bluuebunny/crossref_metadata_2025_split huggingface dataset:
Verification of Applicability of Mercury Meniscus Modified Silver Solid Amalgam Electrode for Determination of Heavy Metals in Plant Matrices
Authors: Čížková Petra , Navrátil Tomáš , Šestáková Ivana , Yosypchuk Bogdan 
Published: November 2006

AbstractThe study is focused on the silver solid amalgam electrode modified by mercury meniscus (m‐AgSAE). After its successful application for determination of heavy metals by differential pulse anodic stripping voltammetry (DPASV) in aqueous solutions, its use in more complicated matrices has followed. Four different reference materials of plant origin were used – White Cabbage, Rye Grass, Aubergine and Lucerne, and the obtained results of Cd, Cu and Pb contents were compared both with (certified) reference values and with results obtained by DPASV with HMDE and by AAS. Statistical evaluation confirmed good correlation between results of all three methods used and as well as with reference values.
Thermo‐Responsive Chitosan‐graft‐poly(N‐isopropylacrylamide) Injectable Hydrogel for Cultivation of Chondrocytes and Meniscus Cells
Authors: Chen Jyh‐Ping , Cheng Tai‐Hong 
Published: November 2006

AbstractSummary: A thermo‐responsive comb‐like polymer with chitosan as the backbone and pendant poly(N‐isopropylacrylamide) (PNIPAM) groups has been synthesized by grafting PNIPAM‐COOH with a single carboxy end group onto chitosan through amide bond linkages. The copolymer exhibits reversible temperature‐responsive soluble‐insoluble characteristics with the lower critical solution temperature (LCST) being at around 30 °C. Results from SEM observations confirm a porous 3D hydrogel structure with interconnected pores ranging from 10 to 40 µm at physiological temperature. A preliminary in vitro cell culture study has demonstrated the usefulness of this hydrogel as an injectable cell‐carrier material for entrapping chondrocytes and meniscus cells. The hydrogel not only preserves the viability and phenotypic morphology of the entrapped cells but also stimulates the initial cell‐cell interactions.
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Linear system solution by null‐space approximation and projection (SNAP)
Authors: Ilić M. , Turner I. W. , Saad Y. 
Published: November 2006

AbstractSolutions of large sparse linear systems of equations are usually obtained iteratively by constructing a smaller dimensional subspace such as a Krylov subspace. The convergence of these methods is sometimes hampered by the presence of small eigenvalues, in which case, some form of deflation can help improve convergence. The method presented in this paper enables the solution to be approximated by focusing the attention directly on the ‘small’ eigenspace (‘singular vector’ space). It is based on embedding the solution of the linear system within the eigenvalue problem (singular value problem) in order to facilitate the direct use of methods such as implicitly restarted Arnoldi or Jacobi–Davidson for the linear system solution. The proposed method, called ‘solution by null‐space approximation and projection’ (SNAP), differs from other similar approaches in that it converts the non‐homogeneous system into a homogeneous one by constructing an annihilator of the right‐hand side. The solution then lies in the null space of the resulting matrix. We examine the construction of a sequence of approximate null spaces using a Jacobi–Davidson style singular value decomposition method, called restarted SNAP‐JD, from which an approximate solution can be obtained. Relevant theory is discussed and the method is illustrated by numerical examples where SNAP is compared with both GMRES and GMRES‐IR. Copyright © 2006 John Wiley & Sons, Ltd.
Establishing a liquid‐phase IEF in combination with 2‐DE for the analysis of Leishmania proteins
Authors: Brobey Reynolds K. B. , Soong Lynn 
Published: November 2006

AbstractThe recent completion of genome sequencing projects for Leishmania major and near completion for two other species, L. infantum and L. braziliensis, has provided the needed genomic information for investigating the proteomes of Leishmania parasites. However, the design of effective 2‐DE‐based proteome mapping for complex protozoan parasites like Leishmania has proven to be severely compromised due to extensive overcrowding of spots especially in the acidic regions, coupled to a relatively low representation of basic proteins. In the present study, we optimized a liquid‐phase IEF in combination with 2‐DE for L. amazonensis promastigote as a way of reducing protein complexity and enhancing representation for low‐abundance proteins on gels. Of 20 pH‐based fractions eluted from Rotofor™ cells, 5 representative fractions selected from acidic, basic or neutral regions of the proteome and with adequate protein concentration were further analyzed by 2‐DE using medium‐range IPG strips. On this basis, we were able to generate high‐resolution 2‐DE maps encompassing both the acidic and basic ends of the proteome with enhanced spot representation.
Chemoprevention of Scutellaria bardata on human cancer cells and tumorigenesis in skin cancer
Authors: Suh Seok‐Jong , Yoon Jong‐Won , Lee Tae‐Kyun , Jin Un‐Ho , Kim Sun‐Lim , Kim Myung‐Sunny , Kwon Dae Young , Lee Young‐Choon , Kim Cheorl‐Ho 
Published: November 2006

