bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solutocapillary convection in germanium‐silicon melts
Authors: Cröll A. , Mitric A. , Aniol O. , Schütt S. , Simon P. 
Published: September 2009

AbstractSurface tension gradients in free crystal growth melts give rise to convective flow. If these gradients are due to thermal gradients, the well known thermocapillary (Marangoni) convection ensues. Concentration gradients due to segregation at the interface during growth can lead to additional solutocapillary convection. A system with large solutocapillary convection is Ge‐Si due to the pronounced segregation and the strong difference in surface tension; solutal buoyancy convection is also present due to the large density difference between Ge and Si. Solutocapillary convection will oppose thermocapillary convection in the Ge‐Si system since Si, having the higher surface tension, is preferentially incorporated into the crystal. A set of experiments directly proving and partially quantifying the effect has been conducted under microgravity during a parabolic flight campaign by recrystallizing Ge‐Si mixtures of different compositions, between 3% and 9% Si, in a crucible with tracers to visualize the movement. Solutocapillary flow with initial flow rates in excess of 5.5 cm/s at the onset of crystallization was measured. A slight dependence of the flow velocity on the initial Si content has been found. Experiments on the ground showed the same effect but with overall smaller speeds; this difference can be explained by the additional action of solutal buoyancy convection. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
TEM investigation of precipitates in VCz GaAs crystals
Authors: Kirmse H. , Kiessling F.‐M. , Häusler I. , Rudolph P. 
Published: September 2009

AbstractBulk GaAs crystals were grown from various Ga‐rich melts by the vapour‐pressure controlled Czochralski method in order to reduce As precipitates. The correlation of the melt composition with both, structural perfection and solid composition was examined by various methods of transmission electron microscopy (TEM). From transmission electron diffraction and diffraction contrast imaging a direct correlation between melt composition and sample properties is missing. High‐resolution TEM imaging hints to inhomogeneities only for the sample grown from a melt with a mole fraction of y = 0.492. Strain analysis of a selected defect reveals a strained crystal lattice in the surrounding of the defect. For the same sample, high angle annular dark‐field imaging and energy dispersive X‐ray spectroscopy verify the formation of precipitates. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth of hierarchical calcium carbonate crystals templated by biomolecules of lotus root
Authors: Chen Long , Hu Fengkai , Zhou Quan , Sun Jinyu , Zhang Hui 
Published: September 2009

AbstractIn this paper, crystal growth of calcium carbonate (CaCO3) in the presence of biomolecules of lotus root was investigated. Scanning electron microscopy, Fourier transform infrared spectroscopy and X‐ray powder diffractometry were used to characterize the products. The results indicate that calcite spherical particles were constructed from small rhombohedral subunits. Similar CaCO3 crystals were also gained when crystal growth of CaCO3 in aqueous solution containing extracts of lotus root was performed, suggesting that the soluble biomolecules of lotus root play a crucial role in directing the formation of hierarchical calcite spherical particles. The possible formation mechanism of the CaCO3 crystals by using lotus root is also discussed, which can be interpreted by particle‐aggregation based non‐classical crystallization laws. The biomolecules of lotus root might induce and control the nucleation and growth of calcium carbonate crystals. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Deposition of CdTe films under microgravity: Foton M3 mission
Authors: Fiederle M. , Benz K. W. , Cröll A. , Zappettini A. , Calestani D. , Dieguez E. , Carotenuto L. , Bassano E. 
Published: September 2009

AbstractExperiments of deposition of CdTe films have been carried out under microgravity in the Russian Foton M3 mission. The influence of gravity has been studied with these experiments and compared to the results of simulations. The measured deposition rate could be confirmed by the theoretical results for lower temperatures. For higher temperatures the measured thickness of the deposited films was larger compared to the theoretical data. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On driving non‐passive macromodels to instability
Authors: Grivet‐Talocia S. 
Published: September 2009

AbstractThis paper illustrates a procedure for demonstrating and quantifying the importance of passivity in linear macromodels. This issue is critical whenever the macromodels are derived from tabulated port responses, either in time or frequency domain. We show an algorithmic procedure for the design of a passive termination network that will drive a given non‐passive macromodel to instability. Several termination structures characterized by various port couplings are investigated. Relaxed passivity conditions are also given, which guarantee the stability of the macromodel under specific reduced‐coupling loading conditions. Theoretical results are applied to a set of application test cases. Copyright © 2008 John Wiley & Sons, Ltd.
Utility of lyophilized PMA and ionomycin to stimulate lymphocytes in whole blood for immunological assays
Authors: Belouski Shelley Sims , Wilkinson Julie , Thomas John , Kelley Keith , Wang Shen‐Wu , Suggs Sid , Ferbas John 
Published: September 2009

