bluuebunny/crossref_metadata_2025_split huggingface dataset:
New technique for crystal growth and Phase Transition in TlInS2 Crystals
Authors: Gamal G. A. 
Published: January 2007

AbstractNew technique for crystal growth was designed in the present work. The electrical conductivity and Hall effect of the TInS2 single crystals, grown by this technique, were measured in the temperature range 150–500 K. From the measurements, the conductivity type, the energy gap, ionization energy of the impurity level, Hall mobility and carrier concentration were determined. Also the measurements revealed a presence of phase transition in the crystal at 189 and 220 K.
Crystallization of an organic intercalation compound: cholic acid
Authors: Kalkura S. Narayana , Kanakavel M. , Ramasamy P. 
Published: January 2007

AbstractCrystals of cholic acid have been grown in silica and tetramethoxy silane gels. Crystals grew with different morphology and Leisegang rings were also seen in some cases. Crystals were analyzed by X‐ray, IR and microhardness studies. The grown crystals were found to be monohydrate and the hardness of the crystals were found to decrease with increase of load.
Hydrothermal Synthesis and Morphology of Thomsonite and Edingtonite
Authors: Ghobarkar H. , Schäf O. 
Published: January 2007

AbstractThe hydrothermal treatment of different glasses of the composition 2 Na2O–8 CaO–10 Al2O3– 20 SiO2 and 2 BaO–2 Al2O3–6 SiO2 at one kilobar pressure in a temperature‐range between 80 °C and 230 °C lead to the formation of the zeolite‐minerals thomsonite (orthorhombic symmetry space‐group Pbmn, a = 13.05 Å, b = 13.09 Å and c = 13.22 Å), and edingtonite (orthorhombic symmetry, space‐group: P2,2,2, a = 9.55 Å, b = 9.67 Å and c = 6.52 Å). Under the chosen hydrothermal conditions both mineral phases are formed in the whole temperature interval.
Understanding and Controlling the Morphology of ZnO Crystallites under Hydrothermal Conditions
Authors: Wang B. G. , Shi E. W. , Zhong W. Z. 
Published: January 2007

AbstractThe morphological features of ZnO crystallites influenced by solution basicity under hydrothermal conditions have been studied from the standpoint of the incorporation of the growth units. A crystal chemistry approach is developed to understand and thus to control a desirable morphology of the crystallites. The effects of the additive OH− on the crystal morphology of ZnO crystallites are qualitatively but satisfactorily explained by a mechanism considering two aspects: (1) solution structures and the structural forms of growth units under a certain growth condition, i.e. the interactions between the solvent molecules and the growth units; and (2) the influence of the solvent molecules or additives on growth interfaces, particularly on two polar faces of ZnO crystallites in terms of the inhibition or promotion of the incorporation of various growth units depending on the solution basicity. Since the incorporation rates of the growth units are different on positive and negative polar faces, the relative growth rates of these faces are different and thus lead to the habit modifications. The approach clearly demonstrates that the hindrance of crystal growth is a consequence of surface adsorption processes.
Temperature Induced Surface Transitions in Liquid Crystal Planar‐Tilted Hybrid Cells
Authors: Moldovan R. , Frunza S. , Beica T. , Tintaru M. , Ghiordanescu V. 
Published: January 2007

AbstractTemperature induced surface transitions in liquid crystal hybrid cells with asymmetrical anchoring, planar to one surface and tilted to the other, are experimentally studied. The results are theoretically explained by an elastic theory and the resulting values for the effective splay‐bend elastic constant for a given liquid crystal, as well as the parameters characterising the anchoring on the boundary surface with tilted anchoring are compared with data from previous experiments, with good agreement.
Crystalloluminescence produced during the micro‐fracture of growing crystallites
Authors: Chandra B. P. , Verma P. K. , Ansari M. H. 
Published: January 2007

AbstractThe present paper reports the theory of crystalloluminescence (CRL) produced during the micro‐fracture of growing crystallites. Surface charges may be developed during the micre‐fracture of crystallites due to several processes like piezoelectrification, movement of charged dislocations, barodiffusion of defects near the moving crack etc. The surface charges may be neutralized by the movement of charge carriers produced due to the dielectric breakdown near the surface of crystallites and consequently the recombination luminescence may occur. Considering the basic concepts of crystallization from the supersaturated solution, expressions are derived which are able to explain satisfactorily the temporal, thermal, spectral concentration and other characteristics of the CRL. It is shown that the induction period for crystal nucleation, lifetime of supersaturation, size of crystallites and time constant for the relaxation of charges on the newly created surfaces may be determined from the CRL measurements.
Phosphate Composition of Precipitates from Urine‐like Liquors
Authors: Grases F. , Villacampa A. I. , Söhnel O. , Königsberger E. , May P. M. 
Published: January 2007

