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Diamond-Like Carbon (DLC) coatings are well known for offering excellent tribological properties. They have been shown to offer low friction and outstanding wear performance in both dry and lubricated conditions. Application of these coatings for automotive components is considered as a promising strategy to cope with the emerging requirements regarding fuel economy and durability. Commercially available oils are generally optimised to work on conventional ferrous surfaces and are not necessarily effective in lubricating non-ferrous surfaces. Recently, the adverse effect of the Molybdenum DialkyldithioCarbamate (MoDTC) friction modifier additive on the wear performance of the hydrogenated DLC has been reported. However, the mechanisms by which MoDTC imposes this high wear to DLC are not yet well understood. A better understanding of DLC wear may potentially lead to better compatibility between DLC surfaces and current additive technology being achieved. In this work, the wear properties of DLC coatings in the DLC/cast iron (CI) system under boundary lubrication conditions have been investigated to try to understand what appears to be a tribocorrosion-type process. A pin-on-plate tribotester was used to run the experiments using High Speed Steel (HSS) plates coated with 15 at.% hydrogenated DLC (a-C:15H) sliding against CI pins or ceramic balls. The lubricants used in this study are typical examples of the same fully formulated oil with and without ZDDP. The friction and wear responses of the fully formulated oils are discussed in detail. Furthermore, Optical Microscopy (OM) and Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray spectroscopy (EDX), Focused Ion Beam (FIB) and Transmission Electron Microscopy (TEM) were used to observe the wear scar and propose wear mechanisms. The X-ray Photoelectron Spectroscopy (XPS) analysis was performed on the tribofilms to understand the tribochemical interactions between oil additives and the DLC coating. Nano-indentation analysis was conducted to assess potential structural modifications of the DLC coating. Coating hardness data could provide a better insight into the wear mode and failure mechanism of such hard coatings. Given the obtained results, the wear behaviour of the hydrogenated DLC coating was found to depend not only on the presence of ZDDP in the oil formulation but also on the counterpart type. This study revealed that the steel counterpart is a critical component of the tribocouple leading to MoDTC-induced wear of the hydrogenated DLC.

In the prehospital setting, early identification of septic shock (SS) at risk of poor outcome is mainly based on clinical vital signs alteration evaluation. The Charlson Comorbidity Index (CCI) is an in-hospital tool used for burden of co-morbidity assessment. We report the relationship between the modified prehospital CCI, and 30-day mortality of SS patients initially cared for in the prehospital setting by a mobile ICU (MICU). SS patients defined according to the 2016 sepsis-3 conference cared for by MICU between February 2017 and December 2021 were retrospectively analysed. The modified prehospital CCI calculation was based on the available comorbid conditions collected in the prehospital setting. A threshold of ≥5, was chosen according to previous results. Five-hundred and twenty-nine patients were included among which 154 suffering from septic shock were analysed. Presumed origin of septic shock was mainly pulmonary (36%), digestive (33%) and urinary (16%). 30 day-mortality reached 33%. Logistic regression after propensity score matching found a significant association between the 30-day mortality in the modified prehospital CCI ≥ 5: aOR = 1.12 [1.07–1.31], p = 0.041. Among septic shock patients initially cared for by a MICU in the prehospital setting, a significant association between 30-day mortality. A modified prehospital CCI of at least 6 appears to be useful for early identification of septic shock patients with poorer outcome.

Guidelines on sepsis management recommend early recognition, diagnosis and treatment, especially early antibiotic therapy (ABT) administration in order to reduce septic shock (SS) mortality. However, the adequacy of probabilistic prehospital ABT remains unknown. From May 2016 to March 2021, all consecutive patients with SS cared for by a prehospital mICU intervention were retrospectively analyzed. Among 386 patients retrospectively analyzed, 119 (33%) received probabilistic prehospital ABT, among which 74% received a 3rd generation cephalosporin: 31% cefotaxime and 42% ceftriaxone. No patient had a serious adverse effect related to ABT administration. Overall mortality rate on day-30 was 29%. Among the 119 patients with prehospital ABT, bacteriological identification was obtained for 81 (68%) patients with adequate prehospital ABT for 65 patients (80%) of which 10 (15%) deceased on day-30. Conversely, among the 16 (20%) patients with inadequate prehospital ABT, 9 patients (56%) were deceased on day-30. Prehospital adequate ABT was significantly different between alive and deceased patients on day-30 (p = 4.10−3). After propensity score matching, a significant association between adequate prehospital ABT administration and day-30 mortality was observed (aOR = 0.09 [0.01–0.47]). Inverse probability treatment weighting with multivariable logistic regression reported a day-30 mortality decrease in the adequate prehospital ABT group: aOR = 0.70 [0.53–0.93]. Among SS cared for by a mICU, probabilistic prehospital ABT is adequate most of the time and associated with a day-30 mortality decrease. Further prospective studies are needed to confirm these results and the weight of prehospital ABT in the prehospital bundle of care for SS.

