73 research outputs found
Twist Promotes Tumor Metastasis in Basal-Like Breast Cancer by Transcriptionally Upregulating ROR1
Rationale: Twist is a key transcription factor for induction of epithelial-mesenchymal transition (EMT), which promotes cell migration, invasion, and cancer metastasis, confers cancer cells with stem cell-like characteristics, and provides therapeutic resistance. However, the functional roles and targeted genes of Twist in EMT and cancer progression remain elusive.
Methods: The potential targeted genes of Twist were identified from the global transcriptomes of T47D/Twist cells by microarray analysis. EMT phenotype was detected by western blotting and immunofluorescence of marker proteins. The dual-luciferase reporter and chromatin immunoprecipitation assays were employed to observe the direct transcriptional induction of ROR1 by Twist. A lung metastasis model was used to study the pro-metastatic role of Twist and ROR1 by injecting MDA-MB-231 cells into tail vein of nude mice. Bio-informatics analysis was utilized to measure the metastasis-free survival of breast cancer patients.
Results: Twist protein was proved to directly activate the transcription of ROR1 gene, a receptor of Wnt5a in non-canonical WNT signaling pathway. Silencing of ROR1 inhibited EMT process, cell migration, invasion, and cancer metastasis of basal-like breast cancer (BLBC) cells. Knockdown of ROR1 also ameliorated the pro-metastatic effect of Twist. Furthermore, analyses of clinical specimens indicated that high expression of both ROR1 and Twist tightly correlates with poor metastasis-free survival of breast cancer patients.
Conclusion: ROR1 is a targeted gene of Twist. Twist/ROR1 signaling is critical for invasion and metastasis of BLBC cells
Particle scattering induced orbital angular momentum spectrum change of vector Bessel–Gaussian vortex beam
In this paper, we obtain the intensity and phase distributions of the scattering and external fields of a vector Bessel–Gaussian vortex beam in the far-field region after being scattered by a particle. In our analysis, we use the Generalized Lorenz–Mie theory (GLMT) and the angular spectrum decomposition method (ASDM). The orbital angular momentum (OAM) spectra of the fields are analyzed by using the spiral spectrum expansion method, which is a frequently used tool for studying the propagation of vortex beams in turbulent atmospheres. Both scattered and external fields show a significant difference in spiral spectra for particles with different characteristic parameters, such as the size and complex refractive index. We also examine sampling the phase along with a circle and show that it is unable to fully express the information of the fields. This study can provide a theoretical basis for the inversion of characteristic parameters of the Bessel–Gaussian vortex beam and spherical particle by OAM spectra with applications in remote sensing engineering
Research on the Filters for Dual-Inverter Fed Open-End Winding Transformer Topology in Photovoltaic Grid-Tied Applications
Owing to the necessity of the transformer for the multi-parallel inverters connected to the medium-voltage (MV) grid, the conventional multi-parallel inverter topology can be reconfigured to the dual-inverter fed open-end winding transformer (DI-OEWT) topology to obtain lower output voltage harmonics, which can reduce the requirement of the filter inductance. However, due to the special structure of the DI-OEWT topology, the arrangement scheme of the filter can be more than one kind, and different schemes may affect the filter performance. In this paper, research on the existing two kinds of filters, as well as a proposed one, for the DI-OEWT topology used in photovoltaic grid-tied applications is presented. The equivalent circuits of these filters are derived, and based on this, the harmonic suppression capability of these filters is analyzed and compared. Furthermore, a brief parameter design method of these filters is also introduced, and based on the design examples, the inductance and capacitance requirements of these filters are compared. In addition, these filters are also evaluated in terms of the applicability for fault tolerance. At last, the analysis is verified through an experiment on a 30 kW dual-three-level inverter prototype
Enhanced Electromagnetic Coupling in the Walnut-Shaped Nanostructure Array
It is a challenging yet valuable work to prepare a surface-enhanced Raman scattering (SERS) substrate with low cost and high performance by simple methods. In this study, the Ag nanoparticles were sputtered on PS spheres by the magnetron sputtering, which was used as the mask to create the nanostructures by etching the spheres. Because of the heating effect in the etching process, the Ag nanoparticles gathered on the surfaces of PS spheres when the etching time was 60 s. Strong electromagnetic coupling was observed between the gathered Ag nanoparticles as confirmed by FDTD simulation and SERS signals from the probe molecule 4-mercaptobenzoic acid. This structure showed the detection limit for thiram down to 10−8 M
Enhanced Electromagnetic Coupling in the Walnut-Shaped Nanostructure Array
It is a challenging yet valuable work to prepare a surface-enhanced Raman scattering (SERS) substrate with low cost and high performance by simple methods. In this study, the Ag nanoparticles were sputtered on PS spheres by the magnetron sputtering, which was used as the mask to create the nanostructures by etching the spheres. Because of the heating effect in the etching process, the Ag nanoparticles gathered on the surfaces of PS spheres when the etching time was 60 s. Strong electromagnetic coupling was observed between the gathered Ag nanoparticles as confirmed by FDTD simulation and SERS signals from the probe molecule 4-mercaptobenzoic acid. This structure showed the detection limit for thiram down to 10−8 M
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