bluuebunny/crossref_metadata_2025_split huggingface dataset:
Free‐breathing cine MRI
Authors: Leung Angela O. , Paterson Ian , Thompson Richard B. 
Published: August 2008

AbstractStandard MRI cine exams for the study of cardiac function are segmented over several heartbeats and thus require a breath‐hold to minimize breathing motion artifacts, which is a current limitation of this approach. The purpose of this study was to develop a method for the measurement and correction of respiratory motion that is compatible with cine imaging. Real‐time images were used to measure the respiratory motion of heart, to allow translations, rotations, and shears to be measured and corrected in the k‐space domain prior to a final gated‐segmented reconstruction, using the same data for both purposes. A method for data rejection to address the effects of through‐plane motion and complex deformations is described (respiratory gating). A radial k‐space trajectory was used in this study to allow direct reconstruction of undersampled real‐time images, although the techniques presented are applicable with Cartesian k‐space trajectories. Corrected and uncorrected free‐breathing gated‐segmented images acquired over 18 sec were compared to the current standard breath‐hold Cartesian images using both quantitative sharpness profiles (mm−1) and clinical scoring (1 to 5 scale, 3: clinically acceptable). Free‐breathing, free‐breathing corrected, and breath‐hold images had average sharpness values of 0.23 ± 0.04, 0.38 ± 0.04, and 0.44 ± 0.04 mm−1 measured at the blood–endocardium interface, and clinical scores of 2.2 ± 0.5, 4.2 ± 0.4, and 4.7 ± 0.5, respectively. Magn Reson Med 60:709–717, 2008. © 2008 Wiley‐Liss, Inc.
Cerebral blood flow MRI in mice using the cardiac‐spin‐labeling technique
Authors: Muir Eric R. , Shen Qiang , Duong Timothy Q. 
Published: August 2008

AbstractContinuous arterial spin labeling MRI with a separate neck labeling coil provides a highly sensitive method to image cerebral blood flow (CBF). In mice, however, this has not been possible because the proximity of the neck coil to the brain uses the neck coil to significantly saturate the brain signal. To overcome this limitation the cardiac spin labeling (CSL) technique is introduced in which the labeling coil is placed at the heart position. To demonstrate its utility, CSL CBF was applied to image quantitative basal CBF and hypercapnia‐induced CBF changes. This approach provides a practical means to image CBF with high sensitivity in small animals, compares favorably to existing mouse CBF imaging techniques, and could broaden CBF applications in mice where many brain disease and transgenic models are widely available. Magn Reson Med 60:744–748, 2008. © 2008 Wiley‐Liss, Inc.
Functional colonography of Min mice using dark lumen dynamic contrast‐enhanced MRI
Authors: Quarles C. Chad , Lepage Martin , Gorden D. Lee , Fingleton Barbara , Yankeelov Thomas E. , Price Ronald R. , Matrisian Lynn M. , Gore John C. , McIntyre J. Oliver 
Published: August 2008

AbstractDark lumen MRI colonography detects colonic polyps by minimization of the intestinal lumen signal intensity. Here we validate the use of perfluorinated oil as an intestinal‐filling agent for dark lumen MRI studies in mice, enabling the physiological characterization of colonic polyps by dynamic contrast‐enhanced MRI. In control and Min (multiple intestinal neoplasia) mice with and without pretreatment with oral dextran sodium sulfate (DSS), polyps as small as 0.94 mm diameter were consistently identified using standard 2D gradient echo imaging (voxel size, 0.23 × 0.16 × 0.5 mm). In serial studies, polyp growth rates were heterogeneous with an average ≈5% increase in polyp volume per day. In DSS‐treated control mice the colon wall contrast agent extravasation rate constant, Ktrans, and extravascular extracellular space volume fraction, ve, values were measured for the first time and found to be 0.10 ± 0.03 min−1 and 0.23 ± 0.09, respectively. In DSS‐treated Min mice, polyp Ktrans values (0.09 ± 0.04 min−1) were similar to those in the colon wall but the ve values were substantially lower (0.16 ± 0.03), suggesting increased cellular density. The functional dark‐lumen colonography approach described herein provides new opportunities for the noninvasive assessment of gastrointestinal disease pathology and treatment response in mouse models. Magn Reson Med 60:718–726, 2008. © 2008 Wiley‐Liss, Inc.
Predictive genetic testing in minors for adult‐onset genetic diseases
Authors: Borry Pascal , Goffin Tom , Nys Herman , Dierickx Kris 
Published: August 2008

