Caracterização fisico-quimica e teor de nitrato em alface do tipo crespa e americana cultivadas sob sistema hidropônico e convencional / Physico-chemical characterization and nitrate content in crisp and American lettuce cultivated under a hydroponic and conventional system

A alface (Lactuca sativa L.) possui grande importância na alimentação humana, como fonte de vitaminas e sais minerais, além de possuir baixo valor calórico. Apesar do cultivo hidropônico estar em expansão no Brasil e ser bastante vantajoso, não há uma legislação específica dos nutrientes a serem utilizados para produção dessas hortaliças, levando ao risco da veiculação de contaminantes como o nitrato por meio da solução nutritiva. O objetivo do trabalho foi avaliar o teor de nitrato e as características físico-químicas de amostras de alface de duas espécies, cultivadas no sistema hidropônico e convencional. As amostras de alface foram coletadas semanalmente, em triplicata, no comércio local, por cinco semanas consecutivas, sendo analisados dois tipos de alface (crespa e/ou americana) produzidos pelo sistema convencional e hidropônico. Observou- se maior variação nos teores de cinzas e nitrato entre os sistemas de cultivo (hidropônico e convencional) e nos teores de vitamina C entre os tipos de alface (crespa e americana). Os maiores teores de nitrato foram encontrados nas amostras de alface hidropônica, com destaque para a cultivar Americana. Os teores de nitrato encontrados não excederam o limite máximo permitido pela legislação internacional.(AU)

Mechanical properties of composites as functions of the syringe storage temperature and energy dose

Objective: To investigate the mechanical properties of different classifications of composites indicated for posterior application as functions of the storage condition and of the energy dose. Material and Methods: Specimens (8x2x2 mm) were obtained according to the factors: I) Composites (3M ESPE): Filtek P60, Filtek Z350XT, and Filtek Silorane; II) Syringe storage conditions: room temperature, aged, oven, refrigerator, and freezer; and III) Energy dose: 24 J/cm2 and 48 J/cm2. After photoactivation, the specimens were stored at 37ºC for 24 h. After storage, a three-point bending test was carried out in a universal testing machine at 0.5 mm/min. Flexural strength (S) and flexural modulus (E) were calculated. Data were analyzed by three-way ANOVA and Tukey's test (α=0.05). Results: Different storage conditions significantly affected the silorane composite for S; conversely, no effects were noted in terms of E. The accelerated aging protocol significantly increased the S of Filtek P60 and Filtek Silorane, whereas storage in the oven significantly decreased the S for all of the composites tested. Filtek P60 was the only composite not affected by the lower storage temperatures tested for S, whereas for the silorane this parameter was impacted at the same conditions. The factor "dose" was not statistically significant. Conclusions: The syringe storage at different temperature conditions proved to influence mostly the flexural strength, a clinically important characteristic considering the posterior indication of the materials tested. The silorane composite should not be stored at lower temperatures. .

Effectiveness of nano-calcium phosphate paste on sensitivity during and after bleaching: a randomized clinical trial

The study aimed to evaluate the effectiveness of in-office bleaching and associated tooth sensitivity on application of nano-calcium phosphate paste as desensitizing agent. Bleaching was performed with 35% hydrogen peroxide gel in 40 patients who were randomly divided into placebo and nano-calcium phosphate paste groups. Bleaching efficacy (BE) was evaluated using a value-oriented Vita shade guide. Tooth sensitivity was recorded using a numeric rating scale (0–4) during bleaching and up to 48 h after each session. The primary outcome of absolute risk of tooth sensitivity was compared using the Fisher’s exact test (α = 0.05). The intensity of tooth sensitivity and the efficacy of in-office bleaching were also statistically evaluated. No significant differences in absolute risk and intensity of tooth sensitivity were detected between the groups (p = 1.0 and p = 0.53, respectively). BE was also found to be similar between the groups (p = 0.67). Although the use of a nano-calcium phosphate paste associated with fluoride and potassium nitrate did not influence the whitening outcome, but it also did not reduce bleaching-induced tooth sensitivity.

