1,009 research outputs found

    Analysis of process variables via CFD to evaluate the performance of a FCC riser

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    Feedstock conversion and yield products are studied through a 3D model simulating the main reactor of the fluid catalytic cracking (FCC) process. Computational fluid dynamic (CFD) is used with Eulerian-Eulerian approach to predict the fluid catalytic cracking behavior. The model considers 12 lumps with catalyst deactivation by coke and poisoning by alkaline nitrides and polycyclic aromatic adsorption to estimate the kinetic behavior which, starting from a given feedstock, produces several cracking products. Different feedstock compositions are considered. The model is compared with sampling data at industrial operation conditions. The simulation model is able to represent accurately the products behavior for the different operating conditions considered. All the conditions considered were solved using a solver ANSYS CFX 14.0. The different operation process variables and hydrodynamic effects of the industrial riser of a fluid catalytic cracking (FCC) are evaluated. Predictions from the model are shown and comparison with experimental conversion and yields products are presented; recommendations are drawn to establish the conditions to obtain higher product yields in the industrial process

    Stellar evolution through the ages: period variations in galactic RRab stars as derived from the GEOS database and TAROT telescopes

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    The theory of stellar evolution can be more closely tested if we have the opportunity to measure new quantities. Nowadays, observations of galactic RR Lyr stars are available on a time baseline exceeding 100 years. Therefore, we can exploit the possibility of investigating period changes, continuing the pioneering work started by V. P. Tsesevich in 1969. We collected the available times of maximum brightness of the galactic RR Lyr stars in the GEOS RR Lyr database. Moreover, we also started new observational projects, including surveys with automated telescopes, to characterise the O-C diagrams better. The database we built has proved to be a very powerful tool for tracing the period variations through the ages. We analyzed 123 stars showing a clear O-C pattern (constant, parabolic or erratic) by means of different least-squares methods. Clear evidence of period increases or decreases at constant rates has been found, suggesting evolutionary effects. The median values are beta=+0.14 day/Myr for the 27 stars showing a period increase and beta=-0.20 day/Myr for the 21 stars showing a period decrease. The large number of RR Lyr stars showing a period decrease (i.e., blueward evolution) is a new and intriguing result. There is an excess of RR Lyr stars showing large, positive β\beta values. Moreover, the observed beta values are slightly larger than those predicted by theoretical models.Comment: 15 pages, 9 figures; to be published in Astronomy and Astrophysics; full resolution version available at http://dbrr.ast.obs-mip.fr/tarot/publis/publis.htm

    Cancer cachexia

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    In recent years many efforts of researchers and clinicians were made to improve our knowledge of cachexia syndrome. Not only cancer, but also many chronic or end-stage diseases such as AIDS, chronic obstructive pulmonary disease (COPD), rheumatoid arthritis, tuberculosis and Crohn's disease are associated with cachexia, a condition of abnormally low weight, weakness, and general bodily decline which deteriorates quality of life and reduces the prognosis of the patients who suffer from it. In the present editorial we will focus cachexia related on cancer and provide some insight into this prognosis-limiting syndrome

    New frontiers in the risk assessment of ship collision

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    Navigation is becoming more and more complex over the years. The increase in maritime traffic and vessel size is inducing a global escalation of ship collision accidents, with consequent losses of human lives and economic assets worth billions. This is particularly true for port basins, with maritime authorities struggling worldwide to keep up with the ever-increasing ship traffic. In this respect, the demand for advanced methods to assess and mitigate ship collision risk has never been higher. The interdependency between physical failures, weather conditions, logistics, governance and human factors requires sophisticated frameworks to effectively assist maritime authorities and navigators in decision-making. The present work reviews the most recent advancements in the risk assessment of ship collision. The article focuses on new, rising technologies, identifying the current main trends and discussing future perspectives and challenges. The review revealed a wide and diversified range of methods, including machine learning, clustering techniques, swarm intelligence algorithms and others. To frame the methods in the current literature and compare them with previous efforts, they are categorized according to literature classifications. Advancements of well-established approaches and new promising tools are discussed, considering methods that allow the inclusion of quantitative and qualitative variables in the assessment. Furthermore, a comprehensive analysis of a database of maritime accidents in port areas is carried out to investigate prevailing trends in both worldwide and Mediterranean Sea contexts. Results indicate that ship collision accidents constitute the majority compared with other types of accidents, especially in the Mediterranean

    A Layered Architecture for Detecting Malicious Behaviors

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    We address the semantic gap problem in behavioral monitoring by using hierarchical behavior graphs to infer high-level behaviors from myriad low-level events that could be parts of many different kinds of behavior. Our experimental system traces the execution of a process, performing data-flow analysis to identify meaningful actions such as \u201cproxying\u201d, \u201ckeystroke logging\u201d, \u201cdata leaking\u201d, and \u201cdownloading and executing a program\u201d from complex combinations of rudimentary system calls. To preemptively address evasive malware behavior, our specifications are carefully crafted to detect alternate sequences of events that achieve the same high-level goal. We tested seven malicious bots and eleven benign programs and found that we were able to thoroughly identify high-level behaviors across this diverse code base. Moreover, we were able to distinguish malicious execution of high-level behaviors from benign by distinguishing remotely-initiated from locally-initiated actions

    Real-imaging cDNA-AFLP transcript profiling of pancreatic cancer patients: Egr-1 as a potential key regulator of muscle cachexia

