Assessment of inherently safer alternatives in biogas production and upgrading

Biogas is becoming an increasingly important resource of energy production from biomass, and a number of alternative technologies are proposed for its production and upgrading. However, in spite of the increasing number of accidents recorded, scarce attention was dedicated to date to the control and mitigation of biogas hazards. In this study, inherent safety of biogas technologies was addressed. A method for the selection of inherently safer alternatives during early design stages was further developed and combined to a Monte Carlo sensitivity analysis, accounting for uncertainty of input parameters and addressing the robustness of the ranking provided. The method was applied to the assessment of several alternative reference process schemes for biogas production and upgrading. The results allowed the identification of critical safety issues and the ranking of inherently safer solutions. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2713–2727, 2016     

Suspended InAs Nanowire-Based Devices for Thermal Conductivity Measurement Using the 3<Emphasis Type="Italic">ω</Emphasis> Method

We demonstrated device architectures implementing suspended InAs nanowires for thermal conductivity measurements. To this aim, we exploited a fabrication protocol involving the use of a sacrificial layer. The relatively large aspect ratio of our nanostructures combined with their low electrical resistance allows to exploit the four-probe 3ω technique to measure the thermal conductivity, inducing electrical self-heating in the nanowire at frequency ω and measuring the voltage drop across the nanostructure at frequency 3ω. In our systems, field effect modulation of the transport properties can be achieved exploiting fabricated side-gate electrodes in combination with the SiO₂/Si?++?substrate acting as a back gate. Our device architectures can open new routes to the all-electrical investigation of thermal parameters in III-V semiconductor nanowires, with a potential impact on thermoelectric applications.     

Characteristics of a Graphene Nanoplatelet Anode in Advanced Lithium‐Ion Batteries Using Ionic Liquid Added by a Carbonate Electrolyte

A Cu‐supported, graphene nanoplatelet (GNP) electrodes are reported a as high performance anode in lithium ion battery. The electrode precursor is an easy‐to‐handle aqueous ink cast on cupper foil and following dried in air. The scanning electron microscopy evidences homogeneous, micrometric flakes‐like morphology. Electrochemical tests in conventional electrolyte reveal a capacity of about 450 mAh g⁻¹ over 300 cycles, delivered at a current rate as high as 740 mA g⁻¹. The graphene‐based electrode is characterized using a N‐butyl‐N‐methyl‐pyrrolidiniumbis (trifluoromethanesulfonyl) imide, lithium‐bis(trifluoromethanesulfonyl)imide (Py_1,4TFSI–LiTFSI) ionic liquid‐based solution added by ethylene carbonate (EC): dimethyl carbonate (DMC). The Li‐electrolyte interface is investigated by galvanostatic and potentiostatic techniques as well as by electrochemical impedance spectroscopy, in order to allow the use of the graphene‐nanoplatelets as anode in advanced lithium‐ion battery. Indeed, the electrode is coupled with a LiFePO₄ cathode in a battery having a relevant safety content, due to the ionic liquid‐based electrolyte that is characterized by an ionic conductivity of the order of 10⁻² S cm⁻¹, a transference number of 0.38 and a high electrochemical stability. The lithium ion battery delivers a capacity of the order of 150 mAh g⁻¹ with an efficiency approaching 100%, thus suggesting the suitability of GNPs anode for application in advanced configuration energy storage systems.     

Effect of functional groups on condensation and properties of sol–gel silica nanoparticles prepared by direct synthesis from organoalkoxysilanes

Silsesquioxane nanoparticles were synthesized from organotrialkoxysilanes in ethanol/water medium by a two-step hydrolysis–condensation process. Regular shaped spheres functionalized by vinyl, methyl, ethyl, phenyl, amyl, octyl, 3-aminopropyl groups were obtained, with sizes in the range 100–400 nm. The integrity of the organic functional groups and the condensation degree of the silsesquioxane networks were detected by multinuclear solid state Nuclear Magnetic Resonance (NMR). The nanoparticles thermal behavior was studied by thermogravimetric analyses, and N₂ sorption was used to measure the particles porosity. Coatings were obtained from particles suspensions by spin coating technique and the surface properties were studied by contact angle measurements. The emission of Rhodamine 6G doped nanoparticles was analyzed in the visible light region. The fluorescence experiments highlight the influence of the different matrices on amount of dye retained into the network and fluorescence intensity.     

