Effect of Spray Tips and Mix Deposition on Common Water Hyacinth Growing with Varied Population Arrangements of Salvinia and Water Lettuce

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Test of a Modular Fault Current Limiter for 220 V Line Using YBCO Coated Conductor Tapes With Shunt Protection

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

Experimental pancreas transplantation: the consequences of the portocaval shunt on the blood glucose, plasma insulin, and glucagon

A proposição foi realizada, no período pós-operatório imediato, em 40 ratos Wistar, distribuídos por sorteio em doi grupos: grupo NC, vinte ratos correspondentes ao grupo controle, não diabético, submetidos a operação simulada e o grupo PT, 20 ratos correspondentes ao grupo diabético que recebeu transplante de pâncreas heterotópico de ratos Wistar normais. Durante sete dias, antes do transplante, e 1, 3, 6, 12, 24, 48, 72, 96 horas após, determinava-se a glicose sanguínea, a insulina plasnática e o glucagon. Estes parâmetros eram obtidos também do grupo NC. Diabetes mellitus experimental era induzida pela administração intravenosa de aloxana. O grupo PT era imunosuprimido com ciclosporina A. O grupo NC apresentou níveis normais de glicose sanguínea, de insulina plásmica e de glucagon, durante todo o experimento. Foi encontrada nítida hiperinsulinemia no sangue venoso periférico do grupo PT. A insulina plasmática era significantemente maior no grupo PT comparada ao grupo NC começando 72 horas após o transplante. O glucagon plasmático, elevado no período pré-transplante, não se alterou após o transplante. Apesar de hiperinsulinemia e hiperglucagonemia, os níveis de glicose sanguínea eram elevados 6 horas após o transplante e mantiveram-se normais após este período. Considerando-se os níveis de glicose sanguínea 12 horas pós-transplante, não houve diferença estatisticamente significante entre os grupos PT e NC, até o sacrifício.

Micromorphologic assessment of CVD (chemical vapor deposition) and conventional diamond tips and their cutting effectiveness

The aim of this study was to compare the micromorphology of CVD diamond tips coupled to ultrasound with conventional high speed diamond tips after cavity preparations, and to measure the width and depth of the cavities obtained. Two hundred bovine teeth were divided into 20 subgroups. Each of the diamond tips (10 CVD and 10 conventional) were used to prepare 10 standardized cavities, using an apparatus that controlled the time (t: 27 s), speed (5.3 mm/s) and load (0.012 KGF) of the tip against the teeth during preparation. The unused and the used (after one, five and 10 preparations) tips were analyzed by scanning electronic microscopy. The images were randomly assessed by 3 examiners with regard to the presence or absence of micromorphologic alterations. Cavity measurements were made after visualization under a stereoscopic microscope. Cavity widths and depths were analyzed by the ANOVA Factorial test (p < 0.05). The CVD diamond tips presented less wear than the conventional tips after all the cavity preparations performed, but produced shallower cavities that were equivalent in width to those made by conventional tips after the fifth preparation. CVD diamond tips may be suggested as an alternative to conventional diamond tips due to their conservative preparation and greater longevity.

Evaluation of the Smear Layer and Hybrid Layer in Noncarious and Carious Dentin Prepared by Air Abrasion System and Diamond Tips

Purpose: To analyze the smear layer and the hybrid layer in noncarious and carious dentin prepared by different cutting instruments and restored with composite resin. Study design: Cavities were randomly prepared in 160 specimens (noncarious and artificial carious dentin) by high-speed diamond tips (KG Sorensen 1013), air abrasion system (Prepstart, Danville Engineering), ultrasonic tip (CVDentus 8.3231-1), and ultrasonic tip associated with ultrasonic cavitation by water for 10 s. Half of the cavities in each group were conditioned with 37% phosphoric acid for 15 s. The amount of smear layer and dentinal tubules present were analyzed using scanning electron microscopy and graded from 0 to 3. Cavities were prepared in another 20 noncarious specimens and 20 carious specimens and restored with adhesive composite resin system. The restorations were hemisected longitudinally and analyzed using scanning electron microscopy to evaluate the hybrid layer and resinous prolongation characteristics, using scores ranging from 1 to 6. Results: The data were statistically analyzed using Kruskal-Wallis and Dunn tests at 5% of significance level. There was evidence that the most efficient smear layer removal was the acid etching in the noncarious dentin and the water ultrasonic cavitation in the carious dentin. The hybrid layer formed on the noncarious and carious dentin prepared by the ultrasonic tip was more regular than in the specimens prepared by high-speed diamond tip, with many resinous prolongations. Conclusion: The ultrasonic tip seems to be a promising tool for carious dentin cavity preparation. Microsc. Res. Tech. 73:597-605, 2010. (C) 2009 Wiley-Liss, Inc.

