bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lamb Wave Interactions with Non‐symmetric Features at Structural Boundaries
Authors: Mofakhami M. R. , Boller C. 
Published: March 2009

AbstractThe paper initially describes on a numerical basis how a Lamb wave would have to perform that has been initiated in a pure mode (either symmetric or anti–symmetric) and what the wave would have to anticipate in terms of mode conversion when being reflected at a surface not perpendicular to its traveling direction. The effects of changing in geometric specifications of non–symmetric artificial features like angle of sloping edge or partially sloping edges are studied. The results obtained from these studies are presented as the reflected and converted parts of the incident wave versus angle of the edge or percentage of the sloped edge. It has been further shown that Lamb waves being generated experimentally by a finite size transducer into a plate like structure thus most likely result in a combination of modes. Reflection of these combined modes at structural boundaries will therefore generate an even more complex coupling of modes. This situation is further aggravated if the structural boundary is not purely perpendicular to the traveling wave but has a slightly varying angle such as it might have to be anticipated at a countersunk rivet, a notch or even more extreme a crack in a metallic component. However from understanding the background of Lamb wave generation, mode separation and superposition, a systematic approach can be established that allows complex Lamb waves, such as they are observed when monitoring true structures, to be interpreted and understood. This approach has been explained on the basis of numerical result obtained from finite element analyses first before proving the findings by some fundamental experiments performed with variable angle beam transducers which demonstrates the difficulties in de–coupling Lamb wave modes and how to handle those coupled modes in terms of structural condition monitoring. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fear of cancer progression and cancer‐related intrusive cognitions in breast cancer survivors
Authors: Mehnert Anja , Berg Petra , Henrich Gerhard , Herschbach Peter 
Published: March 2009

AbstractObjective: To assess the character and frequency of fear of progression (FoP) and to clarify its relationship with cancer‐related intrusive cognitions in breast cancer survivors.Methods: A sample of 1083 patients was recruited in this cross‐sectional study through a population‐based Cancer Registry an average of 47 month following diagnosis (66% response rate). Participants completed self‐report measures assessing fear of cancer progression (FoP‐Q‐SF), posttraumatic stress‐disorder symptoms (PCL‐C), coping strategies (DWI) and quality of life (QoL) (SF‐8).Results: In total, 23.6% of women were classified as having moderate to high FoP. Being nervous prior to doctors' appointments or examinations and being afraid of relying on strangers for activities of daily living were the most frequent fears. FoP was significantly associated with younger age, having children, disease progress, chemotherapy, perceived amount of impairments, physical and mental QoL, but not with time since initial diagnosis. Intrusive cognitions were screened in 37% of the sample. We found significant correlations between FoP and intrusive thoughts (r=0.63), avoidance (r=0.57), hyperarousal (r=0.54) and posttraumatic stress disorder diagnosis (r=0.42). Factors significantly associated with moderate and high FoP included a depressive coping style as well as an active problem‐oriented coping style, intrusion, avoidance and hyperarousal symptoms (Nagelkerke's R2=0.44).Conclusions: Findings of this study give information regarding the frequency and the character of anxiety in breast cancer survivors and underline the relation of FoP to the reality of living with breast cancer. Results suggest that intrusive cognitions as well as avoidance and hyperarousal symptoms seem to be closely related to future‐oriented fears of cancer recurrence. Copyright © 2009 John Wiley & Sons, Ltd.
A novel communication role for CYP17A1 in the progression of castration‐resistant prostate cancer
Authors: Locke Jennifer A. , Fazli Ladan , Adomat Hans , Smyl Jil , Weins Kristin , Lubik Amy A. , Hales Dale B. , Nelson Colleen C. , Gleave Martin E. , Tomlinson Guns Emma S. 
Published: March 2009

