Dense-Frequency Signal-Detection Based on the Primal-Dual Splitting Method.

Aiming to solve the problem of dense-frequency signals in the power system caused by the growing proportion of new energy, this paper proposes a dense-frequency signal-detection method based on the primal-dual splitting method. After establishing the Taylor-Fourier model of the signal, the proposed method uses the sparse property of the coefficient matrix to obtain the convex optimization form of the model. Then, the optimal solution of the estimated phasor is obtained by iterating over the fixed-point equation, finally acquiring the optimal estimation result for the dense signal. When representing the Taylor-Fourier model as a convex optimization form, the introduction of measuring-error entropy makes the solution of the model more rigorous. It can be further verified through simulation experiments that the estimation accuracy of the primal-dual splitting method proposed in this paper for dense signals can meet the M-class PMU accuracy requirements.

MnO2 porous carbon composite from cellulose enabling high gravimetric/volumetric performance for supercapacitor.

Preparing electrode material integrated with high gravimetric/volumetric capacitance and fast electron/ion transfer is crucial for the practical application. Owing to the structural contradiction, it is a big challenge to construct electrode material with high packing density, sufficient ion transport channels, and fast electronic transfer pathways. Herein, MnO2 porous carbon composite with abundant porous structure and 3D carbon skeleton was facilely fabricated from Linum usitatissimum. L stems via NaOH activation and MnO2 introduction. The in-situ introduced MnO2 not only increases the packing density and the electrical conductivity of the porous carbon but also provides more active sites for oxidation reactions. These unique characteristics endow the resultant MnO2 porous carbon composite with remarkable gravimetric capacitance of 549 F g-1, volumetric capacitance of 378 F cm-3, and capacitance retention of 54.9 %. Giving the simple process and low cost, this work might offer a new approach for structural design and the practical application of high-performance electrode materials.

Porous nickel-cobalt phosphate with oxygen-rich vacancies in situ grown on dopamine-modified cellulose textiles as self-supporting high mass loadings supercapacitor electrode.

Transition-metal phosphates/phosphides showcase significant promise for energy-related applications because of their high theoretical electrochemical characteristics. However, sluggish electro/ion transfer rates and kinetically unfavorable reaction sites hinder their application at high mass loading. Herein, a self-supporting electrode based on transition-metal phosphates was successfully fabricated via a one-step electrodeposition process. The nanosheet structure of transition-metal phosphates, formed by interconnecting nanoparticles, effectively mitigates the impact of stress and achieves a high mass-loading (21 mg cm-2) of the electrode. Additionally, the oxygen vacancy-rich and porous nanostructure of transition-metal phosphates endows the as-prepared electrodes with a significantly increased conductivity and fast ion migration rate for enhancing electrochemical kinetics. Consequently, the as-fabricated transition-metal phosphate electrode displays the highest areal specific capacity of 39.2F cm-2. Furthermore, the asymmetric supercapacitor achieves a maximum energy density of 0.79 mWh cm-2 and a high capacity retention of 93.0 % for 10000 cycles under 60 mA cm-2. This work provides an ideal strategy for fabricating flexible electrodes with high mass loading and synthesizing transition-metal phosphate electrodes rich in oxygen vacancies.

Physicochemical characterization of a polysaccharide from Rosa roxburghii Tratt fruit and its antitumor activity by activating ROS mediated pathways.

Rosa roxburghii Tratt fruit is a highly valued fruit that contains abundant functional and nutritional constituents. In this study, a novel polysaccharide, named RTFP-1, was isolated and purified from R. roxburghii Tratt fruit. Structural characterization indicated that RTFP-1 was a homogeneous heteropolysaccharide with the molecular weight (Mw) of 128.7 kDa and consisted of arabinose, galactose, glucose, mannose, xylose, and fucose with molar ratio percentages of 34.84, 40.59, 12.11, 5.06, 3.39, and 4.01%, respectively. A CCK-8 assay indicated that RTFP-1 inhibited the cell growth of HepG2 cells in a dose-dependent manner. Morphological analysis and flow cytometry experiment showed that RTFP-1 promoted the apoptosis of HepG2 cells and increased reactive oxygen species (ROS) level. The underlying molecular mechanisms indicated that RTFP-1 activated the apoptosis of HepG2 cells through ROS-mediated MAPK, STAT, and p53 apoptotic pathways. These results suggest that RTFP-1 might be a potential chemopreventive and antitumor agent.

circRNA_PTPRA functions as a sponge of miR-582-3p to regulate hepatocellular carcinoma cell proliferation, migration, invasion and apoptosis.

