General Motors (Germany)

INTRODUCTIONAmyloid beta and tau pathology are the hallmarks of sporadic Alzheimer's disease (AD) and autosomal dominant AD (ADAD). However, Lewy body pathology (LBP) is found in ≈ 50% of AD and ADAD brains.METHODSUsing an α‐synuclein seed amplification assay (SAA) in cerebrospinal fluid (CSF) from asymptomatic (n = 26) and symptomatic (n = 27) ADAD mutation carriers, including 12 with known neuropathology, we investigated the timing of occurrence and prevalence of SAA positive reactivity in ADAD in vivo.RESULTSNo asymptomatic participant and only 11% (3/27) of the symptomatic patients tested SAA positive. Neuropathology revealed LBP in 10/12 cases, primarily affecting the amygdala or the olfactory areas. In the latter group, only the individual with diffuse LBP reaching the neocortex showed α‐synuclein seeding activity in CSF in vivo.DISCUSSIONResults suggest that in ADAD LBP occurs later than AD pathology and often as amygdala‐ or olfactory‐predominant LBP, for which CSF α‐synuclein SAA has low sensitivity.HighlightsCerebrospinal fluid (CSF) real‐time quaking‐induced conversion (RT‐QuIC) detects misfolded α‐synuclein in ≈ 10% of symptomatic autosomal dominant Alzheimer's disease (ADAD) patients.CSF RT‐QuIC does not detect α‐synuclein seeding activity in asymptomatic mutation carriers.Lewy body pathology (LBP) in ADAD mainly occurs as olfactory only or amygdala‐predominant variants.LBP develops late in the disease course in ADAD.CSF α‐synuclein RT‐QuIC has low sensitivity for focal, low‐burden LBP.

Oxymethylene dimethyl ethers (OMEn ; CH3 (-OCH2 -)n O-CH3 , n=3-5) are a novel class of sustainable synthetic fuels, which are of increasing interest due to their soot-free combustion. Herein a novel anhydrous OMEn synthesis route is presented. Catalyzed by trimethyloxonium salts, dimethoxymethane takes up monomeric gaseous formaldehyde instantaneously and forms high purity OMEn at temperatures of 25-30 °C. This new anhydrous approach using molecular formaldehyde and catalytic amounts of highly active trimethyloxonium salts represents a promising new step towards a sustainable formation of OMEn emanating from CO2 and H2 .

<div class="section abstract"><div class="htmlview paragraph">Environmental authorities such as EPA, VCA have enforced stringent emissions legislation governing air pollutants released into the atmosphere. Of particular interest is the challenge introduced by the limit on particulate number (PN) counting (#/km) and real driving emissions (RDE) testing; with new emissions legislation being shortly introduced for the gasoline direct injection (GDI) engines, gasoline particulate filters (GPF) are considered the most immediate solution. While engine calibration and testing over the Worldwide harmonized Light vehicles Test Cycle (WLTC) allow for the limits to be met, real driving emission and cold start constitute a real challenge.</div><div class="htmlview paragraph">The present work focuses on an experimental durability study on road under real world driving conditions. Two sets of experiments were carried out. The first study analyzed a gasoline particulate filter (GPF) (2.4 liter, diameter 5.2” round) installed in the underfloor (UF) position and driven up to 200k km. A 1.6 liter Gasoline Direct Injection (GDI) engine was used for the investigation. Ash accumulation versus mileage and soot loading were of interest. A parallel investigation up to 160k km with same engine (2 identical vehicles on an “average customer driving” cycle) and GPF installed in close-coupled (CC) position was also carried out. Both UF and CC GPF are NGK 360 cpsi (i.e. cells per square inch), 5 mil wall thickness.</div><div class="htmlview paragraph">As a route to develop a robust 3-D Computational Fluid Dynamics (CFD) model to gather information on the fluid flow and pressure loss characteristics of GPF, a baseline model is introduced in this work. The computational domain refers to full length individual 3-D channels and focuses on two quarters of an inlet and two quarters of an outlet channel with the aim of reducing complexity of the problem and its computational cost. Although this baseline version does not include yet the soot and ash loading models, it can be used for understanding real physical problems and gather insight on velocity and pressure distributions inside filter and its channels.</div></div>

