Relapse after withdrawal from anti-TNF therapy for inflammatory bowel disease: an observational study, plus systematic review and meta-analysis.

Infliximab and adalimumab have established roles in inflammatory bowel disease (IBD) therapy. UK regulators mandate reassessment after 12 months' anti-TNF therapy for IBD, with consideration of treatment withdrawal. There is a need for more data to establish the relapse rates following treatment cessation.This article is freely available via Open Access. Click on the 'Additional Link' above to access the full-text from the publisher's site.Publishe

The effect of surface active elements on the growth of iron nitride precipitates in ferrite

The growth of γ–FeN precipitates at 350° C has been followed in Fe–0·05 wt.-%N alloys containing controlled oxygen and phosphorus levels. The marked retarding effect of small quantities of these elements on the coarsening of the nitride particles is demonstrated for a range of alloys. The particle sizes and the size distributions of the precipitates have been measured and comparisons with the predictions of the Lifshits–Wagner coarsening equations have been made. The particle coarsening behaviour is shown to be consistent with earlier observations of interfacial reaction control of precipitate growth

Microstructural changes on the reduction of hematite to magnetite

The microstructures resulting from the reduction of hematite to magnetite have been examined for a wide range of temperatures and gas conditions. A transition in product morphology from plate or lath magnetite to porous magnetite was found to occur at a constant free energy difference between the reducing gas mixture and the hematite over a range of reaction temperatures. Direct observations of lath nucleation and growth are reported and show the self-accelerating effect of the FeO → FeO transformation. The limits of porous growth are discussed in terms of established theories of discontinuous precipitation and a mechanism for the formation of lath magnetite is proposed

The observation of metastable molybdenum carbides

Copyright 2008 Elsevier B.V., All rights reserved.Peer reviewe

Re-evaluation of the thermodynamic stability of calcium oxide

Copyright 2004 Elsevier B.V., All rights reserved.The reaction CaO+3C = CaC+CO was studied under controlled atmospheres between 1580°C and 1700°C. Reaction was observed to take place at CO pressures higher than those predicted by the available thermodynamic data. By reviewing and combining results of previous studies with those of the present one, a more accurate Free energy of formation of CaO ΔG = -179 190+46.62T is proposed.Peer reviewe

Behaviour of tantalum in the presence of CO and CO/CO mixtures at elevated temperatures

Copyright 2004 Elsevier B.V., All rights reserved.A study of the carburization of tantalum was carded out by reacting it with CO at temperatures in the range from 1073 K to 1573 K. In addition to TaC, TaO also formed as an intermediate product before full conversion to TaC. A thermodynamic analysis showed that such a complex reaction path was followed because the carburizing reactions generate enough CO to oxidize the metal. The reaction of tantalum with CO-CO gas mixtures was also investigated. The kinetics of reaction is discussed in terms of the reaction mechanisms and the reacting gas composition.Peer reviewe