AbstractScutellaria barbata D. Don (Lamiaceae) (SB) is a perennial herb, which is natively distributed throughout Korea and southern China. This herb is known in traditional Chinese medicine as Ban‐Zhi‐Lian and in traditional Korean medicine as Banjiryun. SB has been used as an antiinflammatory and antitumor agent. The SB showed strong growth‐inhibitory activity and cancer chemopreventive activity in assays representing three major stages of carcinogenesis. The SB was found to act as an antimutagen; it mediated antiinflammatory effects; inhibited cyclooxygenase and hydroperoxidase functions (antipromotion activity). In addition, SB inhibited the development of preneoplastic lesions in carcinogen‐treated mouse mammary glands in culture and inhibited tumorigenesis in a mouse skin cancer model. On the other hand, an inhibitory effect of SB on the growth of gynecological cancer cell lines such as HeLa cell and human ovary cancer (HOC) was shown. When HOC cells were treated with SB, the expression of cyclooxygenase‐2 was inhibited. These data suggest that SB merits investigation as a potential cancer chemopreventive agent in humans, especially in gynecological cancers. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis and TGF‐β Receptor Binding Inhibition of Multibranched Compounds
Authors: Subra Gilles , Amblard Muriel , Verdié Pascal , Komesli Sylviane , Dutartre Patrick , Durand Philippe , Renaut Patrice , Martinez Jean 
Published: November 2006

AbstractAs a part of our project aiming at the discovery of novel synthetic ligands of Transforming Growth Factor Beta (TGF‐β) receptors, five libraries were sequentially synthesised and screened. The biological mechanism involved in the TGF‐β signal transduction proceeds through the hetero‐oligomerisation of two TGF‐β subreceptor dimers, Transforming growth factor Beta Receptors (TβR)‐I and II. We hypothesised that synthetic dimers and multibranched‐molecules could mimic the natural hormone action by closing the receptor subunits. Mimotope multipin technology was used to synthesise libraries of dimers and tetramers on solid support. This strategy led to the discovery of one of the most potent TGF‐β receptor ligand on type II TGF‐β receptor, described in the literature today.
An experimental investigation of cross‐layer optimal packet size in space Internet
Authors: Wang Ruhai , Horan Stephen , Chandrasekaran Rama 
Published: November 2006

AbstractStudies of optimal packet size determination in space communication can be found in the literature. However, they are done in an analytical manner. In this paper, we present an experimental study of the cross‐layer optimal packet size for a Transmission Control Protocol (TCP) Internet Protocol (IP) enhancement, Space Communication Protocol Standards (SCPS), using a personal computer (PC)‐based testbed. We study the optimal packet size at the medium access control (MAC) layer considering the cross‐layer interactions at the physical layer. We investigate how the cross‐layer MAC packet size needs to be adjusted for optimal throughput performance based on the feedback of the bit‐error rate (BER), space‐link delay and symmetric/asymmetric channel‐rate configurations at the physical channel, and find the cross‐layer optimal packet size for the maximum throughput over the space‐Internet channels. We find that the default TCP/IP packet size of 1500 bytes for the terrestrial Internet should be chosen as the cross‐layer MAC packet size for optimal throughput performance over space channels with round‐trip time (RTT) around 250 ms and BER⩽10−6. As the channel BER at the physical layer increases, the optimal MAC packet size should be reduced to around 1000 bytes. We also find that it is more significant to have an optimal packet size for asymmetric channel than symmetric channel but the optimal packet size remains the same at a given BER for both channel ratios in our experiment. To our knowledge, this is the first paper to investigate the cross‐layer optimal MAC packet size over space‐Internet channel in the proposed approach. Copyright © 2006 John Wiley & Sons, Ltd.
Structure and intraglyceride distribution of coriolic acid
Authors: Tallent W. H. , Harris Jeanne , Spencer G. F. , Wolff I. A. 
Published: November 2006

