bluuebunny/crossref_metadata_2025 huggingface dataset:
Tunable topographical cellulose matrices for electro-optical liquid crystal cells
Authors: Costa I. , Almeida P. , Filip D. , Figueirinhas J. , Godinho M.
Published: November 2006

In this work we have used acetoxypropylcellulose (APC) to produce free standing solid films (∼60 μm) that were used for assembling electro-optical devices. Thin films were obtained from concentrated lyotropic solutions of cellulose derivatives. Induced by the cast and shearing preparation conditions wrinkles and band textures can be observed in their free-surface plane. In order to eliminate and control these textures we used a process similar to that introducted in literature [1] which consists of storing the films in the same solvent-vapour atmosphere as the solution system. Lyotropic APC liquid crystalline solutions in dymethylacetamide (DMA) with crosslinker were prepared, thin films were obtained by using a shear/casting technique and stored in the solvent-vapour atmosphere until a planar structure was achieved. The dried crosslinked films were analyzed by optical polarised microscopy (POM) and scanning electron microscopy (SEM). The films with different topographies were used to produce optical cells composed by the cellulose derivative film covered on both free surfaces by a layer of the nematic liquid crystal E7 and placed between two transparent conducting substrates. The electro-optical properties of these cells were obtained.
Quantum Phase Transition in Spin Systems Studied through Entanglement Estimators
Authors: Fubini A. , Haas S. , Roscilde T. , Tognetti V. , Verrucchi P.
Published: November 2006

Entanglement represents purely quantum effect involving two or more particles. Spin systems are good candidates for studying this effect and its relation with other collective phenomena ruled by quantum mechanics. While the presence of entangled states can be easily verified, the quantitative estimate of this property is still under investigation. One of the most useful tools in this framework is the concurrence whose definition, albeit limited to S = 1/2 systems, can be related to the correlators. We consider quantum spin systems defined along chains and square lattices, and described by Heisenberg-like Hamiltonians: our goal is to clarify the relation between entanglement and quantum phase transitions, as well as that between the concurrence the and the specific quantum state of the system.
Quantum and Classical Correlations of Spatial and Spin Degrees of Freedom in Quantum Rings
Authors: Kálmán O. , Földi P. , Benedict M. G.
Published: November 2006

A one-dimensional mesoscopic ring with one input and two output leads acts as a spintronic beam splitter. The spatial degree of freedom, i.e., the presence of two different possible output channels, gets intertwined with the spin direction as a consequence of quantum interference and spin-orbit interaction. We investigate this kind of spatial-spin correlation, and show that the output density operator contains no quantum entanglement in the important special case when the device polarizes a perfectly random input spin state. However, the correlations are in general not purely classical, we also present specific input states with maximal spatial-spin entanglement after the ring.
Microbial aspects of linear alkylbenzene sulfonate degradation in coastal water
Authors: Vives‐Rego J. , López‐Amorós R. , García M. T. , Comas J. , Sánchez‐Leal J.
Published: November 2006

Viable and total bacteria were determined during linear alkylbenzene sulfonate (LAS) degradation in coastal seawater. Viable bacteria were determined by plate counts on marine agar media, while total bacteria were determined by flow cytometry after SYTO‐13 staining. LAS degradation was monitored by high‐performance liquid chromatography analysis. Seawater samples with LAS at 5 mg/L, incubated in the laboratory (20°C, 100 rpm, 30 d), showed in most cases a similar evolution in bacterioplankton abundance over time, characterized by three phases: (i) a progressive increase in bacterial density; (ii) a later decrease; and (iii) a fluctuating stationary phase. Bacterioplankton degraded the LAS by growing to populations with a high percentage of viable bacteria. The bacteria were rapidly grazed by protozoa, preventing anomalous high bacterial growth and ensuring the later channeling of LAS carbon to upper trophic levels.
Aquatic toxicity—Are surfactant properties relevant?
Authors: Roberts D. W.
Published: November 2006

There are two potential approaches for quantitative structure‐activity relationships modeling of aquatic toxicity of surfactants. One is to try to relate toxicity to parameters describing the surfactant properties, which can be measured or calculated. The other approach is to try to apply to surfactants parameters such as log P (P=octanol/water partition coefficient), which can also be used to relate toxicity to structure for nonsurfactants. This paper compares the two approaches and presents new data supporting the second approach as the more mechanistically relevant. Further refinements in the calculation method for log P are presented.
Lipid soil removal from cotton fabric after mercerization and carboxymethylation finishing
Authors: Obendorf S. Kay , Borsa Judit
Published: November 2006

Soiling and soil removal from cotton fabrics that had been chemically modified by mercerization and carboxymethylation were studied using electron microscopy and radiotracer techniques. The distribution of lard soil in specimens before and after laudering was determined by means of chemical tagging with osmium tetroxide. Both the chemical and physical changes of the cotton resulted in differences in soiling and soil removal of lipid soil. Mercerization and carboxymethylation of cotton swell the cotton fiber, decrease the crenulation and the lumen, and smooth the fiber surface. These finishes also increase the pore volume and thus the chemical accessibility of the fibrillar structure. In addition, carboxymethylation causes changes in the chemistry of the fiber by increasing the carboxyl group content. These structural changes reduce the amount of soil deposited in the lumen of the fiber, particularly for the carboxymethylated cotton. They also increase soil removal from the crenulation and the interfiber spaces in the yarn bundle. Soil removal from fiber surfaces and from within the fiber—both lumen and secondary wall—was highest for the carboxymethylated cotton, and mercerization also enhanced lipid soil removal. The results of this experiment indicate that chemical accessibility and hydrophilicity of the fiber structure influence both soil deposition and soil removal of lipid soils. Soil removal of these modified cottons is enhanced by multiple mechanisms: (i) the decrease in small crevices and the crenulation or small capillary along the fiber, (ii) the increase in pore volume that enhances chemical accessibility and thus detergency within the fiber structure, (iii) the increase in hydrophilicity that enhances soil removal from the surface by the roll‐up mechanism, (iv) the increase of mechanical action due to enhanced swelling of the carboxymethylated cotton, and (v) the reduction of soil redeposition on carboxymethylated surfaces.
Surface interaction of quaternary amines with hair
Authors: Beard B. C. , Hare J.
Published: November 2006

