Dynamic adsorption of diclofenac onto a magnetic nanocomposite in a continuous stirred-tank reactor.

In this study, a waste-based magnetic activated carbon (MAC) was used for the first time in a continuous-flow stirred tank reactor (CSTR). The aim was to evaluate the dynamic removal of diclofenac (DCF) from water and wastewater. Firstly, the breakthrough curves corresponding to DCF adsorption from distilled water at different feed flow rates and doses of MAC were determined. After selecting the most favourable conditions, namely 0.18 h L-1 flow rate and 400 mg L-1 of MAC, the effect of different aqueous matrices was studied, with the breakthrough curves evidencing a performance decline in wastewater in comparison with distilled water. Finally, the exhausted MAC was magnetically recovered, regenerated by microwave-assisted heating and applied in two subsequent adsorption cycles. The regeneration studies pointed to a decrease of the specific surface area and an improvement of the magnetic retrievability of MAC. After the first regeneration step, just mild effects were observed in the dynamic adsorptive performance of MAC. However, after a second regeneration step, the performance declined ca. 50%. Overall, the results highlight the feasibility of producing waste-based magnetic composites that simultaneously combine high adsorption efficiency under dynamic operation in a CSTR, with easy retrievability and successful one-stage regeneration for further reutilization.

[Anesthesia for cesarean section in a patient with recessive dystrophic epidermolysis bullosa]. / Tratamiento anestésico para cesárea en una paciente con epidermolisis bullosa distrófica recesiva.

Recessive dystrophic epidermolysis bullosa is inherited as a rare autosomal disorder which causes blisters to form in the skin. We describe the treatment of a 39-year-old parturient with this condition. She was scheduled for elective cesarean section at 37 weeks' gestation. The patient had widespread skin lesions, had lost fingers, and had esophageal stenosis. The cesarean was performed under spinal anesthesia without complications. Recessive dystrophic epidermolysis bullosa requires adaptation of anesthetic technique that includes control over posture and careful handling of the skin. Material for attaching monitoring devices and inserting venous lines must be adapted to the particular deformities and skin lesions present.

Co-combustion of different sewage sludge and coal: a non-isothermal thermogravimetric kinetic analysis.

The kinetics of the combustion of coal, two different sewage sludge and their blends (containing different dried weight percentages of sewage sludge) was studied by simultaneous thermogravimetric analysis. Once the weight percentage of sludge in the blend was 10%, the effects on the combustion of coal were hardly noticeable in terms of weight loss. The Arrhenius activation energy corresponding to the co-combustion of the blends was evaluated by non-isothermal kinetic analysis. This showed that, though differences between coal and sewage sludge, the combustion of their blends kept kinetically alike to that of the coal. This work illustrates how thermogravimetric analysis may be used as an easy rapid tool to asses, not only mass loss, but also kinetics of the co-combustion of sewage sludge and coal blends.

Fertilization of maize with compost from cattle manure supplemented with additional mineral nutrients.

An alternative approach for cattle manure management on intensive livestock farms is the composting process. An industrial-scale composting plant has been set up in northwest Spain for producing compost from cattle manure. Manure composting involved an increase in pH, electrical conductivity (EC), cation exchange capacity (CEC) and NO3(-)--N concentration, and a decrease in temperature, moisture content, organic matter (OM) content, NH4+--N concentration and C/N ratio. Cu, Zn and Ni concentrations increased due to the reduction of pile mass during the composting process. The resulting compost was applied to a field to study the viability of applying this compost combined with a nitrogen mineral fertilizer as a replacement for the mineral fertilization conventionally used for maize (Zea mays L.). The thermophilic phase of the composting process was very prolonged in the time, which may have slowed down the decomposition of the organic matter and reduced the nitrification process, leading to an over-short maturation phase. The humification and respirometric indexes, however, determined immediately after compost application to the soil, showed it to be stable. Compost application did not decrease the grain yield. A year later, soil pH, OM content and CEC were higher with the compost treatment. Total P, K, Ca and Na concentrations in compost-amended plots were higher than in mineral-fertilized ones, and no significant differences between treatments were found in soil concentrations of NH4+--N,NO3- --N, available P, Mg and B. Compost caused no heavy metal pollution into the soil. Therefore, this compost would be a good substitute for the mineral fertilizers generally used for basal dressing in maize growing.

