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The impacts of the solid volume fraction Vs and particle size dp on the total and local gas holdups in gas‐liquid‐solid bubble columns under different flow regimes were investigated. The flow regimes discussed were the discrete bubble regime (DBR), transition regime (TR), bubble coalescence regime (BCR), and strong turbulent regime (STR). The results demonstrated that the bed average gas holdup εg decreased with higher solid volume fraction in DBR, TR, and BCR. The increment of the solid volume fraction promoted bubble coalescence and also can enhance the particle effect on the average gas holdup. The εg changed slightly when shifting the Vs or dp in STR. A new correlation for εg was developed considering the particle properties and the flow regimes studied. [ABSTRACT FROM AUTHOR]

Electrochemical CO2 reduction to value‐added chemicals and fuels using renewable energy represents a promising strategy for reducing CO2 emissions and achieving effective energy storage. In this work, nano‐sized CuO catalysts were prepared by using the homogeneous precipitation method for electrochemical CO2 reduction to CO. The CO2 reduction studies combined with the characterization results show that structure‐activity relationships of the CuO catalysts depend on the calcination temperature. The as‐synthesized CuO catalysts calcined at different temperatures are capable of reducing CO2 to generate syngas with tunable CO/H2 ratios of 1 : 2 to 2 : 1. The desired CuO‐400 catalyst exhibits good morphology, small particle size, and enriched oxygen‐vacancy defects and, therefore, shows good performance for electrochemical CO2 reduction to CO. Under the given potential of −0.93 V vs. RHE, CuO‐400 exhibits good reduction activity and selectivity with a great electrochemically active surface area normalized CO partial current density of 1.44 mA/cm2 and a high CO faradaic efficiency of 48.2 %. The deactivation of CuO‐400 in the long‐term test is associated with the increase in particle size, the reduction of CuO to Cu2O and metallic Cu, and the coverage of surface active sites by the formed carbonate species. Our findings indicate that CuO catalysts with tunable physicochemical properties are promising candidates for electrochemical CO2 reduction to produce syngas. [ABSTRACT FROM AUTHOR]

Dihydrotanshinone I (DHTS), extracted from Salvia miltiorrhiza, was found to be the most effective compound of tanshen extracts against cancer cells in our previous studies. However, the therapeutic benefits and underlying mechanisms of DHTS on ovarian cancer remain uncertain. In this study, we demonstrated the cytocidal effects of DHTS on chemosensitive ovarian cancer cells with or without platinum‐based chemotherapy. DHTS was able to inhibit proliferation and migration of ovarian cancer cells in vitro and in vivo through modulation of the PI3K/AKT signalling pathways. Combinatorial treatment of DHTS and cisplatin exhibited enhanced DNA damage in ovarian cancer cells. Overall, these findings suggest that DHTS induces ovarian cancer cells death via induction of DNA damage and inhibits ovarian cancer cell proliferation and migration. [ABSTRACT FROM AUTHOR]

As a highly potent and highly selective oral inhibitor of FLT3/AXL, gilteritinib showed activity against FLT3D835 and FLT3‐ITD mutations in pre‐clinical testing, although its role on colorectal cancer (CRC) cells is not yet fully elucidated. We examined the activity of gilteritinib in suppressing growth of CRC and its enhancing effect on other drugs used in chemotherapy. In this study, we observed that, regardless of p53 status, treatment using gilteritinib induces PUMA in CRC cells via the NF‐κB pathway after inhibition of AKT and activation of glycogen synthase kinase 3β (GSK‐3β). PUMA was observed to be vital for apoptosis in CRC cells through treatment of gilteritinib. Moreover, enhancing induction of PUMA through different pathways could mediate chemosensitization by using gilteritinib. Furthermore, PUMA deficiency revoked the antitumour role of gilteritinib in vivo. Thus, our results indicate that PUMA mediates the antitumour activity of gilteritinib in CRC cells. These observations are critical for the therapeutic role of gilteritinib in CRC. [ABSTRACT FROM AUTHOR]

We reported high-performance organic light-emitting diodes (OLEDs) with a maximum efficiency of 42.3 lm W−1 and color rendering index of 92 by facilitating charge carrier transportation and controlling the recombination zone. In addition, we demonstrated that inserting a thin interlayer in emitting layer prevented energy transfer between blue and green emission layers, providing a relative chromatic-stability OLEDs. Furthermore, the device also exhibit a rather low correlated color temperature (2202 K), corresponding to an excellent warm WOLED, which could meet the special requirement of energy saving and environment protection. [ABSTRACT FROM AUTHOR]

