Unilateral Correction of Space Loss in the Mixed Dentition

Distalization of maxillary molars is indicated for correction of Class II dental malocclusion and for space gain in cases of space deficiency. The ideal treatment with an intraoral fixed appliance for molar distalization should fulfill the following requirements: patient compliance; acceptable esthetics; comfort; minimum anterior anchor loss (as evidenced by inclination of incisors); bodily movement of the molars to avoid undesirable effects and unstable outcomes; and minimum time required during sessions for placement and activations. The purpose of this paper was to present an alternative treatment for space recovery in the area of the maxillary right second premolar when there has been significant mesial movement of the permanent maxillary right first molar. We used a modified appliance that allows unilateral molar distalization in cases of unilateral tooth/arch size discrepancy using the opposite side as anchor, thus reducing the mesialization of the anterior teeth. (Pediatr Dent 2008;30:334-41) Received August 17, 2006 / Last Revision October 17, 2007 / Revision Accepted October 17, 2007

Clinical comparison between the bleaching efficacy of 37% peroxide carbamide gel mixed with sodium perborate with established intracoronal bleaching agent

Objective. The aim was to evaluate the bleaching efficacy of sodium perborate/37% carbamide peroxide paste and traditional sodium perborate/distilled water for intracoronal bleaching. Study design. Thirty patients with dark anterior teeth were divided into 2 groups (n = 15): group A: sodium perborate/ distilled water; and group B: sodium perborate/37% carbamide peroxide paste. The bleaching treatment limited each patient to the maximum of 4 changes of the bleaching agent. Initial and final color shades were measured using the Vita Lumin shade guide. Results. Data was analyzed with Wilcoxon test for initial and final comparison according to the bleaching agent, demonstrating efficacy of the bleaching treatment with both agents. Mann-Whitney test was used for comparison of the efficacy of the bleaching agents, showing that there was no significant difference between them. Conclusion. The sodium perborate/37% carbamide peroxide association for intracoronal bleaching has proven to be as effective as sodium perborate/distilled water. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 107: e43-e47)

Mitochondrial sequence data and Dipsacales phylogeny: Mixed models, partitioned Bayesian analyses, and model selection

Phylogenetic analyses of chloroplast DNA sequences, morphology, and combined data have provided consistent support for many of the major branches within the angiosperm, clade Dipsacales. Here we use sequences from three mitochondrial loci to test the existing broad scale phylogeny and in an attempt to resolve several relationships that have remained uncertain. Parsimony, maximum likelihood, and Bayesian analyses of a combined mitochondrial data set recover trees broadly consistent with previous studies, although resolution and support are lower than in the largest chloroplast analyses. Combining chloroplast and mitochondrial data results in a generally well-resolved and very strongly supported topology but the previously recognized problem areas remain. To investigate why these relationships have been difficult to resolve we conducted a series of experiments using different data partitions and heterogeneous substitution models. Usually more complex modeling schemes are favored regardless of the partitions recognized but model choice had little effect on topology or support values. In contrast there are consistent but weakly supported differences in the topologies recovered from coding and non-coding matrices. These conflicts directly correspond to relationships that were poorly resolved in analyses of the full combined chloroplast-mitochondrial data set. We suggest incongruent signal has contributed to our inability to confidently resolve these problem areas. (c) 2007 Elsevier Inc. All rights reserved.

Mixed multiplicities and the minimal number of generator of modules

Let (R, m) be a d-dimensional Noetherian local ring. In this work we prove that the mixed Buchsbaum-Rim multiplicity for a finite family of R-submodules of R(p) of finite colength coincides with the Buchsbaum-Rim multiplicity of the module generated by a suitable superficial sequence, that is, we generalize for modules the well-known Risler-Teissier theorem. As a consequence, we give a new proof of a generalization for modules of the fundamental Rees` mixed Multiplicity theorem, which was first proved by Kirby and Rees in (1994, [8]). We use the above result to give an upper bound for the minimal number of generators of a finite colength R-submodule of R(p) in terms of mixed multiplicities for modules, which generalize a similar bound obtained by Cruz and Verma in (2000, [5]) for m-primary ideals. (C) 2009 Elsevier B.V. All rights reserved.

