Effects of social support and personality on emotional disclosure on Facebook and in real life

This paper focuses on the roles of personality and social support in affecting the extent of emotional disclosure in social media (SM) and compares them to those in face-to-face encounters. Specifically, we consider the effects of the Big Five personality traits and perceptions of social support from friends, significant others, and family on the extent of sharing positive and negative emotions on Facebook (FB) vs. real life (RL). The data are collected via an online survey of a broad demographic range of FB users. Our findings suggest that certain personality traits (extroversion, agreeableness, and conscientiousness), as well as perceived social support from friends, are significantly related to the disclosure of positive emotions on FB. We also report and discuss the differences between drivers of emotional disclosure in SM and RL, as well as offer suggestions for future research.     

Nanobiosensors based on individual olfactory receptors

The animal olfactory system represents the gold standard of biosensors, due to its ability to identify and discriminate thousands of odorant compounds with very low thresholds. Using olfactory receptors (ORs) as sensing elements instead of chemical sensors, biosensors would benefit the naturally optimized molecular recognition of odorants to develop a new generation of bioelectronic noses. The purpose of SPOT-NOSED European project was the development of nanobiosensors based on single ORs anchored between nanoelectrodes, to mimic the performances of natural olfactory system. Nanobiosensors arrays could then increase odorant sensitivity or widen the odorant detection spectrum. ORs were expressed in yeasts plasmic membrane, and their functionality tested in whole yeasts. Then, nanosomes bearing the ORs were prepared from S. cerevisiae, and Surface Plasmon Resonance was performed on nanosomes for quantitative evaluation of OR response to odorant stimulation. ORs retain full activity and discrimination power in immobilized nanosomes, thus allowing their use in the fabrication of the nanobiosensors. Nanoelectrodes were fabricated using conventional photolithography and focused ion beam milling, with sizes in adequation with the nanosomes. ORs borne by nanosomes were specifically immobilized onto conducting substrates via mixed Self Assembled Monolayers, neutravidin and specific antibody to the ORs. The process was optimized by microcontact printing, and the anchored nanovesicles visualized by Atomic Force Microscopy. A transimpedance preamplifier suited for low-noise wide-bandwidth measurements was designed to be directly connected to the nanoelectrodes. Electrochemical Impedancemetric Spectroscopy detected significant changes upon electrodes functionalization, grafting of ORs carried by nanosomes, and ORs conformational change induced by odorant binding.     

Use of Desulfovibrio and Escherichia coli Pd‐nanocatalysts in reduction of Cr(VI) and hydrogenolytic dehalogenation of polychlorinated biphenyls and used transformer oil

BACKGROUND: Desulfovibrio spp. biofabricate metallic nanoparticles (e.g. ‘Bio‐Pd’) which catalyse the reduction of Cr(VI) to Cr(III) and dehalogenate polychlorinated biphenyls (PCBs). Desulfovibrio spp. are anaerobic and produce H₂S, a potent catalyst poison, whereas Escherichia coli can be pre‐grown aerobically to high density, has well defined molecular tools, and also makes catalytically‐active ‘Bio‐Pd’. The first aim was to compare ‘Bio‐Pd’ catalysts made by Desulfovibrio spp. and E. coli using suspended and immobilized catalysts. The second aim was to evaluate the potential for Bio‐Pd‐mediated dehalogenation of PCBs in used transformer oils, which preclude recovery and re‐use. RESULTS: Catalysis via Bio‐Pd_{D.desulfuricans} and Bio‐Pd_E.coli was compared at a mass loading of Pd:biomass of 1:3 via reduction of Cr(VI) in aqueous solution (immobilized catalyst) and hydrogenolytic release of Cl^? from PCBs and used transformer oil (catalyst suspensions). In both cases Bio‐Pd_{D.desulfuricans} outperformed Bio‐Pd_E.coli by ～3.5‐fold, attributable to a ～3.5‐fold difference in their Pd‐nanoparticle surface areas determined by magnetic measurements (Bio‐Pd_{D.desulfuricans}) and by chemisorption analysis (Bio‐Pd_E.coli). Small Pd particles were confirmed on D. desulfuricans and fewer, larger ones on E. coli via electron microscopy. Bio‐Pd_{D.desulfuricans}‐mediated chloride release from used transformer oil (5.6 ± 0.8 µg mL^?1) was comparable with that observed using several PCB reference materials. CONCLUSIONS: At a loading of 1:3 Pd:biomass Bio‐Pd_{D.desulfuricans} is 3.5‐fold more active than Bio‐Pd_E.coli, attributable to the relative catalyst surface areas reflected in the smaller nanoparticle sizes of the former. This study also shows the potential of Bio‐Pd_{D.desulfuricans} to remediate used transformer oil. Copyright © 2012 Society of Chemical Industry     

