Simultaneous enhancement of out-coupling efficiency, internal quantum efficiency, and color purity in thermally activated delayed fluorescence (TADF) emitters is highly desired for the practical ...application of these materials. We designed and synthesized two isomeric TADF emitters, 2DPyM-mDTC and 3DPyM-pDTC, based on di(pyridinyl)methanone (DPyM) cores as the new electron-accepting units and di(tert-butyl)carbazole (DTC) as the electron-donating units. 3DPyM-pDTC, which is structurally nearly planar with a very small ΔE ST, shows higher color purity, horizontal ratio, and quantum yield than 2DPyM-mDTC, which has a more flexible structure. An electroluminescence device based on 3DPyM-pDTC as the dopant emitter can reach an extremely high external quantum efficiency of 31.9% with a pure blue emission. This work also demonstrates a way to design materials with a high portion of horizontal molecular orientation to realize a highly efficient pure-blue device based on TADF emitters.
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IJS, KILJ, NUK, PNG, UL, UM
Talins are adaptor proteins that regulate focal adhesion signaling by conjugating integrins to the cytoskeleton. Talins directly bind integrins and are essential for integrin activation. We ...previously showed that β1 integrins are activated in metastatic prostate cancer (PCa) cells, increasing PCa metastasis to lymph nodes and bone. However, how β1 integrins are activated in PCa cells is unknown. In this study, we identified a novel mechanism of β1 integrin activation. Using knockdown experiments, we first demonstrated that talin1, but not talin2, is important in β1 integrin activation. We next showed that talin1 S425 phosphorylation, but not total talin1 expression, correlates with metastatic potential of PCa cells. Expressing a non-phosphorylatable mutant, talin1(S425A), in talin1-silenced PC3-MM2 and C4-2B4 PCa cells, decreased activation of β1 integrins, integrin-mediated adhesion, motility and increased the sensitivity of the cells to anoikis. In contrast, reexpression of the phosphorylation-mimicking mutant talin1(S425D) led to increased β1 integrin activation and generated biologic effects opposite to talin1(S425A) expression. In the highly metastatic PC3-MM2 cells, expression of a non-phosphorylatable mutant, talin1(S425A), in talin1-silenced PC3-MM2 cells, abolished their ability to colonize in the bone following intracardiac injection, while reexpression of phosphorylation-mimicking mutant talin1(S425D) restored their ability to metastasize to bone. Immunohistochemical staining demonstrated that talin S425 phosphorylation is significantly increased in human bone metastases when compared with normal tissues, primary tumors or lymph node metastases. We further showed that p35 expression, an activator of Cdk5, and Cdk5 activity were increased in metastatic tumor cells, and that Cdk5 kinase activity is responsible for talin1 phosphorylation and subsequent β1 integrin activation. Together, our study reveals Cdk5-mediated phosphorylation of talin1 leading to β1 integrin activation is a novel mechanism that increases metastatic potential of PCa cells.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The antiferroelectricity in HfZrO 2 (HZO) annealed at 600 °C with an abrupt turn ON of FET characteristics with SSmin = 23 mV/dec and SSavg = 50 mV/dec over 4 decades of IDS is demonstrated. The near ...non-hysteresis is achieved with an antiferroelectric-like HZO due to a small remanent polarization and a coercive field. A feasible concept of coupling the antiferroelectric and ferroelectric type HZO are used for low-power electronics and the memory applications, respectively.
This paper investigates the effectiveness of using securities class action lawsuits in monitoring defendant firms by institutional lead plaintiffs from two aspects: (1) immediate litigation outcomes, ...including the probability of surviving the motion to dismiss and the settlement amount, and (2) subsequent governance improvement such as changes in board independence. Using a large sample of securities lawsuits from 1996 to 2005, we show that institutional investors are more likely to serve as the lead plaintiff for lawsuits with certain characteristics. After controlling for these determinants of having an institutional lead plaintiff, we show that securities class actions with institutional owners as lead plaintiffs are less likely to be dismissed and have larger monetary settlements than securities class actions with individual lead plaintiffs. This effect exists for various types of institutions including public pension funds. We also find that, after the lawsuit filings, defendant firms with institutional lead plaintiffs experience greater improvement in their board independence than defendant firms with individual lead plaintiffs. Our study suggests that securities litigation is an effective disciplining tool for institutional owners.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
A previous genetic study has suggested that schizophrenia, bipolar disorder, major depressive disorder, autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) share common ...disease-associated genes. However, whether individuals with first-degree relatives (FDRs) with schizophrenia have a higher risk of these major psychiatric disorders requires further investigation. This study used Taiwan's National Health Insurance Research Database and identified 151 650 patients with schizophrenia and 227 967 individuals with FDRs with schizophrenia. The relative risks (RRs) of schizophrenia and other major psychiatric disorders were assessed in individuals with FDRs with schizophrenia. The individuals with FDRs with schizophrenia exhibited higher RRs (95% confidence interval) of major psychiatric disorders, namely schizophrenia (4.76, 4.65-4.88), bipolar disorder (3.23, 3.12-3.35), major depressive disorder (2.05, 2.00-2.10), ASD (2.55, 2.35-2.77) and ADHD (1.31, 1.25-1.37) than were found in the total population. Several sensitivity analyses were conducted to confirm these results. A dose-dependent relationship was observed between the risks of major psychiatric disorders and the numbers of FDRs with schizophrenia. The increased risks of major psychiatric disorders were consistent in different family relationships, namely among parents, offspring, siblings and twins. Our study supports the familial dose-dependent co-aggregation of schizophrenia, bipolar disorder, major depressive disorder, ASD and ADHD, and our results may prompt governmental public health departments and psychiatrists to focus on the mental health of individuals with FDRs with schizophrenia.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This paper examines the impact of hedge fund activism on corporate tax avoidance. We find that relative to matched control firms, businesses targeted by hedge fund activists exhibit lower tax ...avoidance levels prior to hedge fund intervention, but experience increases in tax avoidance after the intervention. Moreover, findings suggest that the increase in tax avoidance is greater when activists have a successful track record of implementing tax changes and possess tax interest or knowledge as indicated by their Securities and Exchange Commission (SEC) 13D filings. We also find that these greater tax savings do not appear to result from an increased use of high-risk and potentially illegal tax strategies, such as sheltering. Taken together, the results suggest that shareholder monitoring of firms, in the form of hedge fund activism, improves tax efficiency.
