Submicron patterns in substituted polystyrene resists by focused-ion-beam lithography

Submicron lines in negative working, substituted polystyrene resists by focused-ion-beam lithography were demonstrated. These features were transferred into an underlying molybdenum layer by plasma etching using the resist as an etch mask, with the minimum continuous line having a width of 0.20 μm.     

Pesticide residues in black tea

An investigation of residues of organochlorine and organophosphorous pesticides, as well as of a number of fungicides and of inorganic bromide in 99 samples of black tea taken on the Danish market is reported. The type of pesticide residues involved appear to be very uniform within each country of origin, whereas there are distinct differences between individual countries. Tea from Sri Lanka seems to contain less and fewer residues than tea from the other big tea producing countries. A great many of the samples contained alpha-HCH, lindane and DDT. The use of alpha-HCH and DDT is prohibited in Denmark. Only few other pesticides were detected and at a much lower frequency. None of the teas contained residues that may be regarded as being injurious to health.     

Tobacco-specific nitrosamines in new tobacco products.

New tobacco products, designed to attract consumers who are concerned about the health effects of tobacco, have been appearing on the market. Objective evaluation of these products requires, as a first step, data on their potentially toxic constituents. Tobacco-specific nitrosamines (TSNAs) are an important class of carcinogens in tobacco products, but virtually no data were available on their levels in these products. In the present study, we analyzed several new products-Ariva, Stonewall, Exalt, Revel, Smokey Mountain, and Quest-for TSNAs and compared their TSNA levels with those in nicotine replacement products and conventional smokeless tobacco and cigarette brands. TSNAs were not detected in Smokey Mountain, which is a tobacco-free snuff product. The lowest levels among the new products containing tobacco were in Ariva and Stonewall (0.26-0.28 microg/g wet weight of product). The highest levels in the new products were found in Exalt (3.3 microg/g tobacco), whereas Revel and Quest had intermediate amounts. Only trace amounts were found in nicotine replacement products, and conventional brands had levels consistent with those reported in the literature. These results demonstrate that TSNA levels in new tobacco products range from relatively low to comparable with those found in some conventional brands.     

Effects of dietary α-tocopheryl acetate supplementation on α-tocopherol deposition in porcine m. psoas major and m. longissimus dorsi and on drip loss, colour stability and oxidative stability of pork meat

The effect of feeding supra-nutritional levels of α-tocopheryl acetate on its deposition in two porcine muscles of different metabolic rates (m. longissimus dorsi and m. psoas major) and the effect on meat quality (lipid oxidation, colour stability and drip loss) was studied. Pigs were fed a standard diet supplemented with three levels: 100, 200 and 700 mg/kg of α-tocopheryl acetate from the time of weaning to slaughter at 90kg live weight. Muscle α-tocopherol levels were linearly related to the logarithm of dietary α-tocopheryl acetate supplementation and the linear relationship was estimated for the two muscles. The levels of α-tocopherol in the two muscles differed by a parallel displacement with consistently higher α-tocopherol levels in m. psoas major compared to m. longissimus dorsi. Dietary α-tocopheryl acetate supplementation significantly reduced lipid oxidation as measured by thiobarbituric acid reactive substances (TBARS) in both raw and cooked meat during storage at 4 °C for 6 days. Drip loss and colour stability of raw muscles were not affected by dietary α-tocopheryl acetate levels, 100mg α-tocopheryl acetate/ kg feed resulted in sufficient α-tocopherol levels in muscles to ensure minimum drip loss and optimum colour stability.     

Vitamin D₂ impairs utilization of vitamin D₃ in high-yielding dairy cows in a cross-over supplementation regimen

Vitamin D exists in 2 forms that are important regarding vitamin D status and supply in cattle: vitamin D₂ (D₂) and vitamin D₃ (D₃). To become physiologically active, both D₂ and D₃ must undergo 25-hydroxylation in the liver. The resulting 25-hydroxyvitamin D₂ [25(OH)D₂] and 25-hydroxyvitamin D₃ [25(OH)D₃] are measured as indicators of the physiological vitamin D status of cattle. The study used 14 Danish Holstein cows housed without access to sunlight. The cows were orally administered 250 mg (1.0 × 10⁷ IU) of D₂ and D₃ in a cross-over design with 2 treatment groups and 2 study periods, rendering 4 treatments when carryover effects were taken into account: D₂ given first, D₂ given last after D₃, D₃ given first, and D₃ given last after D₂. Two weeks elapsed between the treatment in the first study period and the treatment in the second study period. Blood samples were collected 0, 3, 6, 14, 17, 20, 23, 26, 40, 48, 70, 94, 166, and 214 h after providing the oral bolus of vitamin to the cows. Comparisons between plasma levels of the metabolites D₂, D₃, 25(OH)D₂, and 25(OH)D₃ over time were made by comparing areas under the plasma concentration curves. Oral administration of D₃ increased plasma D₃ (182.6 ± 17.1 ng/mL; mean ± SEM) and 25(OH)D₃ (103.5 ± 10.0 ng/mL) more efficiently than oral administration of D₂ increased plasma D₂ (49.1 ± 32.6 ng/mL) and 25(OH)D₂ (27.9 ± 2.1 ng/mL). The D₃ given after an oral dose of D₂ was less efficient for increasing plasma concentrations of 25(OH)D₃ (61.2 ± 12.0 ng/mL) compared with D₃ given without previous D₂ administration (103.5 ± 10.0 ng/mL), whereas the plasma concentrations of D₃ itself were the same when given first (182.6 ± 17.1 ng/mL) as when given after D₂ (200.0 ± 123.9 ng/mL). The same occurred for plasma concentrations of D₂ metabolites both if D₂ was given first (49.1 ± 32.6 ng/mL) and after D₃ (54.7 ± 7.7 ng/mL). In conclusion, D₃ given after D₂ is less efficient at increasing the plasma status of 25(OH)D₃ than D₃ given without previous D₂ administration.     

