Osmocondicionamento de sementes de salsa (Petroselinum sativum Hoffm.) em diferentes potenciais hídricos

A germinação de sementes de salsa (Petroselinum sativum Hoffm.) é lenta e desuniforme, sendo a contagem do teste padrão de germinação recomendada aos 10 e 28 dias e a emergência em campo é relativamente longa, justificando o uso de técnicas que acelerem e uniformizem o processo germinativo: um método promissor é o osmocondicionamento. No presente trabalho, objetivou-se avaliar os efeitos dos diferentes potenciais de osmocondicionamento, com PEG 6000, na germinação de sementes de salsa e identificar o potencial osmótico ótimo para aumentar a germinação destas sementes. Sementes das cultivares Lisa e Portuguesa de dois lotes, adquiridas no comércio local foram osmocondicionadas pelo método de imersão direta das mesmas em soluções aquosas com potencial hídrico: 0,0, -0,5, -1,0 e -1,5 MPa, obtidos com a adição de PEG 6.000, sob aeração constante a 25ºC por 144 horas, como testemunha utilizaram-se sementes não osmocondicionadas. As variáveis analisadas foram: porcentagem de germinação (10 e 28 dias), velocidade de germinação e índice de velocidade de germinação. O osmocondicionamento aumenta a porcentagem e a velocidade de germinação de sementes de salsa, sendo que, o potencial osmótico indicado situa-se entre -1,0 e -1,5 MPa.

Curva de absorção de água em sementes de atemóia (Annona cherimola Mill. x Annona squamosa L.) cv. Gefner

O presente trabalho teve o objetivo de caracterizar a curva de absorção de água em sementes de atemóia (Annona cherimola Mill x Annona squamosa L.) cv. Gefner, submetidas a três métodos de embebição: sementes submersas em água destilada (MSSA), sementes entre papel de filtro embebido em água destilada acondicionada em caixa tipo gerbox (MPEA) e teste-padrão (MTP), com sementes mantidas em rolo de papel de filtro umedecido em água destilada. O delineamento experimental foi o inteiramente casualizado, com 6 tratamentos e 4 repetições de 25 sementes por parcela, constituídos por três métodos de embebição, empregando-se sementes vivas e mortas. O tempo de embebição entre 27; 34 e 47 horas, nos métodos MTP, MPEA e MSSA, representam indicativo para tratamento de sementes, podendo funcionar como tempo mínimo necessário para embebição em solução com reguladores vegetais. Conclui-se que os métodos que caracterizaram as três fases de absorção de água em sementes de atemóia foram o MTP e MPEA com mudança entre as fases I e II após 27 e 34 horas, respectivamente, atingindo a fase III com 234 horas, o que permite determinar o tempo de imersão para tratamentos pré-germinativos.

Uso de reguladores vegetais na conservação refrigerada de acerolas (Malpighia glabra L.)

Com o objetivo de avaliar o uso do ácido giberélico (GA3) e da benzilaminopurina (BAP) na conservação de acerolas (Malpighia glabra L.) colhidas no estádio verde e armazenadas sob refrigeração, acerolas foram submetidas aos seguintes tratamentos, sob imersão por 30 minutos: controle (água), 50 mg L-1 e 100 mg L-1 de GA3, 50 mg L-1 e 100 mg L-1 de BAP. Após os tratamentos, os frutos foram deixados para secar ao ar em local fresco e, então, embalados em bandejas de isopor cobertas com filme de polietileno e armazenados em câmara B.O.D a 8±1ºC, por 14 dias. As avaliações foram realizadas em intervalos de 4 dias. Os frutos amostrados foram submetidos a avaliações de coloração, teor de sólidos solúveis, acidez titulável e teor de ácido ascórbico. A análise dos resultados mostrou que a aplicação dos reguladores não teve efeito no aumento da conservação refrigerada de acerolas e que somente a refrigeração foi suficiente para conservá-las durante 14 dias.

