The direct assay of serum progesterone after denaturation of the binding proteins was investigated. 50ul of patients' serum was diluted with 750ul phosphate buffer (0.05M, pH 7.4) and heated to 65 degrees C for 20 minutes. After cooling, 300ul of the treated serum was reacted with a rabbit antiserum to progesterone-11 alpha-hemicuccinyl-bovine serum albumin conjugate (Bioclin, U.K) and 1,2,6,7, tritium labelled progesterone. Separation of bound and free fractions was achieved with dextran coated charcoal. The method correlated well (r = 0.98) with an established method involving ether extraction of progesterone prior to assay. The mean sensitivity was 2.01 nmol/L (range 1.90-2.23nmol/L). The proposed method considerably shortens assay time and removes a tedious and imprecise stage in the conventional method involving extraction of serum.
The phase behaviour of palm olein (PO) and its derivative oils (palm oil methyl esters and medium chain triglycerides) with Imbentin coco 6.9EO, an ethoxylated C12-14 alcohol, in water has been investigated to identify compositions where microemulsions occur. The techniques used were the optical microscope phase penetration scan and small angle X-ray diffraction (SAXS). Mixed surfactant/oil samples were prepared at wt. ratios of 0.1:1, 0.25:1, 0.5:1 and 1:1 for the phase penetration scan. For SAXS analysis, the initial concentration of surfactant in water (W) was fixed at 38% (w/w), which forms a hexagonal mesophase (H1). Palm oil methyl esters (POME) and medium chain triglycerides (MCT) were added to this at 0.04:1 (or 0.05:1 for MCT), 0.1:1, 0.2:1 (or 0.25:1 for MCT), 0.5:1 and 1:1 ratios of oil to surfactant. Schematic phase diagrams were constructed to document the changes of phase structures using both bulk samples and phase penetration scans techniques. The extent of microemulsion formation (or solubilisation) decreases in the sequence POME > MCT > PO, and increases substantially with temperature, particularly for POME and MCT. All of the oils destabilize the hexagonal phase; for POME and MCT there is an increase in the surfactant cloud point temperature by ca. 10 degrees C or more, but the temperature for the onset of the lamellar (Lalpha) phase dispersion region (W + Lalpha) is hardly affected. There was a pronounced tendency for the lamellar phase formed in the presence of high oil concentrations and low water levels to have a reduced melting point. With the highest MCT levels a bicontinuous cubic phase (probably V2) is present at 25 degrees C, although this phase is not present in the binary surfactant/water system. The X-ray diffraction results show that the average area per head group (ao) at the micelle surface is decreased by the addition of the oils, consistent with the observation of a V2 phase. Possible molecular mechanisms for this observation are discussed.
This study evaluates the efficacy of palm oil-based nanoemulsion insecticides in thermal fogging applications against adult Ae. aegypti. The nanoemulsion formulations contained a palm oil methyl ester solvent, water, a non-ionic surfactant, and active ingredient deltamethrin, with nanoemulsion droplet diameters ranging from 362 to 382 nm. Knockdown and mortality rates of caged mosquitoes were measured at various distances up to 18 m from the spray nozzle. After 15 min of insecticide exposure, nanoemulsion insecticides achieved a knockdown rate of >97% at a spraying distance of 4 m, and the knockdown effect increased substantially with exposure time. At an 18 m spraying distance, the best nanoemulsion formulation, NanoEW8, achieved a high mosquito mortality rate of more than 80%, whereas the non-nanoemulsion and the commercial product reached only 14 and 8 m distances, respectively, for comparable mortality. The artificial neural network (ANN) was used to predict the mosquito knockdown distribution over the spraying distances and time intervals. The models predicted that NanoEW8 can still cause knockdown at a maximum distance of 61.5 m from the discharge point 60 min after spraying. The results established that Ae. aegypti was susceptible to the newly developed palm oil-based nanoemulsion insecticide, indicating a high potential for mosquito control.