[Two cases of congenital airway obstruction managed with ex utero intrapartum treatment procedures: anesthetic implications]. / Dos casos de obstrucción congénita de la vía aérea sometidos a E.X.I.T. ("ex-utero intrapartum treatment"): implicaciones anestésicas.

An ex utero intrapartum treatment (EXIT) procedure provides sufficient time to gain control of the potentially obstructed fetal upper airway while uterine placental circulation is maintained during cesarean section. We report 2 cases in which fetal congenital upper airway obstruction was managed without complications during EXIT procedures. We also discuss general considerations concerning the obstetric patient and the performance of intramuscular fetal anesthesia. Before the hysterotomy, sevoflurane at 1.5 minimum alveolar concentration was administered to assure sufficient uterine relaxation during EXIT. The 2 parturients remained hemodynamically stable during the procedure and uterine and placental perfusion was adequate. Nasotracheal intubation was possible in 1 fetus after a cervical mass was dissected. In the other, a tracheostomy was created. After the umbilical cord was clamped, the concentration of sevoflurane anesthetic gas was reduced and oxytocin and methylergometrine were administered to induce adequate uterine contractions within a few minutes. Both neonates survived the EXIT procedure with no complications.

[A review of the clinical application of dyes in gastrointestinal chromoendoscopy, and their magistral formulation]. / Revisión de la aplicación clínica de los colorantes en cromoendoscopia digestiva y su formulación magistral.

OBJECTIVE: To review the drug compounding of dyes employed in chromoendoscopy, and their clinical effectiveness. METHOD: A literature search in Medline, Cochrane Library, and Micromedex was carried out with the term chromoendoscopy as a keyword, and the search was then repeated for each dye found in association with the term endoscopy. A number of monographs, scientific journals, and references quoted in selected papers were also reviewed. Papers collected were then classified according to their methodology. RESULTS: Ninety-six references were found, their original article being recovered for only 57 of these - 13 clinical trials, 21 case series, and 11 reviews. References were found for 7 dyes. Main indications, evidence of effectiveness, administration route, and drug formulation are described for each dye. CONCLUSIONS: The number of papers involved is high, but their accessibility is limited. Evidence is overall scarce, but high in cases such as methylene blue for Barrett s esophagus, lugol in the detection of esophageal carcinoma, and indigo carmine for colonic hyperplastic polyp differentiation. Drug compounding is rather simple, but scarcely developed.

Anaerobic Codigestion of Sludge: Addition of Butcher's Fat Waste as a Cosubstrate for Increasing Biogas Production.

Fat waste discarded from butcheries was used as a cosubstrate in the anaerobic codigestion of sewage sludge (SS). The process was evaluated under mesophilic and thermophilic conditions. The codigestion was successfully attained despite some inhibitory stages initially present that had their origin in the accumulation of volatile fatty acids (VFA) and adsorption of long-chain fatty acids (LCFA). The addition of a fat waste improved digestion stability and increased biogas yields thanks to the higher organic loading rate (OLR) applied to the reactors. However, thermophilic digestion was characterized by an effluent of poor quality and high VFA content. Results from spectroscopic analysis suggested the adsorption of lipid components onto the anaerobic biomass, thus disturbing the complete degradation of substrate during the treatment. The formation of fatty aggregates in the thermophilic reactor prevented process failure by avoiding the exposure of biomass to the toxic effect of high LCFA concentrations.

Selective translocation of protein kinase c isozymes by PAF in rabbit platelets.

The action of platelet activating factor (PAF) on subcellular distribution and activity of protein kinase C (PKC) isoforms in rabbit platelets was analyzed. The results showed an increase of PKC alpha in membrane fraction, concomitantly with a decrease in cytosolic fraction after 5 min PAF treatment, indicating that a translocation of PKC alpha occurred. In addition, PKC zeta was redistributed in a "reverse" form, from the membrane to cytosolic fraction after PAF treatment. PAF induced an increase of PKC alpha activity, whereas a decrease rather than increase in PKC zeta was observed by using immunoprecipitation assays. In addition, some results indicated that PI3 kinase activation was not involved in PAF-induced PKC zeta translocation as occur in several cells and with other agonists. These actions were time- and concentration-dependent, and were inhibited by the treatment with a PAF antagonist. No translocation was observed when the platelets were incubated with lysoPAF, a PAF related compound. The redistribution of PKC isoforms take place through the activation of high specificity PAF binding sites. The pretreatment of the rabbit platelets with staurosporine, a putative inhibitor of PKC, completely blocked the PAF-evoked aggregation without affecting to PAF-evoked shape change and serotonin release. All together, these data could suggest that the specific translocation of PKC isoforms play an important role in the activation of rabbit platelets.