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BFBNIB, CEKLJ, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Chondrosarcoma is the second most common sarcoma in bone malignancy and is characterized by a high metastatic potential. Angiogenesis is essential for the cancer metastasis. Endothelin-1 (ET-1) has ...been implicated in tumor angiogenesis and metastasis. However, the relationship of ET-1 with vascular endothelial growth factor (VEGF) expression and angiogenesis in human chondrosarcoma cells is mostly unknown. Here, we found that the expression of ET-1 and VEGF were correlated with tumor stage and were significantly higher than that in the normal cartilage. Exogenous ET-1 with chondrosarcoma cells promoted VEGF expression and subsequently increased migration and tube formation in endothelial progenitor cells. ET-1 increased VEGF expression and angiogenesis through ETAR, integrin-linked kinase (ILK), Akt and hypoxia-inducible factor-1α (HIF-1α) signaling cascades. Knockdown of ET-1 decreased VEGF expression and also abolished chondrosarcoma conditional medium-mediated angiogenesis in vitro as well as angiogenesis effects in the chick chorioallantoic membrane and Matrigel plug nude mice model in vivo. In addition, in the xenograft tumor angiogenesis model, knockdown of ET-1 significantly reduced tumor growth and tumor-associated angiogenesis. Taken together, these results indicate that ET-1 occurs through ETAR, ILK and Akt, which in turn activates HIF-1α, resulting in the activation of VEGF expression and contributing to the angiogenesis and tumor growth of human chondrosarcoma cells.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We integrated four gene expression profile data sets, namely two different pair-matched stage I lung adenocarcinoma data sets, secondary metastatic tumors vs benign tumors and lung tumor metastasizes ...to the brain, and we identified one kinase, T-LAK Cell-Originated Protein Kinase (TOPK), as a putative gene that promotes metastasis. To delineate the role of TOPK in lung cancer, we showed that overexpression of TOPK, but not a catalytically inactive form of TOPK, can enhance the migration and invasion of lung fibroblasts or cells with low TOPK expression. In addition, TOPK-induced cell migration was shown to be a PI3K/AKT-dependent event. TOPK concurrently promoted AKT phosphorylation at Ser(473) and decreased the phosphatase and tensin homolog (PTEN) levels, whereas TOPK knockdown had the reverse effects. LY294002, a PI3K inhibitor, did not inhibit the TOPK-induced decrease in PTEN, and co-expression of PTEN significantly reduced TOPK-induced AKT phosphorylation in a dose-dependent manner; these results indicate that the TOPK-mediated PTEN decrease has an upstream role in regulating PI3K/AKT-stimulated migration. Using immunohistochemical analysis of lung cancer tissue samples, we showed that a high TOPK expression level correlates strongly with reduced overall and disease-free survivals. Moreover, an inverse correlation between TOPK and PTEN expression was present and is consistent with the biochemical findings. Finally, a combination of high TOPK and low PTEN expression was inversely correlated with overall and disease-free survivals, independent of other pathologic staging factors. Our results suggest that TOPK is a potential therapeutic target in lung cancer that promotes cell migration by modulating a PI3K/PTEN/AKT-dependent signaling pathway; they also suggest that high TOPK expression, either alone or in combination with a low level of PTEN, may serve as a prognostic marker for lung cancer.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A total suspended particulate (TSP) sample was collected hourly in Xi'an, an inland megacity of China near the Loess Plateau, during a dust storm event of 2013 (9 March 18:00-12 March 10:00 LT), ...along with a size-resolved aerosol sampling and an online measurement of PM sub(2.5). The TSP and size-resolved samples were determined for elemental carbon (EC), organic carbon (OC), water-soluble organic carbon (WSOC) and nitrogen (WSON), inorganic ions and elements to investigate chemistry evolution of dust particles. Hourly concentrations of Cl super(-), NO super(-) sub(3), SO sub(4) super(2-), Na super(+) and Ca super(2+) in the TSP samples reached up to 34, 12, 180, 72 and 28 mu g m super(-3), respectively, when dust peak arrived over Xi'an. Chemical compositions of the TSP samples