bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional abnormalities in the primary orofacial sensorimotor cortex during speech in Parkinson's disease
Authors: Rektorova Irena , Barrett Jennifer , Mikl Michal , Rektor Ivan , Paus Tomas 
Published: August 2007

AbstractParkinson's disease (PD) affects speech, including respiration, phonation, and articulation. We measured the blood oxygen level‐dependent (BOLD) response to overt sentence reading in: (1) 9 treated female patients with mild to moderate PD (age; mean 66.0 ± 11.6 years, mean levodopa equivalent 583.3 ± 397.9 mg) and (2) 8 age‐matched healthy female controls (age; mean 62.2 years ± 12.3). Speech was recorded in the scanner to assess which brain regions underlie variations in the initiation and paralinguistic aspects (e.g., pitch, loudness, and rate) of speech production in the two groups. There were no differences in paralinguistic aspects of speech except for speech loudness; it was lower in PD patients compared with that in controls, when age was used as a covariate. In both groups, we observed increases in the BOLD response (reading‐baseline) in brain regions involved in speech production and perception. In PD patients, as compared with controls, we found significantly higher BOLD signal in the right primary orofacial sensorimotor cortex and more robust correlations between the measured speech parameters and the BOLD response to reading, particularly, in the left primary orofacial sensorimotor cortex. These results might reflect compensatory mechanisms and/or treatment effects that take place in mild to moderately ill PD patients with quality of speech yet comparable with that of age‐matched controls. © 2007 Movement Disorder Society
High‐resolution magic‐angle spinning NMR for the identification of reaction products directly from thin‐layer chromatography spots
Authors: Bradley Scott A. , McLaughlin Rebekah L. 
Published: August 2007

AbstractWe have investigated the prospect of identifying organic reaction products directly from separated thin‐layer chromatography (TLC) spots with high‐resolution magic‐angle spinning (HRMAS) NMR. The concept is to use the TLC spots for NMR analysis so that spectra can be obtained before the reaction is worked up, but without having to elute the product from the TLC stationary phase. Thus, the separated spot is scraped from the plate, transferred to an HRMAS sample rotor, and suspended with a deuterated solvent. Herein, we describe the effects of having the stationary phase present during NMR acquisition. Using a Varian 4 mm gHX Nanoprobe and rotenone as a test compound, we found that the presence of the stationary phase during NMR acquisition resulted in (i) a large, broad ‘background’ signal near 4.6 ppm and (ii) a decrease in the signal‐to‐noise ratio due to the adsorption of the product molecules to the adsorbent. However, both effects could be adequately and conveniently eliminated. The background signal was removed by using either a CPMG pulse sequence or chemical exchange. The adsorption was avoided by using a more polar solvent system. Finally, we found that spectra with good signal‐to‐noise ratio and resolution could be acquired in a matter of minutes even for cases of limited product concentration. Therefore, we believe the technique has value and provides the organic chemist with another option to obtain NMR data critical for structural elucidation or verification. Copyright © 2007 John Wiley & Sons, Ltd.
A heuristic cross‐layer mechanism for real‐time traffic over IEEE 802.16 networks
Authors: Triantafyllopoulou Dionysia , Passas Nikos , Salkintzis Apostolis K. , Kaloxylos Alexandros 
Published: August 2007

AbstractIn this paper we propose and study a cross‐layer mechanism that can improve real‐time QoS provisioning over IEEE 802.16 metropolitan area networks. This mechanism utilizes information provided by the physical and MAC layers and using a heuristic algorithm it derives new operational parameters for the physical and application layers, which can improve the performance of real‐time applications. The main idea is to coordinate the adaptive modulation capability of the physical layer and the multi‐rate data‐encoding capability of modern real‐time applications in order to avoid inefficiencies caused by their independent operation. Simulations show that the proposed mechanism can assist 802.16 systems to better adapt to frequent channel and traffic changes, leading to considerably reduced packet loss rates, especially under heavy traffic conditions. Copyright © 2007 John Wiley & Sons, Ltd.
Thermoplastic elastomer based on high‐density polyethylene/natural rubber blends: rheological, thermal, and morphological properties
Authors: Nakason C. , Jamjinno S. , Kaesaman A. , Kiatkamjornwong S. 
Published: August 2007