Microscopic evaluation of vesicles shed by erythrocytes at elevated temperatures

The images of human erythrocytes and vesicles were analyzed by a light microscopy system with spatial resolution of better than 90 nm. The samples were observed in an aqueous environment and required no freezing, dehydration, staining, shadowing, marking, or any other manipulation. Temperature elevation resulted in significant concentration increase of structurally transformed erythrocytes (echinocytes) and vesicles in the blood. The process of vesicle separation from spiculated erythrocytes was video recorded in real time. At a temperature of 37°C, mean vesicle concentrations and diameters were found to be 1.50 ± 0.35 × 10⁶ vesicles per microliter and 0.365 ± 0.065 μm, respectively. The vesicle concentration increased approximately threefold as the temperature increased from 37 to 40°C. It was estimated that 80% of all vesicles found in the blood are smaller than 0.4 μm. Accurate account of vesicle numbers and dimensions suggest that 86% of the lost erythrocyte material is lost not by vesiculation but by another, as yet, unknown mechanism. Microsc. Res. Tech. 76:1163–1170, 2013. © 2013 Wiley Periodicals, Inc.     

Impact of processing of red beet on betalain content and antioxidant activity

Red beet has high concentration betalains that are used as food colorants and food additives due to their health promoting properties. Redbeet is generally processed before consumption which influences the stability of betalains in turn which affects the acceptability and health properties. The objective of the study was to investigate the influence of processing techniques as microwaving, boiling, roasting and vacuuming on the red beet. The impact of processing was evaluated on the basis of belatains content and antioxidant activity of the processed samples. With spectrophotometric results betalains content were found to add up to 20% with vacuum treatment and also with microwave treatment of 900 W and 1800 W for 30 s up to7% and 19% respectively, however there was decrease in boiling and roasting treatments. With HPLC analyses the content of betanin seems to increase in microwave treatments with 450 W and 900 W but reduced with 1800 W. In the case of antioxidant activity there was 2 to 3 fold increase in boiling, roasting and microwave treatments as compared to the control.     

Surface modification of silver microparticles with 4-thioaniline

Silver microparticles have been prepared by chemical reduction method onto a rotating copper disc. It was found that in the presence of polyvinylpyrrolidone (PVP) in the initial AgNO₃ aqueous solution the radius of the Ag particles decreased from 1.18 to 0.48 μm and the formation of dendritic clusters with the fractal dimension of 1.61 occurred. The two-stage modification of the surface of synthesized silver particles with bifunctional 4-thioaniline (TAn) and further grafting of polyaniline (PAn) chains to the end amino-group of formed self-assembled surface layer were carried out. The modified surfaces were studied by scanning electron microscopy and X-ray diffraction methods, the physico-chemical properties of the formed products have been investigated. The obtained results indicate that the highest thermal stability is displayed by the silver particles produced in the presence of PVP, while the sample with grafted polyaniline exhibits the lowest thermal stability among the investigated samples. The reactivity of TAn has been examined by cyclic voltammetric method. In contrast to aniline, the electrochemical oxidation of TAn did not result in the formation of an electroconductive film on Pt electrode. It was found that oxidative condensation of aniline is suppresses by the TAn: when the molar ratio of aniline/TAn is 2:1 the formation of an electrochemically active product is stopped. The phenomenon of inhibition of the oxidative polymerization of aniline with TAn is related to an impossibility of growing of polymeric chains in the result of the “head-to-tail” type of bonding of the thioaniline links.     