AbstractBACKGROUNDCYP17A1 is currently a target for total androgen blockade in advanced prostate cancer (CaP) patients. After castration, or removal of testicular androgens, CYP17A1 can act as a rate‐limiting enzyme in androgen synthesis from cholesterol or other adrenal precursors within the tumor microenvironment ultimately contributing to disease progression. Herein we provide evidence that CYP17A1 could also be a mediator of cell‐to‐cell communication within the CaP tumor microenvironment.METHODSCYP17A1 expression was evaluated by immunohistochemical analysis of human tumor sections and Western blot analysis of CaP patients' serum and exosome isolates. CYP17A1 activity assays were conducted in human serum (and positive control human liver and kidney microsomes) using progesterone as a precursor and an LC‐MS endpoint.RESULTSThese studies revealed that the expression pattern of CYP17A1 is typical of a secretory protein as it is localized to the luminal pole of the cells in exocrine secretory mode. CYP17A1 is expressed in human serum and in fact is elevated in the serum of CaP patients as compared to healthy controls. Serum CYP17A1 activity could not be confirmed, however, verification of CYP17A1 expression in exosomes suggests a role in cell‐to‐cell communication within the tumor microenvironment.CONCLUSIONSCYP17A1 is a crucial enzyme for de novo androgen synthesis within the tumor microenvironment after removal of testicular androgens by castration. We provide evidence for a novel role for CYP17A1 in serum and further reiterate the importance of targeting this enzyme in CaP progression. Prostate 69: 928–937, 2009. © 2009 Wiley‐Liss, Inc.
Temperature‐dependent hard X‐ray photoemission spectra of ternary Tl compounds with high Seebeck coefficient
Authors: Mimura Kojiro , Ishizu Takahiko , Yamamoto Kazuya , Takasu Junta , Yonehira Yuri , Wakita Kazuki , Mamedov Nazim , Taguchi Yukihiro , Ichikawa Kouichi , Yan Ke , Ikenaga Eiji , Kobayashi Keisuke 
Published: March 2009

AbstractThe temperature dependence of the core‐level and valence‐band electronic structures of TlGaTe2 and TlInSe2 that exhibits high values of Seebeck coefficient has been studied by hard X‐ray photoemission spectroscopy over the temperature range 40–450 K. The relative peak position and peak width for Tl 4f, Ga 2p and Te 3d in TlGaTe2 are determined. It is shown that not only chemical shift defying the peak position but also electron‐phonon interaction responsible for temperature line‐broadening has rather peculiar temperature behaviour that reflects incommensurate phase transition. Thermoelectric power of TlGaTe2 is evaluated and found to be very close to that of TlInSe2. It is shown that Tl 4f spectra of both compounds also display close similarity (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth and magnetic properties of Mn‐doped ZnSiAs2/Si heterostructures
Authors: Kochura Aleksey , Fedorchenko Irina , Laiho Reino , Lashkul Alexander , Lähderanta Erkki , Marenkin Sergey , Zakharov Ivan 
Published: March 2009

AbstractMn‐doped ZnSiAs2/Si heterostructures were grown by vacuum‐thermal deposition of ZnAs2 and Mn layers on Si substrates followed by annealing. The surface contained a ZnSiAs2 film, but also micro‐crystals with a composition close to ZnAs2 or ZnSiAs2‐Si‐SiAs eutectic. The temperature and field dependencies of the magnetization were measured. Two types of magnetic phases were detected: a paramagnetic one with the mean magnetic moment of 7.6 Bohr magnetons, formed by Mn2+ ions, and a ferromagnetic one with Curie temperature 340 K in 50 kOe magnetic field, formed by MnAs clusters. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermally activated cation ordering in Zn0.5Mn0.5Ga2Se4 single crystals studied by Raman scattering
Authors: Alonso‐Gutiérrez P. , Sanjuán M. L. , Morón M. C. 
Published: March 2009