Analysis of potential adulteration in herbal medicines and dietary supplements for the weight control by capillary electrophoresis

Four different phytopharmaceutical dosage forms for use in weight control programs were analyzed. Two different ground herbal blends and their correspondent infusions, a capsule and a tincture were investigated for the presence of compounds used as adulterants in these products. A capillary electrophoresis (CE) method was developed and validated. The optimized experimental conditions were: BGE, sodium tetraborate buffer 20 mM, pH 9.2, voltage applied 30 kV, capillary temperature 25 °C, injection sample at 0.5 Psi during 5 s. Ephedrine, norephedrine, caffeine and furosemide were baseline separated in less than 7 min; the migration times were found to be 2.65, 2.90, 3.75 and 6.58 min, respectively. The analysis showed in sample 3 concentrations of 0.45 ± 0.03 mg g⁻¹ (ephedrine), 0.33 ± 0.02 mg g⁻¹ (norephedrine), 1.09 ± 0.41 mg g⁻¹ (caffeine) and 0.80 ± 0.17 mg g⁻¹ (furosemide). Caffeine content in samples 1, 2 and 4 was 0.61 ± 0.06 mg g⁻¹, 15.66 ± 1.05 mg g⁻¹ and 2.27 ± 0.13 mg ml⁻¹, respectively. Linearity was obtained in the concentration range of 1–1000 μg ml⁻¹. Limits of detection (LOD) and quantification (LOQ) were determined as 0.42 μg ml⁻¹ and 1.40 μg ml⁻¹ (ephedrine), 0.47 μg ml⁻¹ and 1.40 μg ml⁻¹ (norephedrine), 0.12 μg ml⁻¹ and 0.48 μg ml⁻¹ (caffeine), 0.22 μg ml⁻¹ and 0.73 μg ml⁻¹ (furosemide).     

Determination of flavour loading in complex delivery systems by time‐domain NMR

The determination of the flavour content of a newly developed encapsulation system based on yeast was attempted using time‐domain NMR (TD‐NMR) and compared to thermo gravimetric analysis (TGA). Flavour content as measured by TD‐NMR is systematically higher than by TGA. The constant discrepancy between the two techniques is attributed to the presence of the phospholipidic membrane inside the yeast. These phospholipids also contribute to the NMR signal as was revealed by high field NMR studies under magic angle spinning conditions. The signal obtained for the empty yeast matched the extra‐contribution to the signal of the flavoured yeast encapsulation system. A classical glassy encapsulation system was used as a comparison to highlight further the presence of the phospholipids in the yeast system. A two step procedure is proposed to correct the reading of the flavoured yeast for the contribution of the yeast cells themselves. Practical applications : TD‐NMR is routinely used for the determination of the liquid content encapsulated in a solid matrix, where the liquid can be any oil, including lipids, or flavour and fragrance oils. As shown in the present study, in order to obtain accurate values of the oil loading, the nature of the carrier material of the encapsulation system must be taken into account. For example, with the conventional TD‐NMR method, flavour loading in encapsulation systems in yeast cells is systematically overestimated since the phospholipid bilayer contributes to the NMR signal of the flavour oil. With the two‐step procedure presented in this article, by subtracting the baseline value obtained for empty yeast cells, accurate loading values for yeast cell carriers can be determined. The modified testing approach is highly accurate and widely applicable to a variety of liquids including flavours, perfumes or nutritive fish oils encapsulated in solid delivery systems.     

