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Ceramic reinforced polyethylene and polystyrene composites were prepared by melt mixing and hot molding techniques. Temperature stable low-loss Ca[[([Li.sub.[1/3]][Nb.sub.[2/3]]).sub.0.8] [Ti.sub.0.2]][O.sub.[3-δ] (CLNT) ceramic was used as the filler to improve the dielectric properties of the polymers. The relative permittivity and dielectric loss in the microwave frequency range were increased with increase in the ceramic loading. As the filler content increased from 0 to 0.50 volume fraction, the relative permittivity increased from 2.3 to 9 and dielectric loss tangent from 0.0006 to 0.005 for poly-ethylene-CLNT composite. In the case of polystyrene-CLNT composite, the relative permittivity and dielectric loss tangent increased from 2.1 to 10.5 and 0.0005 to 0.0032 respectively with increase in filler content from 0 to 0.50 volume fractions. The thermal stability of the relative permittivity of polymer ceramic composites was also investigated. The experimentally observed relative permittivity was compared with theoretical models. POLYM. ENG. SCI., 50:570-576, 2010. [C] 2009 Society of Plastics Engineers, INTRODUCTION The recent developments in the microelectronic industry demand high-performance microwave materials for substrate and packaging applications. Materials for such applications should have low-relative permittivity and low-dielectric loss to reduce [...]

A particle-on-substance stagnation flow reactor (PS-SFR) is used to study the heterogeneous reaction kinetics of gaseous nitric acid (HN[O.sub.3]) with calcium carbonate (CaC[O.sub.3]) particles. The variation of the apparent, pseudo first order rate constant with particle loading and HN[O.sub.3] concentration is consistent with the pseudo first-order reaction assumption and a diffusion kinetic analysis.

The Ca C[H.sub.3]F reaction CaFC[H.sub.3] reaction is studied experimentally and theoretically. An alternative reaction mechanism involving a transfer to triplet potential energy surfaces is proposed.

The effect of copper, zinc and calcium on the structure stability of serum amyloid A (SAA)2.2 in aqueous solution is examined using various probes of quaternary, tertiary, and secondary structure. The result shows that the structure and stability of SAA2.2 are differently affected depending on the metal type and concentration.

The significance of the [gamma]2 calcium-binding site in fibrin polymerization is determined by synthesizing the fibrinogen variant, [gamma]D298,301A. The structure data has indicated that Gly-Pro-Arg-Pro-amide (GPRP) bound to the 'b' site and has induced the same local conformational changes as Gly-His-Arg-Pro-amide (GHRP) to this site.

The interplay between calcium and lectin and chaperone activities of calreticulin (CRT) is studied. It is found that the affinity of CRT for monoglucosylated glycans measured in solution by equilibrium dialysis and fluorescence anisotropy is not affected by the absence of calcium.

The research presents the synthesis, structure, electrical and physical properties of the polar oxysulfide CaZnOS. The compound is found to exhibit a non-phase-matchable second harmonic generation, as it is ferroelectric and contains very small pyroelectric coefficient between the room temperature and the boiling point of water.

The multireference configuration interaction and coupled cluster levels of theory are used to calculate potential energy curves, energy parameters and spectroscopic values for the excited states of CaH. It is observed that the spectroscopic constants and energy parameters for all states are in remarkable agreement with available experimental values.

The consequences of performing rat [beta]- chicken parvalbumin 3 (CPV3) mutations at residues 49, 50, 57, 58, 59, and 60 are explored to the differential behavior dictated by local and remote sequence. The findings strongly suggest that residues outside of the CD site EF-hand motif contribute to the unusual divalent ion-binding signature of the mammalian [beta]-parvalbumin isoform.

