bluuebunny/crossref_metadata_2025 huggingface dataset:
A multivariate analysis approach to the integration of proteomic and gene expression data
Authors: Fagan Ailís , Culhane Aedín C. , Higgins Desmond G.
Published: June 2007

In order to understand even the simplest cellular processes, we need to integrate proteomic, gene expression and other biomolecular data. To date, most computational approaches aimed at integrating proteomics and gene expression data use direct gene/protein correlation measures. However, due to post‐transcriptional and translational regulations, the correspondence between the expression of a gene and its protein is complicated. We apply a multivariate statistical method, co‐inertia analysis (CIA), to visualise gene and proteomic expression data stemming from the same biological samples. Principal components analysis or correspondence analysis can be used for data exploration on single datasets. CIA is then used to explore the relationships between two or more datasets. We further explore the data by projecting gene ontology (GO) information onto these plots to describe the cellular processes in action. We apply these techniques to gene expression and protein abundance data from studies of the human malarial parasite life cycle and the NCI‐60 cancer cell lines. In each case, we visualise gene expression, protein abundance and GO classes in the same low dimensional projections and identify GO classes that are likely to be of biological importance.
Subcellular proteomics of cell differentiation: Quantitative analysis of the plasma membrane proteome of Caco‐2 cells
Authors: Pshezhetsky Alexey V. , Fedjaev Michael , Ashmarina Lyudmila , Mazur Alexander , Budman Lorne , Sinnett Daniel , Labuda Damian , Beaulieu Jean‐François , Ménard Daniel , Nifant'ev Ilya , Levy Émile
Published: June 2007

Human colorectal carcinoma (Caco‐2) cells undergo in culture spontaneous enterocytic differentiation, characterized by polarization and appearance of the functional apical brush border membrane. To provide insights into the biology of differentiation, we have performed a comparative proteomic analysis of the plasma membranes from proliferating cells (PCs) and the apical membranes from differentiated cells (DCs). Proteins were resolved by SDS‐PAGE, in‐gel digested and analyzed by RP‐LC and MS/MS. Alternatively, proteins were digested in solution, and tryptic peptides were labeled with isotopic tags and analyzed by 2‐D LC followed by MS/MS. Among the 1125 proteins identified in both proteomes, 76 were found to be significantly increased in the membranes of DCs and 61 were increased in PCs. Majority of the proteins increased in the apical membranes were metabolic enzymes, proteins involved in the maintenance of cellular structure, transmembrane transporters, and proteins regulating vesicular transport. In contrast, majority of the proteins increased in the membranes of PCs were involved in gene expression, protein synthesis, and folding. Both groups contained many novel proteins with yet to be identified functions, which could provide potential new markers of the intestinal cells or of colorectal cancer.
Coalescence of droplets in viscoelastic matrix with diffuse interface under simple shear flow
Authors: Yu Wei , Zhou Chixing
Published: June 2007

The coalescence process of two droplets in simple shear flow was modeled and simulated by the diffuse interface method. The collision between two droplets was investigated. The systems with small Peclet number, which denotes highly diffuse ability of concentration, were found to coalesce faster and easier due to the overlap of interfacial layers. The effect of matrix elasticity on droplet coalescence was studied thoroughly. The matrix elasticity was found to decrease the hydrodynamic interactions between droplets, and delay the coalescence process. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1856–1869, 2007
On the crystallinity effect on the gas sorption in semicrystalline linear low density polyethylene (LLDPE)
Authors: Compañ Vicente , Del Castillo L. F. , Hernández S. I. , López‐González M. Mar , Riande Evaristo
Published: June 2007

This article describes the solubility of carbon dioxide, ethylene and propane in 1‐octene based polyethylene of 0.94, 0.92, 0.904, and 0.87 densities. The isotherms obtained in the gas sorption experimental device display a sorption behavior similar to that of glassy polymers. We apply the dual model to semicrystalline polymers assuming that Henry's sites are related to the amorphous phase, which decreases when the crystallinity percentage increases, whereas the surface of the crystalline phase acts as a Langmuir site with higher gas‐polymer affinity than glassy polymers. The good concordance of the calculated kD values, using the Flory‐Huggins theory of polymer diluent mixtures, with the experimental results suggest that Henry's gas sorption fulfills this theory and, therefore, it may be a suitable way to estimate polymer‐gas enthalpic interactions. Particularly, the variation of kD with the crystallinity fraction is exponential and the proportionality of the total sorption with the amorphous content seems only apparent. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1798–1807, 2007
Current challenges for FDA‐regulated bioanalytical laboratories for human (BA/BE) studies. Part I: defining the appropriate compliance standards – application of the principles of FDA GLP and FDA GMP to bioanalytical laboratories
Authors: Ocampo Arlene , Lum Steven , Chow Frank
Published: June 2007

This article is the first of a three‐part series that deals with current compliance issues/challenges for bioanalytical laboratories performing analysis for bioavailability/bioequivalence studies. Part 1 of this series provides the application of key elements from the Food and Drug Administration Good Laboratory Practices and the current Good Manufacturing Practices regulations as the framework for the implementation of sound quality systems in a bioanalytical laboratory to be in compliance with current regulatory expectations. Copyright © 2007 John Wiley & Sons, Ltd.
A factor in quality: information on client satisfaction/dissatisfaction
Authors: Constant Paul C
Published: June 2007

