In spite of high piezoelectricity, only a few one-dimensional ferroelectric nano-materials with perovskite structure have been used for piezoelectric nanogenerator applications. In this paper, we report high output electrical signals, i.e. an open-circuit voltage of 3.2 V and a closed-circuit current of 67.5 nA (current density 9.3 nA cm(-2)) at 0.38% strain and 15.2% s(-1) strain rate, using randomly aligned lead-free KNbO(3) ferroelectric nanorods (~1 μm length) with piezoelectric coefficient (d(33) ~ 55 pm V (-1)). A flexible piezoelectric nanogenerator is mainly composed of KNbO(3)-poly(dimethylsiloxane) (PDMS) composite sandwiched by Au/Cr-coated polymer substrates. We deposit a thin poly(methyl methacrylate) (PMMA) layer between the KNbO(3)-PDMS composite and the Au/Cr electrode to completely prevent dielectric breakdown during electrical poling and to significantly reduce leakage current during excessive straining. The flexible KNbO(3)-PDMS composite device shows a nearly frequency-independent dielectric constant (~3.2) and low dielectric loss (<0.006) for the frequency range of 10(2)-10(5) Hz. These results imply that short and randomly aligned ferroelectric nanorods can be used for a flexible high output nanogenerator as well as high-k capacitor applications by performing electrical poling and further optimizing the device structure.

The circulating levels of NET release reflect the coagulation activation and adverse clinical outcomes in patients with DIC, thereby providing potential clinical relevance for mortality prediction in DIC.

PurposeThis study was designed to assess the outcome of the extracorporeal membrane oxygenation (ECMO) in liver transplantation (LT) recipients with refractory septic shock and predict the prognosis of those cases.MethodsFrom February 2005 to October 2012, ECMO was used in 8 cases of refractory septic shock. Laboratory values including lactate and total bilirubin level just before starting ECMO were obtained and sepsis-related organ failure assessment (SOFA) score, acute physiology and chronic health evaluation (APACH) II score and simplified acute physiology score (SAPS) 3 were calculated. Subsequent peak serum lactate and total bilirubin level, and SOFA score after 24 hours of starting ECMO were measured.ResultsComparisons were made between survivors and nonsurvivors. ECMO was weaned off successfully in 3 patients (37.5%) and 2 patients (25%) survived to hospital discharge. Clinical scores including SOFA, APACH II, and SAPS3 and laboratory results including lactate, total bilirubin and CRP were not significantly different between survivor and nonsurvivor groups. Lactate level and SOFA score tended to decrease after ECMO support in survivor group and total bilirubin and CRP level tended to increase in nonsurvivor group.ConclusionOur findings suggest that the implantation of ECMO might be considered in highly selected LT recipients with refractory septic shock.

Serosurveillance studies reveal the actual disease burden and herd immunity level in the population. In Seoul, Korea, a cross-sectional investigation showed 0.07% anti-severe acute respiratory syndrome coronavirus-2 antibody seropositivity among 1,500 outpatients of the university hospitals. Low seroprevalence reflects well-implemented social distancing. Serosurveillance should be repeated as the pandemic progresses.