bluuebunny/crossref_metadata_2025_split huggingface dataset:
Absorption‐ and fluorescence‐spectral sensing of alkali metal ions in anionic micelle solutions containing crowned spirobenzopyrans
Authors: Sakamoto H. , Yamamura T. , Takumi K. , Kimura K. 
Published: May 2007

AbstractSpirobenzopyran derivatives bearing a monoazacrown ether moiety (monoaza‐12‐crown‐4, ‐15‐crown‐5, and ‐18‐crown‐6) and an octadecyl group as a lipophilic moiety, called crowned spirobenzopyrans were synthesized, which can be dissolved in anionic micelle solutions. We examined absorption‐and fluorescence‐spectral changes of micelle solutions containing a crowned spirobenzopyran on addition of alkali metal ions. The crowned spirobenzopyrans are in their merocyanine form in an anionic micelle solution even under dark conditions, showing a significant absorption in the visible region which is attributable to the merocyanine moiety. Crowned spirobenzopyran bearing a monoaza‐12‐crown‐4 moiety exhibited a drastic hypsochromic shift in the absorption and also an enhanced fluorescence on addition of Li+ to the micelle solutions under alkaline conditions. These spectral changes can be attributed to a strong interaction between Li+ bound by the crown ether moiety and a phenolate ion of the merocyanine moiety. Similar absorption and fluorescence‐spectral changes were induced in the anionic micelle solutions containing the other crowned spirobenzopyrans on addition of alkali metal ions. The intensity of the absorption‐spectral changes in the systems of the three crowned spirobenzopyrans, however, differed from each other, depending on the strength of interaction between a metal ion bound to the crown ether moiety and the phenolate ion of the merocyanine moiety. On the other hand, the extent of enhanced relative fluorescence intensity is dependent on the strength of interaction between metal ion and a nitrogen atom of azacrown ether moiety, because the fluorescence spectrum is quenched by photoinduced electron transfer (PET) from the nitrogen atom to the merocyanine moiety. Copyright © 2007 John Wiley & Sons, Ltd.
Copolymerization of vinyl acetate with 1‐octene and ethylene by cobalt‐mediated radical polymerization
Authors: Bryaskova Rayna , Willet Nicolas , Degée Philippe , Dubois Philippe , Jérôme Robert , Detrembleur Christophe 
Published: May 2007

AbstractThe cobalt‐mediated radical polymerization of vinyl acetate was extended to copolymerization with 1‐alkenes (ethylene or 1‐octene). In agreement with the low amount of 1‐alkene that could be incorporated into the copolymer, a gradient structure was predictable, but a rather low polydispersity was observed. A poly(vinyl acetate)‐b‐poly(octene) copolymer was also successfully synthesized, leading to a poly (vinyl alcohol)‐b‐poly(octene) amphiphilic copolymer upon the methanolysis of the poly (vinyl acetate) block. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2532–2542, 2007
Formation of crystalline inclusion compounds of poly (vinyl chloride) of different stereoregularity with γ‐cyclodextrin
Authors: Martínez Gerardo , Gómez Marián A. , Villar‐Rodil Silvia , Garrido Leoncio , Tonelli Alan E. , Balik C. Maurice 
Published: May 2007

AbstractThis work reports the formation and detailed characterization of the γ‐cyclodextrin (γ‐CD) inclusion compounds (ICs) formed with two poly (vinyl chloride) samples with different isotactic content. The ICs were characterized by X‐ray diffraction, solid state 13C‐NMR, solution 1H‐NMR, FT‐infrared, differential scanning calorimetry, and thermogravimetric analysis. Experimental evidence of the inclusion of the guest polymer chains into the narrow channels created by the γ‐CD crystalline host lattice has been obtained. Examination of coalesced poly (vinyl chlorides) (PVCs) obtained after the host γ‐CD is removed reveals different characteristics specifically for the coalesced PVC sample with higher isotactic content. An increase in Tg was observed by DSC for this PVC. To the contrary, the Tg of the coalesced PVC sample with lower isotactic content is almost the same as that of the as‐synthesized sample. Thermogravimetric analysis indicated that coalesced PVC with higher isotactic content acquires a degree of stabilization after modification by threading into and being extracted from its γ‐CD IC. The results suggest that an irreversible conformational change takes place when PVC forms ICs with a solid host lattice like γ‐CD. The PVC molecules extend and reorganize into a more stable conformation in the IC, consequently improving the properties of the coalesced sample. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2503–2513, 2007
Polymorphism of nylon‐6 in nylon‐6/nanoclay/functionalized polyolefin blends
Authors: Li Yuying , Hu Xiao 
Published: May 2007

AbstractThe crystallization behavior of Nylon‐6 and the interaction in Nylon‐6/nanoclay/functionalized polyolefin blends were investigated by X‐ray diffraction and Fourier transform infrared spectroscopy. For samples without any thermal history, the interaction between Nylon‐6 and nanoclay or the interaction between Nylon‐6 and functionalized polyolefin favors the formation of γ form crystal. In contrast, the presence of both nanoclay and functionalized polyolefin together in Nylon‐6 was found to have an antagonistic effect on each other's ability to promote the formation of γ form crystal. This was attributed to the complex interactions between the constituents. The crystallization behavior of Nylon‐6 in Nylon‐6/nanoclay/functionalized polyolefin blends is clearly affected by the cointeraction of these effects. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1494–1502, 2007
Targeting of tumor cells expressing the prostate stem cell antigen (PSCA) using genetically engineered T‐cells
Authors: Morgenroth Agnieszka , Cartellieri Marc , Schmitz Marc , Günes Serap , Weigle Bernd , Bachmann Michael , Abken Hinrich , Rieber Ernst Peter , Temme Achim 
Published: May 2007

AbstractBACKGROUNDCurative therapeutic options for minimal residual disease or advanced tumor stages in prostate cancer (PCa) are still missing. Adoptive transfer of cytotoxic T‐cells that have been polyclonally rendered tumor‐specific by genetic engineering appears to be a promising immunotherapeutic strategy. Among the numerous prostate tissue/tumor antigens identified during the last years, the “prostate stem cell antigen” (PSCA) is an attractive immunotherapeutic target. It is broadly expressed on the surface of primary PCa cells as well as on PCa metastases.METHODSTo generate a chimeric T‐cell receptor (TCR) recognizing PSCA, a monoclonal anti‐PSCA antibody was raised and a single‐chain fragment (scFv) was prepared. The resulting anti‐PSCA scFv 7F5 was fused to the β2 constant region derived from the β‐chain of a TCR and to the CD3ζ‐signaling domain.RESULTSThe chimeric α‐PSCA‐β2/CD3ζ‐TCR, expressed in Jurkat cells, was phosphorylated in the ITAMs of the CD3‐zeta chain upon cross‐linking by insolublized PSCA. When transduced into a mouse cytotoxic T‐cell line, the chimeric receptor specifically activated cytotoxicity against PSCA‐positive tumor cells.CONCLUSIONSWe developed a functional chimeric TCR against PSCA for treatment of PCa. The chimeric α‐PSCA‐β2/CD3ζ‐TCR might now be used for arming human cytotoxic T‐cells for further studies towards a clinical treatment of PCa. Prostate 67: 1121–1131, 2007. © 2007 Wiley‐Liss, Inc.
An approximate method for calculating transfer integrals based on the ZINDO Hamiltonian
Authors: Kirkpatrick James 
Published: May 2007

AbstractIn this article, we discuss a method for calculating transfer integrals for pairs of molecules based on Zerner's Independent Neglect of Differential Overlap Hamiltonian which requires only a single self‐consistent field calculation on an isolated molecule to be performed to determine the transfer integral for a pair of molecules. This method is compared with results obtained by projection of the pair of molecules' molecular orbitals onto the vector space defined by the molecular orbitals of each isolated molecule. The two methods are found to be in good agreement using three compounds as model systems: pentacene, ethylene, and hexabenzocoronene. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Exact and quantum chemistry‐like calculations in helium doped clusters: The He2Br2(X) example
Authors: Roncero O. , de Tudela R. Pérez , de Lara‐Castells M. P. , Prosmiti R. , Delgado‐Barrio G. , Villarreal P. 
Published: May 2007

AbstractA quantum chemistry‐like approach has been recently developed in our group to deal with HeN–BC doped helium clusters, where the BC dopant is a conventional diatomic molecule. The central idea is to consider the He atoms as “electrons” while the B and C atoms play the role of the nuclei in standard electronic structure calculations. The procedure provides energies and wavefunctions allowing to perform spectral simulations and, hence, making feasible to do proper comparisons with current experiments. However, because of the large difference of masses of He and electrons, and also to the replacement of Coulomb potentials by molecular interactions, it is worthy to assess to what extent the approximations involved in this model (decoupling of orbital angular momenta of the He atoms from the BC rotation and adiabatic separation of the BC stretch versus the He motions) lead to accurate results. In this work we address these issues on the 4He2–Br2(X) system, containing a couple of bosonic He atoms for which variational calculations can be performed. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Robust absolute stability criteria for uncertain Lur'e systems of neutral type
Authors: Han Qing‐Long , Xue Anke , Liu Shirong , Yu Xinghuo 
Published: May 2007

AbstractThis paper is concerned with robust absolute stability of uncertain Lur'e systems ofneutral type. Somedelay‐dependentstability criteria are obtained and formulated in the form of linear matrix inequalities. The criteria cover some existing results as their special cases. Neithermodel transformationnorbounding techniquefor cross terms is involved through derivation of the stability criteria. Numerical examples show the effectiveness of the criteria. Copyright © 2007 John Wiley & Sons, Ltd.
Assemblies of Carbon Nanotubes and Unencapsulated Sub‐10‐nm Gold Nanoparticles
Authors: Hang Qingling , Maschmann Matthew R. , Fisher Timothy S. , Janes David B. 
Published: May 2007

AbstractThe development of assemblies consisting of unencapsulated, sub‐10‐nm gold particles attached to individual carbon nanotubes (CNTs) with diameters of 2 nm is described. The assemblies are formed on the surface of a porous anodic alumina (PAA) template on which the CNTs (single‐ or double‐walled) are grown by plasma‐enhanced chemical vapor deposition. The Au nanoparticles are formed through an indirect evaporation technique using a silicon nitride membrane mask, and diffuse along the PAA surface into the regions containing CNTs. The nanoparticles bind relatively strongly to the CNTs, as indicated by observations of nanoparticles that are suspended over pores or that move along with the CNTs. This approach may provide a new method to functionalize CNTs for chemical or biological sensing and fundamental studies of nanoscale contacts to CNTs.
Nanorod‐Coated PNIPAM Microgels: Thermoresponsive Optical Properties
Authors: Karg Matthias , Pastoriza‐Santos Isabel , Pérez‐Juste Jorge , Hellweg Thomas , Liz‐Marzán Luis M. 
Published: May 2007

AbstractNanoparticles and in particular gold nanorods have interesting optical properties arising from two well‐differentiated plasmon modes. The frequency of such modes can be altered by their chemical environment and coupling with neighboring rods. This study investigates new composite materials made of gold nanorods adsorbed on thermoresponsive poly(N‐isopropylacrylamide) (PNIPAM) microgels. It is shown that the thermally induced collapse of the polymer network inside the particles leads to a red shift of the longitudinal plasmon band of the gold rods, which is found to be fully reversible.
Assessment of the corpus callosum at 20–24 weeks' gestation by three‐dimensional ultrasound examination
Authors: Plasencia W. , Dagklis T. , Borenstein M. , Csapo B. , Nicolaides K. H. 
Published: May 2007

AbstractObjectivesTo determine the range of positions of the fetal head in which a three‐dimensional (3D) volume is acquired for subsequent successful imaging of the corpus callosum.MethodsWe used 3D volumes of the fetal head obtained from singleton pregnancies at 20 to 23 + 6 weeks' gestation. The volumes, which had been acquired with the head in different positions, were then reconstructed with the objective of obtaining a mid‐sagittal section of the brain to demonstrate the presence of the corpus callosum.ResultsIn the reconstructed mid‐sagittal sections it was possible to demonstrate the corpus callosum in at least 90% of cases when the 3D volume acquisition plane was (1) mid‐sagittal with the angle between the transducer and the direction of the fetal nose ranging from 0° to 179° and from 330° to 359°, (2) oblique around the crown–rump axis with an angle from the mid‐sagittal plane of less than 30°, (3) oblique around the anteroposterior axis from the axial plane at the level of the biparietal diameter to the mid‐sagittal plane or (4) axial at the level of the biparietal diameter with an angle between the transducer and the midline echo of the brain of 60–119°. In the mid‐sagittal sections either the translucent corpus callosum or a comma‐shaped echogenic structure was seen depending on whether the plane of volume acquisition was sagittal or axial.ConclusionsIn 3D ultrasound examination the extent to which the corpus callosum can be demonstrated to be present is entirely dependent on the plane of volume acquisition. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Efficient duty cycling through prediction and sampling in wireless sensor networks
Authors: Stone Kerri , Colagrosso Michael 
Published: May 2007

AbstractWe present BoostMAC, a CSMA‐based MAC layer protocol for wireless sensor networks that provides an adjustable interface to achieve ultra‐low power operation. To reach low power operation, we adaptively set two radio parameters. First, BoostMAC implements a preamble sampling scheme that allows a mote to dynamically set the length of its duty cycles. Second, we apply machine learning such that a sender can predict its destination's channel polling time and set each outgoing packet's preamble length accordingly. Our two improvements require no extra communication overhead, and each mote in the network implements simple, local models. Energy conservation is one of the most fundamental problems in sensor networks, and by optimizing low‐level operation at the MAC layer, sensor network applications realize an increase in overall performance.We choose habitat monitoring as a motivating sensor network application because it has unique MAC layer demands, such as fluctuating levels of network traffic. Static configuration at the MAC layer inhibits optimal energy conservation within habitat monitoring applications. We implemented BoostMAC in TinyOS simulator (TOSSIM), and we compare its performance to B‐MAC, a well‐known low power MAC protocol with static behavior. We found that BoostMAC saves energy relative to B‐MAC in bursty networks without affecting latency. Copyright © 2007 John Wiley & Sons, Ltd.
Erbliches Pankreaskarzinom
Authors: Rieder H. 
Published: May 2007

Zusammenfassung
Das duktale Adenokarzinom des Pankreas hat eine äußerst ungünstige Prognose, weil es meist erst in fortgeschrittenen Tumorstadien diagnostiziert wird. Das familiäre Pankreaskarzinom ist ein etabliertes Tumorprädispositionssyndrom, das bei etwa 3% der Pankreaskarzinompatienten beobachtet wird. Die Familienanamnese bei Pankreaskarzinompatienten ist ein wertvolles Instrument, um Personen mit einem erhöhten Risiko für ein Pankreaskarzinom zu identifizieren. Dies ist über die Kombination von Familienanamnese, Mutationssuche in Tumorprädispositionsgenen und die Analyse exogener Risikofaktoren möglich. Bei Hochrisikopersonen könnten invasive Methoden zur Erkennung von Frühstadien eingesetzt und somit eine kurative Pankreatektomie ermöglicht werden. In aktuell laufenden prospektiven Studien wird geprüft, ob auf der Basis klinisch-genetischer Kriterien definierte Hochrisikopatienten von einer Früherkennung des Pankreaskarzinoms profitieren.
The spectrum of hand and foot malformations in patients with Greig cephalopolysyndactyly
Authors: Debeer Philippe , Devriendt Koen , De Smet Luc , deRavel Thomy , Gonzalez-Meneses Antonio , Grzeschik Karl-Heinz , Fryns Jean-Pierre 
Published: May 2007

Purpose Greig cephalopolysyndactyly (GCPS) (OMIM 175700), a rare autosomal dominant disorder, is characterized by a distinct combination of craniofacial, hand and foot malformations. The hand and foot malformations often require orthopedic assessment and treatment. The disorder is caused by point mutations or deletions in the GLI3 gene, located on chromosome 7p14.3. Herewith, we review the hand and foot malformations in a cohort of 13 patients referred for genetic testing. Methods We reviewed the medical files of 13 patients with GCPS seen at the Center for Human Genetics in Leuven between 2003 and 2005. Clinical, molecular and radiological findings, when available, were recorded. Results We identified six different point mutations in the GLI3 gene, two microdeletions and three larger chromosomal deletions. In the hands, preaxial polydactyly was never observed, but the malformations included postaxial polydactyly, broad thumbs, clinodactyly of the thumbs and various degrees of syndactyly. In the feet the spectrum of malformations included preaxial polydactyly, postaxial polydactyly, different degrees of syndactyly and broad halluces. Syndactyly of the toes and hallux abnormalities were present in all patients. Most frequently, syndactyly was present between toes 1–2–3. The broadening of the hallux was either due to a complete or partial duplication of the first toe or to broadening of the distal phalanx. Mental retardation was found in three cases and was associated with a large chromosomal deletion of the GLI3 region. Conclusion We found the classic hand and foot malformations associated with GCPS in our cohort of patients. Patients with a large chromosomal deletion had mental retardation, but no structural brain anomalies were found.
Differential role of reactive oxygen species in the activation of mitogen‐activated protein kinases and Akt by key receptors on B‐lymphocytes: CD40, the B cell antigen receptor, and CXCR4
Authors: Lee Rosaline L. , Westendorf Jens , Gold Michael R. 
Published: May 2007

