Thermostable invertases from Paecylomyces variotii produced under submerged and solid-state fermentation using agroindustrial residues

The filamentous fungus Paecylomices variotii was able to produce high levels of cell extract and extracellular invertases when grown under submerged fermentation (SbmF) and solid-state fermentation, using agroindustrial products or residues as substrates, mainly soy bran and wheat bran, at 40A degrees C for 72 h and 96 h, respectively. Addition of glucose or fructose (a parts per thousand yen1%; w/v) in SbmF inhibited enzyme production, while the addition of 1% (w/v) peptone as organic nitrogen source enhanced the production by 3.7-fold. However, 1% (w/v) (NH4)(2)HPO4 inhibited enzyme production around 80%. The extracellular form was purified until electrophoretic homogeneity (10.5-fold with 33% recovery) by DEAE-Fractogel and Sephacryl S-200 chromatography. The enzyme is a monomer with molecular mass of 102 kDa estimated by SDS-PAGE with carbohydrate content of 53.6%. Optima of temperature and pH for both, extracellular and cell extract invertases, were 60A degrees C and 4.0-4.5, respectively. Both invertases were stable for 1 h at 60A degrees C with half-lives of 10 min at 70A degrees C. Mg2+, Ba2+ and Mn2+ activated both extracellular and cell extract invertases from P. variotii. The kinetic parameters K-m and V-max for the purified extracellular enzyme corresponded to 2.5 mM and 481 U/mg prot(-1), respectively.

Bone healing pattern in surgically created circumferential defects around submerged implants: an experimental study in dog

Objective: To describe the healing of marginal defects below or above 1 mm of dimension around submerged implants in a dog model. Material and methods: In 12 Labrador dogs, all mandibular premolars and first molars were extracted bilaterally. After 3 months of healing, full-thickness flaps were elevated in the edentulous region of the right side of the mandible. Two recipient sites were prepared and the marginal 5mm were widened to such an extent to obtain, after implant installation, a marginal gap of 0.5mm at the mesial site (small defect) and of 1.25mm at the distal site (large defect). Titanium healing caps were affixed to the implants and the flaps were sutured allowing a fully submerged healing. The experimental procedures were subsequently performed in the left side of the mandible. The timing of the experiments and sacrifices were planned in such a way to obtain biopsies representing the healing after 5, 10, 20 and 30 days. Ground sections were prepared and histomorphometrically analyzed. Results: The filling of the defect with newly formed bone was incomplete after 1 month of healing in all specimens. Bone formation occurred from the base and the lateral walls of the defects. A larger volume of new bone was formed in the large compared with the small defects. Most of the new bone at the large defect was formed between the 10- and the 20-day period of healing. After 1 month of healing, the outline of the newly formed bone was, however, located at a similar distance from the implant surface (about 0.4mm) at both defect types. Only minor newly formed bone in contact with the implant, starting from the base of the defects, was seen at the large defects (about 0.8mm) while a larger amount was detected at the small defects (about 2.2 mm). Conclusion: Marginal defects around titanium implants appeared to regenerate in 20-30 days by means of a distance osteogenesis. The bone fill of the defects was, however, incomplete after 1 month.

Characterization of a thermostable extracellular tannase produced under submerged fermentation by Aspergillus ochraceus

Background: Tannases are enzymes that may be used in different industrial sectors as, for example, food and pharmaceutical. They are obtained mainly from microorganisms, as filamentous fungi. However, the diversity of fungi stays poorly explored for tannase production. In this article, Aspergillus ochraceus is presented as a new source of tannase with interesting features for biotechnological applications. Results: Extracellular tannase production was induced when the fungus was cultured in Khanna medium with tannic acid as carbon source. The extracellular tannase was purified 9-fold with 2% recovery and a single band corresponding to 85 kDa was observed in SDS-PAGE. The native apparent molecular mass was estimated as 112 kDa. Optima of temperature and pH were 40 degrees C and 5.0, respectively. The enzyme was fully stable from 40 degrees C to 60 degrees C during 1 hr. The activity was enhanced by Mn2+ (33-39%) and NH4+ (15%). The purified tannase hydrolyzed tannic acid and methyl gallate with Km of 0.76 mM and 0.72 mM, respectively, and Vmax of 0.92 U/mg protein and 0.68 U/mg protein, respectively. The analysis of a partial sequence of the tannase encoding gene showed an open read frame of 567 bp and a sequence of 199 amino acids were predicted. TLC analysis revealed the presence of gallic acid as a tannic acid hydrolysis product. Conclusion: The extracellular tannase produced by A. ochraceus showed distinctive characteristics such as monomeric structure and activation by Mn2+, suggesting a new kind of fungal tannases with biotechnological potential. Further, it was the first time that a partial gene sequence for A. ochraceus tannase was described.

