bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of fatty acids of different unsaturation in the oxidation of purified vegetable oils during microwave irradiation
Authors: Yoshida Hiromi 
Published: October 2006

AbstractPurified vegetable oils (soya bean, safflower and rapeseed) containing stearic, oleic, linoleic or linolenic acid at different levels (0.5–10.0 g kg−1), were exposed to microwave irradiation for several periods of time to study the contribution of fatty acids of different unsaturation to the oxidative stability of these oils. The evaluation of the oils was based on peroxide value or carbonyl and anisidine values as an indicator for the primary or secondary oxidation products, respectively. A pro‐oxidative effect of the added fatty acids was established. The extent of this effect depended on the degree of unsaturation of added fatty acids and/or purified vegetable oils. During microwave treatment the oxidative rate of purified vegetable oils was rapid in the presence of the unsaturated fatty acids, but comparatively lower for the corresponding saturated fatty acid or hydrocarbon. The oxidative state of the oils was lower in the rapeseed oil than in the soya bean oil or safflower oil. In assessing the propensity to oxidation particular attention should be paid to not only the type of free fatty acids, but also the difference of glyceride structure in the purified vegetable oils.
Flour, starch and alternative (wheatless) breadmaking quality of various cassava clones
Authors: Eggleston Gillian , Omoaka Paulyn E , Arowshegbe Aduni U 
Published: October 2006

AbstractAlternative (wheatless) cassava breads were made with cassava flour from eight different cassava (Manihot esculenta, Crantz) clones fortified with soya flour (200 g kg−1 total flour) using margarine and egg white, or xanthan, as additives. In this study, bread specific volumes were reliably predicted from only the diastatic activity and maximum paste viscosity of the cassava flour, although further variables still need to be investigated. Flours with diastatic activities above ∼ 145 mg of maltose, and indirectly low maximum paste viscosities, produced dense, pudding‐like structures with completely gelatinised crumbs. The flour diastatic activity was dependent on the moisture content of the freshly harvested tuberous root; above a critical threshold moisture (∼ 75 %) content the specific air intake of the loaves decreased sharply. The extent of starch gelatinisation and solubilisation did not critically affect loaf volumes but affected crumb structures.
Production of a Lactobacillus plantarum starter with linamarase and amylase activities for cassava fermentation
Authors: Giraud Eric , Gosselin Laurent , Raimbault M 
Published: October 2006

AbstractLactobacillus plantarum strain A6 isolated from cassava, cultured on cellobiose MRS medium showed a growth rate of 0.41 h−1, a biomass yield of 0.22 g g−1, and produced simultaneously an intracellular linamarase (76.4 U g−1 of biomass) and an extracellular amylase (36 U ml−1). The synthesis of both enzymes was repressed by glucose. The use of such a strain as a cassava fermentation starter for gari production had the following influences: a change from a hetero‐fermentative pattern observed in natural fermentation to a homofermentation, a lower final pH, a faster pH decline rate and a greater production of lactic acid (50 g kg−1 DM). However, this starter did not appear to play a significant role in cassava detoxification, since it was observed that the level of endogenous linamarase released during the grating of the roots was sufficient to permit the complete and rapid breakdown of linamarin.
Foliar catechol oxidase activity as a measure of copper nutrition of tomato plants
Authors: Onyezili Francis N , Harris Peter J 
Published: October 2006

AbstractThe diagnostic value of catechol oxidase assays as indices of copper nutritional status was investigated in tomato plants (Lycopersicon esculentum Mill) receiving graded copper treatment in sand culture. Foliar copper concentrations ranged from 0.79 to 5.16 μg g−1 dry matter under various copper treatments but these results were misleading because copper‐inadequate plants concentrated the element in older leaves. A colorimetric assay based on catechol oxidase‐catalysed formation of measurable quinones in young tomato leaves discriminated sufficiently between the various copper treatments. The rates of invitro induction of this enzyme amounted to an expression of the plant growth response to copper supply and thus was indicative of the copper requirement of the plant. A paper strip‐based modification of the enzyme assay simplified it further for diagnostic use in field situations.
Glutathione and β‐amylase, peroxidase and o‐diphenolase activities during sprouting of minisett yams (Dioscorea sp)
Authors: Wellington M A , Ahmad M H 
Published: October 2006

