bluuebunny/crossref_metadata_2025 huggingface dataset:
Selective surgery and adjuvant therapy based on risk classifications of well‐differentiated thyroid cancer
Authors: Cross S. , Wei J.P. , Kim S. , Brams D.M.
Published: November 2006

Background

The prognosis of well‐differentiated thyroid cancer has been stratified into low‐ and high‐risk groups. These risk groups can be used to predict prognosis and to guide treatment.

Methods

Retrospective study of 962 patients with well‐differentiated thyroid cancer treated from 1940 to 1998. Stratification into low‐ and high‐risk groups based on age, metastases, extent, and size (AMES). Effects on survival of surgery, lymph node dissection, and radiation therapy were examined.

Results

Seven hundred twenty‐eight cases were papillary and 234 were follicular carcinoma. Seven hundred‐fifty cases were low risk and 207 high risk. Twenty‐year survival was 97.4% in the low‐risk patients and 54.0% in high‐risk patients (P < 0.001); it was 63.2% in the younger high‐risk group and 41.0% in the older high‐risk group (P < 0.001). Older high‐risk patients had a survival advantage with bilateral thyroidectomy. Extent of surgery did not change survival in either the younger high‐risk group or the low‐risk group. Lymph node dissection and radioactive iodine ablation did not have an impact on survival.

Discussion

Well‐differentiated thyroid cancer in low‐risk patients has a favorable outcome regardless of treatment. Low‐risk patients can be safely treated with unilateral thyroidectomy alone. Risk stratification with a modification of the AMES criteria can be used to guide treatment. J. Surg. Oncol. 2006;94:678–682. © 2006 Wiley‐Liss, Inc.
Red Emitting Diphenylpyrrolopyrrole (DPP)‐Based Polymers Prepared by Stille and Heck Coupling
Authors: Zhu Yu , Heim Ingo , Tieke Bernd
Published: November 2006

Summary: Six new soluble conjugated polymers are described, which were prepared by Stille and Heck polycondensation reactions. They alternately consist of dialkylated 1,4‐diketo‐3,6‐diphenyl‐pyrrolo[3,4‐c]pyrrole (DPP) units and divinylbenzene or thiophene‐based units. The polymers were prepared from 1,4‐diketo‐2,5‐dialkyl‐3,6‐di(4‐bromophenyl)‐pyrrolo[3,4‐c]pyrrole with alkyl being hexyl (1a), methyl (1b), and 2‐ethylhexyl (1c) and 2,5‐bis(tributylstannyl)thiophene (2), 5,5′‐bis(tributylstannyl)bithiophene (3), 3,4‐ethylenedioxythiophene (4) and divinylbenzene (5). The new polymers exhibit brilliant red purple color and strong photoluminescence in common organic solvents. The DPP‐phenylenevinylene copolymers exhibit molecular weights up to 41 000 Da, and the poly(DPP‐thienylene)s up to 12 200 Da. In chloroform, the poly(DPP‐thienylene)s exhibit absorption and photoluminescence maxima up to 560 and 624 nm, respectively, the corresponding maxima of the poly(DPP‐phenylenevinylene)s are at 529 and 640 nm, respectively. Quantum yields of fluorescence up to 36% were determined. Cyclic voltammetric studies indicate quasi‐reversible oxidation (p‐doping) of the poly(DPP‐thienylene)s and irreversible reduction (n‐doping) of all polymers.

Molecular structure of polymers.

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Molecular structure of polymers.
Thermal Behavior of Ring‐Band versus Maltese‐Cross Spherulites: Case of Monomorphic Poly(ethylene adipate)
Authors: Woo Eamor M. , Wu Pi Ling , Wu Ming Chien , Yan Kai Cheng
Published: November 2006

Summary: Two types of spherulites, extinction‐ring and Maltese‐cross, in poly(ethylene adipate) (PEA) were identified, isolated, and separately characterized using DSC and polarized‐light optical microscopy (POM). Ring‐band spherulites in PEA occurred only in a very narrow temperature range roughly between 25 and 30 °C, while Maltese‐cross spherulites at 35 °C and above or at 20 °C and below. Thermal behavior of ring‐spherulites is interpreted, analyzed, and compared to that of Maltese‐cross spherulites. The thermal behavior, like the morphology, was found to be significantly different between these two types of spherulites. Among the three multiple melting peaks in PEA, the highest P3 is proven to be related to melting of lamellae in the ring‐band spherulites; P1 and P2, whose relative extent of overlapping is dependent on the temperature of crystallization, are related to melting of lamellae in the regular ringless spherulites. This study has provided urgent and timely evidence for one major step further in the interpretation of relationships between the thermal behavior, melting, and extinction‐ring versus Maltese‐cross spherulites in semi‐crystalline polymers.

DSC curves (10 °C · min−1, scanned from where the trace begins) for: (a) ring‐spherulites in PEA crystallized at 30 °C for 90 min, (b) sample‐(a) heated to 50 °C for 1 min, and (c) sample‐(a) heated to 50 °C, then quenched to 20 °C.

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DSC curves (10 °C · min−1, scanned from where the trace begins) for: (a) ring‐spherulites in PEA crystallized at 30 °C for 90 min, (b) sample‐(a) heated to 50 °C for 1 min, and (c) sample‐(a) heated to 50 °C, then quenched to 20 °C.
The Use of Solution Viscosity to Characterize Single‐Walled Carbon Nanotube Dispersions
Authors: Grady Brian P.
Published: November 2006

Summary: A recent report by Agarwal and coworkers (I. Cotiuga, F. Picchioni, U. S. Agarwal, D. Wouters, J. Loos, P. J. Lemstra, Macromol. Rapid Commun. 2006, 27, 1073) has shown that solution viscosity measured in a capillary rheometer can be used to monitor the dispersion quality of SWNTs. They used solution viscosity to determine the optimal sonication time. Their method is compared and contrasted here with other methods used to monitor dispersion quality, and it is argued that it has some advantages over other methods. Specifically, the method of Agarwal and coworkers is quick to apply, and gives a reliable single‐parameter measure of the relative quality of a SWNT dispersion.

