Search results for "carbonates"

High-pressure NMR spectroscopy: An in situ tool to study tin-catalyzed synthesis of organic carbonates from carbon dioxide and alcohols. Part 2 [1]

2015

Dialkoxide diorganotin(IV) complexes are known to readily react with carbon dioxide under pressure and they are considered as suitable catalyst precursor models for the direct synthesis of organic carbonates. To gain a better understanding of CO2 insertion processes with Sn-OR bonds, the reactivity of n-Bu2Sn(OCH(CH3)(2))(2) (2) was investigated using high-pressure NMR (HP-NMR) spectroscopy. In deuterated solvents (isopropanol-d(8) and toluene-d(8)) under 50 bar of CO2 pressure at 80 degrees C, Sn-119{H-1} NMR experiments revealed the exclusive formation of an unprecedented tetraorganodistannoxane species, characterized as the bis[diisopropycarbonatotetrabutyldistannoxane] complex, {[n-Bu2S…

Phosphorescent hybrid organic-inorganic light-emitting diodes.

2010

An Alternative to the Human Hemoglobin Test in the Investigation of Bloodstains Treated with Active Oxygen: The Human Glycophorin A Test

2011

In criminal investigations, there are three stages involved when studying bloodstains: search and orientation, confirmation, and individualization. Confirmatory tests have two aims: to show that the stain contains a human biological fluid and to confirm the type of biological fluid. The need to determine the nature of the evidence is reflected in the latest bibliography, where the possibility of employing mRNA and miRNA markers for this purpose is proposed. While these new proposals are being investigated, the kits for determining human hemoglobin currently provide a simple solution for resolving this issue. With these kits, the possibility of obtaining false positives and false negatives i…

Bioavailability and assessment of heavy metal pollution in sediment cores off the Mejerda River Delta (Gulf of Tunis): How useful is a multiproxy app…

2016

International audience; Three core samples were taken from zones offshore from the Mejerda River Delta (Tunisia) and analyzed formajor and trace elements to assess their relationships with organic matter, monosulfides and carbonates, aswell as for pollution and bioavailability. Chemical speciation,ΣSEM/AVS, the enrichment factor (EF) and thegeo-accumulation index (I-geo) were used. Iron, cadmium, lead and zinc – the most frequently mined metalsin the Mejerda catchment – were found as contaminants in the offshore areas. Estimations of trace elementaccumulation using the EF and the I-geo index show that lead, and to a lesser extent zinc, are the most pollutingmetals off the Mejerda outlet. Ac…

Copper carbonate as a solid-bed reactor for spectrophotometric determination of doxycycline and oxytetracycline in an unsegmented continuous flow ass…

1993

The FIA-spectrophotometric determination of doxycycline was carried out by reaction of the drug with cupric ions entrapped in a polymeric material in a packed-bed reactor: the complex formed was then injected into a manifold with an alkaline solution as carrier. The developed colour was monitored at 395.0 nm. The method was applied to the determination of doxycycline in different pharmaceutical formulations. The calibration graph for doxycycline hyclate was linear over the range 10.0-80.0 mg ml-1 (n = 8) with a relative standard deviation of 1.4% (at 25 mg ml-1) and a sample throughput of 128 h-1. The proposed procedure was also applied to the determination of oxytetracycline in pharmaceuti…

Nacre calcification in the freshwater mussel Unio pictorum: carbonic anhydrase activity and purification of a 95 kDa calcium-binding glycoprotein.

2008

9 pages; International audience; The formation of the molluscan shell is finely tuned by macromolecules of the shell organic matrix. Previous results have shown that the acid-soluble fraction of the nacre matrix of the freshwater paleoheterodont bivalve Unio pictorum shell displays a number of remarkable properties, such as calcium-binding activity, the presence of extensive glycosylations and the capacity to interfere at low concentration with in vitro calcium carbonate precipitation. Here we have found that the nacre-soluble matrix exhibits a carbonic anhydrase activity, an important function in calcification processes. This matrix is composed of three main proteinaceous discrete fraction…

Source of calcium for pedogenic CaCO3 formation in benchmark soils of a Mediterranean semiarid environment

2004

Calcic and petrocalcic horizons (Bk and Bkm, respectively) commonly occur in soils of arid and semiarid regions. Studies carried out to investigate the source of calcium in CaCO3 formation have shown that dust and parent materials represent the main sources. The aim of this study was to investigate if gypsum may be a source of calcium for calcium carbonate formation and, eventually, to quantify it. Five soil pedons, developing on “Serie Gessoso- Solfifera”, were selected in a very representative forest Mediterranean ecosystem in Sicily (I). Pedons were opened, described in field and sampled according to the sequence of genetic horizons. Soil samples were analyzed to investigate 87/86Sr rati…

Design of novel imidazolium based nanostructures for sustainable catalytic applications

2019

GALACTOSE-DECORATED POLYMERIC CARRIERS FOR HEPATOCYTE-SELECTIVE DRUG TARGETING

2015

In this paper, the current available strategies to realize galactose-decorated nanostructured polymeric systems are summarized. These carriers are designed in order to obtain targeted drug delivery to hepatocytes via galactose (GAL) moieties, i.e., for the treatment of viral hepatitis or liver cancer that are the greater causes of global disability and mortality. Usually, the main followed strategy to obtain galactosylated polymeric carriers is to use galactosylated copolymers. The chemical modifications of preformed polymers with sugar-containing reagents is followed for obtaining lactosaminated human albumin, galactosylated phospholipid-polyaminoacid and polylactide (PLA)- polyaminoacid c…

Multidisciplinary approach for outcropping and subsurface Permian-Cenozoic deepwater carbonates (Central Sicily): outcome for paleogeography of the S…

2016

An integrated stratigraphic study of the outcropping and buried Permian-Cenozoic deep-water carbonate successions have been performed. These successions form some of the tectonic units, mostly buried beneath the Late Neogene sedimentary cover, in the fold and thrust belt of Central Sicily. Three main successions, pertaining to the well known Lercara, Imerese and Sicanian domains, have been reconstructed on the basis of a detailed facies analysis, seismostratigraphic interpretation, biostratigraphy (mostly based on palynological data) and comparison between outcropping and subsurface deep-water sediments. The main results reveal a continuous sedimentation of the deep-water Southern Tethyan S…