58 research outputs found

    Experimental Investigation of the Hydrodynamics in a Liquid-Solid Riser

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    Liquid-Solid Fluid Dynamics Has Been Investigated in a 6-In. (0.15 M) Cold-Flow Circulating Fluidized Bed Riser using Non-Invasive Flow Monitoring Methods. Gamma-Ray Computed Tomography (CT) Was Used to Measure the Time-Averaged Cross-Sectional Solids Volume Fraction Distributions at Several Elevations. the Time-Averaged Mean and Fluctuating Solids Velocity Fields Were Quantified using the Computer-Automated Radioactive Particle Tracking (CARPT) Technique. the Experimental Equipment, Protocol of Implementation, and Data Analysis Have Been Discussed Briefly, with Particular Emphasis on the Specific Features in the Use of These Techniques for Studying High-Density Turbulent Flows as in a Liquid-Solid Riser. the Experimental Study Examines Nine Operating Conditions, that Is, Three Liquid Superficial Velocities and Three Solids Flow Rates. the Solids Holdup Profile is Found to Be Relatively Uniform Across the Cross Section of the Riser, with Marginal Segregation Near the Walls. the Time-Averaged Solids Velocity Profiles Are Found to Have a Negative Component at the Walls, Indicating Significant Solids Backmixing. Detailed Characterization of the Solids Velocity Fields in Terms of RMS Velocities, Kinetic Energies, Hurst Exponents, Residence Time Distributions, Trajectory Length Distributions, Dispersion Coefficients, and So Forth Are Presented. Comparative and Symbiotic Analyses of the Results Were Used to Develop a Coherent Picture of the Solids Flow Field. in Addition, the Work Also Serves to Demonstrate the Power and Versatility of These Flow-Imaging Techniques in Studying Highly Turbulent and Opaque Multiphase Systems. © 2005 American Institute of Chemical Engineers

    Comparative Hydrodynamics Study in a Bubble Column using Computer-Automated Radioactive Particle Tracking (CARPT)/computed Tomography (CT) and Particle Image Velocimetry (PIV)

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    The Hydrodynamics of a 10-Cm-Diameter Cylindrical Bubble Column at the Superficial Gas Velocity of 2, 4, and 8 Cm/s Are Investigated by Computer-Automated Radioactive Particle Tracking (CARPT), Particle Image Velocimetry (PIV), and Computed Tomography (CT). These Experimental Techniques Are Capable of Providing the Knowledge of Velocity and Holdup Fields in a Bubble Column System, Which Are Essential as the Experimental Benchmark for Modeling of Such Systems. the Flow Field of Liquid Phase, as Well as the Reynolds Stresses, Obtained by CARPT and PIV in an Air-Water System Are Compared in Detail. the Results Indicate that CARPT and PIV Complement Each Other Well. Further, the Profile of Gas Holdup Obtained by Gamma Ray based on CT Compares Favorably to the Independently Determined Holdup

    Analysis of Photobioreactors for Culturing High-Value Microalgae and Cyanobacteria Via an Advanced Diagnostic Technique: CARPT

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    Photosynthetic Algal Cultures Are a Potential Source of Many High-Value Products. in Photobioreactors (PBR), the Availability and the Intensity of the Light, Which Are Affected by the Cells\u27 Movement, Are the Major Factors Controlling the Biomass Productivity. Hydrodynamics, Hence, Play a Significant Role in the Reactor\u27s Performance, as They Determine Not Only the Flow Field, I.e. Liquid Flow and Mixing, Shear Stresses, Etc., But Also the Movements of the Cells. in This Work, Computer-Automated Radioactive Particle Tracking (CARPT) Technique Was Employed to Evaluate its Feasibility for Characterizing PBRs. Liquid Velocity Profiles, Cells\u27 Movement, and the Temporal Irradiance Patterns Obtained by Coupling the Cells\u27 Trajectories and the Irradiance Distribution Model Have Been Determined. the Effects of the Biomass Concentration, Reactor Geometry, and the Aeration Rate on the Irradiance Patterns Are Discussed. the Results Demonstrate that the CARPT Technique is Promising for PBR Analysis. It Provides Fundamental Information Needed to Advance the Cells\u27 Growth Prediction and Modeling, and the Design, Scale-Up and Operation of PBRs. © 2003 Elsevier Science Ltd. All Rights Reserved

    Origin and Evolution of TRIM Proteins: New Insights from the Complete TRIM Repertoire of Zebrafish and Pufferfish

