Photocatalytic degradation of C.I. Acid Orange 7 by TiO2 nanoparticles immobilized onto/into chitosan‐based hydrogel

Photocatalytic degradation of dye C.I. Acid Orange 7 in aqueous solution using TiO₂/hydrogel nanocomposite under solar light simulating source was studied. Hydrogel based on chitosan, itaconic and methacrylic acid was modified with colloidal TiO₂ nanoparticles synthetized by acidic hydrolysis of TiCl₄ and commercial Degussa P25 TiO₂ nanoparticles. SEM/EDX analysis confirmed the presence of TiO₂ nanoparticles onto/into hydrogel. It was found that both types of photocatalysts efficiently removed the dye from solution, but sorption rates and photodegradation efficiency were higher in the case of colloidal TiO₂ nanoparticles. They ensured complete discoloration of dye solution. The efficiency of the reused TiO₂/hydrogel nanocomposite showed that photodegradation activity was maintained at satisfactory level after three repeated cycles of illumination. POLYM. COMPOS., 35:806–815, 2014. © 2013 Society of Plastics Engineers     

Platinum-free counter electrodes of plasma-modified hybrid nanomaterials for dye-sensitised solar cells

Molybdenum disulphide (MoS₂) nanotube and tungsten oxide (W₁₈O₄₉) nanowire were coated with poly(3-hexylthiophene) (P3HT) and poly(3,4-ethylenedioxythiophene) (PEDOT) by a radio frequency (RF: 13.56?MHz)-rotating plasma-modification method as alternative counter electrodes for dye-sensitised solar cells (DSSCs). Surface analysis showed the homogenous plasma nanocoating of inorganic nanostructures by P3HT and PEDOT. It was demonstrated that the plasma-modified hybrid platinum-free counter electrodes increased the efficiencies of the DSSCs. The DSSCs based on hybrid nanostructure materials showed a short circuit current density of 9.49, 7.95, 2.59 and 2.57?mAcm^?2 for MoS₂/P3HT, MoS₂/PEDOT, W₁₈O₄₉/PEDOT and W₁₈O₄₉/P3HT samples, respectively. The plasma nanocoating with the nanostructured materials approach for obtaining hybrid counter electrodes in the photovoltaic action shows an alternative route towards cost-effective, green energy conversion.     

May Staphylococcus lugdunensis Be an Etiological Factor of Chronic Maxillary Sinuses Infection?

Staphylococcus lugdunensis is an opportunistic pathogen found in the healthy human skin microbiome bacterial community that is able to cause infections of diverse localization, manifestation, and course, including laryngological infections, such as necrotizing sinusitis. Chronic maxillary sinusitis is a disease present in up to one third of European and American populations, and its etiology is not fully described. Within this study, we aimed to characterize 18 S. lugdunensis strains recovered from maxillary sinuses and evaluate them as etiological agents of chronic disease. We performed MLST analysis, the complex analysis of both phenotypic and genetic virulence factors, antibiotic susceptibility profiles, and biofilm formation assay for the detection of biofilm-associated genes. Altogether, S. lugdunensis strains were clustered into eight different STs, and we demonstrated several virulence factors associated with the chronic disease. All tested strains were able to produce biofilm in vitro with numerous strains with a very strong ability, and overall, they were mostly susceptible to antibiotics, although we found resistance to fosfomycin, erythromycin, and clindamycin in several strains. We believe that further in-depth analysis of S. lugdunensis strains from different niches, including the nasal one, should be performed in the future in order to reduce infection rate and broaden the knowledge about this opportunistic pathogen that is gaining attention.     

Parental attachment, parental control, and early development of alcohol use: A longitudinal study.

The authors explored the predictive influence of both parental attachment and parental control on early onset of alcohol consumption in adolescence by use of a longitudinal sample of 1,012 young adolescents. Whether the relationship between parental control and adolescents' drinking is moderated by parental attachment was also examined. Consistent with other studies, attachment and strict control were cross-sectionally related to adolescents' alcohol use at all 3 measurements. However, the longitudinal results of structural equation modeling analyses suggest that a good attachment relationship between parent and child does not prevent adolescents from drinking. In addition, strict control was related to lower engagement in alcohol use. Furthermore, with regard to the moderating effect, parental attachment did not moderate longitudinally the association between parental control and an early development of alcohol use. Implications for further research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of music and lyrics on personality.

