bluuebunny/crossref_metadata_2025_split huggingface dataset:
The determination of layer charge by curve-fitting of Lorentz- and polarization-corrected X-ray diagrams
Authors: Stanjek H. , Friedrich R. 
Published: November 2006

AbstractThe clay fraction from the B horizon of a Psammentic Hapludalf containing vermiculite and smectite was treated with n-alkylammonium chloride ranging from nc = 6 to nc = 16. X-ray data were obtained by step-scanning, stored in a computer, corrected with the Lorentz and polarization factors and then fitted with a deconvolution programme. The layer charge was determined from the uncorrected, the corrected and the fitted diagrams, respectively. The evaluated confidence limits of ξ decreased in the same order revealing the vermiculite to be a high-charge type. The computed charge distribution of the smectite changed from an unlikely bimodal to a nearly symmetrical distribution.
Facies-related diagenesis in the Main Claymore Oilfield sandstones
Authors: Spark I. S. C. , Trewin N. H. 
Published: November 2006

AbstractFour major sedimentary sequences of the Triassic and Upper Jurassic of the Main Claymore Oilfield of the North Sea each contain a characteristic suite of diagenetic minerals and fabrics. (1) Triassic Skagerrak Formation fluvial sandstones contain early authigenic pore-lining smectite, together with kaolinite and chlorite which form grain replacements and pore fills. Quartz and feldspar overgrowths are minor. Ferroan dolomite forms a late diagenetic patchy poikilotopic cement. Smectite is converted to illite-smectite in a 5 m thick zone beneath the sub-Jurassic unconformity. Smectite formed early in diagenesis prior to oil migration and destroyed permeability. Thus oil is not found in these sandstones although they occur in the oilzone. (2) The Piper Formation (late Oxfordian/early Kimmeridgian) paralic deposits mainly contain authigenic, pore-lining illite-smectite, vermicular kaolinite grain replacements and pore fills. Quartz overgrowths are generally well developed. (3) The Kimmeridge Clay Formation (early Kimmeridgian/early Volgian) comprises thin marine sandstone turbidites, contained within a thick siltstone/shale sequence. In the sandstones (the ‘Ten Foot Sandstone’) discrete double-ended quartz crystals (1–20 µm) developed prior to quartz, K- and Na-feldspar overgrowths. Only minor kaolinite and lllite-smectite are present. Late diagenetic dolomitic occurs as a patchy poikilotopic cement and as clusters of pore-filling rhombs. (4) The Claymore Sandstone Member (early to middle Volgian) thick marine sandstone turbidites are interbedded with thin siltstones/shales. Sandstones have well-developed quartz, K and Na-feldspar overgrowths, and kaolinite and illite-smectite occur as grain replacements and rarely as pore fills. Late-diagenetic dolomite and ferroan dolomite form poikilotopic cement and clusters of pore-filling rhombs. The major factors which control diagenetic features are depositional environment and associated porewater together with original mineralogy. Burial history and textural features of the sandstones also have important influences. Reservoir quality is controlled by a complex interplay of these features.
Measurement of the surface free energy of calcium-montmorillonite
Authors: Chassin P. , Jounay C. , Quiquampoix H. 
Published: November 2006

AbstractThe surface free energy of Ca-montmorillonite has been determined from measurement of the contact angle of water on an oriented deposit immersed in n-alkanes; the oriented deposits were equilibrated at different relative humidities. These experiments provided the polar, γSP, and dispersive, γSD, components of the surface free energy γs. The results indicate that: (1) γs is mainly due to dispersive forces (γSD ≃ 145 mJ.m−2) and, to a lesser degree, polar forces (γSP ≃ 35 mJ.m−2). (2) The value of the apparent surface free energy of the clay, γα, tends towards that measured for water when the solid water content exceeds 50 wt%. (3) The sorption of water molecules substantially modifies the surface free energy of the solid; γs decreases from 180 mJ.m−2 to 60 mJ.m−2 when the water content increases from 0 to 50%. These results agree with other observations made on solids whose surface characteristics are similar to montmorillonite, i.e. micas, silicates and glasses. In addition, variations of γs with water content can be related to the hydration processes of smectites. Finally, these results show that the silicate no longer influences the surface properties when the montmorillonite water content exceeds 60%.
Occurrence, composition and radionuclide sorption characteristics of illite from a fractured granite pluton, Southeastern Manitoba, Canada
Authors: Kamineni D. C. , Ticknor K. V. , Vandergraaf T. T. 
Published: November 2006

