Development of a silicone hollow fiber membrane oxygenator for ECMO application

A new silicone hollow fiber membrane oxygenator for extracorporeal membrane oxygenation (ECMO) was developed using an ultrathin silicone hollow fiber, with a 300 microm outer diameter and a wall thickness of 50 microm. The hollow fibers were mechanically cross-wound on the flow distributor to achieve equal distribution of blood flow without changing the fiber shape. The housing, made of silicone coated acryl, was 236 mm long with an inner diameter of 60 mm. The surface area was 1.0 m2 for prototype 211, and 1.1 m2 for prototype 209. The silicone fiber length was 150 mm, and the silicone membrane packing density was 43% for prototype 211 and 36% for prototype 209. Prototype 211 has a priming volume of 208 ml, and prototype 209 has a priming volume of 228 ml. The prototype 211 oxygenator demonstrates a gas transfer rate of 120 +/- 5 ml/min (mean +/- SD) for O2 and 67 +/- 12 ml/min for CO2 under 2 L of blood flow and 4 L of O2 gas flow. Prototype 209 produced the same values. The blood side pressure drop was low compared with the silicone sheet oxygenator (Avecor, 1500ECMO). These results showed that this new oxygenator for ECMO had efficiency similar to the silicone sheet oxygenator that has a 50% larger surface area. These results suggest that the new generation oxygenator using an ultrathin silicone hollow fiber possesses sufficient gas transfer performance for long-term extracorporeal lung support.     

Survival for 145 days with a total artificial heart

A calf into which a biolized, total artificial heart (TAH) had been implanted survived for 145 days. All measured physiological parameters except central venous pressure (CVP) were back to normal one month after implantation, and thereafter the animal's physiological development was similar to that of a normal calf. The intimal weight, which was 96 kilograms at implantation, reached 190 kilogram at the end of experiment, with a daily gain rate of 0.9 kilogram per day. After the nineteenth postoperative week, signs of congestive heart failure appeared, such as high venous pressure, ascites, and enlarged liver although the calf outwardly appeared well. On postoperative day 146, the animal started foaming at the mouth, and a convulsion occurred; then, the experiment was terminated after 3,494 hours of pumping. At autopsy, there were acute bilateral bronchopneumonia involving mostly both upper lobes, pulmonary edema, slight chronic pneumonitis, and hepatomegaly. There were no serious thrombotic deposits inside the cardiac prosthesis.     

Inroads to Predict in Vivo Toxicology-An Introduction to the eTOX Project

There is a widespread awareness that the wealth of preclinical toxicity data that the pharmaceutical industry has generated in recent decades is not exploited as efficiently as it could be. Enhanced data availability for compound comparison ("read-across"), or for data mining to build predictive tools, should lead to a more efficient drug development process and contribute to the reduction of animal use (3Rs principle). In order to achieve these goals, a consortium approach, grouping numbers of relevant partners, is required. The eTOX ("electronic toxicity") consortium represents such a project and is a public-private partnership within the framework of the European Innovative Medicines Initiative (IMI). The project aims at the development of in silico prediction systems for organ and in vivo toxicity. The backbone of the project will be a database consisting of preclinical toxicity data for drug compounds or candidates extracted from previously unpublished, legacy reports from thirteen European and European operation-based pharmaceutical companies. The database will be enhanced by incorporation of publically available, high quality toxicology data. Seven academic institutes and five small-to-medium size enterprises (SMEs) contribute with their expertise in data gathering, database curation, data mining, chemoinformatics and predictive systems development. The outcome of the project will be a predictive system contributing to early potential hazard identification and risk assessment during the drug development process. The concept and strategy of the eTOX project is described here, together with current achievements and future deliverables.     

Nutritional behavior of cyclists during a 24-hour team relay race: a field study report

Background  

Information about behavior of energy intake in ultra-endurance cyclists during a 24-hour team relay race is scarce. The nutritional strategy during such an event is an important factor which athletes should plan carefully before the race. The purpose of this study was to examine and compare the nutritional intake of ultra-endurance cyclists during a 24-hour team relay race with the current nutritional guidelines for endurance events. Additionally, we analyzed the relationship among the nutritional and performance variables.     

1‐V continuous‐time equalizers for multi‐gigabit short‐haul optical fiber communications

Two new CMOS analog continuous‐time equalizers for high‐speed short‐haul optical fiber communications are presented in this paper. The proposed structures compensate the limited bandwidth‐length product of 1‐mm step‐index polymer optical fiber channels (45 MHz, 100 m) and have been designed in a standard 0.18‐µm CMOS process. The equalizers are aimed for multi‐gigabit short‐range applications, targeting up to 2 Gb/s through a 50‐m step‐index polymer optical fiber. The prototypes operate with a single supply voltage of only 1 V and overcome the severe limitations suffered by the widely used degenerated differential pair caused by the low supply voltage. Copyright © 2012 John Wiley & Sons, Ltd.     

