Post-traumatic ARDS--a potential indication for lung transplantation?

Posttraumatic adult respiratory distress syndrome (ARDS) still involves significant mortality, despite progress in management concepts. Current therapeutic strategies are briefly described, including kinetic therapy, high-frequency jet ventilation and extracorporeal membrane oxygenation. In addition, a spectacular case of the first successful lung transplantation for posttraumatic ARDS after failed ECMO (extracorporeal membrane oxygenation) support is reported. This young man with severe posttraumatic ARDS developed a potentially lethal bilateral pulmonary hemorrhage under treatment with ECMO, and on the basis of this bilateral pulmonary transplantation was considered to be indicated. The patient is alive and well 2 years after the procedure.     

HISYCOL a hybrid computational intelligence system for combined machine learning: the case of air pollution modeling in Athens

The analysis of air quality and the continuous monitoring of air pollution levels are important subjects of the environmental science and research. This problem actually has real impact in the human health and quality of life. The determination of the conditions which favor high concentration of pollutants and most of all the timely forecast of such cases is really crucial, as it facilitates the imposition of specific protection and prevention actions by civil protection. This research paper discusses an innovative threefold intelligent hybrid system of combined machine learning algorithms HISYCOL (henceforth). First, it deals with the correlation of the conditions under which high pollutants concentrations emerge. On the other hand, it proposes and presents an ensemble system using combination of machine learning algorithms capable of forecasting the values of air pollutants. What is really important and gives this modeling effort a hybrid nature is the fact that it uses clustered datasets. Moreover, this approach improves the accuracy of existing forecasting models by using unsupervised machine learning to cluster the data vectors and trace hidden knowledge. Finally, it employs a Mamdani fuzzy inference system for each air pollutant in order to forecast even more effectively its concentrations.     

Detecting invasive species with a bio-inspired semi-supervised neurocomputing approach: the case of Lagocephalus sceleratus

The need to protect the environment and biodiversity and to safeguard public health require the development of timely and reliable methods for the identification of particularly dangerous invasive species, before they become regulators of ecosystems. These species appear to be morphologically similar, despite their strong biological differences, something that complicates their identification process. Additionally, the localization of the broader space of dispersion and the development of invasive species are considered to be of critical importance in the effort to take proper management measures. The aim of this research is to create an advanced computational intelligence system for the automatic recognition, of invasive or another unknown species. The identification is performed based on the analysis of environmental DNA by employing machine learning methods. More specifically, this research effort proposes a hybrid bio-inspired computational intelligence detection approach. It employs extreme learning machines combined with an evolving Izhikevich spiking neuron model for the automated identification of the invasive fish species “Lagocephalus sceleratus” extremely dangerous for human health.

     

Development of an HPLC method for measurements of the stability of Irganox-type polymer antioxidants in fatty food simulants

 A reversed-phase high-performance liquid chromatography (RP-HPLC) method has been developed to measure the stability of four Irganox-type polymer antioxidants (Irganox 245, Irganox 1035, Irganox 1098 and Irganox 3114) in an olive oil food simulant and isooctane, which has been proposed as an alternative fatty food simulant. The tests of stability in olive oil were carried out under three different conditions, i.e. 40°C for 10 days, 100°C for 1 h and 175°C for 1 h. The exposure conditions for isooctane were 60°C for 3 h. Results showed that for all additives tested no instability phenomena in olive oil or isooctane simulants were observed under the exposure conditions applied. The analytical methodology developed could eventually be used for stability testing and migration studies of other similarly structured antioxidants in fatty food simulants. Received: 11 September 1997     

Studies on the usability of recycled PET for food packaging applications

The need of and opportunities for recycling of plastics for food packaging have been recognized, and a lot of work to find meaningful and cost-effective solutions to this issue is in progress. The safety of recycled plastics for food contact use is largely dictated by the ability of post-consumer contaminants to absorb into recycled materials and later diffuse from recycled plastics into the food. The objective of the present study was to establish a suitable analytical approach to identifying and quantifying any chemical substances that derive from the earlier use and remain in the polyethylene terephthalate (PET). A simple gas chromatographic technique using flame ionization detection was developed to allow quantification of solvent extractable compounds in a series of recycled PET samples. Identification of the nature and extent of contaminants in the PET samples was also attempted using GC/MS analysis.     

Determination of water uptake and moisture sorption isotherms of PVC-based food packaging materials: Effect of plasticizer content and temperature

Sorption isotherms of three polymeric mixtures were constructed with the use of a computerized inverse gas chromatographic technique at temperatures of 32°C and 50°C. It was observed that the water uptake increases with decreasing temperature and increasing amount of plasticizer in the polymeric mixtures. The sorption data were applied to the BET and GAB isotherm models. It was found that the two-parameter BET equation fits the sorption data up to a water activity value of 0.6 and the three-parameter GAB equation fits the sorption data up to a water activity value of 0.7. The thermodynamics of the above interaction were studied further by application of the Zimm-Lundberg cluster theory. Results indicate a strong tendency for water molecules to cluster even at low water activity values.     

