bluuebunny/crossref_metadata_2025 huggingface dataset:
Geotechnical properties and behaviour of the Monasavu halloysite clay, Fiji
Authors: Knight D. J.
Published: November 2006

Geotechnical properties and behaviour are described of the very wet, halloysitic, residual clay found in the dense rain forest at Monasavu, Viti Levu, Fiji, where the annual rainfall can exceed 5 m. The tropical climatic conditions have caused deep weathering of sandstones and produced a highly plastic clay with low density and a natural moisture content greatly in excess of the standard compaction optimum. This clay was found to contain halloysite which was ‘amorphous’ rather than crystalline. The material was used in this natural state in an 85-m high rockfill dam at Monasavu Falls as an unusually soft core, the construction of which involved unconventionally light compaction by low-ground-pressure-tracked dozers. Its resulting behaviour in terms of three-dimensional total and effective stresses, stress paths and deformations throughout the construction, impounding and full reservoir stages was closely monitored. This behaviour is examined in the light of the clay's classification, mineralogical, compaction and engineering properties determined before and during construction. Despite its unusual properties, it is concluded that the clay is a good engineering material, behaving like others containing halloysite in the more common tubular form, and, moreover, that the high natural moisture content is of positive benefit.
Diagenesis in Upper Jurassic marine sandstones from the North Sea Well 14/26-1 and its significance
Authors: Jeans C. V. , Fisher M. J.
Published: November 2006

A tightly cemented series of marine sandstones, interbedded with shales and mudstones, occurs in the lower part of the Kimmeridge Clay Formation (Kimmeridgian to Ryazanian) of Arco Well 14/26-1 (Core No. 5, 8067–8085 ft). The well is on the northern flank of the Fraserburgh Spur Basement Ridge. The sediments are in the immature stage of hydrocarbon generation and are now at their maximum temperature and burial depth: the bottom hole temperature is 75°C. The sandstone diagenesis was complex, essentially of an intrinsic type, and took place under considerable overpressures. Initially a series of early cements was precipitated (minor chalcedony, quartz, feldspar, ferroan calcite, non-ferroan dolomite and major ferroan dolomite). A later phase of diagenesis embraced two periods of intrastratal solution (each affecting both the silicate and the carbonate components of the sediment) separated by a phase of calcite precipitation and followed by a phase of kaolinite cementation. The early cements are interpreted as being of the intrinsic miagenetic type. The later phase of diagenesis (alternating intrastratal solution and cement precipitation) resulted from the interaction of (i) the biotic breakdown of organic matter by thermophyllic micro-organisms and (ii) the abiotic thermal alteration of organic matter with the mineral components of the sediment: of particular importance were varying PCO2 and the generation of carboxylic and phenolic acids. The diagenetic pattern is closely comparable to that known from various Upper Jurassic sandy shelf sediments in other parts of the northern North Sea which have very different burial histories.
Septarian crack formation in carbonate concretions from shales and mudstones
Authors: Astin T. R.
Published: November 2006

The textural evidence in septarian concretions shows that the septa formed as tensile fractures during burial and compaction of the host shale. Comparison of the combinations of vertical and horizontal stresses and pore-fluid pressure required for tensile fracture of cemented concretions and those likely to occur during shale burial indicates that septarian fracturing will be favoured by overpressuring and low horizontal stress, most likely to occur during times of rapid burial. Burial histories of septarian concretions from the Eocene London Clay and the Jurassic Kimmeridge Clay show that fracturing can form under as little as 50 m of sediment. By relating episodes of septarian fracturing to times of rapid burial, the timing of diagenetic cement formation can be constrained.
Petrology and formation damage control, Upper Cretaceous sandstone, offshore Gabon
Authors: Pittman E. D. , King G. E.
Published: November 2006

The subarkosic-sublitharenitic Upper Cretaceous sandstone, which has up to 30% porosity and 585 md permeability, produces on salt diapir structures in the Oguendjo West Block, offshore Gabon. The porosity consists of 68% intergranular porosity of primary and secondary origin, 17% secondary intragranular and moldic porosity, and 15% microporosity. A microcrystalline quartz druse, which was derived from alteration of lithic fragments, coats framework grains and retards the development of syntaxial quartz overgrowths. Other cements are patchy ankerite (0·3–13·7 vol%) and kaolinite, which also occurs as a replacement of framework grains. The total kaolinite content ranges from 1·8 to 8·2 vol%. Kaolinite and remnants of altered and partially dissolved lithic fragments are susceptible to movement with fluid flow. Formation sensitivity tests showed that the kaolinite-rich sandstone was stable to 2% NaCl water, but introduction of freshwater caused permeability impairment. Acid treatment to remove damage produced sporadic results. Injection of HCl raised the permeability temporarily, indicating that fines were still being liberated within the pore network. Injection of HCl/HF immediately reduced permeability through partial disaggregation of the rock. Plugging of the formation face by drill mud also damages the reservoir. Reversal of flow at high pressure differentials will remove formation damage produced by face plugging. A guideline for this process established in the laboratory is to backflow with a pressure differential at least as high as the overbalance used in drilling. The combination of oil-based drilling fluids and underbalanced perforating with filtered diesel in the wellbore should eliminate most formation damage in this reservoir.
A novel copper complex induces ROS generation in doxorubicin resistant Ehrlich ascitis carcinoma cells and increases activity of antioxidant enzymes in vital organs in vivo
Authors: Mookerjee Ananda , Basu Jayati Mookerjee , Majumder Surajit , Chatterjee Shilpak , Panda Gouri S , Dutta Pranabananda , Pal Smarajit , Mukherjee Pratima , Efferth Thomas , Roy Syamal , Choudhuri Soumitra K
Published: November 2006

Background

In search of a suitable GSH-depleting agent, a novel copper complex viz., copper N-(2-hydroxyacetophenone) glycinate (CuNG) has been synthesized, which was initially found to be a potential resistance modifying agent and later found to be an immunomodulator in mice model in different doses. The objective of the present work was to decipher the effect of CuNG on reactive oxygen species (ROS) generation and antioxidant enzymes in normal and doxorubicin-resistant Ehrlich ascites carcinoma (EAC/Dox)-bearing Swiss albino mice.

