J.F. Nash

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Papers by J.F. Nash

Probabilistic Aggregate Exposure Modelling for a Broad Spectrum Antimicrobial in Personal Cleansing Products

ISEE Conference Abstracts, 2013

Background:Realistic estimates of chemical aggregate exposure are needed to ensure consumer safet... more

Analysis of dynamic stall using unsteady boundary-layer theory. [effect of pitch rate on the delay in forward movement of the rear flow reversal point]

The unsteady turbulent boundary layer and potential flow about a pitching airfoil are analyzed us... more The unsteady turbulent boundary layer and potential flow about a pitching airfoil are analyzed using numerical methods to determine the effect of pitch rate on the delay in forward movement of the rear flow reversal point. An explicit finite difference scheme is used to integrate the unsteady boundary layer equations, which are coupled at each instant of time to a fully unsteady and nonlinear potential flow analysis. A substantial delay in forward movement of the reversal point is demonstrated with increasing pitch rate, and it is shown that the delay results partly from the alleviation of the gradients in the potential flow, and partly from the effects of unsteadiness in the boundary layer itself. The predicted delay in flow-reversal onset, and its variation with pitch rate, are shown to be in reasonable agreement with experimental data relating to the delay in dynamic stall. From the comparisons it can be concluded (a) that the effects of time-dependence are sufficient to explain ...

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Treatment of poliomyelitis

Southern medicine and surgery, 1952

Locomotive building (in the shipbuilding, engineering, and metal trades group) again contributed ... more

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Harmonisation for sun care product testing and labeling : Whats possible?

Three dimensional compressible boundary-layer computations for a finite swept wing

Three-dimensional, compressible turbulent boundary-layer calculations have been performed for the... more Three-dimensional, compressible turbulent boundary-layer calculations have been performed for the finite supercritical wing of the NASA modified F8 transonic research airplane. Data on the boundary-layer thickness, displacement thickness, skin friction components, and integrated streamwise skin friction are presented for points along the streamwise stations of which the pressure measurements were previously made. Representative velocity profiles are shown, and boundary-layer-thickness contour plots and skin-friction vector plots are presented. Results are given for a Reynolds number of 1.5 million per foot, and for Mach numbers of 0.50 and 0.99.

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Formulation and Artificial Sebum Effects on the Percutaneous Absorption of Zinc Pyrithione through Excised Human Skin

Skin Pharmacology and Physiology, 2019

Background: Zinc pyrithione (ZnPT) is deposited on the skin as a fine particulate and must reach ... more Background: Zinc pyrithione (ZnPT) is deposited on the skin as a fine particulate and must reach microorganisms localized in the stratum corneum and hair follicles in molecular form to exert its broad-spectrum antimicrobial/antifungal activity. Dissolution of ZnPT particles followed by molecular speciation results in the organic portion, i.e. pyrithione, being more susceptible to skin penetration than the inorganic component, i.e. zinc, or the chelate itself, i.e. ZnPT. Objectives: To further test the hypothesis that ZnPT skin penetration is rate-limited by dissolution and molecular speciation, the effect of different formulations and artificial sebum on the in vitro percutaneous absorption of radiolabel associated with Zn[14C]PT was investigated. Method: In vitro penetration of [14C]PT into and through excised human skin was measured following application of Zn[14C]PT prepared as suspensions in distinct vehicles including water-based carboxymethylcellulose (CMC), diluted body wash ...

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Side effects from intense pulsed light: Importance of skin pigmentation, fluence level and ultraviolet radiation—A randomized controlled trial

Lasers in Surgery and Medicine, 2016

Background and ObjectiveIntense pulsed light (IPL) is a mainstream treatment for hair removal. Si... more Background and ObjectiveIntense pulsed light (IPL) is a mainstream treatment for hair removal. Side effects after IPL are known, but risk factors remain to be investigated. The objective of this study was to assess the contribution of skin pigmentation, fluence level, and ultraviolet radiation (UVR) on IPL‐induced side effects.MethodsThe study was a blinded, randomized intra‐individual controlled trial including 16 healthy subjects with Fitzpatrick Skin Types (FST) II–V. Three test areas were each divided into four sites, randomized to a single IPL exposure of 22, 34, 46 J/cm2 or triple stacking of 46 J/cm2. Areas were subsequently randomized to no UVR or single solar‐simulated UVR exposure of 3 Standard Erythema Dose at 30 minutes or 24 hours after IPL. Each area had a corresponding control, resulting in 15 treatment sites. Follow‐up visits were scheduled up to 4 weeks after IPL. Outcome measures were: (i) blinded clinical skin reactions; (ii) objectively measured erythema and pigm...

