The objective of this study is to investigate the intermolecular interactions between the surfactants and the fractions of heavy crude oils. Two possible interactions were considered; polar and ionic interactions for two heavy crude oil-surfactant systems, and 20 surfactant-steam flooding tests were conducted on these crudes by testing nine surfactants (three anionic, three cationic, and three nonionic) with different tail lengths and charged head groups. The performance differences observed in each core flood were discussed through the additional analyses. To explain polar interactions, the pseudo blends of crude oil fractions (fractionation of saturates, aromatics, resins, and asphaltenes) were exposed to the surfactant solutions under vapor and liquid water conditions and their mutual interactions were visualized under an optical microscope. To explain ionic interactions, the charges on asphaltene surfaces were analyzed by zeta potential measurements before and after core flood tests on both the produced and the residual oil asphaltenes. The addition of surfactants improved the oil recovery when compared to steam injection alone. However, different oil recoveries were obtained with different surfactants. Further analyses showed that asphaltenes are key and the interaction of asphaltenes with other crude oil fractions or surfactants determines the success of surfactant-steam processes. The polar interactions favor the emulsion formation more; hence, if the polar interactions are more dominant than the ion interactions in the overall crude oil-surfactant system, the surfactant flooding process into heavy oil reservoir became more successful.
Diabetic ketoacidosis (DKA) is a life-threatening complication of type 1 diabetes mellitus in children. Despite the presence of dehydration, hypertension occurs in a significant proportion of children with DKA. There is a lack of clarity in the literature regarding the management of hypertension in patients with paediatric DKA. Herein, we report the case of an adolescent boy who presented with DKA and severe hypertension. His neurological status was closely monitored. There was a gradual decline in his blood pressure with an improvement in the pH over the next 72 hours. The combination of severe DKA and hypertension can be a challenging clinical dilemma, especially regarding fluid management. Studies on severe DKA in children are exacting, given the rarity of this condition. A multi-centre study is suggested to provide a meaningful analysis of this aspect of DKA.
Poor biopharmaceutical properties and toxicities associated with the intravenous formulation of docetaxel (DTX) necessitate the exploration of an alternate oral route of delivery.
A new robust, simple and economic high performance thin layer chromatographic method was developed for simultaneous estimation of L-glutamic acid and γ-amino butyric acid in brain homogenate. The high performance thin layer chromatographic separation of these amino acid was achieved using n-butanol:glacial acetic acid:water (22:3:5 v/v/v) as mobile phase and ninhydrin as a derivatising agent. Quantitation of the method was achieved by densitometric method at 550 nm over the concentration range of 10-100 ng/spot. This method showed good separation of amino acids in the brain homogenate with Rf value of L-glutamic acid and γ-amino butyric acid as 21.67±0.58 and 33.67±0.58, respectively. The limit of detection and limit of quantification for L-glutamic acid was found to be 10 and 20 ng and for γ-amino butyric acid it was 4 and 10 ng, respectively. The method was also validated in terms of accuracy, precision and repeatability. The developed method was found to be precise and accurate with good reproducibility and shows promising applicability for studying pathological status of disease and therapeutic significance of drug treatment.