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OBJECTIVE: To investigate the effect of hyperthermia on the expression of PANDAR, LncRNA-p21 and ST8SIA genes in the human lung adenocarcinoma A549 cells. METHODS: A549 cells were randomly divided into 4 groups. The A549 cells in control group were cultured at 37 ℃; the cells at experimental groups were cultured at 40, 42 or 44 ℃ respectively. The cells in these 4 groups were incubated for 1 hour, and the levels of PANDAR, LncRNA-p21 and ST8SIA genes were analyzed by real-time fluorescence quantitative polymerase chain reaction. RESULTS: In cells cultured at 40, 42 or 44 ℃ experimental groups, the relative expression of PANDAR gene was lower than that of control group(P<0.05). In cells cultured at 44 ℃ experimental group, the relative expression of PANDAR gene was lower than that of the 40 and 42 ℃ experimental groups(P<0.05). There was no significant change in the relative expression of LncRNA-p21 and ST8SIA genes among the four groups(P>0.05). CONCLUSION: Hyperthermia decrease the expression of PANDAR gene in A549 cells.
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Objective To investigate the expression of miR?126, miR?355 and exportin?5 in lung cancer. Methods The cancer tissue and the tissue adjacent to carcinoma of 47 cases of patients with lung cancer was used to detect the expression of miR?126, miR?355 and Exportin?5 by the real?time fluorescence quantitative PCR. Results Significant difference of the expression of miR?126 (t=2.02,P=0.03) and exportin?5 (t=4.62,P<0.01) was observed in lung cancer tissue and tissue adjacent to carcinoma. Mature miR?126 and pri?miR?126 (R=0.309 , P = 0.044) had a negative correlation in the tissue adjacent to carcinoma. In the cancer tissue,miR?126 and MRP (R=0.432, P=0.019), miR?335 and k167 (R=0.410, P=0.033) were positively correlated, however, exportin?5 and TOPO (R=0.357, P=0.045), the pri?miR?126 and drinking (R=0.340, P=0.024), the pri?miR?126 and MRP (R=0.427, P=0.027) had a negative correlation relationship. Conclusion Expression of miR?126 and exportin?5 was decreased in lung cancer tissue, which may contribute to the occurrence and development of lung cancer.
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OBJECTIVE: To explore the effect of arsenic on the homeobox D10( HOXD10) gene expression in peripheral blood lymphocytes and human lung adenocarcinoma cell A549. METHODS: ⅰ) A total of 59 workers exposed to arsenic from a arsenic factory were selected as the exposure group and 17 local people without arsenic exposure were chosen as controls by using judgment sampling method. Hydride generation-cold hydrazine trapping-atomic absorption spectrometry was used to detect arsenic levels in urine of these 2 groups. The expression of HOXD10 in peripheral blood lymphocytes was detected by real-time fluorescent quantitative polymerase chain reaction( qRT-PCR).ⅱ) The A549 cells were treated with arsenic trioxide( As_2O_3) with concentration of 0. 0,0. 1,0. 5,1. 0 and 2. 0 μmol/L,and the survival rate of cells was examined by colorimetric assay. The expression of HOXD10 was detected by qRT-PCR. RESULTS: ⅰ) The levels of inorganic arsenic,methylarsonic acid,dimethyl arsenate,total arsenic in the urine,and the relative expression of HOXD10 mRNA in peripheral blood lymphocyte in exposure group were higher than that of the control group( P < 0. 05).ⅱ) As_2O_3 decreased the survival rate of A549 cells in a dose-dependent manner( P < 0. 01) and lead to a dose-dependent increase of HOXD10 mRNA expression( P < 0. 01). A549 cell survival rate and relative expression of HOXD10 mRNA showed a negative correlation,the correlation coefficient was-0. 777( P < 0. 01). CONCLUSION: Arsenic can up-regulate HOXD10 expression in the peripheral blood of occupational arsenic exposure individuals. As_2O_3 can inhibit the proliferation of A549 cells,which may be related to the up-regulation of HOXD10 expression.