Change in solution viscosity with sonication time and the corresponding nature of the dispersed carbon nanotubes.

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Change in solution viscosity with sonication time and the corresponding nature of the dispersed carbon nanotubes.
Thermo‐Reversible Hydrogels Based on Poly(N,N‐diethylacrylamide)‐block‐poly(acrylic acid)‐block‐poly(N,N‐diethylacrylamide) Double Hydrophilic Triblock Copolymer
Authors: Angelopoulos Sotirios A. , Tsitsilianis Constantinos
Published: November 2006

Summary: A novel double hydrophilic poly(N,N‐diethylacrylamide)‐poly(acrylic acid)‐poly(N,N‐diethylacrylamide) (PDEAAm‐PAA‐PDEAAm) triblock copolymer was synthesized by sequential anionic polymerization and modification of the poly(tert‐butyl acrylate) middle block by selective hydrolysis and neutralization to its ionic functions. Due to the pH‐sensitivity of the PAA central block and the thermo‐sensitivity of the PDEAAm end‐blocks, it exhibits responsive behavior in aqueous media. At low temperatures and high pH, it is molecularly dissolved while at temperatures above the LCST of the PDEAAm end‐blocks, a sol–gel transition was observed which should be ascribed to the formation of a three‐dimensional transient network comprising PDEAAm hydrophobic physical crosslinks interconnected by PAA negatively charged elastic chains. The sol–gel transition and the rheological properties of the physical gel are strongly influenced by the presence of salt.

Temperature induced sol–gel transition in PDEAAm‐PAA‐PDEAAm aqueous solutions.

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Temperature induced sol–gel transition in PDEAAm‐PAA‐PDEAAm aqueous solutions.
Characteristics of PVdF‐HFP/TiO2 Composite Electrolytes Prepared by a Phase Inversion Technique Using Dimethyl Acetamide Solvent and Water Non‐Solvent
Authors: Kim Kwang Man , Kim Jin‐Chul , Ryu Kwang Sun
Published: November 2006

Summary: Highly porous poly[(vinylidene fluoride)‐co‐hexafluoropropylene] (PVdF‐HFP)/TiO2 membranes were prepared by a phase inversion technique, using dimethyl acetamide (DMAc) as a solvent and water as a non‐solvent. Their physical and electrochemical properties were then characterized in terms of thermal and crystalline behavior, as well as ionic conductivity after absorbing an electrolyte solution of 1 M LiPF6 dissolved in an equal weight mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC). For comparison, cast films and their electrolytes were also made by a conventional casting method without using the water non‐solvent. In contrast to the case of using N‐methyl‐2‐pyrrolidone (NMP) as a solvent, the PVdF‐HFP/TiO2 composite electrolytes, obtained using DMAc, exhibited superior properties of electrochemical stability and interfacial resistance with a lithium electrode but had lower ionic conductivities. It was also demonstrated that the phase inversion membrane was more effective than the cast film as the polymer electrolyte of a lithium rechargeable battery. As a result, a phase inversion membrane with 50 wt.‐% TiO2 was demonstrated to be the optimal choice for application in a lithium rechargeable battery.

Time evolutions of interfacial resistance between polymer electrolyte and lithium electrodes.

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Time evolutions of interfacial resistance between polymer electrolyte and lithium electrodes.
Photochemically Cross‐linked Poly(aryl ether ketone) Rings
Authors: Teasdale Ian , Harper Elizabeth C. , Coppo Paolo , Wilson Brian , Turner Michael L.
Published: November 2006

Summary: Macrocyclic phenyl ether ketones were prepared via pseudo high dilution condensation. Irradiation of these rings with UV light in a solution containing isopropyl alcohol as hydrogen donor resulted in a photo‐induced reduction of benzophenone to benzopinacol and the formation linked macrocycles. These rings can be heated to undergo ring‐opening polymerization and produce a polymer network or they can be added to a polycondensation reaction to prepare poly(ether ether ketones) with variable degrees of cross‐linking.

Photochemical cross‐linking of PEK rings and ring opening polymerization (n: 2–6). (a) hν, iPrOH, DCM; (b) CsF, 260 °C (polymer 3); (c) 4,4′–difluorobenzophenone, hydroquinone, diphenylsulphone, K2CO3, 260 °C (2% polymer 4; 6% polymer 5).

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Photochemical cross‐linking of PEK rings and ring opening polymerization (n: 2–6). (a) hν, iPrOH, DCM; (b) CsF, 260 °C (polymer 3); (c) 4,4′–difluorobenzophenone, hydroquinone, diphenylsulphone, K2CO3, 260 °C (2% polymer 4; 6% polymer 5).
Multiple system atrophy in a patient with the spinocerebellar ataxia 3 gene mutation
Authors: Nirenberg Melissa J. , Libien Jenny , Vonsattel Jean‐Paul , Fahn Stanley
Published: November 2006

