A new infrared spectroscopic method suitable for determining total fatty alcohol and fatty acid ester concentrations in industrial oils has been developed. Oil samples were diluted with toluene (1:3 w/w), the toxicity and volatility of which are relatively low compared with more commonly used IR solvents, like carbon tetrachloride or carbon disulfide. Mixture standards were prepared from dodecanol, tetradecanol, octadecanol, methyl stearate and methyl palmitate. Some analytical and statistical tests were performed on the developed method. The recoveries and the repeatability of the method proved to be sufficient for the quantitative determination of fatty alcohol and fatty acid ester additives in industrial oils. Reproducibility testing in another laboratory also produced satisfactory results. The developed method also proved to be relatively quick and simple. This method was developed to satisfy industry's need to determine the concentrations of these oil additives, and it has already been applied successfully in machinery oil analysis.
An opportunity of designing nontypical double-stranded DNA structures containing nonnatural inserts in a regular nucleotide DNA sequence has been investigated. The looped nucleotide inserts on the basis of adenylates and thymidilates, and nonnucleotide inserts on the basis of phosphodiesters of diethyleneglycol, 1,10-decanediol, and 3-hydroxy-2-hudroxymethyltetrahydrofuran were introduced into the backbone of a 32-mer native DNA duplex. These inserts formed the internal loops in the modified double-stranded DNA fragments which were shown to lead to bending of the linear duplex structure by 16 to 83 degrees. The dependencies of the bend angle of dsDNA on the composition and the length of the looped regions were determined. It was established that the bend of the irregular region of dsDNA depended on the electrostatic interaction of the phosphate residues. The tension in the complex structure could be reduced by the introduction of additional nucleotide units opposite the loop, which led to some relaxation of the bent helix. The resulting parameters of the bend values were shown to be in a good agreement with the published data obtained by NMR spectroscopy. It was demonstrated that the variation of the nature or the length of the insert allowed one to regulate the level of the local perturbation of the duplex structure and, thereby, influence both the bend level of the double helix and the destabilization of the modified complex.
Fifty selected roots from a 7-year-old American ginseng (Panax quinquefolium L.) plant population grown in Denmark, with root weights varying from 191 to 490 g fresh weight (FW), were investigated for bioactive ginsenosides and polyacetylenes (PAs) in order to determine the correlation between the content of ginsenosides and PAs and root FW. PAs (falcarinol, panaxydol) and ginsenosides (Rb(1), Rb(2), Rb(3), Rc, Rd, Re, Rg(1)) were extracted from roots by sequential extraction with ethyl acetate and 80% methanol, respectively, and quantified in extracts by reverse-phase high-performance liquid chromatography (HPLC) using photodiode array detection. Total concentrations of PAs and ginsenosides varied between 150 and 780 mg/kg FW and 5,920 and 15,660 mg/kg FW, respectively. No correlation existed between the content of ginsenosides and PAs and root FW or between the total concentration of ginsenosides and PAs. Strong significant correlation was found between total content of ginsenosides and ginsenoside Rb(1) (r = 0.8190, P
This report describes the first isolation of Mycobacterium shimoidei in Finland from a sputum specimen obtained from an elderly female patient. M. shimoidei, a potential lung pathogen, is difficult to identify by routine methods and only a few cases have been reported. The present study demonstrated that M. shimoidei has a characteristic pattern for fatty acids and alcohols in gas liquid chromatography. This chromatogram and the pattern of mycolic acids on thin-layer chromatography allow it to be distinguished routinely. The unique sequence of the 16S rRNA gene and the 16S-23S rDNA spacer region allows identification by molecular methods.
Common ivy (Hedera helix subsp. helix) is a well-known native and ornamental plant in Europe. Reports on contact dermatitis from ivy have regularly appeared since 1899. Recently, it has been suggested that allergic contact dermatitis from the plant may be under-diagnosed, partly due to lack of commercial patch test allergens. The objective of the article is to present the results of aimed patch testing with the main common ivy allergen, falcarinol, during a 16-year period and review the newer literature. Consecutive patients tested with falcarinol 0.03% petrolatum from May 1993 to May 2009 were included. Cases published since 1987 were retrieved from the PubMed database. One hundred and twenty-seven Danish patients were tested with falcarinol and 10 (7.9%) tested positive. Seven were occupationally sensitized. Between 1994 and 2009, 28 new cases of contact dermatitis from ivy were reported, 2 of which were occupational. Only 11 of the 28 patients were tested with pure allergens. Falcarinol is not only widely distributed in the ivy family, but also in the closely related Apiaceae. Sensitization may occur in childhood or in adults pruning ivy plants or handling them in an occupational setting. In view of the ubiquity of falcarinol-containing plants and the relatively high prevalence of positive reactions in aimed patch testing, falcarinol should be the next plant allergen to be commercially available and included in the plant series worldwide.
The application of new thermodynamic adsorption isotherms allow to improve the description of surfactant adsorption kinetics based on a diffusional transport. While the consideration of interfacial reorientation corrects apparently too high diffusion coefficients, interfacial aggregation avoids too small diffusion coefficients or the assumption of adsorption barriers. The adsorption kinetics of alkyl dimethyl phosphine oxides is influenced by interfacial reorientation. While the lower homologues (C8-C12) follow the classical diffusion model, the higher homologues (C13-C15) yield diffusion coefficients several times larger than the physically reasonable values. Assuming two different adsorption states, the resulting diffusion coefficients agree with those expected from the geometric size of the molecules. The model also works well for oxyethylated non-ionics, such as C10EO8. As a second example, a good theoretical description is obtained for experiments of 1-decanol solutions when a mean surface aggregation number of n = 2.5 is assumed. The same n was obtained from the description of the equilibrium adsorption isotherm of 1-decanol. Assuming that the transition from one into the other state is controlled by a rate constant (change in orientation, formation or disintegration of two-dimensional aggregates) significant changes in the kinetics curves can result. The use of additional rate constants yields an improved fitting to experimental data.