AbstractThermoplastic elastomer (TPE) comprising air‐dried sheet or natural rubber (ADS or NR) and high‐density polyethylene (HDPE) was prepared by a simple blending technique. NR and HDPE were mixed with each type of phenolic compatibilizer (HRJ‐10518 or SP‐1045) or liquid natural rubber (LNR) at 180°C in an internal mixer. The mixing torque, shear stress, and shear viscosity of the blends increased with increasing amounts of NR. Positive deviation blend (PDB) for the blends containing active hydroxyl methyl phenolic resin in HRJ‐10518 or dimethyl phenolic resin in SP‐1045 was obtained. PDB was not observed for the blends without the compatibilizers or with LNR. The blends with HRJ‐10518 or SP‐1045 were compatible or partially compatible while the LNR blends were incompatible. In the phenolic compatibilized blends, NR dispersed in the HDPE matrix was found in the NR/HDPE blends of 20/80, 40/60, and 50/50 ratios. HDPE dispersed in NR matrix was obtained in the NR/HDPE blend of 80/20 ratio, and the co‐continuous phase was accomplished in the NR/HDPE blend of 60/40 ratio. The NR/HDPE blend at 60/40 ratio compatibilized with HRJ‐10518 and fabricated by a simple plastic injection molding machine exhibited higher ultimate tensile strength and elongation at break (EB). Incorporation of parafinic oil caused a decreasing tendency in tensile strength with increases in EB. The TPNRs exhibited high elastomeric nature with low‐tension set. Copyright © 2007 John Wiley & Sons, Ltd.
Preparation and mechanical properties of poly(chitosan‐g‐DL‐lactic acid) fibrous mesh scaffolds
Authors: Wan Ying , Cao Xiaoying , Wu Quan , Zhang Shengmin , Wang Sheng 
Published: August 2007

AbstractDL‐lactic acid was grafted onto chitosan to produce poly(chitosan‐g‐DL‐lactic acid)(PCLA) without using a catalyst. These PCLAs were then spun into filaments and further fabricated into fibrous mesh scaffolds using an improved wet‐spinning technique. The diameter of filaments in different scaffolds could vary from a few micrometers to several tens of micrometers. The scaffolds exhibited various pore sizes ranging from about 20 µm to more than 200 µm and different porosities up to 80%. The several main processing conditions were optimized for obtaining the desired scaffolds with well‐controlled structures. The tensile and compressive mechanical properties of the mesh scaffolds in both dry and hydrated states were mainly examined. Significantly improved tensile strength and modulus, enhanced compressive modulus, and stress as well as the dimensional stability for these mesh scaffolds in their hydrated state were observed. Copyright © 2007 John Wiley & Sons, Ltd.
Sarcomas: genetics, signalling, and cellular origins. Part 1: The fellowship of TET
Authors: Riggi N , Cironi L , Suvà M‐L , Stamenkovic I 
Published: August 2007

AbstractSarcomas comprise some of the most aggressive solid tumours that, for the most part, respond poorly to chemo‐ and radiation therapy and are associated with a sombre prognosis when surgical removal cannot be performed or is incomplete. Partly because of their lower frequency, sarcomas have not been studied as intensively as carcinomas and haematopoietic malignancies, and the molecular mechanisms that underlie their pathogenesis are only beginning to be understood. Even more enigmatic is the identity of the primary cells from which these tumours originate. Over the past 25 years, however, several non‐random chromosomal translocations have been found to be associated with defined sarcomas. Each of these translocations generates a fusion gene believed to be directly related to the pathogenesis of the sarcoma in which it is expressed. The corresponding fusion proteins provide a unique tool not only to study the process of sarcoma development, but also to identify cells that are permissive for their putative oncogenic properties. This is the first of two reviews that cover the mechanisms whereby specific fusion/mutant gene products participate in sarcoma development and the cellular context that may provide the necessary permissiveness for their expression and oncogenicity. Part 1 of the review focuses on sarcomas that express fusion genes containing TET gene family products, including EWSR1, TLS/FUS, and TAFII68. Part 2 (J Pathol 2007; DOI: 10.1002/path.2008) summarizes our current understanding of the genetic and cellular origins of sarcomas expressing fusion genes exclusive of TET family members; it also covers soft tissue malignancies harbouring specific mutations in RTK‐encoding genes, the prototype of which are gastrointestinal stromal tumours (GIST). Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
N‐(3,5‐Di‐tert‐butylsalicylidene)‐4‐iodobenzene, a peculiar case of a nonlinear optical photoswitch
Authors: Spangenberg Arnaud , Sliwa Michel , Métivier Rémi , Dagnélie Romain , Brosseau Arnaud , Nakatani Keitaro , Pansu Robert , Malfant Isabelle 
Published: August 2007

