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For Pd-based catalysts, facile and fast interconversion between Pd and PdO occurs continuously during the CH 4 oxidation reaction, which makes it challenging to determine active sites. Herein, we report that the amount of partially oxidized palladium (PdO x ) on the catalyst surface shows a linear correlation with the CH 4 oxidation activity in a series of Pd/Al 2 O 3 and Pt− Pd/Al 2 O 3 catalysts hydrothermally aged under commercially relevant conditions. We characterized the amount of surface PdO x through diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) using CO as a probe molecule. With careful consideration that the redox cycle of Pd particles occurs continuously during the CH 4 oxidation reaction, the Pd/Al 2 O 3 catalysts were reoxidized before obtaining the CO adsorption DRIFTS data to minimize the discrepancy between the catalytically relevant phases and the characterized surface composition. The IR spectra of CO adsorption on reoxidized Pd/Al 2 O 3 catalysts contain peaks at 2135−2145 cm −1 , which correspond to PdO x . The steady-state CH 4 oxidation activities at 300 °C increased proportionally with the normalized surface PdO x . Furthermore, Pt−Pd bimetallic catalysts also showed the same linear correlation between the surface PdO x and CH 4 oxidation activity irrespective of composition, preparation method, and support. Our results indicate that the surface PdO x plays a critical role in determining CH 4 oxidation activity rather than the electronic properties of Pd. Overall, we report a general correlation between the amount of surface PdO x and the steady-state CH 4 oxidation activities in various Pd-based catalysts. This work will greatly help in achieving the fundamental understanding of the CH 4 oxidation reaction on the PdO x surface and the further development of Pd-based catalysts for CH 4 oxidation with better activity.

Restored tissue levels of ghrelin and improved status of appetite was achieved with gastric ulcer healing and H. pylori eradication.

BackgroundKorean ginseng (Panax ginseng C.A. Meyer) has been used as a botanical medicine throughout the history of Asian traditional Oriental medicine. Formulated red ginseng (one form of Korean ginseng) has been shown to have antioxidant and chemopreventive effects.MethodsThis study investigated the cytoprotective effects and mechanism of action of Korean red ginseng extract (RGE) against severe ROS production and mitochondrial impairment in a cytotoxic cell model induced by AA + iron.ResultsRGE protected HepG2 cells from AA + iron-induced cytotoxicity by preventing the induction of mitochondrial dysfunction and apoptosis. Moreover, AA + iron-induced production of ROS and reduction of cellular GSH content (an important cellular defense mechanism) were remarkably attenuated by treatment with RGE. At the molecular level, treatment with RGE activated LKB1-dependent AMP-activated protein kinase (AMPK), which in turn led to increased cell survival. The AMPK pathway was confirmed to play an essential role as the effects of RGE on mitochondrial membrane potential were reversed upon treatment with compound C, an AMPK inhibitor.ConclusionsOur results demonstrate that RGE has the ability to protect cells from AA + iron-induced ROS production and mitochondrial impairment through AMPK activation.

Background Endoscopic ampullectomy is increasingly performed in patients with FAP (familial adenomatous polyposis)-associated ampullary adenomas. We sought to define the procedure-associated morbidities and long-term outcomes. Methods We performed a retrospective chart review of patients with FAP who underwent endoscopic ampullectomy at two tertiary institutions between 1999 and 2010. The severity of duodenal polyposis was classified according to Spigelman's classification. Results Of 26 FAP patients who underwent endoscopic ampullectomy, 21 arose in the setting of Spigelman's stage II duodenal polyposis. Adverse events associated with endoscopic ampullectomy included acute pancreatitis (19.2%), abdominal pain (7.6%), and bleeding (3.8%). The mean resected adenoma size was 0.99 ± 0.34 cm. Three adenomas (12.0%) contained foci of high-grade dysplasia. Follow-up data were available for 24 patients. The mean follow-up duration was 84.5 ± 36.2 months. Adenoma recurrence was observed in 14 patients (58.3%, 14/24) at a mean of 38.3 months after initial ampullectomy. Adenomas ≥ 10 mm recurred more frequently than smaller adenomas (76.9% vs. 36.4%, p=0.002). Positive margins were not associated with higher recurrence rates. No cancers were observed during long-term follow-up. Three patients underwent a Whipple procedure, but none was performed due to a recurrent ampullary adenoma. Conclusions Endoscopic ampullectomy in FAP can be performed safely. Because ampullary adenomas frequently recur after endoscopic ampullectomy, close surveillance is essential. Smaller tumors are less likely to recur, suggesting a benefit for early recognition of these lesions.

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BackgroundLaminaria japonica has frequently been used as a food supplement and drug in traditional oriental medicine. Among the major active constituents responsible for the bioactivities of L. japonica, fucoxanthin (FX) has been considered as a potential antioxidant. This study was conducted to examine the effects of L. japonica extract (LJE) or FX against oxidative stress on hepatocytes and to elucidate the overall their cellular mechanisms of the effects.MethodsWe constructed an in vitro model with the treatment of arachidonic acid (AA) + iron in HepG2 cells to stimulate the oxidative damage. The cells were pre-treated with LJE or FX for 1 h, and incubated with AA + iron. The effect on oxidative damage and cellular mechanisms of LJE or FX were assessed by cytological examination and several biochemical assays under conditions with or without kinase inhibitiors.ResultsLJE or FX pretreatment effectively blocked the pathological changes caused by AA + iron treatment, such as cell death, altered expression of apoptosis-related proteins such as procaspase-3 and poly (ADP-ribose) polymerase, and mitochondria dysfunction. Moreover, FX induced AMPK activation and AMPK inhibitor, compound C, partially reduced the protective effect of FX on mitochondria dysfunction. Consistent with AMPK activation, FX increased the protein levels of autophagic markers (LC3II and beclin-1) and the number of acridine orange stained cells, and decreased the phosphorylation of mTOR and simultaneously increased the phosphorylation of ULK1. And the inhibition of autophagy by 3-methylanine or bafilomycin A1 partially inhibited the protective effect of FX on mitochondria dysfunction.ConclusionThese findings suggest that FX have the function of being a hepatic protectant against oxidative damages through the AMPK pathway for the control of autophagy.

Lynch syndrome is the most common familial colorectal cancer syndrome. It is linked to germline mutations in one of four DNA mismatch repair (MMR) genes. A comprehensive family history is one important way to identify at-risk individuals. The elucidation of the molecular genetics of this syndrome has made it possible to screen for the disorder with molecular tests. Microsatellite instability and/or immunohistochemistry followed by germline testing for mutations in MMR genes is now a standard approach for clinically suspected cases. Correctly recognizing Lynch syndrome is essential for the application of appropriate screening and surveillance measures. Close surveillance and risk-reducing operations can decrease cancer-related mortality. In addition, counseling is an important component of the management of any family with Lynch syndrome.