Innovative application of brackish groundwater without the addition of nutrients in the cultivation of Spirulina and Chlorella for carbohydrate and lipid production.

Brackish groundwater is promising for the cultivation of economically important microalgae; however, its effects have been evaluated only after nutrient supplementation. In this study, 100% brackish groundwater was evaluated as a culture medium for Spirulina sp. (BGWS) and Chlorella fusca (BGWC). In addition, the effects of supplementation with 25% of the nutrients from Zarrouk (BGWS25) and BG-11 (BGWC25) culture media were evaluated. BGWS and BGWC increased the concentration (68.1% w w-1) and productivity of carbohydrate (35.3 mg L-1 d-1) in Spirulina sp. and increased the concentration (56.4% w w-1) and productivity (13.5 mg L-1 d-1) of lipids in C. fusca biomass, when compared to that in the respective controls. The use of brackish groundwater as the sole culture medium is an innovative alternative for the economic production of biomass rich in carbohydrates and lipids. This has potential applications for biofuel production.

Spirulina sp. LEB 18 cultivation in seawater and reduced nutrients: Bioprocess strategy for increasing carbohydrates in biomass.

This study aimed to evaluate the growth and production of biomolecules by Spirulina sp. LEB 18 cultivated in seawater. The seawater was used without nutrient addition (SW0) and supplemented with 100% (SW100), 50% (SW50), and 25% (SW25) nitrogen, phosphorus, iron, and EDTA concentrations that make up the Zarrouk culture medium. When grown in SW0, Spirulina sp. LEB 18 showed maximum biomass concentration (2.17 g L-1) on the 11th d of cultivation and an increase in the carbohydrate content and productivity by 203% and 52%, respectively, when compared to the control culture. This cultivation strategy demonstrated the feasibility of using seawater as an alternative to freshwater in cultures as well as reduced nutritional requirements for biomass and carbohydrate production.

Bioprocess strategies for enhancing the outdoor production of Nannochloropsis gaditana: an evaluation of the effects of pH on culture performance in tubular photobioreactors.

A priority of the industrial applications of microalgae is the reduction of production costs while maximizing algae biomass productivity. The purpose of this study was to carry out a comprehensive evaluation of the effects of pH control on the production of Nannochloropsis gaditana in tubular photobioreactors under external conditions while considering the environmental, biological, and operational parameters of the process. Experiments were carried out in 3.0 m3 tubular photobioreactors under outdoor conditions. The pH values evaluated were 6.0, 7.0, 8.0, 9.0, and 10.0, which were controlled by injecting pure CO2 on-demand. The results have shown that the ideal pH for microalgal growth was 8.0, with higher values of biomass productivity (Pb) (0.16 g L-1 d-1), and CO2 use efficiency ([Formula: see text]) (74.6% w w-1); [Formula: see text]/biomass value obtained at this pH (2.42 [Formula: see text] gbiomass-1) was close to the theoretical value, indicating an adequate CO2 supply. At this pH, the system was more stable and required a lower number of CO2 injections than the other treatments. At pH 6.0, there was a decrease in the Pb and [Formula: see text]; cultures at pH 10.0 exhibited a lower Pb and photosynthetic efficiency as well. These results imply that controlling the pH at an optimum value allows higher CO2 conversions in biomass to be achieved and contributes to the reduction in costs of the microalgae production process.

Fed-batch cultivation with CO2 and monoethanolamine: Influence on Chlorella fusca LEB 111 cultivation, carbon biofixation and biomolecules production.

The aim of this study was to evaluate the interaction between the periodic addition of monoethanolamine (MEA) and CO2 during the cultivation of Chlorella fusca LEB 111. For this purpose, MEA has been added in abiotic assays, followed by fed-batch cultures with that green alga and the absorbent. BG-11 medium shown a higher potential of CO2 absorption with MEA addition, and the bicarbonate was the chemical species of carbon prevailing in the chemical equilibrium. The periodic addition of MEA did not reduce the kinetics of growth, promoted a higher accumulation of DIC (81.4 mg L-1) in the medium and protein (44.0% w w-1) and lipid (30.8% w w-1) concentrations in the biomass of C. fusca LEB 111. Therefore, it was demonstrated that fed-batch culture with MEA increased CO2 fixation and the biomolecule synthesis as proteins and lipids.