Robust linear mixed models with skew-normal independent distributions from a Bayesian perspective

Linear mixed models were developed to handle clustered data and have been a topic of increasing interest in statistics for the past 50 years. Generally. the normality (or symmetry) of the random effects is a common assumption in linear mixed models but it may, sometimes, be unrealistic, obscuring important features of among-subjects variation. In this article, we utilize skew-normal/independent distributions as a tool for robust modeling of linear mixed models under a Bayesian paradigm. The skew-normal/independent distributions is an attractive class of asymmetric heavy-tailed distributions that includes the skew-normal distribution, skew-t, skew-slash and the skew-contaminated normal distributions as special cases, providing an appealing robust alternative to the routine use of symmetric distributions in this type of models. The methods developed are illustrated using a real data set from Framingham cholesterol study. (C) 2009 Elsevier B.V. All rights reserved.

Influence diagnostics in nonlinear mixed-effects elliptical models

In this work we propose and analyze nonlinear elliptical models for longitudinal data, which represent an alternative to gaussian models in the cases of heavy tails, for instance. The elliptical distributions may help to control the influence of the observations in the parameter estimates by naturally attributing different weights for each case. We consider random effects to introduce the within-group correlation and work with the marginal model without requiring numerical integration. An iterative algorithm to obtain maximum likelihood estimates for the parameters is presented, as well as diagnostic results based on residual distances and local influence [Cook, D., 1986. Assessment of local influence. journal of the Royal Statistical Society - Series B 48 (2), 133-169; Cook D., 1987. Influence assessment. journal of Applied Statistics 14 (2),117-131; Escobar, L.A., Meeker, W.Q., 1992, Assessing influence in regression analysis with censored data, Biometrics 48, 507-528]. As numerical illustration, we apply the obtained results to a kinetics longitudinal data set presented in [Vonesh, E.F., Carter, R.L., 1992. Mixed-effects nonlinear regression for unbalanced repeated measures. Biometrics 48, 1-17], which was analyzed under the assumption of normality. (C) 2009 Elsevier B.V. All rights reserved.

Improvement in the Reduction Behavior of Novel ZrO(2)-CeO(2) Solid Solutions with a Tubular Nanostructure by Incorporation of Pd

In this work, 1 wt % Pd/ZrO(2)-CeO(2) mixed oxide nanotubes with 90 mol % CeO(2) were synthesized following a very simple, high-yield procedure and their properties were characterized by synchrotron radiation X-ray diffraction, X-ray absorption near-edge spectroscopy (XANES), and scanning and high-resolution transmission electron microscopy (SEM and HRTEM). In situ XANES experiments were carried out under reducing conditions to investigate the reduction behavior of these novel nanotube materials. The Pd/CeO(2)-based nanotubes exhibited the cubic phase (Fm3m space group). The nanotube walls were composed of nanoparticles with an average crystallite size of about 7 nm, and the nanotubes exhibited a large specific surface area (85 m(2).g(-1)). SEM and HRTEM studies showed that individual nanotubes were composed of a curved sheet of these nanoparticles. Elemental analysis showed that the Ce:Zr:Pd ratios appeared to be approximately constant across space, suggesting compositional homogeneity in the samples. XANES results indicated that the extent of reduction of these materials is low and that the Ce(4+) state is in the majority over the reduced Ce(3+) state. The results suggest that Pd cations-most likely Pd(2+)-form a Pd-Ce-Zr oxide solid solution and that the Pd(2+) is stabilized against reduction in this phase. However, incorporation of the Pd (1 wt %) into the crystal lattice of the nanotubes also appeared to destabilize Ce(4+) against reduction to Ce(3+) and caused a significant increase in its reducibility.

Combustion iron distribution and deposition

[1] Iron is hypothesized to be an important micronutrient for ocean biota, thus modulating carbon dioxide uptake by the ocean biological pump. Studies have assumed that atmospheric deposition of iron to the open ocean is predominantly from mineral aerosols. For the first time we model the source, transport, and deposition of iron from combustion sources. Iron is produced in small quantities during fossil fuel burning, incinerator use, and biomass burning. The sources of combustion iron are concentrated in the industrialized regions and biomass burning regions, largely in the tropics. Model results suggest that combustion iron can represent up to 50% of the total iron deposited, but over open ocean regions it is usually less than 5% of the total iron, with the highest values (< 30%) close to the East Asian continent in the North Pacific. For ocean biogeochemistry the bioavailability of the iron is important, and this is often estimated by the fraction which is soluble ( Fe(II)). Previous studies have argued that atmospheric processing of the relatively insoluble Fe(III) occurs to make it more soluble ( Fe( II)). Modeled estimates of soluble iron amounts based solely on atmospheric processing as simulated here cannot match the variability in daily averaged in situ concentration measurements in Korea, which is located close to both combustion and dust sources. The best match to the observations is that there are substantial direct emissions of soluble iron from combustion processes. If we assume observed soluble Fe/black carbon ratios in Korea are representative of the whole globe, we obtain the result that deposition of soluble iron from combustion contributes 20-100% of the soluble iron deposition over many ocean regions. This implies that more work should be done refining the emissions and deposition of combustion sources of soluble iron globally.

