Influence of organic shock loads in an ASBBR treating synthetic wastewater with different concentration levels

Safe application of the anaerobic sequencing biofilm batch reactor (ASBBR) still depends on deeper insight into its behavior when faced with common operational problems in wastewater treatments such as tolerance to abrupt variations in influent concentration, so called shock loads. To this end the current work shows the effect of organic shock loads on the performance of an ASBBR, with a useful volume of 5 L, containing 0.5-cm polyurethane cubes and operating at 30 degrees C with mechanical stirring of 500 rpm. In the assays 2 L of two types of synthetic wastewater were treated in 8-h cycles. Synthetic wastewater I was based on sucrose-amide-cellulose with concentration of 500 mg COD/L and synthetic wastewater II was based on volatile acids with concentration ranging from 500 to 2000 mg COD/L. Organic shock loads of 2-4 times the operation concentration were applied during one and two cycles. System efficiency was monitored before and after application of the perturbation. When operating with concentrations from 500 to 1000 mg COD/L and shock loads of 2-4 times the influent concentration during one or two cycles the system was able to regain stability after one cycle and the values of organic matter, total and intermediate volatile acids, bicarbonate alkalinity and pH were similar to those prior to the perturbations. At a concentration of 2000 mg COD/L the reactor appeared to be robust, regaining removal efficiencies similar to those prior to perturbation at shock loads twice the operation concentration lasting one cycle and stability was recovered after two cycles. However, for shock loads twice the operation concentration during two cycles and shock loads four times the operation concentration during one or two cycles filtered sample removal efficiency decreased to levels different from those prior to perturbation, on an average of 90-80%, approximately, yet the system managed to attain stability within two cycles after shock application. Therefore, this investigation envisions the potential of full scale application of this type of bioreactor which showed robustness to organic shock loads, despite discontinuous operation and the short times available for treating total wastewater volume. (c) 2007 Elsevier Ltd. All rights reserved.

Influence of chloride ion concentration and temperature on the electrochemical properties of passive films formed on a superduplex stainless steel

Polarization measurements were conducted to monitor the corrosion behavior of superduplex stainless steel ASTM A995M-Gr.SA/EN 10283-Mat#1.4469(GX2CrNiMo26-7-4) when exposed to a) an electrolyte containing 22,700 parts per million (ppm) of chloride ions at seven different temperatures and b) an electrolyte at 25 GC and different chloride ion concentrations (5800, 22,700, 58,000 and 80,000 ppm of Cl(-)). The polarization curves indicate that the passive films formed are only slightly affected by NaCl concentration, but the pitting potential decreases drastically increasing the temperature, in particular >60 degrees C. The image analysis of the microstructure after potentiodynamic polarization showed that the pitting number and size vary in function of the temperature of the tested medium. Nyquist diagrams were determined by electrochemical impedance spectroscopy to characterize the resistance of the passive layer. According to Nyquist plots, the arc polarization resistance decreases increasing the temperature due to a catalytic degradation of the oxide passive films. (C) 2009 Elsevier Inc. All rights reserved.

Determination of particle concentration in the breathing zone for four different types of office ventilation systems

Many factors affect the airflow patterns, thermal comfort, contaminant removal efficiency and indoor air quality at individual workstations in office buildings. In this study, four ventilation systems were used in a test chamber designed to represent an area of a typical office building floor and reproduce the real characteristics of a modern office space. Measurements of particle concentration and thermal parameters (temperature and velocity) were carried out for each of the following types of ventilation systems: (a) conventional air distribution system with ceiling supply and return; (b) conventional air distribution system with ceiling supply and return near the floor; (c) underfloor air distribution system; and (d) split system. The measurements aimed to analyse the particle removal efficiency in the breathing zone and the impact of particle concentration on an individual at the workstation. The efficiency of the ventilation system was analysed by measuring particle size and concentration, ventilation effectiveness and the indoor/outdoor ratio. Each ventilation system showed different airflow patterns and the efficiency of each ventilation system in the removal of the particles in the breathing zone showed no correlation with particle size and the various methods of analyses used. (C) 2008 Elsevier Ltd. All rights reserved.

