5,533 research outputs found

    Injector fouling and its impact on engine emissions and spray characteristics in gasoline direct injection engines

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    In Gasoline Direct Injection engines, direct exposure of the injector to the flame can cause combustion products to accumulate on the nozzle, which can result in increased particulate emissions. This research observes the impact of injector fouling on particulate emissions and the associated injector spray pattern and shows how both can be reversed by utilising fuel detergency. For this purpose multi-hole injectors were deliberately fouled in a four-cylinder test engine with two different base fuels. During a four hour injector fouling cycle particulate numbers (PN) increased by up to two orders of magnitude. The drift could be reversed by switching to a fuel blend that contained a detergent additive. In addition, it was possible to completely avoid any PN increase, when the detergent containing fuel was used from the beginning of the test. Microscopy showed that increased injector fouling coincided with increased particulate emissions. Based on these results a selection of the injectors was installed in a laboratory injection chamber and the spray patterns were investigated with a high speed camera. Injectors corresponding to the largest PN drift produced the thinnest spray jets with the deepest penetration. These factors amplify the risk of wall wetting and provide an explanation for the increase of PN. The positive effect of the detergent was also reflected in the spray pattern analysis, which illustrates the potential benefits of such fuel additives

    Predictors of patient preference for either whole body magnetic resonance imaging (WB-MRI) or CT/ PET-CT for staging colorectal or lung cancer

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    Introduction: Whole body magnetic resonance imaging (WB-MRI) may be more efficient in staging cancers, but can be harder for patients to tolerate. We examined predictors of patient preference for WB-MRI vs. CT/ PET-CT for staging colorectal or lung cancer. Methods: Patients recruited prospectively to two multicenter trials comparing diagnostic accuracy of WB-MRI with standard staging scans were sent two questionnaires: the first, administered at trial registration, captured demographics, educational level, and comorbidities; the second, administered after staging completion, measured emotional distress (GHQ-12), positive mood (PANAS), perceived scan burden, patients’ beliefs about WB-MRI, and preference for either WB-MRI or CT (colorectal trial), WB-MRI or PET-CT (lung trial). Preference for WB-MRI or CT / PET-CT were analysed using logistic regression. Results: Baseline and post-staging questionnaires were completed by 97 and 107 patients respectively. Overall, 56/107 (52%) preferred WB-MRI over standard scans, and were more likely to have no additional comorbidities, higher positive mood, greater awareness of potential benefits of WB-MRI, and lower levels of perceived WB-MRI scan burden. In adjusted analyses, only awareness of potential WB-MRI benefits remained a significant predictor (OR: 1.516, 95% CIs 1.006 to 2.284, p=0.047). Knowledge that WB-MRI does not use radiation predicted preference (adjusted OR: 3.018, 95% CIs 1.099 to 8.288, p=0.032), yet only 45/107 (42%) patients were aware of this attribute. Conclusions: A small majority of patients undergoing staging of colorectal or lung cancer prefer WB-MRI to CT/ PET-CT. Raising awareness of the potential benefits of WB-MRI, notably lack of ionising radiation, could influence preference

    Predictors of patient preference for either whole body magnetic resonance imaging (WB-MRI) or CT/ PET-CT for staging colorectal or lung cancer.

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    INTRODUCTION: Whole body magnetic resonance imaging (WB-MRI) may be more efficient in staging cancers, but can be harder for patients to tolerate. We examined predictors of patient preference for WB-MRI vs. CT/ PET-CT for staging colorectal or lung cancer. METHODS: Patients recruited prospectively to two multicentre trials comparing diagnostic accuracy of WB-MRI with standard staging scans were sent two questionnaires: the first, administered at trial registration, captured demographics, educational level and comorbidities; the second, administered after staging completion, measured emotional distress (GHQ-12), positive mood (PANAS), perceived scan burden, patients' beliefs about WB-MRI, and preference for either WB-MRI or CT (colorectal trial), WB-MRI or PET-CT (lung trial). Preference for WB-MRI or CT/ PET-CT was analysed using logistic regression. RESULTS: Baseline and post-staging questionnaires were completed by 97 and 107 patients, respectively. Overall, 56/107 (52%) preferred WB-MRI over standard scans and were more likely to have no additional comorbidities, higher positive mood, greater awareness of potential benefits of WB-MRI and lower levels of perceived WB-MRI scan burden. In adjusted analyses, only awareness of potential WB-MRI benefits remained a significant predictor (OR: 1.516, 95% CIs 1.006-2.284, P = 0.047). Knowledge that WB-MRI does not use radiation predicted preference (adjusted OR: 3.018, 95% CIs 1.099-8.288, P = 0.032), although only 45/107 (42%) patients were aware of this attribute. CONCLUSIONS: A small majority of patients undergoing staging of colorectal or lung cancer prefer WB-MRI to CT/ PET-CT. Raising awareness of the potential benefits of WB-MRI, notably lack of ionizing radiation, could influence preference

    Whole-body MRI compared with standard pathways for staging metastatic disease in lung and colorectal cancer: the Streamline diagnostic accuracy studies.