Methods

The effect of CuNG has been studied on ROS generation, multidrug resistance-associated protein1 (MRP1) expression and on activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx).

Results

CuNG increased ROS generation and reduced MRP1 expression in EAC/Dox cells while only temporarily depleted glutathione (GSH) within 2 h in heart, kidney, liver and lung of EAC/Dox bearing mice, which were restored within 24 h. The level of liver Cu was observed to be inversely proportional to the level of GSH. Moreover, CuNG modulated SOD, CAT and GPx in different organs and thereby reduced oxidative stress. Thus nontoxic dose of CuNG may be utilized to reduce MRP1 expression and thus sensitize EAC/Dox cells to standard chemotherapy. Moreover, CuNG modulated SOD, CAT and and GPx activities to reduce oxidative stress in some vital organs of EAC/Dox bearing mice. CuNG treatment also helped to recover liver and renal function in EAC/Dox bearing mice.

Conclusion

Based on our studies, we conclude that CuNG may be a promising candidate to sensitize drug resistant cancers in the clinic.
Readability of pediatric health materials for preventive dental care
Authors: Hendrickson Rachel L , Huebner Colleen E , Riedy Christine A
Published: November 2006

Background

This study examined the content and general readability of pediatric oral health education materials for parents of young children.

Methods

Twenty-seven pediatric oral health pamphlets or brochures from commercial, government, industry, and private nonprofit sources were analyzed for general readability ("usability") according to several parameters: readability, (Flesch-Kincaid grade level, Flesch Reading Ease, and SMOG grade level); thoroughness, (inclusion of topics important to young childrens' oral health); textual framework (frequency of complex phrases, use of pictures, diagrams, and bulleted text within materials); and terminology (frequency of difficult words and dental jargon).

Results

Readability of the written texts ranged from 2ndto 9thgrade. The average Flesch-Kincaid grade level for government publications was equivalent to a grade 4 reading level (4.73, range, 2.4 – 6.6); F-K grade levels for commercial publications averaged 8.1 (range, 6.9 – 8.9); and industry published materials read at an average Flesch-Kincaid grade level of 7.4 (range, 4.7 – 9.3). SMOG readability analysis, based on a count of polysyllabic words, consistently rated materials 2 to 3 grade levels higher than did the Flesch-Kincaid analysis. Government sources were significantly lower compared to commercial and industry sources for Flesch-Kincaid grade level and SMOG readability analysis. Content analysis found materials from commercial and industry sources more complex than government-sponsored publications, whereas commercial sources were more thorough in coverage of pediatric oral health topics. Different materials frequently contained conflicting information.

Conclusion

Pediatric oral health care materials are readily available, yet their quality and readability vary widely. In general, government publications are more readable than their commercial and industry counterparts. The criteria for usability and results of the analyses presented in this article can be used by consumers of dental educational materials to ensure that their choices are well-suited to their specific patient population.
Cell‐Free DNA in Maternal Plasma
Authors: LI YING , HOLZGREVE WOLFGANG , DI NARO EDOARDO , VITUCCI ANGELOANTONIO , HAHN SINUHE
Published: November 2006

Abstract:  Fetal cell‐free DNA (cf‐DNA) represents only a small fraction of the total cf‐DNA in maternal plasma. This feature has rendered it difficult to reliably distinguish fetal alleles which are not very disparate from maternal ones, such as those involving point mutations, by conventional polymerase chain reaction (PCR)‐based approaches. It has recently been shown that cell‐free fetal DNA molecules have a smaller size than comparable cf‐DNA molecules of maternal origin, and that this feature can be exploited for the selective enrichment of fetal DNA sequences, thereby permitting the detection of otherwise masked fetal genetic traits. By the use of this approach, we have shown that it is possible to detect fetal genetic loci for microsatellite markers, as well as point mutations involved in disorders such as achondroplasia and β‐thalassemia.
Detection of a Paternally Inherited Fetal Mutation in Maternal Plasma by the Use of Automated Sequencing
Authors: BUSTAMANTE‐ARAGONES ANA , GARCIA‐HOYOS MARIA , RODRIGUEZ DE ALBA MARTA , GONZALEZ‐GONZALEZ CRISTINA , LORDA‐SANCHEZ ISABEL , DIEGO‐ALVAREZ DAN , TRUJILLO‐TIEBAS M. JOSE , AYUSO CARMEN , RAMOS CARMEN
Published: November 2006

Abstract:  The discovery of circulating fetal DNA in maternal blood has been an encouraging step forward in the prenatal diagnostic field. It has opened up the possibility of development of a noninvasive method for the genetic analysis of the fetus. Many techniques have been applied to the study of this fetal DNA, but automated sequencing has been seldom used. The intention of this study was to use the automated sequencing technique for the detection of a paternally inherited fetal mutation in maternal plasma. Maternal plasma samples from a pregnant woman, whose husband had a mutation (Q134X) in the RP2 gene, which is located in the X‐chromosome, were collected at two different gestational ages (10th and 19th week of gestation) in order to determine whether the paternally inherited fetal mutation could be detected by automated sequencing. Restriction analysis was also performed to confirm the results. The fetal mutation was clearly detected in the maternal plasma by the use of automated sequencing. The automated sequencing enables the possibility of analyzing fetal sequences, at a nucleotide level, in order to detect mutations or polymorphisms which are distinguishable from maternal sequences.
Isolation and Comparative Study of Cell‐Free Nucleic Acids from Human Urine
Authors: BRYZGUNOVA OLGA E. , SKVORTSOVA TATYANA E. , KOLESNIKOVA ELENA V. , STARIKOV ANDREY V. , RYKOVA ELENA YU , VLASSOV VALENTIN V. , LAKTIONOV PAVEL P.
Published: November 2006

