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Simulated microgravity can significantly affect various cell types and multiple systems of the human body, such as cardiovascular system, skeletal muscle system, and immune system, and is known to cause anemia and loss of electrolyte and fluids. Epidermal stem cells (EpSCs) were cultured in a rotary cell culture system (RCCS) bioreactor to simulate microgravity. The metabolites of EpSCs were identified by liquid chromatography-mass spectrometry (LC-MS). Compared with normal gravity (NG) group, a total of 57 different metabolites of EpSCs were identified (P 1), including lipids and lipid-like molecules (51 molecules), amino acids (5 molecules), nucleosides, nucleotides, and analogues (1 molecule). According to the partial least squares discriminant analysis (PLS-DA) score plot, a VIP > 1 and P

The understanding into the pathogenesis and treatment of gastric cancer has improved in recent years; however, a number of limitations have delayed the development of effective treatment. Cancer cells can undergo glycolysis and inhibit oxidative phosphorylation in the presence of oxygen (Warburg effect). Previous studies have demonstrated that a rotary cell culture system (RCCS) can induce glycolytic metabolism. In addition, the potential of regulating cancer cells by targeting their metabolites has led to the rapid development of metabolomics. In the present study, human HGC-27 gastric cancer cells were cultured in a RCCS bioreactor, simulating weightlessness. Subsequently, liquid chromatography-mass spectrometry was used to examine the effects of simulated microgravity (SMG) on the metabolism of HGC-27 cells. A total of 67 differentially regulated metabolites were identified, including upregulated and downregulated metabolites. Compared with the normal gravity group, phosphatidyl ethanolamine, phosphatidyl choline, arachidonic acid and sphinganine were significantly upregulated in SMG conditions, whereas sphingomyelin, phosphatidyl serine, phosphatidic acid, L-proline, creatine, pantothenic acid, oxidized glutathione, adenosine diphosphate and adenosine triphosphate were significantly downregulated. The Human Metabolome Database compound analysis revealed that lipids and lipid-like metabolites were primarily affected in an SMG environment in the present study. Overall, the findings of the present study may aid our understanding of gastric cancer by identifying the underlying mechanisms of metabolism of the disease under SMG.

Osteoarthritis is a common type of degenerative joint disease. Inflammation-related chondrocyte senescence plays a major role in the pathogenesis of osteoarthritis. Omentin-1 is a newly identified anti-inflammatory adipokine involved in lipid metabolism. In this study, we examined the biological function of omentin-1 in cultured chondrocytes. The presence of omentin-1 potently suppresses IL-1β-induced cellular senescence as revealed by staining with senescence-associated beta-galactosidase (SA-β-Gal). At the cellular level, omentin-1 attenuates IL-1β-induced G1 phase cell-cycle arrest. Mechanistically, we demonstrate that omentin-1 reduced IL-1β-induced expression of senescent factors including caveolin-1, p21, and PAI-1 as well as p53 acetylation through ameliorating SIRT1 reduction. Notably, silencing of SIRT1 abolishes IL-1β-induced senescence along with the induction of p21 and PAI-1, suggesting that the action of omentin-1 in chondrocytes is dependent on SIRT1. Collectively, our results revealed the molecular mechanism through which the adipokine omentin-1 exerts a beneficial effect, thereby protecting chondrocytes from senescence. Thus, omentin-1 could have clinical implication in the treatment of osteoarthritis.

