Die Vorgehensweise des Bundesinstitutes für Risikobewertung bei der Abschätzung der dermalen Absorption von Wirkstoffen in Pflanzenschutzmitteln und Biozidprodukten

A correct estimate of dermal absorption of the contained active ingredients is needed for the health risk assessment of plant protection and biocidal products. In this paper, the approach is reported that is currently taken by the Federal Institute for Risk Assessment to derive the dermal absorption rate of active substances in plant protection or biocidal products, depending on the available data. It is explained what use is made of two new guidance documents that were recently released by EFSA and OECD. Basic principles of the assessment of dermal absorption studies are described but also opportunities for estimations in the absence of product-specific experimental data. This publication is considered a first step towards harmonisation of assessment in the authorisation processes for plant protection and biocidal products.     

Welche Bedeutung besitzt die Mehrfachverwendung von Nahrungsergänzungsmitteln? Daten einer deutschlandweiten Verbraucherbefragung

Today the use of dietary supplements in the form of vitamin and mineral preparations is partially widespread. Apart from their importance in relation to health, wellbeing and prevention the risk assessment of dietary supplements and a safe total nutrient intake play a crucial role. The supply of various products with same ingredients and the associated cumulative intakes of substances can be seen as a potential problem. Data on this were not yet available. The aim of this present analysis was to capture and further characterize the multiple use of dietary supplements in adult men and women. The data for this study was obtained from a representative survey in cooperation with the Society for Consumer, market and sales research (GfK) in Germany with 1.070 dietary supplement users. In 94 % of the cases, the supply of a specific nutrient came from a single preparation. With an increasing number of dietary supplements used, the mean vitamin and mineral intake increased as expected, at the same time, the number of supplement users dropped significantly. An exceedance of the Tolerable Upper Intake Level (UL) was of relevance mainly in view of magnesium. 68 % of the magnesium users exceeded the UL with the intake of a single product. Overall, the data obtained here indicated that vitamins and minerals were not taken multiple via different preparations. In this collective, multiple exposures via different dietary supplements harbored no exposed risk.     

Solar panel cooling system with hollow fibres

Photovoltaic (PV) panel overheating drastically reduces their efficiency and lifespan. Overheating also has the potential to form electric arcs which can melt metal fixtures and burn away the module’s insulating materials. Due to these phenomena, the introduction of water-cooling or, more generally, liquid-cooling systems inside the PV panel appears reasonable. Hollow fibre cooling system consisting of plastic tubes of a small diameter (less than 1 mm) was tested as a simple solution. Fibres can be placed in contact with the back surface of a PV panel and coolant flowing through provides efficient and uniform cooling. Heat removed from the panel may be used for domestic or industrial needs or released to the surroundings. Hollow fibres have very thin walls (about 0.1 mm) to transfer heat easily, and the system is light, compact and resistant to corrosion. Experiments confirmed that such system can cool the PV panel, removing up to 1 kW of heat and lowering the module temperature from 90°C to about 50°C. It was observed that cooling improves the electric efficiency of PV cells by about 50%.     

Chemical,technological, and nutritional characteristics of two lines of “farro” (Triticum turgidum ssp. dicoccum)

In recent years, the renewed interest for foods with a natural image has increased the demand for dry pasta produced from “hulled” wheat such as the Triticum turgidum ssp. dicoccum, also known as “farro”. In order to contribute to the general knowledge, two lines of farro were considered in this study. To have a comparison, an old cultivar of Triticum turgidum ssp. durum (Senatore Cappelli) in addition to a commercial semolina were also examined. All semolina samples were used to produce pasta samples. Results showed some differences among pasta samples that seem to be due not to the presence of specific protein subunits but especially to the quantitative ratio between the different subunits. Results also reconfirmed the role played by the drying technology that is able to affect the sensory characteristics of pasta products.     

Boysenberry and blackcurrant drinks increased the plasma antioxidant capacity in an elderly population but had little effect on other markers of oxidative stress

BACKGROUND: The consumption of fruit and vegetables promotes good health by protecting against various degenerative diseases. Even though the constituents responsible are not known, some evidence indicates that the antioxidant properties of fruit and vegetable phytochemicals are responsible. Previous studies have shown that blackcurrant and Boysenberry reduce oxidative stress using in vitro cell systems. The aim of this study was to determine if blackcurrant or Boysenberry drinks could improve measures of oxidative stress and inflammation in an elderly population with below‐average memory abilities. The intervention parallel study was fully blinded with a placebo control. RESULTS: Of the six measures of oxidative stress assessed, only plasma antioxidant capacity significantly increased for both the Boysenberry and blackcurrant treatments compared with the placebo. Plasma malondialdehyde decreased in both the Boysenberry and blackcurrant treatments although the decrease was not statistically significant. Measures of oxidative stress for protein oxidation and lipid peroxidation improved for the berryfruit treatments during the study but were not statistically different from the placebo. CONCLUSION: Long‐term consumption of both the Boysenberry and blackcurrant drinks raised the plasma total antioxidant capacity of the study participants suggesting that Boysenberry and blackcurrant may help protect against oxidative stress‐related health conditions. Copyright © 2007 Society of Chemical Industry     

Translational regulator RpL10p/Grc5p interacts physically and functionally with Sed1p,a dynamic component of the yeast cell surface

