bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stand and shuffle: When does it make energetic sense?
Authors: Sylvester Adam D. , Kramer Patricia A. 
Published: November 2007

AbstractMany reasons for the emergence of bipedalism have been proposed, including postural arguments which highlight that a sub‐optimal form of bipedalism (“shuffling”) might have been used by protohominids to cover short distances between resources that require bipedal standing. Bipedal shuffling may have been employed because it avoids the cost of raising the trunk from the quadrupedal orientation, which we assume is the habitual locomotor stance of protohominids. To date, these postural proposals have not been analytically assessed, a lack we rectify herein. Our model seeks to specify a threshold distance, below which bipedal shuffling uses less energy than quadrupedalism. Parameters for the model include the mechanical cost of transport, the ratio of bipedal to quadrupedal cost, and the cost associated with raising the trunk. We found that, using reasonable model parameters, open distances of ∼9–16 m support the use of bipedal shuffling. Protohominids may have used shuffling as an energetically effective way to traverse between resource patches. Am J Phys Anthropol, 2008. © 2007 Wiley‐Liss, Inc.
Late Pleistocene human remains from Wezmeh Cave, western Iran
Authors: Trinkaus Erik , Biglari Fereidoun , Mashkour Marjan , Monchot Hervé , Reyss Jean‐Louis , Rougier Hélène , Heydari Saman , Abdi Kamyar 
Published: November 2007

AbstractPaleontological analysis of remains from Wezmeh Cave in western Iran have yielded a Holocene Chalcolithic archeological assemblage, a rich Late Pleistocene carnivore faunal assemblage, and an isolated unerupted human maxillary premolar (P3 or possibly P4). Species representation and U‐series dating of faunal teeth place the carnivore assemblage during oxygen isotope stages (OIS) 3 and 2, and noninvasive gamma spectrometry dating of the human premolar places it at least as old as early OIS 2. The human premolar crown morphology is not diagnostic of late archaic versus early modern human affinities, but its buccolingual diameter places it at the upper limits of Late Pleistocene human P3 and P4 dimensions and separate from a terminal Pleistocene regional sample. Wezmeh Cave therefore provides additional Paleolithic human remains from the Zagros Mountains and further documents Late Pleistocene human association with otherwise carnivore‐dominated cave assemblages. Am J Phys Anthropol, 2008. © 2007 Wiley‐Liss, Inc.
Characterization of morphology in chemically modified styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene by solid‐state nuclear magnetic resonance
Authors: Collar Emilia P. , García‐Martínez Jesús M. , Garrido Leoncio 
Published: November 2007

AbstractMultiphase triblock styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene (SEBS) copolymers chemically modified with maleic anhydride (MAH) in the presence of a radical initiator by reactive extrusion were studied by solid‐state 1H‐NMR and 13C‐NMR. In the experiments performed, the concentrations of MAH and initiator were kept constant, whereas the temperature profile in the extruder was varied. Samples with known extents of grafting and crosslinking were analyzed with NMR with techniques based on proton spin diffusion to investigate the microphase structure of the modified copolymers. The 13C‐NMR results show that the size of the rigid domains was about 15 nm and was not significantly changed by the modification. Alterations in the rubbery phase were illustrated by measured changes in proton spin‐spin (T2) relaxation times. The fraction of protons having intermediate mobilities increased slightly in modified SEBS with respect to that observed in unmodified copolymers. These results were found to be independent of the extruder temperature profiles used, at least in the range studied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and properties of novel amphiphilic sulfated ionomers by the ring‐opening reaction of an epoxidized styrene–butadiene–styrene triblock copolymer
Authors: Xie Hong‐Quan , Zhao Wei , Yang Wei , Xie Dong 
Published: November 2007

