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Towards Refinement for Measuring Subcutaneously Transplanted Tumour Models in Mice
Get PDFEvaluation using mouse subcutaneous tumour models is a key process in cancer drug development. Tumour material is implanted subcutaneously and tumour growth measured using callipers. However this methodology can have poor reproducibility and accuracy due to observer variation. Furthermore the physical pressure of using callipers can distress the mouse and lead to tumour damage. Non-invasive digital tumour imaging would reduce handling stresses and allow volume determination without physical contact. This thesis focusses on capturing 2D digital images of subcutaneous tumours, then using image processing and machine learning methods to determine 3D volume. The biggest challenge faced was lack of differentiation between tumour and surrounding skin, rendering tumour boundary identification difficult. Whilst image processing methods such as colour segmentation and edge detection were unsuccessful, machine learning proved more successful. Three convolutional neural networks, VGG-Face, VGG-19 and VGG-16 models were evaluated, with VGG-Face producing the best results. Using the layer FC7 before RELU activation for extraction in the VGC-Face model, a tumour recognition rate of 98.86% was achieved. This was increased to 100% through a semi-automatic step with detection repeated on cropped versions of negatively classified images. Finally, volume was determined through extracting image features using the VGG-Face model and conducting partial least squares regression (error of 0.1). This work has successfully demonstrated that with computational methods the volume of subcutaneous tumours can be evaluated through non-invasive digital imaging without need to have contact with the tumour itself, thus offering refinement benefits to the mice as well as eliminating observer bias
A Review of Modelling of the FCC Unit. Part I: The Riser
Get PDFYesHeavy petroleum industries, including the fluid catalytic cracking (FCC) unit, are useful for producing fuels but they are among some of the biggest contributors to global greenhouse gas (GHG) emissions. The recent global push for mitigation efforts against climate change has resulted in increased legislation that affects the operations and future of these industries. In terms of the FCC unit, on the riser side, more legislation is pushing towards them switching from petroleum-driven energy sources to more renewable sources such as solar and wind, which threatens the profitability of the unit. On the regenerator side, there is more legislation aimed at reducing emissions of GHGs from such units. As a result, it is more important than ever to develop models that are accurate and reliable, that will help optimise the unit for maximisation of profits under new regulations and changing trends, and that predict emissions of various GHGs to keep up with new reporting guide-lines. This article, split over two parts, reviews traditional modelling methodologies used in modelling and simulation of the FCC unit. In Part I, hydrodynamics and kinetics of the riser are dis-cussed in terms of experimental data and modelling approaches. A brief review of the FCC feed is undertaken in terms of characterisations and cracking reaction chemistry, and how these factors have affected modelling approaches. A brief overview of how vaporisation and catalyst deactiva-tion are addressed in the FCC modelling literature is also undertaken. Modelling of constitutive parts that are important to the FCC riser unit such as gas-solid cyclones, disengaging and stripping vessels, is also considered. This review then identifies areas where current models for the riser can be improved for the future. In Part II, a similar review is presented for the FCC regenerator system
Humidification-dehumidification desalination process: Performance evaluation and improvement through experimental and numerical methods
No full textYesModels' accuracy and reliability are important factors for designers of the humidification-dehumidification (HDH) desalination systems. A model used for designing the system must consider all important parameters in order to maintain high accuracy over the wide range of fluctuating conditions. The empirical models for HDH systems which are mostly available in literature are simple and easy to develop but also have limited predictive accuracy for extreme conditions because of consideration of only a few of many influential parameters. Usage of these models may lead to an expensive redesign at latter stages in development of the real system. Therefore, the aim of this paper is to propose the mechanistic model of the HDH desalination process with an improved prediction accuracy as an alternative to conventional models. This model is developed by coupling the heat and mass transfer equations at the water-air interface into enthalpy equations. Performances of the proposed model and an empirical model from literature are compared against experimental data obtained from the HDH system, which is also designed in this work. Results show the proposed model has relatively low mean square error (0.4) hence more accurate than the empirical model with mean square error of 7. It was also found that, the recovery ratio attained by the system increases substantially with an increase of the feed water temperature, but decreases with an increase of water-to-air flow ratio. Freshwater productivity increases with an increasing packing's specific area while doubling of dehumidifiers' surface area improves the recovery ratio by 16%
Efficient Photocatalytic Degradation of Organic Pollutant in Wastewater by Electrospun Functionally Modified Polyacrylonitrile Nanofibers Membrane Anchoring TiO2 Nanostructured.