AbstractThe composition of the solid phases precipitating from urine‐like liquors has been determined at 37°C over the pH range between 6 and 8 for solutions with varying amounts of magnesium, citrate, oxalate and ammonium ions. At pH ⩽7 hydroxyapatite appeared, either alone or, depending on the magnesium ion concentration, in a mixture with brushite. Stravite and calcium phosphates precipitated at pH ⩾ 7.5. No other phosphate solids were observed to precipitate from these urine‐like liquors under physiological conditions. No influence on the nature of the solid phase was exerted by citrate, oxalate or ammonium ions. The variation of solid phase composition caused by changing solution composition is ascribed to kinetic rather than thermodynamic factors.
Effects of Acceptor Modification on Charge Transfer in Crystals of Donor‐Acceptor Systems of TTF
Authors: Salmerón‐valverde A. , Robles‐Martínez J. G. , García‐serrano J. , Gómez R. , Ridaura R. , Quintana M. , Zehe A. 
Published: January 2007

AbstractThe degree of charge transfer has been determined in six TTF‐fluorene derivative charge transfer complexes, using IR and Raman vibrational spectroscopies. It has been found that changes of the intermolecular electronic distribution is strongly influenced by the presence of the dicyanomethylene group, by the increase of the nitro groups, as well as by the symmetry of the acceptor.
Growth and Optical Characterization of CdI2 Single Crystals
Authors: Ajithkumar G. , Ittyachen M. A. , Chaudhary S. K. , Unnikrishnan N. V. 
Published: January 2007

AbstractSingle crystals of CdI2 were grown by employing the horizontal zone refining method. Emission spectra of these crystals were recorded at room temperature and liquid nitrogen temperature. Various emission parameters such as optical gain coefficient, lifetime, gain, stimulated emission cross section were evaluated for the various emission components. The results show high gain at low temperature whereas very low value at rmm temperature. This has been explained by invoking the existence of self trapped excitons in the crystal.
Growth and Properties of Trigonal Aluminium Gallium Orthophosphate Single Crystals Al1‐xGaxPO4
Authors: Xia Hai‐Rui , Qin Zi‐Kai , Yuan Wu , Liu Shi‐Fang , Zou Zhi‐Qiang , Han Jian‐Ru 
Published: January 2007

AbstractThe new piezoelectric solid solution aluminium gallium orthophosphate single crystals have been successfully developed for the first time in our laboratory by hydrothermal method. It has been demonstrated that these crystals are homogeneous, and isomorphous with AIPO4 and GaPO4. The solid solution crystals Al1‐xGaxPO4 are easy to grown and have better optical quality than those of AlPO4 crystals under the same conditions. A phase transition temperature Tα‐β is 587 ± 3 °C for x = 0.12. Cell parameters, and elastic, piezoelectric, and dielectric constants are given.
Growth and Characterization of Na2CaGe6O14 Single Crystals
Authors: Takeda Hiroaki , Uecker Reinhard , Kumatoriya Makoto , Shimamura Kiyoshi , Reiche Peter , Fukuda Tsuguo 
Published: January 2007

AbstractTransparent, crack‐free Na2CaGe6O14 (NCG) single crystals were successfully grown using the Czcchralski technique. The largest crystal had 30 mm in total length and 18 mm in maximal diameter. Best crystal quality was achieved under low temperature gradient arrangement. The crystal structure of NCG has been refined from single crystal X‐ray diffraction data. Some piezoelectric properties of NCG are reported.
Molecular Polarizabilities, Polarizability Anisotropies and Order Parameters of Nematic Liquid Crystals
Authors: Murthy Y. Narasimha , Murthy V. R. 
Published: January 2007

AbstractMean Molecular polarizabilities, polarizability anisotropies and order parameters are evaluated in members of three homologous series, using two theoretical models. The variation of polarizabilities and their anisotropies with number of carbon atoms in the alkyl chain is studied. The temperature dependence of order parameter is also presented. The results are compared with the reported values and the merits of the different models are discussed.
The Effect of Fluoride Concentration and Catalyst Preparation Method on Structural and Thermal Properties of CoMo/Al2O3 Catalysts
Authors: Sarbak Z. 
Published: January 2007

