Demonstration of a Regulatory Method for Aircraft Engine Nonvolatile PM Emissions Measurements with Conventional and Isoparaffinic Kerosene fuels

The aviation industry is exploring the economic viability and environmental sustainability of the use of alternative fuels to power aircraft main engines and auxiliary power units. The International Civil Aviation Organization is also developing a regulatory standard for aircraft engine nonvolatile particulate matter (nvPM) emissions to meet the growing public demand for improvement in air quality. This study compared the nvPM emissions in the exhaust stream of a small (<26.7 kN thrust) mixed turbofan aircraft engine burning a conventional Jet A fuel as well as a Sasol isoparaffinic kerosene (IPK) fuel derived from coal, using a standardized sampling and measurement system. The goal of the study was to demonstrate the regulatory system on a small mixed turbofan engine and to assess the suitability and limitations of using such systems for turbofan engines burning fuels with different fuel properties. Significant reductions in both nvPM number- and mass-based emission indices were observed with the IPK fuel across the full spectrum of engine thrust settings. The percent reduction in nvPM mass-based emissions was higher than the reduction in nvPM number-based emissions for the corresponding engine thrust settings because smaller and fewer particles were generated with IPK fuel combustion. PM size distribution mean diameters for the IPK fuel were found to be smaller than that for Jet A. The composition of the organic PM emissions for the two fuels was almost identical, and the organic PM was also found to be proportional to the soot concentration. The nvPM mass-based emissions for the mixed turbofan engine measured with the standardized system exhibited a high degree of measurement uncertainty at low engine thrust settings. This limitation was not encountered for nvPM number-based emissions

Effects of opioids on immunologic parameters that are relevant to anti-tumour immune potential in patients with cancer: a systematic literature review

Background: The immune system has a central role in controlling cancer, and factors that influence protective antitumour immunity could therefore have a significant impact on the course of malignant disease. Opioids are essential for the management of cancer pain, and preclinical studies indicate that opioids have the potential to influence these tumour immune surveillance mechanisms. The aim of this systematic literature review is to evaluate the clinical effects of opioids on the immune system of patients with cancer. Methods: A systematic search of Ovid MEDLINE (PubMed) and Embase, Cochrane database and Web of Knowledge for clinical studies, which evaluated the effects of opioids on the immune system in patients with cancer, was performed. Results: Five human studies, which have assessed the effects of opioids on the immune system in patients with cancer, were identified. Although all of these evaluated the effect of morphine on immunologic end points in patients with cancer, none measured the clinical effects. Conclusions: Evidence from preclinical, healthy volunteer and surgical models suggests that different opioids variably influence protective anti-tumour immunity; however, actual data derived from cancer populations are inconclusive and definitive recommendations cannot be made. Appropriately designed and powered studies assessing clinical outcomes of opioid use in people with cancer are therefore required to inform oncologists and others involved in cancer care about the rational use of opioids in this patient group