Get PDFYesIn this study, polyacrylonitrile (PAN_P) nanofibers (NFs) were fabricated by electrospinning. The PAN_P NFs membrane was functionalized with diethylenetriamine to prepare a functionalized polyacrylonitrile (PAN_F) NFs membrane. TiO2 nanoparticles (NPs) synthesized in the laboratory were anchored to the surface of the PAN_F NFs membrane by electrospray to prepare a TiO2 NPs coated NFs membrane (PAN_Coa). A second TiO2/PAN_P composite membrane (PAN_Co) was prepared by embedding TiO2 NPs into the PAN_P NFs by electrospinning. The membranes were characterized by microscopic, spectroscopic and X-ray techniques. Scanning electron micrographs (SEM) revealed smooth morphologies for PAN_P and PAN_F NFs membranes and a dense cloud of TiO2 NPs on the surface of PAN_Coa NFs membrane. The attenuated total reflectance in the infrared (ATR-IR) proved the addition of the new amine functionality to the chemical structure of PAN. Transmission electron microscope images (TEM) revealed spherical TiO2 NPs with sizes between 18 and 32 nm. X-ray powder diffraction (XRD) patterns and energy dispersive X-ray spectroscopy (EDX) confirmed the existence of the anatase phase of TiO2. Surface profilometry da-ta showed increased surface roughness for the PAN_F and PAN_Coa NFs membranes. The adsorption-desorption isotherms and hysteresis loops for all NFs membranes followed the IV -isotherm and the H3 -hysteresis loop, corresponding to mesoporous and slit pores, respectively. The photocatalytic activities of PAN_Coa and PAN_Co NFs membranes against methyl orange dye degradation were evaluated and compared with those of bare TiO2 NPs.The higher photocatalytic activity of PAN_Coa membrane (92%, 20 ppm) compared to (PAN_Co) NFs membrane (41.64%, 20 ppm) and bare TiO2 (49.60%, 20 ppm) was attributed to the synergy between adsorption, lower band gap, high surface roughness and surface area
COSMOS next generation - A public knowledge base leveraging chemical and biological data to support the regulatory assessment of chemicals
Get PDFYesThe COSMOS Database (DB) was originally established to provide reliable data for cosmetics-related chemicals within the COSMOS Project funded as part of the SEURAT-1 Research Initiative. The database has subsequently been maintained and developed further into COSMOS Next Generation (NG), a combination of database and in silico tools, essential components of a knowledge base. COSMOS DB provided a cosmetics inventory as well as other regulatory inventories, accompanied by assessment results and in vitro and in vivo toxicity data. In addition to data content curation, much effort was dedicated to data governance - data authorisation, characterisation of quality, documentation of meta information, and control of data use. Through this effort, COSMOS DB was able to merge and fuse data of various types from different sources. Building on the previous effort, the COSMOS Minimum Inclusion (MINIS) criteria for a toxicity database were further expanded to quantify the reliability of studies. COSMOS NG features multiple fingerprints for analysing structure similarity, and new tools to calculate molecular properties and screen chemicals with endpoint-related public profilers, such as DNA and protein binders, liver alerts and genotoxic alerts. The publicly available COSMOS NG enables users to compile information and execute analyses such as category formation and read-across. This paper provides a step-by-step guided workflow for a simple read-across case, starting from a target structure and culminating in an estimation of a NOAEL confidence interval. Given its strong technical foundation, inclusion of quality-reviewed data, and provision of tools designed to facilitate communication between users, COSMOS NG is a first step towards building a toxicological knowledge hub leveraging many public data systems for chemical safety evaluation. We continue to monitor the feedback from the user community at [email protected]
Evaluating the potential for cone beam CT to improve the suspected scaphoid fracture pathway: InSPECTED - A single-centre feasibility study
Get PDFYesThe suspected scaphoid fracture remains a diagnostic conundrum with over-treatment a common risk-averse strategy. Cross-sectional imaging remains the gold standard with MRI recommended but CT used by some because of easier access or limited MRI availability. The aim of this feasibility study was to evaluate whether cone beam computed tomography (CBCT) could support early diagnosis, or exclusion, of scaphoid fractures.
Patients with a suspected scaphoid were recruited fracture between March and July 2020. All underwent a 4-view X-ray. If this examination was normal, they were immediately referred for a CBCT scan of the wrist. Those with a normal scan were discharged to research follow-up at 2 and 6-weeks.
68 participants were recruited, 55 had a normal or equivocal X-ray and underwent CBCT. Nine additional radiocarpal fractures (16.2%) were demonstrated on CBCT, the remainder were discharged to research follow-up. Based on the 2-week and 6-week follow up three patients (4.4%) were referred for MRI to investigate persistent symptoms with no bony injuries identified.