Grindability and combustion behavior of coal and torrefied biomass blends.

Biomass samples (pine, black poplar and chestnut woodchips) were torrefied to improve their grindability before being combusted in blends with coal. Torrefaction temperatures between 240 and 300 °C and residence times between 11 and 43 min were studied. The grindability of the torrefied biomass, evaluated from the particle size distribution of the ground sample, significantly improved compared to raw biomass. Higher temperatures increased the proportion of smaller-sized particles after grinding. Torrefied chestnut woodchips (280 °C, 22 min) showed the best grinding properties. This sample was blended with coal (5-55 wt.% biomass). The addition of torrefied biomass to coal up to 15 wt.% did not significantly increase the proportion of large-sized particles after grinding. No relevant differences in the burnout value were detected between the coal and coal/torrefied biomass blends due to the high reactivity of the coal. NO and SO2 emissions decreased as the percentage of torrefied biomass in the blend with coal increased.

Stereoselective synthesis of (E)-4-alkylidenecyclopent-2-en-1-ones by a tandem ring closure-Michael addition-elimination.

Reaction of (Z)-1,4-diketones with various functionalized nitroalkanes in the presence of DBU gives 4-alkylidenecyclopent-2-en-1-ones with E selectivity. A cyclopentadienone intermediate is probably formed by intramolecular aldol condensation, and this reacts with a nitroalkane giving a Michael addition-elimination.

[Approach to bronchopleural fistula in patients undergoing lung cancer surgery. A prospective study]. / Abordaje de la fístula broncopleural en pacientes intervenidos de cáncer de pulmón. Estudio prospectivo.

Twenty-four cases of bronchopleural fistula were found by fiberoptic bronchoscopy performed in 526 consecutive patients undergoing surgery for diagnosis or treatment of lung cancer between February 1990 and January 1997 in Hospital General Universitario in Valencia (Spain). In 327 of the patients lung resection was performed. Clinical symptoms included fever, purulent or bloodstained expectoration, chest pain, dyspnea and general unfitness, with 83.33% of the patients having pleural empyema. Treatment was based on pleural drainage and broad-spectrum antibiotic therapy, along with planning of the appropriate surgery technique to each patient. Surgery consisted in re-thoracotomy and bronchial closure in early detection cases without evidence of infection (< 48 h); thoracostomy (Clagett) and second stage myoplasty if confirmed pleural infection; thoracoplasty in cases of incomplete fistulas that were unresolved by pleural drainage. Biological glues were delivered by fiberoptic bronchoscope in one patient. The incidence of bronchopleural fistula was studied, as were associated factors and the results obtained by various surgical techniques.

Gasification of rice straw in a fluidized-bed gasifier for syngas application in close-coupled boiler-gasifier systems.

The feasibility and operation performance of the gasification of rice straw in an atmospheric fluidized-bed gasifier was studied. The gasification was carried out between 700 and 850 °C. The stoichiometric air-fuel ratio (A/F) for rice straw was 4.28 and air supplied was 7-25% of that necessary for stoichiometric combustion. Mass and power balances, tar concentration, produced gas composition, gas phase ammonia, chloride and potassium concentrations, agglomeration tendencies and gas efficiencies were assessed. Agglomeration was avoided by replacing the normal alumina-silicate bed by a mixture of alumina-silicate sand and MgO. It was shown that it is possible to produce high quality syngas from the gasification of rice straw. Under the experimental conditions used, the higher heating value (HHV) of the produced gas reached 5.1 MJ Nm(-3), the hot gas efficiency 61% and the cold gas efficiency 52%. The obtained results prove that rice straw may be used as fuel for close-coupled boiler-gasifier systems.

Modelling N mineralization from bovine manure and sewage sludge composts.

Nitrogen mineralization kinetics were compared in three different soils (pH values: 5.2, 7.1 and 8.6) when treated with bovine manure (BM) and sewage sludge (SS) composts. The soil-compost mixtures were kept at a controlled moisture content of 60% of their water holding capacity (WHC) and were incubated in the dark at 25 °C for 2 years. Five mathematical models were compared (simple exponential, double exponential, special model, hyperbolic and parabolic), using as experimental data the mineralized N accumulated during 360 and 720 days of incubation. The results showed that the best fit for describing the mineralization of organic N from the compost after 1 year of experimentation was obtained with the simple exponential model. However, the special model showed the best fit for data from 2 years of incubation and thus better reflected organic N mineralization over a longer time-span. This suggested that the organic N in the two composts was made up of two organic pools of different degrees of stability.

