Inclusion of Dy, Ho and Er in B sites of modified lead titanate

Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.     

Electron microscopy and microchemical analysis of cystic fibrosis diploid fibroblasts in vitro

Fibroblasts derived from cystic fibrosis homozygotes and heterozygotes were compared to normal fibroblasts topologically, ultrastructurally, and microchemically. Topological examinations, by means of scanning electron microscopy (SEM) revealed no significant differences between the 3 genotypes surveyed. The cells were generally flattened and/or fusiform structures that were more or less devoid of surface details. However, the dividing cells, in all of the populations surveyed, were found to have a more or less spherical configuration involving a highly complicated surface. The surface manifestations included blebs, ridges, and microvilli. Representative samples of the cells in all stages of growth, lag phase, exponential phase, and plateau phase, were surveyed in this study. Ultrastructurally, the fibroblasts of the 3 genotypes were found to have similar cytological detail. Highly infolded nuclei, distinct organelle components, and surface details, also seen in the SEM study, were observed. Numerous bundles of microfilaments were noted within the cytoplasm. Metachromatic granules were observed in cells from all 3 genotypes. Microchemical analysis, by means of energy dispersive X-ray analysis, demonstrated slight but recognizable differences in the elemental composition of the 3 genotypes. Of notable interest were the peak intensities of calcium and sulfur. The CF homozygous cells presented higher values for both of the elements when compared to the values observed in the CF heterozygous and normal cell populations. Although consistent differences could be observed in the CF genotypes when compared to the non-CF cells, no attempt was made to quantitate the concentrations of each of the elements within the cells.     

A multigranular linguistic content‐based recommendation model

Recommendation systems are a clear example of an e‐service that helps the users to find the most suitable products they are looking for, according to their preferences, among a vast quantity of information. These preferences are usually related to human perceptions because the customers express their needs, taste, and so forth to find a suitable product. The perceptions are better modeled by means of linguistic information due to the uncertainty involved in this type of information. In this article, we propose a content‐based recommendation model that will offer a more flexible context to improve the final recommendations where the preferences provided by the sources will be modeled by means of linguistic variables assessed in different linguistic term sets. The proposal consists of offering a multigranular linguistic context for expressing the preferences instead of forcing users to use a unique scale. Then the content‐based recommendation model will look for the most suitable product(s), comparing them with the customer(s) information according to its resemblance. © 2007 Wiley Periodicals, Inc. Int J Int Syst 22: 419–434, 2007.     

Antibacterial activity of silver-doped hydroxyapatite nanoparticles against gram-positive and gram-negative bacteria

Ag-doped nanocrystalline hydroxyapatite nanoparticles (Ag:HAp-NPs) (Ca_10-xAg_x(PO₄)₆(OH)₂, x_Ag = 0.05, 0.2, and 0.3) with antibacterial properties are of great interest in the development of new products. Coprecipitation method is a promising route for obtaining nanocrystalline Ag:HAp with antibacterial properties. X-ray diffraction identified HAp as an unique crystalline phase in each sample. The calculated lattice constants of a = b = 9.435 Å, c = 6.876 Å for x_Ag = 0.05, a = b = 9.443 Å, c = 6.875 Å for x_Ag = 0.2, and a = b = 9.445 Å, c = 6.877 Å for x_Ag = 0.3 are in good agreement with the standard of a = b = 9.418 Å, c = 6.884 Å (space group P6₃/m). The Fourier transform infrared and Raman spectra of the sintered HAp show the absorption bands characteristic to hydroxyapatite. The Ag:HAp nanoparticles are evaluated for their antibacterial activity against Staphylococcus aureus, Klebsiella pneumoniae, Providencia stuartii, Citrobacter freundii and Serratia marcescens. The results showed that the antibacterial activity of these materials, regardless of the sample types, was greatest against S. aureus, K. pneumoniae, P. stuartii, and C. freundii. The results of qualitative antibacterial tests revealed that the tested Ag:HAp-NPs had an important inhibitory activity on P. stuartii and C. freundii. The absorbance values measured at 490 nm of the P. stuartii and C. freundii in the presence of Ag:HAp-NPs decreased compared with those of organic solvent used (DMSO) for all the samples (x_Ag = 0.05, 0.2, and 0.3). Antibacterial activity increased with the increase of x_Ag in the samples. The Ag:HAp-NP concentration had little influence on the bacterial growth (P. stuartii).     

