Tetradentate Cyclometalated Platinum(II) Complexes for Efficient and Stable Organic Light-Emitting Diodes

As one of the most important phosphorescent emitters, tetradentate cyclometalated platinum(II) complexes have attracted much attention in recent years, because of the high luminescent efficiency, emission spectra, and color tuned easily, especially for the development of high-efficient deep-blue and “pure” blue emitters and single-doped white organic light-emitting diodes (OLEDs). Also, some platinum(II)-based OLEDs exhibited superior operational stability, indicating their potentials in full-color display and solid-state lighting applications. In this chapter, we will introduce the recent advances of the tetradentate cyclometalated platinum(II) complexes, including pyrazole, N-heterocyclic carbene, imidazole and pyridine-based complexes, molecular design, photophysical properties, and some of their device performances

Preventive Effects of Dendrobium candidum Wall ex Lindl. on the formation of Lung Metastases in BALB/c Mice Injected with 26-M3.1 Colon Carcinoma Cells

Dendrobium candidum Wall ex Lindl. (D. candidum) is a traditional Chinese medicine widely used in Asia. The present study has showed that D. candidum exerted an anti-metastatic effect in mice injected with 26-M3.1 colon carcinoma cells. D. candidum showed the most marked tumor inhibitory rate of 64.5% at a dose of 400 mg/kg body weight (b.w). The mRNA and protein expression of Bax in lung tissue of D. candidum-treated mice was shown to be higher as compared with control mice, whereas the mRNA and protein expression of Bcl-2 showed the opposite trend. Decreased mRNA and protein expression of MMP and increased expression of TIMPs was demonstrated in lung tissues by quantitative polymerase chain reaction and western blot assays. D. candidum reduced the serum cytokine levels of IL-6, IL-12, TNF-α and IFN-γ to a greater extent as compared with the control mice, and administration of 400 mg/kg b.w. resulted in a lower serum cytokine levels as compared with mice treated with 200 mg/kg b.w. Eleven compounds were in the D. candidum leaf, of which the functional contents may help to generate novel treatments for the prevention of lung metastases. The results of the present study have demonstrated that D. candidum had a potent in vivo antitumor and anti-metastatic effect in BALB/c mice injected with 26-M3.1 cells

Root Hair Single Cell Type Specific Profiles of Gene Expression and Alternative Polyadenylation Under Cadmium Stress

Transcriptional networks are tightly controlled in plant development and stress responses. Alternative polyadenylation (APA) has been found to regulate gene expression under abiotic stress by increasing the heterogeneity at mRNA 3′-ends. Heavy metals like cadmium pollute water and soil due to mining and industry applications. Understanding how plants cope with heavy metal stress remains an interesting question. The Arabidopsis root hair was chosen as a single cell model to investigate the functional role of APA in cadmium stress response. Primary root growth inhibition and defective root hair morphotypes were observed. Poly(A) tag (PAT) libraries from single cell types, i.e., root hair cells, non-hair epidermal cells, and whole root tip under cadmium stress were prepared and sequenced. Interestingly, a root hair cell type-specific gene expression under short term cadmium exposure, but not related to the prolonged treatment, was detected. Differentially expressed poly(A) sites were identified, which largely contributed to altered gene expression, and enriched in pentose and glucuronate interconversion pathways as well as phenylpropanoid biosynthesis pathways. Numerous genes with poly(A) site switching were found, particularly for functions in cell wall modification, root epidermal differentiation, and root hair tip growth. Our findings suggest that APA plays a functional role as a potential stress modulator in root hair cells under cadmium treatment

Root Hair Single Cell Type Specific Profiles of Gene Expression and Alternative Polyadenylation Under Cadmium Stress

