Search results for "CEO"
showing 10 items of 398 documents
The environmental impact of air pollution on the built heritage of historic Cairo (Egypt)
2020
In the last decades, many researchers investigated the relation between environmental pollution and the degradation phenomena on the built heritage, because of their rapid increase and growing harmfulness. Consequently, the identification of the main pollution sources has become essential to define mitigation actions against degradation and alteration phenomena of the stone materials. In this way, the present paper is focused on the study of the effect of air pollution on archaeological buildings in Historic Cairo. A multi-methodological approach was used to obtain information about the chemical composition of examined black crusts and to clarify their correlation with the air pollution, sp…
SANS (USH1G) regulates pre-mRNA splicing by mediating the intra-nuclear transfer of tri-snRNP complexes
2021
Abstract Splicing is catalyzed by the spliceosome, a compositionally dynamic complex assembled stepwise on pre-mRNA. We reveal links between splicing machinery components and the intrinsically disordered ciliopathy protein SANS. Pathogenic mutations in SANS/USH1G lead to Usher syndrome—the most common cause of deaf-blindness. Previously, SANS was shown to function only in the cytosol and primary cilia. Here, we have uncovered molecular links between SANS and pre-mRNA splicing catalyzed by the spliceosome in the nucleus. We show that SANS is found in Cajal bodies and nuclear speckles, where it interacts with components of spliceosomal sub-complexes such as SF3B1 and the large splicing cofact…
Comparison of iron acquisition from Fe–pyoverdine by strategy I and strategy II plants
2011
; Iron is an essential micronutrient for plants and associated microorganisms. However, the bioavailability of iron in cultivated soils islow. Plants and microorganisms have thus evolved active strategies of iron uptake. Two different iron uptake strategies have been described in dicotyledonous and monocotyledonous graminaceous species. In bacteria,this strat-egy relies on the synthesis of siderophores. Pyoverdines, a major class of siderophores produced byfluorescent pseudomo-nads, were previously shown topromote ironnutrition of the dicotyledonous species ArabidopsisthalianaL.(Heynh.), whereas contradictory reports were made on the contribution of those siderophores to the nutrition of g…
Comparison of the relative quantities of aroma compounds found in fresh apricot (Prunus armeniaca) from six different varieties
1988
The volatile components of fresh apricot (Prunus armeniaca) were isolated by vacuum distillation and fractionated on a silica gel column. Analysis by gaschromatography coupled with mass spectrometry led to the identification of 82 compounds, 60 of which were found for the first time in this fruit. Six varieties, cultivated in the south of France were compared for their firmness, acidity, sweetness and for their content of 56 volatile components. Precoce de Tyrinthe was the least aromatic variety, but produced fruits very early in the season. Palsteyn gave acidic but rather aromatic fruits. Moniqui possessed large but perishable fruits with flowery aroma due to the presence of terpenic keton…
Inorganic/organic hybrid nanoparticles synthesized in a two-step radiation-driven process
2022
In this work, we have synthesized inorganic-organic hybrid nanoparticles via radiation synthesis of inorganic nanoparticles (Ag and CeO2) in aqueous dispersions containing radiation-synthesized poly(N-vinyl pyrrolidone) (PVP) nanogels (NG). The experiments show that there are strong interactions between the inorganic precursors (Ag+ and Ce3+) and the nanogel prior to irradiation. The two hybrid systems (Ag/NG and CeO2/NG) were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD confirms the formation of crystalline Ag and CeO2. TEM reveals that the inorganic nanoparticles are evenly distributed in/on the nanogel. Both XRD and TEM show that size of the…
Rare earth element contents of Jurassic fish and reptile teeth and their potential relation to seawater composition (Anglo-Paris Basin, France and En…
2002
The rare earth element (REE) chemistry of Jurassic shelf seawater from western Europe (Anglo-Paris Basin) was investigated by analyzing the fish and reptile teeth deposited in shallow to deeper water (<200 m) environments. REE patterns in apatites are controlled by the host sediments. Vertebrate teeth sampled from the siliciclastic sediments (calcareous sandstones and shales) show flat shale-normalized REE patterns that reflect the dominant influence of the continental source from which the REE were derived. Carbonate deposits, protected from the clastic sources, contain fish and reptile teeth whose REE patterns reflect more accurately the REE composition of the overlying water column. The …
Stable isotope composition and rare earth element content of vertebrate remains from the Late Cretaceous of northern Spain (Laño): did the environmen…
2003
Abstract Oxygen and carbon isotope measurements have been performed on phosphatic remains from faunal associations (dinosaurs, crocodiles, turtles and fish) of the Late Cretaceous continental and marine sediments from northern Spain (Basque Country). The environmental meaning of the oxygen isotope record in fossil reptiles is discussed on the basis of known paleoecology, modern fauna analogs, and apatite chemistry (rare earth elements (REE), CO32− and PO43− contents). Fossil remains in sandstones and argillites from two localities (Urria and Cuezva) have low (down to 16‰) and scattered δ18O(PO4,CO3) and δ13C values with REE patterns characterized by strong middle REE enrichments. These geoc…
Residential Exposure to PM2.5 Components and Risk of Childhood Non-Hodgkin Lymphoma in Denmark: A Nationwide Register-Based Case-Control Study
2020
In a recent study, we observed an increased risk of childhood non-Hodgkin lymphoma (NHL) associated with exposure to fine atmospheric particulate matter (PM2.5) and black carbon (BC). In this nationwide register-based case-control study, we focus on specific components of PM2.5 in relation to childhood NHL in Denmark (1981&ndash
New method for the determination of the absolute stereochemistry in antitumoral annonaceous acetogenins
1998
Abstract The absolute configurations at the carbinol centers in several acetogenins were determined through p-bromophenylurethane derivatives and subsequent Mosher ester methodology. This method has been applied on α,α′-dihydroxylated adjacent bis-THF acetogenins with a threo/cis/threo/cis/erythro relative configuration membrarollin (1), a new acetogenin isolated from Rollinia membranacea seeds, rollimembrin (2), membranacin (3) and rolliniastatin-1 (4), and a threo/trans/threo/translerythro relative configuration motrilin (5), squamocin (6), and desacetyluvaricin (7). 1 was found to be the most potent inhibitor of the mammalian mitochondrial complex I.
Lack of antiandrogenic effects of topical bifonazole on sebaceous glands and hairs in the hamster flank organ.
1993
The activity of topically applied bifonazole was evaluated in vivo in the three androgen-dependent structures of the hamster flank organ, i.e. the pigmented spot, sebaceous glands and hairs. Topical bifonazole in our experience did not demonstrate any morphological effect on sebaceous gland and hair even when applied in the dosage of 3 mg/cm<sup>2</sup>/day. On the basis of our morphometric results we can conclude that topically applied bifonazole does not interfere with cutaneous androgen metabolic transformations in the pilosebaceous unit of the flank organ.