遗传程度设计在氟化物非晶态形成的判别条件中的应用

遗传程度设计在氟化物非晶态形成的判别条件中的应用蔡煜东，许伟杰，陈念贻（中国科学院上海冶金研究所上海２０００５０）关键词氟化物，非晶态形成条件，遗传程序设计近几年来，随着遗传程序设计［１］的理论及应用的不断进步，该方法被逐渐应用于模式识别、优化控制、...     

微分方程演化建模用于色谱保留时间的研究

利用演化算法的自适应、自组织、自学习的特性,设计了遗传程序设计与遗传算法相嵌套的混合演化建模算法,以遗传程序设计优化模型结构,以遗传算法优化模型参数,为化合物的液相色谱容量因子随流动相组成变化关系自动建立微分方程演化模型．通过对７个化合物的建模结果表明,演化模型的拟合和预测精度均明显高于常规的ＧＭ（１,１）模型和改进的ＧＭ（１,１）模型．     

遗传算法与遗传编程的联用

遗传算法 ( Genetic algorithm)是一种概率搜索算法 [1] ,它的搜索过程与自然界生物进化过程相似[2 ] ,在搜索过程中不易陷入局部最优 .遗传编程 ( Genetic programming)是近年来随着程序设计自动化而产生和发展起来的一种自动编程技术 [3] .它继承了遗传算法的基本思想 ,是一种更广泛的适应系统方法 [4 ] .本文将遗传算法和遗传编程相结合 ,构造了既有广泛的搜索能力 ,又有很强的局部精化能力的 GA- GP算法 ,充分利用了遗传算法局部精化能力强、遗传编程适应面广的优点 .该算法应用范围广 ,可应用于多种非线性函数式及分式关系的建模 .1…     

便携式智能多道石英晶体微天平的研制与应用

研制出一种能够用于气相和液相检测的便携式智能型多道石英晶体微天平。对其硬件结构、功能和模块化程序设计思想进行了讨论 ,并且给出了部分应用实验结果。本仪器具有精度高、稳定性好和性能、价格比较优越等优点。传感器阵列中的道数可以在 1～ 4之间进行选择。它为混合物测定和物质反应动力学的研究提供了有力的测试手段     

遗传算法及其在分析化学中的应用

遗传算法是模拟生物群体遗传滨基本原理解决问题的一种高效优化方法。本文综述了遗传算法的基本原理、基本过程、发展现状及其在分析化学中的应用。     

气相色谱柱温的智能最佳化II. 程序设计原理及其应用

本文给出了气相色谱柱温智能最佳化的程序设计原理及其应用实例, 用烃/卤代烃混合样作为实际样品进行验证, 预测值与实验值能很好吻合。     

气相色谱柱温的智能最佳化II. 程序设计原理及其应用

本文给出了气相色谱柱温智能最佳化的程序设计原理及其应用实例, 用烃/卤代烃混合样作为实际样品进行验证, 预测值与实验值能很好吻合。     

人工遗传改造生命体的防逃逸技术研究进展

随着合成生物学相关研究的快速发展,被各种遗传技术改良的生命系统在工业、农业、健康和环境等领域的应用正在快速增长.但这些人工遗传改造生命体的泄露或者非受控繁殖可能会对生态环境产生重大危害.为了解决这些人工生命体的环境逃逸和基因转移问题,已有研究关注如何将人工遗传改造的生命体限制于受控的环境中.从三方面简要介绍人工遗传改造生命体防逃逸技术的研究进展:包括(1)传统的防逃逸策略,(2)遗传中心法则的正交化设计策略,和(3)复杂基因网络调控策略.这些防逃逸技术的进一步发展和完善将有利于推动人工改造或全新设计的生命体更广泛的应用.     

生物遗传资源保藏技术与生物安全材料的研究进展

生物遗传资源是人类赖以生存的物质基础,其保藏与利用是国家战略的重要组成部分。尤其是随着医疗与科技水平的提升,人类遗传资源的安全保藏、规范利用引起了我国高度的重视,并颁布了《中华人民共和国人类遗传资源管理条例》。然而,当前生物遗传资源的保藏技术存在标准化难、安全性存疑的问题。本文梳理了几类主要生物遗传资源保藏技术的发展历史、保藏难点和相关生物安全材料的应用情况,并总结了前沿材料对各类遗传资源保藏的最新研究进展,以期为未来开发标准化、生物安全化的遗传资源保藏技术提供全面信息和有力支撑。     