Abstract:  Cell‐free nucleic acids (NA) from human urine were investigated. Concentrations of DNA and RNA in the urine of healthy people were independent of gender and were in the range of 6 ng/mL to 50 ng/mL and 24 ng/mL to 140 ng/mL, respectively. DNA fragments of 150–400 bp represent the main part of cell‐free DNA, along with DNA fragments up to 1,300 bp, which were found in male urine, and DNA fragments up to 19 kbp, which were found in female urine. Analysis of circulating DNA, isolated from blood of breast cancer patients and cell‐free DNA isolated from their urine by methylation‐specific PCR, demonstrates that the presence of methylated promoters of RASSF1A and RARβ2 genes in plasma was accompanied by the detection of the same methylated markers in urine. The data obtained demonstrate applicability of cell‐free urine DNA in cancer diagnostics.
Massive and Specific Dysregulation of Direct Cortical Input to the Hippocampus in Temporal Lobe Epilepsy
Authors: Ang Chyze W. , Carlson Gregory C. , Coulter Douglas A.
Published: November 2006

Epilepsy affects 1–2% of the population, with temporal lobe epilepsy (TLE) the most common variant in adults. Clinical and experimental studies have demonstrated hippocampal involvement in the seizures underlying TLE. However, identification of specific functional deficits in hippocampal circuits associated with possible roles in seizure generation remains controversial. Significant attention has focused on anatomic and cellular alterations in the dentate gyrus. The dentate gyrus is a primary gateway regulating cortical input to the hippocampus and, thus, a possible contributor to the aberrant cortical-hippocampal interactions underlying the seizures of TLE. Alternate cortical pathways innervating the hippocampus might also contribute to seizure initiation. Despite this potential importance in TLE, these pathways have received little study. Using simultaneous voltage-sensitive dye imaging and patch-clamp recordings in slices from animals with epilepsy, we assessed the relative degree of synaptic excitation activated by multiple cortical inputs to the hippocampus. Surprisingly, dentate gyrus-mediated regulation of the relay of cortical input to the hippocampus is unchanged in epileptic animals, and input via the Schaffer collaterals is actually decreased despite reduction in Schaffer-evoked inhibition. In contrast, a normally weak direct cortical input to area CA1 of hippocampus, the temporoammonic pathway, exhibits a TLE-associated transformation from a spatially restricted, highly regulated pathway to an excitatory projection with >10-fold increased effectiveness. This dysregulated temporoammonic pathway is critically positioned to mediate generation and/or propagation of seizure activity in the hippocampus.
GABAergic Excitation in the Basolateral Amygdala
Authors: Woodruff Alan R. , Monyer Hannah , Sah Pankaj
Published: November 2006

GABA-containing interneurons are a diverse population of cells whose primary mode of action in the mature nervous system is inhibition of postsynaptic target neurons. Using paired recordings from parvalbumin-positive interneurons in the basolateral amygdala, we show that, in a subpopulation of interneurons, single action potentials in one interneuron evoke in the postsynaptic interneuron a monosynaptic inhibitory synaptic current, followed by a disynaptic excitatory glutamatergic synaptic current. Interneuron-evoked glutamatergic events were blocked by antagonists of either AMPA/kainate or GABAAreceptors, and could be seen concurrently in both presynaptic and postsynaptic interneurons. These results show that single action potentials in a GABAergic interneuron can drive glutamatergic principal neurons to threshold, resulting in both feedforward and feedback excitation. In interneuron pairs that both receive glutamatergic inputs after an interneuron spike, electrical coupling and bidirectional GABAergic connections occur with a higher probability relative to other interneuron pairs. We propose that this form of GABAergic excitation provides a means for the reliable and specific recruitment of homogeneous interneuron networks in the basal amygdala.
Faserorientierungsmessung an kurzfaserverstärkten PUR-RIM-Bauteilen: Kombination zerstörungsfreier Prüfmethoden zur Optimierung von Simulation und Herstellungsprozess (Fiber Orientation Measurement on Short Fiber Reinforced PUR-RIM Components: Combination of Nondestructive Testing Methods for Optimization of Simulation and Production Process)
Authors: Predak Sabine , Solodov Igor Y. , Busse Gerhard , Bister Viet Huong , Vöhringer Marc C. , Haberstroh Edmund , Ehbing Hubert
Published: November 2006

Im Reinforced-Reaction-Injection-Moulding-Verfahren hergestellte Polyurethanbauteile (PUR-RRIM) weisen produktionsbedingte Faserorientierungsverteilungen auf, die ihre mechanischen Eigenschaften beeinflussen. Deren Messung erfolgt zerstörungsfrei mit Mikrowellen und Ultraschall. Dabei wird der Einfluss von Herstellungsparametern ermittelt, um Simulationsrechnungen und Herstellungsprozess zu optimieren.
Preliminary Understanding of Near-Field Effect of CSAMT in Electric Azimuthally Anisotropic Half-Space
Authors: Xu Yixian , Yue Ruiyong
Published: November 2006

