Abstract  The binding of exogenous fatty acids to the outer-membrane protein FadL of Escherichia coli is specific for long-chain fatty acids (C-14-C-18). Oleoyl alcohol [(Z)-9-octadecen-1-o1] and methyl oleate were unable to displace FadL-specific binding of [H-3]oleate (C-18:1), suggesting that the carboxylate of the long-chain fatty acid was required for binding. Therefore the binding of exogenous fatty acids to FadL is governed, in part, by the carboxy group of the long-chain fatty acid. Treatment of whole cells with I mM diethyl pyrocarbonate (DEPC) depressed binding by 43-73 % over the range of oleate concentrations used (10-500 nM). On the basis of these results and the notion that histidine residues often play a role involving proton transfer and charge-pairing, the five histidine residues within FadL (His(110), His(226), His(327), His(345) and His(418)) were replaced by alanine using site-directed mutagenesis. Altered FadL proteins were correctly localized in the outer membrane at wild-type levels and retained the heat-modifiable property characteristic of the wild-type protein. Initial screening of these fadL mutants revealed that the replacement of His(110) by Ala resulted in a decreased growth rate on minimal oleate/agar plates. The rates of long-chain fatty acid transport for Delta fadL strains harbouring each mutation on a plasmid, with the exception of fadLH110A, were the same, or nearly the same, as those for the wild-type. fadLH110A was also defective in binding, arguing that the functional effect of this mutation was at the level of long-chain-fatty-acid binding. Other mutants had levels of long-chain-fatty-acid binding that were either the same, or nearly the same, as those for the wild-type. On the basis of competition experiments, DEPC treatment and the analyses of the mutants, His(110) may function in carboxylate binding.

Abstract  Alumina particles have successfully been alkylated via a condensation reaction between surface hydroxide sites and different, long chain alcohol molecules, specifically decanol, dodecanol, and octadecanol. These hydrophobic particles have been successfully dispersed in water using different C(n)TAB surfactant molecules, where n = 10, 12, 14, 16. The effect of the length of the surfactant molecule and its concentration was quantified with rheological experiments. Rheology and conductivity measurements were used to determine the minimum amount of the surfactant needed to disperse the alkylated powder. Slurries formulated with the alkylated powder and the proper amount of C,TAB exhibited Newtonian rheology for n >= 10. xi potential measurements showed that the surface charge on the particles was always positive confirming that the C(n)TAB molecules, with a positive head group, surrounded the alkylated particles. Such powder did not have an isoelectric point. In addition, the Newtonian behavior of the alkylated-alumina/C(n)TAB slurry systems were independent of pH.

Abstract  One-hour irradiation of steam exploded lignin in the presence of singlet oxygen gave products showing high molecular weights. The irradiation at different times gave sinapyl alcohol, 4-hydroxy-3,5-dimethoxybenzaldehyde, and 2,4-dioctylphenol. It is interesting to note the isolation of a dehydroabietic acid derivative only after the treatment of lignin with singlet oxygen for 5 h. After 12 h irradiation of the same sample the presence of long chain hydrocarbons (octadecane), alkenes (1-octadecene) or alcohols (1-eicosanol) was detected. (C) 2000 Elsevier Science S.A. All rights reserved.

Abstract  Extraction is a downstream process option in biobased processes. Because knowledge of phase-separation behavior is essential for designing efficient separation processes, this study investigates the settling and coalescence behavior of biobased extraction systems by using a standard laboratory-scale settling cell. The influence of different buffer media and Escherichia coli cells on coalescence was determined for the reactive extraction of hexane-1,6-diamine with isostearic acid and di(2-ethylhexyl)phosphoric acid by using kerosene and oleyl alcohol as diluents. As a result, an increasing pH value of the buffer significantly increases the settling time. The presence of E. coli cells hinders phase separation of the investigated systems, in particular, with dispersed organic phases.