The interrelation of client satisfaction with quality of service or product produced is brought out in the discussion on the importance to know whether a client (customer) is satisfied or dissatisfied with a company's (contractor's) service or product. Nine factors to be considered in determining client satisfaction or dissatisfaction are discussed. An algorithm is given for determining the client's figure of merit, which gives a means for prioritizing clients to be contacted. The nine factors are types of clients, which includes advantages and disadvantages of clients by class and contact comparisons; criteria for selection of clients to be contacted; the four types of contact and considerations for types to use; those to make the contact; when to contact client; contactor training topics; analysis of results of contact findings; documentation of contacts: and follow‐up and follow‐through activities. Items concerning the contact plan also are given as well as a sample plan. The paper closes with a set of inferred conclusions. Copyright © 2007 John Wiley & Sons, Ltd.
Test article analyses in compliance with good laboratory practice in Japan: circumstances and changes
Authors: Namiki Harumi , Shigeta Tetsuya , Ino Yoshitaka , Kimura Kanzo , Inaba Katsutoshi , Kawasaki Sachio , Kitazaki Yasuhide , Imada Sumi
Published: June 2007

In Japan, many test facilities have been inspected by the monitoring agency since 1984 and inspectors pointed out some issues for improvement. The interest in test article analyses in support of Good Laboratory Practice (GLP)‐compliant studies has been rising for the last several years. This paper reports the advice and indications for improvement that were pointed out for test article analyses by the Japanese monitoring agency. In addition, the Japan Society of Quality Assurance (JSQA) conducted surveys using a questionnaire form in 2001 and 2004 in order to understand the present situation and the changes in Japanese test facilities that belong to the member companies of the GLP division of the JSQA. From the results of surveys, it was found that test article analyses have been performed under GLP, reflecting the requirements of the monitoring agency. Copyright © 2007 John Wiley & Sons, Ltd.
What's New?
Authors: Hattemer‐Apostel Rita
Published: June 2007

The What's New? section in the Quality Assurance Journal aims to draw attention to items of importance to QA professionals. There is usually a three‐month interval between final submission of manuscripts and distribution of the journal. For this issue, the entries in the What's New? section arise from the period of 1 September 2006 to 30 November 2006. If you feel that there is any other new information that should be brought to the attention of readers, please let us know by e‐mailing rha@verdandi.ch. Copyright © 2007 John Wiley & Sons, Ltd.
Testing equality of several functions: Analysis of single‐unit firing‐rate curves across multiple experimental conditions
Authors: Behseta Sam , Kass Robert E. , Moorman David E. , Olson Carl R.
Published: June 2007

We consider the problem of comparing noisy functions, here trial‐averaged neuronal firing‐rate curves, across multiple experimental conditions. Of interest are comparisons both within neurons and also among populations of individually recorded neurons. We propose likelihood ratio tests to perform comparisons either pointwise or globally over the entire experimental time. A simulation study of power demonstrates the strength of these tests even for moderate sample sizes. We implement these tests on a group of 233 neurons recorded from primate frontal oculomotor cortex, first, to screen for condition‐related differential activity and, second, to search for neurons displaying interesting time‐locked features that vary with condition. Copyright © 2007 John Wiley & Sons, Ltd.
First‐event or marginal estimation of cause‐specific hazards for analysing correlated multivariate failure‐time data?
Authors: Tai Bee‐Choo , De Stavola Bianca L. , de Gruttola Victor , Gebski Val , Machin David
Published: June 2007

In the analysis of multivariate failure‐time data, the effect of a treatment or an exposure on the
hazard of each failure type is sometimes evaluated using only the information on the first event that occurs in every individual, ignoring all events that follow. A Cox proportional hazards model may be fitted to such data, yielding a cause‐specific hazard ratio (HR) estimate of the exposure for each failure type conditional on surviving all other failure types. However, such an estimate would not fully utilize all the available information on event times. Alternatively, a marginal approach may be implemented to model the time distribution of each failure type beyond the subject's first failure to (any) second and later failures.

We investigate the performance of these two approaches by simulating positive and negative correlated event times from exponential distributions. Surprisingly, our results suggest that the first‐event‐only method (when multiple failures are possible) performs as well as the marginal method in most practical situations. Generally, for a modest sample size of 400, it is possible to achieve at least 85 per cent coverage of the true marginal HR with the first‐event method. Although the coverage is poor for a correlation of 0.7 and beyond, such a high correlation between competing event times may be biologically rather implausible. Copyright © 2007 John Wiley & Sons, Ltd.
Complete nonlinear response of reinforced concrete beams under cyclic loading
Authors: Bai Z. Z. , Au F. T. K. , Kwan A. K. H.
Published: June 2007

Complete nonlinear analysis is carried out for cyclically loaded reinforced concrete (RC) beams made of normal‐ and high‐strength concrete. The loading stage covers not only the pre‐peak stage but also the post‐peak stage in particular. The analysis is based on a numerical method that employs the actual stress–strain curves and takes into account the stress‐path dependence of concrete and steel reinforcement. The complete nonlinear behavior of RC beams under both non‐reversed and reversed cyclic loading is studied based on the moment–curvature relationship obtained. Generally, the response under cyclic loading is found to be dependent on the loading path in bending. The variation of neutral axis depth is different for under‐ and over‐reinforced sections during cyclic loading. The Bauschinger effect of steel reinforcement is insignificant for non‐reversed cyclic loading but notable for reversed cyclic loading, especially when the loading extends into the post‐peak stage. The beneficial effects of concrete tension stiffening are only observed at the service stage and are more significant for under‐reinforced RC beams than over‐reinforced ones. Copyright © 2007 John Wiley & Sons, Ltd.
Decentralized sliding mode control of multistory buildings
Authors: Monajemi‐Nezhad S. , Rofooei F. R.
Published: June 2007

