88 research outputs found
Assessment of the Accuracy of Cable Sheath Fault Location Device and Enhancement of its Performance
As power system networks are being constantly upgraded and extended, there is a greater importance in the reliable transmission of electrical power and fault finding techniques, especially for cables installed underground. Damage to a cable’s protective sheath can damage a cables life span and also lead to disruption of system operation and loss of supply. This study includes research into the literature and techniques used to locate these faults accurately. Bridge resistance and volt drop measurement techniques are the main methods used by sheath fault location devices to locate faults accurately. This task is made more difficult because such devices are hindered by a limited test current. This study carries out an analysis of the accuracy of a leading cable sheath fault location device, which utilizes the volt drop method. Testing was conducted across a series of circuits and a comparison of accuracy was made between this device and a range of measurement devices. After a thorough analysis of test results was carried out, a new method of sheath fault location was developed and examined with the aim of improving fault location accurac
Macrophage Migration Inhibitory Factor Enhances Pseudomonas Aeruginosa Biofilm Formation, Potentially Contributing to Cystic Fibrosis Pathogenesis
Macrophage migration inhibitory factor (MIF) is a key proinflammatory mediator that we have previously shown to be associated with an aggressive clinical phenotype in cystic fibrosis. It possesses unique tautomerase enzymatic activity. However, to date, no human-derived substrate has been identified that has the capacity to interact with this cytokine\u27s unique tautomerase activity. This led us to hypothesize that MIF may have the capacity to interact with external substrates. We describe for the first time how Pseudomonas aeruginosa can utilize human recombinant MIF (rMIF) to significantly (P \u3c 0.01) enhance its endogenous biofilm formation. Our in vivo studies demonstrate that utilizing a small-molecular-weight inhibitor targeting MIF\u27s tautomerase activity (SCD-19) significantly reduces the inflammatory response in a murine pulmonary chronic P. aeruginosa model. In addition, we show that in in vitro experiments, pretreatment of P. aeruginosa with rMIF is associated with reduced bacterial killing by tobramycin. Our novel findings support the concept of an anti-MIF strategy that targets this enzymatic activity as a potential future antibacterial therapeutic approach.-Tynan, A., Mawhinney, L., Armstrong, M. E., O\u27Reilly, C., Kennedy, S., Caraher, E., Jülicher, K., O\u27Dwyer, D., Maher, L., Schaffer, K., Fabre, A., McKone, E. F., Leng, L., Bucala, R., Bernhagen, J., Cooke, G., Donnelly, S. C. Macrophage migration inhibitory factor enhances Pseudomonas aeruginosa biofilm formation, potentially contributing to cystic fibrosis pathogenesis
A preliminary design methodology for fatigue life prediction of polymer composites for tidal turbine blades
Journal articleTidal turbine blades experience significant fatigue cycles during operation and it is expected that fatigue strength will be a major consideration in their design. Glass fibre reinforced polymers are a candidate low-cost material for this application. This article presents a methodology for preliminary fatigue design of glass fibre reinforced polymer tidal turbine blades. The methodology combines: (a) a hydrodynamic model for calculation of local distributions of fluid-blade forces; (b) a finite element structural model for prediction of blade strain distributions; (c) a fatigue damage accumulation model, which incorporates mean stress effects; and (d) uniaxial fatigue testing of two candidate glass fibre reinforced polymer materials (for illustrative purposes). The methodology is applied here for the preliminary design of a three-bladed tidal turbine concept, including tower shadow effects, and comparative assessment of pitch-and stall-regulated control with respect to fatigue performance.peer-reviewe
A review of water injection applied on the internal combustion engine
As a promising technique to reduce the in-cylinder temperature and exhaust temperature, mitigate combustion knock, improve combustion phasing and decrease NOx emissions, water injection applied on different types of engines has attracted extensive attention in recent years to further improve fuel economy and fulfill stricter emission regulations. Since mechanisms of water injection with different aims are distinct, benefits on engine performances and emissions are also varied. This paper intends to give a comprehensive review of water injection applied on the internal combustion engine. First, different implementations of water injection are introduced, followed by a detailed description of water evaporation processes. Second, mechanisms of the in-cylinder combustion process with water addition are discussed with respect to the heat release rate, knock tendency and emission formations. Next, recent works of water injection applied on different kinds of engines are reviewed with special attentions given to the comparisons of different implementations and injection parameters. Furthermore, comparisons and combinations of water injection with other advanced engine techniques are summarized. Finally, critical issues of current research on the water injection technique are discussed.</p
Speciation control during Suzuki-Miyaura cross-coupling of haloaryl and haloalkenyl MIDA boronic esters
Boronic acid solution speciation can be controlled during the Suzuki-Miyaura cross-coupling of haloaryl MIDA boronic esters to enable the formal homologation of boronic acid derivatives. The reaction is contingent upon control of the basic biphase and is thermodynamically driven: temperature control provides highly chemoselective access to either BMIDA adducts at room temperature or BPin products at elevated temperature. Control experiments and solubility analyses have provided some insight into the mechanistic operation of the formal homologation process