AbstractThis article analyses the ethical discussion of predictive genetic testing in minors for genetic conditions for which there is no phenotypic evidence for disease at the considered time of testing and for which there is currently no treatment available to prevent or forestall the development of the condition. After a presentation of the position of various professional guidelines, we discuss the position and arguments that have been advanced in a recent article that defends a position that is opposed to the professional recommendations. In the article, we discuss the position of voluntary choices and autonomous and informed decision‐making in a context of open communication. Thereafter, we analyze the nonmedical benefits and harm related to this type of testing. Finally, we critically analyze 4 arguments: the potential provision of good news if a test is performed, the unbearability of knowing, identity and adjustment, and parental anxiety and uncertainty. Mt Sinai J Med 75:287–296, 2008. © 2008 Mount Sinai School of Medicine
Bipolar disorder: candidate drug targets
Authors: Zarate Carlos A. , Manji Husseini K. 
Published: August 2008

AbstractCurrent pharmacotherapy for bipolar disorder is generally unsatisfactory for a large number of patients. Even with adequate modern bipolar pharmacological therapies, many afflicted individuals continue to have persistent mood episode relapses, residual symptoms, functional impairment, and psychosocial disability. Creating novel therapeutics for bipolar disorder is urgently needed. Promising drug targets and compounds for bipolar disorder worthy of further study include both systems and intracellular pathways and targets. Specifically, the purinergic system, the dynorphin opioid neuropeptide system, the cholinergic system (muscarinic and nicotinic systems), the melatonin and serotonin [5‐hydroxytryptamine receptor 2C] system, the glutamatergic system, and the hypothalamic‐pituitary adrenal axis have all been implicated. Intracellular pathways and targets worthy of further study include glycogen synthase kinase‐3 protein, protein kinase C, and the arachidonic acid cascade. Mt Sinai J Med 75:225–246, 2008. © 2008 Mount Sinai School of Medicine
Diffusion‐weighted imaging of the entire spinal cord
Authors: Wilm B. J. , Gamper U. , Henning A. , Pruessmann K. P. , Kollias S. S. , Boesiger P. 
Published: August 2008

AbstractIn spite of their diagnostic potential, the poor quality of available diffusion‐weighted spinal cord images often restricts clinical application to cervical regions, and improved spatial resolution is highly desirable. To address these needs, a novel technique based on the combination of two recently presented reduced field‐of‐view approaches is proposed, enabling high‐resolution acquisition over the entire spinal cord. Field‐of‐view reduction is achieved by the application of non‐coplanar excitation and refocusing pulses combined with outer volume suppression for removal of unwanted transition zones. The non‐coplanar excitation is performed such that a gap‐less volume is acquired in a dedicated interleaved slice order within two repetition times. The resulting inner volume selectivity was evaluated in vitro. In vivo diffusion tensor imaging data on the cervical, thoracic and lumbar spinal cord were acquired in transverse orientation in each of four healthy subjects. An in‐plane resolution of 0.7 × 0.7 mm2 was achieved without notable aliasing, motion or susceptibility artifacts. The measured mean ± SD fractional anisotropy was 0.69 ± 0.11 in the thoracic spinal cord and 0.75 ± 0.07 and 0.63 ± 0.08 in cervical and lumbar white matter, respectively. Copyright © 2009 John Wiley & Sons, Ltd.
Poly(4‐hydroxyphenylacetic acid): A new material for immobilization of biomolecules
Authors: Silva Tatiana A.R. , Ferreira Lucas F. , Boodts Julien F.C. , Eiras Sebastião P. , Madurro João M. , Brito‐Madurro Ana G. 
Published: August 2008

AbstractThe electrochemical modification, surface analysis, and electrochemical impedance spectroscopy of graphite electrodes modified with polymeric films derived from 4‐hydroxyphenylacetic acid (4‐HPA) were investigated. The electrooxidation and optimization of the immobilization of adenosine monophosphate (AMP) and guanosine monophosphate (GMP) onto poly(4‐HPA) films at different pH values was carried out. Variation of the experimental conditions that influenced the electrode reaction, particularly the pH of the electrolytic solution, showed that the oxidation potentials of the immobilized AMP or GMP onto the modified electrodes decreased with increasing pH of the electrolyte. Higher oxidation current was obtained for AMP in phosphate buffer (pH 7.50) solution and GMP in acetate buffer (pH 4.50) solution. Film surface morphology and roughness in the absence or presence of AMP or GMP have been characterized by atomic force microscopy. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Polymer nanocomposite materials based on polystyrene and a layered aluminate filler
Authors: Matusinović Zvonimir , Rogošić Marko , Šipušić Juraj , Macan Jelena 
Published: August 2008

