bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficient boundary element method solution of potential problems that are large, linear and involve optimization of boundary geometry
Authors: Gale Timothy John , Johnston Peter Rex , Kilpatrick David 
Published: November 2002

AbstractA method was developed for efficient boundary element method solution of potential problems that were large, linear and involved optimization of boundary geometry. The method involved forming an optimization region containing the section of boundary to be optimized, and an invariant region incorporating the remainder of the problem. Solution was by Gaussian elimination. Matrix elements arising from boundary discretization and application of the governing equations were manipulated to permit computations relating to the invariant region to be performed only once. The matrix and vector terms for the invariant region were first calculated, the matrix converted to upper‐diagonal form and the values stored. For each boundary configuration within the optimization region, additional matrix elements were computed and appended to the pre‐computed matrix. The complete set of equations were subsequently solved by conversion of the appended matrix terms to upper‐diagonal form, followed by back‐substitution. A practical example involved determining the electric field arising due to different electrodes implanted in the human heart. Computation time was found to be an order of magnitude less for the second and subsequent electrode configurations than for the first. The method may find application in boundary element method optimization problems involving complex or large regions. Copyright © 2002 John Wiley & Sons, Ltd.
Leaf and peel volatile compounds of an interspecific citrus somatic hybrid [Citrus aurantifolia (Christm.) Swing. + Citrus paradisi Macfayden]
Authors: Gancel Anne‐Laure , Ollé Didier , Ollitrault Patrick , Luro François , Brillouet Jean‐Marc 
Published: November 2002

AbstractThe volatile compounds from leaves and peels of an interspecific citrus somatic hybrid, Citrus aurantifolia (Christm.) Swing. + Citrus paradisi Macfayden, obtained by fusion of protoplasts from lime, Citrus aurantifolia (cv. Mexican Lime) and grapefruit, Citrus paradisi (cv. Star Ruby), were extracted by pentane : ether (1 : 1) from liquid nitrogen ball‐milled leaves and flavedo and examined by GC–MS in comparison to those of its parents. The hybrid quantitatively retained the ability of the lime parent to synthesize in its leaves the major monoterpene aldehydes (neral, geranial) the monoterpene alcohols (nerol, geraniol), and their acetates, and also the capacity of the grapefruit parent to produce a sesquiterpene aldehyde (β‐sinensal) in its leaves and nootkatone in its peel. Conversely, synthesis of most sesquiterpene hydrocarbons and long chain aliphatic aldehydes, which are present in the lime parent leaves and peel, was strongly inhibited in the hybrid, as in the grapefruit parent. In comparison to its parents, the hybrid overproduced citronellal in its leaves and α‐sinensal and β‐sinensal in its peel. Based on these results, the future prospects for a better understanding of the inheritance mechanisms with regards to aroma biosynthesis in citrus leaves and peels are discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Formation of fragrance materials from odourless glycosidically‐bound volatiles by skin microflora (Part 1)
Authors: Ikemoto Takeshi , Okabe Bun‐Ichi , Mimura Kunio , Kitahara Takeshi 
Published: November 2002

AbstractThe applicability of using odourless glycosidically bound volatiles (GBVs) as fragrance materials was investigated. After incubating skin microflora with various kinds of GBVs, the amounts of fragrance materials generated and the remaining glycosides were analysed by GC and HPLC. Most GBVs, particularly β‐D‐glucosides, were metabolized by various skin microflora to release their aglycones as fragrance materials. It was assumed that this was due to differences in enzymatic activity of the microflora. The results also suggest their considerable usefulness as alternative fragrance materials. Copyright © 2002 John Wiley & Sons, Ltd.
Chemical composition of the essential oils from the roots, fruits, leaves and stems of Pimpinella cumbrae Link growing in the Canary Islands (Spain)
Authors: Velasco‐Negueruela Arturo , Pérez‐Alonso María José , Pérez de Paz Pedro Luís , García Vallejo Concepción , Palá‐Paúl Jesús , Iñigo Ana 
Published: November 2002

