Search results for "GC"

Conformación tridimensional y reconocimiento molecular de biopolímeros : aplicación de RMN multidimensional y desarrollo de metodología de cálculo y …

1998

El objetivo principal de la Tesis ha sido la exploración, el análisis y el perfeccionamiento de las técnicas más habituales utilizadas en la determinación de la estructura y dinámica de biopolímeros en disolución. En concreto, se han utilizado métodos teóricos y experimentales para obtener las estructuras de dos biopolímeros entre los grupos más numerosos de ellos: proteínas y ácidos nucleicos. La obtención de la estructura de una proteína de interés bioquímico por sus peculiaridades cinéticas mediante dos técnicas diferentes ha sido uno de los objetivos principales en la Tesis. La aplicación de las técnicas de modelización por homología y la realización de un análisis exhaustivo sobre los …

Contaminación de los cereales y los derivados de cereales por micotoxinas en Rumania

2017

Las micotoxinas son los contaminantes más frecuentes en el trigo y los productos a base de trigo. Las micotoxinas más importantes encontradas en trigo son principalmente las toxinas producidas por el género Fusarium, como deoxinivalenol (DON), zearalenona (ZEA), nivalenol, toxina HT-2 (HT-2), toxina T-2, y, recientemente estudiadas, las micotoxinas emergentes, en particular eniatinas (ENs) y beauvericina. La agricultura y en especial el cultivo de trigo son partes importantes de la economía rumana. A pesar de su alto potencial productor y consumidor, Rumania tiene registrados pocos datos relativos a la presencia de micotoxinas en los productos alimenticios a base de trigo. El objetivo de es…

Quasi-periodic dipping in the ultraluminous X-ray source, NGC 247 ULX-1

2021

Most ultraluminous X-ray sources (ULXs) are believed to be stellar mass black holes or neutron stars accreting beyond the Eddington limit. Determining the nature of the compact object and the accretion mode from broadband spectroscopy is currently a challenge, but the observed timing properties provide insight into the compact object and details of the geometry and accretion processes. Here we report a timing analysis for an 800 ks XMM-Newton campaign on the supersoft ultraluminous X-ray source, NGC 247 ULX-1. Deep and frequent dips occur in the X-ray light curve, with the amplitude increasing with increasing energy band. Power spectra and coherence analysis reveals the dipping preferential…

Harmonizing circumpolar monitoring of Arctic fox: benefits, opportunities, challenges and recommendations.

2017

Source at http://dx.doi.org/10.1080/17518369.2017.1319602 The biodiversity working group of the Arctic Council has developed pan-Arctic biodiversity monitoring plans to improve our ability to detect, understand and report on long-term change in Arctic biodiversity. The Arctic fox (Vulpes lagopus) was identified as a target of future monitoring because of its circumpolar distribution, ecological importance and reliance on Arctic ecosystems. We provide the first exhaustive survey of contemporary Arctic fox monitoring programmes, describing 34 projects located in eight countries. Monitored populations covered equally the four climate zones of the species’ distribution, and there were large dif…

STUDY OF FATTY ACIDS PROFILE IN OVINE AND CAPRINE SICILIAN DAIRY BREED AND ASSOCIATION WITH POSSIBLE CANDIDATE GENES

In Sicilia, le razze bovine, ovine e caprine e le produzioni lattiero-casearie rappresentano una risorsa importante per l’economia del settore zootecnico. L’importanza economica del latte ovino e caprino è soprattutto legata per il primo alla sua trasformazione in prodotti lattiero-caseari, per il secondo al possibile utilisso per il consumo fresco. Per entrambe queste specie, il contenuto di grasso e proteine è importante tanto quanto la produzione di latte. L’individuazione dei geni responsabili delle caratteristiche quanti-qualitative del latte dei piccoli ruminanti permetterebbe quindi di aumentare l’efficienza del miglioramento genetico e di considerare nuovi obiettivi di selezione com…

Gas chromatography-mass spectrometry characterization of the varnish and glue of an ancient 18th century double bass.

2007

A GC–MS investigation is conducted on the double bass “Panormus”, property of Conservatorio di Musica “Vincenzo Bellini” in Palermo. The most important components of the varnish (fatty acids) and of the glue (proteinaceous amino acids), with which the musical instrument was treated in the past, are determined. The analyses are carried out by prior derivatization of fatty acids by acidic methanol and of amino acids by acidic methanol and trifluoroacetic anhydride (TFAA). Analytes identification is achieved by direct comparison with several reference materials and the use of a digitized library.

Distribution maps of vegetation alliances in Europe

2022

Aim The first comprehensive checklist of European phytosociological alliances, orders and classes (EuroVegChecklist) was published by Mucina et al. (2016, Applied Vegetation Science, 19 (Suppl. 1), 3-264). However, this checklist did not contain detailed information on the distribution of individual vegetation types. Here we provide the first maps of all alliances in Europe. Location Europe, Greenland, Canary Islands, Madeira, Azores, Cyprus and the Caucasus countries. Methods We collected data on the occurrence of phytosociological alliances in European countries and regions from literature and vegetation-plot databases. We interpreted and complemented these data using the expert knowledge…

Chromatographic Profiles of the main Secondary Metabolites in the Monarda fistulosa L. Aerial Part

2021

Two different methods of chromatographic analysis have been used in this study for the phytochemical evaluation of main secondary metabolites in the aerial part of bee balm (Monarda fistulosa L.) as the non-officinal medicinal plant of the Lamiaceae Martinov family. The high performance thin layer chromatography (HPTLC) fingerprinting method was developed for the qualitative analyses of phenolic and non-polar compounds in the bee balm herb after its maceration in the solvents of different polarity. Such polyphenols as rosmarinic, caffeic and chlorogenic acids were authentically identified in the methanol extract of herb using HPTLC. Aromatic monoterpenoid thymol was identified by the HPTLC …

Evolution of neodymium isotopic signature of seawater during the Late Cretaceous: implications for intermediate and deep circulation.

2016

20 pages; International audience; Neodymium isotopic compositions (εNd) have been largely used for the last fifty years as a tracer of past ocean circulation, and more intensively during the last decade to investigate ocean circulation during the Cretaceous period. Despite a growing set of data, circulation patterns still remain unclear during this period. In particular, the identification of the deep-water masses and their spatial extension within the different oceanic basins are poorly constrained. In this study we present new deep-water εNd data inferred from the Nd isotope composition of fish remains and Fe–Mn oxyhydroxide coatings on foraminifera tests, along with new εNd data of resid…

Characterization of prehispanic cosmetics found in a burial of the ancient city of Teotihuacan (Mexico)

2012

The present paper reports the chemical data obtained on samples of pigmenting materials contained in 31 miniature vessels found in a burial found in Teopancazco, a multiethnic neighborhood center located in the southeastern sector of the archaeological site of Teotihuacan (Central Mexico) and the analytical protocol established for the complete characterization of these archaeological materials. For this purpose a multi-technique approach based on the combination of several non destructive and micro-destructive instrumental techniques, namely, light microscopy (LM), scanning electron microscopy-X-ray micro-analysis (SEMe EDX), transmission electron microscopy (TEM), voltammetry of micropart…