Processing Effects on Properties of (Fe,Mg,Al)3O4 Spinels as Potential Consumable Anodes for Pyroelectrolysis

A promising concept of consumable anode materials for high‐temperature pyroelectrolysis process, which is expected to overcome the environmental and economical impacts of classical extractive metallurgy, relies on substituted magnetite‐based ferrospinels, presenting high electrical conductivity, appropriate refractoriness, and redox stability. The present work aims assessment of the processing effects on structural, redox, and electrical properties of Fe_2.3Al_0.2Mg_0.5O₄ spinel, prepared by conventional solid‐state route (SSR) and laser floating zone (LFZ) method. The observed trends for high‐temperature electrical conductivity behavior indicated that the electronic transport is only slightly affected by the preparation method, suggesting the minor effects from the grain boundaries. For scaled‐up ferrospinel‐based consumable anodes the impact of oxidation during thermal cycling on electrical properties and electrode integrity can be minimized even in air, by using relatively fast cooling/heating rates.     

Assessing Antibacterial Potential of Components of <Emphasis Type="Italic">Phyllomedusa distincta</Emphasis> Skin and its Associated Dermal Microbiota

The granular glands of anuran skin secrete an array of bioactive molecules that protect a frog against pathogens and predators. The skin also harbors a microbial community. Although there is evidence to suggest that the microbiota complement the innate immune defense systems against pathogen infection, the effect of the frog bioactive molecules on its resident microbiota has not yet been fully investigated. In the present study, the skin microbiota of Phyllomedusa distincta obtained from two different geographical areas was evaluated with molecular and culture-based approaches. The antagonistic effects exhibited by the host’s microbiota and by a novel dermaseptin peptide isolated from P. distincta skin were investigated. Four isolated bacterial colonies displayed antimicrobial activity against known frog pathogens. Our results were consistent with the hypothesis that microbiota from P. distincta may interact with pathogenic microorganisms to protect a frog’s health. On the other hand, the novel dermaseptin peptide exhibited an antimicrobial effect on pathogens as well as on some of the bacteria obtained from the skin microbiota. The richness of bacteria on P. distincta skin was further investigated by 16S rRNA gene clone libraries, which revealed that the family Enterobacteriaceae was prevalent, but a high variability at the species level was observed among individual frogs. Differences observed on the microbiota of frogs from contrasting habitats indicated an influence of the environment on the structure of the skin microbiota of P. distincta.     

Carbon nanostructures-modified expanded vermiculites produced by chemical vapor deposition from ethanol

In this work, chemical vapor deposition using ethanol and FeMo catalysts at 600, 700, 800 and 900 °C was used to modify the surface of expanded vermiculite (EV). Scanning electron microscopy, Raman spectroscopy, X-ray diffraction, Mössbauer spectra, N₂-BET surface areas, and carbon elemental analyses suggested that the FeMo catalyst promoted 2–3% growth of carbon in different forms, mainly nanofibers, on the EV surface. The amount of 2–3% carbon produced by ethanol/CVD process on EV produced a 500% increase in the absorption of soybean, diesel and engine oil, with a concomitant decrease on water absorption. These results were discussed in terms of a hydrophobization of the EV surface by the carbon structures and a “sponge-like” effect due to the entangled nanofibers structure, as it was observed by microscopy, and an increase of N₂-BET surface area from 3 m² g⁻¹ for EV up to 21 m² g^–1 for the ethanol CVD-treated EV.     

Methane reforming of syngas produced by co-gasification of coal and wastes. Effect of catalysts and of experimental conditions

Syngas obtained by co-gasification of coal and wastes was hot cleaned in two catalytic reactors, which allowed destroying tar and gaseous hydrocarbons with more than one carbon atom. H₂S and NH₃ contents were also significantly reduced, but CH₄ concentrations varying between 2% and 10% and small amounts of H₂S (below 100 ppmv) were still found in syngas, depending on coal type and waste composition. This paper studies the effect of experimental conditions on CH₄ destruction by reforming reactions in absence and in presence of catalysts. The effect of experimental conditions (temperature, steam flow rate and syngas composition) on CH₄ destruction and on CO conversion into CO₂ in the absence of catalyst was studied first, using the Equilibrium Reactor model from CHEMKIN modelling software. The selected experimental conditions were then tested in a fixed bed reactor with and without catalyst and the results obtained were consistent with CHEMKIN Equilibrium Reactor model predictions. Commercial Ni-based catalysts were tested (G-90 B5 and G 56B from C&CS). These catalysts were capable of significantly reducing CH₄ content, by promoting reforming reactions. At the experimental conditions used and in absence of steam, G 56B seems to be more effective in CH₄ conversion, as lower CH₄ contents were obtained. In presence of steam both catalysts were capable of completely destroying CH₄. Both catalysts also promoted WGS (water gas shift) reaction to some extent, though they are not specific catalysts for this reaction. Thus, a high increase in H₂ content was observed, due to its formation by both reforming and WGS reactions. For a complete conversion of CO into CO₂ and H₂ a specific catalyst for WGS reaction is still needed.     