用Excel迭代运算程序解决复杂配位平衡体系中的准确计算问题

采用Excel软件工作表格,通过程序设计引导迭代计算方向,解决了两个复杂配位平衡体系中离子浓度的精确计算问题,发展了简便的Excel计算方法,为复杂配位平衡体系中的精确计算提供了思路。     

Ab Initio Molecular Dynamics Simulations of the Interaction between Organic Phosphates and Goethite

Today’s fertilizers rely heavily on mining phosphorus (P) rocks. These rocks are known to become exhausted in near future, and therefore effective P use is crucial to avoid food shortage. A substantial amount of P from fertilizers gets adsorbed onto soil minerals to become unavailable to plants. Understanding P interaction with these minerals would help efforts that improve P efficiency. To this end, we performed a molecular level analysis of the interaction of common organic P compounds (glycerolphosphate (GP) and inositol hexaphosphate (IHP)) with the abundant soil mineral (goethite) in presence of water. Molecular dynamics simulations are performed for goethite–IHP/GP–water complexes using the multiscale quantum mechanics/molecular mechanics method. Results show that GP forms monodentate (M) and bidentate mononuclear (B) motifs with B being more stable than M. IHP interacts through multiple phosphate groups with the 3M motif being most stable. The order of goethite–IHP/GP interaction energies is GP M < GP B < IHP M < IHP 3M. Water is important in these interactions as multiple proton transfers occur and hydrogen bonds are formed between goethite–IHP/GP complexes and water. We also present theoretically calculated infrared spectra which match reasonably well with frequencies reported in literature.     

Biopolymer/Glycopolypeptide‐Blended Scaffolds: Synthesis,Characterization and Cellular Interactions

Three‐dimensional (3D) scaffolds formed from natural biopolymers gelatin and chitosan that are chemically modified by galactose have shown improved hepatocyte adhesion, spheroid geometry and functions of the hepatocytes. Galactose specifically binds to the hepatocytes via the asialoglycoprotein receptor (ASGPR) and an increase in galactose density further improves the hepatocyte proliferation and functions. In this work, we aimed to increase the galactose density within the biopolymeric scaffold by physically blending the biopolymers chitosan and gelatin with an amphiphlic β‐galactose polypeptide (PPO‐GP). PPO‐GP, is a di‐block copolymer with PPO and β‐galactose polypeptide, exhibits lower critical solution temperature and is entrapped within the scaffold through hydrophobic interactions. The uniform distribution of PPO‐GP within the scaffold was confirmed by fluorescence microscopy. SEM and mechanical testing of the hybrid scaffolds indicated pore size, inter connectivity and compression modulus similar to the scaffolds made from 100 % biopolymer. The presence of the PPO‐GP on the surface of the scaffold was tested monitoring the interaction of an analogous mannose containing PPO‐GP scaffold and the mannose binding lectin Con‐A. In vitro cell culture experiments with HepG2 cells were performed on GLN‐GP and CTS‐GP and their cellular response was compared with GLN and CTS scaffolds for a period of seven days. Within three days of culture the Hep G2 cells formed multicellular spheroids on GLN‐GP and CTS‐GP more efficiently than on the GLN and CTS scaffolds. The multicellular spheroids were also found to infiltrate more in GLN‐GP and CTS‐GP scaffolds and able to maintain their round morphology as observed by live/dead and SEM imaging.     

Nuclear motion on the orbitally degenerate electronic ground state of fully deuterated triatomic hydrogen

Nuclear motion in the vicinity of conical intersections of the degenerate electronic ground state of fully deuterated triatomic hydrogen, D(3), is investigated with the aid of a time-dependent wavepacket approach in hyperspherical coordinates. Vibronic energy level spectra and the eigenfunctions are examined by including, for example, (1) geometric phase (GP) correction, (2) diagonal Born-Huang (BH) correction, and (3) both GP and BH corrections to the Born-Oppenheimer adiabatic Hamiltonian and finally by considering the nonadiabatic coupling between the two electronic surfaces explicitly. It emerges from this study that inclusion of both the GP and BH corrections is insufficient to explain the spectral features observed in the experiment. The latter are recovered by considering the complete two-states coupled Hamiltonian only. This study shows that both the GP and BH corrections constitute a minor part of the surface coupling effects, in particular, on the dynamics of the upper adiabatic sheet. Most importantly, we add that the experimental signature of the GP effect appears only in the observed shift of the eigenlevels of the electronic state when compared to those obtained from a completely Born-Oppenheimer Hamiltonian. The detail fine structure of the observed band of the electronic state is shaped by the off-diagonal derivative coupling elements of the nonadiabatic coupling operator.     

