bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of peat compressibility: is there an easy way?
Authors: Price Jonathan S. , Cagampan Jason , Kellner Erik 
Published: October 2005

AbstractPeat compression can significantly alter the hydraulic parameters that govern flow and storage of water. Physical properties of peat (bulk density, state of decomposition (von Post number, vP) and fibre content) were assessed to determine whether they can be used as indicators of peat compressibility. Bulk density and vP were related to each other (positively), and within a given core were related (negatively) to compressibility. Peat from different locations exhibited different compressibility characteristics for a given value of bulk density or vP. Fibre content was unrelated to bulk density, vP, or to peat compressibility. It was concluded that more commonly and relatively easily measured soil parameters are not good indicators of soil compressibility. Copyright © 2005 John Wiley & Sons, Ltd.
Recognition of tandem sialic acid residues by CD38: A theoretical study
Authors: Ueno‐Noto Kaori , Hara‐Yokoyama Miki , Takano Keiko 
Published: October 2005

AbstractThe electronic structures of gangliosides are described using semiempirical and ab inito molecular orbital theories as well as the density functional theory to clarify the causative factors of the differences in inhibitory effects and to elucidate the recognition mechanisms of the enzyme. Our results suggest that CD38 is likely to recognize the two phosphate groups in NAD and the two carboxyl groups in tandem sialic acid residues of gangliosides. The recognition mechanisms of the substrate are proposed based on the good correlation found between the orbital energy of the highest occupied molecular orbital of the gangliosides and the degree of the inhibitory effect. © 2005 Wiley Periodicals, Inc. J Comput Chem 27: 53–60, 2006
Accurate relativistic adapted Gaussian basis sets for hydrogen through xenon without variational prolapse and to be used with both uniform sphere and Gaussian nucleus models
Authors: Haiduke Roberto L.A. , da Silva Albérico B.F. 
Published: October 2005

AbstractAccurate relativistic adapted Gaussian basis sets (RAGBSs) from H (Z = 1) through Xe (Z = 54) without variational prolapse have been developed by employing a polynomial version of the Generator Coordinate Dirac‐Fock (p‐GCDF) method. Two nuclear models have been used in this work: (1) the finite nucleus of uniform proton‐charge distribution, and (2) the finite nucleus with a Gaussian proton–charge distribution. The largest errors observed are only 1.5 mHartree (silver and cadmium) and the RAGBS sizes are much smaller than previous accurate relativistic Gaussian basis sets that were shown to be free of variational prolapse. © 2005 Wiley Periodicals, Inc. J Comput Chem 27: 61–71, 2006
Mitochondrial activity regulates myoblast differentiation by control of c‐Myc expression
Authors: Seyer Pascal , Grandemange Stéphanie , Busson Muriel , Carazo Angel , Gamaléri Frédéric , Pessemesse Laurence , Casas François , Cabello Gérard , Wrutniak‐Cabello Chantal 
Published: October 2005

AbstractWe have previously shown that mitochondrial activity is an important regulator of myoblast differentiation, partly through processes targeting myogenin expression. Here, we investigated the possible involvement of c‐myc in these processes. Inhibition of mitochondrial activity by chloramphenicol abrogated the decrease in c‐myc mRNA and protein levels occurring at the onset of terminal differentiation. Conversely, stimulation of mitochondrial activity by overexpression of the T3 mitochondrial receptor (p43) down‐regulated c‐myc expression. In addition, c‐myc overexpression mimicked the influence of mitochondrial activity inhibition on myoblast differentiation. Moreover, like chloramphenicol, c‐myc overexpression strongly inhibited the myogenic influence of p43 overexpression. These data suggest that c‐Myc is an important target of mitochondrial activity involved in the myogenic influence of the organelle. Lastly, we found that chloramphenicol influence is negatively related to the frequency of post‐mitotic myoblasts in the culture at the onset of treatment, and cell cycle analyses demonstrated that the frequency of myoblasts in G0–G1 phase at cell confluence is increased by p43 overexpression and decreased by chloramphenicol or c‐myc overexpression. These results suggest that irreversible myoblast withdrawal from the cell cycle is a target of mitochondrial activity by control of c‐Myc expression. J. Cell. Physiol. 207: 75–86, 2006. © 2005 Wiley‐Liss, Inc.
Arterial spin labeling: Validity testing and comparison studies
Authors: Ewing James R. , Cao Yue , Knight Robert A. , Fenstermacher Joseph D. 
Published: October 2005