In the present paper, a decentralized control algorithm is considered for actively controlling the response of flexible tall building structures under earthquake excitations. Sliding mode control is used as a base control algorithm and a decentralized scheme of that is presented. In the proposed approach, the building is divided into several substructures and for each subsystem a separate local control algorithm is designed. The control algorithm consists of the sliding surface and the reaching law equations. A numerical example is used to demonstrate the efficiency of the control algorithm in guaranteeing the system's global stability under the effects of subsystem interconnections and earthquake excitations. Copyright © 2007 John Wiley & Sons, Ltd.
On the Fixed Points of the Optimal Reward Operator in Stochastic Dynamic Programming with Discount Factor Greater than One
Authors: Hübner Gerhard
Published: June 2007

It is well‐known that in case of a discount factor β < 1 the optimal reward operator has a unique fixed point which equals the value of the infinite horizon problem. If β > 1 this is in general not true, but a fixed point may nevertheless exist. The existence of a unique fixed point is proved under some additional condition and a method of successive approximation is given. Applications of this algorithm and of policy iteration to estimates for values of the finite stage problems and for the turnpike planning horizon are discussed.
Eine verallgemeinerte Achsenausstrahlungslösung der Wellengleichung und die daraus resultierenden Überschallfelder
Authors: Wellmann J.
Published: June 2007

Aus der Grundlösung der Wellengleichung und den homogenen Potentialen nullter Ordnung wird eine verallgemeinerte Ausstrahlungslösung, die auf der x‐Achse singulär ist und stromauf des Machkegels verschwindet, entwickelt. Diese Lösung enthält die Multipole und die analytische Darstellung kegelsymmetrischer Felder als Sonderfall. Sie ist deshalb geeignet, im Rahmen der linearen Überschalltheorie Strömungsfelder um relativ schlanke Körper mit nicht‐kreisförmigem Querschnitt und deren Nachlauffelder zu erzeugen.
Rate Type Plastic Material with General Work‐Hardening
Authors: Tokuoka T.
Published: June 2007

A rate type plastic material is proposed. A scalar internal variable and a symmetric tensor internal variable are introduced. The constitutive and the evolutional equations are invariant for the change of time‐scale. Two sets of equations are assumed for the loading and the unloading state. Three material functions which define equations in the loading state are assumed to depend on the translated stress, to be pressure insensitive, and to have some symmetricities which imply no Bauschinger effect with respect to the translated stress. Three constant material functions are assumed in the unloading state. The yield criterion and the flow rule which are defined by the rate type constitutive equation may show the kinematic as well as the isotropic workhardening. Two special materials are presented, one has a generalized Huber‐von Mises yield criterion and the other has a generalized Tresca yield criterion. They are a generalization of the materials proposed by the author in the preceding paper.
Symmetrische Koppelkurven mit sechspunktig berührendem Scheitelkrümmungskreis
Authors: Jank Walther
Published: June 2007

Für die Synthese von gleichschenkeligen Gelenkvierecken, die eine symmetrische Koppelkurve mit bestapproximierendem Scheitelkrummungskreis erzeugen, werden einfache Formeln abgeleitet. Zur ersten Auswertung derselben wird überdies eine bequem verwendbare Kurventafel bereitgestellt.
Monotone Einschließung der Moore‐Penrose Pseudoinversen einer Matrix
Authors: Mönch W.
Published: June 2007

Es werden Iterationsverfahren vom Schulz‐Typ angegeben, die eine monotone Einschließung der Moore‐Penrose Pseudoinversen A+ einer vorgegebenen Matrix A erzeugen. Die Verfahren konvergieren überlinear gegen A+.
On Plane Plastic Flow of Compressible Solids
Authors: Telega J. J.
Published: June 2007

Equations of plane compressible flow of perfectly‐plastic solids are derived from a three‐dimensional, tensorially nonlinear theory of Sawczuk and Stutz. In plane flow the flow rule reduces to a linear relation. The flow law is, in general, not associated with the yield condition. The system of stress and velocity equations may be hyperbolic, parabolic or elliptic depending upon the material constants and dilatancy. The second order effects manifest in the expressions describing the stress and velocity fields, the yield condition and the power of dissipation.
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Published: June 2007

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Ein Modell für eine Klasse von Aufgaben optimaler Steuerung
Authors: Bittner Leonhard
Published: June 2007

In dieser Arbeit wird eine abstrakte Steuerungsaufgabe formuliert. Dafür werden notwendige Optimalitätsbedingungen hergeleitet. Das untersuchte Modell stellt eine um zusätzliche Nebenbedingungen erweiterte Fassung des in [1] betrachteten dar und hat eine gewisse Ähnlichkeit zu einem nichtlinearen Optimierungsproblem in Banach‐Räumen. Es ergeben sich notwendige Optimalitätsbedingungen in Form von Variationsungleichungen, die bei passender Konkretisierung Maximumprinzipe und Transversalitätsbedingungen liefern.
Auxiliary Functions for Non‐Stationary One‐Dimensional Diffusion under Forced Convection. Basic Properties and Applications
Authors: Kahlig P.
Published: June 2007

