Effect of initial pH in levan production by Zymomonas mobilis immobilized in sodium alginate

Zymomonas mobilis was immobilized using a cell suspension fixed to 8.6 x 10(7) CFU mL(-1) by spectrophotometry. This biomass was suspended in sodium alginate solution (3%) that was dropped with a hypodermic syringe into 0.2 M calcium chloride solution. Was test two initial pH of fermentation medium (4 and 5) and different sucrose concentrations 15, 20, 25, 30 and 35% at 30 degrees C, without stirring for 24, 48, 72 and 96 hours. The levan production to pH 4 was high in sucrose 25% for 24 (16.51 g L-1) and 48 (15.31 g L-1) hours. The best values obtained to pH 5 was in sucrose 35% during 48 (22.39 g L-1) and 96 (23.5 g L-1) hours, respectively. The maximum levan yield was 40.8% and 22.47% in sucrose 15% to pH 4 and 5, respectively. Substrate consumption to pH 4 was bigger in sucrose 15 (56.4%) and 20% (59.4%) and to pH 5 was in 25 (68.85%) and 35% (64.64%). In relation to immobilization efficiency, Zymomonas mobilis showed high adhesion and colonization in support, indicated by cell growth increased from 107 to 10(9) CFU mL(-1) during fermentation time.

Daily photosynthesis, water relations, and ion concentrations of uuonymus irrigated with treated wastewater

Euonymus japonica Thunb. (euonymus) plants were submitted for 9 months to two irrigation treatments using water from different sources: a control (C) water with electrical conductivity (EC) less than 1.2 dS.m(-1) and reclaimed wastewater (RW) with EC approximate to 4 dS.m(-1). At the end of the experiment, no differences in the total dry weight were observed between treatments, whereas the leaf dry mass increased (to the detriment of the root part in RW plants). Throughout the day, the stem water potential (Psi(stem)) of the RW plants was lower than in C, whereas stomatal conductance (g(S)) was slightly reduced in RW from 0800 HR to 1200 HR, but no significant variation in photosynthesis (P-n) or energy conversion efficiency (F'(v)/F'(m)) in photosystem II was detected through the effect of salinity. Gas exchange and fluorescence showed a tendency to increase after midday in plants treated with RW. The photosynthetic behavior and fluorescence of RW plants may have been related to the nitrogen and chlorophyll content of the leaves, confirming the resistance of the photosynthetic mechanism to salinity in this species in these conditions. The toxic effects produced by high concentrations of boron (B), sodium (Na+) and chloride (Cl-) were offset by the effect of other ions like magnesium (Mg2+), potassium (K+), and phosphorus (P) in plants irrigated with RW, thus improving their physiological status without decreasing their ornamental value.

Síntese e estudo da diapocinina como um inibidor da NADPH Oxidase em neutrófilos e células mononucleares de sangue periférico

Apocynin, a methoxy-catechol originally extracted from the root of Picrorhiza kurroa, has been used as an inhibitor of the NADPH oxidase complex in phagocytic and nonphagocytic cells. Its mechanism of inhibition is linked to their prior activation through the action of peroxidases leading to oxidation of the dimeric product, diapocynin. In this study, dipocinina was synthesized and investigated its effect as an inhibitor of activation NADPH oxidase in neutrophils (PMN) and peripheral blood mononuclear cells (PBMC). The synthesis of diapocinina was performed by oxidation of apocinina by potassium persulphate in the midst of water for 5 minutes at room temperature. The precipitate was filtered and washed with water and methanol. Diapocinina was characterized by mass spectrometry. PMN and PBMC were obtained from peripheral blood of healthy donors and purified for gelatin sedimentation, or centrifugation with Histopaque ®, the red cells were lysed with ice water or ammonium chloride. Diapocinina or apocinina were incubated with opsonized zymosan, activation of PMNs and release of superoxide anion, these monitored by chemiluminescent assay dependent lucigenina. We found that diapocinina inhibitor was no better than the apocinina in PMN. However, diapocinina was more efficient than apocinina as an inhibitor of NADPH oxidase in PBMC. In conclusion, whereas PBMC are relatively poor compared with peroxidases PMN, our results are consistent with the need for oxidation apocinina for its effect as an inhibitor of NADPH oxidase

Como estará a ingestão de sódio após uma sobrecarga de volume combinada ao tratamento com paroxetina?