AbstractArterial spin labeling (ASL) is a potential means of obtaining quantitative images of cerebral blood flow (CBF). However, few validation studies of ASL have been performed in animal models using gold‐standard CBF methods. Other methods that use radiolabeled water as a tracer underestimate CBF in high flow states, but this effect has not been evident in ASL studies. In this study the accuracy of ASL measurements of CBF were modeled and experimentally validated, with particular attention paid to high flow rates. The ASL signal as modeled included the contributions from intravascular labeled spins. The modeling demonstrated linearity of the ASL signal with respect to baseline flow, and linearity of ASL signal changes with respect to changes in flow, including high‐flow conditions. Validation studies using quantitative autoradiography (QAR) to image flow in a rat model of unilateral cerebral ischemia showed that ASL systematically overestimated CBF by 34%. A similar overestimation was also predicted by modeling. These results indicate that ASL signals are linear with respect to flow (even high flow), but ASL‐CBF measurements are systematically overestimated. J. Magn. Reson. Imaging 2005. © 2005 Wiley‐Liss, Inc.
Partial volume effects on arterial input functions: Shape and amplitude distortions and their correction
Authors: van Osch Matthias J.P. , van der Grond Jeroen , Bakker Chris J.G. 
Published: October 2005

AbstractFor quantification of perfusion values from a bolus‐tracking MRI experiment, the measurement of an arterial input function (AIF) is necessary. Gradient‐echo (GE) sequences are commonly used for this type of experiment because they offer a high signal‐to‐noise ratio (SNR) and the potential to quantify the concentration of contrast agent. Measurements of calibration curves for Gd‐DTPA in human blood have shown a quadratic relation between the ΔR2* and the concentration of contrast agent, and a linear relationship between phase changes and the concentration of contrast agent. However, for in vivo studies the spatial resolution is usually limited, which leads to partial volume effects. Partial volume effects result in a complex sum of signal arising from the tissue outside the vessel and a contrast agent concentration‐dependent blood signal. Ignoring the presence of partial volume effects can lead to an overestimation or underestimation of the contrast agent concentration, depending on the experimental conditions. Correction for partial volume effects is feasible in arteries that are parallel to the main magnetic field by estimation and subtraction of the static signal of the surrounding tissue. Patient studies showed a large variation due to the AIF measurements, but it has also been shown that this influence can be minimized by correction for partial volume effects. J. Magn. Reson. Imaging 2005. © 2005 Wiley‐Liss, Inc.
Quantifying CBF with pulsed ASL: Technical and pulse sequence factors
Authors: Wong Eric C. 
Published: October 2005

AbstractWe summarize here current methods for the quantification of CBF using pulsed arterial spin labeling (ASL) methods. Several technical issues related to CBF quantitation are described briefly, including transit delay, signal from larger arteries, radio frequency (RF) slice profiles, magnetization transfer, tagging efficiency, and tagging geometry. Many pulsed tagging schemes have been devised, which differ in the type of tag or control pulses, and which have various advantages and disadvantages for quantitation. Several other modifications are also available that can be implemented as modules in an ASL pulse sequence, such as varying the wash‐in time to estimate the transit delay. Velocity‐selective ASL (VS‐ASL) uses a new type of pulse labeling in which inflowing arterial spins are tagged based on their velocity rather than their spatial location. In principle, this technique may allow ASL measurement of cerebral blood flow (CBF) that is insensitive to transit delays. J. Magn. Reson. Imaging 2005. © 2005 Wiley‐Liss, Inc.
Microwave Accelerated Polymerization of 2‐Phenyl‐2‐oxazoline: Microwave or Temperature Effects?
Authors: Hoogenboom Richard , Leenen Mark A. M. , Wiesbrock Frank , Schubert Ulrich S. 
Published: October 2005

