Interferência do hipoclorito de sódio na absorção de macro e micronutrientes nas culturas da soja e do feijão

The objective of this work was to evaluate the effect of the sodium hypochlorite application in different levels in the fresh and dry biomass and in the uptake of macronutrients and micronutrients in plants of soybean and bean. The experiments were carried at the greenhouse of the "Departamento de Recursos Naturais/Ciência do Solo, FCA/UNESP, Botucatu/SP", in columns of rigid PVC with capacity to 1.0 liter of soil. The experimental design used in each experiment was entirely randomized, with 4 replications. The treatments in each experiment were constituted of 5 doses of sodium hypochlorite (0.0, 0.5, 1.0, 2.0 and 4.0 L ha(-1)). The following parameters were evaluated: fresh and dry biomass, macro and micronutrients contents in the plants leaves. The levels of sodium hypochlorite did not reflect significantly on the fresh and dry biomass of soybean and bean. The soybean dry biomass presented significant difference among the level of sodium hypochlorite. Average contents of macro and micronutrients obtained in bean leaves were not affected by the levels of sodium hypochlorite. The sulphur contents in soybean leaves presented significant difference. The sodium hypochlorite did not affect negatively the macro and micronutrients contents in leaves of soybean and bean.

Improved laboratory safety by decontamination of unstained sputum smears for acid-fast microscopy

Tubercle bacilli may survive in unstained heat-fixed sputum smears and may be an infection risk to laboratory staff. We compared the effectiveness of 1% and 5% sodium hypochlorite, 5% phenol, 2% glutaraldehyde, and 3.7% formalin in killing Mycobacterium tuberculosis present in smears prepared from 51 sputum samples. The smears were decontaminated by the tube and slide techniques. Phenol at 5%, glutaraldehyde at 2%, and buffered formalin at 3.7% for 1 min (tube technique) or for 10 min (slide technique) were effective in decontaminating sputum smears and preserved cell morphology and quantitative acid-fast microscopy results.

Effects of different disinfection treatments on the natural microbiota of lettuce

In this study, water and eight sanitizing solutions (vinegar at 6, 25, and 50%; acetic acid at 2 and 4%; peracetic acid at 80 ppm, sodium hypochlorite at 200 ppm, and sodium dichloroisocyanurate at 200 ppm) were compared in terms of their effectiveness against the natural microbiota of lettuce. All of the samples were kept in contact with the sanitizing solutions for 15 min, and the effectiveness of a sanitizing agent was evaluated on the basis of the number of decimal reductions of the total aerobic mesophilic count, the mold and yeast count, the total coliform count, and the Escherichia coli count. The average initial levels of these organisms in the samples were 6.94 log(10) CFU/g for aerobic mesophilic microorganisms, 5.62 log(10) CFU/g for molds and yeasts, and 3.25 log(10) CFU/g for total coliforms. of 10 samples analyzed, only 4 contained E. coli, and the average initial level of this microorganism in these 4 samples was 1.64 log(10) CFU/g. Salmonella was not detected in any of the samples tested. The decimal reductions of the populations of aerobic mesophilic microorganisms, molds and yeasts, total coliforms, and E. coli were 0.78, 0.87, 0.82, and >0.14 log(10) CFU/g, respectively, in water; 2.89, >3.41, >2.21, and >0.26 log(10) CFU/g, respectively, in 50% vinegar; 2.42, >3.20, >1.99, and >0.26 log(10) CFU/g, respectively, in 25% vinegar; 1.83, 2.57, 1.58, and >0.26 log(10) CFU/g, respectively, in 6% vinegar; 3.91, >3.58, >2.25, and >0.26 log(10) CFU/g, respectively, in 4% acetic acid; 3.37, >3.53, >2.25, and >0.26 log(10) CFU/g, respectively, in 2% acetic acid; 1.85, 2,32, 1.44, and >0.20 log(10) CFU/g, respectively, in 80 ppm of peracetic acid; 2.63, 2.75, 1.91, and >0.26 log(10) CFU/g, respectively, in 200 ppm of sodium hypochlorite; and 3.23, >3.08, >1.95, and >0.26 log(10) CFU/g, respectively, in 200 ppm of sodium dichloroisocyanurate. Statistical analysis of the results showed that the effectiveness levels for all of the sanitizing agents tested were equivalent to or higher than that for sodium hypochlorite at 200 ppm.