AbstractOrder/disorder phenomena in Zn0.5Mn0.5Ga2Se4 related to changes in the cation occupancies are studied by Raman scattering. The cation distribution can be modified by submitting the sample to a controlled heating and cooling cycle. Three different stages of order/disorder type were observed. On heating above an onset temperature of ≈250 °C, the partially disordered as‐grown material (I ‐42m space group) evolves toward an ordered configuration with I ‐4 space group. At a temperature close to 500 °C the samples undergoes an order/disorder phase transition to a partially disordered structure that maintains the ordered stoichiometric vacancies. Slow cooling across the phase transition allows the cations to equilibrate and results in an almost fully ordered cation distribution at RT. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Debye temperatures and Grueneisen parameters of chain TlSe and TlInSe2
Authors: Mamedov Nazim , Wakita Kazuki , Orudzhev Guseyn , Shim YongGu , Mimura Kojiro , Schorr Susan , Hamidov Sadig , Kishigui Koiru , Jafarova Vusala , Yamamoto Nobuyuki 
Published: March 2009

AbstractDebye temperatures and Grueneisen parameters of chain TlSe and TlInSe2 were calculated using our earlier obtained ab‐initio results on phonon band structure and existed experimental data on thermal expansion coefficient. For both compounds, the values of heat capacity at constant volume (Cv) were found to obey cubic law at temperatures less than 2 K. The Debye temperatures were determined to be 95 K and 96 K for TlSe and TInSe2, respectively. The unit cells of TlSe and TInSe2 were relaxed by minimizing Hellman‐Feynman forces and the total energy dependence on the unit cell volume was obtained. The bulk modulus (B0) values in Murnaghan and Birch‐Murnaghan equations of state were shown to be very close to each other. By using above B0 and Cv, as well as available experimental data on linear expansion, the heat capacity at constant pressure (CP) was evaluated. Comparison with experimental CP in a wide temperature range showed a good agreement for TlInSe2 and a noticeable discrepancy for TlSe at temperatures above 170 K. The calculated Grueneisen parameter of TlInSe2 showed a tendency to saturation in a region above Debye temperature. The situation with TlSe is not clear because of the ambiguous character of the available experimental data on thermal expansion. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
NMR shifts for polycyclic aromatic hydrocarbons from first‐principles
Authors: Thonhauser T. , Ceresoli Davide , Marzari Nicola 
Published: March 2009

AbstractWe present first‐principles, density‐functional theory calculations of the NMR chemical shifts for polycyclic aromatic hydrocarbons, starting with benzene and increasing sizes up to the one‐ and two‐dimensional infinite limits of graphene ribbons and sheets. Our calculations are performed using a combination of the recently developed theory of orbital magnetization in solids, and a novel approach to NMR calculations where chemical shifts are obtained from the derivative of the orbital magnetization with respect to a microscopic, localized magnetic dipole. Using these methods we study on equal footing the 1H and 13 shifts in benzene, pyrene, coronene, in naphthalene, anthracene, naphthacene, and pentacene, and finally in graphene, graphite, and an infinite graphene ribbon. Our results show very good agreement with experiments and allow us to characterize the trends for the chemical shifts as a function of system size. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Intramolecular charge‐transfer excitation energies from range‐separated hybrid functionals using the Yukawa potential
Authors: Akinaga Yoshinobu , Ten‐No Seiichiro 
Published: March 2009

AbstractValence and intramolecular charge‐transfer excitation energies of middle‐sized molecules are calculated by time‐dependent density functional theory, with the long‐range corrected hybrid functionals employing the recently developed range‐separation schemes using the Yukawa potential. The Yukawa potential allows modest mixings of the Hartree–Fock exchange over a wide range of electron–electron distance. The Yukawa variant of the Coulomb‐attenuated method (CAM) achieves comparable accuracy in using CAM‐B3LYP functional for predicting not only various types excitation energies but also atomization energies, retaining 100% of the exact exchange potential in large interelectron distances. It is demonstrated that the use of the Yukawa potential is advantageous over the conventional range‐separation schemes with the error function. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Low‐lying excited states of 7‐aminocoumarin derivatives: A theoretical study
Authors: Sakata Tetsuya , Kawashima Yukio , Nakano Haruyuki 
Published: March 2009

