bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microemulsion formation and detergency with oily soils: I. Phase behavior and interfacial tension
Authors: Tongcumpou C. , Acosta E. J. , Quencer L. B. , Joseph A. F. , Scamehorn J. F. , Sabatini D. A. , Chavadej S. , Yanumet N. 
Published: November 2006

AbstractThe ultimate objective of the project was to investigate the relationship between microemulsion phase behavior and detergency for oily soils. In this study, surfactant phase behavior was evaluated for hexadecane and motor oil as model oily soils. Producing microemulsions with these oils is particularly challenging because of their large hydrophobic character. To produce the desired phase behavior we included three surfactants with a wide range of hydrophilic/lipophilic character: alkyl diphenyl oxide disulfonate (highly hydrophilic), dioctyl sodium sulfosuccinate (intermediate character), and sorbitan monooleate (highly hydrophobic). This mixed surfactant was able to bridge the hydrophilic/lipophilic gap between the water and the oil phases, producing microemulsions with substantial solubilization and ultralow interfacial tension. The effects of surfactant composition, temperature, and salinity on system performance were investigated. The transition of microemulsion phases could be observed for both systems with hexadecane and motor oil. In addition, the use of surfactant mixtures containing both anionic and nonionic surfactants leads to systems that are robust with respect to temperature compared to single‐surfactant systems. Under conditions corresponding to “supersolubilization”, the solubilization parameters and oil/microemulsion interfacial tensions are not substantially worse than at optimal condition for a middle‐phase system, so a middle‐phase microemulsion is not necessary to attain quite low interfacial tensions. A potential drawback of the formulations developed here is the fairly high salinity (e.g., 5 wt% NaCl) needed to attain optimal middle‐phase systems. The correlation between interfacial tension and solubilization follows the trend predicted by the Chun‐Huh equation.
Formulating middle‐phase microemulsions using mixed anionic and cationic surfactant systems
Authors: Doan T. , Acosta E. , Scamehorn J. F. , Sabatini D. A. 
Published: November 2006

AbstractAlthough mixtures of anionic and cationic surfactants can show great synergism, their potential to precipitate and form liquid crystals has limited their use. Previous studies have shown that alcohol addition can prevent liquid crystal formation, thereby allowing formation of middle‐phase microemulsions with mixed anionic‐cationic systems. This research investigates the role of surfactant selection in designing alcohol‐free anionic‐cationic microemulsions. Microemulsion phase behavior was studied for three anionic‐cationic surfactant systems and three oils of widely varying hydrophobicity [trichloroethylene (TCE), hexane, and n‐hexadecane]. Consistent with our hypothesis, using a branched surfactant and surfactants with varying tail length allowed us to form alcohol‐free middle‐phase microemulsion using mixed anionic‐cationic systems (i.e., liquid crystals did not form). The anionic to cationic molar ratio required to form middle‐phase microemulsions approached 1∶1 for univalent surfactants as oil hydrophobicity increased (i.e., TCE to hexane to n‐hexadecane); even for these equimolar systems, liquid crystal formation was avoided. To test the use of these anionic‐cationic surfactant mixtures in surfactant‐enhanced subsurface remediation, we performed soil column studies: Greater than 95% of the oil was extracted in 2.5 pore volumes using an anionic‐rich surfactant system. By contrast, cationic‐rich systems performed very poorly (<1% oil removal), reflecting significant losses of the cationic‐rich surfactant system in the porous media. The results thus suggest that, when properly designed, anionic‐rich mixtures of anionic and cationic surfactants can be efficient for environmental remediation. By corollary, other industrial applications and consumer products should also find these mixtures advantageous.
Synthesis and characterization of polyethoxylate surfactants derived from phenolic lipids
Authors: Tyman John H. P. , Bruce Ian E. 
Published: November 2006

AbstractPolyethoxylates from cardanol and from cardol, the main component phenolic lipids in technical cashew nutshell liquid derived from the replenishable source Anacardium occidentale, were obtained by reaction with ethylene oxide under base‐catalyzed conditions. Oligomeric mixtures resulted. In the cardanol series, the first six members of the mixture were independently synthesized for characterization purposes by a variety of reactions. The members in the oligomeric mixture were separated by HPLC, and the composition was determined by 1H NMR spectroscopy and by chromatography. These studies were preparatory to surfactant and biodegradation studies involving comparison with commercially available polyethoxylates derived from petrochemical nonylphenol.
A new test for cleaning efficiency assessment of cleaners for hard surfaces
Authors: Chateau Marie‐Elise , Galet Laurence , Soudais Yannick , Fages Jacques 
Published: November 2006