AbstractThe effect of the sequence of incorporation of F− ions on the properties of fluorinated CoMo/Al2O3 catalysts was investigated by the methods of X‐ray diffraction, infrared spectroscopy and thermal analysis. Three kinds of samples were prepared into which the F− ions were introduced either simultaneously with Co and Mo (sample labelled as CoMoF), or prior to them (F/CoMo) or after them (CoMo/F). The samples contained fixed amounts of Mo (15 wt.% MqO3) and Co (3 wt.% CoO). Formation of surface di‐ and polymolybdate species as well as Al–F was evidenced in all samples. The concentration of molybdenum containing species was the highest in CoMoF sample, while that of fluoride containing species was the highest in CoMo/F samples.
Crystal Structure of 4‐Phenyl‐5‐(2,3,4‐trimetoxyphenyl)‐isoxazole
Authors: Sanmartin R. , Olivera R. , Domínguez E. , Solans X. , Font‐bardia M. , Urtiaga M. K. 
Published: January 2007

AbstractThe X‐ray crystal structure of 4‐phenyl‐5‐(2,3,4‐trimethoxyphenyl)‐isoxole, C18H17NO4, (I) has been determined, revealing an interesting lack of coplanarity for the aromatic rings system. This preferred conformation implies reduction of the conjugation degree, as shown by the C(2)‐C(10) and C(3)‐C(4) bond‐length values. The arrangement of the three methoxy substituents is also examined.
Compensation Mechanism in Vanadium and Gallium Doped CdTe and (Cd,Zn)Te
Authors: Joerger W. , Laasch M. , Kunz T. , Fiederle M. , Meinhardt J. , Benz K. W. , Scholz K. , Wendl W. , Müller‐vogt G. 
Published: January 2007

AbstractVanadium and gallium doped CdTe crystals were grown from the vapour phase (modified Markov method) and (Cd0.9Zn0.1)Te: V from the melt (vertical Bridgman). The crystals were characterized by photoinduced current transient spectroscopy (PICTS), photoluminescence (PL) and time dependent charge measurements (TDCM). Transitions from different charge states (V2+/V3+) of the vanadium donor have been observed in the V‐doped crystals by PICTS. A shallow donor level (dE = 0.068 eV) and the Ga A‐center have been identified by PICTS and PL measurements in CdTe:Ga. In case of V‐doping high resistivity is achieved all over the crystal while Ga‐doping results in a high resistivity region only in the middle of the crystal. Calculation of the resistivity by means of a compensation model shows that for both dopants an additional not observed deep donor has to be assumed in order to describe the resistivity distributions.
Growth of Bi–Sb Gradient Crystals for X‐ray Monochromators by means of the Gradient Projection Method
Authors: Penzel St. , Kleessen H. , Neumann W. 
Published: January 2007

AbstractCrystals with a well defined slope of composition have been grown by the Gradient Projection Method (GPM). In the system Bi–Sb gradient crystals with a lattice parameter gradient of Δa/Δa/dz = 0.835%/cm and Δc/c/dz = 0.79%/cm have been obtained. The concentration profiles of the grown crystals with large single crystalline parts exhibit a linear distribution.The adjustment of the dissolving rate allows to control the growth velocity and thus the quality of the grown crystals is increased.
Liquid Phase Epitaxy (LPE) of YB2Cu3O7‐δ High Tc Superconductors
Authors: Aichele T. , Bornmann S. , Dubs C. , Görnert P. 
Published: January 2007

AbstractYBa2Cu3O7‐δ films were grown by liquid phase epitaxy in Y‐ZrO2 crucibles on (110)NdGaO3 substrates. A change in the preferred crystallographic growth direction was observed reproducibly. The growth mode changes from pure c‐axis oriented over mixed c/a‐axis oriented films to pure a‐axis oriented films with increasing undercooling. X‐ray diffraction measurements and atomic force microscopy investigations with c‐axis oriented as well as a‐axis oriented films are presented. It will be shown that atomically smooth steps with 0.2‐0.8 μM width can be achieved by LPE, which are free from melt remnants. Furthermore the values for the enthalpy of dissolution from literature, which are varying in a wide range, will be combined and a new value will be calculated in terms of a multi particle model.
Single‐fiber electromyography during menstrual exacerbation and ovulatory suppression in MuSK antibody–positive myasthenia gravis
Authors: Stickler David E. , Stickler Laura L. 
Published: January 2007

