bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterisation of Leucaena condensed tannins by size and protein precipitation capacity
Authors: Osborne Nicholas J T , McNeill David M 
Published: September 2002

AbstractThe ability of differently sized condensed tannins from the genus Leucaena, a fodder tree‐legume, to bind protein at different pH values was evaluated to characterise their potential biological effects. Two factors affecting the ability of condensed tannin to bind protein, its major biological activity, have been purported to be the condensed tannin size and the pH of the reaction environment. To test these hypotheses, the protein‐precipitating capacities of condensed tannin extracted from four Leucaena genotypes, L leucocephala (UHK636), L pallida (CQ3439), L trichandra (CPI46568) and L collinsii (OFI52/88), were assessed. Condensed tannin from L leucocephala had approximately 50% of the ability to precipitate protein on a g g−1 basis than L pallida or L trichandra, while L collinsii gave no measurable ability to precipitate protein (reaction environment pH 5.0). Increasing or decreasing the pH of the reaction solution away from pH 5.0 (approximately the isoelectric point of the protein) reduced the ability of condensed tannin from all the species to precipitate protein, the decrease being higher at pH 2.5 than at pH 7.5. Condensed tannins from each Leucaena species were also separated by size exclusion chromatography, and the fractions examined for protein‐precipitating capacity. In general, it was found that the larger‐sized condensed tannin of the accessions L pallida and L trichandra could precipitate more protein than the smaller‐sized condensed tannin. This pattern was not found for L leucocephala.© 2001 Society of Chemical Industry.
Catalytic cracking, dehydrogenation, and aromatization of isobutane over Ga/HZSM‐5 and Zn/HZSM‐5 at low pressures
Authors: Sun Yanping , Brown Trevor C. 
Published: September 2002

AbstractIsobutane cracking, dehydrogenation, and aromatization over Ga/HZSM‐5 and Zn/HZSM‐5 has been investigated in a Knudsen cell reactor and the kinetics of the primary reaction steps for isobutene and propene formation have been accurately determined. Although cracking is the dominant reaction channel, with propene and methane being primary products, methane formation is significantly less than propene formation. This indicates that a proportion of the cracking proceeds via Lewis acid attack at CC bonds, and not just via alkanium ion formation at Bronsted acid sites. This is particularly apparent over Zn/HZSM‐5. Intrinsic rate constants for cracking, calculated from the rate of propene formation, are

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and for dehydrogenation, calculated from the rate of isobutene formation, are

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Large preexponential factors for cracking and dehydrogenation over Ga/HZSM‐5 indicate that either the coverage of active sites is significantly less than the coverage of exposed sites or the intrinsic reaction step involves a large entropy change between reactant and transition state. For Zn/HZSM‐5 the small preexponential factors suggest either small entropy changes during activation, perhaps initiated by Lewis acid sites, or a steady‐state distribution of active and exposed sites is rapidly reached. Differences in intrinsic activation energies may reflect the ratio of Lewis and Bronsted acid sites on the respective catalyst surfaces. Aromatization is more prolific over Ga/HZSM‐5 than over Zn/HZSM‐5 under the low‐pressure conditions. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 467–480, 2002
Bond dissociation energies and the Hammett correlation, Part 1: Remotely substituted aromatic compounds and vitamin E
Authors: Luo Yu‐Ran 
Published: September 2002

AbstractFour hundred and seventy nine experimental values of XZ bond dissociation energies (BDEs) of para‐, ortho‐, meta‐, and multisubstituted aromatic compounds were reproduced by the following simple equations:

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Here X represents a wide variety of univalent atoms or groups; Y is one or several various remote substituents; and Z represents an oxygen, nitrogen, carbon, or sulfur atom. DH0(XZC5H6) is a known reference/anchor point for a series of XZ bonds. Esr is the remote conjugation energy between the substituents and the reaction center (broken bond), and can be expressed as a Hammett‐type correlation. σ+(Y) is the Brown–Okamoto constant of a substituent Y or the sum of several substituent constants. The Hammett slope or reaction constant ρ is a linear function of the difference between the covalent potentials Vx(Z) and Vx(X). It has been found that

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and

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The set of equations are very powerful for the prediction of BDEs, chemical reactivity, and reaction center (or active site) in antioxidants, nutrients, pharmaceuticals, toxicants, carcinogens, and explosives. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 453–466, 2002
Kinetics of hydrogen abstraction reaction between trifluoromethyl formate and OH radical: A theoretical investigation
Authors: Chandra Asit K. , Urata Shingo , Uchimaru Tadafumi , Sugie Masaaki , Sekiya Akira 
Published: September 2002

