RESUMO
An ultra-broadband TE polarizer with outstanding performance is proposed and demonstrated on a 220â nm-thick silicon-on-insulator platform. The proposed TE polarizer consists of six cascaded directional couplers assisted by subwavelength grating (SWG) structures and two Euler bends. The SWG is introduced to control the coupling strength of the fundamental TE and TM modes. Simulations show that our proposed TE polarizer possesses ultra-low insertion loss (IL < 0.3â dB) for the fundamental TE mode and an ultrahigh polarization extinction ratio (PER > 35â dB) for the fundamental TM mode covering all communication bands from 1260â nm to 1675â nm. The experimental results show that the fabricated TE polarizer has excellent performance of IL < 0.6â dB and PER > 35â dB over a 210â nm bandwidth, which is limited by the measurement equipment. To the best of our knowledge, our proposed TE polarizer is the first single-etched all-silicon TE polarizer with such high PER covering all communication bands.
RESUMO
We previously reported 5-((8-methoxy-2-methylquinolin-4-yl)amino)-1H-indole- 2-carbohydrazide derivatives as new Nur77 modulators. In this study, we explored whether the 8-methoxy-2-methylquinoline moiety and bicyclic aromatic rings at the N'-methylene position were critical for their antitumor activity against hepatocellular carcinoma (HCC). For this purpose, a small library of 5-substituted 1H-indole-2-carbohydrazide derivatives was designed and synthesized. We found that the 8-methoxy-2-methylquinoline moiety was a fundamental structure for its biological function, while the introduction of the bicyclic aromatic ring into the N'-methylene greatly improved its anti-tumor effect. We found that the representative compound 10E had a high affinity to Nur77. The KD values were in the low micromolar (2.25-4.10 µM), which were coincident with its IC50 values against the tumor cell lines (IC50 < 3.78 µM). Compound 10E could induce autophagic cell death of liver cancer cells by targeting Nur77 to mitochondria while knocking down Nur77 greatly impaired anti-tumor effect. These findings provide an insight into the structure-activity relation of Quinoline-Indole-Schiff base derivatives and further demonstrate that antitumor agents targeting Nur77 may be considered as a promising strategy for HCC therapy.
Assuntos
Antineoplásicos/síntese química , Morte Celular Autofágica/efeitos dos fármacos , Indóis/química , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Quinolinas/química , Bases de Schiff/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Sítios de Ligação , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Desenho de Fármacos , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/química , Relação Estrutura-AtividadeRESUMO
Nur77 is a potential target for the treatment of cancer such as HCC. Herein, we detailed the discovery of a novel series of 5-((8-methoxy-2-methylquinolin-4-yl)amino)-1H-indole-2-carbohydrazide derivatives as potential Nur77 modulators. The studies of antiproliferative activity and Nur77-binding affinity of target compounds resulted in the discovery of a lead candidate (10g), which was a good Nur77 binder (KD = 3.58 ± 0.16 µM) with a broad-spectrum antiproliferative activity against all tested hepatoma cells (IC50 < 2.0 µM) and was low toxic to normal LO2 cells. 10g could up-regulate Nur77 expression and mediate sub-cellular localization of Nur77 to induce apoptosis in hepatocellular carcinoma cell lines, which relied on 10g inducing Nur77-dependent autophagy and endoplasmic reticulum stress as the upstream of apoptosis. Moreover, the in vivo assays verified that 10g significantly inhibited xenograft tumor growth. These results indicate that 10g has the potential to be developed as a novel Nur77-targeting anti-hepatoma drug.