The cerebellar variant of multiple system atrophy (MSA‐C) has overlapping clinical features with the hereditary spinocerebellar ataxias (SCAs), but can usually be distinguished on a clinical basis. We describe a patient who developed a sporadic, late‐onset, rapidly progressive neurodegenerative disorder consistent with MSA‐C. Genetic testing, however, showed an abnormal expansion of one allele of the spinocerebellar ataxia 3 (SCA3) gene. The clinical impression of MSA‐C was confirmed by identification of numerous α‐synuclein–containing glial cytoplasmic inclusions on autopsy. These findings suggest that abnormal expansion of the SCA3 gene may be a risk factor for the development of MSA‐C. © 2006 Movement Disorder Society
Fatigue in Parkinson's disease: A review
Authors: Friedman Joseph H. , Brown Richard G. , Comella Cynthia , Garber Carol E. , Krupp Lauren B. , Lou Jau‐Shin , Marsh Laura , Nail Lillian , Shulman Lisa , Taylor C. Barr
Published: November 2006

Fatigue is a common problem in Parkinson's disease (PD), often the most troubling of all symptoms. It is poorly understood, generally under‐recognized, and has no known treatment. This article reviews what is known about the symptom, putting it into the context of fatigue in other disorders, and outlines a program for developing better understanding and therapy. © 2006 Movement Disorder Society
Evidence‐based analysis of physical therapy in Parkinson's disease with recommendations for practice and research
Authors: Keus Samyra H.J. , Bloem Bastiaan R. , Hendriks Erik J.M. , Bredero‐Cohen Alexandra B. , Munneke Marten ,   on behalf of the Practice Recommendations Development Group
Published: November 2006

Physical therapy is often prescribed in Parkinson's disease. To facilitate the uniformity and efficacy of this intervention, we analyzed current evidence and developed practice recommendations. We carried out an evidence‐based literature review. The results were supplemented with clinical expertise and patient values and translated into practice recommendations, developed according to international standards for guideline development. A systematic literature search yielded 6 systematic reviews and 23 randomized controlled trials of moderate methodological quality with sufficient data. Six specific core areas for physical therapy were identified: transfers, posture, reaching and grasping, balance, gait, and physical capacity. We extracted four specific treatment recommendations that were based on evidence from more than two controlled trials: cueing strategies to improve gait; cognitive movement strategies to improve transfers; exercises to improve balance; and training of joint mobility and muscle power to improve physical capacity. These practice recommendations provide a basis for current physical therapy in Parkinson's disease in everyday clinical practice, as well as for future research in this field. © 2006 Movement Disorder Society
Progression of tremor and ataxia in male carriers of the FMR1 premutation
Authors: Leehey Maureen A. , Berry‐Kravis Elizabeth , Min Sung‐Joon , Hall Deborah A. , Rice Cathlin D. , Zhang Lin , Grigsby Jim , Greco Claudia M. , Reynolds Ann , Lara Rebecca , Cogswell Jennifer , Jacquemont Sebastien , Hessl David R. , Tassone Flora , Hagerman Randi , Hagerman Paul J.
Published: November 2006

Premutation alleles of the fragile X mental retardation 1 (FMR1) gene give rise to a late‐onset movement disorder, fragile X‐associated tremor/ataxia syndrome (FXTAS), characterized by progressive intention tremor and gait ataxia, with associated dementia and global brain atrophy. The natural history of FXTAS is largely unknown. To address this issue, a family‐based, retrospective, longitudinal study was conducted with a cohort of 55 male premutation carriers. Analysis of the progression of the major motor signs of FXTAS, tremor and ataxia, shows that tremor usually occurs first, with median onset at ∼60 years of age. From the onset of the initial motor sign, median delay of onset of ataxia was 2 years; onset of falls, 6 years; dependence on a walking aid, 15 years; and death, 21 years. Preliminary data on life expectancy are variable, with a range from 5 to 25 years. © 2006 Movement Disorder Society
Family‐based association study of the restless legs syndrome loci 2 and 3 in a European population
Authors: Kemlink David , Polo Olli , Montagna Pasquale , Provini Federica , Stiasny‐Kolster Karin , Oertel Wolfgang , de Weerd Al , Nevsimalova Sona , Sonka Karel , Högl Birgit , Frauscher Birgit , Poewe Werner , Trenkwalder Claudia , Pramstaller Peter P. , Ferini‐Strambi Luigi , Zucconi Marco , Konofal Eric , Arnulf Isabelle , Hadjigeorgiou Georgios M. , Happe Svenja , Klein Christine , Hiller Anja , Lichtner Peter , Meitinger Thomas , Müller‐Myshok Betram , Winkelmann Juliane
Published: November 2006

Three loci for the restless legs syndrome (RLS) on chromosomes 12q, 14q, and 9p (RLS1, RLS2, and RLS3) have been mapped, but no gene has been identified as yet. RLS1 has been confirmed in families from three different populations. We conducted a family‐based association study of 159 European RLS trios. The subjects were genotyped using microsatellite markers evenly covering the candidate regions on chromosomes 14q and 9p with an average intermarker distance of 1.1 cM. Transmission disequilibrium tests were used to analyze the data, and empirical P values were estimated by permutation testing. On chromosome 14q, a significant association (empirical P = 0.0033) was found with a haplotype formed by markers D14S1014 and D14S1017 when analyzing all families. On chromosome 9p, no significant association in the sample of all families and only marginally significant associations were detected, with a haplotype involving markers D9S1846‐D9S171 in a subset of South European trios and with a haplotype at D9S156‐D9S157 in a subset of Central European trios (P = 0.0086 and 0.0077, respectively). These results represent the first confirmation of these loci in a mixed European population. Variable results observed in families of different ethnic groups further corroborate the genetic complexity of RLS. © 2006 Movement Disorder Society
Phenomenology of dreams in Parkinson's disease
Authors: Borek Leora L. , Kohn Robert , Friedman Joseph H.
Published: November 2006

