RESUMEN
Plant factories have attracted increasing attention because they can produce fresh fruits and vegetables free from pesticides in all weather. However, the emission spectra from current light sources significantly mismatch the spectra absorbed by plants. We demonstrate a concept of using multiple broad-band as well as narrow-band solid-state lighting technologies to design plant-growth light sources. Take an organic light-emitting diode (OLED), for example; the resulting light source shows an 84% resemblance with the photosynthetic action spectrum as a twin-peak blue dye and a diffused mono-peak red dye are employed. This OLED can also show a greater than 90% resemblance as an additional deeper red emitter is added. For a typical LED, the resemblance can be improved to 91% if two additional blue and red LEDs are incorporated. The approach may facilitate either an ideal use of the energy applied for plant growth and/or the design of better light sources for growing different plants.
RESUMEN
Hepatitis B virus- (HBV-) associated hepatocellular carcinoma (HCC) is the most common type of liver cancer. However, the underlying mechanism of HCC tumorigenesis is very complicated and HBV-encoded X protein (HBx) has been reported to play the most important role in this process. Activation of downstream signal pathways of epidermal growth factor receptor (EGFR) family is known to mediate HBx-dependent HCC tumor progression. Interestingly, HER2 (also known as ErbB2/Neu/EGFR2) is frequently overexpressed in HBx-expressing HCC patients and is associated with their poor prognosis. However, it remains unclear whether and how HBx regulates HER2 expression. In this study, our data showed that HBx expression increased HER2 protein level via enhancing its mRNA stability. The induction of RNA-binding protein HuR expression by HBx mediated the HER2 mRNA stabilization. Finally, the upregulated HER2 expression promoted the migration ability of HBx-expressing HCC cells. These findings deciphered the molecular mechanism of HBx-mediated HER2 upregulation in HBV-associated HCC.
Asunto(s)
Proteínas ELAV/metabolismo , Regulación Neoplásica de la Expresión Génica , Virus de la Hepatitis B/metabolismo , Neoplasias Hepáticas/metabolismo , Receptor ErbB-2/biosíntesis , Transactivadores/metabolismo , Células Hep G2 , Virus de la Hepatitis B/genética , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/virología , Estabilidad del ARN/genética , ARN Mensajero/biosíntesis , ARN Mensajero/genética , ARN Neoplásico/biosíntesis , ARN Neoplásico/genética , Receptor ErbB-2/genética , Transactivadores/genética , Regulación hacia Arriba/genética , Proteínas Reguladoras y Accesorias ViralesRESUMEN
A series of pyrenoimidazoles that contained various functional chromophores, such as anthracene, pyrene, triphenylamine, carbazole, and fluorene, were synthesized and characterized by optical, electrochemical, and theoretical studies. The absorption spectra of the dyes are dominated by electronic transitions that arise from the pyrenoimidazole core and the additional chromophore. All of the dyes exhibited blue-light photoluminescence with moderate-to-high quantum efficiencies. They also displayed high thermal stability and their thermal-decomposition temperatures fell within the range 462-512 °C; the highest decomposition temperature was recorded for a carbazole-containing dye. The oxidation propensity of the dyes increased on the introduction of electron-rich chromophores, such as triphenylamine or carbazole. The application of selected dyes that featured additional chromophores such as pyrene, carbazole, and triphenylamine as blue-emissive dopants into multilayered organic light-emitting diodes with a 4,4'-bis(9H-carbazol-9-yl)biphenyl (CBP) host was investigated. Devices that were based on triphenylamine- and carbazole-containing dyes exhibited deep-blue emission (CIE 0.157, 0.054 and 0.163, 0.041), whereas a device that was based on a pyrene-containing dye showed a bright-blue emission (CIE 0.156, 0.135).
