A steady state solver for modelling rotating electromechanical devices exploiting the transformation from time to position domain

The paper presents a study on a novel steady state solver for modelling rotating electromechanical devices. As the new contribution, the transformation of the system from time to position domain is exploited to improve the efficiency of computation. The proposed methodology is well suited to optimizing the current or voltage waveforms to drive the system with an imposed reference torque. To illustrate the technique, a brushless direct current motor is considered. Copyright © 2013 John Wiley & Sons, Ltd.     

Modeling of microwave devices with space mapping and radial basis functions

We review recent developments in space mapping techniques for modeling of microwave devices. We present a surrogate modeling methodology that utilizes space mapping combined with radial basis function interpolation. The method has advantages both over the standard space mapping modeling methodology and the recently published space mapping modeling with variable weight coefficients. In particular, it provides accuracy comparable or better than the latter method and computational efficiency as good as the standard space mapping modeling procedure. A comparison between the space mapping modeling methodologies as well as application examples of optimization and statistical analysis of microwave structures is presented. Copyright © 2007 John Wiley & Sons, Ltd.     

Effective Optical Image Assessment of Cellulose Paper Immunostrips for Blood Typing

Novel high-performance biosensing devices, based on a microporous cellulose matrix, have been of great interest due to their high sensitivity, low cost, and simple operation. Herein, we report on the design and testing of portable paper-based immunostrips (IMS) for in-field blood typing in emergencies requiring blood transfusion. Cellulose fibrils of a paper membrane were functionalized with antibodies via supramolecular interactions. The formation of hydrogen bonds between IgM pentamer and cellulose fibers was corroborated using quantum mechanical calculations with a model cellulose chain and a representative amino acid sequence. In the proposed immunostrips, paper with a pore size of 3 µm dia. was used to enable functionalization of its channels with antibody molecules while blocking the red blood cells (RBC) from channel entering. Under the optimized test conditions, all blood types of AB0 and Rh system could be determined by naked eye examination, requiring only a small blood sample (3.5 µL). The durability of IgM immunostrips against storing has been tested. A new method of statistical evaluation of digitized blood agglutination images, compatible with a clinical five-level system, has been proposed. Critical parameters of the agglutination process have been established to enable future development of automatic blood typing with machine vision and digital data processing.     

Dietary Copper Deficiency Leads to Changes in Gene Expression Indicating an Increased Demand for NADH in the Prefrontal Cortex of the Rat’s Brain

Copper is an essential element to brain cells as it is a cofactor and a structural component of various enzymes involved in energy metabolism pathways. Accumulating evidence points to the pivotal role of copper deficiency in neurodegeneration resulting from impaired copper homeostasis. Despite the indisputable role of copper in mitochondrial respiration, its homeostasis regulation in the brain tissue remains unclear. The assessment of changes in the expression of genes encoding key pathways of energy metabolism can greatly benefit further studies exploring copper’s role in neurodegeneration. Using a rat model, we investigate whether the replacement of the inorganic form of copper with metallic nanoparticles containing copper or complete deprivation of copper from the diet have an impact on the expression of genes involved in energy metabolism in the prefrontal cortex of the rats’ brain. Herein, we indicate that removing inorganic copper from the normal standard diet or the replacement with copper nanoparticles can lead to programmed energy metabolism changes. It can be recognized that some of these changes indicate an increased demand for NADH in the prefrontal cortex of the rat’s brain, probably as a result of adaptation effect.     

Apigenin Modulates AnxA6- and TNAP-Mediated Osteoblast Mineralization

Mineralization-competent cells like osteoblasts and chondrocytes release matrix vesicles (MVs) which accumulate Ca²⁺ and P_i, creating an optimal environment for apatite formation. The mineralization process requires the involvement of proteins, such as annexins (Anx) and tissue-nonspecific alkaline phosphatase (TNAP), as well as low molecular-weight compounds. Apigenin, a flavonoid compound, has been reported to affect bone metabolism, but there are doubts about its mechanism of action under physiological and pathological conditions. In this report, apigenin potency to modulate annexin A6 (AnxA6)- and TNAP-mediated osteoblast mineralization was explored using three cell lines: human fetal osteoblastic hFOB 1.19, human osteosarcoma Saos-2, and human coronary artery smooth muscle cells HCASMC. We compared the mineralization competence, the morphology and composition of minerals, and the protein distribution in control and apigenin-treated cells and vesicles. The mineralization ability was monitored by AR-S/CPC analysis, and TNAP activity was determined by ELISA assay. Apigenin affected the mineral structure and modulated TNAP activity depending on the concentration. We also observed increased mineralization in Saos-2 cells. Based on TEM-EDX, we found that apigenin influenced the mineral composition. This flavonoid also disturbed the intracellular distribution of AnxA6 and TNAP, especially blocking AnxA6 aggregation and TNAP attachment to the membrane, as examined by FM analysis of cells and TEM-gold analysis of vesicles. In summary, apigenin modulates the mineralization process by regulating AnxA6 and TNAP, as well as through various effects on normal and cancer bone tissues or atherosclerotic soft tissue.     

Vicarious nucleophilic Substitution of Hydrogen in Pteridine derivatives

Pteridine derivatives react in basic media with carbanions bearing leaving groups at the carbanionic center via the vicarious nucleophilic substitution of hydrogen (VNS) pathway. In the reaction with trihalomethyl carbanions covalent σ-adducts and/or dihalomethylated VNS products can be obtained depending on conditions.     

Accelerated geometry optimization of compact impedance matching transformers using decomposition and adjoint sensitivities

This work addresses the problem of expedited design optimization of decomposable compact microwave structures, particularly impedance matching transformers. The approach proposed here exploits structure decomposition and a bottom‐up technique where the elementary building blocks of the transformer circuit of interest are first optimized with respect to specifications extracted from a conventional circuit design, and subsequently, the entire circuit is optimized using the previously obtained building‐block dimensions as a starting point. The optimization engine for each stage of the process is adjoint‐based gradient search embedded in the trust region framework. The bottom‐up approach turns out to be critical from the reliability standpoint: As the initial dimensions obtained from the optimized building blocks already result in reasonably good characteristics of the entire circuit, no global search is required to find a satisfactory design. This is in contrast to direct adjoint‐based optimization of the entire circuit which leads to a local optimum, which may not satisfy the imposed requirements. At the same time, computational cost of the design process is reduced compared with direct optimization of the entire circuit, because building block optimization is carried out in low‐dimensional search spaces and using simpler (i.e., less expensive) electromagnetic models. Our technique is demonstrated using a three‐section impedance matching transformer. Copyright © 2016 John Wiley & Sons, Ltd.