Synthesis and characterization of electroactive films based on benzo(a)pyrene

The polycyclic aromatic hydrocarbons (PAHs) are a group of compounds that might have practical applications due to their graphene-like properties. Derivatized PAHs can self-assemble in liquid crystal form. The chemical synthesis of large size PAHs can however be complicated and problematic. Electrochemical synthesis of PAHs molecules was studied in this work by cyclic voltammetry. Benzo(a)pyrene was used as the monomer. The resulting electroactive films consist of different PAHs in both size and symmetry. We call this mixture poly(benzopyrene) (PBP). The synthesis conditions of PBP were optimized to obtain thick and electrochemically stable films. The best film quality was achieved by potential scanning in propylene carbonate at low scan rate resulting in continues polymer growth during 10 scans giving approx. a 1 μm thick PBP film. During p- and n-doping studies the reduction and oxidation peaks were observed at 1.0 V and −1.6 V, respectively, with an electrochemical band gap of approx. 2.6 eV. The in situ UV–vis characterization of the PBP films was made by applying a constant potential with increasing steps. The optical band gap was approx. 2.5 eV and the absorption maximum was observed at ca. 420 nm. During p- and n-doping new induced bands were formed in the range 575–600 nm. UV–vis spectroscopy indicate that PBP mainly consist of units consisting of more than 40 carbon atoms and large number of π-electrons.     

Land use impacts of industries and products in the Finnish economy: A comparison of three indicators

The sustainability aspects of land use were assessed with an environmentally extended input-output model of Finland in 2002. The main economic industries and products causing land use were identified and the impacts were estimated with three indicators: biocapacity, human appropriation of net primary production (HANPP) and ecosystem degradation potential (EDP). The results correlated well with expert assessments on the threats to biodiversity, although the influence of animal farming was not clear in all indicators. Most of the domestic land use was caused by final demand outside Finland. Based on a simplified trade balance, Finland was a net exporter of land area, mainly through wood products. Two thirds of the domestic land use was driven by export production. Therefore a regional consumption based approach is not sufficient to mitigate and control the environmental impacts of land use even in a developed country like Finland.     

Electrochemical preparation of oligo(azulene) on nanoporous TiO<Subscript>2</Subscript> and characterization of the composite layer

A nanoporous oligo(azulene)-TiO₂ (OAz-TiO₂) composite layer was formed by electrochemical oxidation of azulene (Az) on a nanoporous ITO/TiO₂ electrode. Polymerization was performed in tetrabutylammonium hexafluorophosphate electrolyte salt dissolved in acetonitrile. The electrochemical and optical properties of the composite layer were studied by cyclic voltammetry (CV) and in situ UV–vis spectroelectrochemistry. The chemical and crystalline structure of the layer was studied by FTIR and X-ray diffraction (XRD) spectroscopy techniques and the morphology by Scanning Electron Microscopy. The TiO₂ layer was found to have a catalytic activity on the polymerization of Az. The CV experiments in monomer-free electrolyte solution demonstrated the electron donor property of OAz by its p-doping and the electron accepting property of TiO₂ by the large reduction current in the negative potential region. The FTIR and XRD spectroscopic measurements showed the well-defined anatase structure of TiO₂ with inclusion of OAz. A composite layer was formed rather than a bilayer structure. The in situ UV–vis spectroelectrochemical measurements gave evidence of a higher delocalization and easier movement of the π-electrons in the composite layer than in pure poly (azulene).     

Fibrin clot structure remains unaffected in young, healthy individuals after transient exposure to diesel exhaust

Exposure to urban particulate matter has been associated with an increased risk of cardiovascular disease and thrombosis. We studied the effects of transient exposure to diesel particles on fibrin clot structure of 16 healthy individuals (age 21- 44). The subjects were randomly exposed to diesel exhaust and filtered air on two separate occasions. Blood samples were collected before exposure, and 2 and 6 hours after exposure. There were no significant changes on clot permeability, maximum turbidity, lag time, fibre diameter, fibre density and fibrinogen level between samples taken after diesel exhaust exposure and samples taken after filtered air exposure. These data show that there are no prothrombotic changes in fibrin clot structure in young, healthy individuals exposed to diesel exhaust.     

Ochratoxin A in liquorice as affected by processing methods

A study of the effect of several processing methods on the concentration of ochratoxin A (OTA) in liquorice and derived products was carried out. The effect of the sorting, washing and peeling of fresh liquorice roots was investigated; as well as the production at a laboratory scale of liquorice extract and block liquorice from dry roots. Finally, the thermal stability of OTA was assessed. The OTA content was analysed by high-performance liquid chromatography-fluorescence and confirmed by methyl ester formation. The OTA level in liquorice extract was stable to heat treatment at 150°C for 60 min. The OTA concentration was unaffected by sorting or washing, but it was much reduced by peeling (a 53.1% reduction). A great reduction in the OTA level was found during the production of liquorice extract (78.6%) and block liquorice (91.8%).     