Background Despite differences in time of sepsis recognition, recent studies support that early initiation of norepinephrine in patients with septic shock (SS) improves outcome without an increase in adverse effects. This study aims to investigate the relationship between 30-day mortality in patients with SS and prehospital norepinephrine infusion in order to reach a mean blood pressure (MAP) > 65 mmHg at the end of the prehospital stage. Methods From April 06th, 2016 to December 31th, 2020, patients with SS requiring prehospital Mobile Intensive Care Unit intervention (MICU) were retrospectively analysed. To consider cofounders, the propensity score method was used to assess the relationship between prehospital norepinephrine administration in order to reach a MAP > 65 mmHg at the end of the prehospital stage and 30-day mortality. Results Four hundred and seventy-eight patients were retrospectively analysed, among which 309 patients (65%) were male. The mean age was 69 ± 15 years. Pulmonary, digestive, and urinary infections were suspected among 44%, 24% and 17% patients, respectively. One third of patients (n = 143) received prehospital norepinephrine administration with a median dose of 1.0 [0.5–2.0] mg h −1 , among which 84 (69%) were alive and 38 (31%) were deceased on day 30 after hospital-admission. 30-day overall mortality was 30%. Cox regression analysis after the propensity score showed a significant association between prehospital norepinephrine administration and 30-day mortality, with an adjusted hazard ratio of 0.42 [0.25–0.70], p < 10 –3 . Multivariate logistic regression of IPTW retrieved a significant decrease of 30-day mortality among the prehospital norepinephrine group: ORa = 0.75 [0.70–0.79], p < 10 –3 . Conclusion In this study, we report that prehospital norepinephrine infusion in order to reach a MAP > 65 mmHg at the end of the prehospital stage is associated with a decrease in 30-day mortality in patients with SS cared for by a MICU in the prehospital setting. Further prospective studies are needed to confirm that very early norepinephrine infusion decreases septic shock mortality.

This paper describes the results of a series of tests on a heavy-duty truck diesel engine using conventional and low viscosity lubricants. The objectives were to explore the impact of reducing lubricant viscosity on wear, friction and fuel consumption. The radiotracing Thin Layer Activation method was used to make on-line measurements of wear at the cylinder liner, top piston ring, connecting rod small end bush and intake cam lobe. The engine was operated under a wide range of conditions (load, speed and temperature) and with lubricants of several different viscosity grades. Results indicate the relationship between lubricant viscosity and wear at four critical locations. Wear at other locations was assessed by analysis of wear metals and post test inspection. The fuel consumption was then measured on the same engine with the same lubricants. Results indicate the relationship between oil viscosity and fuel consumption under a wide range of operating conditions. Expected fuel consumption improvements over a typical drive cycle were calculated. Friction of the whole engine was calculated from measurements of cylinder pressure and brake torque, with two of the low viscosity oils and, in addition, a five stage motored friction teardown test was performed. Together these results were used to explore the relationship between lubricant viscosity and friction across a range of operating conditions.

Background The early identification of sepsis presenting a high risk of deterioration is a daily challenge to optimise patient pathway. This is all the most crucial in the prehospital setting to optimize triage and admission into the appropriate unit: emergency department (ED) or intensive care unit (ICU). We report the association between the prehospital National Early Warning Score 2 (NEWS-2) and in-hospital, 30 and 90-day mortality of SS patients cared for in the pre-hospital setting by a mobile ICU (MICU). Methods Septic shock (SS) patients cared for by a MICU between 2016, April 6th and 2021 December 31st were included in this retrospective cohort study. The NEWS-2 is based on 6 physiological variables (blood pressure, heart rate, respiratory rate, temperature, oxygen saturation prior oxygen supplementation, and level of consciousness) and ranges from 0 to 20. The Inverse Probability Treatment Weighting (IPTW) propensity method was applied to assess the association with in-hospital, 30 and 90-day mortality. A NEWS-2 ≥ 7 threshold was chosen for increased clinical deterioration risk definition and usefulness in clinical practice based on previous reports. Results Data from 530 SS patients requiring MICU intervention in the pre-hospital setting were analysed. The mean age was 69 ± 15 years and presumed origin of sepsis was pulmonary (43%), digestive (25%) or urinary (17%) infection. In-hospital mortality rate was 33%, 30 and 90-day mortality were respectively 31% and 35%. A prehospital NEWS-2 ≥ 7 is associated with an increase in-hospital, 30 and 90-day mortality with respective RRa = 2.34 [1.39–3.95], 2.08 [1.33–3.25] and 2.22 [1.38–3.59]. Calibration statistic values for in-hospital mortality, 30-day and 90-day mortality were 0.54; 0.55 and 0.53 respectively. Conclusion A prehospital NEWS-2 ≥ 7 is associated with an increase in in-hospital, 30 and 90-day mortality of septic shock patients cared for by a MICU in the prehospital setting. Prospective studies are needed to confirm the usefulness of NEWS-2 to improve the prehospital triage and orientation to the adequate facility of sepsis.

