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A polyamine special ion exchange resin was used to adsorb Mo from ammonium tungstate solutions. The effects of adsorption time, S2− concentration, adsorption temperature, CO32− concentration, mass ratio of WO3 to Mo, and Mo concentration on the Mo and WO3 adsorption capacities were investigated. Energy dispersive spectrometer plane scans were used to study the distributions of Mo, W, S, and Na on the loaded polyamine special ion exchange resin and the desorbed polyamine special ion exchange resin. The results showed that the polyamine special ion exchange resin performed well during adsorption and desorption. Under the optimum conditions for the static adsorption experiments, the adsorption capacities for Mo and WO3 were 99.29 mg/mL and 31.97 mg/mL, respectively, and the desorption rates for Mo and WO3 were 99.35% and 99.43%, respectively. Adsorption and desorption of molybdenum and tungsten on the polyamine special ion exchange resin were investigated by dynamic adsorption experiments with an ammonium tungstate solution containing 125.0 g/L WO3, 12.50 g/L Mo, 15.65 g/L S2−, and 0 g/L CO32−. The adsorption capacities for Mo and WO3 were 53.48 mg/mL and 9.79 mg/mL, and the adsorption rates for Mo and WO3 were 99.05% and 1.81%, respectively. The loaded polyamine special resin was desorbed with a 45 g/L sodium hydroxide solution, and the dynamic desorption rates for Mo and WO3 were 99.02% and 99.29%, respectively.

Montmorillonite is a major mineral present in ion-adsorption rare earth ores, and the microscopic adsorption states of rare earth ions on its surface are of a great significance for the efficient exploitation of ion-adsorption rare earth ores. In this article, density functional theory calculations were used to investigate the adsorption mechanisms and bonding characteristics of hydrated Pr, Mg and NH4 ions on the (001) surface of montmorillonite. Pr3+ exhibited a directed tendency geometry with Pr(H2O)103+, which was adsorbed onto montmorillonite by hydrogen bonding with an adsorption energy of −1182 kJ/mol, and one coordinated H2O ligand was separated from the first hydration layer of Pr. Both hydrated Mg and NH4 ions were adsorbed onto the montmorillonite surface through hydrogen bonds, and the adsorption energies were −206 and −188 kJ/mol, respectively, indicating that the adsorption stability of the hydrated Mg ion was slightly higher than that of the hydrated NH4 ion, but both were lower than that of hydrated Pr (−1182 kJ/mol). Hence, higher concentrations of Mg and NH4 ions than rare earth ions would be necessary in the leaching process of ion-adsorption rare earth ores. Additionally, desorption experiments revealed that the recovery of Pr3+ by Mg2+ with a concentration of 38 mmol/L is 80%, while it is only 65% with the same concentration of NH4+, and the concentrations of Mg2+ and NH4+ were much higher than that of Pr3+ in lixivium, which is consistent with the DFT calculations.

BACKGROUND X-chromosome-coupled zinc finger protein (ZFX) in the Zfy protein family is abundantly expressed in both embryonic and hematopoietic stem cells (HSCs). ZFX exist in various tumor cells and is correlated with proliferation and survival of tumor cells. As a malignant tumor with high invasiveness, hepatocellular carcinoma (HCC) may present resistance against chemotherapy and features of stem cells. This study aimed to explore the expression of ZFX in HCC cells, in an attempt to illustrate the role of ZFX in tumorigenesis. MATERIAL AND METHODS The expression of ZFX in tumor tissues was quantified by RT-PCR. The ZFX expression was then silenced to evaluate the stem cell-like features of HCC cells, including self-renewal, colony formation, and cell cycle, along with the sensitivity to cisplatin. Xenograft of ZFX-overexpressed HCC on nude mice was performed to evaluate the in vivo effect of ZFX on tumor growth. RESULTS Quantitative RT-PCR showed over-expression of ZFX in 51.8% of HCC tumors. The silencing of ZFX gene inhibited the self-renewal, colony formation, and proliferation ability of HCC cells (p

Purpose: The fifth most common cancer of the gastrointestinal system is liver cancer. It is also one of the most common cancers worldwide. The available treatment options include surgery, percutaneous ablation, and liver transplantation. Some of the latest modalities for the management of hepatocellular carcinoma (HCC) are radiofrequency ablation, trans-arterial chemoembolization, radioembolization and systemic targeted agents like sorafenib. The process of choice of a particular treatment modality in HCC depends on the tumor stage, patient performance status and liver function reserve. In the recent past with progress in research, the short-term survival of HCC has improved but recurrent disease remains a fundamental problem as the pathogenesis of HCC is a multistep and complex process. The present review is focused on recent advances in the management of HCC. This review will also provide an insight on the upcoming latest modalities including the emerging role of hepatoma-derived growth factor (HDGF) overexpression in liver fibrosis and carcinogenesis.

