978 resultados para 481
Resumo:
The biosynthesis of chondroitinase and hyaluronidase by different isolates of Paracoccidioides brasiliensis was investigated in 20 strains isolated from patients (17 strains), a penguin (Pygocelis adeliae, one strain), an armadillo (Dasypus novemcinctus, one strain) and the environment (dog food, one strain). All the P. brasiliensis isolates studied had the ability to produce chondroitinase and hyaluronidase, although differences in colony morphology and enzyme production were detected among them. These results suggest that further investigations should be carried out in the clinical field in order to clarify the potential role of P. brasiliensis enzyme production in the pathogenesis of paracoccidioidomycosis.
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Channel catfish ponds are treated with salt (sodium chloride) to increase chloride concentration and prevent nitrite toxicity in fish. A survey indicated that most farmers try to maintain chloride concentration of 50 to 100 mg/L in ponds by annual salt applications. Averages and standard deviations for selected water quality variables in salt-treated ponds were as follows: chloride, 87.2 ± 37.5 mg/L; total dissolved solids (TDS), 336 ± 96 mg/L; specific conductance, 512 ± 164 μmhos/cm. Maximum values were 189 mg/L for chloride, 481 mg/L for TDS, and 825 μmhos/cm for specific conductance. Good correlations between specific conductance values and both chloride and TDS concentrations suggest that specific conductance can be a rapid method for estimating concentrations of these two variables in surface water. The maximum limit for chloride concentration in Alabama streams allowed by the Alabama Department of Environmental Management is 230 mg/L. The usual recommended upper limit of TDS for protection of aquatic life in freshwater streams is 1,000 mg/L. Based on the observed relationship between TDS concentration and specific conductance in Alabama catfish ponds, 1,000 mg/L TDS corresponds to 1,733 μmhos/cm specific conductance. It is unlikely that effluents from salt-treated catfish ponds would violate the in-stream chloride standard of 230 mg/L or harm aquatic life in streams. Nevertheless, chloride concentrations in ponds should be measured before salt application as a safe guard against excessive salt application and chloride concentrations above the in-stream chloride standard.
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The cardiovascular, respiratory, and anesthetic effects of medetomidine-ketamine (20 μg/kg bodyweight [BW] and 10 mg/kg BW) (MK group) or dexmedetomidine-ketamine (10 μg/kg BW and 10 mg/kg BW) (DK group) were studied in golden-headed lion tamarins. Heart rate decreased after administration of both combinations; this reduction was statistically greater in the DK group than in the MK group after 15 and 45 minutes. Systolic arterial pressure decreased in a similar way in both groups, except at 15 minutes, when systolic arterial pressure was significantly lower in the DK group. Diastolic arterial pressure, mean arterial pressure, respiratory rate, and rectal temperature were progressively reduced in all groups. Sedation time was significantly shorter and anesthesia time was significantly longer in the DK group compared with MK group. Anesthetic quality and analgesia scores were significantly greater at 5 and 15 minutes in the DK group compared with the MK group. The administration of dexmedetomidine-ketamine is as safe and effective as the administration of medetomidine-ketamine in tamarins.
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This work deals with the effects of the series compensation on the electric power system for small-signal stability studies. Therefore, the system is modeled admitting the existence of the compensation and then, the equations are linearized and a linear model is obtained for a single machine-infinite bus power system with a compensator installed. The resulting model with nine defined constants is very similar to the Heffron & Phillips linear model widely used on the existent literature. Finally, simulations are executed for an example system, to analyze the behavior of these constants when loading the system. © 2004 IEEE.
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We report preparation and the singular filtration properties of an ultrafiltration membrane made with MSU-type mesoporous silica that exhibits cylindrical pores aligned mostly normal to the support. This membrane supported on tubular commercial macroporous alumina supports was prepared by the interfacial growth mechanism between stable silica-surfactant hybrid micelles made of the association of silica oligomers with polyethyleneoxide-based (PEO) surfactants and sodium fluoride, a well-known silica condensation catalyst. It appears that the combined effect of the silica nature of the membrane, whose surface charge can be easily adjusted by changing the pH and the non-connected cylindrical shape of the pores provides a new behavior in the retention properties, as proved by the filtration of polyoxyethylene polymers (PEO) with different molecular weights. Depending on the filtration conditions, a rejection rate of 80 % and a steep cut-off at 2,000 Da can be obtained or, on the reverse, polymers three times bigger than the pore diameter can diffuse through the membrane. This new filtration mechanism, which opens up new modes of separation modes, is explained in the light of both topology of the porous network and pH-dependent interactions between PEO polymers and silica porous media. © 2005 Elsevier B.V. All rights reserved.
