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Arthrospiraplatensis was cultivated in minitanks at 13 klux, using a mixture of KNO(3) and NH(4)Cl as nitrogen source. Fed-batch daily supply of NH(4)Cl at exponentially-increasing feeding rate allowed preventing ammonia toxicity and nitrogen deficiency, providing high maximum cell concentration (X(m)) and high-quality biomass (21.85 mg chlorophyll g cells(-1); 20.5% lipids; 49.8% proteins). A central composite design combined to response surface methodology was utilized to determine the relationships between responses (X(m), cell productivity and nitrogen-to-cell conversion factor) and independent variables (KNO(3) and NH(4)Cl concentrations). Under optimum conditions (15.5mM KNO(3); 14.1mM NH(4)Cl), X(m) was 4327 mg L(-1), a value almost coincident with that obtained with only 25.4mM KNO(3), but more than twice that obtained with 21.5mM NH(4)Cl. A 30%-reduction of culture medium cost can be estimated when compared to KNO(3)-batch runs, thus behaving as a cheap alternative for the commercial production of this cyanobacterium.

This in vitro study aimed to analyze the effect of different parameters of phototherapy with low intensity laser on the viability of human dental pulp fibroblasts under the effect of substances released by bleaching gel. Cells were seeded into 96 wells plates (1 x 10 3 cells/well) and placed in contact with culture medium conditioned by a 35% hydrogen peroxide bleaching gel for 40 minutes, simulating the clinical condition of the in-office bleaching treatment. Cells cultured in ideal growth conditions served as positive control group (PC), and the cells grown in conditioned medium and non-irradiated served as negative control group (NC). Cells grown in conditioned medium were submitted to a single irradiation with a diode laser (40 mW, 0.04 cm²) emitting at visible red (660 nm; RL) or near infrared (780 nm; NIR) using punctual technique, in contact mode and energy densities of 4, 6 or 10 J/cm². The cell viability was analyzed through the MTT reduction assay immediately and 24 hours after the irradiation. The data was compared by ANOVA followed by the Tukey's test (p ≤ 0.05). The cell viability increased significantly in 24 hours within each group. The PC presented cell viability significantly higher than NC in both experimental times. Only the NIR/10 J/ cm² group presented cell viability similar to that of PC in 24 hours. The phototherapy with low intensity laser in defined parameters is able to compensate the cytotoxic effects of substances released by 35% hydrogen peroxide bleaching gel.

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This study was conducted to examine the influence of supplementation of sodium butyrate, sodium monensin or calcium propionate in a starter diet on the performance and selected plasma metabolites (plasma glucose, non-esterified fatty acids and b-hydroxybutyrate) of Holstein calves during pre-and post-weaning periods. Twenty-four newborn Holstein calves were housed in individual hutches until 10 weeks of life, receiving water free choice, and fed four liters of milk daily. Calves were blocked according to weight and date of birth, and allocated to one of the following treatments, according to the additive in the starter: (i) sodium butyrate (150 g/kg); (ii) sodium monensin (30 mg/kg); and (iii) calcium propionate (150 g/kg). During 10 weeks, calves received starter ad libitum, while coast cross hay (Cynodon dactylon (L.) pers.) was offered after weaning, which occurred at the 8th week of age. Weekly, calves were weighted and evaluated for body measurements. Blood samples were taken weekly after the fourth week of age, 2 hours after the morning feeding, for determination of plasma metabolites. No differences were observed among treatments for starter or hay intake, BW and daily gain of the animals. Mean concentrations of selected plasma metabolites were similar in calves fed a starter supplemented with sodium butyrate, sodium monensin and calcium propionate. There was significant reduction in the concentrations of plasma glucose as calves aged. The inclusion of sodium butyrate, calcium propionate or sodium monensin as additives in starter feeds resulted in equal animal performance, before and after weaning, suggesting that sodium monensin may be replaced by organic acid salts. Keywords: additives, early weaning, ionophores, ruminal development ImplicationsThis study was conducted to evaluate organic acid salts inclusion in calf starters as a replacement to the traditional use of ionophore, since these antibiotics were banned as growth promoters in the European Union. Since all commercial starters include ionophores, an alternative additive that could result in the same pattern of animal performance should be studied. The organic acid salts were chosen because they lack the antibiotic effect but could have beneficial effects on the rumen development processes. In addition, as seen in the non-ruminant industry, acidified feeds may have a beneficial effect on the health of the lower gastrointestinal tract. IntroductionCalf rumen development, crucial for the early weaning program, is strongly related to the intake of fermentable organic matter and the resulting short-chain fatty acids (SCFA; Greenwood et al., 1997). Ruminal metabolism studies have pointed out butyric and propionic acids as the main stimuli for rumen development and the maturation process , which suggests that additives that furnish higher SCFA concentrations or alter the rumen fermentation pattern may be used as a tool for reducing the milk feeding period.The inclusion of ionophores in ruminant diets has shown changes in the SCFA concentrations, mainl...

This study aims to investigate whether infrared diode low-level laser therapy (LLLT) increased salivary flow rate and altered pH value, protein concentration, and peroxidase and amylase activities in saliva of rats. Wistar rats were used and divided into three groups. Experimental groups (A and B) had their parotid, submandibular and sublingual glands submitted to diode laser, 808-nm wavelength, on two consecutive days. The dose results were 4 and 8 J/cm(2), respectively. A red guide light was used to visualize the irradiated area. Group C was irradiated only with red pilot beam and served as control. The saliva samples were collected after each irradiation step (first and second collection days) and 1 week after the first irradiation (seventh day). Statistical analysis was performed, and differences were observed according to different days of salivary collection. The results showed that salivary flow rate for groups A and B was higher on the seventh day if it is compared to data obtained for the first day (p < 0.05). LLLT applications on salivary glands are a therapy procedure that requires further studies.