553 research outputs found

    Formation of 4-hydroxynonenal and further aldehydic mediators of inflammation during bromotrichlorornethane treatment of rat liver cells

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    Bromotrichloromethane (CBrCl3) treatment is a model for studies on molecular mechanisms of haloalkane toxicity with some advantages compared with CCl4 treatment. The formation of 4-hydroxynonenal and similar aldehydic products of lipid peroxidation, which play a role as mediators of inflammatory processes, was clearly demonstrated in rat hepatocytes treated with CBrCl3. It may be assumed that haloalkane toxicity is connected with the biological effects of those inflammation mediatory aldehydic compounds

    The buckling of a thin plate due to the presence of an edge dislocation

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    lt is shown that an edge dislocation parallel to the surface of a thin foil causes buckling of this foil by an angle of about θ\theta = b/t. (b = Burgers vector; t = thickness of the foil). The angle θ\theta depends on the position of the dislocation. lt is maximum for a dislocation in the middle of the foil and it tends to zero as the dislocation approaches to the surface. lt is shown that the buckling is responsible for the discontinuous change in contrast along a dislocation as observed in transmission electron microscopy. The sense of buckling which can be determined by means of Kikuchi lines depends on the sign of the dislocation. The effect therefore provides an easy means to determine the sign of edge dislocations

    Surface effects associated with dislocations in layer crystals

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    Dislocation configurations in thin foils cannot be accurately interpreted unless the effects of anisotropy and surfaces on the stresses and energies of edge and screw dislocations are known. Expressions for these effects are derived here for a semi-infinite hexagonal crystal with dislocations in the basal plane. lt is then shown that in plate-like crystals, as used in electron-microscopic investigations, the finite thickness of the specimen leads to observable effects on the dislocation patterns. In particular, the width of a ribbon decreases as it approaches the surface, due to the reduced repulsion between the partials, so that care is needed in deducing stacking fault energies from ribbon widths. Also the energy of a dislocation is a function of its distance from a surface, so that if it is crossed by a surface step it suffers a "refraction" which, in simple cases, follows Snell's law. lt is further shown that dislocations will tend tobe aligned with surface steps, artd the interaction energy between a step and a parallel dislocation line can thus be derived from experimental data. Finally, a method is suggested for obtaining information on the elastic constants from electron microscopic data

    Die direkte Messung von Stapelfehlerenergien

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    Different methods for determining stacking fault energies from dislocation configurations observed in the electron microscope are discussed. Configurations discussed are simple, threefold, and fourfold ribbons, arrays of many parallel ribbons, and dislocation nodes. The latter are treated taking the mutual interaction of the partials approximately into account. Results are given for measurementsin graphite, MoS2_{2}, AIN, and talc

    Observations of sulfur dioxide uptake and new particle formation in a midlatitude cumulus cloud

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    International audienceAirborne measurements, obtained during the Asian Aerosol Characterisation Experiment (ACE-Asia), of SO2 and condensation nuclei (CN) concentrations were made in the local environment of a cumulus cloud band. Conserved quantities, wet equivalent potential temperature ?q, and total water content Q, were used to identify the sources of air detrained on the downwind side of the cumulus band. It was found that ~65% of the detrained air originated from below cloud base and the remainder was air that had been entrained from the free troposphere upwind of the cloud and subsequently been detrained. Calculation of the sources of the detrained air parcels enabled a prediction of the concentration of SO2 and CN, assuming that SO2 and CN experienced no processing within cloud. A comparison of the predicted concentration of SO2 and CN was made with those observed. The concentration of SO2 observed was less than predicted and the amount of SO2 scavenged within cloud was calculated. The CN concentration observed was also less than predicted and, moreover, inclusion of the loss of CN to cloud droplets due to Brownian scavenging resulted in an enhanced decrease of the number concentration of CN predicted. Clear air regions around the cloud exhibited no indication of being a major source of new particles. It was concluded that new particles were formed within cloud

    Low temperature phase diagram and critical behaviour of the four-state chiral clock model

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    The low temperature behaviour of the four-state chiral clock (CC4CC_4) model is reexamined using a systematic low temperature series expansion of the free energy. Previously obtained results for the low temperature phases are corrected and the low temperature phase diagram is derived. In addition, the phase transition from the modulated region to the high temperature paraphase is shown to belong to the universality class of the 3d-XY model.Comment: 17 pages in ioplppt style, 3 figure

    Company ‘Emigration’ and EC Freedom of Establishment: Daily Mail Revisited

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    Following the ECJ’s recent case law on EC freedom of establishment (the Centros, Überseering and Inspire Art cases), regulatory competition for corporate law within the European Union takes place at an early stage of the incorporation of new companies. In contrast, as regards the ‘moving out’ of companies from the country of incorporation, the ECJ once considered a tax law restriction against the transfer abroad of a company’s administrative seat as compatible with EC freedom of establishment (the Daily Mail case). For years, this decision has been regarded as applicable to all restrictions imposed by countries of incorporation, even the forced liquidation of the ‘emigrating’ company. This paper addresses the question whether EC freedom of establishment really allows Member States to place any limit on the ‘emigration’ of nationally registered companies. It argues that EC freedom of establishment covers the transfer of the administrative seat as well as the transfer of the registered office and, therefore, that the country of incorporation cannot liquidate ‘emigrating’ companies. In addition, it addresses the question whether a new Directive is needed to allow the transfer of a com- pany’s registered office and the identity-preserving company law changes. It argues that such a Directive is necessary to avoid legal uncertainty and to protect the interests of employees, creditors and minority shareholders, among others, who could be detrimentally affected by the ‘emigration’ of national companies

    An analysis of the relevance of off-balance sheet items in explaining productivity change in European banking

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    The 1990s have witnessed a significant growth in bank income generated through non-traditional activities, especially for large EU universal banking institutions. Using the non-parametric Malmquist methodology this study analyses the impact of the inclusion of off-balance sheet (OBS) business in the definition of banks' output when estimating total factor productivity change indexes. Whereas the results reinforce the prevalent view in the recent literature, indicating that the exclusion of non-traditional activities leads to a misspecification of banks' output, the impact of the inclusion of these activities varies. Overall, the inclusion of OBS items results in an increase in estimated productivity levels for all countries under study. However, the impact seems to be the biggest on technological change rather than efficiency change. © 2005 Taylor & Francis
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