Dechloranes 602, 603, 604, Dechlorane Plus, and Chlordene Plus, a newly detected analogue, in tributary sediments of the Laurentian Great Lakes

A chlorinated compound (Chlordene Plus, CP), structurally related to Dechloranes (Dec) 602, 603, 604, and Dechlorane Plus (DP), was identified, and concentrations and spatial trends of Dec 602, 603, 604, CP, and DP in tributary sediments of the Laurentian Great Lakes are reported. The dechloranes were widely detected with their concentrations varying considerably across the Great Lakes basin. Spatial trends of Dec 602, 604, and DP in Canadian tributary sediments were similar to that of BDE 209, which suggested these flame retardant chemicals in tributaries were associated with industrial and urban areas. The highest concentrations of Dec 602, 604, and DP observed in tributaries of the Niagara River confirmed that past or ongoing manufacturing of these compounds at plants along the river were important sources to Lake Ontario. Dec 603 was detected in technical products of aldrin and dieldrin, and its spatial trend was consistent with historic pesticide usage. Similarly, CP was detected in technical products of chlordene and chlordane, and it was found in higher concentrations in sediments near urban areas, possibly related to past chlordane use in home termite control.     

The gas chromatographic-mass spectrometric examination of the volatiles produced by the fermentation of a sucrose solution

Summary Gas chromatographic-mass spectrometric examination of the volatiles produced during the fermentation of a sucrose solution has led to the definite identification of 8 alcohols, 6 carbonyls, 9 acetals, 25 esters, and 17 acids, tentative evidence being presented for a further 15 components.

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Gaschromatographisch-massenspektrometrische Untersuchung der durch Gärung einer Saccharoselösung gebildeten flüchtigen Bestandteile

Zusammenfassung Gaschromatographisch-massen-spektrometrische Analyse der während der Gärung einer Saccharoselösung gebildeten flüchtigen Substanzen hat zur endgültigen Identifizierung von 8 Alkoholen, 6 Carbonylverbindungen, 9 Acetalen, 25 Estern und 17 Säuren geführt. Es werden auch vorläufige Beweise für die Anwesenheit von 15 anderen Komponenten erbracht.

     

Effect of high pressure processing on the quality of herring (Clupea harengus) and haddock (Melanogrammus aeglefinus) stored on ice

Fresh herring and haddock were vacuum-packed and subjected to high pressure processing (200, 250 and 300 MPa at 10 °C for both 1 and 3 min) or left untreated as controls. The samples were stored in ice at 2 °C for up to 14 days, during which time the changes in microbial quality, total volatile base nitrogen (TVBN) and trimethylamine (TMA) production were monitored. Microbial shelf-life was determined as the storage time required for psychrotrophic counts to reach 10⁶ CFU g^?1, while chemical shelf-life was estimated as the time taken for TVBN and TMA values to reach 35 mg N 100 g^?1 and 15 mg N 100 g^?1 respectively.High pressure significantly delayed microbial growth (p < 0.05) in both herring and haddock. In the case of herring the microbiological shelf-life was extended from ～4 days in controls to ?13 days in fish pressure-treated at 200 MPa/3 min. Microbial numbers in all the haddock samples tended to be lower throughout the storage period, compared to herring, irrespective of pressure treatment, and none of the pressure-treated samples reached unacceptable psychrotrophic numbers until 14 days in ice compared to 10 days in the controls. The microflora of both the control and pressure-treated herring and haddock at day 0 were predominantly Gram-positive cocci (Micrococcus spp. and Staphylococcus spp.) and spore-forming rods (Clostridium spp. and Bacillus spp.). This microflora did not change significantly during storage of the fish in ice at 2 °C for 10 days.Pressure treatment also delayed TVBN and TMA production in the fish. In the case of herring, predicted values did not reach unacceptable levels until at least 18 days (200 MPa/3 min) compared to 5.5 days in controls. With haddock, TMA and TVBN values in control samples reached unacceptable limits between 6 and 10 days of storage. However, the levels remained below the limits of acceptability in all pressure-treated samples during storage, apart from on day 14, when the TVBN value in samples treated at 200 MPa/1 min exceeded the level of acceptability.Overall, taking account of the various spoilage indicators, the minimum treatment required to increase shelf-life in herring and haddock to ～13 days on ice was found to be 200 MPa for 3 min.     