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We used light and transmission electron microscopy to examine the morphology of the accessory glands of immature and mature adult males of Apis mellifera L. We also made an electrophoretic analysis of the protein content of the mature gland. The glands of the immature male actively secrete a mucous substance that can be seen in the lumen of the gland of the mature male. This secretion stains with mercury bromophenol blue and with periodic acid-Schiff reaction, which stain glyconjugates. The protein content was higher in the lumen secretion than in the gland wall extracts. The electrophoresis patterns of the wall extracts were different from those of the secretion found in the gland lumen.
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We prove that Hénon-like strange attractors of diffeomorphisms in any dimensions, such as considered in [2],[7], and [9] support a unique Sinai-Ruelle-Bowen (SRB) measure and have the no-hole property: Lebesgue almost every point in the basin of attraction is generic for the SRB measure. This extends two-dimensional results of Benedicks-Young [4] and Benedicks-Viana [3], respectively.
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Silica gel with a specific area of 382 m2 g-1 and an average pore diameter of 60 Å was chemically modified with 2-amino-1,3,4-thiadiazole, for the purpose of selective adsorption of heavy metals ions and possible use as a chemically modified carbon paste electrode (CMCPE). The following properties of this functionalized silica gel are discussed: selective adsorption of heavy metal ions measured by batch and chromatographic column techniques, and utilization as preconcentration agent in a chemically modified carbon paste electrode (CMCPE) for determination of mercury(II). The chemical selectivity of this functional group and the selectivity of voltammetry were combined for preconcentration and determination. ©2006 Sociedade Brasileira de Química.
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Lanthanum-modified bismuth titanate, Bi4 - xLaxTi3O12 (BLT) ceramics, with x ranging from 0 to 0.75 were prepared by the polymeric precursor method. Orthorhombicity of the system is decreased with the increase of lanthanum content in the bismuth titanate (BIT) crystal lattice. No secondary phases were evident after lanthanum addition. Increasing lanthanum content causes a structural distortion in the bismuth titanate lattice. The shape of the grains is strongly influenced by the lanthanum added to the system. © 2005 Elsevier B.V. All rights reserved.
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Larvae of Chrysomya albiceps (Wiedemann) and Chrysomya putoria (Wiedemann) were reared on liver tissues from a rabbit that had a malignant tumor in the thoracic cavity. Larval rearing of both blowfly species was conducted at ambient temperature. Larvae that fed on tissues from the rabbit with the tumor developed at significantly faster rates than those feeding on tissues from the control animal.
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In low-order streams, the high and variable water flow rates offer both advantages and disadvantages to the life cycle of fishes. Even closely related species living in similar habitats can show differences in life history patterns. Based on oocyte-size distributions, C. lauroi was classified into the fractional spawning type, and C. alipioi into the total spawning type. The absolute fecundity of C. lauroi ranged from 1,313 to 2,925 oocytes; in C. alipioi the absolute fecundity ranged from 2,213 to 25,550 oocytes. The nonparametric Spearman correlation test showed statistical significance between the gonadosomatic index and fecundity for both species. The growth parameters, natural mortality rate and survival rate for females of C. lauroi were: K = 0.68 yr -1, L ∞ = 8.7 cm, t max = 4.4 years, M= 1.62 yr -1, S = 19.79%, and for males: K = 0.78 yr -1, L ∞ = 6.9 cm, t max = 3.8 years, M = 1.89 yr -1, S = 15.11%. The growth parameters, natural mortality rate and survival rate for females of C. alipioi were: K = 0.90 yr -1, L ∞ = 12.2 cm, t max = 3.3 years, M = 1.81 yr -1, S = 16.37%, and for males: K = 0.76 yr -1, L ∞ = 10.1 cm, t max = 3.9 years, M = 1.71 yr -1, S = 18.10%.