In this study, we suggested the level of miR-1297 was downreguled in the human hepatocellular carcinoma compared to the normal cells. We demonstrate ectopic expression of miR-1297 could significantly suppress hepatocellular carcinoma cells proliferation and enhance the cell apoptosis. In vitro reporter assay suggested EZH2 is a direct target gene of miR-1297. Furthermore, knockdown of EZH2 have the same effect with miR-1297 overeexpression in hepatocellular carcinoma cells. These findings provide evidence that miR-1297 plays a key role in inhibition of the hepatocellular carcinoma cells proliferation, and enhancing cell apoptosis through targeting EZH2, and strongly suggest that ex ogenous miR-1297 may have therapeutic value in treating hepatocellular carcinoma.

PhMeSiH2 reduces ethyl benzoate in the presence of a Cp2TiMe2 (Cp = η5-cyclopentadienyl) catalyst to give PhMeSi(OEt)(OCH2Ph) (1). Small to moderate amounts of toluene are also produced, depending on the reaction conditions. Under 40 psi of H2 the same reaction gives quantitative reduction of the ester to toluene. PhCHO is reduced, under the same conditions as the ester, to a mixture of PhMeSi(OCH2Ph)2 and toluene in proportions similar to that observed with the ester. A stoichiometric reaction of PhMeSiH2, PhCOOEt, and Cp2TiMe2 resulted in the formation of known [Cp2Ti(OEt)]2 (2) in 75% isolated yield. A mechanism is proposed in which the C=O of the ester inserts into a Ti–H bond. A Ti-mediated transfer of the ethoxy group from the resulting (α-ethoxy)benzyloxytitanium intermediate to silicon produces PhMeSi(OEt)H and PhCHO. 1 is generated via hydrosilation of PhCHO by PhMeSi(OEt)H. Both β- and γ-butyrolactones react with PhMeSiH2 in the presence of a catalytic amount of Cp2TiMe2 to produce copolymers -[O-PhMeSi-O(CH2)3CHR]n- (R = H, 3; R = Me, 4) (Mw [Formula: see text] 1 × 103; Mw/Mn [Formula: see text] 1.3). A mechanism analogous to that proposed for the ethyl benzoate reduction is proposed. A reaction of PhMeSiH2 and γ-butyrolactone with a stoichiometric amount of Cp2TiMe2 in the presence of tetrahydofuran (THF) produces Cp2Ti(µ-H)(µ-η1,η5-C5H4)Ti(OC4H8)Cp(5) (65% isolated yield) whose structure is determined by X-ray crystallography.Key words: hydrosilation, esters, lactones, titanocene, catalysis.

A new method for identifying enzyme inhibitors is to conduct their synthesis in the presence of the targeted enzyme. Good inhibitors form in larger amounts than poorer ones because the binding either speeds up synthesis (target-accelerated synthesis) or shifts the synthesis equilibrium (dynamic combinatorial libraries). Several groups have successfully demonstrated this approach with simple systems, but application to larger libraries is challenging because of the need to accurately measure the amount of each inhibitor. In this report, we dramatically simplify this analysis by adding a reaction that destroys the unbound inhibitors. This works similar to a kinetic resolution, with the best inhibitor being the last one remaining. We demonstrate this method for a static library of several sulfonamide inhibitors of carbonic anhydrase. Four sulfonamide-containing dipeptides, EtOC-Phesa-Phe (4a), EtOC-Phesa-Gly (4b), EtOC-Phesa-Leu (4c) and EtOC-Phesa-Pro (4d), were prepared and their inhibition constants measu...

The present study aimed to explore the correlation between cytokine expression of tumor necrosis factor α (TNF‑α), interleukin (IL)‑8 and IL‑10 with occludin production, abdominal symptoms and psychological factors in patients with irritable bowel syndrome‑associated diarrhea (IBS‑D). A total of 42 IBS‑D patients and 20 healthy controls were included, which were recruited from QiLu Hospital in China. ELISA and immunohistochemical analysis were performed for evaluating the cytokines (TNF‑α, IL‑8 and IL‑10) and occludin protein levels in the peripheral blood mononuclear cells (PBMCs) of all subjects. In addition, the abdominal symptoms and psychological status were assessed in IBS‑D patients. Levels of TNF‑α and IL‑8 in the PBMCs of patients with IBS‑D were significantly higher than those in the controls (P