Concentration inequalities and laws of large numbers under epistemic and regular irrelevance

This paper presents concentration inequalities and laws of large numbers under weak assumptions of irrelevance that are expressed using lower and upper expectations. The results build upon De Cooman and Miranda`s recent inequalities and laws of large numbers. The proofs indicate connections between the theory of martingales and concepts of epistemic and regular irrelevance. (C) 2010 Elsevier Inc. All rights reserved.

Phase equilibria for salt-induced lysozyme precipitation: Effect of salt concentration and pH

The salt-induced precipitation of lysozyme from aqueous solutions was studied at 25 degrees C and various pH values by cloud-point investigations, precipitation experiments (analysing the compositions of the coexisting phases) and microscopic investigations of the precipitates. Sodium sulphate as well as ammonium sulphate were used to induce the precipitation. The experimental results are discussed and used to develop a scheme of the phase equilibrium in water-rich aqueous solutions of lysozyme and either Na2SO4 or (NH4)(2)SO4. (C) 2007 Elsevier B.V All rights reserved.

Improved Bioprocess with CHO-hTSH Cells on Higher Microcarrier Concentration Provides Higher Overall Biomass and Productivity for rhTSH

Since the recombinant thyroid-stimulating hormone (rhTSH) is secreted by stably transfected Chinese hamster ovary (CHO-hTSH) cells, a bioprocess consisting of immobilizing the cells on a substrate allowing their multiplication is very suitable for rhTSH recovering from supernatants at relative high degree of purity. In addition, such a system has also the advantage of easily allowing delicate manipulations of culture medium replacement. In the present study, we show the development of a laboratory scale bioprocess protocol of CHO-hTSH cell cultures on cytodex microcarriers (MCs) in a 1 L bioreactor, for the preparation of rhTSH batches in view of structure/function studies. CHO-hTSH cells were cultivated on a fetal bovine serum supplemented medium during cell growth phase. For rhTSH synthesis phase, 75% of supernatant was replaced by animal protein-free medium every 24 h. Cell cultures were monitored for agitation (rpm), temperature (A degrees C), dissolved oxygen (% DO), pH, cell concentration, MCs coverage, glucose consumption, lactate production, and rhTSH expression. The results indicate that the amount of MCs in the culture and the cell concentration at the beginning of rhTSH synthesis phase were crucial parameters for improving the final rhTSH production. By cultivating the CHO-hTSH cells with an initial cell seeding of four cells/MC on 4 g/L of MCs with a repeated fed batch mode of operation at 40 rpm, 37 A degrees C, 20% DO, and pH 7.2 and starting the rhTSH synthesis phase with 3 x 10(6) cells/mL, we were able to supply the cultures with enough glucose, to maintain low levels of lactate, and to provide high percent (similar to 80%) of fully covered MCs for a long period (5 days) and attain a high cell concentration (similar to 9 x 10(5) cells/mL). The novelty of the present study is represented by the establishment of cell culture conditions allowing us to produce similar to 1.6 mg/L of rhTSH in an already suitable degree of purity. Batches of produced rhTSH were purified and showed biological activity.

Lysine biosynthesis and nitrogen metabolism in quinoa (Chenopodium quinoa): Study of enzymes and nitrogen-containing compounds

Aspartate kinase (AK, EC 2.7.2.4), homoserine dehydrogenase (HSDH, EC 1.1.1.3) and dihydrodipicolinate synthase (DHDPS, EC 4.2.1.52) were isolated and partially purified from immature Chenopodium quinoa Willd seeds. Enzyme activities were studied in the presence of the aspartate-derived amino acids lysine, threonine and methionine and also the lysine analogue S-2-aminoethyl-L-cysteine (AEC), at 1 mM and 5 mM. The results confirmed the existence of, at least, two AK isoenzymes, one inhibited by lysine and the other inhibited by threonine, the latter being predominant in quinoa seeds. HSDH activity was also shown to be partially inhibited by threonine, whereas some of the activity was resistant to the inhibitory effect, indicating the presence of two isoenzymes, one resistant and another sensitive to threonine inhibition. Only one DHDPS isoenzyme highly sensitive to lysine inhibition was detected. The results suggest that the high concentration of lysine observed in quinoa seeds is possibly due to a combined effect of increased lysine, synthesis and accumulation in the soluble form and/or as protein lysine. Nitrogen assimilation was also investigated and based on nitrate content, nitrate reductase activity, amino acid distribution and ureide content, the leaves were identified as the predominant site of nitrate reduction in this plant species. The amino acid profile analysis in leaves and roots also indicated an important role of soluble glutamine as a nitrogen transporting compound. (c) 2007 Elsevier Masson SAS. All rights reserved.