In the first part, basic properties of a class of functions (called Omega‐functions) are investigated, e.g. series representation, recurrence relation, asymptotic behavior. In the second part, beginning with Section 12, the solution of some versions of the diffusion equation by a series of Omega‐functions is treated. Omega‐functions may be used as auxiliary functions in the case of onedimensional non‐stationary diffusion under forced convection with or without removal process.
Sprungrelationen und zugehörige Transportgleichungen für die Bachschen Feldgleichungen
Authors: Günther Paul
Published: June 2007

In a general curved space‐time, for which the Bach‐field‐equations are fulfilled, the jump‐relations for the jumps of the fourth derivatives of the fundamental tensor on a characteristic surface are considered. In contrast to the Einstein equations in general the jump‐tensor has not only pure transversal, but also longitudinal‐transversal components. The jump‐tensor satisfies a linear transport equation of second order, the longitudinal‐transversal components satisfy a separate transport equation of first order.
The Initial‐Boundary‐Value Problems in the Theory of Micropolar Fluids
Authors: Sava V. A.
Published: June 2007

The author considers the existence of solutions of the initial‐boundary‐value problem for the equations which describe the flow of incompressible micropolar fluids, by using a related, simpler set of equations and then taking a limit.
Bestimmung der Temperaturverteilung in einem stromdurchflossenen Körper
Authors: Gröger K. , Schleiff M.
Published: June 2007

The present paper is concerned with a system of equations describing the stationary interaction of temperature and electrical tension in a 3‐dimensional body in the case that the electrical conductivity depends on the temperature. It is shown that this system is solvable. This is achieved by reduction of the system to an equation with a pseudo‐monotone operator. A short report is given on attempts to determine temperature and tension in an electrode numerically.
Liquid C‐18 saturated acids derived from linseed oil
Authors: Friedrich J. P. , Teeter H. M. , Cowan J. C. , McManis G. E.
Published: June 2007

Liquid C‐18 saturated monocarboxylic acids that fail to crystallize at 蜢70ŶC. have been prepared from linseed oil, linolenic acid, and tung oil. Heating one part of linseed oil in three parts of glycol (weight‐volume ratio) at 295ŶC. for 1 hr. with 25% excess sodium hydroxide, followed by distillation and hydrogenation of the resulting free fatty acid monomers and separation of the straight‐chain components by low temperature crystallization from acetone, yielded these liquid acids.

The relative proportions of cyclic acids, straight‐chain monomeric acids, and polymer varied with the type of starting material and with the conditions employed. Cyclic acids in excess of 30% yields were obtained from linseed oil. Some hydroxylation of the fatty acids apparently takes place during cyclization; the amount increases with ascending temperatures, as evidenced by a rise in polyester content of the polymer fraction.

Evidence indicates that the bulk of the unhydrogenated cyclic acids are vicinal disubstituted cyclohexadienes. Gas chromatography of the cyclic acids hydrogenated to an iodine value <1 shows that there are several components. These have not as yet been separated and positively identified.
Solubilization of fatty soils by a radiotracer technique
Authors: Ginn M. E. , Brown E. L. , Harris J. C.
Published: June 2007

A technique for measurement of solubilized radiotagged triolein and tristearin fatty soils is described. By using surfactant solutions under standardized conditions of temperature and agitation, the solubilized soils are removed from emulsified materials by filtration through 0.1 and 0.01 micron‐pore size of filters. The radiotagged fat is recovered by solvent extraction from the clear filtrate by salting‐out under centrifugal force and is measured by conventional counting technique.

The nonionic alkanol‐ and alkylphenol‐ethylene oxide (EO) adducts solubilized up to 0.058% triolein (weight percentage at 75ŶC.) while anionic surfactant and sodium tripolyphosphate solubilization was negligible. These findings suggest for these nonionics that solubilization is one of the main, if not the controlling factor in the mechanism of soil removal. Nonionic solubilization was at a maximum for 10 molar EO adducts and at near cloud‐point temperatures.

For the same surfactant more triolein than tristearin was solubilized, possibly on account of spatial considerations. For tridecanol‐10 EO at 0.25% the heat of solubilization of triolein, खHs, was 15 kcal/mole while the heat of micellization of the adduct was 1.3 kcal/mole of adduct. Differences in the colloidal ion lengths of the micelles and their aggregation numbers may explain the differences in solubilization between the anionic and nonionic surfactants tested.
Carbonyls in oxidizing fat. V. The composition of neutral volatile monocarbonyl compounds from autoxidized oleate, linoleate, linolenate esters, and fats
Authors: Gaddis A. M. , Ellis Rex , Currie G. T.
Published: June 2007

The steam volatile monocarbonyl compounds in mildly autoxidized esters of oleic, linoleic, linolenic acids, and animal and vegetable fats were quantitatively estimated. The major aldehydes in oleate and linoleate were those that might be expected from the scission of reported monomeric hydroperoxide isomers. The predominance of hept‐2,4‐dienal and propanal in linolenate suggested that the major monomeric hydroperoxides were 12‐and 16‐hydroperoxy conjugated dienoic isomers. The number of minor aldehydes increased with degree of unsaturation of the fatty acid. The amounts of monocarbonyl compounds in the fats examined generally agreed with their average fatty acid composition. Appreciable amounts of heptanal in lamb and beef fat and heptanal and decanal in butterfat, under the conditions of oxidation, could not have come from the three unsaturated acids. Heating at 165ŶC. in all samples increased the proportions of the most unsaturated major aldehydes.
Enzymatic transesterification of palm olein with nonspecific and 1,3‐specific lipases
Authors: Ghazali H. M. , Hamidah S. , Che Man Y. B.
Published: June 2007

