Background: Daphne Mucronata extract has a decreasing effect on the size of breast adenocarcinoma in rats. So in this study, the effect of Daphne Mucronata purified diterpene were investigated on co culture of human m...Background: Daphne Mucronata extract has a decreasing effect on the size of breast adenocarcinoma in rats. So in this study, the effect of Daphne Mucronata purified diterpene were investigated on co culture of human monocytes and two human leukemia cell lines (K562, CCRF-CEM). Materials and Methods: Each cell line mono-layer culture, in log phase growth, was treated with 10 to 160 μL of the extract (1 g/ml leave powder) and purified compound (0.94 nM). For a comparative study, Taxol (5 to 40 μM) was used in the presence and absence of LPS. Human monocytes were isolated by adhesion method. TNF-α in cultured media were measured by sensitive biotin-streptoavidin ELISA method. Results: Fifty percent of growth inhibition was shown by 160 μL (1:100 dilution, 0.5 g of the powdered leaves/ml) of the extract and 0.94 nM of the purified component, and there was more inhibition in K562 cells (P < 0.05). Four fold increases in growth inhibition was shown in co culture of isolated human monocytes and leukemia cell lines. There was a direct relationship between monocytes TNF-α secretion and growth inhibition degree. Conclusion: Daphne Mucronata extract and its purified diterpene through increasing monocytes TNF-α releasing, potentially inhibit Leukemia cell line.展开更多
Objectives: Multi-drug resistance (MDR) to chemotherapy remains a major obstacle to overcome in the successful treatment of patients with cancers. It was recently discovered that Leptomycin B (LMB) reduces the paclita...Objectives: Multi-drug resistance (MDR) to chemotherapy remains a major obstacle to overcome in the successful treatment of patients with cancers. It was recently discovered that Leptomycin B (LMB) reduces the paclitaxel-induced MDR in CCRF-CEM/Taxol cells. However, the mechanism remains unclear. Here we sought to explore the mechanism of LMB to reduce the MDR induced by paclitaxel. Results: LMB has remarkable cytotoxic effects in both sensitive CCRF-CEM and resistant CCRF-CEM/Taxol cell lines. The paclitaxel-induced MDR was reduced by 0.013 μm of LMB. Lower concentration of LMB regulated cell cycle progress, in situ expressions of P-gp, MRP1, and LRP, expression of CRM1, and localization of P-gp and CRM1 in CCRF-CEM/taxol cells. Study Design: Cytotoxicity of LMB on cancerous cell lines was determined by MTT assay. Cell cycle progress and in situ expressions of P-gp, MRP1, and LRP were analyzed by flow cytometry. Expression of CRM1 in the cells was examined by Western blot. And co-localization between P-gp and CRM1 was determined by laser confocal microscopy. Conclusion: The paclitaxel-induced MDR of CCRFCEM/Taxol cells was reduced by lower concentration of LMB. The mechanisms might be related to decreasing in situ expression of drug transporter proteins, promoting cell cycle progress, and altering co-localization between P-gp and CRM1 in the resistant cells.展开更多
