This paper proposes a novel all-digital background calibration technique for gain and timing mismatches in Time-Interleaved Analog-to-Digital Converters (TIADCs) using adaptive noise canceller (ANC). ...The error signals due to the gain and timing mismatches are expressed in linear regression terms, producing the estimation problem of ANC. The gain and clock skew coefficients are estimated by maximizing the output signal-to-noise ratio in ANC system. The correction is simple by subtracting the re-constructed errors from the TIADC output. The proposed calibration technique eliminates the input spectrum constants as well as removes high-pass filters, which are required in the conventional free-band based calibration technique. In order to validate the proposed approach, simulations are carried out for an 11-bit, 2.7GS/s four-channel TIADC for various input signals. Results show that the proposed calibration produces excellent performance in terms of mismatch distortion suppression. It achieves the SNDR and SFDR improvement of 19dB and 49dB, respectively. Moreover, the synthesized design with hardware co-simulation on Xilinx Kintex-7 field-programmable gate array (FPGA) platform consumes only 7.36% of the hardware resources of the FPGA chip and reduces the mismatch tone level up to -87dB.
Medicinal plants have been used for disease treatment throughout history, especially in Asia. Vietnam is a tropical country which possesses forests with a diversity of plants; among the plants, many ...have been historically used as alternative therapies for various disease treatments. In this study we aimed to evaluate the selective cytotoxicity of some plant extracts (collected from Vietnamese forests) against hepatocellular carcinoma cells HepG2, compared to adipose tissue-derived mesenchymal stem cells (ADSCs).
In this study, we collected nine plants and produced nine extracts from them; these included whole stem of Buchanania lucida, whole stem of Dipterocarpus turbinatus, Hopea recopei, whole stem of Shorea thorelii, bark of Shorea thorelii stem, bark of Dipterocarpus turbinatus stem, whole stem of Dipterocarpus costatus, bark of Dipterocarpus costatus stem, and rhizome of Boesenbergia pandurata. The cytotoxicity of these extracts on hepatocellular carcinoma cells and mesenchymal stem cells were determined based on IC
values calculated using Alamar Blue assay. Based on these IC
values, the side effect index (SEI) of extracts was determined. Only the extracts with low SEI were used in further assays to determine the apoptotic status of both hepatocellular carcinoma cells and mesenchymal stem cells via caspase 3/7 induction assay, nuclei disintegration (using Hoechst 33342 staining), and Annexin V staining assay.
The results showed that B. pandurata extract had strong cytotoxicity toward HepG2 cells with lowest side index on mesenchymal stem cells (IC
on HepG2 of 222 ± 27.82 (μg/ml) but IC
on ADSCs of 382 ± 16.19 (μg/ml)). Nuclear staining showed that B. pandurata extract could induce disintegration of cell nuclei at the concentration of 400 μg/ml. After 3 h of incubation with B. pandurata extract at the concentration of 200 μg/ml, the BP extract induced caspase 3/7 activation in HepG2 cells, but not in mesenchymal stem cells. Annexin V staining showed that the BP extract induced apoptosis in HepG2 cells in a dose-dependent manner.
This study revealed that selective cytotoxicity of some extracts on cancer cells could be determined based on their IC
values on cancer cells and on mesenchymal stem cells. B. pandurata extract displayed the lowest side effect index on mesenchymal stem cells and successfully induced apoptosis in hepatocellular carcinoma cells HepG2 via activation of caspase 3/7.
This paper presents a novel in-memory matching circuit realizing the CAM applications based on Non-volatile resistive memory and 2T-2R bit cell structure that provides reliable lookup operations. The ...evaluations extended to different NV-RAM types (RRAM, PCRAM, and MRAM) demonstrate the high applicability of our design architecture. The advantages of the CAM matching circuit are verified by Monte Carlo simulations using the 65nm CMOS process technology. Compared to other conventional approaches, our proposed design can reach relatively low sensing latencies, varying from 0.14 to 0.24 ns while maintaining a good level of search error rates.
We consider a robust design problem for achieving max-min fairness amongst users in an uplink non-orthogonal multiple access system under imperfect channel state information. Contrary to the ...conventional approach adopted in the literature, we propose an optimal decoding order-based successive interference cancellation technique by introducing new binary variables, which results in a difficult class of mixed-integer nonconvex optimization problem. For a practical application, we devise an efficient suboptimal solution based on the inner convex approximation framework, which solves a second-order-cone program at each iteration. Simulation results are provided to demonstrate its performance gain over state-of-the-art designs. The proposed design also yields data rates close to those obtained by an exhaustive search method.
Aqueous industrial wastes from heavy industry factories contain a large amount of Fe ions, which constitute a hazard for human life even at trace concentrations. Adsorption technology is a promising ...method for removing Fe(III) from aqueous solutions. In this report, the adsorption of the Fe(III) ion on γ- and α-MnO
2
nanostructures was compared. The results showed that the maximum adsorption was obtained at pH = 3.5 for both materials after 120 min for γ-MnO
2
and 80 min for α-MnO
2
. Adsorption isotherm models, such as Langmuir, Freundlich, Sips, Tempkin, and Dubinin–Radushkevich were applied to determine adsorption capacity as well as the nature of the uptake. The highest
R
2
, the smallest of root mean squared error (RMSE), and the nonlinear Chi-square test (χ
2
) values determined that the Sips model was the most appropriate equation to describe the adsorption of Fe(III) on γ- and α-MnO
2
. The maximum monolayer adsorption capacity calculated from the Langmuir model and the maximum adsorption capacity calculated from the Sips model of γ-MnO
2
was more than four times that of α-MnO
2
. The heat of the adsorption as well as the mean free energy estimated from Tempkin and Dubinin–Radushkevich was determined to be less than 8 kJ/mol, which showed that the adsorption on both materials followed a physical process. Kinetic studies showed that a pseudo-second-order model was accurately described on both samples with three stages.