Enraizamento de estacas de atemoieira (Annona Cherimola Mill. x A. squamosa L.) cv. Gefner submetidas a tratamento lento e rápido com auxinas

Realizou-se este trabalho, com o objetivo de avaliar o uso de concentrações de diferentes auxinas no enraizamento de estacas de atemoieira (Annona cherimola Mill. x A. squamosa L.) cv. Gefner, empregando-se tratamento lento e rápido. O delineamento experimental empregado foi inteiramente casualizado, em esquema fatorial 3x7 (auxinas x concentrações), com 5 repetições de 12 estacas por parcela, para cada método de aplicação de auxina (lento e rápido). As estacas foram tratadas com os reguladores vegetais, por meio da imersão da base em soluções, contendo IBA, NAA e 2,4-D, durante 24 horas (tratamento lento) nas concentrações 0 (testemunha), 50, 100, 200, 300, 400 e 500 mg L-1 de cada regulador e 5 segundos (tratamento rápido) nas concentrações 0 (testemunha), 500, 1000, 2000, 3000, 4000 e 5000 mg L-1 de cada regulador. As variáveis avaliadas foram: porcentagem de estacas sobreviventes, enraizadas, sobreviventes com calos, comprimento de raiz por estaca, porcentagem de estacas enraizadas com folhas remanescentes, com brotação e com folhas remanescentes e brotação. Para o enraizamento de estacas de atemoieira cv. 'Gefner' conclui-se que, o tratamento lento, com 200 mg L-1 de NAA, proporcionou incremento ao processo, da mesma forma que o tratamento rápido com IBA, independente da concentração.

Métodos de superação da dormência e temperatura na germinação de sementes de dioclea violácea

The aim of this experiment was to overcome the dormancy and the effect of different temperatures in Dioclea violacea seeds' germination. Two experiments were developed. In the first, it was studied the use of chemical and mechanical scarification in the overcome dormancy seeds. Therefore, were accomplished seven treatments with four replications of 15 seeds each. The experiment constituted of one testify treatment, five chemical scarification treatments (1, 2, 3, 4 and 5 hours of immersion in concentrated sulfuric acid - H(2)SO(4)) and one mechanical scarification treatment. In the second experiment, was studied the temperature effects on germination seeds; it was constituted on six treatments with four replications with 12 seeds each. The treatments constituted of constant temperatures 15 degrees C, 20 degrees C, 25 degrees C, 30 degrees C and 35 degrees C and the alternate temperature 20-30 degrees C ( 16 and 8 hours, respectively). Germination, died seeds, hard seeds percentages, medium time germination and germination speed index were determined. The data were submitted to the variance analysis, and the averages compared by the Tukey test to 5% of probability and regression analysis. It was observed that the dormancy overcome of Dioclea violacea seeds can be done with chemical scarification, 3 to 5 hours in H(2)SO(4), as much as with mechanical scarification. Also, it was possible to conclude that Dioclea violacea seeds germinate in a wide temperature strip, with constant temperatures of 20 degrees C, 25 degrees C and 35 degrees C benefit the germination process.

Antiulcerogenic and analgesic effects of the Austroplenckia populnea extracts in mice

Austroplenckia populnea (Reiss.) Lund. is a Brazilian Cerrado plant belonging to the Celastraceae family. Hexane and methanol extracts of leaves were investigated for their antiulcerogenic (ethanol and indomethacin/bethanecol induced gastric damage) and analgesic (writhing and tail-flick tests) activities in mice. Acute toxic effects also were evaluated. Oral administration of both extracts at a dose of 1000 mg/kg significantly reduced the total area of the lesion, the relative area of lesion and the ulcerative index in ethanol-induced gastric damage, but both extracts were inactive in the indomethacin/bethanecol-induced gastric damage test. A dose dependent effect was determined with the hexane extract in the ethanol-induced lesions test. The hexane and methanol extracts reduced the number of contortions in the writhing test, but both extracts were inactive in the tail-flick immersion test. Copyright (C) 2002 John Wiley Sons, Ltd.

Qualidade de couve-chinesa minimamente processada e tratada com diferentes produtos

O objetivo deste trabalho foi avaliar a qualidade de couve-chinesa minimamente processada e tratada com cloreto de cálcio (CaCl2), ácido ascórbico (vitamina C), ácido etileno-diamino-tetracético (EDTA) e mantida sob refrigeração. Foram realizados os seguintes tratamentos: T1: testemunha (imersão em água contendo 50 mg L-1 clorin/5 minutos); T2: imersão em solução contendo CaCl2 a 1%/5 minutos; T3: imersão em solução contendo CaCl2 a 2%/5 minutos; T4: imersão em solução contendo vitamina C a 1%/5 minutos; T5: imersão em solução contendo Vitamina C a 2%/5 minutos; T6: imersão em solução contendo EDTA a 1%/5 minutos; e T7: imersão em solução contendo EDTA a 2%/5 minutos. Após a realização dos tratamentos a couve-chinesa foi centrifugada, embalada em bandejas de polietileno expandido, recoberta com policloreto de vinila (PVC) e armazenada em temperatura de 5 ± 1 °C e umidade relativa (UR) de 90 ± 2% por 8 dias. As análises físico-químicas, químicas e sensoriais foram realizadas de dois em dois dias. A presença de Salmonella foi verificada somente após a realização dos tratamentos. A partir dos resultados obtidos procedeu-se à análise de variância (ANAVA) e aplicou-se o teste de Tukey considerando-se um nível de significância p < 0,05. Houve influência significativa dos diferentes tratamentos nas características físico-químicas e químicas, como também nas avaliações da aparência geral e escurecimento. Não foi detectada presença de Salmonella em nenhum dos tratamentos realizados. de acordo com os resultados obtidos conclui-se que a couve-chinesa minimamente processada nas condições experimentais utilizadas só estaria apta para o consumo até o quarto dia de armazenamento.