AbstractA new test was developed to assess the efficiency of no‐wiping hard‐surface cleaning. The test allows cleaner comparisons according to their ability to remove greasy soils. The chosen approach minimizes the mechanical forces applied while cleaning so that the interactions between a detergent solution and the soil to be removed can be characterized. For this, immersion cleaning was chosen, with coated stainless steel as substrate and pigmented oils as the model soil. Several parameters were studied in defined ranges using the Experimental Design method and systematic comparisons. The test shows high reliability on degreasing assessments and is there‐fore especially suited to optimization of nonionic surfactant mixes. The originality of the test lies in the possibility of keeping a visual trace of the cleaned substrate appearance by imprinting it on a piece of paper. The validation of the test leads to corroboration of several practical observations. Temperature and agitation play a major role in cleaning efficiency. Detergent solution concentration is a more relevant parameter than pH. Sodium carbonate is shown to have a higher buffering effect than pentahydrated sodium metasilicate. The test is easy to set up, highly sensitive, and can be adapted to solve the problems encountered by formulators of detergent cleaners, such as screening the best ethoxylated fatty alcohol mix for better degreasing properties.
Organization of amphiphiles VI. A comparative study of the orientation of polyoxyethylated alkyl phenols at the air‐water and the silica‐water interface
Authors: Misra Pramila K. , Somasundaran P. 
Published: November 2006

AbstractThe adsorption behavior on silica of a series of polyoxyethylated alkyl phenols of varying hydrophobicities and hydrophilicities was studied by determining the adsorption isotherm along with the zeta potential of silica. An increase in the concentration of each of the surfactants caused the zeta potential to become less negative and ultimately to reach a plateau; similarly, the adsorption isotherm also plateaued. These results were attributed to the flat orientation of the surfactants caused by hydrogen bonding of the oxygen atom of the oxyethylene group with the silanol group of the silica, which led to the formation of a thin oxyethylene layer at the silica‐water interface. This layer masked a constant fraction of the silica surface. A model for the orientation of the surfactants at the silica‐water interface was proposed, based on a “molecular parking area” (i.e., space occupied by the molecule during adsorption at the silica‐water interface) of the surfactants on the silica surface.
Alanine‐based surfactants: Synthesis and some surface properties
Authors: Mohamed A. S. , Mohamed M. Z. , Ismail D. A. 
Published: November 2006

AbstractA homologous series of anionic surfactants, namely, sodium‐N‐(alkyloxycarbonyl) alanine (where alkyl=octyl‐, dodecyl‐, hexadecyl‐, and octadecyl‐) were synthesized having the formula: R‐OCO‐CH2NH‐CH2‐CH2‐COONa. Surface properties of their solutions, including surface tension, critical micelle concentration, effectiveness, maximum surface excess, and minimum surface area, were investigated for different concentrations at 25°C. The effects of these surfactants on the solubilization of a polar and a nonpolar solute were studied. Standard free energies of micellization and adsorption were calculated for the prepared surfactants in aqueous solution.
Mixtures of anionic and cationic surfactants with single and twin head groups: Solubilization and adsolubilization of styrene and ethylcyclohexane
Authors: Fuangswasdi A. , Charoensaeng A. , Sabatini D. A. , Scamehorn J. F. , Acosta E. J. , Osathaphan K. , Khaodhiar S. 
Published: November 2006

