bluuebunny/crossref_metadata_2025_split huggingface dataset:
One‐Pot Ring‐Closing Metathesis‐Alkene Cross Metathesis Reactions of Sulfamide‐Linked Enynes
Authors: Salim Sofia S. , Bellingham Richard K. , Brown Richard C. D. 
Published: February 2004

AbstractRing‐closing metathesis (RCM) of sulfamide‐linked enynes 7, 11 and 12 containing disubstituted alkynes afforded a series of novel 7‐membered cyclic sulfamides 13−15 in good yield. Substrates 5, 9 and 10 containing mono‐substituted alkynes gave either simple RCM products 18a−c or those arising from combinations of enyne RCM and olefin cross metathesis 16/17a−c depending on the reaction conditions. Notably, in the presence of two equivalents of styrene or ethyl acrylate, substrates 5, 9 and 10 containing terminal alkynes underwent selective enyne‐RCM‐olefin‐cross metathesis to provide cyclic sulfamides 17a−c and 19b,c in yields of 54−83%. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Regime switching in the yield curve
Authors: Christiansen Charlotte 
Published: February 2004

AbstractThe article investigates the effect of interest‐rate variance on the shape of the yield curve with the
use of a bivariate two‐state Markov switching model for the short‐rate changes and the yield curve
slope. The two states are characterized by the variance of the short‐rate changes: low and high variance.
In the high‐variance regime the yield curve becomes steeper with the interest‐rate variance; in
the low‐variance regime the slope is independent hereof. A nonswitching specification amounts to
averaging across the two states. The economy is in the high‐variance state during unusual economic
periods. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:315–336, 2004
The index futures markets: Is screen trading more efficient?
Authors: Copeland Laurence , Lam Kin , Jones Sally‐Ann 
Published: February 2004

AbstractThis article uses a nonparametric test based on the arc‐sine law (see, e.g., Feller, 1965), which involves comparing the theoretical distribution implied by an intraday
random walk with the empirical frequency distribution of the daily high/low times, in order to address the
question of whether the abandonment of pit trading has been associated with greater market efficiency. If market
inefficiencies result from flaws in the market microstructure of pit trading, they ought to have been eliminated
by the introduction of screen trading. If, on the other hand, the inefficiencies are a reflection of investor
psychology, they are likely to have survived, unaffected by the changeover. We focus here on four cases. Both the
FTSE‐100 and CAC‐40 index futures contracts were originally traded by open outcry and have moved
over to electronic trading in recent years, so that we are able to compare pricing behavior before and after the
changeover. The equivalent contracts in Germany and Korea, on the other hand, have been traded electronically
ever since their inception. Our results overwhelmingly reject the random‐walk hypothesis both for
open‐outcry and electronic‐trading data sets, suggesting there has been no increase in efficiency
as a result of the introduction of screen trading. One possible explanation consistent with our results would be
that the index futures market is characterized by intraday overreaction. © 2004 Wiley Periodicals, Inc. Jrl
Fut Mark 24:337–357, 2004
Metabolism of Deuterated threo‐Dihydroxy Fatty Acids in Saccharomyces cerevisiae: Enantioselective Formation and Characterization of Hydroxylactones and γ‐Lactones
Authors: Garbe Leif‐A. , Tressl Roland 
Published: February 2004