AbstractWe report a patient with muscle‐specific tyrosine kinase (MuSK) antibody–positive myasthenia gravis who experienced worsening of myasthenic weakness associated with alterations in estrogen and progesterone levels during the administration of oral contraceptive therapy. Single‐fiber electromyography was performed to document changes in neuromuscular transmission associated with the clinical exacerbation and subsequent resolution of the menstrual exacerbation and clinical improvement experienced with continuous monophasic oral contraceptive therapy. The potential long‐term benefit of ovulatory suppression in MuSK antibody–positive myasthenia gravis is discussed. Muscle Nerve, 2007
Single‐Step Purification of Recombinant Thermus aquaticus DNA Polymerase Using DNA‐Aptamer Immobilized Novel Affinity Magnetic Beads
Authors: Oktem Huseyin Avni , Bayramoglu Gulay , Ozalp V. Cengiz , Arica M. Yakup 
Published: January 2007

AbstractA DNA aptamer specific for Thermus aquaticus DNA polymerase (Taq‐polymerase) was immobilized on magnetic beads, which were prepared in the presented study. The effect of various parameters including pH, temperaturem and aptamer concentration on the immobilization of 5′‐thiol labeled DNA‐aptamer onto glutaric dialdhyde activated magnetic beads was evaluated. The binding conditions of Taq‐polymerase on the aptamer immobilized magnetic beads were studied using commercial Taq‐polymerase to characterize the surface complexation reaction. Efficiency of affinity magnetic beads in the purification of recombinant Taq‐polymerase from crude extracts was also evaluated. For this case, the enzyme “recombinant Taq‐DNA polymerase” was cloned and expressed using an Amersham E. coli GST‐Gene Fusion Expression system. Crude extracts were in contact with affinity magnetic beads for 30 min and were collected by magnetic field application. The purity of the eluted Tag‐polymerase from the affinity beads, as determined by HPLC, was 93% with a recovery of 89% in a one‐step purification protocol. Apparently, the system was found highly effective as one step for the low‐cost purification of Taq‐polymerase in bacterial crude extract.
Target Control of Cell Disruption To Minimize the Biomass Electrostatic Adhesion during Anion‐Exchange Expanded Bed Adsorption
Authors: Lin Dong‐Qiang , Dong Jian‐Nan , Yao Shan‐Jing 
Published: January 2007

AbstractExpanded bed adsorption (EBA) is an integrative unit operation for the primary recovery of bioproducts from crude feedstock. Biomass electrostatic adhesion often leads to bad bed stability and low adsorption capacity. The results indicate that effective cell disruption is a potential approach to reduce the biomass adhesion during anion‐exchange EBA. Two common cell disruption methods (sonication treatment and high‐pressure disruption with a French press) were investigated in the present work. The mean size of cell debris reduced dramatically during the cell disruption process, and the absolute value of the ζ potential of cell debris also decreased significantly as the mean size reduced. The biomass transmission index (BTI) obtained through the biomass pulse response experiment was used to quantitatively evaluate the biomass‐adsorbent interaction. Combining the influences of ζ potential of adsorbent (ζA), ζ potential of biomass (ζB), and biomass mean size ( dB), the parameter of (–ζA·ζB· dB) was explored as a reasonable indicator of biomass adhesion in expanded beds. A good linear correlation was confirmed between BTI and (–ζA·ζB· dB) for all biomass and cell disruption conditions tested, which was independent of the cell disruption methods. A target parameter (–ζA·ζB· dB) of 120 mV2μm was derived for BTI above 0.9, which meant a very slight influence of biomass on the stability of the expanded bed. This criterion could be used as a rational control target for cell disruption processes in EBA applications.
Dual Lipid Modification of Arabidopsis Gγ-Subunits Is Required for Efficient Plasma Membrane Targeting
Authors: Zeng Qin , Wang Xuejun , Running Mark P. 
Published: January 2007