AbstractCoriolic [(R)‐13‐hydroxy‐cis‐9,trans‐11‐octadecadienoic] acid (III, R=Z=H) was isolated as the methyl ester from twoCoriaria seed oils in 66 and 68% yields. The double bonds and hydroxyl group were located by periodate‐permanganate oxidation before, and chromic acid oxidation after, hydrogenation of the double bonds. Alternatively the positions of the functional groups were indicated by a convenient micro‐ozonolysis‐gas‐liquid chromatographic procedure. Determination of products from partial hydrolysis of theCoriaria oils with pancreatic lipase (EC 3.1.1.3) revealed a preference of the corioloyl group for the 1,3‐positions in triglyceride molecules. The possible significance of coriolic acid as an intermediate in the biogenetic conversion of linoleic acid to conjugated trienoic acids is discussed.
Volatile compounds from thermally oxidized methyl oleate
Authors: Withycombe D. A. , Libbey L. M. , Lindsay R. C. 
Published: November 2006

AbstractThermal oxidation of methyl oleate was studied over a range of temperatures from 50 C to 150 C for periods of time up to 30 min. Degradation was quantitatively followed by gas liquid chromatography (GLC) and liquid scintillation counting of the products of methyl oleate‐U‐14C heated under a stream of compressed air. Heptane, octane, 2‐decanone, benzene,o‐xylene, methyl hexanoate, methyl heptanoate and methyl octanoate were identified by GLC and mass spectrometry. Mass spectral evidence also was obtained for methyl pimelaldehydate, methyl suberaldehydate and methyl azelaaldehydate. Organic synthesis confirmed the identity of methyl azelaaldehydate. Most of the products formed suggested that autoxidation was responsible for the degradation occurring at the temperatures employed in this study.
The role of economic incentives and social norms in forest resource management
Authors: Satake Akiko 
Published: November 2006

AbstractForests are experiencing increasing pressure from human activities, which is leading to rapid deforestation and loss of ecosystem services. Although deforestation occurs for a wide range of reasons, one important reason is that landowners lack a long‐term management view. I suggest that both economic incentives and social norms will work differently to reduce landowners’ motivation to deforest and to help landowners identify the long‐term benefits that will be obtained by sacrificing short‐term gain.
n−3 fatty acids and human health: Defining strategies for public policy
Authors: Simopoulos Artemis P. 
Published: November 2006

AbstractThe last quarter of the 20th century was characterized by an increase in the consumer's interest in the nutritional aspects of health. As a result, governments began to develop dietary guidelines in addition to the traditional recommended dietary allowances, which have been superseded now by dietary reference intakes. In addition to governments, various scientific societies and nongovernmental organizations have issued their dietary advice to combat chronic diseases and obesity. Human beings evolved on a diet that was balanced in n−6 and n−3 essential fatty acid intake, whereas Western diets have a ratio of n−6/n−3 of 16.74. The scientific evidence is strong for decreasing the n−6 and increasing the n−3 intake to improve health throughout the life cycle. This paper discusses the reasons for this change and recommends the establishment of a nutrition and Food Policy, instead of a Food and Nutrition Policy, because the latter subordinates the nutritional aspects to the food policy aspects. Nutrition and food planning comprise a tool of nutrition and food policy, whose objectives are the achievement of the adequate nutrition of the population as defined by nutritional science. The scientific basis for the development of a public policy to develop dietary recommendations for essential fatty acids, including a balanced n−6/n−3 ratio is robust. What is needed is a scientific consensus, education of professionals and the public, the establishment of an agency on nutrition and food policy at the national level, and willingness of governments to institute changes. Education of the public is essential to demand changes in the food supply
Myocardial membrane fatty acids and the antiarrhythmic actions of dietary fish oil in animal models
Authors: McLennan P. L. 
Published: November 2006

AbstractEpidemiologic studies, animal studies, and more recently, clinical intervention trials all suggest a role for regular intake of dietary fish oil in reducing cardiovascular morbidity and mortality. Prevention of cardiac arrhythmias and sudden death is demonstrable at fish or fish oil intakes that have little or no effect on blood pressure or plasma lipids. In animals, dietary intake of fish oil [containing both eicosapentaenoic acid (EPA, 20∶5n−3) and docosahexaenoic acid (DHA, 22∶6n−3)] selectively increases myocardial membrane phospholipid content of DHA, whereas low dose consumption of purified fatty acids shows antiarrhythmic effects of DHA but not EPA. Ventricular fibrillation induced under many conditions, including ischemia, reperfusion, and electrical stimulation, and even arrhythmias induced in vitro with no circulating fatty acids are prevented by prior dietary consumption of fish oil. The preferential accumulation of DHA in myocardial cell membranes, its association with arrhythmia prevention, and the selective ability of pure DHA to prevent ventricular fibrillation all point to DHA as the active component of fish oil. The antiarrhythmic effect of dietary fish oil appears to depend on the accumulation of DHA in myocardial cell membranes.
Lipid and fatty acid profiles in rats consuming different high‐fat ketogenic diets
Authors: Dell Cynthia A. , Likhodii Sergei S. , Musa Kathy , Ryan Mary Ann , Burnham W. MacIntyre , Cunnane Stephen C. 
Published: November 2006

