Thermal conductivity of transposed multistrand flat superconductor

Longitudinal and transverse thermal conductivities are calculated for a rectangular superconductor consisting of transposed multistrand wires.     

The bradykinin B2 receptor couples less efficiently than the angiotensin AT1 receptor to the G protein Gq in transiently transfected COS-7 cells

The purpose of this study was to compare the efficiency of two different Gq protein-coupled receptors (AT1 receptor for angiotensin II and B2 receptor for bradykinin) to activate phospholipase C (PLC). When the receptors were expressed at a similar level of 0.5 pmol/mg of protein, inositol trisphosphate (IP) accumulation elicited by AT1 receptor was four times higher than that elicited by B2 receptor. Genistein and pertussis toxin did not modify AT1 receptor- or B2 receptor-induced IP accumulation. These results indicate that in COS-7 cells, the two receptors activate PLC beta through G proteins of the Gq family. AT1 or B2 receptors were co-expressed with the alpha subunit of either Gq or G11. Both alpha subunits potentiated to the same extent AT1 receptor-induced IP accumulation. alpha 11 was also as efficient as alpha q to potentiate B2 receptor-induced response. Interestingly, however, the potentiating effect of alpha q and alpha 11 was more important (by 5-fold) on AT1 receptor-mediated response than on B2 receptor-mediated response. These results demonstrate that the extent of activation of PLC beta by different Gq-coupled receptors depends on the level of expression of these receptors and on their coupling efficiency. These are important parameters that determine the relative contribution of specific hormones to different biological processes.     

Oral tissue response to ovine grafting biomaterial: Morphological and morphometric study using scanning electron and light microscopy tissue response to ovine grafting biomaterial

OBJECTIVE: To evaluate the oral tissue response to an experimental particle ovine biomaterial by scanning electron microscopy (SEM) and light microscopy (LM). MATERIAL AND METHODS: Forty‐eight rats had surgical periodontal defects treated with either blood clotting (control), bovine biomaterial? (B), or an experimental ovine biomaterial (O). Data from SEM analysis (defect exposure, root surface exposure, diameter of matrix fibers and bundles, and globuli areas; n = 5) were applied to Shapiro–Wilk, Kruskal–Wallis, and Dunn's test, whereas LM analysis (tissue cicatrization characteristics and diameter defect; n = 3) had data applied to two‐way analysis of variance. Animals were monitored for 1 and 3 weeks. RESULTS: By SEM, the O samples showed significant differences from B and C in the area of defect exposure (H_2,15 = 8.66; P < 0.05). In both periods, O and B samples showed similar results for matrix fiber diameters, differently than C samples (H_2,15 = 14.0; P < 0.05). All other SEM variables were considered equivalent among the groups (P > 0.05). Under LM, an acute and chronic granulomatous inflammation was seen in the presence of both biomaterials (B and O, 1 week); both the control and the ovine grafting samples showed mature bone in the repair site (3 weeks); the defect diameter showed similar values among groups, at both monitoring periods (F_2,12 = 1.0401; P > 0.05). CONCLUSION: The ovine particles of this study showed a favorable response to oral tissue repair, demonstrating to be a potential source for the development of bone grafting biomaterials. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.     

A quantitative study of factors that influence the substantivity of fragrance chemicals on laundered and dried fabrics

Model investigations of physicochemical aspects of the substantivity of fragrance raw materials on laundered fabrics were performed. The overall process was divided into two consecutive steps, laundry and dryout, which were characterized by affinity and tenacity, respectively. The affinities of fifteen fragrance raw materials to cotton and polyacrylonitrile were measured in standard fabric softener and detergent solutions. Affinities correlated with the corresponding partition coefficient, P(o/w). To study the impact of parameters independent of the chemical structure of the fragrance molecules, 1-[³H]-3-methyl-5-phenylpentanol (phenylhexanol) was selected, and aqueous solutions of defined anionic, nonionic and cationic surfactants were used as model detergent and fabric softener media. A sequence of experiments, based on the fractional factorial design, was planted for quantifying the relative contribution on substantivity of a number of variables: the concentration of the fragrance chemical, the type and concentration of the surfactants, the type and weight of the fabrics (cotton or polyacrylonitrile) and the washing temperature in the case of cotton. The affinity that characterizes the washing process depends mainly on the type of fabric and the type of surfactant and, to a lesser extent, on the surfactant concentration and the temperature. Anionic and nonionic surfactants, the main components of detergent powders, behave similarly, whereas the combination of cationic surfactant with cotton markedly enhances the affinity. For phenylhexanol, the tenacity after dryout is largely controlled by the type of fabric. The role of fiber swelling is discussed. The substantivity, which represents the global effect of laundering and dryout, shows the same trend as the affinity. The complexity of the physicochemical phenomena involved is highlighted by the importance of the interactions between the main contributing factors.     

Reducing micropollutants with source control: substance flow analysis of 212 pharmaceuticals in faeces and urine.

Pharmaceuticals in the aquatic environment are raising concern. It is expected that many anthropogenic pharmaceuticals are largely excreted via urine; a popular argument for introducing urine source separation. However, to date, this assumption lacks verification. We close this gap with quantitative screening of official pharmaceutical data. We analysed the excretion pathways of 212 pharmaceuticals' active ingredients (AI), equalling 1,409 products. On average, 64% (+/-27%) of each AI was excreted via urine, and 35% (+/-26%) via faeces. In urine, 42% (+/-28%) of each AI was excreted as metabolites. However, these numbers need cautious interpretation. We found an extreme variability (1) between different therapeutic groups, (2) within some groups and (3) sometimes even between products of the same AI. We discuss various therapeutic groups and include Swiss sales' quantities. For instance, urine source separation could very effectively remove the highly sold and non-degradable x-ray contrast media: 94% (+/-4%) are excreted via urine. However, for different pharmaceuticals belonging to cytostatics, excretion via urine was 6-98%. Because of such large variability we advise caution to introduce the still imperfect urine separation technology solely because of pharmaceuticals. Nonetheless, together with other good arguments for this innovation, removal of pharmaceuticals is a welcome side effect.     