Abstract  The kinetic characteristics of the antiradical activity of cinnamic acid derivatives have been determined by a chemiluminescence method. The effect of some lipid hydroxy compounds -1-octadecanol, 1-palmitoylglycerol and 1,2-dipalmitoylglycerol on the radical scavenging efficiency of hydroxy cinnamic acid derivatives has been investigated. It has been shown that the lipid hydroxy components in a concentration of 0.2-0.4 mmol dm(-3) do not affect the kinetics of the inhibited oxidation of cumene.

Abstract  While it has been known for about 10 years that octadecanol stabilizes Langmuir-Blodgett films of copper tetrakis(cumylphenoxy)phthalocyanine films, the mechanism for this stabilization is not fully understood. To understand more completely the molecular interactions responsible for making octadecanol a good transfer promoter, we studied mixed films' isotherms of tetrakis(cumylphenoxy)phthalocyanine and various saturated alcohols ranging in length from 13 to 24 carbons. By varying mole fraction and alcohol chain length in the Various mixed films, a model of interaction was deduced based on pressure-versus-area isotherms obtained from a Langmuir trough. In this model, the aliphatic chains of the alcohols act as a stabilizing, hydrophobic support around phthalocyanine mounds of a preferred stack height. As film pressure increases, the mounds are forced above the alcohol sea, removing favorable ether-water interactions. Depending on chain length, a single or double collapse is observed, suggesting an adjustable physical barrier to forcing the stacks above the alcohols.

Abstract  An analytic solution is presented for the steady state temperature of an evaporating water droplet with a monolayer coating. The solution is based on the flux matching arguments of Fuchs where the continuum flux is matched to the kinetic flux one mean free path from the droplet surface. Theoretical temperatures are compared to experimental values measured with fluorescence thermometry for evaporating water droplets coated with hexadecanol and octadecanol monolayers.

Abstract  OBJECTIVES: The aim of this study was to prepare a disintegrating gastric floating tablet composed of floating pellets coated with acrylic resin to prolong the gastric residence time and increase the oral bioavailability of famotidine.

METHODS: The gastric floating pellets containing famotidine, stearyl alcohol and microcrystalline cellulose (1 : 10 : 1) were prepared by extrusion-spheronization process and coated with acrylic resin, then compressed into tablets with Avicel PH 301 pellets and cross-linked polyvinylpyrrolidone. The coating weight, volume ratio of Eudragit RL30 D and RS30 D and solid content of coating fluid were optimized by Box-Behnken design.

KEY FINDINGS: In 0.1 M HCl, tablets can immediately disintegrate into pellets which can remain floating and sustained drug releasing over 12 h. The AUC0-∞ of famotidine gastric floating pellets (7776.52 ± 1065.93 h ng/ml) administered into rats was significantly higher than that of marketed rapid release tablets Xingfading® (Xingyi, Shanghai, China) (4166.23 ± 312.43 h ng/ml), while the relative bioavailability was 187.01 ± 22.81%.

CONCLUSIONS: The experimental results indicated that the optimized formulation did offer a new gastro retention and sustained release approach to enhance the oral absorption of famotidine.

Abstract  The influence of water on the adsorption of stearic acid, octadecylamine, and octadecyl alcohol from toluene solutions on the surface of TiO2 was investigated. It was found that in the presence of water the chemisorption of the acid on the pure rutile is decreased, the chemisorption of the amine remains the same as under anhydrous conditions, and there is no chemisorption of the alcohol on TiO2. The magnitude and character of surfactant adsorption is shown to be highly affected by inorganic impurities in TiO2.

Abstract  The interfacial tensions of the water-decyl alcohol (DEA), -undecyl alcohol (UNA), and -dodecyl alcohol (DOA) systems were measured as a function of temperature and pressure. The thermodynamic quantities of interface formation were evaluated from the experimental results; the entropy, volume, and energy were found to have negative values and change discontinuously at the break point on the interfacial tension vs temperature and pressure curves. These results were discussed in terms of the orientation of alcohol molecules at the interface caused by the interaction between alcohol and water molecules. Further, it was suggested that the phase transition takes place between the expanded and condensed states at the interface.