AbstractBiotransformation of (±)‐threo‐7,8‐dihydroxy(7,8‐2H2)tetradecanoic acids (threo‐(7,8‐2H2)‐3) in Saccharomyces cerevisiae afforded 5,6‐dihydroxy(5,6‐2H2)dodecanoic acids (threo‐(5,6‐2H2)‐4), which were converted to (5S,6S)‐6‐hydroxy(5,6‐2H2)dodecano‐5‐lactone ((5S,6S)‐(5,6‐2H2)‐7) with 80% e.e. and (5S,6S)‐5‐hydroxy(5,6‐2H2)dodecano‐6‐lactone ((5S,6S)‐5,6‐2H2)‐8). Further β‐oxidation of threo‐(5,6‐2H2)‐4 yielded 3,4‐dihydroxy(3,4‐2H2)decanoic acids (threo‐(3,4‐2H2)‐5), which were converted to (3R,4R)‐3‐hydroxy(3,4‐2H2)decano‐4‐lactone ((3R,4R)‐9) with 44% e.e. and converted to 2H‐labeled decano‐4‐lactones ((4R)‐(3‐2H1)‐ and (4R)‐(2,3‐2H2)‐6) with 96% e.e. These results were confirmed by experiments in which (±)‐threo‐3,4‐dihydroxy(3,4‐2H2)decanoic acids (threo‐(3,4‐2H2)‐5) were incubated with yeast. From incubations of methyl (5S,6S)‐ and (5R,6R)‐5,6‐dihydroxy(5,6‐2H2)dodecanoates ((5S,6S)‐ and (5R,6R)‐(5,6‐2H2)‐4a), the (5S,6S)‐enantiomer was identified as the precursor of (4R)‐(3‐2H1)‐ and (2,3‐2H2)‐6). Therefore, (4R)‐6 is synthesized from (3S,4S)‐5 by an oxidation/keto acid reduction pathway involving hydrogen transfer from C(4) to C(2).In an analogous experiment, methyl (9S,10S)‐9,10‐dihydroxyoctadecanoate ((9S,10S)‐10a) was metabolized to (3S,4S)‐3,4‐dihydroxydodecanoic acid ((3S,4S)‐15) and converted to (4R)‐dodecano‐4‐lactone ((4R)‐18).
Synthesis of (±)‐Kempa‐6,8‐dien‐3‐ol (=(2aRS,3SR,4aSR,7RS,7aSR,10bSR,10cSR)‐2,2a,3,4,4a,5,6,7,7a,8,10b,10c‐Dodecahydro‐2a,7,10,10c‐tetramethylnaphth[2,18‐cde]azulen‐3‐ol)
Authors: Kato Tadahiro , Tanaka Motoyuki , Takagi Shin‐suke , Nakanishi Keita , Hoshikawa Masahiro 
Published: February 2004

AbstractThe synthesis of kempa‐6,8‐dien‐3β‐ol (4a), as a synthetic leading model of the natural product 4b, was carried out starting from intermediate 12, the synthetic route of which has been developed previously (Scheme 1). The conversion of 12 to the model compound 4a involved the elaboration of three structure modifications by three processes, Tasks A, B, and C (see Scheme 2). Task A was achieved by epoxy‐ring opening of 41 with Me3SiCl (Scheme 9), and Task B being performed by oxidation at the 13‐position, followed by hydrogenation, and then epimerization (Schemes 4 and 5). The removal of the 2‐OH group from 12 (Task C) was achieved via 30b according to Scheme 6, whereby 30b was formed exclusively from 30a/31a 1 : 1 (Scheme 7). In addition, some useful reactions from the synthetic viewpoint were developed during the course of the present experiments.
Berberine/γ‐Cyclodextrin Inclusion Structure Studied by 1H‐NMR Spectroscopy and Molecular‐Dynamics Calculations
Authors: Kamigauchi Miyoko , Kanbara Narumi , Sugiura Makiko , Iwasa Kinuko , Ohishi Hirofumi , Ishida Toshimasa 
Published: February 2004

AbstractTo understand the increased solubility and decreased bitter taste of berberine, a clinically important isoquinoline alkaloid, in the presence of cyclodextrins, the interaction with γ‐cyclodextrin (γ‐CD) in aqueous solution was studied by a combination of 1H‐NMR analyses and molecular‐dynamics calculations. The proposed complexation mode of berberine by γ‐CD could explain the increased solubility in water. No difference in germicidal activity between berberine alone and its inclusion complex with γ‐ or β‐CD was observed, which is important to further develop the pharmacological application of berberine.
Palladium‐MOP Chemistry: Pseudo‐cis‐Allyl MOP Complexes and Flexible Olefin Bonding. Preliminary Communication
Authors: Dotta Pascal , Kumar P. G. Anil , Pregosin Paul S. , Albinati Alberto 
Published: February 2004