AbstractA method for the synthesis of novel sulfated ionomer of styrene–butadiene–styrene triblock copolymer (SBS) was developed. SBS was first epoxidized by performic acid in the presence of a phase‐transfer catalyst; this was followed by a ring‐opening reaction with an aqueous solution of alkali salt of bisulfate. The optimum conditions for the ring‐opening reaction of the epoxidized SBS with an aqueous solution of KHSO4 were studied. During the ring‐opening reaction, both phase‐transfer catalyst and ring‐opening catalyst were necessary to enhance the conversion of epoxy groups to ionic groups. The products were characterized with Fourier transform infrared spectrophotometry and transmission electron microscopy (TEM). After the potassium ions of the ionomer were substituted with lead ions, the lead sulfated ionomer exhibited dark spots under TEM. Some properties of the sulfated ionomer were studied. With increasing ionic groups or ionic potential of the cations, the water absorbency and emulsifying volume of the ionomer and the intrinsic viscosity of the ionomer solution increased, whereas the oil absorbency decreased. The sulfated ionomer possessed excellent emulsifying properties compared with the sulfonated SBS ionomer. The sodium sulfated ionomers in the presence of 10% zinc stearate showed better mechanical properties than the original SBS. When the ionomer was blended with crystalline polypropylene, a synergistic effect occurred with respect to the tensile strength. The ionomer behaved as a compatibilizer for blending equal amounts of SBS and oil‐resistant chlorohydrin rubber. In the presence of 3% ionomer, the blend exhibited much better mechanical properties and solvent resistance than the blend without the ionomer. SEM photographs indicated improved compatibility between the two components of the blend in the presence of the ionomer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Biodegradable poly(sebacic acid‐co‐ricinoleic‐ester anhydride) tamoxifen citrate implants: Preparation andin vitrocharacterization
Authors: Hiremath J. G. , Kusum Devi V. , Devi Kshama , Domb A. J. 
Published: November 2007

AbstractThe aim of this study was to prepare tamoxifen citrate loaded cylindrical polymeric implants for application at tumor sites. The implant was based on poly (sebacic acid‐co‐ricinoleic‐ester anhydride) 70 : 30 w/w [poly(SA‐RA) 70 : 30 w/w], a low‐melting, biodegradable, and biocompatible polymer. Implants were prepared by a standardized melt manufacturing method. Differential scanning calorimetry and scanning electron microscopy were used for implant characterization.In vitrodrug release studies were performed in phosphate‐buffered saline (pH 7.4) at 37 ± 2°C. The drug content was estimated by high‐performance liquid chromatography. The differential scanning calorimetry studies showed that the tamoxifen citrate in the implants was in the amorphous state. The cumulative percentage of drug release from 10 and 20 wt % drug‐loaded poly(SA‐RA) 70 : 30 w/w implants after 30 days was found to be 42.36 and 62.60%, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Treatment of rumination maintained by automatic reinforcement: a comparison of extra portions during a meal and supplemental post‐meal feedings
Authors: Kenzer Amy L. , Wallace Michele D. 
Published: November 2007

AbstractThis study evaluated the effects of two satiation procedures, large portions and supplementary feedings, as interventions for rumination maintained by automatic reinforcement for an individual with developmental disabilities. Results showed that supplemental feedings produced a greater reduction in the rate of rumination than the large portions treatment. Additionally, 30 min supplemental feedings were more effective than 15 min supplemental feedings. Copyright © 2007 John Wiley & Sons, Ltd.
Identification of bacteria using matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry
Authors: Kedney Mollie G. , Strunk Kevin B. , Giaquinto Lisa M. , Wagner Jennifer A. , Pollack Sidney , Patton Walter A. 
Published: November 2007

AbstractMatrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS or simply MALDI)1 has become ubiquitous in the identification and analysis of biomacromolecules. As a technique that allows for the molecular weight determination of otherwise nonvolatile molecules, MALDI has had a profound impact in the molecular biosciences, especially in the field of proteomics. MALDI analysis of whole organisms allows for the generation of a phenotypic profile or “molecular fingerprint;” once established, these fingerprints can be used for identification purposes.
An undergraduate laboratory exercise to study the effect of darkness on plant gene expression using DNA microarray
Authors: Chang Ming‐Mei , Briggs George M. 
Published: November 2007

