bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deep homology: A view from systematics
Authors: Scotland Robert W. 
Published: April 2010

AbstractOver the past decade, it has been discovered that disparate aspects of morphology – often of distantly related groups of organisms – are regulated by the same genetic regulatory mechanisms. Those discoveries provide a new perspective on morphological evolutionary change. A conceptual framework for exploring these research findings is termed ‘deep homology’. A comparative framework for morphological relations of homology is provided that distinguishes analogy, homoplasy, plesiomorphy and synapomorphy. Four examples – three from plants and one from animals – demonstrate that homologous developmental mechanisms can regulate a range of morphological relations including analogy, homoplasy and examples of uncertain homology. Deep homology is part of a much wider range of phenomena in which biological (genes, regulatory mechanisms, morphological traits) and phylogenetic levels of homology can both be disassociated. Therefore, to understand homology, precise, comparative, independent statements of both biological and phylogenetic levels of homology are necessary.
Expression and purification of an antitumor‐analgesic peptide from the venom of Mesobuthus martensii Karsch by small ubiquitin–related modifier fusion in Escherichia coli
Authors: Cao Peng , Yu Jiemiao , Lu Wuguang , Cai Xueting , Wang Zhigang , Gu Zhenhua , Zhang Juan , Ye Tingmei , Wang Min 
Published: April 2010

AbstractTo prevent protein aggregation, some proteins are usually expressed as fusion proteins from which target proteins can be released by proteolytic or chemical reagents. In this report, small ubiquitin‐related modifier (SUMO) linked with a hexa‐histidine tag was used as a fusion partner for the antitumor‐analgesic peptide from the venom of Buthus martensii (Karsch) scorpion (AGAP). The optimal expression level of the soluble fusion protein, SUMO‐AGAP, was up to 40% of the total cellular protein. The fusion protein was purified by Ni‐NTA affinity chromatography and cleaved by a SUMO‐specific protease (Ulp1) to obtain the recombinant AGAP (rAGAP), which was further purified by Ni‐NTA affinity chromatography. The purified final product was >95% pure by SDS‐PAGE stained with Coomassie brilliant blue R‐250. Mass spectroscopic analysis indicated the protein to be 7142.63 Dalton, which equaled the theoretically expected mass. N‐terminal sequencing of rAGAP showed the sequence corresponded to the native protein. MTT assay indicated the rAGAP could significantly inhibit the proliferation of Jurkat and Hut 78 T lymphoma cell lines. The further writhing experiment showed that the rAGAP had an intensive analgesic effect. The expression strategy presented in this study allows convenient high yield and easy purification of the rAGAP with native sequences. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Food for thought: the effect of counterfactual thinking on the use of nutrition information
Authors: Aboulnasr Khaled , Sivaraman Anu 
Published: April 2010

AbstractIn three experiments, we examine the efficacy of counterfactual thinking (CFT) as a strategy to enhance consumers' motivation to process and use nutrition information on food packages. In the first study, we test whether CFT leads to greater motivation to process nutrition label information in the process of forming product attitudes. We also test whether motivation mediates the relationship between CFT and the influence of the nutrition label in product evaluation. In a second study, we test the effect of upward versus downward CFT on motivation. We also examine whether nutrition information on food packages moderates the relationship between CFT and product attitudes. In a third study, we examined the duration of the motivational effect of CFT. Results from the three studies support the role of CFT as a mechanism that enhances consumers' motivation to elaborate on and use nutrition information to form product attitudes. Copyright © 2010 John Wiley & Sons, Ltd.
Isotopic Oxygen Exchange over Pd/Al2O3 Catalyst: Study on C18O2 and 18O2 Exchange
Authors: Ojala Satu , Bion Nicolas , Rijo Gomes Sérgio , Keiski Riitta L. , Duprez Daniel 
Published: April 2010