AbstractThe oil constituents from the roots, fruits, leaves and stems of Pimpinella cumbrae Link gathered in the Canary Islands, Spain, have been studied by GC and GC–MS in combination with retention indices. The major constituents in the root oil were found to be isokessane (17%), β‐dihydroagarofuran (15%), 2‐methyl‐butyric acid (10%), geijerene (10%) and pregeijerene (7%). In the fruit oil the main components found were α‐bisabolol (39%), δ‐3‐carene (16%) and limonene (8%). In the leaf oil, α‐bisabolol (53%) and δ‐3‐carene (11%) were the predominant constituents. The most important compounds from the stem oil were α‐bisabolol (39%), isokessane (10%) and β‐dihydroagarofuran (9%). Pseudoisoeugenol esters were also detected in the oils from the roots, fruits and stems. These components were partially hydrolysed in the course of prolonged hydrodistillation to 2‐methyl‐5‐methoxybenzofuran. Copyright © 2002 John Wiley & Sons, Ltd.
Studies on some bulky triorganotin complexes of germatranyl‐substituted carboxylic acids
Authors: Song Xueqing , Xie Qinglan , Fang Xiaoniu 
Published: November 2002

AbstractEleven tris(2‐methyl‐2‐phenylpropyl)tin as well as four methyl bis[(phenyldimethylsilyl)methyl]tin β‐germatranylpropionates have been synthesized, and their structures were characterized by elemental analyses, IR, multinuclear (1H, 13C, 119Sn) NMR, Mössbauer, and MS spectroscopies. All the spectroscopic studies suggest a tetrahedral geometry for the bulky triorganotin carboxylates. The preliminary bioassays have shown that most of the compounds have good acaricidal activity. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:592–598, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10039
2,4,6‐Tri‐tert‐butylphenyl and 2,4‐di‐tert‐butyl‐6‐methylphenyl groups: Look similar, react differently
Authors: Ionkin Alex S. , Marshall William J. 
Published: November 2002

AbstractThe crystal structures of molecules with two phosphaalkene groups have been determined. Differences in the stabilization of the PC π‐bond by the 2,4,6‐tri‐tert‐butylphenyl and 2,4‐di‐tert‐butyl‐6‐methylphenyl groups were observed. It has been found that lithium supermesityl(trimethylsilyl)phosphide could be a very efficient base to remove a proton from acetonitrile.© 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:662–666, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10083
Synthesis and reactions of indane‐1,3‐dione‐2‐thiocarboxanilides with hydrazonoyl halides and active chloromethylene compounds
Authors: Elwan Nehal M. , Hassaneen Huwaida M. , Hassaneen Hamdi M. 
Published: November 2002

AbstractA novel synthesis of thiadiazoline derivatives 12 and 14 via treatment of indane‐1,3‐dione‐2‐thiocarboxanilides (5) with hydrazonoyl halides 1 and 2 is reported. Also, active chloromethylene compounds 15 react with 5 to give thiazole derivatives 19. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:585–591, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10132
Investigation of the relationship between nitric oxide metabolites' levels and adenosine deaminase activity in 7,12‐dimethylbenz[a]anthracene induced mouse liver
Authors: Ozturk I. Cetin , Batcioglu Kadir 
Published: November 2002

Abstract7,12‐Dimethylbenz[a]anthracene (7,12‐DMBA) is a member of the polycyclic aromatic hydrocarbons with a severe carcinogenic effect. In this study, nitrate levels and ADA (Adenosine deaminase) activity in the liver homogenates of mice were measured and the effect of free radicals induced by 7,12‐DMBA on inducible nitric oxide synthase (iNOS) and ADA activity were investigated. Antioxidant effects of melatonin were also compared. Three groups of mice were included in the study. The first served as control, the second was treated only with 7,12‐DMBA and the third was treated with 7,12‐DMBA + melatonin. Spectrophotometric methods were used at all measurements. Data were analyzed using Kruskal–Wallis Variance Analysis Test and Mann–Whitney U Test that were applied to the groups. The nitrate concentrations of mouse liver were as follows: 4.98 ± 0.63 μmol/L in the control group (n = 10), 8.23 ± 1.58 μmol/L (higher than control group, p < 0.05) in the 7,12‐DMBA‐treated group (n = 10), and 6.43 ± 0.57 μmol/L (lower than 7,12‐DMBA‐treated group, p < 0.05) in the 7,12‐DMBA + melatonin‐treated group (n = 10). Liver ADA activities were measured to be 4.14 ± 0.674 U/L in the control group, 6.25 ± 1.261 U/L (higher than control group, p < 0.05) in the 7,12‐DMBA‐treated group, and 4.93 ± 0.916 U/L (lower than 7,12‐DMBA‐treated group, p < 0.05) in the 7,12‐DMBA+melatonin‐treated group. Differences between free nitrite levels were no significantly. Results demonstrated that nitrate levels and ADA activities were increased by means of free radicals induced by 7,12‐DMBA. Melatonin inhibited the 7,12‐DMBA induced increase that was observed in the activities of ADA enzyme and nitrate levels. It is concluded that determination of ADA activity and nitrate levels can be useful in the assesment of liver damage caused by toxic chemicals. © 2002 Wiley Periodicals, Inc. J Biochem Mol Toxicol 16:260–262, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10041
Lead‐dependent effects on arachidonic acid accumulation and the proliferation of vascular smooth muscle
Authors: Dorman Robert V. , Freeman Ernest J. 
Published: November 2002