Activity of disinfectants against foodborne pathogens in suspension and adhered to stainless steel surfaces

The purpose of this study was to investigate and compare the efficacy of various disinfectants on planktonic cells and biofilm cells of Listeria monocytogenes, Staphylococcus aureus and Escherichia coli. Numbers of viable biofilm cells decreased after treatment with all tested disinfectants (iodine, biguanide, quaternary ammonium compounds, peracetic acid and sodium hypochlorite). Sodium hypochlorite was the most effective disinfectant against biofilm cells, while biguanide was the least effective. Scanning electron microscopy observations revealed that cells adhered on stainless steel surface after treatment with the disinfectants. No viable planktonic cells were observed after treatment with the same disinfectants. Based on our findings, we concluded that biofilm cells might be more resistant to disinfectants than plancktonic cells.

Comprovação da real comunicação entre o endodonto e o periodonto através do canal cavo inter-radicular e sua prevalência em molares inferiores humanos

The neurovascular system of the pulp and of the periodontium is interconnected and among the possible intercommunications between these two tissues, there is the cavo inter-radicular canal. It is a small canal that goes through any inter-radicular dentine and arises in the furca region of the multi-radicular teeth. Its predominance has been studied in the literature, by several methodologies, with divergent results. The objective of this work was to establish, in vitro, the predominance of the cavo inter-radicular canal, in human lower molars, through the diaphanization technique and dye leakage. For this research, 140 teeth (100 first and second 40 lower molars) were selected, extracted due to different reasons, belonging to a teeth bank of the Endodontics discipline of the Dentistry College at Federal University of Rio Grande do Norte. The teeth were preserved in formol until the moment of use and immersed in physiological solution. Had the endodontic access fulfilled and the whole external surface, except for the furcation, sealed with two layers of nail enamel. The cleaning of the pulpar chamber floor was carried out with sodium hypochlorite solution 5%, being this solution renewed every 5 minutes, during 1 hour. The teeth were immersed in Indian dye and, after drying of the dye, they had their crowns split up in the amelo-cemental junction. Then, they were examined in a stereomicroscope, where marks of the coloring were observed in the furcation and on the pulpar floor. After this recording, the sample was diaphanized and with the transparent teeth, it was possible to observe in the stereomicroscope, the true inter-radicular canals. As a result of this experiment, the presence of these canals was observed in 13 % of the first and 7, 5 % of the second evaluated molars. The study showed that both the presence of the cavo inter-radicular canal is real and the diaphanization and dye leakage is an efficient method for this type of research

Desinfestação e estabelecimento in vitro de explantes de bananeira 'Grande Naine' em diferentes concentrações de hipoclorito de sódio

A maioria dos plantios de bananeira ainda é realizada utilizando mudas tradicionais, mas outros métodos de propagação, como a micropropagação in vitro, vêm sendo desenvolvidos e aperfeiçoados, para elevar a taxa de multiplicação em curto espaço de tempo e melhorar a qualidade da produção de mudas. Contudo, a contaminação é um dos maiores problemas desta técnica. Este trabalho teve por objetivo avaliar a eficiência da descontaminação de explantes de bananeira com o uso de diferentes concentrações de cloro ativo durante a assepsia do explante. O delineamento experimental utilizado foi inteiramente casualizado e constituído de cinco tratamentos e cinco repetições, sendo cada repetição representada por 5 explantes em diferentes concentrações de cloro ativo, sendo: T1 (testemunha, sem cloro ativo); T2 (0,5%); T3 (1,0%); T4 (1,5%), e T5 (2%). Os dados obtidos foram submetidos à análise de variância, e as médias, comparadas pelo teste de Tukey, a 5% de probabilidade. Os resultados permitiram concluir que a maior eficiência dentre os tratamentos testados foi a imersão dos explantes em hipoclorito de sódio com 2% de cloro ativo, sendo as doses testadas não tóxicas aos explantes, permitindo o desenvolvimento normal dos mesmos, concluindo assim que essa concentração possa ser utilizada para o controle de contaminações para micropropagação de bananeira cv. Grande Naine.

Uso de antibióticos para o controle de bactérias endógenas visando à micropropagação da figueira