AbstractOxygen mobility on Pd/Al2O3 catalysts is generally considered to be rather slow compared with other noble metal catalysts. This study shows that oxygen can be exchanged from gas‐phase CO2 produced during, for example, methane oxidation, more rapidly than from O2 molecules. The oxygen exchange from C18O2 occurs mainly on Al2O3, whereas 18O2 exchange needs to be carried out in the presence of palladium. However, the presence of Pd on Al2O3 slightly enhances C18O2 exchange according to the number of exchanged atoms in the gas phase. In this case, the calculation of initial rate for C18O2 exchange is not adequate to evaluate oxygen mobility; information on the number of exchanged atoms and on the evolution of the concentrations of the different isotopomers is also needed. The enhancement of oxygen exchange is due to carbonate formation on the catalytic surface, as evidenced by in situ FTIR spectroscopic measurements. A five‐step mechanism is suggested to explain these findings.
Molecular Logic Gates and Switches Based on 1,3,4‐Oxadiazoles Triggered by Metal Ions
Authors: Li Ai‐Fang , Ruan Yi‐Bin , Jiang Qian‐Qian , He Wen‐Bin , Jiang Yun‐Bao 
Published: April 2010

AbstractOrganic molecular devices for information processing applications are highly useful building blocks for constructing molecular‐level machines. The development of “intelligent” molecules capable of performing logic operations would enable molecular‐level devices and machines to be created. We designed a series of 2,5‐diaryl‐1,3,4‐oxadiazoles bearing a 2‐(para‐substituted)phenyl and a 5‐(o‐pyridyl) group (substituent X=NMe2, OEt, Me, H, and Cl; 1 a–e) that form a bidentate chelating environment for metal ions. These compounds showed fluorescence response profiles varying in both emission intensity and wavelength toward the tested metal ions Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, and Pb2+ and the responses were dependent on the substituent X, with those of 1 d being the most substantial. The 1,3,4‐oxadiazole O or N atom and pyridine N atom were identified as metal‐chelating sites. The fluorescence responses of 1 d upon metal chelation were employed for developing truth tables for OR, NOR, INHIBIT, and EnNOR logic gates as well as “ON‐OFF‐ON” and “OFF‐ON‐OFF” fluorescent switches in a single 1,3,4‐oxadiazole molecular system.
Thiotimolin – Ein Nanoreview
Authors: Schneider Thomas 
Published: April 2010

AbstractMit seinen drei berühmten Beiträgen über Thiotimolin, die er zwischen 1948 und 1960 veröffentlichte, gilt Isaac Asimov als Begründer der Chronochemie. Dieser Review gibt einen Überblick über die wichtigsten Eigenschaften und die bisher bekannten Verwendungsmöglichkeiten der ungewöhnlichen Substanz.
Litz wire radiofrequency receive coils for hyperpolarized noble gas MR imaging of rodent lungs at 73.5 mT
Authors: Dominguez‐Viqueira William , Berger Warren , Parra‐Robles Juan , Santyr Giles E. 
Published: April 2010

AbstractMagnetic resonance imaging with hyperpolarized noble gases, 3He or 129Xe, has become a promising approach for visualizing lung anatomy and function. The polarization of hyperpolarized noble gases does not depend on the magnetic field strength of the imaging system providing an opportunity to image at magnetic field strengths considerably lower than those typically used for clinical purposes (<0.1 T). At such low fields, image noise is dominated by electronic sources, particularly those originating from the radiofrequency coils. An improvement in image signal‐to‐noise ratio (SNR) is possible at low fields by reducing radiofrequency coil noise using Litz wire. In this work, radiofrequency coils of similar geometry were constructed with either conventional copper wire or three different types of Litz wire and compared in phantoms and in vivo in rat lungs using hyperpolarized 3He and 129Xe gases. The coils were tuned at either 0.866 MHz or 2.385 MHz, corresponding to the Larmor frequencies of 129Xe and 3He at 73.5 mT. The effect of wire spacing and number of windings was investigated. A SNR improvement of up to 131% was obtained with the Litz wire when compared with that of conventional copper wire. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 37B: 75–85, 2010
A high temperature superconducting imaging coil for low‐field MRI
Authors: Cheong Hoon‐Sin , Wild James , Alford Neil , Valkov Ivelin , Randell Christopher , Paley Martyn 
Published: April 2010