Rapid eye movement sleep behavior disorder (RBD) occurs in approximately one third of patients with Parkinson's disease (PD) and is associated with a loss of muscle atonia during REM sleep and aggressive dream content. We examined the dream characteristics of PD patients to determine whether dream content differed between patients with RBD and without RBD, men and women with RBD, and men and women with PD. One hundred‐twenty patients with a diagnosis of idiopathic PD were consecutively recruited from a movement disorders clinic and were assessed for RBD using clinical diagnostic criteria of the International Classification of Sleep Disorders Revised (2001). Verbatim dream content was obtained from each patient and categorized into dream themes that were coded into nominal categories. Fisher's exact tests determined whether particular dreams were correlated with RBD versus non‐RBD, men and women with RBD, and men and women with PD. RBD patients had a higher percentage of violent dreams compared to non‐RBD patients. There were no significant sex differences in the dream content of RBD patients. Men with PD had more aggressive dreams compared to females with PD. Aggressive dream content was characteristic of RBD patients and sex differences exist in the dream content of the PD population. © 2006 Movement Disorder Society
Chemistry and some biological effects of model melanoidins and pigments as Maillard intermediates
Authors: Hayase Fumitaka , Usui Teruyuki , Watanabe Hirohito
Published: November 2006

Various pigments were formed in the D‐xylose‐glycine reaction system. Blue pigments (Blue‐M1 and Blue‐M2) and red pigments (Red‐M1 and Red‐M2) were generated in the Maillard reaction. Blue‐M2 is presented to have been generated by the reaction between Blue‐M1, which involved two pyrrolopyrrole structures as the major blue pigment, and di‐D‐xyluloseglycine. We identified red pigments as the isomers of addition compounds of D‐xyluloseglycine to condensated compound between pyrroropyrrole‐2‐carbaldehyde and pyrrole‐2‐carbaldehyde compounds. These pigments have polymerizing activities, suggesting that they are important Maillard reaction intermediates through the formation of melanoidins. Blue‐M1 as well as melanoidins effectively suppressed the peroxidation of linoleic acid. The scavenging activity toward Blue‐M1 on hydroxyl and DPPH radicals was also as strong as that of melanoidins. Furthermore, Blue‐M1 prevents the oxidative cell injury. Therefore, Blue‐M1 will be an antioxidant which protects against the oxidative stress in biological systems. Melanoidins induced IFN‐γ mRNA and IL‐12 mRNA expressions in spleen cells exposed to allergen and in macrophage‐like J774.1 cells, respectively. These findings suggest that melanoidins have suppressive effect on allergic reaction as a novel physiological effect.
Intervention with polyphenol‐rich fruit juices results in an elevation of glutathione S‐transferase P1 (hGSTP1) protein expression in human leucocytes of healthy volunteers
Authors: Hofmann Thomas , Liegibel Ute , Winterhalter Peter , Bub Achim , Rechkemmer Gerhard , Pool‐Zobel Beatrice Louise
Published: November 2006

Polyphenols are probably antigenotoxic on account of their antioxidant activities and might alter phase I and II enzymes in a way that results in chemoprotection. We investigated the hypothesis that polyphenols enhance expression of glutathione S‐transferases (GSTs), which increases carcinogen detoxification and thereby provides protection against oxidative stress. HGSTP1 protein expression and GST polymorphisms were determined in leucocytes obtained during an intervention study with healthy subjects consuming two fruit juices in an 8 wk trial (polyphenol‐free run in phase, juice intervention phase, washout phase, second juice intervention phase, each treatment regime lasted for 2 wk). The study had originally shown that juice intervention significantly reduced oxidative DNA damage in leucocytes at week 8 (Bub, A., Watzl, B., Blockhaus, M., Briviba, K. et al., J. Nutr. Biochem. 2003, 14, 90–98). We reanalysed the levels of DNA damage based on GST genotypes. We also treated leucocytes in vitro with mixtures of polyphenols and determined cytotoxicity and expression of 96 genes related to drug metabolism. Key results with leucocytes of the intervention study were that the initial content of hGSTP1 protein was first suppressed at weeks 4 and 6. At week 8, however, hGSTP1 protein expression was significantly increased. HGSTP1 protein levels and DNA damage were inversely correlated (p = 0.005), but there was no difference for cells obtained from subjects with hGSTM1*1 and hGSTM1*0 genotypes, nor was there any difference between cells from subjects consuming the two different juices. The treatment of leucocytes with polyphenol mixtures in vitro did not result in modulated GST gene expression or total GST activity, but in an up‐regulation of other biotransformation enzymes (e. g., members of the cytochrom P450 and the sulphotransferase family). In conclusion, in vitro treatment of leucocytes led to a modulated mRNA expression of selected genes, not directly related to oxidative defence systems. In vivo, however, we observed a delayed enhancement of hGSTP1, which could be associated with an initial repression of oxidative DNA damage in leucocytes from human subjects, consuming juices with high levels of polyphenols.
Numerical investigation of the clogging mechanism in labyrinth channel of the emitter
Authors: Jun Zhang , Wanhua Zhao , Yiping Tang , Zhengying Wei , Bingheng Lu
Published: November 2006