AbstractN‐(3,5‐Di‐tert‐butylsalicylidene)‐4‐iodobenzene (1) is photochromic in the solid state, owing to its ability to yield enol–keto tautomerism. Despite its centrosymmetric structure (P21/c), polycrystalline thin films of 1 show second harmonic generation (SHG). Moreover, this SHG can be reversibly switched by light. Investigations using confocal microscopy showed that a morphology change occurs when the fundamental beam of a Ti:sapphire (990 nm, 1.3 ps) is focused on the material, yielding an SHG‐active solid. Copyright © 2007 John Wiley & Sons, Ltd.
Isothermal crystallization kinetics and spherulitic morphology of poly(4‐hydroxybutyric acid‐alt‐glycolic acid)
Authors: Martínez‐Palau Meritxell , Franco Lourdes , Puiggalí Jordi , Ungar Goran 
Published: August 2007

AbstractIsothermal crystallization behavior of a new regular polyester constituted by glycolic acid and 4‐hydroxybutyric acid units is studied by means of differential scanning calorimetry and hot‐stage optical microscopy. A wide range of crystallization conditions were experimentally accessible, allowing various morphological features to be observed and accurate estimates made of characteristic growth parameters, including radial growth and nucleation rates. Three‐dimensional spherulitic growth from heterogeneous nuclei is deduced from the Avrami analysis, whereas optical micrographs reveal two different spherulitic textures that agree with the existence of two crystallization regimes. These can be well distinguished from the breaks observed in the Lauritzen and Hoffman plots when the linear crystal growth rate or the overall crystallization rate is considered. Ringed and nonringed spherulites with negative and positive birefringence, respectively, can be obtained depending on crystallization conditions and regimes. The studied polyester shows rather complex melting behavior which is interpreted in terms of a recrystallization process involving the two different kinds of spherulites. This study allows polymorphism to be discounted. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2640–2653, 2007
Identification of patients with low‐risk for aneuploidy: Comparative discriminatory models using linear and machine‐learning classifiers in prostate cancer
Authors: Venkataraman Girish , Heinze Georg , Holmes Earle W. , Ananthanarayanan Vijayalakshmi , Bostwick David G. , Paner Gladell P. , Bradford‐De La garza Carrie M. , Brown Henry G. , Flanigan Robert C. , Wojcik Eva M. 
Published: August 2007

AbstractBACKGROUNDProstate needle biopsy (PNB) ploidy status has proven utility to predict adverse outcomes after prostatectomy. We sought to develop models to predict ploidy status using clinicopathologic variables.METHODSWe identified a cohort of 169 patients with a diagnosis of prostatic adenocarcinoma on PNB, and estimated ploidy status (determined using Feulgen stained biopsy tissue) using four predictors, including age, prebiopsy PSA, highest Gleason score (GS), and the percentage of involvement by carcinoma at the biopsy site with the highest GS (PCARBX). Logistic regression (LR), Neural Network (NN), and CART classifiers were constructed.RESULTSUnivariate analyses revealed all four predictors to be significantly associated with ploidy status. On multivariable analyses, LR identified a 2‐parameter model, including GS and PCARBX that had a significant ability to predict ploidy status with a 74% and 75% correct classification rate (CCR), respectively. Using the same variables, CART and NN yielded similar CCRs of 70.4%. Within GS = 6 cohort, the CART model classified over 90% of biopsies as diploid when patients had a PCARBX < 55% and a log(PSA) < 1.7.CONCLUSIONSOur study demonstrates that models using GS and PCARBX are able to predict PNB ploidy status with acceptable accuracy. While machine learning classifier‐derived models yield similar accuracy as LR‐derived models, the latter methodology has the distinct advantage of being applicable in future datasets to estimate case‐specific predictions. This information may be useful in identifying potentially aneuploid patients, who can then be targeted for more aggressive therapy. Prostate 67: 1524–1536, 2007. © 2007 Wiley‐Liss, Inc.
The evaluation of risks of ethoxylation reactors
Authors: Salzano Ernesto , Di Serio Martino , Santacesaria Elio 
Published: August 2007

