bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of lactate and alanine as metabolic biomarkers of prostate cancer using 1H HR‐MAS spectroscopy of biopsy tissues
Authors: Tessem May‐Britt , Swanson Mark G. , Keshari Kayvan R. , Albers Mark J. , Joun David , Tabatabai Z. Laura , Simko Jeffry P. , Shinohara Katsuto , Nelson Sarah J. , Vigneron Daniel B. , Gribbestad Ingrid S. , Kurhanewicz John
Published: August 2008

The goal of this study was to investigate the use of lactate and alanine as metabolic biomarkers of prostate cancer using 1H high‐resolution magic angle spinning (HR‐MAS) spectroscopy of snap‐frozen transrectal ultrasound (TRUS)‐guided prostate biopsy tissues. A long‐echo‐time rotor‐synchronized Carr‐Purcell‐Meiboom‐Gill (CPMG) sequence including an electronic reference to access in vivo concentrations (ERETIC) standard was used to determine the concentrations of lactate and alanine in 82 benign and 16 malignant biopsies (mean 26.5% ± 17.2% of core). Low concentrations of lactate (0.61 ± 0.28 mmol/kg) and alanine (0.14 ± 0.06 mmol/kg) were observed in benign prostate biopsies, and there was no significant difference between benign predominantly glandular (N = 54) and stromal (N = 28) biopsies between patients with (N = 38) and without (N = 44) a positive clinical biopsy. In biopsies containing prostate cancer there was a highly significant (P < 0.0001) increase in lactate (1.59 ± 0.61 mmol/kg) and alanine (0.26 ± 0.07 mmol/kg), and minimal overlap with lactate concentrations in benign biopsies. This study demonstrates for the first time very low concentrations of lactate and alanine in benign prostate biopsy tissues. The significant increase in the concentration of both lactate and alanine in biopsy tissue containing as little as 5% cancer could be exploited in hyperpolarized 13C spectroscopic imaging (SI) studies of prostate cancer patients. Magn Reson Med 60:510–516, 2008. © 2008 Wiley‐Liss, Inc.
Improved calibration technique for in vivo proton MRS thermometry for brain temperature measurement
Authors: Zhu M. , Bashir A. , Ackerman J.J. , Yablonskiy D.A.
Published: August 2008

The most common MR‐based approach to noninvasively measure brain temperature relies on the linear relationship between the 1H MR resonance frequency of tissue water and the tissue's temperature. Herein we provide the most accurate in vivo assessment existing thus far of such a relationship. It was derived by acquiring in vivo MR spectra from a rat brain using a high field (11.74 Tesla [T]) MRI scanner and a single‐voxel MR spectroscopy technique based on a LASER pulse sequence. Data were analyzed using three different methods to estimate the 1H resonance frequencies of water and the metabolites NAA, Cho, and Cr, which are used as temperature‐independent internal (frequency) references. Standard modeling of frequency‐domain data as composed of resonances characterized by Lorentzian line shapes gave the tightest resonance‐frequency versus temperature correlation. An analysis of the uncertainty in temperature estimation has shown that the major limiting factor is an error in estimating the metabolite frequency. For example, for a metabolite resonance linewidth of 8 Hz, signal sampling rate of 2 Hz and SNR of 5, an accuracy of approximately 0.5°C can be achieved at a magnetic field of 3T. For comparison, in the current study conducted at 11.74T, the temperature estimation error was approximately 0.1°C. Magn Reson Med 60:536–541, 2008. © 2008 Wiley‐Liss, Inc.
Strongly modulating pulses for counteracting RF inhomogeneity at high fields
Authors: Boulant N. , Bihan D. Le , Amadon A.
Published: August 2008

A new pulse technique for counteracting RF inhomogeneity at high fields is reported. The pulses make use of the detailed knowledge of the voxels' B1 and B0 amplitude 2D histogram to generate, through an optimization procedure, gates where the flip angle is made uniform. Although most approaches to date require the use of parallel transmission, this method does not and therefore offers several advantages. The data necessary for the algorithm to determine an irradiation scheme requires only one transmit B1 along with a B0 inhomogeneity measurement. The use of a B1 and B0 amplitude 2D histogram instead of their spatial distribution also decreases substantially the complexity of the optimization problem, allowing the algorithm to find an RF solution in less than 30 s. Finally, the optimization procedure is based on an exact calculation and does not use any linear approximation. In this article, the theory behind the method in addition to spoiled gradient echo experimental data at 3T for 3D brain imaging are reported. The images obtained yield a reduction of the standard deviation of the sine of the flip angle by a factor of up to 15 around the desired value, compared to when a standard square pulse calibrated by the scanner is used. Magn Reson Med 60:701–708, 2008. © 2008 Wiley‐Liss, Inc.
Quantitative magnetization transfer imaging using balanced SSFP
Authors: Gloor M. , Scheffler K. , Bieri O.
Published: August 2008