Transcriptional networks are tightly controlled in plant development and stress responses. Alternative polyadenylation (APA) has been found to regulate gene expression under abiotic stress by increasing the heterogeneity at mRNA 3′-ends. Heavy metals like cadmium pollute water and soil due to mining and industry applications. Understanding how plants cope with heavy metal stress remains an interesting question. The Arabidopsis root hair was chosen as a single cell model to investigate the functional role of APA in cadmium stress response. Primary root growth inhibition and defective root hair morphotypes were observed. Poly(A) tag (PAT) libraries from single cell types, i.e., root hair cells, non-hair epidermal cells, and whole root tip under cadmium stress were prepared and sequenced. Interestingly, a root hair cell type-specific gene expression under short term cadmium exposure, but not related to the prolonged treatment, was detected. Differentially expressed poly(A) sites were identified, which largely contributed to altered gene expression, and enriched in pentose and glucuronate interconversion pathways as well as phenylpropanoid biosynthesis pathways. Numerous genes with poly(A) site switching were found, particularly for functions in cell wall modification, root epidermal differentiation, and root hair tip growth. Our findings suggest that APA plays a functional role as a potential stress modulator in root hair cells under cadmium treatment

Nrf2 Down-Regulation by Camptothecin Favors Inhibiting Invasion, Metastasis and Angiogenesis in Hepatocellular Carcinoma

Higher oxidant stress capacity could promote invasion and metastasis. A previous study showed hepatocellular carcinoma (HCC) expressed more Nrf2 than para-carcinoma tissue. The chemotherapeutics such as epirubicin (EPI) could increase Nrf2 expression, while Camptothecin (CPT) could inhibit tumor growth by down-regulating the key molecule of antioxidant stress signal—Nrf2. The role of Nrf2 in invasion and metastasis was still unclear. In this study, we use EPI and CPT to determine the invasion and metastasis in Huh7 cells, H22 and Huh7 mouse models. In Huh7 cells, Nrf2 expression and ROS level were found increased after incubation with EPI by western blot and flow cytometry assay. But with the combination of EPI and CPT, inhibition of Nrf2 could decrease proliferation, invasion, and metastasis, which were investigated by CCK8 assay, wound healing, and Transwell assays. In Huh7 and H22 mouse models, EPI promoted Nrf2 up-regulation and nucleus translocation. Tumor growth was obviously inhibited with a single application of EPI or CPT. The combination of EPI and CPT could inhibit Nrf2 expression but demonstrated more suppressing effect of tumor growth than EPI. Western blot and immunohistochemical staining study revealed that Nrf2 inhibition was beneficial in decreasing the expression of N-cadherin, MMP9, Snail as well as Twist, and increasing E-cadherin, which were associated with epithelial–mesenchymal transition (EMT). Nrf2 down-regulation promoted lung metastasis of H22 cells in vivo. In addition, H&E staining and immunofluorescence staining of VEGFR suggested angiogenesis of Huh7 and H22 tumors was reduced. In conclusion, down-regulation of Nrf2 demonstrated inhibition of invasion, metastasis, and angiogenesis of hepatoma, which may provide a potential therapy in HCC

A comprehensive numerical analysis of cross-flow vortex-induced vibrations for top tension risers under different flows

In this paper, the cross-flow vortex-induced vibration (VIV) response of a top tension riser under different flow fields are comprehensively studied using a numerical simulation model based on time domain analysis. A semi-empirical time-domain analysis model that considers the fluid-structure interaction problem in the riser vibration process is proposed and verified by comparison with the previous experimental results. The influence of the flow velocity, the spanwise length of the flow field, and other factors on the VIV amplitude and frequency characteristics of the riser is analyzed in detail. The results show that the VIV response of the riser exhibits obvious multi-modal characteristics, which are accompanied by modal transition, lock-in vibration, synchronous vibration, etc., and the region where the lock-in or synchronous vibration occurs is exactly the region where the crest of the amplitude curve locates. Besides, the VIV intensity of the riser in the stepped flow and uniform flow fields show a tendency of fluctuating increase with the increase of the flow velocity and spanwise length of the flow field, while the VIV intensity of the riser in shear flow is positively correlated with the flow velocity and spanwise length of the flow field. The present study may provide a reference for the prediction of VIV of marine riser in the complex current environment