AbstractHigh‐fat ketogenic diets are used to treat intractable seizures in children, but little is known of the mechanism by which these diets work or whether fats rich in n−3 polyunsaturates might be beneficial. Tissue lipid and fatty acid profiles were determined in rats consuming very high fat (80 weight%), low‐carbohydrate ketogenic diets containing either medium‐chain triglyceride, flaxseed oil, butter, or an equal combination of these three fat sources. Ketogenic diets containing butter markedly raised liver triglyceride but had no effect on plasma cholesterol. Unlike the other fats, flaxseed oil in the ketogenic diet did not raise brain cholesterol. Brain total and free fatty acid profiles remained similar in all groups, but there was an increase in the proportion of arachidonate in brain total lipids in the medium‐chain triglyceride group, while the two groups consuming flaxseed oil had significantly lower arachidonate in brain, liver, and plasma. The very high dietary intake of α‐linolenate in the flaxseed group did not change docosahexaenoate levels in the brain. Our previous report based on these diets showed that although ketosis is higher in rats consuming a ketogenic diet based on medium‐chain triglyceride oil, seizure resistance in the pentylenetetrazol model is not clearly related to the degree of ketosis achieved. In combination with our present data from the same seizure study, it appears that ketogenic diets with widely differing effects on tissue lipids and fatty acid profiles can confer a similar amount of seizure protection.
Wax ester biosynthesis in the liver of myctophid fishes
Authors: Seo Hwan‐Sook , Endo Yasushi , Moku Masatoshi , Kawaguchi Kouichi , Fujimoto Kenshiro 
Published: November 2006

AbstractThe biosynthetic properties of wax esters in the liver were compared between two types of myctophid fishes having different body lipid composition, i.e., three triglyceriderich species (Lampanyctus jordani, Diaphus theta, and Symbolophorus californiensis) and three was ester‐rich species (L. regalis, Stenobracius nannochir, and Stenobracius leucopsarus). n‐Heptadecanol (17∶0‐ALC) and/or 10‐cis‐heptadecenoic acid (17∶1‐ACID) was incubated with liver homogenate of the six myctophid fishes and with co‐factors such as NADPH and ATP for 2 to 5 h. Considerable amounts of wax esters with odd‐numbered fatty acids and/or alcohols were produced in the liver homogenate of the was ester‐rich species. Stenobracius nannochir and L. regalis, which exclusively contained wax esters as neutral lipids, showed the highest activity of wax ester synthesis, followed by S. leucopsarus, which contained triglyceride as the minor constituent. Only trace amounts at most of odd‐numbered fatty acids and alcohols were incorporated into the wax esters after incubation with the liver homogenates of the triglyceride‐rich fishes. Active interchange between the fatty acids and the alcohols occurred during wax ester biosynthesis in the wax ester‐rich fishes. The chain elongation and shortening of acyl moieties were also observed during incubation. These results suggested that the deposition of lipids in myctophid fishes is mainly due to their biosynthetic activities.
Regulation by long‐chain fatty acids of the expression of cholesteryl ester transfer protein in HepG2 cells
Authors: Hirano Reiko , Igarashi Osamu , Kondo Kazuo , Itakura Hiroshige , Matsumoto Akiyo 
Published: November 2006