It is generally accepted that signal formation in balanced steady‐state free precession (bSSFP) is a simple function of relaxation times and flip angle only. This can be confirmed for fluids, but for more complex substances, magnetization transfer (MT) can lead to a considerable loss of steady‐state signal. Thus, especially in tissues, the analytical description of bSSFP requires a revision to fully take observed effects into account. In the first part of this work, an extended bSSFP signal equation is derived based on a binary spin‐bath model. Based on this new model of bSSFP signal formation, quantitative MT parameters such as the fractional pool size, corresponding magnetization exchange rates, and relaxation times can be explored. In the second part of this work, model parameters are derived in normal appearing human brain. Factors that may influence the quality of the model, such as B1 field inhomogeneities or off‐resonances, are discussed. Overall, good correspondence between parameters derived from two‐pool bSSFP and common quantitative MT models is observed. Short repetition times in combination with high signal‐to‐noise ratios make bSSFP an ideal candidate for the acquisition of high resolution isotropic quantitative MT maps, as for the human brain, within clinically feasible acquisition times. Magn Reson Med 60:691–700, 2008. © 2008 Wiley‐Liss, Inc.
Free‐breathing cine MRI
Authors: Leung Angela O. , Paterson Ian , Thompson Richard B.
Published: August 2008

Standard 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

Continuous 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

Dark 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

This 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

Current 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

In 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

The 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

Exfoliated 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

The 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

This 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

We 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

In 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

Two 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

The 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

In 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

The 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

Background

Cell 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.

Methods

Androgen–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.

Results

LNCaP 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.

Conclusions

Our 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

We 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)
Silicon carbide nanowires: chemical characterization and morphology investigations
Authors: Busiakiewicz A. , Huczko A. , Lange H. , Kowalczyk P. J. , Rogala M. , Kozłowski W. , Klusek Z. , Olejniczak W. , Polan’︁ski K. , Cudziło S.
Published: August 2008

Silicon carbide nanowires (SiCNWs) were efficiently obtained via self‐combustion high‐temperature synthesis (SHS) route from silicon‐bearing/poly(tetrafluoroethylene) (PTFE) mixtures. The SEM and AFM studies were carried out to find out the lengths and diameters of the nanowires (20‐100 nm dia. and several microns in length). XPS was used to investigate the chemical composition of the nanowires. These studies showed that the SiCNWs are N‐doped. The ARXPS results revealed that outer regions of the nanowires are C‐rich. These results along with a low resistance of the nanowires suggest that nitrogen dopant and the carbon rich surface are responsible for good conducting properties of SiCNWs. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Suppression of long ranged coupling between magnetic atoms on carbon nanotubes
Authors: Kirwan D. F. , Rocha C. G. , Costa A. T. , Ferreira M. S.
Published: August 2008

Indirect exchange coupling plays a central role in determining the magnetic order in systems composed of adsorbed magnetic moments on a metallic host. For low dimensional metallic structures, such as nanotubes, this interaction is predicted to decay slowly. Ab‐initio calculations have nevertheless been unable to reproduce this prediction. We show that for Armchair and Zigzag Nanotubes the rate of decay is very sensitive to the location of the impurities within the nanotube host, the range being much shorter when the impurities are located in the centre of a nanotube hexagon. This explains the difficulty in probing the long range character of the indirect exchange coupling from standard ab‐initio calculations. In so doing, we confirm the general long‐ranged character of the coupling but provide a condition for observing shorter range decay. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The electronic band structure of fullerene‐cubane cocrystals
Authors: Zólyomi V. , Koltai J. , Kürti J. , Pekker S.
Published: August 2008

We present a first principles study of the electronic band structure of fullerene‐cubane (C60C8H8) cocrystals, using density functional theory at the local density approximation level. The band structure is calculated along high symmetry lines and compared to that of the fcc fullerene. A contraction of the fullerene bands is found and is attributed to the expansion of the lattice caused by the presence of cubane. Charge transfer between the components of C60C8H8is also calculated by Bader charge analysis. The possibility of a very small charge transfer between the cubane and the fullerene is discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the graphitisation role of oxide supports in carbon nanotube CVD synthesis
Authors: Rümmeli M. H. , Schäffel F. , Arcos T. de los , Haberer D. , Bachmatiuk A. , Kramberger C. , Ayala P. , Borowiak‐Palen E. , Adebimpe D. , Gemming T. , Leonhardt A. , Rellinghaus B. , Schultz L. , Pichler T. , Büchner B.
Published: August 2008

