both the cell lines and the inhibitory activity was proportional to its concentration. These observations indicate that Whole Blueberry Extract possesses potent inhibitory activity on VEGF that results in anti-angiogenic property which helps in the protective action against certain cancers. Cytotoxicity studies were also performed on these cell lines for the effective inhibitory concentrations of the WBE fraction and were found to be non toxic. The above WBE fraction was further fractionated into different polyphenolic fractions and the highly active fraction was determined.

Vaccinium

10.1055/s-0028-1084849

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Evaluation of an Air Quality Health Index for Predicting the Mutagenicity of Simulated Atmospheres

Environmental Science & Technology (2018)

Jose Zavala Jonathan D. Krug Sarah H. Warren Q. Todd Krantz Charly King

No study has evaluated the mutagenicity of atmospheres with a calculated air quality health index (AQHI). Thus, we generated in a UV-light-containing reaction chamber two simulated atmospheres (SAs) with similar AQHIs but different proportions of criteria pollutants and evaluated them for mutagenicity in three Salmonella strains at the air-agar interface. We continuously injected into the chamber gasoline, nitric oxide, and ammonium sulfate, as well as either α-pinene to produce SA-PM, which had a high concentration of particulate matter (PM): 119 ppb ozone (O3), 321 ppb NO2, and 1007 μg/m3 PM2.5; or isoprene to produce SA-O3, which had a high ozone (O3) concentration: 415 ppb O3, 633 ppb NO2, and 55 μg/m3 PM2.5. Neither PM2.5 extracts, NO2, or O3 alone, nor nonphoto-oxidized mixtures were mutagenic or cytotoxic. Both photo-oxidized atmospheres were largely direct-acting base-substitution mutagens with similar mutagenic potencies in TA100 and TA104. The mutagenic potencies [(revertants/h)/(mgC/m3)] of SA-PM (4.3 ± 0.4) and SA-O3 (9.5 ± 1.3) in TA100 were significantly different ( P < 0.0001), but the mutation spectra were not ( P = 0.16), being ∼54% C → T and ∼46% C → A. Thus, the AQHI may have some predictive value for the mutagenicity of the gas phase of air.

Isoprene

10.1021/acs.est.8b00613

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A study of the optimum drying conditions for cabbage seed following selection on the basis of a newly‐emerged radicle

Annals of Applied Biology (1988)

W. E. Finch-Savage J. M. T. McKee

SUMMARY A series of experiments were carried out to study the effects of different drying regimes on the survival of newly‐germinated (radicle emerged 0·5‐1·5 mm through the seed coat) cabbage seeds and to establish a treatment for reducing the moisture content of these germinated seeds. A preliminary surface‐drying step proved necessary to avoid seed agglutination during the main drying stage. Of the drying regimes compared both viability and vigour were most effectively maintained in air, conditioned to between 20 and 30°C and with 80% r.h., flowing through the seeds at 0·25 m s ‐1 . Under these conditions, the viability and vigour of newly‐germinated seed was maintained during drying to an equilibrium moisture content of c. 14%. At this moisture content further radicle growth was prevented and seeds remained free‐flowing and separate for sowing or for further treatment.

Radicle

Recalcitrant seed

10.1111/j.1744-7348.1988.tb03317.x

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The Effect of Growth Rate on Tipburn Occurrence in Lettuce

Journal of Horticultural Science (1976)

E. F. Cox J. M. T. McKee A. S. Dearman

SummaryThe occurrence of tipburn in lettuce has been correlated with relative growth rates for six cultivare grown under a range of controlled environments differing in temperature and light intensity. The results presented support the theory that many of the conditions previously reported as causing tipburn may do so by affecting growth rate. A reduction in the growth rate of field-grown plants brought about by close spacing resulted in a lower incidence of tipburn for some cultivare, but because of the associated reduction in plant size at maturity this method is unlikely to be of economic importance. Speculation as to the reason why rapid growth encourages tipburn involves nutritional aspects related to calcium utilization.

10.1080/00221589.1976.11514693

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Citations (55)

A model of the effects of water stress on seed advancement and germination

New Phytologist (1999)

H. R. Rowse J. M. T. McKee E. C. HIGGS

A model of seed germination is proposed which uses a variable with the units of an osmotic potential (virtual osmotic potential) to integrate the effect of a constant or a varying water potential. This differs from existing models that describe the effects of fixed water potentials on germination, or the effects of fixed priming water potentials on the subsequent germination at a fixed water potential. When a seed is sown, the virtual osmotic potential is assumed to fall at a rate that depends on the ambient water potential, and on the difference between its current and a minimum value. Radicle growth is assumed to initiate when the difference between the ambient water potential and the virtual osmotic potential exceeds a threshold. The germination of carrot and onion seeds at various fixed potentials below 0 MPa was well described by the virtual osmotic potential model. The model was also used to simulate the results of experiments in which seeds were given a single step change in water potential.

Radicle

Osmotic pressure

Water potential

Water Stress

Priming (agriculture)

Osmotic shock

Osmosis

10.1046/j.1469-8137.1999.00455.x

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Citations (20)

21 Ways Women in Management Shoot Themselves in the Foot

J. M. T. McKee

Foot (prosody)

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MCR LIQUID METAL TECHNOLOGY SUMMARY REPORT.

N. Hyman S. Kostman J. M. T. McKee

Corrosion in Cb-1% Zr, type 316 stainless steel (SS), potassium systems was experimentally evaluated under laboratory conditions intended to simulate the MCR.Thirty-one thermal convection loops and one forced circulation loop were utilized.Loop operation of 115,000 hr had been accumulated at termination of the MCR program.Twelve loops operated at 1600°F maximum potassium temperature for at least 5000 hr.Some of the effects of major variables, such as maximum temperatures, potassium purity, velocity, Reynolds number, and surface area ratios, were evaluated.This evaluation indicated that Cb-1% Zr and 316 SS may be satisfactory materials for MCR fuel cladding and primary system containment, respectively.Surface removal rates, based on gross weight change data from Cb-1% Zr in thermal convection loops, can be held to less than 0.1 mil/year by maintaining a low oxygen content in the potassium.Carbon and nitrogen are transferred by the potassium from the stainless steel to form reaction layers on the Cb-1% Zr.Diffusion of carbon and nitrogen into the matrix is sufficiently slow in thermal convection loops to maintain adequate structural properties up to 1600°F for 5000 hr.Hot end stainless steel surface removal rates, as indicated by gross weight change data, are less than 1 mil/year.Deeper intergranular penetration was observed in some localized heater areas.Room temperature tensile testing of sections from a thermal convection loop, which operated for 14,000 hr, indicated that the 316 SS remained ductile.CONFiDENTtAi.••

Liquid metal

10.2172/4517146

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