Emitter clogging is a main factor affecting the performance of drip irrigation products. Considering the small size and intricacy of emitters, numerical methods are introduced to study the clogging mechanism of labyrinth channel in the emitter. A three‐dimensional numerical model of clogging analysis is addressed, where Reynolds stress model with wall function is used to simulate the fluid flow in the Eulerian frame, and stochastic trajectory model is adopted to track the motion of the particles in a Lagrangian co‐ordinate system without taking into account the agglomerating behaviour of particles. The analytical results show that in the labyrinth channel, low‐velocity region is developed ahead of each sawtooth and large vortex is shaped just behind it. Small particles are apt to deposit in those regions due to their better following behaviours than those of large ones. The potential clogging regions predicted by simulation are reasonably consistent with the experimental results. Further, it is also found that the particles ranging from 30 to 50 µm behave best when passing through the labyrinth channel, and particle densities have a remarkable effect on the penetration only when their diameters are large than 50 µm. Copyright © 2006 John Wiley & Sons, Ltd.
Exact quantum solutions of general driven time‐dependent quantum quadratic system
Authors: Fan Kaimin , Zheng Yujun , Ren Weiyi , Ding Shiliang
Published: November 2006

We studied the general time‐dependent linear and quadratic system via dynamical symmetries. In an algebraic framework, we obtained exact solutions of the evolution operators, propagators, and wave functions of the general time‐dependent linear and quadratic system. To illustrate our calculations, we discuss a few special cases, including a particle driven by a monochromatic electric field, and cases of oscillatory, linear, or monotonic with respect to the time of the quadratic system. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Ab initio calculation of the Dzyaloshinskii–Moriya parameters: Spin–orbit GSO‐HF, DFT, and CI approaches
Authors: Takeda R. , Yamanaka S. , Shoji M. , Yamaguchi K.
Published: November 2006

We present ab initio methods to determine the Dzyaloshinskii–Moriya (DM) parameter, which provides the anisotropic effects of noncollinear spin systems. For this purpose, we explore various general spin orbital (GSO) approaches, such as Hartree–Fock (HF), density functional theory (DFT), and configuration interaction (CI), with one‐electron spin–orbit coupling (SOC1). As examples, two simple D3h‐symmetric models, H3 and B(CH2)3, are examined. Implications of the computational results are discussed in relation to as isotropic and anisotropic interactions of molecular‐based magnets. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Approximate lower bounds of the Weinstein and Temple variety
Authors: Marmorino M. G. , Bauernfeind Ryan W.
Published: November 2006

By using the Weinstein interval or coupling the Temple lower bound to a variational upper bound one can in principle construct an error bar about the ground‐state energy of an electronic system. Unfortunately there are theoretical and calculational issues which complicate this endeavor so that at best only an upper bound to the electronic energy has been practical in systems with more than a few electrons. The calculational issue is the complexity of 〈H2〉 which is necessary in the Temple or Weinstein approach. In this work we provide a way to approximate the 〈H2〉 to any desired accuracy using much simpler 〈H〉‐like information so that the lower bound calculations are more practical. The helium atom is used as a testing ground in which we obtain approximate error bars for the ground‐state energy of [−2.904230, −2.903721] hartree using the variational energy with the Temple lower bound and [−2.919098, −2.888344] hartree for the Weinstein interval. For comparison, the slightly larger error bars using the exact value of 〈H2〉 are: [−2.904358, −2.903721] hartree and [−2.919765, −2.887677] hartree, respectively. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Identification of endogenous resolvin E1 and other lipid mediators derived from eicosapentaenoic acid via electrospray low‐energy tandem mass spectrometry: spectra and fragmentation mechanisms
Authors: Lu Yan , Hong Song , Yang Rong , Uddin Jasim , Gotlinger Katherine H. , Petasis Nicos A. , Serhan Charles N.
Published: November 2006

Resolvin E1 (RvE1, 5S,12R,18R‐trihydroxy‐6Z,8E,10E,14Z,16E‐eicosapentaenoic acid) is a novel anti‐inflammatory lipid mediator recently found in humans, mice, and fish in vivo. To identify endogenous RvE1 and other eicosapentaenoic acid (EPA)‐derived lipid mediators using electrospray low‐energy collision‐induced dissociation tandem mass spectrometry (MS/MS), the MS/MS product ion spectra of these compounds were correlated with their structures, and the MS/MS fragmentation mechanisms were studied. Deuterium labeling confirmed the proposed correlations and the fragmentation mechanisms. β‐cleavage was observed for RvE1, and β and γ cleavages were seen for leukotriene B5; however, α‐cleavage was more common. The positions and numbers of hydroxyls and double bonds of these lipid mediators can be deduced from the MS/MS spectra. The MS/MS fragmentation generating chain‐cut ions involved β‐ene, γ‐ene, or α‐H‐β‐ene rearrangement, depending on the specific structure. The m/z value of a detected chain‐cut ion from RvE1 or from an EPA‐derived product is equal to the corresponding hypothetical homolytic segment (cc, cm, mc, or mm) with the addition or extraction of up to two hydrogen atoms (H) from hydroxyls or an α‐carbon; namely, the m/z value of an α‐cleavage‐generated ion is equal to [cc+H], [cm−2H], [mc−H], or [mm]. Wideband activation increased the signal intensities of chain‐cut ions, and therefore was better for trace analysis of RvE1 in biological samples. RvE1, LTB5, PGE3, and other EPA‐derived lipid mediators were found in trout brain or head‐kidney via this approach on the basis of MS/MS spectra and fragmentation mechanisms. Negative ion electrospray low‐collision‐energy MS/MS spectra provide adequate data to elucidate and identify the structures of RvE1 and other EPA‐derived lipid mediators at levels below a few picomoles in trout samples. Copyright © 2006 John Wiley & Sons, Ltd.
How much curriculum change is appropriate? Defining a zone of feasible innovation
Authors: Rogan John M.
Published: November 2006

