597 research outputs found

    Machine learning approach using MLP and SVM algorithms for the fault prediction of a centrifugal pump in the oil and gas industry

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    The demand for cost-effective, reliable and safe machinery operation requires accurate fault detection and classification to achieve an efficient maintenance strategy and increase performance. Furthermore, in strategic sectors such as the oil and gas industry, fault prediction plays a key role to extend component lifetime and reduce unplanned equipment thus preventing costly breakdowns and plant shutdowns. This paper presents the preliminary development of a simple and easy to implement machine learning (ML) model for early fault prediction of a centrifugal pump in the oil and gas industry. The data analysis is based on real-life historical data from process and equipment sensors mounted on the selected machinery. The raw sensor data, mainly from temperature, pressure and vibrations probes, are denoised, pre-processed and successively coded to train the model. To validate the learning capabilities of the ML model, two different algorithms-the Support Vector Machine (SVM) and the Multilayer Perceptron (MLP)-are implemented in KNIME platform. Based on these algorithms, potential faults are successfully recognized and classified ensuring good prediction accuracy. Indeed, results from this preliminary work show that the model allows us to properly detect the trends of system deviations from normal operation behavior and generate fault prediction alerts as a maintenance decision support system for operatives, aiming at avoiding possible incoming failures

    The effect of prime-site occupancy on the hepatitis C virus NS3 protease structure.

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    We recently reported a new class of inhibitors of the chymotrypsin-like serine protease NS3 of the hepatitis C virus. These inhibitors exploit the binding potential of the S′ site of the protease, which is not generally used by the natural substrates. The effect of prime-site occupancy was analyzed by circular dichroism spectroscopy and limited proteolysis-mass spectrometry. Generally, nonprime inhibitors cause a structural change in NS3. Binding in the S′ site produces additional conformational changes with different binding modes, even in the case of the NS3/4A cofactor complex. Notably, inhibitor binding either in the S or S′ site also has profound effects on the stabilization of the protease. In addition, the stabilization propagates to regions not in direct contact with the inhibitor. In particular, the N-terminal region, which according to structural studies is endowed with low structural stability and is not stabilized by nonprime inhibitors, was now fully protected from proteolytic degradation. From the perspective of drug design, P-P′ inhibitors take advantage of binding pockets, which are not exploited by the natural HCV substrates; hence, they are an entry point for a novel class of NS3/4A inhibitors. Here we show that binding of each inhibitor is associated with a specific structural rearrangement. The development of a range of inhibitors belonging to different classes and an understanding of their interactions with the protease are required to address the issue of the most likely outcome of viral protease inhibitor therapy, that is, viral resistanc

    Partial purification and MALDI-TOF MS analysis of UN1, a tumor antigen membrane glycoprotein.

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    UN1 is a membrane glycoprotein that is expressed in immature human thymocytes, a subpopulation of peripheral T lymphocytes, the HPB acute lymphoblastic leukemia (ALL) T-cell line and fetal thymus. We previously reported the isolation of a monoclonal antibody (UN1 mAb) recognizing the UN1 protein that was classified as "unclustered" at the 5th and 6th International Workshop and Conference on Human Leukocyte Differentiation Antigens. UN1 was highly expressed in breast cancer tissues and was undetected in non-proliferative lesions and in normal breast tissues, indicating a role for UN1 in the development of a tumorigenic phenotype of breast cancer cells. In this study, we report a partial purification of the UN1 protein from HPB-ALL T cells by anion-exchange chromatography followed by immunoprecipitation with the UN1 mAb and MALDI-TOF MS analysis. This analysis should assist in identifying the amino acid sequence of UN

    Anomaly Detection for Diagnosing Failures in a Centrifugal Compressor Train

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    Predicting machine failures is of the utmost importance in industrial systems as it can turn expensive crashes and repair costs into affordable maintenance costs. To this end, this paper presents preliminary work for detecting failures in a centrifugal compressor train based on sensorial data. We show the detection capabilities of a two-step process consisting of: (1) a preprocessing step to reduce the dimensionality of the input data using Principal Component Analysis, and (2) an anomaly detection step using the Mahalanobis distance to detect anomalous observations on the sensors' data. The experiments using real-world data demonstrate the feasibility of our approach and the ability of the method to detect the failures eight days in advance

    Carotid beta stiffness association with thyroid function

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    Background: Thyroid hormone modulation of cardiovascular function has been associated with cardiovascular disease. Recent evidence suggests that free thyroxine (FT4) levels are associated with an increase in systemic arterial stiffness, but little is known about the effects of FT4 at the local level of the common carotid artery. β-stiffness index is a local elastic parameter usually determined by carotid ultrasound imaging. Methods: We conducted a cross-sectional analysis in the ProgeNIA cohort, including 4846 subjects across a broad age range. For the purpose of this study, we excluded subjects with increased thyrotropin (TSH) levels and those treated with levothyroxine or thyrostatic. We assessed β stiffness, strain, wall–lumen ratio, carotid cross-sectional area (CSA), and stress and flow in the right common carotid artery. We tested whether FT4, heart rate, and their interactions were associated with carotid parameters. Results: FT4 was positively and independently associated with β stiffness index (β = 0.026, p = 0.041), and had a negative association with strain (β = −0.025, p = 0.009). After adding heart rate and the interaction between FT4 and heart rate to the model, FT4 was still associated with the β stiffness index (β = 0.186, p = 0.06), heart rate was positively associated with the stiffness index (β = 0.389, p < 0.001) as well as their interaction (β = 0.271, p = 0.007). Conclusion: This study suggests that higher FT4 levels increase arterial stiffness at the common carotid level, consistent with a detrimental effect on elastic arteries. The effect of FT4 is likely to be primarily attributable to its effect on heart rate

