Characterisation of a prehistorical ceramic object

Archaeological ceramics findings are usually characterised by a combination of methods to provide as many as possible information about their origin, use and deposition. Unique moon-shaped idol approximately 0.5 m long from the Final Bronze Age was studied by XRD, XRF, Raman spectroscopy and thermal analyses (TG, DTA, DSC). Special attention was given to processes occurring during its thermal treatment, which were specified by thermal analysis. It was proved that the process of kaolinite dehydroxylation proceeded less intensively in the central part of the object and the maximum of peak was shifted to lower temperature compared to the border parts. It is supposed that the moon-shaped idol was thermally treated not until its use, and the border parts of the object were exposed to lower temperatures compared to the central part.     

Improving chemometric results by optimizing the dimension reduction for Raman spectral data sets

In this contribution a new method for improving the accuracy of classification and identification experiments is presented. For this purpose the four most applied dimension reduction methods (principal component analysis, independent component analysis, partial least square dimension reduction and the linear discriminant analysis) are used as starting point for the optimization method. The optimization is done by a specially designed genetic algorithm, which is best suited for this kind of experiments. The presented multi‐level chemometric approach has been tested for a Raman dataset containing over 2200 Raman spectra of eight classes of bacteria species (Bacillus anthracis, Bacillus cereus, Bacillus licheniformis, Bacillus mycoides, Bacillus subtilis, Bacillus thuringiensis, Bacillus weihenstephanensis and Paenibacillus polymyxa). The optimization of the dimension reduction improved the accuracy for classification by 6% compared with the accuracy, if the standard dimension reduction is applied. The identification rate is improved by 14% compared with the dimension reduction. The testing in a classification and identification experiment showed the robustness of the algorithm. Copyright © 2014 John Wiley & Sons, Ltd.     

Comparison between end-tidal CO₂ and respiration volume per time for detecting BOLD signal fluctuations during paced hyperventilation

Respiratory motion and capnometry monitoring were performed during blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) of the brain while a series of paced hyperventilation tasks were performed that caused significant hypocapnia. Respiration volume per time (RVT) and end-tidal carbon dioxide (ETCO(2)) were determined and compared for their ability to explain BOLD contrast changes in the data. A 35% decrease in ETCO(2) was observed along with corresponding changes in RVT. A best-fit ETCO(2) response function, with an average initial peak delay time of 12 s, was empirically determined. ETCO(2) data convolved with this response function was more strongly and prevalently correlated to BOLD signal changes than RVT data convolved with the corresponding respiration response function. The results suggest that ETCO(2) better models BOLD signal fluctuations in fMRI experiments with significant transient hypocapnia. This is due to hysteresis in the ETCO(2) response when moving from hypocapnia to normocapnia, compared to moving from normocapnia to hypocapnia.     

Structure analysis of group I plant nucleases

Anticancer drugs attacking nucleic acids of the target cells have so far been based on animal or fungal ribonucleases. Plant nucleases have been proved to exhibit decreased cytotoxic side effects. Tomato bifunctional nuclease 1 with activity against both single-stranded and double-stranded RNA and DNA was produced in tobacco leaves as recombinant protein. The enzyme crystallizes under several different crystallization conditions. The presence of Zn(2+) ions was confirmed by X-ray fluorescence. First crystallographic data were obtained.     

Anion binding by meta ureido-substituted thiacalix[4]arenes

The regioselective nitration of 25,26,27,28-tetrapropoxythiacalix[4]arene (1,3-alternate) led to the formation of mono- and dinitro derivatives bearing NO₂ groups in the meta positions at the same side of the molecule. Their reduction and subsequent condensation with arylisocyanates gave the new types of anion receptors with a so far unknown meta-substitution pattern. In a highly HB-competitive solvent like DMSO, the novel ligands showed good complexation abilities. Moreover, as can be documented by higher complexation constants, achiral receptors 9a, 9b are better preorganized for anion binding than corresponding stereoisomers 10a, 10b. Our results indicate that anion receptors based on meta-substituted thiacalixarenes possess complexation abilities fully comparable with common para-substituted analogues.     

Multi-parameter determination of TNFα, PCT and CRP for point-of-care testing

A proof of concept for the simultaneous multi-parameter determination of three inflammation and sepsis parameters-TNFα, PCT and CRP-using a compact optical immunosensor is demonstrated. Harmonized assay conditions revealed standard curves with test midpoints (IC(50)) of 380 μg L(-1) for TNFα, 2300 μg L(-1) for PCT, and 2645 μg L(-1) for CRP.