The Role of KV7.3 in Regulating Osteoblast Maturation and Mineralization

KCNQ (K_V7) channels are voltage-gated potassium (K_V) channels, and the function of K_V7 channels in muscles, neurons, and sensory cells is well established. We confirmed that overall blockade of K_V channels with tetraethylammonium augmented the mineralization of bone-marrow-derived human mesenchymal stem cells during osteogenic differentiation, and we determined that K_V7.3 was expressed in MG-63 and Saos-2 cells at the mRNA and protein levels. In addition, functional K_V7 currents were detected in MG-63 cells. Inhibition of K_V7.3 by linopirdine or XE991 increased the matrix mineralization during osteoblast differentiation. This was confirmed by alkaline phosphatase, osteocalcin, and osterix in MG-63 cells, whereas the expression of Runx2 showed no significant change. The extracellular glutamate secreted by osteoblasts was also measured to investigate its effect on MG-63 osteoblast differentiation. Blockade of K_V7.3 promoted the release of glutamate via the phosphorylation of extracellular signal-regulated kinase 1/2-mediated upregulation of synapsin, and induced the deposition of type 1 collagen. However, activation of K_V7.3 by flupirtine did not produce notable changes in matrix mineralization during osteoblast differentiation. These results suggest that K_V7.3 could be a novel regulator in osteoblast differentiation.     

Preparation of highly emissive,thermally stable,UV‐cured polysilsesquioxane/ZnO nanoparticle composites

A high molecular weight polysilsesquioxane (LPMSQ)/ZnO nanocomposite was prepared by blending a methacryl‐substituted polysilsesquioxane and PMMA‐coated ZnO nanoparticle (NP) followed by UV‐curing process. These LPMSQ/ZnO nanocomposites gave high thermal and mechanical stabilities originated from the rigid ladder structured siloxane backbone of LPMSQ. The polysilsesquioxane and surface‐modified ZnO nanoparticles showed excellent compatibility between MMA groups in LPMSQ‐ and PMMA‐capped ZnO nanoparticles to give well‐dispersed LPMSQ/ZnO nanocomposites. Mechanically pliant and flexible free standing films were obtained, and the photo and optical properties of these hybrid nanocomposites were examined. The high photoluminescent properties were maintained even after severe thermal treatments exceeding 400°C. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42333.     

Beyond the basemap of science: mapping multiple structures in research portfolios: evidence from Hungary

As a novel tool for evaluating research competences of R&D actors, science overlay maps have recently been introduced in the scientometric literature, with associated measures for assessing the degree of diversification in research profiles. In this study, we continue the elaboration of this approach: based on science overlay maps (called here m-maps), a new type of map is introduced to reveal the competence structure of R&D institutions (i-maps). It is argued, that while m-maps represent the multidisciplinarity of research profiles, i-maps convey the extent of interdisciplinarity realized in them. Upon i-maps, a set of new measures are also proposed to quantify this feature. With these measures in hand, and also as a follow-up to our previous work, we apply these measures to a sample of Hungarian Research Institutions (HROs). Based on the obtained rankings, a principal component analysis is conducted to reveal main structural dimensions of researh portfolios (of HROs) covered by these measures. The position of HROs along these dimensions then allows us to draw a typology of organizations, according to various combinations of inter- and multidisciplinarity characteristic of their performance.     

Inverse design techniques for improving composite prosthetic devices

The design and performance of composite prosthetic devices can be improved by tailoring the material properties to achieve a prescribed response. An example of such a response would be displacements and stresses exhibited by healthy, undisturbed femoral bone. In this paper, an inverse design methodology, used in the Volumetrically Controlled Manufacturing (VCM) process, is developed and tested for improving the design of orthopedic prosthetic devices. First, a three-dimensional finite element (FE) model is developed based on available Computed Tomography (CT) data. The FE model is used to evaluate the response of the model subjected to a typical load. Second, as a part of the VCM process, the inverse design process is used to formulate a design problem that is in the form of a constrained least-squares problem. The intent is to find the material properties of the FE model to obtain a known displacement field on the stem-cancellous interface. Third, a solution methodology is developed to solve this constrained least squares problem using the finite element analysis for function evaluations and a gradient-based nonlinear programming (NLP) method to solve the design problem. Two test problems are solved to illustrate the developed methodology. The results indicate that material properties can be tailored to meet specific response requirements.     