AbstractLead (Pb2+) has been implicated in the development of hypertension and atherosclerosis. The proliferation of vascular smooth muscle cells (VSMC) is a central feature of both conditions and there is evidence that Pb2+ potentiates serum‐dependent cell growth. The aim of this work was to examine the role of phospholipase A2 in mitogen‐dependent VSMC proliferation and determine if Pb2+ interacts with this system in order to potentiate mitotic events. It was observed that cell proliferation induced by angiotensin II, or fetal bovine serum, required the activation of a Ca2+‐dependent cytosolic phospholipase A2 and the subsequent release of unesterified arachidonic acid. This path was affected by Pb2+ as the metal increased the amount of arachidonic acid accumulation induced by either mitogen. In addition, Pb2+ potentiated mitogen‐induced DNA synthesis when present at lower doses (0.02 or 0.2 mg%), but had no effect on DNA synthesis, or cell numbers, in unstimulated cells. However, a high dose (2 mg%) of Pb2+ attenuated the DNA synthesis stimulated by angiotensin II, or serum, but induced the accumulation of unesterified arachidonic acid in unstimulated cells. A biphasic effect of Pb2+ on cell numbers and viability was also observed as 0.02 or 0.2 mg% Pb2+ did not affect cell numbers or trypan blue exclusion in unstimulated cells, while 2 mg% Pb2+ reduced cell numbers and viability. It appeared, therefore, that the lower concentrations of Pb2+ increased arachidonic acid release and DNA synthesis only in stimulated VSMC, perhaps due to further activation of a Ca2+‐dependent processes. In contrast, the high dose of Pb2+ reduced DNA synthesis in stimulated cells and reduced cell numbers and viability in unstimulated cells, which may relate to the noted increase in unesterified arachidonic acid. © 2002 Wiley Periodicals, Inc. J Biochem Mol Toxicol 16:245–253, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10045
Lack of specificity of cell‐surface protease targeting of a cytotoxic hyperfusogenic gibbon ape leukaemia virus envelope glycoprotein
Authors: Kirkham Lucy A. , Bateman Andrew R. , Melcher Alan A. , Vile Richard G. , Fielding Adele K. 
Published: November 2002

AbstractBackgroundIn a strategy termed “Protease Targeting”, retroviral vectors carrying an EGF infectivity‐blocking domain fused to the N‐terminus of the envelope SU via a MMP (matrix metalloproteinase)‐cleavable linker were successfully used to target gene delivery to EGF receptor‐(EGF‐R‐)positive tumour cells over‐expressing MMPs. In the current study, we aimed to investigate whether this strategy could be applied to (a) limit the cytotoxic activity of a hyperfusogenic GALV therapeutic gene, and (b) enhance the immune‐stimulatory properties of GALV via local, MMP‐mediated release human granulocyte‐macrophage colony stimulating factor (GM‐CSF).MethodsWe generated GALV envelope expression constructs displaying EGF or GM‐CSF blocking ligands at the N‐terminus of GALV envelope SU via a non‐cleavable, Factor Xa protease or MMP‐cleavable linker and investigated their cytotoxicity on MMP‐positive and negative cell lines.ResultsThe unmodified hyperfusogenic GALV envelope was cytotoxic to all cell lines tested. The non‐cleavable linker GALV envelope constructs caused no cytotoxicity, demonstrating efficient inhibition by the displayed domains. Moderate activation of fusion of the protease‐cleavable linker constructs was observed in all cell lines, regardless of their level of MMP expression and of the specificity of the linker. High levels of the ‘blocking domain’ were detected in the cell supernatants due to dissociation of the surface unit (SU) from the transmembrane (TM) component of the GALV envelope glycoprotein TM.ConclusionsUnlike protease targeting in the context of retroviral vectors, protease activation of the cytotoxicity of GALV envelope by cleavage of a fusion blocking ligand at the cell surface does not appear to be specifically mediated by cell‐surface MMPs. In addition, shedding of the SU‐fusion protein from the TM limits the general applicability of this strategy for cancer gene therapy. Specificity of cell‐cell fusion mediated by GALV envelope cannot be manipulated in the same fashion as virus‐cell fusion. Copyright © 2002 John Wiley & Sons, Ltd.
Controlled transgene expression by E1‐E4‐defective adenovirus vectors harbouring a “tet‐on” switch system
Authors: Fender P. , Jeanson L. , Ivanov M. A. , Colin P. , Mallet J. , Dedieu J. F. , Latta‐Mahieu M. 
Published: November 2002

