Descriptors for terpene esters from chromatographic and partition measurements: Estimation of human odor detection thresholds

We have used gas chromatographic retention data together with other data to obtain Abraham descriptors for 30 terpene esters. These include the air-water partition coefficient, as log Kw, for which no experimental values are available for any terpene ester. The other descriptors are the ester dipolarity, S, the hydrogen bond basicity, B, (the ester hydrogen bond acidity is zero for the esters studied), and L the logarithm of the air-hexadecane partition coefficient. Both S and B are larger than those for simple aliphatic esters, as expected from the terpene ester structures that include ring systems and ethylenic double bonds. These descriptors can then be used to obtain a large number of physicochemical and environmental properties of terpene esters. We have analyzed experimental results on human odor detection thresholds and have constructed another equation for the calculation of these thresholds, to go with a previous equation that we have reported. Then the descriptors for terpene esters can be used to estimate the important odor detection thresholds

Selection of Ionic Liquid Solvents for Chemical Separations Based on the Abraham Model

Book chapter on the selection of ionic liquid solvents for chemical separations based on the Abraham model

Prediction of Partition Coefficients and Permeability of Drug Molecules in Biological Systems with Abraham Model Solute Descriptors Derived from Measured Solubilities and Water-to-Organic Solvent Partition Coefficients

Book chapter on the prediction of partition coefficients and permeability of drug molecules in biological systems with Abraham model solute descriptors derived from measured solubilities and water-to-organic solvent partition coefficients

Recruitment and baseline characteristics of the Community of Voices choir study to promote the health and well-being of diverse older adults.

Objective:To describe the recruitment and baseline results of the Community of Voices study that aims to examine the effect of a community choir intervention on the health and well-being of older adults from diverse racial/ethnic and socioeconomic backgrounds. Method:Using community-based participatory research methods, we recruited adults age 60 and over from 12 Administration on Aging-supported senior centers in San Francisco into a 2-arm cluster-randomized controlled trial of the community choir intervention. Multiple outreach methods were used. We tracked outreach, screening, and recruitment metrics and collected demographics and baseline outcomes via community-based, interviewer-administered surveys and performance measures of cognition, physical function, and psychosocial variables. Results:The study contacted 819 individuals, screened 636, and enrolled 390 diverse older adults over a 42-month, phased recruitment period. The mean age was 71.2 (SD = 7.3), and the majority were women. Two-thirds of the sample are non-white, and 20% of participants reported having financial hardship. Discussion:Outreach and recruitment methods used in the Community of Voices trial facilitated enrollment of a large proportion of minority and lower-SES older adults in the final sample. Similar recruitment approaches could serve as a model for recruiting diverse racial/ethnic and socioeconomic older adults into research

Cortisol patterns are associated with T cell activation in HIV.

ObjectiveThe level of T cell activation in untreated HIV disease is strongly and independently associated with risk of immunologic and clinical progression. The factors that influence the level of activation, however, are not fully defined. Since endogenous glucocorticoids are important in regulating inflammation, we sought to determine whether less optimal diurnal cortisol patterns are associated with greater T cell activation.MethodsWe studied 128 HIV-infected adults who were not on treatment and had a CD4(+) T cell count above 250 cells/µl. We assessed T cell activation by CD38 expression using flow cytometry, and diurnal cortisol was assessed with salivary measurements.ResultsLower waking cortisol levels correlated with greater T cell immune activation, measured by CD38 mean fluorescent intensity, on CD4(+) T cells (r = -0.26, p = 0.006). Participants with lower waking cortisol also showed a trend toward greater activation on CD8(+) T cells (r = -0.17, p = 0.08). A greater diurnal decline in cortisol, usually considered a healthy pattern, correlated with less CD4(+) (r = 0.24, p = 0.018) and CD8(+) (r = 0.24, p = 0.017) activation.ConclusionsThese data suggest that the hypothalamic-pituitary-adrenal (HPA) axis contributes to the regulation of T cell activation in HIV. This may represent an important pathway through which psychological states and the HPA axis influence progression of HIV

Equations for the Correlation and Prediction of Partition Coefcients of Neutral Molecules and Ionic Species in the Water-Isopropanol Solvent System

We use literature data on solubilities of 46 compounds in the water-isopropanol (IPA) system to obtain the corresponding partition coefficients, P, for transfer from water to water- IPA mixtures. We have then used our previously constructed linear free energy equation to obtain equations that correlate log10 P at water-IPA intervals across the entire water-IPA system. These equations can then be used to predict partition coefficients and solubilities of further compounds in the water-IPA systems at 298 K. The coefficients in our linear free energy equation encode information on the physicochemical properties of the water- IPA mixtures. We show that the hydrogen bond basicity of the water-IPA mixtures only increases slightly from water to IPA, but that the hydrogen bond acidity of the mixtures decreases markedly from water to IPA in a smooth continuous manner. We have also used data on ions and on ionic species to set out equations for the estimation of their partition coefficients from water to water-IPA mixtures. We find that for partition from water to IPA itself, log10 P = − 1.81 for H+

The Solvation Properties of the Aliphatic Alcohols

Article on the solvation properties of the aliphatic alcohols