bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acute toxicity, behavioral changes, and histopathological effects of deltamethrin on tissues (gills, liver, brain, spleen, kidney, muscle, skin) of Nile tilapia (Oreochromis niloticus L.) fingerlings
Authors: Yildirim M. Zıynet , Benlı A. Çağlan Karasu , Selvı Mahmut , Özkul Ayhan , Erkoç Fıgen , Koçak Oner 
Published: November 2006

AbstractDeltamethrin, a synthetic pyrethroid contaminating aquatic ecosystems as a potential toxic pollutant, was investigated in the present study for acute toxicity. The purpose of this study was to evaluate LC50 values of deltamethrin on Nile tilapia (Oreochromis niloticus L.) fingerlings and investigate histopathological responses of fish exposed to deltamethrin. The 48 h LC50 value for Nile tilapia fingerlings was estimated as 4.85 μg/L using static test system. In addition, behavioral changes at each deltamethrin concentration were observed closely. All fish, exposed to 5 μg/L deltamethrin revealed severe morphological alterations in the gills and liver. In the gills hyperemia, fusion of secondary lamellae and telangiectasis were observed; whereas hydropic degenerations in liver were observed in all examined fish. The results are significant for reporting acute deltamethrin toxicity in terms of behavioral and histopathological changes: Deltamethrin is highly toxic to fingerlings. © 2006 Wiley Periodicals, Inc. Environ Toxicol 21: 614–620, 2006.
Bilinear control system with the reaction‐diffusion term satisfying Newton's law
Authors: Lin P. , Leid P. , Gao H. 
Published: November 2006

AbstractIn this paper, we discuss a parabolic system governed by bilinear control, modeled according to Newton's Law. At first we prove that the system is exactly null controllable in long time T > 0 by locally distributed bilinear control and we further prove the exact null controllability in long time T > 0 of the semilinear parabolic equation yt‐Δ y + b |∇ y|2=ξou with traditionally additive locally distributed control and the existence of the control optimal time for the system. Then, we deduce an exact controllability result to particular stationary functions when we are acting over the whole domain and to particular stationary functions vanishing outside some ball included in the control domain when the control domain is as small as we want.
Enzyme, medium, and reaction engineering to design a low‐cost, selective production method for mono‐ and dioleoylglycerols
Authors: Arcos J. A. , Otero C. 
Published: November 2006

AbstractThe selective enzymic production of mono‐ and diolein (MO, DO) was optimized at high yields. A comparative study of the following distinct enzymic reactions was conducted: ethyl oleate glycerolysis, triolein (TO) glycerolysis, and direct esterification Solvent‐free systems were compared with media that contained different solvents. Native, modified (with polyethylene glycol), and immobilized lipases were used. Mechanical resistance, the support effect on enzyme and glycerol dispersion and on process reproducibility, and hydrophilicity of the support were considered in the process optimization. We report the use of an immobilized lipase on an inorganic support (Celite), which has high activities in both solid‐phase glycerolysis (99% reaction conversion) and esterification (100% conversion). The optimum conditions for the distinct reactions were compared by considering their selectivities, conversions, yields, and cost of the substrates. We found less costly and more selective processes in the absence of solvents for glycerolysis of triolein and direct esterification. Although glycerolysis was the most interesting process to produce diolein, esterification was better for monoolein preparation with this biocatalyst. The esterification reaction yielded 93 wt% of MO, in the absence of either TO or oleic acid (OA), at low cost because of the 100% reaction conversion. Similar costs of the substrates (10.6 and 10.1 $/g) were necessary to obtain 67 and 80 wt% of DO in esterification and glycerolysis, respectively. The glycerolysis conversion was 96%. In esterification, the product mixture was impure, with a high amount of residual OA due to the low conversion (59%). The high activity of PSL‐Celite in these solid‐phase reactions has an advantage over the reactions with nonimmobilized lipases due to the ease of enzyme recovery. The absence of organic solvents reduces the need for solvent removal from the reaction mixtures.
Lipid adsorption on commercial silica hydrogels from hexane and changes in triglyceride complexes with time
Authors: Proctor A. , Adhikari C. , Blyholder G. D. 
Published: November 2006

