Harvesting of Chlorella sorokiniana BR001 cultivated in a low-nitrogen medium using different techniques / Colheita de Chlorella sorokiniana BR001 cultivada em um meio com baixo teor de nitrogênio utilizando diferentes técnicas

ABSTRACT: The harvesting process is a current challenge for the commercial production of microalgae because the biomass is diluted in the culture medium. Several methods have been proposed to harvest microalgae cells, but there is not a consensus about the optimum method for such application. Herein, the methods based on sedimentation, flocculation, and centrifugation were evaluated on the recovery of Chlorella sorokiniana BR001 cultivated in a low-nitrogen medium. C. sorokiniana BR001 was cultivated using a low-nitrogen medium to trigger the accumulation of neutral lipids and neutral carbohydrates. The biomass of C. sorokiniana BR001 cultivated in a low-nitrogen medium showed a total lipid content of 1.9 times higher (23.8 ± 4.5%) when compared to the biomass produced in a high-nitrogen medium (12.3 ± 1.2%). In addition, the biomass of the BR001 strain cultivated in a low-nitrogen medium showed a high content of neutral carbohydrates (52.1 ± 1.5%). The natural sedimentation-based process was evaluated using a sedimentation column, and it was concluded that C. sorokiniana BR001 is a non-flocculent strain. Therefore, it was evaluated the effect of different concentrations of ferric sulfate (0.005 to 1 g L-1) or aluminum sulfate (0.025 to 0.83 g L-1) on the flocculation process of C. sorokiniana BR001, but high doses of flocculant agents were required for an efficient harvest of biomass. It was evaluated the centrifugation at low speed (300 to 3,000 g) as well, and it was possible to conclude that this process was the most adequate to harvest the non-flocculent strain C. sorokiniana BR001.

RESUMO: O processo de colheita é um desafio atual para a produção comercial de microalgas porque a biomassa é diluída no meio de cultivo. Diversos métodos têm sido propostos para coletar células de microalgas, porém não existe um consenso sobre um método ótimo para tal aplicação. Neste estudo, métodos baseados em sedimentação, floculação e centrifugação foram avaliados na recuperação de Chlorella sorokiniana BR001 cultivada em um meio com baixo teor de nitrogênio. C. sorokiniana BR001 foi cultivada em um meio com baixo teor de nitrogênio para induzir ao acúmulo de lipídeos e carboidratos neutros. A biomassa de C. sorokiniana BR001 cultivada em um meio com baixo teor de nitrogênio apresentou um teor de lipídeos 1,9 vezes superior (23,8 ± 4,5%), quando comparada à biomassa produzida em um meio com alto teor de nitrogênio (12,3 ± 1,2%). Adicionalmente, a biomassa da linhagem BR001 cultivada em um meio com baixo teor de nitrogênio apresentou alto teor de carboidratos neutros (52,1 ± 1,5%). O processo baseado em sedimentação natural foi avaliado utilizando uma coluna de sedimentação e concluiu-se que C. sorokiniana BR001 é uma linhagem não floculante. Portanto, o efeito de diferentes concentrações de sulfato férrico (0,005 a 1 g L-1) ou sulfato de alumínio (0,025 a 0,83 g L-1) foram avaliados no processo de floculação de C. sorokiniana BR001, mas altas doses de floculantes foram necessárias para uma colheita de biomassa eficiente. Também foi avaliada a centrifugação em baixa velocidade (300 a 3.000 g), e foi possível concluir que este processo constituiu o mais adequado para a colheita da linhagem não floculante C. sorokiniana BR001.