In this contribution we present various data from CNT grown from supported catalysts. The observed data are in agreement with the catalyst volume to surface area model developed for floating catalysts and which predicts a direct CNT diameter and number of wall dependence on the catalyst size. Further, our studies point to the root of a CNT lying at the support rather than the catalyst. Additional supporting studies point to oxygen playing a critical role in the growth of CNT, viz. the CNT can grow from an oxide support rather than the catalyst. In this scenario the catalysts role is twofold; to precipitate carbon from the catalyst–carbon eutectic upon supersaturation and thus form the embryonic caps and to form circular defect sites at its circumference on the oxide support. These circular defect sites enable continued CNT growth directly from the support. Our findings point to catalytic processes very reminiscent of many other heterogeneous catalytic processes. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Controllable electromagnetic response of onion‐like carbon based materials
Authors: Kuznetsov Vladimir , Moseenkov Sergey , Ischenko Arkady , Romanenko Anatoly , Buryakov Timofey , Anikeeva Olga , Maksimenko Sergey , Kuzhir Polina , Bychanok Dmitriy , Gusinski Aleksander , Ruhavets Olga , Shenderova Olga , Lambin Philippe
Published: August 2008

Here we discussed electromagnetic response of onion‐like carbon (OLC) powders with variable ratio of decreasing in size diamond core and defective curved graphitic shells (sp2/sp3 nanocomposites) in Ka‐band (26‐37 GHz) band. sp2/sp3 ratio in OLC was regulated by increasing of annealing temperature of explosive nanodiamond (ND) using as initial product. The observed one dimensional variable range hopping conductivity (4‐300 K) combined with HR TEM data was attributed to the formation of variable length ribbon‐like defective graphene scales. The increase of ND annealing temperature results in the increase of density states of conductive electrons and corresponding increase of conductivity of OLC produced. The increase of conductivity of OLC provides the increase of EM wave attenuation ability along with light increase of reflecting ability. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Current filamentation and negative differential resistance in C60 diodes
Authors: Stadler Philipp , Hesser Günther , Fromherz Thomas , Matt Gebhard J. , Neugebauer Helmut , Sariciftci Serdar N.
Published: August 2008

Current‐Voltage (IV) measurements of C60 thin film diodes in the temperature range of 300–4.2 K are presented. The fullerene diodes exhibit space charge limited currents as well as reversible voltage instabilities (S‐shape IV characteristics) at temperatures below 200 K and at high current densities. The instabilities are similar to certain charge transport effects in amorphous inorganic semiconductors, which are explained by injection of holes and electrons at the same time and charge trapping near the electrodes. Beyond certain current densities conductive filaments in the fullerene bulk phase are formed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Methane elimination from n‐pentane
Authors: Tsyshevsky Roman V. , Garifzianova Guzel G. , Shamov Alexander G. , Khrapkovskii Grigorii M.
Published: August 2008

The quantum chemical calculations at the different levels of theory were performed with the target being to determine the vibration frequencies and to estimate the barriers to internal rotations of n‐pentane molecules. In connection with the observed losses of CH3 and CH4 from the n‐pentane in gas phase, the calculations at the B3LYP level of theory with the 6‐31G(d) basis set were used to study the ground‐state potential energy surface of the n‐pentane. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Position‐dependent mass Schrödinger equations allowing harmonic oscillator (HO) eigenvalues
Authors: Peña J. J. , Ovando G. , Morales J. , GarcÍa‐Ravelo J. , Pacheco‐García C.
Published: August 2008