AbstractThe structures of and lipid complexes with two commercial silica hydrogels (Trisyl and Sorbsil 40), which contain about 60% moisture, were examined by diffuse reflectance Fourier transform infrared spectroscopy. The spectra suggested that Trisyl contained less moisture than Sorbsil 40. However, the silanol groups of Sorbsil 40 were more active in adsorbing oleic acid, triglyceride, and phosphatidylcholine (PC) from hexane than those of Trisyl. Both adsorbents strongly bound PC through the PC carbonyl and phosphate groups. Lipid adsorption from hexane solution by Trisyl depended solely on trapped moisture, while Sorbsil 40 used moisture and silanol groups on the silica surface. Spectra of triglyceride‐silica hydrogel complexes, obtained 24 and 72 h after obtaining the initial spectra, showed that Sorbsil 40 adsorption was by Van der Waals forces, but the triglyceride reoriented over time with an increase in hydrogen bonding. In contrast, Trisyl initially adosorbed triglyceride by hydrogen bonding which was stable for at least 72 h.
Conversion of oils to monoglycerides by glycerolysis in supercritical carbon dioxide media
Authors: Temelli Feral , King Jerry W. , List Gary R. 
Published: November 2006

AbstractGlycerolysis of soybean oil was conducted in a supercritical carbon dioxide (SC‐CO2) atmosphere to produce monoglycerides (MG) in a stirred autoclave at 150–250°C, over a pressure range of 20.7–62.1 MPa, at glycerol/oil molar ratios between 15–25, and water concentrations of 0–8% (wt% of glycerol). MG, di‐, triglyceride, and free fatty acid (FFA) composition of the reaction mixture as a function of time was analyzed by supercritical fluid chromatography. Glycerolysis did not occur at 150°C but proceeded to a limited extent at 200°C within 4 h reaction time; however, it did proceed rapidly at 250°C. At 250°C, MG formation decreased significantly (P<0.05) with pressure and increased with glycerol/oil ratio and water concentration. A maximum MG content of 49.2% was achieved at 250°C, 20.7 MPa, a glycerol/oil ratio of 25 and 4% water after 4 h. These conditions also resulted in the formation of 14% FFA. Conversions of other oils (peanut, corn, canola, and cottonseed) were also attempted. Soybean and cottonseed oil yielded the highest and lowest conversion to MG, respectively. Conducting this industrially important reaction in SC‐CO2 atmosphere offered numerous advantages, compared to conventional alkalicatalyzed glycerolysis, including elimination of the alkali catalyst, production of a lighter color and less odor, and ease of separation of the CO2 from the reaction products.
Moderate antioxidative efficiencies of flavonoids during peroxidation of methyl linoleate in homogeneous and micellar solutions
Authors: Roginsky V. A. , Barsukova T. K. , Remorova A. A. , Bors W. 
Published: November 2006

AbstractThe relative reactivities as well as the stoichiometric coefficients for a number of flavonoids, catechols, and—for comparison—standard phenolic antioxidants were determined by analyzing the kinetics of oxygen consumption in organic and micellar systems, with peroxidation initiated by lipid‐ and water‐soluble azo initiators. The results demonstrated that the flavonoids did not behave as classic phenolic antioxidants such as α‐tocopherol, but showed only moderate chain‐breaking activities. The results were in line with other structure‐activity relationship studies on the importance of the B‐ring catechol structure, the 2,3‐double bond, and the 3,5‐hydroxy groups. The data are discussed in view of possible explanations of the deviations flavonoids reveal in their behavior compared with regular phenolic antioxidants.
Seed oils ofAcacia holosericea A. Cunn. ex G. Don.: Characteristics and composition
Authors: Prasad N. B. L. , Azeemoddin G. 
Published: November 2006

AbstractLike the fruits ofElaeis guineensis, the seeds ofAcacia holosericea have two types of oils. One is present in the yellow aril (56%), which is attached to the black seed, and the other is in the kernel of the seed (12%). The proximate composition of seed and the physicochemical characteristics of the solvent‐extracted oils are reported. The aril fat is quite different from the seed oil in all respects. In descending order, the major fatty acids in aril fat are 18∶1 (54.35%), 16∶0 (29.3%), and 18∶2 (8.0%), whereas in seed (−aril) oil, the order is 18∶2 (59.45%) 18∶1 (20.2%), and 16∶0 (10.0%). In whole seed (+aril) oil, the order is 18∶2 (53.3%), 18∶1 (25%), 16∶0 (12.6).
Comparison of isopropanol and hexane for extraction of vitamin E and oryzanols from stabilized rice bran
Authors: Hu Weicheng , Wells John Henry , Shin Tai‐Sun , Godber J. Samuel 
Published: November 2006