AbstractGlutathione, β‐amylase, o‐diphenolase (EC 1.10.3.1) and peroxidase (EC 1.11.1.7) activities were assayed in minisetts derived from the head, middle and tail sections of sprouted Dioscorea alata (cv Sweet Yam) and D cayenensis (cv Round Leaf) yam tubers. In both tubers the head portions exhibited highest initial activities followed by the middle and tail, respectively. Minisetts obtained from the head, middle and tail sections of D alata sprouted uniformly whereas those obtained from D cayenensis tubers showed a much slower, sporadic sprouting pattern, with the head portions displaying dominant sprouting, The results revealed that sprouting initiation of the minisetts from both species correlated well with increased glutathione levels. High levels of peroxidase and reduced levels of o‐diphenolase seemed to enhance the sprouting of the minisetts.
Geographical classification of Greek virgin olive oil by non‐parametric multivariate evaluation of fatty acid composition
Authors: Tsimidou Maria , Karakostas Kostas × 
Published: October 2006

AbstractFatty acid compositional data for Greek virgin olive oils from 24 years of harvest and various regions and cultivars were evaluated using chemometric methods. Non‐parametric discriminant analysis after proper transformation of the data seems to be a suitable approach to characterise the oils according to the geographical origin and may produce a scientific basis for the assignment of an ‘appellation d'origine’ trade mark.
Universal and discriminative detection using a miniaturized pulsed discharge detector in comprehensive two‐dimensional GC
Authors: Winniford Bill L. , Sun Kefu , Griffith James F. , Luong Jim C. 
Published: October 2006

AbstractA miniaturized pulsed discharge detector (Mini‐PDD) has been successfully demonstrated for comprehensive 2‐D GC (GC×GC) analysis of pyrolysis gasoline and the pyrolysis GC×GC analysis of a polyethylene copolymer. The detector cell volume of the Mini‐PDD is reduced to 25% of the Valco plug‐in PDD D‐3. An n‐C11 peak width at base is 96 ms for the Mini‐PDD, about 23% larger than a peak width of 78 ms detected by a flame ionization detector (FID). The Mini‐PDD has sufficient response time for most GC×GC applications. When Mini‐PDD is operated in helium photoionization mode (Mini He‐PDD), it is a universal detector for both inorganic and organic compounds. This is especially useful when detection of water is needed in GC×GC applications. When krypton is doped in the helium discharge gas (Mini Kr‐PDD), it can suppress signals of compounds having higher ionization potentials and enhance relative signal intensities of aromatic compounds. The determination of aliphatic to aromatic hydrocarbon ratios is essential to the operation of petroleum crackers. Comparison of the signal from two modes of the Mini‐PDD is a simple and fast way to verify the location of aromatics in comprehensive 2‐D gas chromatograms.
Enantioseparation of phenylalanine analogs on a quinine‐based anion‐exchanger chiral stationary phase: Structure and temperature effects
Authors: Török Roland , Berkecz Robert , Péter Antal 
Published: October 2006

AbstractApplication of a cinchona alkaloid‐based chiral anion‐exchanger stationary phase for the direct high‐performance liquid chromatographic enantioseparation of N‐protected unusual phenylalanine analogs is reported. The N‐benzyloxycarbonyl, N‐3,5‐dinitrobenzyloxycarbonyl, N‐benzoyl and N‐3,5‐dinitrobenzoyl derivatives were well separable with high resolution. To achieve optimal separation of the enantiomers, the chromatographic conditions and temperature were varied. Linear van't Hoff plots were observed in the studied temperature range, 278–343 K, and the apparent changes in enthalpy, Δ(ΔH°), entropy, Δ(ΔS°), and Gibbs free energy, Δ(ΔG°), were calculated. The values of the thermodynamic parameters depended on the nature of the N‐acyl groups, on the structures of the compounds, and especially on the nature of the substituent on C3 of phenylalanine.
Separation and identification of the organic acids in Angelicae Radix and Ligustici Rhizoma by HPLC and CE
Authors: Huang Wen‐Ying , Sheu Shuenn‐Jyi 
Published: October 2006