A descontaminação dos explantes é um dos princípios básicos para o sucesso da cultura de tecidos. Um dos problemas diagnosticados na propagação in vitro da figueira, através de gemas apicais, é a contaminação endógena dos explantes por bactérias. Este trabalho teve como objetivo avaliar a eficiência de alguns antibióticos em meio de cultura para o controle de bactérias endógenas em gemas apicais de figueira. Foram avaliados os seguintes tratamentos: T1(sem adição de antibiótico); T2 (30 mg L-1 de cloranfenicol); T3 (250 mg L-1 de ampicilina sódica); T4 (500 mg L-1 de ácido nalidícico); T5 (150 mg L-1 de cefalotina sódica); T6 (500 mg L-1 de tetraciclina), e T7 (400 mg L-1 de norfloxacina). Após coletados em campo, os segmentos de ramos contendo as gemas foram colocados em recipiente com água corrente. Posteriormente, as gemas apicais foram imersas em álcool etílico a 70% e hipoclorito de sódio a 2,5%. Todo procedimento de desinfestação externa dos explantes foi realizado em câmara de fluxo laminar. Os explantes foram inoculados em tubos de ensaio contendo 15 mL de meio básico MS suplementado, após a autoclavagem, com as doses de antibióticos de acordo com os tratamentos estabelecidos. Após a inoculação, os explantes foram mantidos em sala de crescimento por quatro dias no escuro e, em seguida, sob fotoperíodo de 16 horas de luz branca fria e irradiância de 25 µmol m s-1, na temperatura de 22 ± 3ºC. A assepsia realizada externamente nos explantes foi suficiente para o controle de contaminação fúngica, e a adição de antibióticos ao meio, após autoclavagem, foi eficiente para o controle de bactérias endógenas, cujo antibiótico ampicilina sódica proporcionou mais de 90% de explantes sobreviventes.

Use of vitamin C in delayed tooth replantation

O objetivo deste trabalho foi avaliar microscopicamente, em reimplantes tardios de dentes de rato, os efeitos do tratamento da superfície radicular com diferentes soluções. Foram utilizados 30 ratos Rattus norvegicus albinos da linhagem Wistar que tiveram seus incisivos centrais extraídos e deixados sobre a bancada por 6 h. As polpas foram extirpadas e os canais irrigados com solução de hipoclorito de sódio a 1%. Após o preparo endodôntico, a superfície radicular de cada dente foi tratada com solução de hipoclorito de sódio a 1% por 10 min (trocada a cada 5 min) seguida de soro fisiológico por 10 min, e os dentes foram divididos em três grupos com 10 espécimes em cada um. Nos Grupos I, II e III, respectivamente, a superfície radicular foi tratada com fluoreto de sódio fosfato acidulado a 2%, vitamina C e vitamina C efervescente (2 g, Redoxon®). Após obturação com pasta de hidróxido de cálcio os dentes foram reimplantados e os animais foram sacrificados aos 10 e 60 dias. O Grupo I apresentou maiores áreas de reabsorção por substituição e anquilose. Comparando as formas de vitamina C utilizadas, a efervescente (Grupo III) foi a que apresentou resultados mais favoráveis com mais áreas de anquilose e reabsorção por substituição que áreas de reabsorção inflamatória.

Antimicrobial potential of medicaments used in healing process in dogs' teeth with apical periodontitis

Estudou-se a influência de diferentes irrigantes no potencial antimicrobiano da pasta de hidróxido de cálcio em dentes de cães com periodontite apical. 48 pré-molares de cães adultos tiveram suas câmaras coronárias abertas e expostas à cavidade bucal por 6 meses. Os canais radiculares foram preparados, irrigados e medicados com diferentes substâncias, de acordo com os seguintes grupos: 1) 2,5% NaOCl + CHP; 2) 2% CHX + CHP; 3) vinagre + CHP; 4) vinagre + vinagre. No grupo 4, a solução irrigante e a medicação intracanal utilizada foi o vinagre. Neste grupo, a cada 7 dias, a solução era renovada. Cada amostra foi coletada, mantendo-se o cone de papel esterilizado em posição por 1 min, e a seguir transportado e imerso em 7 mL de Letheen broth, seguido de incubação a 37ºC por 48 h. O crescimento microbiano foi analisado por dois métodos, turbidade do meio de cultura e subcultura em meio nutritivo específico (brain heart infusion). Os resultados mostraram que em todos os grupos experimentais houve crescimento microbiano após 21 dias, em diferentes percentagens: grupo 1 - 30%; grupo 2 - 30%; grupo 3 - 40%; grupo 4 - 60%. Todos os materiais testados apresentaram potencial antimicrobiano. Entretanto, o processo de cura favorecido pela pasta de hidróxido de cálcio não pode ser esquecido, uma vez que muitos estudos já demonstraram sua ação antimicrobiana.

Sealability of MTA and calcium hydroxide-containing sealers

Objectives: The aim of this study was to evaluate the apical sealability of Fillapex (R), Endo-CPM-Sealer (R) and Sealapex (R). Material and Methods: Ninety-four freshly extracted single-rooted teeth were selected and decoronated. All teeth were radiographed to confirm the existence of a single and straight root canal, which was prepared using Protaper Universal and 2.5% sodium hypochlorite. The teeth were randomly divided in groups of 10 specimens each according to the sealer, and the canals were filled using the single cone technique and one of the sealers. Four additional teeth were used as controls. The teeth were submitted to dye leakage with Rhodamine B for 24 h but using vacuum on the initial 15 min. Thereafter, they were cut longitudinally and the leakage was measured in a linear fashion from apex to crown. Data were analyzed by ANOVA and Tukey's tests at 5% significance level. Results: Fillapex (R) and Sealapex (R) showed significantly less dye leakage than Endo-CPM-Sealer (R) (p<0.05). Conclusions: It was concluded that Fillapex (R) and Sealapex (R) were able to prevent apical dye leakage differently from Endo-CPM-Sealer (R).

