Deactivation and regeneration of ruthenium on silica in the liquid-phase hydrogenation of butan-2-one

A Ru/SiO2 catalyst was investigated for the liquid-phase hydrogenation of butan-2-one to butan-2-ol with water as a medium. Although excellent reactivity was observed, a gradual deactivation of the catalyst was found on recycle of the catalyst. The spent catalyst was characterized by using XRD, XPS, TEM, TPR, CO chemisorption, FTIR and ICP analyses. Formation of Ru(OH)(x) surface species is proposed to be the main cause of catalyst deactivation with no significant Ru leaching into the reaction mixture. Following catalyst regeneration, up to 85% of the initial catalytic activity could be recovered successfully. Moreover, adsorption of secondary aliphatic alcohols on the catalyst was found to significantly reduce the formation of Ru(OH)(x) during the reaction, thus protecting the catalyst from deactivation.

Neuropeptide Y (NPY) and NPY Y1 receptor in periodontal health and disease

Abstract
OBJECTIVES:
Neuropeptide Y (NPY) coordinates inflammation and bone metabolism which are central to the pathogenesis of periodontitis. The present study was designed to determine whether NPY was quantifiable in human gingival crevicular fluid (GCF) and to test the null hypothesis that GCF levels of NPY were the same in periodontal health and disease. A subsidiary aim was to determine the potential functionality of released NPY by detecting the presence of NPY Y1 receptors in gingival tissue.
DESIGN:
The periodontitis group consisted of 20 subjects (10 females and 10 males) mean age 41.4 (S.D. 9.6 years). The control group comprised 20 subjects (10 females and 10 males) mean age 37.4 (S.D. 11.7 years). NPY levels in GCF were measured in periodontal health and disease by radioimmunoassay. NPY Y1 receptor expression in gingival tissue was determined by Western blotting of membrane protein extracts from healthy and inflamed gum.
RESULTS:
Healthy sites from control subjects had significantly higher levels of NPY than diseased sites from periodontitis subjects. NPY Y1 receptor protein was detected in both healthy and inflamed gingival tissue by Western blotting.
CONCLUSIONS:
The significantly elevated levels of NPY in GCF from healthy compared with periodontitis sites suggests a tonic role for NPY, the functionality of which is indicated by the presence of NPY Y1 receptors in local gingival tissue.

Tooth loss and implant outcomes in patients refractory to treatment in a periodontal practice

Aim: The aim of this study was to investigate the factors associated with continued significant tooth loss due to periodontal reasons during maintenance following periodontal therapy in a specialist periodontal practice in Norway.
Material and Methods: A case-control design was used. Refractory cases were patients who lost multiple teeth during a maintenance period of 13.4 (range 8-19) years following definitive periodontal treatment in a specialist practice. Controls were age- and gender-matched maintenance patients from the same practice. Characteristics and treatment outcomes were assessed, and all teeth classified as being lost due to periodontal disease during follow-up were identified. The use of implants in refractory cases and any complications relating to such a treatment were recorded.
Results: Only 27 (2.2%) patients who received periodontal treatment between 1986 and 1998 in a specialist practice met the criteria for inclusion in the refractory to treatment group. Each refractory subject lost 10.4 (range 4-16) teeth, which represented 50% of the teeth present at baseline. The rate of tooth loss in the refractory group was 0.78 teeth per year, which was 35 times greater than that in the control group. Multivariate analysis indicated that being in the refractory group was predicted by heavy smoking (p=0.026), being stressed (p=0.016) or having a family history of periodontitis (p=0.002). Implants were placed in 14 of the refractory patients and nine (64%) of these lost at least one implant. In total, 17 (25%) of the implants placed in the refractory group were lost during the study period.
Conclusions: A small number of periodontal maintenance patients are refractive to treatment and go on to experience significant tooth loss. These subjects also have a high level of implant complications and failure. Heavy smoking, stress and a family history of periodontal disease were identified as factors associated with a refractory outcome.

Re-treatment profiles during long-term maintenance therapy in a periodontal practice in Norway

Background: Periodontal therapy coupled with active maintenance has been shown to be effective in maintaining periodontal health, however, the question of re-treatment is rarely alluded to in the literature.

Community Regeneration: An Elite or a ‘Real’ Community Space?

Identifying community interests in the processes of planning and regeneration is less than straightforward. By their very nature programmes encourage the development of particular projects, typically relying on experience from past initiatives to inform current practice. One of the difficulties for partners is juggling the need to comply with administrative demands while engaging in a meaningful way with their community. This article uses empirical evidence to examine power relations within structures of governance. It argues that current processes are unable to identify real community interests and consequently create space that favour elite interests, all of which restrain the impact of governance.

Long-term outcomes for cross-arch stabilizing bridges in periodontal maintenance patients - a retrospective study

Background: Cross-arch bridges are used to stabilize teeth for patients with reduced periodontal support. Little is known about technical or biological complications, whether teeth and implants can be combined in this type of bridge and the long-term effects on tooth loss.

Agitating for a design and regeneration agenda in a postconflict city: the case of Belfast

Introduction

Belfast has been a focus of academic attention for the last forty years with most interest centred on various aspects of ‘the Troubles’. Where there has been interest in the built environment, it has largely been about how the ‘security situation’ impacted directly on architecture and on the design and layout of social housing. This paper seeks to go beyond this to explore how the political- administrative culture of ‘the Troubles’ interacted with ‘normal’ market forces to shape the central area of the city, and to consider the responses of a recently formed activist group, known as the Forum for Alternative Belfast (hereafter referred to as the Forum). The paper is written by three of the directors of the Forum.1 Moreover, the empirical research presented here was undertaken by the Forum as part of a campaign to address issues relating to the design, layout and quality of Belfast’s built environment. In the longstanding tradition of participant observation working within an action-research paradigm, the participants have attempted to offer an account that is evidentially and purposefully selfcritical and reflective. It is of course recognised that while this approach offers many positive attributes, such as phenomenological access through immersion in the project, it also has the potential to bring compromise on research detachment and objectivity.2 To address the latter, the authors have attempted
to avoid polemical argument, and to support claims with primary or secondary research evidence. The authors also acknowledge that action-research has a chequered history; however, they would argue
that their approach is faithful to a concept that sees ‘research’ defined as understanding and ‘action’ defined as seeking change. The Forum’s very purpose is to seek change, but to do this requires evidence, collaboration and demonstration. And in this sense, it is a learning process for all participants, including the research activists, government officials, community organisations and students. The authors also recognise the complexity of factors that affect urban management and change, particularly in a city such as Belfast, which has had to cope with political violence for over thirty years. And they appreciate that in the context of conflict, governance is skewed to cope with political realities. Hamdi reminds us, however, that in practice there is an ‘important dialectic between top-down planning, with its formal and designed laws and structures, and bottom-up selforganizing collectivism—those “quantum and emergent systems” which Jane Jacobs argued long ago give cities their life and order.’3

Contesting Territorial Fixity?: A Case Study of Regeneration in Belfast

This paper looks at urban regeneration in Belfast as a stage on which the interaction between different structural dynamics (political, economic and cultural) is manifested in the city. It discusses how contested ideas of ‘space’, ‘place’ and ‘territory’ frame the ways in which Belfast has changed over recent years and asks if regeneration itself has the potential to transform the dynamic of deep-rooted ethno-national divisions. The research question is explored through a case study of proposed urban regeneration in north Belfast. It is found that, while there is evidence of transition to less exclusivistic attitudes in leisure and work spaces, asymmetrical conflict over residential space persists in ways which reproduce deep-rooted political and cultural patterns of territorial fixity and division.