bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetic resonance imaging for ischemic heart disease
Authors: Sakuma Hajime 
Published: July 2007

AbstractCardiac MRI has long been recognized as an accurate and reliable means of evaluating cardiac anatomy and ventricular function. Considerable progress has been made in the field of cardiac MRI, and cardiac MRI can provide accurate evaluation of myocardial ischemia and infarction (MI). Late gadolinium (Gd)‐enhanced MRI can clearly delineate subendocardial infarction, and the assessment of transmural extent of infarction on late enhanced MRI has been shown to be useful in predicting functional recovery of dysfunctional myocardium in patients after MI. Stress first‐pass contrast‐enhanced (CE) myocardial perfusion MRI can be used to detect subendocardial ischemia, and recent studies have demonstrated the high diagnostic accuracy of stress myocardial perfusion MRI for detecting significant coronary artery disease (CAD). Free‐breathing, whole‐heart coronary MR angiography (MRA) was recently introduced as a method that can provide visualization of all three major coronary arteries within a single three‐dimensional (3D) acquisition. With further improvements in MRI techniques and the establishment of a standardized study protocol, cardiac MRI will play a pivotal role in managing patients with ischemic heart disease. J. Magn. Reson. Imaging 2007;26:3–13. © 2007 Wiley‐Liss, Inc.
Optically mediated nerve stimulation: Identification of injury thresholds
Authors: Wells Jonathon D. , Thomsen Sharon , Whitaker Peter , Jansen E. Duco , Kao Chris C. , Konrad Peter E. , Mahadevan‐Jansen Anita 
Published: July 2007

AbstractBackground and ObjectiveTransient optical nerve stimulation is a promising new non‐contact, spatially precise, artifact‐free neural excitation technique useful in research and clinical settings. This study evaluates safety of this pulsed infrared laser technique by histopathologic examination of stimulated peripheral nerves.Study Design/Materials and MethodsExposed rat sciatic nerves were functionally stimulated with the pulsed Holmium:YAG laser, previously validated as an effective tool for optical stimulation. Nerves were removed immediately and up to 2 weeks after stimulation and assessed histologically for thermal damage. Laser parameters studied include upper limits for radiant exposure, repetition rate, and duration of stimulation.ResultsRadiant exposures with <1% probability of thermal tissue damage (0.66–0.70 J/cm2) are significantly greater than radiant exposures required for reliable stimulation (0.34–0.48 J/cm2). The upper limit for safe laser stimulation repetition rate occurs near 5 Hz. Maximum duration for constant low repetition rate stimulation (2 Hz) is ∼4 minutes with adequate tissue hydration.ConclusionResults confirm that optical stimulation has the potential to become a powerful non‐contact clinical and research tool for brief nerve stimulation with low risk of nerve thermal damage. Lasers Surg. Med. 39:513–526, 2007. © 2007 Wiley‐Liss, Inc.
Clinical and positron emission tomography findings of chorea associated with primary antiphospholipid antibody syndrome
Authors: Wu Steve W. , Graham Brent , Gelfand Michael J. , Gruppo Ralph E. , Dinopolous Argirios , Gilbert Donald L. 
Published: July 2007

AbstractA fourteen‐year‐old right‐handed male with a history of attention deficit hyperactivity disorder (ADHD) presented with alternating hemichorea. Laboratory findings included elevated anticardiolipin IgG and anti‐β2‐glycoprotein I IgG, which were consistent with primary antiphospholipid antibody syndrome. Positron emission tomography (PET) imaging revealed altered striatal metabolism in his left putamen while he was exhibiting right‐sided hemichorea. His symptoms resolved on prednisone; however, his antiphospholipid antibody profile remained markedly abnormal despite being symptom‐free for 26 months. © 2007 Movement Disorder Society
Noninvasive measurement of arterial cerebral blood volume using look‐locker EPI and arterial spin labeling
Authors: Brookes M.J. , Morris P.G. , Gowland P.A. , Francis S.T. 
Published: July 2007

