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Background: There are no studies that have shown the role and underlying mechanism of Polyphyllin I (PPI)-mediated anti-apoptosis activity in nucleus pulposus cells (NPCs). The research aimed to evaluate the effects of PPI in interleukin (IL)-1β-induced NPCs apoptosis in vitro. Methods: Cell Counting Kit-8 (CCK-8) assay was used to detect cell viability, and cell apoptosis was evaluated by double-stained flow cytometry (FITC Annexin V/PI). The expression of miR-503-5p was quantified by real-time quantitative PCR (qRT-PCR), and the expression of Bcl-2, Bax, and cleaved caspase-3 was quantified by Western blot. Dual-luciferase reporter gene assay was used to detect the targeting relationship between miR-503-5p and Bcl-2. Results: PPI at 40 μg·mL−1 markedly promoted the viability of NPCs (P < 0.01). Also, PPI inhibited apoptosis and reduction in proliferative activity induced by IL-1β in the NPCs (P < 0.001, 0.01). PPI treatment significantly inhibited the expression of apoptosis-related protein Bax, cleaved caspase-3 (P < 0.05, 0.01), and enhanced the level of anti-apoptotic protein Bcl-2 (P < 0.01). The proliferative activity of NPCs was significantly decreased and the apoptosis rate of NPCs was increased under IL-1β treatment (P < 0.01, 0.001). Moreover, miR-503-5p was highly expressed in IL-1β-induced NPCs (P < 0.001). Furthermore, the effect of PPI on NPCs viability and apoptosis in IL-1β treatment was dramatically reversed by the overexpression of miR-503-5p (P < 0.01, 0.01). The targeted binding of miR-503-5p to the 3'UTR of Bcl-2 mRNA was confirmed by dual-luciferase reporter gene assays (P < 0.05). In further experiments, compared with miR-503-5p mimics, the effects of PPI on IL-1β-induced NPCs viability and apoptosis were greatly reversed by the co-overexpression of miR-503-5p and Bcl-2 (P < 0.05, 0.05). Conclusion: PPI suppressed the apoptosis of intervertebral disk (IVD) NPCs induced by IL-1β via miR-503-5p/Bcl-2 molecular axis. [ABSTRACT FROM AUTHOR]

In this paper, a novel amino-functionalized Fe3O4-MnO2-SiO2-NH2 adsorbent material was prepared by successive modifying Fe3O4 with KMnO4 and SiO2 to remove heavy metal ions in mixed solution of Pb(II), Cu(II), and Ni(II). The adsorption experiments showed that initial pH value had a significant effect on the adsorption capacity of the materials for heavy metals in solution. Moreover, the materials exhibited strong selective adsorption for Pb(II). Transmission electron microscopy (TEM) results showed that the innermost dark center was the Fe3O4 core with a thickness of about 200 nm, and the outermost light circle was a coated SiO2 shell with a thickness of about 30 nm, while MnO2 can be seen between the dark center and the light circle. Various factors affecting the uptake behavior such as contact time, temperature, pH, and initial concentration of Pb(II) were investigated. The kinetics were evaluated utilizing the Lagergren pseudo-first-order and pseudo-second-order models. The best interpretation for the equilibrium data was given by Freundlich isotherm. The recycling experiment showed that Fe3O4-MnO2-SiO2-NH2 kept its adsorption and desorption efficiencies constant over 5 cycles. Importantly, the Fe3O4-MnO2-SiO2-NH2 was able to selectively remove over 73% of Pb(II) not only in mixed solution of Pb(II), Cu(II), and Ni(II) but also remove 94.7% in only Pb(II) solution at pH 6 within 1 h. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine K-12 physical education teachers' perceptions of ability and usage of technology. Physical educators (n = 114) completed the Physical Education Technology Usage Survey assessing their perceived technology competency, how and why they utilize technology, challenges they face in implementing technology, and where they learned to use technology. Results indicated a high level of perceived competency with many forms of technology but differences based on gender, teaching level, and years of experience. Low competency levels were shown for website creation, PDAs, heart rate monitors, and body composition analyzers. The teachers reported that student learning can be enhanced with technology because it aids the visual learner, facilitates individual development, and is useful for assessment purposes. (Contains 6 tables.)