AbstractMixtures of anionic and cationic surfactants with single and twin head groups were used to solubilized styrene and ethylcyclohexane into mixed micelles and adsolubilize them into mixed admicelles on silica and alumina surfaces. Two combinations of anionic and cationic surfactants were studied: (i) a single‐head anionic surfactant, sodium dodecyl sulfate (SDS), with a twin‐head cationic surfactant, pentamethyl‐octadecyl‐1,3‐propane diammonium dichloride (PODD), and (ii) a twin‐head anionic surfactant, sodium hexadecyl‐diphenyloxide disulfonate (SHDPDS), with a single‐head cationic surfactant, dodecylpyridinium chloride (DPCl). Mixtures of SDS/PODD showed solubilization synergism (increased oil solubilization capacity) when mixed at a molar ratio of 1∶3; however, the SHD‐PDS/DPCl mixture at a ratio of 3∶1 did not show solubilization enhancement over SHDPDS alone. Adsolubilization studies of SDS/PODD (enriched in PODD) adsorbed on negatively charged silica and SHDPDS/DPCl adsorbed on positively charged alumina showed that while mixtures of anionic and cationic surfactants had little effect on the adsolubilization of styrene, the adsolubilization of ethylcyclohexane was greater in mixed SHPDS/DPCl systems than for SHDPDS alone. Finally, it was concluded that whereas mixing anionic and cationic surfactants with single and double head groups can improve the solubilization capacity of micelles or admicelles, the magnitude of the solubilization enhancement depends on the molecular structure of the surfactant and the ratio of anionic surfactant to cationic surfactant in the micelle or admicelle.
Small‐angle neutron scattering studies on sodium dodecylbenzenesulfonate‐tetra‐n‐butylammonium bromide systems
Authors: Kumar Sanjeev , Sharma Daksha , Sharma Deepti , Kabir‐ud‐Din  
Published: November 2006

AbstractA phase study was completed on aqueous sodium dodecylbenzenesulfonate (SDBS) and tetra‐n‐butyl‐ammonium bromide (Bu4NBr) systems, and consolute boundaries were drawn through cloud points. Samples were selected from both miscibility regions [under the lower consolute boundary (LCB) and above the upper consolute boundary (UCB)] for small‐angle neutron scattering (SANS) studies. In the first set of experiments, the effect of varying Bu4NBr concentration on micellular parameters of 100 mM SDBS was studied at 30°C. The pure SDBS micelle has an aggregation number (ns) of 51, and the effective charge on the monomer (α) is 0.17. With the addition of Bu4NBr, the ns of SDBS micelles increases while α decreases. The system with [Bu4NBr]=39.5 mM (an above‐UCB sample) showed clouding near room temperature (≈29°C) and had a high ns value (300) and a low α (=0.09). The data indicated that the micelles lose ionic character in the presence of Bu4NBr. The temperature effect on this sample shows that α remains almost constant, while ns decreases on heating. A similar effect was observed with samples of lower Bu4NBr concentration (32 or 25 mM) in the presence of 100 mM SDBS. The same type of temperature effect was seen on a sample of under‐LCB region (50 mM SDBS+32 mM Bu4NBr); the ns values increased significantly as the LCB was approached. The overall SANS observations suggest that the micelles have low ionic character together with high ns values (a case of micellar growth) near LCB/UCB.
Conjugated linoleic acid supplementation in humans: Effects on body composition and energy expenditure
Authors: Zambell Kirsten L. , Keim Nancy L. , Van Loan Marta D. , Gale Barbara , Benito Paloma , Kelley Darshan S. , Nelson Gary J. 
Published: November 2006

AbstractRecent animal studies have demonstrated that dietary conjugated linoleic acid (CLA) reduces body fat and that this decrease may be due to a change in energy expenditure. The present study examined the effect of CLA supplementation on body composition and energy expenditure in healthy, adult women. Seventeen women were fed either a CLA capsule (3 g/d) or a sunflower oil placebo for 64 d following a baseline period of 30 d. The subjects were confined to a metabolic suite for the entire 94 d study where diet and activity were controlled and held constant. Change in fat‐free mass, fat mass, and percentage body fat were unaffected by CLA supplementation (0.18±0.43 vs. 0.09±0.35 kg; 0.01±0.64 vs. −0.19±0.53 kg; 0.05±0.62 vs. −0.67±0.51%, placebo vs. CLA, respectively). Likewise, body weight was not significantly different in the placebo vs. the CLA group (0.48±0.55 vs. −0.24±0.46 kg change). Energy expenditure (kcal/min), fat oxidation, and respiratory exchange ratio were measured once during the baseline period and during weeks 4 and 8 of the intervention period. At all three times, measurements were taken while resting and walking. CLA had no significant effect on energy expenditure, fat oxidation, or respiratory exchange ratio at rest or during exercise. When dietary intake was controlled, 64 d of CLA supplementation at 3 g/d had no significant effect on body composition or energy expenditure in adult women, which contrasts with previous findings in animals.
High doses of atorvastatin and simvastatin induce key enzymes involved in VLDL production
Authors: Roglans Núria , Verd Joan C. , Peris Cristina , Alegret Marta , Vázquez Manuel , Adzet Tomás , Diaz Cristina , Hernández Gonzalo , Laguna Juan C. , Sánchez Rosa M. 
Published: November 2006