'Synthetic lipase' production from a newly isolated Sporidiobolus pararoseus strain by submerged fermentation

The lipase produced by a newly isolate Sporidiobolus pararoseus strain has potential catalysis ability for esterification reactions. In order to improve its synthetic activity, this work aimed at optimizing 'synthetic lipase' production by submerged fermentation of a conventional media based on peptone, yeast extract, NaCl and olive oil using experimental design technique. According to the results obtained in the first experimental design (2(4-1)), yeast extract and NaCl concentrations were tested to further optimization by response surface methodology. The maximum 'synthetic lipase' activity obtained was 26.9 U/mL in the optimized media (5.0, 6.8, 7.0 and 1.0% (wt/v) of peptone, yeast extract, NaCl and olive oil, respectively), representing a 6.36-fold increase compared to the initial medium. The time course of 'synthetic lipase' production in the optimized condition was evaluated in terms of synthetic activity, protease activity, biomass and total carbon and the maximum synthetic activity was observed during the stationary phase of growth.

Application of Mossbauer spectroscopy to the study of corrosion resistance in NaCl solution of plasma nitrided AISI 316L stainless steel

Corrosion research in steels is one of the areas in which Mossbauer spectroscopy has become a required analytical technique, since it is a powerful tool for both identifying and quantifying distinctive phases (which contain Fe) with accuracy. In this manuscript, this technique was used to the study of corrosion resistance of plasma nitrided AISI 316L samples in the presence of chloride anions. Plasma nitriding has been carried out using dc glow-discharge, nitriding treatments, in medium of 80 vol.% H-2 and 20 vol.% N-2, at 673 K, and at different time intervals: 2, 4, and 7 h. Treated samples were characterized by means of phase composition and morphological analysis, and electrochemical tests in NaCl aerated solution in order to investigate the influence of treatment time on the microstructure and the corrosion resistance, proved by conversion electron Mossbauer spectroscopy (CEMS), glancing angle X-ray diffraction (GAXRD), scanning electron microscopy (SEM) and potentiodynamic polarization. A modified layer of about 8 gin was observed for all the nitrided samples, independently of the nitriding time. A metastable phase, S phase or gamma(N), was produced. It seems to be correlated with gamma`-Fe-4 N phase. If the gamma(N) fraction decreases, the gamma` fraction increases. The gamma(N) magnetic nature was analyzed. When the nitriding time increases, the results indicate that there is a significant reduction in the relative fraction of the magnetic gamma(N) (in) phase. In contrast, the paramagnetic gamma(N) (p) phase increases. The GAXRD analysis confirms the Mossbauer results, and it also indicates CrN traces for the sample nitrided for 7 h. Corrosion results demonstrate that time in the plasma nitriding treatment plays an important role for the corrosion resistance. The sample treated for 4 h showed the best result of corrosion resistance. It seems that the epsilon/gamma` fraction ratio plays an important role in thin corrosion resistance since this sample shows the maximum value for this ratio. (c) 2008 Published by Elsevier B.V.