AbstractSummary: Investigations regarding the cationic ring‐opening polymerization of 2‐phenyl‐2‐oxazoline under microwave irradiation and conventional heating are reported. This study was inspired by contradictory reports of the (non‐)existence of non‐thermal microwave effects that might accelerate the cationic ring‐opening of 2‐oxazolines. The polymerization of 2‐phenyl‐2‐oxazoline was investigated under pressure in acetonitrile and under reflux (or at the boiling point of butyronitrile in a closed vessel) in butyronitrile utilizing a single‐mode microwave reactor and automated synthesis robots with conventional heating.
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Novel Semiconducting Polymer Particles by Supercritical Fluid Process
Authors: Lim Kwon Taek , Subban Ganapathy Hullathy , Hwang Ha Soo , Kim Jung Taek , Ju Chang Sik , Johnston Keith P. 
Published: October 2005

AbstractSummary: A simple method to prepare surfactant‐free and solvent‐free semiconducting polymer particles by using an environmentally benign supercritical carbon dioxide (scCO2) process is reported. The process of the rapid expansion of supercritical solutions (RESS) is used to produce spherical particles of poly[2‐(3‐thienyl)acetyl 3,3,4,4,5,5,6,6,7,7,8,8,8‐tridecafluorooctanoate] (PSFTE), 50–500 nm in size, from 0.1–0.5 wt.‐% PSFTE solutions in CO2 at pre‐expansion temperatures of 40 °C and pre‐expansion pressures of 276 bar.An FESEM image of PSFTE particles produced by the RESS process with CO2.magnified imageAn FESEM image of PSFTE particles produced by the RESS process with CO2.
On the Use of the Nanoindentation Unloading Curve to Measure the Young's Modulus of Polymers on a Nanometer Scale
Authors: Tranchida Davide , Piccarolo Stefano 
Published: October 2005

AbstractSummary: The nanoindentation test is a fundamental tool to assess the link between morphology and mechanical properties. The preliminary results of a more exhaustive study about the applicability to polymers of the most used procedure to determine elastic modulus by indentation are reported in this short communication. A departure of the experimental conditions from the theoretical assumptions and results that give rise to the Oliver and Pharr analysis is shown to occur under a wide range of experimental conditions, with applied loads and penetration depths covering several orders of magnitude and using different indenter geometries. Unloading curves with exponents significantly larger than 2 are observed in disagreement with the contact mechanics approach used by Oliver and Pharr.An AFM image obtained in non contact mode of an indentation induced by a sharp AFM tip with a maximum applied load of ca 1.2 µN on amorphous PET.magnified imageAn AFM image obtained in non contact mode of an indentation induced by a sharp AFM tip with a maximum applied load of ca 1.2 µN on amorphous PET.
Polymerization of Enantiomerically Pure exo‐N‐(Norborn‐2‐ene‐5‐carboxyl)‐L‐phenylalanine Ethyl Ester and endo,endo‐N,N‐(Norborn‐5‐ene‐2,3‐dicarbimido)‐L‐valine Ethyl Ester Using Novel Ruthenium 1,3‐Dimesityl‐3,4,5,6‐tetrahydropyrimidin‐2‐ylidenes
Authors: Wang Dongren , Yang Liangru , Decker Ulrich , Findeisen Matthias , Buchmeiser Michael R. 
Published: October 2005

