RESUMEN
Olivine LiFePO4 covered flocculent carbon layers wrapped with carbon nanotubes (CNTs) prepared by sol-gel method and calcination is used as the cathode material for aqueous rechargeable lithium-ion batteries (ARLBs). The phase structures and morphologies of the composite material are characterized by X-ray diffraction (XRD), selected area electron diffraction (SAED), and transmission electron microscopy (TEM). The mechanism and method through which CNTs and flocculent carbon improve the electrochemical performance are investigated in an aqueous lithium-ion battery by setting up a comparative experiment. The ARLB system is assembled using a LiFePO4/C/CNTs cathode and a zinc anode in 1 mol L-1 ZnSO4·7H2O and saturated LiNO3 aqueous solution (pH = 6), which can deliver a capacity of 158 mA h g-1 at a rate of 1C. Even at a rate of 50C, it still has a capacity of 110 mA h g-1 after 250 cycles with fantastic capacity retention (95.7%). The lithium-ion diffusion coefficient increases by an order of magnitude due to the addition of CNTs together with flocculent carbon. Four LEDs are successfully powered by the ARLBs for more than one minute to demonstrate the practical application. The excellent rate capabilities and thrilling discharge capacity at a high rate indicate that this cathode material possesses excellent electrochemical performance, and this ARLB system exhibits excellent potential as a power source for environmental applications.
RESUMEN
The incidence of advanced hepatocellular carcinoma (HCC) is increasing worldwide, and its prognosis is extremely poor. Interferon-alpha (IFN-α)/5-fluorouracil (5-FU) therapy is reportedly effective in some HCC patients. In the present study, to improve HCC prognosis, we identified the genes that are sensitizing to these agents. The screening strategy was dependent on the concentration of ribozymes that rendered HepG2 cells resistant to 5-FU by the repeated transfection of ribozymes into the cells. After 10 cycles of transfection, which was initiated by 5,902,875 sequences of a ribozyme library, three genes including protein kinase, adenosine monophosphate (AMP)-activated, gamma 2 non-catalytic subunit (PRKAG2); transforming growth factor-beta receptor II (TGFBR2); and exostosin 1 (EXT1) were identified as 5-FU-sensitizing genes. Adenovirus-mediated transfer of TGFBR2 and EXT1 enhanced IFN-α/5-FU-induced cytotoxicity as well as 5-FU, although the overexpression of these genes in the absence of IFN-α/5-FU did not induce cell death. This effect was also observed in a tumor xenograft model. The mechanisms of TGFBR2 and EXT1 include activation of the TGF-ß signal and induction of endoplasmic reticulum stress, resulting in apoptosis. In HCC patients treated with IFN-α/5-FU therapy, the PRKAG2 mRNA level in HCC tissues was positively correlated with survival period, suggesting that PRKAG2 enhances the effect of IFN-α/5-FU and serves as a prognostic marker for IFN-α/5-FU therapy. In conclusion, we identified three genes that chemosensitize the effects of 5-FU and IFN-α/5-FU on HCC cells and demonstrated that PRKAG2 mRNA can serve as a prognostic marker for IFN-α/5-FU therapy.