Nanocomposites consisting of a flexible piezoelectric polymer and a reinforcing phase have shown great potential for constructing high-performance piezoelectric nanogenerators (PENGs). However, the weak interface and poor dispersion of piezoelectric reinforcing phase significantly impair the electromechanical properties (e.g., effective stress/strain, piezoelectric coefficients) of the nanocomposites, thus severely restricting the performance enhancement of the PENGs. In this study, we hydrothermally synthesized the piezoelectric reinforcing phase of BaTiO3 nanowires, and grafted a layer of high-modulus polymethyl methacrylate (PMMA) onto the nanowire surface via surface-initiated polymerization. The PMMA coating layer forms a strong interface between BaTiO3 nanowires and the polymer matrix [i.e., poly(vinylidenefluoride-co-trifluoroethylene)], which efficiently improves dispersion of the BaTiO3 nanowires and stress transfer at the interface, therefore resulting in an enhanced output performance in the fibrous nanocomposite PENGs. The output voltage and current of the PMMA encapsulated BaTiO3 (PMMA@BaTiO3) nanowires-based PENG can reach to 12.6 V and 1.30 μA, with a maximum output power of 4.25 μW, which is 2.2 times and 7.6 times higher than the PENG with unmodified BaTiO3 nanowires and the PENG without BaTiO3 nanowires, respectively. Furthermore, the flexible PENG exhibits great stability that could continuously generate stable electrical pulses for 6000 cycles without any decline. This study provides a feasible approach of interface tailoring for achieving high-performance piezoelectric nanocomposite and shows the promising potential of the fibrous nanocomposites in biomechanical energy harvesters and smart wearable sensors.

Synthetic goethite (FeOOH), magnesium oxide (MgO), and cerium oxide (CeO2) were used as catalysts to enhance the ozonation of filtered raw river water. The UV absorbance (at 254 nm), dissolved organic carbon (DOC), molecular weight distribution (MWD), and also excitation–emission matrix fluorescence (EEM) changes of the filtered water were evaluated before and after catalytic ozonation and single ozonation to compare the degradation efficiency of natural organic matter (NOM) in the filtered water among the systems. The results showed that CeO2 catalytic ozonation performed best on UV254 removal. The addition of tert-butanol (TBA) in the systems had less effect on the removal of UV254, indicating that UV254 removal mainly resulted from direct oxidation. The mineralization of NOM in the filtered water by FeOOH catalytic ozonation and MgO catalytic ozonation was significantly better than that of single ozonation and CeO2 catalytic ozonation. DOC removal depended on hydroxyl radical (HO˙) formation, which could also be verified by the changes of MWD. From the results of EEM, both fulvic acid and humic acid were oxidized effectively during catalytic ozonation and single ozonation while some differences among the systems emerged due to the different degradation mechanisms. Humic acid was oxidized followed by fulvic acid in single ozonation while they were oxidized simultaneously in the catalytic ozonation. Catalytic ozonation in the presence of MgO and FeOOH could oxidize humic acid and fulvic acid effectively due to the formation of HO˙. CeO2 catalytic ozonation would reduce fulvic acid, which was rich in carboxylate more effectively than humic acid mainly through complexation. In brief, catalytic ozonation would shorten the reaction time and also increase the mineralization of organic matter in the filtered water compared with single ozonation. This study has a certain reference value for practical application of catalytic ozonation in the water treatment plants.

a b s t r a c t The adsorption behavior of activated carbon fibers (ACFs) modified by chemical vapor deposition (CVD) method on methylene blue (MB) was investigated in details. The Brunauer-Emmet-Teller (BET) surface area analysis, scanning electron microscope (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) analysis were employed to characterize the samples. The results showed that the pore size of the ACFs had a significant change after CVD modification. In addition, it was found that carbon nanotubes (CNTs) were well distributed on the surface of ACFs. FTIR analysis for mod- ified ACFs after adsorption showed intensity changes of absorption peaks, in comparison to that before adsorption. The adsorption capacity at equilibrium increased with the increase of pH. Moreover, attempts were made to fit the isothermal data using Langmuir and Freundlich equations. The results manifested that the experimental data were well fitted by Freundlich equation. Furthermore, the adsorption kinet- ics was analyzed by pseudo-first-order, pseudo-second-order and intra-particle diffusion models. The results demonstrated that the kinetic data were well described by pseudo-second-order kinetic model. The adsorption rate was controlled by intra-particle diffusion and film diffusion and thermodynamic parameters includingG, � H andS were also determined. This showed that the adsorption process was a spontaneous, endothermic and increasing randomness process. The calculated Ea was 28.33 kJ/mol, indicating that the adsorption could be a physisorption process. © 2012 Elsevier B.V. All rights reserved.