Pulmonary artery banding: long-term telemetric adjustment

Objective: Adjustment of pulmonary blood flow is difficult in pulmonary artery banding for complex congenital heart defects. A new wireless, battery free, telemetrically controlled, implantable device (FloWatch®, EndoArt, S.A., Lausanne, Switzerland) allowing for progressive occlusion/reopening of the device through a remote control at the wanted percentage of occlusion (adjustable pulmonary artery banding) underwent experimental evaluation. Methods: Eleven mini-pigs underwent FloWatch® implantation around the main pulmonary artery through left thoracotomy. The first group (n=4), mean age 18.2±0.1 weeks, mean body weight 12.0±0.1 kg, underwent FloWatch® implantation as device tolerance test. The second group (n=7), mean age 8.6±3.4 weeks, mean body weight 5.1±1.5 kg, underwent functional evaluation: at implantation, 1, 3, 5, 8 and 10 weeks after implantation, the device was progressively occluded and reopened, with Doppler evaluation of the developed pressure gradient. Results: The four mini-pigs of first group were sacrificed at mean age of 42.3±0.1 weeks, mean body weight 25.1±3.2 kg (mean interval of 24 weeks after implantation); the device was still functioning and histology revealed almost normal morphology of the pulmonary artery. In all seven mini-pigs of second group the possibility of narrowing/releasing the pulmonary artery was confirmed at implantation and during follow-up: at last control their mean age was 20.5±2.8 weeks and the body weight 12.7±3.7 kg. Conclusions: Complete adjustment of pulmonary blood flow is now possible with an implantable device allowing for pulmonary artery banding with early and late telemetric flow contro

Non-Sterilized Fermentative Production of Polymer-Grade L-Lactic Acid by a Newly Isolated Thermophilic Strain Bacillus sp. 2–6

-lactic acid is another limitation for PLA polymers to compete with conventional plastics.-lactic acid concentration of 182.0 g/liter was obtained from 30-liter fed-batch fermentation with an average productivity of 3.03 g/liter/h and product optical purity of 99.4%.-lactic acid production from renewable resources

Extended Thromboprophylaxis with Betrixaban in Acutely Ill Medical Patients

Background Patients with acute medical illnesses are at prolonged risk for venous thrombosis. However, the appropriate duration of thromboprophylaxis remains unknown. Methods Patients who were hospitalized for acute medical illnesses were randomly assigned to receive subcutaneous enoxaparin (at a dose of 40 mg once daily) for 10±4 days plus oral betrixaban placebo for 35 to 42 days or subcutaneous enoxaparin placebo for 10±4 days plus oral betrixaban (at a dose of 80 mg once daily) for 35 to 42 days. We performed sequential analyses in three prespecified, progressively inclusive cohorts: patients with an elevated d-dimer level (cohort 1), patients with an elevated d-dimer level or an age of at least 75 years (cohort 2), and all the enrolled patients (overall population cohort). The statistical analysis plan specified that if the between-group difference in any analysis in this sequence was not significant, the other analyses would be considered exploratory. The primary efficacy outcome was a composite of asymptomatic proximal deep-vein thrombosis and symptomatic venous thromboembolism. The principal safety outcome was major bleeding. Results A total of 7513 patients underwent randomization. In cohort 1, the primary efficacy outcome occurred in 6.9% of patients receiving betrixaban and 8.5% receiving enoxaparin (relative risk in the betrixaban group, 0.81; 95% confidence interval [CI], 0.65 to 1.00; P=0.054). The rates were 5.6% and 7.1%, respectively (relative risk, 0.80; 95% CI, 0.66 to 0.98; P=0.03) in cohort 2 and 5.3% and 7.0% (relative risk, 0.76; 95% CI, 0.63 to 0.92; P=0.006) in the overall population. (The last two analyses were considered to be exploratory owing to the result in cohort 1.) In the overall population, major bleeding occurred in 0.7% of the betrixaban group and 0.6% of the enoxaparin group (relative risk, 1.19; 95% CI, 0.67 to 2.12; P=0.55). Conclusions Among acutely ill medical patients with an elevated d-dimer level, there was no significant difference between extended-duration betrixaban and a standard regimen of enoxaparin in the prespecified primary efficacy outcome. However, prespecified exploratory analyses provided evidence suggesting a benefit for betrixaban in the two larger cohorts. (Funded by Portola Pharmaceuticals; APEX ClinicalTrials.gov number, NCT01583218. opens in new tab.

