Evaluation of pre-treatment processes for increasing biodegradability of agro-food wastes

Anaerobic digestion (AD) technology can be employed for treating sewage sludge, livestock waste or food waste. Generally, the hydrolysis stage is the rate-limiting step of the AD processes for solid waste degradation. Therefore, physical, chemical and biological pre-treatment methods or their combination are required, in order to reduce the rate of such a limiting step. In this study, four methods (mechanical shredding, acid hydrolysis, alkaline hydrolysis and sonication) were tested to improve methane production and anaerobic biodegradability of different agro-food wastes and their mixtures. The kinetics of anaerobic degradation and methane production ofpre-treated individual wastes and selected mixtures were investigated with batch tests. Sonication at lower frequencies (37 kHz) proved to give the best results with methane productivity enhancements of over 100% in the case of pig manure and in the range of 10-47% for the other wastes assayed. Furthermore, the ultimate methane production was proportional, in all the cases, to the specific energy input applied (Es). Sonication can, thus, enhance waste digestion and the rate and quantity of biogas generated. The behaviour of the other pre-treatments under the conditions assayed is not significant. Only a slight enhancement of biogas production (around 10%) was detected for whey and waste activated sludge (WAS) after mechanical shredding. The lack of effectiveness of chemical pre-treatments (acid and alkaline hydrolysis) can be justified by the inhibition of the methanogenic process due to the presence of high concentrations of sodium (up to 8 g l(-1) in some tests). Only in the case of WAS did the acid hydrolysis considerably increase the biodegradability of the sample (79%), because in this case no inhibition by sodium took place. Some hints of a synergistic effect have been observed when co-digestion of the mixtures was performed.

Effects of Game Location, Period, and Quality of Opposition in Elite Handball Performances

The aims of the present study were to identify (i) home advantage in elite handball according to the quality of opponent, (ii) the game periods where the teams score more goals, and (iii) the game statistics associated with the teams' success according to the game's location. The sample comprised 480 regular season games (2007–2009) from the Spanish Professional Handball League. The goals scored and shot effectiveness (6 m, 7 m, 9 m and fast breaks) were analyzed for each 5-min. game period in games between players of balanced and unbalanced quality. The home advantage was 64%, with higher values (71%) in balanced and lower values (55%) in unbalanced games. The 5-min. game periods in which teams scored more goals were the last 5-min. period of each half, especially in the second half. The effectiveness was only different in shots closer to the goal (6 m), which supports the territoriality theory of home advantage.

Twelve automated thresholding methods for segmentation of PET images: a phantom study

Tumor volume delineation over positron emission tomography (PET) images is of great interest for proper diagnosis and therapy planning. However, standard segmentation techniques (manual or semi-automated) are operator dependent and time consuming while fully automated procedures are cumbersome or require complex mathematical development. The aim of this study was to segment PET images in a fully automated way by implementing a set of 12 automated thresholding algorithms, classical in the fields of optical character recognition, tissue engineering or non-destructive testing images in high-tech structures. Automated thresholding algorithms select a specific threshold for each image without any a priori spatial information of the segmented object or any special calibration of the tomograph, as opposed to usual thresholding methods for PET. Spherical (18)F-filled objects of different volumes were acquired on clinical PET/CT and on a small animal PET scanner, with three different signal-to-background ratios. Images were segmented with 12 automatic thresholding algorithms and results were compared with the standard segmentation reference, a threshold at 42% of the maximum uptake. Ridler and Ramesh thresholding algorithms based on clustering and histogram-shape information, respectively, provided better results that the classical 42%-based threshold (p < 0.05). We have herein demonstrated that fully automated thresholding algorithms can provide better results than classical PET segmentation tools.

Screening of three commercial plant peroxidases for the removal of phenolic compounds in membrane bioreactors

A comparative study of three plant peroxidases, horseradish (HRP), soybean (SBP) and artichoke (AKPC), was carried out to select the most appropriate one for 4-chlorophenol treatment in an ultrafiltration membrane reactor. Soybean peroxidase showed the highest enzymatic activity, followed by HRP and AKPC. The same tendency was observed in a discontinuous tank reactor, where SBP attained more than 90% of4-chlorophenol removal within the pH range tested. The optimum temperature was 30 degrees C, with SBP showing highest thermostability. With the ultrafiltration membrane reactor, SBP attained the highest operational stability, with 4-chlorophenol conversions of around 90% in the permeate stream for up to 200 minutes. Finally, permeate samples were analysed and no significant amount of enzyme was detected, so the observed loss of activity, less pronounced with SBP, was attributed to enzyme adsorption on the polymeric products deposited on the membrane surface. Soybean peroxidase was selected as the most appropriate peroxidase for future research.

