287 research outputs found

    The erosion-corrosion behaviour of copper-nickel alloys

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    The research focuses on an investigation of the erosion-corrosion behaviour of Cu-Ni-base alloys in aqueous environments. The principal objectives of the research were to examine the fundamental mechanisms of the erosion-corrosion attack. The work was focused on a standard Cu-10%Ni alloy that is used extensively in a variety of marine industries and on Marinel alloy, which is a high strength precipitation-hardened copper-nickel alloy. Erosion-corrosion tests were carried out for exposure times up to 72 hours, in a solid free 3.5% NaCl solution impinging at velocities of 2.38-86 m/sec, (Re=4500-86000), at temperatures of 19°C and 35°C. The overall erosion-corrosion behaviour and the direct corrosion component were monitored using gravimetric and electrochemical-monitoring techniques. Contributes from mechanical erosions were assessed by cathodically protecting specimens under impingement conditions. The research also considered the influence of various parameters such as temperature, time, velocity, salinity variations, and impingement angle. The extent and morphology of material deterioration and protective film formation under various environmental conditions were assessed, utilizing surface profiling equipment and light optical and scanning electron microscopy. The work has quantified the complex contributions of corrosion, erosion and synergy to the overall erosion-corrosion material loss. An important finding was the substantial superior erosion-corrosion resistance of Marinel compared to the standard Cu-10%Ni, with interesting effects of impinging velocity and time of exposure being observed. Also this work provided some clear evidence of significant potential benefits in terms of erosion-corrosion resistance, obtained by the exposure of Marinel at the elevated temperature

    Detailed molecular characterisation of acute myeloid leukaemia with a normal karyotype using targeted DNA capture

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    This work is licensed under a Creative Commons Attribution 3.0 Unported License.-- et al.Advances in sequencing technologies are giving unprecedented insights into the spectrum of somatic mutations underlying acute myeloid leukaemia with a normal karyotype (AML-NK). It is clear that the prognosis of individual patients is strongly influenced by the combination of mutations in their leukaemia and that many leukaemias are composed of multiple subclones, with differential susceptibilities to treatment. Here, we describe a method, employing targeted capture coupled with next-generation sequencing and tailored bioinformatic analysis, for the simultaneous study of 24 genes recurrently mutated in AML-NK. Mutational analysis was performed using open source software and an in-house script (Mutation Identification and Analysis Software), which identified dominant clone mutations with 100% specificity. In each of seven cases of AML-NK studied, we identified and verified mutations in 2-4 genes in the main leukaemic clone. Additionally, high sequencing depth enabled us to identify putative subclonal mutations and detect leukaemia-specific mutations in DNA from remission marrow. Finally, we used normalised read depths to detect copy number changes and identified and subsequently verified a tandem duplication of exons 2-9 of MLL and at least one deletion involving PTEN. This methodology reliably detects sequence and copy number mutations, and can thus greatly facilitate the classification, clinical research, diagnosis and management of AML-NK.We acknowledge the use of the National Institute of Health Research (NIHR) Biomedical Research Centre, University of Cambridge. We thank Drs J Craig and C Crawley of Cambridge University NHS Hospitals trust for allowing us to approach their patients for samples. GV is funded by a Wellcome Trust Senior Fellowship in Clinical Science. Work in GV’s laboratory is also funded by Leukaemia Lymphoma Research and the Kay Kendal Leukaemia Fund.Peer Reviewe

    Dynamic variation of CD5 surface expression levels within individual chronic lymphocytic leukemia clones.