AbstractDNA microarrays are microscopic arrays on a solid surface, typically a glass slide, on which DNA oligonucleotides are deposited or synthesized in a high‐density matrix with a predetermined spatial order. Several types of DNA microarrays have been developed and used for various biological studies. Here, we developed an undergraduate laboratory exercise using an Arabidopsis DNA microarray to study the gene expression of Brassica rapa, Wisconsin Fast Plant. Genes involved in senescence, cell wall loosening/degradation, and sugar transport were the most upregulated, while those involved in photosynthesis, the elimination of reactive oxygen intermediates associated with photooxidative stress and auxin synthesis, were the most downregulated. Students were able to complete the experiment successfully. Throughout the exercise, they learned various important molecular techniques including RNA isolation, quantification, reverse transcription, cRNA synthesis, labeling and purification, and microarray hybridization, washing, scanning, and feature extraction. The exercise can be integrated into a college‐level molecular biology laboratory. The procedure used can be adapted to examine other effects on other organisms.
Binding study of Flos Lonicerae Japonicae with bovine serum albumin using centrifugal ultrafiltration and liquid chromatography
Authors: Qian Zheng‐Ming , Qin Su‐Juan , Yi Ling , Li Hui‐Jun , Li Ping , Wen Xiao‐Dong 
Published: November 2007

AbstractThe screening and analysis of bioactive components in traditional Chinese medicines (TCMs) is very important not only for the quality control of Chinese herbs but also for elucidating the therapeutic principles. This study developed a new method for screening and analyzing bioactive compounds from TCMs using centrifugal ultrafiltration coupled with high‐performance liquid chromatography. The method was successfully applied in the binding study of Flos Lonicerae Japonicae with bovine serum albumin (BSA), and 11 compounds were found to be bound with the BSA. Eight of them were positively identified as chlorogenic acid, caffeic acid, rutin, quercetin‐3‐O‐glucoside, luteolin‐7‐O‐glucoside, lonicerin, 3, 5‐di‐O‐caffeoyl quinic acid and 3,4‐di‐O‐caffeoyl quinic acid. Another three compounds were tentatively identified as two isomers of chlorogenic acid and one isomer of di‐O‐caffeoyl quinic acid by comparing the UV data and MS data with the previous reports. Based on modern pharmacological study, these compounds are the major bioactive components in Lonicera japonica. Therefore, the proposed method could be a good approach to predicting the potential bioactivities of multiple compounds in TCMs simultaneously. Copyright © 2007 John Wiley & Sons, Ltd.
A simple and rapid determination of valproic acid in human plasma using a non‐porous silica column and liquid chromatography with tandem mass spectrometric detection
Authors: Matsuura Katsuhiko , Ohmori Tomofumi , Nakamura Mitsuhiro , Itoh Yoshinori , Hirano Kazuyuki 
Published: November 2007

AbstractA liquid chromatographic tandem mass spectrometric (LC‐MS/MS) assay was developed and validated to determine valproic acid in human plasma. The method involved a solid‐phase extraction of valproic acid and betamethasone valerate, an internal standard, from plasma and detection using an LC‐MS/MS system with electrospray ionization source in negative ion mode. Separation was achieved within 3 min on a non‐porous silica column with mobile phase containing ammonium acetate and methanol. Multiple reaction monitoring was utilized for detection monitoring at 142.89–142.89 for valproic acid and 457.21–457.21 for the internal standard. The calibration curve for valproic acid was linear over the range of 0.5–150 µg/mL. The limit of detection was 0.17 µg/mL and the lower limit of quantification was 0.5 µg/mL, when 0.2 mL plasma was used for extraction. The percentage coefficient of validation for accuracy and precision (inter‐ and intra‐day) for this method was less than 9.5% with recovery ranging from 82.3 to 86.9% for valproic acid. Copyright © 2007 John Wiley & Sons, Ltd.
Inhibition deficits of serious delinquent boys of low intelligence
Authors: Koolhof Roos , Loeber Rolf , Wei Evelyn H. , Pardini Dustin , D'escury Annematt Collot 
Published: November 2007