A pharmacokinetic method for designing prolonged-release formulations—Propoxyphene hydrochloride

Journal of Pharmacokinetics and Biopharmaceutics, 1976

Many prolonged-release preparations are designed so that a certain fraction is immediately availa... more Many prolonged-release preparations are designed so that a certain fraction is immediately available for absorption upon administration, while the remainder becomes available for absorption at an effectively constant rate. Recently, a number of prolonged-release propoxyphene hydrochloride formulations have been designed to dissolve in this manner in vitro. We employed a pharmacokinetic model, product dissolution data, and historical plasma concentration data to predict the plasma propoxyphene concentrations which might result from a particular mix and thus minimize the number of formulations requiring evaluation in subjects.

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Aggregate exposure modelling of zinc pyrithione in rinse-off personal cleansing products using a person-orientated approach with market share refinement

Food and Chemical Toxicology, 2015

Realistic estimates of chemical aggregate exposure are needed to ensure consumer safety. As expos... more Realistic estimates of chemical aggregate exposure are needed to ensure consumer safety. As exposure estimates are a critical part of the equation used to calculate acceptable "safe levels" and conduct quantitative risk assessments, methods are needed to produce realistic exposure estimations. To this end, a probabilistic aggregate exposure model was developed to estimate consumer exposure from several rinse off personal cleansing products containing the anti-dandruff preservative zinc pyrithione. The model incorporates large habits and practices surveys, containing data on frequency of use, amount applied, co-use along with market share, and combines these data at the level of the individual based on subject demographics to better estimate exposure. The daily-applied exposure (i.e., amount applied to the skin) was 3.79 mg/kg/day for the 95th percentile consumer. The estimated internal dose for the 95th percentile exposure ranged from 0.01e1.29 mg/kg/day after accounting for retention following rinsing and dermal penetration of ZnPt. This probabilistic aggregate exposure model can be used in the human safety assessment of ingredients in multiple rinse-off technologies (e.g., shampoo, bar soap, body wash, and liquid hand soap). In addition, this model may be used in other situations where refined exposure assessment is required to support a chemical risk assessment.

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Discussion: “A Momentum Integral Solution of a Three-Dimensional Turbulent Boundary Layer” (Pierce, F. J., and Klinksiek, W. F., 1972, ASME J. Basic Eng., 94, pp. 795–800)

Journal of Basic Engineering, 1972

The flow field selected by the authors for comparison purposes provides an interesting test for t... more The flow field selected by the authors for comparison purposes provides an interesting test for the three-dimensional integral method since the flow is dominated by severe pressure gradients and the effects of cross-flow are substantial. More importantly, Johnston [12] determined the three-dimensional line of separation for this flow field from dye traces on the wall and smoke flow studies. We therefore ask the authors to comment on the applicability of the present integral method for predicting threedimensional'separation of a turbulent boundary layer in the context of the selected flow field. Also, another interesting com-

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Modulation of methylenedioxymethamphetamine-induced striatal dopamine release by the interaction between serotonin and gamma-aminobutyric acid in the substantia nigra

The Journal of pharmacology and experimental therapeutics, 1995

The effects of the amphetamine analog, 3,4-methylenedioxymethamphetamine (MDMA) were compared to ... more The effects of the amphetamine analog, 3,4-methylenedioxymethamphetamine (MDMA) were compared to the effects of d-amphetamine on the in vivo release of dopamine and gamma-aminobutyric acid (GABA) in the striatum and substantia nigra. The brain region-dependent role of the 5-HT2 receptors in the striatum and substantia nigra in regulating MDMA-induced dopamine and GABA release also was studied. Changes in the extracellular concentration of dopamine, 5-HT and GABA were measured simultaneously in the awake rat by in vivo microdialysis. The increase in striatal dopamine produced by systemic administration of MDMA was attenuated by infusion of TTX into the striatum. Infusion of the 5-HT2A/2C antagonist ritanserin into the striatum or the ipsilateral substantia nigra also significantly attenuated MDMA-induced dopamine release in the striatum. At the doses used in this study, MDMA but not d-amphetamine increased the extracellular concentrations of 5-HT and decreased GABA efflux in the subs...