High concordance of BRAF mutational status in matched primary and metastatic melanoma
Background: Techniques for the accurate identification of activating mutations of BRAF in metastatic melanoma are of great clinical importance, due to the availability of targeted therapies for these tumours. There is uncertainty regarding the frequency with which BRAF status differs between primary and metastatic sites. Methods: Between 2011 and 2016, 219 melanoma cases underwent BRAF testing in our institution. In 53 of these, paired primary and metastatic specimens were available for PCR and immunohistochemical evaluation. Results: 52 out of 53 cases (98%) showed concordant BRAF status between primary and metastatic site by IHC. In one case, a metastasis and its matched primary were positive by IHC but the metastasis was negative on PCR. On further investigation, PCR was positive in the primary and repeat PCR in the metastasis was positive, following macrodissection. Conclusions: Our results suggest that discordance of BRAF mutational status between primaries and metastases is a rare occurrence. In one case, immunohistochemistry provided strong evidence that initial PCR testing had provided a false negative result due to low tumour volume. Thus, in cases where tissue is difficult to obtain from a metastasis or unavailable, the primary tumour can be used with confidence
Interrogating Pd(II) anion metathesis using a bifunctional chemical probe : a transmetalation switch
Ligand metathesis of Pd(II) complexes is mechanistically essential for cross-coupling. We present a study of halide→OH anion metathesis of (Ar)Pd(II) complexes using vinylBPin as a bifunctional chemical probe with Pd(II)-dependent cross-coupling pathways. We identify the variables that profoundly impact this event and allow control to be leveraged. This then allows control of cross-coupling pathways via promotion or inhibition of organoboron transmetalation, leading to either Suzuki-Miyaura or Mizoroki-Heck products. We show how this transmetalation switch can be used to synthetic gain in a cascade cross-coupling/Diels-Alder reaction, delivering borylated or non-borylated carbocycles, including steroid-like scaffolds
Commonalities and differences in injured patient experiences of accessing and receiving quality injury care:a qualitative study in three sub-Saharan African countries
Objectives: To understand commonalities and differences in injured patient experiences of accessing and receiving quality injury care across three lower-income and middle-income countries. Design: A qualitative interview study. The interviews were audiorecorded, transcribed and thematically analysed. Setting: Urban and rural settings in Ghana, South Africa and Rwanda. Participants: 59 patients with musculoskeletal injuries. Results: We found five common barriers and six common facilitators to injured patient experiences of accessing and receiving high-quality injury care. The barriers encompassed issues such as service and treatment availability, transportation challenges, apathetic care, individual financial scarcity and inadequate health insurance coverage, alongside low health literacy and information provision. Facilitators included effective information giving and informed consent practices, access to health insurance, improved health literacy, empathetic and responsive care, comprehensive multidisciplinary management and discharge planning, as well as both informal and formal transportation options including ambulance services. These barriers and facilitators were prevalent and shared across at least two countries but demonstrated intercountry and intracountry (between urbanity and rurality) variation in thematic frequency. Conclusion: There are universal factors influencing patient experiences of accessing and receiving care, independent of the context or healthcare system. It is important to recognise and understand these barriers and facilitators to inform policy decisions and develop transferable interventions aimed at enhancing the quality of injury care in sub-Saharan African nations
Adenoviral vectored vaccination protects against Crimean-Congo Haemorrhagic Fever disease in a lethal challenge model.
BACKGROUND: The tick-borne bunyavirus, Crimean-Congo Haemorrhagic Fever virus (CCHFV), can cause severe febrile illness in humans and has a wide geographic range that continues to expand due to tick migration. Currently, there are no licensed vaccines against CCHFV for widespread usage. METHODS: In this study, we describe the preclinical assessment of a chimpanzee adenoviral vectored vaccine (ChAdOx2 CCHF) which encodes the glycoprotein precursor (GPC) from CCHFV. FINDINGS: We demonstrate here that vaccination with ChAdOx2 CCHF induces both a humoral and cellular immune response in mice and 100% protection in a lethal CCHF challenge model. Delivery of the adenoviral vaccine in a heterologous vaccine regimen with a Modified Vaccinia Ankara vaccine (MVA CCHF) induces the highest levels of CCHFV-specific cell-mediated and antibody responses in mice. Histopathological examination and viral load analysis of the tissues of ChAdOx2 CCHF immunised mice reveals an absence of both microscopic changes and viral antigen associated with CCHF infection, further demonstrating protection against disease. INTERPRETATION: There is the continued need for an effective vaccine against CCHFV to protect humans from lethal haemorrhagic disease. Our findings support further development of the ChAd platform expressing the CCHFV GPC to seek an effective vaccine against CCHFV. FUNDING: This research was supported by funding from the Biotechnology and Biological Sciences Research Council (UKRI-BBSRC) [BB/R019991/1 and BB/T008784/1]
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