Innovative polyhydroxybutyrate production by Chlorella fusca grown with pentoses.

The current study aimed to evaluate if the addition of pentoses along with variations in light intensity and photoperiod can stimulate the production of polyhydroxybutyrate (PHB) and other biomolecules by Chlorella fusca LEB 111. The variables evaluated were the addition of xylose and arabinose as sources of organic carbon, different photoperiods (18 h, 12 h and 6 h light) and variations in light intensities (58, 28 and 9 µmolphotons m-2 s-1). The highest PHB accumulation (17.4% w w-1) and protein production (53.2% ww-1) were observed in assays with xylose addition and a photoperiod of 6 h of light provided at 28 and 58 µmolphotons m-2 s-1, respectively. The highest lipid content (24.7% w w-1) was obtained with 18 h of light. The current study contributes to the development of sustainable alternatives for the use of wastes and the production of biomolecules from algae.

Analysis of factors of production in the termination of feedlot lambs to pasture / Análise de fatores de produção na terminação de cordeiros em confinamento a pasto

The objective of this study was to analyze the factors that influence the performance of lambs in pasture confinement, by substituting a concentrate with different levels of the aerial part of cassava in relation to hematocrit indices. The experiment was conducted at the Sheep Technology Center using 56 Pantaneira sheep, of which 28 were male and 28 were female. For female lambs, the globular volume showed a decreasing quadratic effect, with a minimum inclusion of 10.24% PAM in the diet for a hematocrit index of 32.28. A linear effect was observed for the mean crude protein intake in the male lambs based on the diet provided and was estimated to be equivalent to 87.4% of the lambs' final weight. In conclusion, mean crude protein consumption is most strongly correlated with the final weight of male lambs, and NDF is most strongly correlated with the final weight of female lambs, with the level of cyanide consumption influencing the average daily weight gain in female lambs. The hematocrit level of the male lambs decreased with an increase in the inclusion of the aerial part of cassava in the ration of the animals.(AU)

O objetivo do presente trabalho foi analisar os fatores de influência no desempenho de cordeiros em confinamento a pasto, com níveis de substituição de concentrado por parte aérea de mandioca, e sua relação com os índices de hematócritos. O experimento foi conduzido no Centro de Tecnologia de Ovinos (CTO), utilizando-se 56 ovinos da raça Pantaneira, sendo 28 machos e 28 fêmeas. No volume globular do grupo de fêmeas, observou-se efeito quadrático decrescente, com o ponto de mínimo para uma inclusão de 10,24% de PAM na ração com índice de níveis de hematócritos de 32,28. O efeito linear observado para o consumo médio de PB no modelo para cordeiros machos, conforme a dieta fornecida, em função do peso final, foi estimada o equivalente a 87,4% da formação do peso final dos cordeiros. Conclui-se que o consumo médio de proteína bruta é o fator com maior correlação com o peso final dos cordeiros machos e para as fêmeas o fator com maior correlação foi FDN, os níveis de consumo de cianeto influenciaram no ganho de peso médio diário das fêmeas. O nível de hematócritos dos cordeiros machos foi reduzido com o aumento da inclusão da parte aérea da mandioca na ração dos animais.(AU)

Analysis of factors of production in the termination of feedlot lambs to pasture / Análise de fatores de produção na terminação de cordeiros em confinamento a pasto

The objective of this study was to analyze the factors that influence the performance of lambs in pasture confinement, by substituting a concentrate with different levels of the aerial part of cassava in relation to hematocrit indices. The experiment was conducted at the Sheep Technology Center using 56 Pantaneira sheep, of which 28 were male and 28 were female. For female lambs, the globular volume showed a decreasing quadratic effect, with a minimum inclusion of 10.24% PAM in the diet for a hematocrit index of 32.28. A linear effect was observed for the mean crude protein intake in the male lambs based on the diet provided and was estimated to be equivalent to 87.4% of the lambs' final weight. In conclusion, mean crude protein consumption is most strongly correlated with the final weight of male lambs, and NDF is most strongly correlated with the final weight of female lambs, with the level of cyanide consumption influencing the average daily weight gain in female lambs. The hematocrit level of the male lambs decreased with an increase in the inclusion of the aerial part of cassava in the ration of the animals.(AU)

