31 research outputs found

    Bis{2-[(4-bromo­phen­yl)imino­meth­yl]pyridine-κ2 N,N′}copper(I) tetra­phenyl­borate

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    In the crystal structure of the title compound, [Cu(C12H9BrN2)2](C24H20B), the copper(I) cation is coordinated by four N atoms of two crystallographically independent 2-[(4-bromo­phen­yl)imino­meth­yl]pyridine ligands within a distorted tetra­hedron

    Laminin matrix promotes hepatogenic terminal differentiation of human bone marrow mesenchymal stem cells

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    Objective(s):The application of stem cells holds great promises in cell transplants. Considering the lack of optimal in vitro model for hepatogenic differentiation, this study was designed to examine the effects of laminin matrix on the improvement of in vitro differentiation of human bone marrow mesenchymal stem cells (hBM-MSC) into the more functional hepatocyte-like cells. Materials and Methods:Characterization of the hBM-MSCs was performed by immunophenotyping and their differentiation into the mesenchymal-derived lineage. Then, cells were seeded on the laminin-coated or tissue culture polystyrene (TCPS). The differentiation was carried out during two steps. Afterward, the expression of hepatocyte markers such as AFP, ALB, CK-18, and CK-19 as well as the expression of C-MET, the secretion of urea, and the activity of CYP3A4 enzyme were determined. Moreover, the cytoplasmic glycogen storage was examined by periodic acid–Schiff (PAS) staining. Results:The results demonstrated that the culture of hBM-MSC on laminin considerably improved hepatogenic differentiation compared to TCP group. A significant elevated level of urea biosynthesis and CYP3A4 enzyme activity was observed in the media of the laminin-coated differentiated cells (

    Silicon Echoes: Non-Invasive Trojan and Tamper Detection using Frequency-Selective Impedance Analysis

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    The threat of chip-level tampering and its detection has been widely researched. Hardware Trojan insertions are prominent examples of such tamper events. Altering the placement and routing of a design or removing a part of a circuit for side-channel leakage/fault sensitivity amplification are other instances of such attacks. While semi- and fully-invasive physical verification methods can confidently detect such stealthy tamper events, they are costly, time-consuming, and destructive. On the other hand, virtually all proposed non-invasive side-channel methods suffer from noise and, therefore, have low confidence. Moreover, they require activating the tampered part of the circuit (e.g., the Trojan trigger) to compare and detect the modifications. In this work, we introduce a non-invasive post-silicon tamper detection technique applicable to different classes of tamper events at the chip level without requiring the activation of the malicious circuit. Our method relies on the fact that physical modifications (regardless of their physical, activation, or action characteristics) alter the impedance of the chip. Hence, characterizing the impedance can lead to the detection of the tamper events. To sense the changes in the impedance, we deploy known RF tools, namely, scattering parameters, in which we inject sine wave signals with high frequencies to the power distribution network (PDN) of the system and measure the “echo” of the signal. The reflected signals in various frequency bands reveal different tamper events based on their impact size on the die. To validate our claims, we performed measurements on several proof-of-concept tampered hardware implementations realized on FPGAs manufactured with a 28 nm technology. We further show that deploying the Dynamic Time Warping (DTW) distance can distinguish between tamper events and noise resulting from manufacturing process variation of different chips/boards. Based on the acquired results, we demonstrate that stealthy hardware Trojans, as well as sophisticated modifications of P&R, can be detected

    Physical Activity and Exercise Promote Peroxisome Proliferator-Activated Receptor Gamma Expression in Adipose Tissues of Obese Adults

