Synthesis, cytotoxicity, and COMPARE analysis of ferrocene and [3]ferrocenophane tetrasubstituted olefin derivatives against human cancer cells

Herein we report the antiproliferative effects of a series of 28 compounds against the MDA-MB-231 breast cancer cell line, including the synthesis of seven new [3]ferrocenophanyl and four new ferrocenyl compounds. For each p-R-phenyl substitution pattern investigated, the [3]ferrocenophanyl derivatives were more cytotoxic than the corresponding ferrocenyl derivative, with the highest activity found for compounds with protic substituents. Theoretical calculations of the HOMO-LUMO gap for the molecules in the Fe3(+) oxidation state suggest a higher reactivity for the [3]ferrocenophanyl derivatives. A lead compound from each series, a [3]ferrocenophanyl and a ferrocenyl compound, possessing two phenol groups, were screened against the NCI/DTP 60-cell-line panel. The mean activity over all cell lines was better than cisplatin for both compounds, and both compounds showed subpanel selectivity for leukemia, CNS cancer, and renal cancer. Low systemic toxicity and lack of interaction with DNA (when in the reduced form), suggest that the compounds may act as prodrugs.     

Modification of the fat composition of the Iberian pig using Bacillus licheniformis and Bacillus subtilis

The aim of this work was to study the influence of a diet with probiotic bacteria on the lipid composition of different tissues from Iberian pigs. Cholesterol and fatty acid profiles were measured in liver, subcutaneous fat, and Serratus ventralis muscle samples. Feeding Iberian pigs a mixture of probiotic microorganisms for 45 days prior to slaughter affected the tissue composition. The feeds of the control and probiotic groups were identical except for the added Bacillus licheniformis and Bacillus subtilis (1.28 × 10⁹ cfu/kg feed) in the feed of the probiotic group. The diet with probiotics significantly affected the fatty acid profile of liver, subcutaneous fat and Serratus ventralis muscle samples, but no significant differences were found for the cholesterol content. The livers of the probiotic group contained lower levels of n‐6 fatty acids and higher levels of n‐3 fatty acids. The subcutaneous fat contained lower levels of n‐6 fatty acids. Serratus ventralis muscles from the probiotic group contained a significantly higher percentage of oleic acid than those of the control group. Practical applications: This study deals with the effect of the addition of probiotic bacteria to the diet of pigs on both the cholesterol and fatty acid content. B. subtilis and B. licheniformis can be used in pig feed (Regulation EC no. 2148/2004), but there are no studies about their effects on fresh meat or other tissues, particularly regarding the fat composition. Thus, it is interesting to study how feeding these microorganisms affects the different tissues. Including these microorganisms in the basic diet could serve as a strategy to modify the fat composition and to obtain healthier products from pigs.     

Relationship between structure and rheological,mechanical and thermal properties of polylactide/Cloisite 30B nanocomposites

Melt‐state and solid state mechanical properties and thermal stability of polylactide layered silicate nanocomposites elaborated by melt intercalation were studied as a function of clay content. Wide angle X‐ray scattering results, transmission electron microscopy observations, and rheological measurements indicated that the clay was finely distributed in the polylactide matrix. Contrary to nonlinear mechanical properties, thermal and linear mechanical properties were shown to increase with increasing clay fraction. The nanoindentation measurements confirm the significant increase of linear mechanical properties previously observed by tensile tests. The good correlation of linear mechanical properties at the macrometric and nanometric scales is explained by the high dispersion degree of the nanofiller in the biodegradable polymer matrix. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Enhanced nanofluidization by alternating electric fields

We show experimental results on a proposed technique to enhance the fluidization of nanoparticle beds. This technique consists of the application of an alternating electric field to the nanofluidized bed. Three different field configurations have been tested: co‐flow field, cross‐flow field, and variable field configurations. Nanoparticle agglomerates are naturally charged by contact and tribo charging mechanisms and therefore are agitated by the action of the externally applied field, which enhance fluidization. According to our observations, the best results are obtained for the variable field configuration. In this configuration, the electric field strength is higher at the bottom of the bed, whereas it is almost negligible at the free surface. Thus, the larger agglomerates, which tend to sink at the bottom of the bed due to stratification, and usually impede uniform fluidization, are strongly agitated. It is thought that the strong agitation of the bigger agglomerates that usually sink to the bottom of the bed contributes to further homogenize the distribution of the gas flow within the bed by destabilizing the development of gas channels close to the gas distributor. On the other hand, the smaller agglomerates at the vicinity of the free surface are just weakly excited. Consequently, fluidization is greatly enhanced, whereas at the same time excessive elutriation is avoided. It is demonstrated that this technique is even suitable to achieve highly expanded fluidization of unsieved nanopowder samples even though the fluidization state returns to be heterogeneous upon the electric field being turned off. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