Ontogenetic Variation in Ammonia Excretion during the Early Life Stages of the Amazon River Prawn, Macrobrachium amazonicum

Dry mass (DM) and total ammonia-N (TAN) excretion were determined in embryos, larvae (ZI-ZIX, Z = zoea ), and postlarvae (PL) at 1, 7, and 14 d after metamorphosis (PL1, PL7, and PL14) of Macrobrachium amazonicum. Animals in postmolt-intermolt (A-C) stages were sorted according to their developmental stages, and placed into incubation chambers (similar to 30 mL) for 2 h to quantify TAN excretion. After this period, analyses were carried out using Koroleff`s method for TAN determination. Individual TAN excretion generally increased throughout ontogenetic development and varied from 0.0090 +/- 0.0039 mu g TAN/individual/h in embryo to 1.041 +/- 0.249 mu g TAN/individual/h in PL14. There was no significant difference between embryo-ZIV and ZV-ZIX (P > 0.05), whereas PL1, PL7, and PL14 differed (P < 0.05) from each other. Higher increments in individual ammonia-N excretion were observed between ZIV-ZV, PL1-PL7, and PL7-PL14. Mass-specific excretion rates presented two groups, embryo-ZII (P > 0.05) and ZIII-PL14 (P > 0.05). The lowest value was found in embryo (0.17 +/- 0.07 mu g TAN/mg DM/h) and the maximum values in ZV and PL1 (0.65 +/- 0.25 and 0.64 +/- 0.27 mu g TAN/mg DM/h, respectively). Results indicate that metabolic rate is proportional to the body mass in M. amazonicum, during early life stages. Variations in ammonia excretion during this phase may be associated mainly with body size. Data obtained in the present study may be useful in developing and optimizing rearing techniques of M. amazonicum, such as the proportions between biofilter and rearing tank size, and stocking density in culture tanks or in transport bags.

Nutrients removed by Kappaphycus alvarezii (Rhodophyta, Solieriaceae) in integrated cultivation with fishes in re-circulating water

The potential of the red alga Kappaphycus alvarezii to remove nutrients was tested to treat effluents of Trachinotus carolinus fish cultivation, and the production of carrageenan in this condition was analyzed. Experiments were conducted in four tanks of 8000 L with approximately 1200 fishes of 30 g each integrated with three tanks of 100 L with 700 g of K. alvarezii, as initial biomass per tank. Seawater was re-circulated between tanks with seaweed and with fish. As a control, three tanks with seawater circulating in an open system were utilized. Seawater samples were collected daily for 10 days and concentrations of nitrate, nitrite, ammonium and phosphate were determined in the inflow and outflow water of the tanks. Significant differences between both collecting points were considered as nutrient removal by the seaweed. Growth rates and carrageenan yields were also analyzed in seaweed cultivated in seawater and in effluents. Growth rates of seaweed cultivated in tanks were lower than those obtained in open sea and in laboratory cultivation. Effluents had concentrations of nitrate and nitrite ca. 100 times higher than in the control. Maximum values of nutrient removal on effluents were: nitrate= 18.2%; nitrite =50.8%; ammonium =70.5% and phosphate =26.8%. All plants survived throughout the experimental period, but some developed ""ice-ice"", a disease associated with physiological stress. After the experimental period, some plants selected and cultivated in open sea presented higher growth rates in 40 days, indicating nutrient storage. No significant differences between carrageenan yields of K alvarezii cultivated in seawater and in the effluents were observed. Our results show that K. alvarezii can be utilized as a biofilter for fish cultivation effluents, reducing the eutrophication process and can also be processed for carrageenan production, which provides an additional benefit to the fisheries. (C) 2008 Elsevier B.V. All rights reserved.

Titanium surface topography after brushing with fluoride and fluoride-free toothpaste simulating 10 years of use

