The role of Mo species in Ni-Mo catalysts for dry reforming of methane.

The Ni-Mo catalyst has attracted significant attention due to its excellent coke-resistance in dry reforming of methane (DRM) reaction, but its detailed mechanism is still vague. Herein, Mo-doped Ni (Ni-Mox) and MoOx adsorbed Ni surfaces (MoOx@Ni) are employed to explore the DRM reaction mechanism and the effect of coke-resistance. Due to the electron donor effect of Mo, the antibonding states below the Fermi level between Ni and C increase and the adsorption of C decrease, thereby inhibiting the carbonization of Ni. On account of the strong Mo and O interaction, more O atoms gather around Mo, which inhibits the oxidation of Ni and may promote the formation of MoOx species on the Ni-Mo catalyst. The presence of Mo-O species promotes the carbon oxidation, forming a unique redox cycle (MoOx ↔ MoOx-1) similar to the Mars-van Krevelen (MvK) mechanism, explaining the excellent anti-carbon deposition effect on the Ni-Mo catalyst.

Long noncoding RNA MALAT1 inhibits the apoptosis and autophagy of hepatocellular carcinoma cell by targeting the microRNA-146a/PI3K/Akt/mTOR axis.

BACKGROUND: Increased long noncoding RNA (lncRNA) expression is characteristic to hepatocellular carcinoma (HCC) and several other neoplasms. The present study aimed to identify the mechanism underlying modulation of HCC development by the lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1). METHODS: Quantitative real-time polymerase chain reaction was used to determine MALAT1 and microRNA (miR)-146a expression in HCC tissues and cell lines. Western blotting was performed to measure PI3K, Akt, and mTOR levels. Dual-luciferase reporter assay was used to validate the direct targeting and negative regulatory interaction between miR-146a and MALAT1. Cell viability, proliferation, and apoptosis were analyzed using an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, colony formation assay, and flow cytometry, respectively; autophagy was detected based on LC3B expression. RESULTS: MALAT1 expression was higher in HCC tissues than in normal tissues. MALAT1 upregulation promoted HCC cell proliferation, whereas MALAT1 downregulation promoted HCC apoptosis and autophagy. Moreover, effects of MALAT1 downregulation on HCC cells were abolished by miR-146a inhibition. miR-146a directly targeted the 3'-untranslated region of PI3K, and PI3K protein level was clearly decreased upon miR-146a mimic transfection. CONCLUSIONS: MALAT1 may modulate HCC cell proliferation, apoptosis, and autophagy via sponging miR-146a, which regulates HCC progression.

Acute tissue injury activates satellite cells and promotes sarcoma formation via the HGF/c-MET signaling pathway.

Some patients with soft-tissue sarcoma (STS) report a history of injury at the site of their tumor. Although this phenomenon is widely reported, there are relatively few experimental systems that have directly assessed the role of injury in sarcoma formation. We recently described a mouse model of STS whereby p53 is deleted and oncogenic Kras is activated in muscle satellite cells via a Pax7(CreER) driver following intraperitoneal injection with tamoxifen. Here, we report that after systemic injection of tamoxifen, the vast majority of Pax7-expressing cells remain quiescent despite mutation of p53 and Kras. The fate of these muscle progenitors is dramatically altered by tissue injury, which leads to faster kinetics of sarcoma formation. In adult muscle, quiescent satellite cells will transition into an active state in response to hepatocyte growth factor (HGF). We show that modulating satellite cell quiescence via intramuscular injection of HGF increases the penetrance of sarcoma formation at the site of injection, which is dependent on its cognate receptor c-MET. Unexpectedly, the tumor-promoting effect of tissue injury also requires c-Met. These results reveal a mechanism by which HGF/c-MET signaling promotes tumor formation after tissue injury in a mouse model of primary STS, and they may explain why some patients develop a STS at the site of injury.

[Pharmacokinetics and relative bioavailability of ziprasidone tablets in Chinese healthy volunteers].

OBJECTIVE: To investigate the pharmacokinetics and bioavailability of ziprasidone tablets in Chinese healthy volunteers. METHODS: A randomized crossover study was performed in 20 healthy volunteers, who received a single oral dose (40 mg) of the test or reference preparation of ziprasidone. Blood samples were collected from the subjects at different time points following the drug administration, and the plasma concentration of ziprasidone was determined using high-performance liquid chromatography. The pharmacokinetic parameters were analyzed by DAS software and the relative bioavailability was calculated according to the formula F=AUC(t)/AUC(r)x100%. RESULTS: For the test and reference preparation, the pharmacokinetics parameter C(max) was 170.7-/+71.3 and 174.4-/+81.6 ng/ml, t(max) 3.73-/+1.87 and 3.69-/+1.84 h, t((1/2)) 5.57-/+1.62 and 5.61-/+1.73 h, AUC(0-t) 1273-/+252.3 and 1296-/+266.9 ng.h.ml(-1), and AUC(0-infinity)1396-/+276.9 and 1407-/+281.5 ng.h.ml(-1), respectively, with the relative bioavailability of (98.3-/+12.6)%. No significant differences were found in the main parameters of the test and reference preparations as analyzed by ANOVA and two- and one-side t-test. CONCLUSION: The test and reference preparation of ziprasidone are bioequivalent.