Avaliação da utilização do dióxido de carbono proveniente da fermentação alcoólica no cultivo de Spirulina (Arthrospira) platensis: uso simultâneo de nitrato de sódio e sulfato de amônio como fontes de nitrogênio em fotobiorreator abert / Evaluation of the use of carbon dioxide from alcoholic fermentation on Spirulina (Arthrospira) platensis cultivation: simultaneous use of sodium nitrate and ammonium sulphate as nitrogen sources in open photobioreactor

O principal objetivo deste trabalho foi a avaliação do potencial da utilização do dióxido de carbono proveniente da fermentação alcoólica no cultivo Spirulina (Arthrospira) platensis, visando demonstrar a possibilidade do uso de um gás efluente na produção de biomassa microbiana de alto valor comercial. Para tanto, tal cianobactéria foi cultivada em tanques abertos, em escala laboratorial, em temperatura de 30 ± 1 °C e intensidade luminosa de 156 ± 20 µmol fótons m-2 s-1. O estudo de diversas variáveis de cultivo levou à fixação das seguintes condições: concentração do inóculo de 400 ± 20 mg L-1; pH de 9,0 ± 0,3, controlado por meio da adição de dióxido de carbono proveniente de cilindros; meio de cultura Schlõsser, modificado de maneira a conter 0,497 e 16,4 g L-1 de carbonato e bicarbonato de sódio, respectivamente, e apenas 5,9 mM de nitrato de sódio; adição de 7,5 mM de sulfato de amônio no decorrer de 13 dias, em quantidades diárias exponencialmente crescentes, através do processo descontínuo alimentado de cultivo. Sob tais condições foram obtidos os seguintes resultados: concentração celular máxima (Xm) de 2990 mg L-1, produtividade celular (PX) de 185 mg L-1 d-1, velocidade específica máxima de crescimento (µm) de 0,42 d-1, fator de conversão de nitrogênio em células (YX/N) de 8,85 mg mg-1, teor final de clorofila (CLf) de 4,3 mg g-1, e teores de proteínas (PTN) e lipídeos (LIP) de 35 e 21 %, respectivamente. Com a finalidade de estimular o crescimento celular de A. platensis, optou-se por aumentar o valor da intensidade luminosa de 156 para 192 ou 252 ± 20 µmol fótons m-2 s-1 no 5º, 8º ou 11º dia de cultivo. Os melhores resultados cinéticos (Xm = 3954 mg L-1, PX = 253 mg L-1 d-1) e de conteúdo da biomassa (CLf = 4,2 mg g-1, PTN = 28 %, LIP = 19 %) foram obtidos com aumento da intensidade luminosa para 192 ± 20 µmol fótons m-2 s-1 no 8º dia de cultivo. Os ensaios realizados sob tais condições otimizadas, porém com dióxido de carbono...

The main objective of this work was the evaluation of the potential of using carbon dioxide from alcoholic fermentation on Spirulina (Arthrospira) platensis cultivation, aiming to prove the feasibility of applying an effluent gas in the production of high added-value microbial biomass. In order to do so, the cyanobacterium was cultivated in laboratorial-scale open raceway tanks at temperature 30 ± 1 °C and light intensity 156 ± 20 µmol photons m-2 s-1. After the study of several cultivation variables, the following conditions were set: inoculum concentration 400 ± 20 mg L-1; pH 9,0 ± 0,3, controlled by the addition of carbon dioxide from cylinders; Schlõsser medium, modified as to contain 0,497 and 16,4 g L-1 sodium carbonate and bicarbonate, respectively, and only 5,9 mM sodium nitrate; addition of 7,5 mM ammonium sulphate throughout 13 days, at exponentially increasing amounts, by the fed-batch cultivation process. Under such conditions, the following results were obtained: maximum cell concentration Xm = 2990 mg L-1, cell productivity PX = 185 mg L-1 d-1, maximum specific growth rate µm = 0,42 d-1, cell to nitrogen conversion factor YX/N = 8,85 mg mg-1, final chlorophyll content CLf = 4,3 mg g-1, and content of proteins (PTN) and lipids (LIP) of 35 and 21 %, respectively. Objectiving further optimized A. platensis growth, it was chosen to increase the light intensity from 156 to 192 or 252 ± 20 µmol photons m-2 s-1 on the 5th, 8th or 11th day of cultivation. The best results in terms of growth (Xm = 3954 mg L-1, PX = 253 mg L-1 d-1) and biomass content (CLf = 4,2 mg g-1, PTN = 28 %, LIP = 19 %) were reached with increasing the light intensity to 192 ± 20 µmol photons m-2 s-1 on the 8th day of cultivation. The runs carried out under such optimum conditions, but using carbon dioxide from alcoholic fermentation, led to the following results: Xm = 3298 mg L-1, PX = 206 mg L-1 d-1, CLf = 4,0 mg g-1, PTN = 28 %, LIP = 17 %. Conclusively, the...