AbstractThis paper describes a method of noninvasively measuring regional arterial cerebral blood volume fractions (CBVa) in vivo using the combination of Look‐Locker echo‐planar imaging (LL‐EPI) with arterial spin labeling (ASL). Using this technique the arterial inflow curve is rapidly sampled and the regional CBVa is measured, while tissue perfusion signals are suppressed. Two methods of spin labeling (LL‐EPI flow‐sensitive alternating inversion recovery (LL‐EPI‐FAIR) and LL‐EPI signal targeting using alternating radiofrequency (LL‐EPI‐STAR)) are assessed and their advantages discussed. The application of vascular crushing to LL‐EPI‐FAIR is described and used to validate the insensitivity of the sequence to the perfusion difference signal. LL‐EPI‐STAR is used to assess changes in CBVa in response to a finger‐tapping task. LL‐EPI‐STAR signal difference curves are shown to have a shortened vascular transit delay and increased peak signal change on activation. A 33 ± 14% increase in CBVa on activation is found. CBVa is measured with a 6‐s temporal resolution and the temporal response is compared with the BOLD signal change. CBVa is shown to increase more rapidly and return to baseline significantly faster than the BOLD signal change, which supports the suggestion that a change in CBVa is an input to the BOLD response. Magn Reson Med 58:41–54, 2007. © 2007 Wiley‐Liss, Inc.
Modification of Gd‐DTPA cystine copolymers with PEG‐1000 optimizes pharmacokinetics and tissue retention for magnetic resonance angiography
Authors: Mohs Aaron M. , Nguyen Thanh , Jeong Eun‐Kee , Feng Yi , Emerson Lyska , Zong Yuda , Parker Dennis L. , Lu Zheng‐Rong 
Published: July 2007

AbstractThe purpose of this study was to investigate the effect of PEGylation of novel biodegradable macromolecular polydisulfide Gd(III) complexes, gadolinium diethylenetriaminepentaacetate (GdDTPA) cystine copolymers (GDCP), on their pharmacokinetics and long‐term Gd(III) tissue retention, and to demonstrate the potential application of PEGylated GDCP (PEG‐GDCP) for MR angiography (MRA). The pharmacokinetics, biodistribution, and metabolic excretion of PEG1000‐GDCP (42.1–52.1 kDa; PEG: MW = 1000 Da) with three different PEG grafting degrees and GDCP (43.3 kDa) were investigated in Sprague‐Dawley rats. Pharmacokinetic data were analyzed by means of an open two‐compartment model. Initially all three PEG1000‐GDCP contrast agents (CAs) had a higher plasma concentration than GDCP, but after 30 min the Gd(III) concentration from the PEGylated agents rapidly decreased, resulting in significantly lower elimination half‐life values. All of the biodegradable macromolecular CAs demonstrated low long‐term Gd(III) tissue accumulation, while PEG1000‐GDCP had significantly lower accumulation in the liver than GDCP. In the rats, all CAs showed excellent vascular contrast enhancement in an MRA protocol with a long image acquisition time. Because PEG1000‐GDCP remained intravascular for an acceptable period for effective contrast‐enhanced (CE)‐MRA, and then excreted rapidly from the vasculature with minimal tissue retention, PEG1000‐GDCP shows a great promise as a blood‐pool CA for MRA. Magn Reson Med 58:110–118, 2007. © 2007 Wiley‐Liss, Inc.
Gas transport in surface grafted polypropylene films with poly(acrylic acid) chains
Authors: Costamagna Vanina , Strumia Miriam , López‐González Mar , Riande Evaristo 
Published: July 2007

AbstractThis work describes the grafting reaction of poly(acrylic acid) (PA) onto the surface of polypropylene (PP) films carried out with ultraviolet radiation, using benzophenone as photoinitiator and water as solvent. By increasing the reaction time, graft percentages of 3.5, 6.5, 12.9, 19.8, 29.4, and 36.0% were obtained. Micrographs of the modified films show that grafting exclusively occurs on the PP films surface. The values of the permeability coefficient of oxygen, nitrogen, carbon dioxide, carbon monoxide, argon, methane, ethane, ethylene, and propane across the grafted films undergo a sharp drop. The interpretation of the permeation results suggest that radicals created in the tertiary carbons of the grafted chains by effect of UV light or by chain transfer reactions may highly crosslink the PA grafted layer. A rigid layer involving both strong hydrogen bonding and chains crosslinking is formed at grafting percentages of 3.5% that strongly hinders gas permeation across that layer. Destruction of hydrogen bonding by partially replacing protons of acrylic acid residues by sodium/silver cations increases the permeability of the surface grafted films. Finally, the films permselectivity is hardly affected by the grafted layer. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2421–2431, 2007
Factors that Contribute to the Growth of Ag@TiO2 Nanofibers by Plasma Deposition
Authors: Borras Ana , Barranco Ángel , Espinós Juan P. , Cotrino José , Holgado Juan P. , González‐Elipe Agustín R. 
Published: July 2007

