10,000 publications from this institution
An understanding of the evolution of toughness is essential for the mechanistic interpretation of the fracture of cortical bone. In the present study, in vitro fracture experiments were conducted on human cortical bone in order to identify and quantitatively assess the salient toughening mechanisms. The fracture toughness was found to rise linearly with crack extension (i.e., rising resistance- or R-curve behavior) with a mean crack-initiation toughness, K 0 of ∼2MPa√m for crack growth in the proximal–distal direction. Uncracked ligament bridging, which was observed in the wake of the crack, was identified as the dominant toughening mechanism responsible for the observed R-curve behavior. The extent and nature of the bridging zone was examined quantitatively using multi-cutting compliance experiments in order to assess the bridging zone length and estimate the bridging stress distribution. Additionally, time-dependent cracking behavior was observed at stress intensities well below those required for overload fracture; specifically, slow crack growth occurred at growth rates of ∼2×10−9 m/s at stress intensities ∼35% below the crack-initiation toughness. In an attempt to measure slower growth rates, it was found that the behavior switched to a regime dominated by time-dependent crack blunting, similar to that reported for dentin; however, such blunting was apparent over much slower time scales in bone, which permitted subcritical crack growth to readily take place at higher stress intensities.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Serious scholarly analyses of the types and roles of accountability in health care first appeared in the late 1980s. That issue, along with the related issue of responsibility in health care, has continued to interest policymakers, analysts and scholars ever since. Indeed, there has been a renewed surge of interest in recent years, with growing attention to the notion of accountable care organizations in the US, clinical audits in the UK, and governance as stewardship in many other countries. Accountability and responsibility in health care was also the theme of a major international conference organized by the Israel National Institute for Health Policy Research, which was held in Jerusalem in 2009. This book is a collection of scholarly articles on the themes of accountability and responsibility in health care and seeks to be the premier book in that field. It includes selected papers from the 2009 Jerusalem Conference, analytic essays on how accountability and responsibility are playing out in eight different countries, and reprints of some of the classic articles in the field. The book will interest policymakers, managers, researchers and students, and many of the ideas presented here will help shape the development of this field in the years ahead. Some of these ideas have appeared in other forums; the unique contribution of this volume is that it is the first to bring together so many different perspectives on accountability and responsibility in health care. This volume will both acquaint readers with some of the latest thinking on accountability and responsibility in health care, and will serve as a catalyst for future reflection, research and writing in this area
Chloride ion‐induced breakdown of the passive films on polycrystal and single‐crystal (100) nickel surfaces was studied in terms of the film breakdown potential and induction time as a function of chloride concentration. The film was grown in a deaerated chloride‐free borate buffer solution at to a constant thickness of 4.5 mC/cm2, and and were determined potentiodynamically and potentiostatically, respectively, after injecting chloride ion into the solution. The film breakdown potential was found to increase linearly with the potential scan rate, and the critical pitting potential (the breakdown potential at zero scan rate) decreased linearly with . The presence of grain boundaries on the polycrystal surface decreases the intercept of the relationship slightly, but did not significantly change the slope. The intercepts are higher than most of the values reported in the literature, although the slope is similar to previously found values. The induction time for pit nucleation on the two crystal forms for was found to decrease with increasing potential. The experimental data are analyzed in terms of the halide nuclei and point defect models for passivity breakdown.
Abstract Aim Trauma is a major cause of mortality leading to over 16,000 deaths annually in England and Wales alone. Code red traumas are the most extreme of these and a proportion will require immediate operative intervention. The aim of this study was to review the outcomes of patients presenting to a regional major trauma centre as code red traumas requiring immediate transfer to theatre and to identify a pathway to facilitate this process. Method Data were reviewed for all Code Red Traumas requiring immediate operative intervention between April 2017 and April 2021. Electronic records were searched to identify aetiologies, transfer times and post-operative morbidities and mortalities. Datasets were collected and analysed using Microsoft Excel software. Results 57 patients were identified and included. The average age was 39 years old. CT was performed in 52/59 patients (88.1%) and median time to CT was 32 minutes. All patients proceeded to theatre with an overall median time to theatre of 144.5 minutes. In hospital mortality was 19.3% (n = 11). Primary operating speciality varied with general surgery making up the majority with 30 cases. A consultant surgeon was present in 72% of cases and a consultant anaesthetist in 81% of cases. 84% (n = 48) of patients were admitted to ICU post-operatively. Conclusions Major trauma remains a significant cause of mortality in our cohort. We have developed a pathway for those requiring direct access to theatre. It is envisaged that this will facilitate expediated transfer to theatre and lead to improved patient outcomes.
The real missing link in Ebola control efforts to date may lie in the failure to apply core principles of health promotion: the early, active and sustained engagement of affected communities, their trusted leaders, networks and lay knowledge, to help inform what local control teams do, and how they may better do it, in partnership with communities. The predominant focus on viral transmission has inadvertently stigmatized and created fear-driven responses among affected individuals, families and communities. While rigorous adherence to standard infection prevention and control (IPC) precautions and safety standards for Ebola is critical, we may be more successful if we validate and combine local community knowledge and experiences with that of IPC medical teams. In an environment of trust, community partners can help us learn of modest adjustments that would not compromise safety but could improve community understanding of, and responses to, disease control protocol, so that it better reflects their 'community protocol' (local customs, beliefs, knowledge and practices) and concerns. Drawing on the experience of local experts in several African nations and of community-engaged health promotion leaders in the USA, Canada and WHO, we present an eight step model, from entering communities with cultural humility, though reciprocal learning and trust, multi-method communication, development of the joint protocol, to assessing progress and outcomes and building for sustainability. Using examples of changes that are culturally relevant yet maintain safety, we illustrate how often minor adjustments can help prevent and treat the most serious emerging infectious disease since HIV/AIDS.