In Situ Carbon Nanotube Formation in Templated Pores of Polymer‐Derived Ceramics

Multi‐walled carbon nanotubes (MWCNTs) have been formed in situ in porous, polymer derived ceramics, using polystyrene (PS) microbeads as pore formers. The microbeads were coated with nickel acetate, as a transition metal catalyst precursor, and then introduced into the preceramic polymer methylphenylpolysiloxane (PMPS). The PMPS served as a precursor for the ceramic matrix and as carbon source for CNT formation. The PS microbead burnout was observed between 200 and 400 °C, leaving behind nickel nanoparticles at the surface of the templated pore walls. Thermal conversion of the precursor to ceramic was carried out in the temperature range between 500 and 1 200 °C. MWCNTs were formed in the templated pores during the pyrolysis step by converting the carbon from the decomposition of PMPS. The oxidation resistance of these composites has been studied and an interesting catalytic oxidation phenomenon was observed that may be quite important for the oxidation of carbon nanotubes.     

End-group functionalization of poly(3-hexylthiophene) as an efficient route to photosensitize nanocrystalline TiO2 films for photovoltaic applications

Bulk heterojunction (BHJ) and dye-sensitized solar cells (DSSCs) have seen increased popularity over recent years and each technology has experienced tremendous improvements in power conversion efficiencies (PCEs), reaching 8 and 12%, respectively. The two technologies have been on independent improvement pathways, and this work establishes a link between them by using the archetypical hole conductor (poly-3-hexylthiophene, P3HT) in BHJs as a sensitizer on TiO(2) for DSSC applications. Three polymers were synthesized and examined as potential TiO(2) sensitizers in DSSCs under AM1.5 solar radiation. Using Grignard metathesis, regioregular P3HT was synthesized then functionalized with either one or two cyanoacrylic acid linker moieties to bind to the TiO(2) surface. End-group modification resulted in minimal changes to the optical and electronic properties as compared to pristine P3HT. Cyclic voltammetry (CV) experiments at anodic potentials of adsorbed sensitizer quantified the amount of alkylthiophene adsorbed on the TiO(2), whereas under reductive sweeps, cyanoacrylic acid end-group binding was determined. CVs of each polymer indicated that loading was drastically different as compared to pristine P3HT with the lowest loading on TiO(2) and monofunctionalized P3HT exhibited the highest loading. The DSSCs showed power conversion efficiencies (PCEs) of 0.1%, 0.2 and 2.2% for the polymer-sensitized TiO(2) of the unfunctionalized, monofunctionalized and difunctionalized polymers, respectively. DSSCs were then subjected to electrochemical impedance spectroscopy (EIS) in the dark and under monochromatic light radiation. The large variance in performance for the functionalized-P3HT sensitizers is attributed to differences in the adsorption modes of sensitizer on the TiO(2) surface, which in the difunctionalized case limits electrolyte recombination and favors forward charge transfer reactions.     

Fat substitutes promote weight gain in rats consuming high-fat diets.

The use of food products designed to mimic the sensory properties of sweet and fat while providing fewer calories has been promoted as a method for reducing food intake and body weight. However, such products may interfere with a learned relationship between the sensory properties of food and the caloric consequences of consuming those foods. In the present experiment, we examined whether use of the fat substitute, olestra, affect energy balance by comparing the effects of consuming high-fat, high-calorie potato chips to the effects of consuming potato chips that sometimes signaled high calories (using high-fat potato chips) and that sometimes signaled lower calories (using nonfat potato chips manufactured with the fat substitute olestra). Food intake, body weight gain and adiposity were greater for rats that consumed both the high-calorie chips and the low-calorie chips with olestra compared to rats that consumed consuming only the high-calorie chips, but only if animals were also consuming a chow diet that was high in fat and calories. However, rats previously exposed to both the high- and low-calorie chips exhibited increased body weight gain, food intake and adiposity when they were subsequently provided with a high fat, high calorie chow diet suggesting that experience with the chips containing olestra affected the ability to predict high calories based on the sensory properties of fat. These results extend the generality of previous findings that interfering with a predictive relationship between sensory properties of foods and calories may contribute to dysregulation of energy balance, overweight and obesity. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The relationship of parental warm responsiveness and negativity to emerging behavior problems following traumatic brain injury in young children.