O objetivo do presente trabalho foi analisar os fatores de influência no desempenho de cordeiros em confinamento a pasto, com níveis de substituição de concentrado por parte aérea de mandioca, e sua relação com os índices de hematócritos. O experimento foi conduzido no Centro de Tecnologia de Ovinos (CTO), utilizando-se 56 ovinos da raça Pantaneira, sendo 28 machos e 28 fêmeas. No volume globular do grupo de fêmeas, observou-se efeito quadrático decrescente, com o ponto de mínimo para uma inclusão de 10,24% de PAM na ração com índice de níveis de hematócritos de 32,28. O efeito linear observado para o consumo médio de PB no modelo para cordeiros machos, conforme a dieta fornecida, em função do peso final, foi estimada o equivalente a 87,4% da formação do peso final dos cordeiros. Conclui-se que o consumo médio de proteína bruta é o fator com maior correlação com o peso final dos cordeiros machos e para as fêmeas o fator com maior correlação foi FDN, os níveis de consumo de cianeto influenciaram no ganho de peso médio diário das fêmeas. O nível de hematócritos dos cordeiros machos foi reduzido com o aumento da inclusão da parte aérea da mandioca na ração dos animais.(AU)

Chlorella minutissima cultivation with CO2 and pentoses: Effects on kinetic and nutritional parameters.

CO2 emissions and the large quantity of lignocellulosic waste generated by industrialized nations constitute problems that may affect human health as well as the global economy. The objective of this work was to evaluate the effects of using CO2 and pentoses on the growth, protein profile, carbohydrate content and potential ethanol production by fermentation of Chlorella minutissima biomass. CO2 and pentose supplementation can induce changes in the microalgal protein profile. A biomass production of 1.84g.L-1 and a CO2 biofixation rate of 274.63mg.L-1.d-1 were obtained with the use of 20% (v.v-1) CO2. For cultures with 20% (v.v-1) CO2 and reduced nitrogen, the carbohydrate content was 52.3% (w.w-1), and theoretically, 33.9mL.100g-1 of ethanol can be produced. These results demonstrate that C. minutissima cultured with the combined use of CO2 and pentoses generates a biomass with high bioenergetic potential.

Thermal and photo-stability of the antioxidant potential of Spirulina platensis powder / Estabilidade térmica e fotoestabilidade do potencial antioxidante de Spirulina platensis em pó

This work aimed to evaluate the thermal and photo stability of the antioxidant potential (AP) of the Spirulina platensis biomass. Thermal stability was established at 25ºC, 40ºC and 50ºC for 60 days, in the dark, protected from light. Photo stability was evaluated using UV (15 W, λ = 265 nm) and fluorescent (20 W, 0.16 A, power factor FP > 0.5, 50/60 Hz, 60 lm/w, 1200 lm) light for 90 days in capsules, glass and Petri dishes, at room temperature. The AP of the biomass in these conditions was determined at intervals (every 7 and 30 days in the studies of thermal and photo stability, respectively) using the induction of the oxidation of a lipid system by heat and aeration. In this lipid system, the biomass submitted to degradation was used as an antioxidant. The kinetics of the reaction was determined by the Arrhenius method. Thermal degradation was found to follow zero order kinetics, whereas photo degradation followed first order kinetics. The AP decreased 50% after 50 days at 25°C. At 40°C and 50°C, the AP decreased more than 50% after 35 and 21 days of exposition, respectively. The decrease of the AP of Spirulina was more sensible to UV and fluorescence light. After 30 days of exposition, the AP decreased more than 50% in all storage conditions tested. The antioxidant potential of Spirulina platensis is easily degraded when the biomass is exposed to heat and light, indicating the need for care to be taken in its storage.(AU)