AbstractSummary: The polymerization of two chiral, enantiomerically pure monomers, i.e., exo‐N‐(norborn‐2‐ene‐5‐carboxyl)‐L‐phenylalanine ethyl ester (1) and endo,endo‐N,N‐(norborn‐5‐ene‐2,3‐dicarbimido)‐L‐valine ethyl ester (2) using the ruthenium‐based, 1,3‐dimesityl‐3,4,5,6‐tetrahydropyrimidin‐2‐ylidene (Mes2‐THP)‐derived initiators RuCl2(Mes2‐THP)(CH‐2‐(2‐PrO‐)‐5‐NO2C6H3) (3) and RuCl2(Mes2‐THP)(CHC6H5)(pyridine) (4), is described. Polymerization of 1 mediated by either 3 or 4 proceeded in a living manner with good control over molecular weight. The polymerization of 2 mediated by either 3 or 4 yielded a polymer with an exclusive all‐trans structure.Structure of the RuCl2(Mes2‐THP)(CHC6H5)(pyridine) (4) catalyst synthesized here.magnified imageStructure of the RuCl2(Mes2‐THP)(CHC6H5)(pyridine) (4) catalyst synthesized here.
Compulsive eating and weight gain related to dopamine agonist use
Authors: Nirenberg Melissa J. , Waters Cheryl 
Published: October 2005

AbstractDopamine agonists have been implicated in causing compulsive behaviors in patients with Parkinson's disease (PD). These have included gambling, hypersexuality, hobbyism, and other repetitive, purposeless behaviors (“punding”). In this report, we describe 7 patients in whom compulsive eating developed in the context of pramipexole use. All of the affected patients had significant, undesired weight gain; 4 had other comorbid compulsive behaviors. In the 5 patients who lowered the dose of pramipexole or discontinued dopamine agonist treatment, the behavior remitted and no further weight gain occurred. Physicians should be aware that compulsive eating resulting in significant weight gain may occur in PD as a side‐effect of dopamine agonist medications such as pramipexole. Given the known risks of the associated weight gain and obesity, further investigation is warranted. © 2005 Movement Disorder Society
Determination of the hyperfine coupling constant and zero‐field splitting in the ESR spectrum of Mn2+ in calcite
Authors: Garribba Eugenio , Micera Giovanni 
Published: October 2005

AbstractThe hyperfine coupling constant (A in units of energy or A′ in units of magnetic field) and zero‐field splitting (D in units of energy or D′ in units of magnetic field) in the ESR spectrum of Mn2+ in calcite were determined. The spreading of the non‐central allowed transitions |3/2, m〉 → |5/2, m〉, |1/2, m〉 → |3/2, m〉, |−3/2, m〉 → |−1/2, m〉 and |−5/2, m〉 → |−3/2, m〉 was analysed and the experimental transitions were attributed. Particular relevance was given to the difference between the two types of resonances, shoulder or divergence, and to their origin (M, m). The analysis explains the presence of a weak shoulder between each of the five central doublets |−1/2, m〉 → |1/2, m〉. Six independent methods for calculating the hyperfine coupling constant and five methods for calculating the zero‐field splitting, based on the analysis of the allowed and forbidden transitions, were provided. The values of the hyperfine coupling constant range from −93.9 to −94.6 G and those of the zero‐field splitting range from −79.5 to −80.5 G. A critical evaluation of the advantages and drawbacks of the 11 methods is included: the best value for A′ is −94.30 G and that for D′ is −79.95 G. Copyright © 2005 John Wiley & Sons, Ltd.
Eremophilane esters of Robinsonecio gerberifolius and their rearranged products. Study of the coupling constants 2JH, H, 3JH, H and 4JH, H
Authors: Arciniegas Amira , Pérez‐Castorena Ana‐L. , Cuevas Gabriel , del Río‐Portilla Federico , de Vivar Alfonso Romo 
Published: October 2005

AbstractIn the course of the basic hydrolysis of four eremophilane esters isolated from Robinsonecio gerberifolius, some rearrangements, eliminations, and additions occurred. Five compounds were obtained, three of them not previously described. Additionally, a new sesquiterpene was produced by autooxidation of compound 1. The 1H and 13C NMR spectra of these compounds were completely assigned by utilization of HMQC, HMBC, COSY, DEPT, and NOESY techniques. The long‐range coupling constants of the peroxide 10 are reported, and all its coupling constants 2JH, H, 3JH, H, and 4JH, H are calculated at the B3LYP/6‐31G(d,p) level of theory. Their magnitude is explained in terms of electronic delocalization and the additivity of stereoelectronic effects. Copyright © 2005 John Wiley & Sons, Ltd.
Complete assignment of 1H and 13C NMR data of dihydroxyflavone derivatives
Authors: Moon Byoung‐Ho , Lee Youngshim , Ahn Joong‐Hoon , Lim Yoongho 
Published: October 2005