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    BACKGROUND: Whole-body magnetic resonance imaging is advocated as an alternative to standard pathways for staging cancer. OBJECTIVES: The objectives were to compare diagnostic accuracy, efficiency, patient acceptability, observer variability and cost-effectiveness of whole-body magnetic resonance imaging and standard pathways in staging newly diagnosed non-small-cell lung cancer (Streamline L) and colorectal cancer (Streamline C). DESIGN: The design was a prospective multicentre cohort study. SETTING: The setting was 16 NHS hospitals. PARTICIPANTS: Consecutive patients aged ≥ 18 years with histologically proven or suspected colorectal (Streamline C) or non-small-cell lung cancer (Streamline L). INTERVENTIONS: Whole-body magnetic resonance imaging. Standard staging investigations (e.g. computed tomography and positron emission tomography-computed tomography). REFERENCE STANDARD: Consensus panel decision using 12-month follow-up data. MAIN OUTCOME MEASURES: The primary outcome was per-patient sensitivity difference between whole-body magnetic resonance imaging and standard staging pathways for metastasis. Secondary outcomes included differences in specificity, the nature of the first major treatment decision, time and number of tests to complete staging, patient experience and cost-effectiveness. RESULTS: Streamline C - 299 participants were included. Per-patient sensitivity for metastatic disease was 67% (95% confidence interval 56% to 78%) and 63% (95% confidence interval 51% to 74%) for whole-body magnetic resonance imaging and standard pathways, respectively, a difference in sensitivity of 4% (95% confidence interval -5% to 13%; p = 0.51). Specificity was 95% (95% confidence interval 92% to 97%) and 93% (95% confidence interval 90% to 96%) respectively, a difference of 2% (95% confidence interval -2% to 6%). Pathway treatment decisions agreed with the multidisciplinary team treatment decision in 96% and 95% of cases, respectively, a difference of 1% (95% confidence interval -2% to 4%). Time for staging was 8 days (95% confidence interval 6 to 9 days) and 13 days (95% confidence interval 11 to 15 days) for whole-body magnetic resonance imaging and standard pathways, respectively, a difference of 5 days (95% confidence interval 3 to 7 days). The whole-body magnetic resonance imaging pathway was cheaper than the standard staging pathway: £216 (95% confidence interval £211 to £221) versus £285 (95% confidence interval £260 to £310). Streamline L - 187 participants were included. Per-patient sensitivity for metastatic disease was 50% (95% confidence interval 37% to 63%) and 54% (95% confidence interval 41% to 67%) for whole-body magnetic resonance imaging and standard pathways, respectively, a difference in sensitivity of 4% (95% confidence interval -7% to 15%; p = 0.73). Specificity was 93% (95% confidence interval 88% to 96%) and 95% (95% confidence interval 91% to 98%), respectively, a difference of 2% (95% confidence interval -2% to 7%). Pathway treatment decisions agreed with the multidisciplinary team treatment decision in 98% and 99% of cases, respectively, a difference of 1% (95% confidence interval -2% to 4%). Time for staging was 13 days (95% confidence interval 12 to 14 days) and 19 days (95% confidence interval 17 to 21 days) for whole-body magnetic resonance imaging and standard pathways, respectively, a difference of 6 days (95% confidence interval 4 to 8 days). The whole-body magnetic resonance imaging pathway was cheaper than the standard staging pathway: £317 (95% confidence interval £273 to £361) versus £620 (95% confidence interval £574 to £666). Participants generally found whole-body magnetic resonance imaging more burdensome than standard imaging but most participants preferred the whole-body magnetic resonance imaging staging pathway if it reduced time to staging and/or number of tests. LIMITATIONS: Whole-body magnetic resonance imaging was interpreted by practitioners blinded to other clinical data, which may not fully reflect how it is used in clinical practice. CONCLUSIONS: In colorectal and non-small-cell lung cancer, the whole-body magnetic resonance imaging staging pathway has similar accuracy to standard staging pathways, is generally preferred by patients, improves staging efficiency and has lower staging costs. Future work should address the utility of whole-body magnetic resonance imaging for treatment response assessment. TRIAL REGISTRATION: Current Controlled Trials ISRCTN43958015 and ISRCTN50436483. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 66. See the NIHR Journals Library website for further project information

    Angular analysis of B0K(892)0+B^0 \to K^\ast(892)^0 \ell^+ \ell^-

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    We present a measurement of angular observables, P4P_4', P5P_5', P6P_6', P8P_8', in the decay B0K(892)0+B^0 \to K^\ast(892)^0 \ell^+ \ell^-, where +\ell^+\ell^- is either e+ee^+e^- or μ+μ\mu^+\mu^-. The analysis is performed on a data sample corresponding to an integrated luminosity of 711 fb1711~\mathrm{fb}^{-1} containing 772×106772\times 10^{6} BBˉB\bar B pairs, collected at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the asymmetric-energy e+ee^+e^- collider KEKB. Four angular observables, P4,5,6,8P_{4,5,6,8}' are extracted in five bins of the invariant mass squared of the lepton system, q2q^2. We compare our results for P4,5,6,8P_{4,5,6,8}' with Standard Model predictions including the q2q^2 region in which the LHCb collaboration reported the so-called P5P_5' anomaly.Comment: Conference paper for LHC Ski 2016. SM prediction for P6P_{6}' corrected and reference for arXiv:1207.2753 adde
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