Acaricidal activity of ethanolic extract from aerial parts of Tagetes patula L. (Asteraceae) against larvae and engorged adult females of Rhipicephalus sanguineus (Latreille, 1806)

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

Determination of the LC50 of selamectin (active principle of the antiparasitic Revolution (R), Pfizer) applied on engorged female of the tick Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Toxicity effect of the acaricide fipronil in semi-engorged females of the tick Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae): Preliminary determination of the minimum lethal concentration and LC50

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

Determination of LC50 of permethrin acaricide in semi-engorged females of the tick Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae)

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

Vinegar as an antimicrobial agent for control of Candida spp. in complete denture wearers

The use of denture is known to increase the carriage of Candida in healthy patients, and the proliferation of Candida albicans strains can be associated with denture-induced stomatitis. The aim of this study was to evaluate the use of vinegar as an antimicrobial agent for control of Candida spp. in complete upper denture wearers. Fifty-five patients were submitted to a detailed clinical interview and oral clinical examination, and were instructed to keep their dentures immersed in a 10% vinegar solution ( pH less than 3) overnight for 45 days. Before and after the experimental period, saliva samples were collected for detection of Candida, counting of cfu/mL and identification of species by phenotypical tests ( germ tube formation, chlamidoconidia production, and carbohydrate fermentation and assimilation). The results were analyzed using Spearman's correlation and Student's t-test (p=0.05). Candida yeasts were present in 87.3% of saliva samples before the treatment. A significant reduction was verified in CFU/mL counts of Candida after treatment. A positive correlation between Candida and denture stomatitis was verified, since the decrease of cfu/mL counts was correlated with a reduction in cases of denture stomatitis. Although it was not able to eliminate C. albicans, the immersion of the complete denture in 10% vinegar solution, during the night, reduced the amounts (cfu/mL) of Candida spp. in the saliva and the presence of denture stomatitis in the studied patients.

Dentine microhardness after different methods for detection and removal of carious dentine tissue

There are several methods for identifying carious dentinal tissue aiming to avoid removal of healthy dentinal tissue. Objectives: The purpose of this study was to test different methods for the detection of carious dentinal tissue regarding the amount of carious tissue removed and the remaining dentin microhardness after caries removal. Material and methods: The dentin surfaces of 20 bovine teeth were exposed and half of the surface was protected with nail polish. Cariogenic challenge was performed by immersion in a demineralizing solution for 14 days. After transverse cross-section of the crown, the specimens were divided into four groups (n=10), according to the method used to identify and remove the carious tissue: "Papacarie", Caries-detector dye, DIAGNOdent and Tactile method. After caries removal, the cross-sectional surface was included in acrylic resin and polished. In a microhardness tester, the removed dentin thickness and the Vickers microhardness of the following regions were evaluated: remaining dentin after caries removal and superficial and deep healthy dentin. Results: ANOVA and Tukey's test (alpha=0.05) were performed, except for DIAGNOdent, which did not detect the presence of caries. Results for removed dentin thickness were: "Papacarie" (424.7 +/- 105.0; a), Caries-detector dye (370.5 +/- 78.3; ab), Tactile method (322.8 +/- 51.5; bc). Results for the remaining dentin microhardness were: "Papacarie" (42.2 +/- 10.5; bc), Caries-detector dye (44.6 +/- 11.8; bc), Tactile method (24.3 +/- 9.0; d). Conclusions: DIAGNOdent did not detect the presence of carious tissue; Tactile method and "Papacarie" resulted in the least and the most dentinal thickness removal, respectively; Tactile method differed significantly from "Papacarie" and Caries-detector dye in terms of the remaining dentin microhardness, and Tactile method was the one which presented the lowest microhardness values.

