Search results for "GC"

Comparison between Different Techniques for Volatiles Analyses in Coriander (Coriandrum sativum L.)

2011

Although many papers have been devoted to the study of Coriander fruits aromatic pattern, many differences show up according not only to the provenience of seeds, but also to the analytical methods chosen. In our work, samples from one Coriander small-seeded biotype has been analysed, verifying the differences between (1) the oil extracted by means of a Soxhlet apparatus (2) the same oil sampled by means of HS-SPME and (3) the HS-SPME on the roughly ground seeds, all analysed by direct injection in the GC-MS. The volatile composition detected by means of HS-SPME on oil resembles tightly that performed on Soxhlet extract. With respect to the direct injection, the HS-SPME shows a higher sensi…

Analysis of furan in coffee of different provenance by head-space solid phase microextraction gas chromatography-mass spectrometry: effect of brewing…

2009

A simple, sensitive and accurate method for the analysis of furan in roasted coffee has been used based on headspace-solid-phase micro-extraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS). The extraction was performed using 75-microm carboxen/polydimethylsiloxane fiber. Ionic strength, extraction time and temperature, and desorption time were assessed as the most important parameters affecting the HS-SPME procedure and d(4)-furan was used as the internal standard. The linearity range was in the range 0.0075-0.486 ng g(-1); the LOD and LOQ calculated using the signal-to-noise ratio approach were 0.002 and 0.006 ng g(-1), respectively. The inter- and intra-day precisio…

Base composition of DNA from glomalean fungi: high amounts of methylated cytosine.

1997

Glomales (Zygomycetes) are obligate fungal symbionts of roots of land plants and form arbuscular mycorrhiza. Sporal DNA of 10 isolates belonging to nine species was purified and the base composition was determined by RP-HPLC. Base composition fell in a narrow range between 30 and 35% G + C. A high amount of methylated cytosine (mC) accounting for 2-4% of the total nucleotides was found in all taxa. The DNA melting profile was defined for Scutellospora castanea. It corresponded to 32% G + C, and the shape of the denaturation curve suggested a heterogeneity in the GC content within the fungal genome. Knowledge of GC contents and variations between taxa are essential for evaluating nuclear DNA…

Les Hypogées d'Arles-Fontvieille et leur environnement : nouvelles perceptions, nouvelles perspectives

2014

Due to their unique architecture and the exceptional dimensions of the largest monument in the group, the Arles-Fontvieille hypogea are among the most remarkable megalithic monuments in Europe and the western Mediterranean region. A collective research program was launched in 2013 to study these well-known monuments which have, paradoxically, been the subject of relatively few field studies since the 19th century. The research program consisted of an inventory and analysis of the grave goods and associated artefacts, as well as a number of field studies providing an improved archaeological context of a megalithic group too often thought of only in terms of funerary monuments. Various traces…

I tempi della giustizia e la buonuscita dell'ex Presidente dell'AGCOM.

2008

I tempi della giustizia e la buonuscita dell'ex Presidente dell'AGCOM.

Un nouveau modèle d'âge pour l'Autunien du bassin d'Autun à partir de datations U-Pb sur des tonsteins

2021

National audience; Le bassin d’Autun, bassin historique français stéphano-permien connu pour ses huiles de schistes et ses fossiles de plantes et vertébrés terrestres, a permis de définir le stratotype Autunien au 19ème siècle, référence pour les « étages » continentaux du Permien d’Europe. Pendant très longtemps, les âges du bassin et du stratotype Autunien ont reposé sur les biozonations établies par les microflores et macroflores, plus récemment à partir des faunes d’insectes, de crustacés et d’amphibiens (Schneider et al., 2020). L’équivalence d’âge en étages marins reposait sur des corrélations complexes à partir d’environnements mixtes marins et continentaux permettant d’utiliser, ent…

Genome-wide meta-analysis identifies six novel loci associated with habitual coffee consumption

2015

Contains fulltext : 155360.pdf (Publisher’s version ) (Closed access) Coffee, a major dietary source of caffeine, is among the most widely consumed beverages in the world and has received considerable attention regarding health risks and benefits. We conducted a genome-wide (GW) meta-analysis of predominately regular-type coffee consumption (cups per day) among up to 91,462 coffee consumers of European ancestry with top single-nucleotide polymorphisms (SNPs) followed-up in ~30 062 and 7964 coffee consumers of European and African-American ancestry, respectively. Studies from both stages were combined in a trans-ethnic meta-analysis. Confirmed loci were examined for putative functional and b…

Acid Titrations of poly(dG-dC).poly(dG-dC) in Aqueous Solution and in a w/o Microemulsion

2005

The model polynucleotide poly(dG-dC).poly(dG-dC) (polyGC) was titrated with a strong acid (HCl) in aqueous unbuffered solutions and in the quaternary w/o microemulsion CTAB/n-pentanol/n-hexane/water. The titrations, performed at several concentrations of NaCl in the range 0.005 to 0.600 M, were followed by recording the modifications of the electronic absorption and of the CD spectra (210or = lambdaor =350 nm) upon addition of the acid. In solution, the polynucleotide undergoes two acid-induced transitions, neither of which corresponds to denaturation of the duplex to single coil. The first transition leads to the Hoogsteen type synG.C+ duplex, while the second leads to the C+.C duplex. The…

La Tecnica della microestrazione in fase solida (SPME) per l'analisi quantitativa e qualitativa dei feromoni sessuali degli insetti fitofagi: il caso…

2002

Zvaigžņotā Debess: 2008, Rudens

2008

Latvijas Zinātņu akadēmija, Latvijas Universitāte