Surface analysis by X‐ray photoelectron spectroscopy (XPS) has shown specific 1∶1 (ionic) interaction between cationic alkyl quaternary surfactant molecules and the anionic sulfonate groups present on the hair surface. The primary driving force for the adsorption of alkyl quaternary amine molecules to the surface of the hair from aqueous solution is the ionic interaction between quaternary groups and the surface SO3− on the hair. Cationic quaternary molecules incorporating ester and alcohol functionalities (ester quats) demonstrate a lower number of surface quaternary nitrogens per sulfonate group, indicating an altered surface interaction mechanism. For the ester quats, a combination of electrostatic interaction modes exists in addition to the ionic N+/SO3− interaction, specifically, H‐bonding interactions of the −C−O, −C−OH, and −C(O)O− polar groups with SO3− and other polar groups on the hair. Surface coverage of the ester quat is not reduced despite the decrease in ionic interaction at the surface. Both types of molecules orient their alkyl tails toward the surface. Molecular dynamics modeling of the surfactant/hair surface interaction indicates higher adsorption energies due to increased dipolar interactions for ester quat molecules.
Synthesis and properties of N‐(α‐carboxyalkyl)acrylamide telomer‐type surfactants having multihydrocarbon chains
Authors: Yoshimura Tomokazu , Kiridoshi Yasuhiro , Koide Yoshifumi , Shosenji Hideto , Esumi Kunio
Published: November 2006

N‐(α‐Carboxyalkyl)acrylamide telomer‐type surfactants (xCn−1AmAc where n is alkyl chain length=6, 8, 10, 12; and x is degree of polymerization=3.3–13.1) were synthesized by the telomerization of monomer (Cn−1AmAc) in the presence of the corresponding alkanethiol as a chain transfer agent and then investigated for their surface‐active properties. xCn−1AmAc telomers lowered the surface tension of aqueous solutions that were at pH 9–10. The critical micelle concentrations (CMC) of the telomers were lower than those of the monomers with the same alkyl chain length, and the CMC values shifted to lower concentrations with both increasing alkyl chain length and polymerization degree. xC9AmAc with x=3.3–6.3 gave the highest efficiencies in lowering the surface tension. The cross‐sectional molecular areas per molecule of xCn−1AmAc telomers were smaller than the values estimated on the assumption that they are assemblies of Cn−1AmAc monomer units. The foaming abilities and the foam stabilities were both in the orders of xC7AmAc>xC9AmAc>xC5AmAc>xC11AmAc. Mixtures of aqueous solutions of xCn−1AmAc telomers and toluene formed oil‐in‐water emulsions. The emulsion‐stabilizing abilities were in the orders of xC7AmAc>xC5AmAc>xC9AmAc=xC11AmAc. The addition of Ca2+ to the mixed solutions of telomers and toluene resulted in formation of water‐in‐oil type emulsions. Thus, the surface‐active properties of the telomers were influenced significantly by the alkyl chain length and the polymerization degree of the telomers. In addition, these properties could be correlated with the hydrophilic‐lipophilic balance (HLB); the highest surface activities were observed by using xCn−1AmAc with HLB of 14–18.
Study of the amination of fatty alcohols catalyzed by Cu−Ni catalysts
Authors: Qiuxiao Li , Gaoyong Zhang , Shaoyi Peng
Published: November 2006

Amination of fatty alcohols by hydrogenation and dehydrogenation catalysis is one of the main commercial processes for the production of dimethylalkylamines. The key factor in this process is the preparation of catalysts with high selectivity. A study of amination catalyzed by Cu−Ni catalysts supported on CaCO3 is reported in this paper. Selectivity of the catalysts was adjustable by varying the ratio of Cu to Ni or by adding a third element (Zn or Mg). The promotion of catalyst selectivity was mainly attributable to the effect of the components on the reducibility of Ni2+ in the catalysts. Lower reducibility of Ni2− led to higher catalyst selectivity.
Effect of different additives on the cloud point of a polyethylene oxide‐polypropylene oxide‐polyethylene oxide block copolymer in aqueous solution
Authors: Sharma Rakesh , Bahadur P.
Published: November 2006

