Fabrication and characterization of anisotropic dielectrics for low-loss microwave applications

New magneto-photonic assembly designs for high-gain antennas require dielectrics with a significant anisotropy and low loss at GHz frequencies. This paper describes an approach to fabricate such dielectrics from ceramic laminates. These laminates consist of two ceramics with largely different permittivities and low dielectric losses. Alternating layers of commercially available α-Al₂O₃ and Nd-doped BaTiO₃ were laminated using organic adhesives. Equivalent permittivity tensors and loss tangents were characterized using a resonant cavity-based approach, which was coupled with a finite-element method full-wave solver. Measured permittivity values were in good agreement with mean field predictions; a minimum loss tangent 1.1 × 10^?3 was obtained when using one-component epoxy (Loctite^®-3982) adhesive. Application of two-component epoxy (M-bond 610) adhesive results in a slightly higher loss but better mechanical properties and machinability. These laminates were used to demonstrate high gain in a prototype antenna with 6 misaligned anisotropic dielectric layers.     

Quantitative analysis of the microstructural homogeneity of zirconia-toughened alumina composites

The Voronoi diagram approach was applied to quantify the level of microstructural homogeneity of ceramic ZTA samples. From SEM pictures of polished cross-sections of ZTA samples a point pattern representing the distribution of the zirconia phase in the composite was generated. This point pattern was converted into a Voronoi diagram. The level of microstructural homogeneity was quantified by statistical analysis of the relevant properties (area, perimeter and number of faces) of the Voronoi polygons. A dimensionless parameter defining the level of microstructural homogeneity was calculated from the different sets of statistical data. The calculated parameters indicated significant differences in homogeneity between the ZTA samples. These differences were in qualitative agreement with previously published wear rates of the same ZTA composites. This illustrates the relevance of microstructural homogeneity for wear performance.     

In vivo bioactivity of herbal‐drug‐incorporated nanofibrous matrixes

Aloe‐vera‐incorporated polycaprolactone nanofibrous matrixes were prepared by an electrospinning method. These developed matrixes were evaluated for their water absorption capacity, water vapor permeability, and contact angle, and, in an in vivo animal model, wound‐healing ability. The incorporation of the herbal drug made the matrixes hydrophilic with improved water retention and permeability properties. The in vivo studies were carried out in a rat model and showed improved results with respect to healing. Thus, this study confirmed that the developed matrixes could be used for wound‐healing applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42178.     

Assessing nutrient flows in septic tanks by eliciting expert judgement: a promising method in the context of developing countries

Simple models based on the physical and biochemical processes occurring in septic tanks, pit and urine diversion latrines were developed to determine the nutrient flows in these systems. Nitrogen and phosphorus separation in different output materials from these on-site sanitation installations were thus determined. Moreover, nutrient separation in septic tanks was also assessed through literature values and by eliciting expert judgement. Use of formal expert elicitation technique proved to be effective, particularly in the context of developing countries where data is often scarce but expert judgement readily available. In Vietnam, only 5-14% and 11-27% of the nitrogen and phosphorus input, respectively, are removed from septic tanks with the faecal sludge. The remaining fraction leaves the tank via the liquid effluent. Unlike septic tanks, urine diversion latrines allow to immobilize most of the nutrients either in form of stored urine or dehydrated faecal matter. These latrines thus contribute to reducing the nutrient load in the environment and lowering consumption of energy and non-renewable resources for fertiliser production.     

Molecular Subtyping of Invasive Breast Cancer Using a PAM50-Based Multigene Expression Test-Comparison with Molecular-Like Subtyping by Tumor Grade/Immunohistochemistry and Influence on Oncologist’s Decision on Systemic Therapy in a Real-World Setting