AbstractWe show that both palladium(0) and palladium(II) metal centers are capable of coordinating two monodentate MOP (=(R)‐2‐(diarylphosphino)‐1,1′‐binaphthalene) ligands in a pseudo‐cis orientation, despite published statements to the contrary. In addition to [Pd(η3‐C3H5)(MeOMOP)2]BF4 (MeOMOP=(R)‐2‐(diphenylphosphino)‐2′‐methoxy‐1,1′‐binaphthalene), the first examples of chiral bis κC1‐prop‐2‐enyl (η1‐CH2CHCH2) complexes [cis‐Pd(κC1‐C3H5)2(MeOMOP or MOP)2], are shown to be relatively stable. Further, coordinated MOP and MeOMOP both show stronger propensity towards novel intramolecular π‐olefin complexation than the CNMOP analogue. The solid‐state structure of [Pd(fumaronitrile)(MOP)2] is reported.
Phosphodiesterase‐Inhibiting Glycosides from Symplocos racemosa
Authors: Ahmad Viqar Uddin , Abbasi Muhammad Athar , Zubair Muhammad , Fatima Naheed , Farooq Umar , Choudhary M. Iqbal 
Published: February 2004

AbstractPhytochemical investigation of Symplocos racemosa resulted in the isolation of two new glycosides, symploracemoside (1) and symplomoside (2), which are structurally related to the reported benzoylsalireposide (3) and salireposide (4). The structure elucidation of the isolated compounds was based primarily on 1D‐ and 2D‐NMR analysis, including COSY, NOESY, HMQC, and HMBC correlations. These glycosides showed inhibitory activity against snake‐venom phosphodiesterase I.
Construction of a GBS‐GAS DNA subtraction library allows discovery of previously unidentified GBS genes and rapid location of unique regions on the GBS chromosome
Authors: Suvorov Alexander N. , Ferretti Joseph J. 
Published: February 2004

AbstractA subtraction library of group B streptococcus (GBS) strain O9OR with GAS chromosomal DNA (strain SF370) was constructed and more than 100 plasmid clones sequenced. DNA sequences of the plasmid inserts were analyzed using the BLAST gene search. Most inserts had little or no homology to GAS chromosomal DNA and 26 clones from the library had no gene homologues in the gene bank. The majority of genes discovered represented house keeping GBS genes, but several could be considered as possible virulence factors. Inserts from 21 clones were labeled and used as probes for hybridization with GBS DNA fragments separated by pulsed field electrophoresis. A genetic map of GBS strain O9OR was constructed.
Examination of membrane protein expression in Paracoccus denitrificans by two‐dimensional gel electrophoresis
Authors: Bouchal Pavel , Kučera Igor 
Published: February 2004

AbstractThe well‐known metabolic versatility of the soil bacterium Paracoccus denitrificans poses a challenge for modern proteomic approaches. We describe here improved preparation conditions that allow good separation and quantitative analyses of hundreds of membrane or periplasmic proteins. To illustrate this optimized procedure, the results of a screening for membrane proteins associated predominantly with aerobic or anaerobic (denitrifying) modes of growth are presented.
Isolation and characterization of pathogenic Vibrio alginolyticus from diseased cobia Rachycentron canadum
Authors: Liu Ping‐Chung , Lin Ji‐Yang , Hsiao Pei‐Tze , Lee Kuo‐Kau 
Published: February 2004