AbstractExfoliated polystyrene nanocomposites have been synthesized by in situ bulk multistep polymerization of polystyrene (PS) in the presence of the filler. The filler was layered double hydroxide (LDH)–tetracalcium aluminate hydrate, modified by the intercalation of benzoate anions (Ca4Al2(OH)12(C6H5COO)2·xH2O). Benzoate anions were found to increase the interlayer distance of the original filler. At the same time, the organophilicity of the filler was increased. The LDH was prepared using a variant of the rehydration method. The PS/LDH composites were characterized by X‐ray diffraction (XRD), infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis (TGA), and transmission electron microscopy methods. XRD and TGA results pointed to the successful incorporation of the filler within the polymer matrix. However, XRD results indicated that a characteristic layered structure of the filler had disappeared, i.e. the delamination had occurred. The filler was dispersed within the matrix in a form of nanosized monolayer particles, i.e. a nanocomposite material was prepared. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Predicting wear from mechanical properties of thermoplastic polymers
Authors: Brostow Witold , Hagg Lobland Haley E. 
Published: August 2008

AbstractThe wear of polymer‐based materials is connected to their brittleness. We have previously formulated a quantitative definition of brittleness in terms of elongation at break and storage modulus for thermoplastic polymers. We provide a formula connecting brittleness to viscoelastic recovery (healing) after sliding wear. Our model fits a selection of ten thermoplastics representing several classes of polymers with different chemical structures and mechanical properties. Now including polyvinylidene fluoride, poly(methylmethacrylate), and polyphenylsulfone, we demonstrate that from our formula we can predict the percentage recovery in sliding wear from our measure of brittleness. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Stress cracking and photodegradation behavior of polycarbonate. The combination of two major causes of polymer failure
Authors: Timóteo G.A.V. , Fechine G.J.M. , Rabello M.S. 
Published: August 2008

AbstractThis work investigates the effects of photodegradation on the environmental stress cracking resistance of polycarbonate (PC). Injection molded samples were exposed to the ultraviolet (UV) light for various times in the laboratory prior to solvent contact. The bars were then stressed with two different loads in a tensile testing machine under the presence of ethanol. During this period, the stress relaxation was monitored and, after unloading, the ultimate properties were evaluated. Complementary tests were done by size exclusion chromatography, UV–visible spectroscopy, scanning electron microscopy, and light microscopy. The results indicated that ethanol causes significant modification in PC, with extensive surface crazing as well as reduction in mechanical properties. The previous degraded samples showed a higher level of stress relaxation and a greater loss in tensile strength in comparison with the undegraded ones. The synergist action of photodegradation and stress cracking in PC may be a consequence of the chemical changes caused by oxidation. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Effects of surface plasma treatment on tribology of thermoplastic polymers
Authors: Bismarck Alexander , Brostow Witold , Chiu Rachel , Hagg Lobland Haley E. , Ho Kingsley K.C. 
Published: August 2008

AbstractWe have subjected polycarbonate (PC), low density polyethylene (LDPE), polystyrene (PS), polypropylene (PP), and Hytrel® (HY, a thermoplastic elastomer) to atmospheric pressure oxygen plasma treatment for varying amounts of time. Effects of the treatment have been evaluated in terms of the water wetting angle, dynamic friction, scratch resistance, and sliding wear. Although PS, PP, and HY do not undergo significant tribological changes as a result of the interaction with plasma, PC and LDPE show more pronounced and useful effects, such as a lowering of dynamic friction in PC and wear reduction in LDPE. These results can be explained in terms of the changes in chemical structures and increase of hydrophilicity. Based on the effects of oxygen plasma treatment on PC and LDPE, these two polymers have been subjected to longer oxygen plasma treatments and to argon, nitrogen, and air plasmas. Resulting effects on friction and scratch resistance are compared to determine the mechanisms responsible for the various surface behaviors. Chemical surface modification—as represented by changing contact angles—contributes to the tribological responses. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Grafting of maleic anhydride on polypropylene and its effect on blending with poly(ethylene terephthalate)
Authors: Gartner Carmiña , Suárez Marizabel , López Betty Lucy 
Published: August 2008

