In this study, a quantitative comparison was performed to investigate the change rule of the hydroxyl radical (·OH) concentration and the total ·OH concentration generated by Fenton/Electro-Fenton ...(EF) reactions using the coumarin capture ·OH method. The relationship between the oxidation activity (total ·OH concentration) of the polishing slurry, coefficient of friction (COF), thickness of the oxide layer, and polishing effect was systematically studied through an immersion oxidation experiment, a friction and wear experiment, and a Fenton/Electro-Fenton chemical mechanical polishing (Fenton-CMP/EF-CMP) experiment. The enhancement mechanism of the EF reaction in the CMP of SiC was also analysed. The results indicated that the application of an electric field significantly improved the oxidation activity and the polishing effect. When the H2O2 concentration was 5.0 wt%, and the applied voltage increased from 0.0 V to 1.5 V and 3.0 V, the oxidation activity increased by 133.47% and 196.24%; COF increased by 9.05% and 13.36%; and material removal rate (MRR) increased by 32.26% and 65.59%, respectively. At a high voltage (3.0 V) and high H2O2 concentration (7.5 wt%), the polishing slurry exhibited the most potent oxidation activity, the oxidised SiC surface was the roughest, the COF and MRR were the highest, and the polishing quality was the best. The application of the electric field accelerated the conversion of Fe3+ to Fe2+ and generated a small amount of the H2O2 in situ, realising the electrical parameter control of the generated total ·OH concentration, such that the EF reaction produced more ·OH than the Fenton reaction, significantly enhancing the oxidation activity of the polishing slurry, which in turn enhanced the oxidation and polishing effects of SiC. The oxidation activity of the polishing slurry, COF, oxide layer thickness, and MRR exhibited a perfect linear correlation; the stronger oxidation activity increased the SiC oxidation effect. A higher SiC roughness after oxidation produced a greater COF, thicker oxide layer, higher MRR after polishing.
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•Quantitative detection of ·OH concentration using coumarin.•Enhancement mechanism of Electro-Fenton reaction in CMP for SiC was revealed.•Relationship between oxidation activity, COF, and MRR of the SiC was studied.•Electro-Fenton significantly improved oxidation activity and SiC polishing effect.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Aiming at the material removal of single-crystal SiC in chemical-magnetorheological compound finishing (CMRF), polishing slurries with different components were designed to conduct polishing ...experiments in this study. On this basis, the mechanical, chemical, and combined effects in the polishing process were studied and the material removal model of SiC in CMRF was established. The results showed that materials are mainly removed via mechanical removal through micro-cutting of abrasive particles. Among those factors influencing material removal, mechanical removal plays a dominant role, which removes much more material than the chemical effect. Moreover, the abrasive components in the CMRF slurry determine the mechanical removal capacity of materials. The carbonyl iron powder (CIP) content influences various parameters, such as the stiffness of the CMRF pads, the constraining force on the abrasive particles, the contact state, and chemical reactivity between catalysts and workpiece surfaces. Greater contents of the abrasive and the carbonyl iron powder yield stronger material removal capacity of the CMRF, leading to more contribution to material removal from the mechanical effect than from the chemical effect. The contribution of the mechanical effect of abrasives to the material removal rate reached 63.41 to 91.42%, while those of the polishing pad and the chemical effect to material removal are 4.81 to 10.37%, and 3.74 to 26.22%, respectively.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Chemoresistance is one of the leading causes for the failure of tumor treatment. Hence, it is necessary to study further and understand the potential mechanisms of tumor resistance to design and ...develop novel anti-tumor drugs. Post-translational modifications are critical for proteins' function under physiological and pathological conditions, among which ubiquitination is the most common one. The protein degradation process mediated by the ubiquitin-proteasome system is the most well-known function of ubiquitination modification. However, ubiquitination also participates in the regulation of many other biological processes, such as protein trafficking and protein-protein interaction. A group of proteins named deubiquitinases can hydrolyze the isopeptide bond and disassemble the ubiquitin-protein conjugates, thus preventing substrate proteins form degradation or other outcomes. Ubiquitin-specific protease 7 (USP7) is one of the most extensively studied deubiquitinases. USP7 exhibits a high expression signature in various malignant tumors, and increased USP7 expression often indicates the poor tumor prognosis, suggesting that USP7 is a marker of tumor prognosis and a potential drug target for anti-tumor therapy. In this review, we first discussed the structure and function of USP7. Further, we summarized the underlying mechanisms by which tumor cells develop resistance to anti-tumor therapies, provided theoretical support for targeting USP7 to overcome drug resistance, and some inspiration for the design and development of USP7 inhibitors.