AbstractLow-dip fractures in the Lac du Bonnet granite pluton, SE Manitoba, contain abundant illite. Petrographic examination showed that the illite has three modes of occurrence: (i) alteration product of biotite, (ii) microfracture (< 1 mm width) filling, (iii) macrofracture (> 1 mm) filling. Microprobe analyses of these three types of illites in a single sample gave distinct compositional characteristics that defined an evolutionary trend, depicting Al2O3 enrichment, on an Al2O3−(K2O + Na2O)−(MgO + FeO) triangular diagram. White micas in the rock matrix adjacent to illite-bearing fractures have higher K and Al contents than all the three types of illites, implying that they formed under different conditions. The sorption of four radionuclides, 137Cs, 147Pm, 241Am and 90Sr, under oxic conditions on illite-bearing polished sections was also investigated, using autoradiography combined with petrographic examination. Illite showed greater sorption compared with other minerals present in the polished sections.
Short-wavelength sensitive opsin (SWS1) as a new marker for vertebrate phylogenetics
Authors: van Hazel Ilke , Santini Francesco , Müller Johannes , Chang Belinda SW 
Published: November 2006

Abstract

Background
Vertebrate SWS1 visual pigments mediate visual transduction in response to light at short wavelengths. Due to their importance in vision, SWS1 genes have been isolated from a surprisingly wide range of vertebrates, including lampreys, teleosts, amphibians, reptiles, birds, and mammals. The SWS1 genes exhibit many of the characteristics of genes typically targeted for phylogenetic analyses. This study investigates both the utility of SWS1 as a marker for inferring vertebrate phylogenetic relationships, and the characteristics of the gene that contribute to its phylogenetic utility.

Results
Phylogenetic analyses of vertebrate SWS1 genes produced topologies that were remarkably congruent with generally accepted hypotheses of vertebrate evolution at both higher and lower taxonomic levels. The few exceptions were generally associated with areas of poor taxonomic sampling, or relationships that have been difficult to resolve using other molecular markers. The SWS1 data set was characterized by a substantial amount of among-site rate variation, and a relatively unskewed substitution rate matrix, even when the data were partitioned into different codon sites and individual taxonomic groups. Although there were nucleotide biases in some groups at third positions, these biases were not convergent across different taxonomic groups.

Conclusion
Our results suggest that SWS1 may be a good marker for vertebrate phylogenetics due to the variable yet consistent patterns of sequence evolution exhibited across fairly wide taxonomic groups. This may result from constraints imposed by the functional role of SWS1 pigments in visual transduction.
Neoadjuvant Use of Hormonal Therapy in Elderly Patients with Early or Locally Advanced Hormone Receptor–Positive Breast Cancer
Authors: Macaskill E. Jane , Renshaw Lorna , Dixon J. Michael 
Published: November 2006

Abstract
The management of the elderly patient with breast cancer is a challenge to the breast care team for a number of reasons. The higher rate of comorbidity in elderly patients increases the risk for complications and mortality following surgery and other adjuvant treatments such as chemotherapy and radiotherapy. The advent of using endocrine therapy in the neoadjuvant setting allows disease control and downstaging of tumors to allow less extensive surgery, with less morbidity compared with other available treatments. Tamoxifen has traditionally been the hormone therapy of choice for patients unable to undergo surgery, but development of resistance is a common feature. Newer third-generation aromatase inhibitors, in particular letrozole, are superior to tamoxifen in this setting with greater downstaging of tumor and disease control. The aromatase inhibitors are now the treatment of choice in elderly patients with estrogen receptor–positive breast cancer who are being considered for neoadjuvant therapy. These drugs are particularly suitable to the needs of an elderly population.
Comparison of the performance of chitosan and a cationic polyacrylamide as flocculants of emulsion systems
Authors: Pinotti A. , Bevilacqua A. , Zaritzky N. 
Published: November 2006

