11 research outputs found

    Propulsion Study for Small Transport Aircraft Technology (STAT)

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    Propulsion requirements were determined for 0.5 and 0.7 Mach aircraft. Sensitivity studies were conducted on both these aircraft to determine parametrically the influence of propulsion characteristics on aircraft size and direct operating cost (DOC). Candidate technology elements and design features were identified and parametric studies conducted to select the STAT advanced engine cycle. Trade off studies were conducted to determine those advanced technologies and design features that would offer a reduction in DOC for operation of the STAT engines. These features were incorporated in the two STAT engines. A benefit assessment was conducted comparing the STAT engines to current technology engines of the same power and to 1985 derivatives of the current technology engines. Research and development programs were recommended as part of an overall technology development plan to ensure that full commercial development of the STAT engines could be initiated in 1988

    Radiotherapy after radical prostatectomy: Effect of timing of postprostatectomy radiation on functional outcomes

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    Introduction and objectiveThe timing of radiotherapy (RT) after prostatectomy is controversial, and its effect on sexual, urinary, and bowel function is unknown. This study seeks to compare patient-reported functional outcomes after radical prostatectomy (RP) and postprostatectomy radiation as well as elucidate the timing of radiation to allow optimal recovery of function.MethodsThe Comparative Effectiveness Analysis of Surgery and Radiation (CEASAR) study is a prospective, population-based, observational study of men with localized prostate cancer. Patient-reported sexual, urinary, and bowel functional outcomes were measured using the 26-item Expanded Prostate Index Composite at baseline and at 6, 12, 36, and 60 months after enrollment. Functional outcomes were compared among men undergoing RP alone, post-RP adjuvant radiation (RP + aRT), and post-RP salvage radiation (RP + sRT) using multivariable models controlling for baseline clinical, demographic, and functional characteristics.ResultsAmong 1,482 CEASAR participants initially treated with RP for clinically localized prostate cancer, 11.5% (N = 170) received adjuvant (aRT, N = 57) or salvage (sRT, N = 113) radiation. Men who received post-RP RT had worse scores in all domains (sexual function [-9.0, 95% confidence interval {-14.5, -3.6}, P < 0.001], incontinence [-8.8, {-14.0, -3.6}, P < 0.001], irritative voiding [-5.9, {-9.0, -2.8}, P < 0.001], bowel irritative [-3.5, {-5.8, -1.2}, P = 0.002], and hormonal function [-4.5, {-7.2, -1.7}, P = 0.001]) compared to RP alone at 5 years of follow-up. Compared to men treated with RP alone in an adjusted linear model, sRT was associated with significantly worse scores in all functional domains. aRT was associated with significantly worse incontinence, urinary irritation, and hormonal function domain scores compared to RP alone at 5 years of follow-up. On multivariable modeling, RT administered approximately 24 months after RP was associated with the smallest decline in sexual domain score, with an adjusted mean decrease of 8.85 points (95% confidence interval [-19.8, 2.1]) from post-RP, pre-RT baseline.ConclusionsIn men with localized prostate cancer, post-RP RT was associated with significantly worse sexual, urinary, and bowel function domain scores at 5 years compared to RP alone. Radiation delayed for approximately 24 months after RP may be optimal for preserving erectile function compared to radiation administered closer to the time of RP

    Phytoremediation of polyaromatic hydrocarbons, anilines and phenols

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    International audiencePhytoremediation technologies based on the combined action of plants and the microbial communities that they support within the rhizosphere hold promise in the remediation of land and waterways contaminated with hydrocarbons but they have not yet been adopted in large-scale remediation strategies. In this review plant and microbial degradative capacities, viewed as a continuum, have been dissected in order to identify where bottle-necks and limitations exist. Phenols, anilines and polyaromatic hydrocarbons (PAHs) were selected as the target classes of molecule for consideration, in part because of their common patterns of distribution, but also because of the urgent need to develop techniques to overcome their toxicity to human health. Depending on the chemical and physical properties of the pollutant, the emerging picture suggests that plants will draw pollutants including PAHs into the plant rhizosphere to varying extents via the transpiration stream. Mycorrhizosphere-bacteria and -fungi may play a crucial role in establishing plants in degraded ecosystems. Within the rhizosphere, microbial degradative activities prevail in order to extract energy and carbon skeletons from the pollutants for microbial cell growth. There has been little systematic analysis of the changing dynamics of pollutant degradation within the rhizosphere; however, the importance of plants in supplying oxygen and nutrients to the rhizosphere via fine roots, and of the beneficial effect of microorganisms on plant root growth is stressed. In addition to their role in supporting rhizospheric degradative activities, plants may possess a limited capacity to transport some of the more mobile pollutants into roots and shoots via fine roots. In those situations where uptake does occur (i.e. only limited microbial activity in the rhizosphere) there is good evidence that the pollutant may be metabolised. However, plant uptake is frequently associated with the inhibition of plant growth and an increasing tendency to oxidant stress. Pollutant tolerance seems to correlate with the ability to deposit large quantities of pollutant metabolites in the 'bound' residue fraction of plant cell walls compared to the vacuole. In this regard, particular attention is paid to the activities of peroxidases, laccases, cytochromes P450, glucosyltransferases and ABC transporters. However, despite the seemingly large diversity of these proteins, direct proof of their participation in the metabolism of industrial aromatic pollutants is surprisingly scarce and little is known about their control in the overall metabolic scheme. Little is known about the bioavailability of bound metabolites; however, there may be a need to prevent their movement into wildlife food chains. In this regard, the application to harvested plants of composting techniques based on the degradative capacity of white-rot fungi merits attention
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