Rheology methods are used to monitor the sol - gel transition in aqueous alginate systems induced by in situ released calcium cations. The critical exponents were independent of alginate concentration and close to the percolation prediction in alginate with lower molecular weight and in alginate with higher molecular weight, the critical exponents changed with alginate sample and concentration suggesting two categories of the gelation as growth and cross-link

With growing understanding of the differences between solid residues from the fluidized bed combustion of petroleum coke and of coal, the significance of fuel-derived and sorbent-derived components of the ash has become clearer. It is well documented that hydration of the ashes is necessary prior to disposal or utilization or as a reactivation method. Initially, hydration of the lime was thought to involve water reacting only with CaO to form Ca[(OH).sub.2] but when the free lime content of the ashes is looked at before and after hydration, it is apparent that the process is more complex. Detailed analyses have shown that the free lime can decrease and vary within the same ash in different particle size ranges. The complexity of the reactions is reflected in problems with the assessment of the free lime content of the materials and the effect of hydration on different particle size fractions of the ash. The free lime content of the ash is significantly lower than expected based on the elemental analysis. Bed ash from the circulating fluidized bed combustion boilers owned and operated by the Nelson Industrial Steam Company Ltd. (NISCO) was examined in detail to elucidate the fate of calcium in the ash during hydration, using a range of techniques. The objective of the study is to determine the amount of CaO available for hydration/reactivation and to better understand interactions of Ca and other mineral components of the ash. Analysis results indicate that in NISCO ashes up to about 6% of the analytical CaO may be combined as acid soluble and insoluble OCCs (other calcium compounds). This implies up to about 10% less free lime than would be inferred from standard chemical analyses. About 1% of the missing CaO can be present as acid insoluble Ca and Mg vanadates, with up to 2% bound in soluble OCCs. The remaining 3-4% is still not accounted for. It is clear that even very minor quantities of mineral matter, other than CaO or Ca[SO.sub.4], associated mainly with the coarser size fractions, are important. The amount of bound water in the hydrated ash, other than that combined in portlandite or brucite, can be as large as 3-5%. This cannot be ignored when sample mass change on hydration or heating is used as a measure of the extent of CaO to Ca[(OH).sub.2] conversion. [DOI: 10.1115/1.2358144] Keywords: petroleum coke, FBC ash, calcium balance, free lime, hydration, Ca[(OH).sub.2], vanadium

Absorption, light emission and upconversion properties of [Tm.sup.2+]-doped CsCa[l.sub.3] and RbCa[l.sub.3] are presented and compared. It is illustrated that the two title compounds are the influence of the structural environment on the optical spectroscopic properties of [Tm.sup.2+].

The first molecular structure of an alkaline-earth-metal carbene complex is presented. This calcium bis(iminophosphorno)methandiide chelate complex crystallizes as a dimer in which the carbene carbons bridge the metal centers.

The impacts of three classes of organic cations on the inhibition of the plasma membrane Ca pump were determined and compared to inhibition of the Na pump. It was found that the monovalent cation quarternary amines are unable to form hydrogen bonds, and that the positive charge is localized at the center of the compound sterically hindered from direct contact with amino acid side chains.

A detailed thermo mass spectrometry and thermogravimetry/differential thermal analysis (TG-DTA) investigation are carried out on the various thermoluminescence (TL) samples of CaS[O.sub.4]:Tm, using an extremely slow rate of temperature elevation and solid state proton nuclear magnetic resonance measurements. The results have indicated distinct evidence of solid-state reactions with water vapor in air and decomposition of S[O.sub.4.sup.2-] that occurred at higher annealing temperatures.

Highly polar-axis-oriented CaBi2Nb2O9 (CBNO) thin films are deposited on platinum coated silicon substrates by the polymeric precursor method. The a/b-axis orientation of the ferroelectric films is considered to associate with the preferred orientation of Pt substrate.

A calcium vanadate apatite (VAp) in which [PO4.sup.3-] of hydroxyapatite (HAP), Ca10(PO4)6(OH)2, is completely substituted by V[O.sup.3-] in the apatite framework, was synthesized. The VAp acts as a high-performance heterogeneous base catalyst for various carbon-carbon bond-forming reactions such as Michael and aldol reactions in aqueous media and the H-D exchange reaction using deuterium oxide.

An investigation of the influence of the binding of the calmodulin-binding domain of calmodulin kinase I is conducted on the fast internal dynamics of calcium-saturated calmodulin. The results reveal a fundamental role for residual protein entropy in molecular recognition by calmodulin.