Application of passive radiative cooling for dew condensation

Dew water was collected from several passive foil-based radiative condensers established in a variety of geographic settings: continental (Grenoble, in an alpine valley, and Brive-la-Gaillarde, in the Central Massif volcanic area, both in France), French Atlantic coast (Bordeaux), eastern Mediterranean (Jerusalem, Israel), and the island of Corsica (Ajaccio, France) in the Mediterranean Sea. In Ajaccio two large 30 m² condensers have been operating since 2000. Additional semi-quantitative dew measurements were also carried out for Komi?a, island of Vis (Croatia) in the Adriatic Sea, and in Mediterranean Zadar and Dubrovnik (both in Croatia). Dew potential was calculated for the Pacific Ocean island of Tahiti (French Polynesia). The data show that significant amounts of dew water can be collected. Selected chemical and biological analyses established that dew is, in general, potable. Continued research is required for new and inexpensive materials that can enhance dew condensation.     

Controlling the Self‐Assembly of Periodic Defect Patterns in Smectic Liquid Crystal Films with Electric Fields

Large‐area periodic defect patterns are produced in smectic A liquid crystals confined between rigid plate electrodes that impose conflicting parallel and normal anchoring conditions, inducing the formation of topological defects. Highly oriented stripe patterns are created in samples thinner than 2 μm due to self‐assembly of linear defect domains with period smaller than 4 μm, whereas hexagonal lattices of focal conic domains appear for thicker samples. The pattern type (1d/2d) and period can be controlled at the nematic–smectic phase transition by applying an electric field, which confines the defect domains to a thin surface layer with thickness comparable to the nematic coherence length. The pattern morphology persists in the smectic phase even after varying the field or switching it off. Bistable, non‐equilibrium patterns are stabilized by topological constraints of the smectic phase that hinder the rearrangement of defects in response to field variations.     

Laser-induced self-organization of nano-wires on SiO2/Si interface

Original observation of new graded band gap structures formed on the surface of elementary Si semiconductor at studying the optical properties of Si nano-hills formed at the SiO₂/Si interface by pulsed Nd:YAG laser irradiation is reported. The self-organized nano-hills on Si surface are characterized by a strong photoluminescence in the visible range of spectrum with a shoulder extended to the long-wave part of the spectrum. The feature is explained by the quantum confinement effect in nano-hills-nano-wires of gradually changing diameter.     

Novel magnetite-silica nanocomposite (Fe3O4-SBA-15) particles for DNA binding and gene delivery aided by a magnet array

Novel magnetite-silica nanocomposite particles were prepared using SBA-15 nanoporous silica as template. Magnetite nanoparticles were impregnated into the nanopore array of the silica template through thermal decomposition of iron(III) acetylacetonate, Fe(AcAc)3 at 200 degrees C. These composite particles were characterized using TEM, XRD and SQUID magnetometry. The TEM images showed that the size of composite particles was around 500 nm and the particles retained the nanoporous array of SBA-15. The formation of magnetite nanoparticles was confirmed by the powder XRD study. These composite particles also exhibited ferrimagnetic properties. By coating with short chain polyethyleneimine (PEI), these particles are capable of binding DNA molecules for gene delivery and transfection. With an external magnetic field, the transfection efficiency was shown to have an increase of around 15%. The results indicated that these composite nanoparticles may be further developed as a new tool for nanomagnetic gene transfection.