    Random laser action in self-organized para-sexiphenyl nanofibers grown by hot-wall epitaxy

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    We report on the observation of amplified spontaneous emission and random lasing in self-organized crystalline para-sexiphenyl nanofibers. Using subpicosecond excitation, a lasing threshold is observed on the 0-1 emission band near 425 nm at excitation fluences as low as 0.5 muJ/cm(2) (6x10(16) cm(-3) equivalent density), near the onset of density-dependent recombination processes. The dependence of the nonlinear emission spectrum on both the pump intensity and position of the excitation area are attributed to the interplay between random lasing and amplified spontaneous emission occurring along the nanofibers

    New evidence of mis 3 relative sea level changes from the messina strait, Calabria (Italy)

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    none12Investigation of sea-level positions during the highly-dynamic Marine Isotope Stage 3 (MIS 3: 29–61 kyrs BP) proves difficult because: (i) in stable and subsiding areas, coeval coastal sediments are currently submerged at depths of few to several tens of meters below the present sea level; (ii) in uplifting areas, the preservation of geomorphic features and sedimentary records is limited due to the erosion occurred during the Last Glacial Maximum (LGM) with sea level at a depth of −130 m, followed by marine transgression that determined the development of ravinement surfaces. This study discusses previous research in the Mediterranean and elsewhere, and describes new fossiliferous marine deposits overlaying the metamorphic bedrock at Cannitello (Calabria, Italy). Radiocarbon ages of marine shells (about 43 kyrs cal BP) indicate that these deposits, presently between 28 and 30 m above sea level, formed during MIS 3.1. Elevation correction of the Cannitello outcrops (considered in an intermediate-to-far-field position with respect to the ice sheet) with the local vertical tectonic rate and Glacial Isostatic Adjustment (GIA) rate allows the proposal of a revision of the eustatic depth for this highstand. Our results are consistent with recently proposed estimates based on a novel ice sheet modelling technique.openAntonioli F.; Calcagnile L.; Ferranti L.; Mastronuzzi G.; Monaco C.; Orru P.; Quarta G.; Pepe F.; Scardino G.; Scicchitano G.; Stocchi P.; Taviani M.Antonioli, F.; Calcagnile, L.; Ferranti, L.; Mastronuzzi, G.; Monaco, C.; Orru, P.; Quarta, G.; Pepe, F.; Scardino, G.; Scicchitano, G.; Stocchi, P.; Taviani, M

    Dietary Supplementation of Hericium erinaceus Increases Mossy Fiber-CA3 Hippocampal Neurotransmission and Recognition Memory in Wild-Type Mice

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    Hericium erinaceus (Bull.) Pers. is a medicinal mushroom capable of inducing a large number of modulatory effects on human physiology ranging from the strengthening of the immune system to the improvement of cognitive functions. In mice, dietary supplementation with H. erinaceus prevents the impairment of spatial short-term and visual recognition memory in an Alzheimer model. Intriguingly other neurobiological effects have recently been reported like the effect on neurite outgrowth and differentiation in PC12 cells. Until now no investigations have been conducted to assess the impact of this dietary supplementation on brain function in healthy subjects. Therefore, we have faced the problem by considering the effect on cognitive skills and on hippocampal neurotransmission in wild-type mice. In wild-type mice the oral supplementation with H. erinaceus induces, in behaviour test, a significant improvement in the recognition memory and, in hippocampal slices, an increase in spontaneous and evoked excitatory synaptic current in mossy fiber-CA3 synapse. In conclusion, we have produced a series of findings in support of the concept that H. erinaceus induces a boost effect onto neuronal functions also in nonpathological conditions

    Colorectal cancer early detection in stool samples tracing CPG islands methylation alterations affecting gene expression

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    Colorectal cancer (CRC) is a major cause of cancer mortality. Early diagnosis is relevant for its prevention and treatment. Since DNA methylation alterations are early events in tumourigenesis and can be detected in cell-free DNA, they represent promising biomarkers for early CRC diagnosis through non-invasive methods. In our previous work, we identified 74 early altered CpG islands (CGIs) associated with genes involved in cell cross-talking and cell signalling pathways. The aim of this work was to test whether methylation-based biomarkers could be detected in non-invasive matrices. Our results confirmed methylation alterations of GRIA4 and VIPR2 in CRC tissues, using MethyLight, as well as in stool samples, using a much more sensitive technique as droplet digital PCR. Furthermore, we analysed expression levels of selected genes whose promoter CGIs were hypermethylated in CRC, detecting downregulation at mRNA and protein levels in CRC tissue for GRIA4, VIPR2, SPOCK1 and SLC6A3. Most of these genes were already lowly expressed in colon normal tissues supporting the idea that cancer DNA methylation targets genes already barely expressed in the matched normal tissues. Our study suggests GRIA4 and VIPR2 as biomarkers for early CRC diagnosis using stool samples and confirms downregulation of genes hypermethylated in CRC
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