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The separation of azeotropic refrigerant mixtures is an important issue due to recent legislation requiring regulation and phase down. The ability to separate and recycle refrigerants is needed, as many refrigerants will be at end-of-life over the next couple of decades. Polymeric membranes provide the ability to separate refrigerant mixtures based on differences in solubility and diffusivity. The current study investigates the use of a copolymer of perfluoro(2,2-dimethyl-1,3-dioxole) (PDD) and vinyl acetate (VA) for refrigerant separation. The permeability, solubility, and diffusivity of HFC-32 (CH2F2), HFC-125 (CHF2CF3), HFC-134a (CF3CH2F), HFO-1234yf (CH2═CFCF3), and HCFC-22 (CHClF2) were measured in PDD-co-VA at 308.15, 323.15, 348.15, and 373.15 K. Arrhenius relationships were used to obtain the activation energy of permeation for each refrigerant. Arrhenius solubility and diffusivity relationships were applied to HFC-32 and HFC-125 to obtain the activation energy of diffusion and heat of sorption. Results indicate that selectivity decreases as the temperature increases. A high selectivity of 35 can be obtained for HFC-32/HFC-125 while maintaining a high permeability at 308.15 K. High selectivities of HFC-32/HFC-125, HFC-32/HFO-1234yf, HFC-32/HFC-134a, and HCFC-22/HFC-125 indicate the commercial potential of this polymer in the separation of refrigerant mixtures.

The increasing adoption of dicamba-tolerant soybean (Glycine max) increases the potential exposure of wine grape (Vitis sp.) to dicamba, to which off-target injury may occur via particle drift or vapor drift. In Missouri, at one site in 2017 and at two sites in 2018, research of production vineyards focused on the effects of dicamba on hybrid 'Vidal blanc' grapevines. During flowering and early fruit set, bearing grapevines were exposed to low rates of dicamba delivered as a spray solution of 81 or 161 ppm or by vapor from treated soil. Grapevines were highly sensitive to dicamba, and visible symptoms extended throughout the growing season. The severity of dicamba injury (leaf cupping and feathering) was similar at two of three site-years, with greater injury related to particle drift than to vapor drift of dicamba. Early-season injury resulted in dicamba impacting the total soluble solids (TSS) content of grape berries and grape yield. At harvest during two site-years, yield reductions of up to 45% were associated with dicamba exposure at flowering. Across all site-years, no significant effects of dicamba drift were observed in the TSS content of berries during veraison in August, as measured by refractometer. However, the final TSS content of berries at harvest in September was reduced by 12% from dicamba as particle drift. At a minimum detection level of 10 ng·mL-1, high-performance liquid chromatography mass spectrometry identified dicamba at levels up to 33 ng·mL-1 in grape must over all site-years. Unexpectedly, this was up to 125 d after grapevine exposure despite low levels of visible dicamba symptomology. [ABSTRACT FROM AUTHOR]

I was excited when I saw the article on Constantin Stanislavsky in the March issue, but my excitement quickly turned to disappointment. It is surprising to see that many theatre [...]

Abstract: Several studies have shown that microbial action is responsible for many compounds responsible for human odour. In this paper, we compare the pattern of microbial profiles and that of chemical profiles of human axillary odour by using multivariate pattern matching techniques. Approximately 200 subjects from Carinthia, Austria, participated in the study. The microbial profiles were represented by denaturing gradient gel electrophoresis (DGGE) analysis and the axillary odour profiles were determined in the sweat samples collected by a stir-bar sampling device and analysed by gas chromatography/mass spectrometry (GC/MS). Both qualitative and quantitative distance metrics were used to construct dissimilarity matrices between samples which were then used to represent the patterns of these two types of profiles. The distance matrices were then compared by using the Mantel test and the Procrustean test. The results show that on the overall dataset there is no strong correlation between microbial and chemical profiles. When the data are split into family groups, correlations vary according to family with a range of estimated p values from 0.00 to 0.90 that the null hypothesis (no correlation) holds. When 32 subjects who followed four basic rules of behaviour were selected, the estimated p-values are 0.00 using qualitative and <0.01 using quantitative distance metrics, suggesting excellent evidence that there is a connection between the microbial and chemical signature.

Individuals are thought to have their own distinctive scent, analogous to a signature or fingerprint. To test this idea, we collected axillary sweat, urine and saliva from 197 adults from a village in the Austrian Alps, taking five sweat samples per subject over 10 weeks using a novel skin sampling device. We analysed samples using stir bar sorptive extraction in connection with thermal desorption gas chromatograph–mass spectrometry (GC–MS), and then we statistically analysed the chromatographic profiles using pattern recognition techniques. We found more volatile compounds in axillary sweat than in urine or saliva, and among these we found 373 peaks that were consistent over time (detected in four out of five samples per individual). Among these candidate compounds, we found individually distinct and reproducible GC–MS fingerprints, a reproducible difference between the sexes, and we identified the chemical structures of 44 individual and 12 gender-specific volatile compounds. These individual compounds provide candidates for major histocompatibility complex and other genetically determined odours. This is the first study on human axillary odour to sample a large number of subjects, and our findings are relevant to understanding the chemical nature of human odour, and efforts to design electronic sensors (e-nose) for biometric fingerprinting and disease diagnoses.