Aortic regurgitation (AR) is still common in developing countries as secondary of rheumatic fever, and its incidence have increased in senile degenerative form. The AR develops severe myocardial hypertrophy. A common comorbidity associated with cardiovascular disease is depression. Among the most prescribed antidepressants in the world are the serotonin selective reuptake inhibitors (SSRIs). Central serotonergic pathways are involved with the inhibition of sodium intake and can be modify the excretion of this íon. Therefore, we investigated whether treatment with an antidepressants SSRI, the paroxetine, for four weeks can modfy the behavior of water and NaCl 0,3M intake, excretion of sodium and morphofunctional parameters of rats with AR induce. Wistar rats (280 - 300g) underwent surgery for AR (n=15) or control surgery (n=14). The AR was induced by retrograde puncture of valve leaflets. The animals were divided into 4 groups: AR + paroxetine (n=8), AR + control (n=7), control + paroxetine (n=7), control + control (n=7). From the 4th to the 8th week after inductuin of AR was administered paroxetine (10mg/kg pc) daily and subcutaneously. In the 4th and 8th week after induction of AR echocardiograms were performed to collect data morphofunctional. During the 4 weeks of treatment were analyzed intake of water and saline daily and once a week urine samples were collected for analysis by flame photometer of excretion of sodium and potassium. In the 10th week the animals were submitted to a challenge protocol hidromineral by combining furosemide (10 mg / kg bw) associated with the low dose of Captopril (5 mg / kg bw). During the challenged urine samples were collected for analysis by flame photometer of excretion of sodium and potassium at the time zero and after 2 hours of treatment. As a result we found that treatment with paroxetine in rats with AR determined an improvement in fractional shortening (shortening fraction: 52.7 ± 2.2% vs. RA ...

Renal and vascular effects of Crotalus durissus cumanensis venom and its crotoxin fraction

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Bothropoides pauloensis venom effects on isolated perfused kidney and cultured renal tubular epithelial cells

Coordenadação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Rainwater chemical composition and annual atmosphere depositon in Sorocaba (SP)

This work evaluated the rainwater chemical composition and the annual atmospheric deposition in Sorocaba, (Sao Paulo State), Brazil. One sampling ˜ point was chosen and forty samples were collected between January and December 2006. The analyses were performed for pH, electrical conductivity, sodium, calcium, potassium, magnesium, sulphate, nitrate, phosphate, alkalinity and chloride. The rainwater pH varied from 5.20 to 6.40, being Ca2+ the main ion responsible for controlling the rainwater pH. The ionic concentration decreases in the following order: Ca2+>Na+> K+>Mg2+ for cations and SO2− 4 >HCO− 3 >NO− 3 >Cl−>PO3− 4 for anions. The annual atmospheric deposition appears to be controlled by the following sources: mining activities and cement factories (Ca2+ and HCO− 3 ), agricultural activities (K+, NO− 3 and PO3− 4 ), soil dust (Na+, Mg2+ and HCO− 3 ) and fossil fuel burning (SO2− 4 )

Tifton 419 Bermudagrass (Cynodon dactylon C. transvaaliensis) response to plant grow inhibitors

