Effects of coenzyme Q10, α-tocopherol and ascorbic acid on oxidation of cholesterol in chicken liver pâté

The aim of this study was to determine whether supplemental addition of coenzyme Q₁₀ and ascorbic acid or α-tocopherol, either alone or together, can prevent oxidative damage in chicken liver pâté, as reflected by reduced formation of cholesterol oxidation products (COPs) and by preservation of sensorial quality. Separate groups of chicken liver pâtés had no supplements (control) or were supplemented with coenzyme Q₁₀ (0.2 g/kg) and either ascorbic acid (2 g/kg) or α-tocopherol (0.2 g/kg), or both. All products were pasteurised (82 °C) or sterilised (121 °C). Four COPs were found: 7α-, 7β-, 20α- and 25-hydroxycholesterol. The COP radical scavenger function of coenzyme Q₁₀ (control, 5.16 mg/kg; plus Q₁₀, 3.94 mg/kg) and the synchronous actions of coenzyme Q₁₀ and α-tocopherol (2.6 mg/kg) were confirmed in sterilised pâtés. Generally, in pasteurised and sterilised pâtés, the most efficient scavenger function was with ascorbic acid either alone or together with α-tocopherol, where the formation of COPs was below the limit of detection. An increase of 1.9 mg/kg in COP production during heating was also seen in samples without added antioxidants. There was a weak interdependence between the content of COPs and the sensory parameters of the pâté. For addition of antioxidants, in the pasteurised pâté, colour and smell were slightly improved, but flavour deteriorated; in the sterilised pâté, colour was slightly worse, with a more tender texture. Overall, instrumentally measured colour and sensory properties (except texture) showed no significant differences between pasteurisation and sterilisation.     

Mercury,selenium, PCBs and fatty acids in fresh and canned fish available on the Slovenian market

In order to contribute to the general understanding of the risks and benefits of consuming fish and fish products, total mercury (THg), monomethylmercury (MeHg), polychlorinated biphenyls (PCBs), selenium (Se), n-3 and n-6 fatty acids were determined in fresh and canned fish on the Slovenian market. Furthermore, the mercury exposure of pregnant women in Slovenia was assessed by determining total mercury (THg) in hair, and through fresh and canned fish consumption obtained by a food frequency questionnaire. Based on the frequency of fish consumption and levels of MeHg, THg and PCBs determined in the present study, it can be concluded that fish available on the Slovenian market do not represent a health risk. It was also confirmed that fish are important sources of selenium and n-3 fatty acids.     

Adaptive control of ARMA plants using worst-case design by semi-infinite optimization

This paper presents a new approach to on-line control system tuning, based on worst-case design using semi-infinite optimlzation, together with a plant uncertainty identification scheme which this approach requires.     

Durability and surface chemistry of horizontally aligned CNT films as electrodes upon electrolysis of acidic aqueous solution

We devised a simple and effective method of electrochemical functionalization of horizontally aligned CNT films in diluted HCl and H₂SO₄ solutions upon their electrolysis under a constant current mode. We were able to cause notable generation of carbon–oxygen and carbon–chlorine functional groups on the CNT film anodes as proven by EDX, XPS, and Raman spectroscopy. As a consequence, we observed significant changes of the morphology of the material under electron microscopy, what translated into improved compatibility of CNTs with hydrophilic media. In turn, application of CNT films as cathodes was found as a powerful tool for a thorough cleaning of the nanotubes. Finally, we demonstrated that by the selection of appropriate conditions, CNT films can act as easy-to-make and flexible electrodes with a high stability and performance superior to graphite for generation of non-oxidizing gases such as hydrogen from solution. CNT film electrodes are two orders of magnitude lighter and require much lower overpotential for faradaic splitting of water.     

Assessment of the Superheater Ash Fouling Using a Numerical Model of the Superheater

ABSTRACT

Superheaters are high-temperature cross-flow heat exchangers. Steam flows inside the tubes, and the flue gas outside in a direction perpendicular to the axes of the tubes. However, they differ very substantially from the other heat exchangers operating at low temperatures. Superheaters are characterized by complex flow system and high tube walls temperature. Superheaters are among the most exposed to damaging pressure elements of steam boilers. Damage to the superheater causes about 40% of emergency shutdowns of boilers. The paper presents the boiler superheater model with distributed parameters, which is used to determine on-line the degree of superheater fouling by ash.     

