bluuebunny/crossref_metadata_2025_split huggingface dataset:
Linear polyurethanes derived from alditols and diisocyanates
Authors: Paz Ma Violante de , Marín Romina , Zamora Francisca , Hakkou Khalid , Alla Abdelilah , Galbis Juan A. , Muñoz‐Guerra Sebastián 
Published: July 2007

AbstractA set of linear [m,n]‐type polyurethanes was synthesized by polycondensation in solution from hexamethylene diisocyanate and 4,4′‐methylene‐bis(phenyl isocyanate) with alditols. Threitol, arabinitol, and xylitol bearing the secondary hydroxy groups blocked as methyl ethers were used. Either regioregular or nonregioregular polymers (depending on the configuration of the alditol) were obtained in high yields and with number‐average molecular weights within the 20,000–30,000 range. All these polyurethanes were amorphous with Tg being highly dependent on the aliphatic or aromatic nature of the diisocyanate used, but scarcely depending on the chemical structure of the alditol moiety. They were found to be stable up to near 300 °C, decomposing at higher temperatures through a complex three‐stage mechanism. Polyurethanes obtained from threitol did not show significant enhancement of hydrolytic degradability as compared with polyurethanes obtained from 1,4‐butanediol. Conversely, polyurethane prepared from xylitol and hexamethylendiisocyanate was found to be almost fully hydrolyzed in 1 month when incubated in water either at 80 °C and pH 7.4 or at 37 °C and pH 10. It was concluded that the alditol size seems to be of prime importance in determining the hydrodegradability of these sugar containing polyurethanes. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4109–4117, 2007
Codendronized polymers pendent with alternating dendritic wedges
Authors: Zhang Yanhong , Xu Zizhen , Li Xiaokai , Chen Yongming 
Published: July 2007

AbstractCodendronized polymers pendent with Fréchet‐type poly(benzyl ether) dendron and polyester dendron alternating structure have been produced by combining macromonomer and graft‐from approach. Alternating copolymerization of the styryl dendrons of three generations and N‐(2‐hydroxyethyl)maleimide was used to prepare the polymer backbone bearing the first kind of dendritic wedges, then polyester dendrons were grown up from the pendant hydroxy groups through iterative esterification and deprotection reactions. Then, a kind of codendronized polymer bearing different dendritic wedges with an alternating structure was thus obtained. Since the pendent dendrons were different and each of them was well‐defined, such codendronized polymer can be a multicompartment wormlike molecule. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3994–4001, 2007
A novel rate‐accelerating additive for atom transfer radical polymerization of styrene
Authors: Jiaming Zhuang , rui Lin , Jianying Huang , Jiayan Chu , Xurong Lin , Yutai Luo , Yousi Zou 
Published: July 2007

AbstractThe polymerization of styrene was mediated by copper (I) bromide/pentramethldiethyltriamine (PMDETA) using ethyl 2‐bromopropionate (EBP) as initiator and a catalytic amount of malononitrile (MN) as a novel rate‐accelerating additive. The optimal molar ratios of MN/EBP under which the polymerization of styrene can proceed fastest was 4:1. The rate‐enhancement‐efficiency had a dependence on temperature and the apparent rate constant of polymerization improved by a factor of 2.67 at 85 °C. Polymerization resulted in a conversion as high as 87% in 4.3 h in the presence of MN, while a conversion of 79.7% was gained even in 10 h without MN at 85 °C. The polymerizations of styrene in the presence of MN proceeded in a living fashion indicated by the first‐order kinetic plots, with the increase of Mn with respect to conversion and the relatively narrow polydispersity. The possible rate enhancing mechanism is that the addition of MN weakens the coordination between the copper center and ligand and facilitates the atom transfer process. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4082–4090, 2007
Comparative Chemometric and QSAR/SAR Study of Structurally Unrelated Substrates of a MATE Efflux Pump VmrA from V. parahaemolyticus: Prediction of Multidrug Resistance
Authors: Kiralj Rudolf , Ferreira Márcia M. C. 
Published: July 2007

