Structure and Properties of Polyamide Fabrics with Insect-Repellent Functionality by Electrospinning and Oxygen Plasma-Treated Surface Coating
Authors: Xiang, Chunhui; Etrick, Nicholas R.; Frey, Margaret W.; Norris, Edmund J.; Coats, Joel R.
The need for light-weight and high-strength insect-repellant fabrics is of critical importance to the cessation of viral diseases. The goal of the study is to investigate the structure and properties of insect-repellent polyamide fabrics for use in protective garments to guard against mosquitos. Permethrin was applied to the polyamide fabrics through incorporation into the nylon 6 polymer solution during electrospinning and dip coating onto the control untreated and oxygen plasma-treated polyamide fabrics: electropun nylon 6 nanofiber nonwovens, commercially available nylon 6 warp knit tricot, and nylon 66 double weft, knit interlock fabrics. The incorporation of permethrin into the polymer solution before the formation of fibers demonstrated the most efficient way to apply permethrin to the fiber/fabric systems. The plasma treatment significantly increased the amount of permethrin on the surface of the fabrics. All permethrin-containing polyamide fabrics showed excellent fastness of the insecticide to light. The electrospun nylon 6 nonwovens demonstrated the best fastness to washing among the plasma-treated electrospun nylon 6, nylon 66 double weft knit, and nylon 6 warp-knit tricot. All permethrin-treated fabrics were repellent and caused higher percentage of mosquito escape compared to the control untreated fabrics.
The effect of blood transfusion on outcomes among African children admitted to hospital with Plasmodium falciparum malaria: a prospective, multicentre observational study
Authors: Ackerman, Hans; Ayestaran, Aintzane; Olola, Christopher H. O.; Jallow, Muminatou; Agbenyega, Tsiri; Bojang, Kalifa; Roberts, David J.; Krishna, Sanjeev; Kremsner, Peter G.; Newton, Charles R.; Taylor, Terrie; Valim, Clarissa; Casals-Pascual, Climent
Background Infection with Plasmodium falciparum leads to severe malaria and death in approximately 400 000 children each year in sub-Saharan Africa. Blood transfusion might benefit some patients with malaria but could potentially harm others. The aim of this study was to estimate the association between transfusion and death among children admitted to hospital with P falciparum malaria. Methods In this prospective, multicentre observational study, we analysed admissions to six tertiary care hospitals in The Gambia, Malawi, Gabon, Kenya, and Ghana that participated in the Severe Malaria in African Children network. Patients were enrolled if they were younger than 180 months and had a Giemsa-stained thick blood smear that was positive for P falciparum. Blood transfusion (whole blood at a target volume of 20 mL per kg) was administered at the discretion of the responsible physicians who were aware of local and international transfusion guidelines. The primary endpoint was death associated with transfusion, which was estimated using models adjusted for site and disease severity. We also aimed to identify factors associated with the decision to transfuse. The exploratory objective was to estimate optimal haemoglobin transfusion thresholds using generalised additive models. Findings Between Dec 19, 2000, and March 8, 2005, 26 106 patients were enrolled in the study, 25 893 of whom had their transfusion status recorded and were included in the primary analysis. 8513 (32.8%) patients received a blood transfusion. Patients were followed-up until discharge from hospital for a median of 2 days (IQR 1-4). 405 (4.8%) of 8513 patients who received a transfusion died compared with 689 (4.0%) of 17 380 patients who did not receive a transfusion. Transfusion was associated with decreased odds of death in site-adjusted analysis (odds ratio [OR] 0.82 [95% CI 0.71-0.94]) and after adjusting for the increased disease severity of patients who received a transfusion (0.50 [0.42-0.60]). Severe anaemia, elevated lactate concentration, respiratory distress, and parasite density were associated with greater odds of receiving a transfusion. Among all study participants, transfusion was associated with improved survival when the admission haemoglobin concentration was up to 77 g/L (95% CI 65-110). Among those with impaired consciousness (Blantyre Coma Score <= 4), transfusion was associated with improved survival at haemoglobin concentrations up to 105 g/L (95% CI 71-115). Among those with hyperlactataemia (blood lactate >= 5.0 mmol/L), transfusion was not significantly associated with harm at any haemoglobin concentration-ie, the OR of death comparing transfused versus not transfused was less than 1 at all haemoglobin concentrations (lower bound of the 95% CI for the haemoglobin concentration at which the OR of death equals 1: 90 g/L; no upper bound). Interpretation Our findings suggest that whole blood transfusion was associated with improved survival among children hospitalised with P falciparum malaria. Among those with impaired consciousness or hyperlactataemia, transfusion was associated with improved survival at haemoglobin concentrations above the currently recommended transfusion threshold. These findings highlight the need to do randomised controlled trials to test higher transfusion thresholds among African children with severe malaria complicated by these factors.