The article grapples with the question of how much curriculum change is appropriate in a given context and in a given time frame. How can a balance be struck between stagnation, on the one hand, and the promotion of unrealistic innovation on the other? In answer to this dilemma, the concept of a zone of feasible innovation (ZFI) is proposed and explored, drawing on the literature of school development, teacher professional development, and of developmental psychology, the work of Vygotsky in particular. A series of procedures are suggested to help define the nature and scope of a ZFI in any given situation. Finally, vignettes from case studies of innovation in science education are evoked to provide real‐life counterpoints to the theoretical constructs of the literature. © 2006 Wiley Periodicals, Inc. Sci Ed, 91:439–460, 2007
Hands on what? The relative effectiveness of physical versus virtual materials in an engineering design project by middle school children
Authors: Klahr David , Triona Lara M. , Williams Cameron
Published: November 2006

“Hands‐on” activities play an important, but controversial, role in early science education. In this study we attempt to clarify some of the issues surrounding the controversy by calling attention to distinctions between: (a) type of instruction (direct or discovery); (b) type of knowledge to be acquired (domain‐general or domain‐specific); and (c) type of materials that are used (physical or virtual). We then describe an empirical study that investigates the relative effectiveness of the physical–virtual dimension. In the present study, seventh and eighth grade students assembled and tested mousetrap cars with the goal of designing a car that would go the farthest. Children were assigned to four different conditions, depending on whether they manipulated physical or virtual materials, and whether they had a fixed number of cars they could construct or a fixed amount of time in which to construct them. All four conditions were equally effective in producing significant gains in learners' knowledge about causal factors, in their ability to design optimal cars, and in their confidence in their knowledge. Girls' performance, knowledge, and effort were equal to boys' in all conditions, but girls' confidence remained below boys' throughout. Given the fact that, on several different measures, children were able to learn as well with virtual as with physical materials, the inherent pragmatic advantages of virtual materials in science may make them the preferred instructional medium in many hands‐on contexts. © 2006 Wiley Periodicals, Inc. J Res Sci Teach
Detecting spatial interactions in the ragweed (Ambrosia artemissifolia L.) and the ragweed beetle (Ophraella communa LeSage) populations
Authors: Yamanaka Takehiko , Tanaka Koichi , Otuka Akira , Bjørnstad Ottar N.
Published: November 2006

We observed a weed (Ambrosia artemissifolia)–beetle herbivore (Ophraella communa) system for three years in a spatially continuous field (≈200 ha). We analyzed our field data in the light of two contrasting theories: the resource‐concentration hypothesis and reaction–diffusion theory. For the resource‐concentration hypothesis, we calculated the correlation coefficients between weed and beetle abundances for every season in each year. Although we found weak support for resource concentration in some seasons, we could not find any clear relationships in other seasons. We discuss a dispersal‐based mechanism to explain the differences observed among seasons in lieu of the resource‐concentration hypothesis. For the reaction–diffusion theory, we estimated the nonparametric spatial covariance functions for the spatial autocorrelation of weeds and beetles. Although we could not find any strong spatial structure for the individual species, we found evidence of spatial interactions between weeds and beetles using time lagged cross‐correlation functions. Weed abundance enhanced local beetle abundance. Through time, there was evidence of beetle spillover to adjacent locations at roughly the one beetle‐generation time scale. Sites with large number of beetles did not seem to reduce subsequent weed abundance.
Determination of iodine value with a fourier transform‐near infrared based global calibration using disposable vials: An international collaborative study
Authors: Cox R. , Lebrasseur J. , Michiels E. , Buijs H. , Li Hui , van de Voort F. R. , Ismail A. A. , Sedman J.
Published: November 2006

A method for the determination of iodine value (IV) by Fourier transform‐near infrared (FT‐NIR) spectroscopy was developed and evaluated in an international collaborative study. The FT‐NIR analyzer employed in this work uses disposable vials for sample handling and incorporates validation protocols designed to ensure that the calibration will give accurate results from analyzer to analyzer and stability over time without any further calibration development work. The global IV calibration was developed from over 1,200 animal, marine, and vegetable oils and fats, which were obtained on a number of different instruments worldwide. The Standard Error of Cross Validation measured from a range of 0–190 IV varied from ±0.2–1.4 IV (1 sigma). The repeatability for all models was on the order of 0.1 IV, which states that most of the error was inherited from the primary methods. Finally, an international interlaboratory study was carried out with 16 samples obtained from the AOCS Smalley Laboratory Proficiency Program and an oil processor. The average reproducibility error in any one lab was better than 0.15, and the average reproducibility between labs was better than 0.33. An uncertainty of 0.45 was calculated from the average FT‐NIR values obtained from the collaborative study vs. the AOCS Certified Wijs method (Cd 1d‐92).
Viscosity prediction for fatty systems
Authors: Rabelo Juliana , Batista Eduardo , Cavaleri Fl vio W. , Meirelles Antonio J. A.
Published: November 2006

Viscosity data have been measured as a function of temperature for two pure polyunsaturated fatty compounds (linoleic acid and trilinolein), for two multicomponent fatty systems, for a commercial‐grade oleic acid (approximately 80% pure), and for canola oil. The measurements were performed in Cannon Fenske glass capillary kinematic viscometers. The contents of a large data bank, containing viscosity data for saturated, monousaturated, and polyunsaturated pure fatty substances, were correlated by an equation based on the number of carbon atoms and double bonds. By using this equation for pure compounds and the UNIMOD group contribution method for mixtures, the viscosity data for model fatty systems, commercial oleic acid, and canola oil were predicted. The good results obtained in the present work indicate that this approach can be a valuable tool for designing or evaluating chemical process equipment for the oil industry.
Processing effects on the polyaromatic hydrocarbon content of grapeseed oil
Authors: Moret S. , Dudine A. , Conte L. S.
Published: November 2006