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    BACKGROUND: Cancer cachexia is a progressive wasting syndrome and the most prevalent characteristic of cancer in patients with advanced pancreatic adenocarcinoma. We hypothesize that genes expressed in wasted skeletal muscle of pancreatic cancer patients may determine the initiation and severity of cachexia syndrome. EXPERIMENTAL DESIGN: We studied gene expression in skeletal muscle biopsies from pancreatic cancer patients with and without cachexia utilizing Real-Imaging cDNA-AFLP-based transcript profiling for genome-wide expression analysis. RESULTS: Our approach yielded 183 cachexia-associated genes. Ontology analysis revealed characteristic changes for a number of genes involved in muscle contraction, actin cytoskeleton rearrangement, protein degradation, tissue hypoxia, immediate early response and acute-phase response. CONCLUSIONS: We demonstrate that Real-Imaging cDNA-AFLP analysis is a robust method for high-throughput gene expression studies of cancer cachexia syndrome in patients with pancreatic cancer. According to quantitative RT-PCR validation, the expression levels of genes encoding the acute-phase proteins α-antitrypsin and fibrinogen α and the immediate early response genes Egr-1 and IER-5 were significantly elevated in the skeletal muscle of wasted patients. By immunohistochemical and Western immunoblotting analysis it was shown, that Egr-1 expression is significantly increased in patients with cachexia and cancer. This provides new evidence that chronic activation of systemic inflammatory response might be a common and unifying factor of muscle cachexia

    Avelumab Plus Axitinib as First-Line Therapy for Advanced Renal Cell Carcinoma: Long-Term Results from the JAVELIN Renal 100 Phase Ib Trial.

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    BACKGROUND: Progression-free survival was significantly longer in patients who received avelumab plus axitinib versus sunitinib as first-line treatment for advanced renal cell carcinoma (aRCC) in a randomized phase III trial. We report long-term safety and efficacy of avelumab plus axitinib as first-line treatment for patients with aRCC from the JAVELIN Renal 100 phase Ib trial (NCT02493751). MATERIALS AND METHODS: In this open-label, multicenter, phase Ib study, patients with untreated aRCC received avelumab 10 mg/kg every 2 weeks plus axitinib 5 mg twice daily or with axitinib for 7 days followed by avelumab plus axitinib. Safety and efficacy were assessed in all patients receiving at least one dose of avelumab or axitinib. RESULTS: Overall, 55 patients were enrolled and treated. Median follow-up was 55.7 months (95% CI, 54.5-58.7). Treatment-related adverse events of any grade or grade ≥3 occurred in 54 (98.2%) and 34 (61.8%) patients, respectively. The confirmed objective response rate was 60.0% (95% CI, 45.9-73.0), including complete response in 10.9% of patients. Median duration of response was 35.9 months (95% CI, 12.7-52.9); the probability of response was 65.8% (95% CI, 46.7-79.4) at 2 years. Median progression-free survival was 8.3 months (95% CI, 5.3-32.0). Median overall survival was not reached (95% CI, 40.8-not estimable); the 5-year overall survival rate was 57.3% (95% CI, 41.2-70.5). CONCLUSION: Five-year follow-up for combination treatment with avelumab plus axitinib in previously untreated patients with aRCC showed long-term clinical activity with no new safety signals, supporting use of this regimen within its approved indication in clinical practice (Clinicaltrials.gov NCT02493751)

    Direct identification of clinically relevant neoepitopes presented on native human melanoma tissue by mass spectrometry

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    Although mutations may represent attractive targets for immunotherapy, direct identification of mutated peptide ligands isolated from human leucocyte antigens (HLA) on the surface of native tumour tissue has so far not been successful. Using advanced mass spectrometry (MS) analysis, we survey the melanoma-associated immunopeptidome to a depth of 95,500 patient-presented peptides. We thereby discover a large spectrum of attractive target antigen candidates including cancer testis antigens and phosphopeptides. Most importantly, we identify peptide ligands presented on native tumour tissue samples harbouring somatic mutations. Four of eleven mutated ligands prove to be immunogenic by neoantigen-specific T-cell responses. Moreover, tumour-reactive T cells with specificity for selected neoantigens identified by MS are detected in the patient's tumour and peripheral blood. We conclude that direct identification of mutated peptide ligands from primary tumour material by MS is possible and yields true neoepitopes with high relevance for immunotherapeutic strategies in cancer

    The double-mode nature of the HADS star GSC 00144-03031 and the Petersen diagram of the class

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    The double--mode pulsation of GSC 00144-03031 has been detected when searching for COROT targets. A very large dataset composed of 4722 photometric measurements was collected at six observatories in Europe and America. There is no hint of the excitation of additional modes (down to 0.6 mmag) and therefore GSC 00144-03031 seems to be a pure double--mode pulsator, with a very short fundamental radial mode (P=84 min). From Stromgren photometry and evolutionary tracks it appears to be a Pop. I star with M=1.75 solar masses, located in the middle of the instability strip, close to the Zero--Age Main Sequence. We also discovered other new double--mode pulsators in the databases of large--scale projects: OGLE BW2_V142, OGLE BW1_V207, ASAS3 094303-1707.3, ASAS3 000116-6037.0, NSVS 3234596 and NSVS 3324715. An observational Petersen diagram is presented and explained by means of new models. A common sequence connecting Pop. I stars from the shortest to the longest periods is proposed and the spreads in the period ratios are ascribed to different metallicities (at the shortest periods) and to different masses (at the longest ones). The paper is based on data collected at S. Pedro Martir and Sierra Nevada Observatories and on the contributions from several amateur astronomers.Comment: 9 pages, 5 pages, accepted for publication in Astronomy and Astrophysic
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