Root Canal Area Increase Promoted by the EndoSequence and ProTaper Systems: Comparison by Computed Tomography

Introduction: The aim of this study was to compare the increase of the root canal area after instrumentation with EndoSequence or ProTaper rotary systems. Methods: Twenty-two mesial root canals from mandibular molars were instrumented. Teeth were mounted on a base, numbered, and divided into 2 groups; teeth from 1-11 (PT group) were instrumented by using the ProTaper system, and teeth from 12-22 (ES group) were instrumented by using the EndoSequence system. Cone beam computed tomography was performed on all teeth before and after instrumentation. Measurements at 3,5, and 7 mm as well as differences in instrument performance were statistically compared by the Student t test at 5% significance level. Results: Both systems increased significantly the root canal area (P < .05) at all levels. Comparison between the rotary systems showed significantly greater increase (P < .05) for EndoSequence at 3 mm, with no statistically significant difference (P < .05) at the other levels. Conclusions: Both rotary systems increased significantly the root canal area. (J Endod 2010;36:1179-1182)

Schottky emission in nanoscopically crystallized Ce-doped SnO2 thin films deposited by sol-gel-dip-coating

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Calculation of the vacuum pressure gradient in field emission displays

The usual design of field-emission displays (FEDs) often results in high vacuum pressure gradients inside the glass plates of the device, and this is the main limitation to the widespread availability of large area FEDs. In this paper, we perform theoretical calculations using the finite element method for determining the pressure distributions in several pumping configurations, including a new FED configuration known as porous FED or pFED. The approach here is capable of clarifying the design issues influencing the final pressure relevant to the field-emission display devices. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Evaluating craniofacial asymmetry with digital cephalometric images and cone-beam computed tomography

Introduction: The aim of this study was to evaluate craniofacial asymmetry by using 2-dimensional (2D) poster-oanterior cephalometric images, 3-dimensional cone-beam computed tomography (CBCT), and physical measurements (gold standard). Methods: Ten dry human skulls were assessed, and radiopaque markers were placed on 17 skeletal landmarks. Twenty linear measurements were taken on each side to compare the right and left sides and to compare these measurements with the physical measurements made with a digital caliper. To acquire the 2D posteroanterior radiographs, an Extraoral Phosphor Storage Plate (Air Techniques, Chicago, Ill) was used as the image receptor with a Eureka x-ray-Duocon Machlett unit (Machlett Laboratores, Chicago, Ill). Three-dimensional imaging data were acquired from a CB MercuRay (Hitachi Medical, Tokyo, Japan). Results: on average, the right side was larger than the left for most of the 20 distances evaluated in the digital 2D and the CBCT images, and there was poor agreement between the digital 2D images and the physical measurements (kappa = 0.0609) and almost perfect agreement (kappa = 0.92) between the CBCT and physical measurements when individual measurements were considered. Conclusions: Human skulls, with no apparent asymmetry, had some differences between the right and left sides, with dominance for the right side but with no clinical significance. CBCT can better evaluate craniofacial morphology when compared with digital 2D images. (Am J Orthod Dentofacial Orthop 2011; 139: e523-e531)

Contrasting continuous emission versus freeze-out via HDT

The effect of continuous emission hypothesis on the two-pion Bose-Einstein correlation is discussed and compared with the corresponding results based on the usual freeze-out ansatz. Sizable differences in the correlation function are observed when comparing these two scenarios of the decoupling process. They could lead to entirely different interpretation of properties of the hot matter formed in high-energy heavy-ion collisions.

Morphology and Blue Photoluminescence Emission of PbMoO4 Processed in Conventional Hydrothermal

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Structural XANES characterization of Ca0.99Sm0.01TiO3 perovskite and correlation with photoluminescence emission

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Very Intense Distinct Blue and Red Photoluminescence Emission in MgTiO3 Thin Films Prepared by the Polymeric Precursor Method: An Experimental and Theoretical Approach

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Rugged, Portable Tungsten Coil Atomic Emission Spectrometer

Tungsten coil atomic emission spectrometry is an ideal technique for field applications because of its simplicity, low cost, low power requirement, and independence from cooling systems. A new, portable, compact design is reported here. The tungsten coil is extracted from an inexpensive 24 V, 250 W commercial light bulb. The coil is housed in a small, aluminum cell. The emission signal exits from a small aperture in the cell, while the bulk of the blackbody emission from the tungsten coil is blocked. The resulting spectra exhibit extremely low background signals. The atomization cell, a single lens, and a hand-held charge coupled device (CCD) spectrometer are fixed on a 1 x 6 x 30 cm ceramic base. The resulting system is robust and easily transported. A programmable, miniature 400 W solid-state constant current power supply controls the temperature of the coil. Fifteen elements are determined with the system (Ba, Cs, Li, Rb, Cr, Sr, Eu, Yb, Mn, Fe, Cu, Mg, V, Al, and Ga). The precision ranges from 4.3% to 8.4% relative standard deviation for repetitive measurements of the same solution. Detection limits are in the 0.04 to 1500 mu g/L range. Accuracy is tested using standard reference materials for polluted water, peach leaves, and tomato leaves. For those elements present above the detection limit, recoveries range from 72% to 147%.