Geometric phase effects in the H+H2 reaction: quantum wave-packet calculations of integral and differential cross sections

We report quantum wave-packet calculations on the H+H(2) reaction, aimed at resolving the controversy over whether geometric phase (GP) effects can be observed in this reaction. Two sets of calculations are reported of the state-to-state reaction probabilities, and integral and differential cross sections (ICSs and DCSs). One set includes the GP using the vector potential approach of Mead and Truhlar; the other set neglects the phase. We obtain unequivocal agreement with recent results of Kendrick [J. Phys. Chem. A 107, 6739 (2003)], predicting GP effects in the state-to-state reaction probabilities, which cancel exactly on summing the partial waves to yield the ICS. Our results therefore contradict those of Kuppermann and Wu [Chem. Phys. Lett. 349 537 (2001)], which predicted pronounced GP effects in the cross sections. We also agree with Kendrick in predicting that there are no significant GP effects in the full DCS at energies below 1.8 eV, and in the partial (0相似文献   

Maturation of murine bone marrow-derived dendritic cells induced by Radix Glycyrrhizae polysaccharide

Radix Glycyrrhizae polysaccharide (GP), the most important component of Radix Glycyrrhizae, has been reported to have many immunopharmacological activities. However, the mechanism by which GP affects dendritic cells (DCs) has not been elucidated. In this study, we investigated the effect of GP on murine bone marrow-derived DCs and the potential pathway through which GP exerts this effect. Mononuclear cells (MNCs) were isolated from murine bone marrow and induced to become DCs by culturing with GM-CSF and IL-4. Six days later, DCs were divided into three groups: control group, GP group and LPS group. After 48 h of treatment, phenotypic figures and antigen uptake ability were determined by FACS analysis. The proliferation of DC-stimulated allogenic CD3+ T cells was detected by WST-1. IL-12 p70 and IFN-γ, which are secreted by DCs and CD3+ T cells respectively, were quantified by ELISA. Additionally, IL-12 p40 mRNA expression was determined by real-time PCR. Alterations in TLR4-related signaling pathways were examined by performing an antibody neutralization experiment. Treatment of DCs with GP resulted in the enhanced expression of the cell surface molecules CD80, CD86 and MHC I-A/I-E. GP also increased the production of IL-12 p70 by DCs in a time-dependent manner. The endocytosis of FITC-dextran by DCs was suppressed by GP administration. Furthermore, GP-treated DCs enhanced both the proliferation and IFN-γ secretion of allogenic CD3+ T cells. Finally, the effects of GP on DCs were partially reduced by using inhibitors of TLR4, NF-κB, p38 MAPK or JNK. In conclusion, GP can induce the maturation of DCs, and does so, in part, by regulating a TLR4-related signaling pathway.     

Down-regulation of Treg cells and up-regulation of TH1/TH2 cytokine ratio were induced by polysaccharide from Radix Glycyrrhizae in H22 hepatocarcinoma bearing mice

Radix Glycyrrhizae polysaccharide (GP) possesses multiple pharmacological activities. However, the effect of GP on CD4+CD25+ regulatory T (Treg) cells has not been elucidated. This study aimed to investigate the effects of GP on Treg cells and Th1/Th2 cytokines in H22 hepatocarcinoma tumor-bearing mice. The results demonstrated that GP inhibits tumor progression. In the lymph nodes of the tumor microenvironment and spleen, the proportion of Treg cells was significantly higher in the tumor-bearing mice. GP administration down-regulated the population of Treg cells (P < 0.01) and decreased lymph node Foxp3 and IL-10 mRNA expression (P < 0.01). In addition, GP treatment decreased IL-10 and TGF-β level (P < 0.01) and increased IL-2 and IL-12p70 level in serum (P < 0.01). In conclusion, GP reduced the proportion of Treg cells and Foxp3 lowered expression in Treg cells, and up-regulated Th1/Th2 cytokine ratio in serum in the tumor bearing mice, which might partially cause the inhibition of tumor growth.     