AbstractPosttranslational lipid modifications are important for proper localization of many proteins in eukaryotic cells. However, the functional interrelationships between lipid modification processes in plants remain unclear. Here we demonstrate that the two heterotrimeric G-protein γ-subunits from Arabidopsis (Arabidopsis thaliana), AGG1 and AGG2, are prenylated, and AGG2 is S-acylated. In wild type, enhanced yellow fluorescent protein-fused AGG1 and AGG2 are associated with plasma membranes, with AGG1 associated with internal membranes as well. Both can be prenylated by either protein geranylgeranyltransferase I (PGGT-I) or protein farnesyltransferase (PFT). Their membrane localization is intact in mutants lacking PFT activity and largely intact in mutants lacking PGGT-I activity but is disrupted in mutants lacking both PFT and PGGT-I activity. Unlike in mammals, Arabidopsis Gγs do not rely on functional Gα for membrane targeting. Mutation of the sixth to last cysteine, the putative S-acylation acceptor site, causes a dramatic change in AGG2 but not AGG1 localization pattern, suggesting S-acylation serves as an important additional signal for AGG2 to be targeted to the plasma membrane. Domain-swapping experiments suggest that a short charged sequence at the AGG2 C terminus contributes to AGG2's efficient membrane targeting compared to AGG1. Our data show the large degree to which PFT and PGGT-I can compensate for each other in plants and suggest that differential lipid modification plays an important regulatory role in plant protein localization.
GlutathioneS-Transferase Interacting with Far-Red Insensitive 219 Is Involved in Phytochrome A-Mediated Signaling in Arabidopsis
Authors: Chen Ing-Chien , Huang I-Ching , Liu Ming-Jung , Wang Zhi-Gong , Chung Shu-Shiang , Hsieh Hsu-Liang 
Published: January 2007

AbstractFar-red (FR) insensitive 219 (FIN219) was previously shown to be involved in phytochrome A-mediated FR light signaling. To further understand its function and regulatory relation with other light-signaling components, a yeast two-hybrid approach was used to isolate FIN219-interacting partners. Here, we demonstrate that FIN219-interacting protein 1 (FIP1) interacts with FIN219 in vitro and in vivo and is composed of 217 amino acids that belong to the tau class of the large glutathione S-transferase gene family. FIP1 was further shown to have glutathione S-transferase activity. The gain of function and partial loss of function of FIP1 resulted in a hyposensitive hypocotyl phenotype under continuous FR (cFR) light and a delayed flowering phenotype under long-day conditions, which suggests that FIP1 may exist in a complex to function in the regulation of Arabidopsis (Arabidopsis thaliana) development. In addition, FIP1 mRNA was down-regulated in the suppressor of phytochrome A-105 1 mutant and differentially expressed in constitutive photomorphogenic 1-4 (cop1-4) and cop1-5 mutants under cFR. Intriguingly, FIP1 expression was up-regulated in the fin219 mutant under all light conditions, except cFR. Furthermore, promoter activity assays revealed that FIP1 expression was light dependent, mainly associated with vascular tissues, and developmentally regulated. Subcellular localization studies revealed that the β-glucuronidase-FIP1 fusion protein was localized in the nucleus and cytoplasm. Taken together, these data indicate that FIP1 may interact with FIN219 to regulate cell elongation and flowering in response to light.
PIP5K9, an Arabidopsis Phosphatidylinositol Monophosphate Kinase, Interacts with a Cytosolic Invertase to Negatively Regulate Sugar-Mediated Root Growth
Authors: Lou Ying , Gou Jin-Ying , Xue Hong-Wei 
Published: January 2007

Abstract
Phosphatidylinositol monophosphate 5-kinase (PIP5K) plays an essential role in coordinating plant growth, especially in response to environmental factors. To explore the physiological function of PIP5K, we characterized Arabidopsis thaliana PIP5K9, which is constitutively expressed. We found that a T-DNA insertion mutant, pip5k9-d, which showed enhanced PIP5K9 transcript levels, had shortened primary roots owing to reduced cell elongation. Transgenic plants overexpressing PIP5K9 displayed a similar root phenotype. Yeast two-hybrid assays identified a cytosolic invertase, CINV1, that interacted with PIP5K9, and the physiological relevance of this interaction was confirmed by coimmunoprecipitation studies using plant extracts. CINV1-deficient plants, cinv1, had reduced activities of both neutral and acid invertases as well as shortened roots. Invertase activities in pip5k9-d seedlings were also reduced, suggesting a negative regulation of CINV1 by PIP5K9. In vitro studies showed that PIP5K9 interaction indeed repressed CINV1 activities. Genome-wide expression studies revealed that genes involved in sugar metabolism and multiple developmental processes were altered in pip5k9-d and cinv1, and the altered sugar metabolism in these mutants was confirmed by metabolite profiling. Together, our results indicate that PIP5K9 interacts with CINV1 to negatively regulate sugar-mediated root cell elongation.