Pulpal temperature increase with high-speed handpiece, ER : YAG laser and ultrasound tips

The aim of this study was to compare intrapulpal temperature increase produced by high-speed handpiece, Er:YAG laser and CVDentus ultrasound tips during cavity preparation. Thirty bovine mandibular incisors with an enamel/dentin thickness of 4 mm at buccal surface had their roots amputated and were allocated to the following groups (n=10): Group I- high-speed handpiece; Group II- noncontact Er:YAG laser (250 mJ/4Hz); and Group III- CVDentus ultrasouns tips. All devices were used with water cooling. Class V cavities were prepared to a depth of 3.5 mm, measured with a periodontal probe. A type T thermocouple was placed inside the pulp chamber to determine the temperature increase (degrees C), which was recorded by a data acquisition system ADS 2000 IP (Lynx Technology) linked to a notebook computer. Data were analyzed statistically by oneway ANOVA and Tukey's test (p=0.05). The mean temperature rises were: 1.10 degrees C ( 0.56) for Group 1, 0.84 degrees C (0.55) for Group II, and 3.00 degrees C (1.34) for Group III. There were no statistically significant differences (p > 0.05) between Groups I and II, but both of them differed significantly from Group III (p < 0.05). In conclusion, the use of Er:YAG laser and high-speed handpiece for cavity preparation resulted in similar temperature increase. Although ultrasound tips generated significantly higher intrapulpal temperature increase, it remained below the critical value of 5.5 degrees C and may be considered safe for use.

Effects of desflurane, sevoflurane and isoflurane on pulmonary shunt in dogs during spontaneous ventilation

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

Right-to-left shunt determination in dog lungs under inhalation anesthesia with rebreathing and non-rebreathing system

OBJETIVO: Comparar a formação de shunt venoso-arterial em pulmões de cães submetidos a anestesia geral inalatória utilizando-se sistemas de anestesia com e sem reinalação, com fração inspirada de oxigênio de 0,4 e 0,9, respectivamente. MÉTODOS: Empregaram-se 20 cães induzidos com tiopental sódico (30mg/kg) e mantidos com sevoflurano (3%) e alocados em dois grupos (n=10); os animais de GI foram ventilados com modalidade controlada em sistema semifechado, sem reinalação, F I O2 = 0,9, e os de GII, com modalidade controlada, sistema semifechado, com reinalação e F I O2 = 0,4. Os atributos analisados durante o experimento foram: freqüência cardíaca, pressão arterial média, shunt pulmonar venoso-arterial, hematócrito, hemoglobina, pressão parcial de oxigênio arterial, pressão parcial de oxigênio no sangue venoso misto, saturação de oxigênio no sangue venoso misto, pressão parcial de dióxido de carbono arterial e pressão de vapor de água nos alvéolos (P VA). RESULTADOS: A P VA foi significativamente maior em GII. A análise estatística dos valores encontrados de shunt mostrou que GI e GII apresentaram diferenças significativas, sendo que os resultados de GI são maiores que os de GII em todos os momentos avaliados. Já a análise de momentos dentro de um mesmo grupo não demonstrou diferenças. CONCLUSÃO: O sistema de anestesia sem reinalação com F I O2 = 0,9 desenvolveu maior grau de shunt pulmonar venoso-arterial que o sistema de anestesia com reinalação e F I O2 = 0,4. A umidificação dos gases em GII contribuiu para diminuir o shunt.

