Qualitative analysis of two reconstruction techniques and their application in dentistry

Although visualization in the field of dentistry has some of the same requirements as the medicine field, the differences in goal demand specific approaches. This paper reports on the implementation of two fundamentally different approaches to reconstruction of structures from planar cross sections and their application to dentistry data. One of the approaches was an implementation of a distance-based sampling technique, and the other is a new algorithm, based on the Delaunay triangulation. Both were tested using contour data of teeth and the results are compared here in the light of the target applications, which are teaching and training dentistry, as well as simulation of dental procedures and illnesses. Widely mentioned problems encountered in local reconstruction methods such as marching cubes for these cases are clearly illustrated in this paper, and a very satisfactory alternative is given. © 2000 SPIE and IS&T.

Crystallographic and spectroscopic studies on palladium(II) complexes containing pyrazole and thiocyanate ligands

Mononuclear palladium(II) complexes containing both pyrazole-type ligands and thiocyanate, of general formula [Pd(SCN) 2(L) 2] {L = pyrazole (HPz) and l-phenyl-3-methylpyrazole (phmPz)} have been prepared and characterized by elemental analysis, i.r. and n.m.r. spectroscopy and by single crystal X-ray diffraction methods. The Pd atom in these structures lies on the crystallographic inversion center; in a square-planar coordination geometry made by two sulfur and two nitrogen atoms of the ligands, both in trans positions.

Synthesis and spectroscopic characterization of a novel coordination polymer of palladium(II) with pyrazole and azido ligands

The one-dimensional coordination polymer of palladium(II) with pyrazolato (Pz -) and azide (N 3 -) as bridging ligands, of formula [Pd 3(μ-N 3)(μ-Pz) 5] n, has been prepared. From IR and Raman studies it was evidenced the exobidentate nature of pyrazole ligands as well the μ-1,1-bridging coordination of azido groups. NMR experiments showed two sets of broadened signals with different intensities indicating the presence of pyrazolato groups in distinct chemical environments. The proposed structure of [Pd 3(μ-N 3)(μ-Pz) 5] n consists of a zigzag ribbon in which each (Pz) 2Pd(Pz) 2 entity is bound to two stacked planar units [Pd(μ-Pz)(μ-N 3)Pd core] with very weak Pd-Pd interaction, based on UV-Vis spectroscopy.

Erbium-activated HfO2-based waveguides for photonics

70SiO2 - 30HfO2 planar waveguides, activated by Er3+ concentration ranging from 0.3 to 1 mol%, were prepared by solgel route, using dip-coating deposition on silica glass substrates. The waveguides showed high densification degree, effective intermingling of the two components of the film, and uniform surface morphology. Propagation losses of about 1 dB/cm were measured at 632.8 nm. When pumped with 987 nm or 514.5 nm continuous-wave laser light, the waveguides showed the 4I 13/2→4I15/2 emission band with a bandwidth of 48 nm. The spectral features were found independent both on erbium content and excitation wavelength. The 4I13/2 level decay curves presented a single exponential profile, with a lifetime between 2.9-5.0 ms, depending on the erbium concentration.

Synthesis, characterization, and biological activity of a new palladium(II) complex with deoxyalliin

Synthesis, characterization, and biological activity of a new water-soluble Pd(II)-deoxyalliin (S-allyl-L-cysteine) complex are described in this article. Elemental and thermal analysis for the complex are consistent with the formula [Pd(C6H10NO2S)2]. 13C NMR, 1H NMR, and IR spectroscopy show coordination of the ligand to Pd(II) through S and N atoms in a square planar geometry. Final residue of the thermal treatment was identified as a mixture of PdO and metallic Pd. Antiproliferative assays using aqueous solutions of the complex against HeLa and TM5 tumor cells showed a pronounced activity of the complex even at low concentrations. After incubation for 24 h, the complex induced cytotoxic effect over HeLa cells when used at concentrations higher than 0.40 mmol/L. At lower concentrations, the complex was nontoxic, indicating its action is probably due to cell cycle arrest, rather than cell death. In agreement with these results, the flow cytometric analysis indicated that after incubation for 24 h at low concentrations of the complex cells are arrested in G0/G1. © 2005 NRC Canada.

Photoluminescence-structure relationships in ormosils for integrated optical devices

Planar waveguides with low losses in the infrared (from 0.6-1.1 dB/cm) were prepared with sol-gel derived poly(oxyethylene)/siloxane hybrid doped with zirconium(IV) n-propoxide (ZPO) and methacryloxypropyltrimethoxysilane (MAPTMS). The doped nanohybrids were characterized by small angle X-ray scattering, 29Si nuclear magnetic resonance and photoluminescence spectroscopy and compared with the undoped hybrid material. The results indicate an effective interaction between the zirconium particles and the siliceous nanodomains. © 2005 Materials Research Socicty.

