Search results for "Delta"
showing 10 items of 471 documents
Vitamin C as a promoter of γδ T cells
2020
none
Revisión de la sección del yacimiento del Mas de la Chimenea Alta (Formación Arcillas de Morella, Castellón) y significado en el contexto paleoambien…
2012
Desde los primeros estudios estratigráficos y paleontológicos, que datan de principios del siglo XX, la Fm Morella se ha caracterizado por su coloración rojiza y su contenido fósil. La mayor parte de sus depósitos se han interpretado como continentales, aunque con intercalaciones locales de materiales marinos. En esta unidad se da la paradoja de que muchos de los lugares descritos con fauna de vertebrados continentales se encuentran en depósitos interpretados como ambientes marinos poco profundos y de transición. La sección del Mas de la Chimenea Alta es un ejemplo. Ésta contiene yacimientos con fósiles de vertebrados que son claramente alóctonos, pero también otros, con icnitas que permite…
Sedimentation and tropical vegetation changes in Southern Benin (West Africa), carbon-13 tracing of organic matter dynamics and fluctuations of the s…
2007
International audience
Reconstitution des environnements de dépôtdu Carbonifère supérieur/ Permien inférieurau Sud du bassin de Paris : implicationgéodynamique
2016
National audience; La période Carbonifère-Permien marque un changement drastiquede régime tectonique (fin de l’Orogenèse hercynienne -début d’une phase de rifting). Cette transition s’enregistre dansles bassins sédimentaires contemporains. En Europe de l’Ouest,ces bassins, principalement constitués de sédiments continentauxet de séries volcano-sédimentaires (largement sous-estimées),sont mal contraints sur beaucoup d’aspects (sédimentaire, tectonique,volcanique et corrélations spatio-temporelles). Le cadrechronologique de ces bassins est également mal connu dans lamesure où les principaux âges ont été estimés par palynologie àpartir de faciès floristiques ayant pu coexister dans le temps.Un…
Single-cell RNA sequencing unveils the shared and the distinct cytotoxic hallmarks of human TCRVδ1 and TCRVδ2 γδ T lymphocytes
2019
γδ T lymphocytes represent ∼1% of human peripheral blood mononuclear cells and even more cells in most tissues of vertebrates. Although they have important anticancer functions, most current single-cell RNA sequencing (scRNA-seq) studies do not identify γδ T lymphocytes because their transcriptomes at the single-cell level are unknown. Here we show that high-resolution clustering of large scRNA-seq datasets and a combination of gene signatures allow the specific detection of human γδ T lymphocytes and identification of their T cell receptor (TCR)Vδ1 and TCRVδ2 subsets in large datasets from complex cell mixtures. In t -distributed stochastic neighbor embedding plots from blood and tumor sa…
Determinación de anticuerpos anti-Anisakis y relación con las subpoblaciones linfocitarias αβ Y γδ en pacientes con Enfermedad de Crohn
2015
La enfermedad de Crohn (EC) es una enfermedad de etiopatogenia y fisiopatología compleja, que se desarrolla sobre una base de múltiples alteraciones inmunes, tanto de la inmunidad innata como de la inmunidad adquirida. Siguiendo nuestra línea de investigación en relación a la deficiencia de LTγδ en pacientes con enfermedad de Crohn, planteamos la hipótesis de trabajo de que parásitos como Anisakis simplex, ingerido frecuentemente mediante el consumo de pescado, podrían aprovechar este estado de inmunidad alterada en la enfermedad de Crohn para infectar con mayor frecuencia a estos pacientes que a la población sana. Hemos realizado un estudio prospectivo de casos y controles desde junio de 2…
Immunotherapy targeting colon cancer stem cells
2010
In the last 10 years, cancer stem cells have interested the scientific community because this small tumorigenic population is also associated with tumor progression in human patients and specific targeting of cancer stem cells could be a strategy to eradicate cancers currently resistant to conventional therapy. Clinical studies have recently demonstrated that adding immune therapy to chemotherapy has survival benefits in comparison with chemotherapy alone that can sensitize tumors to immune cell-mediated killing (e.g., increasing sensitivity of tumor cells to subsequent cytotoxicity by T cells via upregulation of death receptors DR5 and Fas). However, loss of MHC molecules is often observe…
Revisiting delta-6 desaturase regulation by C18 unsaturated fatty acids, depending on the nutritional status.
2009
Dietary polyunsaturated fatty acids (PUFA) play a key role in regulating delta-6 desaturase (D6D), the key enzyme for long-chain PUFA biosynthesis. Nevertheless, the extent of their effects on this enzyme remains controversial and difficult to assess. It has been generally admitted that C18 unsaturated fatty acids (UFAs) regulate negatively delta-6 desaturase (D6D). This inhibition has been evidenced in regard to a high glucose/fat free (HG/FF) diet used in reference. However, several nutritional investigations did not evidence any inhibition of desaturases when feeding fatty acids. Because the choice of the basal diet appeared to be of primary importance in such experiments, our goal was t…
Thymine content of sea water as a measure of biosynthetic potential
1977
A hydrolysis procedure along with a high-pressure liquid chromatographic procedure is given enabling simple and reliable thymine determinations in the nanogram range in different fractions of sea-water samples taken from three different locations in the Northern Adriatic Sea. The levels corresponded to 1–3 μg DNA per liter. From total polyanionic thymine, which had been precipitated as the cetyltrimethylammonium salt, the highest percentage was linked to the particulate fraction, with a definite subsurface minimum at 10 to 15 m. There was a corresponding maximum of a high molecular “non-particulate” thymine-containing fraction at the corresponding depth. From the bottom at 30 m upwards to a…
Ab initio molecular orbital study of the substituent effect on phosphine–borane complexes
1998
Abstract Ab initio molecular orbital calculations have been used to study the substituent effect on H 3 BPH n Me 3− n and Me 3− n H n BPH 3 ( n =0–3) phosphine–borane complexes. The ab initio results show that successive methyl substitution on the phosphine favours complex formation, contrary to successive methyl substitution on the borane. The natural bond orbitals partitioning scheme suggests that, in general, there is no correlation between the charge transfer and the complexation energies. It also shows the shortening of the P–H and P–C bond lengths, upon complexation, is due to the increasing `s' character of these bonds.