This paper reviews the spatial characteristics of electromagnetic fields induced by a horizontal electric dipole on the surface of a horizontal layered earth with azimuthal anisotropy. It is well known that depth of investigation becomes independent of frequency and dependent upon array geometry in the near-field zone, thus limiting the interpretation of data by conventional MT methods. On the basis of existing theory, we estimate the far-field distance (FFD) of a homogeneous half-space with azimuthal anisotropy through numerical modeling. To define FFD, there are two criteria suggested in the study. If the anisotropic parameter is constant, the FFD is linearly increasing with resistivity increasing in strike direction for all operating frequencies. From comprehensive analysis, the FFD along the strike direction should be estimated by comparing a relative difference between the responses of CSAMT and MT in TM-mode; the FFD along the direction perpendicular to the strike should be estimated by comparing relative difference between responses of CSAMT and MT in TE-mode. In an azimuthally anisotropic half-space, the near-field effect is more severe in the strike direction than in its orthogonal direction. These simple but quantitative analyses aim to understand the near-field effect before inverting data using a far field approximation for CSAMT exploration in azimuthally anisotropic conductive media.
Fungal osteomyelitis of the axial border of the proximal sesamoid bones in a horse
Authors: Sherman Kevin M. , Myhre Grant D. , Heymann Elizabeth I.
Published: November 2006

Case Description—A 12-year-old Standardbred gelding was referred for swelling of the right metacarpophalangeal joint.

Clinical Findings—Ultrasonography of the right metacarpal area revealed hypoechoic areas in the right digital sheath and metacarpophalangeal joint consistent with synovial effusion. Radiography of the right metacarpophalangeal joint revealed lysis of the axial border of the proximal sesamoid bones. Aspergillus fumigatus was detected on fungal culture of synovial fluid.

Treatment and Outcome—Regional limb perfusion (150 mg of amikacin in 60 mL of saline [0.9% NaCl] solution perfused for 30 minutes) was performed 2 and 4 days after admission. Itraconazole (5 mg/kg [2.27 mg/lb], PO, q 24 h) was administered for approximately 9 weeks. Joint lavage with amikacin (500 mg) in 1 L of saline solution was performed 4 times. Three months after discharge, the owner reported that the horse was mildly lame during trotting but was moving freely and comfortably during all gaits and had gained a considerable amount of weight. Because the osteoarthritis was not expected to improve and because it was recommended that the horse not return to purposeful exercise, the owner decided to retire the horse from racing.

Clinical Relevance—Various diagnostic imaging methods and fungal cultures are useful for diagnosing fungal osteomyelitis of the axial borders of the proximal sesamoid bones in horses. Fungal osteomyelitis of the sesamoid bones and erosive arthritis should be considered as a differential diagnosis for horses in which corticosteroids have been administered intra-articularly.
Temperature and salt‐induced micellization of some block copolymers in aqueous solution
Authors: Desai Mihir , Jain Nirmesh J. , Sharma Rakesh , Bahadur Pratap
Published: November 2006

Micellization of three commercial samples of ethylene oxide (EO)‐propylene oxide (PO) (PEO‐PPO‐PEO) triblock copolymers (pluronics) P65 (EO25PO30EO25, mw PPO=1750, %PEO=50), P85 (EO25PO40EO25, mw PPO=2250, %PEO=50), and F88 (EO102PO40EO102, mw PPO=2250, %PEO=80) in aqueous sodium chloride solution (0–3 M) was examined by cloud point, surface tension, dye spectral change, fluorescence, and viscosity measurements over a temperature range of 25–50°C. Salt‐induced micellization and micelle growth were observed. The presence of sodium chloride enhanced hydrophobicity in the PPO moiety and reduced hydrophilicity of PEO moieties, favoring micellization at relatively lower concentrations than in water at ambient temperature. The effect of salt on micellization is similar to that of increasing temperature. The critical micelle concentrations (CMC) and critical micelle temperatures showed a marked decrease in the presence of added salt. CMC obtained by different methods were in good agreement.
Antistatic and wetting properties of chemodegradable cationic surfactants containing 1,3‐dioxolane moiety
Authors: Wilk Kazimiera A. , Poźniak Ryszard , Sokoŀowski Adam
Published: November 2006

In this paper we report some performance properties of [(2‐alkyl‐1,3‐dioxolane‐4‐yl)methyl]trimethylammonium bromides (Cn‐D‐TAB, where Cn=n‐C9H19, n‐C11H23, n‐C13H27), [(2,2‐dialkyl‐1,3‐dioxolane‐4‐yl)methyl] dimethylammonium bromides (CnCm‐D‐TAB, where Cn=n‐C8H17, n‐C10H21 and Cm=CH3 or Cn=Cm=n‐C6H13), in relation to classical alkyltrimethylammonium bromides (Cn‐TAB, where Cn=n‐C12H25, n‐C14H29 or C16H33) and dialkyldimethylammonium bromides (CnCm‐DAB, where Cn=Cm=n‐C10H21 and C12H25). Antistatic properties were measured by means of surface resistance (Rs), half charge decay time τ1/2, and maximal voltage induced (Uind) on polyethylene (PE) film and polypropylene (PP) nonwoven fabric. Wetting ability is reported as the concentration of surfactant necessary for immersion of a cottonfabric ring in 100 s, according to the Polish Standard PN‐74/C‐04800. All acetal‐type surfactants showed the antistatic effect. The best results were given by C9‐D‐TAB [Rs=8.5·107 (PE), 1.1·108 Ω (PP); τ1/2=0.25 (PE), 0.30 s (PP); Uind=205 (PE), 220 V (PP)] and C11‐D‐TAB [Rs=8.7·107 (PE), 1.3·108 Ω (PP); τ1/2=0.25 (PE), 0.30 s (PP); Uind=190 (PE), 340 V (PP)] in relation to pure PE foils and PP fabric: Rs=3.0·1014 (PE), 9.8·1014 Ω (PP); τ1/2=>600 (PE), >600 s (PP); Uind=985 (PE), 940 V (PP). Both C9‐D‐TAB and C11‐D‐TAB indicate similar degrees of antistatic ability compared to C10C10‐DAB. All Cn‐TAB compounds do not show any antistatic effects. It was concluded that addition of the 1,3‐dioxolane moiety to the hydrophobic tail of quaternary ammonium salts promotes both antistatic and wetting properties. Additionally, methyl or n‐hexyl group incorporation at the C‐2 carbon atom in the 1,3‐dioxolane ring significantly decreases the surface conductivity.
Surface activity of mixtures of oxyethylated methyl dodecanoate and sodium dodecylbenzenesulfonate
Authors: Makowska Danuta , Hreczuch Wieslaw , Zimoch Jolanta , Bogacki Mariusz B. , Szymanowski Jan
Published: November 2006

