NMR of 89Y in T′-Phase La1.5 Y0.5CuO4

We report measurements of NMR spin-lattice (T ₁ ) and spin-spin (T ₂ ) relaxation times for ₈₉ Y in the parent structure of the electron–doped copper–oxide superconductors. T ₁ data exhibit non–exponential recovery with T ₁ 20 s. T ₂ decreases rapidly with temperature above the Néel temperature, but remains constant above 425 K. We discuss these behaviors by considering fluctuating antiferromagnetic spin clusters associated with oxygen defects.     

Rapid Determination of Trace Elements in Macedonian Grape Brandies for Their Characterization and Safety Evaluation

A graphite furnace atomic absorption spectrometry (GFAAS) was used for determination of trace elements (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in “rakija” samples, a grape brandy traditionally produced in Republic of Macedonia by distillation of grape pomace or wine, for characterization and safety evaluation. Cd, Pb, Cr, and Ni were determined directly, while Cu, Fe, Mn, and Zn were quantified after appropriate dilution. The calibration curves of all elements were linear with correlation coefficients (R ²) ranging from 0.9995 to 0.9998. The accuracy of the method was checked with a standard addition method showing good repeatability and reproducibility (relative standard deviation (RSD) <10 %). Relationship between several metal concentrations (Cu, Fe, Mn, Zn) in brandies and distillation system (homemade/industrial) on one side and aging mode (oak barrels/oak chips) on the other side were demonstrated. Two homemade brandies showed Cu, Fe, and Zn concentrations higher than industrial distillates and thus were found to be not safe for consumption because of Cu and Zn over the maximum allowed values. For the industrially produced brandies, Mn was identified to be a suitable marker related to aging with oak chips regardless variety, while Cu a marker for the influence of oak chip type. Principal component analysis applied on the content of elements clearly showed a good separation in terms of distillation and aging method.     

Black Phosphorus Nanoparticles Potentiate the Anticancer Effect of Oxaliplatin in Ovarian Cancer Cell Line

During the past few years, growing attention has been paid to black phosphorus (BP) and its unique optical, electrical, and catalytic properties. Furthermore, BP has proven to be biocompatible and biodegradable; qualities that present new opportunities for its utilization in the field of life sciences. However, despite all its suitable properties and applicability, its utilization in biomedicine is still in its infancy. This study reports on the synthesis of black phosphorus nanoparticles (BP NPs) and exploration of thier applicability in targeted drug delivery. BP NPs are loaded with platinum agents—cisplatin and oxaliplatin—and subjected to in vitro evaluation of targeted drug delivery. The BP NPs are not only able to load the investigated platinum derivatives on their surfaces, but also to transfer the therapeutic cargo to target specific tissue and to combine their effect with oxaliplatin, which leads to further potentiation of the anticancer effect.     

Syneresis and rheology mechanisms of a latex-HEUR associative thickener system

This study focuses on the phase behavior, rheology, and interactions of polymer latex particles and a hydrophobically modified ethoxylated urethane (HEUR) associative thickener in water. At constant 0.25 latex particle volume fraction, increasing HEUR caused stable, followed by phase separated (syneresis), and stable mixtures as HEUR concentration increased from 0% to 2.0% (by weight) in the latex-thickener aqueous mixture. The mixtures that underwent syneresis were flocculated. The relationship between the flocculation behavior and the composition of the latex-HEUR mixtures is consistent with previous work reported by other investigators. However, detailed rheological data on systems like these that have undergone syneresis have not been reported. This paper presents detailed viscosity vs shear rate data and correlates viscosity trends with the both flocculation and syneresis behavior. The stable latex-HEUR mixtures at low HEUR levels show Newtonian or shear-thinning viscosity with well-defined low-shear Newtonian plateaus. As HEUR level is increased to levels at which syneresis is observed, erratic rheological profiles with shear thinning as well as thickening are observed. This type of shear thickening has been attributed to bridging flocculation by other investigators. When HEUR level is further increased to levels at which no syneresis is observed, low-shear Newtonian plateaus re-appeared, albeit at higher viscosities. Detailed analysis of syneresis and shear-thickening behavior of a latex-HEUR mixture containing 0.5% (by weight) HEUR showed two shear-thickening regions, one between 0.1 and 0.5 s^?1 shear rate range and another between 30 and 100 s^?1 shear rate range. Molecular weight distribution (MWD) of the HEUR thickener indicates that the two shear-thickening regions are related to the bi-modal nature of the thickener’s MWD.     