CBCT scans enabled a rapid pathway for the diagnosis or exclusion of scaphoid fractures, identifying other fractures and facilitating early treatment. The rapid pathway also enabled those with no bony injury to start rehabilitation, suggesting that patients can be safely discharged with safety-net advice following a CBCT scan
Tensile, rheological and morphological characterizations of multi-walled carbon nanotube/polypropylene composites prepared by microinjection and compression molding
Get PDFYesPolypropylene (PP) reinforced with 2 and 4 wt% of multi-walled carbon nanotubes (MWNT) were melt-blended in twin screw extruder and then molded by compression or micromolding process. The impact of injection speed on the surface morphology, rheological and tensile characteristics was investigated by using a scanning electron microscope, parallel plate rheometry, and tensiometry. Results showed that the tensile properties of micro-molded specimens were remarkably higher than those of the compression molded sheets. Compared to compression molded sheets, micromolded specimens demonstrated up to 40 and 244% higher tensile stiffness and yield strength, respectively, most likely due to the alignment of polymer chain segments in the flow direction induced during the micromolding process. It was observed that the fast filling speed caused a drop in the tensile properties of the nanocomposites and polymer. Rheological examination revealed that the presence of a rheological percolation network in the nanocomposites produced by micromolding and the fast injection speed was beneficial for establishing the percolated network. Morphological examination revealed that the size of nanotube agglomerations that appeared in micromolded specimens was up to five times smaller than in compression molded sheets and the agglomeration size decreased with the increase of the injection speed
A systematic review to identify key elements of effective public health interventions that address barriers to health services for refugees
Get PDFYesRefugees often face barriers to accessing health services, especially after resettlement. The aim of this study is to identify key elements of effective public health interventions that address barriers to health services for refugees.
Methods: Key online databases were searched to identify studies published between 2010 and 2019. Six studies met the inclusion criteria: two qualitative, one quantitative and three mixed-methods studies. An adapted narrative synthesis framework was used which included thematic analysis for systematic reviews.
Results: Five themes were identified: peer support, translation services, accessible intervention, health education and a multidisciplinary approach.
Conclusion: These key elements identified from this review could be incorporated into public health interventions to support refugees’ access to health services. They could be useful for services targeting refugees generally, but also supporting services targeting refugee resettlement programmes such as the Syrian resettled refugees in the UK. Future research is needed to evaluate the impact of public health interventions where these elements have been integrated into the intervention
Laser capture microdissection on surgical tissues to identify aberrant gene expression in impaired wound healing in type 2 diabetes
No full textNoThe global prevalence Type 2 diabetes mellitus (T2DM) is escalating at a rapid rate. Patients with T2DM suffer from a multitude of complications and one of these is impaired wound healing. This can lead to the development of non-healing sores or foot ulcers and ultimately to amputation. In healthy individuals, wound healing follows a controlled and overlapping sequence of events encompassing inflammation, proliferation, and remodelling. In T2DM, one or more of these steps becomes dysfunctional. Current models to study impaired wound healing in T2DM include in vitro scratch wound assays, skin equivalents, or animal models to examine molecular mechanisms underpinning wound healing and/or potential therapeutic options. However, these do not fully recapitulate the complex wound healing process in T2DM patients, and ex vivo human skin tests are problematic due to the ethics of taking punch biopsies from patients where it is known they will heal poorly. Here, a technique is described whereby expression profiles of the specific cells involved in the (dys)functional wound healing response in T2DM patients can be examined using surplus tissue discarded following amputation or elective cosmetic surgery. In this protocol samples of donated skin are collected, wounded, cultured ex vivo in the air liquid interface, fixed at different time points and sectioned. Specific cell types involved in wound healing (e.g., epidermal keratinocytes, dermal fibroblasts (papillary and reticular), the vasculature) are isolated using laser capture microdissection and differences in gene expression analyzed by sequencing or microarray, with genes of interest further validated by qPCR. This protocol can be used to identify inherent differences in gene expression between both poorly healing and intact skin, in patients with or without diabetes, using tissue ordinarily discarded following surgery. It will yield greater understanding of the molecular mechanisms contributing to T2DM chronic wounds and lower limb loss.European Commission 7th Framework Programme for Research and Technical Development - Marie Curie Innovative Training Networks (ITN), Grant agreement no 607886. Aveda, Hair Innovation & Technology, US
Impacts of sedimentation on rainwater quality: case study at Ikorodu of Lagos, Nigeria
Get PDFYesThis study investigated the impact of sedimentation on rainwater storage system using a case study at the Ikorodu area of Lagos state, a rural area in Nigeria. In this investigation, the proportions of Escherichia coli (E. coli) that were settleable (due to sedimentation) and those that were at the free phase have been studied. Water samples were collected from different depths in the inspected rainwater storage tank at two different periods (i.e. rainy and dry periods) for 20 days. The samples collected from these periods
have been analysed for physical and microbial measures before passing it through the serial filters with pore sizes of 500 μm, 100 μm, 10 μm and 1.5 μm to measure the retained particle mass. From the results, it was observed that: (1) the water quality at the free-phase zone was better than that at the tank’s
bottom; (2) the settleable bacteria rapidly sinked to bottom; (3) the correlation of turbidity, E. coli and
total suspended solids (TSS) for all the rain events showed a relatively high Pearson’s coefficient of 0.9 to one another; and (4) over 70% of settling TSS occurred within first 36 hours. Finally, it has been found that the physical sedimentation process can significantly reduce the microbial measures