Genotoxicity and mutagenicity of water contaminated with tannery effluents, as evaluated by the micronucleus test and comet assay using the fish Oreochromis niloticus and chromosome aberrations in onion root-tips

Cytotoxicity of metals is important because some metals are potential mutagens able to induce tumors in humans and experimental animals. Chromium can damage DNA in several ways, including DNA double strand breaks (DSBs) which generate chromosomal aberrations, micronucleus formation, sister chromatid exchange, formation of DNA adducts and alterations in DNA replication and transcription. In our study, water samples from three sites in the Córrego dos Bagres stream in the Franca municipality of the Brazilian state of São Paulo were subjected to the comet assay and micronucleus test using erythrocytes from the fish Oreochromis niloticus. Nuclear abnormalities of the erythrocytes included blebbed, notched and lobed nuclei, probably due to genotoxic chromium compounds. The greatest comet assay damage occurred with water from a chromium-containing tannery effluent discharge site, supporting the hypothesis that chromium residues can be genotoxic. The mutagenicity of the water samples was assessed using the onion root-tip cell assay, the most frequent chromosomal abnormalities observed being: c-metaphases, stick chromosome, chromosome breaks and losses, bridged anaphases, multipolar anaphases, and micronucleated and binucleated cells. Onion root-tip cell mutagenicity was highest for water samples containing the highest levels of chromium.

Possible shunt compensation strategies based on Conservative Power Theory

Considering the Conservative Power Theory (CPT), this paper proposes some novel compensation strategies for shunt passive or active devices. The CPT current decompositions result in several current terms (associated with specific physical phenomena), which were used for the definition of different selective current compensators, in terms of minimizing particular disturbing effects. Simulation results have been demonstrated in order to validate the possibilities and performance of the proposed strategies for single and three-phase four wired circuits.

Effectiveness of intraoral suction systems and aspirating tips for evacuation of aluminum oxide particles during use of air-abrasion

Aim: The purpose of this study was to compare the effectiveness of a high-volume evacuation and a conventional intraoral suction system and aspirating tips for capturing aluminum oxide particles during use of an air-abrasion device. Methods: A phantom head was fixed at the dental chair head with secured a metallic device with 5 horizontal shafts, corresponding to operator's clockrelated working positions, and one vertical shaft to simulate the operator's nasal cavity. Petri plates were fixed to the shafts at distances of 20, 40 and 60 cm from the center of the oral cavity of the phantom head to collect the aluminum oxide particles spread over during air abrasion. The dust was aspirated with two types of suction tips used with both suction systems: a conventional saliva ejector and a saliva ejector customized by the adaptation of a 55-mm-diameter funnel. Results: The amount of particles showed that the greatest abrasive particle deposition occurred at a distance of 20 cm from the center of the oral cavity of the phantom head at 9 o'clock operatory position with the conventional saliva ejector attached to high-volume evacuation system. Conclusions: The greatest deposition of aluminum oxide particles occurred at the shortest distance between the operator and the center of the oral cavity, while using the high-volume evacuation system associated to the conventional suction tip.

Possible shunt compensation strategies based on conservative power theory

Considering the Conservative Power Theory (CPT), this paper proposes some novel compensation strategies for shunt passive or active devices. The CPT current decompositions result in several current terms, which are associated with specific physical phenomena (average power consumption P, energy storage Q, load and source distortion D, unbalances N). These current components were used in this work for the definition of different current compensators, which can be selective in terms of minimizing particular disturbing effects. Compensation strategies for single and three-phase four-wire circuits have also been considered. Simulation results have been demonstrated in order to validate the possibilities and performance of the proposed strategies. © 2010 IEEE.

Test results of fault current limiter using YBCO tapes with shunt protection

A Fault Current Limiter (FCL) based on high temperature superconducting elements with four tapes in parallel were designed and tested in 220 V line for a fault current peak between 1 kA to 4 kA. The elements employed second generation (2G) HTS tapes of YBCO coated conductor with stainless steel reinforcement. The tapes were electrically connected in parallel with effective length of 0.4 m per element (16 elements connected in series) constituting a single-phase unit. The FCL performance was evaluated through over-current tests and its recovery characteristics under load current were analyzed using optimized value of the shunt protection. The projected limiting ratio achieved a factor higher than 4 during fault of 5 cycles without degradation. Construction details and further test results will be shown in the paper. © 2010 IOP Publishing Ltd.