A three-layer ONIOM-based QM-MM method is used to study the interactions of [Mg.sup.2+] and [Ca.sup.2+] ions with the phosphate group of a DNA. The binding of hydrated [Mg.sup.2+] and [Ca.sup.2+] ions to dianion model of DNA showed true picture of DNA-alkaline-earth metal interactions in cell as compared to anon model, which is in good agreement with earlier reports.

The bromate-sulfite-ferrocyanide oscillating chemical reaction is coupled with the complexation of calcium ion by EDTA in order to construct a system that generates periodic pulses of free [Ca.sup.2+] with amplitude of two orders of magnitude and a period of ca. 20 min. The systematic design procedure and the properties of the first abiotic calcium-based chemical oscillator are described.

Calcium fluxes in the subpopulation of PAR-1 stimulated platelets are examined by measuring fluorescence changes in Fura Red/AM-loaded platelets following PAR-1 stimulation. Fluorescence changes in all platelets indicated calcium release from internal stores and influx of external calcium, a subpopulation of platelets displayed a pronounced increase in calcium transients and positive factor IXa binding, indicating that PAR-1 stimulated development factor IXa binding sites is dependent upon release of calcium from internal stores leading to sustained and pronounced calcium transients.

An investigation was conducted on the effect of calcium sulfate and calcium chloride on the enzymatic and structural properties of actomyosin isolated from sardine. Emphasis is given in understanding the effect of these compounds on the physiochemical and functional properties of proteins during storage at -20 degrees Celsius.

The discrepancies in the literature about the requirement for Ca(super 2+) in the activation process of calpain 3, called p94, and in its subsequent activity are resolved by using the simplified protease core. Results show that the proteolytic activity of the core of p94 and its deletion mutant lacking NS and insertion sequence 1 are strictly Ca(super 2+)-dependent and a two-stage model of activation of the proteolytic core of p94 is proposed.

The melting relationships in the system CaMg[Si.sub.2][O.sub.6] (Di)--C[O.sub.2] have been studied in the 3-8 GPa pressure range to determine if there is an abrupt decrease in the temperature of the solidus accompanying the stabilization of carbonate as a subsolidus phase. Such a decrease has been observed previously in peridotitic and some eclogitic systems. In contrast, the solidus in the Di--C[O.sub.2] system was found to decrease in a gradual fashion from 3 to 8 GPa. This decrease accompanies an evolution in the composition of the melt at the solidus from silicate-rich with minor C[O.sub.2] at 3 GPa to carbonatitic at 5.5 GPa, where the carbonation reaction Diopside + C[O.sub.2] = Dolomite (Dol) + Coesite (Cst) intersects the solidus. The near-solidus melt remains carbonatitic at higher pressure, consistent with carbonate being the dominant contributor to the melt. Based on previous studies in both eclogitic and peridotitic systems, this conclusion can be extended to more complicated systems: once carbonate is a stable subsolidus phase, it plays a major role in controlling both the temperature of melting and the composition of the melt produced.

The potential contribution of chromogranin B (CGB) on IP(sub 3-)dependent Ca(super 2+) mobilization in the nucleas is investigated using both neuroendorcrine PC12 and nonneuroendorcine NIH3T3 cells. The results highlight critical contribution of CGB in the IP(sub 3-)induced Ca(super 2+) release in the nucleus.

A study is conducted to show that neural activity directs the mRNA of the Drosophila Ca(super 2+), Calcium/Calmodulin-dependent Kinase II (CaMKII), to postsynaptic sites, where it is rapidly translated. It is concluded that degradative control of the RNA-induced silencing complex (RISC) pathway underlies the pattern of synaptic protein synthesis associated with a stable memory.

