Molecular Insights on the Role of (CTA+)(SiO−) Ion Pair into the Catalytic Activity of [CTA+]–Si–MCM-41

Topics in Catalysis - In this work, a theoretical study in conjunction with a spectroscopic analysis by FTIR were carried out in order to obtain molecular insights on the role of...     

Foliar Spraying of Silicon Associated with Salicylic Acid Increases Silicon Absorption and Peanut Growth

Silicon - Silicon (Si) combined with foliar spraying of salicylic acid (SA) can affect the absorption of this beneficial element. A study with Si non-accumulators plants (soybean and bean) observed...     

MicroRNA Profiling of B Cell Subsets from Systemic Lupus Erythematosus Patients Reveals Promising Novel Biomarkers

MicroRNAs control the differentiation and function of B cells, which are considered key elements in the pathogenesis of systemic lupus erythematosus (SLE). However, a common micro(mi)RNA signature has not emerged since published data includes patients of variable ethnic background, type of disease, and organ involvement, as well as heterogeneous cell populations. Here, we aimed at identifying a miRNA signature of purified B cells from renal and non-renal severe SLE patients of Latin American background, a population known to express severe disease. Genome-wide miRNA expression analyses were performed on naive and memory B cells and revealed two categories of miRNA signatures. The first signature represents B cell subset-specific miRNAs deregulated in SLE: 11 and six miRNAs discriminating naive and memory B cells of SLE patients from healthy controls (HC), respectively. Whether the miRNA was up or down-regulated in memory B cells as compared with naive B cells in HC, this difference was abolished in SLE patients, and vice versa. The second signature identifies six miRNAs associated with specific pathologic features affecting renal outcome, providing a further understanding for SLE pathogenesis. Overall, the present work provided promising biomarkers in molecular diagnostics for disease severity as well as potential new targets for therapeutic intervention in SLE.     

Dodecatungstocobaltate supported over ZSM-5 zeolite as novel solid catalyst in selective sulfide oxidation

The catalytic behavior of a Keggin type potassium dodecatungstocobaltate (II) salt supported on ZSM-5 zeolite for wet peroxide oxidation of 2-(methylthio)benzothiazole, as a model organic sulfide, was thoroughly studied. Microporous ZSM-5 zeolite was obtained by the hydrothermal crystallization method. The Keggin salt was incorporated in the MFI zeolite matrix by the wet impregnation method followed by calcination at 350 °C. Catalysts were further characterized by X ray diffraction, UV–Vis diffuse reflectance spectroscopy and scanning electron microscopy-EDAX techniques. Supported and bulk Keggin dodecatungstocobaltate (II) were compared with pure H-ZSM-5 zeolite as catalysts for the sulfide oxidation. When the reaction was not catalyzed, just a 9 mol% of sulfide conversion was obtained. Reaction parameters, such as nature of the solvent, hydrogen peroxide concentration, reaction time, catalyst mass, substrate initial concentration and reaction temperature, were evaluated to reach the optimum reaction conditions, considering substrate conversion and sulfoxide and sulfone selectivities. Catalyst stability in several oxidation cycles was also examined.     

Guarino Guarini and Universal Mathematics

Guarini considered the mathematical studies to be of fundamental importance for all artists and scholars. His own knowledge of mathematics was vast and profound. The aim of this present paper is to show, through an analysis of the most substantial of his mathematical works, Euclides adauctus, along with the Appendix to this printed a few months later, the role that philosophical and mathematical studies had on his cultural formation, on the new and original research that he conducted, and on his teaching activities, while looking for traces of the mathematical sources that he consulted and cited that indicate which authors and works exerted the greatest influence on him.     

An output formation consensus control for leader–follower networked multi-agent systems under communication constraints and switching topologies

In this paper, the formation consensus problem for a class of leader–follower networked multi-agent systems under communication constraints and switching topologies is investigated. A networked predictive control scheme is proposed to achieve stability and output formation consensus with the switching topology, capable of compensating for data loss and time delays in the network. By equating the whole closed-loop networked multi-agent system with the proposed control scheme to the corresponding switched system, the sufficient and necessary condition of output formation consensus and stability for agents is given. Finally, using three-degree-of-freedom air-bearing spacecraft simulators as the control objects, the proposed scheme is demonstrated to be able to actively compensate for the communication constraints through numerical simulations, and it is also verified to have a good control performance by further realizing the formation task of the simulators through practical experiments.     

Experimental study of diffusion-based extraction from a cell suspension

A recently proposed application of microfluidics is the post-thaw processing of biological cells. Numerical simulations suggest that diffusion-based extraction of the cryoprotective agent dimethyl sulfoxide (DMSO) from blood cells is viable and more efficient than centrifugation, the conventional method of DMSO removal. In order to validate the theoretical model used in these simulations, a prototype was built and the flow of two parallel streams, a suspension of Jurkat cells containing DMSO and a wash stream that contained neither cells nor DMSO, was characterized experimentally. DMSO transport in a rectangular channel (depth 500 μm, width 25 mm and overall length 125 mm) was studied as a function of three dimensionless parameters: depth ratio of the streams, cell volume fraction in the cell solution, and the Peclet number (Pe) based on channel depth, average flow rate and the diffusion coefficient for DMSO in water. In our studies, values of Pe ranged from O(10³) to O(10⁴). Laminar flow was ensured by keeping the Reynolds number between O(1) and O(10). Experimental results based on visual and quantitative data demonstrate conclusively that a microfluidic device can effectively remove DMSO from liquid and cell laden streams without compromising cell recovery. Also, flow conditions in the microfluidic device appear to have no adverse effect on cell viability at the outlet. Further, the results demonstrate that we can predict the amount of DMSO removed from a given device with the theoretical model mentioned previously.     

Tagged Systems: A Framework for the Specification of History-dependent Properties

We propose a general method for the treatment of history-dependent runtime errors. When one has to control this kind of errors, a tagged version of the language is usually defined, in which tags capture only the necessary information of the history of processes. We will characterize such tagged languages as being quotients of the reachability tree defined by the computations of the original language. From this fact we can conclude that the property characterized by each tagged language is indeed a property of the original one. In this way, we can work in a common framework, instead of defining an ad hoc semantics for each property. In particular, we could still use the analysis machinery existing in the calculus in order to prove that or other related properties. We have applied this methodology to the study of resource access control in a distributed π-calculus, called Dπ. In particular, we have proved that the tagged version of Dπ is indeed a tagging according to our definition.     

Measuring and improving the quality of development processes based on usability and accessibility

Universal Access in the Information Society - Measurement of both usability and accessibility is an important concern in software development today. However, while a great amount of attention has...     

My personal reactions to Rogers (1957): The facilitative but neither necessary nor sufficient conditions of therapeutic personality change.

In this brief commentary regarding Rogers' (1957) paper (see record 2007-14639-002), I comment on Rogers' statement about personality change, the six conditions, and the resulting hypotheses. I conclude that the construct of therapeutic personality change needs to be reformulated to include interpersonal changes, and that the six conditions can facilitate therapeutic personality change, but are neither necessary nor sufficient for therapeutic personality change. I also suggest that several components from current common factors models (e.g., building expectations of change, encouraging corrective experiences) and a consideration of boundaries need to be included into a reformulation of Rogers' propositions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)