•Impacts of economic and structural dependences are jointly investigated.•Assembly operation and its impact the components degradation are discussed.•An multi-level opportunistic predictive ...maintenance policy is proposed.•An optimization approach is developed to find the optimal decision variables.•A comparison study with a conventional maintenance policy is investigated.
For maintenance optimization of multi-component systems, opportunistic maintenance has been addressed in many studies since it allows considering the advantages of dependences between components in maintenance decision-making process. In the literature, economic dependence, which implies that joint maintenance of several components can reduce the maintenance cost, has been widely studied in the framework of opportunistic maintenance. There are however very few existing studies considering the advantages of structural dependence, whereby maintenance of a component requires disassembly of other components, in maintenance optimization. To face this issue, the objective of this paper is to propose a multi-level opportunistic predictive maintenance approach considering both economic and structural dependence. In that way, the economic and structural dependences between components are firstly formulated. A degradation model considering disassembly impacts is then developed. For opportunistic maintenance decision-making, two opportunistic thresholds are introduced. When corrective/preventive maintenance occurs, the first opportunistic threshold (eRo) is defined to select non-disassembled components for opportunistic maintenance. This first opportunistic decision allows considering the economic dependence between components. In addition, the maintenance of the selected components may require disassembly of other components which could be also good candidates to be opportunistically maintained. So, the second opportunistic threshold, sRo(sRo≥eRo), is then developed to select one or several disassembled components to be opportunistically maintained. To evaluate the performance of the proposed opportunistic maintenance approach, a cost model is developed. Particle swarm optimization algorithm is then applied to find the optimal decision variables. Finally, the proposed opportunistic maintenance approach is illustrated through a conveyor system to show its feasibility and added value in maintenance optimization framework.
The climate change and global warning have been appeared as an emerging issue in recent decades. In which, the drought problem has been influenced on economics and life condition in Vietnam. In order ...to solve this problem, in this paper, we have designed and deployed a long range and energy efficient drought monitoring based on IoT (Internet of Things) for real time applications. After being tested in the real condition, the proposed system has proved its high dependability and effectiveness. The system is promising to become a potential candidate to solve the drought problem in Vietnam.
SARS-CoV-2 RNA loads in Vietnamese children Thanh, Ton That; Nhan, Nguyen Thi Thanh; Anh, Nguyen To ...
Journal of infection/The Journal of infection,
04/2022, Letnik:
84, Številka:
4
Journal Article
Introduction: Cancer cells rely on glycolysis to generate energy and synthesize biomass for cell growth and proliferation (the Warburg effect). Recent studies have shown that citrate has an ...inhibitory effect on several cancer cells, such as human gastric cancer and ovarian cancer, by inhibiting glycolysis. In this study, we investigated the effects of citrate on the proliferation and apoptosis induction of hepatocellular carcinoma cells.
Methods: HepG2 hepatocellular carcinoma cell line was used in this study. The cell proliferation was evaluated by Alamar blue assay. The apoptotic status of the HepG2 cells was recorded by Annexin V/7-AAD assay and caspase 3/7 activation assay. DNA fragmentation was evaluated by nucleus staining assay with Hoechst 33342.
Results: The results showed that citrate is able to inhibit the proliferation of HepG2 cells and induce apoptosis in these cells. The initiation time of apoptosis is 4 hours after treatment with 10 mM citrate. Morphology characteristics of DNA fragmentation and broken membranes were also recorded in the apoptotic cells.
Conclusion: In conclusion, our study demonstrates that citrate causes HepG2 cell death by the apoptosis pathway.
Uranyl ammonium carbonate (AUC), with the chemical formula UO2CO3·2(NH4)2CO3, plays a crucial role in the wet conversion of uranium hexafluoride (UF6) into uranium dioxide (UO2) or triuranium ...octaoxide (U3O8) for nuclear fuel production, and is used in commercial and research reactors. In this study, the precipitation of AUC from uranyl fluoride (UO2F2) solution and its subsequent conversion into U3O8 powder were investigated. AUC precipitation was performed at uranium concentrations in UO2F2 solution of 80–120 gL-1, ammonium carbonate (NH4)2CO3 concentrations of 200–400 gL-1, and (NH4)2CO3 to U (C/U) ratios of 5–9. The conversion of AUC into U3O8 powder was studied and sintering of the U3O8 nuclear material derived from ammonium uranyl carbonate (ex-AUC U3O8) was conducted at temperatures of 1000–1800 °C. The kinetics of AUC precipitation from the UO2F2 solution were studied using fundamental kinetic equations, and the kinetics of AUC conversion into UO3 were examined using an isoconversion method based on the thermogravimetric analysis of AUC. The final product of U3O8 nuclear material was characterized using typical techniques, such as thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy. This study provides valuable insights into the production and characterization of AUC and U3O8 nuclear materials, which are key materials in the nuclear fuel industry.
The uranyl ammonium carbonate precipitation and conversion into triuranium octaoxide. Display omitted
•Extensive research was conducted on the precipitation of AUC from UO2F2 solution and its subsequent conversion into U3O8.•The kinetics of both the AUC precipitation and the conversion into UO3 were carefully determined.•These studies aimed to produce high-density U3O8 nuclear material suitable for research reactors.
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