Objectives: To conduct a controlled study contrasting titanium surface topography after procedures that simulated 10 years of brushing using toothpastes with or without fluoride. Methods: Commercially pure titanium (cp Ti) and Ti-6Al-4V disks (6 mm circle divide x 4 mm) were mirror-polished and treated according to 6 groups (n = 6) as a function of immersion (I) or brushing (B) using deionised water (W), fluoride-free toothpaste (T) and fluoride toothpaste (FT). Surface topography was evaluated at baseline (pretreatment) and post-treatment, using atomic force microscope in order to obtain three-dimensional images and mean roughness. Specimens submitted to immersion were submerged in the vehicles without brushing. For brushed specimens, procedures were conducted using a linear brushing machine with a soft-bristled toothbrush. Immersion and brushing were performed for 244 h. IFT and BFT samples were analysed under scanning electron microscope with Energy-Dispersive X-ray Spectroscopy (EDS). Pre and post-treatment values were compared using the paired Student T-test (alpha = .05). Intergroup comparisons were conducted using one-way ANOVA with Tukey post-test (alpha = .05). Results: cp Ti mean roughness (in nanometers) comparing pre and post-treatment were: IW, 2.29 +/- 0.55/2.33 +/- 0.17; IT, 2.24 +/- 0.46/2.02 +/- 0.38; IFT, 2.22 +/- 0.53/1.95 +/- 0.36; BW, 2.22 +/- 0.42/3.76 +/- 0.45; BT, 2.27 +/- 0.55/16.05 +/- 3.25; BFT, 2.27 +/- 0.51/22.39 +/- 5.07. Mean roughness (in nanometers) measured in Ti-6Al-4V disks (pre/post-treatment) were: IW, 1.79 +/- 0.25/2.01 +/- 0.25; IT, 1.61 +/- 0.13/1.74 +/- 0.19; IFT, 1.92 +/- 0.39/2.29 +/- 0.51; BW, 2.00 +/- 0.71/2.05 +/- 0.43; BT, 2.37 +/- 0.86/11.17 +/- 2.29; BFT, 1.83 +/- 0.50/15.73 +/- 1.78. No significant differences were seen after immersions (p > .05). Brushing increased the roughness of cp Ti and of Ti-6Al-4V (p < .01); cp Ti had topographic changes after BW, BT and BFT treatments whilst Ti-6Al-4V was significantly different only after BT and BTF. EDS has not detected fluoride or sodium ions on metal surfaces. Conclusions: Exposure to toothpastes (immersion) does not affect titanium per se; their use during brushing affects titanium topography and roughness. The associated effects of toothpaste abrasives and fluorides seem to increase roughness on titanium brushed surfaces. (C) 2012 Elsevier Ltd. All rights reserved.

Corrosion protection of aluminium alloy by cerium conversion and conducting polymer duplex coatings

The corrosion protection of AA6063 aluminium alloy by cerium conversion, polyaniline conducting polymer and by duplex coatings has been investigated. The electrochemical behaviour was evaluated in aerated 3.5 wt.% NaCl. All coatings tested shifted the corrosion and pitting potentials to more positive values, indicating protection against corrosion. The duplex coatings are significantly more effective than each coating alone: corrosion and pitting potentials were shifted by +183 and +417 mV(SCE), respectively, by duplex coatings in relation to the untreated aluminium alloy. Optical microscopy and scanning electron microscopy are in agreement with the electrochemical results, reinforcing the superior performance of duplex coatings. (C) 2012 Elsevier Ltd. All rights reserved.

Short implants (6 mm) installed immediately into extraction sockets: An experimental study in dogs

Aim: To evaluate the effect of implant length (6 mm vs. 11 mm) on osseointegration (bone-toimplant contact) of implants installed into sockets immediately after tooth extraction. Material and methods: In six Labrador dogs, the pulp tissue of the mesial roots of P-3(3) was removed and the root canals were filled. Flaps were elevated bilaterally, the premolars hemisectioned and the distal roots removed. Recipient sites were prepared in the distal alveolus and a 6 mm or an 11 mm long implant was installed at the test and control sites, respectively. Non-submerged healing was allowed. After 4 months of healing, block sections of the implant sites were obtained for histological processing and peri-implant tissue assessment. Results: No statistically significant differences were found between test and control sites both for hard and soft tissue parameters. The bone-to-implant contact evaluated at the apical region of the implants was similar as well. Although not statistically significant, the location of the top of the bony crest at the buccal aspect was more apical in relation to the implant shoulder at the test compared with the control sites (2.0 +/- 1.4 and 1.2 +/- 1.1 mm, respectively). Conclusions: Shorter implants (6 mm) present with equal osseointegration than do longer implants (11 mm).