Cloud point studies on aqueous solutions of a polyethylene oxide (PEO)‐polypropylene oxide‐PEO triblock copolymer (Pluronic® L64: EO13PO30EO13, total m.w.=2900, PEO=40%; EO=ethylene oxide; PO=propylene oxide) in the presence of different additives show some interesting features. The effect of various inorganic salts was an increase or decrease in cloud point based on their salting in and salting out action and followed the Hofmeister lyotropic series. Nonelectrolytes and hydrotropes increased the cloud point by influencing water structure. Hydrotropes altered the cloud point of the copolymer at much lower concentrations than inorganic salts. Ionic surfactants produced a marked increase in the cloud point of copolymer solutions. The effect was greater for surfactants with greater hydrophobicity. Alcohols and other organic liquid additives that are infinitely miscible with water increase the cloud point of the copolymer, whereas additives that are partially miscible in water decrease the cloud point.
Micelle ionization degree of anionic gemini surfactant having N,N‐dialkylamide and carboxylate groups
Authors: Tsubone Kazuyuki , Ghosh Soumen
Published: November 2006

The critical micelle concentration (cmc) behavior in aqueous NaCl solutions of the anionic gemini surfactant N,N′‐ethylenebis(sodium N‐dodecanoyl‐β‐alanate), (CH2)2[N‐(COC11H23)CH2CH2(CO2Na)]2 (212), having N,N‐dialkylamide and carboxylate groups in a molecule was investigated to measure the value of micelle ionization degree (α). For comparison, the behavior of sodium N‐dodecanoyl‐N‐methyl‐β‐alanate (SDMA), a monomer corresponding to 212, also was investigated. The α value obtained from the Corrins‐Harkins plot for 212 is 0.97 when [Na+]≤0.025 M and the value for SDMA is 0.51 when [Na[+]≤0.1 M. That the α for 212 is larger than that for SDMA reflects the higher pKa1 value for 212 than the pKa value of SDMA. For 212, when [Na+]≤0.025 M the amount of Na+ released during micellization is so large that the Na+ concentration above the cmc is almost equal to that below the cmc, and therefore 212 nearly behaves as a nonionic surfactant.
Micellar‐improved synthesis of bis‐quaternary ammonium salts by the epichlorohydrin route
Authors: Ricci C. G. , Cabrera M. I. , Luna J. A. , Grau R. J.
Published: November 2006

A convenient procedure for the synthesis of bis‐quaternary ammonium salts from long‐chain alkyldimethylamines and epichlorohydrin is studied. An improved preparation of bis‐quaternary ammonium salts from N,N‐dimethyloctylamine, N,N‐dimethyldodecylamine or N,N‐dimethyloleylamine, their amine hydrochlorides, and epichlorohydrin can be achieved by carrying out the reaction in an aqueous micellar medium. The amine hydrochlorides are used as functional surfactants to produce the self‐micellization and solubilization of reactants. The formation of micelles is a necessary condition for a successful quaternization. Comparison of the quaternization performance in ethanol, ethanol/water mixtures, and aqueous micellar medium leads to the conclusion that this micellar‐improved synthesis enables easier and cheaper access to bis‐quaternary ammonium salts by avoiding the formation of the mono‐quaternary ammonium salts as intermediates, and by using water as solvent under mild reaction conditions. Mechanistic aspects of the quaternization reaction in micellized medium are also suggested.
Catalytic destruction of malathion by metallomicelle layers
Authors: Badawi A. M. , Hafiz A. A. , Ibrahim H. A.
Published: November 2006

Two micellized Cu(II) and Fe(III) ion complexes were synthesized and found to possess good catalytic activity in the cleavage of the malathion/dupric (ferric) complex thionate ester. The complexes form metallomicelles, which bind the substrate by coordinating with the thionate sulfur in the malathion (which is chemically similar to the nerve agent sarin). Possible reasons for the rate acceleration include enhanced electrophilicity of the micellized metals, enhanced surface activity, and the recognized ability of cationic micelles to accelerate the cleavage of the thionate ester. The results of kinetic data (half‐life times) for malathion degradation were 13.7 and 8.3 min in the presence of Cu(II) and Fe(III) metallomicelle layers, respectively.
Synthesis and evaluation of polytriethanolamine monooleates for oil‐based muds
Authors: Hafiz A. A. , Abdou M. I.
Published: November 2006

New emulsifiers were developed by esterification of polytriethanolamine based on the dimerization and trimerization of triethanolamine. The dimer and trimer were esterified with oleic acid to prepare monoesters of di‐triethanolamine and tri‐triethanolamine. The synthesized esters were evaluated as water‐in‐oil emulsifiers in oil‐based muds, which are the circulating fluids used in rotary drilling to perform various functions required in the drilling operation, such as control of density, flow, and filtration properties. The dimer and trimer of triethanolamine were also esterified with hydrolyzed cottonseed oil, and the resulting esters were evaluated as commercial emulsifiers for oil‐base muds.
Enhancement of enzymatic catalysis of Bacillus amyloliquefaciens α‐amylase by nonionic surfactant micelles
Authors: Hoshino Eiichi , Tanaka Atsushi
Published: November 2006