Cumulative risk assessment of the intake of organophosphorus and carbamate pesticides in the Danish diet

The aim of the study is to evaluate the potential cumulative effects of organophosphorus and carbamate pesticides that act through a common mechanism of toxicity, and to assess the long- and short-term risks for the Danish population. The intake estimates are based on dietary intake data collected in the Danish nation-wide food consumption survey in 1995. The pesticide data are based on the Danish pesticide residue-monitoring programme from 1996-2001. The amount of 35 organophosphorus pesticides and carbamates were included in the cumulative risk assessment. Processing factors, such as reduction of pesticide levels by rinsing and peeling, were applied in the exposure assessment. The "Toxicity Equivalence Factor" (TEF) approach was used to normalise the toxicity of the different organophosphorus and carbamate pesticides. Cumulative chronic exposure of organophosphorus and carbamates pesticides via fruit, vegetables and cereals is for adults 0.8-2% of the Acceptable Daily Intake (ADI) in chlorpyrifos equivalents, and 0.03-11% of the ADI in methamidophos equivalents; and for children 2-5% of the ADI in the chlorpyrifos equivalents, and 0.07-27% of the ADI in methamidophos equivalents. Neither Acute Reference Dose (ARfD) nor ADI was exceeded for any of the compounds studied. The results indicate that the Danish population is neither exposed to any cumulative chronic risk, nor at risk of acute exposure, from consumption of organophosphorus and carbamate pesticides from fruit, vegetables and cereals.     

Solubility and absorption rate of carbon dioxide into non-respiring foods. Part 3: Cooked meat products

The solubility and diffusion of carbon dioxide into cooked meat products (cooked ham and meat sausage with different pH-levels) was determined at different starting pressures and gas to product volume ratios by monitoring pressure changes over time in a closed chamber at constant temperatures (0, 4, and 8 °C). Good correlation of the CO₂ solubility between the packaging parameters (gas to product volume ratio and initial partial pressure) and the meat products water content was found. The solubility of CO₂ followed Henry’s law and the initial partial pressure of CO₂ influenced the solubility mostly. Only small variations in the diffusion constants and absorption rates were found within the experimental design. A pH difference of 0.5 in the two meat sausage types did not influence either solubility or diffusion significantly.     

Effects of level of social contact on dairy calf behavior and health

Housing preweaned dairy calves in pairs rather than individually has been found to positively affect behavioral responses in novel social and environmental situations, but concerns have been raised that close contact among very young animals may impair their health. In previous studies, the level of social contact permitted in individual housing has been auditory, visual, or physical contact. It is unclear how these various levels of social contact compare with each other and to pair housing, when their effects on behavior and health are considered, and whether the timing of pair housing has an effect. To investigate this, 110 Holstein calves (50 males, 60 females) in 11 blocks were paired according to birth date. Within 60 h of birth, each pair of calves was allocated to 1 of 5 treatments: individual housing with auditory contact (I), individual housing with auditory and visual contact (V), individual housing with auditory, visual, and tactile contact (T), pair housing (P), or individual housing with auditory and visual contact the first 2 wk followed by pair housing (VP). At 6 wk of age, calves were subjected to a social test and a novel environment test. In the social test, all pair-housed calves (P and VP) had a shorter latency to sniff an unfamiliar calf than did individually housed calves (I, V, and T), whereas calves with physical contact (T, P, and VP) sniffed the unfamiliar calf for longer than calves on the remaining treatments (I and V). In the novel environment test, calves with physical contact (T, P, and VP) had a lower heart rate, and more of these calves vocalized during the test compared with calves without physical contact (I and V). No effect of treatment was found for clinical scores, levels of the 5 most common pathogens in feces, or in development of serum antibodies against the 3 most common respiratory pathogens. Calves housed individually are more fearful of unfamiliar calves than are pair-housed calves. Contrary to common belief, the allowance of physical contact and pair housing had no effects on the health of the calves.     

The choice of homogenisation equipment affects lipid oxidation in emulsions

Milk proteins are often used by the food industry because of their good emulsifying properties. In addition, they can also provide oxidative stability to foods. However, different milk proteins or protein components have been shown to differ in their antioxidative properties, and their localisation in emulsions has been shown to be affected by the emulsification conditions. The objective of this study was to investigate the influence of homogenisation equipment (microfluidizer vs. two-stage valve homogeniser) on lipid oxidation in 10% fish oil-in-water emulsions prepared with two different milk proteins. Emulsions were prepared at pH 7 with similar droplet sizes. Results showed that the oxidative stability of emulsions prepared with sodium caseinate was not influenced by the type of homogeniser used. In contrast, the type of homogenisation equipment significantly influenced lipid oxidation when whey protein was used as emulsifier, with the microfluidizer resulting in lower levels of oxidation.