Biogenesis of an active ribosome complement and a dynamic cell surface complement are two major determinants of cellular growth. In yeast, the 60S ribosomal subunit protein RpL10p/Grc5p functions during successive stages in ribosome biogenesis, specifically rRNA processing, nucle(ol)ar preribosomal subunit assembly, nucleo-cytoplasmic transport and cytoplasmic maturation of ribosomes. Here, we report that a two-hybrid screen identified yeast genes SED1, ACS2 and PLB3 as encoding proteins physically interacting with both ribosomal RpL10p/Grc5p and its human homologue hRpL10p/QMp. SED1 encodes a differentially expressed cell wall protein which is proposed to be first transiently secreted to the plasma membrane as a GPI (glycosylated derivative of phosphoinositol)-anchored form and to be then transferred to the glucan layer of the cell wall. Ectopic expression of SED1 rescues both the aberrant growth phenotype and the translation defect of grc5-1(ts) temperature-sensitive cells. Furthermore, we report that Sed1p associates with translating ribosomes suggesting a novel, cytoplasmic role for Sed1p. ACS2 encodes one of the two yeast acetyl-CoA synthases and represents a key enzyme in one of several metabolic routes to produce acetyl-CoA, which in turn is indispensable for lipid biosynthesis. PLB3 encodes a phospholipase, which is active in the breakdown of membrane lipids. Our results support the view that Grc5p/RpL10p links ribosome function to membrane turnover and cell surface biogenesis.     

Modelling the effects of climate change on the energy system—A case study of Norway

The overall objective of this work is to identify the effects of climate change on the Norwegian energy system towards 2050. Changes in the future wind- and hydro-power resource potential, and changes in the heating and cooling demand are analysed to map the effects of climate change. The impact of climate change is evaluated with an energy system model, the MARKAL Norway model, to analyse the future cost optimal energy system. Ten climate experiments, based on five different global models and six emission scenarios, are used to cover the range of possible future climate scenarios and of these three experiments are used for detailed analyses. This study indicate that in Norway, climate change will reduce the heating demand, increase the cooling demand, have a limited impact on the wind power potential, and increase the hydro-power potential. The reduction of heating demand will be significantly higher than the increase of cooling demand, and thus the possible total direct consequence of climate change will be reduced energy system costs and lower electricity production costs. The investments in offshore wind and tidal power will be reduced and electric based vehicles will be profitable earlier.     

The inhibition by naphthoquinones and anthraquinones of 2-amino-3-methylimidazo[4,5-f ]quinoline metabolic activation to a mutagen: a structure-activity relationship study

 Nine naphthoquinones, 19 anthraquinones, and nine structurally related monoketonic compounds such as anthrone, xanthone, etc., inhibited mutagenicity induced by 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) in Salmonella typhimurium TA 98 in the presence of rat liver S9 with distinct structure-activity relationships. A carbonyl function was a prerequisite for antimutagenicity while, in general, anthraquinones (IC₅₀ values: 2.3–>213 nmol/ml top agar) were more potent antimutagens than structurally related monoketonic compounds (IC₅₀ values: 25.3–94.9 nmol/ml top agar) and naphthoquinones (IC₅₀ values: 3.7–90.7 nmol/ml top agar). The parent compounds and methyl substituted derivatives were already the most potent while introduction of polar substituents such as COOH and SO₃H considerably reduced antimutagenicity. Introduction of OH functions had equivocal effects: with increasing numbers, antimutagenic potencies were concomitantly reduced; however, anthraflavic acid, chrysazin, quinizarin, and especially 5,8-dihydroxy-1,4-naphthoquinone were more potent than the parent compounds. The patterns of inhibition by quinones of 7-ethoxyresorufin-O-dealkylase activities in rat liver microsomes, linked to cytochrome P-450-dependent oxidation of IQ to N-hydroxy-IQ (N-OH-IQ), were in general identical with those obtained in the Salmonella/reversion assay except for chrysophanic acid, emodin, and some naphthoquinones which were very potent in this assay (IC₅₀: 0.20–45.0 μM). On the other hand, mutagenicity of N-OH-IQ in S. typhimurium TA 98NR was not inhibited by nonpolar quinones (except 1,4-naphthoquinone) but rather by polar compounds and especially by hydroxyquinones (IC₅₀ values: 5.3–106.7 nmol/ml top agar or not reached). Inhibition of mutagenic activities of IQ, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, 2-amino-6-methyldipyrido[1,2-a:3′,2′-d]imidazole, and 3-amino-1-methyl-5H-pyrido[4,3-b]indole by chrysazin, chrysophanic acid, physicon, and purpurin varied, but no clearcut structure-activity relationships of the mutagens were observed. Received: 29 May 1998     

A Peltier cells differential calorimeter with kinetic correction for the measurement of cp(H,T) and Δs(H,T) of magnetocaloric materials

In this paper we describe and test a setup for the characterization of the magnetocaloric effect around room temperature. The setup is a differential calorimeter able to measure both the specific heat c(p)(H,T) under constant magnetic field H and the isothermal entropy change induced by changing H, Δs(H,T), in the room temperature range. The setup uses miniaturized Peltier cells to measure the heat flux, with resolution of about 1 μW, and power Peltier cells to regulate the temperature in the range from 243 K (-30 °C) to 343 K (+70 °C). The kinetic effects due to the heat capacity of the measuring cells are taken into account by a simple model of the heat flux diffusion in the calorimetric cell. As measurement examples, we show the characterization of the magnetocaloric effect in magnetic materials with a second order transition [without latent heat and without hysteresis, as in the La(1)(Fe(1-x-y)Co(y)Si(x))(13) alloy with x=0.077 and y=0.079] and with a first order transitions (with latent heat and hysteresis as in Ni(50)Mn(36)Co(1)Sn(13)). As a result we compare the entropy change Δs(H,T) derived from (i) the integration of the specific heat c(p)(H,T) and (ii) the direct isothermal measurements, obtaining an excellent agreement.