AbstractOutbreaks of serious mortality among cultured juvenile cobia Rachycentron canadum L. (weighing 8–10 g) characterized by lethargy, dark skin and ascites in the peritoneal cavity while some fish possessing damaged eyes occurred in July and August of 2001 in Taiwan. Fifteen motile bacterial strains were isolated from head kidney and/or the ascites on tryptic soy agar supplemented with 1% NaCl (TSA1) and/or thiosulphate citrate bile salt (TCBS) sucrose agar plates during the two outbreaks. All the isolates were characterized and identified as Vibrio alginolyticus on the basis of biochemical characteristics, and comparisons with those of the reference strain V. alginolyticus ATCC 17749. The strain C3c01 (a representative of the 15 similar field isolates), was virulent to the cobia with an LD50 value of 3.28 × 104 colony forming units/g fish body weight. All the moribund/dead fish exhibited lethargy, dark skin and ascites in the peritoneal cavity as that observed in natural outbreaks. The same bacteria could be reisolated from kidney and the ascites of fish after bacterial challenge using TSA1 and TCBS plates. The results reveal that V. alginolyticus is an infectious agent of vibriosis in the cobia.
The synergy between deformation and anodic dissolution of an austenitic stainless steel in acidic chloride solution
Authors: Yanliang H. 
Published: February 2004

AbstractIn corrosion medium, metals can deform under tensile stress and form a new active surface with the anodic dissolution of the metals being accelerated. At the same time, the anodic dissolution may accelerate the deformation of the metals. The synergy can lead to crack nucleation and development and shorten the service life of the component. Austenitic stainless steel in acidic chloride solution was in active dissolution condition when stress corrosion cracking (SCC) occurred. It is reasonable to assume that the anodic dissolution play an important role, so it's necessary to study the synergy between anodic dissolution and deformation of austenitic stainless steels. The synergy between deformation and anodic dissolution of AISI 321 austenitic stainless steel in an acidic chloride solution was studied in this paper. The corrosion rate of the steel increased remarkably due to the deformation‐accelerated anodic and cathodic processes. The creep rate was increased while the yield strength was reduced by anodic dissolution. The analysis by thermal activation theory of deformation showed a linear relationship between the logarithm of creep rate and the logarithm of anodic current. Besides, the reciprocal of yield strength was also linearly dependent on the logarithm of anodic current. The theoretical deductions were in good agreement with experimental results.
A solution to identities problem in 2‐element HSI‐algebras
Authors: Asatryan Gurgen R. 
Published: February 2004

AbstractAll arithmetical identities involving 1, addition, multiplication and exponentiation are valid in every 2‐element HSI‐algebra. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quasi‐complements of the cappable degrees
Authors: Wu Guohua 
Published: February 2004

AbstractSay that a nonzero c. e. degree b is a quasi‐complement of a c. e. degree a if a ∩ b = 0 and a ∪ b is high. It is well‐known (due to Shore) that each cappable degree has a high quasi‐complement. However, by the existence of the almost deep degrees, there are nonzero cappable degrees having no low quasi‐complements. In this paper, we prove that any nonzero cappable degree has a low2 quasi‐complement. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low‐temperature route to thermoplastic polyamide elastomers
Authors: Rabani Gouher , Rosair Georgina M. , Kraft Arno 
Published: February 2004

AbstractThermoplastic polyamide elastomers were obtained by polymerization of aminobenzoyl‐substituted telechelics derived from poly(tetrahydrofuran)‐diols (number‐average molecular weight: 1400 or 2000 g mol−1) with several diacid dichlorides (terephthaloyl dichloride, 4,4′‐biphenyldicarbonyl dichloride, or 2,6‐naphthalenedicarbonyl dichloride) and chlorotrimethylsilane in N,N‐dimethylacetamide at 0–20 °C. The as‐prepared polymers had melting temperatures above 190 °C and exhibited elastic properties at room temperature, as evidenced by dynamic mechanical analysis and stress–strain measurements. The polymer with 2,6‐naphthalenedicarboxamide hard segments had the widest rubbery plateau within the series, the highest extension at break, and good recovery properties. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1449–1460, 2004
Effect of the synthetic method and support porosity on the structure and performance of silica‐supported CuBr/pyridylmethanimine atom transfer radical polymerization catalysts. I. Catalyst preparation and characterization
Authors: Nguyen Joseph V. , Jones Christopher W. 
Published: February 2004

