Interaction between microwave-induced brain hyperthermia and high dose rate radiation in the BT4 An brain glioma in rats

In primary cocultures of neurons and glial cells prepared from the neonatal rat brain, lipopolysaccharide (LPS) reduced the numbers of neuronal cells but the effects were markedly inhibited by NG-monomethyl-L-arginine, indicating the involvement of NO and LPS-induced NO synthase in neuronal death. LPS stimulated the expression of inducible NOS (iNOS) in preparations of primary cultured microglias/astrocytes, but not in primary cultured neurons. In addition, LPS caused DNA fragmentation only in NG108-15 cells but not in primary cultured astrocytes as well as astrocytes in cocultures of the two cell types, suggesting that NOS induces the apoptosis of neurons but not glial cells. We then examined the NO-induced neuronal death in NG108-15 cells using NO donors. SNP, and NO donor, caused NO-2 accumulation in the reaction medium and lactate dehydrogenase (LDH) leakage from NG108-15 cells. Although SNP stimulated guanylyl cyclase and accumulated cGMP, cGMP analogs did not affect LDH leakage. In addition, SNP induced chromosomal condensation and fragmentation of nuclei in NG108-15 cells. Gel electrophoretic analysis of cellular DNA extracted from SNP-treated cells, confirmed the internucleosomal DNA fragmentation typical of apoptosis in this culture. SNP increased the amount of radioisotopic labeled glyceraldehyde-3 phosphate dehydrogenase (GAPDH) in the presence of [32P]NAD and inhibited the enzyme activity. The results suggested that SNP-induced cell death is partly due to the NO-induced inhibition of GAPDH, perhaps by stimulating the binding of NAD to GAPDH.     

Negative ion production rates in rare gas-halide lasers

This paper reports on dissociative electron attachment in F2, NF3, Cl2, and I2. The principle of the method is to produce a short burst of photoelectrons from a photocathode by means of light from an argon-fluoride laser. Subsequently, by studying the motion of electrons and negative ions in a constant electric field (E) region, information is obtained about drift velocities and effective attachment cross sections. Helium, argon, and nitrogen were used as buffer gases. Of particular interest is a very strong temperature dependence of the attachment coefficient in I2. Measurements were taken from 35 to 110°C, covering anE/Nrange of 1-50 Townsend. An explanation based on vibrational excitation is presented.     

Rye bread reduces plasma cholesterol levels in hypercholesterolaemic pigs when compared to wheat at similar dietary fibre level

BACKGROUND: Rye is a whole‐grain cereal with the potential of contributing to a healthy diet, but research on rye in relation to chronic diseases is scarce compared to wheat and oats. In this study, a total of 17 hypercholesterolaemic pigs were fed high‐fat high‐cholesterol rye (n = 9) or wheat‐based buns (n = 8) with similar dietary fibre (DF) content for 9–10 weeks to study the effect on cardiovascular risk factors. RESULTS: Ingestion of rye bread resulted in a 40% lower plasma total and LDL cholesterol compared to the wheat group, whereas HDL cholesterol, insulin and glucose concentrations were not affected by dietary treatments. Intestinal viscosity was 7.2 times higher, and organic matter and fat digestibility significantly reduced in the pigs fed rye buns. The hepatic expression of the cholesterol 7α‐hydroxylase gene (CYP7A1) was lower in rye‐fed pigs, whereas four other key genes involved in cholesterol metabolism were not affected. Plasma cholesterol correlated inversely with intestinal viscosity and organic matter digestibility. CONCLUSION: The ability of DF from rye to interfere with digestion and absorption is more important for whole‐body cholesterol homeostasis than regulation in the liver at gene level. Copyright © 2008 Society of Chemical Industry     

Mössbauer spectroscopy study of the chemical state of iron in Danish Mesozoic sediments

The chemical state of iron in sediments from six wells in the Danish North Sea and the Danish land area has been studied by use of Mössbauer spectroscopy. It was found that iron was mainly present in pyrite, clay minerals and the carbonates siderite and ankerite. The relative amounts of iron in different minerals have been determined as a function of depth in the wells. A comparison of the results with available data for source rock maturity suggests that there may be a correlation between the presence of ankerite and the formation of oil and gas in the sediments.     

Sex, BMI and age in addition to dietary intakes influence blood concentrations and congener profiles of dioxins and PCBs

Scope: The aim of this study was to i) characterize dietary polychlorinated biphenyls (PCBs) and dioxin exposure in consumers of fish from the PCB contaminated Lake Mjøsa in Norway ii) examine the influence of demographic factors on blood concentrations and congener composition of dioxins and PCBs, iii) characterize dietary sources and possible exposures above tolerable intake. Methods and results: Blood samples were analysed for dioxin‐like (dl) compounds (PCDD/Fs and dl‐PCBs) and non‐dl‐PCBs (ndl‐PCBs). Dietary exposures were calculated using food frequency questionnaires (n=64). Men had higher median intake of dl‐compounds than women (1.2 and 0.85 pg TEQ/kg bw/day), but similar blood concentrations (23.3 and 25.8, pg TEQ/g lipid weight (lw)). For non‐dl‐PCBs, intakes (6.5 and 4.5 ng/kg bw/day) and blood concentrations (381 and 224 ng/g lw) were higher in men than in women. Blood concentrations correlated with dietary intakes in men only. Increasing BMI and age elevated blood concentrations mainly in women. Men and women had different blood congener profiles, with a higher share of PCB‐126 in women, despite similar dietary congener profiles. Eleven participants exceeded the tolerable intake for dl‐compounds. Fish from Lake Mjøsa was the main dietary source. Conclusion: The higher influence of BMI and age for women than for men may have implications for risk assessment.     