Some enzymes are considerably more stable when formulated with nonionic surfactants than when formulated with anionic surfactants. The effect of a nonionic surfatant, polyoxyethylene mono‐N‐dodecyl ether (Brij 35; number of units of ethylene oxide moieties, 23), on the kinetic behavior of hydrolysis of amylopectin with Bacillus amyloliquefaciens α‐amylase (BAA) was studied at a temperature of 25°C and a pH of 7.0. The hydrolytic rate was accelerated by the addition of the nonionic surfactant above its critical micelle concentration. Lineweaver‐Burk plots for the enzymatic hydrolysis in the absence and presence of the nonionic surfactant at 0.5 to 2.5% (wt/vol) had linear relationships, and the kinetic parameters, Km and kcat were obtained. The value of kcat was increased with an increased concentration of Brij 35, whereas the Km value was approximately constant. Therefore, the increase in kcat contributed to the acceleration of the apparent hydrolytic rate. The interaction of amylopectin with the surfactant was examined by a surface tension measurement, and the result confirmed the corresponding binding between the substrate and the surfactant. A fluorescence analysis due to tryptophan in BAA suggested that BAA bound to the nonionic micelles. The increase in kcat suggested that hydrolytic catalysis at the micellar pseudophase was more efficient than that at the aqueous pseudophase. The enhancement of the catalytic rate contributed to the effective removal of food stains containing starch when BAA was added with Brij 35 in a laundry detergent washing test.
Fourier‐transform infrared spectra of fatty acid salts—Kinetics of high‐oleic sunflower oil saponification
Authors: Poulenat Gaëlle , Sentenac Sabine , Mouloungui Zéphirin
Published: November 2006

Sodium, lithium, and calcium soaps obtained by saponification of high‐oleic sunflower oil were studied by Fourier‐transform infrared spectroscopy. Spectra of crude mixtures containing soap, glycerin, residual alkali, and triacylglycerols were compared to those of pure soaps obtained from fatty acids. The infrared spectra of crude soaps showed the same characteristic bands as pure ones. The absorption bands of asymmetric (ω2) and symmetric (ω1) stretching vibrations of the carboxylate group indicated that the metal‐oxygen bonds of these soaps had an ionic character whose strength differed from one cationic counterion to another. Once the characteristic absorption bands of the soaps were assigned, a kinetics study of saponification was performed. Saponification by sodium, anhydrous lithium, and calcium hydroxides was an autocatalytic reaction, characterized by an S‐shaped kinetics curve, whereas saponification by aqueous lithium hydroxide was stoichiometric. The structure of the metal‐oxygen bond played a role in the kinetic mechanisms.
The evolution of anionic surfactant technology to meet the requirements of the laundry detergent industry
Authors: Scheibel Jeffrey J.
Published: November 2006

Surfactants are the single most important ingredients in laundry and household cleaning products, comprising from 15 to 40% of the total detergent formulation. They play a key role in the $60 billion detergent market, which is the focus of this review. The past, present, and future trends of mainframe anionic surfactants and the key technological developments for these surfactants are discussed. The focus of this review is on how surfactants are changed (i) to meet changing environmental requirements, (ii) to take advantage of advances in process technology, and (iii) to address changes in consumer habits.
Clouding phenomenon in ionic micellar solutions: Role of the counterion
Authors: Kumar Sanjeev , Khan Ziya Ahmad , Kabir‐ud‐Din
Published: November 2006

Clouding is rarely observed with ionic surfactants. Herein we report the occurrence of clouding in sodium dodecyl sulfate (SDS, an anionic surfactant) solutions on addition of different symmetrical and unsymmetrical quaternary phosphonium bromides (tetra‐n‐butylphosphonium, tetraphenylphosphonium, and n‐propyltriphenylphosphonium). Cloud point (CP) measurements were made with solutions having different SDS/salt combinations. The nature of the counterion had a crucial role in the occurrence of the phenomenon, whereas substitution of an alkyl chain by a phenyl ring made the salt more effective near ambient temperature. A linear relationship between the SDS and salt concentrations was obtained. It is proposed that both the electrostatic charge and the hydration state of the headgroup region are influenced by counterion addition and that the net charge or volume of the counterion has a key role to play in the overall phenomenon. The effect of the addition of some hydroxy compounds on CP variations in these SDS+salt systems was also studied, and the data were interpreted on the basis of incorporation of these compounds in the micellar headgroup region. The nature of the counterions influenced this incorporation.
The self‐aggregation of sodium perfluorooctanoate in aqueous solution at different temperatures
Authors: González‐Pérez Alfredo , Ruso Juan M. , Prieto Gerardo , Sarmiento Félix
Published: November 2006

Electrical conductivities of sodium perfluorooctanoate (SPFO) in aqueous solutions were measured at different temperatures (range 294–328 K). Critical micelle concentrations (CMC) and the degree of ionization (α) of the micelles were derived from such data. The results revealed that temperature dependence of CMC is U‐shaped with a minimum at 316 K. Gibbs free energies, enthalpies, and entropies of micelle formation as a function of temperature were estimated from the CMC and α values using the charged pseudo‐phase separation model. To correlate the enthalpic and entropic contributions, the compensation phenomenon was studied, with a compensation temperature of 309 K and an intercept of −27.7 kJ·mol−1. Apparent molar volumes and adiabatic compressibilities of SPFO were determined from density and ultrasound velocity measurements in the same temperature range as conductivities. Positive deviation from the Debye‐Hückel limiting law of the apparent molar volume in the range of temperatures studied evidenced hydrogen bonding‐type interactions between monomers and the existence of dimers in the premicellar region. With micellization, the apparent molar volumes decrease with rising temperature, indicating that the structure of micelles is looser than that of monomers. The isentropic apparent molar adiabatic compressibilities following micellization were positive, indicating the predominant role of the decrease in hydrophobic hydration in the association process.
Synthesis, characterization, and surface properties of phenylalanine‐glycerol ether surfactants
Authors: Varka E.‐M. , Coutouli‐Argyropoulou E. , Infante M. R. , Pegiadou S.
Published: November 2006