AbstractThe effects of solvent‐to‐bran ratio (2∶1 and 3∶1, w/w), extraction temperature (40 and 60°C), and time (5, 10, 15, 20, and 30 min) were studied for hexane and isopropanol extraction. Increasing the solvent‐to‐bran ratios and extraction temperature increased the amounts of crude oil, vitamin E and oryzanol recovered for both solvents. An extraction time of 15 min was sufficient for optimum crude oil, vitamin E, and oryzanol extraction. Preheated isopropanol (3∶1 solvent/bran ratio and 60°C) extracted less crude oil (P<.05) but more vitamin E (P<.05) and similar amounts of oryzanol (P>.05) relative to preheated hexane. The data suggest that isopropanol is a promising alternative solvent to hexane for extraction of oil from stabilized rice bran.
Influence of pH and salt concentration on protein solubility, emulsifying and foaming properties of sesame protein concentrate
Authors: Inyang U. E. , Iduh A. O. 
Published: November 2006

AbstractThe effects of pH and NaCl concentration on protein solubility, emulsification, and foamability of sesame protein concentrate from dehulled seeds were investigated. The protein content of the concentrate was 70.7%. Protein solubility, emulsion, and foaming capacities varied with pH and ionic strength. Protein solubility, which was least at pH 4, (2.1%) ranged from 6.6% at pH 2 to 13.1% at pH 10. The solubility increased with increase in ionic strength, ranging from 9.8% at 0.0 M to 16.1% at 1.0 M concentration. The emulsion capacity ranged from 6.2 mL oil/g sample at pH 2 to 19.4 mL oil/g sample at pH 10. The emulsion capacity increased from 11.5 mL oil/g sample at 0.0 M to 20.9 mL oil/g sample at 1.0 M salt concentration. Stability of the emulsion increased with increase in NaCl concentration, ranging from 42% at 0.0 M concentration to 70% at 1.0 M concentration, but 0.5 M NaCl produced the most stable foam after 120 min of whipping while the least stable was at 1.0 M.
Emulsifying capacity of coconut proteins as a function of salt, phosphate, and temperature
Authors: Kwon K. S. , Rhee K. C. 
Published: November 2006

AbstractNitrogen solubilities of proteins in defatted coconut flour (CF) and coconut protein concentrate (CPC), prepared by ultrafiltration, were determined in water and 2% NaCl. The effect of temperature, disodium phosphate, and salt on emulsifying capacities (EC) of these products also were investigated by a model system. Between pH 4.0 and 5.0, nitrogen solubilities of CF and CPC in water were lower than those in salt solutions. In salt solutions, the nitrogen solubility was lowest at pH 1, and increased steadily as pH increased from 3.0 to 6.0. CF had higher EC values than CPC at all salt and phosphate levels. Additionally, increased phosphate level generally increased the EC at both salt levels, but these increases were not significant at 0.9% phosphate level as compared to the 0.7% phosphate level (P<0.05). Although the emulsifying temperature of 40°C showed higher EC values than both 60 and 80°C at all salt and phosphate levels, the overall temperature effect was not significant (P>0.05). However, EC decreased significantly with the addition of salt at all phosphate levels.
γ‐Linolenic and stearidonic acids in Mongolian Boraginaceae
Authors: Tsevegsüren Nanzad , Aitzetmüller Kurt 
Published: November 2006

AbstractSeeds of nine Central Asian species of Boraginaceae were investigated for the first time for their oil content and for the fatty acid composition of their seed oils by capillary gas chromatography. Levels of γ‐linolenic acid ranged from 6.6 to 13.0% and levels of stearidonic acid ranged from 2.4 to 21.4% of total seed fatty acids. The seed oil ofHackelia deflexa exhibited the highest stearidonic acid content (21.4%) that has been found so far in nature. Other high contents of this fatty acid were in threeLappula species (17.2 to 18.1%). Seed oils ofCynoglossum divaricatum andAmblynotus rupestris contain considerable amounts ofcis‐11‐eicosenoic (5.3 to 5.8%) andcis‐13‐docosenoic acid (7.0 to 9.7%) besides γ‐linolenic (10.2 to 13.0%) and stearidonic acid (2.4 to 6.5%), which distinguish these oils from those of other Boraginaceae genera.
Supercritical fluid chromatographic analysis of new crop seed oils and their reactions
Authors: Hayes Douglas G. , Kleiman Robert 
Published: November 2006