AbstractStructures of 12 structurally unrelated agents (training set) and 19 diverse agents (prediction set) were modeled at the PM3 level and the molecular descriptors obtained were correlated with pMIC (pMIC=−log(MIC/mol/dm3) values for E. coli strains KAM32 (without VmrA efflux pump) and KAM32/pVCJ6 (with VmrA). Partial Least Squares (PLS) and Principal Component Regression (PCR) models were built and used to predict pMICs. Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) were performed for training and training+prediction sets. Agent–receptor interaction descriptors were calculated for complexes with these or the most similar agents, as retrieved from the Protein Data Bank (PDB). Good substrates of VmrA from Vibrio parahaemolyticus AQ3334 are nonlinear, rigid, and condensed heteroaromatics, rather hydrophobic, involved in aromatic–aromatic, hydrophobic–hydrophobic, hydrophobic–hydrophilic, and hydrogen bond contacts with VmrA. Qualitative and quantitative structure–activity relationships [(Q)SARs] predicted well the resistance/sensitivity of VmrA to 19 agents. This can have practical application in assays with V. parahaemolyticus and other noncholera Vibrio spp. Agent–receptor interaction descriptors correlate with experimental and predicted pMICs, giving a new insight into possible VmrA‐mediated agent efflux mechanisms.
Identification of bupropion urinary metabolites by liquid chromatography/mass spectrometry
Authors: Petsalo Aleksanteri , Turpeinen Miia , Tolonen Ari 
Published: July 2007

AbstractHuman urinary metabolism of the antidepressant bupropion was studied using liquid chromatography/time‐of‐flight mass spectrometry (LC/TOFMS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS). A total of 20 metabolites were detected and identified. The phase I metabolism included formation of morpholinohydroxybupropion, threo‐ and erythrohydrobupropion, aromatic hydroxylation, butyl group hydroxylation with ketone hydrogenation and dihydroxylation. These metabolites were detected either as the free form or as glucuronide and/or sulphate conjugates. In addition also m‐chlorohippuric acid was detected. Of the phase I metabolites, a dihydroxylation to the aromatic ring and to the methyl group in the middle of the substrate molecule was reported here for the first time, as well as eight of the glucuronide conjugates (to hydroxy, dihydroxy, hydroxy and hydrogenation metabolites) and three of the sulphate conjugates (to aromatic hydroxy and hydroxy and hydrogenation metabolites). Copyright © 2007 John Wiley & Sons, Ltd.
Wavelength‐dependent Coulomb explosion in carbon disulphide (CS2) clusters: generation of energetic multiply charged carbon and sulphur ions
Authors: Sharma Pramod , Vatsa Rajesh K. 
Published: July 2007

AbstractA gigawatt laser‐induced Coulomb explosion has been observed in carbon disulphide (CS2) clusters generating energetic, multiply charged [C]m+ (m = 1–4) and [S]n+ (n = 1–6) atomic ions of carbon and sulphur. The Coulomb explosion shows wavelength dependence. Comparison of these results with our earlier work shows that the polarizability and dipole moment might help in energy absorption from the laser field but they are not mandatory conditions for this low‐intensity Coulomb explosion. The results show that in a field of 109 W/cm2, absorption of 266 and 355 nm laser radiation by CS2 clusters leads to multiphoton dissociation/ionization whereas at 532 nm the whole cluster explodes generating multiply charged atomic ions. Copyright © 2007 John Wiley & Sons, Ltd.
Mass spectrometric identification of Rab23 phosphorylation as a response to challenge by cytidine 3′,5′‐cyclic monophosphate in mouse brain
Authors: Bond A. Elizabeth , Dudley Edward , Tuytten Robin , Lemière Filip , Smith Christopher J. , Esmans Eddy L. , Newton Russell P. 
Published: July 2007

AbstractWhile the functions and mechanisms of action of adenosine 3′,5′‐cyclic monophosphate (cAMP) and guanosine 3′,5′‐cyclic monophosphate (cGMP) are well established and are the basis of the action of a large number of successful pharmaceuticals, the role of a third naturally occurring cyclic nucleotide, cytidine 3′,5′‐cyclic monophosphate (cCMP), remains to be elucidated. Immobilized metal affinity chromatography (IMAC) was used to selectively extract proteins phosphorylated in mouse brain in response to challenge by cAMP, cGMP and cCMP, followed by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐ToFMS) and liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS) of tryptic digests to identify Rab23 as the first protein reported to be phosphorylated only in response to cCMP. Copyright © 2007 John Wiley & Sons, Ltd.
Determination of sultones in anionic surfactants
Authors: Macmillan W. D. , Wright H. V. 
Published: July 2007