变温核磁共振对壳聚糖/磷酸甘油盐温敏性水凝胶的初步研究

采用变温核磁共振技术对壳聚糖/磷酸甘油盐温敏性水凝胶体系的凝胶化过程进行跟踪研究. 实验结果表明, 壳聚糖中氢和磷酸甘油盐中磷的化学位移均随着温度的升高而变化, 其中壳聚糖中氢的化学位移向高场移动而磷酸甘油盐中磷的化学位移向低场移动. 在凝胶温度附近, 壳聚糖中H-2(D)的化学位移变化出现转折点, 表明其所处的化学环境发生了突变. 随着体系中磷酸甘油盐含量的增加或者pH值的增大, 壳聚糖中H-2(D)的化学位移愈加偏向高场, 体系的凝胶温度则越低. 由此, 我们提出如下壳聚糖/磷酸甘油盐温敏性水凝胶的凝胶机理: 随着温度的升高, 壳聚糖通过氨基正离子与磷酸甘油盐形成的静电吸引被破坏, 随之由于壳聚糖分子链间形成大量氢键而发生凝胶化.     

原位合成石墨烯负载的Co-P催化剂及光解水制氢

在石墨烯(GP)基底上利用光电子原位还原合成了具有非晶态结构的Co-P/GP光催化剂。通过X射线衍射仪(XRD)和透射电子显微镜(TEM)表征,证明所制备的催化剂在石墨烯载体上分散性好、粒径小,具有非晶态结构。由XPS表征了催化剂的表面电子状态,发现催化剂表面的Co和P主要是以还原态存在,有利于表面富集电子。经过曙红敏化,催化剂在可见光辐照下具有很好的光催化制氢性能。考察了不同物质的量之比nCo∶nP的制氢速率,当nCo∶nP=5∶1时,3 h的平均制氢量为24.5 mmol·h~(-1)·gCo~(-1)。考察了不同波长条件下催化剂制氢的量子效率,当波长为430 nm时,Co-P/GP催化剂的制氢量子效率AQE达到8.4%,比没有添加P的Co/GP催化剂提高了1.5倍。     

Immunochemical Study of the Effect of F<Subscript>2</Subscript>Glc on Glycogen Synthase Translocation and Glycogen Synthesis in Isolated Rat Hepatocytes

The compound 2-deoxy-2-fluoro-α-d-glucopyranosyl fluoride (F₂Glc), which is a nonmetabolized superior glucose analogue, is a potent inhibitor of glycogen phosphorylase and pharmacological properties are reported. Glycogen phosphorylase (GP) and glycogen synthase (GS) are responsible of the degradation and synthesis, respectively, of glycogen which is a polymer of glucose units that provides a readily available source of energy in mammals. GP and GS are two key enzymes that modulate cellular glucose and glycogen levels; therefore, these proteins are suggested as potential targets for the treatment of diseases related to glycogen metabolism disorders. We studied by Western Blot technique that F₂Glc decreased GP activity, and we also showed that F₂Glc did not affect GS activity and its translocation from a uniform cytosolic distribution to the hepatocyte periphery, which is crucial for glycogen synthesis, using immunoblotting and immunofluorescence labeling techniques. F₂Glc specifically inhibits glycogenolysis pathway and permits a greater deposition of glycogen. These observations open up the possibility of further develop drugs that act specifically on GP. The ability to selectively inhibit GP, which is a key enzyme for the release of glucose from the hepatic glycogen reserve, may represent a new approach for the treatment of hyperglycemia in type 2 diabetes.     

Printing graphene-carbon nanotube-ionic liquid gel on graphene paper: Towards flexible electrodes with efficient loading of PtAu alloy nanoparticles for electrochemical sensing of blood glucose

The increasing demands for portable, wearable, and implantable sensing devices have stimulated growing interest in innovative electrode materials. In this work, we have demonstrated that printing a conductive ink formulated by blending three-dimensional (3D) porous graphene–carbon nanotube (CNT) assembly with ionic liquid (IL) on two-dimensional (2D) graphene paper (GP), leads to a freestanding GP supported graphene–CNT–IL nanocomposite (graphene–CNT–IL/GP). The incorporation of highly conductive CNTs into graphene assembly effectively increases its surface area and improves its electrical and mechanical properties. The graphene–CNT–IL/GP, as freestanding and flexible substrates, allows for efficient loading of PtAu alloy nanoparticles by means of ultrasonic-electrochemical deposition. Owing to the synergistic effect of PtAu alloy nanoparticles, 3D porous graphene–CNT scaffold, IL binder and 2D flexible GP substrate, the resultant lightweight nanohybrid paper electrode exhibits excellent sensing performances in nonenzymatic electrochemical detection of glucose in terms of sensitivity, selectivity, reproducibility and mechanical properties.