AbstractBackground:The need to implement robust biomarkers in clinical trials has never been greater, and such efforts can be easily compromised by reagent instability or simple human error during assay set‐up. Many biotechnology and pharmaceutical companies are introducing efforts to conduct biomarker studies under more rigorous settings, and the use of plates or tubes pre‐loaded with stimulation or staining reagents could be of value for studies that involve flow cytometry.Methods:Five reagents lyophilized from ethanol or CHAPS buffer stock solution of phorbol 12‐myristate 13‐acetate (PMA) and ionomycin were benchmarked against standard DMSO liquid formulation for their stimulation equivalency. The median fluorescence intensity of phosphorylated ribosomal protein S6 in lymphocytes was assessed on a BD FACSCalibur™.Results:We demonstrate here that tubes pre‐loaded with lyophilized versions of the liquid reagents can provide equivalent stimulation in healthy volunteer specimens.Conclusions:The value of this approach is that it safeguards against omission or erroneous addition of bulk liquid formulations of PMA and ionomycin to the reaction vessel (i.e., plate or tube) and also lends itself to extended stability/shelf‐life of these reagents. On the basis of this initial success, we plan to expand our evaluation of lyophilized reagents so that they can be incorporated into our clinical biomarker campaigns as appropriate. © 2009 Clinical Cytometry Society
Altered hypoxia‐inducible factor‐1 alpha expression levels correlate with coronary vessel anomalies
Authors: Wikenheiser Jamie , Wolfram Julie A. , Gargesha Madhusudhana , Yang Ke , Karunamuni Ganga , Wilson David L. , Semenza Gregg L. , Agani Faton , Fisher Steven A. , Ward Nicole , Watanabe Michiko 
Published: September 2009

AbstractThe outflow tract myocardium and other regions corresponding to the location of the major coronary vessels of the developing chicken heart, display a high level of hypoxia as assessed by the hypoxia indicator EF5. The EF5‐positive tissues were also specifically positive for nuclear‐localized hypoxia inducible factor‐1 alpha (HIF‐1α), the oxygen‐sensitive component of the hypoxia inducible factor‐1 (HIF‐1) heterodimer. This led to our hypothesis that there is a “template” of hypoxic tissue that determines the stereotyped pattern of the major coronary vessels. In this study, we disturbed this template by altering ambient oxygen levels (hypoxia 15%; hyperoxia 75–40%) during the early phases of avian coronary vessel development, in order to alter tissue hypoxia, HIF‐1α protein expression, and its downstream target genes without high mortality. We also altered HIF‐1α gene expression in the embryonic outflow tract cardiomyocytes by injecting an adenovirus containing a constitutively active form of HIF‐1α (AdCA5). We assayed for coronary anomalies using anti‐alpha‐smooth muscle actin immunohistology. When incubated under abnormal oxygen levels or injected with a low titer of the AdCA5, coronary arteries displayed deviations from their normal proximal connections to the aorta. These deviations were similar to known clinical anomalies of coronary arteries. These findings indicated that developing coronary vessels may be subject to a level of regulation that is dependent on differential oxygen levels within cardiac tissues and subsequent HIF‐1 regulation of gene expression. Developmental Dynamics 238:2688–2700, 2009. © 2009 Wiley‐Liss, Inc.
Prx1 and Prx2 cooperatively regulate the morphogenesis of the medial region of the mandibular process
Authors: Balic Anamaria , Adams Douglas , Mina Mina 
Published: September 2009

AbstractMice lacking both Prx1 and Prx2 display severe abnormalities in the mandible. Our analysis showed that complete loss of Prx gene products leads to growth abnormalities in the mandibular processes evident as early as embryonic day (E) 10.5 associated with changes in the survival of the mesenchyme in the medial region. Changes in the gene expression in the medial and lateral regions were related to gradual loss of a subpopulation of mesenchyme in the medial region expressing eHand. Our analysis also showed that Prx gene products are required for the initiation and maintenance of chondrogenesis and terminal differentiation of the chondrocytes in the caudal and rostral ends of Meckel's cartilage. The fusion of the mandibular processes in the Prx1/Prx2 double mutants is caused by accelerated ossification. These observations together show that, during mandibular morphogenesis, Prx gene products play multiple roles including the cell survival, the region‐specific terminal differentiation of Meckelian chondrocytes and osteogenesis. Developmental Dynamics 238: 2599–2613, 2009. © 2009 Wiley‐Liss, Inc.
Syntheses, Crystal Structures, Spectroscopic Properties, and Catalytic Aerobic Oxidations of Novel Trinuclear Non‐Heme Iron Complexes
Authors: Rabe Volker , Frey Wolfgang , Baro Angelika , Laschat Sabine , Bauer Matthias , Bertagnolli Helmut , Rajagopalan Subramanian , Asthalter Tanja , Roduner Emil , Dilger Herbert , Glaser Thorsten , Schnieders David 
Published: September 2009