Hepatocellular carcinoma (HCC) is a lethal disease and one of the most common types of cancer. HCC is associated with exponentially increasing morbidity and mortality rates. Accumulating evidence has identified circular RNAs (circRNAs) to be regulators of cancer progression. However, to the best of our knowledge, the potential effect of circRNA protein tyrosine phosphatase receptor type A (circRNA_PTPRA) in HCC and its mechanism remain unknown. The present study aimed to assess the effects and underlying mechanism of circRNA_PTPRA in a HCC Huh-7 cells model. The sites of interaction between circRNA_PTPRA and microRNA (miR)-582-3p were predicted using the StarBase software and verified using dual luciferase reporter and RNA immunoprecipitation (RIP) assays in Huh-7 cells. HCC cell viability, apoptosis, migration and invasion were measured using MTT, flow cytometry and Transwell assays, respectively. The expression levels of circRNA_PTPRA, miR-582-3p, cyclin D1, MMP-9, Bcl-2 and Bax were analyzed using reverse transcription-quantitative PCR and western blotting. The results of the dual luciferase reporter and RIP assays demonstrated that miR-582-3p directly targeted circRNA_PTPRA. Compared with the human normal hepatocyte cell line, THLE-2, the expression levels of circRNA_PTPRA were upregulated, which were found to be inversely correlated with those of miR-582-3p expression in Huh-7 and HCCLM3 cells. miR-582-3p overexpression using mimics suppressed cell proliferation, migration and invasion, whilst downregulating cyclin D1 and MMP-9 expression in Huh-7 cells. In addition, transfection of HCC cells with the miR-582-3p mimic promoted apoptosis by downregulating Bcl-2 expression and upregulating Bax expression in Huh-7 cells. Knocking down circRNA_PTPRA expression using small interfering RNA (siRNA) markedly downregulated circRNA_PTPRA expression levels and upregulated miR-582-3p expression, but was reversed by co-transfection with the miR-582-3p inhibitor. Furthermore, reduced HCC cell proliferation, migration and invasion, increased levels of cell apoptosis, upregulated Bax expression and downregulated cyclin D1, MMP-9 and Bcl-2 expression were all observed after knocking down circRNA_PTPRA. All these effects aforementioned were reversed by co-transfection with the miR-582-3p inhibitor. In conclusion, findings from the present study suggested that circRNA_PTPRA may regulate HCC cell proliferation, invasion, apoptosis and migration by sponging miR-582-3p. This indicates that the circRNA_PTPRA/miR-582-3p axis may represent a potential target for HCC diagnosis and treatment.

Application of simultaneous saccharification and fermentation (SSF) from viscosity reducing of raw sweet potato for bioethanol production at laboratory, pilot and industrial scales.

The aim of this work was to research a bioprocess for bioethanol production from raw sweet potato by Saccharomyces cerevisiae at laboratory, pilot and industrial scales. The fermentation mode, inoculum size and pressure from different gases were determined in laboratory. The maximum ethanol concentration, average ethanol productivity rate and yield of ethanol after fermentation in laboratory scale (128.51 g/L, 4.76 g/L/h and 91.4%) were satisfactory with small decrease at pilot scale (109.06 g/L, 4.89 g/L/h and 91.24%) and industrial scale (97.94 g/L, 4.19 g/L/h and 91.27%). When scaled up, the viscosity caused resistance to fermentation parameters, 1.56 AUG/g (sweet potato mash) of xylanase decreased the viscosity from approximately 30000 to 500 cp. Overall, sweet potato is a attractive feedstock for be bioethanol production from both the economic standpoints and environmentally friendly.