In intermediate risk hormone receptor (HR) positive, HER2 negative breast cancer (BC), the decision regarding adjuvant chemotherapy might be facilitated by multigene expression tests. In all, 142 intermediate risk BCs were investigated using the PAM50-based multigene expression test Prosigna® in a prospective multicentric study. In 119/142 cases, Prosigna® molecular subtyping was compared with local and two central (C1 and C6) molecular-like subtypes relying on both immunohistochemistry (IHC; HRs, HER2, Ki-67) and IHC + tumor grade (IHC+G) subtyping. According to local IHC, 35.4% were Luminal A-like and 64.6% Luminal B-like subtypes (local IHC+G subtype: 31.9% Luminal A-like; 68.1% Luminal B-like). In contrast to local and C1 subtyping, C6 classified >2/3 of cases as Luminal A-like. Pairwise agreement between Prosigna® subtyping and molecular-like subtypes was fair to moderate depending on molecular-like subtyping method and center. The best agreement was observed between Prosigna® (53.8% Luminal A; 44.5% Luminal B) and C1 surrogate subtyping (Cohen’s kappa = 0.455). Adjuvant chemotherapy was suggested to 44.2% and 88.6% of Prosigna® Luminal A and Luminal B cases, respectively. Out of all Luminal A-like cases (locally IHC/IHC+G subtyping), adjuvant chemotherapy was recommended if Prosigna® testing classified as Prosigna® Luminal A at high / intermediate risk or upgraded to Prosigna® Luminal B.     

Coenzymes Q in lemon shark liver

Earlier studies have shown that some extracts of nonpolar lipids from lemon shark liver are able to stimulate the reticuloendothelial system (RES) of experimental animals. This communication reports the identification of the coenzymes Q as the constituents of a fraction from lemon shark liver lipid which showed intense biological activity.     

Impact of Melatonin on RAW264.7 Macrophages during Mechanical Strain

The concentration of melatonin is elevated during the night when patients mainly wear removable orthodontic appliances. Next to periodontal ligament fibroblasts and osteoblasts, macrophages react to mechanical strain with an increased expression of inflammatory mediators. Here, we investigated the impact of melatonin on RAW264.7 macrophages exposed to tensile or compressive strain occurring during orthodontic tooth movement in the periodontal ligament. Before exposure to mechanical strain for 4 h, macrophages were pre-incubated with different melatonin concentrations for 24 h, to determine the dependence of melatonin concentration. Afterwards, we performed experiments with and without mechanical strain, the most effective melatonin concentration (25 µM), and the melatonin receptor 2 (MT2) specific antagonist 4P-PDOT. The expression of inflammatory genes and proteins was investigated by RT-qPCR, ELISAs, and immunoblot. Both tensile and compressive strain increased the expression of the investigated inflammatory factors interleukin-1-beta, interleukin-6, tumor necrosis factor alpha, and prostaglandin endoperoxide synthase-2. This effect was inhibited by the addition of melatonin. Incubation with 4P-PDOT blocked this anti-inflammatory effect of melatonin. Melatonin had an anti-inflammatory effect on macrophages exposed to mechanical strain, independent of the type of mechanical strain. As inhibition was possible with 4P-PDOT, the MT2 receptor might be involved in the regulation of the observed effects.     

Coulomb fission event resolved progeny droplet production from isolated evaporating methanol droplets

An electrodynamic balance was used to levitate a single methanol droplet while it evaporated down to, and just beyond, its first encountered Coulomb fission limit as ascertained by the time dependence of its laser light scatter signal. At its Coulomb limit, the primary droplet fragmented and approximately 81% of its net charge was released in the form of small droplets that are termed progeny. The window of time over which the progeny droplets were ejected from the electrodynamic balance was deltat = 850 ms, indicating that these droplets were formed with a range of mass-to-charge values. An average of 13.2 (+/-4.4) progeny droplets were detected as a result of this fragmentation event. On the assumption that the average initial radius of the progeny droplets were one-tenth the radius of the droplet undergoing the Coulomb fission event, approximately 50% of the total net charge ejected would not have been carried by the 13 progeny droplets detected.     

Perspective in a box

Perspective is an optional subject for students of some levels in Dutch secondary schools. A proper final task on this subject is the analysis of existing perspective drawings or paintings. This task is sometimes supplemented by a more creative and challenging assignment, that is, the design and construction of a perspective box. A perspective box is an empty box with, on the inner sides, perspective pictures giving a surprising spatial effect when observed through the peephole. The students who take up the challenge are in the first place inspired by the six still existing antique wooden perspective boxes, especially because they were created by Dutch seventeenth-century painters of architecture and interiors. In this article the setup of the perspective in these boxes will be discussed. But for a clear comprehension, we begin by reviewing the principles of linear perspective and their implications for the way perspective images can best be viewed.