AbstractIntroduction Studies have shown that low intelligence (IQ) and delinquency are strongly associated. This study focuses on inhibitory deficits as the source for the association between low IQ and delinquency. Further, the authors explore whether serious delinquent boys with a low IQ are exposed to more risk factors than serious delinquent boys with an average to high IQ. They also examine the extent to which low IQ and higher IQ serious delinquents incurred contact with the juvenile court because of their delinquent behaviour.Methods Cross‐sectional and longitudinal data from the Pittsburgh Youth Study were used to constitute four groups of boys: low IQ serious delinquents (n = 39), higher IQ serious delinquents (n = 149), low IQ non‐to‐moderate delinquents (n = 21) and higher IQ non‐to‐moderate delinquents (n = 219).Results Low IQ serious delinquents committed more delinquent acts than higher IQ serious offenders. Low IQ serious delinquent boys also exhibited the highest levels of cognitive and behavioural impulsivity. There were no differences between low IQ and higher IQ serious delinquents on measures of empathy and guilt feelings. Instead, elevations on these characteristics were associated with serious offenders as a whole. Compared with higher IQ serious delinquents, low IQ serious delinquents were exposed to more risk factors, such as low academic achievement, being old for grade, depressed mood and poor housing.Conclusions Inhibition deficits appear important in the aetiology of delinquency, especially among low IQ boys. Serious delinquent boys are all impulsive, but the higher IQ serious delinquents seem to have a better cognitive control system. Interventions aimed at low IQ boys should focus on the remediation of behavioural impulsivity as well as cognitive impulsivity. Copyright © 2007 John Wiley & Sons, Ltd.
Supramolecule‐Regulated Photophysics of Oligo(p‐phenyleneethynylene)‐Based Rod–Coil Block Copolymers: Effect of Molecular Architecture
Authors: Pu Kan‐Yi , Qi Xiao‐Ying , Yang Yan‐Lian , Lu Xiao‐Mei , Li Ting‐Cheng , Fan Qu‐Li , Wang Chen , Liu Bin , Chan Hardy Sze On , Huang Wei 
Published: November 2007

AbstractThree new topology‐varied rod–coil block copolymers, comprising the same oligo(p‐phenyleneethynylene) (OPE) rod components and the same coil components, were synthesized by atom‐transfer radical polymerization. Their photophysical properties were systematically studied and compared in consideration of their solid‐state structures and self‐assembly abilities. These copolymers have similar intrinsic photophysical properties to the OPE rods, as reflected in dilute solution. However, their photophysical properties in the solid state are manipulated to be dissimilar by supramolecular organization. Wide‐angle X‐ray diffraction (WAXD) and atomic force microscopy (AFM) data demonstrate that these copolymers possess different self‐assembly abilities due to the molecular‐architecture‐dependent π–π interactions of the rods. Hence, the aggregates in the solid state are formed with a different mechanism for these copolymers, bringing about the discrepancy in the solid‐state luminescent properties.
A Phosphine‐Mediated Through‐Space Exchange Coupling Pathway for Unpaired Electrons in a Heterobimetallic Lanthanide–Transition Metal Complex
Authors: Raturi Ritu , Lefebvre Julie , Leznoff Daniel B. , McGarvey Bruce R. , Johnson Samuel A. 
Published: November 2007

