Health assessment of artisanal gold miners in Indonesia

Small scale miners use mercury to extract gold from ore in many countries. An environmental and health assessment was performed in Indonesia in two regions, Galangan in Central Kalimantan and Talawaan in Northern Sulawesi. The environmental assessment showed severe mercury contamination of the sediments, and increased mercury levels in local fish. For the health investigation 281 volunteers were recruited and examined by a standardized questionnaire, a neurological examination and neuro-psychological tests. A medical score was used consisting of significant factors of mercury intoxication. Mercury exposed workers showed typical symptoms of mercury intoxication, such as movement disorders (ataxia, tremor, dysdiadochokinesia, etc.). Blood, urine and hair samples were taken from any participant and analyzed for mercury. The mercury concentration in the biomonitors was high, partly extreme high in the working population, increased in the population living in the same habitat and low in the control group. By a standard protocol which includes a combination of threshold values of mercury in the biomonitors and a medical sum score the diagnosis of chronic mercury intoxication was made for highly burdened workers (amalgam smelters) in 55% in Sulawesi and in 62% in Kalimantan. Less exposed mineral processors and the general population in the mining areas were also intoxicated to a high percentage.     

Perspektiven für zuckerhaltige Amphiphile mit Amid bindung

Perspektiven for Carbohydrate Containing Amphiphiles with Amide Linkages. Carbohydrate containing amphiphiles can easily be prepared by amide linkage. Reaction of the aldonic acid lactones of glucose and maltose with alkyl amines or of the N-(2-aminoethyl)aldon amides with alkanoic acids in the range of C₆-C₂₀ allows the molecular structure and the hydrophilic-hydrophobic ratio to be varied systematically. Products with one or two non-substituted amide linkages, as well as N-methylated compounds have been prepared. Strong hydrogen bonding between the amide bridges and the carbohydrate head groups of the hydrophilic part leads to the formation of highly ordered aggregates in aqueous solution: (a) Stable monolayers (C₁₂-C₂₀), suitable for the preparation of technical membranes; (b) Gels, formed from diluted solution (C₆-C₁₀), which according to electron micrographs are composed of a loose network of regularly twisted helical strands; (c) Lyotropic liquid-crystalline phases in more concentrated solutions, most pronounced with the N-methylated samples (C₁₀), or with compounds containing a disaccharide head group and a longer alkyl chain (C₁₆-C₁₈). In the latter case hydrophobic hydrocarbon interaction is dominant. These studies exemplify in which way the desired properties of compounds for different fields of application can be regulated by chemical modification. The crucial role played by the carbohydrate head groups of the glycolipids in biological systems may also be deduced.     

Multiparameter microscopy and spectroscopy for single-molecule analytics

The ability to monitor several parameters simultaneously from distinct individual fluorescent reporter molecules facilitates the disentanglement of complex and interacting systems and opens new perspectives in areas from basic science to biopharmaceutical technology. By combining annular illumination microscopy, time-correlated single-photon counting, and multichannel detection, we were able to determine 14 independent parameters from one individual fluorophore. The whole set of parameters was deduced from the few properties of the fluorescence photons, i.e., arrival time, wavelength, and polarization. With this approach, the intensity, the polarization, and the spectral dynamics can be analyzed on a nanosecond time scale and the mean values can be monitored with submillisecond time resolution. Nanosecond spectral dynamics of single molecules has been observed, to the best of our knowledge, for the first time. From our experience, we can determine all parameters for more than 30% of the illuminated fluorophores in biological samples and for more than 80% in doped polymeric films.     

Size distributions of nanoscaled particles and gas temperatures from time-resolved laser-induced-incandescence measurements

Laser-induced-incandescence (LII) signal decays are measured in sooting premixed atmospheric and low-pressure flames. Soot particle temperatures are obtained from LII signals measured at two wavelengths. Soot particle size distributions P(r) and flame temperatures T are measured spatially resolved by independent techniques. Heat and mass transfer kinetics of the LII process are determined from measured soot particle temperatures, flame temperatures, and particle sizes. Uncertainties of current LII models are attributed to processes during the absorption of the laser pulse. Implications for LII experiments are made in order to obtain primary soot particle sizes. Soot particle size distributions and flame temperatures are assessed from measured particle temperature decays by use of multi-D nonlinear regression.