Search results for "Oxide"
showing 10 items of 6424 documents
Biological effects of inorganic arsenic on primary cultures of rat astrocytes
2010
It is well established that inorganic arsenic induces neurotoxic effects and neurological defects in humans and laboratory animals. The cellular and molecular mechanisms of its actions, however, remain elusive. Herein we report the effects of arsenite (NaAsO2) on primary cultures of rat astrocytes. Cells underwent induction of heat shock protein 70 only at the highest doses of inorganic arsenic (30 and 60 microM), suggesting a high threshold to respond to stress. We also investigated arsenic genotoxicity with the comet assay. Interestingly, although cells treated with 10 microM arsenite for 24 h maintained >70% viability, with respect to untreated cells, high DNA damage was already observed…
Speciation and oxidation kinetics of arsenic in the thermal springs of Wiesbaden spa, Germany.
2001
Since 1886 arsenic has been known to be present as a trace component in the Wiesbaden thermal waters at concentrations of over 100 microg L(-1). In this study for the first time molecular level speciation of arsenic was measured both in the water (by HG-AAS) and in wellstone scale deposits (by XANES). Most of the arsenic in the anoxic NaCl-type waters is in the reduced arsenite form. Hydrous ferric oxide (HFO) precipitates in the scale deposits scavenge only the minor dissolved arsenate portion which is, however, accumulated up to 3% w/w. Isothermal precipitation experiments at in-situ temperatures showed a difference between the progress of both arsenic and iron oxidation and precipitation…
Effect of ADH II Deficiency on the Intracellular Redox Homeostasis in Zymomonas mobilis
2011
Mutant strain of the facultatively anaerobic, ethanol-producing bacteriumZymomonas mobilis, deficient in the Fe-containing alcohol dehydrogenase isoenzyme (ADH II), showed impaired homeostasis of the intracellular NAD(P)H during transition from anaerobic to aerobic conditions, and also in steady-state continuous cultures at various oxygen supplies. At the same time, ADH II deficiency in aerobically grown cells was accompanied by a threefold increase of catalase activity and by about 50% increase of hydrogen peroxide excretion. It is concluded that ADH II under aerobic conditions functions to maintain intracellular redox homeostasis and to protect the cells from endogenous hydrogen peroxide.
Development of Eco-Friendly and Self-Cleaning Lime-Pozzolan Plasters for Bio-Construction and Cultural Heritage
2020
Summarization: Nowadays, the design and use of multi-functional mortars has increased significantly, with interesting applications in the green building and cultural heritage conservation sectors. A key point for a correct adoption of these innovative materials is their behavior along time and their resistance to the weathering. The objective of this project was to define the performance and durability of innovative mortars, in order to use them correctly and to avoid irreparable damage over time. For the development of this project, lime–metakaolin and hydraulic lime–metakaolin based mortars (hereinafter called A, B), as well as A and B with the addition of nano-TiO2 and perlite (hereinaft…
Artificial ventilation for basic life support leads to hyperventilation in first aid providers.
2003
The 'Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care - International Consensus on Science' recommend an artificial ventilation volume of 10 ml/kg bodyweight (equivalent to a tidal volume of 700-1000 ml) without the use of supplemental oxygen in adults with respiratory arrest. For first aid providers using the mouth-to-mouth or mouth-to-nose-ventilation technique, respectively, a ventilation volume of approximately 9.6 l/min results. Additionally, a deep breath is recommended before each ventilation to increase the end-expiratory oxygen concentration of the air exhaled by the first aid provider. To investigate the effects of these recommendations in health…
ChemInform Abstract: Efficient Synthesis of Racemic and Chiral Alkenyl Sulfoxides by Palladium-Catalyzed Suzuki Coupling.
2010
Alkenyl sulfoxide derivatives are obtained in high yields through a palladium-catalyzed Suzuki/Miyaura cross-coupling reaction of racemic and chiral 1-halo sulfoxides with aryl and alkenyl boronic acids. Chiral substrates react with no loss of optical purity and high optical yields. The reaction takes place with different palladium catalysts, such as Pd(PPh 3 ) 4 or Pd(OAc) 2 /DABCO. Although nitrogen ligands like DABCO lead to an active palladium catalyst, they are less effective than the phosphine ones.
Senataxin defective in ataxia oculomotor apraxia type 2 is involved in the defence against oxidative DNA damage
2007
Adefective response to DNA damage is observed in several human autosomal recessive ataxias with oculomotor apraxia, including ataxia-telangiectasia. We report that senataxin, defective in ataxia oculomotor apraxia (AOA) type 2, is a nuclear protein involved in the DNA damage response. AOA2 cells are sensitive to H2O2, camptothecin, and mitomycin C, but not to ionizing radiation, and sensitivity was rescued with full-length SETX cDNA. AOA2 cells exhibited constitutive oxidative DNA damage and enhanced chromosomal instability in response to H2O2. Rejoining of H2O2-induced DNA double-strand breaks (DSBs) was significantly reduced in AOA2 cells compared to controls, and there was no evidence fo…
CO2 and H2S concentrations in the atmosphere at the Solfatara of Pozzuoli
1984
The CO2 and H2S concentration in the Solfatara atmosphere has been measured. The concentrations of both gases are higher neraby the more active areas and decrease away from them. A sharp horizontal and vertical gradient of the CO2 content has been recognized.
Air pollution in European countries and life expectancy—modelling with the use of neural network
2019
Abstract The present paper discusses a novel methodology based on neural network to determine air pollutants’ correlation with life expectancy in European countries. The models were developed using historical data from the period 1992–2016, for a set of 20 European countries. The subject of the analysis included the input variables of the following air pollutants: sulphur oxides, nitrogen oxides, carbon monoxide, particulate matters, polycyclic aromatic hydrocarbons and non-methane volatile organic compounds. Our main findings indicate that all the variables significantly affect life expectancy. Sensitivity of constructed neural networks to pollutants proved to be particularly important in …
Diurnal variability, photochemical production and loss processes of hydrogen peroxide in the boundary layer over Europe
2019
Hydrogen peroxide (H2O2) plays a significant role in the oxidizing capacity of the atmosphere. It is an efficient oxidant in the liquid phase and serves as a temporary reservoir for the hydroxyl radical (OH), the most important oxidizing agent in the gas phase. Due to its high solubility, removal of H2O2 due to wet and dry deposition is efficient, being a sink of HOx (OH+HO2) radicals. In the continental boundary layer, the H2O2 budget is controlled by photochemistry, transport and deposition processes. Here we use in situ observations of H2O2 and account for chemical source and removal mechanisms to study the interplay between these processes. The data were obtained during five ground-base…