Bacterial cell-surface attachment of macromolecular complexes maintains the microorganism in close proximity to extracellular substrates and allows for optimal uptake of hydrolytic byproducts. The cellulosome is a large multienzyme complex used by many anaerobic bacteria for the efficient degradation of plant cell-wall polysaccharides. The mechanism of cellulosome retention to the bacterial cell surface involves a calcium-mediated protein-protein interaction between the dockerin (Doc) module from the cellulosomal scaffold and a cohesin (Coh) module of cell-surface proteins located within the proteoglycan layer. Here, we report the structure of an ultra-high-affinity ([K.sub.a] = 1.44 x [10.sup.10] [M.sup.-1]) complex between type II Doc, together with its neighboring X module from the cellulosome scaffold of Clostridium thermocellum, and a type II Coh module associated with the bacterial cell surface. Identification of X module-Doc and X module-Coh contacts reveal roles for the X module in Doc stability and enhanced Coh recognition. This extremely tight interaction involves one face of the Coh and both helices of the Doc and comprises significant hydrophobic character and a complementary extensive hydrogen-bond network. This structure represents a unique mechanism for cell-surface attachment in anaerobic bacteria and provides a rationale for discriminating between type I and type II Coh modules. cellulose degradation | cellulosome | protein-protein interaction | calcium

Structural and thermodynamic properties of crystal hexagonal calcium apatities were investigated using an all-atom Born-Huggins-Mayer potential by a molecular dynamics technique. The accuracy of the model at room temperature and atmospheric pressure was checked against crystal structural data, with maximum deviations of ca. 4% for the haloapatites and 8% for hydroxyapatite.

The utility of basis set superposition error (BSSE) extrapolation is examined to predict accurate binding energies of alkaline earth metal clusters Y(sub n) (Y = Be, Mg, Ca; n= 2-8) by investigating the effect of BSSE and core-correlation on ab initio binding energies at the MP2 and CCSD(T) levels. The results suggest that, while BSSE has a negligible effect for valence-electron-correlated calculations, including the most basic set, its magnitude becomes more pronounced for ail-electron-correlated calculations, including core electrons.

CaF2(11) surface is used, where atomic resolution force microscopy allows identification of the positions of the Ca(super 2-) and F2 ions in the obtained images to demonstrate that short-range interaction forces can be measured selectively above chemically identified surface site. Combing theoretical and experimental results allows a quantification of the strength and distance dependence of the interaction of a tip-terminating cluster with particular surface ions.

The functional role of the flexible hinge region centered near the sequence TIEMP(super 21) that connects the N-terminal cytosolic and C-terminal membrane-spanning helical domains of phospholamban (PLB) is investigated. Results suggest that unstructured characteristics of the flexible hinge region in PLB are critical for optimal inhibitory interactions with the Ca-ATPase.

The synthesis, crystal structure and chemical bonding of a new ternary polar intermetallic phase, Ca(sub 6)Cu(sub 2)Sn(sub 7) are described. It is found that Ca (sub 6)Cu(sub 2)Sn(sub 7) is metallic compound and exhibits temperature- independent paramagnitism.

The binding of W7 to the separated domains of cTnC is examined to simplify the spectra analysis. The results show that the estimation of the stoichiometry of binding, when coupled with the spatial distribution of binding sites, directly imply the primary binding sites for W7 in cTnC to be the functionally important hydrophobic pocket.

Ryanodine receptors (RyRs) are presented as a family of intracellular Ca(super 2)(super plus) channels that are regulated by calmodulin (CaM), which is sensitive to redox regulations. It demonstrates that corresponding amino acid substitutions in the CaM binding site differentially affect CaM binding and CaM regulation of RyR3 and those of the two other isoforms.

A novel application of photochromic molecules is to mimic physiological oscillatory calcium signals by reversibly binding and releasing calcium ions in response to light. Subsequent changes on the largely unexplored photochromic bisbenzospiropyran scaffold led to significant changes in thermal fading rates in several organic solvents.

The dynamics of the photoinduced reaction producing electronically excited CaF when 1:1 Ca.CH(sub 3)F complexes are deposited at the surface of large argon clusters are examined using the 'cluster isolated chemical reactions' technique. The observations suggest that a profound alteration of the calcium electronic structure and a control of the reaction by the CF stretch in CH(sub 3)F.

The study was conducted on calcium-dependent stability of extracellular domains 1 and 2 of epithelial cadherin as a two-domain construct (MECAD12). The result from the study reveals that the modular domains of epithelial cadherin exhibit context-dependent behavior in both the apo and calcium-bound states.