由北京怡和智策咨询有限公司和Cardiovascular Research Foundation(CRF)合作的永铭诚道(北京)咨询有限公司(CCRF)近日在北京成立。CCRF将致力于临床研究监查工作,以使心血管器械和药物等在中国乃至全世界范围内,得到更安全、更有效地...由北京怡和智策咨询有限公司和Cardiovascular Research Foundation(CRF)合作的永铭诚道(北京)咨询有限公司(CCRF)近日在北京成立。CCRF将致力于临床研究监查工作,以使心血管器械和药物等在中国乃至全世界范围内,得到更安全、更有效地研发、使用和发展。宗旨是为心血管病患者提供更好的生存和生活质量。CCRF将在国际大规模、多中心的临床研究试验,为临床实践开发和研究新的医疗器械、药物和治疗措施,心血管临床研究结果寻找循证医学证据过程中,进行严格的临床监察,获得更为真实、可信和准确的研究结果,填补了中国心血管病临床研究监察事业的空白。展开更多
针对如何产生均匀和稳定的超声速非平衡等离子体这一科学问题,为进一步探究超声速气流电容耦合射频放电特性,建立了超声速非平衡电离磁流体动力技术实验系统,开展了Ma=3.4条件下,超声速气流边界层与主流中心区的电容耦合射频放电特性研...针对如何产生均匀和稳定的超声速非平衡等离子体这一科学问题,为进一步探究超声速气流电容耦合射频放电特性,建立了超声速非平衡电离磁流体动力技术实验系统,开展了Ma=3.4条件下,超声速气流边界层与主流中心区的电容耦合射频放电特性研究;同时针对超声速放电等离子体的实时诊断问题,基于均匀射频放电模型,联立能量平衡方程,建立等离子体诊断模型对平均电子数密度与电子温度等参数进行诊断。结果表明:超声速气流条件下,通过电容耦合射频可以产生均匀和稳定的放电等离子体;分子数密度是影响超声速气流放电特性的主要因素,同时超声速气流对平均电子温度的影响很小,约为0.46 e V。展开更多
The effect of the grounded electrode diameter on the ignition voltage using 13.56 MHz in argon gas is studied experimentMly. The results indicate a systematic decrease of the breakdown voltage with increasing electrod...The effect of the grounded electrode diameter on the ignition voltage using 13.56 MHz in argon gas is studied experimentMly. The results indicate a systematic decrease of the breakdown voltage with increasing electrode area for the same pd value. No multi-valued breakdown voltages are observed. The Paschen minimum is not affected by the electrode diameter as long as the parallel plane approximation is valid. A modified Paschen equation which takes into account indirect discharge via the chamber walls at high pd values gives reasonable fits to the experimental data.展开更多
针对领域本体构建中概念上下位关系获取难的问题,提出融合句子结构特征的概念上下位语义关系抽取方法。首先利用层叠条件随机场(cascaded conditional random fields,CCRFs)算法建模实现概念上下位实体识别,然后通过对句子结构特征分析...针对领域本体构建中概念上下位关系获取难的问题,提出融合句子结构特征的概念上下位语义关系抽取方法。首先利用层叠条件随机场(cascaded conditional random fields,CCRFs)算法建模实现概念上下位实体识别,然后通过对句子结构特征分析得出融合概念上下位关系的句子结构特征,最后利用融入句法特征基于支持向量机(support vector machine,SVM)建模的方法实现概念上下位关系抽取。为验证提出方法的有效性,以旅游领域上下位实体关系抽取为例进行了相关实验。实验结果表明:基于CCRFs模型的识别效果相对于现有的单层模型有较大改进,其F值提高了6.57%;加入句法特征基于SVM概念上下位关系抽取方法较现有的基于条件随机场(conditional random fields,CRFs)概念上下位关系抽取方法更有效,其F值提高了4.68%。展开更多
文摘Background: Daphne Mucronata extract has a decreasing effect on the size of breast adenocarcinoma in rats. So in this study, the effect of Daphne Mucronata purified diterpene were investigated on co culture of human monocytes and two human leukemia cell lines (K562, CCRF-CEM). Materials and Methods: Each cell line mono-layer culture, in log phase growth, was treated with 10 to 160 μL of the extract (1 g/ml leave powder) and purified compound (0.94 nM). For a comparative study, Taxol (5 to 40 μM) was used in the presence and absence of LPS. Human monocytes were isolated by adhesion method. TNF-α in cultured media were measured by sensitive biotin-streptoavidin ELISA method. Results: Fifty percent of growth inhibition was shown by 160 μL (1:100 dilution, 0.5 g of the powdered leaves/ml) of the extract and 0.94 nM of the purified component, and there was more inhibition in K562 cells (P < 0.05). Four fold increases in growth inhibition was shown in co culture of isolated human monocytes and leukemia cell lines. There was a direct relationship between monocytes TNF-α secretion and growth inhibition degree. Conclusion: Daphne Mucronata extract and its purified diterpene through increasing monocytes TNF-α releasing, potentially inhibit Leukemia cell line.