Quantum chemical systems with a position‐dependent mass have attracted the attention due to their relevance in describing the features of many microstructures of current interest. In this work, the point canonical transformation method applied to Schrödinger equations with a position‐dependent mass (SEPDM) is presented. Essentially, the proposal is aimed to transform the Schrödinger equation with a position‐dependent mass into a standard Schrödinger‐like equation for constant mass in such a way that the position‐dependent mass distribution (PDMD) becomes incorporated into the effective potential. As an useful application of the proposal, it is considered as effective potential the one‐dimensional harmonic oscillator potential model, which leads to those isospectral potentials related to different forms of PDMD. For example, the exactly solvable isospectral potentials involved in the SEPDM for some PDMD such as , , , , , xα, and , are worked out explicitly including their raising and lowering operators that factorize the SEPDM for each PDMD allowing HO eigenvalues. However, the proposal is general and can be straightforwardly applied to other effective potential models as well as other PDMD that could be useful in quantum chemical applications. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
First‐principles simulations of chiral double‐wall carbon nanotubes
Authors: Jayasekera Thushari , Landis B. A. , Mintmire J. W.
Published: August 2008

We discuss the use of helical symmetry to carry out first‐principles band structure calculations of double‐wall carbon nanotubes (DWNTs). While several first‐principles calculations have been carried out for double‐wall armchair nanotubes using translational symmetry since the early work by Charlier and Michenaud in 1993, few calculations have been carried out for double‐wall carbon nanotubes containing chiral single‐wall nanotubes. The use of helical symmetry reduces the size of the unit cell, and consequently reduces the computational difficulty of calculating the electronic structure of chiral DWNTs. Calculations carried out for a range of interlayer separations show a minimum cohesive energy around 0.35 nm as expected from experimental results. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Team AnnieWAY's autonomous system for the 2007 DARPA Urban Challenge
Authors: Kammel Sören , Ziegler Julius , Pitzer Benjamin , Werling Moritz , Gindele Tobias , Jagzent Daniel , Schröder Joachim , Thuy Michael , Goebl Matthias , Hundelshausen Felix von , Pink Oliver , Frese Christian , Stiller Christoph
Published: August 2008

This paper reports on AnnieWAY, an autonomous vehicle that is capable of driving through urban scenarios and that successfully entered the finals of the 2007 DARPA Urban Challenge competition. After describing the main challenges imposed and the major hardware components, we outline the underlying software structure and focus on selected algorithms. Environmental perception mainly relies on a recent laser scanner that delivers both range and reflectivity measurements. Whereas range measurements are used to provide three‐dimensional scene geometry, measuring reflectivity allows for robust lane marker detection. Mission and maneuver planning is conducted using a hierarchical state machine that generates behavior in accordance with California traffic laws. We conclude with a report of the results achieved during the competition. © 2008 Wiley Periodicals, Inc.
Caroline: An autonomously driving vehicle for urban environments
Authors: Rauskolb Fred W. , Berger Kai , Lipski Christian , Magnor Marcus , Cornelsen Karsten , Effertz Jan , Form Thomas , Graefe Fabian , Ohl Sebastian , Schumacher Walter , Wille Jörn‐Marten , Hecker Peter , Nothdurft Tobias , Doering Michael , Homeier Kai , Morgenroth Johannes , Wolf Lars , Basarke Christian , Berger Christian , Gülke Tim , Klose Felix , Rumpe Bernhard
Published: August 2008

The 2007 DARPA Urban Challenge afforded the golden opportunity for the Technische Universität Braunschweig to demonstrate its abilities to develop an autonomously driving vehicle to compete with the world's best. After several stages of qualification, our team CarOLO qualified early for the DARPA Urban Challenge Final Event and was among only 11 teams from initially 89 competitors to compete in the final. We had the ability to work together in a large group of experts, each contributing his expertise in his discipline, and significant organizational, financial, and technical support by local sponsors, who helped us to become the best non‐U.S. team. In this report, we describe the 2007 DARPA Urban Challenge, our contribution, “Caroline,” the technology, and algorithms, along with her performance in the DARPA Urban Challenge Final Event on November 3, 2007. © 2008 Wiley Periodicals, Inc.
Junior: The Stanford entry in the Urban Challenge
Authors: Montemerlo Michael , Becker Jan , Bhat Suhrid , Dahlkamp Hendrik , Dolgov Dmitri , Ettinger Scott , Haehnel Dirk , Hilden Tim , Hoffmann Gabe , Huhnke Burkhard , Johnston Doug , Klumpp Stefan , Langer Dirk , Levandowski Anthony , Levinson Jesse , Marcil Julien , Orenstein David , Paefgen Johannes , Penny Isaac , Petrovskaya Anna , Pflueger Mike , Stanek Ganymed , Stavens David , Vogt Antone , Thrun Sebastian
Published: August 2008