Abstract  We report the synthesis and detailed in vitro evaluation of zwitterionic ultrasmall superparamagnetic iron oxide NPs (USPIONs) comprising oleic acid/oleyl alcohol-stabilized magnetite particles (5 nm core diameter) coated with an amphiphilic zwitterionic polymer, poly(maleic anhydridealt-1-decene) substituted with 3-(dimethylamino) propylamine (PMAL). These particles display a near-neutral zeta potential at pH >= 7 and possess high colloidal stability, maintaining a hydrodynamic diameter of ca. 15-20 nm over a wide range of pHs (4-10) and ionic strength (up to 1m NaCl). They exhibit very low levels of nonspecific protein binding upon exposure to serum, and negligible uptake by phagocytic and non-phagocytic hepatocarcinoma cells, which suggests that they may be able to resist rapid accumulation in the liver and spleen, a common in vivo fate for NPs. The PMAL-USPIONs exhibit very low cytotoxicity and do not elicit an inflammatory response or display hemolytic activity in vitro. Minimal nonspecific uptake by either cancerous or non-cancerous cell lines was observed, an important precondition to achieve highly selective targeting upon further functionalization with an active targeting agent (e.g., antibody or peptide). Overall, this study establishes the considerable potential of PMAL-USPIONs as a platform for the future development of "stealth" NP-based imaging and/or therapeutic agents.

Abstract  A novel silane based adsorbent material, [stearyl alcohol (SA)-grafted-epichlorohydrin (E)]-grafted-aminoproypyl silanetriol (APST) was synthesized and functionalized with sulfonic acid [(SA-g-E)-g-APST/SO3H]. The adsorbent material was characterized by FTIR, XRD, SEM and BET analysis. Protein-particle interaction was studied by the immobilization of trypsin (TRY) using batch adsorption process. Maximum adsorption was attained at pH 7.0. Adsorption process followed pseudo-second-order kinetics; film diffusion controlled and Sips isotherm mechanism. Evaluation of separation factor (R-L) and thermodynamic parameters revealed the favorability of adsorption process. Adsorption/desorption studies, for over six cycles showed the repeatability and regeneration capability of the adsorbent. (C) 2013 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Abstract  Combined experimental and computational studies on biologically important minor constituents of olive oil, i.e., 1-eicosanol, squalene, alpha-tocopherol, erythrodiol, stigmasterol, beta-sitosterol, campesterol, and cycloartenol, have been performed for analyzing their H-1 and C-13 NMR spectra. The correlation equations for estimating experimental H-1 and C-13 NMR chemical shifts from the calculated chemical shifts have been derived and tested for the molecules in which dispersion is effective. The presently obtained experimental NMR signals of these molecules were then assigned on the basis of quantum chemical calculations. The discriminative NMR signals of the minor constituents were determined and discussed. H-1 diffusion ordered spectroscopy (DOSY) NMR has been employed to discriminate the minor constituents and determine their diffusion coefficients in deuterated chloroform. We calculated some physicochemical parameters of these molecules involving their shapes and sizes as well as their interaction with solvent. Then, we found a regression equation that can be used in estimating diffusion coefficients of other compounds.

Abstract  Phenolic extracts from Sorbus aucuparia (L.) were lipophilized in the presence of Candida antarctica lipase using octadecanol as the alkyl donor. The antioxidant activity of the lipophilized extract was assessed in refined, bleached and deodorized rapeseed oil during accelerated storage at 65 degrees C and frying at 180 degrees C. Rapeseed oil fortified with lipophilized extract showed significantly higher storage stability with 43% decrease in peroxide value at the end of the 7-day storage compared to rapeseed control sample without extract; however, no significant difference was observed in the performance of lipophilized extract and the native extract. On the contrary, the lipophilized extract exhibited markedly better protection against thermo-oxidative degradation during frying, inhibiting polar component formation and polymerization of triacylglycerol by up to 48%, compared to 30% by the native extract. At the end of the frying, French fries prepared in the presence of lipophilized extract had 7 times more phenolic compounds compared to fries prepared in the native extract indicating better solubilization of the phenolic compounds in the frying medium. Thus, lipophilization of phenolic compounds enhanced their protective activity in frying oil and improved the functionality of the prepared food. (C) 2014 Elsevier Ltd. All rights reserved.