Este trabalho objetivou avaliar a estabilidade térmica e a foto-estabilidade do potencial antioxidante (PA) da biomassa da Spirulina platensis. A estabilidade térmica foi avaliada a 25ºC, 40ºC e 50ºC por 60 dias. A foto-estabilidade foi avaliada usando luz UV (15 W, λ = 265 nm) e fluorescente (20 W, 0.16 A, fator de potência FP > 0.5, 50/60 Hz, 60 lm/w, 1200 lm) por 90 dias em cápsulas, vidro e placas de Petri. O PA da biomassa nessas condições foi determinado em intervalos de tempo (a cada 7 e 30 dias nos estudos de estabilidade térmica e foto-estabilidade, respectivamente), usando a indução da oxidação de um sistema lipídico por calor e aeração. Neste sistema lipídico, a biomassa submetida à degradação foi usada como antioxidante. A cinética da reação foi determinada pelo método de Arrhenius. A degradação térmica seguiu uma cinética de zero ordem, enquanto que a fotodegradação seguiu uma cinética de primeira ordem. O PA diminuiu 50% depois de 50 dias a 25°C. A 40°C e 50°C, o PA diminuiu mais de 50% depois de 35 e 21 dias de exposição, respectivamente. A diminuição do PA da Spirulina foi mais sensível à luz UV e fluorescente. Depois de 30 dias de exposição, o PA diminuiu mais de 50% em todas as condições de armazenamento testadas. O potencial antioxidante da Spirulina platensis é facilmente diminuído quando a biomassa é exposta ao calor e a luz, indicando a necessidade de cuidados durante seu armazenamento..(AU)

Thermal and photo-stability of the antioxidant potential of Spirulina platensis powder / Estabilidade térmica e fotoestabilidade do potencial antioxidante de Spirulina platensis em pó

Abstract This work aimed to evaluate the thermal and photo stability of the antioxidant potential (AP) of the Spirulina platensis biomass. Thermal stability was established at 25ºC, 40ºC and 50ºC for 60 days, in the dark, protected from light. Photo stability was evaluated using UV (15 W, λ = 265 nm) and fluorescent (20 W, 0.16 A, power factor FP > 0.5, 50/60 Hz, 60 lm/w, 1200 lm) light for 90 days in capsules, glass and Petri dishes, at room temperature. The AP of the biomass in these conditions was determined at intervals (every 7 and 30 days in the studies of thermal and photo stability, respectively) using the induction of the oxidation of a lipid system by heat and aeration. In this lipid system, the biomass submitted to degradation was used as an antioxidant. The kinetics of the reaction was determined by the Arrhenius method. Thermal degradation was found to follow zero order kinetics, whereas photo degradation followed first order kinetics. The AP decreased 50% after 50 days at 25°C. At 40°C and 50°C, the AP decreased more than 50% after 35 and 21 days of exposition, respectively. The decrease of the AP of Spirulina was more sensible to UV and fluorescence light. After 30 days of exposition, the AP decreased more than 50% in all storage conditions tested. The antioxidant potential of Spirulina platensis is easily degraded when the biomass is exposed to heat and light, indicating the need for care to be taken in its storage.

Resumo Este trabalho objetivou avaliar a estabilidade térmica e a foto-estabilidade do potencial antioxidante (PA) da biomassa da Spirulina platensis. A estabilidade térmica foi avaliada a 25ºC, 40ºC e 50ºC por 60 dias. A foto-estabilidade foi avaliada usando luz UV (15 W, λ = 265 nm) e fluorescente (20 W, 0.16 A, fator de potência FP > 0.5, 50/60 Hz, 60 lm/w, 1200 lm) por 90 dias em cápsulas, vidro e placas de Petri. O PA da biomassa nessas condições foi determinado em intervalos de tempo (a cada 7 e 30 dias nos estudos de estabilidade térmica e foto-estabilidade, respectivamente), usando a indução da oxidação de um sistema lipídico por calor e aeração. Neste sistema lipídico, a biomassa submetida à degradação foi usada como antioxidante. A cinética da reação foi determinada pelo método de Arrhenius. A degradação térmica seguiu uma cinética de zero ordem, enquanto que a fotodegradação seguiu uma cinética de primeira ordem. O PA diminuiu 50% depois de 50 dias a 25°C. A 40°C e 50°C, o PA diminuiu mais de 50% depois de 35 e 21 dias de exposição, respectivamente. A diminuição do PA da Spirulina foi mais sensível à luz UV e fluorescente. Depois de 30 dias de exposição, o PA diminuiu mais de 50% em todas as condições de armazenamento testadas. O potencial antioxidante da Spirulina platensis é facilmente diminuído quando a biomassa é exposta ao calor e a luz, indicando a necessidade de cuidados durante seu armazenamento.