Parenting behaviors play a critical role in the child's behavioral development, particularly for children with neurological deficits. This study examined the relationship of parental warm responsiveness and negativity to changes in behavior following traumatic brain injury (TBI) in young children relative to an age-matched cohort of children with orthopedic injuries (OI). It was hypothesized that responsive parenting would buffer the adverse effects of TBI on child behavior, whereas parental negativity would exacerbate these effects. Children, ages 3–7 years, hospitalized for TBI (n = 80) or OI (n = 113), were seen acutely and again 6 months later. Parent–child dyads were videotaped during free play. Parents completed behavior ratings (Child Behavior Checklist; T. M. Achenbach & L. A. Rescorla, 2001) at both visits, with baseline ratings reflecting preinjury behavior. Hypotheses were tested using multiple regression, with preinjury behavior ratings, race, income, child IQ, family functioning, and acute parental distress serving as covariates. Parental responsiveness and negativity had stronger associations with emerging externalizing behaviors and attention-deficit/hyperactivity disorder symptoms among children with severe TBI. Findings suggest that parenting quality may facilitate or impede behavioral recovery following early TBI. Interventions that increase positive parenting may partially ameliorate emerging behavior problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Executive functions and social competence in young children 6 months following traumatic brain injury.

Objective: This study examined the impact of traumatic brain injury (TBI) in young children on executive functions and social competence, and particularly on the role of executive functions as a predictor of social competence. Method: Data were drawn from a prospective, longitudinal study. Participants were children between the ages of 3 years 0 months and 6 years 11 months at time of injury. The initial sample included 23 with severe TBI, 64 with moderate TBI, and 119 with orthopedic injuries (OI). All participants were assessed at 3 and 6 months postinjury. Executive functions were assessed using neuropsychological tests (Delayed Alternation task and Shape School) and parent ratings on the Behavior Rating Inventory of Executive Function and Child Behavior Questionnaire. Parents rated children's social competence on the Adaptive Behavior Assessment System, Preschool and Kindergarten Behavior Scales, and Home and Community Social Behavior Scales. Results: Children with severe TBI displayed more negative outcomes than children with OI on neuropsychological tests, ratings of executive functions, and ratings of social competence (η2 ranged from .03 to .11). Neuropsychological tests of executive functions had significant but weak relationships with behavioral ratings of executive functions (ΔR2 ranged from .06 to .08). Behavioral ratings of executive functions were strongly related to social competence (ΔR2 ranged from .32 to .42), although shared rater and method variance likely contributed to these associations. Conclusions: Severe TBI in young children negatively impacts executive functions and social competence. Executive functions may be an important determinant of social competence following TBI. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Discovering small-molecule estrogen receptor α/coactivator binding inhibitors: high-throughput screening, ligand development, and models for enhanced potency

Small molecules, namely coactivator binding inhibitors (CBIs), that block estrogen signaling by directly inhibiting the interaction of the estrogen receptor (ER) with coactivator proteins act in a fundamentally different way to traditional antagonists, which displace the endogenous ligand estradiol. To complement our prior efforts at CBI discovery by de?novo design, we used high-throughput screening (HTS) to identify CBIs of novel structure and subsequently investigated two HTS hits by analogue synthesis, finding many compounds with low micromolar potencies in cell-based reporter gene assays. We examined structure-activity trends in both series, using induced-fit computational docking to propose binding poses for these molecules in the coactivator binding groove. Analysis of the structure of the ER-steroid receptor coactivator (SRC) complex suggests that all four hydrophobic residues within the SRC nuclear receptor box sequence are important binding elements. Thus, insufficient water displacement upon binding of the smaller CBIs in the expansive complexation site may be limiting the potency of the compounds in these series, which suggests that higher potency CBIs might be found by screening compound libraries enriched with larger molecules.     

Therapeutic targets for inhibitors of glycosylation

Small molecule inhibitors of glycoconjugate metabolism are being exploited for therapeutic benefit in a number of human disorders. As examples of this class of compound, imino sugars, as monosaccharide mimics, have a number of advantages for compound design and synthesis to define biological activity. As polyhydroxylated molecules, each chiral centre offers manipulation to generate isomers with restricted or enhanced mimicry, and the endocyclic nitrogen atom is readily modified to gain selectivity, increase potency or improve pharmacodynamics. This review focuses on the discovery of imino sugars that have considerable potential for treating a diverse range of diseases, from lysosomal storage disorders diabetes and cystic fibrosis to viral pathogenesis, and addresses the mechanism of action that is dictated by structural modification.