Ex vivo evaluation of the effectiveness of bleaching agents on the shade alteration of blood-stained teeth

Aim To evaluate ex vivo effectiveness of the three formulations of bleaching materials for intracoronal bleaching of root filled teeth using the walking bleach technique.Methodology Extracted premolar teeth were stained artificially with human blood. After biomechanical preparation, the root canals were filled and a 3-mm thick intermediate base of zinc phosphate cement was placed at the level of the cementoenamel junction. The teeth were divided into four groups (n = 12): C (control, without bleaching material), A1 (sodium perborate + distilled water), A2 (sodium perborate + 10% carbamide peroxide) and A3 (sodium perborate + 35% carbamide peroxide). The bleaching materials were changed at 7 and 14 days. Evaluation of shade was undertaken with aid of the VITA Easyshade (TM) (Delta E*ab) and was performed after tooth staining and at 7, 14 and 21 days after bleaching, based on the CIELAB system. Data were analysed by ANOVA for repeated measurements, Tukey and Dunnett tests (alpha = 0.05).Results The Tukey test revealed that group A1 (10.58 +/- 4.83 Delta E*ab) was statistically different from the others (A2, 19.57 +/- 4.72 Delta E*ab and A3, 17.58 +/- 3.33 Delta E*ab), which were not different from each other. At 7 days: A1 was significantly different from A2; at 14 and 21 days: A2 and A3 were significantly better than A1; the Dunnett test revealed that the control group was different from A1, A2 and A3 at all periods (P < 0.05).Conclusion Sodium perborate associated with both 10% and 35% carbamide peroxide was more effective than when associated with distilled water.

Multi-criteria spatial decision analysis for demarcation of greenway: A case study of the city of Rio Claro, São Paulo, Brazil

Concern regarding hydrological resources has been a theme of growing importance in Brazil, associating the development of new management policies and maintenance of natural areas related to rivers. An efficient way to maintain natural areas around rivers has been the development of greenways, and some cites have already adopted specific legislation in this respect. Following this growing evolution in the treatment of hydrological resources, this study was carried out to demarcate a greenway along the Corumbatai River in the state of São Paulo, Using multi-criteria analysis in a GIS environment. First, thematic maps were elaborated based on Landsat 7 satellite, aerial photographs and digital topographic base, Supported by field activities. With the use of multi-criteria analysis, for which ad hoe consultations were conducted to attribute weights to the thematic maps, a suitability map was elaborated for the allocation of the greenway. Sites that should be included in the greenway were also selected, such as areas appropriate for leisure activities, and ecologically important areas. Based on the suitability map, a pathway analysis was done, connecting the relevant points of interest, thus generating a greenway that runs along the Corumbatai River, with the aim of contributing to the conservation of this important hydrological resource. (c) 2007 Elsevier B.V. All rights reserved.

Complete Assignments of ¹H and 13C-NMR Spectra of the 3,4-seco-Triterpene Canaric Acid isolated from Rudgea jasminoides

O ácido canárico 1 foi isolado das folhas de Rudgea jasminoides. A substância isolada é um derivado triterpênico do tipo seco-lupano e teve sua estrutura elucidada com base nos dados espectrais, principalmente em experimentos de RMN a 1D e 2D. O sitosterol, o estigmasterol e os ácidos ursólico e oleanólico também foram isolados.

Seed morphology and post-seminal development of Tillandsia L. (Bromeliaceae) from the Campos Gerais, Paraná, Southern Brazil

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

Yield of four Agaricus bisporus strains in three compost formulations and chemical composition analyses of the mushrooms

Três formulações de composto, à base de palhas de Cynodom dactylon (L.) Pers. (cultivares Coast-cross e Tyfton) e Aveia-Avena sativa, foram testadas no cultivo das linhagens ABI-01/01, ABI-04/02, ABI-05/03 e ABI-06/04 de A. bisporus. O delineamento experimental foi em esquema fatorial, inteiramente casualizado com 12 tratamentos (4 linhagens de A. bisporus x 3 tipos de composto) e 8 repetições. Cada unidade experimental constou de uma caixa com 1212,5 kg de composto fresco úmido. Os dados foram submetidos à análise de variância e as médias foram comparadas pelo teste de Tukey. de acordo com os resultados obtidos verificou-se que a produção de cogumelos foi influenciada pela linhagem e/ou pelo tipo de composto. Também verificou-se que o teor de proteína bruta, cinzas e fibra bruta de basidiomas variou com a linhagem de A. bisporus e com o tipo de palha utilizada na formulação do composto.