AbstractAngelicae Radix (AR) and Ligustici Rhizoma (LR) are both derived from the Umbelliferae plants and contain similar organic acids as their bioactive compounds. Nine of these organic acids, including nicotinic acid, protocatechuic acid, phthalic acid, folinic acid, p‐hydroxybenzoic acid, folic acid, vanillic acid, caffeic acid, and ferulic acid were separated by HPLC and CE. Detection at 210 nm with a linear gradient containing 20 mM KH2PO4 (pH 3.5) and H2O–CH3CN in HPLC and with a buffer solution containing 10 mM LTAC, 2 mM Na2HPO4, 9 mM Na2B4O7 (pH 9.56), and CH3CN in CE were found to be the most efficient eluents for this separation. The contents of the nine components in crude extracts of either AR or LR could easily be determined within 60 min by LC and within 20 min by CE. The structures of the individual peaks in the LC chromatogram were identified by LC‐MS. The effects of buffers on the separation and validation of the two methods were examined.
An evaluation of GC‐MS and HPLC‐FD methods for analysis of protein binders in paintings
Authors: Přikryl Petr , Havlíčková Lenka , Pacáková Věra , Hradilová Janka , Štulík Karel , Hofta Petr 
Published: October 2006

AbstractTwo chromatographic methods have been compared for analysis of protein‐binding media used in paintings, namely, HPLC with fluorescence detection and GC‐MS. The proteins were hydrolyzed to the corresponding amino acids (AAs) by gaseous HCl and the AAs were derivatized with methyl chloroformate, followed by GC‐MS or by HPLC after derivatization with the AccQ fluorescence reagent. The hydrolysis, derivatization reactions and the chromatographic procedures have been optimized and applied to standard binding media, model and real samples of paintings. The methods have been compared and critically evaluated.
Magnetic IDA‐modified hydrophilic methacrylate‐based polymer microspheres for IMAC protein separation
Authors: Přikryl Petr , Horák Daniel , Tichá Marie , Kučerová Zdenka 
Published: October 2006

AbstractPreparation of a new type of magnetic non‐porous poly(2‐hydroxyethyl methacrylate‐co‐glycidyl methacrylate) microspheres with hydrophilic properties containing coupled iminodiacetic acid (IDA) is described. The prepared microspheres were used for the immobilization of Ni(II) or Fe(III) ions to show their application in protein binding studies. Human IgG was bound to magnetic Ni(II)‐IDA‐modified microspheres and conditions of its adsorption and elution were optimized. Non‐specific binding of the protein to magnetic microspheres in the absence of Ni(II) ions was low. Fe(III) ions immobilized on magnetic IDA‐modified microspheres were used for the specific binding of porcine pepsin, as a model phosphoprotein. The ability of phosphate buffer to release the adsorbed enzyme from the microspheres and a low adsorption of the dephosphorylated protein indicate the participation of phosphate groups in the pepsin interaction. The elaborated method represents a rapid technique that can be used not only for the separation of proteins but also for analytical purposes.
High‐speed analyses using rapid resolution liquid chromatography on 1.8‐μm porous particles
Authors: Yoshida Tatsunari , Majors Ronald E. 
Published: October 2006

AbstractThe potential of high‐speed analyses by rapid resolution liquid chromatography (RRLC) and RRLC/MS on 1.8‐μm porous particles packed into short columns operated at high flow‐rate was investigated and compared with the performance of 5‐μm porous particles packed into conventional columns. Using similar chemistries, the ease of conversion from conventional HPLC to an RRLC method was demonstrated. In order to display the practicality of RRLC separations, the analysis of pesticides in crops and catechins in Japanese green tea was selected. Using the Japanese Food Hygiene Law method, which employs a conventional 5‐μm RP column (250 mm×4.6 mm) for quantification of pesticides in crops, the analysis time was 25 min under isocratic conditions. Using the RRLC method on the short (50 mm×4.6 mm) column packed with 1.8‐μm porous particles, the same separation could be performed in 0.8 min with the RRLC/MS method without a loss in resolution. At the highest flow rate, compared to the conventional method, the time could be reduced by a factor of 31. In gradient elution, the fastest separation of catechins in Japanese green tea was achieved by RRLC on 50‐mm×4.6‐mm id or 50‐mm×2.1‐mm id RRLC columns packed with 1.8‐μm particles. The analysis time at 5 mL/min was less than 1 min. Compared to the conventional HPLC method on a 150‐mm column packed with 5‐μm particles, time was reduced by a factor of 15. The effect of other experimental parameters such as the column temperature, acquisition rate of the detector and the influence of cell volume on chromatographic performance was also investigated. After the optimization, the analysis precision under the fastest RRLC conditions was examined. RSDs of retention time and peak area were 0.2% and 0.47%, respectively.
Validation in context of bioanalytical research papers
Authors: Rogatsky Eduard , Tomuta Vlad , Stein Daniel T. 
Published: October 2006