AbstractSaturated and unsaturated 1,3‐ and saturated 1,4‐sultones in anionic surfactants are identified and measured by a series of separation maneuvers. The sultones are separated from the surfactant by ion‐exchange treatment and concentrated by thin layer chromatography. By the use of high performance liquid chromatography, the sultones are identified on the basis of their retention times and are measured by comparing their peak areas with those of reference compounds. Adequate responses are obtained from 5 μg quantities of sultone, corresponding to 0.1 ppm sultone in a 50 g sample of alkylethoxy sulfate paste. All the sultones of interest are separated from each other. Chlorosultones can be determined after first treating them with collidine, which dehydrohalogenates them to the unsaturated sultones.
The linolenic acid content of peanut oil
Authors: Worthington R. E. 
Published: July 2007

AbstractOils prepared from eight peanut cultivars grown in four locations were analyzed for linolenic acid (18:3) content by gas liquid chromatography. Columns packed with either OV 225 or butanediol succinate provided excellent separation of 18:3 from major fatty acids and from trace constituents exhibiting retention times suggestive of 19:0 and 19:1. Average linolenic acid values for cultivars ranged between 0.03 and 0.13 weight percent of total fatty acids.
GC/MS analysis of some long chain esters, ketones and propanediol diesters
Authors: Vajdi M. , Nawar W. W. , Merritt C. 
Published: July 2007

AbstractIdentification of radiolysis products which are formed in lipids in the range of molecular weights from 400‐600 has been established on the basis of gas chromatography/mass spectrometry (GC/MS) studies of long chain authentic samples of alkyl esters, ketones and propanediol diesters. This paper describes the GC/MS behavior of these compounds. Double hydrogen rearrangement was found to be the predominant ion in the spectrum of long chain saturated esters whereas in the unsaturated esters, a peak corresponding to the loss of alcohol from the molecular ion was more pronounced. On the contrary to short chain ketones, McLafferty rearrangement did not appear to be the major fragmentation in the spectrum of saturated and unsaturated long chain ketones. α‐Cleavage was found to be the predominant fragmentation in the spectrum of these ketones. The “McLafferty + 1” rearrangement peak was more pronounced for the long chain ketones than those found in the spectrum of smaller ketones. Fragmentation patterns of propanediol diesters were shown to be similar to those in triglycerides, giving rise to predominant peaks corresponding to acylium ion [RCO]+ and parent minus acyloxy ion [R‐COO]+.
Cocoa butter substitutes from mango fat
Authors: Baliga B. P. , Shitole A. D. 
Published: July 2007

AbstractMango fat obtained by solvent extraction of the kernels of the mango fruit (Magnifera indica) has been studied for its suitability in making cocoa butter substitutes. The fat has been fractioned from acetone at low temperatures in one and/or two stages in order to segregate suitable solid fractions having physical properties closer to cocoa butter. The data pertaining to the solidification characteristics and dilatometric behavior of the mango fat, its acetone‐fractionated products and their admixtures with cocoa butter in equal proportions have been determined in order to assess their compatibility with cocoa butter. Fractionated mango fat can serve as a good partial substitute for cocoa butter.
Soybean protein food in China
Authors: Yung‐Shung Chu 
Published: July 2007

AbstractThis paper introduces the history of soybeans and soybean protein foods in China. For 4,000 years, soybeans have been one of the main crops cultivated in this country. The history of extracting protein to prepare a protein food (bean curd, tu‐fu) is about 1,000 years old. Our ancestors had long been aware of the edible value of the soybean and had developed a technique for preparing many kinds of soybean foods. The traditional methods of preparing soybean protein foods such as bean curd (tu‐fu), fermented bean curd (fu‐ru) and dried bean milk cream (fu‐tsu) are discussed.
Current future fat‐based raw materials for soap manufacture
Authors: Sonntag Norman O. V. 
Published: July 2007

AbstractThe traditional use of coconut and palm oils for soap manufacture can be expected to continue indefinately. Certain oils of the oleic/ linoleic acid group are too unsaturated to yield soaps of the desired degree of hardness and stability. They may be hydrogenated to form suitable hard soap fats; a quantity of these oils is used regularly in the preparation of soft soaps and in blends with harder fats. The chief animal fat used in soapmaking is tallow. Other fats and oils less frequently used include babassu, palm kernel and olive oil. The ratio of tallow/coconut oil used for the manufacture of toilet soaps ranges from 85:15 to 75:25. A correlation of soap properties with the ratio of 95:5 to 75:25 of tallow and coconut oil demonstrates that properties such as cracking, swelling and hardness are not as sensitive to the changes in the blend ratios as are erosion characteristics, slushing and lather. Present production of Russian and Eastern European soap is from huge quantities of straight‐chain, odd‐ and even‐numbered, carbon saturated synthetic fatty acids (SFA). Future fat‐based raw materials might include certain fractionated fatty acids, methyl ester intermediates, acidulated sunflower and/or safflower soapstocks. Jojoba wax might be a surprising new raw material.
Evaluation of peanut and cottonseed oils for deep frying
Authors: Du Plessis L. M. , Van Twisk P. , van Niekerk P. J. , Steyn M. 
Published: July 2007