Removal efficiency and toxicity reduction of 4-chlorophenol with physical, chemical and biochemical methods

Chlorophenols are well-known priority pollutants and many different treatments have been assessed to facilitate their removal from industrial wastewater. However, an absolute and optimum solution still has to be practically implemented in an industrial setting. In this work, a series ofphysical, chemical and biochemical treatments have been systematically tested for the removal of 4-chlorophenol, and their results have been compared in order to determine the most effective treatment based on removal efficiency and residual by-product formation. Chemical treatments based on advanced oxidation processes (AOP) produced the best results on rate and extent of pollutant removal. The non-chemical technologies showed advantages in terms of complete (in the case of adsorption) or easy (enzymatic treatments) removal of toxic treatment by-products. The AOP methods led to the production of different photoproducts depending on the chosen treatment. Toxic products remained in most cases following treatment, though the toxicity level is significantly reduced with combination treatments. Among the treatments, a photochemical method combining UV, produced with a KrCl excilamp, and hydrogen peroxide achieved total removal of chlorophenol and all by-products and is considered the best treatment for chlorophenol removal.

Continuous tank reactors in series: an improved alternative in the removal of phenolic compounds with immobilized peroxidase

Immobilized derivatives of soybean peroxidase, covalently bound to a glass support, were used in a continuous stirred tank reactor in series, in order to study the removal of two phenolic compounds: phenol and 4-chlorophenol. The use of two reactors in series, rather than one continuous tank, improved the removal efficiencies of phenol and 4-chlorophenol. The distribution of different amounts of enzyme between the two tanks showed that the relative distributions influenced the removal efficiency reached and the degree of the enzyme deactivation. The highest removal percentages were reached at the outlet of the second tank for a distribution of 50% of the enzyme in each tank. However, with a distribution of 75% in the first tank and 25% in the second, the elimination percentage in the second tank was slightly lower than in the previous case, and the effects of deactivation of the enzyme in the first tank were less pronounced. In all the distributions assayed it was observed that the first tank acts as a filter for the second one, which receives a feed with a smaller load of phenolic compounds, thus diminishing enzyme deactivation in the second tank.

Infliximab salvage therapy after failure of ciclosporin in corticosteroid-refractory ulcerative colitis: a multicentre study

BACKGROUND

Ciclosporin has proven to be effective in patients with corticosteroid-refractory ulcerative colitis (UC). When therapy with this drug fails, infliximab can be considered to avoid colectomy. The efficacy and safety of this sequential approach remain unknown.

AIM

To assess the efficacy and safety profile of treatment with infliximab after failure of ciclosporin in patients with a corticosteroid-refractory flare of UC.

METHODS

Retrospective review of medical records of patients with a corticosteroid-refractory flare of UC who did not respond to ciclosporin and received salvage therapy with infliximab within a month of discontinuing ciclosporin. The severity of the flare and response to the treatment were graded using the Lichtiger index. Cumulative rates of colectomy were calculated using Kaplan-Meier analysis. Cox regression analysis was performed to identify predictors of colectomy. To evaluate the safety profile of this treatment strategy, any adverse event occurring after the first infusion of infliximab was considered.

RESULTS

The study population comprised 47 patients with corticosteroid-refractory UC treated with infliximab after failure of ciclosporin. The median baseline Lichtiger index was 13. The mean time from the last ciclosporin dose to the first infliximab infusion was 6 days. After the first infliximab infusion, 13% of patients achieved remission, and 74% partial response. Of the 35 patients who received the third infliximab infusion, 60% achieved remission, and 37% partial response. Fourteen patients (30%) underwent colectomy. The rate of adverse events was 23%. One death occurred in a 40-year-old man who failed ciclosporin and infliximab and underwent surgery 10 days after the first infliximab infusion; he died of nosocomial pneumonia.

CONCLUSIONS

Treatment with infliximab makes it possible to avoid colectomy in two-thirds of corticosteroid-refractory UC patients in whom ciclosporin fails. However, the rates of adverse events and mortality mean that the decision to administer sequential therapy (ciclosporin-infliximab) should be taken on an individual basis.