Research over the past decade has suggested important roles for pseudogenes in glioma. This study aimed to show that pseudogene PRELI domain-containing 1 pseudogene 6 (PRELID1P6) promotes glioma ...progression. Aberrant expression of genes was screened using The Cancer Genome Atlas database. We found that mRNA level of PRELID1P6 was highly upregulated in glioma and was associated with a shorter survival time. Functional studies showed that the knockdown of PRELID1P6 decreased cell proliferation, sphere formation, and clone formation ability and blocked the cell cycle transition at G0/G1, while overexpression of PRELID1P6 had the opposite effects. Mechanistically, knockdown of PRELID1P6 changed the cellular localization of heterogeneous nuclear ribonucleoprotein H1 (hnRNPH1) from nucleus to cytoplasm, which promoted ubiquitin-mediated degradation of hnRNPH1. RNA-sequence and gene set enrichment analysis suggested that knockdown of PRELID1P6 regulates the apoptosis signaling pathway. Western blotting showed that PRELID1P6 increased TRF2 expression by hnRNPH1-mediated alternative splicing effect and activated the Akt/mTOR pathway. Furthermore, Akt inhibitor MK2206 treatment reversed the oncogenic function of PRELID1P6. PRELID1P6 was also found to be negatively regulated by miR-1825. Our result showed that PRELID1P6 promotes glioma progression through the hnHNPH1-Akt/mTOR pathway. These findings shed new light on the important role of PRELID1P6 as a novel oncogene for glioma.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In the forming grinding of a cemented carbide micro-drill, edge burrs are generated. To explore the formation of the edge burrs, the grinding parameters, such as feed rate, grinding depth, wheel ...service time, and wheel rotation, are analyzed experimentally. Results show that the burrs on the micro-drill edge are caused by material plastic flow and cumulative effect of deformation under the grinding wheel cutting edge. At the same time, the greater the grinding depth, the greater the material flow and accumulation, and the bigger the edge burrs. When decreasing the feed rate to the grinding wheel, the number of grinding cycles will be increased, and the material accumulation on the micro-drill edge can be removed timeously by abrasive particles. This brought considerable relief in edge burr formation. The grinding wheel turning direction has a significant effect on material plastic deformation and its flowing. The cutting angle of abrasive particles is an acute angle when the grinding wheel rotates clockwise, much material accumulates near the blade, and the edge burrs on the blade are bigger. The cutting angle of an abrasive particle is obtuse when the grinding wheel rotates anticlockwise. The material is gathered towards the back face and departs from the micro-drill with no edge burrs being generated. When the grinding wheel is sharp, there are no distinct edge burrs generated. The results also show that, after grinding for 72 h, the edge burrs are generated as the sharpness decreases: the longer the grinding wheel is used, the bigger the edge burrs.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
With a view to ultra-precision polishing of SiC wafers, the chemical-magnetorheological compound finishing (CMRF) method was proposed based on the principle of the Fenton reaction. To study material ...removal characteristics of CMRF, a force model for polishing pads based on magnetorheological (MR) effects was built. Through the theory of solid-phase particles, this study conducted a force analysis of carbonyl iron powders and abrasives and calculated polishing forces of a single polishing pad based on MR effects on a workpiece surface. Based on this, according to the Preston equation, a material removal model was established. By conducting the CMRF test on monocrystalline SiC wafers, it is found that the test results were consistent with theoretical calculations.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Remarkable progress has been made in reducing the cathodic Pt loading of PEMFCs; however, a huge performance loss appears at high current densities, indicating the existence of a large oxygen ...transport resistance associated with the ultralow Pt loading catalyst layer. To reduce the Pt loading without sacrificing cell performance, it is essential to illuminate the oxygen transport mechanism in the catalyst layer. Toward this goal, an experimental approach to measure the oxygen transport resistance in catalyst layers is proposed and realized for the first time in this study. The measuring approach involves a dual-layer catalyst layer design, which consists of a dummy catalyst layer and a practical catalyst layer, followed by changing the thickness of dummy layer to respectively quantify the local and bulk resistances via limiting current measurements combined with linear extrapolation. The experimental results clearly reveal that the local resistance dominates the total resistance in the catalyst layer.