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    Tripartite motif proteins (TRIM) constitute a large family of proteins containing a RING-Bbox-Coiled Coil motif followed by different C-terminal domains. Involved in ubiquitination, TRIM proteins participate in many cellular processes including antiviral immunity. The TRIM family is ancient and has been greatly diversified in vertebrates and especially in fish. We analyzed the complete sets of trim genes of the large zebrafish genome and of the compact pufferfish genome. Both contain three large multigene subsets - adding the hsl5/trim35-like genes (hltr) to the ftr and the btr that we previously described - all containing a B30.2 domain that evolved under positive selection. These subsets are conserved among teleosts. By contrast, most human trim genes of the other classes have only one or two orthologues in fish. Loss or gain of C-terminal exons generated proteins with different domain organizations; either by the deletion of the ancestral domain or, remarkably, by the acquisition of a new C-terminal domain. Our survey of fish trim genes in fish identifies subsets with different evolutionary dynamics. trims encoding RBCC-B30.2 proteins show the same evolutionary trends in fish and tetrapods: they evolve fast, often under positive selection, and they duplicate to create multigenic families. We could identify new combinations of domains, which epitomize how new trim classes appear by domain insertion or exon shuffling. Notably, we found that a cyclophilin-A domain replaces the B30.2 domain of a zebrafish fintrim gene, as reported in the macaque and owl monkey antiretroviral TRIM5α. Finally, trim genes encoding RBCC-B30.2 proteins are preferentially located in the vicinity of MHC or MHC gene paralogues, which suggests that such trim genes may have been part of the ancestral MHC

    Genetic Resistance to Rhabdovirus Infection in Teleost Fish Is Paralleled to the Derived Cell Resistance Status

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    Genetic factors of resistance and predisposition to viral diseases explain a significant part of the clinical variability observed within host populations. Predisposition to viral diseases has been associated to MHC haplotypes and T cell immunity, but a growing repertoire of innate/intrinsic factors are implicated in the genetic determinism of the host susceptibility to viruses. In a long-term study of the genetics of host resistance to fish rhabdoviruses, we produced a collection of double-haploid rainbow trout clones showing a wide range of susceptibility to Viral Hemorrhagic Septicemia Virus (VHSV) waterborne infection. The susceptibility of fibroblastic cell lines derived from these clonal fish was fully consistent with the susceptibility of the parental fish clones. The mechanisms determining the host resistance therefore did not associate with specific host immunity, but rather with innate or intrinsic factors. One cell line was resistant to rhabdovirus infection due to the combination of an early interferon IFN induction - that was not observed in the susceptible cells - and of yet unknown factors that hamper the first steps of the viral cycle. The implication of IFN was well consistent with the wide range of resistance of this genetic background to VSHV and IHNV, to the birnavirus IPNV and the orthomyxovirus ISAV. Another cell line was even more refractory to the VHSV infection through different antiviral mechanisms. This collection of clonal fish and isogenic cell lines provides an interesting model to analyze the relative contribution of antiviral pathways to the resistance to different viruses

    Duration of androgen deprivation therapy with postoperative radiotherapy for prostate cancer: a comparison of long-course versus short-course androgen deprivation therapy in the RADICALS-HD randomised trial

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    Background Previous evidence supports androgen deprivation therapy (ADT) with primary radiotherapy as initial treatment for intermediate-risk and high-risk localised prostate cancer. However, the use and optimal duration of ADT with postoperative radiotherapy after radical prostatectomy remains uncertain. Methods RADICALS-HD was a randomised controlled trial of ADT duration within the RADICALS protocol. Here, we report on the comparison of short-course versus long-course ADT. Key eligibility criteria were indication for radiotherapy after previous radical prostatectomy for prostate cancer, prostate-specific antigen less than 5 ng/mL, absence of metastatic disease, and written consent. Participants were randomly assigned (1:1) to add 6 months of ADT (short-course ADT) or 24 months of ADT (long-course ADT) to radiotherapy, using subcutaneous gonadotrophin-releasing hormone analogue (monthly in the short-course ADT group and 3-monthly in the long-course ADT group), daily oral bicalutamide monotherapy 150 mg, or monthly subcutaneous degarelix. Randomisation was done centrally through minimisation with a random element, stratified by Gleason score, positive margins, radiotherapy timing, planned radiotherapy schedule, and planned type of ADT, in a computerised system. The allocated treatment was not masked. The primary outcome measure was metastasis-free survival, defined as metastasis arising from prostate cancer or death from any cause. The comparison had more than 80% power with two-sided α of 5% to detect an absolute increase in 10-year metastasis-free survival from 75% to 81% (hazard ratio [HR] 0·72). Standard time-to-event analyses were used. Analyses followed intention-to-treat principle. The trial is registered with the ISRCTN registry, ISRCTN40814031, and ClinicalTrials.gov , NCT00541047 . Findings Between Jan 30, 2008, and July 7, 2015, 1523 patients (median age 65 years, IQR 60–69) were randomly assigned to receive short-course ADT (n=761) or long-course ADT (n=762) in addition to postoperative radiotherapy at 138 centres in Canada, Denmark, Ireland, and the UK. With a median follow-up of 8·9 years (7·0–10·0), 313 metastasis-free survival events were reported overall (174 in the short-course ADT group and 139 in the long-course ADT group; HR 0·773 [95% CI 0·612–0·975]; p=0·029). 10-year metastasis-free survival was 71·9% (95% CI 67·6–75·7) in the short-course ADT group and 78·1% (74·2–81·5) in the long-course ADT group. Toxicity of grade 3 or higher was reported for 105 (14%) of 753 participants in the short-course ADT group and 142 (19%) of 757 participants in the long-course ADT group (p=0·025), with no treatment-related deaths. Interpretation Compared with adding 6 months of ADT, adding 24 months of ADT improved metastasis-free survival in people receiving postoperative radiotherapy. For individuals who can accept the additional duration of adverse effects, long-course ADT should be offered with postoperative radiotherapy. Funding Cancer Research UK, UK Research and Innovation (formerly Medical Research Council), and Canadian Cancer Society