Asunto(s)
Antimetabolitos Antineoplásicos/uso terapéutico , Carcinoma Hepatocelular/genética , Fluorouracilo/uso terapéutico , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Factores Inmunológicos/uso terapéutico , Interferón-alfa/uso terapéutico , Neoplasias Hepáticas/genética , Proteínas Quinasas Activadas por AMP/genética , Adulto , Anciano , Animales , Antimetabolitos Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/tratamiento farmacológico , Supervivencia Celular/efectos de los fármacos , Estrés del Retículo Endoplásmico/efectos de los fármacos , Femenino , Fluorouracilo/farmacología , Células Hep G2 , Humanos , Factores Inmunológicos/farmacología , Interferón-alfa/farmacología , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/tratamiento farmacológico , Masculino , Ratones , Ratones SCID , Persona de Mediana Edad , N-Acetilglucosaminiltransferasas/genética , Pronóstico , Proteínas Serina-Treonina Quinasas/genética , Receptor Tipo II de Factor de Crecimiento Transformador beta , Receptores de Factores de Crecimiento Transformadores beta/genética , Resultado del TratamientoRESUMEN
Large polystyrene particles stabilized by poly(acrylic acid) (PAA) (L-PS(PAA)) (as the core) and small polystyrene particles stabilized by poly(vinyl pyrrolidone) (PVP) (S-PS(PVP)) (as the corona) were successfully used to prepare raspberry-like particles by a heterocoagulation technique utilizing the hydrogen bonding interaction between PAA and PVP. The coverage of L-PS(PAA) by S-PS(PVP) could be controlled by adding PVP homopolymer to the L-PS(PAA) dispersion and by changing the molecular weight of the stabilizers. Moreover, the heterocoagulation of large poly(methyl methacrylate) particles stabilized by PAA (L-PMMA(PAA)) and S-PS(PVP) particles was also accomplished, resulting in the formation of L-PMMA(PAA)-core/S-PS(PVP)-corona raspberry-like composite particles. These results suggested that the raspberry-like particles composed of various polymer particles could be formed by the heterocoagulation technique utilizing the hydrogen bonding interaction.
RESUMEN
Micron-sized monodisperse poly(ionic liquid) (PIL) particles, poly([2-(methacryloyloxy)ethyl]trimethylammonium bis(trifluoromethanesulfonyl)amide), were prepared by dispersion polymerization at 70 °C in methanol with poly(vinylpyrrolidone) as a stabilizer. The obtained particle size could be controlled by addition of ethanol to the methanol medium while maintaining narrow monodispersity. The PIL particles exhibit unique properties; they can be observed by scanning electron microscopy without platinum coating, which is generally used to avoid an electron charge. Moreover, the solubility of the PIL particles can be easily changed by changing the counter anion, similar to the process for ionic liquids.
Asunto(s)
Líquidos Iónicos/química , Polímeros/química , Tamaño de la Partícula , Polimerizacion , Polímeros/síntesis química , Propiedades de SuperficieRESUMEN
The phase-transfer behavior of poly(acrylic acid) (PAA) particles from the hydrophobic ionic liquid N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl)amide phase to the water phase in the particle state, which we reported previously, was examined in more detail. PAA particles were prepared in the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([Bmim][TFSA]) and the organic solvent chloroform and were extracted. The transfer of PAA particles to water in the particle state was also observed in [Bmim][TFSA] systems. In contrast, the transfer phenomenon was not observed in the chloroform system. It was clarified that water/oil interfacial tension γ(wo) is an important parameter in the extraction of PAA in the particle state from the viewpoint of free energy. When the cationic surfactant tetradecyltrimethylammonium bromide, aqueous solution was used as the extraction medium, the PAA particles were extracted in the particle state from chloroform to water, in which γ(wo) became as low as that of the ionic liquid. This suggests that the phase-transfer phenomenon of PAA particles in the particle state was induced by the ionic liquid's unique property of low interfacial tension with water despite its high hydrophobic character.
Asunto(s)
Resinas Acrílicas/química , Reactivos de Enlaces Cruzados/química , Líquidos Iónicos/química , Agua/química , Resinas Acrílicas/síntesis química , Tamaño de la Partícula , Transición de Fase , Propiedades de SuperficieRESUMEN
OBJECTIVE AND DESIGN: To clarify the molecular mechanism of polyenylphosphatidylcholine (PPC), we examined the involvement of reactive oxygen species (ROS) and NADPH oxidase 4 (Nox4) in human hepatic stellate cells (HSCs). MATERIAL: Using human LX-2 HSC cells, we examined the effects of PPC on expression of α-smooth muscle actin (α-SMA) and collagen 1, generation of ROS, Nox4 expression, p38 activation and cell proliferation, induced by transforming growth factor ß1 (TGFß1). RESULTS: PPC suppressed ROS which are induced by TGFß1, phosphorylation of p38MAPK, and expression levels of α-SMA and collagen 1 in a dose-dependent manner. Higher concentrations of PPC also suppressed Nox4 levels. CONCLUSION: These results suggest that ROS and Nox4 induced by TGFß1 are the therapeutic targets of PPC in the suppression of human hepatic stellate cell activation.