Category Archives: MyResearch

Nanoparticle motion through heterogeneous hydrogels

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Over the last couple of years, we have been transitioning a technique, which we developed for tracking the motion of nanoparticles using caustics [see ‘Slow moving nanoparticles‘ on December 13th 2017], from its initial use in exploring mechanics at the nanoscale to applications in nanobiology [See ‘Label-free real-time tracking of individual bacterium‘ on January 25th, 2023] where it has the advantages of functioning in real-time and being label-free (chemical labels can impact motion, protein interactions and cell behaviour).  In the summer, we had couple of articles published in consecutive issues of the Nature journal, Scientific Reports which describe our recent work.  In the first, we have explored the diffusion of nanoparticles through a synthetic analogue of the vitreous humour in order to support the design of novel therapeutics for retinal diseases.  Retinal diseases, such as macular degeneration and diabetic retinopathy, affects millions of people globally and treatment often involves frequent intravitreal injections of anti-vascular endothelium growth factor agents and corticoids.  Delivery of the appropriate dose to the retinal cell layer is challenging due to the complex nature of the vitreous and functionalised nanoparticles offer a potential solution.  In vivo animal testing is inappropriate because of the ethical concerns and poor representation of human eyes and ex vivo testing of cadaveric eyes is unreliable due to the instability of biomechanical and biochemical properties of the vitreous humour.  Hence, we used agar-hyaluronic acid hydrogels as an in vitro model of the vitreous and employed the caustic technique to track the motion of nanoparticles through the hydrogels.  The hydrogels had been validated as a representative model of the vitreous humour by other research groups.  Our tracking technique revealed that the electric charge on the nanoparticles did not affect their diffusion through the hydrogel; however, both the diameter of the particles and the heterogeneous nature of the gel influenced the diffusion.  Nanoparticles with diameters of 200, 100 and 50 nm moved progressively more quickly and over a larger area.  The diffusion rates in hydrogels with a high viscosity (about 450  Pa.s) were consistent throughout the gel implying that the gel was homogeneous, while gels with medium (about 40 Pa.s) to low (about 3 Pa.s) viscosity generated diffusion rates that were distributed bi-modally suggesting a heterogeneous gel with zones of low and high density in which the particles moved more or less freely.  The heterogeneity of a gel renders a global value for viscosity somewhat meaningless and makes comparisons difficult with the vitreous humour because it is also heterogeneous; however, global values of viscosity for porcine vitreous humour are typically 1 Pa.s.  We are continuing this research; however, our published work has demonstrated that the use of caustics in an optical microscope is a reproducible and inexpensive technique for exploring the design of novel nanoscale drug delivery systems for the eye.

Source: Lorenzo Lopez M, Kearns VR, Curran JM, Patterson EA. Diffusion of nanoparticles in heterogeneous hydrogels as vitreous humour in vitro substitutes. Scientific reports. 2024 Jul 29;14(1):1744.

Image: Random track of a nanoparticle superimposed on its image generated in the microscope using a pin-hole and narrowband filter.

Commoditisation of civil nuclear power

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Logo for BBC Inside ScienceA colleague and I published a paper last month that we hope will bring about a paradigm shift in the nuclear power industry. I was interviewed on BBC Radio 4’s Inside Science on the day following its publication – its the first time one of my scientific papers has made that big a splash in the media!  You can listen to the programme on BBC Sounds at https://www.bbc.co.uk/sounds/play/m001zdwv.

In the paper we describe a blueprint for the factory-production of sealed micro-power units with a digitally-enabled, holistic assurance framework.  Currently, several designs of micro-reactors are progressing to the prototype stage with hazards contained on-site.  The integration of these approaches enables a transformation of the regulatory regime to type or series approval at the factory, similar to the aerospace industry, and supported by digital tools such as block chains to provide transparent quality assurance within the supply chain.  The transformation of the regulatory regime and the shift to ‘flow’ production in a factory would remove the financial risk from the power plant to the factory thereby enabling nuclear power to become a realistic competitor for intermittent green energy sources, such as wind and solar, both in terms of financial and ecological costs.  The output from three production lines could replace the current electricity generating capacity from fossil fuels in the UK over approximately 15 years thus making a significant contribution to achieving net zero greenhouse gas emissions.  We propose a design philosophy for the micro-power units that will allow them to go unnoticed in an urban environment or even become an iconic product that signals a community’s commitment to responsible stewardship of the Earth’s resources.  Our blueprint represents a revolutionary change for the nuclear power industry that would likely lead to the commoditisation of nuclear power whereas the status quo probably leads to extinction.