AbstractA series of 2,6‐diacylpyridine ligand precursors 5a–d·HCl with different tether lengths between the carboxyl and pyridine moiety was prepared and converted into the correspondig trinuclear Fe3(μ3‐O) complexes 8a–d and 10. Under slow precipitation conditions a tetranuclear complex 9 was isolated instead of 8a. Single‐crystal X‐ray diffraction analyses were performed on ligands 5a–d and complexes 9 and 10. Characterization by X‐ray absorption spectroscopy (XAS) proved a trinuclear Fe3(μ3‐O) core for complexes 8a–d. When complex 8a was submitted to Gif‐type oxidations (O2, Zn, pyridine, HOAc), Mössbauer and nuclear inelastic scattering (NIS) suggested the formation of mononuclear species. The trinuclear ferric complex 10 has an isosceles molecular structure, which is manifested in the 57Fe Mössbauer spectrum by two quadrupole doublets with a 2:1 intensity ratio. The magnetic measurements reveal two moderate antiferromagnetic exchange interactions of –22.1 and –33.8 cm–1. Spin concentrations of complex 10 were determined by EPR spectroscopy, which supports the Mössbauer and magnetic studies. Complexes 8–10 were employed in catalytic aerobic oxidations of adamantane 11, cyclohexene 19, and α‐pinene 23. For adamantane 11, the oxidation of secondary C–H bonds to the corresponding ketone 14 is favored. In addition, adamantylpyridines 15–18 were isolated, thus supporting a radical pathway. A strong preference of allylic oxidation versus epoxidation was found for cyclohexene 19 and α‐pinene 23. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Metalloamphiphiles with [Cu2] and [Cu4] Headgroups: Syntheses, Structures, Langmuir Films, and Effect of Subphase Changes
Authors: Hindo Sarmad Sahiel , Shakya Rajendra , Shanmugam Rama , Heeg Mary Jane , Verani Cláudio N. 
Published: September 2009

AbstractThe metalloamphiphiles [(LPM18)2Cu2Cl2]·H2O (1), [(LPMtax)2Cu2Cl2]·2MeOH (2), [(LOF18)2Cu2Cl2] (3), [(LOF18)2Cu4(μ4‐O)(μ2‐OAc)4] (4), [(LOF14)2Cu4(μ4‐O)(μ2‐OAc)4] (5) were synthesized and characterized by means of several spectroscopic and spectrometric methods. The acronyms LPMC18, LPMtax, LOF18, and LOF14 indicate the deprotonated forms of pseudomacrocyclic (PM) and open‐frame (OF) ligands based on 2,6‐bis(iminomethyl)‐4‐methylphenol attached to octadecyl (18), trialkoxyamine (tax) and tetradecyl (14) moieties, whereas Cl– and OAc– indicate chlorido and acetato coligands. Crystal structures were obtained for 4 and 5 that crystallize in triclinic crystal systems with P$\bar {1}$ space groups. The average Cu–Ophenolate and Cu–Nimine bond lengths are approximately 2.0 Å. Species 1–5 were analyzed by means of isothermal compression and Brewster angle microscopy (BAM). Moderate collapse pressures of approximately 15 mN m–1 were observed for 3, 4, and 5, while 1 collapses at approximately 30 mN m–1. Species 1, 3, 4, and 5 are responsive to several subphase changes such as temperature and addition of terephthalate ions, which leads to considerable Langmuir film enhancement. In presence of terephthalate the collapse pressure for 3, 4, and 5 nearly doubles, whereas a minimal effect was observed for 1. It appears that as temperature decreases, collapse pressure increases. The variation of pH produced inconclusive data. It is suggested that terephthalate ion interacts with the amphiphiles at a molecular level to generate discrete molecules rather than extended systems.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Six‐Membered N‐Heterocyclic Carbenes with a 1,1′‐Ferrocenediyl Backbone: Bulky Ligands with Strong Electron‐Donor Capacity and Unusual Non‐Innocent Character
Authors: Siemeling Ulrich , Färber Christian , Leibold Michael , Bruhn Clemens , Mücke Philipp , Winter Rainer F. , Sarkar Biprajit , von Hopffgarten Moritz , Frenking Gernot 
Published: September 2009