AbstractTreatments with high doses of 3‐hydroxy‐3‐methylglutaryl‐coenzyme A (HMG‐CoA) reductase inhibitors may induce the expression of sterol regulatory element binding protein (SREBP)‐target genes, causing different effects from those attributed to the reduction of hepatic cholesterol content. The aim of this study was to investigate the effects of high doses of statins on the key enzymes involved in VLDL production in normolipidemic rats. To examine whether the effects caused by statin treatment are a consequence of HMG‐CoA reductase inhibition, we tested the effect of atorvastation on these enzymes in mevalonatefed rats. Atorvastatin and simvastatin enhanced not only HMG‐CoA reductase but also the expression of the SREBP‐2 gene itself. As a result of the overexpression of SREBP‐2 caused by the statin treatment, genes regulated basically by SREBP‐1, as FA synthase and acetyl‐coenzyme A carboxylase, were also induced and their mRNA levels increased. DAG acyltransferase and microsomal IG transfer protein mRNA levels as well as phosphatidate phosphohydrolase activity were increased by both statins. Simvastatin raised liver cholesterol content, ACAT mRNA levles, and CTP:phosphocholine cytidylyltransferase activity, whereas it reduced liver DAG and phospholipid content. Mevalonate feeding reversed all changes induced by the atorvastatin treatment. These results show that treatment with high doses of statins induces key enzymes controlling rat liver lipid synthesis and VLDL assembly, probably as a result of SREBP‐2 overexpression. Despite the induction of the key enzymes involved in VLDL production, both statins markedly reduced plasma TG levels, suggesting that different mechanisms may be involved in the hypotriglyceridemic effect of statins at high or low doses.
Effect of dietary cholesterol oxidation products on the plasma clearance of chylomicrons in the rat
Authors: Vine D. F. , Croft K. D. , Beilin L. J. , Mamo J. C. L. 
Published: November 2006

AbstractOxidized cholesterols in the diet have been shown to exacerbate arterial cholesterol deposition and the development of atherosclerosis in animal models. Dietary oxidized cholesterols are absorbed through the intestine and incorporated into lymph chylomicrons. The aim of this study was to investigate the effect of oxidized cholesterols on the metabolism of nascent chylomicrons in vivo. It was shown that oxidized cholesterols markedly delay the clearance of chylomicrons from plasma compared to rats given TG alone. However, there was no difference in the clearance of chylomicrons containing oxidized cholesterols vs. purified cholesterol, although the presence of oxysterols did appear to exacerbate the removal of these particles from circulation. The impaired clearance of chylomicrons containing oxidized cholesterols was not due to impaired lipolysis and slower conversion to the remnant form. Moreover, the incorporation of oxidized cholesterols did not alter the hepatic or splenic uptake of chylomicrons compared to chylomicrons isolated from rats given purified cholesterol or TG alone. Collectively, the results of this study suggest that the exacerbated delay in clearance of chylomicron remnants enriched with oxysterols may be due to impaired uptake by tissues other than the liver and spleen. Apolipoprotein (apo) analysis showed that oxysterol incorporation reduced the apoE content and altered the apoC phenotype of chylomicrons, which may have an impact on the removal of chylomicron remnants from plasma. In conclusion, dietary oxysterols appear to have the potential to adversely affect chylomicron metabolism. Therefore, further investigations in humans are required to determine whether dietary oxidized cholesterols found in cholesterol‐rich processed foods delay the clearance of postprandial remnants, which may contribute to and exacerbate the development of atherosclerosis.
Peroxisome proliferator‐activated receptor α,γ coagonist LY465608 inhibits macrophage activation and atherosclerosis in apolipoprotein E knockout mice
Authors: Zuckerman Steven H. , Kauffman Raymond F. , Evans Glenn F. 
Published: November 2006