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Objective:To evaluate the effects of three bond agents on bond strength of titanium- ceramic system. Methods: The pure titanium specimens were randomly divided into three groups. Three different manufacturers' porcelains(Super Ti22,Duceratin,Titankeramik) were used specially for titanium- ceramic bonding. The specimens in each group were further divided into two subgroups:bond agent group and no bond agent group. Bond strength of specimens was measured by the three- point bending test according to ISO9693. The titanium- ceramic interfaces were investigated by SEM/EDS. Results:The bond strength of Super Ti22(35.84±2.17) MPa and Duceratin(35.45±2.37) MPa with bond agent group was significantly higher than that of no bond agent group(P<0.05). Titankeramik with bond agent group showed a little higher bond strength than without bond agent, but no significant difference in statistics(P>0.05). The interfaces of Super Ti22 and Duceratin with bond agent groups were compact, while there were visible cracks and pores at the interface of other groups. Conclusion:The application of bond agent can improve bond strength of titanium- ceramic system.
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Objective; To evaluate the influence of electrolyte's concentration at micro-arc oxide treatment on the bonding strength of titanium to porcelain. Methods; CP titanium specimens with size of 25 mm ×3 mm ×0. 5 mm were treated with micro-arc oxidation (MAO) in Na_2SiO_3 solution of three different concentrations. After ultra-low-fusing porcelain was applied, a three-point-flexure-test was used to evaluate the bonding strength of titanium to porcelain. The surface of the specimens was observed by SEM and EDS, as well as the interface between titanium and porcelain. Results; The bonding strength values between titanium treated with MAO and porcelain was significantly higher then the control groups, Croup 20 g/L has the highest bonding strength values. SEM/EDS suggested that a porous thin layer of oxide which contains Si element is created by MAO, and higher concentration of Na_2SiO_3 leads to more Si element in oxide. Conclusion; MAO treating can improve the bonding strength between titanium and ceramic. Electrolyte's concentration has an effect on the bond strength between titanium and porcelain.
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Objective:To study effects of the cooling rate on the bonding characteristics of titanium porcelain bonded to cast titanium.Methods:According to ISO 9693,24 cast titanium plates(25 mm?3 mm?0.5 mm)were prepared.The middle of the samples(8 mm?3 mm) were bonded with bonding porcelain,opaque porcelain and dentin porcelain.The specimens from each porcelain-metal combination group were randomly assigned into four experimental cooling rate conditions,namely cooling rate of 15,40,50 and 100 ℃/min.A three-point-flexure-test was used to evaluate the bonding strength of titanium porcelain bonded to cast pure titanium.SEM/EDS were taken to characterize the failed surface of the titanium-porcelain interface.Statistical analyses were made by one-way analysis of variance(ANOVA).Results:The bonding strength of 15 ℃/min group was significantly higher than other groups.There were no significant differences in bond strength between 40 ℃/min and 50 ℃/min groups.SEM/EDS revealed that with an increase cooling rate,the remained porcelains on the titanium side were decreased.Conclusion:The 15 ℃/min cooling rate might be an effective method to improve the titanium-porcelain bonding strength.
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Objective:To evaluate the effects of three bond agents on bond strength of titanium-ceramic system.Methods:The pure titanium specimens were randomly divided into three groups.Three different manufacturers' porcelains(Super Ti22,Duceratin,Titankeramik)were used specially for titanium-ceramic bonding.The specimens in each group were further divided into two subgroups:bond agent group and no bond agent group.Bond strength of specimens was measured by the three-point bending test according to ISO9693.The titanium-ceramic interfaces were investigated by SEM/EDS.Results:The bond strength of Super Ti22(35.84?2.17)MPa and Duceratin(35.45?2.37)MPa with bond agent group was significantly higher than that of no bond agent group(P0.05).The interfaces of Super Ti22 and Duceratin with bond agent groups were compact,while there were visible cracks and pores at the interface of other groups.Conclusion:The application of bond agent can improve bond strength of titanium-ceramic system.