Effect Of 1-octanol Research Articles

Effect of 1-octanol on the stabilization of crude oil emulsions with hydrophobically modified polyacrylamide

The formation of a stable crude oil emulsion is of great significance for enhancing oil recovery in oilfield development. The effect of 1-octanol (C8OH) on the emulsifying properties of hydrophobically modified polyacrylamide (HMP) was studied based on a novel multiple light scattering method. The emulsions stabilized by different polymer systems were evaluated in terms of stability and rheological properties. The obtained results show that the combined system of HMP + C8OH gives more stable emulsion with smaller droplet size compared to individual HMP. There is a strong bulk and interface interaction between HMP and C8OH for stabilizing emulsions, while such effect was observed neither between partially hydrolyzed polyacrylamide and 1-octanol nor between HMP and 1-octane. In the bulk phase of aqueous solution, the C8OH can be solubilized in the micro-domains of HMP, enhancing the intermolecular association structure and slowing down the creaming rate of the corresponding emulsions. The adsorption at the oil-water interface of HMP can be enhanced and tighter interfacial film can be formed due to the formation of the hydrogen bond between HMP and C8OH. The obtained results are of obvious importance for designing the amphiphilic polymer-containing emulsion more suitable to improve oil recovery as well as for better understanding the self-assembling mechanism of amphiphilic polymers and fatty alcohols.

Dynamic Leidenfrost temperature increase of impacting droplets containing high-alcohol surfactant

Methods to avoid the dynamic Leidenfrost effect are of great importance for high heat flux spray cooling which needs an efficient contact of liquid and superheated surface. In this paper, a novel method of increasing dynamic Leidenfrost temperature is proposed through addition of high-alcohol surfactant (HAS). Effects of 1-Octanol and 2-ethyl-hexanol surfactants on dynamic Leidenfrost temperature and spreading dynamic of droplets impacting on superheated surface were investigated for the first time using high-speed photography. Empirical correlations of dynamic Leidenfrost temperature and maximum spreading factor were obtained based on our experimental data. A possible explanation for the dynamic Leidenfrost temperature increase caused by HAS was proposed based on bubble bursting and bubble coalescence. The results show that dynamic Leidenfrost temperature is significantly increased by addition of HAS because of surface tension reduction. The empirical correlations of dynamic Leidenfrost temperature and maximum spreading factor show good agreement with maximum error of 5% and 10% respectively. These empirical correlations could provide reference value for the future research.

Dynamic light scattering studies on the aggregation behavior of tributyl phosphate and straight chain dialkyl amides during thorium extraction

Dynamic light scattering (DLS) studies were carried out to investigate the aggregation behavior of 1.1M solutions of tributyl phosphate (TBP), N,N-dihexyl octanamide (DHOA) and of N,N-dihexyl decanamide (DHDA) in n-dodecane equilibrated with varying concentrations of nitric acid (0.1–6M) and of Th (10–200g/L). There was a gradual increase in thorium extraction with increased aqueous phase acidities. A significant enhancement in the aggregate sizes was observed with increasing concentration of thorium in the organic phase. The effect of 1-octanol as phase modifier was also investigated on the aggregation behavior of extracted species for TBP system.

Redox Behavior of Neptunium(V) in Tributyl Phosphate and N,N-Dihexyl Octanamide Extractants Dissolved in n-Dodecane

Spectrophotometric investigations have been carried out on the disproportionation of Np(V) to form Np(IV) and Np(VI) in 1.1 mol⋅L−1 solutions of tributyl phosphate (TBP) and in N,N-dihexyl octanamide (DHOA) in n-dodecane medium. The Np(V) was found to coordinate with Np(IV) in 1.1 mol⋅L−1 TBP solution in n-dodecane to form a mixed valence “cation–cation” complex by bonding through an axial oxo group on Np(V). By contrast, this interaction was less prominent in the case of 1.1 mol⋅L−1 DHOA solutions. The effect of 1-octanol, added as phase modifier, on the disproportionation behavior of Np(V) was also investigated. An attempt was made to calculate the disproportionation/reduction rate constants for Np(V) under the conditions of these studies. Absorbance measurements on the Np stripped from organic phases revealed the occurrence of Np(V) in the aqueous phase.