AbstractExcited states of three 7‐aminocoumarin derivatives, coumarin 120 (7‐amino‐4‐methylcoumarin), pyrrolyl coumarin 7‐(1H‐pyrrol‐1‐yl)‐4‐methyl‐2H‐1‐benzopyran‐2‐one, and carbazole‐coumarin hybrid 10H‐4‐methyl‐2H‐2‐oxopyrano[5,6‐b]carbazole, have been studied using B3LYP time‐dependent density functional theory (TDDFT). The solvent effect has been taken into account using the polarizable continuum model. The spectra calculated using TDDFT agree well with the experimental absorption spectra. The electronic structures and the solvent effect for the low‐lying singlet excited states have been investigated. The HOMO of the pyrrolyl coumarin is localized on the pyrrolyl ring, while the HOMO in the other 7‐aminocoumarins is delocalized over the entire molecule. This leads to the weak fluorescence of the pyrrolyl coumarins found in experiments. The HOMO and next HOMO in carbazole‐coumarin hybrids have similar orbital energy values, which is not the case in the other 7‐aminocoumarin derivatives. This leads to the additional peaks found in the 30,000–40,000 cm−1 region of the observed absorption spectra, which are specific for carbazole‐coumarin hybrids. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Symmetry breaking in spin‐restricted, open‐shell Hartree–Fock wave functions
Authors: Li Xiangzhu , Paldus Josef 
Published: March 2009

AbstractRelying on a unitary group approach (UGA) to coupled‐cluster (CC) theory for open‐shell systems we formulate a spin‐free analogue of Thouless' theorem and derive stability conditions for spin‐restricted, open‐shell Hartree–Fock (ROHF) solutions. The formalism is illustrated on the ground states of the oxygen and boron molecules. For the O2 molecule, the broken‐space‐symmetry solution appears already for a slightly stretched OO bond. For the B2 molecule we find a broken‐symmetry solution even at the equilibrium geometry and, in fact, in almost an entire region of intermolecular separations. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
On a manifestly covariant classical mechanics or ruminations on “The Computable Universe” and the role of mathematical physics in solving the natural resource problems of the future
Authors: Nooijen Marcel , Upadhyay Debajyoti 
Published: March 2009

AbstractWe informally discuss a number of puzzling fundamental issues that illustrate one might view the laws of physics as a loosely connected patchwork of different theories, rather than a grand unified scheme, even within the realm of chemistry. One long‐lasting difficulty is the merging of special relativity and quantum mechanics: the many‐body Dirac equation, which is the most satisfactory description of the effects of relativity in chemistry, is not Lorentz invariant. In this article, we address the formulation of a manifestly Lorentz invariant classical mechanics in which each particle is described by individual space and time coordinates, while the system as a whole evolves according to a Hamiltonian dynamics based upon a universal evolution parameter. The physical interpretation of the theoretical framework, or its agreement with experiment, in particular when the transition would be made to a quantum theory in four dimensions, is not clear at present. Our search for an understanding of the physical concepts underlying the covariant mechanics has led to a broader view on the use of mathematical and theoretical physics: it could possibly be at the basis for a “computable physics” in which the laws of physics are redesigned such that they are optimally suited for computer simulations, rather than aim for the accurate description of physical reality. In the final section of the article, it is argued that this may be a fertile way to address some of the natural resource problems the world is likely to face in the future. This article essentially covers much of the material presented by one of the authors (MN) at the Odyssey meeting in Edmonton, June 2008, and we hope reflects some of the stimulating discourse that can ensue when people from different disciplines are brought together to share their thoughts. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Magnebike: A magnetic wheeled robot with high mobility for inspecting complex‐shaped structures
Authors: Tâche Fabien , Fischer Wolfgang , Caprari Gilles , Siegwart Roland , Moser Roland , Mondada Francesco 
Published: March 2009

