Forty elements in 21 coastal marine sediment samples collected duringthe second Antarctic scientific expedition from 18 different sites of Brekilenarea located at the coast of Antarctica were analysed by instrumental neutronactivation analysis (INAA) to detect eventual pollution. Radio-assay schemesfor three sets of elements after neutron irradiation and cooling were evolvedto avoid matrix effects. Data have been compared with those for sedimentsof various stations at Antarctica and two other regions in different continents.Lower concentration of certain elements in the Antarctic sediments reflectsless environmental exposition. Enrichment factors (EF) were calculated forall the elements using the earth crust as reference matrix, based on elementalvalues by MASON, TAYLOR and WEDEPOHL which show a normal pattern near to unityexcept for Ag and Br. The data obtained could also serve as a reference pointfrom which changes in the global environment can be studied. The quality assuranceof data was performed using standard reference materials (SRMs) of a similarmatrix (IAEA Marine Sediment SD-M/TM and Chinese Marine Sediment GBW 07313).
Authors:Donatella Senatra, R. Pratesi, and L. Pieraccini
Three component percolative W/O microemulsions were studied by differential scanning calorimetry. Water-AOT-Decane, D2O-AOT-Decane, Water-AOT-Isooctane and Water-Ca(AOT)2-Decane systems were analyzed. Thus by changing, in the order, the dispersed phase, the dispersing medium, and by modifying
the interphase region. The thermal history of the samples was monitored by a suitable thermal program. Following the latter,
first order phase transitions associated with the freezing and/or melting of the two massive phases were obtained, as well
as the higher order phase transition associated with the percolation process. From the melting spectra an estimate of the
amount of water bound to the hydrophilic groups of the AOT as well as of that of oil bound to the hydrophobic surfactant tails
was obtained. The latter result shows a difference in the behaviour of the continuous oily phase at the O/W interphase. From
the freezing spectra, the percolative character of the microemulsion was evidenced by the exotherms associated with the freezing
of the water phase.
Authors:Petar M. Ristivojević and Gertrud E. Morlock
The quality of three types of beer (dark, light and non-alcoholic) was assessed using high-performance thin-layer chromatography (HPTLC) combined with high-resolution mass spectrometry and chemometrics. An HPTLC separation of the polar beer components in the ethyl acetate extract was developed. The polar components were detected either by the in situ 2,2-diphenyl-1-pic-rylhydrazyl (DPPH*) assay or by derivatization with the Neu’s reagent, followed by the PEG solution. This directly allowed the visual comparison and evaluation of the phenolic/flavonoid or radical scavenging (antioxidative) beer profile. Although the three types of beer showed a very similar chemical HPTLC pattern, the signal intensities were different. Detected by the Neu's reagent, the dark beer extracts contained a high amount of phenolic compounds, and the light beer extracts showed a moderate content, while the non-alcoholic beer extracts had the lowest phenolic content. The HPTLC-DPPH* assay confirmed the higher radical scavenging activity of dark beer extracts, if compared to light and non-alcoholic beer extracts. The most active bands with regard to the radical scavenging property were identified to be desdimethyl-octahydro-iso-cohumulone and iso-n/ad-humulone. The use of pattern recognition techniques showed a clear differentiation between dark and non-alcoholic beer extracts, while light beer extracts did overlap with both beer types. This HPTLC screening allowed the (1) direct comparison of beer samples/types via classification and pattern recognition, (2) the assessment of the beer quality with regard to its antioxidative potential, and (3) the reference to single components.
Authorship identity has long been an Achilles’ heel in bibliometric analyses at the individual level. This problem appears
in studies of scientists’ productivity, inventor mobility and scientific collaboration. Using the concepts of cognitive maps
from psychology and approximate structural equivalence from network analysis, we develop a novel algorithm for name disambiguation
based on knowledge homogeneity scores. We test it on two cases, and the results show that this approach outperforms other
common authorship identification methods with the ASE method providing a relatively simple algorithm that yields higher levels
of accuracy with reasonable time demands.