The homogeneous catalytic hydrosilation-hydrogenation of pyridines is observed in the presence of Cp2TiMe2 (Cp = η5-C5H5) and CpCp*TiMe2 (Cp* = η5-C5Me5) as catalysts and using PhSiH3 or PhMeSiH2 as the source of Si-H. Under appropriate conditions, and with appropriate ring-substitution, good yields of the N-silyl-dihydropyridine or N-silyltetrahydropyridine products are be obtained. Although complete saturation is not achieved with organosilane alone, carrying out the reaction under moderate H2 pressures can give excellent yields of N-silylpiperidines. Under moderate pressures of H2, [Cp2TiH]2 catalyzes rapid H-D exchange between H2 and the 2- and 6-positions of C5D5N. Under the same conditions, only traces of hydrogenation are observed. This, together with the regioselectivity of 3-picoline hydrosilation-hydrogenation, leads to the conclusion that the key step in the reaction is probably addition of Ti-Si to C=N.Key words: hydrosilation, hydrogenation, pyridines, dimethyltitanocene, catalysis.

The color change from yellow to violet allows the formation of the intermediate [Cp2 Ti(SiHMePh)(pyridine)] to be monitored in the reaction of PhMeSiH2 with a pyridine in the presence of the precatalyst [Cp2 TiMe2 ] [Eq. (a)]; the hydride [Cp2 TiH] is postulated to be the key intermediate in the catalytic cycle. The regioselective hydrosilylation of pyridine and also substituted pyridines can be catalyzed by the titanocene [Cp2 TiMe2 ]. R=Me, CO2 Et.

Anhand des Farbwechsels von Gelb zu Violett last sich die Bildung der Zwischenstufe [Cp2Ti(SiHMePh)(Pyridin)] bei der Reaktion von PhMeSiH2 mit einem Pyridin in Gegenwart der Katalysatorvorstufe [Cp2TiMe2] verfolgen [Gl. (a)]; als Schlusselintermediat im Katalysecyclus wird das Hydrid [Cp2TiH] diskutiert. Mit dem Titanocen [Cp2TiMe2] kann die regioselektive Hydrosilylierung von Pyridinen katalysiert werden, die auch substituiert sein konnen. R=Me, COOEt.

The color change from yellow to violet allows the formation of the intermediate [Cp2 Ti(SiHMePh)(pyridine)] to be monitored in the reaction of PhMeSiH2 with a pyridine in the presence of the precatalyst [Cp2 TiMe2 ] [Eq. (a)]; the hydride [Cp2 TiH] is postulated to be the key intermediate in the catalytic cycle. The regioselective hydrosilylation of pyridine and also substituted pyridines can be catalyzed by the titanocene [Cp2 TiMe2 ]. R=Me, CO2 Et.

A new method for identifying enzyme inhibitors is to conduct their synthesis in the presence of the targeted enzyme. Good inhibitors form in larger amounts than poorer ones because the binding either speeds up synthesis (target-accelerated synthesis) or shifts the synthesis equilibrium (dynamic combinatorial libraries). Several groups have successfully demonstrated this approach with simple systems, but application to larger libraries is challenging because of the need to accurately measure the amount of each inhibitor. In this report, we dramatically simplify this analysis by adding a reaction that destroys the unbound inhibitors. This works similar to a kinetic resolution, with the best inhibitor being the last one remaining. We demonstrate this method for a static library of several sulfonamide inhibitors of carbonic anhydrase. Four sulfonamide-containing dipeptides, EtOC-Phe(sa)-Phe (4a), EtOC-Phe(sa)-Gly (4b), EtOC-Phe(sa)-Leu (4c) and EtOC-Phe(sa)-Pro (4d), were prepared and their inhibition constants measured. These inhibitors migrated to the carbonic anhydrase compartment of a two-compartment vessel. Although higher concentrations of the better inhibitors were observed in the carbonic anhydrase compartment, the concentration differences were small (1.83:1.71:1.54:1.46:1 for 4a:4b:4c:4d:5, where 5 is a noninhibiting dipeptide EtOC-Phe-Phe). Addition of a protease rapidly cleaved the weaker inhibitors (4d and 5). Intermediate inhibitor 4c was cleaved at a slower rate, and at the end of the reaction, only 4a and 4b remained. In a separate experiment, the ratio of 4a to 4b was found to increase over time to a final ratio of nearly 4:1. This is greater than the ratio of their inhibition constants (approximately 2:1). The theoretical model predicts that these ratios would increase even further as the destruction proceeds. This removal of poorer inhibitors simplifies identification of the best inhibitor in a complex mixture.