AbstractThe reaction of P(CH2OH)3 with methyl anthranilate NH2C6H4‐2‐CO2Me produced the ligand precursor P(CH2NHC6H4‐2‐CO2Me)3 (1). The reaction of 1 with [Y{N(SiMe3)2}3] produced hexadentate yttrium complex [Y{P(CH2NC6H4‐2‐CO2Me)3}] (2), in which the metal centre is coordinated by three amido donors and the three carbonyl oxygen atoms of the ester groups. The 31P{1H} NMR spectrum features 1JY,P=15 Hz, and DFT calculations demonstrate that through‐space interaction between the minor lobe of the phosphine lone pair and the yttrium centre allows a large Fermi contact contribution to this spin coupling constant. The EPR spectrum of the analogous paramagnetic Gd complex [Gd{P(CH2NC6H4‐2‐CO2Me)3}] (3) can be modelled by using a B20 crystal field parameter of ±0.19 cm−1. Heterodinuclear complexes were prepared by the reactions of 1 and 3 with [5,10,15,20‐tetrakis(4‐methoxyphenyl)porphinato]cobalt(II), by binding of the phosphine lone pair to the d7 cobalt centre. The solid‐state EPR spectrum of the heterodinuclear yttrium complex 4 exhibits large superhyperfine coupling to the phosphorus nucleus, indicative of an S=1/2 complex in which the unpaired electron resides in the cobalt d orbital directed at the phosphine donor. The magnetic susceptibility of the heterodinuclear Gd–Co complex 5 demonstrates that through‐space antiferromagnetic coupling occurs between unpaired electrons on the gadolinium and cobalt centres.
Sequence‐Specific Alkylation by Y‐Shaped and Tandem Hairpin Pyrrole–Imidazole Polyamides
Authors: Sasaki Shunta , Bando Toshikazu , Minoshima Masafumi , Shinohara Ken‐ichi , Sugiyama Hiroshi 
Published: November 2007

AbstractTo extend the target DNA sequence length of the hairpin pyrrole–imidazole (Py–Im) polyamide 1, we designed and synthesized Y‐shaped and tandem hairpin Py–Im polyamides 2 and 3, which possess 1‐(chloromethyl)‐5‐hydroxy‐1,2‐dihydro‐3H‐benz[e]indole (seco‐CBI) as DNA‐alkylating moieties. High‐resolution denaturing polyacrylamide gel electrophoresis by using 5′‐Texas‐Red‐labeled 465 base pair (bp) DNA fragments revealed that conjugates 2 and 3 alkylated the adenine of the target DNA sequences at nanomolar concentrations. Conjugate 2 alkylated adenine N3 at the 3′ end of two 8 bp match sequences, 5′‐AATAACCA‐3′ (site A) and 5′‐AAATTCCA‐3′ (site C), while conjugate 3 recognized one 10 bp match sequence, 5′‐AGAATAACCA‐3′ (site A) in the 465 bp DNA fragments. These results demonstrate that seco‐CBI conjugates of Y‐shaped and tandem hairpin polyamides have extended their target alkylation sequences.
Quantitative Conformational Study of Redox‐Active [2]Rotaxanes, Part 1: Methodology and Application to a Model [2]Rotaxane
Authors: Altobello Silvano , Nikitin Kirill , Stolarczyk Jacek K. , Lestini Elena , Fitzmaurice Donald 
Published: November 2007

AbstractThis paper reports a novel methodology for the conformational analysis of [2]rotaxanes. It combines NMR spectroscopic (COSY, NOESY and the recently reported paramagnetic line‐broadening and suppression technique) and electrochemical techniques to enable a quantitative analysis of the co‐conformations of interlocked molecules and the conformations of their components. This methodology was used to study a model [2]rotaxane in solution. This [2]rotaxane consists of an axle that incorporates an electron‐poor, doubly positively charged viologen that threads an electron‐rich crown ether. It has been shown that the axle of the [2]rotaxane in its dicationic state adopts a folded conformation in solution and the crown ether is localised at the viologen moiety. Following a one‐electron reduction of viologen, the paramagnetic radical cation of the [2]rotaxane retains its folded conformation in solution. The data also demonstrate that in the radical cation the crown ether remains localised at the viologen, despite its reduced affinity for the singly reduced viologen. The combined quantitative NMR spectroscopic and electrochemical characterisation of the electromechanical function of the model [2]rotaxane in solution provides an important reference point for the study of switching in structurally related bistable [2]rotaxanes, which is the subject of the second part of this work.
Revealing Phenylium, Phenonium, Vinylenephenonium, and Benzenium Ions in Solution
Authors: Manet Ilse , Monti Sandra , Grabner Gottfried , Protti Stefano , Dondi Daniele , Dichiarante Valentina , Fagnoni Maurizio , Albini Angelo 
Published: November 2007