AbstractA model experiment on the plasma deposition of TiO2 on silver is described which can help to identify the factors that control the formation of supported Ag@TiO2 nanofibers during plasma deposition of TiO2 at T > 130 °C. The plasma oxidation of silver and the plasma deposition of TiO2 on dispersed metal particles have also been studied and correlated with film topography. The species in the plasma have been analysed and fiber growth has been followed as a function of deposition time. The experimental evidence indicates that factors controlling fiber formation include silver mobility, stress relaxation of oxidized silver surfaces, chemical reduction of silver oxide, and inhomogeneities of the plasma sheath.magnified image
Evidence for distinct DNA‐ and RNA‐based mechanisms of 5‐fluorouracil cytotoxicity in Saccharomyces cerevisiae
Authors: Hoskins Jason , Scott Butler J. 
Published: July 2007

Abstract5‐Fluorouracil (5FU) is an effective chemotherapeutic drug developed as an inhibitor of thymidylate synthetase (TS). Inhibition of TS leads to ‘thymine‐less death’, a condition resulting from depletion of dTTP pools and misincorporation of dUTP into newly synthesized or repaired DNA. 5FU is also incorporated into RNA and a growing body of evidence suggests that RNA‐based effects play a significant role in its cytotoxicity. Indeed, recent experiments in yeast showed that defects in the nuclear RNA exosome subunit Rrp6p cause hypersensitivity to 5FU. The present study asked whether the 5FU hypersensitivity of an rrp6‐Δ yeast strain reflects the DNA‐ or RNA‐based effects of 5FU. Genetic analyses suggest that while a DNA repair mutation, apn1‐Δ, causes sensitivity to 5FU‐induced DNA damage, an rrp6‐Δ mutation causes hypersensitivity, due to the RNA‐based effects of 5FU. Analysis of a strain with normal DNA and RNA metabolism grown in the presence of 5FU shows that UMP suppresses the 5FU‐induced defect more than dTMP, suggesting that the RNA‐based toxicity of 5FU predominates in these cells. These findings underscore the importance of understanding the RNA‐based mechanism of 5FU cytotoxicity and highlight the use of yeast as a model system for elucidating its details. Copyright © 2007 John Wiley & Sons, Ltd.
Cyclization of eleostearic acid
Authors: Paschke R. F. , Wheeler D. H. 
Published: July 2007

Summary

Methyl eleostearate has been thermally cyclized in good yields, and a concentrate of the cyclic product has been prepared.

Using small amounts, a technique has been devised for a) aromatization of the resultant cyclohexadiene, b) oxidation to orthophthalic acid, and c) characterization of the acid as the anhydride and the imide.

The significance of cyclic fatty acids in industrial processes is discussed.
The fractionation of marine‐oil fatty acids with urea
Authors: Domart Claude , Miyauchi D. T. , Sumerwell W. N. 
Published: July 2007

SummaryIn two series of experiments, marine‐animal‐oil fatty acids were fractionated with urea using methanol as solvent.In the first series, menhaden‐oil fatty acids were fractionated at 1°C. Almost all the saturated and monoenoic fatty acids were removed at mole ratios of 12∶1 to 13∶1. At higher ratios increasing amounts of the less stable dienoic fatty acids were precipitated. By the use of the appropriate ratio, fractions having iodine values above 300 were prepared.In the second series, fatty acids from the oils of menhaden, herring, tuna, seal, salmon eggs, and salmon heads and viscera were fractionated at a mole ratio of urea to fatty acid of 9.2∶1. At 25° and 1° the complexes were composed almost entirely of saturated and monoenoic fatty acids, but as the temperature was lowered to −30°, the content of dienoic fatty acids in the precipitates increased.
Carbonyl compounds in rancid corn oil
Authors: Buss C. D. , Mackinney Gordon 
Published: July 2007

SummaryFourteen petroleum ether‐soluble and 16 insoluble DNPH derivatives have been isolated from rancid corn oil and their properties discussed. Evidence suggests that n‐undecanal and n‐undecenal are among the components of the rancid oil.
Isolation of pure natural linoleic and linolenic acids as their methyl esters by adsorption fractionation on silicic acid
Authors: Riemenschneider R. W. , Herb S. F. , Nichols Peter L. 
Published: July 2007

SummaryAn effective procedure is described for fractionating methyl esters of oils rich in linoleic and linolenic acids by adsorption on silicic acid columns. Pure methyl linoleate from methyl esters of tobacco seed oil and pure methyl linolenate from methyl esters of linseed and perilla oils were isolated by this procedure. These compounds were characterized by the usual physical and chemical constants and by spectrophotometric examination. These natural acid esters differed significantly from corresponding debromination acid esters in the intensity of ultraviolet absorption at their maxima under the conditions of the alkali‐isomerization spectrophotometric method of analysis.
Comparison of fatty acid content of imported peanuts
Authors: How James S.L , Young Clyde T. 
Published: July 2007