The enzymatic transesterification of palm olein was conducted in a low‐moisture medium with nonspecific and 1,3‐specific lipases from microbial sources. The enzymes were first immobilized on Celite, lyophilized for 4 h and then added to a reaction medium that consisted of 10% (wt/vol) palm olein in water‐saturated hexane. The catalytic performance of the enzymes was evaluated by determining the changes in triglyceride (TG) composition and concentrations by reverse‐phase high‐performance liquid chromatography (HPLC) and the formation of free fatty acids by titration. Studies with lipase fromCandida rugosa showed that the degree of hydrolysis was reduced by drying the immobilized preparation and that the best drying time was 4 h. In all cases, the transesterification process resulted in the formation of PPP, a TG initially undetected in the oil, and increases in the concentrations of OOO (1.3–2.1‐fold), OOL (1.7–4.5‐fold), and OLL (1.7–4.3‐fold), where P, O, and L are palmitic, oleic, and linoleic acids, respectively. SOS (where S is stearic acid), another TG not detected in the oil, was synthesized byRhizomucor miehei andPseudomonas lipases, with the latter producing more of this TG. There was a corresponding decrease in the concentrations of POP, PLP, POO, and POL. PPP concentration ranged from 1.9% (w/w) forMucor javanicus lipase to 6.2% (w/w) forPseudomonas lipase after 24 h. The greatest degree and fastest rate of change were caused byPseudomonas lipase, followed by the enzymes fromR. miehei andAspergillus niger. The effects of transesterification and hydrolysis of palm olein by the various lipases resulted in changes in the overall degree of saturation of the triglyceride components. There seems to be no clear correlation between the enzyme positional specificity and the products formed. Possible mechanisms for the formation of PPP, OOL, OLL, OOO, and SOS are discussed.
Alternative hydrocarbon solvents for cottonseed extraction: Plant trials
Authors: Wan P. J. , Hron R. J. , Dowd M. K. , Kuk M. S. , Conkerton E. J.
Published: June 2007

Hexane has been used for decades to extract oil from cottonseed and is still the solvent of choice for the edible‐oil industry. Due to increased regulations as a result of the 1990 Clean Air Act and potential health risks, the edible‐oil extraction industry urgently needs an alternate hydrocarbon solvent to replace hexane. Based on laboratory‐scale extraction tests, two hydrocarbon solvents, heptane and isohexane, were recommended as potential replacements for hexane. A cottonseed processing mill with a 270 MT/day (300 tons/day) capacity agreed to test both solvents with their expander‐solvent process. Extraction efficiencies of isohexane and heptane, judged by extraction time and residual oil in meal, refined and bleached color of miscella refined oil, and solvent loss, were comparable to that of hexane. However, fewer problems were encountered with the lower‐boiling isohexane than with the higher‐boiling heptane. With isohexane, the daily throughput increased more than 20%, and natural gas consumption decreased more than 40% as compared to hexane.
n‐fatty acids: Comparison of published densities and molar volumes
Authors: Fisher Charles H.
Published: June 2007

Because some publishedn‐fatty acid densities and molar volumes disagree significantly with others, an attempt was made, based primarily on the principle of homology, to distinguish between reasonably accurate and inaccurate data. Literature densities compatible with each other and with requirements of homology (including limiting densities) were identified. These densities, considered to be at least reasonably accurate, were used as standards and compared with other published densities. Most publishedn‐fatty acid densities, judged by these criteria, appear to be reasonably accurate.
Determination of oxidation stability of soybean oil with the oxidative stability instrument: Operation parameter effects
Authors: Hill Steven E. , Perkins Edward G.
Published: June 2007

Operation parameters of the oil stability index instrument were evaluated to determine their effect on the oxidative stability of commercial soybean oil. A factorial design was developed to evaluate the following three parameters, each at two levels, sample weight (2.5 or 5.0 g), conductivity tube temperature (20 or 30°C), and air flow rate (12 or 20 L/h), for a total of eight observations. Significance testing indicated that sample size and air flow rate affected oil oxidative stability independently (P<0.001), but not in combination. The conductivity tube temperature did not affect the oxidation stability index.
Carica papaya latex lipase:sn‐3 stereoselectivity or short‐chain selectivity? Model chiral triglycerides are removing the ambiguity
Authors: Villeneuve P. , Pina M. , Montet D. , Graille J.
Published: June 2007

Short‐chain fatty acids are usually located at positionsn‐3 in natural triglycerides, particulary in dairy fats. As a result, it is extremely difficult to differentiate betweensn‐3 stereospecificity and short‐chain typoselectivity in many lipases and acyltransferases that perform in this way. This ambiguity can be removed through successive use of a chiral triglyceride with a short fatty acid in positionsn‐1 and of its racemic in controlled hydrolysis reactions. After checking that the proposed method effectively confirmed the type of activity of control biocatalysts (Candida cylindracea nonspecific lipase andMucor miehei 1–3 regiospecific lipase), we confirmed thatCarica papaya latex has a strictsn‐3 stereospecificity.
Measurement and assessment of substrates containing fluorescent whitening agents
Authors: Anders G. , Daul C.
Published: June 2007