AbstractFood industries contribute significantly to the pollution of water streams. Oil in wasterwaters must be removed to prevent fouling of process equipment, to reduce interference with subsequent water‐treatment units, and to comply with water‐discharge requirements. Polyelectrolytes are frequently used to coagulate and flocculate colloidal systems. A model system of a sunflower oil/water emulsion was used to analyze the effect of:(i) emulsion droplet sizes, (ii) surfactant chain length (sodium dodecyl sulfate and sodium tetradecyl sulfate), (iii) ionic strength, and (iv) pH, on the doses of chitosan (natural cationic polyelectrolyte) and a cationic polyacrylamide, necessary to neutralize electrical charge and to get flocculation. Methods used were: turbidimetry, jar test, colloidal titration, and light microscopy observation. Results showed that the increase of NaCl concentration reduces the doses of chitosan and polyacrylamide to reach zero colloidal charge; these doses increase with the surfactant chain length. pH variation did not show any influence on the chitosan dose necessary to flocculate the system. Redispersion of the emulsion was observed in chitosan and polyacrylamide treatments.
Synthesis of enhanced biosurfactant by Bacillus subtilis MTCC 2423 at 45°C by foam fractionation
Authors: Makkar Randhir S. , Cameotra Swaranjit S. 
Published: November 2006

AbstractProduction of a lipopeptide surfactant in a 6.5‐L batch fermentor was carried out using Bacillus subtilis MTCC 2423 at 45°C. A good yield was obtained from sucrose (2%) substrate fermentation by continuous removal of the product by foam fractionation. The biosurfactant was recovered from collapsed foam by acid precipitation. The biosurfactant yield (4.5 g/L) was about 4.5 times higher than the yield (ca. 1 g/L) obtained by shake‐flask fermentation. Surface activity of the collapsed foam was very high, and total surface activity was observed in the collapsed foam. The structural characterization of this biosurfactant produced at 45°C by the strain used in this study was recently reported. The biosurfactant was analyzed by thin‐layer chromatography, infrared, 1H nuclear magnetic resonance, and mass spectroscopy and was found to be identical to surfactin, a lipopeptide surfactant.
Tethering of long‐chain amino acids to a rigid aromatic core—A new type of preorganized surfactants acting as flotative agents
Authors: Müller P. , Weber E. , Helbig C. , Baldauf H. 
Published: November 2006

AbstractNew oligofunctional surfactants prepared from ethyl 2‐aminododecanoate hydrochloride and positional isomers of aromatic acid di‐ and trichloridesviaamide bond formation, including also the monofunctional compound of comparison, have been synthesized. Surface properties of the new compounds, in particular critical micelle concentration (CMC), surface tension at the CMC, effectiveness, and maximum surface excess, were determined. Moreover, their effectiveness at flotation using the model mineral fluorite was studied. We found that the surfactant parameters clearly depend on the number and position of the amphiphilic subunits attached to the aromatic core. We also found that a bundling of amphiphilic subunits, as performed, is profitable in the flotation of fluorite and that effects of preorganization due to the proximity and geometric grouping of the amphiphilic subunits are of importance. As a rule, the more amphiphilic subunits are included in the surfactant structure, the more efficient is the collecting agent, involving approximate enhancements of fluorite flotation by powers of 10 when going from mono‐ to bi‐ and trifunctional surfactant analogs, respectively. Nevertheless, the surface properties of the newly synthesized surfactants do not directly correlate with the flotation data, which makes relations between surfactant structure and efficiency of fluorite flotation at the current stage of development difficult to determine. Future studies relating to this problem are suggested.
Solubilization of phospholipid vesicular structures into mixed micelles of zwitterionic surfactants
Authors: Sehgal Pankaj , Doe Hidekazu , Bakshi Mandeep Singh 
Published: November 2006