Effect of two hemostatic agents on the bonding strength of total-etch and self-etch adhesive systems in primary tooth dentin / 口腔疾病防治

Objective @#To explore the effects of two hemostatic agents on the bonding strength of different bonding systems in primary tooth dentin.@*Methods @# Seventy-two retained deciduous teeth were randomly selected. Forty-eight teeth were used to construct the microleakage model, the other 24 teeth were cut along the mesial and distal directions and 48 samples were obtained to construct the shear bond strength model. The two experiments were divided into 2 groups. Group A was the total-etch group: A1 (ViscoStat + Spectrum Bond NT); A2 (ViscoStat Clear + Spectrum Bond NT); and A3 (Non + Spectrum Bond NT); Group B was the self-etch group: B1 (ViscoStat + Single bond Universal Adhesive); B2 (ViscoStat Clear + Single bond Universal Adhesive); and B3 (Non + Single bond Universal Adhesive). Microleakage experiments and shear bond strength experiments were carried out respectively and the morphology of the fracture surface was observed by scanning electron microscopy.@* Results @#There was no significant difference in microleakage among groups A1, A2, and A3 (P > 0.05). There was no significant difference in microleakage among groups B1, B2, and B3 (P > 0.05). There was no significant difference in the shear bond strength among groups A1, A2 and A3 (P > 0.05). The shear bond strength of groups B1 and B2 was significantly lower than that of group B3 (P < 0.05). There was no significant difference between groups B1 and B2 (P > 0.05). @*Conclusion@#ViscoStat and ViscoStat Clear had no effect on the marginal integrity of deciduous tooth dentin under the different bonding systems. The two hemostatic agents reduced the shear bonding strength of deciduous tooth dentin under the self-etch adhesive system, but had no effect on the shear bonding strength of deciduous tooth dentin under the total-etch adhesive system.

Initial inflammatory response after the pulpotomy of rat molars with MTA or ferric sulfate

Abstract Purpose To compare, both qualitatively and quantitatively, the inflammatory cells, vascular density and IL-6 immunolabeled cells present in the pulp after pulpotomy with white MTA versus 15.5% ferric sulfate (FS). Methodology Forty-eight mandibular first molars from 24 Wistar rats were divided into MTA or FS groups and subdivided according to the period after pulpotomy procedure (24, 48 and 72 hours). Four teeth (sound and untreated) were used as controls. Histological sections were obtained and assessed through the descriptive analysis of morphological aspects of pulp tissue and the quantification of inflammatory cells, vascular density and interleukin-6 (IL-6) expression. Data were statistically analyzed (p<0.05). Results The number of inflammatory cells was similar in both groups, being predominantly localized at the cervical radicular third. In the MTA group, increased inflammation was observed at 48 hours. Vascular density was similar in both groups and over time, being predominant in the medium radicular third. No correlation was found between the number of inflammatory cells and the vascular density. Pulp tissue was more organized in MTA-treated teeth. In both groups, a weak to moderate IL-6 expression was detected in odontoblasts and inflammatory cells. Comparing both groups, there was a greater IL-6 expression in the cervical radicular third of teeth treated with MTA at 24 hours and in the medium and apical thirds at 72 hours, while in the FS group a greater IL-6 expression was found in the apical third at 24 hours. Conclusion The MTA group presented better histological features and greater IL-6 expression than the FS group. However, no difference was observed between the groups regarding the inflammatory status and vascularization, suggesting the usefulness of FS as a low-cost alternative to MTA.

Clinical, radiographic and histological evaluation of primary teeth pulpotomy using mta and ferric sulfate

Abstract The aim of this study was to evaluate the clinical, radiographic and histological outcomes of the dentin-pulp complex from primary molars after pulpotomy with mineral trioxide aggregate (MTA) and 15.5% ferric sulfate (FS). Thirty-one primary molars were randomly allocated into MTA or FS groups. Clinical and radiographic evaluations were recorded at 3-, 6-, 12- and 18-month follow-up. Teeth at the regular exfoliation period were extracted and processed for histological analysis. Clinical and radiographic data were tested by statistical analysis (p≤0.01). Histological outcomes were analyzed descriptively. All of the treated teeth presented clinical success over the experimental periods. Both groups exhibited 100% of radiographic success at 3, 6 and 12 months. At the 18-month follow-up, one tooth from FS group presented inter-radicular radiolucency (p>0.01). Histologically, the treated teeth presented pulp vitality and absence of inflammatory infiltrate into the connective tissue. Only MTA group showed hard tissue barrier surrounded by odontoblasts over the pulp stumps. Both MTA and 15.5% FS are effective for pulpotomies of primary teeth. Although MTA is considered the first-choice material, FS may be a suitable alternative when treatment cost is an issue.