AbstractSix flavone derivatives were studied. Previously reported NMR data of three of these derivatives were corrected and the NMR data for the other three derivatives not studied previously were completely assigned on the basis of the basic 1D and 2D NMR experiments and molecular modeling. Copyright © 2005 John Wiley & Sons, Ltd.
Different types of hydrogen bonds in 2‐substituted pyrroles and 1‐vinyl pyrroles as monitored by 1H, 13C and 15N NMR spectroscopy and ab initio calculations
Authors: Afonin Andrei V. , Ushakov Igor A. , Sobenina Lyubov' N. , Stepanova Zinaida V. , Petrova Ol'ga V. , Trofimov Boris A. 
Published: October 2005

AbstractAccording to the 1H, 13C and 15N NMR spectroscopic data and ab initio calculations, the strong NH···O intramolecular hydrogen bond in the Z‐isomers of 2‐(2‐acylethenyl)pyrroles causes the decrease in the absolute size of the 1J(N,H) coupling constant by 2 Hz in CDCl3 and by 4.5 Hz in DMSO‐d6, the deshielding of the proton and nitrogen by 5–6 and 15 ppm, respectively, and the lengthening of the NH link by 0.025 Å. The NH···N intramolecular hydrogen bond in the 2(2′‐pyridyl)pyrrole leads to the increase of the 1J(N,H) coupling constant by 3 Hz, the deshielding of the proton by 1.5 ppm and the lengthening of the NH link by 0.004 Å. The CH···N intramolecular hydrogen bond in the 1‐vinyl‐2‐(2′‐pyridyl)‐pyrrole results in the increase of the 1J(C,H) coupling constant by 5 Hz, the deshielding of the proton by 1 ppm and the shortening of the CH link by 0.003 Å. Different behavior of the coupling constants and length of the covalent links under the hydrogen bond influence originate from the different nature of the hydrogen bonding (predominantly covalent or electrostatic), which depends in turn on the geometry of the hydrogen bridge. The Fermi‐contact mechanism only is responsible for the increase of the coupling constant in the case of the predominantly electrostatic hydrogen bonding, whereas both Fermi‐contact and paramagnetic spin‐orbital mechanisms bring about the decrease of coupling constant in the case of the predominantly covalent hydrogen bonding Copyright © 2005 John Wiley & Sons, Ltd.
1H and 19F PGSE diffusion and HOESY NMR studies on cationic palladium (II) 1,3‐diphenylallyl complexes in THF solution
Authors: Fernández Ignacio , Pregosin Paul S. 
Published: October 2005

AbstractTHF solutions of the cationic chiral 1,3‐diphenylallyl bidentate phosphine complexes [Pd(η3‐PhCHCHCHPh)(Duphos)](CF3SO3), Duphos = 1,2‐Bis‐((2R,5R)‐2,5‐dimethylphospholano)benzene), 2, and [Pd(η3‐PhCHCHCHPh)(P,S)]BF4, 4, P,S = [8‐((o‐(diphenylphosphino)benzyl) thiomethyl]—(7,7′‐dimethyl)‐exo‐norborneol, have been studied via pulsed gradient spin‐echo (PGSE) diffusion, 1H, 19F HOESY and a variety of other multi‐dimensional NMR methods. On the basis of the 1H, 19F HOESY data, the anions show a preference for a specific structural position with respect to the η3‐PhCHCHCHPh allyl ligand, i.e. the anion does not move evenly around the periphery of the cation. THF is shown to promote significant ion pairing, although neither 2 nor 4 shows 100% ion pairing. Copyright © 2005 John Wiley & Sons, Ltd.
Transcription of ribosomal RNA genes is initiated in the third cell cycle of bovine embryos
Authors: Jakobsen Anne S. , Avery Birthe , Dieleman Steph J. , Knijn Hiemke M. , Vos Peter L.A.M. , Thomsen Preben D. 
Published: October 2005

