Cerium conversion coating as an environmentally friendly conversion film can improve the corrosion resistance of materials. Cerium conversion coating was prepared on X80 by electrochemical deposition, and the corrosion behavior of the coating on X80 in 0.1 MPa and 20 MPa hydrostatic pressure 3.5% NaCl solution was studied. Open circuit potential, electrochemical impedance spectroscopy, linear polarization resistance and polarization curve were carried out by high temperature and high pressure online electrochemical testing autoclave. Scanning electron microscopy, energy disperse spectroscopy and contact angle meter were used to analyze the topography, elements and hydrophilicity of the surface before and after corrosion. Results show that the cerium conversion coating can significantly improve the electrochemical properties of X80 in shallow sea with a hydrostatic pressure of 0.1 MPa, while open circuit potential, linear polarization resistance and electrochemical impedance spectroscopy of cerium conversion coating on X80 obviously decline and corrosion current density increases in deep sea with a hydrostatic pressure of 20 MPa. Cerium conversion coating on X80 has much cracks after corrosion in deep sea with a hydrostatic pressure of 20 MPa, while no obvious defects is found in shallow sea with a hydrostatic pressure of 0.1 MPa. Cerium conversion coating shows hydrophilicity before corrosion, while contact angle increases after corrosion, showing hydrophobicity.
A scheme is studied for a coherent population trapping (CPT) atomic clock with counterpropagating left and right circularly polarized lasers, wherein the vertical-cavity surface-emitting laser and the partially reflecting mirror form an external cavity of an established length. With cancellation of spin-polarized dark states and interaction repeated with atoms, a CPT signal is obtained that is eight times larger than that of the conventional scheme. For the improvement of modulation efficiency, CPT resonance still can be excited with a lower microwave power compared with the conventional scheme. The experimental results suggest that it is an alternative for low-power atomic clocks. (C) 2019 Optical Society of America
In order to suppress the effects of carrier and high-order sidebands on the coherent population trapping (CPT) signal, a scheme of interaction between an elliptically polarized beam and alkali atoms using the magneto-optic rotation detection is examined. By canceling the spin-polarized dark state in the CPT state preparation, a CPT resonance signal with a contrast of 32.5% is obtained. Our scheme requires minor modifications of the optical path in the prevalent scheme, and the short-term frequency stability of our scheme is five times better than that of the prevalent scheme, making it ideal for miniaturized CPT atomic clock applications. (C) 2019 Optical Society of America
OBJECTIVE: This study aims to explore the regulatory effect of microRNA-193a-3p on rheumatoid arthritis (RA) and its underlying mechanism. PATIENTS AND METHODS: Expression level of microRNA-193a-3p in synovial tissues extracted from 30 RA patients and healthy controls was detected by quantitative Real-time polymerase chain reaction (qRT-PCR). MH7A cells were subjected to TNF-alpha induction for constructing the in vitro RA model. After transfection of microRNA-193a-3p inhibitor in MH7A cells, proliferation and apoptosis were detected by cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. Enzyme-linked immunosorbent assay (ELISA) was conducted to determine levels of interleukin 6 (IL-6) and IL-8 in MH7A cells. Subsequently, the dual-luciferase reporter gene assay was carried out to verify the binding condition between microRNA-193a-3p and IGFBP5. Rescue experiments were conducted to evaluate the proliferation and apoptosis of MH7A cells with knockdown of microRNA-193a-3p and IGFBP5. RESULTS: MicroRNA-193a-3p was highly expressed in synovial tissues of RA patients and TNF-alpha-induced MH7A cells than those of controls. TNF-alpha induction significantly increased the proliferative rate of MH7A cells, reaching the peak at 96 h. After knockdown of microRNA-193a-3p, the promoted proliferation by TNF-alpha induction was significantly inhibited. In addition, TNF-alpha induction significantly inhibited the apoptosis of MH7A cells. After inhibition of microRNA-193a-3p expression, the inhibited apoptosis by TNF-alpha induction remarkably increased. TNF-alpha induction upregulated levels of IL-6 and IL-8 in MH7A cells, which were remarkably reduced after microRNA-193a-3p knockdown. Dual-luciferase reporter gene assay confirmed that IGFBP5 could bind to microRNA-193a-3p, and its expression was negatively regulated by microRNA-193a-3p. The regulatory effects of microRNA-193a-3p on proliferation and apoptosis of MH7A cells were reversed by IGFBP5 knockdown. CONCLUSIONS: MicroRNA-193a-3p is highly expressed in the synovial tissues and cells of rheumatoid arthritis. MicroRNA-193a-3p participates in the process of rheumatoid arthritis by regulating the proliferation, apoptosis and inflammatory response of MH7A cells through targeting IGFBP5.
The aim of this study is to investigate the expression of CD62P and CD154 in peripheral blood of patients with rheumatoid arthritis (RA) and their correlation with the clinical indexes of RA. A total of 60 RA patients diagnosed and treated in the Department of Rheumatism in our hospital from January to December 2016 were selected as the RA group, and 60 cases of healthy subjects were selected as the control group. CD62P and CD154 levels in peripheral blood were determined by flow cytometry using the FACS Vantage flow cytometer, and the correlation analysis with the clinical indexes of RA patients were conducted. The levels of CD62P and CD154 in the peripheral blood of RA group were 28.75% +/- 1.48% and 26.84% +/- 1.03%, respectively, which were significantly higher than those of the control group (P < 0.05). The levels of white blood cell (WBC), platelet (PLT), erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), C-reactive protein (CRP), and interleukin (IL)-37 in the RA group were significantly higher than those in the control group (P < 0.05). Pearson test showed that CD62P and CD154 levels in the peripheral blood in the RA group were positively correlated with serum WBC, PLT, ESR, RF, CRP, IL-37, and disease activity score 28 (DAS28) (P < 0.05), but not correlated with disease course (P > 0.05). The expression of CD62P and CD154 in peripheral blood of patients with RA was upregulated, and their expression levels were correlated with the activity of RA and the degree of joint lesion.
Deep-sea hydrothermal area has a lot of mineral resources, and study the corrosion behavior of metal in deep-sea hydrothermal area is useful for marine resource development. Electrochemical impedance spectroscopy, linear polarization, potentiodynamic polarization and Mott-Schottky analysis were used to study the electrochemical properties of 2205 steel in 20 MPa hydrostatic pressure 3.5% NaCl solution with different temperatures. Corrosion morphologies and corrosion products of 2205 steel after electrochemical tests were analyzed by SEM, EDS and white light interferometry. The results show that 2205 steel has good pitting resistance under 25 degrees C in simulated hydrothermal area, pit occurred on the surface of 2205 steel after the solution temperature reaching 65 degrees C crack-shaped pit occurred on the surface of 2205 steel under 150 and 200 degrees C Pit occurs in austenite phase at 65 degrees C and occurs in ferrite phase at 100 similar to 200 degrees C Impedance and linear polarization resistance of 2205 steel first decrease and then increase with temperature increasing in simulated hydrothermal area, and impedance and linear polarization resistance under 150 degrees C are lowest. Pitting potential of 2205 steel first negative shift and then positive shift, and carrier density of passive film formed in simulated hydrothermal area increase with temperature increasing.