AbstractSilica‐supported CuBr/pyridylmethanimine (PMI) complexes that facilitate the atom transfer radical polymerization of methyl methacrylate have been prepared and characterized. Four different synthetic routes, including multistep‐grafting (M1), two‐step‐grafting (M2), one‐pot (M3), and preassembled‐complex (M4) methods, have been evaluated on three different silica supports (mesoporous SBA15 with 48‐ and 100‐Å pores and nonporous Cab‐O‐Sil EH5). The resulting solids have been characterized by a battery of techniques, including thermogravimetric analysis/differential scanning calorimetry, FT‐Raman spectroscopy, 13C and 29Si magic‐angle‐spinning and cross‐polarity/magic‐angle‐spinning spectroscopy, low‐temperature nitrogen physisorption, and elemental analysis. The combination of elemental analysis and spectroscopic results has indicated that a variety of different surface species likely exist for most catalysts, including copper species that are both monocoordinated and biscoordinated by PMI ligands, and PMI‐free copper bromide species interacting with the silica surface. M4 appears to give a material that has the smallest amount of the uncomplexed ligand (by FT‐Raman spectroscopy) and is, therefore, the most homogeneous. After M4, the metallation efficiency decreases in the order M2 ≥ M3 > M1, with M1 giving a material with a highly heterogeneous surface composition. The ligand loading on all the catalysts has been determined to be approximately 1 mmol/g of SiO2, with Cab‐O‐Sil‐supported materials giving much higher ligand densities because of its lower surface area. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1367–1383, 2004
Effect of the synthetic method and support porosity on the structure and performance of silica‐supported CuBr/pyridylmethanimine atom transfer radical polymerization catalysts. II. Polymerization of methyl methacrylate
Authors: Nguyen Joseph V. , Jones Christopher W. 
Published: February 2004

AbstractA systematic study of the effect of the synthesis method and catalyst structure on the atom transfer radical polymerization (ATRP) performance of copper(I) bromide/pyridylmethanimine complexes supported on silica is described. Four different synthetic routes, including multistep‐grafting (M1), two‐step‐grafting (M2), one‐pot (M3), and preassembled‐complex (M4) methods, have been evaluated on three different silica supports (mesoporous SBA15 with 48‐ and 100‐Å pores and nonporous Cab‐O‐Sil EH5). The resulting solids have been used for ATRP of methyl methacrylate. The catalysts allow for moderate to poor control of the polymerization, with polydispersity indices (PDIs) ranging from 1.46 to greater than 2. The materials made with the preassembled‐complex (M4) and one‐pot (M3) approaches are generally more effective than those prepared with a grafting method (M1 and M2) on porous silica, whereas all the methods provide similarly performing catalysts on the nonporous support. Nonporous Cab‐O‐Sil EH5 is the most effective support because of its small particle size, lack of porosity, and relative compatibility in the reaction media. All the catalysts leach copper into solutions in small amounts. In addition, the catalysts can be effectively recycled, with improved controlled character in recycle runs (PDI ∼ 1.2). Control experiments have shown that this improved performance of the used catalysts is likely due to the presence of a soluble Cu(II) complex in the materials that effectively deactivates the growing polymer chain, leading to narrow PDIs and controlled molecular weights. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1384–1399, 2004
Dendritic aromatic polyamides and polyimides
Authors: Jikei Mitsutoshi , Kakimoto Masa‐aki 
Published: February 2004

AbstractThe syntheses and properties of dendritic and hyperbranched aromatic polyamides and polyimides are reviewed. In addition to conventional stepwise reactions for dendrimer synthesis, an orthogonal/double‐stage convergent approach and dendrimer syntheses with unprotected building blocks are described as new synthetic strategies for dendritic polyamides. Hyperbranched polyamides and polyimides composed of various repeating units are presented. Besides the self‐polycondensation of AB2‐type monomers, new polymerization systems with AB4, AB8, A2 + B3, and A2 + BB′2 monomers have been developed for hyperbranched polyamides and polyimides. The copolymerization of AB2 and AB monomers is discussed separately with respect to the effects of branching units on the properties. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1293–1309, 2004
Formation of hydrogen bonding in ionized poly(N‐isopropylacrylamide) gels by continuous water exchange
Authors: Hirashima Y. , Tamanishi H. , Sato H. , Saito K. , Naito A. , Suzuki A. 
Published: February 2004