Particle size and concentration of poly(epsilon-caprolactone) and adipate modified starch blend on mineralization in soils with differing textures

The objective of this study was to evaluate the effect of particle size and concentration of poly(F.-caprolactone) and adipate modified starch blend on mineralization in soils with differing textures, comparing it with polyethylene under the same experimental conditions. Two soil types were used: a Kandiudalfic Eutrudox with a clayey texture and an Arenic Hapludult with a sandy texture. The two different plastic specimens were incorporated in the form of plastic films with three increasing particle sizes and six doses, from 0 to 2.5 mg C g(-1) soil. Each plastic dose was incorporated into 200 g of soil placed in a hermetically closed jar at 28 degrees C, and incubated for a 120-day period to determine CO(2) evolution. Once again it was confirmed that polyethylene is almost non-biodegradable, in contrast to PCL/S, which can be defined as a biodegradable material. Soil texture affected the mineralization kinetics of the plastic specimens, with higher values for the clayey soil. No changes in soil microbial biomass-C or -N were observed by adding polyethylene and PCL/S to the soil. Also, no significant differences were observed on seed emergence and development of rice seedlings (Oryza sativa L.) in plastic modified soil. (C) 2009 Elsevier Ltd. All rights reserved.

Diet-induced milk fat depression: Association with changes in milk fatty acid composition and fluidity of milk fat

This experiment was designed to examine changes in milk fatty acids during fish oil-induced milk fat depression (MFD) and to test the theory that these changes are related to milk fat fluidity. The experiment was divided into three periods: 1) Baseline: all cows (n = 12) received a high fiber diet without fish oil (FO) for 12 days; 2) Treatment: 4 cows/group received the following treatments for 21 days: a) Low fiber diet without FO (LF), b) High fiber diet+FO (HF+FO) and c) Low fiber diet+FO (LF+FO); 3) Post-treatment: cows returned to the baseline diet and were monitored for 12 days. FO was included at 1.6% DM and HF and LF diets had 40 and 26% NDF, respectively. Milk fat content and yield were unchanged by the LF diet, but were reduced by FO diets at both dietary fiber levels and recovered in the post-treatment period. FO diets caused a pronounced reduction in stearic and oleic acid concentrations in milk fat and an equally pronounced increase in trans-18:1 fatty acid concentrations. Milk fat mean melting point (MMP) was correlated with MFD (r=0.73) and with milk oleic acid concentration (r=-0.92). The ratio of oleic:stearic in milk fat increased gradually and consistently in response to FO. Trans-C18:1 isomers with double bounds at carbon :<= 10 increased with greater MFD and those with double bonds at carbon ! I I decreased with greater MFD. Trans-9 cis-11 CLA explained more than 80% of MFD and was strongly correlated with trans-10 C18:1. Maintenance of MMP below 39-40 degrees C suggests that the mammary gland was able to secrete only milk fat with adequate fluidity and that MFD could be an adaptation mechanism to prevent secretion of milk with higher MMP. (C) 2007 Elsevier B.V. All rights reserved.

Determination of the median lethal concentration (LC(50)) of mycoinsecticides for the control of Ceratitis capitata (Diptera: Tephritidae)

The aim of this study was to determine the median lethal concentration (LC(50)) of the commercial products Boveril WP (R) (Beauveria bassiana) and Metarril WP (R) (Metarhizium anisopliae) on the larvae and pupae of the fruit Ceratitis capitata. Insects used in this study came from a laboratory colony. The evaluated product concentrations were 10.00, 15.00, 20.00 and 25.00 g/L of water, which correspond, respectively, to 5.00x10(9), 7.50x10(9), 10.00x10(9) and 12.50x10(9) viable conidia/L of water for the two products, and in the control only water was applied. Third instar larvae and pupae of C. capitata were used in this study. Results showed an overall mortality of larvae with all conidial concentrations of M. anisopliae. The LC(50) values for larvae were 2.99 and 2.97 g/L for Boveril (R) and Metarril (R), respectively, while for pupae they were 3.12 and 4.74 g/L for Boveril (R) and Metarril (R), respectively. The high pathogenicity demonstrated by lower conidial concentrations of the tested products may mean greater efficiency from both economic and environmental points of view.