AbstractAlkoxylations are commonly performed in industry for the production of surfactants and polyglycols by means of a simple semi‐batch liquid‐stirred reactor. More recent processes use semi‐batch Venturi Loop Reactors (VCR) or Spray Tower Loop Reactors (SLR), where liquid phase is dispersed into the gaseous oxides through recirculation loops. In this article, a risk analysis is made on the recirculation loops to compare these three reactor types. More specifically, the analysis of consequences for the ethoxylation of dodecanol with different ethylene oxide partial pressures and process temperatures are studied. The atmospheric wind velocity was varied for a range of releases from the recirculation loop or from small releases from flanges and valves along the same pipeline.This article shows that the risks of the VLR and SLR are lower than the semi‐batch reactor. The higher risks for recirculation loops are only related to toxicity in the proximity of reactor.Explosions give high overpressures only in the case of near‐instantaneous releases of the reactor contents (large releases).Although this analysis was specifically made for alkoxylation reactors, the methods and conclusions can also be used for comparing the risks of other semi‐batch reactors to loop reactors. © 2007 American Institute of Chemical Engineers Process Saf Prog 26, 2007
Multivariate explanation of the 1985–1990 and 1995–2000 destination choices of newly arrived immigrants in the United States: the beginning of a new trend?
Authors: Liaw Kao‐Lee , Frey William H. 
Published: August 2007

AbstractOn page 11, one sentence was deleted in error. The paragraphs should have read as follows:(.  .  .) We assume that most of the individuals in the first term retired as a consequence of entering into the 65–69 age group in 1985–1990. For each state as a potential destination for the 1995–2000 new immigrants, this place attribute was computed from the 2000 Census data in an analogous way.In light of the possibility that the destination choice behaviours of the new immigrants might be affected by the severity of winter, we specify the following climatic factor.ColdnessFor each state, this variable was defined as a weighted average of the heating degree‐days of cities with records from 1951 to 1980, using city populations as the weights. The unit was 1000 degree (F)‐days.This error will be corrected prior to print publication.The publishers apologise for this error, and any inconvenience it may have caused.
First‐principles study on electronic structures and absorption bands of CaWO4 crystals with interstitial oxygen atoms
Authors: Ze‐Xu Shao , Qi‐Ren Zhang , Ting‐Yu Liu , Jian‐Yu Chen 
Published: August 2007

AbstractThe electronic structures of CaWO4 crystals with interstitial oxygen atoms are studied within the framework of the fully relativistic self‐consistent Dirac–Slater theory, using a numerically discrete variation (DV‐Xα) method. It is concluded by the calculation that interstitial oxygen atoms combine with two formal lattice oxygen ions forming oxygen molecular ions, which exhibits donor energy level locating in the forbidden bands. The optical transition energy is 3.85 eV, which correspond to the 324 nm absorption bands. It is predicted that the 324 nm absorption bands originate from the interstitial oxygen in CaWO4 crystals. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Defects in diamond
Authors: Dannefaer S. 
Published: August 2007

AbstractDiamond is one of the remarkable forms of carbon. For example, it can be found in nature with an impurity content of less than 1 ppm, or it can be synthesized either as a single‐crystal or as a polycrystalline deposit on various surfaces. Furthermore, boron doping makes it a p‐type semiconductor, and even superconducting. Diamond is also one of the few materials where optical absorption (OA) yields relevant information on defects, including the omnipresent nitrogen impurity. This is so because in diamond many defects have sharp zero‐phonon lines. Irradiation produces vacancies and interstitials both of which have been identified by OA and electron paramagnetic resonance, and also by positron annihilation (vacancy only). Irradiation‐produced defects are remarkable stable, with the monovacancy becoming mobile at 700 °C, and the divacancy surviving to at least 1000 °C. In this contribution are reviewed relevant aspects of diamond physics and what positron annihilation has contributed so far. Diamond provides the opportunity for a correlation between optical absorption and positron results, including the difficult issue of the electrical charge of a defect. Such combined experiments are presently searching for the elusive positively charged monovacancy in irradiated B doped single crystalline diamond. Future positron experiments could with benefit be aimed at investigating vacancy impurity complexes, such as the one claimed by OA as a four nitrogen‐vacancy complex. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature dependence of positronium lifetime in cylindrical pores
Authors: Zaleski R. , Goworek J. , Kierys A. 
Published: August 2007