AbstractBackgroundThe “tet switch system” was originally described under the tet‐off configuration with its components encoded by two separate plasmids. Since then, many virus vectors harbouring tet‐off components have been designed and their regulation by tetracycline is widely reported. On the contrary, tet‐on regulation by viral vectors is poorly documented.MethodsE1‐E4‐defective adenoviruses harbouring either rtTA or the luciferase gene under a minimal inducible promoter (TK* or CMV*) or both components in a single genome were produced. Using either a double or a single virus strategy, induction of luciferase expression was investigated in various cell lines, in mice muscle and in rat brain.ResultsOver 400‐fold induction can be reached with PC12 and NHA cells using a double virus strategy. Comparison of the background activity of different minimal inducible promoters revealed a significant difference between TK* and CMV* promoters both with the cell culture and the in vivo experiments. Interestingly, a single virus strategy permitted an induction exceeding 600‐fold with human astrocyte primary cells. Moreover, the E1‐E4‐defective adenovirus‐mediated tet‐on system can be quickly switched off and turned back on again. Depending on the cell line, the level of rtTA derived by the single virus strategy differed, resulting in different efficiencies. Experiments performed in rat striatum and mouse muscle confirmed the importance of rtTA expression and minimal promoter used on both doxycycline‐independent expression and induction efficiency. Under appropriated rtTA expression, a 32‐fold induction is observed in mouse muscle.ConclusionsIn the recombinant adenovirus context, the CMV* but not the TK* promoter is sensitive to transcriptional interference resulting in high doxycycline‐independent expression. By paying attention to the rtTA expression, moderate and high induction can be obtained in vivo and in vitro accordingly. Copyright © 2002 John Wiley & Sons, Ltd.
Gene therapy for rheumatoid arthritis
Authors: Bessis Natacha , Doucet Christelle , Cottard Virginie , Douar Anne‐Marie , Firat Hüseyin , Jorgensen Christian , Mezzina Mauro , Boissier Marie‐Christophe 
Published: November 2002

AbstractRheumatoid arthritis (RA) is a severe autoimmune systemic disease. Chronic synovial inflammation results in destruction of the joints. No conventional treatment is efficient in RA. Gene therapy of RA targets mainly the players of inflammation or articular destruction: TNF‐α or IL‐1 blocking agents (such as anti‐TNF‐α monoclonal antibodies, soluble TNF‐α receptor, type II soluble receptor of IL‐1, IL‐1 receptor antagonist), antiinflammatory cytokines (such as IL‐4, IL‐10, IL‐1), and growth factors. In this polyarticular disease, the vector expressing the therapeutic protein can be administered as a local (intra‐articular injection) or a systemic treatment (extra‐articular injection). All the main vectors have been used in experimental models, including the more recent lentivirus and adeno‐associated virus. Ex vivo gene transfer was performed with synovial cells, fibroblasts, T cells, dendritic cells, and different cells from xenogeneic origin. In vivo gene therapy is simpler, although a less controlled method. Clinical trials in human RA have started with ex vivo retrovirus‐expressing IL‐1 receptor antagonists and have demonstrated the feasibility of the strategy of gene therapy. The best target remains to be determined and extensive research has to be conducted in preclinical studies. Copyright © 2002 John Wiley & Sons, Ltd.
The point‐estimate method with large numbers of variables
Authors: Christian John T. , Baecher Gregory B. 
Published: November 2002

AbstractRosenbleuth's point‐estimate method has become widely used in geotechnical practice for reliability calculations. Although the point‐estimate method is a powerful and simple method for evaluating the moments of functions of random variables, it is limited by the need to make 2n evaluations when there are n random variables. Modifications of the method reduce this to 2n evaluations by using points on the diameters of a hypersphere instead of at the corners of the inscribed hypercube. However, these techniques force the co‐ordinates of the evaluation points farther from the means of the variables; for a bounded variable, the points may easily fall outside the domain of definition of the variable. The problem can be avoided by using other techniques for some special cases or by reducing the number of random variables that must be considered. Copyright © 2002 John Wiley & Sons, Ltd.
Comments on use of the Barcelona Basic Model for unsaturated soils
Authors: Wheeler S. J. , Gallipoli D. , Karstunen M. 
Published: November 2002