The aerobic oxidation of ethylbenzene is an effective way to produce acetophenone, in which solvent-free conditions and oxygen as the sole oxidant are the best choice. At present, the catalytic activity and selectivity are still at an unsatisfactory level, because efficient catalysts need to achieve both C–H bond activation and O2 activation. In this work, the 2-methylimidazole-induced hydrolysis strategy was used to prepare a new class of CoNi-layered double hydroxide (CoNi-LDH) materials with different metal ratios. High-Resolution Transmission Electron Microscopy (HRTEM) showed that CoNi-LDH had obvious weak crystallinity and a thin lamellar structure. X-ray Photoelectron Spectroscopy (XPS) reveals the consistency between the content of the M–O component in the host layer and the proportion of Co3+, among which CoNi-LDH with a feed ratio (Co : Ni) of 2 : 1 (Co2Ni-LDH) has the highest M–O content and Co3+ ratio. The formation of M–O is due to the H-vacancy generated by the breaking of the hydroxyl group, which can be used for the H abstraction of C–H bonds. The redox effect caused by M2+/M3+ facilitates the transfer of electrons, which promotes the activation of O2 to the superoxide radical anion (˙O2−). Thereby, Co2Ni-LDH shows the highest catalytic activity for the oxidation of ethylbenzene. Under solvent-free conditions and with oxygen as the sole oxidant, 97.8% conversion of ethylbenzene and 98.8% selectivity of acetophenone can be obtained. The excellent catalytic performance is related to the structure of CoNi-LDH, and is also the best when compared with the reported results. Various types of aromatic hydrocarbons containing benzyl C–H bonds can be effectively oxidized by CoNi-LDH to produce the corresponding ketone products. [ABSTRACT FROM AUTHOR]

In this paper, the dynamical behaviors of a multiple delayed HIV-1 infection model which describes the interactions of humoral, cytotoxic T lymphocyte (CTL) immune responses, and two modes of transmission that are the classical virus-to-cell infection and the direct cell-to-cell transmission are investigated. The model incorporates three delays, including the delays of cell infection, virus production and activation of immune response. We first prove the well-posedness of the model, and calculate the biological existence of equilibria and the reproduction numbers, which contain virus infection, humoral immune response, CTL immune response, CTL immune competition, and humoral immune competition. Further, the threshold conditions for the local and global stability of the equilibria for infection-free, immune-free, antibody response, CTL response, and interior are established by utilizing linearization method and the Lyapunov functionals. The existence of Hopf bifurcation with immune delay as a bifurcation parameter is investigated by using the bifurcation theory. Numerical simulations are carried out to illustrate the theoretical results and reveal the effects of some key parameters on viral dynamics. [ABSTRACT FROM AUTHOR]

We construct a daily liquidity index of China's government bond market using transaction data from the national interbank market during 2001–2020. The index is a composite of popular price-based and quantity-based metrics of liquidity. The composite indices, obtained by averaging across different metrics and by applying the principal component analysis, respectively, both point to a better liquidity condition after 2010. Market liquidity swings appear to be highly correlated with domestic funding liquidity and financial market volatility, but display fewer correlations with global macrofinancial indicators. Our findings suggest that the further deepening of the government bond market would support domestic financial stability and monetary operations down the road. [ABSTRACT FROM AUTHOR]

In this paper, the novel fluorescence probe XP based on Schiff-base was designed, synthesized and characterized, which could detect Y3+selectively and sensitively. The recognition mechanism of XP toward Y3+ was studied by Job's plot and HRMS. It was investigated that stoichiometric ratio of the probe XP conjugated with Y3+ was 1:2. And the detection limit was calculated as 0.30 μM. In addition, Y3+ was recognized by the test paper made from XP. And the probe XP could detect Y3+ selectively in Caenorhabditis elegans and the main organs of mice. Thus, XP was considered to have some potential for application in bioimaging. [ABSTRACT FROM AUTHOR]