Feeding habits of the atlantic spotted dolphin, Stenella frontalis, in southeastern Brazil

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

A multimetric index based on fish fauna for the evaluation of the biotic integrity of streams at a mesohabitat scale

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

Gastric cryptosporidiosis as a clue for the diagnosis of the acquired immunodeficiency syndrome

Infecções oportunistas do trato gastrointestinal constituem ameaça à população crescente de portadores de imunossupressão. O comprometimento do estômago por Cryptosporidium é incomum. Quando identificado no exame histopatológico da mucosa gástrica, é mandatória a investigação do estado imunológico do hospedeiro. São apresentados os dados clinicopatológicos e endoscópicos de uma paciente de 64 anos com gastrite erosiva associada à infecção por Cryptosporidium. O encontro deste agente oportunista no exame histopatológico da mucosa gástrica foi fundamental para esclarecer a doença de base da paciente, que era a síndrome da imunodeficiência adquirida.

Postharvest conservation of the tuberous roots of Pachyrhizus Ahipa (Wedd) Parodi

O objetivo deste trabalho foi avaliar o período de armazenamento em diferentes temperaturas e embalagens na conservação das raízes de Pachyrhizus ahipa. As raízes foram colhidas, lavadas e armazenadas em bandejas de isopor, no refrigerador, câmara fria e à temperatura ambiente. As embalagens utilizadas foram PVC, saco plástico e sem embalagem (controle). As bandejas foram retiradas do seu ambiente de armazenamento e analisadas quanto a acidez total titulável, sólidos solúveis totais, pH, teores de cinzas, lipídios, carboidrato total e proteínas em base seca. A menor perda de massa das raízes foi em câmara fria e em saco plástico. A ATT manteve-se maior nas raízes armazenadas em câmara fria e na embalagem de PVC; os menores teores de SST foram observados em câmara fria não variando entre as embalagens. em todos os tratamentos a porcentagem média de carboidratos foi 84,9%. A porcentagem de lipídios foi maior nas raízes armazenadas em temperatura ambiente, entretanto, o teor de proteína e cinzas foram maiores nas armazenadas na geladeira. A melhor condição para o armazenamento das raízes é em câmara fria e embaladas com saco plástico, onde as raízes mantiveram a qualidade apropriada para comercialização durante até 30 dias de armazenamento.

The Effect of the Aminic Substituent on the Thermal Decomposition of Cyclic Dithiocarbamates

Estudos termogravimétricos e calorimétricos diferenciais para ditiocarbamatos de NH4+, Na+, Zn2+, Cd2+ e Pb2+, derivados de aminas cíclicas contendo nitrogênio como heteroátomos, foram realizados em atmosferas de ar e nitrogênio, para avaliar a influência da tensão angular dos anéis na decomposição térmica destes compostos, em relação à formação de tiocianatos metálicos como via de decomposição. Os intemediários formados foram caracterizados por difração de raios-X, tendo sido encontrados oxissulfatos de Zn2+, Cd2+ e Pb2+, sob atmosfera de ar, o que sugere a decomposição térmica nestas condições como via sintética para estes compostos. Os produtos de decomposição final obtidos foram sulfetos metálicos sob nitrogênio e óxidos dos metais de transição e sulfato de sódio sob ar. Entalpias de fusão são também descritas, com base nos resultados de DSC.