Photoluminescence behavior of Eu(3+) ion doped into gamma- and alpha-alumina systems prepared by combustion, ceramic and Pechini methods

Al(2)O(3):Eu(3+)(1%) samples were prepared by combustion, ceramic, and Pechini methods annealed from 400 to 1400 degrees C. XRD patterns indicate that samples heated up to 1000 degrees C present disordered character of activated alumina (gamma-Al(2)O(3)). However, alpha-Al(2)O(3) phase showed high crystallinity and thermostability at 1200-1400 degrees C. The sample characterizations were also carried out by means of infrared spectroscopy (IR), scanning electron microscopy (SEM) and specific surface areas analysis (BET method). Excitation spectra of Al(2)O(3):Eu(3+) samples present broaden bands attributed to defects of Al(2)O(3) matrices and to LMCT state of O -> Eu(3+), however, the narrow bands are assigned to (7)F(0) -> (5)D(J),(5)H(J) and (5)L(J) transitions of Eu(3+) ion. Emission spectra of samples calcined up to 1000 degrees C show broaden bands for (5)D(0) -> (7)F(J) transitions of Eu(3+) ion suggesting that the rare earth ion is in different symmetry sites showed by inhomogeneous line broadening of bands, confirming the predominance of the gamma-alumina phase. For all samples heated from 1200 to 1400 degrees C the spectra exhibit narrow (5)D(0) -> (7)F(J) transitions of Eu(3+) ion indicating the conversion of gamma to alpha-Al(2)O(3) phases, a high intensity narrow peak around 695 nm assigned to R lines of Cr(3+) ion is shown. Al(2)O(3):Eu(3+) heated up to 1100 degrees C presents an increase in the Omega(2) intensity parameter with the increase of temperatures enhancing the covalent character of metal-donor interaction. The disordered structural systems present the highest values of emission quantum efficiencies (eta). CIE coordinates of Al(2)O(3):Eu(3+) are also discussed. (C) 2007 Elsevier Inc. All rights reserved.

Tetragonal-cubic phase boundary in nanocrystalline ZrO(2)-Y(2)O(3) solid solutions synthesized by gel-combustion

By means of synchrotron X-ray powder diffraction (SXPD) and Raman spectroscopy, we have detected, in a series of nanocrystalline and compositionally homogeneous ZrO(2)-Y(2)O(3) solid solutions, the presence at room temperature of three different phases depending on Y(2)O(3) content, namely two tetragonal forms and the cubic phase. The studied materials, with average crystallite sizes within the range 7-10 nm, were synthesized by a nitrate-citrate gel-combustion process. The crystal structure of these phases was also investigated by SXPD. The results presented here indicate that the studied nanocrystalline ZrO(2)-Y(2)O(3) solid solutions exhibit the same phases reported in the literature for compositionally homogeneous materials containing larger (micro)crystals. The compositional boundaries between both tetragonal forms and between tetragonal and cubic phases were also determined. (C) 2011 Elsevier B.V. All rights reserved.

QCD sum rules for the production of the X(3872) as a mixed molecule-charmonium state in B meson decay

We use QCD sum rules to calculate the branching ratio for the production of the meson X(3872) in the decay B -> X(3872)K, assumed to be a mixture between charmonium and exotic molecular vertical bar c (q) over bar vertical bar vertical bar q (c) over bar vertical bar states with J(PC) = 1(++). We find that in a small range for the values of the mixing angle, 5 degrees <= theta <= 13 degrees, we get the branching ratio B(B -> XK) = (1.00 +/- 0.68) x 10(-5), which is in agreement with the experimental upper limit. This result is compatible with the analysis of the mass and decay width of the mode J/psi(n pi) and the radiative decay mode J/psi gamma performed in the same approach. (C) 2011 Elsevier B.V. All rights reserved.

