On k-Strong Distance in Strong Oriented Graphs

对强连通有向图D的一个非空顶点子集S,D中包含S的具有最少弧数的强连通有向子图称为S的S teiner子图,S的强S teiner距离d(S)等于S的S teiner子图的弧数.如果S=k,那么d(S)称为S的k-强距离.对整数k 2和强有向图D的顶点v,v的k-强离心率sek(v)为D中所有包含v的k个顶点的子集的k-强距离的最大值.D中顶点的最小k-强离心率称为D的k-强半径,记为sradk(D),最大k-强离心率称为D的k-强直径,记为sd iamk(D).本文证明了,对于满足k+1 r,d n的任意整数r,d,存在顶点数为n的强竞赛图T′和T,″使得sradk(T)′=r和sd iamk(T)″=d;进而给出了强定向图的k-强直径的一个上界.For a nonempty vertex set S in a strong digraph D,the strong distance d(S) of S isthe minimum size(the number of edges) of a strong subdigraph of D containing the vertices of S.IfS contains k vertices,then d(S) is referred to as the k-strong distance of S.For an integer k 2 anda vertex v of a strong digraph D,the k-strong eccentricity sek(v) of v is the maximum k-strongdistance d(S) among all sets S of k vertices in D containing v.The minimum k-strong eccentricityamong the vertices of D is the k-strong radius of D sradk(D) and the maximum k-strong eccentricityis the k-strong diameter of D sdiamk(D).In this paper,we will show that for any integers r,d withk+1 r,d n,there exist strong tournaments T′and T″of order n such that sradk(T′)=r andsdiamk(T″)=d.And we also give an upper bound on the k-strong diameter of strong orientedgraphs.TheProjectSupportedbyNSFC(10331020

Autophagy Inhibition by Chloroquine Sensitizes Cervical Cancer SiHa Cells to CPT Treatment

自噬诱导是肿瘤细胞对化疗药物抵抗性的原因之一,该研究探讨溶酶体抑制剂氯喹对喜树碱(camptothecin,CPT)诱导的宫颈癌细胞Si Ha死亡的增敏效果。CPT和/或氯喹处理宫颈癌Si Ha细胞,MTT法检测细胞增殖,DAPI和TUNEL染色观察细胞凋亡,Western blot和免疫荧光检测自噬及凋亡相关蛋白。结果发现,CPT处理后,Si Ha细胞MAP1LC3B荧光点和LC3II(microtubuleassociated protein light chain 3II)蛋白水平增加,p62荧光点和蛋白质水平则减少;而采用氯喹特异抑制自噬后,可明显提高CPT诱导的细胞凋亡、caspase-9的激活和PARP(poly ADP-ribose polymerase)的切割,而全长caspase-2水平显著下降。以上结果提示,氯喹可通过抑制细胞自噬而增强宫颈癌细胞株Si Ha对CPT诱导细胞凋亡的敏感性。The autophagy induction is one of the reasons for the resistance of tumor cells to chemotherapy drugs. In this study, the enhanced sensitivity of cervical cancer Si Ha cells to camptothecin(CPT)-induced cell death by chloroquine(a lysosome inhibitor) was investigated. The cell viability was detected by MTT assay, meanwhile, apoptosis was observed by DAPI and TUNEL, autophagy related proteins and apoptosis proteins were analyzed by immunofluorescence(IF) staining and Western blot in Si Ha cells after CPT treatment alone or combined with chloroquine. The results found that in Si Ha cells with CPT treatment the autophagy related protein LC3 foci and microtubule-associated protein light chain 3II(LC3II) protein level was increased, but p62 foci and protein level was decreased. When autophagy was inhibited by chloroquine, the CPT-induced apoptosis was obviously enhanced, and caspase-9 was activated and PARP was cleaved, but full length caspase-2 was decreased. Taken together, these results indicated that the inhibition of autophagy by chloroquine could sensitize cervical cancer Si Ha cells to CPT inducing cell apoptosis.山西省自然科学基金(批准号:2014021037-9);; 山西医科大学汾阳学院博士启动基金(批准号:1301);山西医科大学汾阳学院科研项目基金(批准号:1422)资助的课题~