To track bone mineral acquisition in adolescents with type 1 diabetes (DM).

The purpose of this study was to investigate the utility of cyclodextrins as a safer alternative to the commonly used cosolvent ethanol in topical N,N-diethyl-3-methylbenzamide (DEET) formulations. Ethanol is a known penetration enhancer and would ideally not be used in a formulation containing DEET, a compound known for its potential toxicity. DEET formulations were prepared containing up to 20% w/w γ-cyclodextrin (GCD) or 30% w/w hydroxypropyl-β-cyclodextrin (HPBCD). These formulations were evaluated by determining the release rate of DEET from its vehicle through a synthetic membrane into a receiver medium with a high affinity for DEET using a fully automated Franz-diffusion cell system. DEET release was measured by ultraviolet spectrophotometry at 260 nm. Both the traditional Higuchi release model and an alternate repeated measures analysis of variance with nested factors were used to analyze the data. The influence of the cyclodextrins on the volatility of DEET was determined by solid-phase microextraction. Morphological characterization of the formulations was performed by light microscopy. Physical stability of the formulations was evaluated by rheology in an accelerated study performed at 50°C for 28 days. The cyclodextrins caused a decrease in the release of DEET from its vehicle compared with an ethanol-containing formulation. This effect became more pronounced as the amount of cyclodextrin in the formulation was increased. The addition of the cyclodextrins resulted in a cream-like product compared with the ethanol formulation, which was a lotion. The DEET formulations had the following rank order of volatility: ethanol &lt; DEET = GCD &lt; HPBCD. Examination of the formulations by light microscopy indicated that the CD-based formulations produced a smaller and more homogeneous droplet size distribution than the ethanol-based formulations. The accelerated physical stability study indicated that cyclodextrin-based formulations are both technically and commercially feasible. Cyclodextrins are a promising alternative to ethanol in DEET-containing formulations. The reduced release rate of DEET from these formulations suggests that the toxic potential of DEET may be decreased in these products, while its repellency and stability are maintained. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91:101–110, 2002

The purpose of this study was to investigate the utility of cyclodextrins as a safer alternative to the commonly used cosolvent ethanol in topical N,N‐diethyl‐3‐methylbenzamide (DEET) formulations. Ethanol is a known penetration enhancer and would ideally not be used in a formulation containing DEET, a compound known for its potential toxicity. DEET formulations were prepared containing up to 20% w/w γ‐cyclodextrin (GCD) or 30% w/w hydroxypropyl‐β‐cyclodextrin (HPBCD). These formulations were evaluated by determining the release rate of DEET from its vehicle through a synthetic membrane into a receiver medium with a high affinity for DEET using a fully automated Franz‐diffusion cell system. DEET release was measured by ultraviolet spectrophotometry at 260 nm. Both the traditional Higuchi release model and an alternate repeated measures analysis of variance with nested factors were used to analyze the data. The influence of the cyclodextrins on the volatility of DEET was determined by solid‐phase microextraction. Morphological characterization of the formulations was performed by light microscopy. Physical stability of the formulations was evaluated by rheology in an accelerated study performed at 50°C for 28 days. The cyclodextrins caused a decrease in the release of DEET from its vehicle compared with an ethanol‐containing formulation. This effect became more pronounced as the amount of cyclodextrin in the formulation was increased. The addition of the cyclodextrins resulted in a cream‐like product compared with the ethanol formulation, which was a lotion. The DEET formulations had the following rank order of volatility: ethanol < DEET = GCD < HPBCD. Examination of the formulations by light microscopy indicated that the CD‐based formulations produced a smaller and more homogeneous droplet size distribution than the ethanol‐based formulations. The accelerated physical stability study indicated that cyclodextrin‐based formulations are both technically and commercially feasible. Cyclodextrins are a promising alternative to ethanol in DEET‐containing formulations. The reduced release rate of DEET from these formulations suggests that the toxic potential of DEET may be decreased in these products, while its repellency and stability are maintained. © 2002 Wiley‐Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91:101–110, 2002

The poem "Apples to elephants" by Sarah L. Dixon is presented. First Line: We threw apples; Last Line: to elephants.

Several letters to the editor are presented in response to articles in previous issues including one on the need for changes at the National Rugby League (NRL), one on Melbourne Storm supporters, and "Your Shout" in the April 28, 2010 issue.