Phenolic compounds in raw and cooked rice (Oryza sativa L.) and their inhibitory effect on the activity of angiotensin I-converting enzyme

Whole rice has been widely studied due to the abundance of bioactive compounds in its pericarp. Some of the beneficial effects of these compounds on human health have been attributed to their antioxidant and other biological activities, such as enzyme inhibition. In this work, we evaluated the contents of total, soluble and insoluble phenolic compounds of 6 red and 10 non-pigmented genotypes of whole rice as well as their inhibitory effect on the activity of angiotensin I-converting enzyme (ACE). The effects of cooking on phenolics and their inhibitory activities were also investigated. Red genotypes showed high content of phenolics, mainly soluble compounds, at an average of 409.7 mg ferulic acid eq./100 g, whereas overall lower average levels (99.4 mg ferulic acid eq./100 g) at an approximate soluble/insoluble compound ratio of 1:1 were observed in non-pigmented rice. Pigmented rice displayed a greater inhibitory effect on ACE than non-pigmented rice. In fact, a significant correlation between the content of soluble phenolics and ACE inhibition was observed (r = 0.8985, p < 0.05). In addition to significantly reducing the levels of total phenolics and ACE inhibition, cooking altered the soluble/insoluble compound ratio, especially among red rice genotypes. (C) 2011 Elsevier Ltd. All rights reserved.

Hydrolysis Influence on Phytochemical Composition, Antioxidant Activity, Plasma Concentration, and Tissue Distribution of Hydroethanolic Ilex paraguariensis Extract Components

The infusion of aerial parts of Ilex paraguariensis is widely consumed. Its antioxidant activity suggests an important role of this plant in the treatment/prevention of oxidative stress related diseases. Plant extract active compounds are frequently found in esterified form that may be poorly absorbed. Hydrolysis of the extract is a possible approach to increase its bioavailability. The aim of this study was to perform a phytochemical analysis and evaluate in rats the plasma concentration and tissue distribution of antioxidant compounds in the hydroethanolic extract of Ilex paraguariensis, before and after enzymatic hydrolysis. Both extracts presented high antioxidant activity and phenolic content. Rats given single or repeated doses of the hydrolyzed extract showed increased plasma antioxidant activity and higher plasma levels of caffeic acid. However, no changes of endogenous antioxidants were observed. In conclusion, hydrolysis of the extract of Ilex paraguariensis is a strategy to improve its bioavailability and in vivo antioxidant activity.

Increased MMA concentration and body mass index are associated with spontaneous abortion in Brazilian women A pilot study

Background: The pathophysiology of spontaneous abortion is complex and may involve the interaction of genetic and environmental factors. We evaluated the predictors of spontaneous abortion in Brazilian pregnant women. The effects of age, gestational age. body mass index (BMI), cigarette smoking, alcohol ingestion, use of multivitamins and concentrations of vitamins (folate, cobalamin and vitamin 136) and vitamin-dependent metabolites were analyzed. Methods: Study population included 100 healthy women that attended pre-natal care in 2 health centers of Sao Paulo, Brazil, and in whom pregnancy outcome was known. Folate and cobalamin status was measured in blood specimens collected between 4 and 16 weeks. The genotypes for 8 gene polymorphisms were evaluated by PCR-RFLP. Results: Eighty-eight women had normal pregnancy outcome (Group 1), while 12 experienced a miscarriage after blood collection (Group 2). Increased methylmalonic acid (MMA) concentrations were found in Group 2 (median [25th-75th percentile]=274 [149-425] nmol/l) relative to Group 1 (138 [98-185]) (P<0.01). No differences between the groups were observed for serum cobalamin, serum or red cell folate, and serum total homocysteine or allele frequencies for 8 polymorphisms. In a conditional logistic regression analysis including age, gestational age, serum creatinine, MMA, cystathionine, body mass index (BMI), cigarette smoking, alcohol ingestion and use of multivitamins the risk of abortion was significantly associated with MMA (OR [95% CI] = 3.80 [1.36, 10.62] per quartile increase in MMA), BMI (OR [95% CI] = 5.49 [1.29,23.39] per quartile) and gestational age (OR [95% CI] = 0.10 [0.01, 0.77] per increase of interval in gestational age). Conclusions: Increased serum MMA and BMI concentrations are associated with spontaneous abortion in Brazilian women. (C) 2009 Elsevier B.V. All rights reserved.