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    Chronic lymphocytic leukemia (CLL) is characterized by the accumulation of clonally derived mature CD5high B cells; however, the cellular origin of CLL is still unknown. Patients with CLL also harbor variable numbers of CD5low B cells, but the clonal relationship of these cells to the bulk disease is unknown and can have important implications for monitoring, treating, and understanding the biology of CLL. Here, we use B-cell receptors (BCRs) as molecular barcodes to first show by single-cell BCR sequencing that the great majority of CD5low B cells in the blood of CLL patients are clonally related to CD5high CLL B cells. We investigate whether CD5 state switching was likely to occur continuously as a common event or as a rare event in CLL by tracking somatic BCR mutations in bulk CLL B cells and using them to reconstruct the phylogenetic relationships and evolutionary history of the CLL in four patients. Using statistical methods, we show that there is no parsimonious route from a single or low number of CD5low switch events to the CD5high population, but rather, large-scale and/or dynamic switching between these CD5 states is the most likely explanation. The overlapping BCR repertoires between CD5high and CD5low cells from CLL patient peripheral blood reveal that CLL exists in a continuum of CD5 expression. The major proportion of CD5low B cells in patients are leukemic, thus identifying CD5low B cells as an important component of CLL, with implications for CLL pathogenesis, clinical monitoring, and the development of anti-CD5-directed therapies

    Phosphorus Magnetic Resonance Spectroscopy (31P MRS) and cardiovascular disease: The importance of energy

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    Background and Objectives: The heart is the organ with the highest metabolic demand in the body, and it relies on high ATP turnover and efficient energy substrate utilisation in order to function normally. The derangement of myocardial energetics may lead to abnormalities in cardiac metabolism, which herald the symptoms of heart failure (HF). In addition, phosphorus magnetic resonance spectroscopy (31P MRS) is the only available non-invasive method that allows clinicians and researchers to evaluate the myocardial metabolic state in vivo. This review summarises the importance of myocardial energetics and provides a systematic review of all the available research studies utilising 31P MRS to evaluate patients with a range of cardiac pathologies. Materials and Methods: We have performed a systematic review of all available studies that used 31P MRS for the investigation of myocardial energetics in cardiovascular disease. Results: A systematic search of the Medline database, the Cochrane library, and Web of Science yielded 1092 results, out of which 62 studies were included in the systematic review. The 31P MRS has been used in numerous studies and has demonstrated that impaired myocardial energetics is often the beginning of pathological processes in several cardiac pathologies. Conclusions: The 31P MRS has become a valuable tool in the understanding of myocardial metabolic changes and their impact on the diagnosis, risk stratification, and prognosis of patients with cardiovascular diseases

    The combined effect of erythropoietin and granulocyte macrophage colony stimulating factor on liver regeneration after major hepatectomy in rats

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    <p>Abstract</p> <p>Background</p> <p>The liver presents a remarkable capacity for regeneration after hepatectomy but the exact mechanisms and mediators involved are not yet fully clarified. Erythropoietin (EPO) and Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) have been shown to promote liver regeneration after major hepatectomy.</p> <p>Aim of this experimental study is to compare the impact of exogenous administration of EPO, GM-CSF, as well as their combination on the promotion of liver regeneration after major hepatectomy.</p> <p>Methods</p> <p>Wistar rats were submitted to 70% major hepatectomy. The animals were assigned to 4 experimental groups: a control group (n = 21) that received normal saline, an EPO group (n = 21), that received EPO 500 IU/kg, a GM-CSF group (n = 21) that received 20 mcg/kg of GM-CSF and a EPO+GMCSF group (n = 21) which received a combination of the above. Seven animals of each group were killed on the 1st, 3rd and 7th postoperative day and their remnant liver was removed to evaluate liver regeneration by immunochemistry for PCNA and Ki 67.</p> <p>Results</p> <p>Our data suggest that EPO and GM-CSF increases liver regeneration following major hepatectomy when administered perioperatively. EPO has a more significant effect than GM-CSF (p < 0.01). When administering both, the effect of EPO seems to fade as EPO and GM-CSF treated rats have decreased regeneration compared to EPO administration alone (p < 0.01).</p> <p>Conclusion</p> <p>EPO, GM-CSF and their combination enhance liver regeneration after hepatectomy in rats when administered perioperatively. However their combination has a weaker effect on liver regeneration compared to EPO alone. Further investigation is needed to assess the exact mechanisms that mediate this finding.</p
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