AbstractThe stable, crystalline N‐heterocyclic diaminocarbene fc[N(CH2tBu)‐C‐N(CH2tBu)] (2d, fc = 1,1′‐ferrocenediyl) was prepared by deprotonation of its formamidinium precursor fc[N(CH2tBu)‐CH‐N(CH2tBu)][BF4] (1d) and used for the preparation of the 16 valence electron complexes [Mo(2d)(CO)4], [RhCl(2d)(cod)] (cod = 1,5‐cyclooctadiene) and [RhCl(2d)(CO)2]. 1d, 2d and [RhCl(2d)(cod)] were structurally characterised by single‐crystal X‐ray diffraction studies. The electrochemical properties of 2d, its 2‐adamantyl analogue 2c, its complex [RhCl(2d)(CO)2] and of the precursors 1d and 1,1′‐bis(neopentylamino)ferrocene were investigated by electrochemistry. The carbenes are easily oxidised to the corresponding radical cation, whose persistent nature is unprecedented in the chemistry of N‐heterocyclic carbenes. The spin density is located at the Fe atom and the carbene C atom according to the results of EPR spectroscopic studies and DFT calculations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Star‐Shaped D‐π‐A Molecules Containing a 2,4,6‐Tri(thiophen‐2‐yl)‐1,3,5‐triazine Unit: Synthesis and Two‐Photon Absorption Properties
Authors: Zou Li , Liu Zijun , Yan Xiaobing , Liu Yan , Fu Yang , Liu Jun , Huang Zhenli , Chen Xingguo , Qin Jingui 
Published: September 2009

AbstractA series of new star‐shaped donor‐π‐acceptor (D‐π‐A) molecules containing the 2,4,6‐tri(thiophen‐2‐yl)‐1,3,5‐triazine unit were synthesized and characterized. The 1,3,5‐triazine group, as a strong electron‐accepting center, is connected to three electron‐donating end groups through π‐conjugated bridges. As a result of the coexistence of the electron acceptor and donor, these compounds show reversible or quasireversible redox behavior. Through changing the peripheral end group the optical properties can be modified. All compounds exhibit two‐photon absorption activity in the range of 720–880 nm and show large two‐photon absorption cross sections that are closely related to the intramolecular charge transfer and π‐conjugated length of the molecule.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Electrochemical Study of Phenolic Compounds as Enhancers in Laccase‐Catalyzed Oxidative Reactions
Authors: Díaz González María , Vidal Teresa , Tzanov Tzanko 
Published: September 2009

AbstractSixteen phenolic compounds, twelve of which derived from lignin, were evaluated as potential mediators for laccase‐assisted bleaching of pulp. The electrochemical behavior of these phenols, alone and in the presence of the lignin model compound veratryl alcohol, was studied by means of cyclic voltammetry. All phenolic compounds showed catalytic effect on the veratryl alcohol electrochemical oxidation. However, they could not be considered as mediators, since their oxidation products are not stable and regeneration of their reduced forms was not observed. The redox potentials of the phenolic compounds seem to have a negligible effect on their catalytic efficiency, supporting a H‐abstraction oxidation mechanism. This mechanism was also confirmed by electrochemical studies of 2,4,6‐trimethylphenol in acetonitrile and in the presence of benzyl alcohols.
The Use of an Electroactive Marker as a SERS Label in an E‐melting Mutation Discrimination Assay
Authors: Mahajan Sumeet , Richardson James , Gaied Nouha Ben , Zhao Zhengyun , Brown Tom , Bartlett Philip N. 
Published: September 2009

AbstractIn this paper we describe the first example of the use of an electroactive label as a SERS marker for detecting and quantifying target oligonucleotides and distinguishing mutations using a combination of voltammetry and electrochemically induced melting (E‐melting). The experiments were carried out on sphere segment void substrates selected to show strong surface enhancement for SERS at 633 nm. DNA analysis was carried out for CFTR sequences using synthetic 22‐mer oligonucleotides labelled with a modified anthraquinone at the 3′‐end. Discrimination between the wild type, 1653C/T (point mutation) and ΔF508 (triple deletion) is demonstrated.
Electrochemical Monitoring of Singlet Oxygen Production
Authors: Sharp Duncan , Forsythe Stephen , Davis James 
Published: September 2009