Grapeseed oil can occasionally have dangerous levels for human health of polycyclic aromatic hydrocarbons (PAH) due to the drying process, which involves direct contact with combustion gases. Oil samples extracted from grapeseeds before and after drying were analyzed for their PAH content with a new, fast, bi‐dimensional liquid chromatography method. Samples collected before drying had relatively high PAH amounts; Benzo(a)pyrene (BaP) content ranged from 0.9 to 2.4 ppb with an average of 1.4 ppb. The high contamination level found in the raw material is probably due to the practice of compacting pomace with bulldozers to reduce its volume before storage. The drying process did not significantly influence the light PAH content, but caused a large increase of the heavy fraction. BaP with an average content of 20.2 ppb, had the largest increase.
Odor significance of undesirable degradation compounds in heated triolein and trilinolein
Authors: Neff W. E. , Warner K. , Byrdwell W. C.
Published: November 2006

To better understand production of undesirable or negative odors such as fruity, plastic, and waxy that are characteristic of higher oleic acid‐containing oils, model heated oil systems of triolein and trilinolein were studied. Identification of the odor significance of volatile compounds produced by fractionated and nonfractionated triolein and trilinolein was done by purge and trap‐gas chromatography‐ion trap mass spectrometry‐olfactometry. The predominant odors of the triolein heated 1, 3, and 6 h at 190°C were fruity and plastic, with other negative odors of acrid and grassy. Some of the volatile compounds that produced negative odors in heated triolein, in order of increasing concentration, were hexanal (grassy), octanal (fruity), (E)‐2‐decenal (plastic), nonanal (fruity), and (E)‐2‐undecenal (plastic). Some of the negative odor compounds in trilinolein heated for 1, 3 and 6 h, in order of increasing concentration, included (E)‐2‐nonenal (plastic), pentanal (grassy), and hexanal (grassy). However, the amount of volatile compounds produced and the intensity levels of the odors were lower in trilinolein than in triolein. Formation of many of the volatiles was explained after identification of the volatile precursors, including epoxy, keto, and dimer oxidation products that were produced during heating.
A simple HPLC method for the simultaneous analysis of phosphatidylcholine and its partial hydrolysis products 1‐ and 2‐acyl lysophosphatidylcholine
Authors: Adlercreutz Dietlind , Wehtje Ernst
Published: November 2006

A simple HPLC method for the simultaneous analysis of phosphatidylcholine (PC), 1‐acyl lysophosphatidylcholine (1‐acyl LPC), and 2‐acyl lysophosphatidylcholine (2‐acyl LPC) with refractive index detection is described. The separation of these three compounds was achieved on a Waters (Milford, MA) Spherisorb amino phase column using a mixture of ethanol and an aqueous oxalic acid solution as eluent. The optimal mixture of ethanol to oxalic acid solution was 92∶8 (vol/vol). PC and the two regioisomers of LPC eluted within 15 min. The calibration curves were linear in a concentration range from 0.05 to 2.5 mM. Natural PC or LPC eluted in a single peak, despite the diversity in the fatty acid composition. There was no rearrangement between 1‐acyl LPC and 2‐acyl LPC during analysis or storage in ethanol within 23 h. This method is thus especially suitable for studying reactions on PC and acyl migration in LPC.
Measurement of particle size distribution of tripalmitin crystals in a model solution using a laser diffraction method
Authors: Fitzgerald Andrea M. , Barnes O. John , Smart Ian , Wilson D. Ian
Published: November 2006

The form and size distribution of tripalmitin (PPP) crystals formed by quenching a solution in a batch crystallizer have been studied using scanning electron microscopy and a laser diffraction technique. Although the accuracy of the laser technique for particle sizing was affected by the nonsphericity of the crystals, the technique proved to be effective and very reproducible. Crystals recovered by filtration and sonication for laser sizing exhibited markedly different particle size distributions (PSD) and shapes compared to those prepared using another standard route, namely, suspension in butanol and centrifugation. Solutions of 2–10 wt% PPP in a paraffin solvent were crystallized at 25–40°C and displayed two ranges of behavior: (i) rapid growth under strongly supersaturated conditions, yielding narrow PSD of plate and needle‐like crystals; and (ii) slow growth in the metastable regime, yielding spherulitic aggregates of platelets that broke down under sonication during preparation for laser sizing. Suspension in alcohol followed by centrifugation yielded aggregates that did not break down under sonication, indicating that the sample preparation route affected the result of the analysis.
Thin‐film test to investigate liquid oxypolymerization of nonvolatile analytes: Assessment of vegetable oils and biodegradable lubricants
Authors: Asadauskas Svajus , Erhan Sevim Z.
Published: November 2006

A thin‐film oxidation test was developed to investigate liquid oxypolymerization of nonvolatile analytes. Gel permeation chromatography (GPC) showed that the test delivered the required degree of oxidation with better than ±5% accuracy. The following oils were ranked according to their decreasing resistance to oxypolymer formation at 150°C: 90% oleic sunflower oil, triolein, meadowfoam oil, castor oil, canola oil, lesquerella oil, and soybean oil. Higher degrees of oxidation demonstrated the occurrence of oxidative gelation. Oxypolymerization tendencies of hydraulic fluids based on canola and rapeseed oils were comparable to those of canola oil without additives. The relative amount of C‐C polyunsaturation present in the fatty acid chain was a major differentiating factor. However, oxidation inhibitors also reduced the rates of oxypolymerization, as demonstrated by sunflower oil‐based hydraulic fluid. Canola and rapeseed lubricants needed better oxypolymerization control.
Synthesis of Δ2‐Isoxazoline fatty acid ester heterocycles
Authors: Kenar James A. , Erhan Sevim Z.
Published: November 2006

