Platinum (Pt) is recognized as an excellent cocatalyst which not only suppresses the charge carrier recombination of the photocatalyst but also reduces the overpotential for photocatalytic H2 generation. Albeit of its good performance, the high cost and low abundance restricted the utilization of Pt in large-scale photocatalytic H2 generation. Pt based transition metal alloys are demonstrated to reveal enhanced activities towards various catalytic reactions, suggesting the possibility to substitute Pt as the cocatalyst. In the present work, Pt was partially substituted with Co, Ni, and Fe and Pt-M (M = Co, Ni, and Fe)/g-C3N4 composites were constructed through co-reduction of H2PtCl6 and transition metal salts by the reductant of ethylene glycol. The crystal structure and valence states were measured by X-ray diffractometer (XRD) and X-ray photoelectron spectrometer (XPS), respectively. The higher degree of XRD peaks and larger binding energies for Pt 4f5/2 and Pt 4f7/2 after incorporating Co 2+ ions indicated that Co was successfully introduced into the lattice of Pt and Pt-Co bimetallic alloys was attained through the solvothermal treatment. The morphology was subsequently observed by transmission electron microscope (TEM), which showed a good dispersion of Pt-Co nanoparticles on the surface of g-C3N4.Meanwhile, the shrinkage of lattice fringe after introducing cobalt salt further confirmed the presence of Pt-Co bimetallic alloys. The UV-Vis absorption spectra of g-C3N4 and Pt, Pt-Co deposited g-C3N4 were subsequently performed. It was found that the absorption edges were all consistent for all three samples as anticipated, implying that the band gap energy was maintained after hybridizing with Pt or Pt-Co alloys. Furthermore, the photocatalytic H2 generation was carried out over the as-prepared composites with triethanolamine (TEOA) as sacrificial reagent. Under visible-light illumination, the1% (w) Pt2.5M/g-C3N4 (M = Co, Fe, Ni) composites all exhibited higher or comparable activity towards photocatalytic H2 generation when compared to 1% (w) Pt loaded counterpart. In addition, the atomic ratios of Pt/Co and the loading amount of Pt-Co cocatalyst were modified to optimize the photocatalytic performance, among which, 1% (w) Pt2.5Co/g-C3N4 composite revealed the highest activity with a 1.6-time enhancement. Electrochemical impedance spectra (EIS) and photoluminescence (PL) spectra indicated that the enhancement might be attributed to improved charge transfer from g-C3N4 to Pt2.5Co cocatalyst and inhibited charge carrier recombination in the presence of Pt2.5Co cocatalyst. Therefore, the present study demonstrates the great potential to partially replace Pt with low-cost and abundant transition metals and to fabricate Pt based bimetallic alloys as promising cocatalysts for highly efficient photocatalytic H2 generation.
The photocatalytic performance of donor–acceptor structured g-C3N4 was enhanced by up to 3.83-fold due to the accelerated intramolecular charge transfer.
Based on many studies, trichosanthin (TCS) has an antiviral effect that regulates immune response, and targets cancer cells to exert broad-spectrum anti-tumor pharmacological activities. It is speculated that TCS may be a potential natural active drug for preventing as well as treating cervical cancer. But the clearer impact along with underlying TCS mechanism on cervical cancer are still unclear. The purpose of this study is to investigate the function and potential mechanism of TCS in cervical cancer. We measured the viability of cervical cancer cell lines (HeLa & caski cells) using CCK-8 analysis, detected cell proliferation efficiency through Ki-67 staining, analyzed cell apoptosis rate via flow cytometry as well as annexin V-FITC/PI double staining, performed apoptosis-related protein expression through western blotting, evaluated cell migration along with invasion by wound as well as transwell assays, carried out MMP via JC-1 and Rh123 fluorescent probes, as well as detected intracellular ATP and ROS levels by flow cytometry, respectively, to evaluate the effects of TCS. We found that TCS inhibited viability along with proliferation, induced apoptosis, as well as inhibited HeLa & caski cell migration along with invasion in a time-and dose-dependent manner. Additionally, TCS also reduced MMP, and the production of adenosine triphosphate, as well as induced the increase of intracellular reactive oxygen species in cancer cell lines. In accordance with the present studies, TCS inhibits HeLa & caski cell proliferation along with migration but promotes their apoptosis, which may be mediated by regulating oxidative stress.
Accurate and automatic carotid artery segmentation for magnetic resonance (MR) images is eagerly expected, which can greatly assist a comprehensive study of atherosclerosis and accelerate the translation. Although many efforts have been made, identification of the inner lumen and outer wall in diseased vessels is still a challenging task due to complex vascular deformation, blurred wall boundary, and confusing componential expression. In this paper, we introduce a novel fully automatic 3D framework for simultaneously segmenting the carotid artery from high-resolution multi-contrast MR sequences based on deep learning. First, an optimal channel fitting structure is designed for identity mapping, and a novel 3D residual U-net is used as a basic network. Second, high-resolution MR images are trained using both patch-level and global-level strategies, and the two pre-segmentation results are optimized based on structural characteristics. Third, the optimized pre-segmentation results are cascaded with the patch-cropped MR volume data and trained to segment the carotid lumen and wall. Extensive experiments demonstrate the proposed method outperforms the state-of-the-art 3D Unet-based segmentation models.
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