PHYSIOLOGICAL QUALITY OF OSMOPRIMED EGGPLANT SEEDS

Eggplant seeds germination can be slow and uneven, justifying the use of pre-germinative treatments to improve the performance of seed lots. One option of treatment is the controlled hydration of seeds by priming. In this way, this study aimed to evaluate the performance of eggplant seeds cv. Embu submitted to different methodologies of priming. The seeds used in the experiment were stored in cold chamber (15 degrees C and 55% RH) in paper bags. The research was carried out at Central Laboratory of Seeds/UFLA. The seeds were submitted to the priming in aerated solutions varying the following factors: temperature (15 degrees C and 25 degrees C), time (24, 48 and 72 hours) and solution (water, PEG, KNO3 and PEG+KNO3). Seeds were washed in running water and dried at 30 degrees C, until the return to the initial moisture content, around 10%. The variables analyzed were percentage of germination, percentage of emergence, speed index of emergence and electrical conductivity. The treatments were arranged in a completely randomized design, according to a factorial arrangement 2x3x4+1 (control - seeds without priming). The results showed that priming improves the vigour of eggplant seeds with no effect on viability; the priming in water or KNO3 is efficient to improve the seed vigour and priming in water or KNO3 may use temperature of 15 degrees C or 25 degrees C for 24, 48 or 72 hours.

Inward-Inclined Implant Platform for the Amplified Platform-Switching Concept: 18-Month Follow-up Report of a Prospective Randomized Matched-Pair Controlled Trial

Purpose: This prospective randomized matched-pair controlled trial aimed to evaluate marginal bone levels and soft tissue alterations at implants restored according to the platform-switching concept with a new inward-inclined platform and compare them with external-hexagon implants. Materials and Methods: Traditional external-hexagon (control group) implants and inward-inclined platform implants (test group), all with the same implant body geometry and 13 mm in length, were inserted in a standardized manner in the posterior maxillae of 40 patients. Radiographic bone levels were measured by two independent examiners after 6, 12, and 18 months of prosthetic loading. Buccal soft tissue height was measured at the time of abutment connection and 18 months later. Results: After 18 months of loading, all 80 implants were clinically osseointegrated in the 40 participating patients. Radiographic evaluation showed mean bone losses of 0.5 +/- 0.1 mm (range, 0.3 to 0.7 mm) and 1.6 +/- 0.3 mm (range, 1.1 to 2.2 mm) for test and control implants, respectively. Soft tissue height showed a significant mean decrease of 2.4 mm in the control group, compared to 0.6 mm around the test implants. Conclusions: After 18 months, significantly greater bone loss was observed at implants restored according to the conventional external-hexagon protocol compared to the platform-switching concept. In addition, decreased soft tissue height was associated with the external-hexagon implants versus the platform-switched implants. INT J ORAL MAXILLOFAC IMPLANTS 2012;27:927-934.

Effects of Positive End-expiratory Pressure Titration and Recruitment Maneuver on Lung Inflammation and Hyperinflation in Experimental Acid Aspiration-induced Lung Injury

Background: In acute lung injury positive end-expiratory pressure (PEEP) and recruitment maneuver are proposed to optimize arterial oxygenation. The aim of the study was to evaluate the impact of such a strategy on lung histological inflammation and hyperinflation in pigs with acid aspiration-induced lung injury. Methods: Forty-seven pigs were randomly allocated in seven groups: (1) controls spontaneously breathing; (2) without lung injury, PEEP 5 cm H2O; (3) without lung injury, PEEP titration; (4) without lung injury, PEEP titration + recruitment maneuver; (5) with lung injury, PEEP 5 cm H2O; (6) with lung injury, PEEP titration; and (7) with lung injury, PEEP titration + recruitment maneuver. Acute lung injury was induced by intratracheal instillation of hydrochloric acid. PEEP titration was performed by incremental and decremental PEEP from 5 to 20 cm H2O for optimizing arterial oxygenation. Three recruitment maneuvers (pressure of 40 cm H2O maintained for 20 s) were applied to the assigned groups at each PEEP level. Proportion of lung inflammation, hemorrhage, edema, and alveolar wall disruption were recorded on each histological field. Mean alveolar area was measured in the aerated lung regions. Results: Acid aspiration increased mean alveolar area and produced alveolar wall disruption, lung edema, alveolar hemorrhage, and lung inflammation. PEEP titration significantly improved arterial oxygenation but simultaneously increased lung inflammation in juxta-diaphragmatic lung regions. Recruitment maneuver during PEEP titration did not induce additional increase in lung inflammation and alveolar hyperinflation. Conclusion: In a porcine model of acid aspiration-induced lung injury, PEEP titration aimed at optimizing arterial oxygenation, substantially increased lung inflammation. Recruitment maneuvers further improved arterial oxygenation without additional effects on inflammation and hyperinflation.

