Polyethyleneimine/poly-(γ-glutamic acid)/poly(lactide-co-glycolide) nanoparticles for loading and releasing antiretroviral drug

Nanoparticles (NPs) with ternary components of polyethyleneimine (PEI), poly-(γ-glutamic acid) (γ-PGA), and poly(lactide-co-glycolide) (PLGA) were applied to carry and release saquinavir (SQV). Hydrophobic SQV was encapsulated in the particle core composed of PLGA to form SQV-PLGA NPs, and the surface of SQV-PLGA NPs was grafted successively with hydrophilic γ-PGA and PEI (PEI/γ-PGA/SQV-PLGA NPs). The morphological images revealed that PEI/γ-PGA/SQV-PLGA NPs were spheroid-like, in general. An increase in the concentration of didecyl dimethylammonium bromide and a reduction in the dose of SQV enhanced the entrapment efficiency of SQV in PLGA NPs. In addition, an increment in the molecular weight of γ-PGA reduced the grafting efficiency of PEI on γ-PGA/SQV-PLGA NPs. An increase in the weight percentage of PEI enhanced the average particle diameter. However, the grafting efficiency of PEI on γ-PGA/SQV-PLGA NPs and the dissolution rate of SQV from PEI/γ-PGA/SQV-PLGA NPs reduced when the weight percentage of PEI increased. PEI/γ-PGA/SQV-PLGA NPs are an innovative drug delivery system and can be used for antiretroviral trials.     

Expression of ornithine decarboxylase during the transport of saquinavir across the blood-brain barrier using composite polymeric nanocarriers under an electromagnetic field

The expression of human ornithine decarboxylase (ODC) and permeability of saquinavir (SQV) across the blood-brain barrier were studied using nanoparticles (NPs) composed of poly(lactide-co-glycolide) (PLGA), poly-(γ-glutamic acid) (γ-PGA), and polyethyleneimine (PEI). SQV was encapsulated in the particle core to traverse a monolayer of human brain-microvascular endothelial cells (HBMECs) with the regulation of human astrocytes under an electromagnetic field (EMF). An increase in the weight percentage of PEI enhanced the particle size, zeta potential, and permeability of SQV. However, the viability of HBMECs reduced when the weight percentage of PEI increased. In addition, an increment in the molecular weight of γ-PGA enhanced the particle size and viability of HBMECs, and reduced the zeta potential. The permeability of SQV and expression of ODC were in the order: an EMF with amplitude modulation (AM)>an EMF with frequency modulation>no EMF. At 0.04% PEI, the AM EMF increased 2.38 times the uptake of NPs and 2.72 times the expression of ODC. The combination of PEI/γ-PGA/PLGA NPs and EMF can be an innovative strategy for delivering SQV into the brain.     

加工安排问题的优化方法及其自组织并行实现

针对加工安排这类实际问题，提出一类以顺时安排为基础结合隐枚举思想的近似算法，并给出利用多处理机并行系统解决这一问题的自组织异步并行实现方案．     

混合放号业务在固网运营中的应用与研究

混合放号业务是固网运营商为防止客户流失而开放的一项增值业务。实现该业务是通过在固网中引入SHLR网元,将逻辑号码和物理号码相分离,使得用户的逻辑号码不变,而物理号码随着端局的变化而改变。由于物理号码对客户是透明的,因此混合放号能够让固话用户在辖区内任意移机而保持用户的使用号码即逻辑号码不发生改变。介绍利用SHLR对NP（移机不改号）业务进行改造,将NP的呼叫路由从SSP改为指向软交换,从而将NP业务割接为混合放号业务。     

Generic separations and leaf languages

In the early nineties of the previous century, leaf languages were introduced as a means for the uniform characterization of many complexity classes, mainly in the range between P (polynomial time) and PSPACE (polynomial space). It was shown that the separability of two complexity classes can be reduced to a combinatorial property of the corresponding defining leaf languages. In the present paper, it is shown that every separation obtained in this way holds for every generic oracle in the sense of Blum and Impagliazzo. We obtain several consequences of this result, regarding, e. g., universal oracles, simultaneous separations and type‐2 complexity.     

用模拟退火算法求解旅行商问题

用模拟退火算法对求解旅行商组合优化问题作了一定的研究，提出了多种不同的随机抽样方式，并对其进行了分析计算。通过实验表明，在满足模拟退火算法全局收敛性的情况下，子排列反序并移位抽样方式对求解NP完全问题是非常有效的。     

一种约束布局求解算法的改进

针对一个实际问题,讨论了一种约束布局的启发式算法,提出了约束布局求解的启发式规则及相应的布局方案求解策略,改进后的算法具有很强的灵活性和柔性,同时还对该算法的实际性能进行了仿真,结果表明了改进算法的有效性和合理性.     

基于无线网络安全的ECC点积算法研究

椭圆曲线因其自身的优越性应用于无线网络安全中。椭圆曲线密码应用中常使用的两类椭圆曲线为定义在有限域GF（P）上的素曲线和在有限域GF（2^m）上的二元曲线。素曲线计算因不需二元曲线所需要的位混淆运算，常应用于软件：而对硬件应用而言，则最好使用二元曲线，它可用很少的门电路来得到快速且功能强大的密码体制．在椭圆曲线加密体制中，NP问题是制约其应用和发展的瓶颈的核心问题。文中提出了基于无线网络安全的GF（2^m）域上的椭圆曲线点积算法的改进。且本文将椭圆曲线的基点和随机点的点积算法区别开来，具有重要的现实实现意义。     

求有限集合覆盖的构造方法

在近似算法领域,集合覆盖问题是研究的比较早和比较透彻的问题之一.文中解决与经典SCP不同的另一问题,针对有限集合覆盖的构造,提出一种构造有限集合上的集合覆盖的算法,并且给出了该算法的完备性证明.该算法简单有效,是一种用于构造集合覆盖的规范方法.     

Theoretical study on the electrochemical behavior of norepinephrine at Nafion multi-walled carbon nanotubes modified pyrolytic graphite electrode

DFT-B3LYP/6-31G (d, p) and HF/6-31G (d, p) calculations are performed for deoxidized norepinephrineat (NP(R)) and its oxidized form (NP(O)). The electrochemistry of norepinephrineat (NP) was studied by cyclic voltammetry (CV) at a pyrolytic graphite electrode modified by Nafion multi-walled carbon nanotubes (MWNTs) in phosphate buffers at pH 6.0, showing that the standard electrode potential of half reaction for NP(O), H+/NP(R) is 0.75l V. This experimental standard electrode potential of half reaction is consistent with that calculated using the energies of solvation and sum of electronic and thermal free energies of NP(R) and NP(O). The frontier orbital theory and Mülliken charges of molecular explain the electrochemical behavior of CV at modified electrode well. The singlet vertical excited states for NP(R) and NP(O) are also discussed.