Mechanisms of Inhibition of T-Type Calcium Current in the Reticular Thalamic Neurons by 1-Octanol: Implication of the Protein Kinase C Pathway

Recent studies indicate that T-type calcium channels (T-channels) in the thalamus are cellular targets for general anesthetics. Here, we recorded T-currents and underlying low-threshold calcium spikes from neurons of nucleus reticularis thalami (nRT) in brain slices from young rats and investigated the mechanisms of their modulation by an anesthetic alcohol, 1-octanol. We found that 1-octanol inhibited native T-currents at subanesthetic concentrations with an IC(50) of approximately 4 muM. In contrast, 1-octanol was up to 30-fold less potent in inhibiting recombinant Ca(V)3.3 T-channels heterologously expressed in human embryonic kidney cells. Inhibition of both native and recombinant T-currents was accompanied by a hyperpolarizing shift in steady-state inactivation, indicating that 1-octanol stabilized inactive states of the channel. To explore the mechanisms underlying higher 1-octanol potency in inhibiting native nRT T-currents, we tested the effect of the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA) and PKC inhibitors. We found that PMA caused a modest increase of T-current, whereas the inactive PMA analog 4alpha-PMA failed to affect T-current in nRT neurons. In contrast, 12-(2-cyanoethyl)-6,7,12,13-tetrahydro-13-methyl-5-oxo-5H-indolo(2,3-a)pyrrolo(3,4-c)-carbazole (Go 6976), an inhibitor of calcium-dependent PKC, decreased baseline T-current amplitude in nRT cells and abolished the effects of subsequently applied 1-octanol. The effects of 1-octanol were also abolished by chelation of intracellular calcium ions with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid. Taken together, these results suggest that inhibition of calcium-dependent PKC signaling is a possible molecular substrate for modulation of T-channels in nRT neurons by 1-octanol.

Abstract #4: Therapeutic Effect of 1-Octanol in Essential Tremor Likely Mediated Through Octanoic Acid: Data from a High-Dose Extension Study

Background The therapeutic efficacy of the eight-chain alcohol oral 1-octanol in adults with essential tremor has been demonstrated in doses up to 64 mg/kg (Shill, 2004). A phase-2 clinical trial assessing pharmacokinetic properties of 1-octanol revealed a dose-dependent plasma response of octanoic acid (OA), while 1-octanol was only detectable at very low plasma levels ( clinicaltrials.gov NCT00102596 ). To further assess the clinical and pharmacokinetic properties of 1-octanol, we escalated the dose in two patients to 128 mg/kg. Methods Two right-handed patients (1 f, 1 m), who participated in the 64 mg/kg fixed-dose study phase, received oral 1-octanol at a dose of 128 mg/kg. Plasma samples were collected 5, 20, 45, 70, 100, 130, 160, 210, and 360 min post dose. Efficacy was assessed using digitizing-tablet based Archimedes spirals drawn by patients at multiple time points after administration and washout, as well as wrist-worn uniaxial accelerometers, worn throughout the entire study. Results OA plasma levels were already detectable 5 min after administration, rising to a peak at 100 min, while 1-octanol was only detectable at low levels lacking a dose-response relation. Calculated OA plasma half-life was 88.9 min. Spirography showed a reduction of tremor velocity at spectral peak frequency with a maximum effect starting at 90 min, persisting further until the 360 min time point. Mean tremor reduction of the right hand in this time period was 39% with a maximum of 56%. Mean accelerometric tremor severity, calculated based on previously described algorithms (Van Someren, 2006; Nahab, 2007), showed a reduction of 49% over a 5-hour period after administration of the study drug. Conclusions 1-octanol is effective and safe up to 128 mg/kg in ET, with an exponential dose-response curve of OA plasma levels. The effect is most likely mediated through rapid conversion of 1-octanol to OA.

Uncoupling of horizontal cells alters the receptive fields of retinal bipolar cells.

Effects of uncoupling of horizontal cells by 1-octanol, a non-specific gap junction uncoupling agent, on the receptive field organization of cone-dominant bipolar cells were investigated in isolated, superfused carp retina, using intracellular recording techniques. At 1 mM, 1-octanol increased responses of cone driven horizontal cells to light spots, but decreased those to light annuli, indicating a reduction of the receptive field size of these cells by uncoupling. Furthermore, 1-octanol eliminated the surround response of OFF type bipolar cells and increased their center response. Similar effects of 1-octanol on the center and surround responses were observed in ON type bipolar cells. These results suggest that uncoupling of horizontal cells can significantly alter the receptive field organization of retinal bipolar cells.

Octanol antagonism of ethanol teratogenesis.