AbstractThe paper discusses some aspects of the Barcelona Basic Model (BBM), which is one of the most widely used elasto‐plastic models for unsaturated soils. In addition to modelling those unsaturated soils where the collapse potential increases with increasing net stress (as envisaged by the original authors), the BBM can also be used to model soils where the collapse potential decreases with increasing net stress, by selecting suitable values for the model parameters r and pc. A practical procedure is suggested for selecting a value for the important model parameter pc from laboratory test data. Problems with use of the BBM are discussed, including the difficulty of correctly matching the locations of the normal compression lines for different values of suction and the possibility of non‐convexity of the yield curve. Copyright © 2002 John Wiley & Sons, Ltd.
Stereochemical assignment of naturally occurring 2,3‐epoxy‐2‐methylbutanoate esters
Authors: Torres‐Valencia J. Martín , León Guadalupe I. , Villagómez‐Ibarra J. Roberto , Suárez‐Castillo Oscar R. , Cerda‐García‐Rojas Carlos M. , Joseph‐Nathan Pedro 
Published: November 2002

AbstractA method to determine the absolute configuration of 2,3‐epoxy‐2‐methylbutanoate ester residues in natural products is presented, based on (i) the reduction of the ester function to yield a 2‐methyl‐1,2‐butanediol, (ii) esterification of the obtained primary alcohol with either (R)‐(+)‐ or (S)‐(−)‐Mosher's acid to afford the corresponding Mosher's ester, and (iii) 1H‐NMR spectral comparison of the final product with that of the Mosher's esters prepared from 2‐methyl‐1,2‐butanediols of known stereochemistry. Copyright © 2002 John Wiley & Sons, Ltd.
Capillary zone electrophoresis of syringyl and guaiacyl monomers resulting from lignin thioacidolysis
Authors: Fournand David , Mila Isabelle , Lapierre Catherine 
Published: November 2002

AbstractA capillary zone electrophoretic method has been developed for the quantitative determination of syringyl (S) and guaiacyl (G) monomers resulting from lignin thioacidolysis. The effects on the separation of altering a number of parameters have been investigated, resulting in an efficient and rapid separation. Analysis times were about 10 min instead of 50 min for the conventional GC methods, with no requirement for a derivatisation step prior to analysis. Relative standard deviations ranged between 8 and 12% for the absolute determination of S and G monomers, and between 1.4 and 3.5% for the S/G ratio. Copyright © 2002 John Wiley & Sons, Ltd.
NMR shift data of neo‐clerodane diterpenes from the genus Ajuga
Authors: Coll Josep 
Published: November 2002

AbstractThe complete assignment of the NMR spectra of ajugarin I and ajugareptansin, as models for other neo‐clerodane diterpenoids isolated from the genus Ajuga, is reported in order to improve their usefulness as reference compounds. Conflicting NMR shift data for some members of this group are discussed, and plausible reassignments are proposed [i.e. the identity of ajugacumbin C and ajugamarin A2; the revision of ajugacumbin D as 12‐hydroxyajugacumbin A, and of ajugacumbin E as 12‐hydroxy‐1‐(3‐hydroxy‐2‐methylenebutanoyloxy)ajugarin I] in order to provide a unified basis for future use. Copyright © 2002 John Wiley & Sons, Ltd.
A Graph Theoretic Approach for Modeling Mobile Robot Team Formations
Authors: Desai Jaydev P. 
Published: November 2002

AbstractThis paper addresses a new approach for modeling and control of multiple
teams of mobile robots navigating in a terrain with obstacles, while maintaining
a desired formation and changing formations when required. We model each team
as a triple, (g,r, ℋ︁ ), consisting of a group element,
g∈SE(2), that describes the gross position of the lead robot,
a set of shape variables, r, that describe the relative positions of
robots, and a control graph, ℋ︁, that describes the behaviors of the robots
in the formation. We assume that all the robots are equipped with the appropriate
sensors to detect and avoid other robots and obstacles in the environment.
Our framework enables the representation and enumeration of possible control
graphs, and the coordination of transitions between any two control graphs.
Further, we describe an algorithm that allows each team of robots to move
between any two formations, while avoiding obstacles. As the number of robots
increases, the number of possible control graphs increases. However, because
the control computations are decentralized, the algorithms scale with the
number of robots. We present examples to illustrate the control graphs and
the algorithm for transitioning between them in the presence and absence of
sensor noise. © 2002 Wiley Periodicals, Inc.