High-rate low-temperature dc pulsed magnetron sputtering of photocatalytic TiO2 films: the effect of repetition frequency

The article reports on low-temperature high-rate sputtering of hydrophilic transparent TiO₂ thin films using dc dual magnetron (DM) sputtering in Ar + O₂ mixture on unheated glass substrates. The DM was operated in a bipolar asymmetric mode and was equipped with Ti(99.5) targets of 50 mm in diameter. The substrate surface temperature T_surf measured by a thermostrip was less than 180 °C for all experiments. The effect of the repetition frequency f_r was investigated in detail. It was found that the increase of f_r from 100 to 350 kHz leads to (a) an improvement of the efficiency of the deposition process that results in a significant increase of the deposition rate a_D of sputtered TiO₂ films and (b) a decrease of peak pulse voltage and sustaining of the magnetron discharge at higher target power densities. It was demonstrated that several hundreds nm thick hydrophilic TiO₂ films can be sputtered on unheated glass substrates at a_D = 80 nm/min, T_surf < 180 °C when high value of f_r = 350 kHz was used. Properties of a thin hydrophilic TiO₂ film deposited on a polycarbonate substrate are given.     

Nonlocal exchange interaction removes half-metallicity in graphene nanoribbons

Band gap studies of zigzag-edge graphene ribbons are presented. While earlier calculations at LDA level show that zigzag-edge graphene ribbons become half-metallic when cross-ribbon electric fields are applied, our calculations with hybrid density functional demonstrate that finite graphene ribbons behave as half-semiconductors. The spin-dependent band gap can be changed in a wide range, making possible many applications in spintronics.     

Enrichment of words by visual images: Books, slides, and videos.

This article reviews additions to 3 ways of visually enriching verbal accounts of the history of psychology: illustrated books, slides, and videos. Although each approach has its limitations and its merits, taken together they constitute a significant addition to the printed word. As such, they broaden the toolkits of both the learners and the teachers of the history of psychology. Reference is also made to 3 earlier publications. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behaviour of Titanium Dioxide Particles in Artificial Body Fluids and Human Blood Plasma

The growing application of materials containing TiO₂ particles has led to an increased risk of human exposure, while a gap in knowledge about the possible adverse effects of TiO₂ still exists. In this work, TiO₂ particles of rutile, anatase, and their commercial mixture were exposed to various environments, including simulated gastric fluids and human blood plasma (both representing in vivo conditions), and media used in in vitro experiments. Simulated body fluids of different compositions, ionic strengths, and pH were used, and the impact of the absence or presence of chosen enzymes was investigated. The physicochemical properties and agglomeration of TiO₂ in these media were determined. The time dependent agglomeration of TiO₂ related to the type of TiO₂, and mainly to the type and composition of the environment that was observed. The presence of enzymes either prevented or promoted TiO₂ agglomeration. TiO₂ was also observed to exhibit concentration-dependent cytotoxicity. This knowledge about TiO₂ behavior in all the abovementioned environments is critical when TiO₂ safety is considered, especially with respect to the significant impact of the presence of proteins and size-related cytotoxicity.     

VIS absorption spectrophotometry of disperse dyes

In the investigations of the dyeing processes, the low solubility of disperse dyes in water represents a practical problem for the determination of dye concentration in dyebaths and waste waters. Therefore the use of an organic solvent which, dissolves disperse dyes, is recommended in visible spectrophotometry of disperse dyes. Three organic solvents (ethanol, N,N-dimethylformamide, acetone) and two disperse dyes, the disazo dye C.I. Disperse Orange 29 and the anthraquinone dye C.I. Disperse Blue 56, were used for spectroscopic analysis in this present work. The absorbance of aqueous dye dispersions and various organic solvent dye solutions was measured to evaluate the effect of the solvent on the shape and intensity of the absorption spectra and on the wavelength shift of maximum absorption. The validity of Beer–Lambert’s law in each system was ascertained. A suggestion is made how VIS absorption spectrophotometry can be used to determine the dye concentration in disperse dyebaths. The addition of organic solvent to the dyebath leads to dye dissolution, and the Beer-Lambert’s law is then fulfilled. The optimum ratio between the dyebath dispersion and the organic solvents for the dyes investigated is also determined.     

Atmospheric corrosion inhibitors for copperin the electronics industry

Inhibiting efficiencies of various imidazole derivatives on atmospheric corrosion of copper on printed circuit boards were investigated. Experiments were carried out on double sided copper boards using a procedure based on international standards and applied in the electronics industry. Electrochemical measurements were performed on copper in solutions containing imidazole derivatives, under stationary and flow conditions. The influence of flow velocity and temperature on the inhibiting characteristics was investigated. The imidazole derivatives studied have good inhibiting properties for copper against atmospheric corrosion.     

Biodiesel from rapeseed oil,methanol and KOH. 3. Analysis of composition of actual reaction mixture

Detailed analysis is described of the samples taken after suitable reaction times from the actual reaction mixture during the production of biodiesel fuel using methanolysis of rapeseed oil catalyzed by KOH. Three methods for stoppage of reaction (neutralisation of catalyst, dilution by two suitable solvents) in the sample are used. The contents of mono‐, di‐ and triacylglycerols, methylesters of fatty acids (biodiesel) and potassium salts of fatty acids of rapeseed oil, glycerol (by HPLC method), basicity (by potentiometric titration) and water (by GC and Karl‐Fischer method) in the samples are determined. An example of these determinations is described.     

Molecular Consequences of Depression Treatment: A Potential In Vitro Mechanism for Antidepressants-Induced Reprotoxic Side Effects

The incidence of depression among humans is growing worldwide, and so is the use of antidepressants. However, our fundamental understanding regarding the mechanisms by which these drugs function and their off-target effects against human sexuality remains poorly defined. The present study aimed to determine their differential toxicity on mouse spermatogenic cells and provide mechanistic data of cell-specific response to antidepressant and neuroleptic drug treatment. To directly test reprotoxicity, the spermatogenic cells (GC-1 spg and GC-2 spd cells) were incubated for 48 and 96 h with amitriptyline (hydrochloride) (AMI), escitalopram (ESC), fluoxetine (hydrochloride) (FLU), imipramine (hydrochloride) (IMI), mirtazapine (MIR), olanzapine (OLZ), reboxetine (mesylate) (REB), and venlafaxine (hydrochloride) (VEN), and several cellular and biochemical features were assessed. Obtained results reveal that all investigated substances showed considerable reprotoxic potency leading to micronuclei formation, which, in turn, resulted in upregulation of telomeric binding factor (TRF1/TRF2) protein expression. The TRF-based response was strictly dependent on p53/p21 signaling and was followed by irreversible G2/M cell cycle arrest and finally initiation of apoptotic cell death. In conclusion, our findings suggest that antidepressants promote a telomere-focused DNA damage response in germ cell lines, which broadens the established view of antidepressants’ and neuroleptic drugs’ toxicity and points to the need for further research in this topic with the use of in vivo models and human samples.