382 research outputs found
Multi-scale investigation of uranium attenuation by arsenic at an abandoned uranium mine, South Terras
Detailed mineralogical analysis of soils from the UK’s historical key uranium mine, South Terras, was performed to elucidate the mechanisms of uranium degradation and migration in the 86 years since abandonment. Soils were sampled from the surface (0 – 2 cm) and near-surface (25 cm) in two distinct areas of ore processing activities. Bulk soil analysis revealed the presence of high concentrations of uranium (<1690 ppm), arsenic (1830 ppm) and beryllium (~250 ppm), suggesting pedogenic weathering of the country rock and ore extraction processes to be the mechanisms of uranium ore degradation. Micro-focus XRF analysis indicated the association of uranium with arsenic, phosphate and copper; µ-XRD data confirmed the presence of the uranyl-arsenate minerals metazeunerite (Cu(UO2)2(AsO4)2·8H2O) and metatorbernite (Cu(UO2)2(PO4)2·8H2O) to be ubiquitous. Our data are consistent with the solid solution of these two uranyl-mica minerals, not previously observed at uranium-contaminated sites. Crystallites of uranyl-mica minerals were observed to coat particles of jarosite and muscovite, suggesting that the mobility of uranium from degraded ores is attenuated by co-precipitation with arsenic and phosphate, which was not previously considered at this site
An Approach to Mapping the Development of Professional Skills in a Structural Engineering Programme
Engineers of the future will be presented with complicated, complex problems and their role in the development of sustainable solutions to global problems will become even more critical. Recent literature highlights the need for the development of a set of professional skills in order to address these challenges. These skills include technical, non-technical and attitudinal skills. This paper describes a case study of a whole-of-programme review of teaching and assessment of professional skills in a structural engineering programme. In a systematic process, lecturing staff mapped the modules they teach against a set of professional skills, which were distilled from literature review. The programme map was then analysed to provide insight into the depth to which professional skills are being taught and assessed. This analysis underpinned a review of the teaching of professional skills and led to the identification of both gaps and opportunities to introduce new learning outcomes, teaching activities and assessment techniques
Promiscuous recognition of MR1 drives self-reactive Mucosal-Associated Invariant T cell responses
Automated mineralogical profiling of soils as an indicator of local bedrock lithology: a tool for predictive forensic geolocation
This is the author accepted manuscript. The final version is available from Geological Society of London via the DOI in this record The use of soil evidence to identify an unknown location is a powerful tool to determine the provenance of an item in an investigation. We are particularly interested in the use of these indicators in nuclear forensic cases, whereby identification of locations associated with, for example, a smuggled nuclear material, may be used to indicate the provenance of a find. The use of soil evidence to identify an unknown location relies on understanding and predicting how soils vary in composition depending on their geological/geographical setting. In this study, compositional links between the mineralogy of 40 soils and the underlying bedrock geology, as documented in local-scale geological maps, were established. The soil samples were collected from locations with broadly similar climate and land use across a range of geological settings in a ‘test bed’ 3500 km2 area of SW England. In this region, the soils formed through chemical weathering of the bedrock, representing a worst case scenario for this type of forensic geolocation owing to the high degree of alteration of the parent rock during soil formation. The mineralogy was quantified using automated scanning electron microscopy–energy dispersive X-ray spectrometry analysis based on QEMSCAN technology. Soil mineralogy and texture as measured using this technique are consistent with the underlying geology as indicated by regional-scale geological mapping. Furthermore, differences between individual units of the same bedrock lithology, such as different granites, were identified by examining trace mineralogical signatures. From an investigative viewpoint, this demonstrated that rapid automated mineral profiling of soil samples could be used, in conjunction with readily available geological mapping or similar datasets, to provide indication of the areas from which a soil sample of unknown origin could, or could not, have been sourced
Chronic Porphyromonas gingivalis infection accelerates the occurrence of age-related granules in ApoE-/- mice brains
This study explored the origin of age-related granules in the apolipoprotein E gene knockout (ApoE−/−) B6 background mice brains following chronic gingival infection with Porphyromonas gingivalis for 24 weeks. Intracerebral localization of P. gingivalis was detected by fluorescence in situ hybridization (FISH) and its protease by immunohistochemistry. The age-related granules were observed by periodic acid–Schiff (PAS), silver impregnation, and immunostaining. FISH showed intracerebral dissemination of P. gingivalis cells (p = 0.001). PAS and silver impregnation demonstrated the presence of larger inclusions restricted to the CA1, CA2, and dentate gyrus sectors of the hippocampus. A specific monoclonal antibody to bacterial peptidoglycan detected clusters of granules with variable sizes in mice brains infected with P. gingivalis (p = 0.004), and also highlighted areas of diffuse punctate staining equating to physical tissue damage. Mouse immunoglobulin G was observed in the capillaries of the cerebral parenchyma of all P. gingivalis–infected brains (p = 0.001), and on pyramidal neurons in some severely affected mice, compared with the sham-infected mice. Gingipains was also observed in microvessels of the hippocampus in the infected mice. This study supports the possibility of early appearance of age-related granules in ApoE−/− mice following inflammation-mediated tissue injury, accompanied by loss of cerebral blood-brain barrier integrity