Abstract  Quasi-monodisperse hydrophobic transition-metal ferrite MFe(2)O(4)(M = Mn, Fe, Co, Ni, Zn) nanocrystals were synthesized by the thermolysis of transition-metal acetates in oleyl alcohol Solutions under aerobic conditions. The proposed reaction protocol is simple, rapid, and highly versatile because it takes advantage of the multiple roles of the oleyl alcohol molecules, namely, solvent for the precursors, reaction medium, and capping ligand for the metal oxide nanoparticles. A systematic FT-IR spectroscopy study has indicated that the transition-metal ferrite nanoparticles are precipitated in oleyl alcohol Solutions via a thermal decomposition process with no evidence about a potential esterification reaction, involving the long-chain alcohol and the metal acetate salt. A detailed characterization of the oleyl alcohol capped ferrite nanoparticles was performed by XRD, TEM, SAED, EXAFS, FT-IR, and SQUID measurements. The as-prepared transition-metal ferrite nanocrystals are spherically shaped, and their average diameter can be conveniently tuned between 4 and 15 nm by increasing the heating rate of the Solution. The surface composition of the nanoparticles can be modified via ligand-exchange reactions through which the nanocrystals can be rendered soluble in polar solvents without altering their morphology. The oleyl alcohol capped ferrite nanocrystals typically exhibit a superparamagnetic behavior with blocking temperatures depending on both the nature of the transition metal and the size of the nanocrystals.

Abstract  In this study, we investigate the nature of a Reynolds ridge formed by wind shear. We have simultaneously imaged the water surface, with a deposit of a monolayer of the surfactant, oleyl alcohol, subject to different wind shears, by using a high-resolution infrared (IR) detector and a high-speed (HS) digital camera. The results reveal that the regions around the wind-driven Reynolds ridge, which have subtle manifestations in visual imagery, possess surprisingly complex hydrodynamical and thermal structures when observed in the infrared. The IR measurements reveal a warm, clean region upstream of the ridge, which is composed of the so called fishscale structures observed in earlier investigations. The region downstream of the ridge is composed of colder fluid which forms two counter-rotating cells. A region of intermediate temperature, which we call the mixing (wake) region, forms immediately downstream of the ridge near the channel centerline. By measuring the velocity of the advected fishscales, we have determined a surface drift speed of about 2% of the wind speed. The spanwise length-scale of the structures has also been used to estimate the wind shear. In addition, a comparison of IR and visual imagery shows that the thermal field is a very sensitive indicator of the exact position of the ridge itself.

Abstract  The addition of water to hydrophobic alkyd resin containing a hydrophilic nonionic surfactant (polyethoxylated-20-oleyl alcohol) was used to produce the emulsion morphology change from W/O to O/W in a small thermostated reactor (50 mL). The so-called catastrophic phase inversion of the water/alkyd resin system was detected by monitoring both, the viscosity by torque measurement and the electrical conductivity, until an equal weight fraction of water and resin is attained (f(w) = 0.5). The two methods provide similar values of the phase inversion point (PIP). Although the determination of the PIP exhibits a small inaccuracy, it is clear that different torque profiles and PIP are observed depending on the resin neutralization level, the surfactant concentration and the water addition rate. For the non-neutralized resin, both, PIP and emulsion drop size, decrease with surfactant concentration increase. The completely neutralized resin could be emulsified using a minimum of 2 wt % of surfactant in the final emulsion. In such a case the water fraction at which inversion occurs (f(w,Inv) = 0.36) is independent of the surfactant concentration and a small resin drop diameter (< 200 nm) can be obtained. A more precise study of the reached drop size of the emulsion versus resin neutralization (0, 25, 50, 75, 100 and 125%) indicates that a minimum diameter is obtained around 90-100% neutralization, with no effect of over neutralization. For non-neutralized resin a maximum f(w,Inv) (0.25) can be obtained by reducing water addition rate allowing the production of 0.5 mu m droplets in a longer process.

