Error detection: a study in anaesthesia

Although error has been shown as the main cause of accidents in complex systems, little attention has been paid to error detection. However, reducing the consequences of error depends largely on error detection. The goal of this paper is to synthesize the existing scientific knowledge on error detection, mostly based on studies conducted in laboratory or self reporting and to further knowledge through the analysis of a corpus of cases collected in a complex system, anaesthesia. By doing this, this paper is better able to describe how this knowledge can be used to improve understanding of error detection modes. An anaesthesia accident reporting system developed and organized at two Belgian University Hospitals was used in order to collect information about the error detection patterns. Results show that detection of errors principally occurred through the standard check (routine monitoring of the environment). Significant relationships were found between the type of error and the error detection mode, and between the type of error and the training level of the anaesthetist who committed the error.     

Impact of Endocrine Disruptors upon Non-Genetic Inheritance

Similar to environmental factors, EDCs (endocrine-disrupting chemicals) can influence gene expression without modifying the DNA sequence. It is commonly accepted that the transgenerational inheritance of parentally acquired traits is conveyed by epigenetic alterations also known as “epimutations”. DNA methylation, acetylation, histone modification, RNA-mediated effects and extracellular vesicle effects are the mechanisms that have been described so far to be responsible for these epimutations. They may lead to the transgenerational inheritance of diverse phenotypes in the progeny when they occur in the germ cells of an affected individual. While EDC-induced health effects have dramatically increased over the past decade, limited effects on sperm epigenetics have been described. However, there has been a gain of interest in this issue in recent years. The gametes (sperm and oocyte) represent targets for EDCs and thus a route for environmentally induced changes over several generations. This review aims at providing an overview of the epigenetic mechanisms that might be implicated in this transgenerational inheritance.     

Duplex SiCN/DLC coating as a solution to improve fretting—Corrosion resistance of steel

Fretting corrosion damages are commonly observed when two metallic bodies, which are in contact with each other, are subjected to oscillatory motions of low amplitude. Such kind of degradation mode is often responsible for limited durability of aeronautical joints. In the present paper, a multifunctional duplex coating based on Si–C–N and diamond-like carbon (DLC) materials, combining corrosion resistance and good tribological properties is described. Amorphous hydrogenated SiC, SiCN, SiC/DLC and SiCN/DLC were deposited on steel substrates by a plasma assisted chemical vapour deposition (PACVD) technique, using tetramethylsilane (TMS), ammonia (NH₃) or acetylene (C₂H₂) as gas precursors. Nitrogen incorporation has shown to improve the corrosion protection ability of SiC coatings. The corrosion behaviour and the tribological performance in aqueous media of SiCN/DLC coating have therefore been investigated. A test rig has been designed to validate the fretting resistance of this duplex coating for aeronautic applications. It was found that the combination of a SiCN-based PACVD sublayer with a DLC topcoat could provide an enhanced solution to withstand both fretting and corrosion.     

Electrochemical boron-doped diamond film microcells micromachined with femtosecond laser: application to the determination of water framework directive metals

Planar electrochemical microcells were micromachined in a microcrystalline boron-doped diamond (BDD) thin layer using a femtosecond laser. The electrochemical performances of the new laser-machined BDD microcell were assessed by differential pulse anodic stripping voltammetry (DPASV) determinations, at the nanomolar level, of the four heavy metal ions of the European Water Framework Directive (WFD): Cd(II), Ni(II), Pb(II), Hg(II). The results are compared with those of previously published BDD electrodes. The calculated detection limits are 0.4, 6.8, 5.5, and 2.3 nM, and the linearities go up to 35, 97, 48, and 5 nM for, respectively, Cd(II), Ni(II) Pb(II), and Hg(II). The detection limits meet with the environmental quality standard of the WFD for three of the four metals. It was shown that the four heavy metals could be detected simultaneously in the concentration ratio usually measured in sewage or runoff waters.     

Biocompatibility of heparin-grafted hemodialysis membranes: impact on monocyte chemoattractant protein-1 circulating level and oxidative status

This prospective observational study aimed at evaluating efficacy and biocompatibility performances of the new heparin-coated Evodial dialyzers with/without systemic heparin reduction. After a 4-week wash-out period with reference polysulfone F70S dialyzers, 6 hemodialysis patients were sequentially dialyzed with Evodial, F70S, and Evodial dialyzers using 30% heparin reduction, each period of treatment was 4 weeks. Removal rates (RR) (urea, creatinine, and β2-microglobulin), dialysis dose, and instantaneous clearances (urea and creatinine) were measured as well as inflammatory (C-reactive protein, fibrinogen, interleukin 6, tumor necrosis factor α, and monocyte chemoattractant protein-1) and oxidative stress (OS) (superoxide anion, homocysteine, and isoprostanes) parameters at the end of each study period. Patients treated with Evodial or F70S dialyzers for 4 weeks presented comparable dialysis efficacy parameters including urea and creatinine RR, dialysis dose and instantaneous clearances. By contrast, a significantly lower but reasonably good β2-microglobulin RR was achieved with Evodial dialyzers. Regarding biocompatibility, no significant difference was observed with inflammation and OS except for postdialysis monocyte chemoattractant protein-1 which significantly decreased with Evodial dialyzers. Thirty percent heparinization reduction with Evodial dialyzers did not induce any change in inflammation but led to an improvement in OS as demonstrated by a decrease in postdialysis superoxide production and predialysis homocysteine and isoprostane. This bioactive dialyzer together with heparin dose reduction represents a good trade-off between efficacy and biocompatibility performance (improvement in OS with a weak decrease in efficacy) and its use is encouraging for hemodialysis patients not only in reducing OS but also in improving patient comorbid conditions due to lesser heparin side effects.     

