Search results for " carbon"
showing 10 items of 1750 documents
Protein oxidation in metabolic syndrome
2013
Purpose: Oxidative stress plays a pivotal role in the pathogenesis of the metabolic syndrome and in the progression of its complications. Carbonylated proteins are a stable marker of severe oxidative stress because damage to the protein structure is irreversible and may cause an inhibition of their enzymatic activity or an increased susceptibility to proteolysis. There are few data regarding protein oxidation in metabolic syndrome, although elevated levels of carbonyl groups are often detected in subjects with obesity, diabetes mellitus, hypertension or dyslipidemia, well-known components of the metaboic syndrome. In particular, obesity, insulin resistance and diabetes mellitus are frequent…
Analysis of radiolucent gallstones by computed tomography for in vivo estimation of stone components.
1990
. Successful oral litholytic and other non-operative therapies of gallstones require exact determination of the stone components. Since computed tomography (CT) provides highly sensitive measurement of density, we performed a study to evaluate whether CT measurement of stone density allows a prediction of the composition of radiolucent gallstones. Twenty-eight patients presenting with 29 radiolucent gallbladder (n= 17) or common bile duct stones (n=12) were included. Prior to operative or endo-scopic therapy the attenuation values (Hounsfield Units, HU) were assessed in vivo by CT under standardized conditions (Somatom II, 125 KV, 130 mAs). After surgical or endoscopic stone removal the con…
First combined flux chamber survey of mercury and CO2 emissions from soil diffuse degassing at Solfatara of Pozzuoli crater, Campi Flegrei (Italy): M…
2014
Abstract There have been limited studies to date targeting gaseous elemental mercury (GEM) flux from soil emission in enriched volcanic substrates and its relation with CO 2 release and tectonic structures. In order to evaluate and understand the processes of soil–air exchanges involved at Solfatara of Pozzuoli volcano, the most active zone of Campi Flegrei caldera (Italy), an intensive field measurement survey has been achieved in September 2013 by using high-time resolution techniques. Soil–air exchange fluxes of GEM and CO 2 have been measured simultaneously at 116 points, widely distributed within the crater. Quantification of gas flux has been assessed by using field accumulation chamb…
The role of biotic and abiotic processes in the origin of Messinian evaporate-associated carbonates (Southern Italy)
2013
Formation of microbial organic carbonates during the Late Jurassic from the Northern Tethys (Amu Darya Basin, Uzbekistan): implications for Jurassic …
2020
23 pages; International audience; The Late Jurassic was a period of major global carbon cycle perturbations with episodes of anoxia leading to regional accumulation of organic matter in sediments worldwide. The Tubiegatan section (SW Gissar Mountains, Uzbekistan) located in the Northern Tethys, shows atypical organic-rich limestone and marl deposits (up to 6% of total organic carbon) marked by pronounced negative excursions of δ13Ccarb (amplitude of ca. 12‰) and δ13Corg (amplitude of ca. 4‰) recorded during the Middle Oxfordian (Transversarium Zone). A transdisciplinary approach including sedimentology, palynofacies characterization, mineralogy, organic and inorganic geochemistry was carrie…
Response of Soil Microbial Communities to Iron-Porphyrin Catalytic Amendments.
2010
Intensive agricultural practices strongly increase CO2 emission from soil. Synthetic metal-porphyrins were shown to significantly decreased CO2 emission from soil due to an in-situ catalysis of oxidative polymerization of soil organic matter. This research aimed to assess the effects of iron-porphyrin (POR) amendments on soil microbial communities in three arable soils under wheat and maize cropping located in Naples, Turin and Piacenza, characterized by different pedological and climatic conditions. Bulk-soil and rhizo-soil were sampled during 4 years and the microbial groups directly involved in organic matter (OM) mineralization and in key processes of the nitrogen cycle were examined. M…
Effect of iron-porphyrin treatment on soil microbial communities
2009
Intensive agricultural management have led to an increasing transfer of carbon from soil organic matter (SOM) to atmospheric CO2. It is noteworthy that the flux of CO2 from the soil is ten times greater than fossil fuel emission from industrial and automotive activities. Piccolo and co-workers (1999) suggested that hydrophobic humic components in soil exerted hydrophobic protection towards easily degradable compounds. They postulated that associations of apolar molecules deriving from plant degradation and microbial activity incorporate more polar molecules, thus preventing their otherwise rapid microbial degradation and enhancing their persistence in soil. Moreover, synthetic metal-porphyr…
Effect of agricultural practices on soil microbial communities
2008
Soil carbon sequestration is an important and immediate sink for removing atmospheric carbon dioxide and slowing global warming. Agricultural practices strongly impact CO2 emission from the soil and the loss of soil organic matter is lower when “no-till” agriculture is practiced. The present work was performed in order to investigate effects of different agricultural practices on soil microbial communities. Field experiments took place at three Italian locations strongly differing in pedological, chemical and climatic characteristics: Naples, Turin and Piacenza. Soils were subjected to four management practices such as traditional (TRA), minimum tillage (MIN) and amendments with compost (CO…
Amorphous Polyphosphate and Ca‐Carbonate Nanoparticles Improve the Self‐Healing Properties of both Technical and Medical Cements
2020
Cement is used both as a construction material and for medical applications. Previously, it has been shown that the physiological polymer inorganic polyphosphate (polyP) is morphogenetically active in regeneration of skin, bone, and cartilage. The present study investigates the question if this polymer is also a suitable additive to improve the self-healing capacity not only of construction cement but also of inorganic bone void fillers. For the application in the cement, two different polyP-based amorphous nanoparticles (NP) are prepared, amorphous Ca-polyP NP and amorphous Ca-carbonate (ACC) NP. The particles are integrated into poly(methyl methacrylate) in a concentration ratio of 1:10. …