AbstractIn low field MRI (<0.5T), the signal‐to‐noise ratio (SNR) is predominantly degraded by thermal noise due to the electrical resistance of the imaging coil. This means using an imaging coil made of materials with a low intrinsic resistivity such as high temperature superconductors (HTS) should improve the SNR significantly when compared to an equivalent copper coil. The aim of this study was to perform a quantitative analysis on the performance of a cryogenically‐cooled HTS coil in low field MRI. A 70 mm circular spiral HTS resonator was fabricated by using YBa2Cu3O7 (YBCO) onto a sapphire substrate. The HTS coil was placed inside a cryogenic Dewar flask made of G10 materials to allow cooling using liquid nitrogen. A copper coil with the same layout was also fabricated to provide reference data for SNR comparisons. From the quality factor (Q) measurement results, the cryogenically‐cooled HTS coil was estimated to give SNR gains of 4.0 and 1.9 when compared to the copper coil at room temperature (292 K) and at the same cryogenic temperature (81.5 K) respectively. The phantom imaging results showed good agreement with these estimations in which SNR gains of 3.7 and 1.8 were recorded for the same comparisons. Similar SNR gains of 3.2 and 1.8 were also measured from in‐vivo hand imaging results, confirming the advantage of HTS coils over equivalent copper coils in low field MRI. Meanwhile, the SNR gain of the HTS coil against the room temperature copper coil dropped to 1.8 when the coil‐to‐sample separation in the latter setup was minimized to around 1 mm. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 37B: 56–64, 2010
Haptic interaction of organs based on the spherical harmonic representation
Authors: Yang Zhengyi , Vegh Viktor , Tieng Quang M. , Olsen‐Kettle Louise M. , Wang Deming 
Published: April 2010

AbstractVisual and haptic organ interactions in real time are essential in virtual reality–based medical simulations to provide training, early diagnosis, and improved treatment planning. This work presents a robust method of computing the deformation of an elastic object when external forces are applied. Point‐based haptic interaction between the user of the haptic device and an object is outlined and is formulated as a deformation problem over the surface. The model is expressed in the spherical harmonic basis, from which both haptic device force feedback and object surface updates are calculated. Haptic and visual updates are performed in the same basis, in turn providing significant benefits of computing efficiency and multiresolution modeling. Partially, this is due to the fact that in the model the objects are represented as surfaces. A haptic device is used to probe different prostates that have been segmented and reconstructed from MR images to validate the findings. The calculated deformation and feedback force is further validated against the established finite element method. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 37B: 45–55, 2010
Clinical significance of the 21‐gene signature (Oncotype DX) in hormone receptor‐positive early stage primary breast cancer in the Japanese population
Authors: Toi Masakazu , Iwata Hiroji , Yamanaka Takeharu , Masuda Norikazu , Ohno Shinji , Nakamura Seigo , Nakayama Takahiro , Kashiwaba Masahiro , Kamigaki Shunji , Kuroi Katsumasa 
Published: April 2010

AbstractBACKGROUND:The 21‐gene signature has been intensively studied and incorporated into major guidelines for treatment decision in early breast caner. However, it remains to be examined whether this system is applicable to Asian populations.METHODS:The authors collected 325 tumor tissues from estrogen receptor (ER)‐positive primary breast cancer patients who had undergone surgery and were treated with tamoxifen between 1992 and 1998. The tissues were analyzed for the 21‐gene signature, and the patients were classified into groups of low, intermediate, or high risk based on the Recurrence Score.RESULTS:A total of 280 patients were eligible, with adequate reverse transcription polymerase chain reaction profiles for the Recurrence Score. Of those, 200 and 80 patients had lymph node‐negative and lymph node‐positive disease, respectively. The proportions of lymph node‐negative patients categorized as being at low, intermediate, or high risk were 48%, 20%, and 33%, respectively. In lymph node‐negative patients, the Kaplan‐Meier estimates of the distant recurrence rate at 10 years were 3.3% (95% confidence interval [95% CI], 1.1‐10.0%), 0%, and 24.8% (95% CI, 15.7‐37.8%) for those in the low‐risk, intermediate‐risk, and high‐risk groups, respectively. The risk of distant recurrence in the low‐risk group was significantly lower than that in the high‐risk group when the entire Kaplan‐Meier plots were compared (P < .001, log‐rank test). There was a significant difference for overall survival between the low‐risk and the high‐risk groups (P = .008, log‐rank test).CONCLUSIONS:This is the first report to show that the 21‐gene signature has value in providing prognostic information in Asian populations with ER‐positive, lymph node‐negative breast cancer. Cancer 2010. © 2010 American Cancer Society.
Quality meshing based on STL triangulations for biomedical simulations
Authors: Marchandise E. , Compère G. , Willemet M. , Bricteux G. , Geuzaine C. , Remacle J.‐F. 
Published: April 2010