Comparison of the biocompatibility of different root canal irrigants

The purpose of this study was to compare the reaction of rat subcutaneous connective tissue to 0.9% sterile saline, 2.5% sodium hypochlorite (NaOCl), 5.25% NaOCl and 2% chlorhexidine gluconate solution or gel. Six circles were demarcated on the dorsal skin of 24 male Wistar rats, leaving 2 cm between each circle. Using a syringe, 0.1 mL of each root canal irrigant was injected subcutaneously into 5 circles. In the 6th circle, the needle of an empty syringe was introduced into the skin, but no irrigant was injected (control group). Evaluations were undertaken at 2 h, 48 h, 14 days and 30 days post-procedure. Tissue samples were excised, embedded in paraffin blocks and 3-mu m-thick sections were obtained and stained with hematoxylin and eosin. The areas of inflammatory reaction were evaluated and analyzed statistically by ANOVA and Tukey's test. The control group showed few or no inflammatory reaction areas in the subcutaneous tissue. 0.9% saline solution, 2.0% chlorhexidine solution and 2.5% NaOCl showed a good biocompatibility, as very mild inflammatory reaction was detected at 14 days and tissue repair occurred at 30 days. 5.25% NaOCl was the most toxic irrigant, as the number of inflammatory cells remained elevated at 14 and 30 days. The group treated with 2.0% chlorhexidine gluconate gel presented a moderate inflammatory response at 14 days, which decreased at 30 days, being considered similar to that of the control group, 0.9% saline solution, 2.0% chlorhexidine solution and 2.5% NaOCl at this experimental period.

Tissue Reaction to Silver Nanoparticles Dispersion as an Alternative Irrigating Solution

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

The effect of disinfectant solutions on the hardness of acrylic resin denture teeth

This investigation studied the effects of disinfectant solutions on the hardness of acrylic resin denture teeth. The occlusal surfaces of 64 resin denture teeth were ground flat with abrasives up to 400-grit silicon carbide paper. Measurements were made after polishing and after the specimens were stored in water at 37 degreesC for 48 h. The specimens were then divided into four groups and immersed in chemical disinfectants (4% chlorhexidine; 1% sodium hypochlorite and sodium perborate) for 10 min. The disinfection methods were performed twice to simulate clinical conditions and hardness measurements were made. Specimens tested as controls were immersed in water during the same disinfection time. Eight specimens were produced for each group. After desinfection procedures, testing of hardness was also performed after the samples were stored at 37 degreesC for 7, 30, 60, 90 and 120 days. Data were analysed using two-way analysis of variance (anova) and Tukey's test at 95% confidence level. According to the results, no significant differences were found between materials and immersion solutions (P > 0.05). However, a continuous decrease in hardness was noticed after ageing (P < 0.05). It was conclude that the surfaces of both acrylic resin denture teeth softened upon immersion in water regardless the disinfecting solution.

The effect of long-term disinfection procedures on hardness property of resin denture teeth

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

Effect of Incorporation of Disinfectant Solutions on Setting Time, Linear Dimensional Stability, and Detail Reproduction in Dental Stone Casts

Purpose: The aim of this paper was to analyze the influence of incorporation of disinfectants during the cast die stone-setting time. Setting time, linear dimensional stability, and reproduction details on casts were measured.Materials and Methods: Die stone type IV specimens with disinfection solutions (sodium hypochlorite 1%, glutaraldehyde 2%, chlorhexidine 2%) were incorporated in two concentrations (50%, 100%). The detail reproduction, dimensional stability, and setting time were tested in accordance with ADA recommendations.Results: Disinfecting solutions promoted an increase in setting time compared to control; sodium hypochlorite was responsible for the highest setting time. The addition of undiluted sodium hypochlorite 1.0% led to contraction during setting, but the groups with 50% diluted sodium hypochlorite 1.0% and undiluted chlorhexidine 2.0% resulted in intermediate values compared to the other groups, thus matching the control. The others did not demonstrate any effect on expansion. For detail reproduction, it was observed that the control group presented results similar to the others, except those where sodium hypochlorite was added.Conclusions The addition of sodium hypochlorite in both dilutions significantly altered, negatively, all the evaluated properties. But the addition of glutaraldehyde and chlorhexidine did not promote any significant alterations in the evaluated properties.