Biogas use in high temperature fuel cells: Enhancement of KOH-KI activated carbon performance toward H2S removal

Activated carbons (ACs) treated with KOH-KI are very effective sorbents for deep H₂S removal, as required by biogas use in high temperature fuel cell systems. For this application, the performance of a commercial KOH-KI treated AC was investigated through a systematic study based on dynamic adsorption tests. With reference to the composition of a real biogas produced in a wastewater treatment plant located in Barcelona, the present work presents a sensitivity performance analysis on singular and synergetic effects of gas matrix, humidity and oxygen on AC KOH-KI performance.The results revealed a positive role of water (up to 90% of relative humidity (R.H.)) for different gas matrices, enhanced by the simultaneous presence of small percentages of oxygen (2%_v). A relevant influence of gas matrix composition was found (except for the case of oxygen addition to dry inlet streams), specifically in terms of a marked negative effect of CO₂ and a significant sorption capacity increase for high percentage of methane. Sulfur dioxide was not detected in the outlet gas-phase for the investigated operating parameters (O₂ 2%_v, R.H. 0–90%, H₂S 100 ppm_v, temperature 45 °C). Therefore, even in the case of further oxidation of adsorbed elemental sulfur to SO₂, this product could be completely removed by AC KOH-KI.     

Epoxy coatings containing clays and organoclays: Effect of the filler and its water content on the UV-curing process

UV-cured coatings were prepared by photoinitiated cationic ring-opening polymerisation of epoxides in the presence of natural montmorillonite and different organically modified clays (5 wt%). The curing was monitored by FTIR in real time while irradiating the formulations by UV light. Significant changes of both the rate of curing and the final conversion were found. Only in the presence of a suitable montmorillonite and after a suitable pre-treatment, the process showed the same polymerisation rate, guaranteed a higher conversion than the neat epoxide and the formation of intercalated nanostructured coatings.     

Angiotensin-converting enzyme inhibitory activity of water-soluble extracts of Asiago d'allevo cheese

The angiotensin-converting enzyme (ACE) inhibitory activity of water-soluble extracts (WSE) from Asiago cheeses was assayed in two cheese production systems and with different ripening times. The WSE were ultrafiltered through 10 kDa and 3 kDa cut-off membranes to evaluate the ACE inhibitory activity of long and short peptides, respectively. The cheese production systems had no significant effect on the ACE inhibitory activity, whereas 6-month-old cheeses had higher inhibitory potency than the more ripened ones. Moreover, the fraction containing peptides smaller than 3 kDa made a more considerable contribution to ACE inhibitory activity than the fraction smaller than 10 kDa, suggesting an inhibitory effect due to short peptides. The peptidic fraction was characterized using RP-HPLC coupled to mass spectrometric detection. Simulated gastrointestinal digestion was carried out to evaluate the effects of digestive enzymes on the generation of bioactive peptides, but this did not significantly affect the inhibitory activity.     

Graphene-based four-port circulator with an elliptical resonator for THz applications

Journal of Computational Electronics - We suggest a new graphene-based four-port circulator for THz applications that consists of two parallel graphene waveguides coupled to an elliptical graphene...     

Assessing allergenicity of different tomato ecotypes by using pooled sera of allergic subjects: identification of the main allergens

An evaluation of the potential allergenicity of different tomato ecotypes is reported. Twelve tomato ecotypes were assessed through a proteomic approach, using pools of sera of allergic patients from two different regions (Emilia Romagna in Northern Italy and Campania in Southern Italy), in order to identify the major allergens and evaluate differences in IgE binding properties of the tomato cultivars. Pooled sera of allergic people from Emilia Romagna showed as the main allergen a suberization-associated anionic peroxidase, whereas pooled sera of allergic patients from Campania were mostly reactive to profilin. The two proteins were identified through a proteomic approach based on the use of high-resolution mass spectrometric techniques. Quite interestingly, in some cases, several ecotypes showed a less reactivity toward patients?? sera than other, potentially indicating the possibility to identify ipoallergenic varieties. Anyway, the allergenic pattern response to tomatoes was serum-specific, indicating that the allergenic properties of different tomato ecotypes are defined by the specific proteins to which the patient is sensitized, a strong indication that ipoallergenicity of the different ecotypes is possible, but mostly related to the individual susceptibility.     