Fatty ester Δ‐2 heterocycles were prepared in good yields and excellent regioselectivity from 1,3‐dipolar cycloaddition reactions between methyl 10‐undecenoate and nitrile oxides. This methodology provides convenient access to the methyl esters of margaric (4b) and stearic (4c) acids in 63–66% yield that contain the isoxazoline heterocycle between C‐10 and C‐12. These fatty heterocycle compounds are synthesized in a one‐pot sequence in which methyl 10‐undecenoate is used to trap the reactive nitrile oxide intermediates that are generated by reacting aldoximes with aqueous sodium hypochlorite and a catalytic amount of triethylamine or by directly reacting hydroximic acid chlorides with a stoichiometric amount of base. The fatty ester Δ2‐isozazoline heterocycles represent a versatile synthon that may be useful to obtain oleochemicals with potentially new and interesting properties not easily accessible by other methods.
Supercritical fluid extraction of encapsulated oil products
Authors: Shih F. , Daigle K.
Published: November 2006

Standard methods of oil analysis, for example, Soxhlet extraction and supercritical fluid extraction (SFE), were ineffective for recovering oil from encapsulated food products. Efforts were made to enhance SFE of the oil for these products. Samples were hydrated and heated, which helped to break down the encapsulating structure. In addition, extra diatomaceous earth was needed to absorb and disperse the added water. Optimal extraction conditions were established, and quantitative extraction of oil was achieved for various laboratory‐prepared and commercially encapsulated food products.
Enzyme‐assisted aqueous extraction of peanut oil
Authors: Sharma Aparna , Khare S. K. , Gupta M. N.
Published: November 2006

Enzyme‐assisted aqueous extraction of oil from oilseeds is a relatively recent technique. In the present study, peanut oil was extracted under optimized aqueous extraction conditions using Protizyme™, which is predominantly a mixture of acid, neutral, and alkaline proteases. The optimal conditions were: enzyme concentration of 2.5% (w/w) in 10 g of peanut seeds, pH 4.0, 40°C, and 18 h incubation with constant shaking at 80 rpm. Centrifuging the mixture at 18,000 × g for 20 min separated the oil with a recovery of 86–92%. The merits of this process over existing solvent extraction and/or mechanical pressing methods are discussed.
An evaluation of supercritical fluid extraction as an analytical tool to determine fat in canola, flax, solin, and mustard
Authors: Barthet Véronique J. , Daun James K.
Published: November 2006

Supercritical fluid extraction (SFE) with carbon dioxide was used to extract oil from soft oilseeds (flax, solin, canola, and mustard). Oil content determinations from the SFE method AOCS Am 3–96, with and without ethanol as a modifier, were compared to results obtained with an exhaustive extraction using petroleum ether (FOSFA as in AOCS Am 2–93). Without the modifier, oil recoveries using SFE were 10 to 15% lower than oil contents by the FOSFA method for the flax and canola samples. For mustard, the oil recoveries by SFE were about 20 to 30% lower than oil contents by the FOSFA method. In the presence of the modifier, oil recoveries for flax and canola were about 3% lower than the FOSFA recoveries. Varying the time, temperature, and amount of modifier (ethanol) showed that recoveries increased with time, pressure, temperature, and amount of modifier independently of the oilseeds tested. Kinetics of the SFE extraction showed that the oil recoveries increased with the extraction time and reached a plateau after 60 min. Multiple extractions (2×30 min), however, gave better recoveries than a single extraction for the same amount of time (60 min). The best results were obtained using multiple extractions without modifier or a combination of multiple extractions first without and then with 15% modifier. Under these last two conditions, oil recoveries were close to 100% for flax, solin, and canola, but mustard oil recoveries were still 10% lower than recoveries using the FOSFA method. Mustard samples gave the lowest oil recovery from SFE when compared to FOSFA method recoveries whatever conditions were tested, suggesting a matrix effect on the oil recovery. The acyl lipid content of the various extracts was studied using the sum of all FA expressed as TAG as a measure of acyl lipid extraction. The acyl lipid contents of the extracts were close to 100% when no modifier was used during the SFE. In the presence of modifier, the acyl lipid contents of the extracts were 10 to 15% lower than the results obtained without modifier. The amount of acyl lipid in the extract decreased as the quantity of modifier increased. This suggests that increasing the ethanol modifier increased the amount of polar compounds extracted without significantly increasing the total amount of lipids. The FA profiles were constant throughout the various extraction procedures.
One‐step methodology for the synthesis of FA picolinyl esters from intact lipids
Authors: Destaillats Frédéric , Angers Paul
Published: November 2006

Picolinyl derivatives are used for structural determination of FA by GC‐MS. Although they provide reliable diagnostic fragments, the usual multistep methodologies applied for their preparation require TAG hydrolysis or acid chloride formation prior to picolinyl synthesis. These reaction conditions may result in the presence of artifact molecules in the samples and thus compromise analytical quality and accuracy. To address these problems, a rapid, simple and quantitative methodology for the synthesis of FA picolinyl esters from intact lipids was developed. It involves their transesterification under basecatalyzed conditions using 3‐potassiooxamethylpyridine in methylene chloride. The catalyst was prepared by proton exchange between potassium tert‐butoxide and anhydrous 3‐hydroxymethylpyridine. Mild reaction conditions allowed complete derivatization of TAG and phospholipids in 2 min at room temperature, and of FAME in 15 min at 45°C. The proposed procedure, which can be used on a routine basis, was applied to Ipomoae imperialis seed lipids and used to confirm occurrence of γ‐linoleic acid at a level of 0.9%.