On the kinetics of the autoxidation of fats

The mechanism of fat autoxidation is elucidated from the rate data. All the data treated here and in an earlier publication follow the same basic rate equation, including the time function f(t) empirically derived for heterogeneous oxidation. Metals and glass (the wall of the reaction vessel) are catalysts. Depending on the state of the catalyst, f(t)=t² or f(t)=t. When f(t)=t, the kinetics are first-order as found for monolayer autoxidation, but in bulk phase they are complicated by a transient stage caused by the solubilization of O₂ into the hydroperoxide micelles produced in the exponential (“autocatalytic”) part of the oxidation. Certain additives, such as inhibitors, affect the catalyst and thereby f(t). The kinetics, as determined by O₂ consumption or by analysis of the remaining unreacted substrate, show the first oxidation step. It is unaffected by further chemical changes of the primary oxidation products,e.g., decomposition of hydroperoxides and trimerization in the autoxidation of 9,11-octadecadienoic acid methyl ester.     

The effect of probiotic fermented milk and inulin on the functions and microecology of the intestine

We investigated the effects of a probiotic fermented milk and inulin on gastrointestinal function and microecology. The study was double-blinded and comprised 66 healthy adults (22 male, 44 female), mean age 40 years (range, 22-60 years). After a 12-d baseline period the subjects were randomized to consume, for 3 weeks, 3x200 ml daily of either (1) a fermented milk with probiotics (Bifidobacterium longum BB536, Bifidobacterium spp. 420 and Lactobacillus acidophilus 145), (2) a fermented milk with the same probiotics plus 4 g inulin, or (3) a control fermented milk. During the last 7 d of the baseline and the intervention periods, the subjects kept a record of their defaecation frequency and gastrointestinal symptoms, and collected all their faeces. Intestinal transit time, stool weight and faecal enzyme activities were measured. Thirty-nine subjects were randomized to give faecal samples for analysis of pH and microbes, including lactobacilli, bifidobacteria, coliforms, Escherichia coli, Bacteroides and Clostridium perfringens. Consumption of fermented milk with probiotics or with probiotics and inulin increased the faecal number of lactobacilli (P=0.009, P=0.003) and bifidobacteria (P=0.046, P=0.038) compared with the baseline. Compared with the control fermented milk, both active products increased lactobacilli (P=0.005, ANCOVA). Subjects consuming fermented milk with probiotics and inulin suffered from gastrointestinal symptoms, especially flatulence, more than the others (P<0.001). In conclusion, the probiotic fermented milk product had a positive effect by increasing the number of lactobacilli and bifidobacteria in the colon. Inulin did not alter this effect but it increased gastrointestinal symptoms.     

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)     

Thermodynamic and spectroscopic speciation to explain the blackening process of hematite formed by atmospheric SO2 impact: the case of Marcus Lucretius House (Pompeii)

After many decades exposed to a polluted environment, in some areas of Marcus Lucretius House, there are clear signs that plasters and hematite pigments are suffering deterioration. In the exhaustive analysis of the black layer covering the red pigment hematite it was possible to identify magnetite (Fe(3)O(4)) as responsible for the black colour, which always appears in combination with gypsum. Thermodynamic modelling stated that the presence of gypsum as well as the transformation of hematite into magnetite is a consequence of the attack of atmospheric SO(2).     

Homogeneous detection of avidin based on switchable lanthanide luminescence

We have developed switchable lanthanide luminescence-based binary probe technology for homogeneous detection of avidin, which is a tetrameric protein. Two different nonluminescent label moieties--a light-absorbing antenna ligand and a lanthanide ion carrier chelate--were conjugated to separate biotins, which is known as avidin's natural ligand. The assay was based on binding of the two differently labeled biotins on separate binding sites on the target protein and consequent self-assembly of a luminescent complex from the two label moieties. Specific luminescence signal was observed only at the presence of the target protein. The characteristics of the switchable lanthanide luminescence assay were compared to the reference assay, based on lanthanide resonance energy transfer. Both assays had a limit of detection in the low-picomolar concentration range; however, the lanthanide chelate complementation-based assay had wider dynamic range and its optimization was more straightforward. The switchable lanthanide luminescence technology could be further applied to generic protein detection, using reagents that are analogous to the proximity ligation assay principle.     

Weight maintenance through behaviour modification with a cooking course or neurolinguistic programming

We compared the effect on weight regain of behaviour modification consisting of either a gourmet cooking course or neurolinguistic programming (NLP) therapy. Fifty-six overweight and obese subjects participated. The first step was a 12-week weight loss program. Participants achieving at least 8% weight loss were randomized to five months of either NLP therapy or a course in gourmet cooking. Follow-up occurred after two and three years. Forty-nine participants lost at least 8% of their initial body weight and were randomized to the next step. The NLP group lost an additional 1.8 kg and the cooking group lost 0.2 kg during the five months of weight maintenance (NS). The dropout rate in the cooking group was 4%, compared with 26% in the NLP group (p=0.04). There was no difference in weight maintenance after two and three years of follow-up. In conclusion, weight loss in overweight and obese participants was maintained equally efficiently with a healthy cooking course or NLP therapy, but the dropout rate was lower during the active cooking treatment.     