Nanotechnology in the regulation of stem cell behavior

Abstract

Stem cells are known for their potential to repair damaged tissues. The adhesion, growth and differentiation of stem cells are likely controlled by the surrounding microenvironment which contains both chemical and physical cues. Physical cues in the microenvironment, for example, nanotopography, were shown to play important roles in stem cell fate decisions. Thus, controlling stem cell behavior by nanoscale topography has become an important issue in stem cell biology. Nanotechnology has emerged as a new exciting field and research from this field has greatly advanced. Nanotechnology allows the manipulation of sophisticated surfaces/scaffolds which can mimic the cellular environment for regulating cellular behaviors. Thus, we summarize recent studies on nanotechnology with applications to stem cell biology, including the regulation of stem cell adhesion, growth, differentiation, tracking and imaging. Understanding the interactions of nanomaterials with stem cells may provide the knowledge to apply to cell–scaffold combinations in tissue engineering and regenerative medicine.     

Variations in Hole Injection due to Fast and Slow Interfacial Traps in Polymer Light‐Emitting Diodes with Interlayers

Detailed studies on the effect of placing a thin (10 nm) solution‐processable interlayer between a light‐emitting polymer (LEP) layer and a poly(3,4‐ethylenedioxythiophene)/poly(styrenesulfonic)‐acid‐coated indium tin oxide anode is reported; particular attention is directed at the effects on the hole injection into three different LEPs. All three different interlayer polymers have low ionization potentials, which are similar to those of the LEPs, so the observed changes in hole injection are not due to variations in injection barrier height. It is instead shown that changes are due to variations in hole trapping at the injecting interface, which is responsible for varying the hole current by up to two orders of magnitude. Transient measurements show the presence of very fast interfacial traps, which fill the moment charge is injected from the anode. These can be considered as injection pathway dead‐ends, effectively reducing the active contact surface area. This is followed by slower interfacial traps, which fill on timescales longer than the carrier transit time across the device, further reducing the total current. The interlayers may increase or decrease the trap densities depending on the particular LEP involved, indicating the dominant role of interfacial chain morphology in injection. Penetration of the interlayer into the LEP layer can also occur, resulting in additional changes in the bulk LEP transport properties.     

Mechanical Properties of the Cerebrum: Application in Neurosurgical Procedures

Abstract: The development of robotics technology, especially the emergence of automatic surgical tools and robots, as well as the rapid advances in virtual reality techniques, require closer examination of the mechanical properties of the brain and its tissues at moderate and slow loading velocities corresponding to the strain rates of surgical procedures. In order to obtain comprehensive information about the mechanical properties of the brain, non‐destructive instrumented indentation was performed on the adult ovine cerebrum under various conditions, i.e. (i) in four measuring regions (consistent with the frontal and parietal lobes of both cerebral hemispheres) and (ii) at three loading velocities. The shear and elastic moduli show loading velocity dependence and weak regional dependence. The mean shear and elastic moduli of the ovine brain’s frontal lobe are higher than those of its parietal lobe. In addition, the left lobe is insensibly stiffer than the right lobe at each of the loading velocities.     

Behavior scoring model for coalition loyalty programs by using summary variables of transaction data

OKCashbag (OCB), the largest coalition loyalty program in Korea, offers a number of benefits such as sharing customer data with participating firms and cross-selling. There is great value in utilizing information pertaining to coalition loyal patrons. However, the size of transaction data is huge. We propose how to create necessary summary information by reducing the dimension of coalition transaction data. This information is then utilized to develop a behavior-scoring model. We expect that our study results can contribute to big data analysis for coalition loyalty program.