Redox doping behaviour of poly(3,4-ethylenedithiothiophene) - The counterion effect

Poly(3,4-ethylenedithiothiophene) - PEDTT, an alkylene sulphur derivative of PEDOT, presents itself as an interesting polymer with a number of disparate redox and chromic properties compared to its close analogue - PEDOT. In this study we present the results of an investigation into the electrochemical doping process of PEDTT, using four different electrolyte solutions, differing in anion content of the chosen salt. The results show that the anion identity plays a key role in the redox reactions accompanying these processes in what could be interpreted as anion ionochromism. In situ UV-Vis spectroelectrochemical experiments reveal an intriguing double electrochromic transition of PEDTT films during their oxidative doping, going from golden-yellow through green to pomegranate - a quality not so common within the family of electroactive conjugated polymers. The evolution of each UV-Vis spectrum over a potential range indicates that different redox states of the polymer are responsible for the chromatic changes. In the reduction half-cycle, the dedoping process of PEDTT appears to follow a path dissimilar to the p-doping one, featuring only one, direct electrochromic transition of the film’s colour, bypassing the green state, and a distinct two-step bleaching process of doping-induced charge carrier bands. The observed electrochemical and spectral phenomena have been accredited to the specific redox behaviour of doping-induced radical cation and cationic defect states interacting with the dithioalkylene sulphur atom.     

Expression of inducible nitric oxide synthase and formation of peroxynitrite in posttransplant obliterative bronchiolitis

BACKGROUND: Obliterative bronchiolitis is characterized histologically by inflammation, epithelial cell damage and loss, fibrosis, and eventual obliteration of airways. Production of high levels of the potential cytotoxin nitric oxide by inducible nitric oxide synthase has been implicated in several inflammatory diseases. The damaging effects of nitric oxide are mediated by peroxynitrite, are formed from nitric oxide and superoxide, and can be demonstrated by the detection of nitrotyrosine. Our previous finding of high inducible nitric oxide synthase expression in inflamed airway epithelium led us to hypothesize that release of nitric oxide in obliterative bronchiolitis mediates the characteristic epithelial damage. METHODS: Immunocytochemistry was carried out to seek expression of inducible nitric oxide synthase and nitrotyrosine in transplant samples from patients with obliterative bronchiolitis (n=10) and, as controls, unused donor lungs (n=5). RESULTS: Inducible nitric oxide synthase was strongly expressed in the damaged airway epithelium in obliterative bronchiolitis and in inflammatory cells, where its distribution was matched by that of nitrotyrosine. Normal controls showed little or no immunoreactivity for any of the antigens studied. CONCLUSIONS: Our findings suggest that nitric oxide may play a role in the pathogenesis of obliterative bronchiolitis and indicate that further work is essential to fully understand the processes and mechanisms involved.     

A CMOS IC for Gb/s Viterbi decoding: system design and VLSIimplementation

At present, the Viterbi algorithm (VA) is widely used in communication systems for decoding and equalization. The achievable speed of conventional Viterbi decoders (VD's) is limited by the inherent nonlinear add-compare-select (ACS) recursion. The aim of this paper is to describe system design and VLSI implementation of a complex system of fabricated ASIC's for high speed Viterbi decoding using the “minimized method” (MM) parallelized VA. We particularly emphasize the interaction between system design, architecture and VLSI implementation as well as system partitioning issues and the resulting requirements for the system design flow. Our design objectives were 1) to achieve the same decoding performance as a conventional VD using the parallelized algorithm, 2) to achieve a speed of more than 1 Gb/s, and 3) to realize a system for this task using a single cascadable ASIC. With a minimum system configuration of four identical ASIC's produced by using 1.0 μ CMOS technology, the design objective of a decoding speed of 1.2 Gb/s is achieved. This means, compared to previous implementations of Viterbi decoders, the speed is increased by an order of magnitude