AbstractThis work describes an automatic approach to recover a high‐quality surface mesh from low‐quality or oversampled inputs (STL‐files) obtained from medical imaging through classical segmentation techniques. The approach combines a robust method of parametrization based on harmonic maps (Int. J. Numer. Meth. Engng. 2009; accepted) with a recursive call to a multi‐level edge partitioning software. By doing so, we are able to get rid of the topological and the geometrical limitations of harmonic maps. The overall remeshing procedure is implemented, together with the finite element discretization procedure required for computing harmonic maps, in the open‐source mesh generator Gmsh (Int. J. Numer. Meth. Engng. 2009; 79(11):1309–1331). We show that the proposed method produces high‐quality meshes and we highlight the benefits of using those high‐quality meshes for biomedical simulations. Copyright © 2010 John Wiley & Sons, Ltd.
Linear Dichroism in the XANES of Partially Oriented Samples: Theory and Application to the Photosynthetic Manganese Complex
Authors: Liebisch Peter , Dau Holger 
Published: April 2010

AbstractFor molecular systems which are partially ordered with respect to one macroscopic axis, for example, the sample–surface normal, X‐ray absorption spectroscopy (XAS) with linearly polarized synchrotron radiation can provide information on structure and orientation of the X‐ray absorbing site (polarized or linear‐dichroism XAS). Examples for such partially oriented systems are protein‐carrying membrane particles deposited in the form of multilayers on surfaces, layered minerals, surface films or imperfect 2D crystals, planar electrodes or catalytic surfaces. For electric dipole transitions, equations are derived describing how partial unidirectional orientation determines the linear dichroism (LD). The approach presented facilitates description of 1) LD in multiple‐scattering contributions of the extended X‐ray absorption fine‐structure (EXAFS) and 2) of LD in the X‐ray absorption near‐edge structure (LD‐XANES). Structural and orientation information becomes accessible by combination with ab initio XANES calculations. The LD‐XANES approach is applied to the water‐oxidizing Mn complex of photosystem II. The results suggest that the (μ‐O)‐(μ‐O) vectors of the Mn‐(μ‐O)2‐Mn units are at an average angle to the membrane normal of 30–45°. The best‐fit structure in connection with crystallographic data suggests a specific oxidation‐state assignment: Mn(1)IIIMn(2)IIIMn(3)IVMn(4)IV. However, currently this assignment remains uncertain. In future studies, the LD‐XANES analysis should play an important role in construction of unequivocal atomic‐resolution model of the photosynthetic Mn complex.
Prediction of Local pH Variations during Amperometric Monitoring of Vesicular Exocytotic Events at Chromaffin Cells
Authors: Amatore Christian , Arbault Stéphane , Bouret Yann , Guille Manon , Lemaître Frédéric 
Published: April 2010

AbstractElectrochemical monitoring of the exocytosis process is generally performed through amperometric oxidation of the electroactive messengers released by single living cells. Herein, we consider the vesicular release of catecholamines by chromaffin cells. Each exocytotic event is thus detected as a current spike whose morphology (intensity, duration, area, etc.) features the efficiency of the secretion process. However, the electrochemical oxidation of catechols produces quinone derivatives and protons. As a consequence, unless specific mechanisms may be adopted by a cell to regulate the pH near its membrane, the local pH between the cell membrane and the electrode necessarily drops within the electrode–cell cleft. Though this consequence of amperometric detection is generally ignored, it has been investigated in this work through simulation of the local pH drop created during the amperometric recording of a sequence of exocytotic events. This was performed based on frequencies and magnitudes of release detected at chromaffin cells. The corresponding acidification was shown to severely depend on the microelectrode radius. For usual 10 μm diameter carbon fiber electrodes, pH values below six were predicted to be reached within the electrode–cell cleft after monitoring a few current spikes.
Si modified Ge10 cluster: the preparation and characterization of single crystal Na4(Ge,Si)9O20
Authors: Xiao Peng‐Yan , Ren Tie‐Zhen , Wang Zhi‐Qiang , Christensen K. E. 
Published: April 2010