AbstractKinetics and mechanism of the hydrogen abstraction reaction between trifluoromethyl formate, CF3OCHO, and OH radical have been investigated by using ab initio molecular orbital theory up to G2(MP2) level. The hydrogen abstraction rate constant has been calculated for the first time over a temperature range of 250–450 K by using standard transition state theory including the tunneling correction. Arrhenius parameters of the reaction have been estimated from the temperature dependence of the calculated rate constant. The calculated value for the rate constant (2.0 × 10−14 cm3 molecule−1 s−1) at 298 K is found to be in very good agreement with the recent experimental results. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 500–507, 2002
Gangliosides in rat femoral injury: Early effect on intimal hyperplasia
Authors: Castro Leonardo C. , Montero Edna F.S. , Pedrosa Marcelo E. , Von Kossel Karen , Simões Manuel J. , Nigro Amaury J.T. 
Published: September 2002

AbstractPrevious studies demonstrated that some immunosupressive agents inhibit arterial intimal hyperplasia. Our previous studies demonstrated that gangliosides (Gang) have an immunosuppressive effect on as well as an anti‐inflammatory role in the wound‐healing process. Therefore, we decided to examine the effect of Gang on intimal hyperplasia. Twenty Wistar isogenic rats received a transverse division of the anterior wall of the femoral artery, followed by suturing using mononylon 10‐0 under surgical microscopy and were then divided into two groups: Gang group, 3 mg/kg per day of Gang, and control group, vehicle, intramuscularly from surgery to death (1 and 3 weeks, respectively). Concentric intimal hyperplasia was observed in arteries stained by hematoxylin‐eosin in control and Gang groups. However, the media layer did not demonstrate any major alterations. After 3 weeks, the Gang group showed more intimal hyperplasia than the control group. Therefore, because intimal hyperplasia worsened in the presence of Gang after 3 weeks, further studies will be necessary to clarify its role in intimal proliferation. © 2001 Wiley‐Liss, Inc. MICROSURGERY 21:170–172 2001
Antigenic load and peripheral chimeric levels in entire and partial liver allograft recipients
Authors: Sun Junhong , Qin Guang , Wu Lujia , Wang Chuanmin , Ross Sheil A.G. 
Published: September 2002

AbstractOrthotopic partial liver transplantation (PLT) models were developed in rats to explore the unique role of the liver in transplant tolerance. In PVG rats, syngeneic PLT established that surgical reduction to one‐third of the liver and orthotopic transplantation permitted survival. Allogeneic PLT in the PVG to DA liver‐tolerant model, both 50% and 33%, did not affect the tolerogeneic property of the liver, with all PLT recipients surviving indefinitely. Blood samples taken at various time points for detection of donor cells using flow cytometry showed a steady increase in donor cell chimerism in both PLT and whole liver transplantation (WLT) recipients that persisted throughout the 3‐month observation period. At each time point, the level of donor cell chimerism in PLT was higher than that in WLT. We conclude that transplantation of one‐third of the liver is compatible with survival in rats. Reduction of antigenic load by means of hepatectomy does not affect the tolerogenic effect of the liver in the PVG to DA LT model because of the remarkable regeneration capability of the liver. Peripheral chimeric levels increase progressively after WLT, suggesting that this is an ongoing immunological phenomenon. The earlier and increased chimerism after PLT may be associated with liver regeneration. © 2001 Wiley‐Liss, Inc. MICROSURGERY 21:183–187 2001
A comparison between two hybrid techniques for the scattering from finite frequency‐selective surfaces
Authors: Pochini C. , Toso G. , Pelosi G. , Roederer A. 
Published: September 2002

AbstractThe scattering from finite frequency selective surfaces (FSSs) characterized by planar interfaces is analyzed, resorting to two PO‐based hybrid techniques. The hybrid techniques, validated with a full‐wave numerical technique, are easy to implement, fast, and already quite accurate for medium‐size FSSs. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 248–252, 2001.
Pulse‐wave velocity measured in one heartbeat using MR tagging
Authors: Macgowan Christopher K. , Henkelman R. Mark , Wood Michael L. 
Published: September 2002