Pentoses and light intensity increase the growth and carbohydrate production and alter the protein profile of Chlorella minutissima.

High concentrations of carbon, which is considered a necessary element, are required for microalgal growth. Therefore, the identification of alternative carbon sources available in large quantities is increasingly important. This study evaluated the effects of light variation and pentose addition on the carbohydrate content and protein profile of Chlorella minutissima grown in a raceway photobioreactor. The kinetic parameters, carbohydrate content, and protein profile of Chlorella minutissima and its theoretical potential for ethanol production were estimated. The highest cellular concentrations were obtained with a light intensity of 33.75µmol.m-2.s-1. Arabinose addition combined with a light intensity of 33.75µmol.m-2.s-1 increased the carbohydrate content by 53.8% and theoretically produced 39.1mL·100g-1 ethanol. All of the assays showed that a lower light availability altered the protein profile. The luminous intensity affects xylose and arabinose assimilation and augments the carbohydrate content in C. minutissima, making this microalga appropriate for bioethanol production.

Thermal and photo-stability of the antioxidant potential of Spirulina platensis powder.

This work aimed to evaluate the thermal and photo stability of the antioxidant potential (AP) of the Spirulina platensis biomass. Thermal stability was established at 25ºC, 40ºC and 50ºC for 60 days, in the dark, protected from light. Photo stability was evaluated using UV (15 W, λ = 265 nm) and fluorescent (20 W, 0.16 A, power factor FP > 0.5, 50/60 Hz, 60 lm/w, 1200 lm) light for 90 days in capsules, glass and Petri dishes, at room temperature. The AP of the biomass in these conditions was determined at intervals (every 7 and 30 days in the studies of thermal and photo stability, respectively) using the induction of the oxidation of a lipid system by heat and aeration. In this lipid system, the biomass submitted to degradation was used as an antioxidant. The kinetics of the reaction was determined by the Arrhenius method. Thermal degradation was found to follow zero order kinetics, whereas photo degradation followed first order kinetics. The AP decreased 50% after 50 days at 25°C. At 40°C and 50°C, the AP decreased more than 50% after 35 and 21 days of exposition, respectively. The decrease of the AP of Spirulina was more sensible to UV and fluorescence light. After 30 days of exposition, the AP decreased more than 50% in all storage conditions tested. The antioxidant potential of Spirulina platensis is easily degraded when the biomass is exposed to heat and light, indicating the need for care to be taken in its storage.

Nitrogen balancing and xylose addition enhances growth capacity and protein content in Chlorella minutissima cultures.

This study aimed to examine the metabolic changes in Chlorella minutissima cells grown under nitrogen-deficient conditions and with the addition of xylose. The cell density, maximum photochemical efficiency, and chlorophyll and lipid levels were measured. The expression of two photosynthetic proteins, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and the beta subunit (AtpB) of adenosine triphosphate synthase, were measured. Comparison of cells grown in medium with a 50% reduction in the nitrogen concentration versus the traditional medium solution revealed that the cells grown under nitrogen-deficient conditions exhibited an increased growth rate, higher maximum cell density (12.7×10(6)cellsmL(-1)), optimal PSII efficiency (0.69) and decreased lipid level (25.08%). This study has taken the first steps toward protein detection in Chlorella minutissima, and the results can be used to optimize the culturing of other microalgae.

Optimization of carbon dioxide supply in raceway reactors: Influence of carbon dioxide molar fraction and gas flow rate.

Influence of CO2 composition and gas flow rate to control pH in a pilot-scale raceway producing Scenedesmus sp. was studied. Light and temperature determined the biomass productivity whereas neither the CO2 molar fraction nor the gas flow rate used influenced it; because pH was always controlled and carbon limitation did not take place. The CO2 molar fraction and the gas flow rate influenced carbon loss in the system. At low CO2 molar fraction (2-6%) or gas flow rate (75-100l·min(-1)) the carbon efficiency in the sump was higher than 95%, 85% of the injected carbon being transformed into biomass. Conversely, at high CO2 molar fraction (14%) or gas flow rate (150l·min(-1)) the carbon efficiency in the sump was lower than 67%, 32% of the carbon being fixed as biomass. Analysis here reported allows the pH control to be optimized and production costs to be reduced by optimizing CO2 efficiency.