showed that during the whole observation period NH super(+) sub(4) and NO super(-) sub(3) were linearly correlated with each other (r super(2)=0.76) with a molar ratio of 1 : 1, while SO sub(4) super(2-) and Cl super(-) were well correlated with Na super(+), Ca super(2+), Mg super(2+) and K super(+) (r super(2) > 0.85). Size distributions of NH super(+) sub(4) and NO super(-) sub(3) presented a same pattern, which dominated in the coarse mode (> 2.1 mu m) during the event and predominated in the fine mode (< 2.1 mu m) during the non-event. SO sub(4) super(2-) and Cl super(-) also dominated in the coarse mode during the event hours, but both exhibited two equivalent peaks in both the fine and the coarse modes during the non-event, due to the fine-mode accumulations of secondarily produced SO sub(4) super(2-) and biomass-burning-emitted Cl super(-) and the coarse-mode enrichments of urban soil-derived SO sub(4) super(2-) and Cl super(-). Linear fit regression analysis further indicated that SO sub(4) super(2-) and Cl super(-) in the dust samples possibly exist as Na sub(2)SO sub(4), CaSO sub(4) and NaCl, which directly originated from Gobi desert surface soil, while NH super(+) sub(4) and NO super(-) sub(3) in the dust samples exist as NH sub(4)NO sub(3). We propose a mechanism to explain these observations in which aqueous phase of dust particle surface is formed via uptake of water vapor by hygroscopic salts such as Na sub(2)SO sub(4) and NaCl, followed by heterogeneous formation of nitrate on the liquid phase and subsequent absorption of ammonia. Our data indicate that 54 plus or minus 20% and 60 plus or minus 23% of NH super(+) sub(4) and NO super(-) sub(3) during the dust period were secondarily produced via this pathway, with the remaining derived from the Gobi desert and Loess Plateau, while SO sub(4) super(2-) in the event almost entirely originated from the desert regions. Such cases are different from those in the East Asian continental outflow region, where during Asia dust storm events SO sub(4) super(2-) is secondarily produced and concentrates in sub-micrometer particles as (NH sub(4)) sub(2)SO sub(4) and/or NH sub(4)HSO sub(4). To the best of our knowledge, the current work for the first time revealed an infant state of the East Asian dust ageing process in the regions near the source, which is helpful for researchers to understand the panorama of East Asian dust ageing process from the desert area to the downwind region.
Three blue‐light emitting dipyrenylbenzene derivatives, 1‐(4‐(1‐pyrenyl)phenyl)pyrene (PPP), 1‐(2,5‐dimethoxy‐4‐(1‐pyrenyl)phenyl)pyrene (DOPPP), and 1‐(2,5‐dimethyl‐4‐(1‐pyrenyl)phenyl)pyrene ...(DMPPP), have been prepared by the Suzuki coupling reaction of aryl dibromides with pyreneboronic acid in high yields. These compounds exhibit high glass‐transition temperatures of 97–137 °C and good film‐forming ability. As revealed from single‐crystal X‐ray analysis, these dipyrenylbenzenes adopt a twisted conformation with inter‐ring torsion angles of 44.5°–63.2° in the solid state. The twisted structure is responsible for the low degree of aggregation in the thin films that leads to fluorescence emission of the neat films at 446–463 nm, which is shorter than that of the typical pyrene excimer emission. The low degree of aggregation is also conducive for the observed high fluorescence quantum yields of 63–75%. In organic light‐emitting diode (OLED) applications, these dipyrenylbenzenes can be used as either the charge transporter or host emitter. The non‐doped blue OLEDs that employ these compounds as the emissive layer can achieve a very high external quantum efficiency (ηext) of 4.3–5.2%. In particular, the most efficient DMPPP‐based device can reach a maximum ηext of 5.2% and a very high luminescence of 40 400 cd m–2 in the deep‐blue region with Commission Internationale d'Énclairage (CIE) coordinates of (0.15, 0.11).
The three dipyrenylbenzene derivatives, 1‐(4‐(1‐pyrenyl)phenyl)pyrene (PPP), 1‐(2,5‐dimethoxy‐4‐(1‐pyrenyl)phenyl)pyrene (DOPPP), and 1‐(2,5‐dimethyl‐4‐(1‐pyrenyl)phenyl)pyrene (DMPPP), exhibit efficient blue photo‐ and electro‐luminescence in the thin film state. The non‐doped blue organic light‐emitting diodes that use these compounds as the emissive layer can achieve very high external quantum efficiencies of 4.3–5.2 %.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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