bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mutagenicity and antioxidant assessment of Stachitarpheta jamaicensis (L.) Vahl.
Authors: Ramos Alberto , Piloto Janet , Visozo Angel , García Arilia , Lastra Humberto , de León Heidy Ponce 
Published: August 2002

AbstractStachitarpheta jamaicensis (L.) Vahl. is a member of the Verbenaceae commonly used in Cuba, mainly as vermifugue and against diarrhoea. The mutagenic potential of a hydroalcohol extract of its aerial parts was assessed in vitro using the Salmonella/microsome assay and in vivo in the mouse bone marrow micronucleus test. No positive response was observed in a battery of four Salmonella typhimurium strains employed: TA 1535, TA 1537, TA 98 and TA 100, when exposed to concentrations up to 5 mg/plate, with and without mammalian metabolic activation. In the same way, no increase in the micronucleus frequency in mitotic erythropoietic tissue was observed when animals were administered the extract orally in doses of 500, 1000 and 2000 mg/kg. The extract inhibited lipid peroxidation in the rat liver microsomal fraction (IC50 = 3.6 µg/mL) but it does not seem to be an effective ·OH radical scavenger (IC50 = 76.7 µg/mL). Noteworthy, it increased in a dose dependent way the level of revertant colonies in E. coli IC 203, a strain sensitive to oxidative mutagenesis, when assayed together with hydrogen peroxide and ferrous sulphate, which suggests a pro‐oxidant action. Copyright © 2001 John Wiley & Sons, Ltd.
Antimicrobial study of bark from five tree species
Authors: Pérez G. Salud , Zavala S. Miguel A. , Arias G. Lucina , Pérez G. Cuauhtemoc , Pérez G. Rosa M. 
Published: August 2002

AbstractThe antimicrobial activities of chloroform, methanol and aqueous extracts of the bark of Gymnanthes lucida, Gliricidia sepium, Lysiloma divaricata, Lysiloma tergemina and Coccolaba cozumelensis were tested against S. lutea, E. coli, S. epidermidis, L. monocytogenes, S. choleraesuis, S. aureus, P. aeruginosa, B. pumillus, S. typhimurium, P. vulgaris, V. cholerae and C. albicans.It was found that methanol extracts of the two Lysiloma species and G. sepium had antimicrobial effects against S. epidermidis, S. aureus, P. aeruginosa, B. pumillus and V. cholerae at doses of 200 µg. The major inhibitory effect was observed with L. tergemina which showed a bacteriostatic effect on S. epidermidis at doses of 400 µg/mL. Copyright © 2001 John Wiley & Sons, Ltd.
Neuroprotective Effects of Withania somnifera Dunn. in Hippocampal Sub‐regions of Female Albino Rat
Authors: Jain Sushma , Shukla Sunil Dutt , Sharma Kanika , Bhatnagar Maheep 
Published: August 2002

AbstractThe neuroprotective effects of W. somnifera were studied on stressed adult female Swiss albino rats. Experimental rats were subjected to immobilization stress for 14 h and were treated with a root powder extract of W. somnifera available as Stresscom capsules (Dabur India Ltd). Control rats were maintained in completely, non stressed conditions. Thionin stained serial coronal sections (7 μm) of brain passing through the hippocampal region of stressed rats (E1 group) demonstrated 85% degenerating cells (dark cells and pyknotic cells) in the CA2 and CA3 sub‐areas. Treatment with W. somnifera root powder extract significantly reduced (80%) the number of degenerating cells in both the areas. The study thus demonstrates the antistress neuroprotective effects of W. somnifera. Copyright © 2001 John Wiley & Sons, Ltd.
Antihypertensive effect of an aqueous extract of Zygophyllum coccineum L. in rats
Authors: Gibbons S. , Oriowo M. A. 
Published: August 2002

AbstractThe effects of an aqueous extract of Zygophyllum coccineum L. on rat blood pressure (BP) and on the mesenteric vascular bed were investigated. The extract dose‐dependently reduced BP and heart rate in normotensive and spontaneously hypertensive rats (SHRs). It also reduced BP in pithed SHRs. In vitro, the extract had no effect on basal perfusion pressure of the mesenteric vascular bed. When the perfusion pressure was raised with noradrenaline or potassium chloride, the extract produced a dose‐dependent reduction in perfusion pressure. However, in preparations in which the perfusion pressure was raised with KCl, the depressor response to lower doses of the extract was abolished while higher doses produced responses that were reduced in magnitude when compared with similar responses in preparations in which the perfusion pressure was raised with noradrenaline. It was concluded that extracts of Z. coccineum possess significant antihypertensive activity that may involve some membrane hyperpolarization. Copyright © 2001 John Wiley & Sons, Ltd.
Quaternary benzo[c]phenanthridine alkaloids as inhibitors of aminopeptidase N and dipeptidyl peptidase IV
Authors: Šedo Aleksi , Vlašicová Květoslava , Barták Petr , Vespalec Radim , Vičar Jaroslav , Šimánek Vilim , Ulrichová Jitka 
Published: August 2002