Substantial individual differences characterize the changes induced by total sleep deprivation on cognitive functions. Despite some progress having been achieved, the mechanisms of individual differences in response to total sleep deprivation have not been clearly elucidated. Cerebral metabolism in the resting state is among the key physiological processes supporting the daily function of the brain, and may play an important role in these individual differences. Twenty-two right-handed participants (nine females and 13 males) between 20 and 26 years old completed a mathematical processing task both in resting wakefulness and after 24 h of total sleep deprivation. Fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography was used to investigate brain metabolism changes. The mathematical task was performed after the positron emission tomography scans were completed. Correlation analysis was used to investigate the correlations between cognitive performance changes and brain metabolism changes. Large inter-individual differences were found in the throughput changes, but these inter-individual differences were not associated with baseline or post-deprivation performance levels. Specifically, deterioration of throughput on the mathematical processing task was significantly correlated with metabolism changes in the superior frontal medial gyrus. These findings suggested that frontal metabolic activity contributes to individual differences in waking-induced impairment of cognitive performance. [ABSTRACT FROM AUTHOR]

Direct carbon fuel cell (DCFC) is a device, which converts chemical energy of carbon into electrical energy through electrochemical oxidisation directly and its performance enormously depends on the characteristics of the fuel used. In this study, oak sawdust is used to prepare the activated carbon for the DCFC, with K2CO3 as the activating agent. Nickel catalyst is applied to improve the electrical conductivity, while HNO3 treatment is used for the purpose of surface modification and ash removal. The performance of the prepared activated carbon in DCFC is evaluated in a self-built DCFC anode apparatus. The results show that the BET surface area of activated carbon reaches 1240 m2/g under the following conditions: activation temperature, 1173 K; activation time, 2 h; and impregnation ratio, 1. Electrical conductivity is well improved through the nickel catalyst while the amount of surface oxygen functional groups is increased and ash content is decreased through the HNO3 treatment. When used as the fuel in the DCFC anode, the self-made activated carbon exhibits predominant performance among all tested carbon fuels, including graphite, activated carbon fibre, etc. © 2011 Canadian Society for Chemical Engineering [ABSTRACT FROM AUTHOR]

Summary The mitogen-activated protein kinase (MAPK) pathway is important in melanoma. In this pathway, DUSP6 phosphatase negatively controls the activation of extracellular signal-regulated (ERK) kinase. Through comparison of melanoma signalling pathways between immortal mouse melanocytes and their tumourigenic derivatives, retrieved from mouse xenografts, we identified a molecularly distinct subtype of melanoma, characterized by reduced ERK activity and increased DUSP6 expression. Overexpression of DUSP6 enhanced anchorage-independent growth and invasive ability of immortal mouse melanocytes, suggesting that increased DUSP6 expression contributes to melanoma formation in the mouse xenografts. In contrast, reduced tumourigenicity was observed after DUSP6 overexpression in human melanoma cells. A minority of thick human primary melanomas had high DUSP6 expression and the same poor melanoma-specific survival as the majority of thick primaries with low DUSP6 levels. We have demonstrated that DUSP6 is important in melanoma and that it plays a different role in our distinct subtype of mouse melanoma compared with that in classic human melanoma. [ABSTRACT FROM AUTHOR]

Summary Increased expression of DNA repair genes contributes to the extreme resistance shown by melanoma to conventional DNA-damaging chemotherapeutics. One such chemotherapeutic effective against a range of other cancers, but not melanoma, is cisplatin. The DNA repair protein, ERCC1, is needed to remove cisplatin-induced DNA damage. We have shown that ERCC1 is essential for melanoma growth and resistance to cisplatin in a mouse xenograft model. Untreated xenografts of our transformed Ercc1-proficient melanocyte cell line grew very rapidly as malignant melanoma. Cisplatin treatment caused initial shrinkage of xenografts, but cisplatin-resistant regrowth soon followed. Cells reisolated into culture had twofold elevated levels of ERCC1 compared to both input cells and cells reisolated from untreated xenografts. An isogenic Ercc1-deficient derivative grew equally well in vitro as the Ercc1-proficient melanocyte cell line. However, in xenografts, the Ercc1-deficient melanomas were much slower to establish and were completely cured by just two cisplatin treatments. [ABSTRACT FROM AUTHOR]