Ion exchange behaviour and charge compensation mechanism of polypyrrole in electrolytes containing mono-, di- and trivalent metal ions

The electrochemical quartz crystal microbalance technique was used to examine the ion exchange behaviour and charge compensation mechanism of polypyrrole (PPy) doped with polystyrene sulfonate (PSS) immersed in electrolytes containing singly, doubly and triply charged metal ions. New insights were obtained concerning the mechanism of charge compensation and ion exchange behaviour of PPy/PSS films in electrolytes with triply and doubly charged transition metal ions. Understanding the ion exchange behaviour of conducting polymers immersed in these types of aqueous media could play a pivotal part in the development of methods for removing toxic metals from water supplies. Charge compensation occurred predominantly by means of cation movement for PPy/PSS films when the electrolyte was KNO₃, Ca(NO₃)₂, Mn(NO₃)₂ or Co(NO₃)₂. After prolonged redox cycling the electroactivity of the polymer decreases slightly, and the charge compensation mechanism becomes complex owing to movement of ions and neutral species in opposite directions. The charge compensation mechanism for PPy/PSS films immersed in aqueous Cr(NO₃)₃ and Al(NO₃)₃ solutions was also complex, with the ion exchange behaviour shifting towards anion movement to and from the polymer.     

Long-term impact of parental divorce on intimate relationship quality in adulthood and the mediating role of psychosocial resources.

The purpose of this 16-year prospective follow-up study was to investigate the association between parental divorce in childhood and intimate relationship quality in adulthood. The mediating role of psychosocial resources (parent-child relationships at 16 years, self-esteem and social support at 32 years) in this association was also studied. All 16 year olds of one Finnish city completed questionnaires at school and were followed up by postal questionnaires at 32 years of age (n = 1,471). Results showed that women and men from divorced families were more often divorced or separated at the age of 32 years than those from nondivorced families. However, parental divorce was associated with poorer intimate relationship quality only among women. Women from divorced families also had poorer relationships with their father and mother in adolescence, and they had lower self-esteem and satisfaction with social support in adulthood than women from intact families. No such associations were found among men. The impact of parental divorce on intimate relationship quality among women was partially mediated by mother-daughter relationship, self-esteem, and satisfaction with social support. The mediating role of mother-daughter relationship was not direct, however, but was mediated via self-esteem and satisfaction with social support. Our findings indicate that parental divorce affects daughters more than sons. In the context of parental divorce, the mother-daughter relationship in adolescence is important for the development of later psychosocial resources and, via them, for intimate relationship quality. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A perspective on the electrical stunning of animals: are there lessons to be learned from human electro-convulsive therapy (ECT)?

Animals have been slaughtered by humans since time immemorial. Over the last few generations attention has been focused on minimizing the animal's pain and suffering during slaughter. Based on the assumption that loss of consciousness due to electrical stunning combined with exsanguination is a humane technique of slaughter, this procedure has become one of the most widely employed methods in commercial meat production, being used in almost all species. In recent years, some shortcomings with this method of minimizing the animal's suffering have been noted. Electrical stunning is probably more akin to human electro-convulsive therapy (ECT) than to epilepsy, and some of the negative aspects of unmodified ECT may be present during electrical stunning, further questioning the use of electrical stunning in the slaughter of animals.     

Comparison of sampling procedures for recovery of Listeria monocytogenes from stainless steel food contact surfaces

A number of techniques exist for microbiological sampling of food processing environments in food industries. In the present study the efficacies of nine sampling procedures for the recovery of Listeria monocytogenes from food contact surfaces, including a new sampling device consisting of a miniroller, were evaluated and compared. A stainless steel table was inoculated with L. monocytogenes strain 935 (serovar 4b, human origin) and L. monocytogenes strain 437/07 (serovar 1/2b, food origin), at 10(5) CFU/100 cm(2). L. monocytogenes strain 935 was best recovered with the minirollers (recovery of up to 6.27%), while poor recoveries (<0.30%) were obtained with the towel (one-ply composite tissue), alginate swab, metallic swab, and Petrifilm methods. In the case of L. monocytogenes strain 437/07 the replicate organism detection and counting (RODAC) ALOA contact plates yielded the best recoveries (4.15%), followed by the minirollers (up to 1.52%). Overall, recovery percentages with the minirollers were higher with stomacher homogenization than with Vibromatic agitation. The recovery percentages obtained for the Listeria strain of human origin were higher than those obtained with the food strain for all sampling procedures except Petrifilm and RODAC ALOA. With the miniroller device coated with wool fiber, the recovery of L. monocytogenes can be improved from 2 to 17 times over recoveries obtained with the sponge and cotton swab. This is the first report of a miniroller device for microbiological sampling in the available literature. The novel sampling procedure is convenient to apply on surfaces, is cost-effective, and results in better recovery of L. monocytogenes than do the conventional methods.     

A chiral diamine bis-phenolate complex of dioxomolybdenum(VI)

A new dioxomolybdenum(VI) complex with a chiral tetradentate ligand is reported. The tripodal ligand containing two nitrogen atoms and two phenolic oxygen atoms was synthesized starting from a chiral diamine precursor. Further reaction with [MoO₂(acac)₂] yielded a monomeric molybdenum complex as a bright yellow solid. The structures of the molybdenum complex and the free diamine bis-phenol ligand were determined by X-ray diffraction.