AbstractVariability in fatty acid compositions of peanuts imported from six different countries into the United States were studied to determine their effect on processing and storage conditions. The oil content ranged from 44.1 to 50.4%. Major fatty acids, palmitic acid (C16:0), oleic acid (C18:l), and linoleic acid (C18:2) ranged from 8.6 to 12.7, 35.9 to 61.1 and 21.7 to 44.2%, respectively. Oleic and lino‐leic acids together comprised ca. 78.0–83.0% of the total fatty acids. Highly significant differences (P<.01) in fatty acid compositions were obtained between samples and between locations (countries of origin). Indicators of stability of the peanut samples as measured by the oleic/linoleic acid ratio (O/L) and iodine value (IV) of the extracted peanut oils showed variable but significant differences (P <.05) between locations. Generally, higher O/L ratios corresponding to lower IV indicate better stability and longer shelf‐life of the samples.
Biochemistry of unsaturated fatty acid isomers
Authors: Emken E. A. 
Published: July 2007

AbstractRecognition that catalytic hydrogenation changes the configuration and position of double bonds and alters the physical properties of unsaturated fats prompted numerous early investigations on the bio‐chemical effects of ldtrans isomers.” Recent research has provided data on positional isomer metabolism. Some aspects of fatty acid isomer metabolism are now reasonably well understood, but other issues are not resolved. Human and animal data have provided good evidence that isomers in partially hydrogenated oils are well adsorbed and incorporated into all organs and tissues. Analyses of human tissues also indicate that hydrogenated oils are the major source of fatty acid isomers in the US diet. Tissue composition data combined with isolated enzyme studies and isotope tracer experiments with whole organisms show unquestionably that structural differences between various fatty acid isomers influence specific biochemical transformations. Examples are differences in the reaction rates and/ or specificities of acyl transferase, lipase, desaturase and cholesteryl esterase/hydrolase for various positional fatty acid isomers. Isolated microsomes and mitochondria also have been used to identify dif‐ferences in acyl CoA activation, oxidation, and elongation of positional isomers. In addition, isotope tracer experiments show that preferential metabolism of individual positional isomers occurs in vivo. In vivo studies with hydrogenated vegetable oil diets containing adequate levels of linoleic acid produced no obvious physiological changes. Experiments with specific polyunsaturated isomers have produced changes in blood cell properties, pulmonary weight, lino‐leic acid requirements and tissue lipid composition. These changes may be related to a number of factors such as membrane fluidity and permeability, cell function, synthesis of arachidonic acid, homo‐gamma‐linoleic acid or prostaglandins. Whether differences in the biochemistry of fatty acid isomers are desirable or undesirable and whether these differences contribute to long‐term or subtle effects important to the etiology of atherosclerosis and cancer are not resolved.
Eicosapentaenoic acid geometrical isomer artifacts in heated fish oil esters
Authors: Wijesundera R. C. , Ratnayake W. M. N. , Ackman R. G. 
Published: July 2007

AbstractGas liquid chromatography (GLC) on polar capillary columns showed that the ester of eicosapentaenoic acid (EPA) in distilled fish oil methyl and ethyl esters sometimes is accompanied by several artifacts. The same EPA artifacts did not arise from saponification and/or esterification but were formed in a significantly high yield during prolonged heating of the authentic acid. Physicochemical studies, isolation and partial degradation showed that these artifacts are mainly geometrical (cis‐trans) isomers of the naturalcis ethylenic bonds of eicosapentaenoic acid. Several C20 mono‐and diethylenic geometrical isomers were prepared and the GLC equivalent chain length values determined. On the basis of measured and calculated equivalent chain length values on two different GLC phases, some of the EPA artifacts were identified as 20:5‐Δrans‐5,cis‐8,cis‐11,cis‐14,cis‐17; 20:5‐Δcis‐5,trans‐8,cis‐11,cis‐14,cis‐17; and 20:5‐Δcis‐5,cis8,cis‐11,cis‐14,trans‐17. No evidence was found for any positional isomers.
Chemical degumming of canola oils
Authors: Diosady L. L. , Sleggs P. , Kaji T. 
Published: July 2007