A novel homologous series of 1‐N‐l‐phenylalanine‐glycerol ether surfactants was synthesized in satisfactory yieldsviareaction of epichlorohydrin with aliphatic alcohols with alkyl chains of 10–15 carbon atoms. Structural assignment of the new compounds was made on the basis of elemental analysis and spectroscopic data. Critical micelle concentration (CMC), surface tension at the CMC (γCMC), surfactant concentration required to reduce the surface tension of the solvent by 20 mN/m (pC20), and the interfacial area occupied by the surfactant molecules (Amin) were determined from aqueous surface tension measurements using the Wilhelmy plate technique.
Sulfoxidation of fatty acid methyl esters: Conversion and selectivity
Authors: Cohen Leon , Soto Fernando , Pratesi C. , Faccetti L.
Published: November 2006

In this work several batch sulfoxidation reactions of different fatty acid methyl esters, having chain lengths of C12 to C18, in the presence of SO2, O2, and ultraviolet light of 253 nm have been carried out. The average reaction conversion for each methyl ester has been calculated and the selectivity determined by liquid chromatography. The results indicate that conversion increases dramatically with the increase of carbon chain length, whereas selectivity to monosulfonate seems to increase slightly as the chain length increases.
Head group‐modified sophorolipids: Synthesis of new cationic, zwitterionic, and anionic surfactants
Authors: Zerkowski Jonathan A. , Solaiman Daniel K. Y. , Ashby Richard D. , Foglia Thomas A.
Published: November 2006

Amino acid‐glycolipid conjugates were prepared using carbodiimide‐mediated coupling methods. The amino acid units were multifunctional and possessed a para‐aminobenzoic acid linker. The glycolipid used was a stearic sophoroside. The aim of preparing these modified sophorolipids was to increase their water solubility as well as to introduce sites at the polar head groups that permitted further chemical derivatization. After acidolytic or hydrogenolytic deprotection of the amino acid N‐terminus or side chain, water‐soluble compounds were obtained that displayed good surfactant properties. Critical micelle concentration values were clustered in the range of high 10−6 to low 10−5 M, and minimum surface tension values were below 40 mN m−1. Two of the compounds represented more complicated structural classes, namely, gemini and bolaform surfactants.
Precipitation in solutions containing mixtures of synthetic anionic surfactant and soap. I. Effect of sodium octanoate on hardness tolerance of sodium dodecyl sulfate
Authors: Rodriguez Cheryl H. , Chintanasathien Chanin , Scamehorn John F. , Saiwan Chintana , Chavadej Sumaeth
Published: November 2006

The effect of sodium octanoate (SO) and pH on the precipitation of sodium dodecyl sulfate (SDS) with calcium (hardness tolerance) in water was investigated. SO can exist as octanoate anion (O−) or as the protonated nonionic fatty acid (HO) with the HO/O− ratio increasing with decreasing pH. At intermediate pH levels, SO or SO/SDS systems are composed of mixtures of anionic and nonionic surfactants, resulting in enhancement of micelle formation due to nonideal mixed micelle formation. Above the critical micelle concentration (CMC), the highest hardness tolerance at each pH level occurs at a mole ratio of 80∶20 SDS/SO due to synergism in the SDS/SO mixtures. This synergism also results in an increase in hardness tolerance of SDS with decreasing pH above the CMC.
Properties of soaps derived from distilled palm stearin and palm kernel fatty acids
Authors: Kuntom Ainie , Kifli Hamirin
Published: November 2006

Soaps made from blends of distilled palm stearin (PS) and palm (PK) kernel fatty acids were evaluated for total fatty matter, sodium chloride content, moisture content, hardness, Hunter whiteness, foamability, iodine value, titer value, and acid value. Data showed that these soaps had properties similar to palm‐based soaps made from distilled palm oil and palm kernel fatty acids. The soaps showed good whiteness (greater than 80%) and foamability. Total fatty matter ranged from 10–18%, sodium chloride content was 0.5%, and free caustic was 0.1% except for blend 8 containing 10 PS:90 PK, which had a free caustic of 0.03%. Initial penetration value, a reflection of soap hardness, ranged from 32–126 mm, with an average value of 54 mm. This value is within the range of the best blends of palm‐based soaps (50–63 mm). There was no obvious trend observed. Penetration value, however was found to stabilize after a month of storage with an average value of 19.4 mm. Soap with this hardness value is relatively hard and therefore should be blended with a small amount of soft oils.
Enhancing storage stability of emulsions by binding detergents with soy protein isolate and its hydrolysates
Authors: Wu Wu , Hettiarachchy N. S. , Rhee K. C.
Published: November 2006

Sodium dodecyl sulfate (SDS) is a frequently used anionic detergent, and proteins are among the widely used minor ingredients in cosmetic products. Proteins may enhance the detergent functions and protect human skin from irritation caused by detergents. Soy protein hydrolysates (SPH) were prepared by modifying soy protein (SP) with papain. Varying concentrations of SP or SPH were mixed with various concentrations of SDS at different pH values to determine: (i) molecular characteristics, degree of hydrolysis (DH), and surface hydrophobicity (S0) of SP and SPH; (ii) the effect of SDS concentrations on the S0 of SP; (iii) the storage stabilities of oil‐in‐water emulsions formed by SDS, SP, SPH, SP‐SDS, and SPH‐SDS; and (iv) the effect of protein concentration (0.01 to 1.5%), DH (1.2 to 12.5%), and pH (3.0, 5.0, 7.0, and 9.0) on storage stabilities of emulsions formed by SP‐SDS or SPH‐SDS. An increase in emulsion stability (ES) with increasing protein concentration was observed. The ES values of emulsions formed by SPH‐SDS complexes were significantly higher than those formed by SP‐SDS at pH 7.0 and 9.0. The ES of emulsions formed by the complexes were low at pH 5.0 and increased with increasing pH. At pH 3.0 the emulsions formed by SP‐SDS at 1 to 1.5% protein concentration and by SPH‐SDS at 1.5% protein concentration were very stable. The results indicate that at least one‐half of SDS content can be replaced by SP or SPH while maintaining emulsion stability.
Colloidal flocculation of micellar solutions of anionic surfactants
Authors: Paton P. , Talens‐Alesson F. I.
Published: November 2006