Tifton 419' bermudagrass cultivar [Cynodon dactylon (L.) Pers. x C. transvaalensis Burtt-Davy] is the most preferred turfgrass for sportive, commercial and residential lawns. On similar species, such as Stenotaphrum secundatum and Zoysia japonica, gibberellic acid-inhibiting plant growth regulators (PGRs) are used to decrease mowing frequency. A very limited research has been reported yet on the PGRs regarding seasonal effects of single vs. multiple applications of these products on turfgrass quality and clipping production on South America. This study aimed to evaluate the effect of sequential applications of different plant growth inhibitors during re-growth and flower rachis emission of 'Tifton 419' Bermudagrass. The treatment pattern includes an initial application followed by one sequential application at 14 days intervals, according to the following: prohexadione-calcium at 100+100 or 200+200 g a.i. ha-1, bispyribac-sodium at 40+40 or 60+60 g a.i. ha-1, trinexapac-ethyl at 113+113, 226+113, 226+226, 452+113, 452+226, 452+452, 678+0 or 904+0 g a.i. ha-1, and untreated control. The treatment effect was evaluated based on measurements of visual injury, height of plants, height and number of flower rachis, and clipping total dry mass production. The results showed that only bispyribac-sodium provided visual injury on 'Tifton 419' Bermudagrass, but the symptoms quickly tend towards zero at 21 days after second application (DASA). 'Tifton 419' Bermudagrass greens could be better handle by sequential application of trinexapac-ethyl, or prohexadione-calcium or bispyribac-sodium, once the height of plants, seedhead emission and total clipping dry mass reduction were over than 37%, 91% and 88%, respectively, for a period up to 60 DASA.

Efeito de diversos protocolos de dessensibilização dentinária na obliteração de túbulos dentinários, resistência de união do sistema adesivo e formação de camada hibrida na dentina cervical

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito de diversos protocolos de dessensibilização dentinária na obliteração de túbulos dentinários, resistência de união do sistema adesivo e formação de camada hibrida na dentina cervical

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Interaction between Trypanosoma rangeli and the Rhodnius prolixus salivary gland depends on the phosphotyrosine ecto-phosphatase activity of the parasite

Trypanosoma rangeli is the trypanosomatid that colonizes the salivary gland of its insect vector, with a profound impact on the feeding capacity of the insect. In this study we investigated the role of the phosphotyrosine (P-Tyr) ecto-phosphatase activity of T. rangeli in its interaction with Rhodnius prolixus salivary glands. Long but not short epimastigotes adhered to the gland cells and the strength of interaction correlated with the enzyme activity levels in different strains. Differential interference contrast microscopy demonstrated that clusters of parasites are formed in most cases, suggesting cooperative interaction in the adhesion process. The tightness of the correlation was evidenced by modulating the P-Tyr ecto-phosphatase activity with various concentrations of inhibitors. Sodium orthovanadate, ammonium molybdate and zinc chloride decreased the interaction between T. rangeli and R. prolixus salivary glands in parallel. Levamisole, an inhibitor of alkaline phosphatases, affected neither process. EDTA strongly inhibited adhesion and P-Tyr ecto-phosphatase activity to the same extent, an effect that was no longer seen if the parasites were pre-incubated with the chelator and then washed. When the P-Tyr ecto-phosphatase of living T. ranged epimastigotes was irreversibly inactivated with sodium orthovanadate and the parasite cells were then injected into the insect thorax, colonization of the salivary glands was greatly depressed for several days after blood feeding. Addition of P-Tyr ecto-phosphatase substrates such as p-nitrophenyl phosphate (pNPP) and P-Tyr inhibited the adhesion of T. rangeli to salivary glands, but P-Ser, P-Thr and beta-glycerophosphate were completely ineffective. Immunoassays using anti-P-Tyr-residues revealed a large number of P-Tyr-proteins in extracts of R. prolixus salivary glands, which could be potentially targeted by T. rangeli during adhesion. These results indicate that dephosphorylation of structural P-Tyr residues on the gland cell surfaces, mediated by a P-Tyr ecto-phosphatase of the parasite, is a key event in the interaction between T. rangeli and R. prolixus salivary glands. (C) 2012 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Photo-Fenton oxidation of phenol and organochlorides (2,4-DCP and 2,4-D) in aqueous alkaline medium with high chloride concentration

A highly concentrated aqueous saline-containing solution of phenol, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenol (2.4-DCP) was treated by the photo-Fenton process in a system composed of an annular reactor with a quartz immersion well and a medium-pressure mercury lamp (450 W). The study was conducted under special conditions to minimize the costs of acidification and neutralization, which are usual steps in this type of process. Photochemical reactions were carried out to investigate the influence of some process variables such as the initial concentration of Fe2+ ([Fe2+](0)) from 1.0 up to 2.5 mM, the rate in mmol of H2O2 fed into the system (F-H2O2,F-in) from 3.67 up to 7.33 mmol of H2O2/min during 120 min of reaction time, and the initial pH (pH(0)) from 3.0 up to 9.0 in the presence and absence of NaCl (60.0 g/L). Although the optimum pH for the photo-Fenton process is about 3.0, this particular system performed well in experimental conditions starting at alkaline and neutral pH. The results obtained here are promising for industrial applications, particularly in view of the high concentration of chloride, a known hydroxyl radical scavenger and the main oxidant present in photo-Fenton processes. (C) 2012 Elsevier Ltd. All rights reserved.

