Search results for "reduction"
showing 10 items of 2058 documents
NADH dehydrogenase deficiency results in low respiration rate and improved aerobic growth of Zymomonas mobilis.
2008
The respiratory chain of the ethanol-producing bacterium Zymomonas mobilis is able to oxidize both species of nicotinamide cofactors, NADH and NADPH. A mutant strain with a chloramphenicol-resistance determinant inserted in ndh (encoding an NADH : CoQ oxidoreductase of type II) lacked the membrane NADH and NADPH oxidase activities, while its respiratory d-lactate oxidase activity was increased. Cells of the mutant strain showed a very low respiration rate with glucose and no respiration with ethanol. The aerobic growth rate of the mutant was elevated; exponential growth persisted longer, resulting in higher biomass densities. For the parent strain a similar effect of aerobic growth stimulat…
Cerium effect on the phase structure, phase stability and redox properties of Ce-doped strontium ferrates
2006
Nanostructured perovskite-type Sr1−aCeaFeO3−x, (0⩽a<0.15) powders have been prepared by citrate–nitrate smoldering auto-combustion. Their phase structure and stability, surface and morphological properties, reduction behavior and interaction with oxygen have been investigated by X-ray Powder Diffraction combined with Rietveld Analysis, 57Fe Mossbauer and X-ray Photoelectron Spectroscopies, N2-adsorption method, Temperature Programmed Reduction and Oxidation experiments. Our results reveal that citrate–nitrate auto-combustion method is effective in obtaining single phase Sr1−aCeaFeO3−x. The Sr1−aCeaFeO3−x structure is cubic only for a⩾0.06, while for a<0.06 remains tetragonal. Moreover, for …
Structural and morphological properties of Co-La catalysts supported on alumina/lanthana for hydrocarbons oxidation
2004
Abstract Two Al 2 O 3 (24 wt%)–La 2 O 3 (76 wt%) supported Co–La oxides with Co loading 4 wt% and different La content (1 and 9 wt%) were prepared by co-impregnation of the support, the aluminum–lanthanum oxide, with cobalt and lanthanum nitrates in aqueous solution and successive calcination at 800 °C for 4 h. The alumina–lanthana was synthesized by the sol–gel method. The samples were characterized by X-ray diffraction (XRD) and Rietveld refinement in order to identify the crystalline phases and their relative weight. H 2 -TPR (Temperature Programmed Reduction) experiments were recorded with the aim to identify the different Co phases present. Co 3 O 4 and LaCoO 3 were formed for La loadi…
Evidence, and replication thereof, that molecular-genetic and environmental risks for psychosis impact through an affective pathway
2022
AbstractBackgroundThere is evidence that environmental and genetic risk factors for schizophrenia spectrum disorders are transdiagnostic and mediated in part through a generic pathway of affective dysregulation.MethodsWe analysed to what degree the impact of schizophrenia polygenic risk (PRS-SZ) and childhood adversity (CA) on psychosis outcomes was contingent on co-presence of affective dysregulation, defined as significant depressive symptoms, in (i) NEMESIS-2 (n = 6646), a representative general population sample, interviewed four times over nine years and (ii) EUGEI (n = 4068) a sample of patients with schizophrenia spectrum disorder, the siblings of these patients and controls.ResultsT…
Systematic review on physician's knowledge about radiation doses and radiation risks of computed tomography.
2010
Abstract Background The frequent use of computed tomography is a major cause of the increasing medical radiation exposure of the general population. Consequently, dose reduction and radiation protection is a topic of scientific and public concern. Aim We evaluated the available literature on physicians’ knowledge regarding radiation dosages and risks due to computed tomography. Methods A systematic review in accordance with the Cochrane and PRISMA statements was performed using eight databases. 3091 references were found. Only primary studies assessing physicians’ knowledge about computed tomography were included. Results 14 relevant articles were identified, all focussing on dose estimatio…
Robotic face milling path correction and vibration reduction
2015
In this paper the developed method for off-line compensation of tool deflections and vibration reduction when milling aluminum with an industrial robot is presented. The efficiency of this approach is verified with high precision measurements of deflections using a laser tracker. The compensation method is based on the static milling process model which can predict the mean value components of the tool forces and the passive damping system mounted on the spindle to reduce vibrations. With a process model such as the one presented in this paper and estimates of the robot's joint stiffness values, the tool path can be adjusted to counteract deflections of the tool during milling operations. T…
Rolling Over EUAs and CERs
2012
Whatever derivative contract has a finite life limited by their maturity. The construction of long series, however, is of interest for academic, hedging and investments purposes. In this study, we analyze the relevance of the choice of the rollover date on European Union Allowances (EUAs) and Certified Emissions Reduction (CERs) futures contracts. We have used five different methodologies to construct long series and the results show that, regardless of the criterion applied, there are not significant differences between the resultant return distribution series. Therefore, the least complex method, which is to roll on the last trading day, can be used in order to reach the same conclusions.…
Infinite coordination polymer networks metallogelation of aminopyridine conjugates and in situ silver nanoparticle formation
2018
Herein we report silver(i) directed infinite coordination polymer network (ICPN) induced self-assembly of low molecular weight organic ligands leading to metallogelation. Structurally simple ligands are derived from 3-aminopyridine and 4-aminopyridine conjugates which are composed of either pyridine or 2,2'-bipyridine cores. The cation specific gelation was found to be independent of the counter anion, leading to highly entangled fibrillar networks facilitating the immobilization of solvent molecules. Rheological studies revealed that the elastic storage modulus (G') of a given gelator molecule is counter anion dependent. The metallogels derived from ligands containing a bipyridine core dis…
Engineered Trx2p industrial yeast strain protects glycolysis and fermentation proteins from oxidative carbonylation during biomass propagation
2012
Abstract Background In the yeast biomass production process, protein carbonylation has severe adverse effects since it diminishes biomass yield and profitability of industrial production plants. However, this significant detriment of yeast performance can be alleviated by increasing thioredoxins levels. Thioredoxins are important antioxidant defenses implicated in many functions in cells, and their primordial functions include scavenging of reactive oxygen species that produce dramatic and irreversible alterations such as protein carbonylation. Results In this work we have found several proteins specifically protected by yeast Thioredoxin 2 (Trx2p). Bidimensional electrophoresis and carbony…
Acid excreting mutants of yeast Saccharomyces cerevisiae.
2004
Saccharomyces cerevisiae mutants acidifying glucose medium containing bromocresol purple were shown to excrete protons when placed in unbuffered water in the absence of any external carbon source. The mutants belong to 16 different complementation groups. Most of them do not grow on glycerol and the excreted protons are associated to particular sets of organic anions such as citrate, aconitate, succinate, fumarate or malate. These novel types of respiratory mutations seem to be located in genes operating in the Krebs or glyoxylate cycle.