Micellar solutions of anionic surfactants usually precipitate in the presence of cations, following a mechanism by which initially cations bind themselves to the micellar surface until saturation is achieved. At higher cation concentrations, unbound cations precipitate with surfactant monomers. In a few cases cations, and especially Al3+, cause surfactant micelles to flocculate. These flocs have properties as adsorbents of acidic organic compounds, which might be used in water treatment processes. Both α‐olefinsulfonates C14−C16, and laurylsulfate micellar solutions are fast flocculation colloidal systems in the presence of Al3+.
Improving solubilization in microemulsions with additives. Part III: Lipophilic linker optimization
Authors: Salager Jean‐Louis , Graciaa Alain , Lachaise Jean
Published: November 2006

Polar oil additives are able to substantially improve the solubilization in surfactant‐oil‐water microemulsions through the so‐called lipophilic linker effect. Long‐chain alcohols (above C8) and their low ethoxylation derivatives were found to produce such an improvement. A method is proposed to evaluate the lipophilic linker performance and to compare lipophilic linker candidates in different oil‐surfactant systems. The best lipophilic linker was found to have a hydrophobe chain length as an average between that of the surfactant tail and the n‐alkane oil. The experimental data agree with that obtained by using a simple model based on the estimation of molecular interactions.
Diversity of mouse lipoxygenases: Identification of a subfamily of epidermal isozymes exhibiting a differentiation‐dependent mRNA expression pattern
Authors: Heidt Markus , Fürstenberger Gerhard , Vogel Sonja , Marks Friedrich , Krieg Peter
Published: November 2006

By using reverse transcription‐polymerase chain reaction technology (RT‐PCR) and Northern blot analysis, the tissue‐specific mRNA expression patterns of seven mouse lipoxygenases (LOX)—including 5S‐, 8S‐, three isoforms of 12S‐, 12R‐LOX, and a LOX of an as‐of‐yet unknown spacificity, epidermis‐type LOX‐3 (e‐LOX‐3)—were investigated in NMRI mice. Among the various tissues tested epidermis and forestomach were found to express the broadest spectrum of LOX. With the exception of 5S‐and platelet‐type 12S‐LOX (p12S‐LOX) the remaining LOx showed a preference to exclusive expression in stratifying epithelia of the mouse, in particular the integumental epidermis. The expression of the individual LOX in mouse epidermis was found to depend on the state of terminal differentiation of the keratinocytes. mRNA of epidermis‐type 12S‐LOX (e12S‐LOX) was detected in all layers of neonatal and adult NMRI mouse skin, whereas experission of p12S‐LOX, 12R‐LOX, and e‐LOX‐3 was restricted to suprabasal epidermal layers of neonatal and adult mice. 8S‐LOX mRNA showed a body‐sitedependent expression in that it was detected in stratifying epithelia of footsole and forestomach but not in back skin epidermis. In the latter, 8S‐LOX mRNA was strongly induced upon treatment with phorbol esters. With the exception of e12S‐LOX and p12S‐LOX, the isozymes that are preferentially expressed in stratifying epithelia are structurally related and may be grouped together into a distinct subgroup of epidermis‐type LOX.
Liver and intestinal fatty acid‐binding protein expression increases phospholipid content and alters phospholipid fatty acid composition in L‐cell fibroblasts
Authors: Murphy Eric J. , Prows Daniel R. , Stiles Thomas , Schroeder Friedhelm
Published: November 2006

Although fatty acid‐binding proteins (FABP) differentially affect fatty acid uptake, nothing is known regarding their role(s) in determining cellular phospholipid levels and phospholipid fatty acid composition. The effects of liver (L)‐ and intestinal (I)‐FABP expression on these parameters were determined using stably transfected L‐cells. Expression of L‐ and I‐FABP increased cellular total phospholipid mass (nmol/mg protein) 1.7‐ and 1.3‐fold relative to controls, respectively. L‐FABP expression increased the masses of choline glycerophospholipids (ChoGpl) 1.5‐fold, phosphatidylserine (PtdSer) 5.6‐fold, ethanolamine glycerophospholipids 1.4‐fold, sphingomyelin 1.7‐fold, and phosphatidylinositol 2.6‐fold. In contrast, I‐FABP expression only increased the masses of ChoGpl and PtdSer, 1.2‐ and 3.1‐fold, respectively. Surprisingly, both L‐ and I‐FABP expression increased ethanolamine plasmalogen mass 1.6‐ and 1.1‐fold, respectively, while choline plasmalogen mass was increased 2.3‐ and 1.7‐fold, respectively. The increase in phospholipid levels resulted in dramatic 48 and 33% decreases in the cholesterol‐to‐phospholipid ratio in L‐ and I‐FABP expressing cells, respectively. L‐FABP expression generally increased polyunsaturated fatty acids, primarily by increasing 20∶4n−6 and 22∶6n−3, while decreasing 18∶1n−9 and 16∶1n−7. I‐FABP expression generally increased only 20∶4n−6 proportions. Hence, expression of both I‐ and L‐FABP differentially affected phospholipid mass, class composition, and acyl chain composition. Although both proteins enhanced phospholipid synthesis, the effect of L‐FABP was much greater, consistent with previous work suggesting that these two FABP differentially affect lipid metabolism.
Dietary n−3 long‐chain polyunsaturated fatty acid deprivation, tissue lipid composition, ex vivo prostaglandin production, and stress tolerance in juvenile dover sole (Solea solea L.)
Authors: Logue J. A. , Howell B. R. , Bell J. G. , Cossins A. R.
Published: November 2006

