34 research outputs found

    Epigenetic mechanisms of Strip2 in differentiation of pluripotent stem cells

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    Significant evidence points to Strip2 being a key regulator of the differentiation processes of pluripotent embryonic stem cells. However, Strip2 mediated epigenetic regulation of embryonic differentiation and development is quite unknown. Here, we identified several interaction partners of Strip2, importantly the co-repressor molecular protein complex nucleosome remodeling deacetylase/Tripartite motif-containing 28/Histone deacetylases/Histone-lysine N-methyltransferase SETDB1 (NuRD/TRIM28/HDACs/SETDB1) histone methyltransferase, which is primarily involved in regulation of the pluripotency of embryonic stem cells and its differentiation. The complex is normally activated by binding of Krueppel-associated box zinc-finger proteins (KRAB-ZFPs) to specific DNA motifs, causing methylation of H3 to Lysin-9 residues (H3K9). Our data showed that Strip2 binds to a DNA motif (20 base pairs), like the KRAB-ZFPs. We establish that Strip2 is an epigenetic regulator of pluripotency and differentiation by modulating DNA KRAB-ZFPs as well as the NuRD/TRIM28/HDACs/SETDB1 histone methyltransferase complex

    Resonant Frequency Characteristics of a SAW Device Attached to Resonating Micropillars

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    Recently we reported experimental and simulation results on an increase in resonance frequency of a SAW resonator caused by mass loading of micropillars made of SU-8, attached normal to the surface of the resonator. We concluded that SAW resonator and the SU-8 micropillars in unison form a system of coupled resonators. We have now extended this work and performed a finite element method simulation to study the resonance frequency characteristics of the SAW-based coupled resonator. In this paper we report the effect of the resonance frequency of the micropillars on the resonance frequency of the system of coupled resonators, and observe the coupling of micropillar resonance and the propagating SAW as described in the well known Dybwad system of coupled resonators

    Live-Cell Imaging of the Contractile Velocity and Transient Intracellular Ca²⁺ Fluctuations in Human Stem Cell-Derived Cardiomyocytes

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    Live-cell imaging techniques are essential for acquiring vital physiological and pathophysiological knowledge to understand and treat heart disease. For live-cell imaging of transient alterations of [Ca²⁺]i in human cardiomyocytes, we engineered human-induced pluripotent stem cells carrying a genetically-encoded Ca²⁺-indicator (GECI). To monitor sarcomere shortening and relaxation in cardiomyocytes in real-time, we generated a alpha-cardiac actinin (ACTN2)-copepod (cop) green fluorescent protein (GFP⁺)-human-induced pluripotent stem cell line by using the CRISPR-Cas9 and a homology directed recombination approach. The engineered human-induced pluripotent stem cells were differentiated in transgenic GECI-enhanced GFP⁺-cardiomyocytes and ACTN2-copGFP⁺ -cardiomyocytes, allowing real-time imaging of [Ca²⁺]i transients and live recordings of the sarcomere shortening velocity of ACTN2-copGFP⁺ -cardiomyocytes. We developed a video analysis software tool to quantify various parameters of sarcoplasmic Ca²⁺ fluctuations recorded during contraction of cardiomyocytes and to calculate the contraction velocity of cardiomyocytes in the presence and absence of different drugs affecting cardiac function. Our cellular and software tool not only proved the positive and negative inotropic and lusitropic effects of the tested cardioactive drugs but also quantified the expected effects precisely. Our platform will offer a human-relevant in vitro alternative for high-throughput drug screenings, as well as a model to explore the underlying mechanisms of cardiac diseases

    Replacement of conventional reference electrode with platinum electrode for electronic tongue based analysis of dairy products

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    This work demonstrates the utility of platinum metal electrode as replacement for conventional Ag/AgCl reference electrode for voltammetric electronic tongue based analysis of edible dairy products. It overcomes the limitations of conventional silver-based reference electrode that presents a potential health hazard when employed for analysis of edible dairy products. Various dairy products like toned milk, Lassi and skimmed milk powder were tested using a cluster of platinum, gold and rhodium working electrodes. Responses of electrode cluster were captured using cyclic voltammetry. Comparative investigations were carried out between responses with platinum reference electrode and Ag/AgCl reference electrode. Repeatability and reproducibility of results have been examined. Our results suggest that platinum metal reference electrode can be reliably used for voltammetric electronic tongue based analysis of dairy products. Further this shall pave way for commercial development of electronic tongue technology in food sector adhering to hygienic and food safety regulations

    Adsorption of Small Molecules on Niobium Doped Graphene: A Study Based on Density Functional Theory

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    An Efficient Implementation Approach to FFT Processor for Spectral Analysis

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    This article presents an efficient hardware implementation approach to a variable-size fast Fourier transform (FFT) processor for spectral analysis. Due to its capability to handle different frame sizes, it can be adapted in situations where operating parameters necessitate adhering to different standard requirements. A serial real-valued processor with a new data-flow graph is considered, as it requires the least number of multipliers. By joint use of stage-specific optimization and multiplierless structure, the overall hardware efficiency of the proposed design is enhanced. Clock gating is employed to enable the variable-size processor operation along with power reduction. A fixed-point (FP) analysis of the proposed design is considered. The proposed novel multiplierless structure is based on shift and accumulation (SA). This also includes the generation (and sharing) of partial products (PPs) based on their symmetries. The proposed design offers low area and low power as compared with the state of the art. It is demonstrated for spectral analysis of electroencephalogram (EEG) signals for machine-learning-based epileptic seizure prediction on a field-programmable gate array (FPGA) platform.</p
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