An experiment tested whether music can produce significant changes in the experience of one's own personality traits under laboratory conditions. Participants were 87 first-year undergraduates at a large Canadian university (58 women and 29 men; mean age = 18.3 years). After completing a set of questionnaires including the Big Five Inventory, they were divided into 3 groups: the music-and-lyrics group listened to a classical song while reading the English translation of lyrics, the music-only group listened to a classical song and followed along the text of lyrics in German, and the lyrics-only group listened to the English translation of the lyrics, while following its text as well. Participants were then readministered the Big Five Inventory within another set of questionnaires. The results show that music produced significant increases, and lyrics significant decreases, in the short-term self-reported experience of change of one's personality traits. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Reinforcement Learning in the Multi-Robot Domain

This paper describes a formulation of reinforcement learning that enables learning in noisy, dynamic environments such as in the complex concurrent multi-robot learning domain. The methodology involves minimizing the learning space through the use of behaviors and conditions, and dealing with the credit assignment problem through shaped reinforcement in the form of heterogeneous reinforcement functions and progress estimators. We experimentally validate the approach on a group of four mobile robots learning a foraging task.     

MoxWx–1S2 Nanotubes for Advanced Field Emission Application

Transition metal dichalcogenide (TMDC) nanotubes complement the field of low-dimensional materials with their quasi-1D morphology and a wide set of intriguing properties. By introducing different transition metals into the crystal structure, their properties can be tailored for specific purpose and applications. Herein, the characterization and a subsequent preparation of single-nanotube field emission devices of Mo_xW_x-1S₂ nanotubes prepared via the chemical vapor transport reaction is presented. Energy-dispersive X-ray spectroscopy, Raman spectroscopy, and X-ray diffraction  indicate that the molybdenum and tungsten atoms are randomly distributed within the crystal structure and that the material is highly crystalline. High resolution transmission electron microscopy  and electron diffraction (ED) patterns further corroborate these findings. A detailed analysis of the ED patterns from an eight-layer nanotube reveal that the nanotubes grow in the 2H structure, with each shell consists of one bilayer. The work function of the nanotubes is comparable to that of pure MoS₂ and lower of pure WS₂ NTs, making them ideal candidates for field emission applications. Two devices with different geometrical setup are prepared and tested as field emitters, showing promising results for single nanotube field emission applications.     

Physiologically-Based Pharmacokinetic Modeling of the Postbiotic Supplement Urolithin A Predicts its Bioavailability Is Orders of Magnitude Lower than Concentrations that Induce Toxicity,but also Neuroprotective Effects

Scope

A range of health benefits are attributed to consuming urolithin A (UA), such as improved muscle health, anti-aging activity, and neuroprotection, whereas few studies raise possible adverse effects at high doses, including genotoxicity and estrogenic effects. Therefore, understanding UA bioactivity and safety depends on its pharmacokinetics. However, there is no physiologically-based pharmacokinetic (PBPK) model available for UA, thus limiting reliable assessment of effects observed from in vitro experimentation.

Methods and results

We characterizes glucuronidation rates of UA by human S9 fractions. Partitioning and other physicochemical parameters are predicted using quantitative structure–activity relationship tools. Solubility and dissolution kinetics are determined experimentally. These parameters are used to construct a PBPK model, and results are compared with data from human intervention studies. We evaluates how different supplementation scenarios may influence UA plasma and tissue concentrations. Concentrations at which either toxic or beneficial effects are previously observed in vitro appear unlikely to be achieved in vivo.

Conclusion

A first PBPK model for UA is established. It enables prediction of systemic UA concentrations and is critical for extrapolating in vitro results to in vivo uses. Results support the safety of UA, but also challenge the potential for readily achieving beneficial effects by postbiotic supplementation.