AbstractThe effects of continuous water exchange on the swelling behavior of poly(N‐isopropylacrylamide‐co‐sodium acrylate) gel were studied. The diameter of gels and the Na+ concentration in the solvent were measured at several constant intervals after the solvent (the distilled deionized water) was exchanged. The diameter decreased at room temperature as the solvent was exchanged with water, and it continued to decrease even after more than about 97% of the initial Na+ diffused into the water. Thus, the final swelling ratio of the gel was only slightly larger than that of the neutral poly(N‐isopropylacrylamide) gel. To reveal the structural change in molecular level, solid‐state 13C cross‐polarization/magic‐angle spinning, solid‐state 1H combined rotation and multiple‐pulse spectroscopy, and swollen‐state 13C dipolar decoupled/magic‐angle spinning NMR experiments were carried out for several dried and swollen samples by varying the times of water exchange. As a result, the intensity and position of the carboxyl peak changed, and the relative intensity of the nonionized carboxyl groups of gels increased with an increasing number of water exchanges. These results indicated that hydrogen bonding was formed between the two, nonionized carboxyl groups (COOH) and/or between the COOH and CONH groups. The macroscopic polymer network shrinkage is discussed in terms of the replacement of counterions Na+ by H+ and of the formation of intermolecular hydrogen bonding. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 1090–1098, 2004
Thermally stimulated depolarization current in electron‐irradiated poly(vinylidene fluoride‐trifluoroethylene) (56/44 mol %) copolymers
Authors: Guo S. S. , Li W. P. , Zhao X.‐Z. , Peng Z. , Lau S. T. , Chan H. L. W. , Choy C. L. 
Published: February 2004

AbstractThe effect of electron irradiation on poly(vinylidene fluoride‐trifluoroethylene) (56/44 mol %) copolymers was studied with dielectric constant measurements, differential scanning calorimetry (DSC), X‐ray diffraction, thermally stimulated depolarization current (TSDC) spectroscopy, and polarization hysteresis loops. The dielectric relaxation peaks, obeying the Vogel–Fulcher law, indicated that the copolymers were transformed from a normal ferroelectric to a relaxor ferroelectric. The X‐ray and DSC results showed that both the crystalline and polar ordering decreased after irradiation, indicating a partial recovery from trans–gauche bonds to local trans bonds (polar ordering). Moreover, the peak temperature decreased with the irradiation dose in the TSDC spectra; this demonstrated fewer dipoles and crystalline regions in the irradiated copolymer films during the ferroelectric–paraelectric transition and was consistent with polarization hysteresis loop measurements. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 1099–1105, 2004
Inhibition of microbial growth in ready‐to‐eat food stored at ambient temperature by modified atmosphere packaging
Authors: Chen S. C. , Lin C.‐A. , Fu A.‐H. , Chuo Y. W. 
Published: February 2004

AbstractThis study was undertaken to develop a modified atmosphere package to control microbial growth in ready‐to‐eat (RTE) products stored at ambient temperature. Ethanol and/or limonene associated with modified atmosphere (CO2 : O2 : N2 = 30% : 5% : 65%) was used to inhibit the growth of total air‐borne microorganisms and Escherichia coli in RTE products stored at 25°C. The results indicated that 0.05% ethanol vapour in the headspace was effective to inhibit the growth of air‐borne microorganisms and E. coli at 25°C for 72 h in a model study, and the effectiveness was related to ethanol content. Both 73 ppm limonene and 0.05% ethanol vapour enhanced the bacteriostatic effect of modified atmosphere in RTE sushi roll products, and no off‐flavour was detected using this formulated gas; however, no significant inhibitory effect was observed for RTE cold noodle products. This study concludes that combinations of carbon dioxide, ethanol or limonene vapours are effective to inhibit microbial growth in RTE food at ambient temperature, and the outcome may be due to the hurdle effect. Copyright © 2003 John Wiley & Sons, Ltd.