AbstractA comparative study of cottonseed and peanut oils for frying of potato chips was undertaken. Industrial scale frying was conducted for 5 days with cottonseed and 5 days with peanut oil and frying oils and chips were sampled twice a day. Frying oils and oils extracted from stored chips were analyzed for ultraviolet absorption (A232 and A268), peroxide and acid values. Tocopherol and tertiary butylhydroquinone levels were determined by high performance liquid chromatography. Chips stored at room temperature for 12 weeks were organoleptically evaluated. During the first 20 hr frying the A232, free acid and peroxide values of cottonseed oil increased rapidly, exceeding that of peanut oil, which increased moderately. For both oils, constant values were attained during the next 80 hr period, followed by moderate increases during the last 23 hr. Peanut frying oil lost 55% of its tocopherols and 54% of its tertiary butylhydroquinone during frying (103 hr), whereas cottonseed frying oil retained these compounds at the original levels. Tocopherols were also better retained in chips fried in cottonseed oil than in peanut oil. The fatty acid patterns of frying oils and oils extracted from chips did not show significant changes due to frying and storage, respectively. These results, therefore, suggest that cottonseed oil is sufficiently stable to be used as a substitute for peanut oil in deep frying.
Radicals generated in autoxidized methyl linoleate by light irradiation
Authors: Chiba T. , Fujimoto K. , Kaneda T. , Kubota S. , Ikegami Y. 
Published: July 2007

AbstractThe structure of free radicals generated in the autoxidation of methyl linoleate (ML) was studied by the spin trapping technique using deuterated nitrosodurene, (CD3)4C6HNO, as the spin trap. The secondary alkyl radicals were trapped after irradiation of ML with UV light. The formation rate of secondary alkyl radicals increased upon shortening the wavelength of irradiation light and was closely correlated with the peroxide value of autoxidized ML when a UV light longer than 250 nm was employed. When hydroperoxides separated from autoxidized ML were added to ML, the relationship between the formation rate of secondary alkyl radicals and the amounts of added hydroperoxides was nearly linear. These results suggest that secondary alkyl radicals are generated by proton abstraction of the active radicals, such as RO and HO, which are produced by the photolysis of hydroperoxides with UV light. The spin trapping technique can be applied to the study of lipid oxidation and/or photolysis of autoxidized lipid.
Conversion of visual to instrumental measurement of yellowness
Authors: Hunter R. S. 
Published: July 2007

AbstractYellowness is the result of a tendency of many materials (especially organic) to absorb more light in the blue end than in the rest of the visible spectrum. For approximately 100 years, yellowness of materials has been rated by visual comparisons with either standardized glasses or standardized solutions of reagent grade chemicals. Since 1942, paints, textiles, plastics and many other materials have been rated for yellowness by photoelectric measurements based on the spectral response characteristics of the normal human eye. Four of the long‐established and widely used visual scales for yellowness are related herein to four of the newer and more precise photo‐electric tristimulus scales. The four visual scales are Lovibond, Hazen, Gardner and FAC. The tristimulus scales are ASTM D1925, ASTM E313, Hunter b and CIELAB b*. These interrelations between scales were actually developed more than 20 years ago by Ron Stillman of the AOCS, but his data were so voluminous that no opportunity for their publication was ever found.
Antioxidant activity of amino acids bound to trolox‐C
Authors: Taylor M. J. , Richardson T. , Jasensky R. D. 
Published: July 2007