Resumo O objetivo deste estudo foi avaliar os resultados clínicos, radiográficos e histológicos do complexo dentino-pulpar de molares decíduos após pulpotomia com agregado trióxido mineral (MTA) e sulfato férrico (SF) 15,5%. Trinta e um molares decíduos foram alocados aleatoriamente nos grupos MTA ou SF. As avaliações clínicas e radiográficas foram realizadas aos 3, 6, 12 e 18 meses de acompanhamento. Os dentes no período regular de esfoliação foram extraídos e processados ​​para análise histológica. Os dados clínicos e radiográficos foram analisados estatisticamente (p≤0,01). O resultados histológicos foram analisados ​​descritivamente. Todos os dentes tratados apresentaram sucesso clínico ao longo dos períodos experimentais. Ambos os grupos exibiram 100% de sucesso radiográfico aos 3, 6 e 12 meses. Aos 18 meses de acompanhamento, um dente do grupo SF apresentou radiolucidez interradicular (p>0,01). Histologicamente, os dentes tratados apresentaram vitalidade pulpar e ausência de infiltrado inflamatório no tecido conjuntivo. Somente o grupo MTA mostrou barreira de tecido duro rodeada por odontoblastos sobre os cotos pulpares. MTA e SF 15,5% são eficazes para pulpotomias de dentes decíduos. Embora o MTA seja considerado o material de primeira escolha, o SF pode ser uma alternativa adequada quando o custo do tratamento é um problema.

Biologic response of local hemostatic agents used in endodontic microsurgery

Appropriate use of local hemostatic agent is one of the important factors on the prognosis of endodontic microsurgery. However, most investigations to date focus on the hemostatic efficacy of the agents, whereas their biologic characteristics have not received enough attention. The purpose of this paper was to review the biologic response of local hemostatic agents, and to provide clinical guidelines on their use during endodontic microsurgery. Electronic database (PUBMED) was screened to search related studies from 1980 to 2013, and 8 clinical studies and 18 animal studies were identified. Among the materials used in these studies, most widely-investigated and used materials, epinephrine, ferric sulfate (FS) and calcium sulfate (CS), were thoroughly discussed. Influence of these materials on local tissue and systemic condition, such as inflammatory and foreign body reaction, local ischemia, dyspigmentation, delayed or enhanced bone and soft tissue healing, and potential cardiovascular complications were assessed. Additionally, biological property of their carrier materials, cotton pellet and absorbable collagen, were also discussed. Clinicians should be aware of the biologic properties of local hemostatic agents and their carrier materials, and should pay attention to the potential complications when using them in endodontic microsurgery.

Intoxicación aguda por hierro / Acute iron poisoning

Los pacientes intoxicados representan un reto en el enfoque diagnóstico y terapéutico en los serviciosde urgencias. La intoxicación por hierro es una condición médica relativamente frecuente en los pacientes pediátricos y gestantes, dada la fácil adquisición de este mineral en los suplementosvitamínicos, que son corrientemente formulados en las consultas médicas de promoción y prevención y en los programas de control prenatal. La intoxicación aguda por hierro representa un alto potencialletal y para llegar a dicho estado se requieren dosis extremadamente altas como 200 a 250 mg/kg de hierro elemental, aunque recientemente se describe con valores mayores de 150 mg/kg y otros con 75 mg/kg; sin embargo, se empiezan a observar manifestaciones de toxicidad con ingestas mayores de 15 a 20 mg/kg. En el presente artículo se hace una revisión de la intoxicación aguda por hierro desde su metabolismo básico, pasando por los mecanismos existentes para la regulación de las sobrecargasférricas agudas y tomando conceptos necesarios para la comprensión de los procesos fisiopatológicosde las manifestaciones de toxicidad, según el órgano blanco potencialmente lesionado. Se hace una reseña de las modalidades diagnósticas y terapéuticas establecidas, así como los aportes de algunas investigaciones para la posible identificación de antídotos distintos a la deferoxamina. Por último, sepresenta un algoritmo diagnóstico y terapéutico en base a la revisión hecha.