AbstractIn the present work, maleic anhydride was used for grafting polypropylene (PP) by a free radical reaction in the melt and subsequent blending with highly crystalline polyethylene terephthalate (PET), to determine how functionalization and blending influence their properties. The optimum conditions for the grafting reaction of PP were found, and degree of grafting was measured by the carbonyl index using a Fourier transformer infrared spectrophotometer. Both noncompatibilized and compatibilized PP/PET blends of different compositions were prepared in a laboratory mixing extruder. They were characterized by differential scanning calorimetry to observe their thermal behavior, by scanning electron microscopy to study their particular morphology, and by water vapor permeability measurements to determine their water barrier performance. For compatibilized blends, a partial solubility of PP in PET longer chains and the development of a complex morphology were seen. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Biodegradable nanosize particles of poly(L,L‐lactide)‐b‐poly(ethylene glycol)‐b‐poly(L,L‐lactide)
Authors: Drumond Walker S. , Mothé Cheila Gonçalves , Wang Shu Hui 
Published: August 2008

AbstractTwo series of poly(L,L‐lactide‐b‐ethylene glycol‐b‐L,L‐lactide) copolymers, PLA‐PEO‐PLA, were synthesized by polymerization of L,L‐lactide using a dihydroxy‐terminated poly(ethylene glycol) (PEG) (Mn = 4000 or 600 g/mol) as coinitiator and stannous 2‐ethylhexanoate, Sn(Oct)2, as initiator. The synthesized copolymers have shown high stereoregularity as observed by 13C NMR analyses. The nanoparticles were prepared by using a solvent diffusion method and the self‐assemblage process and were characterized by NMR and SEM. It was possible to conclude that the self‐assembled particles presented a core‐shell structure characterized by a hydrophobic PLA core and a hydrophilic PEG shell, thus the NMR of the aqueous solutions indicated a quasi‐solid behavior for the particles' interior. The diameters of the spherical particles as observed by SEM were in the 50–250 nm range, depending on the copolymer composition and the preparation procedure. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Amphiphilic derivatives of carboxymethylcellulose: Evidence for intra‐ and intermolecular hydrophobic associations in aqueous solutions
Authors: Vidal Rosangela Regia Lima , Balaban Rosangela , Borsali Redouane 
Published: August 2008

AbstractThe intra and/or intermolecular associations of CMC‐g‐poly(N,N‐dihexylacrylamide) copolymers in aqueous systems were studied by static (SLS) and dynamic (DLS) light scattering, viscometry, and rheology. The copolymers containing 1 to 6 mol % of hydrophobic groups were synthesized by free radical micellar copolymerization. Their associations were evaluated in different solvents (0.5 M NaCl, synthetic formation water (SFW) and Milli‐Q water), as a function of the polymer concentration, hydrophobicity, temperature, and ionic strength. Rheological behavior was investigated in SWF at 55°C. The results indicated that polymer–polymer interactions increase with the increase of the hydrophobic group lengths grafted onto the CMC backbone. The copolymer with the highest concentration of hydrophobic groups (6 mol %) had the lowest values of intrinsic viscosity, weight‐average molar mass (Mw), and hydrodynamic radius (RH), indicating a strongly compact structure due to intramolecular hydrophobic associations. The rheological behavior of the copolymers in SFW showed that the high polymer concentration and the high temperature together with the intermolecular hydrophobic interactions and the bridges formed between divalent cations and carboxilate groups were not enough to promote a significant increase in the size of the aggregates. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Polyaniline/multiwalled carbon nanotube systems: Dispersion of CNT and CNT/PANI interaction
Authors: Zelikman E. , Narkis M. , Siegmann A. , Valentini L. , Kenny J.M. 
Published: August 2008