Geometric parameters, atomization energies, and heats of formative are calculated for a series of small calcium-containing molecules using high-level quantum chemical methods. The W2C-best heats of formation are generally in good agreement with experimental values however there are discrepancies for a small number of molecules.

The binding energies of alkali metal monocations and alkaline-earth metal dications to a series of small oxygen and nitrogen bases is evaluated by means of CCSD(T) calculations on B3-LYP optimized structures. Conclusions reveal that although the neutral, ion interaction energy for alkali and alkaline-earth metal cations is dominated by electrostatic contributions, in many cases the correct basicity trends are only attained once polarization effects are also included in the model.

A microfluidic method to study the contraction of a single cardiac myocyte (heart muscle cell) has been developed. This method integrates various single-cell operations as well as on-chip dye loading, and quantitative analysis of intracellular calcium concentration, [[[Ca.sup.2+]].sub.i]. After the channel enlargement by on-chip etching to accommodate large-sized cardiac myoytes, a single cell is selected and retained at a V-shaped cell retention structure within the microchip. Owing to the fragile property of the cardiac myocytes that could easily be damaged by centrifugation, the calcium-sensitive fluorescent dye was loaded in the cell by on-chip dye loading. This on-chip method minimized the damage to the cells from the use of a centrifuge in the conventional method and provided a way of cellular analysis of fragile cells. Subsequently, quantitative analysis of [[[Ca.sup.2+]].sub.i] of a single cardiac myocyte by fluorescence measurement was achieved for the first time in a microfluidic chip, thanks to the intracellular calcium stimulant of ionomycin. The resting [[[Ca.sup.2+]].sub.i] of the cardiomyocyte determined was consistent with the literature value. From the spontaneous contraction study, it was found that fluorescence intensity cannot represent the [[[Ca.sup.2+]].sub.i] variation accurately, which implied the importance of the quantitative analysis of [[[Ca.sup.2+]].sub.i].

The structure of the Ca(super 2+)-saturated form of the EGF3-4 pair of protein S is described, that is successfully folded to a native conformation after being expressed in Escherichia coli. The structure reveals that the interdomain interactions between EGF3 and EGF4 conform to those previously described.

A series of samples with the composition Ca1-xNa2xAl2B2O7 were investigated and a hexagonal structure with unusually large range of homogeneity was revealed. The hexagonal phase consist of [AL2b2O7](infinity)(super 2-) lamellae stacked along the c axis, as in CaAl2B2O7 and Na2Al2B2O7.

Twenty five amino acids within the 'N', 'P', and 'A' domains of Calcium(super 2+) ATPase(SERCA1) headpiece were subjected to site directed mutagenesis, taking advantage of high yield expression system. Functional and conformational effects of mutations were interpreted systematically in the light of the high resolution WT(wild type) structure.

Several ways to synthesize solvated and desolvated calcium tetrahydroaluminate by wet-chemical and mechanochemical methods are presented. The result show that the diethyl ether (DEE) and tetrahydrofuran (THF) adducts of calcium tetrahydroaluminate can be prepared by ball miling under inert conditions or by mechanically assisted wet-chemical synthesis.

The detailed mechanisms of Ca(super 2+) activation and positive cooperativity for the C2 domain of cytosolic phospholipase A2, which binds two Ca(super 2+) ions in sites I and II, separated by only 4.1 angstrom is presented using both experimental and computational approaches. Each of the five coordinating side chains in the Ca(super 2+) -binding cleft is individually mutated and the effect on Ca(super 2+) -binding affinity and cooperativity is measured.

The linker region and the C-terminus of cysteine string proteins (Csp) are interfering with exocytosis and could assign two functions to the C-terminus in Ca(super 2+)-simulated cells, that is the interaction with SNARE protein VAMP and modulation of Csp homodeimerization. Cross-linking in permeabilized clonal beta-cells revealed homodeimerization of Csp, which is stimulated by Ca(super 2+) and again modulated by the variant C-terminus.

Scanning tunneling microscopy and low-energy electron diffraction are used to examine the structure of ordered adlayers of Ca on TiO2(110)-1x1 formed by metal vapor deposition. A comparison is made with structures formed by segregation of Ca from the bulk, with similar structures being found for the two preparation methods below a monolayer coverage.