Insights into iodine behaviour and speciation in the Phébus primary circuit

The Phébus FP integral test series studies a large spectrum of the phenomenology of severe accidents in water-cooled nuclear reactors. These tests represent a unique source of representative integral source term data, covering fuel rod degradation and behaviour of fission-products released via the coolant system into the containment. The present analysis concerns the behaviour of iodine in the test circuit representing the Reactor Coolant System (RCS) which reaches gas temperatures of nearly 1600 C at the circuit entrance and descending to 150 C before entry into the containment. The stake in the data analysis is a better understanding of iodine phenomenology in RCS. This is indeed all the more serious as iodine is one of the most radiological important fission products released from the fuel and may exist under highly volatile forms even within cold leg thermal-hydraulics conditions. Complex and coupled phenomena arise in the primary circuit during the tests as the temperature decreases (drops) from the inlet of the circuit to the outlet. These are respectively for the iodine vapours and aerosols: chemical transformation, condensation on walls/aerosols, homogeneous nucleation into aerosols and agglomeration, deposition by thermophoresis. Depending on the location in the primary circuit, a combination of these phenomena occurred simultaneously. The phenomenological behaviour of iodine in RCS2 will be appraised through the analyses of the iodine transport, retention, vapour speciation and gaseous occurrence in the Phébus FP primary circuit during the four Phébus-bundle tests. In these tests, the impact of different oxido-reducing and thermal-hydraulics conditions prevailing in the primary circuit as well as the impact of boron and control rod materials on iodine behaviour has been investigated. In this test series, iodine behaviour in the FPT3 primary circuit clearly departed from the others because a much higher iodine retention was observed upstream the steam generator (due to partial boron-rich blockage after 14,500 s) but above all a much higher gaseous iodine fraction in hot and cold legs was formed as compared to other tests. In the three other Phébus FP tests, iodine was generally poorly retained in the primary circuit (70% of released iodine reaching the containment vessel). Two main zones of significant deposition were identified coinciding with sections in which temperatures dropped rapidly. These were the fuel bundle exit (upper plenum and vertical line) where the gas cooled from very high fuel temperatures down to 700 C and the steam generator riser (upstream part and hot leg entrance) where temperatures cooled from 700 C to 150 C. As expected, iodine was mainly transported under vapour forms in the circuit hot leg. However, Phébus FP tests provided new insights into iodine transport, as several volatile iodine vapour species not associated to caesium were evidenced. In all tests, a significant amount of iodine under a gaseous form was found in the containment early during the bundle transient phase, implying that this gas was originated from the circuit. Except for FPT3, measurements of gaseous iodine in the circuit, from discrete samplings, were however more contradictory as only negligible amounts of gaseous iodine were generally measured in the cold leg. Due to the limitations of such measurements (trapping efficiencies, limited period of samplings) the gaseous iodine occurrence in the primary circuit during FPT0/1/2 could neither be stated nor refuted. Finally, Phébus FP test analyses that were performed using equilibrium gas-phase chemistry models evidenced that it becomes necessary to reconsider iodine species behaviour along their transport in the RCS not only as a function of oxido-reducing conditions, material release kinetics, but also in the light of potential kinetics limitations in vapour chemical transformations. Indeed, even if a strong connection between B, Cs, Mo, Cd and I chemistry was evidenced; in general, calculations were only partly satisfactory in reproducing the main aspects of the observed iodine/caesium behaviour and speciation. A better prediction of the volatile iodine speciation, the level of association of I to Cs and the gaseous iodine occurrence are the main objective of the experimental international and cooperative programme CHIP launched by IRSN in support of the Phébus FP programme interpretation. This programme was especially dedicated to investigate the kinetic limitations of iodine chemical reactions in a model primary circuit. © 2013 Elsevier B.V. All rights reserved

Paths to Stability in the Assignment Problem

We study a labor market with finitely many heterogeneous workers and firms to illustrate the decentralized (myopic) blocking dynamics in two-sided one-to-one matching markets with continuous side payments (assignment problems, Shapley and Shubik [24]). Assuming individual rationality, a labor market is unstable if there is at least one blocking pair, that is, a worker and a firm who would prefer to be matched to each other in order to obtain higher payoffs than the payoffs they obtain by being matched to their current partners. A blocking path is a sequence of outcomes (specifying matchings and payoffs) such that each outcome is obtained from the previous one by satisfying a blocking pair (i.e., by matching the two blocking agents and assigning new payoffs to them that are higher than the ones they received before). We are interested in the question if starting from any (unstable) individually rational outcome, there always exists a blocking path that will lead to a stable outcome. In contrast to discrete versions of the model (i.e., for marriage markets, one-to-one matching, or discretized assignment problems), the existence of blocking paths to stability cannot always be guaranteed. We identify a necessary and sufficient condition for an assignment problem (the existence of a stable outcome such that all matched agents receive positive payoffs) to guarantee the existence of paths to stability and show how to construct such a path whenever this is possible