Larval Dover sole fed an Artemia diet supplemented with n−3 long‐chain (C20+C22) polyunsaturated fatty acids (PUFA) are known to be more resistant to low‐temperature injury. Here we explore the relationship between tissue fatty acid composition and tolerance of stressful environmental conditions over the larval and early juvenile periods. Artemia nauplii supplemented with n−3 long‐chain PUFA‐deficient and PUFA‐enriched oil emulsions were fed to two groups of larvae. Whole body tissue samples from the resulting PUFA‐deficient and‐enriched juveniles possessed 12.1 and 21.9% n−3 long‐chain PUFA, respectively. These differences were at the expense of C18 PUFA, while proportions of saturated fatty acids, monousaturated fatty acids, and total PUFA were unaffected. Brain and eye tissues from the PUFA‐deficient fish contained lower levels of 22∶6n−3, known to be important for optimal nervous system function, incorporation instead a range of fatty acids of lower unsaturation. PUFA‐deprived juveniles showed substantially greater mortality when exposed to a combination of low temperature and low salinity, as well as to high temperature and to hypoxia. After adaptation to the different diets, both dietary groups were fed a common formulated feed high in n−3 long‐chain PUFA. Tissue PUFA in both groups progressively increased to the same high value, with a consequent loss of the differences in cold‐susceptibility. These correlated changes support a link between dietary manipulation of n−3 long‐chain PUFA and development of a stress‐sensitive phenotype. PUFA deprivation had no detectable effect upon static hydrocarbon order of purified brain membranes (as assessed by fluorescence polarization) but was associated with an increase in the whole‐body content of prostaglandins. We conclude that susceptibility to environmental stress is responsive to dietary n−3 long‐chain PUFA manipulation, possibly due to altered tissue development or the overproduction of eicosanoids.
Determination of the conjugated linoleic acid‐containing triacylglycerols in New Zealand bovine milk fat
Authors: Robinson Nicholas P. , MacGibbon Alastair K. H.
Published: November 2006

Reversed‐phase high‐performance liquid chromatography (HPLC) with ultraviolet (UV) detection at 233 nm was used to separate, quantify, and identify the triacylglycerols (TAG) of milk fat that contain conjugated linoleic acid (CLA). The absorbance at 233 nm was substantially due to CLA‐TAG (chromatography of some representative TAG devoid of CLA, such as tripalmitin and triolein, showed poor responses at 233 nm, 1/800th that of CLA‐TAG). A CLA molar extinction coefficient at 233 nm of 23 360 L mol−1 cm−1 and an HPLC UV response factor were obtained from a commercially available cis‐9, trans‐11‐CLA standard. This molar extinction coefficient was only 86% reported literature values. Summation of all chromatographic peaks absorbing at 233 nm using the corrected response factor gave good agreement with independent determinations of total CLA by gas chromatography and UV spectrophotometry. This agreement allowed quantification of individual CLA‐TAG peaks in the HPLC separation of a typical New Zealand bovine milk fat. Three CLA‐containing TAG, CLA‐dipalmitin, CLA‐oleoyl‐palmitin and CLA‐diolein, were prepared by interesterification of tripalmitin with the respective fatty acid methyl esters and used to assign individual peaks in the reversed‐phase chromatography of total milk fat, of which CLA‐oleoyl‐palmitin was coincident with the largest UV peak. Band fractions from argentation thin‐layer chromatography of total milk fat were similarly employed to identify five predominant CLA‐TAG groups in total milk fat: CLA‐disaturates, CLA‐oleoyl‐saturates, CLA‐vaccenyl‐saturates, CLA‐vaccenyl‐olein, and CLA‐diolein.
Gas chromatography—High resolution selected‐ion mass spectrometric identification of trace 21∶0 and 20∶2 fatty acids eluting with conjugated linoleic acid isomers
Authors: Roach John A. G. , Yurawecz Martin P. , Kramer John K. G. , Mossoba Magdi M. , Eulitz Klaus , Ku Yuoh
Published: November 2006

High‐resolution selected‐ion recording (SIR) of the exact molecular ion mass was used to confirm unambiguously the presence of conjugated linoleic acid (CLA) derivatives in biological matrices and standard mixtures and to differentiate non‐CLA derivatives from CLA derivatives in the CLA region of the gas chromatogram. The success of this method was based on the selectivity of the SIR technique and its sensitivity, which was comparable to that of flame‐ionization detection. A minor fatty acid methyl ester (FAME) was identified as methyl heneicosanoate (21∶0), and six isomers of 20∶2 FAME were found to elute in the CLA region. Isomerization of a standard CLA mixture resulted in a non‐CLA flame‐ionization response eluting in the CLA region of the gas chromatogram. It is therefore recommended that the identification of minor CLA isomers in natural products of biological matrices should include their direct confirmation by mass spectrometry
The role of docosahexaenoic acid in retinal function
Authors: Jeffrey Brett G. , Weisinger Harrison S. , Neuringer Martha , Mitchell Drake C.
Published: November 2006