Surface and interfacial tension and detergency of mixtures containing oxyethylated methyl dodecanoate and sodium dodecylbenzenesulfonate were determined. Synergism in the surface tension reduction was not observed. The competition for adsorption at the air/water interface between oxyethylated methyl dodecanoate and sodium dodecylbenzenesulfonate depended on the considered surface tension, the weight ratio of surfactants in the aqueous phase, and the hydrophile‐lipophile balance of the nonionic surfactant. Generally, coverage of the interface with oxyethylated methyl dodecanoate increased when surface tension decreased. Nonionics were the dominant species at the interface in the important region of surface activity, i.e., for surface tensions below 40 mN m−1. The mole fraction of the hydrophobic nonionic at the interface was higher than the contribution of hydrophilic oxyethylates. An increase of the surfactant ratio in the bulk phase affects the interfacial ratio of surfactants in the same way. The lowest interfacial tension (1.5 mN m−1) at the hexadecane/water interface was observed for oxyethylated methyl dodecanoate having an average degree of oxyethylation equal to 8 and 10. Nearly 5 min was needed to achieve equilibrium value. Mixtures with sodium dodecylbenzenesulfonate decreased the interfacial tension somewhat less efficiently but the equilibrium was rapidly established. The standard washing powders containing oxyethylated methyl dodecanoates exhibited washing ability similar to that obtained for the powder with traditional alcohol oxyethylate.
Fatty amide ethoxylates: Synthesis and self‐assembly
Authors: Folmer Britta M. , Holmberg Krister , Klingskog Eva Gottberg , Bergström Karin
Published: November 2006

A series of fatty acid monoethanolamide ethoxylates was synthesized. Tensiometry and fluorescence were used to study the solution behavior of this surfactant series. The effec of the amide bond, the effect of unsaturations in the hydrocarbon chains, and the effects of the oxyethylene chain length were investigated. The presence of the amide group was found to lead to a decrease in the critical micelle concentration (CMC), an effect that is probably due to the formation of hydrogen bonds between neighboring molecules. The surface tension at the CMC was higher when an amide bond was present in the surfactant. This probably reflects the increase in size of the polar group (decrease in the critical packing parameter value) which is unfavorable for close alignment of surfactant molecules at the air‐water interface. The presence of unsaturations in the hydrophobic tail gave an increase in the CMC. This may partly be due to the surfactants becoming more hydrophilic and partly to the increased bulkiness of the chains, rendering packing into closed aggregates and formation of hydrogen bonds between amide groups more difficult. The cross‐sectional headgroup areas of the surfactants increased with the degree of unsaturation as a consequence of more unfavorable packing at the surface.
Synthesis and characterization of surface‐active compounds derived from cholesterol derivatives and glucose
Authors: Piispanen Peter S. , Byström Styrbjörn , Svensson Martin , Kronberg Bengt , Blute Irena , Norin Torbjörn
Published: November 2006

The synthesis and characterization of surface‐active compounds based on various steroid derivatives and glucose are presented. The hydrophobic and hydrophilic parts of the compounds were linked via glucosidic bonds. All compounds were found to have very low water solubility and only limited solubility in various organic solvents. The compounds were investigated according to their ability to interact with an anionic surfactant, sodium dodecylsulfate (SDS), in order to induce a decrease in the critical micelle concentration (CMC) of the surfactants. This synergistic effect was pronounced for cholestanol‐6‐on‐β‐D‐glucopyranoside and for cholestan‐3,6‐diol‐β‐D‐glucopyranoside. These two compounds lowered the CMC from 8 to 6 and 0.6 mM, respectively, for water solutions of SDS/glucoside with a molar ratio of 92∶8. Furthermore, the ability of the compounds to stabilize lipid membranes, in liposomes, at varying concentrations of Ca2+, was studied. The compounds were, as expected, found to induced stabilization similar to that of cholesterol.
A didodecyldimethylammonium bromide ternary system: Characterization of three‐phase stable emulsions by optical microscopy
Authors: Mele Stefania , Khan Ali , Monduzzi Maura
Published: November 2006

A preliminary characterization of the didodecyldimethyl ammonium bromide (DDAB)/water (W)/per fluorooctane (PFO) ternary system at 25°C is presented. The gradual addition of water, followed by mixing, to DDAB/PFO mixtures produces very stable emulsions for water contents greater than 20 wt%. On the basis of macroscopic observation, at least four different types of emulsions form up to a water content of around 97 wt%. On the basis of high conductivity values, a water‐continuous domain is suggested at all compositions. A second phase diagram, considerably different in phase boundaries, is obtained by adding the PFO oil to DDAB/W samples. This allowed us to ascertain the swelling properties of Lα1 and Lα2 lamellar phases. Optical microscopy in the presence and in the absence of polarized light revealed the formation of lamellar liquid crystals either as randomly localized islands or as rings surrounding the oil droplets. Vesicles are identified at high water content. The contemporaneous presence of both Lα1 and Lα2 lamellar phases causes a synergistic effect in the PFO stabilization.
Biosurfactant production by Bacillus coagulans
Authors: Huszcza Ewa , Burczyk Bogdan
Published: November 2006

