RESUMO
After the publication of the article, an interested reader drew to the authors' attention that there appeared to be a pair of overlapping data panels in Fig. 4C on p. 1726 [specifically, the 'Untransfected' and 'Control shRNA' data panels for the ADM (24 h) experiments]. The authors have consulted their original data, and have realized that this figure was inadvertently assembled incorrectly. Furthermore, they have noticed that Fig. 1 on p. 1724 also contained errors that arose during its assembly; essentially, several of the data panels in Fig. 1C, showing the detection of FANCD2 focus formation via immunofluorescence experiments, were selected inappropriately. The corrected versions of Figs. 1 and 4, containing the corrected data panels for Figs. 1C and 4C respectively, are shown on the next page. Note that these errors did not affect the results or the conclusions reported in this work. The authors all agree to this Corrigendum, and are grateful to the Editor of Oncology Reports for allowing them to have the opportunity to correct these mistakes. Lastly, the authors apologize to the readership for any inconvenience these errors may have caused. [Oncology Reports 29: 17211729, 2013; DOI: 10.3892/or.2013.2295].
RESUMO
Two-dimensional (2D) materials with the advantage of low interlayer shear strain are ultilized as lubricants in aerospace and precision manufacturing. Moiré superlattices (MSL), with attractive physical properties of electronic structures, interlayer hybridization and atomic forces, have been widely investigated in superlubricity, which is caused by elimination of interlayer lock-in by incommensurate atomic reconstruction. Although the foundations of superlubricity and the development of 2D lubricants via vanishing friction have been investigated, it is still important to comprehensively reveal the influence of MSL on the interlayer van der Waals (vdW) interactions of 2D lubricants. Here, the contributions of lattice distortions of solute-doped twisted bilayers (Mo, X)S2 (X = Al, Ti, V and Cr) to superlubricity are comprehensively investigated by high-throughput modelling and DFT-D2 calculations. It is revealed that the lattice distortion not only breaks the interlayer balance of repulsion and van der Waals interactions but also yields layer corrugation. These layer-corrugation-induced changes of the interlayer interactions and spacing distances are utilized to optimize lubricity, which matches with the experimental friction coefficients in the order of (Mo, Al)S2 > (Mo, Cr)S2 > MoS2 >(Mo, V)S2 >(Mo, Ti)S2. The evolutions of the band structures show an exponential relationship of the band edge width and layer deformations, paving a path to accelerate the development of advanced superlubricity materials via lattice distortions.
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Atomic oxygen (AO) has an important influence on the performance of solid lubricating materials applied in space. The tribological behaviors of both sputtered WS2 films without and with a dense layer were mainly investigated under the ex situ AO irradiation condition. AO irradiation results in the worse tribological property for the WS2 film without a dense layer. On the contrary, it is surprising that the WS2 film with the dense layer exhibits a lower friction coefficient after irradiation, which is different from the reported results that the solid lubricating films always increased the friction and wear because the surfaces of the films were oxidized by AO. Meanwhile, it is found that the generated W oxides contributes to the partial surface of the wear track becoming smooth because of the shear and slip of crystal planes for WS2 crystals on the surface of the dense layer. Eventually, the lubricating mechanisms of the irradiated WS2 films are also revealed via correlating the friction and wear characteristics of the films.
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To find a facile way to produce a hydrophobic sponge that can effectively absorb oils is urgent to resolve the environmental pollution and ecological disaster caused by oil spillage. Here, alkylated carbon dots (C dots) were prepared from pyrolysis of a mixture of dodecylamine and citric acid followed by purification through silica gel column chromatography. Polyurethane sponge was modified by alkylated C dots by a simple dip-coating method, which endows the photoluminescent and hydrophobic sponge with good absorption capacities for various oils and nonpolar organic solvents with high recyclability. The water contact angle of the modified sponge can reach 138.8°. Interestingly, the sponge enables visual absorption under UV irradiation in the dark, which has not been achieved by other carbon-based adsorbents. The sponge was further made ferromagnetic by introducing alkylated Fe3O4 nanoparticles into its structure, which allowed controllable oil-water separation.
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Hydrogenated graphite-like carbon composite films containing silicon (Si) and silver (Ag) (g-C:H:Si:Ag) were prepared by middle frequency magnetron sputtering deposition in argon (Ar) and acetylene (C2H2) mixture gases. The effects of precursor C2H2 fraction on the microstructure and properties were studied. The results of Raman and X-ray photoelectron spectroscope (XPS) revealed that the films were dominated by sp² carbon sites. It was observed from transmission electron microscope (TEM) that the films contained nanoparticles mainly consisting of Ag, and their size increased with the decrease in the C2H2 fraction. Si was also found to aggregate in the areas where Ag nanoparticles formed in films with high Si content. The comparative studies on the frictional behaviors of films sliding against aluminum oxide were carried out in ambient air and saline solution. The g-C:H:Si:Ag films still exhibited outstanding frictional properties even when the test environment shifts from ambient air to saline solution.
