Microfluidic adhesion analysis of single glioma cells for evaluating the effect of drugs

Cancer metastasis is one of the most serious problems for tumor therapy, which is closely related to cell adhesion and deadhesion process. Better comprehension of cell adhesion ability will benefit drug research. Here, a biomimetic microfluidic enzyme digestion method was proposed to gently measure the influence of drugs on cell-matrix adhesion ability at the single cell level.The method can selectively digest the extracellular matrix(ECM) that linked to a single cell, and the trypsin concentration around the cell is relatively uniform and constant, thus the measured cell adhesion strength should be precise. Commercially available anti-cancer agents including 5-fluorouracil(5-FU), actinomycin D(Act D), temozolomide(TMZ) and allicin were evaluated, and the data showed only TMZ and allicin can inhibit cell adhesion significantly under our experiment conditions. The influence of TMZ became more and more obvious as the increase of duration and the effect became prominent only after 6 h adhesion process, which could provide a quick evaluation of whether the drugs are effective to cancer cell(compared with Calcein-AM/PI cell viability test). The adhesion strength of U87 cells decreased when the concentration of TMZ increased, and the effect of TMZ can be effectively inhibited by adding lactic acid to culture medium, which indicated acidic tumor microenvironment could promote drug resistance of tumor cells. Different from conventional evaluation methods which focus on the drugs' influence on cellular viability or metabolism, this work provides a new perspective to study the effect of drugs, which is helpful to enrich the drug evaluation system.     

A self‐adaptive intelligence gray prediction model with the optimal fractional order accumulating operator and its application

The self‐adaptive intelligence gray predictive model (SAIGM) has an alterable‐flexible model structure, and it can build a dynamic structure to fit different external environments by adjusting the parameter values of SAIGM. However, the order number of the raw SAIGM model is not optimal, which is an integer. For this, a new SAIGM model with the fractional order accumulating operator (SAIGM_FO) was proposed in this paper. Specifically, the final restored expression of SAIGM_FO was deduced in detail, and the parameter estimation method of SAIGM_FO was studied. After that, the Particle Swarm Optimization algorithm was used to optimize the order number of SAIGM_FO, and some steps were provided. Finally, the SAIGM_FO model was applied to simulate China's electricity consumption from 2001 to 2008 and forecast it during 2009 to 2015, and the mean relative simulation and prediction percentage errors of the new model were only 0.860% and 2.661%, in comparison with the ones obtained from the raw SAIGM model, the GM(1, 1) model with the optimal fractional order accumulating operator and the GM(1, 1) model, which were (1.201%, 5.321%), (1.356%, 3.324%), and (2.013%, 23.944%), respectively. The findings showed both the simulation and the prediction performance of the proposed SAIGM_FO model were the best among the 4 models.     

The effect of sample size on the grey system model

Some forecasting models have been developed, each has its own application condition. The grey model is used for small sample forecasting, but until now there is no reasonable explanation for the reason why it is not used for large sample. Therefore, in this paper, matrix perturbation theory is employed to explain the reason. The results of practical numerical examples from previous works demonstrate that the small sample usually has more accuracy than the large sample when establishing grey model in theory. Furthermore, we used the grey model with small samples to analyse the trend of syphilis incidence in China.     

On the properties of small sample of GM(1,1) model

In grey prediction modeling, the more samples selected the more errors. This paper puts forward new explanations of “incomplete information and small sample” of grey systems and expands the suitable range of grey system theory. Based on the geometric sequence, it probes into the influence on the relative errors by selecting the different sample sizes. The research results indicate that to the non-negative increasing monotonous exponential sequence, the more samples selected, the more average relative errors. To the non-negative decreasing monotonous exponential sequence, a proper sample number exists that has the least average relative error. When the initial value of the sequence of raw data of new information GM(1,1) model changes, the development coefficient remains unchanged. The segmental correction new information GM(1,1) model (SNGM) can obviously improve the simulation accuracy. It puts forward the mathematic proofs that the small sample usually has more accuracy than the large sample when establishing GM(1,1) model in theory.     

钯催化芳基乙炔对氧/氮杂苯并降冰片烯开环反应研究

过渡金属催化的碳亲核试剂对氧/氮杂苯并降冰片烯的开环反应是合成氢化萘衍生物的有效方法之一. 在该类反应中, 采用末端炔烃作为碳亲核试剂在反应操作、底物适用范围等多个方面都具有已报道的各种有机金属亲核试剂所不具备的优势. 目前, 对末端炔烃与氧/氮杂苯并降冰片烯的开环反应的研究进展有限, 只有Ni(dppe)Cl₂/ZnCl₂/Zn和手性的Rh两种催化体系被应用到该类反应当中, 但都面临一些不足. 为该类反应开发简单有效的新型催化体系仍然具有重要的意义和价值. 我们通过研究发现: PdCl₂与Xantphos的配合物是芳基乙炔对氧/氮杂苯并降冰片烯亲核开环反应的有效催化剂. 在优化后的反应条件下, 该Pd催化剂具有良好的催化活性和底物适应能力, 能够实现各种取代的芳基乙炔对氧/氮杂苯并降冰片烯的亲核加成, 并以较好的收率生成目标开环产物.     

基于灰色关联分析的神经网络轧制力预报模型的研究

为了进一步提高采用神经网络对热轧机轧制力的预报精度及建模速度,在分析研究目前已有的各种轧制力预报模型的基础上提出:在采用神经网络进行轧制力预报时,必须首先根据对象合理确定神经网络的输入变量.本文采用灰色关联分析法,利用生产现场实际数据,对影响轧制力设定值计算的多种因素与轧制力进行了相关性分析,最终简化了神经网络的结构,提高了模型的在线应用能力.     

Grey system model with the fractional order accumulation

The perturbation theory of least squares method is applied to explain why the traditional accumulated generating operator violates the principle of new information priority of Grey system theory. A new Grey system model with the fractional order accumulation is put forward and the priority of new information can be better reflected when the accumulation order number becomes smaller in the in-sample model. But Grey system model cannot deal with the systems with memory when the accumulation order number is 0 in the in-sample model. The results of practical numerical examples demonstrate that the new Grey model provides very remarkable predication performance compared with the traditional Grey model for small sample.     

基于CORBA的聚龙一号装置控制系统的研制

建成的聚龙一号装置PTS由24个基于Marx发生器和水线的性能、结构相同的模块组成,运行控制节点众多,控制规模大,试验过程复杂。根据分布式对象技术CORBA的技术特点,介绍了基于CORBA的聚龙一号装置控制系统的研制,重点分析了聚龙一号装置控制系统框架和结构及CORBA技术的应用。目前该控制系统已稳定运行1年,为聚龙一号装置提供了安全有效的运行及维护服务,对于即将开展的X射线自由电子激光装置等大型物理实验装置控制系统的总体设计具有一定的参考价值和意义。     

AgOTf‐Catalyzed Tandem Reaction of Oxabenzonorbornadienes with Arylacetylenes

A tandem isomerization/hydroarylation reaction of oxabenzonorbornadienes and arylacetylenes was realized by using AgOTf as catalyst. 1,1‐Diarylethylenes could be easily generated as products in moderate to good yields in this tandem reaction.