Abstract  Fluorescence microscopy, surface potential, and activity measurements were used to investigate the influence of fatty acids and fatty alcohols on the lipolytic activity of several lipases. We have determined the lateral lipid distribution and interfacial properties of Langmuir mixed monolayers composed of 1,2-didecanoylglycerol/eicosanoic acid or 1,2-didecanoylglycerol/1-octadecanol molecules and have measured lipase activities toward these films. Enzymatic activities are remarkably influenced by the addition of fatty acid. Activity decreases continuously up to a mole fraction of approximate to 0.1 fatty acid, where phase separation and a change in surface potential are observed. Higher concentrations of fatty acid have only marginal effects on the lipase activities. The relative activity between the different lipases varies substantially and there is an indication that the level of inhibition correlates with the isoelectric point (pI) of the enzymes. A simpler mechanism is observed by the addition of fatty alcohol. Within the concentration range studied, 1-octadecanol is immiscible in the diacylglyceride matrix, forming liquid-condensed domains. The inhibitory effect is related to the reduction of available diacylglyceride area to the enzyme; Direct imaging of the lipolytic hydrolysis of these monolayers show that relatively small domains are formed, suggesting that the enzyme preferentially acts on pure diacylglyceride patches.

Abstract  The sterol distributions in the steryl chlorin esters (SCEs) from three marine and two lacustrine sediments have been compared with the free sterols and known water column sterol distributions. The comparison provides further evidence that the SCE sterol distributions are more representative of the original phytoplanktonic sterol distribution than are the free sterol distributions. This is most clearly seen in the relative abundance of C-26 sterols and 4-methyl sterols, and in the stanol/stenol ratios. It appears that in general the SCE sterols are less susceptible to selective biodegradation than the free sterols. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.

Abstract  A method for disintegrating waste office paper using kerosene was reported in our previous paper, which achieved almost a 100% liberation of toner from paper fibers. The liberated toner must be completely separated to realize effective deinking. Recently, a new method for deinking waste officer paper by magnetic separation after hetero-coagulation of magnetic and non-magnetic toner by I-octadecanol was reported by Augusta et al. Under this method, coagulation was carried out at 72degreesC. The I-octadecanol liquid was then cooled to produce strong solid coagulates. As reported in our previous paper, kerosene has the ability to soften toner, and strong coagulates for magnetic separation may be produced by their adhesion when used as a flocculant. The present study investigated the size of toner particles liberated by the kerosene disintegration method, and compared the bonding strength between the toner particles coagulated by the addition of kerosene as a flocculant to those coagulated with I-octadecanol. After these investigations, the coagulating and deinking properties of kerosene and I-octadecanol were compared by rejecting toner coagulates with a neodymium-boron magnet. The results showed that nearly perfect deinking can be achieved with little paper loss, even in ambient temperature, due to the large and strong coagulates produced by this method. When kerosene was used in the disintegration and coagulation stages, the average coagulate size was 1114 mum, and a deinking percentage of 98.4% was attained through separation with a neodymium-boron magnet.

