Expanded bed adsorption: a study of bed behaviour during the recovery of a typical bioproduct

The majority of work in this Thesis will investigate the use of expanded beds for different separations in the field of Biotechnology and consider how best to utilise expanded beds most efficiently and effectively. The aims of the project were to develop a novel affinity purification from initial method scouting to pilot plant expanded bed level, and then to consider and develop a more effective and faster method of monitoring and control of and expanded bed than traditionally used off-line manual techniques. A protocol was successfully developed for the purification of yeast alcohol dehydrogenase (ADH) from unclarified homogenate using immobilised metal ion affinity chromatography in a STREAMLINETM expanded bed adsorption system, demonstrating high levels of recovery of the target protein. A novel system of breakthrough monitoring and control was developed using a combination of in-bed sampling and a rapid stopped flow analysis system. This enabled accurate control of product breakthrough at different levels when purifying ADH from crude homogenate feedstock. In addition this monitoring technique demonstrated variation in matrix utilisation with axial position, providing scope for the final section of work noted here. In-bed sampling also allowed the physical properties of the matrix to be studied and experimental radial and axial particle size distributions during expansion were obtained, along with the development of a method for measuring voidage in short sections of the bed under expansion. Finally, matrix utilisation was studied using segregated beds of varying particle size ranges in order to establish dynamic binding capacities and hence matrix productivity. Determination of dynamic capacities at different breakthrough levels for beds consisting of smallest and largest particles showed that, while smaller particles have more than double the total binding capacity of larger particles, at low breakthrough levels the larger particles have a higher dymanic binding capacity and hence a higher productivity

Batteries and supercapacitors – an equivalent circuit comparative study

Using more renewable power is necessary to reach the sustainability goals set by the United Nations and reducing greenhouse gas emissions. Increased use of renewable energy is also required as many different sectors need to be electrified. Furthermore, the war in Ukraine has shown that relying on a foreign state’s energy supply to guarantee enough power is not a viable strategy, and that more locally produced energy is needed. In order to achieve these ambitions, it is necessary to be able to store energy. Subsequently, both efficient supercapacitors and batteries are needed. In this thesis a review of batteries and supercapacitors were carried out. First a short literature review was performed to see where batteries and supercapacitors are being used and how they perform. A second literature study was performed to study the modelling of batteries and supercapacitors. Equivalent circuit models for both batteries and supercapacitors were made. Two different batteries and supercapacitors were chosen for simulations. The batteries simulated were based on lithium ion and NiMH technology. The supercapacitors were chosen from two popular brands; Nichion and Eaton. The parameters for the different devices were decided by assuming that they behaved the same way as found in other studies in the literature. The devices were then simulated using a resistive load for a discharge cycle. Longrange simulations using CC-CV profiles were used. Simulations showed that batteries were able to provide a charge for a longer time compared to the supercapacitors during discharging on a resistive load. During the CC-CV long-range simulation the Eaton 400F supercapacitor had the highest power output. Both supercapacitors were able to accomplish more cycles than both the batteries. The NiMH was able to do ½ cycle more than the lithium battery. The SOH calculations showed that the Nichion supercapacitor was able to achieve the most cycles. The lithium battery was able to perform more cycles than the NiMH battery

An assessment of the Tackling Knives and Serious Youth Violence Action Programme (TKAP) - phase ll (Research Report 53)

The Tackling Knives Action Programme (TKAP) ran initially from June 2008 until March 2009 and aimed to reduce teenage knife crime in ten police force areas in England and Wales. TKAP Phase II was then launched and the programme re-branded into the Tackling Knives and Serious Youth Violence Action Programme. Phase II ran from April 2009 to March 2010 in 16 police force areas (the original ten TKAP forces and six new areas)1 and aimed to reduce all serious violence involving 13- to 24-year-olds using a range of enforcement, education and prevention initiatives

Impact of poloxamer 188 (Pluronic F-68) additive on cell mechanical properties, quantification by real-time deformability cytometry