A new biosurfactant producer, Bacillus coagulans, was isolated from soil. Its 24‐h‐old culture broth had a low surface tension (27–29 mN/m). Optimization of cell growth of this bacterium led to maximal biosurfactant production with glucose or starch as the organic carbon source, a pH in the range 4.0–7.5, and incubation temperatures from 20 to 45°C. The crude biosurfactants obtained after neutralization and lyophilization of the acid precipitate yielded a minimal aqueous solution surface tension value of 29 mN/m and an interfacial tension value of 4.5 mN/m against hexadecane. The critical micelle concentration of the crude biosurfactants was 17 mg/L. Addition of NaCl to the aqueous solution of the crude product caused lowering of surface tension at both the aqueous solution‐air and aqueous solution‐n‐hexadecane interfaces. These results indicate that the biosurfactants obtained have potential environmental and industrial applications and may have uses in microbially enhanced oil recovery.
Novel glucose‐derived gemini surfactants with a 1,1′‐ethylenebisurea spacer: Preparation, thermotropic behavior, and biological properties
Authors: Laska Urszula , Wilk A. , Maliszewska Irena , Syper Ludwik
Published: November 2006

In the search for environmentally safe surfactants made from inexpensive and renewable sources, the interest has mainly been focused on new saccharide derivatives. This report describes the synthesis of newly designed nonionic gemini compounds comprising two reduced sugar headgroups, two alkyl tails, and a 1,1′‐ethylenebisurea entity as the spacer linking two amphiphilic glucose‐derived moieties. Thus, the series of N,N′‐bis[(3‐alkyl‐3‐deoxy‐d‐glucitol)ureido]ethylenediamines (bis(CnGT), with Cn=n‐C9H9, n‐C6‐H13, n‐C8H17, n‐C10H21, or n‐C12H25), were prepared using a convenient procedure starting from easily accessible reagents such as d‐glucose, n‐alkylamines, urea, and ethylenediamine. Their structure and purity were confirmed by means of elemental analysis, electrospray ionization mass spectrometry, and 1H and 13C nuclear magnetic resonance spectroscopy. Additionally, the present contribution introduces selected properties of these surfactants, including their thermotropic behavior and biological properties. The presence of two phase transition points, determined using the differential scanning calorimetry method, indicates liquid‐crystalline mesophase formation upon heating. Furthermore, using the closed‐bottle test (OECD Guideline 301D) as well as the biological oxygen demand test for insoluble substances for biodegradability measurements, it has been concluded that the tested glucose‐derived gemini structures achieve more than 60% biodegradation after 64–75 test days. All tested surfactants were practically nontoxic to bacteria, yeast, and molds. Owing to their fitting aggregation ability as well as their nontoxicity, they constitute an interesting group of surfactants for various applications.
Microemulsion phase behavior of anionic‐cationic surfactant mixtures: Effect of tail branching
Authors: Upadhyaya A. , Acosta E. J. , Scamehorn J. F. , Sabatini D. A.
Published: November 2006

This research evaluated middle‐phase microemulsion formation by varying the mole ratio of anionic and cationic surfactants in mixtures with four different oils (trichloroethylene, n‐hexane, limonene, and n‐hexadecane). Mixtures of a double‐tailed anionic surfactant (sodium dihexyl sulfosuccinate, SDHS) and an unbalanced‐tail (i.e., doubletailed with tails of different length) cationic surfactant (benzethonium chloride, BCl) were able to form microemulsions without alcohol addition. The amount of NaCl required to form the middle‐phase microemulsion decreased dramatically as an equimolar anionic‐cationic surfactant mixture was approached. Although the mixture of anionic and cationic surfactants demonstrated a higher critical microemulsion concentration (cμc) compared to the anionic surfactant alone, the Winsor Type IV single‐phase microemulsion started at lower surfactant concentrations for the anionic‐cationic mixture than for the anionic surfactant alone. Under optimum middlephase microemulsion conditions, mixed anionic‐cationic surfactant systems solubilized more oil than the anionic surfactant alone. Pretreatment detergency studies were conducted to test the capacity of these mixed surfactant systems to remove oil form fabrics. It was found that anionic‐rich mixed surfactant formulations yielded the largest oil removal, followed by cationic‐rich systems.
Synergism in the wetting properties of ternary surfactant mixtures
Authors: Hauthal Hermann G. , Jürges Peter , Möhle Lothar , Ohlerich Udo
Published: November 2006

It has been shown that ternary surfactant synergism can be predicted on the basis of nonideality parameters of binary subsystems derived from advancing contact angles. Studies with appropriate surfactant mixtures of glucamides, ether sulfates, secondary alkane sulfonates, and alkylamidopropyl betaines were performed on substrates of different polarity.
The effect of mixed surfactants on enhancing oil recovery
Authors: El‐Batanoney M. , Abdel‐Moghny Th. , Ramzi M.
Published: November 2006

Micelles composed of mixed surfactants with different structures (mixed micelles) are of great theoretical and industrial interest. This work pertains tomaximizing interfacial tension (IFT) reduction via surfactant pairs. In this respect, four types of fatty acid amides based on lauric, myristic, palmitic, and stearic acids were blended with dodecyl benzene sulfonic acid at a molar ratio of 4∶1 and designated as A1, A2, A3, and A4, respectively. The IFT was measured for each blend at different concentrations using Badri crude oil. The most potent formula (A4) was evaluated for using in enhanced oil recovery (EOR). The IFT was tested in the presence of different electrolyte concentrations with different crude oils at different temperatures. Finally several runs were devoted to study the displacement of Badri crude oil by A4 surfactant solution using different slug sizes of 10, 20, and 40% of pore volume (PV). The study reveled that Badri crude oil gave ultra‐low IFT at lowest surfactant concentration and 0.5% of NaCl. The recovery factor at a slug size of 20% PV was 83% of original oil in place compared with 59% in case of conventional water flood.
Detergency and foam studies on linear alkylbenzene sulfonate and secondary alkyl sulfonate
Authors: Goon Piyali , Bhirud R. G. , Kumar V. V.
Published: November 2006