Evaluation of interface characterization and adhesion of glass ceramics to commercially pure titanium and gold alloy after thermal- and mechanical-loading

Objectives. This study evaluated the effect of thermal- and mechanical-cycling on the shear bond strength of three low-fusing glassy matrix dental ceramics to commercial pure titanium (cpTi) when compared to conventional feldspathic ceramic fused to gold alloy.Methods. Metallic frameworks (diameter: 5 min, thickness: 4 mm) (N = 96, n = 12 per group) were cast in cpTi and gold alloy, airborne particle abraded with 150 mu m aluminum oxide. Low-fusing glassy matrix ceramics and a conventional feldspathic ceramic were fired onto the alloys (thickness: 4mm). Four experimental groups were formed; Gr1 (control group): Vita Omega 900-Au-Pd alloy; Gr2: Ticeram-cpTi; Gr3: Super Porcelain Ti-22-cpTi and G4: Vita Titankeramik-cpTi. While half of the specimens from each ceramic-metal combination were randomly tested without aging (water storage at 37 C for 24h only), the other half were first thermocycled (6000 cycles, between 5 and 55 C, dwell time: 13 s) and then mechanically loaded (20,000 cycles under SON load, immersion in distilled water at 37 C). The ceramic-alloy interfaces were loaded under shear in a universal test machine (cross-head speed: 0.5 mm/min) until failure occur-red. Failure types were noted and the interfaces of the representative fractured specimens from each group were examined with stereo microscope and scanning electron microscope (SEM). in an additional study (N = 16, n = 2 per group), energy dispersive X-ray spectroscopy (EDS) analysis was performed from ceramic-alloy interfaces. Data were analyzed using ANOVA and Tukey's test.Results. Both ceramic-metal combinations (p < 0.001) and aging conditions (p < 0,001) significantly affected the mean bond strength values. Thermal- and mechanical-cycling decreased the bond strength (MPa) results significantly for Gr3 (33.4 +/- 4.2) and Gr4 (32.1 +/- 4.8) when compared to the non-aged groups (42.9 +/- 8.9, 42.4 +/- 5.2, respectively). Gr1 was not affected significantly from aging conditions (61.3 +/- 8.4 for control, 60.7 +/- 13.7 after aging) (p > 0.05). Stereomicroscope images showed exclusively adhesive failure types at the opaque ceramic-cpTi interfacial zone with no presence of ceramic on the substrate surface but with a visible dark titanium oxide layer in Groups 2-4 except Gr1 where remnants of bonder ceramic was visible. EDS analysis from the interfacial zone for cpTi-ceramic groups showed predominantly 34.5-85.1% O(2) followed by 1.1-36.7% Aland 0-36.3% Si except for Super Porcelain Ti-22 where a small quantity of Ba (1.4-8.3%), S (0.7%) and Sn (35.3%) was found. In the Au-Pd alloy-ceramic interface, 56.4-69.9% O(2) followed by 15.6-26.2% Si, 3.9-10.9% K, 2.8-6% Na, 4.4-9.6% Al and 0-0.04% Mg was observed.Significance. After thermal-cycling for 6000 times and mechanical-cycling for 20,000 times, Triceram-cpTi combination presented the least decrease among other ceramic-alloy combinations when compared to the mean bond strength results with Au-Pd alloy-Vita Omega 900 combination. (c) 2008 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Mechanical and thermal cycling effects on the flexural strength of glass ceramics fused to titanium

This study evaluated the effects of mechanical and thermal cycling on the flexural strength (ISO 9693) of three brands of ceramics fused to commercially pure titanium (cpTi). Metallic frameworks of 25 x 3 x 0.5 mm dimensions (N = 84) were cast in cpTi, followed by 150-mu m aluminum oxide airborne particle abrasion at a designated area of the frameworks (8 x 3 mm). Bonder and opaque ceramic were applied on the frameworks, and then the corresponding ceramic (Triceram, Super Porcelain Ti-22, Vita Titankeramik) was fired onto them (thickness: 1 mm). Half of the specimens from each ceramic-metal combination were randomly tested without aging (only water storage at 37 degrees C for 24 hours), while the other half were mechanically loaded (20,000 cycles under 10 N load, immersion in distilled water at 37 degrees C) and thermocycled (3,000 cycles, between 5-55 degrees C, dwell time of 13 seconds). After the flexural strength test, failure types were noted. Mechanical and thermal cycling decreased the mean flexural strength values significantly (p<0.05) for all the three ceramic-cpTi combinations tested when compared to the control group. In all the three groups, failure type was exclusively adhesive at the opaque ceramic-cpTi interfacial zone with no presence of ceramic on the substrate surface except for a visible oxide layer.