The Formation of Calcified Nanospherites during Micropetrosis Represents a Unique Mineralization Mechanism in Aged Human Bone

Osteocytes—the central regulators of bone remodeling—are enclosed in a network of microcavities (lacunae) and nanocanals (canaliculi) pervading the mineralized bone. In a hitherto obscure process related to aging and disease, local plugs in the lacuno‐canalicular network disrupt cellular communication and impede bone homeostasis. By utilizing a suite of high‐resolution imaging and physics‐based techniques, it is shown here that the local plugs develop by accumulation and fusion of calcified nanospherites in lacunae and canaliculi (micropetrosis). Two distinctive nanospherites phenotypes are found to originate from different osteocytic elements. A substantial deviation in the spherites' composition in comparison to mineralized bone further suggests a mineralization process unlike regular bone mineralization. Clearly, mineralization of osteocyte lacunae qualifies as a strong marker for degrading bone material quality in skeletal aging. The understanding of micropetrosis may guide future therapeutics toward preserving osteocyte viability to maintain mechanical competence and fracture resistance of bone in elderly individuals.     

TLM modeling of a probe‐coupled cylindrical cavity based on compact wire model in the cylindrical mesh

This article describes an implementation of a compact wire model into the three‐dimensional transmission‐line matrix (TLM) cylindrical mesh for the purpose of an efficient analysis of probe‐coupled cylindrical microwave cavity devices. Because of a cylindrical grid structure and empirical nature of the compact model, this implementation has to take into account a change of wire model parameters with a variable cross section of the TLM nodes through which a wire conductor passes. The model accuracy has been experimentally verified and compared with the corresponding results reached by the TLM method based on a rectangular grid in order to consider its advantages. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.     

The Adaptive Solar Facade: From concept to prototypes

The Adaptive Solar Facade (ASF) is a modular, highly integrated dynamic building facade.The energetic behavior as well as the architectural expression of the facade can be controlled with high spatio-temporal resolution through individually addressable modules. We present the general design process, the current mechanical design, and simulation results on photovoltaic power production and building energy consumption. We introduce the controller concept and show results on solar tracking as well as user interaction. Lastly, we present our current and planned prototypes.     

Deposition of silver ions onto DBD and DCSBD plasma treated nonwoven polypropylene

The aim of this work is plasma activation of nonwoven polypropylene (PP) using two different ambient air plasma sources: volume dielectric barrier discharge (DBD) and diffuse coplanar surface barrier discharge (DCSBD) and its functionalization by silver ion deposition.     

Microencapsulation of Sulfadiazine with Cellulose Acetate Pethalate

Microencapsulation of a relatively insoluble drug sulfadiazine was carried out by allowing drops of' a suspension of the drug in an aqueous cellulose acetate phthalate solution to fall into an acetic acid hardening solution. Spherical microcapsules could readily be obtained when a surfactant polyoxyethylene 20 sorbitan monooleate was added to the suspensior. Increased drug concentration in the suspension yielded larger microcapsules with shorter disintegration times. The incorporation of viscosity agents into the suspension yielded microcapsules with altered disintegration times     

Scanning ion conductance microscopy of living cells

Currently there is a great interest in using scanning probe microscopy to study living cells. However, in most cases the contact the probe makes with the soft surface of the cell deforms or damages it. Here we report a scanning ion conductance microscope specially developed for imaging living cells. A key feature of the instrument is its scanning algorithm, which maintains the working distance between the probe and the sample such that they do not make direct physical contact with each other. Numerical simulation of the probe/sample interaction, which closely matches the experimental observations, provides the optimum working distance. The microscope scans highly convoluted surface structures without damaging them and reveals the true topography of cell surfaces. The images resemble those produced by scanning electron microscopy, with the significant difference that the cells remain viable and active. The instrument can monitor small-scale dynamics of cell surfaces as well as whole-cell movement.     

Direction of arrival estimation of mobile stochastic electromagnetic sources with variable radiation powers using hierarchical neural model

Hierarchical neural model for an efficient one‐dimensional direction of arrival (DoA) estimation of stochastic electromagnetic (EM) sources with a variable radiation power is proposed. Model is trained to provide an azimuth position of such sources based on a spatial correlation matrix obtained by a signal sampling at a reception point and then used as an input to a neural model. It consists of two hierarchical levels realized by the multilayer perceptron (MLP)‐based neural networks. The first level is responsible to reduce the dimensionality of the considered DoA problem which allows for its easier solution at the second level. Accuracy and run‐time of the proposed model is verified on an example of determining the azimuth position of two stochastic EM sources in noisy conditions through comparison with a standalone MLP model and a model based on the root MUSIC algorithm.