AbstractCrude oil produced from 2 varieties of canola (low thioglucoside rapeseed), i.e., Candle and Tower, were chemically degummed using 54 reagents. Phosphorus, iron, calcum and free fatty acid levels, and Lovibond colors were measured. Inorganic and organic acids or their anhydrides gave the best results in terms of phosphorus removal. Phosphoric, nitric and citric acids, and maleic anhydride were used in laboratory refining tests to determine the effects of chemical degumming on the refining process and on refined oil quality. Citric acid and maleic anhydride gave residual phosphorus levels of less than 50 mg/kg, and after refining, resulted in the best quality oil in terms of color, flavor and stability. The chemical degumming agents behaved similarly for expressed, solvent‐extracted and blended oils of both varieties tested. One anomalous result was observed: Candle oil was not efficiently degummed by hydrocholoric acid, whereas the Tower oil gave excellent results. The experiments suggest that chemical degumming can significantly improve the quality of crude canola oil, and will lead to improved final products at lower cost to the refiner.
Inhibitors of the prooxidant activity of α‐tocopherol
Authors: Cillard J. , Cillard P. 
Published: July 2007

AbstractThe prooxidant activity ofα‐tocopherol (α‐T) can be reduced or inverted into antioxidant activity by various compounds.An important antioxidant activity was obtained by the association ofα‐T with cysteine, BHT, hydro‐quinone and ascorbyl palmitate. EDTA 10‐4M, phos‐phoric, malonic and citric acids can partially decrease the prooxidant effect ofα‐T, although the strong acids exhibited no antioxidant activity withoutα‐T. Other amino acids such as glycine and alanine do little to reduce the prooxidant behavior of α‐T while they showed a strong antioxidant activity without α‐T.The distribution of hydroperoxide isomers of linoleic acid formed with and withoutα‐T was not modified by the addition of the various compounds except BHT, which led to the production of only 13c,t and 9c,t isomers as observed withα‐T.The oxidation ofα‐T in the presence of linoleic acid was completely inhibited by the addition of cysteine, phosphoric, malonic and citric acids, BHT, hydro‐quinone, ascorbyl palmitate and EDTA 10‐4M.The inhibitors of the prooxidant activity ofα‐T could act in two different ways: by chelating the prooxidant metals traces (i.e., amino acids, EDTA) and/or by regeneratingα‐T, thus reducing the concentration of chromanoxy radical which would be involved in the prooxidant activity (i.e. phosphoric, malonic, citric acids, cysteine and the common antioxidants).
Hydrocarbon carotenoid profiles of palm oil processed fractions
Authors: Tan B. , Grady C. M. , Gawienowski A. M. 
Published: July 2007

AbstractAnalysis by gradient‐elution normal phase open column chromatography, thin layer chromatography and ultraviolet‐visible spectroscopy (confirmation by two to three peaks), including calculation of peak ratios, tentatively revealed seven previously unreported hydrocarbon carotenoids in palm oil fractions. They were phytoene, phytofluene, ξ‐carotene,α‐zeacarotene, β‐zeacarotene, neurosporene and δ‐carotene. In addi‐tion, the presence ofα‐,β‐ andδ‐carotenes and lycopene was confirmed. The carotenoid profiles of crude palm oil, crude palm olein and filtered palm olein were similar; carotenoids in these fractions totalled 700–800 ppm. Carotenoids were not found in refined, filtered and deodorized palm olein, while palm kernel oil contained 0.3 ppm ofα‐zeacarotene. The yield of hydrocarbon carotenoids was 30% lower in the absence of the antioxidant butylated hydroxytoluene.
The study of aluminum soap‐hydrocarbon systems: Effect of additives and metathesis
Authors: Smith Gerould H. , Rogers Lockhart B. , Mysels Karol J. 
Published: July 2007

SummaryMany additives have pronounced and manifold effects on the behavior of aluminum soaps‐hydrocarbon systems. Some additives accelerate the formation of jellies, other retard it. Some thicken the jellies, others liquefy them. The mechanism of the action of additives is probably manifold, too. One of the many possible mechanisms is that of metathesis between the fatty acid radical of the soap and acidic additives. The actual occurrence of such metathesis is demonstrated by both qualitative observations of a variety of systems and by the preparation in benzene of aluminum dibenzoate from the dilaurate.
Recent research on sesamin, sesamolin, and related compounds
Authors: Budowski P. 
Published: July 2007

AbstractThis review covers the literature on sesamin, sesamolin and related compounds published since 1951. The topics reviewed include structural con‐siderations, natural occurrence, influence of oil processing, analytical methods, isolation proce‐dures and commercial preparations, various bio‐logical effects and stability questions.Recent developments in pyrethrum synergists are discussed at length, since they owe so much to the discovery of the synergistic activities of sesamin and sesamolin.