AbstractChelerythrine, sanguinarine and an alkaloid extract from Macleaya cordata—sanguiritrin—were found to be inhibitors of aminopeptidase A and dipeptidyl peptidase IV, while fagaronine inhibited dipeptidyl peptidase IV only. At 50 μM, chelerythrine, sanguinarine and sanguiritrin inhibited aminopeptidase N by 82%, 82%, 88%, DPP IV by 38%, 62%, 57%, and fagaronine by 34%, respectively. When bovine serum albumin (500 μg/mL) was added, the inhibition of both proteases by quaternary benzo[c]phenanthridine alkaloids (QBA) (50 μM) was significantly diminished. Strong interaction of chelerythrine and sanguinarine with bovine and human serum albumin was proved by electrophoretic determination of their respective conditional binding constants. Copyright © 2002 John Wiley & Sons, Ltd.
Metabolism of 1,8‐dihydroxy 3‐hydroxy methyl anthraquinone (aloe‐emodin) isolated from the leaves of Cassia tora in albino rats
Authors: Maity Tapan K. , Mandal Subhash C. , Bhakta T. , Pal M. , Saha B. P. 
Published: August 2002

AbstractCassia tora is a wellknown plant of India. Aloe‐emodin was isolated from the leaves of this plant and its metabolism pattern was studied. The results showed that about 15.4% of the administered aloe‐emodin was excreted and the rest was probably bound or metabolized in the system. Copyright © 2001 John Wiley & Sons, Ltd.
What's new?
Authors: Bohaychuk Wendy 
Published: August 2002

AbstractStarting with this issue, the Quality Assurance Journal introduces a section which aims to draw your attention to significant events of importance to quality assurance (QA) professionals. Each item will be linked to the relevant Internet address which you might add to your ‘favourites’ folders and check regularly yourselves. If there is any other new information which should be brought to the attention of readers, please let us know by e‐mailing gcrpc@compuserve.com Copyright © 2001 John Wiley & Sons, Ltd.
Bayesian tolerance interval control limits for attributes
Authors: Hamada Michael 
Published: August 2002

AbstractThe probability content of standard control limits for attributes can vary because distribution parameters that appear in the control limits are estimated based on previous data. This paper proposes using Bayesian tolerance interval control limits which control the probability content at a specified level with a given confidence. Bayesian tolerance interval control limits are developed for np, p, c and u charts and are illustrated with four examples from the literature. Moreover, Bayesian tolerance interval control limits can be used for processes at start‐up. Published in 2002 by John Wiley & Sons, Ltd.
An embedded QM/MM study for different SiO2/Al2O3 ratios of the HZSM‐5 zeolite and for their interaction with n‐heptane
Authors: Martínez‐Magadán J. M. , Cuán A. , Castro M. 
Published: August 2002

AbstractWe carried out a theoretical study of the HZSM‐5 zeolite, for different SiO2/Al2O3 ratios, that interacts with the n‐heptane molecule. The study was performed using a QM/MM (quantum mechanics/molecular mechanics) methodology. For the QM part, we have chosen a hybrid Hartree‐Fock density functional theory (DFT). The hybrid ACM/DZP approach, as implemented in Turbomole, was used for the treatment of the QM cluster containing 84 atoms that represents a ring structure model of the zeolite‐n‐heptane interacting system. The MM part was represented by means of an electrostatic forcefield (ESFF), which assesses the electronic embedding. The chosen QM/MM silicalite base model contains 3862 atoms. The studied SiO2/Al2O3 ratios were 2300, 573.5, 287.7, and 189.83, containing 1, 4, 8, and 12 Al atoms, respectively. For the first ratio, the site for the substitution of Al for Si was that of minimum QM total energy value, because this replacement was done in the QM region. For the other SiO2/Al2O3 ratios, the Al atoms were randomly spread through the MM region in accordance with the Lowenstein substitution rule. These results show the importance of the environment on the electronic properties in the QM region, where the active site lies, and their effects on the earlier steps on the activation experienced by the n‐heptane moiety. A minimal content of 12 Al atoms produces significant effects of the environment on the electronic structure of the QM region. Moreover, the carbocationic character of n‐heptane increases with the aluminum content. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002
Theoretical study of the structural, vibrational, and topologic properties of the charge distribution of the molecular complexes between thiophene and Brönsted acid sites of zeolites
Authors: Soscún Humberto , Castellano Olga , Hernández Javier , Hinchliffe Alan 
Published: August 2002