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Tungsten disulfide-polydopamine-copper (WS2-PDA-Cu) nanocomposites were first prepared by a green and effective biomimetic strategy and then used as a lubricant additive in polyalkylene glycol (PAG). The biomimetic strategy is inspired by the adhesive proteins in mussels. WS2 nanosheets were decorated by uniformly dispersed Cu nanoparticles (Cu NPs). The WS2-PDA-Cu nanocomposites with good dispersion stability, showed better friction reducing and anti-wear properties than WS2, Cu NPs and WS2-Cu dispersed in PAG base oil. The average friction coefficient and wear volume were reduced by 33.56% and 97.95%, respectively, at 150 °C under a load of 100 N for the optimal concentration of 0.9 wt%. The lubrication mechanism was discussed.
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Doped graphite-like coating (GLC) has aroused great interest as one of the most promising protective materials in marine applications. However, there is a lack of systematic research on the tribocorrosion and antifouling performance of doped GLC coatings in harsh marine environments. Herein, a multifunctional (Cr, Cu)-GLC coating with combined antifouling and tribocorrosion properties was prepared via a magnetron sputtering method. The experimental results indicate that the resultant coatings changed from a dense structure to a loose columnar structure with the increment of Cr and Cu doping amount. At the same time, the hardness of the coating gradually decreases, but the contact angle between coating and seawater gradually increases. The algae adhesion test reveal that the algae density on the surface of the (Cr, Cu)-GLC coating decreases from about 565 to 70/mm2 as the amount of doping increased. However, on the contrary, the friction coefficient of the coating under OCP condition increases from 0.06 to about 0.35. Overall, the mild doped (Cr, Cu)-GLC coating exhibits the best comprehensive properties, combining antifouling and tribocorrosion properties. The corresponded mechanisms are discussed in terms of the coating microstructure, antifouling, and tribocorrosion behavior.
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Molybdenum disulfide (MoS2) was prepared successfully via hydrothermal reaction at 200 degrees C in water/ethanol (1:1) solvent system using the ammonium molybdate and sodium thiosulfate as the molybdenum sources and sulfur sources, 1-butyl-3-methylimidazolium chloride salt [BMIM][Cl] as the additive agent. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the morphology and structure of flower-like products. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy spectrum analysis results show that the as-prepared product is a pure phase of MoS2. The prepared products are used as electrode materials for Li-ion batteries and showed excellent cycle stability and high Coulombic efficiency at a current density of 200 mA x g(-1) in the voltage range of 0.01 - 3.00 V (vs. Li/Li+). In addition, this paper also examined the influence of the reaction time and the amount of template agent on morphology, and discussed the reaction mechanism of the formation of flower-like morphology.
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In the present study, we downregulated FANCF expression by small interfering RNA (siRNA) in OVCAR ovarian cancer cells to address the effects of decreased FANCF expression on the function of the Fanconi anemia (FA)/breast cancer susceptibility gene (BRCA) pathway. Furthermore, we investigated whether this method increases the sensitivity of OVCAR3 cells to adriamycin (ADM) and the possible mechanism(s). We found that silencing of FANCF inactivated the FA/BRCA pathway by decreasing the monoubiquitination and focus formation of FANCD2 and reduced the function of the FA/BRCA pathway, resulting in the inhibition of cell proliferation, increased cell apoptosis and DNA damage in OVCAR3 cells. Moreover, we observed that silencing of FANCF enhanced the antiproliferative effect of ADM in OVCAR3 cells and increased ADM intracellular accumulation consequently sensitizing OVCAR3 cells to ADM. Furthermore, silencing of FANCF increased cell apoptosis of OVCAR3 cells which was caused by decreased mitochondrial membrane potential (MMP)-induced DNA damage, activated Jun N-terminal kinase (JNK), increased release of cytochrome c, increased expression of cleaved caspase-3 and poly(ADP-ribose) polymerase (PARP) dependent on JNK activation following treatment of ADM. Collectively, we confirm that silencing of FANCF sensitizes OVCAR3 ovarian cancer cells to ADM, suggesting that FANCF may serve as a potential target for therapeutic strategies in the treatment of ovarian cancer.
Assuntos
Apoptose/efeitos dos fármacos , Doxorrubicina/farmacologia , Proteína do Grupo de Complementação F da Anemia de Fanconi/genética , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/terapia , RNA Interferente Pequeno/genética , Apoptose/genética , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Caspase 3/genética , Caspase 3/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Terapia Combinada , Citocromos c/genética , Citocromos c/metabolismo , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/genética , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Anemia de Fanconi/genética , Anemia de Fanconi/metabolismo , Proteína do Grupo de Complementação F da Anemia de Fanconi/metabolismo , Feminino , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Potencial da Membrana Mitocondrial/genética , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/metabolismo , Poli(ADP-Ribose) Polimerases/genética , Poli(ADP-Ribose) Polimerases/metabolismo , Interferência de RNA , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genéticaRESUMO
A highly crosslinking network combined with a fullerene-like structure is disclosed in a hydrogenated amorphous carbon film. The very soft carbon film exhibits super-low friction and excellent wear resistance even under a Hertzian contact pressure comparable to its hardness under vacuum, which is an extraordinary tribological behavior in the filed of solid lubrication films or coatings.