Flow and transport in tissue engineering scaffolds: A network modelling approach

This paper was presented at the 2nd Micro and Nano Flows Conference (MNF2009), which was held at Brunel University, West London, UK. The conference was organised by Brunel University and supported by the Institution of Mechanical Engineers, IPEM, the Italian Union of Thermofluid dynamics, the Process Intensification Network, HEXAG - the Heat Exchange Action Group and the Institute of Mathematics and its Applications.Tissue engineers aim to grow functional tissues in the laboratory. One approach is to seed cells on a porous biomaterial scaffold, which is then cultured in a flow perfusion bioreactor. Such bioreactors enhance the transport of nutrients and growth factors to the cells by convection, and provide mechanical loads to mechanosensitive tissues. In this paper, we adopt a network modelling approach to provide insight into the nature of the flow, nutrient transport and cell distribution through the porous scaffold. The approach resolves flow and nutrient transport at the pore scale, and thus enables the local cellular environment to be determined. We demonstrate how this method can be used to study the impact of scaffold geometry (e.g. porosity, connectivity) on the cellular environment, and hence provide insight into the optimum culture conditions required to obtain functional tissues.This study is funded by the EPSRC

Mathematical modelling of nanoparticle delivery to vascular tumours

This paper was presented at the 2nd Micro and Nano Flows Conference (MNF2009), which was held at Brunel University, West London, UK. The conference was organised by Brunel University and supported by the Institution of Mechanical Engineers, IPEM, the Italian Union of Thermofluid dynamics, the Process Intensification Network, HEXAG - the Heat Exchange Action Group and the Institute of Mathematics and its Applications.The goal of any cancer therapy is to achieve efficient, tissue-specific targeting of drugs to cancer cells. However, most anticancer agents act on healthy and malignant tissue alike, potentially resulting in side effects to healthy tissue. This has motivated the development of treatment strategies that are cancer-cell specific; one approach uses biomimetic polymer vesicles (BPV) to deliver chemotherapeutic drugs into cells before releasing them. BPVs are synthetic membrane enclosed, nanometre-sized structures, and provide ideal drug delivery vectors because specific targeting to cancer cells can be achieved by coating with tumourspecific molecules. We present several mathematical models covering a wide range of length-scales pertinent to BPV-mediated delivery protocols and focus on capturing the in vivo environment by evaluating the impact of the underlying vascular structure upon the governing transport mechanisms. Firstly, we present models of specific binding of BPVs to cancer cells. Subsequently we examine the implications of these model outputs in the contexts of both discrete capillary architectures and higher level homogenized-models that track blood and BPV transport at the tissue scale (both intra- and extra-tumorally). Numerical solutions are discussed, and recommendations are presented on that optimal integration of the models to generate quantitative predictions associated with BPV treatment efficacy

A history of scientific journals : publishing at the Royal Society, 1665-2015

Funding information: For financial support, we thank the Arts & Humanities Research Council, whose grant (AH/K001841) funded four years of intensive research, by three postdoctoral researchers, at the archives of the Royal Society, among other places. We also thank the University of St Andrews open access fund, for support with the final publication of this book.Publisher PD

A History of Scientific Journals

Modern scientific research has changed so much since Isaac Newton’s day: it is more professional, collaborative and international, with more complicated equipment and a more diverse community of researchers. Yet the use of scientific journals to report, share and store results is a thread that runs through the history of science from Newton’s day to ours. Scientific journals are now central to academic research and careers. Their editorial and peer-review processes act as a check on new claims and findings, and researchers build their careers on the list of journal articles they have published. The journal that reported Newton’s optical experiments still exists. First published in 1665, and now fully digital, the Philosophical Transactions has carried papers by Charles Darwin, Dorothy Hodgkin and Stephen Hawking. It is now one of eleven journals published by the Royal Society of London. Unrivalled insights from the Royal Society’s comprehensive archives have enabled the authors to investigate more than 350 years of scientific journal publishing. The editorial management, business practices and financial difficulties of the Philosophical Transactions and its sibling Proceedings reveal the meaning and purpose of journals in a changing scientific community. At a time when we are surrounded by calls to reform the academic publishing system, it has never been more urgent that we understand its history

350 years of scientific periodicals

PostprintPeer reviewe

Drava na prekretnici

In this paper, we consider the Royal Society's attitudes towards the copying, reprinting, and reuse of material from its Philosophical Transactions during the long nineteenth century. The contents of the Transactions circulated in print in a variety of ways beyond its traditional biannual parts and bound annual volumes. This included the private circulation of authors' separate copies of papers; the reissuing of papers in authors' collected works; the incorporation of material into other books; and the reporting and excerpting of material in the general scientific periodical literature. The Royal Society attempted to protect the originality and priority of the research published under its imprint, but it never sought to use copyright legislation to prevent (or to profit from) the reprinting or reuse of its research. We argue that copyright was in fact a poor tool for learned institutions like the Royal Society, which were more concerned with reputational credit than with financial credit and were adept at managing the delicate balance between institutional interests and those of individual authors. We demonstrate that the Royal Society's approach to reprinting and reuse was based on the philanthropic concept of a scholarly common good. It typically relied on a code of conduct enforced through tradition and moral suasion, rather than legislation.PostprintPeer reviewe

Recommendations for defining preventable HIV-related mortality for public health monitoring in the era of Getting to Zero: an expert consensus

Getting to Zero is a commonly cited strategic aim to reduce mortality due to both HIV and avoidable deaths among people with HIV. However, no clear definitions are attached to these aims with regard to what constitutes HIV-related or preventable mortality, and their ambition is limited. This Position Paper presents consensus recommendations to define preventable HIV-related mortality for a pragmatic approach to public health monitoring by use of national HIV surveillance data. These recommendations were informed by a comprehensive literature review and agreed by 42 international experts, including clinicians, public health professionals, researchers, commissioners, and community representatives. By applying the recommendations to 2019 national HIV surveillance data from the UK, we show that 30% of deaths among people with HIV were HIV-related or possibly HIV-related, and at least 63% of these deaths were preventable or potentially preventable. The application of these recommendations by health authorities will ensure consistent monitoring of HIV elimination targets and allow for the identification of inequalities and areas for intervention

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability