bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proteomic analysis reveals a novel role for the actin cytoskeleton in vincristine resistant childhood leukemia – An in vivo study
Authors: Verrills Nicole M. , Liem Natalia L. , Liaw Tracy Y. E. , Hood Brian D. , Lock Richard B. , Kavallaris Maria 
Published: February 2006

AbstractIntrinsic or acquired resistance to vincristine (VCR), an antimicrotubule agent used in the treatment of childhood acute lymphoblastic leukemia (ALL), is a major clinical problem. Using a clinically relevant NOD/SCID mouse xenograft model of ALL, we established that alterations in the actin and tubulin cytoskeleton are involved in in vivo VCR resistance. Altered protein expression between VCR‐sensitive ALL xenografts, and xenografts with intrinsic or acquired VCR resistance, was identified using 2‐D DIGE coupled with MS. Of the 19 proteins displaying altered expression, 11 are associated with the actin cytoskeleton. Altered expression of the actin‐ and/or tubulin‐binding proteins gelsolin, moesin, ezrin, tropomyosin, CAP‐G, HSP27, HSP70, TCP‐1, and stathmin were associated with in vivo VCR resistance. The actin‐regulating protein gelsolin was increased in both acquired and resistant leukemia as confirmed by immunoblotting and gene expression. The major cytoskeletal protein, γ‐actin, was down‐regulated in the VCR‐resistant leukemia xenografts; in contrast, there was no significant change in β‐actin expression. This study provides the first evidence for a role of the actin cytoskeleton in intrinsic and acquired in vivo antimicrotubule drug resistance in childhood leukemia and highlights the power of 2‐D DIGE for the discovery of resistance markers, pharmacoproteomics, and signaling pathways in cancer.
Synthesis, characterization, effect of architecture on crystallization, and spherulitic growth of poly(L‐lactide)‐b‐poly(ethylene oxide) copolymers with different branch arms
Authors: Cai Chen , Wang Lu , Dong Chang‐Ming 
Published: February 2006

AbstractWell‐defined poly(L‐lactide)‐b‐poly(ethylene oxide) (PLLA‐b‐PEO) copolymers with different branch arms were synthesized via the controlled ring‐opening polymerization of L‐lactide followed by a coupling reaction with carboxyl‐terminated poly(ethylene oxide) (PEO); these copolymers included both star‐shaped copolymers having four arms (4sPLLA‐b‐PEO) and six arms (6sPLLA‐b‐PEO) and linear analogues having one arm (LPLLA‐b‐PEO) and two arms (2LPLLA‐b‐PEO). The maximal melting point, cold‐crystallization temperature, and degree of crystallinity (Xc) of the poly(L‐lactide) (PLLA) block within PLLA‐b‐PEO decreased as the branch arm number increased, whereas Xc of the PEO block within the copolymers inversely increased. This was mainly attributed to the relatively decreasing arm length ratio of PLLA to PEO, which resulted in various PLLA crystallization effects restricting the PEO block. These results indicated that both the PLLA and PEO blocks within the block copolymers mutually influenced each other, and the crystallization of both the PLLA and PEO blocks within the PLLA‐b‐PEO copolymers could be adjusted through both the branch arm number and the arm length of each block. Moreover, the spherulitic growth rate (G) decreased as the branch arm number increased: G6sPLLA‐b‐PEO < G4sPLLA‐b‐PEO < G2LPLLA‐b‐PEO < GLPLLA‐b‐PEO. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2034–2044, 2006
Phase behavior, crystallization, and nanostructures in thermoset blends of epoxy resin and amphiphilic star‐shaped block copolymers
Authors: Guo Qipeng , Wang Ke , Chen Ling , Zheng Sixun , Halley Peter J. 
Published: February 2006

AbstractThis article reports thermoset blends of bisphenol A‐type epoxy resin (ER) and two amphiphilic four‐arm star‐shaped diblock copolymers based on hydrophilic poly(ethylene oxide) (PEO) and hydrophobic poly(propylene oxide) (PPO). 4,4′‐Methylenedianiline (MDA) was used as a curing agent. The first star‐shaped diblock copolymer with 70 wt % ethylene oxide (EO), denoted as (PPO‐PEO)4, consists of four PPO‐PEO diblock arms with PPO blocks attached on an ethylenediamine core; the second one with 40 wt % EO, denoted as (PEO‐PPO)4, contains four PEO‐PPO diblock arms with PEO blocks attached on an ethylenediamine core. The phase behavior, crystallization, and nanoscale structures were investigated by differential scanning calorimetry, transmission electron microscopy, and small‐angle X‐ray scattering. It was found that the MDA‐cured ER/(PPO‐PEO)4 blends are not macroscopically phase‐separated over the entire blend composition range. There exist, however, two microphases in the ER/(PPO‐PEO)4 blends. The PPO blocks form a separated microphase, whereas the ER and the PEO blocks, which are miscible, form another microphase. The ER/(PPO‐PEO)4 blends show composition‐dependent nanostructures on the order of 10−30 nm. The 80/20 ER/(PPO‐PEO)4 blend displays spherical PPO micelles uniformly dispersed in a continuous ER‐rich matrix. The 60/40 ER/(PPO‐PEO)4 blend displays a combined morphology of worm‐like micelles and spherical micelles with characteristic of a bicontinuous microphase structure. Macroscopic phase separation took place in the MDA‐cured ER/(PEO‐PPO)4 blends. The MDA‐cured ER/(PEO‐PPO)4 blends with (PEO‐PPO)4 content up to 50 wt % exhibit phase‐separated structures on the order of 0.5–1 μm. This can be considered to be due to the different EO content and block sequence of the (PEO‐PPO)4 copolymer. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 975–985, 2006
Thermo‐hygro‐mechanical behavior of spider dragline silk: Glassy and rubbery states
Authors: Plaza Gustavo R. , Guinea Gustavo V. , Pérez‐Rigueiro José , Elices Manuel 
Published: February 2006

AbstractSpider silk is considered as the basis of a new family of high performance fibers that would reproduce the excellent mechanical properties of the silk, in particular its extreme toughness. However, it has been observed that the mechanical properties of spider silk are severely influenced by humid environments that give rise to significant decreases in its length and elastic modulus. The change from stiff to compliant tensile properties is associated with the glass transition from a glassy to a rubbery state; here, we have found that it depends on both temperature and relative humidity. The glass transition was identified at different temperatures and relative humidities by monitoring the variation of the elastic modulus and observing the emergence of supercontraction. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 994–999, 2006
Effect of molecular size on cooperative dynamics of low mass compounds in polystyrene
Authors: Urakawa O. , Ohta E. , Hori H. , Adachi K. 
Published: February 2006

AbstractWe studied the dielectric relaxation behavior of low mass compounds (LMC) mixed in polystyrene (PS). Specifically, LMCs that are used are alkyl‐cyanobenzene (nCBz, n = 0), alkyl‐cyanobiphenyl (nCB, n = 0, 1, 3, 5, and 7), and alkyl‐cyanoterphenyl (nCT, n = 5), where n represents the number of carbon atoms of the normal alkyl groups of the LMCs. Owing to a much larger dipole moment of the cyano group than that of PS, only motions of the LMCs were observed. In a blend of 5CT (5 wt %)/PS, single relaxation process designated as α was observed. On the other hand, in nCB (5 wt %)/PS, partially overlapped two relaxation processes (α and β) were observed in the order of decreasing temperature. We assigned the α process to cooperative motions between the LMC molecules and the PS segments, and the β process to spatially restricted motions of the LMC molecules in the glassy state. In 0CBz (8 wt %)/PS, the α and β processes were observed in distinct temperature regions and the intensity of the α peak was comparable to that of pure PS, indicating that the 0CBz molecules do not move cooperatively with the PS segments. We conclude the existence of two critical sizes (I and II) of LMC in relation to cooperativity: when an LMC molecule is smaller than the size‐I, the motions of the LMCs and PS segments decouple each other, but above the size‐I, they become cooperative. Above the size‐II, the spatially restricted motion (β‐process) of LMC does not occur. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 967–974, 2006
Effective supergravity from the weakly coupled heterotic string
Authors: Gaillard M.K. 
Published: February 2006

AbstractThe motivation for Calabi‐Yau‐like compactifications of the weakly coupled E8 ⊗ E8 heterotic string theory, its particle spectrum and the issue of dilaton stabilization are briefly reviewed. Modular invariant models for hidden sector condensation and supersymmetry breaking are described at the quantum level of the effective field theory. Their phenomenological and cosmological implications, including a possible origin for R‐parity, are discussed.
Thermodynamical properties of some coset CFT backgrounds
Authors: Giveon A. , Konechny A. , Rabinovici E. , Sever A. 
Published: February 2006

AbstractWe investigate the thermodynamical features of two Lorentzian signature backgrounds that arise in string theory as exact CFTs and possess more than two disconnected asymptotic regions: the 2‐d charged black hole and the Nappi‐Witten cosmological model. We find multiple smooth disconnected Euclidean versions of the charged black hole background. They are characterized by different temperatures and electro‐chemical potentials. We find that there is no straightforward analog of the Hartle‐Hawking state that would express these thermodynamical features. We also obtain multiple Euclidean versions of the Nappi‐Witten cosmological model and study their singularity structure. It suggests to associate a non‐isotropic temperature with this background.
Supersymmetric models for fermions on a lattice
Authors: Ilieva N. , Narnhofer H. , Thirring W. 
Published: February 2006

AbstractWe investigate the large‐N behaviour of simple examples of supersymmetric interactions for fermions on a lattice. Witten's supersymmetric quantum mechanics and the BCS model appear just as two different aspects of one and the same model. For the BCS model, supersymmetry is only respected in a coherent superposition of Bogoliubov states. In this coherent superposition mesoscopic observables show better stability properties than in a Bogoliubov state.
Solution structure and binding specificity of FBP11/HYPA WW domain as Group‐II/III
Authors: Kato Yusuke , Hino Yumi , Nagata Koji , Tanokura Masaru 
Published: February 2006

AbstractThe Group‐II/III WW domains bind Pro‐rich sequences, the most frequent protein motif found in eucaryotic genomes. We have proposed that the Group‐II and ‐III WW domains be merged into a larger group because the members of each group have relatively wide specificity and bind to the common ligands [Kato et al., J Biol Chem 2004;279:31833–31841]. We have also proposed that Group‐II/III has a common surface patch, the XP2 groove, to bind the ligands. The first WW domain of FBP11/HYPA is one of the Group‐II/III WW domains. The solution structure of the 26 residue‐long converged region exhibits an antiparallel triple stranded β‐sheet with a small hydrophobic core. The WW domain of FBP11/HYPA has both XP and XP2 grooves on its surface. Ligand titration by 1H15N HSQC NMR spectra revealed that the WW domain of FBP11/HYPA binds all the peptides with the PL, PP, and PR motifs. The profile patterns of chemical shift perturbation were quite similar among the spectra titrated with all three ligands. In addition, the titration significantly shifts the signals of the residues that compose the XP2 groove. All these findings suggest the functional importance of the XP2 groove and group definition of Group‐II/III of the WW domains. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Structural and thermodynamic consequences of removal of a conserved disulfide bond from equine β‐lactoglobulin
Authors: Yamada Yoshiteru , Nakagawa Kanako , Yajima Takeo , Saito Keiko , Tokushima Akihito , Fujiwara Kazuo , Ikeguchi Masamichi 
Published: February 2006

AbstractA disulfide bond between cysteine 66 and cysteine 160 of equine β‐lactoglobulin was removed by substituting cysteine residues with alanine. This disulfide bond is conserved across the lipocalin family. The conformation and stability of the disulfide‐deleted mutant protein was investigated by circular dichroism. The mutant protein assumes a native‐like structure under physiological conditions and assumes a helix‐rich molten globule structure at acid pH or at moderate concentrations of urea as the wild‐type protein does. The urea‐induced unfolding experiment shows that the stability of the native conformation was reduced but that of the molten globule intermediate is not significantly changed at pH 4 by removal of the disulfide bond. On the other hand, the molten globule at acid pH was destabilized by removal of the disulfide bond. This difference in the stabilizing effect of the disulfide bond was interpreted by the effect of the disulfide in keeping the molecule compact against the electrostatic repulsion at acid pH. In contrast to the wild‐type protein, the circular dichroism spectrum in the molten globule state at acid pH depends on anion concentration, suggesting that the expansion of the molecule through electrostatic repulsion induces α‐helices as observed in the cold denatured state of the wild‐type protein. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Robotic whole body stereotactic radiosurgery: clinical advantages of the Cyberknife®integrated system
Authors: Coste‐Manière È , Olender D , Kilby W , Schulz R A 
Published: February 2006

AbstractRadiosurgery is defined as the delivery of high doses of ionising radiation, in mono‐ or hypo‐ fractionated treatments, to destroy tumours or focal areas of pathology. The clinical requirements of designing a radiosurgical treatment system include providing: a) a highly precise beam delivery to targets located throughout the body, b) a highly conformal dose distribution, c) the ability to irradiate both small and/or large complex‐shaped lesions while minimising the dose to adjacent radiosensitive tissues and d) the ability to interactively track lesion motion due to normal patient motion. To accomplish this, the CyberKnife®radiosurgery system has pioneered in this area by taking advantage of the inherent geometrical targeting precision of a commercial arm‐based robotic system carrying a compact X‐band linear accelerator and integrated with X‐ray imaging and visualisation feedback systems. The arm‐mounted linear accelerator, equipped with patient specific anatomical models, registered to the patient in real‐time with image guidance, dynamically and safely delivers conformal and homogeneous radiation for therapeutic benefit. This paper details the components of the CyberKnife system and their integration in the clinical workflow of radiosurgery. Copyright © 2005 Robotic Publications, Ltd.
Precision placement of instruments for minimally invasive procedures using a “needle driver” robot
Authors: Cleary K , Watson V , Lindisch D , Taylor R H , Fichtinger G , Xu S , White C S , Donlon J , Taylor M , Patriciu A , Mazilu D , Stoianovici D 
Published: February 2006

AbstractMedical practice continues to move toward less invasive procedures. Many of these procedures require the precision placement of a needle in the anatomy. Over the past several years, our research team has been investigating the use of a robotic needle driver to assist the physician in this task. This paper summarizes our work in this area. The robotic system is briefly described, followed by a description of a clinical trial in spinal nerve blockade. The robot was used under joystick control to place a 22 gauge needle in the spines of 10 patients using fluoroscopic imaging. The results were equivalent to the current manual procedure. We next describe our follow‐up clinical application in lung biopsy for lung cancer screening under CT fluoroscopy. The system concept is discussed and the results of a phantom study are presented. A start‐up company named ImageGuide has recently been formed to commercialize the robot. Their revised robot design is presented, along with plans to install a ceiling‐mounted version of the robot in the CT fluoroscopy suite at Georgetown University. Copyright © 2005 Robotic Publications Ltd.
Distinctive Sorghum Starch Granule Morphologies Appear to Improve Raw Starch Digestibility
Authors: Benmoussa Mustapha , Suhendra Budhi , Aboubacar Adam , Hamaker Bruce R. 
Published: February 2006

AbstractVarious factors, including starch granule channels, have been suggested to contribute to the control of sorghum starch digestibility for animal feed. Isolated starch from two normal sorghum lines (P721N, IS6986) and one high protein digestibility (HPD) mutant line (111) that differed in starch granule morphology were selected to study the influence of these factors on starch digestibility. Scanning electron micrographs were taken of raw and digested starches. Microscopy results confirmed that in all three sorghum lines channels in starch granules are the main route of enzyme penetration and the central cavity area is the starting point of enzyme digestion. Channel density was more pronounced in the HPD sorghum mutant line than in normal lines, which may have been responsible for its relatively high digestibility. Micrographs of IS6986 showed unique starch granule morphology with a collapsed ”doughnut‐shaped” structure in a portion of the granules. These unusual granules were rapidly digested and, unlike normal spherical granules, totally disappeared after 30 min of digestion. Amylases appeared to have fast access to the collapsed‐appearing starch granules. Digestion profiles, following incubation with pepsin and α‐amylase, showed that IS6986 and the HPD mutant (111) had the highest initial rate of starch digestion, followed by P721N. These findings provide insight as to how new sorghum cultivars might be developed with high starch digestibility for animal feed use.
Influence of Jet‐Cooking Temperature and Ionic Strength on Size and Structure of Cationic Potato Amylopectin Starch as Measured by Asymmetrical Flow Field‐Flow Fractionation Multi‐Angle Light Scattering
Authors: Modig Gustaf , Nilsson Per‐Ola , Wahlund Karl‐Gustav 
Published: February 2006

AbstractAsymmetrical flow field‐flow fractionation (AsFlFFF) in combination with multi‐angle light scattering (MALS) was applied to cationic potato amylopectin (CPAP) to investigate how molar mass, root‐mean‐square (r.m.s.) radius and shape was influenced by different conditions of jet‐cooking. The effect of different jet‐cooking temperatures in the range 110°C – 140°C was studied in an excess steam jet‐cooker. This equipment is used in the industry for dissolution of starch and starch derivatives before technical application. The effect of different ionic strengths conditions was examined in the range of 10–200 mM. The weight‐average molar mass decreased from about 34×107 g/mol to 2.6×107 g/mol when the jet‐cooking temperature was increased from 110°C to 140°C. Concurrently the root‐mean‐square radius decreased from ca 380 nm to 90 nm. The decrease in size was reflected by a decrease in viscosity with increasing temperature. The root‐mean‐square radius was reduced when increasing the ionic strength. This decrease in size was correlated with a decrease in viscosity. Conformation and Kratky plots showed that at low ionic strength (≤ 10 mM) CPAP behaved as a flexible chain with high degree of branching, close to hyperbranching. Increase of the ionic strength gave a more compact structure and changes in the internal structure were observed as well. Consequently, by using AsFlFFF – MALS the effect of technical processing on the molar mass, molecular radius, conformational structure, and shape could be determined in a size region where standard methodology commonly fails.
Preparation and Properties of Octenyl Succinic Anhydride Modified Early Indica Rice Starch
Authors: Song Xiaoyan , He Guoqing , Ruan Hui , Chen Qihe 
Published: February 2006

AbstractOctenyl succinic anhydride (OSA) modified early indica rice starch was prepared in aqueous slurry systems and the major factors affecting the esterification were investigated systematically. The physicochemical properties of the products were determined by means of Fourier transform infrared (FT‐IR) spectroscopy, scanning electron microscopy (SEM), X‐ray diffraction and Rapid Visco Analyser (RVA). The results indicated that the suitable parameters for the preparation of OSA starch from early indica rice starch in aqueous slurry systems were as follows: concentration of starch slurry 35% (in proportion to water, w/w), reaction period 4 h, pH of reaction system 8.5, reaction temperature 35°C, amount of OSA 3% (in proportion to starch, w/w). The degree of substitution (DS) was 0 018 and the reaction efficiency (RE) was 78%. FT‐IR spectroscopy showed characteristic absorption of the ester carbonyl groups in the OSA starch at 1724 cm‐1. SEM and X‐ray diffraction revealed that OSA groups acted by first attacking the surface and some pores formed, but OSA modification caused no change in the crystalline pattern of rice starch up to DS 0.046. RVA results indicated that the starch derivatives gelatinized at shorter time to achieve higher viscosities with increased OSA modification.
Characterisation and Modelling of Specific Enthalpy and Heat Conductivity of Corn Grits under Consideration of Water Sorption Behaviour
Authors: Potente Helmut , Heim Hans‐Peter , Ernst Wolfgang , Föhrer Thorsten 
Published: February 2006

AbstractExtrusion of starch is a common process not only in food industry, but also for technical applications. In this context, a special type of extruder with a very short plastication unit allows the processing of foamed products like loose‐fill based on non‐modified, starch‐containing raw materials. A crop product which has been defined as very suitable for this process is corn grit. In order to describe the process behaviour of an extrusion machine, the knowledge of the relevant material properties is indispensable.This paper provides results from investigations focused on the determination of material data like specific enthalpy (SE) Δh and heat conductivity (HC) λ. Both characteristics increase with rising temperature and water content. Based on these experimental results, mathematical models have been formulated in order to calculate the specific enthalpy and heat conductivity in dependence on temperature and moisture content, which in turn depends on air temperature and relative humidity during the storing of the material before processing. Therefore, the water vapour sorption behaviour of this material was also investigated. The GAB model for the mathematical description of sorption behaviour of starch could also be applied to corn grits and integrated into the models for the calculation of Δh and λSpecific enthalpy has been determined by DSC (differential scanning calorimetry), heat conductivity has been measured by using a device working with the “Line‐Source‐Method”.