Abstract  Two novel functionalized polythiophenes, poly[3-(6-hydroxyhexyl)thiophene] and poly(3-octanethio-2,2'-bithiophene), were used as selective coating materials for quartz crystal microbalance (QCM) sensors. These conductive polymers on admixture with stearyl alcohol were deposited on QCM devices by the Langmuir-Blodgett (LB) technique. These LB films exhibited a selective adsorption for the first-row transitions ions in the Irving-Williams order due to the complexation of metal ions with sulfur atoms in the polymers. These LB film coated QCM sensors were found applicable in detecting heavy metal ions in aqueous solution, which are major pollutants in wastewater. The coated QCM sensors can selectively adsorb heavy metal ions (Hg2+) from solution over a wide range from 0.1 to 100 ppm concentration by complexation with sulfur atoms in the polymers. The bound mercury could be removed by ethylenediaminetetraacetic acid (EDTA) solution. The presence of ferrous, lead, cobalt, and chromium cations in the solution did not interfere with the detection of mercury ions.

Abstract  The hypothesized reaction mechanisms for U reduction by the dehydrogenation of hydroxyl groups and aliphatic hydrocarbonaceous moieties of lignite were verified by kinetic U reduction experiments using simple alcohols (1 -octadecanol and 2-propanol) and aliphatic hydrocarbons (n -octacosane). The rate constants and activation energies for U reduction by these alcohols are similar to those obtained for U reduction by lignite. The rate-determining step for U reduction by both simple and natural organic matter is hypothesized to be controlled by oxygen diffusion through U oxides. The equilibria of the system lignite-aqueous uranyl have been used to calculate standard free energy changes DELTAG-degrees for lignite dehydrogenation. Their comparison with those for the dehydrogenation of simple organic molecules supports the proposed reactions thermodynamically.

Abstract  Bladder dysfunction secondary to benign prostatic hyperplasia (BPH) is a major affliction associated with ageing. As the disease slowly progresses, the bladder changes from a state of compensation to decompensation, in which there are severe, irreversible alterations in bladder function. Using a rabbit model of partial outlet obstruction we have identified three major cellular changes in the bladder which result from such obstruction. These include progressive denervation, mitochondrial dysfunction and disturbances of calcium storage and release from the sarcoplasmic reticulum. Our hypothesis is that outlet obstruction results in bladder hypertrophy which induces ischaemia. This leads to a release of intracellular calcium, leading to activation of specific enzymes and generation of free radicals. These then attack the membranes of nerves, sarcoplasmic reticulum and mitochondria. We have demonstrated that pretreatment of rabbits with Pygeum africanum extract (Tadenan) significantly reduced the severity of both the contractile and metabolic dysfunctions induced by partial outlet obstruction. Our current hypothesis is that Tadenan may either prevent the activation of degradative enzymes (or generation of free radicals), or protect the intracellular membranes against the destructive effects of free radicals or degredative enzymes. In conclusion, identifying cellular mechanisms responsible for bladder dysfunction induced by partial outlet obstruction provides new possibilities for non-surgical treatment of BPH. Our studies on Tadenan support this concept that the bladder provides a novel target for therapeutic intervention.

Abstract  This research is focused on the immediate contribution of the bees and combs to honey volatiles in order to exclude these compounds as botanical-origin biomarkers for honey authentification. Therefore, the bees were closed in a hive containing empty combs under controlled food-flow conditions (saccharose solution). The obtained 'saccharose honey' probe samples were subjected to ultrasonic solvent extraction (USE), followed by gas chromatography and mass spectrometry analyses (GC and GC/MS). A total of 66 compounds were identified. Higher alcohols made up ca. 50% of the total volatiles, mainly (Z)-octadec-9-en-1-ol, hexadecan-1-ol, and octadecan-1-ol, with minor percentages of undecan-1-ol, dodecan-1-ol, tetradecan-1-ol, pentadecan-1-ol, and heptadecan-1-ol. Other abundant compounds were saturated long-chain linear hydrocarbons, C(10)-C(25), C(27), and C(28), particularly C(23), C(25), and C(27)). Identified chemical structures were related to the composition of combs and cuticular waxes, and less to the bee pheromones. In addition, the impact of two-hour heat treatment at 80 degrees and one-year storage at room temperature on the same probe was investigated in order to identify thermal and storage artefacts. These findings can be considered as blank-trial probe (no plant source) for honey chemical profiling and identification of reliable botanical origin biomarkers.