AbstractA noninvasive method for measuring the aortic pulse‐wave velocity (PWV) in a single heartbeat is introduced. The method sinusoidally tags a column of blood within the vessel, and rapidly acquires a series of 1D projections of the tags as they move (in practice, 64 projections at 4‐ms intervals). From these projections, the relative motion of blood at different positions along the vessel is measured. The PWV is obtained by fitting a mathematical model of blood flow to the tag trajectories. Tests of this method in a pulsatile flow phantom are presented using latex and polyurethane tubes. The PWV measured in these tubes was (mean ± standard deviation) 4.4 ± 0.5 m/s and 2.3 ± 0.2 m/s, respectively. The distensibility of each tube was calculated from the PWV (latex = (7 ± 2) 10−3 mm Hg−1, poly. = (25 ± 4) 10−3mmHg−1) and found to agree within error with distensibility measurements based on the change of tube area with pressure (latex = (6.3 ± 0.3) 10−3mmHg−1, poly. = (27 ± 1) 10−3 mmHg−1). To test its feasibility, the PWV measurement was applied to four normal volunteers. The measured PWV values were 3.9 ± 0.8 m/s, 3.6 ± 0.9 m/s, 3.9 ± 0.5 m/s, and 5.3 ± 0.8 m/s. By acquiring an independent PWV measurement each heartbeat, errors introduced by arrhythmia and trigger variability appear to be avoided with this method. Magn Reson Med 48:115–121, 2002. © 2002 Wiley‐Liss, Inc.
Validation of diffusion tensor MRI‐based muscle fiber tracking
Authors: Damon Bruce M. , Ding Zhaohua , Anderson Adam W. , Freyer Andrea S. , Gore John C. 
Published: September 2002

AbstractDiffusion‐tensor (DT) MRI fiber tracking may potentially be used for in vivo structural analysis. The purpose of this study was to assess quantitatively the ability of a DT‐MRI fiber‐tracking algorithm to measure the fiber orientation (pennation) in skeletal muscle in vivo. In five adult Sprague‐Dawley rats, the pennation angle (θ) was measured in the rat lateral gastrocnemius with DT‐MRI (θDT‐MRI) and by direct anatomical inspection (DAI) (θDAI). The mean θDT‐MRI was not significantly different from the mean θDAI. In addition, the two methods were highly correlated (r = 0.89) and the regression of θDT‐MRI on θDAI resulted in a slope not significantly different from 1 and an intercept not significantly different from zero. These data indicate that DT‐MRI‐based fiber tracking as implemented here is a valid tool for in vivo structural analysis of small‐animal skeletal muscle. Magn Reson Med 48:97–104, 2002. © 2002 Wiley‐Liss, Inc.
Discontinuous analysis of softening solids under impact loading
Authors: Wells G. N. , Sluys L. J. 
Published: September 2002

AbstractSoftening solids are analysed under impact loading using a new numerical method which allows displacement discontinuities to propagate arbitrarily through a finite element mesh. The Dirac‐delta distributions that arise in the strain field of classical continuum theory in the presence of strain softening are interpreted as discontinuities in the displacement field. A new finite element procedure with Heaviside jumps added to the underlying displacement interpolation basis is able to capture displacement jumps independent of the spatial discretisation. The amplitudes of displacement jumps are represented by extra degrees of freedom at existing nodes. Numerical results for mode‐I and mode‐II failure due to impact loading are presented. The numerical results highlight the objectivity of the approach with respect to spatial discretisation under dynamic loading conditions. Copyright © 2001 John Wiley & Sons, Ltd.
Evolution of elastic properties in finite poroplasticity and finite element analysis
Authors: Bernaud D. , Deudé V. , Dormieux L. , Maghous S. , Schmitt D.P. 
Published: September 2002

AbstractThe formulation of the poroelastoplastic constitutive equations at large strains of a fully saturated material is performed focusing on the usually ignored influence of large strain plasticity on the poroelastic properties. A micromechanics approach allows to take into account the evolution of the microstructure geometry which in turn induces a coupling between elasticity and plasticity. Such a coupling results in an additional term in the macroscopic Cauchy stress rate equation derived from inclusion‐based estimates that leads to a modified Jaumann derivative. The pressure rate equation is also analysed. The finite element discretization of finite poroplasticity is then presented taking into account the elasticity–plasticity coupling. Application to the consolidation situation shows that the coupling may lead to non‐negligible effects. Copyright © 2002 John Wiley & Sons, Ltd.
Nonconforming Galerkin methods for the Helmholtz equation
Authors: Douglas Jim , Santos Juan E. , Sheen Dongwoo 
Published: September 2002