AbstractWe have noticed the growing amount of application papers, mainly focused on detailed description of analytical assay validation with limited discussion of method development and optimization in top‐ranked chromatographic journals. We analyze the implications of this trend and suggest a re‐emphasis on the intellectual component in method development.
Identification of a risk haplotype of the α‐synuclein gene in Japanese with sporadic Parkinson's disease
Authors: Kobayashi Hideaki , Ujike Hiroshi , Hasegawa Junko , Yamamoto Mitsutoshi , Kanzaki Akihiro , Sora Ichiro 
Published: October 2006

Abstractα‐Synuclein is one of the main components of Lewy bodies, a pathological marker of Parkinson's disease (PD). Certain missense mutations of the α‐synuclein gene cause familial PD, but the role of the gene in sporadic PD is still controversial. We scrutinized polymorphisms of the α‐synuclein gene in a Japanese population and investigated their associations with sporadic cases of PD. The 5′ flanking region to intron 2 of the α‐synuclein gene (3.8 kb) and two polymorphisms in intron 4 previously reported in Caucasian sporadic cases of PD were analyzed in 185 sporadic PD and 191 controls. Five novel single nucleotide polymorphisms (SNPs), 16 reported SNPs, and one reported polynucleotide polymorphism (PNP) were found. Most of the polymorphisms examined were in linkage disequilibrium. Significant associations with PD were found in 15 of 21 SNPs, especially in intron 1 (IVS1+155 TmAn PNP and the IVS1+719 C>T SNP, P < 0.0001). Haplotype analysis showed that T10A7‐A‐A and T11A6‐G‐G haplotypes at three loci (IVS1+155 – IVS1+273 – IVS1+608) were strongly negative and positive risk factors of sporadic PD, respectively (odds ratios were 0.23 [95% confidence interval, 0.16–0.32] and 1.51 [95% confidence interval, 1.29–1.75]). In conclusion, our findings indicate that genetic variations of the α‐synuclein gene affect the development of sporadic PD. © 2006 Movement Disorder Society
Rapidly progressive sporadic dentatorubral pallidoluysian atrophy with intracytoplasmic inclusions and no CAG repeat expansion
Authors: Espay Alberto J. , Bergeron Catherine , Chen Robert , Lang Anthony E. 
Published: October 2006

AbstractA 48‐year‐old man developed progressive hemidystonia and postural impairment with falls, followed by choreoathetosis, hyporeflexia, ataxia, supranuclear vertical gaze palsy, and dementia, lasting only 3.5 years from symptom onset to death. Family history and genetic testing were unrevealing. Neuropathology showed findings identical to genetic dentatorubral pallidoluysian atrophy (DRPLA), except for the absence of intranuclear inclusions and the presence of intracytoplasmic inclusions in the pons, striatum, thalamus, and subthalamic nucleus. This case expands the clinical and neuropathological spectrum of DRPLA and supports the hypothesis that aggregates may not be intrinsically pathogenic. © 2006 Movement Disorder Society
Short‐term effects of tetrabenazine on chorea associated with Huntington's disease
Authors: Kenney Christopher , Hunter Christine , Davidson Anthony , Jankovic Joseph 
Published: October 2006

AbstractWe sought to assess the short‐term clinical effects of tetrabenazine (TBZ) on choreic movements in Huntington's disease patients. A total of 10 patients on stable doses of TBZ were enrolled in this observational study. Patients took their evening dose of TBZ and presented the next day to the Baylor College of Medicine Movement Disorders Clinic without taking the usual morning dose. They were assessed using the Unified Huntington's Disease Rating Scale (UHDRS) motor assessment and Beck Depression Inventory. The usual morning dose of TBZ was then administered and patients were followed with serial UHDRS motor examinations approximately every 2 hours until choreic movements subsided and then returned. TBZ decreased the UHDRS chorea score on average 42.4% ± 17.8%. The duration of effect varied from a minimum of 3.2 hours to a maximum of 8.1 hours (mean = 5.4 ± 1.3). No patient experienced an adverse event related to TBZ or its withdrawal. During short‐term follow‐up after a single dose, TBZ improves chorea for approximately 5 hours. © 2006 Movement Disorder Society
Multinuclear NMR and microscopic MRI studies of the articular cartilage nanostructure
Authors: Shinar Hadassah , Navon Gil 
Published: October 2006