Bypass surgery versus stenting for the treatment of multivessel disease in patients with unstable angina compared with stable angina
BACKGROUND: Earlier reports have shown that the outcome of balloon angioplasty or bypass surgery in unstable angina is less favorable than in stable angina. Recent improvements in percutaneous treatment (stent implantation) and bypass surgery (arterial grafts) warrant reevaluation of the relative merits of either technique in treatment of unstable angina. Methods and Results- Seven hundred fifty-five patients with stable angina were randomly assigned to coronary stenting (374) or bypass surgery (381), and 450 patients with unstable angina were randomly assigned to coronary stenting (226) or bypass surgery (224). All patients had multivessel disease considered to be equally treatable by either technique. Freedom from major adverse events, including death, myocardial infarction, and cerebrovascular events, at 1 year was not different in unstable patients (91.2% versus 88.9%) and stable patients (90.4% versus 92.6%) treated, respectively, with coronary stenting or bypass surgery. Freedom from repeat revascularization at 1 year was similar in unstable and stable angina treated with stenting (79.2% versus 78.9%) or bypass surgery (96.3% versus 96%) but was significantly higher in both unstable and stable patients treated with stenting (16.8% versus 16.9%) compared with bypass surgery (3.6% versus 3.5%). Neither the difference in costs between stented or bypassed stable or unstable angina (3627) nor the cost-effectiveness was significantly different at 1 year. CONCLUSIONS: There was no difference in rates of death, myocardial infarction, and cerebrovascular event at 1 year in patients with unstable angina and multivessel disease treated with either stented angioplasty or bypass surgery compared with patients with stable angina. The rate of repeat revascularization of both unstable and stable angina was significantly higher in patients with stents
Polyaniline nanofibres as templates for the covalent immobilisation of biomolecules
The attachment of antibodies onto polyaniline nanofibres using covalent chemistry was investigated for the first time. Polyaniline nanofibres were functionalised post-polymerisation to attach either amide or carboxylic acid side-groups. These templates could then be further modified to attach antibodies, specifically in this instance mouse immunoglobulin G (IgG). The resultant conjugates were characterised using a variety of techniques including infrared, UV–vis and Raman spectroscopy. Conjugates were then used to detect secondary antibodies (anti-IgG). Results from enzyme-linked immunoassay studies indi- cate successful binding of the antibody to the polyaniline nanofibres. Carboxyl functionalised polyaniline nanofibres are shown in particular to decrease non-specific binding in the immunoassay. Direct electri- cal communication between polyaniline nanofibres covalently linked to peroxidase-labelled antibodies was observed during cyclic voltammetry, which demonstrates their potential for further development as nano-dimensional immunosensors
NR4A Receptors Differentially Regulate NF-κB Signaling in Myeloid Cells
Dysregulation of inflammatory responses is a hallmark of multiple diseases such as atherosclerosis and rheumatoid arthritis. As constitutively active transcription factors, NR4A nuclear receptors function to control the magnitude of inflammatory responses and in chronic inflammatory disease can be protective or pathogenic. Within this study, we demonstrate that TLR4 stimulation using the endotoxin lipopolysaccharide (LPS) rapidly enhances NR4A1–3 expression in human and murine, primary and immortalized myeloid cells with concomitant gene transcription and protein secretion of MIP-3α, a central chemokine implicated in numerous pathologies. Deficiency of NR4A2 and NR4A3 in human and murine myeloid cells reveals that both receptors function as positive regulators of enhanced MIP-3α expression. In contrast, within the same cell types and conditions, altered NR4A activity leads to suppression of LPS-induced MCP-1 gene and protein expression. An equivalent pattern of inflammatory gene regulation is replicated in TNFα-treated myeloid cells. We show that NF-κB is the critical regulator of NR4A1–3, MIP-3α, and MCP-1 during TLR4 stimulation in myeloid cells and highlight a parallel mechanism whereby NR4A activity can repress or enhance NF-κB target gene expression simultaneously. Mechanistic insight reveals that NR4A2 does not require DNA-binding capacity in order to enhance or repress NF-κB target gene expression simultaneously and establishes a role for NF-κB family member Relb as a novel NR4A target gene involved in the positive regulation of MIP-3α. Thus, our data reveal a dynamic role for NR4A receptors concurrently enhancing and repressing NF-κB activity in myeloid cells leading to altered transcription of key inflammatory mediators
Depression, lifestyle factors and cognitive function in people living with HIV and comparable HIV-negative controls
Objectives
We investigated whether differences in cognitive performance between people living with HIV (PLWH) and comparable HIV‐negative people were mediated or moderated by depressive symptoms and lifestyle factors.
