21 research outputs found

    Cold Modelling of an Internally Circulating Fluidized Bed Membrane Reactor

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    A novel fluidized bed membrane reactor with internal catalyst circulation is being developed for the production of high-purity H2 from an autothermal reformer. In order to provide guidance to pilot reactor testing, a cold model was built to study the influence of reactor configuration on hydrodynamics and catalyst circulation. It was found that catalyst circulation was reproducible, but that parallel non-communicating flow channels could lead to flow instability. Solids circulation was found to be adequate for design of the autothermal reformer

    Tumor-derived interleukin-10 as a prognostic factor in stage III patients undergoing adjuvant treatment with an autologous melanoma cell vaccine.

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    OBJECTIVES: Interleukin-10 (IL-10) downregulates T-cell-mediated immune responses. We studied the association between IL-10 production by freshly isolated melanoma cell suspensions in vitro and overall survival in patients undergoing adjuvant treatment with a vaccine prepared from the same autologous melanoma cells modified with a hapten, dinitrophenyl (DNP). METHODS: Forty-four patients with cutaneous melanoma (29 stage III and 15 stage IV) were prospectively evaluated. Tumor cells were extracted from metastatic deposits for production of DNP-modified autologous melanoma cell vaccine. Small aliquots of the melanoma cell suspensions were separated prior to vaccine processing and cultured overnight for IL-10 production. Based on a blind assessment of the distribution of IL-10 levels in the culture supernatants, a cutoff of 200 pg/ml was used to define high versus low IL-10 producers. Cox regression model was used for multivariate analysis. Overall survival was calculated using the Kaplan-Meier method, and survival curves were compared with the log-rank test. RESULTS: Out of 44 patients, 29 were low and 15 were high IL-10 producers. The median OS was significantly worse for high compared with low IL-10 producers (10.5 months vs. 42 months; P = 0.022). In stage III patients, the multivariate hazard ratio for high versus low IL-10 producers was 2.92 (95% CI, 1.04-8.20; P = 0.041). The corresponding hazard ratio in stage IV patients was 0.92 (95% CI, 1.04-8.20; P = 0.888). CONCLUSIONS: High IL-10 production in the tumor microenvironment could be a determinant of clinical outcomes in stage III melanoma patients receiving autologous melanoma cell vaccine

    Slope Stability Assessment and Landslide Susceptibility Map Production of Wadi Dhahr Area, Northwest of Sana’a, Yemen

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    A slope stability assessment of Wadi Dhahr area, located northwest of Sana’a the capital of Yemen, was carried out in this study. The study area consists of sandstone and volcanic rocks that are deformed by number of faults, joints and basaltic dykes. All the important factors affecting slope stability in the area such as slope angle, slope height, discontinuities measurements, weathering, vegetation cover, rainfall and previous landslides were evaluated. The study was conducted based on the integration of field investigation and satellite image processing. A landslide susceptibility map was produced with the Landslide Possibility Index (LP1) System, and the correlation values were computed between the factors measured and Landslide Possibility Index values. The fractures counted by satellite image were categorised according to their length and zones based on their concentrations. It was found that plain sliding and rockfall are the main modes of failure in the area, while rolling and toppling are rare. Some remedial measures are proposed to protect the slopes where it is needed,  such as the removal of rock overhangs, unstable blocks and trees, and by supporting the toe of slopes and overhanging parts by retaining walls and erecting well sealed drainage conduits. The results will assist in slope management and land use planning in the area

    IL-10 expression by CT26 colon carcinoma cells inhibits their malignant phenotype and induces a T cell-mediated tumor rejection in the context of a systemic Th2 response

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    In spite of the evidence that IL-10 has Th1-immunosuppressive and anti-inflammatory effects, it has been shown that IL-10 may reduce the tumorigenic capacity of certain tumor cell types. In order to characterize the responses elicited by IL-10, we explored the effect of transducing murine CT26 colon carcinoma cells with a recombinant retrovirus expressing mIL-10. IL-10 gene transfer of CT26 cells had no effect on tumor cell growth on plastic surface but inhibited the anchorage-independent growth capacity of tumor cells and their metastatic potential as assessed by their invasive and migration ability. Expression of IL-10 also elicited an antitumor immune response involving both CD4+ and CD8+ T cells. Assessment of the immune status of the animals demonstrated that mice injected with CT26-IL10 cells showed prevalence of a systemic and tumor-specific Th2 response. Spleen cells obtained from these mice showed an increased production of IL-4 and no changes in IFNgamma levels, characteristic of a Th2 response. These results demonstrate that IL-10 affects CT26 tumor cell growth by both inhibiting the malignant phenotype and by recruiting and activating a T cell-mediated antitumor response. This T cell response occurs in the context of a shift towards a Th2 response.Facultad de Ciencias Veterinaria

    Methane Steam Reforming in a Pd-Ru Membrane Reactor

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    Methane steam reforming has been carried out in a Pd-Ru membrane reactor at 500-600°C. The membrane reactor consisted of a Pd-6%Ru tube of 100 μm wall thickness and commercial catalysts packed outside of the membrane. The methane conversion was significantly enhanced in the membrane reactor in which reaction equilibrium was shifted by selective permeation of hydrogen through the membrane. The methane conversion at 500°C was improved as high as 80% in the membrane reactor, while equilibrium conversion in a fixed-bed reactor was 57%. The effect of gas flow rate and temperature on the performance of the membrane reactor was investigated and the results were compared with the simulated result from the model. The model prediction is in good agreement with the experimental result. In order to apply the membrane in practice, however, the thickness of the membrane has to be reduced. Therefore, the effect of membrane thickness on performance of the membrane reactor was estimated using the model
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