Infrared and Raman microspectrometry study of fluor-fluor-hydroxy and hydroxy-apatite powders

Visible Raman and infrared microspectrometry studies performed on fluorapatite and hydroxyapatite powders have shown similar results. Small modifications of the 2 and 4 PO3-4 tetrahedra bending modes are observed. A small frequency shift of the 1 mode and modifications on the 3 mode region accompanied with a simplification of the hydroxyapatite and fluorapatite respective spectra from seven to four bands were observed. A broad and weak band which could be attributed to the Ca–F bond is detected at 311 cm-1 on the Raman fluorapatite spectra. The phosphate vibration modes are little disturbed by fluoride substitution. This could indicate that phosphate groups interact strongly between themselves and weakly with substituted atoms (i.e. hydroxyle and fluoride atoms). Whatever crystallographic model is considered, the number of bands observed is always lower than the number of calculated ones, even for hydroxyapatite, whose symmetry is lower than that of fluorapatite.     

拥挤收费政策交通影响评价

以拥挤收费政策交通影响评价为研究对象,运用非集计出行需求预测理论,建立了拥挤收费政策交通影响评价指标体系和居民政策响应行为预测模型系统,从出行方式、时间、空间分布等多方面综合评价拥挤收费政策对交通系统产生的影响,并对佛山市南海区实施拥挤收费政策的可行性进行了实证分析。结果表明,该政策的实施有利于南海区平衡出行时间分布,降低拥挤区域道路饱和度,但在交通结构优化和出行时间调整方面效果不甚理想。本文建立的以非集计理论为基础的"交通状况分析-管理政策制定-响应行为预测-实施效果评价"分析模式对我国城市制定、评价和实施相关交通需求管理政策有一定借鉴意义。     

基于GA-Transmodeler的动态OD矩阵估计方法*

采用系统仿真与遗传优化算法相结合的方法完成离线状态下多时段OD矩阵的估计。系统仿真旨在对多时段的动态OD矩阵实现连续动态交通分配,以得到在各个时段的OD流量对观测路段的分配比例矩阵,遗传算法则通过种群内个体的交叉、变异等遗传算子求解最优条件下的OD矩阵。仿真结果表明,这种仿真优化结合的方法能够充分体现动态交通流的延续性,且遗传算法具有较强的全局收敛性。     

两层应急抢修系统选址问题的核搜索算法

提出了用于描述两层应急抢修系统选址问题的0-1整数线性规划模型, 该模型能保证整个应急抢修系统的服务质量。设计了求解该问题的两种核搜索算法, 在两种方法中分别根据原问题的线性松弛和拉格朗日松弛确定原问题的核问题和子问题, 从而大大减小了问题的规模。用提出的算法对56个计算实例进行求解, 算例计算结果表明, 与MOSEK软件直接求解得到的结果进行比较, 基于拉格朗日松弛的核搜索算法可以在相对较短的时间内求得较好的解, 这说明拉格朗日松弛对偶问题的最优解能为求解原问题提供非常有效的信息。     

基于有限理性的弹性需求随机用户均衡交通分配模型*

为了同时考虑路网的随机变化特征和出行者的感知误差,在有限理性框架下基于累积前景理论建立了一个弹性需求随机用户均衡模型,给出了等价的变分不等式,设计了求解算法并通过算例进行了验证,结合参数敏感性对均衡状态出行者的认知和心理特征进行了分析。结果表明,OD出行需求和网络均衡态具有显著的参照点依赖效应,出行者对路况满意度越高OD出行需求越大,对路况熟悉程度越高OD出行需求越小。模型及算法可以加深对出行行为的理解,改进传统模型理论假设及适用性的局限,更加精确描述交通流的实际分布形态。     

风致驰振型压电-电磁复合俘能器等效电路建模及参数影响分析

为了研究与标准直流接口电路相连的风致驰振型压电-电磁复合俘能器的发电性能,建立了风致驰振型压电-电磁复合俘能器的等效电路模型,利用电路仿真软件仿真分析了接口电路串联和并联配置、激励风速和负载电阻对压电-电磁复合俘能器输出功率的影响关系.结果表明,俘能器起振后,直流接口并联连接比串联连接具有更高的功率输出.对于并联接口电路,在低负载阻抗区,压电-电磁复合俘能具有比单一压电和单一电磁俘能更高的输出功率;在高负载阻抗区,压电-电磁复合俘能与单一压电俘能的输出功率相当,电磁俘能表现出对高阻抗负载的不适用性.本文参数化分析结果有助于理解连接标准直流接口电路的压电-电磁复合俘能器发电性能.     

KRT4 suppresses oral squamous cell carcinoma development by reducing ATG4B-mediated autophagy

Head and neck squamous cell carcinoma is the sixth most common tumor worldwide, and half of head and neck squamous cell carcinoma patients are with oral squamous cell carcinoma (OSCC). 300,000 new cases of OSCC were reported annually. Even with multi-modality treatment, the prognosis of OSCC remains unsatisfactory. Thus, it is urgent to discover novel therapeutic targets for OSCC. Some microarray studies have revealed that Keratin 4 (KRT4) is downregulated in OSCC, whereas its role in OSCC development remains unknown. The present study revealed that KRT4 suppressed OSCC progression by inducing cell apoptosis and inhibiting cell invasion. In addition, KRT4 over-expression inhibited autophagy by blocking the interaction of autophagy-related 4B cysteine peptidase (ATG4B) and microtubule-associated protein 1A/1B light chain 3 (LC3) to regulate apoptosis and invasion of OSCC. In conclusion, KRT4 played an important role in OSCC development through regulating ATG4B-mediated autophagy and may be a novel therapeutic drug target of OSCC.     

Biomedical overview of melanin. 2. Updating molecular modeling,synthesis mechanism,and supramolecular properties regarding melanoma therapy

Melanins represent one of the most ancient and important group of natural macromolecular pigments. They have multiple biological roles in almost all organisms across the Phyla, examples being photoprotection, anti-oxidative action, radical scavenger activity, and heavy metal removal. From the biomedical point of view, melanocytes are involved in the origin of melanoma tumors, and the main therapeutic advances for their treatment have been revised in Part 1 of this review. The chemical structure of eumelanin is a biological concern of great importance, and therefore, exploring theoretical molecular models and synthesis mechanisms will be here described, as well as molecular orbital features and supramolecular organization, which are responsible for the key properties that make these biological pigments so important, and so fascinating. Ultimately, this updated overview is devoted to describe present structural models and physico-chemical characteristics of eumelanin, in order to explain and utilize melanin properties on which new photothermal and ultrasonic protocols for melanoma treatment can be devised and applied.

     

THREE PHASE COUNTERCURRENT EXTRACTION

Partitioning of bovine serum albumin (BSA) in an aqueous double countercurrent distribution (DCCD) using a three-phase system was studied and compared with countercurrent distribution using a two-phase system. The two-phase system was composed of Dextran and Polyethylene glycol (PEG) solulions, and the three-phase system consisted of Dextran, Ficoll, and PEG solutions. In the double countercurrent distribution experiment, BSA was partitioned from the stationary bottom phase into the moving middle and top phases. Two peaks resulted from these transfers. A mathematical model that predicts peak positions and shapes based on the partitioning behavior of the solute is provided. Based on model predictions, the DCCD method has potential extraction selectivity and recovery advantages over the traditional CCD method.