福州市2010年甲型H1N1流感病毒分离株血凝素基因分子进化分析

目的了解福州市2010年甲型Hl N1流感病毒HA基因的突变和分子进化。方法采用RT-PCR技术扩增流感病毒A/Fuzhou/2/2010(H1N1)血凝素HA基因,测定核苷酸序列,用Clus-talX 1.83软件进行序列比对,用Bi-oedit软件的Clusta W程序进行序列同源性分析,用Mega 5.0软件以邻位相连算法(NJ)构建系统进化树。结果福州市2010年甲型Hl N1流感分离株A/Fuzhou/2/2010(H1N1)与福州市2009年首例甲型Hl N1流感病毒株HA基因同源性为98.9%,与疫苗参考株A/California/07/2009 HA基因同源性为98.5%;HA1区段有11个位点发生改变。结论福州市2010年甲型Hl N1流感病毒血凝素虽然个别氨基酸位点发生了突变,但在抗原决定簇位点的氨基酸并没有发生变化,未出现具有显著意义的抗原漂移

中国式学科评估:问题与出路

今年四月份,教育部学位与研究生教育发展中心(以下简称"教育部学位中心")邀请全国学位授予单位参加全国第四轮一级学科整体水平评估。随之,各个高校展开了一场大规模、高级别的学科评估申报及材料提交总动员。第四轮学科评估自发布起也引发了学界的广泛关注和热烈讨论。高等教育是中国崛起的思想发动机,关涉民族复兴的未来,而学科评估是近年来中国高等教育学科建设成就的集中展示,其意义和影响可谓深远。为了更好推进学科评估科学进行,特别是促进高等教育健康发展,《探索与争鸣》编辑部邀请全国

Empirical analysis of financial contagion based on nonlinear similarity

采用相空间重构和改进符号的非线性动力学相似性模型,研究了2007-2012年全球金融危机前后美国与英国、法国、德国、日本、中国金融股指的相似性.计算数据表明,各国的市场指数都在不同时段和不同程度对美国指数表现出动力学相似性,即经济繁荣阶段,美国经济影响其他国家;金融危机时期,危机也确实从美国传染到了他国市场.模型计算的走势及反应的现象证明使用改进符号的非线性动力学相似性模型适用于金融市场,是一种研究金融危机传染的可行新方法

Nonlinear Similarity Model of Financial Contagion: The Difference of the Subprime Crisis and the European Debt Crisis

This study develops a sign-modified nonlinear similarity model to study the contagion in financial crisis. We use the similarity index as an indicator to analyze the contagion of the United States and Greece to other six countries during the subprime crisis and the European debt crisis. Our results show that in the 2007-2009 subprime crisis the United States is the contagion source; and that in the 2010-2012 European debt crisis, the impacts of Greece to other countries are smaller than those of the United States except for Italy and Spain. We conclude that the harm of the financial crisis from a large economy is more severe than that from a small economy and the small economy's crisis mainly shocks the neighboring countries with similar economy

微小孔径激光器的研制与近场测试

介绍了一种用于高密度近场存储领域的新型微小孔径激光器(VSAL).为了解决由腔面金属膜造成的激光器PN结短路的问题,在激光器中引入了窗口隔离区,不仅降低了器件制备的难度,而且也提高了器件的性能和成品率.采用聚焦离子束刻蚀技术成功地制备了输出功率为0.3mW的激光器,利用矩阵方法通过远场测量值估算了激光器的近场分布

高铝AlxGa1-xAs氧化层对垂直腔面发射激光器的影响

针对可见光垂直腔面发射激光器的制备,通过湿氮氧化实验和测量微区光致发光谱分别研究了高铝组分AlxGa1-xAs的氧化特性及氧化产物的收缩应力对有源区的影响,结合器件结构设计确定了氧化限制层AlxGa1-x-As的铝组分和最佳位置,并制备出了低阈值电流的AlGaInP系垂直腔面发射激光器