AbstractThe main interaction between thiophene and zeolites leads to the formation of a hydrogen bond between the S atom of thiophene and the OH group of zeolites, giving 1:1 stable molecular complexes. The present work reports a theoretical study about the structural, vibrational, and topologic properties of the charge distribution of the molecular complexes between thiophene and a series of Brönsted acid sites of zeolites, modeled as the H3SiOHAlH3(B1), (OH)3Si(OH)Al(OH)3(B1OH), and H3Si(OH)Al(OH)2OSiH3(B2) clusters. The studied properties were calculated at a Hartree–Fock level with the standard 6‐31+G(d,p) basis set. Additionally, electron correlation effects for geometric and vibrational properties were evaluated at second‐order Møller–Plesset (MP2) and BLYP for B1–thiophene complex, whereas the BLYP technique was employed for the complexes of thiophene with B1OH and B2 clusters. Symmetry restriction was considered for structure calculations, beingC2vfor thiophene,Csfor zeolite clusters, andCslinear conformation for the complexes. It was found that these linear thiophene–zeolite complexes reproduce the tendencies in the experimental frequency shifts of the OH vibration mode from the adsorption of thiophene in ZSM5 zeolites. The topologic properties of the complexes give a pattern for the interaction of thiophene–zeolite. The results are compared with previous ones from silanol–thiophene calculations. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Henry constants predicted using multipole expansion for the interaction energies
Authors: Tielens Frederik , Geerlings Paul 
Published: August 2002

AbstractIn line with the former studies of our group concerning the ab initio (parameter‐free) calculation of adsorption‐related properties, a new simple and powerful method is presented and applied to the adsorption of N2, O2, CO, CO2, and C2H2in zeolite Y. The calculation method is investigated and some refinements on the calculation strategy are introduced. The calculation method is based on the expansion of the interaction energy in terms of the multipole moments and polarizabilities. The molecular electrical properties were calculated at a high level on the B3LYP/cc‐aug‐pV(Q or 5)Z. A relationship between the van der Waals radius and the radius of an atom of the interacting molecule in a charge field is proposed. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 84: 58–69, 2001
Approximate transferability in alkanenitriles
Authors: López Jos Luis , Mandado Marcos , Graña Ana M. , Mosquera Ricardo A. 
Published: August 2002

AbstractThe atomic and bond properties of a series of alkanenitriles were calculated in order to analyze the transferability of the CN, methyl, and methylene groups. The calculations were carried out using the atoms in molecules (AIM) theory on RHF/6‐31++G**// RHF/6‐31G** wave functions obtained for compounds CN–R (R ranging from H to C11H23). Linear correlations betweenL(Ω) andN(Ω) were used to establish N(CH2) and N(CH3) nearly transferable values. Average values and maximum differences to the mean value of several properties were used for classifying the CN group. It shows a transferable behavior along the CN–R series for R>Et. The methyl group presents specific properties when R<Pr. The methylene groups can be classified considering both their position with respect to the end of the chain and the position with respect to the CN group. The atomic energy displays a dependence on the molecular size. Although this behavior does not allow to consider this property as transferable, both the ab initio total electronic molecular energies and the experimental heats of formation can be fitted, by linear regression analysis, as a function of the number of methylene groups. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
Ion fragmentation in an electrospray ionization mass spectrometer interface with different gases
Authors: Schneider Bradley B. , Douglas D. J. , Chen David D. Y. 
Published: August 2002