Methods
A cross‐sectional study of 637 ‘older’ PLWH aged ≥ 50 years, 340 ‘younger’ PLWH aged < 50 years and 276 demographically matched HIV‐negative controls aged ≥ 50 years enrolled in the Pharmacokinetic and Clinical Observations in People over Fifty (POPPY) study was performed. Cognitive function was assessed using a computerized battery (CogState). Scores were standardized into Z‐scores [mean = 0; standard deviation (SD) = 1] and averaged to obtain a global Z‐score. Depressive symptoms were evaluated via the Patient Health Questionnaire (PHQ‐9). Differences between the three groups and the effects of depression, sociodemographic factors and lifestyle factors on cognitive performance were evaluated using median regression. All analyses accounted for age, gender, ethnicity and level of education.
Results
After adjustment for sociodemographic factors, older and younger PLWH had poorer overall cognitive scores than older HIV‐negative controls (P < 0.001 and P = 0.006, respectively). Moderate or severe depressive symptoms were more prevalent in both older (27%; P < 0.001) and younger (21%; P < 0.001) PLWH compared with controls (8%). Depressive symptoms (P < 0.001) and use of hashish (P = 0.01) were associated with lower cognitive function; alcohol consumption (P = 0.02) was associated with better cognitive scores. After further adjustment for these factors, the difference between older PLWH and HIV‐negative controls was no longer significant (P = 0.08), while that between younger PLWH and older HIV‐negative controls remained significant (P = 0.01).
Conclusions
Poorer cognitive performances in PLWH compared with HIV‐negative individuals were, in part, mediated by the greater prevalence of depressive symptoms and recreational drug use reported by PLWH
Connective tissue growth factor(CCN2), a pathogenic factor in diabetic nephropathy. What does it do? How does it do it?
Connective tissue growth factor (CTGF/CCN2) is a member of the CCN family of matricellular proteins. Its expression is induced by a number of factors including TGF-β. It has been associated with fibrosis in various tissues including the kidney. Diabetic nephropathy (DN) develops in about 30% of patients with diabetes and is characterized by thickening of renal basement membranes, fibrosis in the glomerulus (glomerulosclerosis), tubular atrophy and interstitial fibrosis, all of which compromise kidney function. This review examines changes in CTGF expression in the kidney in DN, the effects they have on glomerular mesangial and podocyte cells and the tubulointerstitium, and how these contribute to driving fibrotic changes in the disease. CTGF can bind to several other growth factors modifying their function. CTGF is also able to interact with receptors on cells, including integrins, tyrosine receptor kinase A (TrkA), low density lipoprotein receptor-related protein (LRP) and heparan sulphate proteoglycans. These interactions, the intracellular signalling pathways they activate, and the cellular responses evoked are reviewed. CTGF also induces the expression of chemokines which themselves have pharmacological actions on cells. CTGF may prompt some responses by acting through several different mechanisms, possibly simultaneously. For example, CTGF is often described as an effector of TGF-β. It can promote TGF-β signalling by binding directly to the growth factor, promoting its interaction with the TGF-β receptor; by triggering intracellular signalling on binding the TrkA receptor, which leads to the transcriptional repression of Smad7, an inhibitor of the TGF-β signalling pathway; and by binding to BMP-7 whose own signalling pathway opposing TGF-β is inhibited, leading to enhanced TGF-β signalling
- …