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IJS, KILJ, NUK, PNG, UL, UM
Mechanical manufacturing process of electric motor induces a residual stress, which increases the iron loss, and affects the efficiency and performance of machine. In this paper, a shear test was ...carried out on a non-oriented electrical steel sheet with a thickness of 0.50 mm and a relative clearance range of 2–12% of the thickness, and the shear force was detected during shearing process. The sheared surface morphology, microhardness distribution and magnetic properties after the shearing processing were also tested. The obtained experimental results indicate that: as the shear clearance increases, the shear force increases, the plastic deformation zone enlarges, and the flow of microstructure becomes intense. In addition, as the shear clearance increases, the depth and work-hardening degree of the work-hardened layer increase, resulting in degraded magnetic properties of the electrical steel. Moreover, when the lateral clearance is 5%, a complete and smooth shear section can be obtained.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Glioma is a kind of lethal malignant tumor, and lacks efficient therapies. Combination therapy has been claimed to be a promising approach to combat cancer, due to its increased anti-cancer effects ...and reduced side effects. This study aimed to investigate the anti-cancer effect and mechanism of combining imatinib with irinotecan or its active metabolite 7-ethyl-10-hydroxycamptothecin (SN-38). First, we found that this drug combination exerted synergistic antitumor effects against glioma in vitro and in vivo. In addition, flow cytometry results proved that the SN-38-induced apoptosis was further enhanced by imatinib, and similar results were observed by determining the protein expression levels of apoptosis biomarkers. Interestingly, p53 expression was elevated by the SN-38 mono-treatment, and was not further increased after the co-treatment; besides, knockdown of p53 could only reduce the expression of cleaved-PARP partially, and weaken the enhanced proliferation inhibition induced by SN-38 plus imatinib, indicating that there might be other factors involved in the synergistic effects besides p53. Meanwhile, the markedly elevated p21 expression was observed only in the combination group, instead of the mono-treated groups. According to the results of p21 knockdown, we found that p21 was also required for the synergistic inhibitory effects. Moreover, we explored and ruled out the possibility of imatinib enhancing the sensitivity of irinotecan by inhibiting drug efflux pumps. Thus, our findings collectively suggest that combining irinotecan with imatinib could be a promising new strategy to fight against glioma.
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•Imatinib synergizes with SN-38 to inhibit glioma cells in vitro.•Imatinib synergizes with irinotecan to arrest tumor growth in vivo.•Both p53 and p21 are required for this synergistic inhibitory effects.•Imatinib didn't affect intracellular accumulation of SN-38 in glioma cells.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Metastasis is the leading cause of death of patients with esophageal squamous cell carcinoma (ESCC). Although an increasing number of studies have demonstrated the involvement of G3BP2 in several ...human cancers, how G3BP2 interacts with long noncoding RNAs and regulates mRNA transcripts in mediating ESCC metastasis remains unclear. In this study, we uncovered that G3BP2 was upregulated in ESCC. Further analysis revealed that upregulation of G3BP2 was significantly correlated with lymph node metastasis, depth of tumor invasion and unfavorable outcomes in ESCC patients. Both in vitro and in vivo functional assays demonstrated that G3BP2 dramatically enhanced ESCC cell migration and invasion. Mechanistically, LINC01554 maintained the high G3BP2 expression in ESCC by protecting G3BP2 from degradation through ubiquitination and the interaction domains within LINC01554 and G3BP2 were identified. In addition, RNA-seq revealed that HDGF was regulated by G3BP2. G3BP2 bound to HDGF mRNA transcript to stabilize its expression. Ectopic expression of HDGF effectively abolished the G3BP2 depletion-mediated inhibitory effect on tumor cell migration. Intriguingly, introduction of compound C108 which can inhibit G3BP2 remarkedly suppressed ESCC cell metastasis in vitro and in vivo. Collectively, this study describes a newly discovered regulatory axis, LINC01554/G3BP2/HDGF, that facilitates ESCC metastasis and will provide novel therapeutic strategies for ESCC.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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