Essential rosemary oil protects testicular cells against DNA-damaging effects of H2O2 and DMNQ

Rosemary oil (RO) is popular in the Mediterranean region as a culinary additive which has the ability to protect delicate organs such as liver, brain and heart. We examined the effect of RO consumption on resistance of rat testicular cells (TCs) against DNA-damaging effects of the oxidative agents H₂O₂ and DMNQ and on the activity of the antioxidant enzymes glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD). DNA lesions were detected by conventional and modified comet assay and the activities of GSH-Px and SOD were measured spectrophotometrically. Since TCs represent a mixture of haploid, diploid and tetraploid cells, we used flow cytometry for their differentiation and calculation of DNA-damaging effects of H₂O₂ and DMNQ in cells of different ploidy. The results showed that the oxidative DNA lesions were significantly reduced in TCs from rats administered RO; however, the activity of antioxidant enzymes did not differ in TCs from control and RO-supplemented rats.     

Effects of Salvia officinalis and Thymus vulgaris on oxidant-induced DNA damage and antioxidant status in HepG2 cells

Salvia officinalis (SO) and Thymus vulgaris (TV) are medicinal plants well known for their curative powers. However, the molecular mechanisms responsible for these abilities of sage and thyme have not been fully understood yet. In this study we investigated the composition and the quantitative estimation of plant extracts, the protective effects of plant extracts against hydrogen peroxide- and 2,3-dimethoxy-1,4-naphthoquinone-induced DNA damage, and levels of enzymatic and non-enzymatic antioxidants (superoxide dismutase, glutathione peroxidase, glutathione) in human HepG2 cells. To measure antioxidative activity of plant extracts we used three assays: 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The results showed that the oxidant-induced DNA lesions were significantly reduced in cells pre-treated with the plant extracts studied. The observed DNA-protective activity could be explained by both elevation of GPx activity in cells pre-treated with SO and TV and antioxidant activity of SO and TV.     

Structural changes during sintering of powder of the metastable alloy Al-5% Cu prepared by centrifugal atomization of melt

The formation of liquid-phase interlayers between particles of rapidly cooled powder of the alloy Al-5% Cu during sintering was studied by the methods of complex thermal analysis and electron-scanning metallography. It was found that fluctuations of the chemical potential which arise as a result of the decomposition of the solid solution and excess grain-boundary energy drive the sintering process. Contact bridges between the particles are formed as a result of extrusion of melt to the particle surface during grain growth.     

Synthesis and Biological Evaluation of Pyrazoline and Pyrrolidine-2,5-dione Hybrids as Potential Antitumor Agents

In search of novel and effective antitumor agents, pyrazoline-substituted pyrrolidine-2,5-dione hybrids were designed, synthesized and evaluated in silico, in vitro and in vivo for anticancer efficacy. All the compounds exhibited remarkable cytotoxic effects in MCF7 and HT29 cells. The excellent antiproliferative activity toward MCF7 (IC₅₀=0.78±0.01 μM), HT29 (IC₅₀=0.92±0.15 μM) and K562 (IC₅₀=47.25±1.24 μM) cell lines, prompted us to further investigate the antitumor effects of the best compound S2 (1-(2-(3-(4-fluorophenyl)-5-(p-tolyl)-4,5-dihydro-1H-pyrazol-1-yl)-2-oxoethyl)pyrrolidine-2,5-dione). In cell-cycle analysis, S2 was found to disrupt the growth phases with increased cell population in G₁/G₀ phase and decreased cell population in G₂/M phase. The excellent in vitro effects were also supported by inhibition of anti-apoptotic protein Bcl-2. In vivo tumor regression studies of S2 in HT29 xenograft nude mice, exhibited equivalent and promising tumor regression with maximum TGI, 66 % (i. p. route) and 60 % (oral route) at 50 mg kg⁻¹ dose by both the routes, indicating oral bioavailability and antitumor efficacy. These findings advocate that hybridization of pyrazoline and pyrrolidine-2,5-dioes holds promise for the development of more potent and less toxic anticancer agents.     

A general correlation for the stagnation point Nusselt number of an axisymmetric impinging synthetic jet

Whereas the heat transfer mechanisms in steady impinging jets are well understood, the available knowledge of heat transfer to impinging synthetic jets remains inconsistent. This paper provides an objective comparison of the stagnation point heat transfer performance of axisymmetric impinging synthetic jets versus established steady jet correlations. Furthermore, a general correlation for the stagnation point Nusselt number is proposed including the effect of all appropriate scaling parameters: Reynolds number (500 ? Re ? 1500), jet-to-surface spacing (2 ? H/D ? 16) and stroke length (2 ? L₀/D ? 40). Based on the ratio of stroke length to jet-to-surface spacing L₀/H, four heat transfer regimes are identified.     

The effect of the liquid motion induced by air and vapor bubbles on heat transfer around a cylinder

This paper reports on a study into the effects of bubble-induced motion on heat transfer around a cylinder. Local heat flux due to vapor or air injected bubble motion is measured at different positions around a heated copper cylinder using a hot film technique as well as a heat flux sensor. The first set of experiments, carried out during the first stages of nucleate boiling, showed a dependence of the heat transfer on surface orientation. A similar conclusion was reached in the second set of experiments where the air bubbles were injected using an external source. Average heat flux values computed in the two cases on the upper part of the cylinder were shown to compare relatively well. Finally, the mechanisms involved in the heat transfer enhancement at the same location, on the upper part of the cylinder, in the two sets of experiments are described using a simultaneous analysis of the heat flux time-series and bubble motion.