Pharmacokinetic studies of benoxaprofen after therapeutic doses with a review of related pharmacokinetic and metabolic studies

The Journal of rheumatology. Supplement, 1980

The pharmacokinetics of benoxaprofen in therapeutic doses of 400 or 600 mg as a solution, capsule... more The pharmacokinetics of benoxaprofen in therapeutic doses of 400 or 600 mg as a solution, capsule or tablet were determined in 44 men after single or multiple doses. The plasma levels of the drug after oral administration of a solution best fitted a 2-compartment open pharmacokinetic model, whereas the levels after the solid dosage forms more appropriately fitted the simple 1-compartment open model. The plasma elimination half-life of the drug, when in solid dosage form, was found to be in the range of 19-26 h, justifying once-a-day dosage. Steady state levels of benoxaprofen were obtained after the 5th dose of a 400 mg capsule every 24 h.

Action of the anti-inflammatory agents, acetylsalicylic acid, indomethacin and fenoprofen on the gastric mucosa of dogs

Research communications in chemical pathology and pharmacology, 1975

Into the Heidenhain pouches of 3 dogs 30 ml of 0.1N HCl was instilled and removed at 30-minute in... more Into the Heidenhain pouches of 3 dogs 30 ml of 0.1N HCl was instilled and removed at 30-minute intervals for 6 hours. During the 3rd and 4th periods the acid instillate contained 4.5 mg/ml or 12.4 mM of ASA, indomethacin or fenoprofen. All 3 agents affected the functional integrity of the mucosal barrier, but the characteristics of their actions were different. The H+ concentration was decreased by ASA and fenoprofen and increased by indomethacin when the instillate contained drug. All 3 drugs increased the net flux of Na+, K+, Ca++ and Mg++. Following initial augmentation of instillate volume and H+ concentration, indomethacin caused sustained back diffusion of acid from lumen to mucosa; this was accompanied by mucosal bleeding. Peak effects of ASA on the net flux of ions occurred during or immediately after drug infusion and were greater than those of indomethacin and fenoprofen. Fenoprofen at 12.5 nM had no effect on concentrations of Ca++ and Mg++ while both were significantly i...

Non-linear two-dimensional aerodynamics by multidimensional singular integral computational analysis

Forschung im Ingenieurwesen, 2003

Planar airfoils are studied for the unsteady flow motion in two-dimensional aerodynamics. Such pr... more Planar airfoils are studied for the unsteady flow motion in two-dimensional aerodynamics. Such problems are reduced to the solution of a non-linear multidimensional singular integral equation, when the form of the source and vortex strength distribution is dependent on the history of these distributions on the NACA airfoil surface. A turbulent boundary layer model is also proposed, based on the formulation of the unsteady behavior of the momentum integral equation. Finally, an application is given to the determination of the velocity and pressure coefficient field around an aircraft by assuming constant vortex distribution.

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Esters of gentisic acid and their toxicities. I. Preparation and analyses of new esters of gentisic acid

Journal of the American Pharmaceutical Association, 1953

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Benoxaprofen kinetics in renal impairment

Clinical Pharmacology and Therapeutics, 1982

Benoxaprofen is a benzoxazole derivative of propionic acid with anti-inflammatory, antipy- retic,... more Benoxaprofen is a benzoxazole derivative of propionic acid with anti-inflammatory, antipy- retic, and analgesic properties. Unlike other nonsteroidal anti-inflammatory drugs, it is only a weak inhibitor of prostaglandin synthetase.4 6, " Benoxaprofen is highly bound to plasma proteins and is little affected by first-pass hepatic metab- olism. Although only unchanged benoxaprofen is detected in plasma, about 60% is excreted in the urine as the p-glucuronide and about 40% is excreted in feces as the parent compound.9 The drug's relatively long half-life (0/2) in those with normal renal function allows it to be given as a single daily dose. This study was undertaken to determine benoxaprofen and benoxaprofen glucuronide kinetics in patients with impaired renal function and to establish dosage guidelines for these patients.