Could the beneficial effects of dietary calcium on obesity and diabetes control be mediated by changes in intestinal microbiota and integrity?

Evidence from animal and human studies has associated gut microbiota, increased translocation of lipopolysaccharide (LPS) and reduced intestinal integrity (II) with the inflammatory state that occurs in obesity and type 2 diabetes mellitus (T2DM). Consumption of Ca may favour body weight reduction and glycaemic control, but its influence on II and gut microbiota is not well understood. Considering the impact of metabolic diseases on public health and the role of Ca on the pathophysiology of these diseases, this review critically discusses possible mechanisms by which high-Ca diets could affect gut microbiota and II. Published studies from 1993 to 2015 about this topic were searched and selected from Medline/PubMed, Scielo and Lilacs databases. High-Ca diets seem to favour the growth of lactobacilli, maintain II (especially in the colon), reduce translocation of LPS and regulate tight-junction gene expression. We conclude that dietary Ca might interfere with gut microbiota and II modulations and it can partly explain the effect of Ca on obesity and T2DM control. However, further research is required to define the supplementation period, the dose and the type of Ca supplement (milk or salt) required for more effective results. As Ca interacts with other components of the diet, these interactions must also be considered in future studies. We believe that more complex mechanisms involving extraintestinal disorders (hormones, cytokines and other biomarkers) also need to be studied.

A new biomaterial of nanofibers with the microalga Spirulina as scaffolds to cultivate with stem cells for use in tissue engineering.

The association of stem cells (SCs) with biomaterials promises to be the protagonist for future regenerative medicine in the treatment of tissue and organ lesions. Stem cells were cultivated in scaffolds constructed by the electrospinning technique, using poly-D,L-lactic acid (PDLLA) associated or not with Spirulina biomass (PDLLA/Sp), which has bioactive components of interest for tissue engineering (TE). Physicochemical analyses were performed, such as morphology, fiber diameter, degradability, residual solvent, roughness, contact angle with water, among others. SCs adhesion, proliferation and scaffold cytotoxicity were also evaluated. Nanofibers without beads and with characteristics similar to the natural extracellular matrix (ECM) in terms of mechanical and topographical properties were obtained. In biological tests it was found that SCs adhered more and had greater viability in the PDLLA/Sp molds, when compared with the PDLLA scaffolds. The scaffolds were shown to be atoxic for the SCs. It can be concluded that the scaffolds developed in this work have the characteristics to be a new biomaterial suitable for use in TE.

Intake and Performance of Yearling Steers Grazing Guineagrass (Panicum maximum cv. Tanzânia) Pasture Supplemented with Different Energy Sources.

The aim of this study was to evaluate the efficiency of supplements containing different energy sources in relation to mineral supplementation of steers grazing guineagrass (Panicum maximum cv Tanzânia) pasture, during the dry season. The experimental design was a randomized block with three treatments and four replications. The treatments consisted of a mineral supplementation and two other supplements, one based on corn seed and the other based on soybean hulls, and provided at 0.8% of body weight. Forty-eight, 12 month-old crossbred steers with an average initial body weight of 267 kg, were assigned to twelve paddocks (1,125 ha) of guineagrass. The animals that were fed with soybean hulls and corn seed presented a greater average daily gain (0.982 and 0.937) when compared with the mineral supplementation. Soybean hulls can be used as a satisfactory food source, replacing corn as an energy source in the supplementation of beef cattle without compromising animal performance.

Extra-facial melasma: clinical, histopathological, and immunohistochemical case-control study.