Ecological and aromatic impact of two Gram-negative bacteria (Psychrobacter celer and Hafnia alvei) inoculated as part of the whole microbial community of an experimental smear soft cheese

The impact of the growth of two Gram-negative bacteria, Psychrobacter celer and Hafnia alvei, inoculated at 10² and 10⁶ cfu/g, on the dynamics of a multispecies community as well as on volatile aroma compound production during cheese ripening was investigated. Results showed that P. celer was able to successfully implant itself in cheese, regardless of its inoculation level. However, when it was inoculated at a high level, the bacterial biodiversity was drastically lowered from day 25 to the end of ripening. Overall, the presence of P. celer led to the higher production of volatile aroma compounds such as aldehydes, ketones and sulfur compounds. Regardless of its inoculation level, H. alvei barely affected the growth of the bacterial community and was subdominant at the end of ripening. It influenced total volatile aroma compound production with volatile sulfur compounds being the most abundant. Overall, these two bacteria were able to implant themselves in a cheese community and significantly contributed to the aromatic properties of the cheese. Their role in flavoring and their interactions with the technological microorganisms must be considered during cheese ripening and should be further investigated.     

Does hemodiafiltration improve the removal of homocysteine?

High prevalence of hyperhomocysteinemia is common in hemodialysis (HD) patients and could contribute to worsen the cardiovascular risk. Beyond vitamin B status, dialysis modality itself could influence homocysteine (Hcy) levels. The objective was compare the reduction rate (RR) of Hcy and cysteine in stable dialyzed patients treated by standard HD or hemodiafiltration (HDF). Seventy‐five patients undergoing stable dialysis through standard high‐flux HD (n = 35) or HDF (n = 40) were included. Biological parameters were determined before and after a midweek dialysis session. Urea percent reduction per session and Kt/V index (K, body urea clearance, T, time of dialysis, and V, urea distribution volume), defined as a marker of dialysis efficacy, were similar between HD and HDF groups. By contrast, higher RR of beta2 microglobulin (β2m) was observed in HDF compared with HD (78.6 vs. 72.0%, respectively; P < 0.001). Likewise, higher RR of Hcy was obtained with HDF compared to HD (46.0 vs. 41.5%, respectively; P < 0.05), whereas the RR of cysteine was similar in both groups. Interestingly, a positive correlation between Hcy RR and urea Kt/V index was observed (r = 0.29, P < 0.05) and between Hcy RR and β2m RR (r = 0.45, P < 0.001). Time‐averaged concentration (TAC) of Hcy was lower with HDF compared with HD (17.8 vs. 19.1 μmol/L, respectively), although not significant. There was no difference in median Hcy according to dialysis modality for neither pre‐ nor postdialysis levels. Significant higher removal of Hcy was observed with HDF compared with standard HD, although urea Kt/V index was similar. Enhanced removal of middle molecules, such as β2m, could be involved in Hcy RR improvement with HDF.     

Outdoor rearing of cull sows: Effects on carcass, tissue composition and meat quality

The objective of this study was to provide some information on the influence of outdoor rearing on pasture (O) compared with indoor (I) on carcass and meat quality of cull sows. Twelve sows (6 per group) originating from the same breeding unit were slaughtered 11 days after their last weaning. O sows had heavier and fatter carcasses, however lipid content in Longissimus (L) and Triceps brachii (TB) muscles was not affected. Grazing of O sows led to a high increase in the n − 3 fatty acid content, particularly the C18:3 linolenic acid in the backfat and L muscle, thus improving the meat nutritional quality. Vitamin E content appeared (P = 0.13) to be increased in the backfat of O sows, but not in the muscles. Lipid oxidation in meat during storage was similar between groups. Histological and metabolic observations showed that outdoor rearing increased the glycolytic capacity of the L muscle, and the oxidative capacity of the TB. Outdoor rearing did not influence meat pH1 and pHu, but decreased colour (a¹ and b¹ values) of the TB, and increased the processing yield of loin into cured bacon. Outdoor rearing decreased the red colour intensity and homogeneity, but improved tenderness of cured loins.     

Potentials Produced by Arbitrary Current Sources in an Infinite-and Finite-Length Circular Conducting Cylinder

In electrophysiology, the analytical expression of the potentials at the outer surface of a cylinder, caused by an embedded current source distribution, is useful in studies where measured potentials have to be related to unknown generators. The solutions found in the literature for different types of current sources are unfortunately contradictory. This paper rederives the solution to the general case of an arbitrary monopolar or dipolar current source and discloses where and how an error arose in earlier work. The problems encountered during the numerical implementation of the new equations are extensively discussed.     

The effect of 2D and 3D visual modes on surgical task performance: role of expertise and adaptation processes

The aim of this paper is to analyze how novices and experts are able to safely adapt and transfer their skills to new technology in medical domain. In order to answer this question, we compared the performance of 12 novices (medical students) with the performance of 12 laparoscopic surgeons (using a 2D view) and 4 robotic surgeons, using a new robotic system that allows 2D and 3D view. Our results showed a trivial effect of expertise (surgeons generally performed better than novices). Moreover, they revealed that experts have adaptive transfer capacities and are able to transfer their skills independently of the human–machine system. However, even if we observe transfer of skills, we showed that expert’s performance may be disturbed by changes in their usual environment. In a safety perspective but also for novice and expert training, this study emphasizes the necessity to take into account the impact of these environmental changes and the expert’s adaptive capacities but also the limits of expert’s adaptive capacities.