    Adding 6 months of androgen deprivation therapy to postoperative radiotherapy for prostate cancer: a comparison of short-course versus no androgen deprivation therapy in the RADICALS-HD randomised controlled trial

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    Background Previous evidence indicates that adjuvant, short-course androgen deprivation therapy (ADT) improves metastasis-free survival when given with primary radiotherapy for intermediate-risk and high-risk localised prostate cancer. However, the value of ADT with postoperative radiotherapy after radical prostatectomy is unclear. Methods RADICALS-HD was an international randomised controlled trial to test the efficacy of ADT used in combination with postoperative radiotherapy for prostate cancer. Key eligibility criteria were indication for radiotherapy after radical prostatectomy for prostate cancer, prostate-specific antigen less than 5 ng/mL, absence of metastatic disease, and written consent. Participants were randomly assigned (1:1) to radiotherapy alone (no ADT) or radiotherapy with 6 months of ADT (short-course ADT), using monthly subcutaneous gonadotropin-releasing hormone analogue injections, daily oral bicalutamide monotherapy 150 mg, or monthly subcutaneous degarelix. Randomisation was done centrally through minimisation with a random element, stratified by Gleason score, positive margins, radiotherapy timing, planned radiotherapy schedule, and planned type of ADT, in a computerised system. The allocated treatment was not masked. The primary outcome measure was metastasis-free survival, defined as distant metastasis arising from prostate cancer or death from any cause. Standard survival analysis methods were used, accounting for randomisation stratification factors. The trial had 80% power with two-sided α of 5% to detect an absolute increase in 10-year metastasis-free survival from 80% to 86% (hazard ratio [HR] 0·67). Analyses followed the intention-to-treat principle. The trial is registered with the ISRCTN registry, ISRCTN40814031, and ClinicalTrials.gov, NCT00541047. Findings Between Nov 22, 2007, and June 29, 2015, 1480 patients (median age 66 years [IQR 61–69]) were randomly assigned to receive no ADT (n=737) or short-course ADT (n=743) in addition to postoperative radiotherapy at 121 centres in Canada, Denmark, Ireland, and the UK. With a median follow-up of 9·0 years (IQR 7·1–10·1), metastasis-free survival events were reported for 268 participants (142 in the no ADT group and 126 in the short-course ADT group; HR 0·886 [95% CI 0·688–1·140], p=0·35). 10-year metastasis-free survival was 79·2% (95% CI 75·4–82·5) in the no ADT group and 80·4% (76·6–83·6) in the short-course ADT group. Toxicity of grade 3 or higher was reported for 121 (17%) of 737 participants in the no ADT group and 100 (14%) of 743 in the short-course ADT group (p=0·15), with no treatment-related deaths. Interpretation Metastatic disease is uncommon following postoperative bed radiotherapy after radical prostatectomy. Adding 6 months of ADT to this radiotherapy did not improve metastasis-free survival compared with no ADT. These findings do not support the use of short-course ADT with postoperative radiotherapy in this patient population

    Measurements of top-quark pair differential cross-sections in the eμe\mu channel in pppp collisions at s=13\sqrt{s} = 13 TeV using the ATLAS detector

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    Search for single production of vector-like quarks decaying into Wb in pp collisions at s=8\sqrt{s} = 8 TeV with the ATLAS detector

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    Search for dark matter in association with a Higgs boson decaying to bb-quarks in pppp collisions at s=13\sqrt s=13 TeV with the ATLAS detector

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