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Notes: Abstract A double focusing ICP-MS, equipped with a Micro Concentric Nebulizer, has been used to determine concentrations and isotopic ratios of lead in recent snow samples (1993–1996) from high alpine sites in Switzerland. Concentrations varied between 0.02 ± 0.002 and 5.5 ± 0.15 ng/g and are slightly lower than concentrations reported by Atteia [1], by Batifol et al. [2], and by Wagenbach et al. [3] for precipitation samples from similar remote sites in Europe. Since concentrations of lead in the fresh snow samples were mainly in the lower pg/g range, the method to determine the isotopic ratios 207Pb/206Pb and 208Pb/206Pb had to be optimized. They could finally be determined with an average standard error of 0.14% within 12 min and a total sample consumption of 0.8 mL. The average ratios 207Pb/206Pb and 208Pb/206Pb were 0.875 and 2.117, respectively. These values are comparable to isotopic compositions of lead in aerosols collected in Western Europe [4] and are less radiogenic than predicted by Grousset et al. [5]. Our data indicate that, although lead emissions from traffic have decreased largely during the last 10 years, the contribution from this source in modern snow is still detectable and seems to be equal to the lead input from other anthropogenic sources (e.g. waste incineration, industry).

Notes: Plant secondary metabolites such as flavonoids, isoflavones and phytosterols have been proposed as cosmetic ingredients displaying anti-aging effects. On the cellular level, however, the activity profiles of these ingredients are only partially understood. In this study we analyzed the effects of apple seed phytosterols on age-related structural and functional parameters using cell biochemical, molecular biological and bioengineering techniques. The expression of age-related genes was studied using skin equivalents and cDNA microarrays. Incubation of skin equivalents with apple seed phytosterols had significant consequences: (i) differential regulation of a set of genes associated with keratinocyte proliferation and differentiation, (ii) stimulation of hyaluronic acid synthesis, and (iii) increase of epidermal thickness. In vivo studies revealed that apple seed phytosterols improve skin elasticity and decrease skin roughness. In conclusion, apple seed phytosterols display distinct biological effects and significantly improve the structure and function of mature skin.

Notes: Summary Isothermal solid state experiments on the diffusion of Cu, Fe, Zn and In and related effects have been carried out in sphalerite single crystals. The driving force for the diffusion and corresponding reactions are chemical potential gradients which are established by differences in sulfur fugacity, oxygen fugacity and the chemical activity between sulfide powders as metal sources and receptor crystals. Studies in the system ZnS-CuInS2 show replacement rims in sphalerite produced by the formation of solid solutions between ZnS and CuInS2. These differences reflect the extent of mutual solid solution. The composition profiles of these rims at different temperatures and sulfur fugacities are calculated to diffusion coefficients for the coupled substitution of Cu+ + In3+ versus 2 Zn2+. The interdiffusion coefficients of (Cu + In) in Fe-free sphalerite at the Fe/FeS sulfur fugacity of the sources obey to the relation: D [cm2/s] = 1 * 10−3 * exp(5.53 * N) * exp((E + 2 * N)/RT) (E = -168.6 [kJ/mole]; N = mole fraction of Cu0.5In0.5S in ZnS). The interdiffusion coefficients increase with the sulfur fugacity, the Fe-content of sphalerite and in the presence of water. If Fe-bearing sphalerite crystals are used, the diffusion experiments in the ZnS-CuInS2 system at higher fS2 additionally show “chalcopyrite disease”. Using different Cu- or (Cu + Fe)-bearing sources like CUS, Cu2S, CuFeS2, Cu5 FeS4 Fe-free sphalerite and Fe-bearing sphalerites at all fS2 show replacement rims. Fe-bearing sphalerites reveal “disease” phenomena in addition to diffusion rims and replacements depending on fS2 at corresponding metal ratios in the source. Based on the experimental studies we propose the expression “diffusion induced segregations (DIS)” instead of “disease”. The mineral phases and the texture of the DIS depend on sulfur fugacity, Cu contents of the source, annealing times and temperature. The grain sizes, forms and orientation of the DIS bodies depend on the annealing temperatures and times and the defects of the sphalerite single crystals. The DIS phases chalcopyrite and bornite are formed by reaction of the diffusing Cu with the Fe contained in sphalerite which is oxidized from 2+ to 3+ within the chemical potential gradient. If the critical Fe-content of 2–3 at % is exceeded and a minimum fS2 is reached, additionally to the occurrence of DIS, Fe decreases in the primary sphalerites. If the critical Fe-content is not reached Fe can be introduced into the sphalerite. These different phenomena can be directly correlated to natural occurrences. Following our experimental studies and descriptions of natural parageneses the “chalcopyrite disease” has to be extended to corresponding phenomena of bornite and digenite.