AbstractA Si modified Ge10 cluster with structure Na4(Ge,Si)9O20 (denoted as HUT‐1) was synthesized by hydrothermal synthesis at 160 °C with a sodium silicate source. The compound was characterized by single crystal, powder X‐ray diffraction and TGA‐DSC analysis. HUT‐1 crystallizes in space group I41 (80) with calculated unit cell (a=14.966(5) Å, c=7.343(2) Å, V=1644.8(9) Å3), which has the same structure as Na4Ge9O20. HUT‐1 has a high Si/Ge ratio with an approximate formula of Na4Ge7.68Si1.32O20. Single crystal X‐ray structure refinements together with results from X‐ray powder diffraction (XRPD) confirm the occupancy of Si at two tetrahedral sites. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Three‐dimensional study of the pressure field and advantages of hemispherical crucible in silicon Czochralski crystal growth
Authors: Mokhtari F. , Bouabdallah A. , Merah A. , Zizi M. , Hanchi S. , Alemany A. 
Published: April 2010

AbstractThe effects of several growth parameters in cylindrical and spherical Czochralski crystal process are studied numerically and particularly, we focus on the influence of the pressure field. We present a set of three‐dimensional computational simulations using the finite volume package Fluent in two different geometries, a new geometry as cylindro‐spherical and the traditional configuration as cylindro‐cylindrical. We found that the evolution of pressure which is has not been studied before; this important function is strongly related to the vorticity in the bulk flow, the free surface and the growth interface. It seems that the pressure is more sensitive to the breaking of symmetry than the other properties that characterize the crystal growth as temperature or velocity fields. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization and growth of CdS nanoparticles by a cost effective chemical reduction method
Authors: Bhattacharya R. , Manna A. , Das T. K. , Saha S. 
Published: April 2010

AbstractA simple chemical reduction method is followed to grow CdS nanoparticles at room temperature with different duration of time. The grown samples are ultrasonicated in ethanol. The dispersed samples are characterized using electron diffraction techniques. Simultaneously optical absorption, photoluminescence and longtime photorelaxation of these samples are studied at room temperature. An increase in band gap is observed in each case as compared to bulk CdS. Also particle size increases with increase of growth time and hence there is decrease of band gap with increase of growth duration. Simultaneously long time relaxation increases with increase of growth time. An attempt is made to correlate the structural, optical, electrical and opto‐electrical properties. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis, characterization and dielectric properties of EuBa2SbO6 nanocrystals
Authors: Kavitha V. T. , Vijayakumar C. , Wariar P. R. S. , Koshy J. 
Published: April 2010

AbstractNanoparticles of EuBa2SbO6, a complex perovskite metal oxide were synthesized by a self‐sustained combustion method employing citric acid as the complexing agent. The powders were characterized by X‐ray diffraction, IR and Raman spectroscopy, transmission electron microscopy and scanning electron microscopy. Nanocrystals of EuBa2SbO6 were sintered to 97 % of theoretical density at 1450 °C for 4 h without any sintering aid. The dielectric properties (dielectric constant, εr and loss factor, tanδ) of the ceramics have been measured in the frequency range 50 Hz to 5 MHz at room temperature. The chemical non‐reactivity of EuBa2SbO6 with YBa2Cu3O7‐δ makes it an ideal substrate for YBa2Cu3O7‐δ superconductors. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Addition to the theory of LPE growth: Crystallization mechanisms
Authors: Peev N. S. 
Published: April 2010

AbstractDifferent possible mechanisms of crystal growth for the used in the practice LPE techniques are considered in the present paper. The time dependences of the super saturation for the cases of normal growth mechanism and screw dislocations growth mechanism are presented. The values of the stationary super saturation, of the stationary growth rate and of the time constant for the transient growth process are obtained. The effect of the initial super saturation on the growth rate is considered. Relation between the stationary value of the super saturation, the time constant of the transient process, the cooling rate and the liquidus surface slope has been ascertained. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)