Polymorphisms of the DNA repair genes XRCC1 and XRCC3 in a Brazilian population

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

ANTAGONISM OF THE MYOTOXIC EFFECTS OF BOTHROPS-JARARACUSSU VENOM AND BOTHROPSTOXIN BY POLYANIONS

The effects of heparin and other polyanions on the myotoxicity of Bothrops jararacussu venom and purified bothropstoxin (BthTX) were investigated. The release rate of creatine kinase (CK) from isolated extensor digitorum longus muscle and the plasma CK activity of mice were used to quantify the results. The myotoxic effects of B. jararacussu venom or BthTX were inhibited by preincubation of these agents with one of the following: a heterogeneous heparin preparation (designated 'heparin'), low mol. wt heparin (H-4500) or dextran sulfates (DS-8000 and DS-500,000). Non-sulfated dextran (D-40,000) and two chondroitin sulfates were ineffective. The antimyotoxic effects of the polyanions are ascribed to their forming inactive acid-base complexes with the basic myotoxins of Bothrops venoms. Gel-filtration experiments in Sephadex provided direct evidence for complex formation between heparin and BthTX. Intravenous (i.v.) administration of H-4500 or DS-8000 opposed the increase in plasma CK activity induced by a subsequent i.m. injection of venom or BthTX. In contrast, pretreatment with i.v. heparin or DS-500,000 enhanced the venom-induced increase in plasma CK activity. This effect was not observed (1) when the animals were treated with a polyvalent antivenom, which inhibits the coagulation and local stasis induced by Bothrops venoms, and (2) when BthTX, which has no thrombotic or hemorrhagic properties, was the myotoxic agent. The potentiation of the venom-induced increase in plasma CK activity by heparin and DS-500,000 is ascribed to improved washout of the CK released from damaged fibers, because of the anticoagulant properties of the drugs.

Submucous myomas: A new presurgical classification to evaluate the viability of hysteroscopic surgical treatment - Preliminary report

STUDY OBJECTIVE: To develop a new preoperative classification of submucous myomas for evaluating the viability and the degree of difficulty of hysteroscopic myomectomy.DESIGN: Retrospective study (Canadian Task Force classification II-3)SETTING: University teaching hospitals.PATIENTS: Fifty-five patients who underwent hysteroscopic resection of submucous myomas.INTERVENTION: the possibility of total resection of the myoma, the operating time, the fluid deficit, and the frequency of any complications were considered. The myomas were classified according to the Classification of the European Society for Gynaecological Endoscopy (ESGE) and by our group's new classification (NC), which considers not only the degree of penetration of the myoma into the myometrium, but also adds in such parameters as the distance of the base of the myoma from the uterine wall, the size of the nodule (cm), and the topography of the uterine cavity. The Fisher's exact test, the Student's t test, and the analysis of variance test were used in the statistical analysis. A p value less than .05 in the two-tailed test was considered significant.MEASUREMENTS AND MAIN RESULTS: In 57 myomas, hysteroscopic surgery was considered complete. There was no significant difference among the three ESGE levels (0, 1, and 2). Using the NC, the difference between the numbers of complete surgeries was significant (p < .001) for the two levels (groups I and H). The difference between the operating times was significant for the two classifications. With respect to the fluid deficit, only the NC showed significant differences between the levels (p = .02).CONCLUSIONS: We believe that the NC gives more clues as to the difficulties of a hysteroscopic myomectomy than the standard ESGE classification. It should be stressed that the number of hysteroscopic myomectomies used in this analysis was low, and it would be interesting to evaluate the performance of the classification in a larger number of patients. (c) 2005 AAGL. All rights reserved.

Laser weld: microstructure and corrosion study of Ag-Pd-Au-Cu alloy of the dental application

The laser Welding process was introduced into dentistry by the end of the 1980s, resulting on a great impulse to that area with the development of cheaper and smaller equipment, using simpler technique. This allowed greater use of that process on the confection of prostheses compared to the brazing process since the heat source for that process is a concentrated light beam of high power, which minimizes distortion problems on the prosthetic pieces. Ag-Pd-Au-Cu alloy used on the confection of dental implant prostheses was observed before and after subjection to the laser welding process. The microstructure was analyzed with the. use of optic microscopy and the corrosion resistance was studied by the traditional electrochemical techniques and by electrochemical impedance, under environmental conditions simulating the aggressiveness found in the mouth cavity. A structural change was detected on the weld area, which presented a refined microstructure deriving from the high-speed cooling. The base metal out of the weld area presented a fusion coarse microstructure. The electrochemical essays showed differences on the potentiodynamic polarization behavior in both weld and metal base areas, indicating superior corrosion resistance in the weld area. The impedance spectra were characterized by capacitive distorted components, presenting linear impedance in the low frequencies area. (C) 2002 Elsevier B.V. B.V. All rights reserved.