Authors:G. Mangini, D. Nigro, B. Margiotta, P. De Vita, A. Gadaleta, R. Simeone, and A. Blanco
During the last century wheat landraces were replaced by modern wheat cultivars leading to a gradual process of genetic erosion. Landraces genotyping and phenotyping are strategically useful, as they could broaden the genetic base of modern cultivars. In this research, we explored Single Nucleotide Polymorphism (SNP) markers diversity in a collection of common and durum wheats, including both landraces and Italian elite cultivars. A panel of 6,872 SNP markers was used to analyze the genetic variability among the accessions, using both the Principal Components Analysis (PCA) and the Neighbour Joining clustering method. PCA analysis separated common wheat accessions from durum ones, and allowed to group separately durum landraces from durum elite cultivars. The Neighbour joining clustering validated PCA results, and moreover, separated common wheat landraces from common elite cultivars. The clustering results demonstrated that Italian durum landraces were poorly exploited in modern breeding programs. Combining cluster results with heterozygosity levels observed, it was possible to clarify synonymy and homonymy cases identified for Bianchetta, Risciola, Saragolla, Timilia and Dauno III accessions. The SNP panel was also used to detect the minimum number of markers to discriminate the studied accessions. A set of 33 SNPs were found to be highly informative and used for a molecular barcode, which could be useful for cultivar identification and for the traceability of wheat end-products.
Two different botanical sources, Eclipta alba and Wedelia calendulacea are used as “Bhringaraja” in the Ayurvedic s ystem o f medicine. In the present study, an effort has been made to evaluate different sources by using high-performance thin-layer chromatography (HPTLC) as an analytical tool. Wedelolactone, one of the primary constituents of these plants, was taken as the marker compound for the evaluation. An HPTLC method was developed and validated for the evaluation of different sources of “Bhringaraja”. The chromatographic system was developed using silica gel 60 F254 HPTLC plates with the mobile phase toluene–chloroform–ethyl alcohol–formic acid (5:4:1:0.5, v/v). Linearity was found between the concentration ranges of 80 to 280 ng spot−1 (R2: 0.9994), and limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.36 ng spot−1 and 1.09 ng spot−1. The study has shown the presence of wedelolactone at the concentration of 0.26% w/w and 0.05% w/w in E. alba and W. calendulacea, respectively, whereas it was absent in another closely related species, Wedelia trilobata. At the same time, all the three plants were subjected to evaluation of quality-control parameters as per the World Health Organization (WHO) guidelines. Certain parameters such as foaming index, total alkaloids, and total bitter principles were significantly different in the three plants. Hence, the present HPTLC method development, and the validation and evaluation of quality-control parameters would be helpful in the standardization of individual plants and their formulations.
Authors:He Zhang, Mei Meng, Li Chen, Fang Wang, Jing Zhang, Ying Jiang, and Wen Wang
The newly emerged chromatographic fngerprint analysis represents a rational approach assessment of Traditional Chinese Medicine (TCM) and its preparations. In the present paper, a quick and reliable analytical method was developed for the quality assessment of QiYi capsules (QY) using high-performance thin-layer chromatography (HPTLC) with the reference of Tripterygium wilfordii. The unique properties of the HPTLC fngerprint were validated by analyzing 10 batches of QY samples. The 9 common peaks of the HPTLC images of QY and the different RF and peak area ratios of the chemical distribution could directly discern the stability by comparison of 10 samples, and also, the 9 common peaks were selected to evaluate the similarities of QY; the similarities of 10 batches of QY were more than 0.960, which indicated a standardized consistency and reliable quality of QY. Therefore, the newly developed HPTLC fngerprint method provided an easy way for sample characterization and differentiation; it allowed for the quality assessment of QY capsules with the reference of T. wilfordii.
Authors:Z. Á. Nagy, J. J. Bakonyi, Virág Som, and T. Érsek
Brurberg, M. B., Hannukkala, A. and Hermansen, A. (1999): Genetic variability of Phytophthora infestans in Norway and Finland as revealed by mating type and fingerprint probe RG57. Mycol. Res. 103 , 1609-1615.