Electric field gradients in (111)In-doped (Hf/Zr)(3)Al(2) and (Hf/Zr)(4)Al(3) mixed compounds: ab initio calculations, perturbed angular correlation measurements and site preference

The quadrupolar hyperfine interactions of in-diffused (111)In -> (111)Cd probes in polycrystalline isostructural Zr(4)Al(3) and Hf(4)Al(3) samples containing small admixtures of the phases (Zr/Hf)(3)Al(2) were investigated. A strong preference of (111)In solutes for the contaminant (Zr/Hf)(3)Al(2) minority phases was observed. Detailed calculations of the electric field gradient (EFG) at the Cd nucleus using the full-potential augmented plane wave + local orbital formalism allowed us to assign the observed EFG fractions to the various lattice sites in the (Zr/Hf)(3)Al(2) compounds and to understand the preferential site occupation of the minority phases by the (111)In atoms. The effects of the size of the supercell and relaxation around the oversized In and Cd probe atoms were investigated in detail.

Effect of urea and glycine fuels on the combustion reaction synthesis of Mn-Zn ferrites: Evaluation of morphology and magnetic properties

The goal of this study is to evaluate the influence of the urea and glycine fuels on the synthesis of Mn-Zn ferrite by combustion reaction The morphology and magnetic properties of the resulting powders were investigated. The powders were characterized by X-ray diffraction (XRD), nitrogen adsorption (BET), scanning and transmission electron microscopy (SEM and TEM), and magnetic measurement of M x H curves. The X-lay diffraction patterns indicated that the samples containing urea resulted in the formation of crystalline powders and the presence of hematite as a secondary phase The samples containing glycine presented only the formation of crystalline and monophases (Mn,Zn)Fe(2)O(4). The average crystallite size was 18 and 35 nm and saturation magnetization was 3.6 and 75 emu/g, respectively, for the samples containing urea and glycine. The samples synthesized with glycine fuel showed better magnetic properties for application as soft magnetic devices. (C) 2009 Elsevier B.V All rights reserved

Infrared emissions, visible up-conversion, thermoluminescence and defect centres in Er(3)Al(5)O(12) phosphor obtained by solution combustion reaction

The Er(3)Al(5)O(12) phosphor powders were prepared using the solution combustion method. Formation and homogeneity of the Er(3)Al(5)O(12) phosphor powders have been verified by X-ray diffraction and energy-dispersive X-ray analysis respectively. The frequency up-conversion from Er(3)Al(5)O(12) phosphor powder corresponding to the (2)H(9/2) -> (4)I(15/2), (2)H(11/2) -> (4)I(15/2), (4)S(3/2) -> (4)I(15/2), (4)F(9/2) -> (4)I(15/2) and the infrared emission (IR) due to the (4)I(13/2) -> (4)I(15/2) transitions lying at similar to 410, similar to 524, similar to 556, 645-680 nm and at similar to 1.53 mu m respectively upon excitation with a Ti-Sapphire pulsed/CW laser have been reported. The mechanism responsible for the frequency up-conversion and IR emission is discussed in detail. Defect centres induced by radiation were studied using the techniques of thermoluminescence and electron spin resonance. A single glow peak at 430A degrees C is observed and the thermoluminescence results show the presence of a defect center which decays at high temperature. Electron spin resonance studies indicate a center characterized by a g-factor equal to 2.0056 and it is observed that this center is not related to the thermoluminescence peak. A negligibly small concentration of cation and anion vacancies appears to be present in the phosphor in accordance with the earlier theoretical predictions.

Effect of pH on the production of dispersed Bi4Ge3O12 nanoparticles by combustion synthesis

This paper reports the production of bismuth germanate ceramic scintillator (Bi4Ge3O12) by combustion synthesis (SHS) method, focusing on the influence of the synthesis parameters on the crystalline phases and agglomeration of the nanoparticles. The synthesis and sintering conditions were investigated through thermal analysis, X-ray diffraction as function of temperature, dilatometry and scanning electron microscopy. Well-dispersed Bi4Ge3O12 powder was accomplished by the combustion of the initial solution at pH 9, followed by low temperature calcination and milling. Sintered ceramics presented relative density of 98% and single crystalline Bi4Ge3O12 phase. The luminescent properties of the ceramics were investigated by photo- and radio- luminescence measurements and reproduced the typical Bi4Ge3O12 single-crystal spectra when excited with UV, beta and X-rays. The sintered ceramics presented light output of 4.4 x 10(3) photons/McV. (c) 2008 Published by Elsevier Ltd.