White, as a color sensation, can be determined by colorimetric methods of measurement. With other than colorimetric methods, no satisfactory correlation between measured value and visual assessment can be expected. The contribution of hue, saturation and luminosity to the degree of whiteness as found by six formulas widely used in industry was analyzed and the results were plotted in the form of a graph. An easy‐to‐use nomogram for whiteness determination was developed, based on the CIE 1931 2°‐color system. Another nomogram is presented which provides an easy means to determine the hue of a sample treated with fluorescent whiteining agents (FWAs). The new whiteness determination is based on the measurement of true tristimulus values for fluorescent samples using the new International Commission on Illumination standard illuminant D 65. The magnitude of the just perceptible difference in whiteness was determined in a panel test using 11 samples and 22 observers. The results were evaluated statistically. Pending standardization of an illuminant, not only for colorimetric measurements, but also for visual assessment of white samples containing FWAs, it would scarcely seem possible to arrive at a more accurate determination of degrees of whiteness. All visual rankings of fluorescent white substrates are widely scattered around a mean value for the different phases of natural daylight. The relative energy emitted by artificial daylight lamps in the near UV region is insufficient in many cases. Xenon lamps are quite satisfactory for instrumental evaluation. In an internationally approved system, with a known hue preference, it would be possible to compare an objective measured value with each subjective result obtained by visual evaluation.
Oxidation at intermediate moisture contents
Authors: Labuza T. P. , Heidelbaugh N. D. , Silver M. , Karel M.
Published: June 2007

In the study of the oxidation rate of methyl linoleate in protein and cellulose systems, a prooxidant effect was found at intermediate moisture contents. At low water content, water hydrates metals and hydrogen bonds with peroxides, and an overall decrease in the rate of lipid oxidation results. With an increase in the water content to the region with a water activity of 0.6 to 0.7, the water predominantly acts as a solvent to dissolve and mobilize previously unavailable trace metals with the result of increased oxidation rates. Use of chelating agents such as ethylenediaminetetraacetic acid and citric acid reduced oxidation significantly although some antioxidant activity was also observed for butylated hydroxyanisole. These results have important implications in the preparation of intermediate moisture foods.
A simplified method for the evaluation of antioxidants
Authors: Miller H. E.
Published: June 2007

A procedure is described for rapid evaluation of antioxidants. Dilute aqueous emulsions of an antioxidant, carotene and lipid were prepared in spectrometer tubes. The oxidative destruction of carotene in the emulsion was observed directly with a colorimeter. The antioxidants were then evaluated according to their effect on the rate of carotene decolorization.
Some problems in altering the gossypol content of cottonseed through breeding
Authors: Lee Joshua A.
Published: June 2007

Cultivated cottons have small, pigment‐bearing glands in their embryonic tissues or seed meats. These glands contain gossypol, a polyphenolic substance toxic to various animals. The presence of glands in cottonseed is controlled by alleles at two loci. Substitution of mutant alleles for active alleles at both loci produce cottons that are devoid of glands and gossypol. Glandlessness is thus a character of great potential worth, and breeders seek to develop glandless varieties of cotton which give high yields of quality fiber. Although some success has been achieved, recent work shows that both glandless genes are linked to factors which reduce yield of fiber. Methods for ameliorating these difficulties are discussed.
Hydroformylation of unsaturated fatty esters
Authors: Frankel E. N. , Metlin S. , Rohwedder W. K. , Wender I.
Published: June 2007

Unsaturated fatty esters and vegetable oils were hydroformylated with H2 and CO (3500–4600 psi) and Co2(CO)8 to give fatty aldehydes at 100–110 C and fatty alcohols at 175–190 C. Yields of distillable C19 oxo products varied from 42% to 84%. Distilled products contained from 50% to 90% branched isomers and from 4% to 16% linear isomers. The proportion of linear isomers increased at higher reaction temperatures and in the presence of tributylphosphine‐cobalt carbonyl complex. Linear and branched hydroxy products were separated by silicic acid column, thin‐layer, and gas‐liquid chromatography. The linear hydroxy product (from oleate and linoleate) was identified as methyl 19‐hydroxynonadecanoate by nuclear magnetic resonance and mass spectrometry. Isomeric branched products were analyzed by mass spectrometry as the diester derivatives. They were identified as a mixture of 5‐ to 13‐carbomethoxy methyl octadecanoate.
Hydrogenation of unsaturated fatty acids to unsaturated fatty alcohols: II. Kinetics and mechanism of the reaction using Cu and Cd oleates as catalysts
Authors: Richter J. D. , van den Berg P. J.
Published: June 2007

The kinetics and mechanism of the Cu and Cd‐soap‐catalyzed hydrogenation of oleic acid have been studied. The reaction is first order in Cd and H2, and also first order in Cu if the double bond is completely preserved during reduction of the carboxyl group to the hydroxyl group. It will deviate from this order if the selectivity is lower owing to an increased Cu concentration. The reaction rate‐determining step is independent of the Cd concentration. Its activation energy, of 13.4 kcal/mole, corresponds to that of the chemisorption of hydrogen on Cu. Unsaturated and saturated fatty acids of the same chain length have the same reaction rate. A decrease of the chain length causes a decrease in the reaction rate and in the final degree of conversion. Water and low molecular weight acids have an inhibitory effect on the reaction. A reaction mechanism is proposed which is based on the assumption that cadmium oleate plays a double role: it stabilizes the copper sol and is intermediate for the hydrogenation.
Oxidative stability of safflower oil
Authors: Bratcher Sharon S. , Kemmerer A. R. , Rubis D. D.
Published: June 2007