AbstractTranscription from the embryos own ribosomal genes is initiated in most species at the same time as the maternal‐embryonic transition. Recently data have indicated that a minor activation may take place during the third embryonic cell cycle in the bovine, one cell cycle before the major activation of the embryonic genome. In the present study, ribosomal RNA (rRNA) transcription was investigated by visualization of the rRNA by fluorescent in situ hybridization, and subsequent visualization of the argyrophilic nucleolar proteins by silver staining. A total of 145 in vivo developed and 200 in vitro produced bovine embryos were investigated to allow comparison of transcription initiation. Signs of active transcription of rRNA were observed in the third cell cycle in 29% of the in vitro produced embryos (n = 35) and in 58% of the in vivo developed embryos (n = 11). Signs of active transcription of rRNA were not apparent in the early phase of the fourth cell cycle but restarted later on. All embryos in the fifth or later cell cycles were all transcribing rRNA. The signs of rRNA synthesis during the third and fourth embryonic cell cycle could be blocked by actinomycin D, which is a strong inhibitor of RNA polymerase I. In conclusion, rRNA transcription is initiated during the third cell cycle at a low level in both in vivo developed and in vitro produced bovine embryos. Transcription seems to be interrupted during the G1 phase of the fourth cell cycle, but reinitiates in the late half of the cycle and persists during subsequent cell cycles. Mol. Reprod. Dev. © 2005 Wiley‐Liss, Inc.
Expression of aquaporins in the efferent ductules, sperm counts, and sperm motility in estrogen receptor‐α deficient mice fed lab chow versus casein
Authors: Ruz Ricardo , Gregory Mary , Smith Charles E. , Cyr Daniel G. , Lubahn Dennis B. , Hess Rex A. , Hermo Louis 
Published: October 2005

AbstractEstrogens play an important role in the male reproductive tract, and this is especially so for the efferent ductules, where α‐estrogen receptors (ERα) have been localized. Mice deficient in ERα (αERKO mice) are infertile, and the effect appears to be due in part to retention of water at the level of the efferent ductules. In the present study, we examined the consequences of ERα deletion on the distribution of certain aquaporins (AQPs), water protein channels, in the efferent ductules and on sperm numbers and motility. In addition, the effects of feeding mice a regular lab chow diet, which contains phytoestrogens, known to affect male reproductive tract functions, and a casein diet, which lacks phytoestrogens, were also assessed. Light microscope immunolocalizations of AQP‐1 and AQP‐9 revealed dramatic reduction and patchier staining in αERKO mice with distal areas of the efferent ductules being more affected than proximal areas. No other changes in immunolocalizations were noted as a consequence of diet. Computer‐assisted sperm analyses demonstrated a 62% reduction in cauda epididymal sperm/ml in αERKO mice fed lab chow, whereas 87% fewer sperm/ml were observed in αERKO mice fed casein, suggesting an enhanced role for sperm production and concentration in a diet containing phytoestrogens. All sperm motility parameters were altered to some degree in αERKO mice fed lab chow. Alterations in sperm motility parameters were also detected, but were less dramatic in αERKO mice fed casein. These data suggest that the decrease in AQP expression in the efferent ductules of αERKO mice contributes in part to water retention in this tissue, eventually leading to backflow of water into the testis, with subsequent decreases in sperm concentration and motility. The data also suggest that phytoestrogens, which are present in regular lab chow, can influence the male reproductive tract with and without the presence of ERα, promoting efferent ductule and epididymal functions when ERα is expressed, but inhibiting these same functions when ERα is missing. Taken together the data underscore the importance of estrogens and ERα in maintaining sperm maturation and preventing male infertility. Mol. Reprod. Dev. © 2005 Wiley‐Liss, Inc.