SPECIFIC AIMSAlcohol may cause birth defects in part by disrupting the developmentally critical L1 cell adhesion molecule. Because 1-octanol antagonizes ethanol inhibition of L1-mediated cell adhesion, we used mouse whole embryo culture to test whether 1-octanol also prevents ethanol teratogenicity.PRINCIPAL FINDINGS1. Low concentrations of 1-octanol are not toxic in whole embryo cultureTo determine the toxicity of 1-octanol, gestational day 8 (GD8) whole mouse embryos were cultured for 6 h in the absence and presence of 1-octanol and transferred to control medium for an additional 20 h. Somite pairs were counted after a total of 26 h in culture. Based on somite counts, treatment with 3 μM 1-octanol did not produce a delay in embryonic development, whereas 10 μM and higher concentrations of 1-octanol caused increasing dysmorphogenesis (Fig. 1a⤻ ). Figure 1.Effect of 1-octanol and ethanol on the morphology of cultured C57Bl/6J GD8 mouse embryos. a) Mean ± se number of somite pairs after treatment for 6 h w...

Subchronic sensitivity of one-, four-, and seven-day-old fathead minnow (Pimephales promelas) larvae to five toxicants

The fathead minnow (Pimephales promelas) larval survival and growth test was used to evaluate the relative sensitivity of 1-, 4-, and 7-d-old larvae to five contaminants, KCl, NaCl, 1-octanol, carbaryl, and benzaldehyde. The no observable effect concentration (NOEC) for survival of the two inorganic compounds, KCl and NaCl, was not affected by age of the larvae. The subchronic valve (SCV) for NaCl was always determined by survival. Hypothesis testing of biomass always gave the same NOEC for the three age groups for each of the two inorganic compounds, and a minimum significant difference (MSD) was always calculable. The effect of 1-octanol on growth was more sensitive than the effect on survival in eight of the nine toxicity tests. Within a set of 1-, 4-, and 7-d-old larvae tests the SCV varied only twofold; however, between sets of tests the variation was fourfold. The SCV of carbaryl was determined by the effect on growth in five of six tests. Except for one test the SCV varied only twofold. The 1-d larvae were more sensitive to benzaldehyde than 1- and 7-d larvae in two sets of tests. The SCV was determined on the basis of survival for 1-d-old larvae and on themore » basis of growth for 4- and 7-d-old larvae.« less

Growth on octane alters the membrane lipid fatty acids of Pseudomonas oleovorans due to the induction of alkB and synthesis of octanol

Growth of Pseudomonas oleovorans GPo1, which contains the OCT plasmid, on octane results in changes in the membrane phospholipid fatty acid composition. These changes were not found for GPo12, an OCT-plasmid-cured variant of GPo1, during growth in the presence or absence of octane, implying the involvement of OCT-plasmid-encoded functions. When recombinant strain GPo12(pGEc47) carrying the alk genes from the OCT plasmid was grown on octane, the cells showed the same changes in fatty acid composition as those found for GPo1, indicating that such changes result from induction and expression of the alk genes. This finding was corroborated by inducing GPo12(pGEc47) with dicyclopropylketone (DCPK), a gratuitous inducer of the alk genes. Further experiments showed that the increase of the mean acyl chain length of fatty acids is related to the expression of alkB, which encodes a major integral membrane protein, while the formation of trans unsaturated fatty acids mainly results from the effects of 1-octanol, an octane oxidation product.

Phospholipid/cholesterol membranes containing n-alkanols: a 2H-NMR study

The influences of 1-octanol and 1-decanol on aqueous multilamellar dispersions of 1- hexadecanoyl(octadecanoyl)-2-[ 2H 31]hexadecanoyl -sn- glycero-3-phosphorylcholine ( PC-d 31) cholesterol (3:1) have been examined using 2H-NMR. The gel to liquid crystalline phase transition of the PC- d 31/cholesterol dispersion is modulated by the addition of 1-alkanol, which reduces the onset temperature and increases the width of the transition. 1-Octanol has a greater effect on the transition onset and completion temperatures than does 1-decanol, as determined from analysis of the temperature-dependent 2H-NMR spectra. 2H-NMR C- 2H bond order parameters as a function of phospholipid acyl chain position at 60 °C, where all dispersions are fully liquid crystalline, have been calculated from the depaked spectra. 1-Decanol reduces the phospholipid order by only 2%. This can be attributed to the lower effective cholesterol concentration in the 1-alkanol/PC- d 31/cholesterol dispersions. 1-Octanol, however, reduces the phospholipid order by 10% at 60 °C. Correlations between the effects of 1-octanol and 1-decanol on phospholipid order parameters and phospholipid/cholesterol phase transitions are discussed.