Advances in cellular therapies have led to the development of new approaches for cell product purification and formulation, e.g., utilizing cell endogenous properties such as size and deformability as a basis for separation from potentially harmful undesirable by-products. However, commonly used additives such as Pluronic F-68 and other poloxamer macromolecules can change the mechanical properties of cells and consequently alter their processing. In this paper, we quantified the short-term effect of Pluronic F-68 on the mechanotype of three different cell types (Jurkat cells, red blood cells, and human embryonic kidney cells) using real-time deformability cytometry. The impact of the additive concentration was assessed in terms of cell size and deformability. We observed that cells respond progressively to the presence of Pluronic F-68 within first 3 h of incubation and become significantly stiffer (p-value < 0.001) in comparison to a serum-free control and a control containing serum. We also observed that the short-term response manifested as cell stiffening is true (p-value < 0.001) for the concentration reaching 1% (w/v) of the poloxamer additive in tested buffers. Additionally, using flow cytometry, we assessed that changes in cell deformability triggered by addition of Pluronic F-68 are not accompanied by size or viability alterations

Deformability-induced lift force in spiral microchannels for cell separation

Cell sorting and isolation from a heterogeneous mixture is a crucial task in many aspects of cell biology, biotechnology and medicine. Recently, there has been an interest in methods allowing cell separation upon their intrinsic properties such as cell size and deformability, without the need for use of biochemical labels. Inertial focusing in spiral microchannels has been recognised as an attractive approach for high-throughput cell sorting for myriad point of care and clinical diagnostics. Particles of different sizes interact to a different degree with the fluid flow pattern generated within the spiral microchannel and that leads to particles ordering and separation based on size. However, the deformable nature of cells adds complexity to their ordering within the spiral channels. Herein, an additional force, deformability-induced lift force (FD), involved in the cell focusing mechanism within spiral microchannels has been identified, investigated and reported for the first time, using a cellular deformability model (where the deformability of cells is gradually altered using chemical treatments). Using this model, we demonstrated that spiral microchannels are capable of separating cells of the same size but different deformability properties, extending the capability of the previous method. We have developed a unique label-free approach for deformability-based purification through coupling the effect of FD with inertial focusing in spiral microchannels. This microfluidic-based purification strategy, free of the modifying immuno-labels, allowing cell processing at a large scale (millions of cells per min and mls of medium per minute), up to high purities and separation efficiency and without compromising cell quality

Respiratory sinus arrhythmia and heart period in infancy as correlates of later oppositional defiant and callous-unemotional behaviors

Extant literature suggests that oppositional defiant (ODD) and callous-unemotional (CU) behaviors in childhood and adolescence are associated with distinct patterns of psychophysiological functioning and that individual differences in these patterns have implications for developmental pathways to disorder. Very little is known about the associations between psychophysiological functioning in infancy and later ODD and CU behaviors. This study examined associations between basal autonomic nervous system (ANS) functioning in infancy and ODD and CU behaviors in later childhood. Using longitudinal heart period (HP) and respiratory sinus arrhythmia (RSA) data from the Durham Child Health and Development Study (N = 206), the current study tested associations, within a structural equation modeling framework, between continuous measures of HP and RSA across the first two years of life and later ODD and CU behaviors at first grade. Results indicate that ODD and CU behaviors in childhood are associated with lower baseline RSA, but not HP, across infancy. The implications of these findings for developmental models of ODD and CU behaviors are discussed

Optically enhanced acoustophoresis

Regenerative medicine has the capability to revolutionise many aspects of medical care, but for it to make the step from small scale autologous treatments to larger scale allogeneic approaches, robust and scalable label free cell sorting technologies are needed as part of a cell therapy bioprocessing pipeline. In this proceedings we describe several strategies for addressing the requirements for high throughput without labeling via: dimensional scaling, rare species targeting and sorting from a stable state. These three approaches are demonstrated through a combination of optical and ultrasonic forces. By combining mostly conservative and non-conservative forces from two different modalities it is possible to reduce the influence of flow velocity on sorting efficiency, hence increasing robustness and scalability. One such approach can be termed "optically enhanced acoustophoresis" which combines the ability of acoustics to handle large volumes of analyte with the high specificity of optical sorting