AbstractCholesteryl ester transfer protein (CETP) is an important determinant of lipoprotein function, especially high density lipoprotein (HDL) metabolism, and contributes to the regulation of plasma HDL levels. Since saturated and polyunsaturated fatty acids (FA) appear to influence the CETP activity differently, we decided to investigate the effects of FA on the expression of CETP mRNA in HepG2 cells using an RNA blot hybridization analysis. Long‐chain FA (>18 carbons) at a 0.5 mM concentration were added to the medium and incubated with cells for 48 h at 37°C under 5% CO2. After treatment with 0.5 mM arachidonic (AA), eicosapentaenoic (EPA), and docosahexaenoic acid (DHA), the levels of CETP mRNA were less than 50% of the control levels (AA, P=0.0005; EPA, P<0.01; DHA, P<0.0001), with a corresponding significant decrease in the CETP mass. These results suggest that FA regulate the gene expression of CETP in HepG2 and this effect is dependent upon the degree of unsaturation of the acyl carbon chain in FA.
Triple‐bonded unsaturated fatty acids are redox active compounds
Authors: Peterson Douglas A. , Reeve Helen L. , Nelson Daniel , Archer Stephen L. , Weir E. Kenneth 
Published: November 2006

AbstractUnsaturated fatty acids with triple bonds are used as inhibitors of unsaturated fatty acid metabolism or cytochrome P450 reactions because they are believed to be chemically inert. In this paper we use in vitro cytochrome C reduction to show that two commonly used triple‐bonded unsaturated fatty acids are in fact potent electron transfer agents and could affect the multiple cellular systems that are redox‐modulated.
Factors affecting the storage and excretion of toxic lipophilic xenobiotics
Authors: Jandacek Ronald J. , Tso Patrick 
Published: November 2006

AbstractLipophilic toxins have been introduced into the environment both as functional compounds, such as pesticides, and as industrial waste from incineration or the manufacture of electrical transformer components. Among these substances are compounds that are carcinogenic and that affect the endocrine system. Accidental high exposures of humans to some lipophilic toxins have produced overt disease symptoms including chloracne and altered liver function. These toxic materials have been the recent focus of international effort to reduce or eliminate classes of halogenated hydrocarbons from the environment. Evidence of the widespread distribution of lipophilic toxins in the biosphere has been obtained by analyses of human tissues and human milk. The principal route of entry of lipophilic toxins into humans is through the food chain, and most of them are stored in adipose tissue. A common route of excretion is in bile, but there is also evidence of nonbiliary excretion into the intestine. Enterohepatic circulation of many of these compounds slows their removal from the body. Substances that interrupt the enterohepatic circulation of compounds that enter the intestine by the biliary and nonbiliary routes increase the rate of their removal from the body and reduce their storage half‐lives. Reduction in body fat, along with these dietary substances that interrupt enterohepatic circulation, further enhances the excretion rate. Areas for further research include optimizing regimens for body burden reductions, understanding the nature of nonbiliary excretion, and following the effects of tissue redistribution during loss of body fat.
Effect of dexamethasone on the fatty acid composition of total liver microsomal lipids and phosphatidylcholine molecular species
Authors: Brenner Rodolfo R. , Ayala Sixta , Garda Horacio A. 
Published: November 2006

AbstractDexamethasone depresses Δ6 and Δ5 and increases Δ9 desaturase and synthase activities. Therefore, we investigated the effect on the fatty acid composition of microsomal liver lipids and phosphatidylcholine (PtdCho) molecular species. After 15 d of treatment we found a notable decrease in arachidonic acid, a small decrease in stearic acid, and increases of linoleic, oleic, palmitoleic, and palmitic acids in liver microsomal total lipids and PtdCho. The study of the distribution of the PtdCho molecular species indicated that 18∶0/20∶4n−6, 16∶0/20∶4n−6, and 16∶0/18∶2n−6 predominated in the control animals. Dexamethasone, as expected because of its depressing effect on arachidonic acid synthesis and activation of oleic and palmitic acid synthesis, evoked a very significant decrease in 18∶0/20∶4n−6 PtdCho (P<0.001) and an important increase in 16∶0/18∶2n−6. The invariability of 16∶0/20∶4n−6 PtdCho could be related to the antagonistic effect of arachidonic and palmitic acid synthesis. PtdCho species containing oleic acid were not significant. The bulk fluidity and dynamic properties of the microsomal lipid bilayer measured by fluorometry using the probes 1,6‐diphenyl‐1,3,5‐hexatriene and 4‐trimethylammonium‐phenyl‐6‐phenyl‐1,3,5‐hexatriene showed no significant modification, probably owing to a compensatory effect of the different molecular species, but changes of particular domains not detected by this technique are possible. However, the extremely sensitive Laurdan detected increased lipid packing in the less‐fluid domains of the polar‐nonpolar interphase of the bilayer, possibly evoked by the change of molecular species and cholesterol/phospholipid ratio. The most important effect found is the decrease of arachidonic acid pools in liver phospholipids as one of the corresponding causes of dexamethasone‐dependent pharmacological effects.