AbstractPositron Annihilation Lifetime Spectroscopy (PALS) results for ordered mesoporous silica sieves (MCM‐41 and its fibre form MSF) are used to verify predictions of the Extended Tao‐Eldrup (ETE) model. Cylindrical pores (R ∼ 1–2 nm) in these materials have well defined geometry and size, thus the structure of MCM‐41 and MSF reproduces the model assumptions. Positron lifetimes were measured in the range 100‐500K. In MCM‐41, due to low intensity of pore related ortho‐positronium component, it is difficult to determine the component's lifetime precisely. Accuracy of the lifetime fitting is better for MSF, where temperature dependence is in a good agreement with the ETE model results. For comparison, the ETE model predictions fit the lifetime of the pore related component in the Vycor sample only for T > 200 K. Below this value the lifetime exceeds the model predictions by over 30%. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of the chemical vicinity of open volume defects in magnesium and AZ31 with coincident Doppler broadening spectroscopy
Authors: Stadlbauer M. , Hugenschmidt C. , Schreckenbach K. 
Published: August 2007

AbstractMagnesium alloys experience an increasing interest for industrial applications due to their low specific weight, high elasticity and mechanical strength. For the high performance of these materials a homogeneous distribution of the alloy constituents is required. Therefore it is of great interest to investigate the behaviour of the elemental distribution in the vicinity of open volume defects. In order to investigate the influence of defects and their chemical surrounding, polished and annealed samples of pure magnesium and the alloy AZ31 (3 wt.% Al and 1 wt.% Zn) were irradiated with Zn, Al and Mg ions respectively. The energy of the ions was chosen between 1.4 MeV and 3.0 MeV according to 2.3 µm mean implantation depth. First, Doppler‐broadening measurements as a function of the positron implantation energy as well as lateral position with a resolution of 2 mm were recorded in order to image the irradiated area on the sample. Secondly, coincident Doppler‐broadening spectra were measured at different positron penetration depths according to the Makhovian profile, which clearly show strong deviations depending on the ion type of the irradiated samples. The relation between elemental signature and defect concentration in the sample is discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Density change of ion irradiated polystyrene studied by positron annihilation and SAICAS
Authors: Saito F. , Fujii Y. , Nagashima Y. , Yotoriyama T. , Nakao A. , Suzuki Y. , Iwaki M. , Nishiyama I. , Hyodo T. 
Published: August 2007

AbstractIon‐irradiated polystyrene was investigated using positron annihilation DBS, AFM and SAICAS. SAICAS revealed effective crosslink formation and molecular chain scission. Due to efective crooslink formation, the subsidence of the surface hardly produced as shown in the AFM image. From positron annilation and SAICAS, the density of the irradiated layer was estimated to be 0.8 and 0.6 g/cm3 for the ion irradiation of fluence 5×1015 and 1×1016 ions/cm2, respectively, while the density of the as received sample was 1.02 g/cm3. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
First positron flux measurements at the Argonne Positron Source (APosS)
Authors: Chemerisov Sergey , Jonah Charles D. , Jean Y. C. , Chen Hongmin , Schrader David , Hunt Alan W. 
Published: August 2007

AbstractThe development of the APosS at the Argonne low‐energy linac is discussed. We measured the yields and outline strategies to increase the number of slow positrons. We describe the measurement of the yield of slow positrons as a function of electron‐beam energy and compare these results with theoretical calculations. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ejection of electrons and positrons in collisions of positronium with atoms
Authors: Starrett C. , Walters H. R. J. 
Published: August 2007

AbstractWe discuss the observation of electrons and positrons ejected in collisions of positronium with atomic targets. We consider processes in which the target is excited or ionized or where the observed electron is ejected from the target rather than from the positronium. Example calculations based upon the impulse approximation and the first Born approximation are presented for total ionization cross sections, cross sections differential in the longitudinal energy of the ejected particle, and double differential cross sections in the energy and angle of the ejectile. Comparison is made with experimental data where available. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)