AbstractThe apolipoprotein F (apoF) knockout mouse has provided an approach to the investigation of the effect of both cellular and humoral processes on atherosclerotic lesion progression. In the present study, pharmacologic modulation of both interferon gamma (IFNγ)‐inducible macrophage effector functions, and atherosclerotic lesions in the apoE knockout mouse were investigated using the peroxisome proliferator‐activated receptor (PPAR) α,γ coagonist LY465608. LY465608 inhibited, in a concentration‐dependent manner, IFNγ induction of both nitric oxide synthesis and the β2 integrin CD11a in elicited peritoneal macrophages from apoE knockout mice. Similar effects were observed ex vivo following 10 d of treating mice with 10 mg/kg of LY465608. Treatment of apoE knockout mice for 18 wk with LY465608 resulted in a statistically significant 2.5‐fold reduction in atherosclerotic lesion area in en face aorta preparations. These effects were apparent in the absence of any reduction in total serum cholesterol or in lipoprotein distribution. Finally, treatment of apoE knockout mice with established atherosclerotic disease resulted in a modest but not statistically significant decrease in aortic lesional surface area. These results demonstrate the utility of PPAR coagonists in reducing the progression of the atherosclerotic lesion.
Evidence of a tetradocosahexaenoic cardiolipin in some marine bivalves
Authors: Kraffe Edouard , Soudant Philippe , Marty Yanic , Kervarec Nelly , Jehan Philippe 
Published: November 2006

AbstractSeparation of phospholipid classes in lipid extracts from the scallop Pecten maximus, the Pacific oyster Crassostrea gigas, and the blue mussel Mytilus edulis was conducted using HPLC. An isolated polar lipid fraction was found to contain a very high level of DHA, up to 80 mol% of the total FA. MS with electrospray ionization in the positive‐ion mode, tandem MS (MS‐MS) and multidimensional NMR spectroscopy were used to analyze the detailed chemical structure of this polar lipid fraction. The isolated fraction contained exclusively cardiolipin (CL) molecules, predominantly in a form with four docosahexaenoyl chains (Do4CL). To the best of our knowledge, this is the first time that such a CL form has been analytically characterized and described in these three bivalve species. This tetradocosahexaenoic CL is presumed to reflect a specific adaptation in bivalves that enhances the structural and functional mechanisms of biomembranes in response to variations in environmental conditions (temperature, salinity, emersion).
Analysis of FA contents in individual lipid fractions from human placental tissue
Authors: Klingler M. , Demmelmair H. , Larque E. , Koletzko B. 
Published: November 2006

AbstractData on FA contents in the human placenta are limited. Different methods have been used for the FA analysis, and only percentage results have been presented. We developed and evaluated a method for the determination of FA concentrations in placental tissue. Lipids were extracted from placental tissue with a chloroform/methanol mixture; and phospholipids (PL), nonesterified FA (NEFA), TG, and cholesterol esters (CE) were isolated by TLC. Individual lipid fractions were derivatized with methanolic hydrochloric acid, and the FAME, were quantified by GC with FID. The CV of intra‐assay (n=8) of absolute concentrations were evaluated for FA showing a, tissue content >0.01 mg/g. CV ranges were 4.6–11.0% for PL, 6.4–9.3% for NEFA, 6.1–8.9% for TG, and 11.4–16.3% for CE. The relative FA composition across a term placenta indicated no differences between samples of central and peripheral locations of maternal and fetal site (CV 0.5–9.9%), whereas the absolute FA concentrations were only reproducible in the PL fraction (CV 7.0–12.8%). The method shows a reasonably high precision that is well suited for physiological and nutritional studies.
Astonishing diversity of natural surfactants: 4. Fatty acid amide glycosides, their analogs and derivatives
Authors: Dembitsky Valery M. 
Published: November 2006

AbstractFA amide glycosides are of great interest, especially for the medicinal and pharmaceutical industries. These biologically active natural surfactants are good prospects for future chemical preparation of compounds useful as antibiotics, anticancer agents, or for industry. More than 200 unusual and interesting natural surfactants, including their chemical structures and biological activities, are described in this review article.