AbstractNitrogen, argon, and krypton are used as curtain gases in an electrospray ionization mass spectrometer in an attempt to study the effect of these gases on the extent of ion fragmentation between the orifice and the skimmer of the interface region. A previously published collision model predicts that the degree of ion fragmentation increases with increasing mass of the curtain gas. However, the fragmentation yields are found to be the opposite to that expected. It is believed that the reversed trend with argon and krypton is caused by condensation of the gases within the free jet expansion between the orifice and the skimmer. A condensation parameter can be used to predict the degree of clustering of gases within a free jet expansion. When the condensation parameter is minimized, the predicted trend of fragmentation with mass is observed. Copyright © 2001 John Wiley & Sons, Ltd.
δ13C‐ and δ18O‐Values of glycerol of food fats
Authors: Fronza Giovanni , Fuganti Claudio , Grasselli Piero , Serra Stefano , Reniero Fabiano , Guillou Claude 
Published: August 2002

AbstractThe average values of carbon and oxygen isotopic contents (δ13C and δ18O) of 36 glycerol samples from fats have been determined. The examined samples arise from many fats of animal and plant origin, as well as from the three Italian hard cheeses Parmigiano‐Reggiano, Grana Padano and Trentingrana. The total 13C content allows one to distinguish between glycerol from plants with the C‐4 carbon fixation pathway (maize, mean δ13C = −14.4‰) and that from plants with the C‐3 pathway (mean δ13C = −30.7‰). The δ13C‐values of glycerols of animal origin seem to depend on the diet of the animal, as suggested by the mean values −29.6, −29.0 and −25.1‰, respectively, observed for Parmigiano‐Reggiano, Trentingrana and Grana Padano. Additionally, the mean total 18O content of glycerol samples of vegetable origin is approximately 23.8‰, while that from animal fat is 15.1‰. However, the δ18O mean values relative to Parmigiano‐Reggiano, Grana Padano and Trentingrana are 11.8, 16.0 and 13.8‰, respectively. The combination of the 13C and 18O measurements relative to the fat glycerol of the three cheeses might be considered a potential criterion of authentication. Copyright © 2001 John Wiley & Sons, Ltd.
Analysis of plant phosphatidylcholines by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Zabrouskov Vladimir , Al‐Saad Khalid A. , Siems William F. , Hill Herbert H. , Knowles N. Richard 
Published: August 2002

AbstractThe use of matrix‐assisted laser desorption/ionization (MALDI) time‐of‐flight (TOF) mass spectrometry (MS) for the quantitative determination of phospholipid (PL) molecular species has been problematic, due primarily to the formation of multiple signals (corresponding to the molecular ion and other adducts) for some classes of PL. For example, analysis of phosphatidylcholine (PC) yielded signals that corresponded to protonated and sodiated molecules in the MALDI spectrum. The resulting spectral overlap among various molecular species (e.g. [PC(16:0/18:2) + Na] and [PC(18:2/18:3)]) made it impossible to ascertain their relative amounts using this technique. Other spectral ambiguities existed among different structural isomers, such as PC(18:1/18:1) and PC(18:0/18:2). We determined that molecular species could be resolved by MALDI‐TOFMS by first removing the polar head (e.g. phosphocholine) from the phospholipid to effect production of only the sodiated molecules of the corresponding diacylglycerols (DAGs). Analysis of the resulting spectrum allowed unequivocal determination of the molecular species profile of PC from potato tuber and soybean. Estimation of fatty acid composition based on the molecular species determined by MALDI‐TOFMS analysis agreed with that from GC‐FID analysis. Post‐source decay (PSD) was used to resolve standard isomers of PC (e.g. 18:1/18:1 vs. 18:0/18:2). Our results indicated that PSD is a useful approach for resolving structural isomers of PL molecular species. Copyright © 2001 John Wiley & Sons, Ltd.
Removal, Handling, and Thermal Desorption Treatment Techniques for Manufactured Gas Plant Wastes
Authors: Musterait Todd M. 
Published: August 2002

AbstractDue to the nature of contamination typically found at former MGP (manufactured gas plant) sites,
excavation and thermal desorption of MGP wastes has proven to be an effective method for the remediation of
MGP‐contaminated soil. The use of on‐site thermal desorption enables MGP sites to be quickly
remediated at a low cost. Tar pits, holders, and other underground storage structures typically contain coal tar
residuals and waste from former operations, and the areas around these structures are often significantly
contaminated. Thus, excavation techniques, odor and vapor management, and material preparation for the treatment
method are important factors to consider when developing a site remediation strategy. This article reviews
typical excavation and handling methods associated with the remediation of former MGP sites and discusses the
treatment of MGP wastes using on‐site thermal desorption technology. © 2001 John Wiley & Sons,
Inc.
Managing contaminated sites and the role of domestic and international forums
Authors: Guerin Turlough F. 
Published: August 2002

