Engineering aspects of the aqueous noble metal catalysed alcohol oxidation.

The aqueous noble metal catalysed alcohol oxidation is a reaction which can profitably be applied in fine-chemistry and for carbohydrate conversion. In this paper engineering aspects of this reaction are treated, i.e. the reaction kinetics, oxygen mass transfer restrictions, catalyst deactivation and reactivation, and implications for reactor design and operation. First a reaction mechanism is proposed, which is very helpful for understanding the observed phenomena. Also a short summary is given on catalyst deactivation mechanisms. Two different reaction regimes can clearly be distinguished: the oxygen mass transfer limited regime and the intrinsic kinetic regime, which are treated separately. Oxidations using noble metal catalysts promoted with less noble metals, like Pb, Bi, generally fall in the first regime, those using unpromoted noble metals in the second. Reaction rate data are evaluated for the Pd/Bi catalysed oxidation of glucose and the Pt catalysed oxidation of methyl-glucoside, respectively, illustrating the typical kinetic behaviour in both regimes. From oxidation kinetics in the mass transfer limited regime, it is concluded that adherence of catalyst particles to the gas¿liquid interface, is a major factor determining reaction kinetics. Oxygen transfer, direct from the gas to the catalyst particle, is likely. For the Pt catalysed oxidation, a kinetic model is presented for catalyst deactivation by over-oxidation and for catalyst reactivation. Finally specific reactor options and suggestions for future engineering research are given: slurry catalyst versus fixed bed catalyst operation, avoidance of explosion risks, redox cycle reactors, electrochemical reactors, and multi-functional reactor

Synthesis of 6-methoxy-4H-1-benzopyran-7-ol, a character donating component of the fragrance of Wisteria sinensis.

A

Patient-Reported Outcome Data From an Early Rheumatoid Arthritis Trial: Opportunities for Broadening the Scope of Treating to Target

OBJECTIVE: Treating early, intensively, and to target leads to rapid disease control, preventing joint damage and loss of function in early rheumatoid arthritis (RA). We report the effect of such an approach on patient-reported outcomes and explore the contribution of rapid and persistent disease control to well-being after 1 year of treatment. METHODS: This study is part of the Care in Early RA trial, a prospective, 2-year, investigator-initiated, randomized controlled trial rooted in daily practice and implementing the treat-to-target principle. Short Form 36 (SF-36) health survey and Revised Illness Perception Questionnaire (IPQ-R) data were collected prospectively. We defined 4 clinical response profiles based on speed and consistency of the treatment response within the first year, defined as the Disease Activity Score in 28 joints using the C-reactive protein level <2.6. Linear regression analyses including these response profiles and treatment type were constructed to predict the SF-36 dimensions of vitality, social functioning, role emotional, and mental health, and the IPQ-R illness perception subscales of consequences, treatment control, and illness coherence at year 1. RESULTS: A total of 333 patients were available for the main analyses, including 140 early persistent responders. Variation in each of the psychosocial outcomes at year 1 was explained mostly by baseline values, followed by the clinical response profiles. Patients with an early persistent response reported significantly higher vitality, more positive beliefs about disease consequences and treatment effect. Treatment type did not matter. CONCLUSION: Rapid and persistent disease control and not treatment type were associated with favorable patient-reported health and illness perceptions at year 1, but baseline psychosocial variables mattered most. Our data indicate opportunities to broaden the scope of the treat-to-target principle in early RA.status: publishe

In situ Characterisation of Practical Heterogeneous Catalysts

In situ methods are considered as a curiosity within the standard methodology of practical catalyst characterization. The methods are not commercially available and need to be adapted and validated for each specific problem. The great advantage of these methods is, however, that they deliver immediately relevant characteristics of the working state of a heterogeneous catalyst and allow justified structure-function relations to be deduced. To achieve this it is essential that the experiments are planned and conducted in such away that the proven to be active state of the catalyst is investigated. This can only be ascertained if simultaneous kinetic and spectroscopic data are acquired. The contribution lists a selection of methods with their main characteristics that allows to choose from the wide spectrum of information those that are most relevant for the given problem. A tabulated selection of case studies from the literature gives some insight in the current practice