Thermal behaviour and kinetics of coal/biomass blends during co-combustion.

The thermal characteristics and kinetics of coal, biomass (pine sawdust) and their blends were evaluated under combustion conditions using a non-isothermal thermogravimetric method (TGA). Biomass was blended with coal in the range of 5-80 wt.% to evaluate their co-combustion behaviour. No significant interactions were detected between the coal and biomass, since no deviations from their expected behaviour were observed in these experiments. Biomass combustion takes place in two steps: between 200 and 360 degrees C the volatiles are released and burned, and at 360-490 degrees C char combustion takes place. In contrast, coal is characterized by only one combustion stage at 315-615 degrees C. The coal/biomass blends presented three combustion steps, corresponding to the sum of the biomass and coal individual stages. Several solid-state mechanisms were tested by the Coats-Redfern method in order to find out the mechanisms responsible for the oxidation of the samples. The kinetic parameters were determined assuming single separate reactions for each stage of thermal conversion. The combustion process of coal consists of one reaction, whereas, in the case of the biomass and coal/biomass blends, this process consists of two or three independent reactions, respectively. The results showed that the chemical first order reaction is the most effective mechanism for the first step of biomass oxidation and for coal combustion. However, diffusion mechanisms were found to be responsible for the second step of biomass combustion.

Co-gasification of different rank coals with biomass and petroleum coke in a high-pressure reactor for H(2)-rich gas production.

Four coals of different rank were gasified, using a steam/oxygen mixture as gasifying agent, at atmospheric and elevated pressure in a fixed bed reactor fitted with a solids feeding system in continuous mode. Independently of coal rank, an increase in gasification pressure led to a decrease in H(2) + CO production and carbon conversion. Gasification of the different rank coals revealed that the higher the carbon content and reactivity, the greater the hydrogen production. Co-gasification experiments of binary (coal-biomass) and ternary blends (coal-petcoke-biomass) were conducted at high pressure to study possible synergetic effects. Interactions between the blend components were found to modify the gas production. An improvement in hydrogen production and cold gas efficiency was achieved when the coal was gasified with biomass.

Mechanical durability and combustion characteristics of pellets from biomass blends.

Biofuel pellets were prepared from biomass (pine, chestnut and eucalyptus sawdust, cellulose residue, coffee husks and grape waste) and from blends of biomass with two coals (bituminous and semianthracite). Their mechanical properties and combustion behaviour were studied by means of an abrasion index and thermogravimetric analysis (TGA), respectively, in order to select the best raw materials available in the area of study for pellet production. Chestnut and pine sawdust pellets exhibited the highest durability, whereas grape waste and coffee husks pellets were the least durable. Blends of pine sawdust with 10-30% chestnut sawdust were the best for pellet production. Blends of cellulose residue and coals (<20%) with chestnut and pine sawdusts did not decrease pellet durability. The biomass/biomass blends presented combustion profiles similar to those of the individual raw materials. The addition of coal to the biomass in low amounts did not affect the thermal characteristics of the blends.

Laboratory appraisal of organic carbon changes in mixtures made with different inorganic wastes.

Mixtures of organic and inorganic wastes were incubated to examine the changes in organic C (OC) contents. An anaerobic sludge and a CaO-treated aerobic sludge, with OC concentrations of 235 and 129 gkg(-1), were used. The inorganic wastes used - referred to as "conditioners" - were shot blasting scrap, fettling, Linz-Donawitz slag, foundry sand (FS), and fly ash from wood bark combustion (FA). The total OC (TOC) and KMnO(4)(-) oxidized OC were determined. DTA-TGA profiles and FTIR spectra were also obtained. Mixtures made with the FS contained significantly lower (P<0.05) amounts of TOC (45 gkg(-1)) than the rest of mixtures, which was attributed to the non-existence of reactive surfaces in the conditioner and the increased aeration induced by this material. Those made with FA contained significantly higher (P<0.05) amounts of TOC (170 gkg(-1)), which was attributed to: (i) the addition of an extra source of C - black carbon (BC) - in the FA, and (ii) the inhibition of mineralization from the compounds present in this conditioner (e.g., amorphous aluminosilicates, BC). The results highlight the importance of the characteristics of the conditioners on the fate of the OM originating from the sludges.