AbstractInteractions between the binary combination of dimethyltetradecylammoniopropanesulfonate (TPS) and l‐α‐phosphatidylcholine (PC), 1,2‐didecanoyl‐sn‐glycero‐3‐phosphocholine, and 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine in the aqueous bulk phase were evaluated with the help of pyrene fluorescence (l1/l3) measurements by studying the aggregation processes of TPS in pure water and in the presence of 7–36 μM of fixed concentrations of each lipid. The fluorescence measurements showed that TPS monomers undergo two kinds of aggregation process, which were identified by the three breaks. The first break, C1, and the second, C2, indicated the onset and completion of bilayer solubilization, respectively, on the incorporation of TPS monomers into the bilayer assemblies, which led to bilayer solubilization in the form of mixed micelles. This process was not clearly visible in the presence of PC, whereas some kinds of structure transitions were observed upon the incorporation of surfactant monomers. The partition coefficient (K), which defines the degree of partitioning of surfactant monomers into the bilayers with respect to the aqueous medium, was evaluated. A high K value of TPS‐lipid aggregates indicated stronger interactions between surfactant and bilayer assemblies of lipid. The K values determined for the three phospholipids are close to each other, which indicates that K values do not depend on the hydrocarbon chain length of the phospholipid but of the surfactant used.
Corrosion inhibition of some novel hydrazone derivatives
Authors: Negm Nabel A. , Morsy Salwa M. I. , Said Medhat M. 
Published: November 2006

AbstractA novel series of surfactants was synthesized via direct interaction of the hydrogen‐accepting benzyl monophenyl hydrazone and different hydrogen‐donating sulfate, sulfonate, sulfosuccinate, or taurate species in their acid form. The double salt surfactants produced had a benzyl monophenyl hydrazonium (PH) moiety as the cation, and lauryl sulfate, dodecylbenzene sulfonate, dioctyl sulfosuccinate, N‐cetyloxycarbonyl ethyltaurate (COCET), and N‐stearyloxycarbonyl ethyltaurate as the anion. The structural elucidation of the synthesized compounds was carried out using different analytical tools such as elemental analyses, sharp melting points, and Fourier transform infrared and 1H nuclear magnetic resonance spectroscopy. Surface properties of these synthesized hydrazonium derivatives, including surface tension and emulsion stability, were measured and correlated with their chemical structure. The corrosion inhibition efficiency of these hydrazonium derivatives at different concentrations (20, 40, 60, 80, and 100 ppm) was measured in brine containing 5% H2S as the corrosive medium. The inhibition efficiency results were discussed according to the inhibitor concentrations in the corrosive medium, chemical structures, surface properties, and hydrophile‐lipophile balance of these inhibitors. The corrosion inhibition measurements of these compounds showed that PH‐COCET exhibits good efficiency at all concentration ranges.
The effects of anionic and cationic surfactants on the hydrolysis of sodium barbital
Authors: Qian Junhong , Qian Shaohua , Guo Rong 
Published: November 2006

AbstractAlkaline hydrolysis reactions of sodium barbital in micelles of sodium dodecyl sulfate (the anionic surfactant SDS), micelles of cetyl trimethylammonium bromide (the cationic surfactant CTAB), and mixed micelles of surfactant/n‐C5H11OH/H2O were studied by ultraviolet‐visible spectrometry. The reaction rate and the activation energy of the hydrolysis of sodium barbital were calculated. The results showed that the rate of sodium barbital hydrolysis decreased with an increase in CTAB content, whereas it increased in the presence of SDS and n‐C5H11OH. The different effects of CTAB and SDS on the hydrolysis of sodium barbital may be related to their interaction with sodium barbital.
Corrosion inhibition of triethanolammonium bromide mono‐ and dibenzoate as cationic inhibitors in an acidic medium
Authors: Negm Nabel A. , Morsy Salwa M. I. 
Published: November 2006

AbstractA weight loss technique was used to determine the corrosion inhibition efficiency of synthesized alkyl mono‐and dibenzoate triethanolammonium bromide derivatives (TEAMB, TEADB) in an acidic medium (2 N HCl) at different doses (50, 100, and 200 ppm). The results showed that monoderivatives had a higher corrosion inhibition efficiency than diderivatives. The results were correlated with several factors, including the alkyl chain length of the hydrophobic chains, interfacial tension (IT), critical micelle concentration (CMC), and adsorption free energy of these inhibitors. Increasing the geometric length of the alkyl chains in the synthesized inhibitors had an increasing effect on their corrosion inhibition efficiency, whereas decreasing the CMC and IT had an increasing effect on their tendency toward corrosion inhibition. The number of hydrophobic chains attached to the inhibitor molecules had a vital influence on their efficiency as corrosion inhibitors.
Synthesis, stability, and biodegradability studies of a surface‐active amide
Authors: Stjerndahl Maria , Holmberg Krister 
Published: November 2006