Electrospun polyurethane membrane with Ag/ZnO microparticles as an antibacterial surface on polyurethane sheets

A method of antibacterial modification of the polyurethane (PU) surface is presented in this article. An electrospun PU membrane with an incorporated antibacterial agent was applied as a coating of the PU sheets. As an antibacterial agent, a hybrid bimetallic filler was used; it combined the antibacterial effects of silver and zinc oxide. With an electrospun submicrometer‐fiber membrane, the filler was uniformly and thinly applied on the PU surface by compression molding. The antibacterial activities of three filler concentrations were tested, and they demonstrated an effective antibacterial action against Staphylococcus aureus and Escherichia coli. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43020.     

Gender-related consequences of Internet use perceived by parents in a representative quota sample of adolescents

Only few studies have investigated gender differences in consequences of adolescent Internet use in a general population sample. In this study, we surveyed a representative German quota sample of N=1744 adolescents aged between 14 and 17 years and their caregivers with standardised questionnaires. Parents’ reports showed significant differences between male and female youth in 8 out of 10 problem areas (summarised in a ‘difficulties index’, Cronbach's alpha=0.89) caused by adolescent Internet use. According to parents’ assessment, male adolescents neglected school obligations and friendships outside the Internet more frequently than female adolescents. Compared to girls, boys spent more time and money using the Internet, regarded media use as more important, set wrong priorities in selecting online content, and rather ran into cost traps or legal consequences. More parents of boys than of girls observed adverse effects on adolescents’ physical and mental development. Both parents and adolescents consistently reported excessive media use more frequently for boys. By conducting a multiple linear regression analysis for the full sample, approximately one-third (34%) of the variance in the ‘difficulties index’ was explained by frequency of excessive Internet use. The results highlight the importance of gender-related analyses regarding the consequences of adolescent Internet use.     

Quantitative proteomics for investigating psychiatric disorders

The underlying pathophysiology of psychiatric disorders remains elusive. The use of quantitative proteomics to investigate disease-specific protein signatures holds great promise to improve the understanding of psychiatric disorders and identify relevant biomarkers. In this review, we discuss quantitative proteomic approaches for elucidating molecular mechanisms of psychiatric disorders, i.e. anxiety, schizophrenia, bipolar disorder and depression, by studying specimens from animal models and patients. We present gel-based, label-free and stable isotope-labeling methodologies and evaluate their strengths and limitations in the context of psychiatric research, with a focus on (15)N metabolic labeling of live animals due to its increased accuracy and potential for future applications. We also review biomarker candidate validation methods and present quantitative proteomic studies from the literature that aim to disentangle the molecular pathobiology of psychiatric disorders and identify candidate biomarkers. Finally, we explore the applicability of implementing proteomic methods as a routine diagnostic tool in the clinical laboratory.     

Qualitative detection of Mg content in a leaf of Hedera helix by using X-ray radiation from a laser plasma source

In this article, a method to reveal the presence of Mg content inside the different parts of leaves of Hedera helix is presented. In fact a sample of a Hedera helix's leaf, commonly characterized by a green and a white side, is analyzed under X-ray radiation. The presence of two zones with different colors in the Hedera helix's leaf has not been explained. In this connection, there are presently three hypotheses to explain the characteristic double-color appearance of the leaf. The first hypothesis suggests a different cytoplasmic inheritance of chloroplasts at the cell division, the second a different allelic composition, homozygote and heterozygote, between the two zones, and finally the third the action of a virus which changes the color properties in the Hedera's leaves. The resulting effect is a different content of "something" between the green and the white side. We utilized X-ray radiation, obtained from a plasma source with a Mg target, to image Hedera helix leaves and we found that the green side of the leaf is highlighted. We may suppose that the reason why the X-rays from a Mg plasma source, allow us to pick up the green side is probably due to the greater presence of the amount of Mg (from chlorophyll or other complexes and/or salts) in the two sides, green and white, of the leaf.