Cyclopalladation of 2-tert-butyl-4,4-dimethyl-2-oxazoline in solution and on silica gel

Cyclopalladation of 2-tert-butyl-4,4-dimethyl-2-oxazoline (1) using Pd(OAc)₂ was performed in acetic acid and on silica gel. Treatment of the crude product formed in each reaction with LiCl afforded a dimeric cyclopalladated complex (4) in 76 and 93% yield, respectively. The ¹H, ¹³C{¹H} NMR and IR spectroscopy data for complex 4 confirmed the formation of the palladacycle with an (sp³)C–Pd bond and suggested the presence of two geometrical isomers in solution.     

Quality loss during the frozen storage of sea salmon (Pseudopercis semifasciata). Effect of rosemary (Rosmarinus officinalis L.) extract

Lipid and protein alterations during the frozen storage (−11 °C) were analyzed in minced sea salmon muscles to evaluate the effect of the application of rosemary extract (200 and 500 mg/kg). Lipid oxidation reached maximum TBA values between 3 and 4 months of storage in untreated muscles. The main polyunsaturated fatty acids affected were 22:6-ω3, 22:5-ω3 and 20:4-ω6 acids. Phospholipid hydrolysis was also detected. Rosemary extract reduced lipid oxidation for 6 months (500 mg/kg, muscle with 10.8 g/kg lipids) or 3 months (200 mg/kg, muscle with 5.3 g/kg lipids). Myofibrillar proteins showed a decrease of extractability (80%) after 2 months of storage. Myosin denaturation was evident by DSC at 3 months, while myosin and actin peaks disappeared at 6 months. A diminution of extractable polypeptides of high molecular weight was recorded by SDS-PAGE after 3 months. The available lysine content suffered a reduction starting at 3 months of storage, suggesting some interaction involving the free amino groups of lysine. Fluorescent compounds' determination did not show changes due to the interaction of lipid oxidation products and proteins, while protein alterations could not be reduced by the rosemary extract. Furthermore, the antioxidant reduced the loss of red color in the muscle.     

Chemical composition,antioxidant activity and anti‐lipase activity of Origanum vulgare and Lippia turbinata essential oils

This study reported the chemical composition, phenolic content, antioxidant and anti‐lipase activity of oregano and Lippia essential oils. The major compounds found in oregano essential oil were γ‐terpinene (32.10%), α‐terpinene (15.10%), p‐cymene (8.00%) and thymol (8.00%). In Lippia essential oil, α‐limonene (76.80%) and 1,8‐cineole (4.95%) represented the major compounds. Oregano essential oil had higher phenolic content (12.47 mg gallic acid mL^?1) and DPPH scavenging activity (IC₅₀ 0.357 μg mL^?1) than Lippia essential oil (7.94 mg gallic acid mL^?1 and IC₅₀ 0.400 μg mL^?1, respectively). Both essential oils had similar antioxidant indexes (about 1.2) determined by Rancimat. Moreover, oregano essential oil had also higher anti‐lipase activity (IC₅₀ 5.09 and 7.26 μg mL^?1). Higher phenolic content in the essential oils was related with higher scavenging and anti‐lipase activities. Oregano and Lippia essential oils could be used as natural antioxidants on food products.     

Lemur Tyrosine Kinases and Prostate Cancer: A Literature Review

The members of the Lemur Tyrosine Kinases (LMTK1-3) subfamily constitute a group of three membrane-anchored kinases. They are known to influence a wide variety of key cellular events, often affecting cell proliferation and apoptosis. They have been discovered to be involved in cancer, in that they impact various signalling pathways that influence cell proliferation, migration, and invasiveness. Notably, in the context of genome-wide association studies, one member of the LMTK family has been identified as a candidate gene which could contribute to the development of prostate cancer. In this review, of published literature, we present evidence on the role of LMTKs in human prostate cancer and model systems, focusing on the complex network of interacting partners involved in signalling cascades that are frequently activated in prostate cancer malignancy. We speculate that the modulators of LMTK enzyme expression and activity would be of high clinical relevance for the design of innovative prostate cancer treatment.