Among anionic surfactants used in detergent products, the sodium salt of linear alkylbenzene sulfonate (NaLAS) is the only surfactant belonging to the aromatic class; the others are aliphatic, e.g., the sodium salt of secondary alkyl sulfonate (NaSAS). We observed earlier that certain conformational changes taking place in aromatic anionic surfactants (NaLAS) upon micellization can be brought about in aliphatic anionic surfactants (NaSAS) by addition of phenol. In this paper we examined how conformational changes at the molecular level translated into macroscopic properties such as foam and detergency. We performed foam and detergency measurements on NaLAS, NaSAS, and NaSAS/phenol systems. Foam behavior of these systems is shown to be dependent only upon calcium ion sensitivities of the surfactants whereas the detergency results have a dependence on conformational changes at the molecular level.
A single oral administration of conjugated linoleic acid enhanced energy metabolism in mice
Authors: Ohnuki Koichiro , Haramizu Satoshi , Oki Kasumi , Ishihara Kengo , Fushiki Tohru
Published: November 2006

We investigated the effect of a single oral administration of conjugated linoleic acid (CLA) on energy metabolism in mice. Male Std ddY mice were orally administered CLA (5 mL/kg weight) or linoleic acid (5 mL/kg weight) (both solutions at concentrations of 73.5%) as a control. Oxygen consumption was significantly greater in the CLA‐administered mice than in the control mice. Respiratory quotient was slightly lower in the CLA‐administered mice than in the control mice. We calculated fat and carbohydrate oxidation from oxygen consumption and respiratory quotient. Fat oxidation in the CLA‐administered mice was significantly higher than in the control mice, and there was no difference in carbohydrate oxidation. Serum concentrations of noradrenalin and adrenalin in the CLA administered mice were significantly higher than in the control mice. These results suggested that CLA enhanced sympathetic nervous activity and energy metabolism.
PC and PE synthesis: Mixed micellar analysis of the cholinephosphotransferase and ethanolaminephosphotransferase activities of human choline/ethanolamine phosphotransferase 1 (CEPT1)
Authors: Wright Marcia M. , McMaster Christopher R.
Published: November 2006

The human choline/ethanolamine phosphotransferase 1 (CEPT1) gene codes for a dual‐specificity enzyme that catalyzes the de novo synthesis of the two major phospholipids through the transfer of a phosphobase from CDP‐choline or CDP‐ethanolamine to DAG to form PC and PE. We used an expression system devoid of endogenous cholinephosphotransferase and ethanolaminephosphotransferase activities to assess the diradylglycerol specificity of CEPT1. A mixed micellar assay was used to ensure that the diradylglycerols delivered were not affecting the membrane environment in which CEPT1 resides. The CEPT1 enzyme displayed an apparent Km of 36 μM for CDP‐choline and 4.2 mol% for di‐18∶1 DAG with a Vmax of 14.3 nmol min−1 mg−1. When CDP‐ethanolamine was used as substrate, the apparent Km was 98 μM for CDP‐ethanolamine and 4.3 mol% for di‐18∶1 DAG with a Vmax of 8.2 nmol min−1 mg−1. The preferred diradylglycerol substrates used by CEPT1 with CDP‐choline as the phosphobase donor were di‐18∶1 DAG, di‐16∶1 DAG, and 16∶0/18∶1 DAG. A major difference between previous emulsion‐based assay results and the mixed micelle results was a complete inability to use 16∶0(O)/2∶0 as a substrate for the de novo synthesis of platelet‐activating factor when the mixed micelle assay was used. When CDP‐ethanolamine was used as the phosphobase donor, 16∶0/18∶1 DAG, di‐18∶1 DAG, and di‐16∶1 DAG were the preferred substrates. The mixed micelle assay also allowed the lipid activation of CEPT to be measured, and both the cholinephosphotransferase and ethanolaminephosphotransferase activities displayed the unusual property of product activation at 5 mol%, implying that specific lipid activation binding sites exist on CEPT1. The protein kinase C inhibitor chelerythrine and the human DAG kinase inhibitor R59949 both inhibited CEPT1 activity with IC50 values of 40 μM.
Phospholipid FA of piezophilic bacteria from the deep sea
Authors: Fang Jiasong , Chan Olivia , Kato Chiaki , Sato Takako , Peeples Tonya , Nigggemeyer Karl
Published: November 2006

Phospholipid FA (PLFA) profiles were determined on four piezophilic bacteria from the deep sea: Moritella japonica DSK1, Shewanella violacea DSS12, S. benthica DB6705, and S. benthica DB21MT‐2. The total concentrations of PLFA were higher in strains grown at low pressure (DSK1, 10 MPa, 27.0 mg/g dry wt cells; DSS12, 50 MPa, 24.0 mg/g), and lower in strains grown at high pressure (DB6705, 85 MPa, 1.9 mg/g; DB21MT‐2, 100 MPa, 3.0 mg/g). The piezophilic bacteria were characterized by a high abundance of unsaturated FA (62–73% of total FA). In particular, PUFA were detected in all piezophiles examined. Moritella japonica DSK 1 produced 22∶6n−3 (DHA), whereas the three Shewanella strains produced 20∶5n−3 (EPA) with trace amounts of DHA. The detection of low levels of the medium‐chain‐length PUFA 18∶2n−6 and 18∶3 (DSK1) and 20∶2 (DB6705 and DB21MT‐2) suggests that the biosynthesis of EPA and DHA may be regulated by the formation and desaturation of di‐and tri‐unsaturated FA.
Docosahexaenoic acid‐and eicosapentaenoic acid‐enriched cardiolipin in the manila clam Ruditapes philippinarum
Authors: Kraffe Edouard , Soudant Philippe , Marty Yanic , Kervarec Nelly
Published: November 2006