AbstractThe exploitation of singlet oxygen generating compounds as a means of targeted therapies drives the need to develop methods for assessing the efficacy of such compounds and their capacity for generating the reactive oxygen species. Degradation of diphenylisobenzofuran by singlet oxygen is widely used as a spectroscopic probe but its application can be problematic. An alternative detection strategy exploiting the electrochemical monitoring of the quencher concentration, by square wave voltammetry, has been shown to provide a more sensitive and flexible option that could be used to address the increasing interest in photosensitizing materials.
Ion Transfer Square Wave Voltammetry of Ionic Liquid Cations with a Solvent Polymeric Membrane Ion Sensor
Authors: Ortuño Joaquín A. , Serna Carmen , Molina Angela , Torralba Encarnación 
Published: September 2009

AbstractSquare wave voltammetry (SWV) with a solvent polymeric membrane ion sensor has been applied to study the ion transfer of several ionic liquid cations, from water to a poly(vinyl chloride) membrane plasticized with 2‐nitrophenyl octyl ether. The study has mainly been focused on dialkylimidazolium and alkylpyridinium cations. The experimental voltammograms obtained are in good agreement with the theoretical predictions. The standard ion transfer potentials of the ionic liquid cations have been obtained and the values found have been used to draw some conclusions on the relationship between structure and lipophilicity. Also, a relationship between the toxicity and the ion transfer potentials of dialkylimidazolium homologues has been found.
Investigation of deformation and breakup of a moving droplet by the method of lattice Boltzmann equations
Authors: Fakhari A. , Rahimian M. H. 
Published: September 2009

AbstractThe subject of the present study is to investigate the deformation and fragmentation of a moving droplet in a zero gravity uniform gas flow. The lattice Boltzmann method is employed to simulate different modes of deformation and breakup of the drop. Two‐dimensional results are compared with axisymmetric computations and major difference in the mechanisms of breakup and the rate of deformations is shown. Influence of the drop and gas viscosities as well as surface tension effect is investigated for some range of the Reynolds and Weber numbers. It is seen that the increase of the Reynolds or Weber number results in the increase of drop deformation and finally breakup. The quality of the findings is similar to the experimental observations. Different breakup regimes such as bag breakup and shear breakup are observed. The primary breakup time and the cross‐stream radius of the axisymmetric drop before bag breakup are shown to be in satisfactory agreement with experimental data. Copyright © 2009 John Wiley & Sons, Ltd.
Source‐based morphometry of gray matter volume in men with first‐episode schizophrenia
Authors: Kašpárek Tomáš , Mareček Radek , Schwarz Daniel , Přikryl Radovan , Vaníček Jiří , Mikl Michal , Češková Eva 
Published: September 2009

AbstractObjectives: There is a lot of variability between the results of studies reporting the pattern of gray matter volume changes in schizophrenia. Methodological issues may play an important role in this heterogeneity. The aim of the present study was to replicate the better performance of multivariate “source‐based morphometry” (SBM) over the mass‐univariate approach. Experimental design: Voxel‐based morphometry of Jacobian‐modulated gray matter volume images, using voxel and cluster level inference, and SBM were performed in a group of first‐episode schizophrenia patients (N = 49) and healthy controls (N = 127). Results: Using SBM we were able to find a significant reduction of gray matter volume in fronto‐temporo‐cerebellar areas whereas no significant results were obtained using voxel‐based morphometry. Conclusion: Multivariate analysis of gray matter volume seems to be a suitable method for characterization of the pattern of changes at the beginning of the illness in schizophrenia subjects. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.
Environmental influence on L1 retrotransposons in the adult hippocampus
Authors: Muotri Alysson R. , Zhao Chunmei , Marchetto Maria C.N. , Gage Fred H. 
Published: September 2009

AbstractIt is well established that neuronal circuits can be shaped by experience. Neuronal plasticity can be achieved by synaptic competitive interactions and the addition of new neuronal units in neurogenic regions of the adult brain. Recent data have suggested that neuronal progenitor cells can accommodate somatic LINE‐1 (Long Interspersed Nuclear Elements‐1 or L1) retrotransposition. Genomic L1 insertions may up‐ or down‐regulate transcriptional control of gene expression. Here, we show that exercise has a positive effect on a L1‐EGFP reporter in vivo. We found that neurons from mice that experience voluntary exercise are more likely to activate an EGFP reporter marker, representing L1 insertions in the brain, when compared with sedentary animals. In the hippocampus, a neurogenic region of the adult brain, EGFP expression is mainly found in cells localized in the subgranular layer of the dentate gyrus. This observation implies that neuronal progenitor cells may support de novo retrotransposition upon exposure to a new environment. Such evidence suggests that experience‐dependent L1 retrotransposition may contribute to the physiological consequences of neuronal plasticity. © 2009 Wiley‐Liss, Inc.