The paper is published with open access (its free) at Patterson EA & Taylor RJ, 2024, The commoditisation of civil nuclear power, Royal Society Open Science, 11:240021.

Evolutionary model of knowledge management

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Towards the end of last year, I wrote about the challenges in deploying digital technologies in holistic approaches to knowledge management in order to gain organizational value and competitive advantage [see ‘Opportunities lost in knowledge management using digital technology’ on October 25th, 2023].  Almost on the last working day of 2023, we had an article published in PLOS ONE (my first in the journal) in which we explored ‘The impact of digital technologies on knowledge networks in two engineering organizations’.  We used social network analysis and semi-structured interviews to investigate the culture around knowledge management, and the deployment of digital technologies in support of it, in an engineering consultancy and an electricity generator.  The two organizations had different cultures and levels of deployment of digital technologies.  We proposed a new evolutionary model of the culture of knowledge management based on Hudson’s evolutional model of safety culture that is widely used in industry. Our new model is illustrated in the figure from our article, starting from ‘Ignored: we have no knowledge management and no plans for knowledge management’ through to ‘Embedded: knowledge management is integrated naturally into the daily workflow’.  We also proposed that social networks could be used as an indicator of the stage of evolution of knowledge management with low network density and dispersed networks representing higher stages of evolution, based on our findings for the two engineering organizations.

Sources:

Hudson, P.T.W., 2001. Safety management and safety culture: the long, hard and winding road. Occupational health and safety management systems, pp.3-32, 2001

Patterson EA, Taylor RJ, Yao Y. The impact of digital technologies on knowledge networks in two engineering organisations. PLoS ONE 18(12): e0295250, 2023.

 

Opportunities lost in knowledge management using digital technology

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Decorative imageRegular readers of this blog will know that I occasionally feature publications from my research group.  The most recent was ‘Predicting release rates of hydrogen from stainless steel’ on September 13th, 2023 and before that ‘Label-free real-tracking of individual bacterium’ on January 25th 2023 and ‘A thermal emissions-based real-time monitoring system for in situ detection of cracks’ in ‘Seeing small changes is a big achievement’ on October 26th 2023.  The subject of these publications might seem a long way apart but they are linked by my interest in trying to measure events in the real-world and use the data to develop and validate high-fidelity digital models.  Recently, I have stretched my research interests still further through supervising a clutch of PhD students with a relatively new collaborator working in the social sciences.  Two of the students have had their first papers published by the ASME (American Society of Mechanical Engineers) and the IEEE (Institute of Electrical and Electronics Engineers).  Their papers are not directly connected but they both explore the use of published information to gain new insights on a topic.  In the first one [1], we have explored the similarities and differences between safety cases for three nuclear reactors: a pair of research reactors – one fission and one fusion reactor; and a commercial fission reactor.  We have developed a graphical representation of the safety features in the reactors and their relationships to the fundamental safety principles set out by the nuclear regulators. This has allowed us to gain a better understanding of the hazard profiles of fission and fusion reactors that could be used to create the safety case for a commercial fusion reactor.  Fundamentally, this paper is about exploiting existing knowledge and looking at it in a new way to gain fresh insights, which we did manually rather than automating the process using digital technology.  In the second paper [2], we have explored the extent to which digital technologies are being used to create, collate and curate knowledge during and beyond the life-cycle of an engineering product.  We found that these processes were happening but generally not in a holistic manner.  Consequently, opportunities were being lost through not deploying digital technology in knowledge management to undertake multiple roles simultaneously, e.g., acting as repositories, transactive memory systems (group-level knowledge sharing), communication spaces, boundary objects (contact points between multiple disciplines, systems or worlds) and non-human actors.  There are significant challenges, as well as competitive advantages and organisational value to be gained, in deploying digital technology in holistic approaches to knowledge management.  However, despite the rapid advances in machine learning and artificial intelligence [see ‘Update on position of AI on hype curve: it cannot dream’ on July 26th 2023] that will certainly accelerate and enhance knowledge management in a digital environment, a human is still required to realise the value of the knowledge and use it creatively.

References

  1. Nguyen, T., Patterson, E.A., Taylor, R.J., Tseng, Y.S. and Waldon, C., 2023. Comparative maps of safety features for fission and fusion reactors. Journal of Nuclear Engineering and Radiation Science, pp.1-24
  2. Yao, Y., Patterson, E.A. and Taylor, R.J., 2023. The Influence of Digital Technologies on Knowledge Management in Engineering: A Systematic Literature Review. IEEE Transactions on Knowledge and Data Engineering.