An important role for docosahexaenoic acid (DHA) within the retina is suggested by its high levels and active conservation in this tissue. Animals raised on n‐3‐deficient diets have large reductions in retinal DHA levels that are associated with altered retinal function as assessed by the electroretinogram (ERG). Despite two decades of research in this field, little is known about the mechanisms underlying altered retinal function in n‐3‐deficient animals. The focus of this review is on recent research that has sought to elucidate the role of DHA in retinal function, particularly within the rod photoreceptor outer segments where DHA is found at its highest concentration. An overview is also given of human infant studies that have examined whether a neonatal dietary supply of DHA is required for the normal development of retinal function.
Randomized trials with polyunsaturated fatty acid interventions in preterm and term infants: Functional and clinical outcomes
Authors: Gibson Robert A. , Chen Wenxiong , Makrides Maria
Published: November 2006

The role of polyunsaturated fatty acids (PUFA) in infant nutrition has now been well studied through many randomized controlled trials (RCT) that provide us with high‐quality evidence, particularly in relation to efficacy. As a result of a systematic search of the literature for RCT of supplementation of formulas of term and preterm infants with long‐chain polyunsaturated fatty acids (LC‐PUFA), we have identified 21 studies that have physiological responses or growth as outcomes. There have been 11 RCT involving preterm infants, and many of these claim a beneficial effect on visual, neural, or developmental outcomes. There are some reports of negative effects on growth in relation to the addition of n−3 LC‐PUFA to preterm formulas but not when AA is added with n−3 LC‐PUFA. Small studies have shown no differences in prostanoid formation or peroxidative stress between n−3 IC‐PUFA‐supplemented and unsupplemented infants. There have been 10 RCT involving term infants; whereas some studies report an effect on visual/neural/developmental outcomes, an equal number report no effect. There have been no reports of negative effects of n−3 LC‐PUFA on growth in term infants. In summary, there appear to be few safety concerns relating to the use of LC‐PUFA in infant nutrition. The potential medium‐ and long‐term effects of including these compounds in the early diet of infants remain to be assessed.
Essential fatty acids in visual and brain development
Authors: Uauy Ricardo , Hoffman Dennis R. , Peirano Patricio , Birch David G. , Birch Eileen E.
Published: November 2006

Essential fatty acids are structural components of all tissues and are indispensable for cell membrane synthesis; the brain, retina and other neural tissues are particularly rich in long‐chain polyunsaturated fatty acids (LC‐PUFA). These fatty acids serve as specific precursors for eicosanoids, which regulate numerous cell and organ functions. Recent human studies support the essential nature of n‐3 fatty acids in addition to the well‐established role of n−6 essential fatty acids in humans, particularly in early life. The main findings are that light sensitivity of retinal rod photoreceptors is significantly reduced in newborns with n−3 fatty acid deficiency, and that docosahexaenoic acid (DHA) significantly enhances visual acuity maturation and cognitive functions. DHA is a conditionally essential nutrient for adequate neurodevelopment in humans. Comprehensive clinical studies have shown that dietary supplementation with marine oil or single‐cell oil sources of LC‐PUFA results in increased blood levels of DHA and arachidonic acid, as well as an associated improvement in visual function in formula‐fed infants matching that of human breast‐fed infants. The effect is mediated not only by the known effects on membrane biophysical properties, neurotransmitter content, and the corresponding electrophysiological correlates but also by a modulating gene expression of the developing retina and brain. Intracellular fatty acids or their metabolites regulate transcriptional activation of gene expression during adipocyte differentiation and retinal and nervous system development. Regulation of gene expression by LC‐PUFA occurs at the transcriptional level and may be mediated by nuclear transcription factors activated by fatty acids. These nuclear receptors are part of the family of steroid hormone receptors. DHA also has significant effects on photoreceptor membranes and neurotransmitters involved in the signal transduction process; rhodopsin activation, rod and cone development, neuronal dendritic connectivity, and functional maturation of the central nervous system.
Mechanisms of action of docosahexaenoic acid in the nervous system
Authors: Salem Norman , Litman Burton , Kim Hee‐Yong , Gawrisch Klaus
Published: November 2006

Abtract

This review describes (from both the animal and human literature) the biological consequences of losses in nervous system docosahexaenoate (DHA). It then concentrates on biological mechanisms that may serve to explain changes in brain and retinal function. Brief consideration is given to actions of DHA as a nonesterified fatty acid and as a docosanoid or other bioactive molecule. The role of DHA‐phospholipids in regulating G‐protein signaling is presented in the context of studies with rhodopsin. It is clear that the visual pigment responds to the degree of unsaturation of the membrane lipids. At the cell biological level, DHA is shown to have a protective role in a cell culture model of apoptosis in relation to its effects in increasing cellular phosphatidylserine (PS); also, the loss of DHA leads to a loss in PS. Thus, through its effects on PS, DHA may play an important role in the regulation of cell signaling and in cell proliferation. Finally, progress has been made recently in nuclear magnetic responance studies to delineate differences in molecular structure and order in biomembranes due to subtle changes in the degree of phospholipid unsaturation.