AbstractNonconforming Galerkin methods for a Helmholtz‐like problem arising in seismology are discussed both for standard simplicial linear elements and for several new rectangular elements related to bilinear or trilinear elements. Optimal order error estimates in a broken energy norm are derived for all elements and in L2 for some of the elements when proper quadrature rules are applied to the absorbing boundary condition. Domain decomposition iterative procedures are introduced for the nonconforming methods, and their convergence at a predictable rate is established. © 2001 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 17: 475–494, 2001
Characterisation of new oligoglycosidic compounds in two Chinese medicinal herbs
Authors: Apers Sandra , Huang Ying , Miert Sabine Van , Dommisse Roger , Berghe Dirk Vanden , Pieters Luc , Vlietinck Arnold 
Published: September 2002

AbstractA series of caffeic acid derivatives (3,5‐dicaffeoyl‐quinic acid, 3,4‐dicaffeoyl‐quinic acid, and 4,5‐dicaffeoyl‐quinic acid), and the new compound β,3,4‐trihydroxyphenethyl‐O‐[β‐apiofuranosyl‐(1→4)‐α‐rhamnopyranosyl‐(1→3)]‐(4‐O‐caffeoyl)‐β‐glucopyranoside (wedelosin), as well as three known flavonoid glycosides (quercetin 3‐O‐β‐glucoside, kaempferol 3‐O‐β‐apiosyl‐(1‐2)‐β‐glucoside, and astragalin or kaempferol 3‐O‐β‐glucoside) were isolated from the Chinese medicinal herb Wedelia chinensis. Wedelosin showed an inhibitory activity on both the classical and the alternative activation pathway of the complement system. Another Chinese medicinal herb, Kyllinga brevifolia, yielded two known flavonoid glycosides [kaempferol 3‐O‐β‐apiosyl‐(1‐2)‐β‐glucoside and isorhamnetin 3‐O‐β‐apiosyl‐(1‐2)‐β‐glucoside], and a new quercetin triglycoside [quercetin 3‐O‐β‐apiofuranosyl‐(1→2)‐β‐glucopyranoside 7‐O‐α‐rhamnopyranoside]. The latter compound showed a moderate anti‐viral activity. Copyright © 2002 John Wiley & Sons, Ltd.
First trimester PAPP‐A in the detection of non‐Down syndrome aneuploidy
Authors: Ochshorn Yifat , Kupferminc Michael J. , Wolman Igal , Orr‐Urtreger Avi , Jaffa Ariel J. , Yaron Yuval 
Published: September 2002

AbstractCombined first trimester screening using pregnancy associated plasma protein‐A (PAPP‐A), free β‐human chorionic gonadotrophin, and nuchal translucency (NT), is currently accepted as probably the best combination for the detection of Down syndrome (DS). Current first trimester algorithms provide computed risks only for DS. However, low PAPP‐A is also associated with other chromosome anomalies such as trisomy 13, 18, and sex chromosome aneuploidy. Thus, using currently available algorithms, some chromosome anomalies may not be detected. The purpose of the present study was to establish a low‐end cut‐off value for PAPP‐A that would increase the detection rates for non‐DS chromosome anomalies. The study included 1408 patients who underwent combined first trimester screening. To determine a low‐end cut‐off value for PAPP‐A, a Receiver–Operator Characteristic (ROC) curve analysis was performed. In the entire study group there were 18 cases of chromosome anomalies (trisomy 21, 13, 18, sex chromosome anomalies), 14 of which were among screen‐positive patients, a detection rate of 77.7% for all chromosome anomalies (95% CI: 55.7–99.7%). ROC curve analysis detected a statistically significant cut‐off for PAPP‐A at 0.25 MoM. If the definition of screen‐positive were to also include patients with PAPP‐A<0.25 MoM, the detection rate would increase to 88.8% for all chromosome anomalies (95% CI: 71.6–106%). This low cut‐off value may be used until specific algorithms are implemented for non‐Down syndrome aneuploidy. Copyright © 2001 John Wiley & Sons, Ltd.
Allele‐specific amplification for preimplantation genetic diagnosis (PGD) of spinal muscular atrophy
Authors: Moutou Céline , Gardes Nathalie , Rongières Catherine , Ohl Jeanine , Bettahar‐Lebugle Karima , Wittemer Christiane , Gerlinger Pierre , Viville Stéphane 
Published: September 2002