AbstractSupercritical fluid chromatography (SFC) with an open tubular column of nonpolar stationary phase separated triglycerides from crambe, meadowfoam,Euphorbia lagascae, and vernonia oils based on their molecular weight. The triglyceride compositions were consistent with the literature. SFC proved also to be a valuable tool in analyzing lipase‐catalyzed transesterification reactions where lesquerella oil and estolides were among the substrates employed. Analyte molecular weights could be estimated from a retention time‐ (or elution density‐) molecular eeight calibration curve. An increase in isothermal column temperature during SFC pressure or density programming improved the resolution of high‐molecular‐weight (>600 Da) analytes but yielded poorer resolution for analytes of molecular weight <200. A simultaneous pressure and temperature ramping program proved superior in enhancing resolution in several instances.
Improving the low‐temperature properties of alternative diesel fuels: Vegetable oil‐derived methyl esters
Authors: Dunn R. O. , Shockley M. W. , Bagby M. O. 
Published: November 2006

AbstractThis work explores near‐term approaches for improving the low‐temperature properties of triglyceride oil‐derived fuels for direct‐injection compression‐ignition (diesel) engines. Methyl esters from transesterified soybean oil were evaluated as a neat fuel and in blends with petroleum middle distillates. Winterization showed that the cloud point (CP) of methyl soyate may be reduced to −16°C. Twelve cold‐flow additives marketed for distillates were tested by standard petroleum methodologies, including CP, pour point (PP), kinematic viscosity, cold filter plugging point (CFPP), and low‐temperature flow test (LTFT). Results showed that additive treatment significantly improves the PP of distillate/methyl ester blends; however, additives do not greatly affect CP or viscosity. Both CFPP and LTFT were nearly linear functions of CP, a result that compares well with earlier studies with untreated distillate/methyl ester blends. In particular, additives proved capable of reducing LTFT of neart methyl esters by 5–6°C. This work supports earlier research on the low‐temperature properties; that is, approaches for improving the cold flow of methyl ester‐based diesel fuels should continue to focus on reducing CP.
Ether lipids based on the glyceryl ether skeleton: Present state, future potential
Authors: Urata Kouichi , Takaishi Naotake 
Published: November 2006

AbstractLipids from natural sources consist mainly of saponifiable substances, such as glycerides, along with some unsaponifiable lipids, some of which are ether lipids. Typical ether lipids are monoalkyl ethers of glycerin, also called alkyl/alkenyl glyceryl ethers. Alkyl/alkenyl glyceryl ethers have also been reported in marine organisms and in human feces. Several chemical syntheses of such ether lipids have been reported. Typical examples are alkyl glyceryl ether formation by the addition reaction of alkyl glycidyl ether and the telomerization reaction of butadiene with glycerin and a transition metal catalyst. Characteristic chemical structures, such as terpene alkyl glyceryl ethers, archaebacterial macrocyclic ether lipids, and glyceryl ethers of condensed cyclic planar molecules, have been obtained as well. Over the past few decades, industry has shown much interest in the chemistry and application of highly branched fatty acids. For example, isostearyl glyceryl ether (GE‐IS) with methyl branching in the middle chain was already known, but it is now prepared at an industrial scale by proprietary alkyl glycidyl ether methods. The characteristic behavior of GE‐IS toward water, such as formation of water‐in‐oil emulsions containing large amounts of water and of liquid crystals, has made it applicable for use in hair and skin‐care cosmetics. Based on these studies and considerations, glyceryl ether lipids, which are rarely investigated, may become one of the most important and useful lipids in the industry.
Synthesis and characterization of cleavable surfactants derived from poly(ethylene glycol) monomethyl ether
Authors: Yue Chengyun , Harris J. Milton , Hellberg Per‐Erik , Bergstrom Karin 
Published: November 2006

AbstractA series of noncyclic acetal‐linked cleavable surfactants were simply prepared by condensation of aldehydes with poly(ethylene glycol) monomethyl ethers. All of the products were characterized by1H nuclear magnetic resonance. Their hydrophile‐lipophile balance, surface tension, cloud point, critical micelle concentration, and foam height were determined. Hydrolysis kinetic studies, followed by gas chromatography, showed that they had higher hydrolytic reactivity in acidic solution than cyclic acetal‐linked cleavable surfactants.
The bioconversion of ethanol to biosurfactants and dye by a novel coproduction technique
Authors: Osman M. , Ishigami Y. , Someya J. , Jensen Harald B. 
Published: November 2006

AbstractRhamnolipids, multifunctional glycolipid biosurfactants, and pyocyanine, a phenazine dye, were coproduced byPseudomonas BOP100 from ethanol as the sole carbon source. Bacterial growth was dependent on the ethanol concentration in the medium. Pyocyanine was produced only during the exponential phase, while rhamnolipids production continued during the stationary phase, indicating two different ways of production for each of the products. Maximum coproduction capacity was observed at a concentration of 3% ethanol; yield of rhamnolipids was 3 g/L, and of pyocyanine 0.2 g/L. The products were characterized to confirm their chemical structures.
An improved falling‐film reactor for viscous liquids
Authors: Talens F. I. , Gutierrez J. M. , Mans C. 
Published: November 2006