AbstractStudies of the structure of articular cartilage by a number of NMR spectroscopic and imaging techniques are reviewed. Advantage is taken of the fact that the NMR investigations can be done non‐invasively on the intact tissue and do not require sectioning, slicing and decalcification as in the case of electron microscopy. The different contributions to 1H T2 relaxation are described and it is pointed out that ignoring the biexponential behavior of the transverse relaxation can lead to serious errors in the proton density measurements and the T2 characterization of the articular cartilage. A way to slow the transverse relaxation and to minimize its angular dependence by the use of dipolar echo is described. 2H double quantum filtered spectroscopic MRI is a powerful technique to follow the orientation and density of the collagen fibers in articular cartilage. Using this technique, it was found that attachment of the cartilage to the bone has a stabilizing effect on the collagen matrix and that the hydroxyapatite in the calcified zone resides near the collagen fibers but does not contribute to their order. In response to mechanical pressure, it was shown that the collagen fibers flatten near the surface and become crimped near the bone. A number of NMR techniques have been described for the measurement of 23Na residual quadrupolar interaction. It was found that this can serve as a very sensitive measure of the depletion of proteoglycans. Finally, a combination of the above techniques was used to study a maturation of articular cartilage in pigs. The increased order and density of the collagen fibers from newborn to adult pigs revealed itself as a shortening of T2 and significant increase of the residual quadrupolar interaction of both 2H and 23Na nuclei. Copyright © 2006 John Wiley & Sons, Ltd.
MRI assessment of cartilage ultrastructure
Authors: Gründer Wilfried 
Published: October 2006

AbstractInT2‐weighted MRI images joint cartilage can appear laminated. The multilaminar appearance is visualized as zones of different intensity. This appearance is based on the dipolar interaction of water molecules within cartilage zones of different collageneous network structures. Therefore, the MR visualization of zones of anisotropic arrangement of the collagen fibers depends upon their orientation to the static magnetic field (magic‐angle effect). The aim of this article is to demonstrate the potential of high‐resolution MRI for characterizing cartilage network structuring and biomechanical properties. Information equivalent to that from polarization light microscopy can be derived noninvasively. Based on NMR microscopic (µMRI) data, potential new possibilities of MRI for quantitative assessment of collagen structuring and intracartilagenous load distribution are presented. These methods use MR intensity angle dependence and load influence on cartilage visualization. Alternatively to the determination of mechanical parameters from cartilage deformation, it is demonstrated that stress distribution and biomechanical properties can be derived in principle from the local intensity variation of anisotropic fiber orientation zones. The limitations with respect to a clinical application of the proposed methods are discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Sodium and T1ρ MRI for molecular and diagnostic imaging of articular cartilage
Authors: Borthakur Arijitt , Mellon Eric , Niyogi Sampreet , Witschey Walter , Kneeland J. Bruce , Reddy Ravinder 
Published: October 2006

AbstractIn this article, both sodium magnetic resonance (MR) and T1ρ relaxation mapping aimed at measuring molecular changes in cartilage for the diagnostic imaging of osteoarthritis are reviewed. First, an introduction to structure of cartilage, its degeneration in osteoarthritis (OA) and an outline of diagnostic imaging methods in quantifying molecular changes and early diagnostic aspects of cartilage degeneration are described. The sodium MRI section begins with a brief overview of the theory of sodium NMR of biological tissues and is followed by a section on multiple quantum filters that can be used to quantify both bi‐exponential relaxation and residual quadrupolar interaction. Specifically, (i) the rationale behind the use of sodium MRI in quantifying proteoglycan (PG) changes, (ii) validation studies using biochemical assays, (iii) studies on human OA specimens, (iv) results on animal models and (v) clinical imaging protocols are reviewed. Results demonstrating the feasibility of quantifying PG in OA patients and comparison with that in healthy subjects are also presented. The section concludes with the discussion of advantages and potential issues with sodium MRI and the impact of new technological advancements (e.g. ultra‐high field scanners and parallel imaging methods). In the theory section on T1ρ, a brief description of (i) principles of measuring T1ρ relaxation, (ii) pulse sequences for computing T1ρ relaxation maps, (iii) issues regarding radio frequency power deposition, (iv) mechanisms that contribute to T1ρ in biological tissues and (v) effects of exchange and dipolar interaction on T1ρ dispersion are discussed. Correlation of T1ρ relaxation rate with macromolecular content and biomechanical properties in cartilage specimens subjected to trypsin and cytokine‐induced glycosaminoglycan depletion and validation against biochemical assay and histopathology are presented. Experimental T1ρ data from osteoarthritic specimens, animal models, healthy human subjects and as well from osteoarthritic patients are provided. The current status of T1ρ relaxation mapping of cartilage and future directions is also discussed. Copyright © 2006 John Wiley & Sons, Ltd.