Oils from a number of varieties of safflower (Carthamus tinctorius L.) seeds (achene) were measured for oxidative stability by the gain in weight method. The induction periods of oils containing 75% to 80% linoleic acid ranged from 288 to 715 hr. Safflower oils containing 79% to 80% oleic acid and only 11% to 15% linoleic acid had induction periods ranging from 1274 to 2374 hr. No correlation between induction period and total tocopherol content was observed. However, there were indications that oils from pigmented seeds were less stable than oils from pigmentless seeds. Blending of an oil containing a high amount of linoleic acid with an oil containing a high amount of oleic acid gave a blend with an induction period intermediate between the two. However, the induction period was considerably less than the theoretical average calculated for the mixture.
The formation of 1‐octen‐3‐ol in soybeans during soaking
Authors: Badenhop A. F. , Wilkens W. F.
Published: June 2007

The soaking of soybeans in water as a pretreatment for soy milk manufacture was found to result in the production of significant quantities of 1‐octen‐3‐ol. The amount of this compound formed at a soak temperature of 50 C increased with length of soak time and reached a maximum after approximately 6 hr. The rate of formation had a pH optimum of 6–7. A pure fraction of 1‐octen‐3‐ol, isolated by a preparative GLC technique, was found to be levorotatory ([a]D17 = −11.7; [a]D13 = −11.8). Based on these findings, the mode of formation of 1‐octen‐3‐ol in this case is presumed to be enzymatic. The flavor threshold of 1‐octen‐3‐ol in soy milk was determined to be between 0.5 and 1.0 ppm.
Atmospheric‐pressure ionization mass‐spectrometric analysis of new anionic surfactants: The alkylpolyglucoside esters
Authors: Facino Roberto Maffei , Carini Marina , Depta Gabriele , Bernardi Paolo , Casetta Bruno
Published: June 2007

Atmospheric‐pressure ionization mass spectrometry has been successfully applied to characterization of a new class of anionic surfactants, the alkylpolyglucoside esters of sulfosuccinic, citric and tartaric acid. Complex mixtures of final and intermediate products were injected directly into the ion source without prior chromatographic separation. The constituents were identified on the basis of quasi‐molecular ions: cationized ions or solute‐solute cluster ions in positive‐ion mode, and deprotonated ions in negative‐ion mode. The mass‐spectrometric data show that all three final products contain one nonionic and two different types of anionic surfactants. The “real time,” highly sensitive mass‐spectrometric approach proposed here is well suited for quality control testing of tensides, to ensure the safety of the final product, and for the validation of the manufacturing process, because it is able to identify the individual components of the mixture.
Protease stabilization by highly concentrated anionic surfactant mixtures
Authors: Lalonde Jim , Witte E. Jane , O’Connell Mary L. , Holliday Lynn
Published: June 2007

We have found that anionic surfactants such as linear alkylbenzene sulfonate (LAS) can solubilize proteases in a substantially nonaqueous environment without loss of proteolytic activity. Moreover, in mixtures of anionic and nonionic surfactants with a moderate amount of water (water less than 30 wt%), controlled levels of LAS and water solubilize proteases; yet, in these concentrated surfactant mixtures, enzymes maintain their activity for extended periods. Experimental design techniques have been used to delineate the relationship between protease stability and the water, pH and anionic surfactant levels in these surfactant concentrates. As the sum of water and LAS levels is increased, maximum enzyme stability is observed, after which stability falls off. At low water and LAS levels (sum of both <20%), protease solubility is low, while at high levels of water and LAS (sum of LAS and water >45%), denaturation predominates. Additionally, we have developed a new and simple method to predict protease stability by which a synthetic peptide is used to measure protease activity directly in the surfactant concentrate. From the application of this new technique to our system and to commercial liquid detergent formulations, it is apparent that water facilitates the loss of activity of proteases in surfactant concentrates by increasing the rate of autolysis.
Enzymatic synthesis of polyglycerol‐fatty acid esters in a solvent‐free system
Authors: Charlemagne D. , Legoy M. D.
Published: June 2007

The enzymatic transesterification of fatty acid methyl esters from vegetable oil and polyglycerol has been successfully performed in the presence of Lipozyme without any solvent. The optimal conditions to obtain a mixture with lipophilic tensioactive properties were found to be a molar ratio of fatty acid methyl esters and polyglycerol of 1.33:1 at 60°C. Evaporation of the methanol produced in this reaction increased the yield of the reaction. Moreover, for this reaction, adsorption of the polyol on silica gel prior to the transesterification allowed the completion of the reaction and improved the kinetic properties. Hydrophile‐lipophile balance and surface activity of the polyglycerol esters were measured to determine the emulsifying properties of these molecules.
Reaction of sodium perborate with a chlorinated cyclic hindered amine (TMP‐Cl): I. Quantitative evaluation of active oxygen species in fabric bleaching
Authors: Fujiwara Masami , Tamura Takamitsu , Akabane Yasuhiro
Published: June 2007

