Search results for "NAD"
showing 10 items of 2033 documents
Thermal-Infrared Spectral and Angular Characterization of Crude Oil and Seawater Emissivities for Oil Slick Identification
2014
Previous work has shown that the emissivity of crude oil is lower than that of the seawater in the thermal-infrared (TIR) spectrum. Thus, oil slicks cause an emissivity decrease relative to the seawater in that region. The aim of this paper was to carry out experimental measurements to characterize the spectral and angular variations of crude oil and seawater emissivities. The results showed that the crude oil emissivity is lower than the seawater emissivity and that it is essentially flat in the atmospheric window of 8-13 μm. The crude oil emissivity has a marked emissivity decrease with the angle (from 0.956 ± 0.005 at 15 ° to 0.873 ± 0.007 at 65 °), which is even higher than that of the …
A Deficiency in Respiratory Complex I in Heart Mitochondria from Vitamin A-Deficient Rats Is Counteracted by an Increase in Coenzyme Q
1997
Defects of NADH:coenzyme Q oxidoreductase (complex I) of mitochondria have been described in many congenital and acquired diseases. Administration of coenzyme Q (CoQ, ubiquinone) has been shown to benefit patients with some of these diseases. However, the mechanisms by which CoQ exerts the therapeutic effects are not clearly understood. A reason could be the lack of saturation of CoQ, in kinetic terms, for complex I activity. However, this hypothesis has not been proved in vivo because of the difficulty to incorporate CoQ into the mitochondrial membranes. We have found a deficiency in respiratory complex I in heart mitochondria from vitamin A-deficient rats which was accompanied by high CoQ…
Integración de restos arqueológicos Almohades en el metropolitano de Granada. La investigación multidisciplinar para el proyecto y desarrollo de infr…
2014
The execution of the Granada Metropolitan’s underground line made possible the discovery of archeological remains of a water tank in Alcázar Genil, a royal muslim residence of the 13th century. The water tank, 419 × 88 ft, was destroyed at its ends due to the growth of the city of Granada during the 20th century and today remains only its center section, under Camino de Ronda, exactly where the future Metropolitan will take place. The location of an underground station will allow the recovery, the integration and the exhibition of the archaeological remains of this water tank. The Alcázar Genil station project brings together the work of several disciplines which put in the same level engin…
Revisión de la sección del yacimiento del Mas de la Chimenea Alta (Formación Arcillas de Morella, Castellón) y significado en el contexto paleoambien…
2012
Desde los primeros estudios estratigráficos y paleontológicos, que datan de principios del siglo XX, la Fm Morella se ha caracterizado por su coloración rojiza y su contenido fósil. La mayor parte de sus depósitos se han interpretado como continentales, aunque con intercalaciones locales de materiales marinos. En esta unidad se da la paradoja de que muchos de los lugares descritos con fauna de vertebrados continentales se encuentran en depósitos interpretados como ambientes marinos poco profundos y de transición. La sección del Mas de la Chimenea Alta es un ejemplo. Ésta contiene yacimientos con fósiles de vertebrados que son claramente alóctonos, pero también otros, con icnitas que permite…
NAD(P)H regeneration is the key for heterolactic fermentation of hexoses in Oenococcus oeni
2002
Oenococcus oeni (formerly Leuconostoc oenos) can perform malolactic fermentation, converting L-malate to L-lactate and carbon dioxide, in wines. The energy and redox potential required to support the growth of the micro-organism are supplied mainly by the consumption of carbohydrates via the heterolactic pathway. In the first steps of hexose metabolism two molecules of NAD(P)(+) are consumed, which must be regenerated in later reactions. The aim of this work was to test if aerobic growth of O. oeni promotes higher cell yields than anaerobic conditions, as has been shown for other lactic acid bacteria. O. oeni M42 was found to grow poorly under aerobic conditions with glucose as the only car…
Supporting scalable video transmission in MANETs through distributed admission control mechanisms
2009
Emerging multimedia applications over mobile devices are becoming very popular, especially over infrastructure wireless networks such as cellular and WLANs. However, providing this kind of services over infrastructureless networks like ad hoc networks presents many additional problems. One of these problems is how to share resources fairly among the users involved. In this article we propose a QoS framework supporting scalable video streaming in mobile ad hoc networks based on distributed admission control and video traffic awareness. Our framework promotes fairness between video flows in terms of resource consumption. It also guarantees a significant reduction of the idle times experienced…
On the mechanisms involved in the tensile strength of a dissimilar Ti6Al4V/316L laser welded assembly
2021
International audience; The aim of the present work is to analyze the thermomechanical behavior of dissimilar laser seams by means of FE modeling. The case of a Ti6Al4V/316L assembly with vanadium insert was considered. Effective mechanical properties of the main materials and cords were first estimated from NHT measurements. Modeling of the double pass laser welding process was performed first by considering shrinking of the two weld seams during manufacturing, to get the residual stress state in the welded assembly. Modeling of the tensile test was performed in a second step to study the assembly behavior during loading. In these modeling results, the mesh was the cross-section of the mic…
Vascular oxidative stress, nitric oxide and atherosclerosis.
2014
In the vascular wall, reactive oxygen species (ROS) are produced by several enzyme systems including NADPH oxidase, xanthine oxidase, uncoupled endothelial nitric oxide synthase (eNOS) and the mitochondrial electron transport chain. On the other hand, the vasculature is protected by antioxidant enzyme systems, including superoxide dismutases, catalase, glutathione peroxidases and paraoxonases, which detoxify ROS. Cardiovascular risk factors such as hypercholesterolemia, hypertension, and diabetes mellitus enhance ROS generation, resulting in oxidative stress. This leads to oxidative modification of lipoproteins and phospholipids, mechanisms that contribute to atherogenesis. In addition, oxi…
Sildenafil protects epithelial cell through the inhibition of xanthine oxidase and the impairment of ROS production
2009
Recent reports suggest that xanthine oxidase (XO), a modified form of the native xanthine dehydrogenase enzyme, plays an important role in various forms of ischemic and vascular injuries, inflammatory diseases, and chronic heart failure. The XO inhibitors allopurinol and its oxidation product oxypurinol held considerable promises in the treatment of these conditions both in experimental animals and in human clinical trials. More recently, an endothelium-based protective effect of sildenafil, a well-known type-5 phosphodiesterase inhibitor, has been reported in preconditioning prior to ischemia/reperfusion in healthy human subjects. Based on the structural similarities between allopurinol an…
Xanthine oxidase catalyzes the synthesis of retinoic acid
2001
Milk xanthine oxidase (xanthine: oxygen oxidoreductase; XO; EC 1.1.3.22) was found to catalyze the conversion of retinaldehyde to retinoic acid. The ability of XO to synthesize all trans-retinoic acid efficiently was assessed by its turnover number of 31.56 min-1, determined at pH 7.0 with 1 nM XO and all trans-retinaldehyde varying between 0.05 to 2 microM. The determination of both retinoid and purine content in milk was also considered in order to correlate their concentrations with kinetic parameters of retinaldehyde oxidase activity. The velocity of the reaction was dependent on the isomeric form of the substrate, the all trans- and 9-cis-forms being the preferred substrates rather tha…