Structure and properties of Ti4+-Ureasil organic-inorganic hybrids

Hybrid planar waveguides were prepared from Ti4+-acetylacetone (acac)-Ureasil sols deposited on glass substrates. Structural features have been investigated by spectroscopic measurements (Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS) and Raman scattering) and Small Angle X-ray Scattering (SAXS). Addition of Ti 4+-acac to the ureasil (Ti:Si molar ratio 1:1) leads to the formation of bonds between the Ti complex and the siloxane groups, whereas further addition of Ti4+ (Ti:Si molar ratio 5:1) leads to the additional formation of titanium-rich nanoclusters. The optical parameters of the waveguides such as refractive index, thickness, propagating modes and attenuation coefficient were measured at 632.8, 543.5 and 1550 nm by the prism coupling technique. The refractive index can be tuned by the Ti4+ relative content. The few microns thick planar waveguides support well confined propagating modes with low attenuation loss for all compositions. ©2006 Sociedade Brasileira de Química.

Magnetic resonance study of the crystallization behavior of InF3-based glasses doped with Cu2+, Mn2+ and Gd3+

The crystallization of fluoroindate glasses doped with Gd3+, Mn2+ and Cu2+ heat treated at different temperatures, ranging from the glass transition temperature (Tg) to the crystallization temperature (Tc), are investigated by electron paramagnetic resonance (EPR) and 19F nuclear magnetic resonance (NMR). The EPR spectra indicate that the Cu2+ ions in the glass are located in axially distorted octahedral sites. In the crystallized glass, the g-values agreed with those reported for Ba2ZnF6, which correspond to Cu2+ in a tetragonal compressed F- octahedron and to Cu2+ on interstitial sites with a square-planar F- co-ordination. The EPR spectra of the Mn2+ doped glasses exhibit a sextet structure due to the Mn2+ hyperfine interaction. These spectra suggest a highly ordered environment for the Mn2+ ions (close to octahedral symmetry) in the glass. The EPR spectra of the recrystallized sample exhibit resonances at the same position, suggesting that the Mn2+ ions are located in sites of highly symmetric crystalline field. The increase of the line intensity of the sextet and the decrease of the background line in the thermal treated samples suggest that the Mn2+ ions move to the highly ordered sites which contribute to the sextet structure. The EPR spectra of the Gd3+ doped glasses exhibit the typical U-spectrum of a s-state ion in a low symmetry site in disordered systems. The EPR of the crystallized glasses, in contrast, have shown a strong resonance in g ≈ 2.0, suggesting Gd3+ ions in environment close to cubic symmetry. The 19F NMR spin-lattice relaxation rates were also strongly influenced by the crystallization process that takes over in samples annealed above Tc. For the glass samples (doped or undoped) the 19F magnetization recoveries were found to be adjusted by an exponential function and the spin-lattice relaxation was characterized by a single relaxation time. In contrast, for the samples treated above Tc, the 19F magnetization-recovery becomes non-exponential. A remarkable feature of our results is that the changes in the Cu2+, Mn2+, Gd3+ EPR spectra and NMR relaxation, are always observed for the samples annealed above Tc. © 2006 Elsevier B.V. All rights reserved.

Is 44-hour better than 24-hour ambulatory blood pressure monitoring in hemodialysis?

The aim of this study is to evaluate if hemodialysis (HD) patients with similar blood pressure (BP) in the whole inter-HD period could have different target organ lesions and survival if the behavior of BP differs from the first to the second day of the inter-HD period. The present study compares 44-hour ambulatory BP monitoring (ABPM) patterns in 45 HD patients. Three BP patterns emerged: group A (n = 15) had similar BPs throughout (138 ± 11/88 ± 12 in the first 22 h vs. 140 ± 11/87 ± 12 mm Hg in the second 22-hour period); group B (n = 15) had a significant systolic BP rise from the first to the second period (132 ± 15/80 ± 12 vs. 147 ± 12/86 ± 13 mm Hg, p < 0.05); group C (n = 15) had significantly higher BPs (p < 0.05) than the other 2 groups throughout the whole inter-HD period, with no significant change between the 2 halves (172 ± 14/108 ± 12 vs. 173 ± 18/109 ± 14 mm Hg). Ventricular mass and survival during the 30-month follow-up period were statistically significantly better in group A, intermediate in group B and worse in group C. The data suggest that a 44-hour ABPM is more accurate than a 24-hour one in evaluating organ lesion and prognosis in HD patients. Copyright © 2006 S. Karger AG.