AbstractThis paper describes the Magnebike robot, a compact robot with two magnetic wheels in a motorbike arrangement, which is intended for inspecting the inner casing of ferromagnetic pipes with complex‐shaped structures. The locomotion concept is based on an adapted magnetic wheel unit integrating two lateral lever arms. These arms allow for slight lifting off the wheel in order to locally decrease the magnetic attraction force when passing concave edges, as well as laterally stabilizing the wheel unit. The robot has the main advantage of being compact (180 × 130 × 220 mm) and mechanically simple: it features only five active degrees of freedom (two driven wheels each equipped with an active lifter stabilizer and one steering unit). The paper presents in detail design and implementation issues that are specific to magnetic wheeled robots. Low‐level control functionalities are addressed because they are necessary to control the active system. The paper also focuses on characterizing and analyzing the implemented robot. The high mobility is shown through experimental results: the robot not only can climb vertical walls and follow circumferential paths inside pipe structures but it is also able to pass complex combinations of 90‐deg convex and concave ferromagnetic obstacles with almost any inclination regarding gravity. It requires only limited space to maneuver because turning on the spot around the rear wheel is possible. This high mobility enables the robot to access any location in the specified environment. Finally the paper analyzes the maximum payload for different types of environment complexities because this is a key feature for climbing robots and provides a security factor about the risk of falling and slipping. © 2009 Wiley Periodicals, Inc.
Ly-1 Antibody Reactive Clone Is an Important Nucleolar Protein for Control of Self-Renewal and Differentiation in Embryonic Stem Cells
Authors: Li Hui , Wang Beibei , Yang Acong , Lu Rui , Wang Weicheng , Zhou Yang , Shi Guilai , Kwon Sung Won , Zhao Yingming , Jin Ying 
Published: March 2009

Abstract
Embryonic stem cells (ESCs) possess the capacity to self-renew and differentiate into all cell types of an organism. It is essential to understand how these properties are controlled for the potential usage of their derivatives in clinical settings and reprogramming of differentiated somatic cells. Although transcriptional factors, such as Oct4, Sox2, and Nanog, have been considered as a part of the core regulatory circuitry, a growing body of evidence suggests that additional factors exist and contribute to the control of ESC self-renewal and differentiation. Here, we report that Ly-1 antibody reactive clone (LYAR), a zinc finger nucleolar protein highly expressed in undifferentiated ESCs, plays a critical role in maintaining ESC identity. Its downregulation significantly reduces the rate of ESC growth and increases their apoptosis. Moreover, reduced expression of LYAR in ESCs impairs their differentiation capacity, failing to rapidly silence pluripotency markers and to activate differentiation genes upon differentiation. Mechanistically, LYAR forms a complex with another nucleolar protein, nucleolin, and prevents its self-cleavage, maintaining a normal steady-state level of nucleolin protein in undifferentiated ESCs. Interestingly, the downregulation of nucleolin is detrimental to the growth of ESCs and increases the rate of apoptosis, similarly to the knockdown of LYAR. Thus, our data emphasize the fact that other genes besides Oct4 and Nanog are uniquely required for ESC self-renewal and differentiation and demonstrate that LYAR functions to control the stability of nucleolin protein, which in turn is essential for maintaining the self-renewal of ESCs.
Disclosure of potential conflicts of interest is found at the end of this article.
Adiponectin levels correlate with the severity of hypertriglyceridaemia in glycogen storage disease Ia
Authors: Bandsma R. H. J. , Smit G. P. A. , Reijngoud D.‐J. , Kuipers F. 
Published: March 2009

SummaryGlycogen storage disease type Ia (GSD Ia) is characterized by severe hypercholesterolaemia and hypertriglyceridaemia. Little is known about the aetiology of the hyperlipidaemia in GSD Ia. Adipokines play an important regulatory role in lipid metabolism. We investigated whether adipokine concentrations were correlated with the degree of hyperlipidaemia in GSD Ia patients. Six patients with GSD Ia were studied in semi‐fasted conditions. Adiponectin, but not leptin, correlated (r2 = −0.79, p = 0.02) with plasma triglyceride concentrations in the GSD Ia patients. Leptin correlated well with BMI (r2 = 0.59, p < 0.01). However, neither body mass index (BMI) nor homeostasis model assessment (HOMA), as a marker of insulin sensitivity, correlated with triglyceride concentrations. Although a small number of patients were studied, these results indicate that adiponectin concentrations are correlated with the degree of hypertriglyceridaemia in GSD Ia. Pharmacological treatment aimed at increasing adiponectin levels might improve the metabolic status of these patients.