Color tunability of intense upconversion emission from Er3+-Yb3+ co-doped SiO2-Ta2O5 glass ceramic planar waveguides

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Multicolor up conversion emission and color tunability in Yb3+/Tm3+/Ho3+ triply doped heavy metal oxide glasses

Multicolor and white light emissions have been achieved in Yb3+, Tm3+ and Ho3+ triply doped heavy metal oxide glasses upon laser excitation at 980 nm. The red (660 nm), green (547 nm) and blue (478 nm) up conversion emissions of the rare earth (RE) ions triply doped TeO2-GeO2-Bi2O3-K2O glass (TGBK) have been investigated as a function of the RE concentration and excitation power of the 980 nm laser diode. The most appropriate combination of RE in the TGBK glass host (1.6 wt% Yb2O3, 0.6 wt% Tm2O3 and 0.1 wt% Ho2O3) has been determined with the purpose to tune the primary colors (RGB) respective emissions and generate white light emission by varying the pump power. The involved infrared to visible up conversion mechanisms mainly consist in a three-photon blue up conversion of Tm3+ ions and a two-photon green and red up conversions of Ho3+ ions. The resulting multicolor emissions have been described according to the CIE-1931 standards. (C) 2011 Elsevier B.V. All rights reserved.

The compulsive-like aspect of the head dipping emission in rats with chronic electrolytic lesion in the area of the median raphe nucleus

Head dipping (HD) is a behavioral pattern considered to have a risk assessment or an exploratory role and is used as a complementary parameter to evaluate anxiety in experimental animals. Since rats with electrolytic lesion in the area of the median raphe nucleus displayed high frequencies of HD in a previous study, the present investigation was undertaken to confirm this observation and to determine its anxiety-related origin. HD episodes were counted in adult male Wistar rats (270-350 g) with electrolytic lesion (N = 11) and sham-lesioned controls (N = 12). When HD was measured for 60 min on an elevated open platform, lesioned rats emitted 13 times more HD than controls (264.7 ± 93.3 vs 20.3 ± 7.6 episodes), with the difference being statistically significant (P < 0.05). HD counts during 10-min sessions held 7, 14, 21, 27, and 63 days after lesion showed significantly higher means (range: 28.14 ± 5.38 to 62.85 ± 9.48) compared to sham-lesioned controls (range: 7.37 ± 1.13 to 8.5 ± 1.45). Normal rats stepped down into their home cages when the vertical distance between them and the cage was short (16 cm), and the step-down latencies increased with increasing depths (36.7 ± 7.92 to 185.87 ± 35.44 s). Lesioned rats showed a similar behavior when facing the shortest depth, but had a significantly increased number (23.28 ± 2.35 episodes) and latency (300 ± 0.00 s) of HD compared to normal rats (9.25 ± 1.37 episodes and 185.87 ± 35.44 s) when facing the greatest depth (30 cm). This suggests that HD may be a depth-measuring behavior related to risk assessment.

Visible emission from Er-doped SnO2 thin films deposited by sol-gel

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Carbon dioxide emission related to chemical properties of a tropical bare soil

In this work the relationship between CO2 emissions and the soil properties of a tropical Brazilian bare soil was investigated. Carbon dioxide emissions were measured on three different days at different soil temperature and the soil moisture conditions, and the soil properties were investigated at the same points that emissions were measured. The soil CO2 emissions were correlated to carbon content, cation exchange capacity and free iron content at the 65 points studied in an area of 100 x 100 m located in southern Brazil. (C) 2000 Elsevier B.V. Ltd. All rights reserved.

High resolution spectroscopy of (CH3OH)-C-13 around the 10R(20) CO2 laser emission: New FIR laser lines, frequency measurements and assignments

We investigated the IR absorption spectrum of (CH3OH)-C-13 around the frequency of the 10R(20) CO2 laser line. We found two absorption lines which can be excited by 10R(20) and studied the FIR laser emissions excited by this pump line using a waveguide CO2 laser of 300 MHz tunability: We report two new FIR laser lines of large offset, not previously observed due to their weakness and closeness to other stronger lines. We measured the frequencies of five FIR laser lines for the first time by an accurate heterodyne technique and present the complete assignments of the IR-FIR laser systems relative to this pump line. Furthermore we present new frequency values for two FIR laser lines whose frequencies had been previously wrongly measured. Copyright (C) 1997 Elsevier B.V. Ltd.