Sintering Effect on Material Properties of Electrochemical Reactors Used for Removal of Nitrogen Oxides and Soot Particles Emitted from Diesel Engines

In the present work, 12‐layered electrochemical reactors (comprising five cells) with a novel configuration including supporting layer lanthanum strontium manganate (LSM)‐yttria stabilised zirconia (YSZ), electrode layer LSM‐gadolinia‐doped cerium oxide (CGO) and electrolyte layer CGO were fabricated via the processes of slurry preparation, tape casting and lamination and sintering. The parameters of porosity, pore size, pore size distribution, shrinkage, flow rate of the sintered reactors and the electrical conductivities of the supporting layer and the electrode in the sintered reactors were characterised. The effect of sintering temperature on microstructures and properties of the sintered samples was discussed, and 1,250 °C was determined as the appropriate sintering temperature for reactor production based on the performance requirements for applications. Using the present ceramic processing route, porous, flat and crack‐free electrochemical reactors were successfully achieved. The produced electrochemical reactors have the potential application in the removal of NO_x and soot particles emitted from the diesel engines.     

Change trajectories and key biotopes—Assessing landscape dynamics and sustainability

This paper presents a methodological synthesis of two congruent approaches into a common landscape change trajectory analysis and the assessment of landscape dynamics and sustainability. The emphasis of the analysis is on the retrospective relationship between the past and the present-day landscape patterns and associated key biotopes. The example key biotopes, oak woodlands and grasslands, represent valuable habitats in the hemiboreal landscapes of Finland and Sweden. The paper presents a conceptual stepwise approach for change trajectory analysis utilising multiple spatio-temporal data and techniques available in image processing and geographical information systems (GIS) including the following steps: (I) specification of spatio-temporal data and their representation of target objects, (II) the choice of direct or indirect change trajectory analysis, (III) hierarchical structuring of landscape information, (IV) compilation of landscape information into a GIS database, and (V) identification of paths for landscape change trajectory analysis. In this case study, we have focused on three interlinked trajectory analysis approaches, and their role in the assessment of landscape sustainability from a potential biodiversity perspective. We conclude that proposed landscape change trajectory analysis can improve the assessment of the key biotopes as well as present-day landscape characteristics, in maintaining biodiversity and related ecological values by providing information on landscape stability, continuity, change processes and boundary dynamics. This approach can be useful in the assessment of natural capital, but requires data-specific and context sensitive data processing and analysis solutions. The results should be interpreted as an approximation and generalisation of the spatio-temporal complexity of landscape reality and therefore be used in conjunction with additional habitat function measures.     

Emissions of soot,PAHs, ultrafine particles,NOx, and other health relevant compounds from stressed burning of candles in indoor air

Burning candles release a variety of pollutants to indoor air, some of which are of concern for human health. We studied emissions of particles and gases from the stressed burning of five types of pillar candles with different wax and wick compositions. The stressed burning was introduced by controlled fluctuating air velocities in a 21.6 m³ laboratory chamber. The aerosol physicochemical properties were measured both in well-mixed chamber air and directly above the candle flame with online and offline techniques. All candles showed different emission profiles over time with high repeatability among replicates. The particle mass emissions from stressed burning for all candle types were dominated by soot (black carbon; BC). The wax and wick composition strongly influenced emissions of BC, PM_2.5, and particle-phase polycyclic aromatic hydrocarbons (PAHs), and to lower degree ultrafine particles, inorganic and organic carbon fraction of PM, but did not influence NO_x, formaldehyde, and gas-phase PAHs. Measurements directly above the flame showed empirical evidence of short-lived strong emission peaks of soot particles. The results show the importance of including the entire burn time of candles in exposure assessments, as their emissions can vary strongly over time. Preventing stressed burning of candles can reduce exposure to pollutants in indoor air.     

Prediction ability of a lumped-element equivalent-circuit model for thickness-shear mode resonators in liquids

The viscosity-density prediction ability of a lumped-element equivalent-circuit model for a thickness-shear mode resonator operating in Newtonian liquids is examined. The model is a Butterworth-Van Dyke equivalent-circuit modification that describes the near-resonance electrical characteristics of a liquid-loaded resonator. By comparing the relative significance of different load contributions, a simplified liquid-phase lumped-element model is introduced. This model is calibrated with an admittance measurement on a resonator in contact with water. With the calibrated model, the liquid viscosity-density product is predicted from measurements made in aqueous glycerol solutions. These predictions are found to be accurate compared to the literature values. In addition, the predicted value for the average surface roughness of the resonator is consistent with the presented SEM micrographs.