Reactive Commercial Ni/Al Nanolayers for Joining Lightweight Alloys

Reactive nanoscale multilayer foils for use in joining techniques have attracted a great deal of attention. A common feature of these nanolayers is the large amount of heat released during the reaction between the layers to form a new phase. In this study, films of alternated Ni and Al nanolayers (NanoFoil^® made by the Indium Corporation) with period (bilayer thickness) close to 54 nm and with a thickness of 60 μm were used as local heat sources to bond lightweight alloys. The as-deposited Ni and Al alternated nanolayers evolve into NiAl nanometric grains when the multilayer, ignited by an electrical discharge, reacts. Joining of lightweight alloys was performed at room temperature under pressures of 10-80 MPa. The ability of the nanolayers to join these alloys by high temperature diffusion bonding was also investigated. The microstructural and chemical characterizations of the interfaces were performed on cross-sections of the joints by scanning electron microscopy and energy dispersive x-ray spectroscopy. Ni/Al nanolayers are an effective means of joining titanium alloys at room temperature. A sound interface, mainly composed by NiAl grains, is obtained in joints of TiAl/TiAl and TiAl/Inconel, produced with NanoFoil^® by annealing at 700 ºC, during 60 min under a pressure of 10 MPa. The low shear strength revealed a weak adhesion of the nanofoil to the base materials.     

Assessment of resistance spot welding quality based on ultrasonic testing and tree-based techniques

Classification and regression tree (CART) and random forest techniques were proposed as pattern recognition tools for classification of ultrasonic oscillograms of resistance spot welding (RSW) joints. The results showed that CART models produced an acceptable error rate with high interpretability. These features may be used to understand and control the decision processes, instruct other human operators, compare margins of safety or modify them depending on the criticality of the industrial process. Compared with CART trees, random forests reduced the error rate at the cost of decreasing decision interpretability. The use of the agreement of the forest was proposed as a measure to reduce the workload of human operators, who would only have to focus on the analysis of ultrasonic oscillograms that are difficult to interpret.     

Quasi-spherical focal spot in two-photon scanning microscopy by three-ring apodization

We present a beam-shaping technique for two-photon excitation (TPE) fluorescence microscopy. We show that by inserting a properly designed three-ring pupil filter in the illumination beam of the microscope, the effective optical sectioning capacity of such a system improves so that the point spread function gets a quasi-spherical shape. Such an improvement, which allows the acquisition of 3D images with isotropic quality, is obtained at the expense of only a small increase of the overall energy in the axial sidelobes. The performance of this technique is illustrated with a scanning TPE microscopy experiment in which the image of small beads is obtained. We demonstrate an effective narrowing of 12.5% in the axial extent of the point spread function, while keeping the 82% of the spot-fluorescence efficiency.     

Effects of the substrate temperature on the deposition of thin SiOx films by atmospheric pressure microwave plasma torch (TIA)

The effect of surface temperature on the deposition of silicon oxide (SiO_x) films with a non-thermal microwave axial injection torch (TIA) was investigated in an open air reactor. Argon was used as plasma gas and hexamethyldisiloxane (Si₂O₂C₆H₁₈) as silicon precursor. The parametric study reported here focuses on the influence of the substrate temperature on the morphological and chemical properties of the films deposited in the interval [0 °C–130 °C]. A similar effect of low and high surface temperature on the deposition process and on the microstructure of the deposited films was highlighted. Macroscopically, particles were promptly produced in the gas phase and incorporated to the film, which generates high surface roughness. Microscopically, FTIR results have shown a high carbon contamination of the deposited films at low and high temperatures, resulting in understoichiometric SiO_x films. They have also demonstrated that an optimum growth window for smooth and particle free SiO_x was to keep the surface temperature between 30 and 60 °C. Simple reaction mechanisms for powder formation and continuous silicon oxide thin films growth are suggested for each temperature ranges.     

Fractional adaptive control for an automatic voltage regulator

This paper presents the application of a direct Fractional Order Model Reference Adaptive Controller (FOMRAC) to an Automatic Voltage Regulator (AVR). A direct FOMRAC is a direct Model Reference Adaptive Control (MRAC), whose controller parameters are adjusted using fractional order differential equations. Four realizations of the FOMRAC were designed in this work, each one considering different orders for the plant model. The design procedure consisted of determining the optimal values of the fractional order and the adaptive gains for each adaptive law, using Genetic algorithm optimization. Comparisons were made among the four FOMRAC designs, a fractional order PID (FOPID), a classical PID, and four Integer Order Model Reference Adaptive Controllers (IOMRAC), showing that the FOMRAC can improve the controlled system behavior and its robustness with respect to model uncertainties. Finally, some performance indices are presented here for the controlled schemes, in order to show the advantages and disadvantages of the FOMRAC.