Purpose Respiratory dysfunction is one of the most frequent symptoms observed during sepsis reflecting hypoxemia and/or acidosis that may be assessed by the ROX index (ratio of oxygen saturation by pulse oximetry/fraction of inspired oxygen to respiratory rate). This study aimed to describe the relationship between the prehospital ROX index and 30-day mortality rate among septic shock patients cared for in the prehospital setting by a mobile intensive care unit (MICU). Methods From May 2016 to December 2021, 530 septic shock patients cared for by a prehospital MICU were retrospectively analysed. Initial ROX index value was calculated at the first contact with MICU. A Cox regression analysis after propensity score matching was performed to assess the relationship between 30-day mortality rate and a ROX index ≤ 10. Results Pulmonary, digestive and urinary sepsis were suspected among 43%, 25% and 17% patients, respectively. The 30-day overall mortality reached 31%. Cox regression analysis showed a significant association between 30-day mortality and a ROX index ≤ 10: adjusted hazard ratio of 1.54 [1.08–2.31], p  < 0.05. Conclusions During the prehospital stage of septic shock patients cared for by a MICU, ROX index is significantly associated with 30-day mortality. A prehospital ROX ≤ 10 value is associated with a 1.5-fold 30-day mortality rate increase. Prospective studies are needed to confirm the ability of prehospital ROX to predict sepsis outcome since the prehospital setting.

In the prehospital setting, early identification of septic shock (SS) with high risk of mortality aims to initiate early treatments and to decide delivery unit (emergency department (ED) or intensive care unit (ICU)). In this context, there is a need for a prognostic measure of severity and death in order to early detect patients with a higher risk of pejorative evolution. In this study, we describe the association between prehospital shock index (SI) and mortality at day 28 of patients with SS initially cared for in the prehospital setting by a mobile intensive care unit (MICU). Patients with SS cared for by a MICU between January 2016 and May 2019 were retrospectively analyzed. Using propensity score, the association between SI and mortality was assessed by Odd Ratio (OR) with 95 percent confidence interval [95 CI]. One-hundred and fourteen patients among which 78 males (68%) were analysed. The mean age was 71 ± 14 years old. SS was mainly associated with pulmonary (55%), digestive (20%) or urinary (11%) infection. Overall mortality reached 33% (n = 38) at day 28. Median SI [interquartile range] differed between alive and deceased patients: 0.73 [0.61–1.00] vs 0.80 [0.66–1.10], p < 0.001*). After adjusting for confounding factors, the OR of SI > 0.9 was 1.17 [1.03–1.32]. In this study, we report an association between prehospital SI and mortality of patients with prehospital SS. A SI > 0.9 is a readily available tool correlated with increased mortality of patients with SS initially cared for in the prehospital setting.

Reduction of pollutant emissions is one of the key drivers in the field of combustion engine development. In this context, in particular start stop systems are applied in order to further reduce the total fuel consumption and subsequently minimize pollutant emissions. However, this application leads to completely new operating conditions for the powertrain. In particular, hydrodynamic bearing systems are burdened by these operational changes and the increased proportion of solid friction contacts. In order to ensure safe bearing operation, in depth research in the field of start stop bearing dimensioning is required. This paper covers an extensive investigation of journal bearing systems under start stop operation conditions. With the aid of a novel component close test methodology the start stop wear characteristics of various bearing materials are investigated and compared. Furthermore, the impact of the lubricant viscosity and chemical additive formulation of engine lubricants on the start stop lifetime performance of journal bearing systems are discussed.