Diverse levels of an inwardly rectifying potassium conductance generate heterogeneous neuronal behavior in a population of dorsal cochlear nucleus pyramidal neurons

Leao RM, Li S, Doiron B, Tzounopoulos T. Diverse levels of an inwardly rectifying potassium conductance generate heterogeneous neuronal behavior in a population of dorsal cochlear nucleus pyramidal neurons. J Neurophysiol 107: 3008-3019, 2012. First published February 29, 2012; doi:10.1152/jn.00660.2011.-Homeostatic mechanisms maintain homogeneous neuronal behavior among neurons that exhibit substantial variability in the expression levels of their ionic conductances. In contrast, the mechanisms, which generate heterogeneous neuronal behavior across a neuronal population, remain poorly understood. We addressed this problem in the dorsal cochlear nucleus, where principal neurons exist in two qualitatively distinct states: spontaneously active or not spontaneously active. Our studies reveal that distinct activity states are generated by the differential levels of a Ba2+-sensitive, inwardly rectifying potassium conductance (K-ir). Variability in K-ir maximal conductance causes variations in the resting membrane potential (RMP). Low K-ir conductance depolarizes RMP to voltages above the threshold for activating subthreshold-persistent sodium channels (Na-p). Once Na-p channels are activated, the RMP becomes unstable, and spontaneous firing is triggered. Our results provide a biophysical mechanism for generating neural heterogeneity, which may play a role in the encoding of sensory information.

Reducing Water and Chloride Penetration Through Silicate Treatments for Concrete as a Mean to Control Corrosion Kinetics

There are currently many types of protective materials for reinforced concrete structures and the influence of these materials in the chloride diffusion coefficient and water penetration still needs more research. The aim of this work is to analyze the contributions regarding the typical three surface concrete protection systems (coatings, linings and pore blockers) and discusses the results of three pore blockers (sodium silicate) tested in this work. To this end, certain tests were used: one involving permeability mechanism (low pressure-immersion absorption), one involving capillary water absorption, and the last, a migration test used to estimate the effective chloride diffusion coefficient in saturated condition. Results indicated reduction in chloride diffusion coefficients and capillary water absorption, therefore, restrictions to water penetration from external environmental. As a consequence, a reduction of the corrosion kinetics and a control of the chloride ingress are expected.

DETERMINATION OF DICLOFENAC SODIUM IN RABBIT PLASMA BY HPLC/UV: EVALUATION AND CHARACTERIZATION OF ITS CRYSTALLINE FORMS, ANHYDROUS AND HYDRATE, ON THE ANTIPYRETIC EFFECT

Diclofenac sodium (DS) is a non-steroidal anti-inflammatory drug that is widely prescribed for the treatment of rheumatoid arthritis and post-surgery analgesia. The active pharmaceutical ingredient is the anhydrous form; however, it can also exist in hydrate form. In this context, knowing the properties of the solid state is important and relevant in the pharmaceutical area because they have a significant impact on the solubility, bioavailability, and chemical stability of the drugs. In the present study, data from XRPD, FTIR spectroscopy, and thermal analysis were used for the identification and characterization of DS forms (anhydrous and hydrate). An HPLC method was optimized to evaluate the plasma concentration of DS in rabbits. The optimized method exhibited good linearity over the range 0.1-60 mu g/mL with correlation coefficients of >0.9991. The mean recovery was 100%. Precision and accuracy were determined within acceptable limits. Finally, to compare the pharmacological properties of anhydrous and hydrate DS forms, we investigated their effects in the febrile response induced by lipopolysaccharide from E. coli in rabbits. The results show that the antipyretic effect of anhydrous and hydrate DS forms are similar.