Avaliação de teores de nitrato e nitrito em linguiças, na cidade de Campo Grande, MS / Evaluation of levels of nitrate and nitrite in sausages in the city of Campo Grande, MS

Embora não haja estudos conclusivos relacionando dieta com altas concentrações de nitrito e câncer, a presença destes aditivos nos alimentos é preocupante devido a sua combinação com aminas, formando nitrosaminas, que são carcinogênicas em animais de experimentação. O objetivo deste estudo foi verificar o atendimento à portaria n. 1004 da ANVISA, quanto aos teores de nitrato e nitrito em amostras de linguiças no município de Campo Grande, MS. Foram coletadas pela vigilância sanitária e analisadas 207 amostras de linguiças de estabelecimentos comerciais dos cinco distritos sanitários, no período de março de 2004 a março de 2005. Os teores de nitrato e nitrito foram determinados segundo as Normas Analíticas do Instituto Adolfo LUtz. Os resultados identificaram diferenças entre as medianas dos teores de nitrato não significativas (p=0,1104) entre os 4 tipos de linguiças, porém, significativas entre os distritos sanitários sul e central e entre oeste e central (p=0,0030); e também para nitrito nos distritos sul e central (p=0,0045) , e para linguiças bovinas e mistas (p=0.0292). Entre os tipos de processamentos as diferenças não foram significativas para nitrato (p=0,2888) e nitrito (p=0,6390). Concluiu-se que nove amostras (4% com nitrato e uma amostra com nitrito (0,5%) apresentaram teores acima do máximo permitido pela legislação.

Clinical efficacy of 0.2% glyceryl trinitrate ointment for anal fissures

To validate the clinical efficacy of 0.2% glyceryl trinitrate ointment, a nitric oxide donor, in the management of anal fissures. A prospective clinical study conducted on consecutive patients with anal fissures presented to the surgical clinic of Jinnah Hospital and Allama Iqbal Medical College Complex Lahore. These patients were treated with topical 0.2% glyceryl trinitrate paste in soft white paraffin three times a day. Patients were examined at regular intervals to evaluate the fissure status, adverse reactions, symptomatic control and recurrence. All subjects were followed-up until they were pronounced cured or treatment terminated. 121 patients comprised this study group. 6 cases were lost to follow-up and 109 [94.7%] of the remaining 115 subjects were cured. Of those cured, 13 [11.3%] presented with acute and 102 [88.7%] chronic fissures. There were 98 male and 17 female patients with median age of 41 years [range, 14-70 years]. Complete symptomatic relief w as achieved in all patients within one month of therapy. Treatment had to be terminated in 6 [5.2%] patients: 5 [4.3%] experienced intolerable adverse effects and 1 [0.8%] patient failed to respond. All these cases were successfully treated with lateral internal sphincterotomy. There was no change of continence in this series. Glyceryl trinitrate ointment produces healing of the anal fissures and adequate symptomatic relief and should be considered as the first line treatment for anal fissures

Evaluation of possible goitrogenic and anti-thyroidal effect of nitrate, a potential environmental pollutant.

Nitrate is a wide spread contaminant of ground and surface water. The source of nitrate in the ground water may be from run off or seepage from fertilized soil, municipal or industrial waste water, land fills, septic system, urban drainage or decaying plants. Human and animal systems are affected severely on nitrate exposure. The study was to investigate the effect of dietary nitrate exposure on the thyroid status along with the state of iodine nutrition. Rats were fed diet containing 3% potassium nitrate (KNO3) for 4 weeks and then thyroid status was evaluated by thyroid gland weight, urinary iodine excretion pattern, thyroid peroxidase (TPO) activity, serum levels of total thyroxine (T4), triiodothyronine (T3) and thyroid stimulating hormone (TSH) concentrations. In nitrate treated animals, the weight of thyroid gland was increased significantly (P<0.001) while thyroid peroxidase activity (P<0.01), serum T4 (P<0.01) and serum T3 levels (P<0.001) were reduced; but serum TSH level was increased (P<0.001) along with slightly elevated iodine excretion level (P<0.001) in comparison to control animals. The overall results indicated the development of a relative state of functional hypothyroidism with enlarged thyroid after nitrate exposure. This study can explain a part for the persistence of residual goitre in the post-salt iodization phase.

Atividade de derivados imidazólicos contra espécies de candida isoladas de pacientes com câncer / Imidazole antibiotics activities against Candida species recovered from cancer patients

Foram avaliadas as atividades fungicida e fungistática de quatro derivados imidazólicos contra espécies de Candida, isoladas de pacientes com câncer e submetidos à quimioterapia ou à radioterapia. Embora a atividade antifúngica desses antibióticos tenha variado conforme a espécie estudada, a µg/ml o cetoconazol foi agente inibidor mais efetivo, agindo sobre 90,3 (por cento) das leveduras, enquanto o clotrimazol foi o menos efetivo, agindo sobre 26,4 (por cento). O nitrato de econazol e o nitrato de miconazol foram fungistáticos para, praticamente, a mesma percentagem de leveduras (63,8 e 63,4 (por cento) respectivamente), porém, assim como os outros imidazóicos, foram icapazes de exercer açäo fungicida contra a maioria delas (au)