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Due to great difficulty of penetration of drugs through skin, different organized systems, such as liposomes, have been studied in order to increase percutaneous penetration. The aims of this work were to obtain and characterize small unilamellar liposomes containing caffeine (CAF). Liposomes composed by soy phosphatidylcholine - PS (40 mM) or hydrogenated PS - PSH (40 mM), with and without cholesterol - CHO (6 mM) and CAF (30 mg/mL), were characterized by size distribution, determination of mean diameter and encapsulation efficiency. Uniform size distribution with low polidispersity was observed. The mean of diameters obtained were: PS/CHO (64 nm), PS (80 nm), PSH/CHO (85 nm), PS/CAF (145 nm), PS/CHO/CAF (147 nm), PSH/CHO/CAF (152 nm), PSH (166 nm) and PSH/CAF (481 nm). The obtained encapsulation efficiency was 10.84% for PSH/CHO/CAF, followed by PS/CHO (6.61%), PSH/CAF (3.07%) and PS/CAF (1.57%).
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The different combination possibilities of emission uniformity and field slope within the operational unities of localized irrigation systems favor the occurence of some configurations in the irrigation system, and consequently different hydraulic head distributions, discharge and system management. After the system has been implanted, it is necessary to verify pressure and discharge distribution in the operational unit. This work objective was to verify pressure and discharge uniformity on derivation line and lateral lines with micro sprinkle in data gotten from operational research. The results allow to check that despite analyzed declivity; the higher the emission uniformity calculated for the line of derivation in the project is, the higher its pressure uniformity is. Previously the results of discharge in the emitters of the operational unit showed a constant variation entering the point of higher discharge and lower discharge, even though differently from the three tested irrigation blades.
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This study sought to assess the pulp chamber temperature in different groups of human teeth that had been bleached using hydrogen peroxide gel activated with halogen lamps or hybrid LED/laser appliances. Four groups of ten teeth (maxillary central incisors, mandibular incisors, mandibular canines, and maxillary canines) were used. A digital thermometer with a K-type thermocouple was placed inside pulp chambers that had been filled with thermal paste. A 35% hydrogen peroxide-based red bleaching gel was applied to all teeth and photocured for a total of three minutes and 20 seconds (five activations of 40 seconds each), using light from an LED/laser device and a halogen lamp. The temperatures were gauged every 40 seconds and the data were analyzed by three-way ANOVA, followed by Tukey's test. Regardless of the light source, statistically significant differences were observed between the groups of teeth. The mean temperature values (±SD) were highest for maxillary central incisors and lowest for mandibular canines. The halogen lamp appliance produced more pulp chamber heating than the LED/laser appliance. The increase in irradiation time led to a significant increase in temperature.
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BACKGROUND AND OBJECTIVES: Due to the high incidence of technical and neurological complications, continuous spinal blocks were not performed for several years. With the advent of intermediate catheters the technique has been used more often and gaining acceptance among anesthesiologists. The objective of this report was to demonstrate the usefulness of the technique as a viable alternative for medium and major size surgeries. CASE REPORT: This is a 58 years old female patient, weighing 62 kg, physical status ASA I, with a history of migraines, low back pain, and prior surgeries under spinal block without intercurrence. The patient was scheduled for exploratory laparotomy for a probable pelvic tumor. After venoclysis with an 18G catheter, monitoring with cardioscope, non-invasive blood pressure and pulse oximetry was instituted; she was sedated with 2 mg of midazolam and 100 μg of fentanyl, and placed in left lateral decubitus. The patient underwent continuous spinal block through the median approach in L 3-L 4; 9 mg of 0.5% hyperbaric bupivacaine and 120 μ g of morphine sulfate were administered. Inspection of the abdominal cavity revealed a gastric stromal tumor that required an increase in the incision for a partial gastrectomy. A small dose of hyperbaric solution was required for the entire procedure, which was associated with complete hemodynamic stability. Postoperative admission to the ICU was not necessary; the patient presented a good evolution without complaints and with a high degree of satisfaction. She was discharged from the hospital after 72 hours without intercurrence. CONCLUSIONS: Intermediate catheters used in continuous spinal blocks have shown the potential to turn it an attractive and useful technique in medium and large size surgeries and it can even be an effective alternative in the management of critical patients to whom hemodynamic repercussions can be harmful.