Preparation,characterization, and release properties of hydrogels based on hyaluronan for pharmaceutical and biomedical use

Hyaluronic acid (HA) is a natural polysaccharide that is widely distributed in the human body. Its physicochemical properties and high biocompatibility make it a good candidate for biomedical and pharmaceutical uses. In the present work, we report HA‐based hydrogels that could be applied as drug delivery systems or as implants for the treatment of joint diseases. We use butanediol diglycidyl ether as a chemical crosslinker to obtain HA hydrogels. Using a new dissolution tester and ketoprofen (KP) as a model drug, we study the release properties of the hydrogels. We obtain homogeneous and transparent hydrogels with high strength and elasticity. The swelling ratio (SR) depends on the crosslinker concentration and pH of the medium. We also reveal differences between the release profile of KP from swollen and unswollen hydrogels. The characteristics and differences in KP release profiles depending on the SR suggest the possibility of obtaining controlled release from HA‐based hydrogels. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1377‐1382, 2013     

Chemical Desensitization of Explosives. Part 1. Effect of Ethyl Centralite on the Properties of an RDX-Based PBX

The effects of the addition of ethyl centralite, a commonly used stabilizer in double-base propellants, on a cyclotrimethylenetrinitramine (RDX)-based polymer-bonded explosive (PBX) were investigated. A reduction in sensitivity to impact was observed with increasing ethyl centralite content along with a reduction in explosiveness. Small-scale gap tests also show a reduction in sensitivity to shock initiation. High-performance liquid chromatography (HPLC) analysis of impact-stressed samples showed traces of 4-nitro- and 2-nitro-ethyl centralite and N-ethyl-N-nitrosoaniline; these results indicate the possibility that the mechanism of desensitization may, at least partially, be chemical in nature.     

Study of the ultrasound effects on yeast lees lysis in winemaking

This work focused on the study of ultrasound (US) treatment effects on wine lees, in order to verify the possibility of accelerating the protective colloids (i.e., polysaccharides) release. Moreover, these effects were compared with the usual practices of aging wine over lees and with the enzyme treatment of lees by means of beta-glucanases able to demolish the glucans and facilitate the release of intracellular components. This work was performed considering the possibility of setting up a technology applicable in a cellar. Ultrasound treatment on wine lees resulted in an increase in total colloids, proteins, and polysaccharides in the medium with a reduction in the colloids particle diameter. These results were mainly correlated with treatment duration rather than its intensity. Treatment at 90 % amplitude for 3 min provided good enough results in terms of colloids release, and therefore, it was used for the comparative study with natural lysis and enzyme treatment. The parameters evaluated showed that the ultrasound treatment resulted in an increased release of colloids from yeast (polysaccharides and glycoproteins); therefore, a significant effect on the extraction of cellular components compared to the long stay on the lees was detected, indicating the interesting advantage that this new technological application can bring to the winemaking process.     

A medial‐axis‐based model for propagating cracks in a regularised bulk

A new continuous‐discontinuous strategy for the simulation of failure is presented. The continuous bulk is regularised by means of a gradient‐enhanced damage model, where non‐locality is introduced at the level of displacements. As soon as the damage parameter is close or equal to 1, a traction‐free crack is introduced. To determine the direction of crack growth, a new criterion is proposed. In contrast to traditional techniques, where mechanical criteria are used to define the crack path, here, a geometrical approach is used. More specifically, given a regularised damage field D( x ), we propose to propagate the discontinuity following the direction dictated by the medial axis of the isoline (or isosurface in 3D) D( x ) = D*. The proposed approach is tested on different two‐dimensional and three‐dimensional examples that illustrate that this combined methodology is able to deal with damage growth and material separation. Copyright © 2014 John Wiley & Sons, Ltd.     

Concentrations and determinants of organochlorine levels among pregnant women in Eastern Spain

Persistent organic pollutants (POPs) comprise a large variety of toxic substances with ample distribution. While exposure to these toxins occurs mainly through diet, maternal POP levels may be influenced by certain sociodemographic, environmental, or lifestyle factors. This is important given that these substances may have adverse effects on fetal development. The aim of this study is to examine the sociodemographic, environmental, lifestyle, and dietary determinants of the levels of hexachlorobenzene (HCB), b-hexachlorocyclohexane (b-HCH), 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (4,4′-DDT), 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (4,4′-DDE), and polychlorinated biphenyls (PCB congeners 118, 138, 153, 180) measured in the blood of pregnant women participating in a mother-child cohort study conducted in Valencia (Spain).The study population consisted of 541 pregnant women who formed part of the INMA (Childhood and the Environment) cohort (2004-2006). POP levels were determined in blood taken during the 12th week of pregnancy with the aid of gas chromatography with electron capture detection. Sociodemographic, environmental, and dietary information was obtained from a questionnaire. Multivariate Tobit regression models were constructed in order to assess the association between POP levels and selected covariates.The results showed that all the women had detectable levels of at least one of these compounds while in 43% of the subjects, all eight compounds were detected. The compounds found in the greatest number of women were 4,4′-DDE (100%) and PCBs 153 and 180 (95%). The most important determinants of high POP levels were the mother's age, country of origin, increased body mass index, and number of weeks of breastfeeding after previous pregnancies. With regard to diet, 4,4′-DDT and 4,4′-DDE levels increased with the intake of meat, fruit, and cereal. PCB 153 levels increased with the intake of seafood. The levels of HCB, b-HCH, 4,4′-DDT, and 4,4′-DDE observed in this study were slightly higher than in other studies, whereas the PCB levels were similar.