Behaviour of RO98pHt polyamide membrane in reverse osmosis and low reverse osmosis conditions for phenol removal

Phenolic compounds and their derivatives are very common pollutants in wastewaters. Among the methods described for their removal, pressure-driven membrane processes are considered as a reliable alternative. Our research group has previously studied phenol removal in reverse osmosis (RO) conditions and obtained very low rejection percentages. Subsequently, when low reverse osmosis (LRO) conditions were studied, the organic rejection percentages improved. To further our knowledge in this respect, the main objective of this work was to study the behaviour of the polyamide thin-film composite membrane RO98pHt used for phenol removal in RO and LRO conditions. The influence of different operating pressures, phenol feed concentrations and pH on permeate flux and phenol rejection was studied. Low reverse osmosis conditions led to higher phenol rejection percentages in all the assayed conditions, suggesting that other factors related to the molecular characteristics of the organic molecules, such as solubility, acidity and hydrogen bonding capacity, play an important role in the rejection percentage attained. As expected, permeate flux was greater in RO conditions.

Relationships between antithrombin activity, anticoagulant efficacy of heparin therapy and perioperative variables in patients undergoing cardiac surgery requiring cardiopulmonary bypass

INTRODUCTION

A study on 149 cardiopulmonary bypass (CPB) patients was performed to elucidate possible relationships between antithrombin (AT) activity and a subject's clinical profile or surgery characteristics.

METHODS

An initial dose (300 IU/kg) of heparin was administered before CPB. Additional boluses (100 IU/kg) were administered if the activated clotting time (ACT)≤460 s. AT activity and hematological parameters were determined preoperatively, during and after CPB, and at 12, 24, 36, and 48 hours post-intervention.

RESULTS

29.5% patients required an additional dose of heparin during CPB. Preoperative AT was 96.5 ± 13.9% in all but 4 patients. AT was significantly lower during CPB and upon leaving the operating room (59.7%-80.0%). A small, but significant, inverse correlation was observed between AT at the end of CPB and the patient's age, as well as between basal preoperative AT and total heparin administered.

CONCLUSIONS

Patient's age could be a moderate indicator of AT activity drop and low preoperative AT activity could be a sign of reduced anticoagulant efficacy of heparin during CPB.

[Transfusion requirements, morbidity and mortality in cardiac surgery and the use of antifibrinolytic agents: a comparison of aprotinin and tranexamic acid]

OBJECTIVE

To evaluate transfusion requirements, morbidity and mortality when 2 antifibrinolytic agents (aprotinin and tranexamic acid) were used in patients undergoing cardiac surgery.

PATIENTS AND METHODS

Comparison of the effects of 2 antifibrinolytic agents in 243 patients undergoing cardiac surgery between December 2006 and June 2008. We recorded the surgical procedures used, blood product transfusions required, complications (particularly renal), mortality, and length of hospital stay.

RESULTS

The patients were distributed into 2 groups to receive tranexamic acid (n = 144) or aprotinin (n = 99). The incidence of transfusion in the tranexamic acid group (31.94%) was nonsignificantly lower than in the aprotinin group (38.38%) (PF = .31). The mean (SD) number of units of packed red blood cells transfused was 0.67 (1.18) in the tranexamic acid group and 1.01 (1.54) in the aprotinin group (P = .07). The mean preoperative hemoglobin concentration in the tranexamic acid group (11.79 [1.71] mg/dL) was significantly lower than in the aprotinin group (12.35 [1.70] mg/dL) (P < .01). Incipient postoperative renal failure tended to occur more frequently in the aprotinin group (19.6% compared to 16%; P = .47). Mortality at 1 year was 9.02% in the tranexamic acid group (compared to 14.14% in the aprotinin group; PF-.21); the trend for mortality related to postoperative renal failure was similar (7.6% in the tranexamic acid group compared to 12.4% in the aprotinin group; P = .22). No significant differences were observed in postoperative complications or length of hospital stay. However, the lack of randomization and the small sample size do not allow for definitive conclusions.

CONCLUSIONS

This study, subject to the aforementioned limitations, shows that tranexamic acid is as effective as aprotinin for reducing transfusion requirements in cardiac surgery in Spain.

Influence of Wheat Milling on Low-hydration Bread Quality Developed by Sheeting Rolls

It is well known that milling influences the characteristics of flour and products made from it. This article analyzed the influence of milling on the quality of low-hydration bread. In general, milling influenced the quality of these products more than the type of wheat selected. Among the various mill streams, the last break and reduction streams produced lower quality bread and must be eliminated in milling. These streams had a higher protein and ash content, showing the presence of components of the outer layers of the grain. The flour was able to absorb more water, but had less extensibility in kneading and the dough generated was weaker due the poorer quality of its proteins and the influence of elements from the outer layers. Thus, bread made from these streams had smaller volume, had a firmer texture and had both darker crumb and crust. These differences, along with the effect of the kind of flour on the flavor and aroma of the bread, made it less acceptable than flour from the rest of the streams studied.