BACKGROUND: Extra-facial melasma is a prevalent dermatosis in some populations with special characteristics in relation to its clinical aspects and probable etiopathogenic factors. Few studies have attempted to address this alteration of pigmentation, which has become a challenge in clinical Dermatology. OBJECTIVE: To assess the clinical histopathological and immunohistochemical characteristics of extra-facial melasma, comparing affected, and unaffected sites. METHODS: Case-control study with 45 patients in each group (melasma and disease-free volunteers), assessing their clinical characteristics. In 36 patients, biopsies were performed on the lesion and the normal perilesional skin. Specimens were stained with HE and Fontana-Masson, and melanocytes analysed by immunohistochemistry. Objective measurements were accomplished by a specifically designed image analysis software. RESULTS: The melasma group had a mean age ± SD of 56.67 ± 8 years, the majority of them were women (86.7%) and 82.1% of the female cases had reached menopause. There were no significant differences between groups in terms of presence of comorbidities, use of medications or hormone therapies. For extra-facial melasma patients, family history of this dermatose and of previous facial melasma was significantly higher than in the control group (P < 0.05). The HE staining showed increased rectification and basal hyperpigmentation, solar elastosis, and collagen degeneration in the pigmented area (P < 0.05). There was a significant increase in melanin density in melasma biopsies, but the immunohistochemical tests did not detect a difference between the groups in terms of number of melanocytes. CONCLUSION: Extra-facial melasma appears to be related to menopause, family history, and personal history of facial melasma, in the studied population. Histopathology revealed a pattern similar to what has been described for facial melasma, with signs of solar degeneration, and a similar number of melanocytes, when comparing patients, and controls, suggesting that the hyperpigmentation is most likely the result of abnormal melanin production or distribution.

Vertical tubular photobioreactor for semicontinuous culture of Cyanobium sp.

We evaluated the kinetic culture characteristics of the microalgae Cyanobium sp. grown in vertical tubular photobioreactor in semicontinuous mode. Cultivation was carried out in vertical tubular photobioreactor for 2 L, in 57 d, at 30 °C, 3200 Lux, and 12 h light/dark photoperiod. The maximum specific growth rate was found as 0.127 d(-1), when the culture had blend concentration of 1.0 g L(-1), renewal rate of 50%, and sodium bicarbonate concentration of 1.0 g L(-1). The maximum values of productivity (0.071 g L(-1) d(-1)) and number of cycles (10) were observed in blend concentration of 1.0 g L(-1), renewal rate of 30%, and bicarbonate concentration of 1.0 g L(-1). The results showed the potential of semicontinuous cultivation of Cyanobium sp. in closed tubular bioreactor, combining factors such as blend concentration, renewal rate, and sodium bicarbonate concentration.

Push-out strength of methacrylate resin-based sealers to root canal walls.

AIM: To assess the push-out strength of Epiphany SE, Epiphany and Hybrid Root SEAL to the dentine walls of root canals. METHODOLOGY: Sixty roots of canines were prepared and distributed to six groups (n = 10) according to the filling material: GI - Epiphany SE, GII - Epiphany primer and sealer, GIII - Epiphany primer, sealer and resinous solvent, GIV - Clearfil DC Bond and Epiphany sealer, GV - Clearfil, Epiphany sealer and solvent and GVI - Hybrid Root SEAL. Resilon cones were used in all groups. Roots were sectioned transversally to obtain three slices from each third. One slice was subjected to the push-out test (MPa), and results were analysed by anova and Tukey's test (P < 0.05). The other two slices were prepared for scanning electron microscopy (SEM). Failure mode was also analysed. RESULTS: A statistically significant difference (P <0.05) occurred between Hybrid Root SEAL (5.27 +/- 2.07) and the other materials, GI (0.40 +/- 0.23), GII (0.78 +/- 0.45), GIII (0.57 +/- 0.28), GIV (0.40 +/- 0.24) and GV (0.50 +/- 0.41), which did not differ significantly from each other (P > 0.05). Adhesive failures predominated in groups I, II, IV and V, whilst mixed and cohesive failures were the most frequent in groups III and VI, respectively. There were gaps in the adhesive interface of GI and GII, continuity areas of the filling material with dentine in GIV and GV and good adaptation of the interface of GVI. CONCLUSION: Hybrid Root SEAL had greater push-out strength to root canal dentine than Epiphany SE and Epiphany. The use of primer, solvent and adhesive system did not influence the adhesion of Epiphany.