AbstractVarious amino acids, selected for their potential antioxidant activity, were, covalently attached to 6‐hydroxy‐2,5,7,8‐tetramethylchroman‐2‐carboxylic acid (Trolox‐C), a lower homolog of vitamin E that has great antioxidant effectiveness. The resulting Troloxylamino acids (T‐AA) had greater antioxidant effectiveness than Trolox‐C in a linoleate emulsion system oxidized by hemoglobin. Troloxyl‐tryptophan‐methyl ester and Troloxyl‐methionine‐methyl ester were the most effective T‐AA evaluated in the linoleate emulsion. However, butylated hydroxyanisole (BHA), butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and α‐tocopherol were more antioxidant than any T‐AA in the emulsion system. In a Schaal oven test at 45 C. Trolox‐C was by by far the most effective antioxidant evaluated in corn oil. BHT and Troloxylcysteine had significant antioxidant activity in corn oil, but no other T‐AA was antioxidant in corn oil. In butter oil, Trolox‐C again had the highest antioxidant activity, and BHA and BHT were also highly antioxidant. All t‐AA had antioxidant activity in butter oil, with Troloxyl‐methioninc and Troloxyl‐cysteine having the grcatest antioxidant effectiveness. The T‐AA of highest antioxidant activity were hydrolyzed by chymotrypsin and/or trypsin, in vitro.
Hexane losses in solvent extracted soya meal: Measurement by gas chromatography and brief evaluation
Authors: House R. J. R. , Harcombe A. O. , Guinness R. G. 
Published: July 2007

AbstractHexane losses in solvent extraction plants arise from a variety of causes. With the constantly increasing price of hexane, it has become imperative to identify the major loss areas and quantify losses in these areas. Hexane lost in meal leaving the desolventizer‐toaster (D‐T) is an obvious choice for investigation. A method has been developed for determining relatively high levels of hexane in hot meal leaving the D‐T. The method was designed to minimize the loss of solvent by cvaporation between the time of sampling and the actual measurement by gas chromatography (GC) Examination of the reults confirmed that losses of hexane as a result of inadequate stripping of the meal in the D‐T formed a very significant part (10–40%) of total hexane losses.
A new wide‐line NMR analyzer and its use in determining the solid‐liquid ratio in fat samples
Authors: Mansfield Peter B. 
Published: July 2007

AbstractA new, simple, inexpensive wide line NMR analyzer is commercially available and suitable for several applications in the oils and fats industry. Its use to determine the solid‐liquid ratio in fats has been studied in particular, and it has been found that the solids content of a fat can be determined at four temperatures in approximately one hour. The reproducibility of the measurements is 1% absolute solids. The results obtained are compared with those obtained by dilatometry on the same samples. Several different methods of calculation and operation were tried; differences in the results are given. Arguments for and against four particular methods of calibration are discussed.
Wide‐line NMR for product and process control in fat industries1
Authors: Wettstrom R. B. 
Published: July 2007

AbstractA modified method is described for the determination of the content of solid phase in fats at various temperatures using a Varian PA‐7 wide Une NMR instrument with temperature accessory. To avoid variations in instrument sensitivity a liquid soybean oil was used as reference. There was no need for corrections depending on the IV of the fat or the temperature. The optimal instrument settings were determined and the importance of a standardized temperature conditioning of the sample was confirmed. With the observance of proper conditions a standard deviation of 0.7% solid phase was obtained. Using this method a large number of samples can be examined with only a reasonable amount of work, but there is an increased demand for faster and more exact temperature conditioning of the samples, better stability and easier handling to fit more routine conditions. With these improvements the NMR method does offer some advantages for product control over solid fat index. However, for the time being the NMR method cannot be used for process control of hydrogenation because the need to condition the sample does not permit the determination of the result in less than 1 hr. On the other hand, a direct measurement of fat content of pressmeal gave a standard deviation (1.3% fat) too large for satisfactory production control.
Role of detergent builders in fabric washing formulations
Authors: Hollingsworth M. W. 
Published: July 2007

AbstractThe role of a detergent builder in fabric washing formulations is complex because the builder is multifunctional. The primary function of a builder is to counteract the detrimental effects of hardness ions (Ca2+ and Mg2+) which arise in the wash solution not only from the tap water but also from the washload. The need to control the free hardness ion level to 0.1 °FH is well established and is mainly required to release calcium bound soil and prevent further calcium soil interaction during the wash process. The most elegant way of doing this is with a sequestrant. Sodium triphosphate is the preferred material. Measurement of the equilibrium constants of sequestrants with Ca2+/Mg2+/Na+/H+ as a function of temperature and ionic strength allows prediction of free hardness ion levels over a wide range of conditions such as temperature, pH, water hardness, and dosage. Secondary functions such as specific adsorption effects are important, and a true builder will aid not only soil removal but alleviate soil redeposition.