Poisoned patients represent a challenge at the diagnostic and therapeutic approach in theemergency department. Iron poisoning is a relativelycommon medical condition in pregnantand pediatric patients due the easy acquisition of the mineral in supplements often prescribedin medical consultations and prenatal care programs. This poisoning has a high lethal potential,however to reach that state are required extremely high doses as 200 to 250 mg/kg of elementaliron, but recently it´s describe doses of 150 mg/kg and some authors reports of 75 mg/Kg,but are beginning to show signs of toxicity with intakes of 15 - 20 mg/kg. In this paper, we madea review of acute iron poisoning, from basic metabolism, through existing mechanisms for theregulation of acute iron overload and taking concepts for understanding the pathophysiologicalprocesses. This review provides an overview of established diagnostic and therapeutic modalities,as well as input from some research forthe possible identification of various antidotes different to deferoxamine. Finally, it presents a diagnostic and therapeutic algorithm based on the review done.

Pulpotomías con sulfato férrico y MTA en dientes primarios: serie de casos / Ferric sulfate and MTA pulpotomies in primary teeth: a case series

En 11 pacientes se realizaron 7 pulpotomías con agregado trióxido mineral (MTA) y 6 con Sulfato Férrico (SF). Se incluyeron pacientes que presentaron dientes primarios con exposición accidental de la pulpa durante la remoción de caries en ausencia de signos y síntomas clínicos y/o radiográficos de patología pulpar. Las piezas tratadas fueron restauradas con coronas preformadas de acero inoxidable y controladas clínica y radiográficamente cada 6 meses. El seguimiento promedio fue de 15,6 meses para ambos grupos, con éxito clínico de un 100 por ciento para ambos medicamentos. El éxito radiográfico fue de 85,71 por ciento para el MTA y de 83,33 por ciento para el SF. Si bien ambos medicamentos presentaron un buen desempeño clínico y radiográfico durante el periodo de seguimiento, el SF fue más económico y necesitó un menor tiempo de trabajo, característica deseable en odontopediatría.

In eleven patients 7 pulpotomies were performed with Mineral Trioxide Aggregate (MTA) and 6 with ferric sulphate (FS). We included patients who had primary teeth with accidental exposure of the pulp during caries removal in the absence of clinical signs and symptoms and / or radiographic evidence of pulpal pathology. The treated pieces were restored with preformed stainless steel crowns and controlled clinically and radiographically every 6 months. The average follow-up was 15.6 months for both groups, with clinical success of 100 percent for both treatments. Radiographic success was 85.71 percent for the MTA and 83.33 percent for SF.ÊAlthough both procedures showed good performance during the clinical and radiographic follow-up period, the SF was cheaper and required less working time, a desirable characteristic in pediatric dentistry.

Determination of Two Constituents in Compound Streptomycin Cream / 中国药房

OBJECTIVE:To determine streptomycin sulfate and sulfonamide in compound streptomycin cream by UV spectrophotometry.METHODS:The maltol-ammonium ferric sulfate colourimetry was adopted in which the ammonium ferric sulfate was taken as the developer,the absorbability of streptomycin sulfate was determined with the wavelength at521nm;The absorbability of sulfonamide was determined at a wavelength of251nm with0.1%mol/L NaOH taken as the sol-vent.RESULTS:The linear ranges of streptomycin sulfate and sulfonamide were200～950?g/ml(r=0.9994)and1.464～7.784?g/ml(r=0.9998)respectively;Their respective average recovery were99.1%(RSD=1.90%)and99.7%(RSD=1.60%).CONCLUSION:The method can be used as the quality control for compound streptomycin cream.