AbstractA homolog pure nonionic surfactant, tetra(ethylene glycol) mono‐n‐octaneamide, was synthesized. The surfactant was characterized by determining the critical micelle concentration, cloud point, and biodegradation. Hydrolysis catalyzed by an acid, an alkali, a peroxide, and enzymes [peptidase from porcine, amidase from Pseudomonas aeruginosa, and two lipases, Mucor miehei lipase (MML) and Candida antarctica lipase B (CALB)] was investigated using 1H nuclear magnetic resonance. The surfactant was stable toward the acid, alkali, and peroxide. When subjected to peptidase and CALB, the amide was cleaved, although at a low rate. No reaction was obtained when using the amidase or MML. The biodegradation test resulted in more than 60% degradation after 28 d. Based on these results, the amide surfactant can be considered chemically stable, yet highly biodegradable, which generally is an ideal combination of properties for a surfactant.
Alpha‐sulfonated methyl ester as an active ingredient in palm‐based powder detergents
Authors: Maurad Zulina Abd , Ghazali Razmah , Siwayanan Parthiban , Ismail Zahariah , Ahmad Salmiah 
Published: November 2006

AbstractPalm‐based alpha‐sulfonated methyl esters (SME) were successfully produced using a 20 kg/h‐capacity pilot plant at the Malaysian Palm Oil Board. This anionic surfactant was used as an active ingredient to formulate powder detergent. The production of palm‐based powder detergents (PPD) was carried out at the pilot‐plant scale. The performance of powder detergents formulated with SME was found to be excellent. At a total concentration of 0.8 g/L, good detergency of PPD was obtained when only using 12% to 18% SME, compared to the commercial detergent with 27% surface‐active agent. The foaming power and wetting characteristics of PPD were also comparable to the values for the commercial detergent. The study has shown that PPD were able to biodegrade faster than the commercial detergent, where the maximum time period to reach the pass level (60%) is within 14 days. The toxicity of the PPD, which ranged from 5.66 to 8.0 mg/L, is similar to the toxicity of the commercial detergent. A detailed description of the SME application technologies in powder detergents and the properties of formulated powder detergents are highlighted in this paper.
Biosurfactant production by microorganisms on unconventional carbon sources
Authors: Makkar Randhir S. , Cameotra Swaranjit S. 
Published: November 2006

AbstractIn recent years natural biosurfactants have attracted attention because of their low toxicity, biodegradability, and ecological acceptability. However, for reasons of functionality and production cost, they are not competitive with chemical surfactants. Use of inexpensive substrates can drastically decrease the production cost of biosurfactants. This review describes the use of unconventional carbon sources for biosurfactant production. These sources include urban as well as agroindustrial wastes. With suitable engineering and microbiological modifications, these wastes can be used as substrates for large‐scale production of biosurfactants.
Absorption of canthaxanthin by the rat is influenced by total lipid in the intestinal lumen
Authors: Clark Richard M. , Furr Harold C. 
Published: November 2006

AbstractIn this study the effect of luminal lipid on the absorption of canthaxanthin (CTX) was investigated using the lymph duct cannulated rat. Treatments were emulsions designed to deliver increasing amounts of olive oil (10, 30, 50, 70, or 90 mg/h) and CTX (12.5 nmol/h). Emulsions were continuously infused into the duodenum for 12 h, and lymph was collected during the final 6 h of infusion for analysis. As the amount of lipid in the emulsion increased, a linear increase in the absorption of CTX was observed. The recovery of CTX in the lymph when infused with 10 mg/h olive oil was 14.2±1.2% and with 90 mg/h was 26.9±5.7%. The efficiency of CTX absorption nearly doubled by increasing the amount of lipid infused with CTX. The correlation between lipid load and CTX absorbed was r=0.85. We conclude that luminal lipid load affects CTX absorption.