This article presents the architecture of Junior, a robotic vehicle capable of navigating urban environments autonomously. In doing so, the vehicle is able to select its own routes, perceive and interact with other traffic, and execute various urban driving skills including lane changes, U‐turns, parking, and merging into moving traffic. The vehicle successfully finished and won second place in the DARPA Urban Challenge, a robot competition organized by the U.S. Government. © 2008 Wiley Periodicals, Inc.
Little Ben: The Ben Franklin Racing Team's entry in the 2007 DARPA Urban Challenge
Authors: Bohren Jonathan , Foote Tully , Keller Jim , Kushleyev Alex , Lee Daniel , Stewart Alex , Vernaza Paul , Derenick Jason , Spletzer John , Satterfield Brian
Published: August 2008

This paper describes “Little Ben,” an autonomous ground vehicle constructed by the Ben Franklin Racing Team for the 2007 DARPA Urban Challenge in under a year and for less than $250,000. The sensing, planning, navigation, and actuation systems for Little Ben were carefully designed to meet the performance demands required of an autonomous vehicle traveling in an uncertain urban environment. We incorporated an array of a global positioning system (GPS)/inertial navigation system, LIDARs, and stereo cameras to provide timely information about the surrounding environment at the appropriate ranges. This sensor information was integrated into a dynamic map that could robustly handle GPS dropouts and errors. Our planning algorithms consisted of a high‐level mission planner that used information from the provided route network definition and mission data files to select routes, whereas the lower level planner used the latest dynamic map information to optimize a feasible trajectory to the next waypoint. The vehicle was actuated by a cost‐based controller that efficiently handled steering, throttle, and braking maneuvers in both forward and reverse directions. Our software modules were integrated within a hierarchical architecture that allowed rapid development and testing of the system performance. The resulting vehicle was one of six to successfully finish the Urban Challenge. © 2008 Wiley Periodicals, Inc.
The Accuracy of Sentinel Lymph Node Biopsy in the Treatment of Multicentric Invasive Breast Cancer Using a Subareolar Injection of Tracer
Authors: Cipolla Calogero , Vieni Salvatore , Fricano Salvatore , Cabibi Daniela , Graceffa Giuseppa , Costa Renato , Latteri Stefania , Latteri Mario A.
Published: August 2008

Background

The aim of this study was to evaluate the feasibility and the accuracy of sentinel lymph node biopsy in multicentric breast cancer (MBC) performed by means of a subareolar (SA) injection of both 99Tc‐labeled human albumin colloid and lymphazurin.

Methods

Between January 2002 and October 2007, 34 patients with MBC with clinically negative axilla underwent sentinel lymph node biopsy (SLNB) followed by total axillary node dissection (AD). Overall successful identification rate of SLN was 100%; there were no false negatives and overall accuracy rate was 100%.

Results

The mean number of sentinel lymph nodes (SLNs) identified was 1.8 ± 0.88 (range = 1–4); the mean number of axillary lymph nodes examined was 21.4 ± 5.76 (range = 8–36).

Conclusions

The authors conclude that SA injection of the tracer is feasible and efficacious in the identification of the SLN. The accuracy of SLNB in MBC is comparable to that obtained in unifocal disease.
Photosynthetic response to dynamic changes of light and air humidity in two moss species from the Tibetan Plateau
Authors: Cui Xiaoyong , Gu Song , Wu Jing , Tang Yanhong
Published: August 2008

Bryophytes are widely distributed in alpine meadow and wetlands on the Tibetan Plateau, where light intensity and air moisture are highly variable in time. To address how bryophytes respond to their light and moisture environments, we examined dynamic photosynthesis in two moss species,Distichium inclinatumcommon in meadow, andEncalypta alpinefrequently found in wetland. Photosynthetic induction response was faster in the two moss species than in most vascular species. In both species the 90% induction time after a sudden light increase from 50 to 600 μmol m−2s−1was within 3 min. The induction was faster in mosses experiencing a period of weak light than in those in total darkness.E. alpina, the wetland species, showed more rapid induction response and shorter post‐illumination CO2fixation to sunflecks thanD. inclinatum, the meadow species. Photosynthetic rate (Amax) under saturated light in the two species increased linearly with increasing air relative humidity (RH). The meadow speciesD. inclinatumshowed higherAmaxunder low RHs, but exhibited lowerAmaxunder high RHs in comparison with the wetland mossE. alpina. Moreover, the quantum efficiency increased linearly with increasing RH, indicating that air humidity plays a critical role in photochemical activities in the alpine mosses. The study suggests that there are acclimations in dynamic photosynthesis in response to light and humidity, and the acclimations would benefit a high leaf carbon gain in the two alpine moss species in their common habitats.