The reaction of N‐chloro‐4‐hydroxy‐2,2,6,6‐tetramethylpiperidine (TMP‐Cl) with sodium perborate (PB) was investigated with special reference to the generation of singlet oxygen and the possible application to a new oxidative bleaching process. Generation of the singlet oxygen (1O2), the hydroxyl radical (HO·) and superoxide anion radical (O2·−) in the PB/TMP‐Cl mixed solution was confirmed by the trapping reagent method. From the results of another experiment, in which the bleaching abilities of each active oxygen species were confirmed, the main active oxygen species contributing to the bleaching of purpurogallin, the skeleton of black tea pigment, in the PB/TMP‐Cl system was concluded to be1O2.
Influence of 2‐phenyl alkane and tetralin content on solubility and viscosity of linear alkylbenzene sulfonate
Authors: Cohen L. , Vergara R. , Moreno A. , Berna J. L.
Published: June 2007

Cloud and clear points and viscosities of linear alkylbenzene sulfonates (LAS) have been determined as a function of 2‐phenyl alkane and/or tetralin content over a wide interval. While the 2‐phenyl content significantly affects the solubility, tetralins have a marked depressive effect on viscosity. The investigation has established that LAS solubility can be explained by assuming eutectic types of isomer and homolog mixtures, which are dependent on internal to external isomer ratios.
Aggregation of unsaturated long‐chain fatty alcohols in nonaqueous systems
Authors: Dunn R. O. , Bagby M. O.
Published: June 2007

Aggregation and related phenomena in nonaqueous binary and ternary solutions containing unsaturated long‐chain fatty alcohol amphiphiles have been studied. Six C18 fatty alcohols were studied—oleyl alcohol (9Z‐octadecen‐1‐ol), elaidyl alcohol (9E‐octadecen‐1‐ol), linoleyl alcohol (9Z, 12Z‐octadecadien‐1‐ol), elaidolinoleyl alcohol (9E, 12E‐octadecadien‐1‐ol), linolenyl alcohol (9Z, 12Z, 15Z‐octadecatrien‐1‐ol) and elaidolinolenyl alcohol (9E, 12E, 15E‐octadecatrien‐1‐ol). Equivalent conductivity and photon correlation spectroscopy confirmed that unsaturated long‐chain fatty alcohols form large and polydisperse aggregates in methanol. Critical micelle concentration (CMC) results showed that the degree of unsaturation and configuration of the double bonds in the fatty alcohol significantly influences aggregation. Aggregation of oleyl alcohol in a series of straight and branched medium‐chainlength (C3‐C8) alkanol solvents was studied. For shorter‐chained alkanols (C1‐C4), decreasing solvent dielectric constant decreases the CMC; however, for longer‐chained alkanols (C4‐C8), no significant effects occurred on the CMC. The effect of solubilized soybean oil on the viscosity of long‐chain fatty alcohol/methanol solutions was also analyzed. Relative viscosity results were consistent with those expected for microemulsions. Although preliminary in nature, these results generally support the notion that soybean oil is solubilized by incorporation into large soybean oil‐in‐fatty alcohol aggregates in methanol solvent, resembling a nonaqueous detergentless microemulsion.
Study of the ditallowdimethylammonium chloride interaction with cellulose
Authors: Crutzen André M.
Published: June 2007

From a theoretical standpoint, the driving force for the deposition of ditallowdimethylammonium chloride (“DTDMAC” or “quat”) onto cotton must be distinguished from the nature of its interaction with cellulose. We found that the driving force is purely hydrophobic. Due to its strong hydrophobicity, DTDMAC is expelled out of the aqueous rinse bath and deposits onto available surfaces. Besides its tendency not to leave the cotton surface and return to solution (hydrophobic effect), it binds to cellulose by weak London dispersion forces. A strong Coulombic interaction occurs only when a negative charge is present. Consequently, the strong affinity of DTDMAC for cellulose mainly results from the large specific surface area of the fiber; negative charges play a secondary role. Much experimental evidence supports the hydrophobic nature of DTDMAC adsorption onto cellulose. DTDMAC deposits onto charge‐free surfaces; its deposition is mainly governed by the available surface area, not by the surface nature. The hydrophobic nature of the interaction of DTDMAC with cotton may be displayed and distinguished from electrostatic binding. Structural effects demonstrate the correlation between hydrophobicity, deposition and the softening power of quaternaries. This model proposes a single mechanism to account for the deposition of DTDMAC onto cotton and synthetics. It is consistent with experimental facts that remain unexplained by the electrostatic model.
The interaction between co‐polymer of vinylpyrrolidone and vinylacetate and anionic surfactants in aqueous solutions
Authors: Esumi Kunio , Maekawa Tetsuya
Published: June 2007

The interaction of co‐polymers of vinylpyrrolidone‐vinylacetate with anionic surfactants, such as lithium dodecyl sulfate (LiDS), lithium perfluorooctane sulfonate (LiFOS) in aqueous solution, has been studied. When the content of vinylacetate in the co‐polymers increases, reduction in the surface tension of co‐polymers alone becomes significant. In mixtures of co‐polymers and surfactants, co‐polymer‐LiFOS complexes are formed at lower surfactant concentration than that of co‐polymer‐LiDS. The micropolarity of the co‐polymers‐surfactant complexes depends on the composition of co‐polymers and is higher for co‐polymer‐LiFOS than that for co‐polymer‐LiDS. Further, the solubilization behavior of α‐(o‐tolylazo‐)‐β‐naphthylamine (Yellow OB) (Tokyo Kasei Co., Ltd., Tokyo, Japan) in the co‐polymer‐surfactant complexes is almost independent of the co‐polymer composition, but different from the surfactants, where a very low solubilized amount of Yellow OB is observed for co‐polymer‐LiFOS.