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    Background: Peroxisome proliferator-activated receptor gamma (PPARγ) has recently been studied for its potential influence on the functional response of the human body to exercise. We aimed to investigate the association of habitual physical activity (PA) with PPARγ mRNA level in the visceral and subcutaneous adipose tissues (VAT and SAT) in non-obese and obese non-diabetic adults. Methods: VAT and SAT were obtained from 95 individuals, including 40 non-obese (BMI<30kg/m2) and 55 obese (BMI≥30kg/m2) who underwent elective abdominal surgery (Tehran, Iran, 2012-2015). The assessment of habitual PA was performed by a valid and reliable International PA Questionnaire-long form, and the metabolic equivalent of task (MET) was evaluated. Real-time quantitative reverse transcriptase-PCR evaluated the PPARγ expression in VAT and SAT. Results: PPARγ expression in both VAT (1.18 vs. 0.37 fold change, P<0.001) and SAT (2.07 vs. 0.29 fold change, P=0.004) among obese subjects was higher than the non-obese group. After controlling for age, sex, and total energy intake, a positive association was found between total METs and PPARγ expression in both VAT and SAT among obese participants (β=0.22, P=0.007 and β=0.12, P<0.001, respectively). Among obese participants, there was a direct association between leisure time-related METs with VAT PPARγ expression (β=0.05, P=0.026). Moreover, in this group, an association was observed between occupation-related METs with PPARγ in both fat tissues (β=0.11, P=0.002 and β=0.17, P=0.013, respectively), and household work-related METs with SAT PPARγ (β=0.21, P=0.011). Conclusion: High PA as an indispensable part of a healthy lifestyle may exert its beneficial effect by regulating PPARγ expression.

    High-performance supercapacitor electrode materials based on chemical co-precipitation synthesis of nickel oxide (NiO)/cobalt oxide (Co3O4)-intercalated graphene nanosheets binary nanocomposites

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    Graphene (Gr)/metal oxide nanocomposites, as advanced electrode materials, have drawn significant attention in supercapacitors due to their two components' synergistic cooperation, which compensates each other's drawbacks and hence perform better than their individual components. In this study, two graphene/metal oxide nanocomposites, Gr/NiO and Gr/Co3O4 binaries were separately synthesized by a co-precipitation method in which NiO or Co3O4 as interlayer spacers were inserted into the graphene structure. The as-synthesized electroactive materials were drop-cast on the as-grown Cu(OH)2 nanowire arrays/Cu substrates fabricated by drenching copper into a rich-alkaline solution. Three-electrode's electrochemical characterizations in 6 M KOH electrolyte showed that Gr/Co3O4 and Gr/NiO exhibit high capacitances of 342.6 and 652 F g−1 at the scan sweep of 5 mV s−1, and 278.5 and 667.58 F g−1 at the current density of 1 A g−1, respectively. In addition, the power density of 250 W kg−1 leads to the energy densities of23.17 and 9.7 Wh kg−1 for Gr/NiO and Gr/Co3O4, respectively. The Gr/NiO with the cyclic stability of 95% has a better electrochemical performance than Gr/Co3O4 (with the cyclic stability of 83%), implying more pseudocapacitance contribution of the NiO nanoparticles embedded within the graphene nanosheets and more efficient synergistic cooperation between these two components. Furthermore, full Gr/NiO/Cu(OH)2/Cu||Gr/NiO/Cu(OH)2/Cu and Gr/Co3O4/Cu(OH)2/Cu||Gr/Co3O4/Cu(OH)2/Cu symmetric cells in the organic electrolyte of 1 M TEA-BF4 in acetonitrile within the potential window of 2 V were also assembled and at 10 mV s−1, exhibited the highest specific capacitances of 32.67 and 24.86 F g−1, respectively.Peer reviewe

    Structural properties and supercapacitive performance evaluation of the nickel oxide/graphene/polypyrrole hybrid ternary nanocomposite in aqueous and organic electrolytes

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    Recently, hybrid supercapacitors have attracted tremendous attention as promising energy storage and conversion devices due to their excellent energy density and high power density. In the present work, a novel pioneering hybrid ternary nanocomposite of NiO/Gr/PPy was synthesized by a low-cost co-precipitation method, followed by heat treatment and in-situ chemical polymerization. The as-synthesized nanocomposite was drop-cast on a modified Cu current collector to enhance the supercapacitive performance and stability in the electrolyte. The results of electrochemical characterization in 6 M KOH revealed the high specific capacitance and energy density of 970.85 F g−1 and 33.71 Wh kg−1 at 1 A g−1, respectively. This can be attributed to the synergic effect and hybrid performance of NiO, Gr, and PPy. Moreover, a full symmetric cell was assembled by using this hybrid ternary nanocomposite and evaluated in TEA-BF4/AN. The results showed the high specific capacitance and energy density of 66.17 F g−1 and 36.76 Wh kg−1 within the 2 V potential window, respectively.Peer reviewe
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