AbstractBackgroundAntibodies produced by B‐lymphocytes play a key role in the host defense against infection. The development, survival, and activation of B cell is regulated by multiple receptors including the B cell antigen receptor (BCR), which detects the presence of pathogens, CD40, which binds co‐stimulatory molecules on activated T cells, and chemokines such as SDF‐1 (CXCL12) that play key roles in B cell development and trafficking. Signaling by many receptors results in the generation of reactive oxygen species (ROS) that function as second messengers by regulating the activity of redox‐sensitive kinases and phosphatases. We investigated the role of ROS in signaling by the BCR, CD40, and CXCR4, the receptor for SDF‐1. We focused on activation of ERK, JNK, p38, and Akt, kinases that regulate multiple processes including cell survival, proliferation, and migration.ResultsUsing the anti‐oxidants N‐acetyl L‐cysteine (NAC) and ebselen to deplete intracellular ROS, we identified a differential requirement for ROS in the activation of ERK, JNK, p38, and Akt by these receptors. We found that CD40 activated JNK, p38, and Akt via redox‐dependent pathways that were sensitive to ROS depletion by NAC and ebselen. In contrast, BCR‐induced activation of ERK, JNK, p38, and Akt was not affected by ROS depletion. We also found that CXCR4‐induced Akt activation was ROS‐dependent even though activation of the ERK, JNK, and p38 MAP kinases by CXCR4 occurred via ROS‐independent pathways.ConclusionThe differential requirement for ROS in the activation of ERK, JNK, p38, and Akt by the BCR, CD40, and CXCR4 likely reflects the multiplicity of upstream activators for each of these kinases, only some of which may be regulated in a redox‐dependent manner. These findings support the idea that ROS are important second messengers in B cells and suggest that oxidants or anti‐oxidants could be used to modulate B cell activation.
The use of bundling in B2B online reverse auctions
Authors: Schoenherr Tobias , Mabert Vincent A. 
Published: May 2007

AbstractIn industrial purchasing a request for quotation (RFQ) can consist of a single item, but is most often composed of two or more products and/or services bundled together. While such bundles are used in offline purchase negotiations, their criticality is heightened in online auctions due to their usual short duration and constrained bidding environment. Despite this importance, little systematic discussion or evaluation has taken place concerning bundling practice, especially as it relates to the individual items included in the bundle, the overall bundle composition, and the resulting supply base and ultimate bundle performance. This study investigates these issues by developing a conceptual model and testing it with a large‐scale survey completed by purchasing professionals practicing bundling in B2B online auctions. Results indicate that crafting a more homogeneous bundle is most important in achieving a successful outcome. Furthermore, more complex or difficult‐to‐specify items do not impact perceived bundle performance, but do influence the supply base that is willing and able to bid on the business.
A phylogenetic Gibbs sampler that yields centroid solutions forcis-regulatory site prediction
Authors: Newberg Lee A. , Thompson William A. , Conlan Sean , Smith Thomas M. , McCue Lee Ann , Lawrence Charles E. 
Published: May 2007

AbstractMotivation: Identification of functionally conserved regulatory elements in sequence data from closely related organisms is becoming feasible, due to the rapid growth of public sequence databases. Closely related organisms are most likely to have common regulatory motifs; however, the recent speciation of such organisms results in the high degree of correlation in their genome sequences, confounding the detection of functional elements. Additionally, alignment algorithms that use optimization techniques are limited to the detection of a single alignment that may not be representative. Comparative-genomics studies must be able to address the phylogenetic correlation in the data and efficiently explore the alignment space, in order to make specific and biologically relevant predictions.Results: We describe here a Gibbs sampler that employs a full phylogenetic model and reports an ensemble centroid solution. We describe regulatory motif detection using both simulated and real data, and demonstrate that this approach achieves improved specificity, sensitivity, and positive predictive value over non-phylogenetic algorithms, and over phylogenetic algorithms that report a maximum likelihood solution.Availability: The software is freely available at http://bayesweb.wadsworth.org/gibbs/gibbs.htmlContact: William_Thompson_1@brown.eduSupplementary information: Supplementary data are available at Bioinformatics online.