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The evolution of sunscreen products in the United States — a 12-year cross sectional study

Photochemical & Photobiological Sciences, 2013

Excessive exposure from ultraviolet (UV) radiation contributes to the development of skin cancers... more Excessive exposure from ultraviolet (UV) radiation contributes to the development of skin cancers and photoaging. Topical sunscreen products remain one of the most widely used forms of protection for the majority of the public. The objective of this analysis was to examine photoprotection trends (e.g., SPF value) and the degree of UVA I protection from 1997 to 2009 in the United States. Sunscreen products purchased and evaluated in 1997 (N = 59), 2003 (N = 188) and again in 2009 (N = 330), totaling 577, were included in this analysis. Information regarding (1) the SPF value, (2) name and concentration of the active ingredients, (3) type of products (i.e., daily vs. recreational/beach), and (4) claims of UVA protection was recorded and analyzed. In addition, the critical wavelength (CW) of 330 products from 2009 was determined. The results showed an increase in the SPF values of products from 1997 to 2009. The percentage of low SPF products (SPF 4-14) decreased from 27% in 1997 to 6% in 2009. The number of products containing a known UVA-I filter (i.e., avobenzone or zinc oxide) increased from 5% in 1997 to 70% in 2009. Lastly, approximately, 225 (68%) of the products tested in 2009 attained CW > 370 nm. In the past decade, sunscreen products have undergone fundamental improvements, the most significant of which is the breadth of protection against UVA I. † This article is published as part of a themed issue on current topics in photodermatology.

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Ketanserin pretreatment attenuates MDMA-induced dopamine release in the striatum as measured by microdialysis

Life Sciences, 1990

Systemic administration of the amphetamine analogue, 3,4-methylenedioxymethamphetamine (MDMA) pro... more Systemic administration of the amphetamine analogue, 3,4-methylenedioxymethamphetamine (MDMA) produced a dose-dependent increase in the extracellular concentration of dopamine (DA) in the striatum as measured by in vivo microdialysis in awake, freely-moving rats. The extracellular concentration of the DA metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC), was significantly decreased in dialysate samples following the administration of MDMA (10 and 20 mg/kg, i.p.). The serotonin-2 (5-HT2) antagonist ketanserin (3 mg/kg, i.p.) had no effect on the extracellular concentration of DA or DOPAC in the striatum of vehicle- treated rats. The administration of ketanserin (3 mg/kg) 1 hr prior to MDMA (20 mg/kg) significantly attenuated the MDMA- induced increase in the extracellular concentration of DA without affecting the decrease in DOPAC concentrations. These data are suggestive that MDMA administration increases DA release in the striatum of awake, freely-moving rats. In addition, MDMA-induced increase in the extracellular concentration of DA in the striatum is mediated, in part, via 5-HT2 receptor mechanisms.

In vitro assessment of the broad-spectrum ultraviolet protection of sunscreen products

Journal of the American Academy of Dermatology, 2000

T he spectral distribution of solar UV radiation reaching the surface of the earth encompasses wa... more T he spectral distribution of solar UV radiation reaching the surface of the earth encompasses wavelengths between 290 and 400 nm. Commonly defined ranges for specific bands of the terrestrial UV spectrum are UVB (290-320 nm) and UVA (320-400 nm). In addition, the UVA waveband is often further divided into UVA2 (320-340 nm) and UVA1 (340-400 nm), generally reflecting the higher erythemogenic efficiency of shorter UVA wavelengths (UVA2). 1 Importantly, the division between these UV wavebands is arbitrary and anthropogenic; human skin is exposed primarily to solar UV, which includes all UV wavebands.

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GLC determination of chlormadinone acetate in plasma

Journal of Pharmaceutical Sciences, 1972

A decreased particle size in these drug-excipient systems was confirmed by differential thermal a... more A decreased particle size in these drug-excipient systems was confirmed by differential thermal analysis data; in most cases, a 2-3" depression in the melting point was observed. Hydrogen bonding in a gel matrix was apparently responsible for the formation of a metastable configuration in two systems: indomethacin and probucol. The polymorphic forms were first detected by differential thermal analysis and confirmed by X-ray and IR data. The existence of multiphase solids was a consequence of the presence of fumed silicon dioxide acting as a nucleating agent for the metastable crystals. Although the dissolution rates of the isolated polymorphs were found to be identical t o those of the original compounds, it is quite possible that in the dispersed state the metastable form dissolved at a rate faster than the stable form. Since drug-excipient interactions d o readily occur in normal manufacturing procedures, and since these interactions not only alter the physical and chemical properties of the drug but also appreciably affect the physiological availability of the drug from the dosage form, it is highly desirable that such interactions be considered as a part of strict in-process quality control.

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J.F. Nash

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