AbstractDomestic and international cooperation in the field of contaminated‐site management has increased
dramatically in the past decade. The expected benefits of this cooperation include the reduction of duplication
in remediation efforts, the coordination of contaminated‐site research, improved synergy between various
stakeholders, enhanced policy development, and better information dissemination and technology transfer. This
article identifies and briefly discusses key domestic and international collaborations, partnerships, and
networks relating to contaminated‐site management and remediation. Also provided is information on how the
forums can be accessed. Common themes identified across the forums discussed in this article include
(1) the development and demonstration of innovative technologies, (2) the use of risk
assessment, (3) the use of toxicology, bioavailability, and ecotoxicity testing, and (4) the
increasing need to find holistic approaches for managing contaminated sites, such as guaranteed remediation
programs and transfer of environment liability, and the need for understanding implications of remediation
financing mechanisms. © 2001 John Wiley & Sons, Inc.
A real‐time dual‐arm collision avoidance algorithm for assembly
Authors: Lee Sukhan , Moradi Hadi 
Published: August 2002

AbstractMultirobot workcells provide efficiency of space, time, and materials in assembly. However, this advantage cannot be fully utilized unless an efficient off‐line/on‐line collision‐free trajectory planner is in charge of controlling the arms. In this article a new algorithm which provides the on‐line and real‐time generation of dual‐arm collision‐free trajectories has been established. The algorithm is capable of generating dual‐arm collision‐free trajectories in real‐time despite the fact that the initial configurations of two arms are not synchronized. The algorithm is based on two sections: collision detection and path planning. The collision detection section uses a fast geometric approach based on link intersection. The path planning section, the key component of the algorithm, uses the virtual road map which gives the best collision‐free motion at each given arm configuration. © 2001 John Wiley & Sons, Inc.
Classification of reaches in the Missouri and lower Yellowstone Rivers based on flow characteristics
Authors: Pegg Mark A. , Pierce Clay L. 
Published: August 2002

AbstractSeveral aspects of flow have been shown to be important determinants of biological community structure and function in streams, yet direct application of this approach to large rivers has been limited. Using a multivariate approach, we grouped flow gauges into hydrologically similar units in the Missouri and lower Yellowstone Rivers and developed a model based on flow variability parameters that could be used to test hypotheses about the role of flow in determining aquatic community structure. This model could also be used for future comparisons as the hydrological regime changes. A suite of hydrological parameters for the recent, post‐impoundment period (1 October 1966–30 September 1996) for each of 15 gauges along the Missouri and lower Yellowstone Rivers were initially used. Preliminary graphical exploration identified five variables for use in further multivariate analyses. Six hydrologically distinct units composed of gauges exhibiting similar flow characteristics were then identified using cluster analysis. Discriminant analyses identified the three most influential variables as flow per unit drainage area, coefficient of variation of mean annual flow, and flow constancy. One surprising result was the relative similarity of flow regimes between the two uppermost and three lowermost gauges, despite large differences in magnitude of flow and separation by roughly 3000 km. Our results synthesize, simplify and interpret the complex changes in flow occurring along the Missouri and lower Yellowstone Rivers, and provide an objective grouping for future tests of how these changes may affect biological communities. Copyright © 2002 John Wiley & Sons, Ltd.
Linear waste of best fit bin packing on skewed distributions
Authors: Kenyon Claire , Mitzenmacher Michael 
Published: August 2002

AbstractWe prove that Best Fit bin packing has linear waste on the discrete distribution U{j, k} (where items are drawn uniformly from the set {1/k, 2/k, …, j/k}) for sufficiently large k when j = αk and 0.66 ≤ α < 2/3. Our results extend to continuous skewed distributions, where items are drawn uniformly on [0, a], for 0.66 ≤ a < 2/3. This implies that the expected asymptotic performance ratio of Best Fit is strictly greater than 1 for these distributions. © 2002 Wiley Periodicals, Inc. Random Struct. Alg., 20:441–464, 2002
A note on disagreement percolation
Authors: Häggström Olle 
Published: August 2002

AbstractWe construct a coupling of two distinct Gibbs measures for Markov random fields with the same specifications, such that the existence of an infinite path of disagreements between the two configurations has probability 0. This shows that the independence assumption in the disagreement percolation method for proving Gibbsian uniqueness cannot be dropped without being replaced by other conditions. A similar counterexample is given for couplings of Markov chains. © 2001 John Wiley & Sons, Inc. Random Struct. Alg., 18, 267–278, 2001