Effect of adsorbent particle size and temperature on water-ethanol separation by starchy and cellulosic substrates

Inverse gas chromatography was used to study the adsorption of water and ethanol on two starchy (cornmeal and wheatflour) and one cellulosic (wheat straw) substrate, in the temperature range 50–90??°C. Three particle size fractions of each substrate were investigated – 180–250?μm, 160–180?μm and 125–160?μm, denoted, respectively, by: 60–80 mesh, 80–100 mesh and 100-120 mesh. Values for the separation factor and for thermodynamic parameters, such as Gibbs free energy and enthalpy of adsorption, were calculated from the chromatographic retention data. The results showed that water was adsorbed more strongly than ethanol on all substrates, at all temperatures. In addition, it was found that lower temperatures were more favourable for the adsorption of both solutes. There was no significant difference between values of separation capacity of the three fractions of wheat straw. In contrast, the separation capacities of starchy materials with smaller particle sizes, i.e. 80–100 mesh and 100–120 mesh, were greater. The 100–120 mesh wheatflour fraction exhibited the highest separation at all temperatures.     

The effects of γ‐irradiation on compositional changes in plastic packaging films

Sterilization of packaging materials for pharmaceutical or food products with ionizing irradiation can cause chemical and physical changes in polymer materials. The effects of γ‐irradiation on the formation of solvent extractable radiolysis products of six flexible packaging materials for foodstuffs and/or pharmaceutical applications were studied after treatment in a ⁶⁰Co‐irradiation plant. The polymer materials polyethylene, polypropylene, poly(ethylene terephthalate), polyamide, polystyrene and poly(vinyl chloride) were investigated after treating with an irradiation dose of 44 kGy. The compositional changes in solvent extractable radiolysis products of each packaging material were quantified. In most cases the radiolysis products formed could be identified using GC/MS. The polyolefine materials (PE and PP) showed an increase of low volatile compounds after irradiation due to an oxidative decomposition of the polymer and typical polymer substances like oligomers and additives. Other packaging materials such as PET, PA and PS did not significantly change their amount of solvent extractable compounds after irradiation with 44 kGy. The PVC packaging material used in this study was not resistant to irradiation treatment at all. Because of the release of HCl during irradiation a large amount of volatile substances could be extracted from the PVC sheet. For consumer protection and also to meet general food packaging legislative requirements for irradiated packaging materials, it is necessary to evaluate the compositional changes in the polymers during irradiation, especially for irradiated polyolefines and PVC. Most attention should be paid to low volatile radiolysis products which are the most likely to migrate into a foodstuff or a pharmaceutical product. Copyright © 1999 John Wiley & Sons, Ltd.     

Determination of low levels of aziridine in official EU food simulants by capillary gas chromatography

 An analytical method for the determination of the specific migration of aziridine (ethyleneimine) into food simulants at trace levels is described. The method comprises a two-phase (aqueous-organic solvent) derivatization procedure with 4-fluorobenzoyl chloride, using propyleneimine as an internal standard. The derivatization reaction is accomplished very quickly and the organic layer containing the derivatized imine is analysed by capillary gas chromatography using selective nitrogen detection (nitrogen-phosphorus detector). The detection limits of the method were lower than 5 μg/kg in the food simulant. Received: 5 June 1996     

Influence of a monomeric plasticizer on the water-sorption behaviour of food-grade plastics packaging materials

The interaction of water with poly(vinylchloride) and poly(vinylidene chloride-vinylchloride) (p(VdC-VC)) plasticized with different amounts of a monomeric plasticizer (dioctylphthalate) has been studied using inverse gas chromatography. The present work was focused on the effect of temperature and plasticizer content on the water sorption behaviour of these plastics packaging materials. Values for thermodynamic parameters such as Gibb's free energy (ΔG_s), enthalpy (ΔH_s), entropy (ΔS_s) and activity coefficient (γ) corresponding to sorption of water by the polymers have been calculated using chromatographic retention data. It was found that the sorption of water vapours increases with increasing the amount of plasticizer and decreases with increasing temperature. The Van Deemter equation was found to be applicable to these systems and was used to determine diffusion coefficients and activation energies for diffusion. Diffusion coefficient values increase with increasing amounts of plasticizer and they also increase with increasing temperature; this latter increase is accompanied by a decrease in the activation energy for diffusion. Present results were also compared to our own previous data, using a polymeric plasticizer.