AbstractThis paper presents the design of a sulfonation reactor that is intended for enhanced performance when the viscosity of the liquid phase increases, thus reducing gas‐liquid transfer rates. The proposed design allows adequate transfer rates to be maintained by progressively increasing the shear stress exerted by the gas over the liquid film. The effectiveness of the design has been tested in runs in which dodecylbenzene and lauryl alcohol 1.80E are sulfonated/sulfated.
Solubilizing effects caused by the nonionic surfactant octyl glucoside in phosphatidylcholine liposomes
Authors: de la Maza Alfonso , Parra Jose Luis 
Published: November 2006

AbstractThe mechanisms governing the interaction of the nonionic surfactant octyl glucoside (OG) on phosphatidylcholine (PC) liposomes were investigated. Permeability alterations were detected as a change in 5(6)‐carboxyfluorescein (CF) released from the interior of vesicles, and bilayer solubilization was determined as a decrease in the static light scattered by liposome suspensions. A direct relationship was established in the initial interaction steps (10–50% CF release) between the growth of vesicles, the leakage of entrapped CF, and the effective molar ratio of surfactant to phospholipid in bilayers (Re). This dependence was also detected during the solubilization range of Re values between 1.3 and 3.0, where the decrease in the surfactant‐PC aggregate size and in the light scattering of the system depended on the Re parameter and, hence on the composition of these aggregates. The free OG concentrations at subsolubilizing and solubilizing levels showed lower and similar, respectively, values than its critical micelle concentration (CMC). These findings indicated that the alterations in bilayer permeability were due to the action of surfactant monomers, whereas bilayer solubilization was determined by the formation of mixed micelles. This finding supports the generally accepted assumption that the concentration of free surfactant must reach the CMC for solubiliation to occur.
Surface activity and premicellar aggregation of some novel diquaternary gemini surfactants
Authors: Rosen Milton J. , Liu Letian 
Published: November 2006

AbstractA series of novel cationic gemini surfactants, CnH2n+1 N+(CH3)2CH2CHOHCHOHCH2N+(CH3)2CnH2n+1·2Br−, have been synthesized, and their surface properties were investigated in water, 0.1 N NaCl, and 0.1 N NaBr at 25°C. From surface tension‐log molar concentration plots, the pC20, critical micelle concentration (CMC), and γCMC values have been determined, and the area/molecule at the aqueous solution/air interface was calculated. When the number of carbon atoms in the alkyl (hydrophobic) chains is above a certain number, which depends upon the molecular environment, the surface activity of the compounds is less than expected. This appears to be due to formation of small, soluble aggregates below the CMC. Equilibrium constants calculated for this aggregation indicate that a series of oligomers are formed.
Molar volume and ultrasonic studies of europium soaps in mixed organic solvents
Authors: Mehrotra K. N. , Chauhan M. , Shukla R. K. 
Published: November 2006

AbstractThe ultrasonic velocity and density measurements of europium soaps in a mixture of benzene and methanol (3:2, vol/vol) were used to evaluate various acoustic parameters and molar volume and to determine the critical micelle concentration. The results showed that the ultrasonic velocity, specific acoustic impedance, molar sound velocity, and molar compressibility increase, and intermolecular free length, adiabatic Compressibility, and relative association decrease with increasing concentration and chainlength of the soap. The results were interpreted in terms of soap‐solvent interaction.
Catalytic effect of dipotassium glycyrrhizinate on the hydrolysis of nonionic ester surfactants
Authors: Koide Misao , Takahashi Masahiko , Tamagaki Seizo , Tagaki Waichiro 
Published: November 2006

AbstractThe family of dipotassium glycyrrhizinate (GK2) catalyzes the hydrolysis of nonionic ester surfactants (NES), such as hydrogenated castor oil with 60 oxyethylene units attached (HCO‐60) and monostearate with 25 oxyethylene units attached (SA‐25), even in the pH range of 3–6, where NES are generally stable in the absence of GK2. Long‐chain fatty acids also accelerate the hydrolysis reaction. Analyses, based on circular dichroism spectroscopy, and empirical force field calculations suggest that a GK2 and an NES molecule form an energetically stable complexvia hydrophobic interactions in which the ester carbonyl is in close contact with either one of the three different carboxyl groups in GK2, acting as an acid catalyst.