AbstractThe 4‐methoxyphenylium ion has been generated in the triplet state (3An+) by photolysis of 4‐chloroanisole in polar media and detected by flash photolysis (λmax=400 nm). This is the first detection of a phenylium ion in solution by flash photolysis and the assignment is supported by time‐dependent density functional theory (TD‐DFT) calculations. In neat solvents, the cation was reduced to anisole, a process initiated by electron transfer from the starting compound (3An++AnCl→An.+AnCl.+, with the radical cation detected at 470 nm, then An.→AnH). Addition of π nucleophiles to the 3An+ cation offers a novel access to a number of other cationic intermediates under mild, nonacidic conditions. Two intermediates are successively formed with alkenes, a diradical cation and the phenonium ion, which are detected at 440 and 320 nm, respectively, by flash photolysis and are in accordance with calculations. Allylanisoles or β‐alkoxyalkylanisoles are the end products, with a small amount of α‐alkoxyalkylanisoles that arises from a Wagner–Meerwein rearrangement to form benzyl cations. Further intermediates that have been predicted and detected are the phenylvinylium ion, possibly in equilibrium with the vinylenephenonium ion, with 1‐hexyne (λmax=340 nm) and the benzenium ion with benzene (λmax=380 nm). The final products were anisylhexyne and methoxybiphenyl (an analogous product and intermediate were detected with thiophene).
Huge Deuterated Effect on Permittivity in a Metal–Organic Framework
Authors: Zhao Hong , Ye Qiong , Qu Zhi‐Rong , Fu Da‐Wei , Xiong Ren‐Gen , Huang Songping D. , Chan Philip Wai Hong 
Published: November 2007

AbstractColorless block crystals of MOF (metal‐organic framework) 1 and 2 were prepared in respective yields of 65 and 60 % by thermal treatment of HQA (HQA=6‐methoxyl‐(8S,9R)‐cinchonan‐9‐ol‐3‐carboxylic acid) with ZnBr2 in either H2O or D2O and 2‐butanol at 70 °C for 1–2 days. The MOFs 1 and 2 are isostructural, one‐dimensional chains in which the local coordination geometry around the Zn center can be best described as a slightly distorted tetrahedron defined by two bromine atoms, one nitrogen atom of quinoline from HQA, and an oxygen atom of carboxylate from HQA. The nitrogen atom of the quinuclidine of HQA is protonated in a zwitterionic form. The MOFs 1 and 2 crystallize in a polar point group (C2, space group P21) which belongs to ferroelectric active compounds. MOFs 1 and 2 display both ferroelectric behavior and large dielectric constants. Interestingly, at low frequency range the dielectric response to water can achieve an approximate increase of more than 600 %. Crystal parameters: 1: C20H28Br2NO7Zn, M=619.62, monoclinic, P21, a=9.5711(8), b=12.0486(10), c=11.1972(9) Å, α=γ=90, β=98.4(2)°, V=1277.39(18) Å3, Z=2, ρcald=1.611 mg m−3, R1=0.0499, wR2=0.0982, μ=4.126 mm−1, S=1.015, Flack value=0.032(13); 2: C20H22D6Br2NO7Zn, M=625.66, monoclinic, P21, a=9.5650(9), b=12.0392(11), c=11.1973(10) Å, α=γ=90, β=98.44(2)°, V=1275.5(2) Å3, Z=2, ρcald=1.629 mg m−3, R1=0.0543, wR2=0.1072, μ=4.133 mm−1, S=1.056, Flack value=0.025(17).