文摘Objectives: Multi-drug resistance (MDR) to chemotherapy remains a major obstacle to overcome in the successful treatment of patients with cancers. It was recently discovered that Leptomycin B (LMB) reduces the paclitaxel-induced MDR in CCRF-CEM/Taxol cells. However, the mechanism remains unclear. Here we sought to explore the mechanism of LMB to reduce the MDR induced by paclitaxel. Results: LMB has remarkable cytotoxic effects in both sensitive CCRF-CEM and resistant CCRF-CEM/Taxol cell lines. The paclitaxel-induced MDR was reduced by 0.013 μm of LMB. Lower concentration of LMB regulated cell cycle progress, in situ expressions of P-gp, MRP1, and LRP, expression of CRM1, and localization of P-gp and CRM1 in CCRF-CEM/taxol cells. Study Design: Cytotoxicity of LMB on cancerous cell lines was determined by MTT assay. Cell cycle progress and in situ expressions of P-gp, MRP1, and LRP were analyzed by flow cytometry. Expression of CRM1 in the cells was examined by Western blot. And co-localization between P-gp and CRM1 was determined by laser confocal microscopy. Conclusion: The paclitaxel-induced MDR of CCRFCEM/Taxol cells was reduced by lower concentration of LMB. The mechanisms might be related to decreasing in situ expression of drug transporter proteins, promoting cell cycle progress, and altering co-localization between P-gp and CRM1 in the resistant cells.
文摘由北京怡和智策咨询有限公司和Cardiovascular Research Foundation(CRF)合作的永铭诚道(北京)咨询有限公司(CCRF)近日在北京成立。CCRF将致力于临床研究监查工作,以使心血管器械和药物等在中国乃至全世界范围内,得到更安全、更有效地研发、使用和发展。宗旨是为心血管病患者提供更好的生存和生活质量。CCRF将在国际大规模、多中心的临床研究试验,为临床实践开发和研究新的医疗器械、药物和治疗措施,心血管临床研究结果寻找循证医学证据过程中,进行严格的临床监察,获得更为真实、可信和准确的研究结果,填补了中国心血管病临床研究监察事业的空白。
文摘针对如何产生均匀和稳定的超声速非平衡等离子体这一科学问题,为进一步探究超声速气流电容耦合射频放电特性,建立了超声速非平衡电离磁流体动力技术实验系统,开展了Ma=3.4条件下,超声速气流边界层与主流中心区的电容耦合射频放电特性研究;同时针对超声速放电等离子体的实时诊断问题,基于均匀射频放电模型,联立能量平衡方程,建立等离子体诊断模型对平均电子数密度与电子温度等参数进行诊断。结果表明:超声速气流条件下,通过电容耦合射频可以产生均匀和稳定的放电等离子体;分子数密度是影响超声速气流放电特性的主要因素,同时超声速气流对平均电子温度的影响很小,约为0.46 e V。
文摘The effect of the grounded electrode diameter on the ignition voltage using 13.56 MHz in argon gas is studied experimentMly. The results indicate a systematic decrease of the breakdown voltage with increasing electrode area for the same pd value. No multi-valued breakdown voltages are observed. The Paschen minimum is not affected by the electrode diameter as long as the parallel plane approximation is valid. A modified Paschen equation which takes into account indirect discharge via the chamber walls at high pd values gives reasonable fits to the experimental data.
文摘针对领域本体构建中概念上下位关系获取难的问题,提出融合句子结构特征的概念上下位语义关系抽取方法。首先利用层叠条件随机场(cascaded conditional random fields,CCRFs)算法建模实现概念上下位实体识别,然后通过对句子结构特征分析得出融合概念上下位关系的句子结构特征,最后利用融入句法特征基于支持向量机(support vector machine,SVM)建模的方法实现概念上下位关系抽取。为验证提出方法的有效性,以旅游领域上下位实体关系抽取为例进行了相关实验。实验结果表明:基于CCRFs模型的识别效果相对于现有的单层模型有较大改进,其F值提高了6.57%;加入句法特征基于SVM概念上下位关系抽取方法较现有的基于条件随机场(conditional random fields,CRFs)概念上下位关系抽取方法更有效,其F值提高了4.68%。