Stilbene levels and antioxidant activity of Vranec and Merlot wines from Macedonia: Effect of variety and enological practices

The content of the stilbenes trans-resveratrol and piceid as well as the antioxidant activity of Macedonian red wines from the two main grape varieties Vranec and Merlot have been evaluated. Тhe effects of time of maceration, type of yeast and the level of sulphur dioxide applied on stilbene content and antioxidant activity have been studied. The most important factor in winemaking technology is the maceration time since the highest concentrations of trans-resveratrol, piceid and highest antioxidant activity were found following 6 and 10 days of maceration. Concerning the yeast type, higher concentrations of trans-resveratrol and piceid have been obtained with French yeast “Levuline CHP” in comparison to Macedonian yeast “Vinalco”. In contrast, the higher antioxidant activity of wines from both varieties of grapes was observed by application of Macedonian yeast “Vinalco”.     

Atomic‐Scale Imaging and Quantification of Electrical Polarisation in Incommensurate Antiferroelectric Lanthanum‐Doped Lead Zirconate Titanate

Lanthanum doping of zirconium rich lead zirconate titanate gives rise to incommensurate, long‐period antiferroelectric structures. The structure of two stacking sequences in this incommensurate phase is determined using quantitative analysis of high‐resolution scanning transmission electron microscopy images, with the lead atom positions located with an exceptional precision of about 6 pm. This allows the estimation of local polarisation variations across the stacking units, and the polarisation varies in an approximately sinusoidal fashion along the stacking direction. The measured peak Pb atom displacements of about 28 pm and peak polarisation values of about 60 μC cm^?2 match extremely well to reported values for the commensurate antiferroelectric PbZrO₃ phase.     

PyACTS: A Python Based Interface to ACTS Tools and Parallel Scientific Applications

Many computational applications rely heavily on numerical linear algebra operations. A good number of these applications are data and computation intensive that need to run in high performance computing environments. The ACTS Collection brings robust and high-end software tools to the hands of application developers. However, this transfer of technology is not always successful due in part to the intricacy of the interfaces associated with the software tools. To alleviate this, here we present PyACTS, a set of Python based interfaces to some of the tools in the ACTS collection. We illustrate some examples of these interfaces and their performance, and evaluate not only their performance but also how user friendly they are compared to the original calls. We also present some examples of scientific applications that use PyACTS.     

ROS-Induced DNA-Damage and Autophagy in Oral Squamous Cell Carcinoma by Usnea barbata Oil Extract—An In Vitro Study

Oxidative stress is associated with aging, cancers, and numerous metabolic and chronic disorders, and phenolic compounds are well known for their health-promoting role due to their free-radical scavenging activity. These phytochemicals could also exhibit pro-oxidant effects. Due to its bioactive phenolic secondary metabolites, Usnea barbata (L.) Weber ex. F.H. Wigg (U. barbata) displays anticancer and antioxidant activities and has been used as a phytomedicine for thousands of years. The present work aims to analyze the properties of U. barbata extract in canola oil (UBO). The UBO cytotoxicity on oral squamous cell carcinoma (OSCC) CLS-354 cell line and blood cell cultures was explored through complex flow cytometry analyses regarding apoptosis, reactive oxygen species (ROS) levels, the enzymatic activity of caspase 3/7, cell cycle, nuclear shrinkage (NS), autophagy (A), and synthesis of deoxyribonucleic acid (DNA). All these studies were concomitantly performed on canola oil (CNO) to evidence the interaction of lichen metabolites with the constituents of this green solvent used for extraction. The obtained data evidenced that UBO inhibited CLS-354 oral cancer cell proliferation through ROS generation (316.67 × 10⁴), determining higher levels of nuclear shrinkage (40.12%), cell cycle arrest in G0/G1 (92.51%; G0 is the differentiation phase, while during G1 phase occurs preparation for cell division), DNA fragmentation (2.97%), and autophagy (62.98%) than in blood cells. At a substantially higher ROS level in blood cells (5250.00 × 10⁴), the processes that lead to cell death—NS (30.05%), cell cycle arrest in G0/G1 (86.30%), DNA fragmentation (0.72%), and autophagy (39.37%)—are considerably lower than in CLS-354 oral cancer cells. Our work reveals the ROS-mediated anticancer potential of UBO through DNA damage and autophagy. Moreover, the present study suggests that UBO pharmacological potential could result from the synergism between lichen secondary metabolites and canola oil phytoconstituents.