Contexto tectônico dos granitóides neoproterozóicos da faixa de dobramentos paraguai, MS e MT

The Neoproterozoic Granitic Province from the southeast of Mato Grosso and Mato Grosso do Sul region is constituted by seven distinctive granitic bodies, emplaced in the epimetamorphic rocks of the Cuiabá Group and related to the evolution of Paraguai Folded Belt. The Northern portion crops out in Mato Grosso State and is constituted by São Vicente, Araguaiana and Lajinha batholiths; the Southern portion crops out in the Mato Grosso do Sul State and is represented the Sonora, Coxim Rio Negro and Taboco massifs. The structural evolution is evidenced by the presence of three deformational phases, the first one is characterized by axial planar foliation (S 1), parallel or sub parallel to S 0, with attitude N60E/70NW; the second constitutes the most important phase for the tectonic arrangement and is defined by a slaty and/or crenulation cleavages (S 2), with attitude N10W/30SW and contact metamorphism associated to the emplacement of granitic bodies, the third phase is characterized by a weak retrometamorphic cleavage (S 3) with attitude N10E/ 80NW, that evolves local and gradually to strike-slip shear zones. The geological data suggest that this province was formed syn- to post tectonic to the D2 deformational set associated to the end of the collisional event in the Southeastern of the Amazonian Craton.

Interplanetary natural routes via Moon and Lagrangiam points L1 and L2

Swing-by techniques are extensively used in interplanetary missions to minimize fuel consumption and to raise payloads of spaceships. The effectiveness of this type of maneuver has been proven since the beginning of space exploration. According to this premise, we have explored the existence of a natural and direct links between low Earth orbits and the lunar sphere of influence, to obtain low-energy interplanetary trajectories through swing-bys with the Moon and the Earth. The existence of these links are related to a family of retrograde periodic orbits around the Lagrangian equilibrium point L1 predicted for the circular, planar, restricted three-body Earth-Moon-particle problem. The trajectories in these links are sensitive to small disturbances. This enables them to be conveniently diverted reducing so the cost of the swing-by maneuver. These maneuvers allow us a gain in energy sufficient for the trajectories to escape from the Earth-Moon system and to stabilize in heliocentric orbits between the Earth and Venus or Earth and Mars. On the other hand, still within the Earth sphere of influence, and taking advantage of the sensitivity of the trajectories, is possible to design other swing-bys with the Earth or Moon. This allows the trajectories to have larger reach, until they can reach the orbit of other planets as Venus and Mars.(3σ)Broucke, R.A., Periodic Orbits in the Restricted Three-Body Problem with Earth-Moon Masses, JPL Technical Report 32-1168, 1968.

Molecular and crystal structure of trans-(dicyanato)-bis(triphenylphosphine)palladium(II)

The triphenylphosphine (PPh3) displaces the acetonitrile from [PdCl2(CH3CN)2], and subsequent addition of the potassium cyanate causes substitution of the chloro ligand by NCO- to yield trans-[Pd(NCO)2(PPh3)2]. The complex was characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The title compound was crystallized in a triclinic system, space group P1 with a = 9.213(3)Å, b = 9.781(7)Å, c = 10.483(5)Å, α = 111.39(5)°, β = 93.49(3)°, γ = 103.81(4)°, V = 845.0(1)Å3, Z = 1. The coordination geometry around Pd(II) in this complex is nearly square-planar, with the ligands in a trans relationship. 2008 © The Japan Society for Analytical Chemistry.

Molecular and crystal structure of Di(μ-N,S-thiocyanato)-bis[(N,N-dimethylbenzylamine-C2, N)palladium(II)]

The cyclopalladated complex [Pd(C2,N-dmba)(μ-SCN)]2, where dmba = N,N-dimethylbenzylamine, was structurally characterized by single-crystal X-ray diffraction. This compound crystallizes in the monoclinic system, space group P21/n with a = 9.578(1)Å, b = 12.323(2)Å, c = 10.279(2)Å, β = 117.03(1)°, V = 1080.7(3)Å3, Z = 2. Each Pd(II) center displays a distorted square-planar coordination environment, formed by the C and N atoms from the dmba ligand, and one set of N and S atoms from the bridging SCN groups. 2009 © The Japan Society for Analytical Chemistry.

A decomposition heuristic for the maximal covering location problem

This paper proposes a cluster partitioning technique to calculate improved upper bounds to the optimal solution of maximal covering location problems. Given a covering distance, a graph is built considering as vertices the potential facility locations, and with an edge connecting each pair of facilities that attend a same client. Coupling constraints, corresponding to some edges of this graph, are identified and relaxed in the Lagrangean way, resulting in disconnected subgraphs representing smaller subproblems that are computationally easier to solve by exact methods. The proposed technique is compared to the classical approach, using real data and instances from the available literature. © 2010 Edson Luiz França Senne et al.

Optimal trajectory and solution of the inverse kinematics of a robotic manipulator by genetic algorithms

This paper presents the generation of optimal trajectories by genetic algorithms (GA) for a planar robotic manipulator. The implemented GA considers a multi-objective function that minimizes the end-effector positioning error together with the joints angular displacement and it solves the inverse kinematics problem for the trajectory. Computer simulations results are presented to illustrate this implementation and show the efficiency of the used methodology producing soft trajectories with low computing cost. © 2011 Springer-Verlag Berlin Heidelberg.