Effects of sonication on bacteria viability in wastewater treatment plants evaluated by flow cytometry--fecal indicators, wastewater and activated sludge

The application of sonication to wastewater or sludge contributes to the dispersion of aggregates, the solubilisation of particulate matter with an increase in its biodegradability, the damage of microorganisms due to the loss of cellular membrane integrity. This research is aimed at investigating the effects of sonication at 20kHz frequency on viability of microorganisms present in raw wastewater and activated sludge taken from a municipal wastewater treatment plant, as well as pure strains of Escherichia coli and E. faecalis. Flow cytometry was applied for the identification and quantification of viable and dead bacteria free in the bulk liquid, after the fluorescent staining of cellular nucleic acids. The main results showed that: (i) cells of E. coli were highly sensitive to sonication, even at low specific ultrasonic energy (E(s)), and disintegration of a large amount of cells was observed; (ii) on the contrary E. faecalis were more resistant than E. coli, even if high levels of E(s) were applied; (iii) bacteria in raw wastewater exhibited a dynamic of viable and dead bacteria similar to E. coli; (iv) in activated sludge samples, low levels of E(s) produced a prevalent disaggregation of flocs releasing single cells in the bulk liquid, while disruption of bacteria was induced only by very high levels of E(s).     

Fingerprint-imprinted polymer: rational selection of peptide epitope templates for the determination of proteins by molecularly imprinted polymers

The pool of peptides composing a protein allows for its distinctive identification in a process named fingerprint (FP) analysis. Here, the FP concept is used to develop a method for the rational preparation of molecularly imprinted polymers (MIPs) for protein recognition. The fingerprint imprinting (FIP) is based on the following: (1) the in silico cleavage of the protein sequence of interest with specific agents; (2) the screening of all the peptide sequences generated against the UniProtKB database in order to allow for the rational selection of distinctive and unique peptides (named as epitopes) of the target protein; (3) the selected epitopes are synthesized and used as templates for the molecular imprinting process. To prove the principle, NT-proBNP, a marker of the risk of cardiovascular events, was chosen as an example. The in silico analysis of the NT-proBNP sequence allowed us to individuate the peptide candidates, which were next used as templates for the preparation of NT-pro-BNP-specific FIPs and tested for their ability to bind the NT-proBNP peptides in complex samples. Results indicated an imprinting factor, IF, of ~10, a binding capacity of 0.5-2 mg/g, and the ability to rebind 40% of the template in a complex sample, composed of the whole digests of NT-proBNP.     

Can the properties of carbon nanotubes influence their internalization by living cells?

Carbon nanotubes (CNTs) are widely used for biomedical applications as intracellular transporters of (bio)molecules, due to their high propensity to cross cell membranes. However, there is a clear discrepancy in the literature about their uptake mechanism, which should be related to the differences existing in the nanotube materials, as well as the experimental procedures. Despite the fact that there are some studies on the influence of the CNT surface chemistry, the role of the properties of non-functionalized CNTs in cellular uptake has not been much investigated to a great extent. In this work, different kinds of multi-wall CNTs (MWCNTs) are produced and fully characterized, in terms of diameter, length, metal impurity, carbon soot and surface chemistry. These MWCNT samples are tested in vitro, and the cellular uptake is indirectly evaluated by using standard fluorescent probes and confirmed by TEM images. Our assays demonstrate that nanotube length clearly influences their uptake and shorter (sub-1 μm) MWCNTs are easier to be internalized through an energy-independent pathway. The results of this investigation may be useful for the design of promising CNT-based vectors for cell therapy.