Ascorbic acid concentration is reduced in the secondary aqueous humour of glaucomatous patients

P>Background: We aimed to evaluate the ascorbic acid concentration in secondary aqueous humour (AH) from glaucomatous patients and to compare it with primary AH from primary open-angle glaucoma patients and non-glaucomatous patients. Methods: Primary AH samples were prospectively obtained from clinically uncontrolled primary open-angle glaucoma patients and senile cataract patients (controls) prior to trabeculectomy and cataract surgery. Secondary AH samples were obtained from eyes with previous intraocular surgery, prior to trabeculectomy or cataract surgery. AH (0.1 mL) was aspirated by inserting a 26-gauge needle into the anterior chamber just before surgery and then immediately stored at -80 degrees C. The ascorbic acid concentration was determined in a masked fashion by high-pressure liquid chromatography. Results: A total of 18 patients with senile cataract, 16 glaucomatous patients with primary AH (no previous intraocular surgery) and 11 glaucomatous patients with secondary AH (previous intraocular surgery) were included. There was no difference in mean age between groups (P = 0.15). The mean +/- standard deviation concentration of ascorbic acid in the secondary AH from glaucomatous patients (504 +/- 213 mu mol/L [95% confidence interval {CI}, 383-624]) was significantly lower than the concentration of ascorbic acid found in the primary aqueous of primary open-angle glaucoma (919 +/- 427 mu mol/L [95% CI, 709-1128]) and control patients (1049 +/- 433 mu mol/L [95% CI, 848-1249]; P < 0.01, Kruskal-Wallis test). Conclusions: The ascorbic acid concentration in secondary AH of glaucomatous patients was approximately twofold lower in comparison with primary AH of glaucomatous and cataract patients. The implications of a reduced concentration of ascorbic acid in the secondary AH deserve further investigation.

Inhibitory effects of Solidago chilensis Meyen hydroalcoholic extract on acute inflammation

Aim of the study: Alcoholic or hydroalcoholic preparations of the plant Solidago chilensis Meyen (Asteraceae) are employed in popular medicines to treat inflammation. The anti-inflammatory effects of the hydroalcoholic extract of aerial parts of the plant (93% ethanol) were investigated and the main components of the extract were identified. Materials and methods: Ear oedema was induced in male Wistar rats by topical application of the chloroform fraction of latex-extract from Euphorbia milii. Leukocyte mobilisation was quantified after air-pouch inflammation evoked by oyster glycogen. Leukocyte-endothelial interactions and mast cell degranulation were quantified by intravital microscopy. The extract itself was characterised via HPLC-DAD-MS and HPLC-MS/MS. Results: Topical (12.5-50 mg/kg) or intraperitoneal (25 or 50 mg/kg) administrations of the extract reduced ear oedema formation (>25% reduction). Intraperitoneal applications of 25 mg/kg of extract inhibited the migration of polymorphonuclear cells into the inflamed cavity (about 50%). In addition, the rolling behaviour and adherence of circulating leukocytes to postcapillary venules of the mesentery network was diminished (50%), but the mast cell degranulation in the perivascular area was not affected. The major components of the extract were identified as caffeoylquinic acid derivatives and the flavonoid rutin. Conclusions: The data presented herein show local and systemic anti-inflammatory effects of the hydroalcoholic extract of aerial parts of Solidago chilensis, and implicate the inhibition of leukocyte-endothelial interactions as an important mechanism of the extract`s action. (C) 2009 Elsevier Ireland Ltd. All rights reserved.