Abstract. Power stations, ships and air traffic are among the most potent greenhouse gas emitters and are primarily responsible for global warming. Iron salt aerosols (ISAs), composed partly of iron and chloride, exert a cooling effect on climate in several ways. This article aims firstly to examine all direct and indirect natural climate cooling mechanisms driven by ISA tropospheric aerosol particles, showing their cooperation and interaction within the different environmental compartments. Secondly, it looks at a proposal to enhance the cooling effects of ISA in order to reach the optimistic target of the Paris climate agreement to limit the global temperature increase between 1.5 and 2 °C. Mineral dust played an important role during the glacial periods; by using mineral dust as a natural analogue tool and by mimicking the same method used in nature, the proposed ISA method might be able to reduce and stop climate warming. The first estimations made in this article show that by doubling the current natural iron emissions by ISA into the troposphere, i.e., by about 0.3 Tg Fe yr−1, artificial ISA would enable the prevention or even reversal of global warming. The ISA method proposed integrates technical and economically feasible tools.

<div class="section abstract"><div class="htmlview paragraph">Abnormal ignition, especially preignition, in gasoline engines has been a phenomenon that has been reported for many decades, going back to at least the 1920s in the literature. In the last 10 years, another abnormal combustion issue that has been deemed as preignition has been observed and documented. It is not clear if these issues from the early years are related or similar in nature to the present ones. Was the issue solved and now back again? Did changes occur in engine designs that caused this abnormal combustion phenomena to reappear? This paper serves as a review of literature from the 1920s through the 2000s on instances of abnormal ignition by fuel and lubricant derivatives, and what has been observed and learned. The different terms used to describe these phenomena are defined and clarified. Trends observed with the mechanisms and causes are discussed. Similarities between historical and more modern observations are highlighted, and areas of possible future work are suggested. Quick resolution of the current fuel/lubricant derivative ignition issue is required to minimize risk of engine hardware damage and enable utilization of advanced technologies to significantly improve vehicle fuel economy.</div></div>

<div class="section abstract"><div class="htmlview paragraph">This study investigates the effects of octane quality on the performance, i.e., acceleration and power, and fuel economy (FE) of one late model US vehicle, which is powered by a small displacement, turbocharged, gasoline direct injection (GDI) engine.</div><div class="htmlview paragraph">The relative importance of the gasoline parameters Research and Motor Octane Number (RON and MON) in meeting the octane requirement of this engine to run at an optimum spark timing for the given demand was considered by evaluating the octane index (OI), where OI = (1-<i>K</i>) RON <i>+ K</i> MON and <i>K</i> is a constant depending on engine design and operating conditions.</div><div class="htmlview paragraph">Over wide open throttle (WOT) accelerations, the average <i>K</i> of this <i>Pontiac Solstice</i> was determined as −0.75, whereby a lower MON would give a higher OI, a higher knock resistance and better performance. Over a part load cycle, a positive average <i>K</i> value was identified, whereby higher MON would give a (generally desirable) higher octane index, however, because lower load operation tends to be less constrained by knock, the impact of MON (high or low) on FE and efficiency under such conditions is smaller.</div><div class="htmlview paragraph">Results from the one car tested for this report support the observation that the <i>K</i> value of an engine depends on speed and load - a clear negative correlation between charge pressure and <i>K</i> value was recorded.</div></div>

The purposes of this study were to determine whether two bolus transition durations (oral transit time and pharyngeal transit time) were different during oropharyngeal swallowing in post-stroke patients who aspirated and who did not aspirate and to examine those differences across varying bolus viscosities. Means and standard deviations of oral transit time and pharyngeal transit time were analyzed on 5 ml of thin and nectar thick liquids and puree swallows from videofluoroscopic swallowing examinations of 30 post-stroke patients. Statistical comparisons were made by repeated measures analysis of variance, with the within-subject variable being the three consistencies and the between-subject variable being the two groups. Significance level was set at P < 0.025. Oral transition of the bolus did not differ between the two patient groups. Pharyngeal transition of the bolus differentiated the patients who aspirated from the patients who did not aspirate. Both the oral and pharyngeal transitions differed significantly for the puree compared with the thin and nectar thick liquids. Patients who demonstrate prolonged pharyngeal transit times may be at risk for aspiration.