Evaluation of urea-formaldehyde adhesives performance by recently developed mechanical tests

In the open literature, two main strategies can be found for synthesizing urea-formaldehyde (UF) resins. One is the alkaline-acid process, which takes place in three steps, usually an alkaline methylolation followed by an acid condensation and then the addition of a final amount of urea. The other process consists of four steps, the main difference being an initial condensation in strongly acid environment.In this work, we evaluate the curing behaviour of four resins produced using the aforementioned processes by the Integrated Pressing and Testing System (IPATES) and the Automated Bonding Evaluation System (ABES).The characterisation of the bond strength development during hot pressing by ABES and IPATES shows that the four resins will have different performances in the bonding process of wood-based composites. For each resin, the effect of pressing parameters such as temperature, adhesive and hardener ratios on shear strength (ABES) and internal bond (IPATES) during hot pressing is put into evidence.     

Pulmonary artery thrombosis in a patient with mitral-tricuspid valve disease. Added value of peroperative transesophageal echocardiogram

The performance of peroperative transesophageal echocardiography on a 60 year old woman with mitral and tricuspid valve disease discovered a previously undiagnosed thrombus in the right pulmonary artery that completely occluded the inferior lobar branches. Following valvular surgery, a successful thromboendarterectomy was performed.     

Transcervical chorionic villus sampling beyond 12 weeks of gestation

While patients with esophageal cancer are operated, a large quantity of non-functional extracelluler fluid (ECF) are appeared. Mediastinum, intestines, visceral vessels, wound of thoracotomy and laparotomy, etc, become so called "third space", then much water, Na are shifted and restored there. Moreover, plenty of water are evaporated from operated fields and lymph issues are active. A long time ago, intraoperative fluid infusion was little, but recently more fluid (Hartmann solution) are infused (8 approximately 10/ml/kg/hr). Intraoperative blood transfusion is often done because blood tends to lose. But it sometimes had serious side effects, example for GVHD (graft-versus-host disease), infections. In order to prevent from thease, autotransfusion and irradiation to transfused blood are recommended.     

The kinetic parameters of sodium currents in maturing acutely isolated rat hippocampal CA1 neurones

Whole-cell voltage clamp techniques were used to characterize the kinetics of INa in immature (P3-5) and older (P > 25) acutely isolated rat CA1 hippocampal neurones. Fast-rising and fast-inactivating currents were recorded at all stages of maturation, evocable from Vm values of -55 to -50 mV. Currents were sensitive to TTX (1 microM) and to sodium removal from the perfusate. Current density and maximum slope conductance increased with maturation. Current decay was described by two exponentials, the faster component dominating at -35 mV or more depolarized Vm values; the ratio fast/slow inactivating component decreased with maturation. The voltage-dependence of conductance was taken as an approximation of m infinity. In younger cells, V1/2 values of the steady-state inactivation (h infinity) and activation curves (m infinity) were depolarized. Shifts of h infinity and m infinity curves were accompanied by shifts in the corresponding tau h and tau m voltage-dependence curves. In younger cells, activation curves had comparatively higher slope factors (Vs), which is an indication of a lower voltage sensitivity of activation. m infinity, tau m, h infinity, and tau h parameters were used to calculate the forward and backward activation and inactivation rate constants (alpha m, beta m, alpha h and beta h). P3-5 cells had relatively higher beta m values accounting for the lower voltage sensitivity of activation. The findings are an indication of a dominant channel variety in the younger cells with a closed state higher probability. The results are consistent with lower depolarization rates previously reported in CA1 cells at early stages of maturation. Faster inactivation due to poor expression of the slower inactivating component may compensate for poorer repolarization mechanisms due to the immaturity of outward currents previously reported at early stages of maturation.     

Permanent response to alpha-interferon therapy in chronic hepatitis C is preceded by rapid clearance of HCV-RNA from serum

BACKGROUND/AIMS: Prediction of response to interferon therapy is important in the management of chronic hepatitis C. Pre-therapy data are valuable but they may be inaccurate in some cases. Our aim was to investigate whether the biochemical and virological events that occur early during interferon therapy in chronic hepatitis C may predict the final result of the treatment. METHODS: ALT and serum HCV-RNA were serially measured in 53 HCV-RNA-positive patients who received a standard 6-month course of interferon therapy. Eleven patients with a sustained response, 23 who responded but subsequently relapsed and 19 who did not respond were studied. HCV-RNA was measured with a commercial kit (Amplicor HCV). RESULTS: After 4 weeks of treatment, HCV-RNA became negative in 73% of sustained responders, in 26% of transient responders (p = 0.02) and in none of the non-responders. Corresponding figures after 8 weeks of therapy were 82% in sustained responders, 61% in transient responders and 9% in non-responders. The difference between sustained and transient responders at this time was not significant. After 4 weeks of therapy, 82% of sustained responders, 52% of transient responders and none of the non-responders presented normalization of alanine transferase. The difference between sustained and transient responders was not significant. Corresponding figures for normalization of alanine transferase at 8 weeks were 82%, 96% and 0% respectively. At the end of treatment, all sustained responders, 70% of transient responders and none of the non-responders had cleared HCV-RNA from serum. CONCLUSIONS: A rapid normalization of alanine transferase induced by interferon therapy is associated with response, but does not differentiate between transient and permanent response. In contrast, clearance of HCV-RNA after 4 weeks of treatment, but not after 8 weeks, is significatively associated with sustained response. Testing for HCV-RNA early during interferon administration may be valuable for further decisions concerning therapy in patients with chronic hepatitis C.