1,322 research outputs found

    Investigation on the Structural Behavior of Shear Walls with Steel Truss Coupling Beams under Seismic Loading

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    Based on existing experimental results, the finite element analyses were carried out on shear wall structures with steel truss coupling beams. This work studied the seismic behaviors and the working mechanism of the steel truss coupling beam at the ultimate state and put forward two parameters: the area ratio of web member to chord and the stiffness ratio of coupling beam to shear wall. The seismic optimum design method of the coupling beam was also proposed. Afterwards, a comparative analysis was implemented on the three-dimensional shear wall model with steel truss coupling beams designed by the proposed design method. The results show that the structures designed by the proposed method have excellent seismic behaviors, the steel truss coupling beams have enough stiffness to connect shear walls effectively, and its web members have appropriate cross sections to dissipate seismic energy

    ApoG2 induces cell cycle arrest of nasopharyngeal carcinoma cells by suppressing the c-Myc signaling pathway

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    <p>Abstract</p> <p>Background</p> <p>apogossypolone (ApoG2) is a novel derivate of gossypol. We previously have reported that ApoG2 is a promising compound that kills nasopharyngeal carcinoma (NPC) cells by inhibiting the antiapoptotic function of Bcl-2 proteins. However, some researchers demonstrate that the antiproliferative effect of gossypol on breast cancer cells is mediated by induction of cell cycle arrest. So this study was aimed to investigate the effect of ApoG2 on cell cycle proliferation in NPC cells.</p> <p>Results</p> <p>We found that ApoG2 significantly suppressed the expression of c-Myc in NPC cells and induced arrest at the DNA synthesis (S) phase in a large percentage of NPC cells. Immunoblot analysis showed that expression of c-Myc protein was significantly downregulated by ApoG2 and that the expression of c-Myc's downstream molecules cyclin D1 and cyclin E were inhibited whereas p21 was induced. To further identify the cause-effect relationship between the suppression of c-Myc signaling pathway and induction of cell cycle arrest, the expression of c-Myc was interfered by siRNA. The results of cell cycle analysis showed that the downregulation of c-Myc signaling pathway by siRNA interference could cause a significant arrest of NPC cell at S phase of the cell cycle. In CNE-2 xenografts, ApoG2 significantly downregulated the expression of c-Myc and suppressed tumor growth <it>in vivo</it>.</p> <p>Conclusion</p> <p>Our findings indicated that ApoG2 could potently disturb the proliferation of NPC cells by suppressing c-Myc signaling pathway. This data suggested that the inhibitory effect of ApoG2 on NPC cell cycle proliferation might contribute to its use in anticancer therapy.</p

    miRNA-145 inhibits non-small cell lung cancer cell proliferation by targeting c-Myc

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    MicroRNAs are important gene regulators that potentially play a profound role in tumorigenesis. Increasing evidence indicates that miR-145 is a tumor suppressor capable of inhibiting breast and colon cancer cell growth both in vitro and in vivo. However, the biological function of miR-145 in non-small cell lung cancer (NSCLC) is largely unknown. In colon cancer cells, c-Myc is a confirmed direct target for miR-145. The aim of this work was to investigate the effect of miR-145 and c-Myc on proliferation of NSCLC cells, using the NSCLC cell lines A549 and H23 as models. We determined the expression level of miR-145 in tumor tissues relative to adjacent non-tumor tissues, and in NSCLC cell lines relative to non-malignant lung cells. Downregulation of miR-145 was seen in tumor tissues and the two NSCLC cell lines by real-time quantitative reverse transcription polymerase chain reaction. MTT and focus formation assays were conducted to measure cell proliferation rates. Cell growth was inhibited and the G1/S transition was blocked by miR-145 in transfection assays of A549 and H23 cells. We further showed that c-Myc was a direct target for miR-145. Introduction of miR-145 dramatically suppressed the c-Myc/eIF4E pathway, which was demonstrated to be crucial for cell proliferation in NSCLC cells. Furthermore, we found that CDK4 was regulated by miR-145 in cell cycle control. Taken together, our study results demonstrate that miR-145 inhibits proliferation of NSCLC cells through c-Myc. Increasing miR-145 expression may provide a novel approach for the treatment of NSCLC

    A saúde mental é o fator mais importante que influencia a qualidade de vida de idosos deixados para trás quando as famílias emigram da China rural

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    OBJECTIVES: to investigate the quality of life and the associated factors on left behind elderly in rural China. METHOD: the research was conducted cluster sampling to select 456 elderly left behind when family members migrated out of rural China to participate in a cross-sectional study by completing a general data questionnaire and Quality of Life questionnaire. RESULTS: 91.5% of the elderly requested psychological counseling and education. For the elderly, scores for mental health (39.56±13.73) were significantly lower compared with Chinese standard data (61.6±13.7) (POBJETIVOS: investigar la calidad de vida y los factores asociados a los adultos mayores que se quedan en las zonas rurales de China. MÉTODO: la investigación se realizó por medio de muestreo por conglomerados para seleccionar 456 adultos mayores que se quedaron cuando los miembros de la familia emigraron de zonas rurales de China, para participar en un estudio de corte transversal, completando un cuestionario de datos generales y cuestionario de calidad de vida. RESULTADOS: el 91.5% de los adultos mayores solicitó asistencia psicológica y educación. Para los adultos mayores, las puntuaciones de salud mental (39.56±13.73) fueron significativamente más bajos en comparación con los datos estándar de China (61.6±13.7) (pOBJETIVOS: investigar a qualidade de vida e fatores associados de idosos deixados para trás na China rural. MÉTODO: foi realizada amostragem por conglomerado para selecionar 456 idosos deixados para trás quando os membros da família emigram da China rural. Este é um estudo transversal com preenchimento de um questionário de dados gerais e de qualidade de vida. RESULTADOS: 91,5% dos idosos convidados solicitaram aconselhamento e educação psicológicos. Para os idosos, os escores de saúde mental (39,56±13,73) foram significativamente menores em comparação aos dados padrões chineses (61,6±13,7) (
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