AbstractIn this article, preparation and characterization of nanocomposites consisting of polyaniline (PANI) doped with dodecyl benzene sulfonic acid (DBSA) as a matrix with multiwalled carbon nanotubes (MWCNT) are described. Dispersion of MWCNT was conducted by ultrasonication in water/DBSA solution (1%) by ultrasonication. The resultant dispersion was mixed either with a ready PANI dispersion or with aniline followed by polymerization. High resolution scanning electron microscope (HRSEM) micrographs show an outstanding level of MWCNT dispersion in the PANI matrix, for nanocomposites prepared by mixing the MWCNT dispersion with a ready PANI dispersion. TGA measurements of these nanocomposites show that MWCNT significantly change the thermal stability of PANI. Rotational rheology results suggest that CNT function as interparticle bridges in MWCNT/PANI/DBSA dispersions. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Particle nucleation in high solids batch miniemulsion polymerization stabilized with a polymeric surfactant
Authors: Bohórquez Silfredo J. , Asua José M. 
Published: August 2008

AbstractThe nucleation of polymer particles in the miniemulsion polymerization of vinyl acetate/VeoVa10 (VAc/VeoVa10) stabilized with PVOH was studied. The effect of costabilizer type, PVOH concentration, and type (thermal water‐soluble and oil‐soluble; and redox water‐soluble) and concentration of initiator on the extent of droplet nucleation were studied. Droplet nucleation was maximized by improving miniemulsion stability and using efficient initiators. These high solids dispersions could not be obtained by using a conventional batch emulsion polymerization. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6407–6415, 2008
Bicalutamide inhibits androgen‐mediated adhesion of prostate cancer cells exposed to ionizing radiation
Authors: Wang Tao , Alavian Michael R. , Goel Hira Lal , Languino Lucia R. , FitzGerald Thomas J. 
Published: August 2008

AbstractBackgroundCell adhesion plays an important role in proliferation, metastasis, and tumor growth and may represent a potential vulnerability in treatment of prostate cancer patients. Bicalutamide (Casodex) has been used as an anti‐androgen agent for prostate cancer patients during hormone ablation therapy. This study focuses on the effect of Bicalutamide on cell adhesion to fibronectin (FN) in prostate cancer cells.MethodsAndrogen–dependent LNCaP prostate cancer cells were stimulated with androgen before being irradiated with doses of 0, 5, 10, or 15 Gy. Cell adhesion to fibronectin was then measured to ascertain androgen's role in integrin mediated prostate cancer cell adhesion. Flow cytometry was used to analyze surface expression of integrin subtypes in LNCaP cells.ResultsLNCaP cell adhesion to FN was significantly increased by stimulation with androgen when treated with 10 or 15 Gy ionizing radiations but not at 0 or 5 Gy. This increase was inhibited by treatment with Bicalutamide. LNCaP cells exposed to high dose radiation showed an increased expression of αV and β1 integrins in response to androgen treatment while Bicalutamide abolished this effect.ConclusionsOur data show that Bicalutamide inhibits the effect of androgen on cell adhesion to FN through changes of integrin subtypes in cells given high dose radiation. This suggests new molecular targets and possible treatment strategies for prostate cancer patients to improve the outcome during hormone ablation therapy and radiation therapy. Prostate © 2008 Wiley‐Liss, Inc.
Photoemission study of electronic structures of fullerene and metallofullerene peapods
Authors: Nakayama Yuji , Fujiki Shinichiro , Hirado Yasuharu , Shiozawa Hidetsugu , Ishii Hiroyoshi , Miyahara Tsuneaki , Maniwa Yutaka , Kodama Takeshi , Achiba Yoji , Kataura Hiromichi , Kubozono Yoshihiro , Nakatake Masashi , Saitoh Tomohiko 
Published: August 2008

AbstractWe have investigated the electronic structures of single‐wall carbon nanotubes (SWCNTs) encapsulating C70 fullerene and metallofullerenes M@C82 (M = La, Gd, Dy), C70 peapods (C70@SWCNT) and metallofullerene peapods (M@C82@SWCNT), using photoemission spectroscopy. The photoemission spectra of C70 and M@C82 peas are obtained by subtracting the spectrum of pristine SWCNTs from those of the corresponding peapods. The electronic structure of the C70 peas is similar to that of the C70 film. For the M@C82 peapods, on the other hand, the electronic structures of the M@C82 peas are different. For the La@C82 peapods, the singly occupied molecular orbital (SOMO) for the La@C82 peas is located nearer to the Fermi level when compared with that in the La@C82 film. For the Dy@C82 peapods, the effective Dy valence is estimated to be +2.9. This result demonstrates that effective charges move back from the C82 cage to Dy following encapsulation of Dy@C82 peas in the SWCNTs because of the strong hybridization interaction between Dy 4f and C 2p electrons, taking into account the Dy valence of +3 in the Dy@C82 film. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)