The FA composition of cardiolipin (CL) from the Manila clam Ruditapes philippinarum was investigated in whole body and individual organs. CL was isolated by HPLC and its chemical structure characterized using NMR spectroscopy. Two prominent FA, EPA and DHA, were found in approximately equal proportions, contributing together up to 73 mol% of the total FA. The FA composition of CL is presumed to reflect a specific synthesis pathway independent of diet and of total glycerophospholipid FA composition. To the best of our knowledge, this is the first time that a CL dominated by the two PUFA 22∶6n−3 and 20∶5n−3 has been characterized and described. This EPA+DHA specificity of the CL in the Manila clam is though to reflect a functional and structural modification of mitochondrial membranes of this bivalve species compared with scallops, oysters, and mussels that possess a CL dominated by DHA. The FA composition and levels of CL differed little between separated organs, and the large pool of DHA and EPA was found fairly equally distributed in gills, mantle, foot, siphon, and muscle. However, whereas DHA and PUFA levels were most stable between organs, EPA and arachidonic acid were significantly more variable and seemed to be interrelated.
Modulation of respiratory syncytial virus‐induced prostaglandin E2production by n−3 long‐chain polyunsaturated fatty acids in human respiratory epithelium
Authors: Bryan Dani‐Louise , Hart Prue , Forsyth Kevin , Gibson Robert
Published: November 2006

Infection with respiratory syncytial virus (RSV) results in substantial infant morbidity and has been associated with the subsequent development of childhood asthma. Inflammatory mediators produced by both the epithelium and tissue leukocytes during RSV infection stimulate the release of chemotactic factors by the respiratory epithelium and the subsequent influx of inflammatory cells, predominantly neutrophils. We investigated the production of inflammatory mediators [prostaglandin E2(PGE2), interleukin (IL)‐1β, tumor necrosis factor α] and chemokines [IL‐8, RANTES (regulation on activation, normal T cell expressed and secreted)] by alveolar epithelial cells in response to RSV infection. Infection of a human alveolar epithelial transformed cell line (A549 cells) with live RSV substantially increased production of PGE2, IL‐8, and RANTES. By altering cell membrane FA through incorporation of the long‐chain PUFA (LCPUFA) arachidonic acid, EPA, and DHA, we were subsequently able to significantly modulate PGE2production by the infected epithelium. Because of the dynamic nature of the effects of PGE2on lung function, regulation of this prostaglandin during RSV infection by n−3 LCPUFA has the potential to significantly alter the disease process.
New ceramides from Rantherium suaveolens
Authors: Oueslati M. Habib , Mighri Zine , Jannet H. Ben , Abreu Pedro M.
Published: November 2006

A mixture of five new ceramides was isolated from the aerial parts of Rantherium suaveolens and characterized by spectroscopic and chemical methods. Their structures were elucidated by spectroscopic and chemical methods as (2S, 3S, 4R, 2′R, 14E)‐2‐(2′‐hydroxydocosanoylamino)‐14‐octadecene‐1,3,4‐triol (1), (2S,3S,4R,2′R, 14F)‐2‐(2′‐hydroxytricosanoylamino)‐14‐octadecene‐1,3,4‐triol (2), (2S,3S,4R,2′R,14F)‐2‐(2′‐hydroxytetracosanoylamino)‐14‐octadecene‐1,3,4‐triol (3), (2S,3S,4R,2′R,14E)‐2‐(2′‐hydroxypentacosanoylamino)‐14‐octadecene‐1,3,4‐triol (4), and (2S,3S,4R,2′R,14E)‐2‐(2′‐hydroxyhexacosanoylamino)‐14‐octadecene‐1,3,4‐triol (5).
Conversion of linoleic acid into novel oxylipins by the mushroom Agaricus bisporus
Authors: Wadman Mayken W. , van Zadelhoff Guus , Hamberg Mats , Visser Tom , Veldink Gerrit A. , Vliegenthart Johannes F. G.
Published: November 2006

Oxylipins are associated with important processes of the fungal life cycle, such as spore formation. Here, we report the formation of FA metabolites in Agaricus bisporus. Incubation of a crude extract of lamellae with linoleic acid (18∶2) led to the extensive formation of two oxylipins. They were identified as 8(R)‐hydroxy‐9Z,12Z‐octadecadienoic acid (8‐HOD) and 8(R),11(S)‐dihydroxy‐9Z,12Z‐octadecadienoic acid (8,11‐diHOD) by using RP‐HPLC, GC‐MS, IR, GC‐MS analysis of diastereomeric derivatives, and 1H NMR and 13C NMR spectroscopy. Neither compound has been reported before in A. bisporus. Oleic (18∶1), α‐linolenic (18∶3n−3), and γ‐linolenic (18∶3n−6) acids were converted into their 8‐hydroxy derivatives as well, and 18∶3n−3 was further metabolized to its 8,11‐diol derivative. Reactions with [U‐13C]18∶2 demonstrated that the compounds 8‐HOD and 8,11‐diHOD were formed from exogenously supplied 18∶2. When [U‐13C]8‐HOD was supplied, it was not converted into 8,11‐diHOD, indicating that it was not an intermediate in the formation of 8,11‐diHOD. When a crude extract of A. bisporus was incubated under an atmosphere of 16O2/18O2, the two hydroxyl groups of 8,11‐diHOD contained either two 18O atoms or two 16O atoms. Species that contained one of each isotope could not be detected. We propose that the formation of the 8,11‐dihydroxy compounds occurs through either an 8,11‐endoperoxy, an 8‐peroxo free radical, or an 8‐hydroperoxy intermediate. In the latter case, the reaction should be catalyzed by dioxygenase with novel specificity.