How large is the lung recruitability in early acute respiratory distress syndrome: a prospective case series of patients monitored by computed tomography

Introduction: The benefits of higher positive end expiratory pressure (PEEP) in patients with acute respiratory distress syndrome (ARDS) have been modest, but few studies have fully tested the "open-lung hypothesis". This hypothesis states that most of the collapsed lung tissue observed in ARDS can be reversed at an acceptable clinical cost, potentially resulting in better lung protection, but requiring more intensive maneuvers. The short-/middle-term efficacy of a maximum recruitment strategy (MRS) was recently described in a small physiological study. The present study extends those results, describing a case-series of non-selected patients with early, severe ARDS submitted to MRS and followed until hospital discharge or death. Methods: MRS guided by thoracic computed tomography (CT) included two parts: a recruitment phase to calculate opening pressures (incremental steps under pressure-controlled ventilation up to maximum inspiratory pressures of 60 cmH(2)O, at constant driving-pressures of 15 cmH(2)O); and a PEEP titration phase (decremental PEEP steps from 25 to 10 cmH2O) used to estimate the minimum PEEP to keep lungs open. During all steps, we calculated the size of the non-aerated (-100 to +100 HU) compartment and the recruitability of the lungs (the percent mass of collapsed tissue re-aerated from baseline to maximum PEEP). Results: A total of 51 severe ARDS patients, with a mean age of 50.7 years (84% primary ARDS) was studied. The opening plateau-pressure was 59.6 (+/- 5.9 cmH(2)O), and the mean PEEP titrated after MRS was 24.6 (+/- 2.9 cmH(2)O). Mean PaO2/FiO(2) ratio increased from 125 (+/- 43) to 300 (+/- 103; P < 0.0001) after MRS and was sustained above 300 throughout seven days. Non-aerated parenchyma decreased significantly from 53.6% (interquartile range (IQR): 42.5 to 62.4) to 12.7% (IQR: 4.9 to 24.2) (P < 0.0001) after MRS. The potentially recruitable lung was estimated at 45% (IQR: 25 to 53). We did not observe major barotrauma or significant clinical complications associated with the maneuver. Conclusions: MRS could efficiently reverse hypoxemia and most of the collapsed lung tissue during the course of ARDS, compatible with a high lung recruitability in non-selected patients with early, severe ARDS. This strategy should be tested in a prospective randomized clinical trial.

Period adding cascades: Experiment and modeling in air bubbling

Period adding cascades have been observed experimentally/numerically in the dynamics of neurons and pancreatic cells, lasers, electric circuits, chemical reactions, oceanic internal waves, and also in air bubbling. We show that the period adding cascades appearing in bubbling from a nozzle submerged in a viscous liquid can be reproduced by a simple model, based on some hydrodynamical principles, dealing with the time evolution of two variables, bubble position and pressure of the air chamber, through a system of differential equations with a rule of detachment based on force balance. The model further reduces to an iterating one-dimensional map giving the pressures at the detachments, where time between bubbles come out as an observable of the dynamics. The model has not only good agreement with experimental data, but is also able to predict the influence of the main parameters involved, like the length of the hose connecting the air supplier with the needle, the needle radius and the needle length. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3695345]