Search results for "IONIZATION"
showing 10 items of 1255 documents
The Formation of Glycerol Oligomers with Two New Types of End Groups in the Presence of a Homogeneous Alkaline Catalyst
2019
The purpose of this work was to synthesize and characterize oligoglycerols with the chains of more than four repeating units. Those oligoglycerols may have some interesting applications, among others, as polyoxyalkylation starters. The glycerol oligomerization process was carried out during 12 h, at 230 °
Failure analysis of normally-off GaN HEMTs under avalanche conditions
2020
Gallium nitride (GaN) high electron-mobility transistors (HEMTs) are promising devices in the power electronics field owing to their wide bandgap (WBG). However, all the potential advantages provided by their WBG require reliability improvement. In industrial applications, robustness is one of the main factors considered by circuit designers. This study focuses on the observation of the degradation behavior of the main waveforms of unclamped inductive-switching (UIS) test circuits of two different commercial GaN HEMT structures. The relevance of this study lies in the potential applications of these devices to high-voltage applications and automotive systems where they are subjected to many…
PLA2-mediated catalytic activation of its inhibitor 25-acetyl-petrosaspongiolide M: serendipitous identification of a new PLA2 suicide inhibitor.
2004
Abstract25-Acetyl-petrosaspongiolide M (PMAc) (1), a mild non-covalent PLA2 inhibitor, unexpectedly recovers, after incubation with bvPLA2, the ability to covalently modify the enzyme target. This study demonstrates the catalytic effect of bvPLA2 in converting 1 in its deacetylated congener petrosaspongiolide M (PM) (2), a strong covalent PLA2 inhibitor whose molecular mechanism of inhibition has already been clarified. Moreover, our findings outline the potential role of PMAc as anti-inflammatory pro-drug, by virtue of its ability of delivering the active PM agent at the site of inflammation, functioning as a suicide inhibitor.
Molecular mass of macromolecules and subunits and the quaternary structure of hemoglobin from the microcrustacean Daphnia magna
2006
The molecular masses of macromolecules and subunits of the extracellular hemoglobin from the fresh-water crustacean Daphnia magna were determined by analytical ultracentrifugation, multiangle laser light scattering and electrospray ionization mass spectrometry. The hemoglobins from hypoxia-incubated, hemoglobin-rich and normoxia-incubated, hemoglobin-poor Daphnia magna were analyzed separately. The sedimentation coefficient of the macromolecule was 17.4 +/- 0.1 S, and its molecular mass was 583 kDa (hemoglobin-rich animals) determined by AUC and 590.4 +/- 11.1 kDa (hemoglobin-rich animals) and 597.5 +/- 49 kDa (hemoglobin-poor animals), respectively, determined by multiangle laser light sca…
Evolution of nacre: biochemistry and proteomics of the shell organic matrix of the cephalopod Nautilus macromphalus.
2009
12 pages; International audience; In mollusks, one of the most widely studied shell textures is nacre, the lustrous aragonitic layer that constitutes the internal components of the shells of several bivalves, a few gastropods, and one cephalopod: the nautilus. Nacre contains a minor organic fraction, which displays a wide range of functions in relation to the biomineralization process. Here, we have biochemically characterized the nacre matrix of the cephalopod Nautilus macromphalus. The acid-soluble matrix contains a mixture of polydisperse and discrete proteins and glycoproteins, which interact with the formation of calcite crystals. In addition, a few bind calcium ions. Furthermore, we h…
A proteomic approach to studying plant response to crenate broomrape (Orobanche crenata) in pea (Pisum sativum)
2004
Abstract Crenate broomrape ( Orobanche crenata ) is a parasitic plant that threatens legume production in Mediterranean areas. Pea ( Pisum sativum ) is severely affected, and only moderate levels of genetic resistance have so far been identified. In the present work we selected the most resistant accession available (Ps 624) and compared it with a susceptible (Messire) cultivar. Experiments were performed by using pot and Petri dish bioassays, showing little differences in the percentage of broomrape seed germination induced by both genotypes, but a significant hamper in the number of successfully installed tubercles and their developmental stage in the Ps 624 compared to Messire. The prote…
Comparative Quantitative Analysis of Porcine Optic Nerve Head and Retina Subproteomes
2019
Optic nerve head (ONH) and retina (RET) are the main sites of damage in neurodegenerative optic neuropathies including glaucoma. Up to date, little is known about the molecular interplay between these two adjoining ocular components in terms of proteomics. To close this gap, we investigated ONH and RET protein extracts derived from porcine eyes (n = 12) (Sus scrofa domestica Linnaeus 1758) using semi-quantitative mass spectrometry (MS)-based proteomics comprising bottom-up LC&ndash
A proteomic-based approach for the identification ofCandida albicans protein components present in a subunit vaccine that protects against disseminat…
2006
Candidiasis has become a prevalent infection in different types of immunocompromised patients. The cell wall of Candida albicans plays important functions during the host-fungus interactions. Cell wall (surface) proteins of C. albicans are major elicitors of host immune responses during candidiasis, and represent candidates for vaccine development. Groups of mice were vaccinated subcutaneously with a beta-mercaptoethanol (beta-ME) extract from C. albicans containing cell wall proteins. Vaccinated mice were then infected with a lethal dose of C. albicans. Increased survival and decreased fungal burden were observed in vaccinated mice as compared to a control group, and 75% of vaccinated mice…
Cellular effects of bacterial N-3-Oxo-dodecanoyl-L-Homoserine lactone on the sponge Suberites domuncula (Olivi, 1792): insights into an intimate inte…
2014
International audience; Sponges and bacteria have lived together in complex consortia for 700 million years. As filter feeders, sponges prey on bacteria. Nevertheless, some bacteria are associated with sponges in symbiotic relationships. To enable this association, sponges and bacteria are likely to have developed molecular communication systems. These may include molecules such as N-acyl-L-homoserine lactones, produced by Gram-negative bacteria also within sponges. In this study, we examined the role of N-3-oxododecanoyl-L-homoserine lactone (3-oxo-C12-HSL) on the expression of immune and apoptotic genes of the host sponge Suberites domuncula. This molecule seemed to inhibit the sponge inn…
Proteomic differentiation pattern in the U937 cell line
2011
The U937 cell line, originally established from a histiocytic lymphoma, has been widely used as a powerful in vitro model for haematological studies. These cells retain the immature cell phenotype and can be induced to differentiate by several factors, among which 12-O-tetradecanoyl-13-phorbol acetate (TPA). Fully differentiated cells acquire the adherent phenotype and exhibit various properties typical of macrophages. However, in spite of a great deal of research devoted to the U937 cellular model, the molecular basis of biological processes involved in the monocyte/macrophage differentiation remains unclear. The present study has been undertaken to contribute to this knowledge, in order t…