The manufacturing of composites of ultra high molecular weight polyethylene and ceramics with conductive properties has been investigated. Attention has been focused on the lowering of the amount of filler necessary to achieve low resistivity. Using segregated networks, mixing large polymer particles and submicron metal or conductive ceramic particles may be an interesting route, provided that the processing method enables to generate the desired structures. Because sintering avoids the intimate blending of the components, it is a suitable technique for this aim. The combined effects of temperature, pressure and sintering time have been investigated. The influence of the blending of the solids on the covering of the polyethylene particles before the sintering has also been pointed out. The typical features related to the concept of a segregated network are discussed in connection with the morphologies of the polymer and ceramic particles. The successful application of the reduction of the percolation threshold by a segregated network in conductive composites of polymer and metallic particles is described.

Alteration of tissue perfusion is a main contributor of organ dysfunction. In cardiac surgery, the importance of organ dysfunction is associated with worse outcome. Central venous-arterial difference in CO tension (ΔCO) has been proposed as a global marker of the adequacy of tissue perfusion in shock states. We hypothesized that ΔCO could be increased in case of postoperative organ failure or worse outcome. In this monocentric retrospective cohort study, we retrieved, from our database, 220 consecutive patients admitted in intensive care after an elective cardiac surgery. Four time points were formed: ICU admission, and 6, 24 and 48 h after. A ΔCO below 6 mmHg defined the normal range values. The SOFA score, intensive care unit and hospital length of stay, hospital and 6-month mortality rate were recorded. We compared patient with low ΔCO (<6 mmHg) and high ΔCO (≥6 mmHg). We included 55 (25 %) and 165 patients in low and high ΔCO groups, respectively. The SOFA score, the hospital and 6 months mortality rate were higher in patients with low ΔCO. Surprisingly, we did not find results previously published in other surgical settings. In cardiac surgery, ΔCO has a low predictive value of outcome.

This study confirms, through a non-invasive technology, a significant but transient alteration of the microcirculation during elective cardiac surgery. However, as these microvascular alterations were not correlated with patient's outcome, NIRS-derived parameters seem to be of limited interest in the cardiac surgery setting.

Although our study showed overall improvement of quality of life after cardiac operations, more than one-quarter of the patients manifested deterioration of HRQOL at 6 months postoperatively. The findings from this study should help clinicians to inform patients about their likely postoperative functional status and quality of life.