Small-angle X-ray scattering experiments and computer simulations to characterise anisotropy of activated carbons prepared from wood

Small-angle scattering was measured from activated carbon monoliths prepared from three different wood species (European beech, Pedunculate oak and Norwegian spruce). Substantial differences were found in the scattering images of axial and tangential slices, attributed to their characteristic phytogenic structures. The decrease in anisotropy in the nanostructured carbon matrix due to the activation process is also different among the three investigated types of wood. For quantitative characterization of the anisotropy and its decrease, the degree of alignment was calculated from the azimuthal scattering curves. A simple numeric model was constructed on the basis of direct information obtained by atomic force microscopy. Scattering patterns calculated from the model were compared with the experimental ones to explain the possible structural changes in the carbon skeleton.     

Quercetin content in stored onions (Allium cepa L.): effects of storage conditions,cultivar, lifting time and nitrogen fertiliser level

Storage experiments with commercial cultivars of onion (Allium cepa L.) were performed at low constant temperature (1°C) and at higher variable temperature (～8°C). Cultivar differences in quercetin glucoside content were significant, but neither nitrogen fertiliser level nor lifting time had more than minor effects at start of storage or after 3 or 5 months of storage. The role of onion size for quercetin glucoside content and composition was inconsistent but seemed to be of minor importance. Irrespective of storage conditions, the content of quercetin glucosides only showed minor reduction and the composition was unchanged. After 5 months of storage, onion sprouting was recorded during a shelf‐life period of 9 weeks at room temperature. Early lifting resulted in onions with low sprouting and good storage abilities without negative effects on quercetin glucoside content. The results suggest that it may be possible to minimise nitrogen fertiliser levels without negative effects on onion yield, quercetin glucoside content or storage capacity. Copyright © 2007 Society of Chemical Industry     

Bromide concentration in Swedish precipitation, surface and ground waters

The occurrence of bromide in precipitation, surface and ground waters in Sweden has been investigated (300 samples). The concentration of bromide in precipitation is 0.05–0.15 μM in the south and <0.05 μM in the north of Sweden. The concentrations of bromide and chloride are well correlated. For river water the same areal distribution pattern as for precipitation is found, but the concentrations are 2–4 times higher. The molar ratio Br/Cl is 1 × 10⁻³ which is lower than that for sea water (1.54 × 10⁻³) and, most likely, also lower than for precipitation. A detailed study of Lake Mälaren has been made. The north-eastern feeder streams, passing an area of post-glacial clay, showed unusually high bromide concentrations (0.3–3 μM) and Br/Cl quotients (2 × 10⁻³-8 × 10⁻³). No correlation between the concentrations of bromide and chloride was found. Rough calculations indicate that fertilizers and chemicals added to the fields could only contribute a minor fraction of the bromide found. Analysis of 18 ground water samples indicated increased bromide levels as compared to surface waters.     

Mechanical and Thermal Properties of Pulsed Electric Current Sintered (PECS) Cu-Diamond Compacts

In this work, dispersion strengthening of copper by diamonds is explored. In particular, the influence of 50- and 250-nm diamonds at contents of 3 and 6 vol. pct on the mechanical and thermal properties of pulsed electric current sintered (PECS) Cu composites is studied. The composite powders were prepared by mechanical alloying in argon atmosphere using a high-energy vibratory ball mill. The PECS compacts prepared had high density (>97 pct of T.D.) with quite evenly distributed diamonds. The effectiveness of dispersoids in increasing the microhardness was more pronounced at a smaller particle size and larger volume fraction, explained by Hall–Petch and Orowan strengthening models. The microhardness of Cu with 6 and 3 vol. pct nanodiamonds and pure sm-Cu (submicron-sized Cu) was 1.77, 1.46, and 1.02 GPa, respectively. In annealing experiments at 623 K to 873 K (350 °C to 600 °C), the composites with 6 vol. pct dispersoids retained their hardness better than those with less dispersoids or sm-Cu. The coefficient of thermal expansion was lowered when diamonds were added, being the lowest at about 14 × 10^?6 K^?1 between 473 K and 573 K (200 °C and 300 °C). Good bonding between the copper and diamond was qualitatively demonstrated by nanoindentation. In conclusion, high-quality Cu-diamond composites can be produced by PECS with improved strength and better thermal stability than for sm-Cu.