AbstractWe have developed a new allele‐specific amplification method for the preimplantation genetic diagnosis (PGD) of spinal muscular atrophy (SMA; Werdnig‐Hoffmann disease) from a single cell. This method is based on the detection of the deletion of exon 7 of the telomeric copy of the survival motor neurone (SMNt) gene. An oligonucleotide was designed to be specific to the SMNt nucleotidic sequence with exonic mismatch G (for SMNt)→A (for SMNc) at its 3′ end. This test produces reliable PCR products in 95% of single lymphoblasts (85/88) tested as well as in 16/16 blastomeres from normal controls. Specificity analysis showed that we were able to detect homozygous deletion of the SMNt gene in 99% of single lymphoblasts (103/104) from a SMA patient. No contamination was detected in 68 blanks tested. Multiple cell and DNA dilution analysis revealed that the test is accurate and specific up to 100 pg DNA and should thus also be suitable for PGD at the blastocyst stage. This rapid procedure requires a single round of fluorescent PCR and no restriction digestion, while previously described single cell methods include nested PCR followed by restriction enzyme digestion. Two PGD cycles for SMA using this procedure were performed in our centre. Copyright © 2001 John Wiley & Sons, Ltd.
Preimplantation genetic diagnosis of the fragile X syndrome by use of linked polymorphic markers
Authors: Apessos A. , Abou‐Sleiman P. M. , Harper J. C. , Delhanty J. D. A. 
Published: September 2002

AbstractFragile X syndrome is the most common cause of familial mental retardation. The most common mutation is expansion of a triplet (CGG)n repeat in the 5′ untranslated region of the FMR1 gene on Xq27.3. The expansion is refractory to PCR due to preferential amplification of the smaller allele in heterozygous cells and the high GC content of the repeat and surrounding sequences. Direct detection of the normal parental alleles in preimplantation embryos has been used for preimplantation genetic diagnosis (PGD) of this disorder. However, this approach is only suitable for approximately 63% of couples due to the heterozygosity of the repeat in the normal population. As an alternative we investigated the use of polymorphic markers flanking the mutation to track the normal and premutation carrying maternal chromosomes in preimplantation embryos. Using a panel of 11 polymorphisms, six (CA)n repeats and five single nucleotide polymorphisms, diagnosis was developed for 90% of referred couples. Multiplex amplification of informative markers was tested in 300 single buccal cells from interested couples with efficiency and allele drop out (ADO) rates ranging from 69% to 96% and 6% to 18%, respectively. Use of this approach is accurate and applicable to a larger number of patients at risk of transmitting fragile X to their offspring. Copyright © 2001 John Wiley & Sons, Ltd.
Prenatal ultrasonographic detection of gastrointestinal obstruction: results from 18 European congenital anomaly registries
Authors: Haeusler Martin C. H. , Berghold Andrea , Stoll Claude , Barisic Ingeborg , Clementi Maurizio 
Published: September 2002

AbstractObjectivesWe evaluated the prenatal detection of gastrointestinal obstruction (GIO, including atresia, stenosis, absence or fistula) by routine ultrasonographic examination in an unselected population all over Europe.MethodsData from 18 congenital malformation registries in 11 European countries were analysed. These multisource registries used the same methodology. All fetuses/neonates with GIO confirmed within 1 week after birth who had prenatal sonography and were born during the study period (1 July 1996 to 31 December 1998) were included.ResultsThere were 670 793 births in the area covered and 349 fetuses/neonates had GIO. The prenatal detection rate of GIO was 34%; of these 40% were detected ≤24 weeks of gestation (WG). A total of 31% (60/192) of the isolated GIO were detected prenatally, as were 38% (59/157) of the associated GIO (p=0.26). The detection rate was 25% for esophageal obstruction (31/122), 52% for duodenal obstruction (33/64), 40% for small intestine obstruction (27/68) and 29% for large intestine obstruction (28/95) (p=0.002). The detection rate was higher in countries with a policy of routine obstetric ultrasound. Fifteen percent of pregnancies were terminated (51/349). Eleven of these had chromosomal anomalies, 31 multiple malformations, eight non‐chromosomal recognized syndromes, and one isolated GIO. The participating registries reflect the various national policies for termination of pregnancy (TOP), but TOPs after 24 WG (11/51) do not appear to be performed more frequently in countries with a liberal TOP policy.ConclusionThis European study shows that the detection rate of GIO depends on the screening policy and on the sonographic detectability of GIO subgroups. Copyright © 2002 John Wiley & Sons, Ltd.