Fibre–Wood Laminate Biocomposites: Seawater Immersion Effects on Flexural and Low Energy Impact Properties

The present paper explores a new concept of a hybrid eco-composite by substituting the natural fibre plies with thin wood veneers. The new composite, named Fibre–Wood Laminate (FWL), is inspired by fibre–metal laminate materials. The studied FWL configuration consisted of a single thin pinewood veneer at each of the outer layers of a flax woven fabric reinforced bio-epoxy composite manufactured by infusion. Three-point bending results showed that wood veneer gives a highly anisotropic nature to the FWL. In the best case, with the grain of the wood at 0°, the stiffness and the strength increased by 28 and 41%, respectively, but reduced the strain-at-break by 27% compared to the flax fibre reinforced bio-epoxy (FFRB). The penetration and perforation energy thresholds and the peak force of the FWL obtained by falling weight impact tests were 32, 29, and 31% lower than those of the FFRB, respectively. This weakening was due to using single wood veneers, so the challenge for improving impact properties will be to explore thicker FWLs with different stacking sequences and orientations. The effect of immersing the FWL in seawater also showed considerable differences. The epoxy matrix filled the cellular structure of the wood veneers, creating a barrier effect and reducing the amount of water absorbed by the flax fibres.The research in this paper was supported by the Vice-Ministry of Universities and Research of the Basque Government (Grants No. IT1613-22 and IT1514-22)

Aerosol Delivery by Inhalation Catheter and Trachea Digitalization

Neonatal respiratory distress syndrome (RDS) is related with high mortality and morbidity in preterm infants and the best approach to treat it is an open research field. The use of perfluorocarbons (PFC) together with non-invasive respiratory support techniques, such as nasal continuous positive airway pressure (CPAP), has confirmed its effectiveness to achieve a more homogeneous surfactant distribution. The goal of the current study was to evaluate the main features of the aerosol generated by an intracorporeal inhalation catheter, which consists of one central lumen delivering the liquid and six peripheral lumens delivering compressed air. Firstly, experiments were made through an Aerodynamic Particle Sizer (APS) with sterile water and perfluorocarbon FC75 with a driving pressure of 4 bar to analyze properties linked with lung deposition such as the aerodynamic diameter (Da), mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD). Subsequently, a numerical model was developed with CFD techniques. The experimental validation of the numerical model provides an accurate prediction of the air flow axial velocity.This work has been supported by Consolidated Groups from the Basque Government. Technical and human support provided by IZO-SGI, SGIker is gratefully acknowledged

Aerosol Delivery by Inhalation Catheter and Trachea Digitalization

Neonatal respiratory distress syndrome (RDS) is related with high mortality and morbidity in preterm infants and the best approach to treat it is an open research field. The use of perfluorocarbons (PFC) together with non-invasive respiratory support techniques, such as nasal continuous positive airway pressure (CPAP), has confirmed its effectiveness to achieve a more homogeneous surfactant distribution. The goal of the current study was to evaluate the main features of the aerosol generated by an intracorporeal inhalation catheter, which consists of one central lumen delivering the liquid and six peripheral lumens delivering compressed air. Firstly, experiments were made through an Aerodynamic Particle Sizer (APS) with sterile water and perfluorocarbon FC75 with a driving pressure of 4 bar to analyze properties linked with lung deposition such as the aerodynamic diameter (Da), mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD). Subsequently, a numerical model was developed with CFD techniques. The experimental validation of the numerical model provides an accurate prediction of the air flow axial velocity.This work has been supported by Consolidated Groups from the Basque Government. Technical and human support provided by IZO-SGI, SGIker is gratefully acknowledged

Experimental and Numerical Modeling of Aerosol Delivery for Preterm Infants

Respiratory distress syndrome (RDS) represents one of the major causes of mortality among preterm infants, and the best approach to treat it is an open research issue. The use of perfluorocarbons (PFC) along with non-invasive respiratory support techniques has proven the usefulness of PFC as a complementary substance to achieve a more homogeneous surfactant distribution. The aim of this work was to study the inhaled particles generated by means of an intracorporeal inhalation catheter, evaluating the size and mass distribution of different PFC aerosols. In this article, we discuss different experiments with the PFC perfluorodecalin (PFD) and FC75 with a driving pressure of 4-5 bar, evaluating properties such as the aerodynamic diameter (Da), since its value is directly linked to particle deposition in the lung. Furthermore, we develop a numerical model with computational fluid dynamics (CFD) techniques. The computational results showed an accurate prediction of the airflow axial velocity at different downstream positions when compared with the data gathered from the real experiments. The numerical validation of the cumulative mass distribution for PFD particles also confirmed a closer match with the experimental data measured at the optimal distance of 60 mm from the catheter tip. In the case of FC75, the cumulative mass fraction for particles above 10 mu m was considerable higher with a driving pressure of 5 bar. These numerical models could be a helpful tool to assist parametric studies of new non-invasive devices for the treatment of RDS in preterm infants.Consolidated Groups from the Basque Government supported this work. Technical and human support provided by IZO-SGI, SGIker (UPV/EHU) is gratefully acknowledged

All-cause mortality in the cohorts of the Spanish AIDS Research Network (RIS) compared with the general population: 1997Ł2010

Abstract Background: Combination antiretroviral therapy (cART) has produced significant changes in mortality of HIVinfected persons. Our objective was to estimate mortality rates, standardized mortality ratios and excess mortality rates of cohorts of the AIDS Research Network (RIS) (CoRIS-MD and CoRIS) compared to the general population. Methods: We analysed data of CoRIS-MD and CoRIS cohorts from 1997 to 2010. We calculated: (i) all-cause mortality rates, (ii) standardized mortality ratio (SMR) and (iii) excess mortality rates for both cohort for 100 personyears (py) of follow-up, comparing all-cause mortality with that of the general population of similar age and gender. Results: Between 1997 and 2010, 8,214 HIV positive subjects were included, 2,453 (29.9%) in CoRIS-MD and 5,761 (70.1%) in CoRIS and 294 deaths were registered. All-cause mortality rate was 1.02 (95% CI 0.91-1.15) per 100 py, SMR was 6.8 (95% CI 5.9-7.9) and excess mortality rate was 0.8 (95% CI 0.7-0.9) per 100 py. Mortality was higher in patients with AIDS, hepatitis C virus (HCV) co-infection, and those from CoRIS-MD cohort (1997. Conclusion: Mortality among HIV-positive persons remains higher than that of the general population of similar age and sex, with significant differences depending on the history of AIDS or HCV coinfection

Aerosol Delivery by Inhalation Catheter and Trachea Digitalization

Neonatal respiratory distress syndrome (RDS) is related with high mortality and morbidity in preterm infants and the best approach to treat it is an open research field. The use of perfluorocarbons (PFC) together with non-invasive respiratory support techniques, such as nasal continuous positive airway pressure (CPAP), has confirmed its effectiveness to achieve a more homogeneous surfactant distribution. The goal of the current study was to evaluate the main features of the aerosol generated by an intracorporeal inhalation catheter, which consists of one central lumen delivering the liquid and six peripheral lumens delivering compressed air. Firstly, experiments were made through an Aerodynamic Particle Sizer (APS) with sterile water and perfluorocarbon FC75 with a driving pressure of 4 bar to analyze properties linked with lung deposition such as the aerodynamic diameter (Da), mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD). Subsequently, a numerical model was developed with CFD techniques. The experimental validation of the numerical model provides an accurate prediction of the air flow axial velocity.This work has been supported by Consolidated Groups from the Basque Government. Technical and human support provided by IZO-SGI, SGIker is gratefully acknowledged