Water content of roasted coffee: impact on grinding behaviour,extraction, and aroma retention

Normal and long time roasting trials were carried out on industrial scale. Different amounts of water were applied during quenching, resulting in water contents in the range of 2.3–8.8 g/100 g wb. Coffees were ground immediately after cooling, and after equilibration times of 6 and 24 h. Particle size distribution of ground coffees, percolation time, and extraction properties were investigated on an espresso coffee machine. Coffees ground after 24 h resting time were subjected to storage trials to determine aroma stability as influenced by water content. Coffees with high moisture content exhibited coarser particles upon grinding, and equilibration time prior to grinding was needed for coffees with high water content to improve grinding results. Coffees with low water content did not exhibit this time dependency prior to grinding. Coffees with low water content were extracted more effectively than high moisture coffees, and percolation was slower. During open and closed storage, evolution of hexanal and sulfides was highly sensitive to water content. However, differences in evolution of other aroma compounds were found during closed storage only, where moisture content had a negative impact on aroma stability of the coffees subjected to investigation.     

In vitro assessment of modes of toxic action of pharmaceuticals in aquatic life

An ecotoxicological test battery based on a mode-of-action approach was designed and applied to the hazard identification and classification of modes of action of six pharmaceuticals (carbamazepine, diclofenac, ethinyl estradiol, ibuprofen, propranolol, and sulfamethoxazole). The rationale behind the design of the battery was to cover the relevant interactions that a compound may have with biological targets. It is thus not comprehensive but contains representative examples of each category of mode of toxic action including nonspecific, specific, and reactive toxicity. The test battery consists of one test system for nonspecific toxicity (baseline toxicity or narcosis), two test systems for specific effects, and two test systems for reactive toxicity. The baseline toxicity was quantified with the Kinspec test, which detects membrane leakage via measurements of membrane potential. This test system may also be used to detect the specific effects on energy transduction, although this was not relevant to any compound investigated in this study. As examples of specific receptor-mediated toxicity, we chose the yeast estrogen screen (YES) as a specific test for estrogenicity, and the inhibition of chlorophyll fluorescence in algae to assess specific effects on photosynthesis. Reactive modes of action were assessed indirectly by measuring the relevance of cellular defense systems. Differences in growth inhibition curves between a mutant of Escherichia coli that could not synthesize glutathione and its parent strain indicate the relevance of conjugation with glutathione as a defense mechanism, which is an indirect indicator of protein damage. DNA damage was assessed by comparing the growth inhibition in a strain that lacks various DNA repair systems with that in its competent parent strain. Most compounds acted merely as baseline toxicants in all test systems. As expected, ethinylestradiol was the only compound showing estrogenic activity. Propranolol was baseline-toxic in all test systems exceptforthe photosynthesis inhibition assay, where it surprisingly showed a 100-fold excess toxicity over the predicted baseline effect. The exact mode of toxic action could not be confirmed, but additional chlorophyll fluorescence induction experiments excluded the possibility of direct interference with photosynthesis through photosystem II inhibition. Mixture experiments were performed as a diagnostic tool to analyze the mode of toxic action. Compounds with the same mode of toxic action showed the expected concentration addition. In the photosynthesis inhibition assay, agreement between experimental results and prediction was best for two-stage predictions considering the assigned modes of action. In a two-stage prediction, concentration addition was used as a model to predict the mixture effect of the baseline toxicants followed by their independent action as a single component combined with the specifically acting compound propranolol and the reference compound diuron. A comparison with acute toxicity data for algae, daphnia, and fish showed generally good agreement for the nonspecifically acting compounds but also that the proposed test battery offered better diagnostic value in the case of the specifically acting compounds.     

Evaluation of bioanalytical assays for toxicity assessment and mode of toxic action classification of reactive chemicals

The toxicity of electrqphiles, including reactive organochlorines, epoxides, and compounds with an activated double bond was investigated. A set of different bioanalytical assays based on genetically modified Escherichia coli strains was set up to quantify cytotoxicity and specific reactivity toward the important biological nucleophiles DNA and glutathione (GSH). The significance of GSH for detoxification was assessed by cellular GSH depletion as well as by growth inhibition of a GSH-deficient strain. Tests for DNA damage comprised the measurement of induction of DNA repair systems, DNA fragmentation, and growth inhibition of a strain deficient in major DNA repair mechanisms. The most suitable assays for detection of mechanisms that underlie the observable cytotoxicity of the tested electrophiles were two sets of strains either lacking GSH or DNA repair in combination with their corresponding parent strains. Comparison of toxicity observed in those strains suggests three clearly distinguishable modes of toxic action for electrophilic chemicals: "DNA damage", "GSH depletion-related toxicity", and "unspecific reactivity". The class of chemicals causing DNA damage includes the epoxides 1,2-epoxybutane, (2,3-epoxypropyl)benzene, and styrene oxide. The class of chemicals with GSH depletion-related toxicity includes compounds with an activated double bond, like acrylates and acrolein. All reactive organochlorines and some epoxides were classified as unspecifically reactive because their toxicity is initiated by reactions with both biological nucleophiles. The work presented here is a contribution for an alternative hazard and effect assessment of organic pollutants based on mode of toxic action classification.