非等时空距灰色模型在液相色谱保留值研究中的应用

本文运用灰色理论中的非等时空距ＧＭ（１，１）模型，对液相色谱中的流动相组成及容量因子的关系进行了研究。所建灰色模型经过检验其精度为Ｉ级。实验结果表明，不仅等时空距灰色模型，而且非等时空距灰色模型，同样适用于色谱保留值的研究。     

色谱灰色数模的建立及应用研究（Ⅳ）：CGM（1,1,N）模型的 …

应用灰色系统理论，推导出灰色Ｎ参数模型ＣＧＭ（１，１，Ｎ），突破了现有单参数灰色模型的局限性，并用该模型讨论了色谱保留值与分子结构参数间绎烷基苯的同分异构体色谱保留值及疏水性参数进行了预测，经实例验证，其预测精度较单参数灰色模型高，这为溶质保留行为的预测提供了一个实用方法，同时也拓宽了灰色模型的应用范围。     

连续型非等时空距灰色模型在液相色谱保留值研究中的应用

本运用灰色理论中的连续型等时空距ＧＭ（１，１）模型，对液相色谱中流动相组成与容量因子间的关系进行了研究，建立了可进行连续预测的数学模型，所建模型与实际情况吻合很好，经检验各模型精度均达到Ｉ级。     

灰色理论在液相色谱保留值研究中的应用

本文应用灰色理论中的ＧＭ（１，１）模型，对液相色谱中的Ф和ｋ＇的关系进行了研究，其结果达到用Ｓｃｈｏｅｎｍａｋｅｒｓ公式和卢佩章公式预测及计算ｋ＇的水平。结果指出：灰色理论完全适用于对色谱保留问题的研究，其方法也这无全能满足实际工作中的应用。     

改进的GM（1,1）模型及其在色谱保留值研究中的应用

由于常规ＧＭ（１，１）模型对批相ＨＰＬＣ中化合物容量因子与流动相组成间非线性关系的线性近似以及常规ＧＭ（１，１）模型建模方法所固的缺点，使得常规ＧＭ（１，１）模型的预测精度难以提高。本文用近代非线性回归分析法对建模方法作了改进，建立了具有更高精度的ＧＭ（１，１）模型，并将其用于多环芳烃容量因子随流动相组成变化关系的建模，获得了满意的结果。     

灰色模型预测气相色谱法中的保留值

应用灰色理论中的ＧＭ（１,１）模型,对气相色谱法中容量因子ｋ＇和温度倒数１／Ｔ之间的关系进行了研究,求出了许多火炸药组分的ａ和ｕ值,并随机预测了几种火炸药组分的ｋ＇值。结果指出,灰色理论完全适用于对气相色谱保留值问题的研究,方法也完全能应用于实际工作中。     

色谱保留值参数与灰色模型参数的关系

用数学方法对灰色ＧＭ（１,１）模型与色谱中表述ｋ′和φ关系的Ａ,Ｂ值间的参数关系进行了推导,得出了两者间的函数关系式,从而预测了化合物的出峰位置以及各种混合组分分离分析的可能性,并对实验数据进行了检验,提出了一个获得适当的修正关系式的方法。结果表明：灰色ＧＭ（１,１）模型完全适合于对色谱参数值问题的研究。     

静态GM（0,6）灰色模型在预测气相色谱保留指数上的应用

本文从麦克雷诺（ＭｃＲｅｙｎｏｌｄｓ）相常数法出发推导了五种标准物质与任意溶质ｉ的色谱保留指数之间的关系符合灰色ＧＭ（０，６）模型，对它们进行了灰色建模。获得了很高的模型精度，并根据模型式预测了涂有不同固定液色谱柱中的溶质ｉ的保留指数。通过预测值与文献值的比较，得到了良好的预测精度。     

色谱灰色数模的建立及其应用研究(Ⅱ)——NLCGM(1,1)模型的建立及芳烃保留行为的预测

色谱保留值与流动相组成间关系的研究一直是色谱工作者关心的课题［１,２］．灰色模型对于处理具有不确定关系的两因素间的关系问题具有独到之处,在容量因子（ｋ）与流动相组成（φ）关系的研究方面已得到了应用［３～８］．传统ＧＭ（１,１）模型将ｋ与φ之间的关...     

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．     

The Role of Monosialoganglioside GM1 in LTP-Induction in Rat Hippocampal Slices

The effect of monosialoganglioside GM1 of different doses on the long-term potentiation (LTP) of synaptic transmission has been studied in the CA1 region of rat hippocampal slices, and the possible role that calcium ion and NMDA receptor play has also been investigated. The results reveal that larger magnitude of LTP is induced in hippocampal slices pre-incubated with GM1. The dose-response curve appears in diphase, and the largest magnitude of LTP has been obtained at the GM1 concentration of 50 mg/L in incubation ACSF. Moreover, the magnitude of LTP induced from the slices pre-incubated with GM1 at lower calcium ion concentration is similar to that obtained from the control slices at normal calcium ion concentration. Under higher calcium ion concentration, the enhancing effect of GM1 on LTP seems relatively feeble. After NMDA receptors were blocked, no enhancing effect of GM1 was observed. The mechanism of GM1 action on LTP is discussed.     

色谱灰色数模的建立及其应用研究(Ⅰ)──连续GM(1,N)模型的建立及色谱保留行为的预测

应用灰色系统理论和最小二乘原理，推导出连续GM（1，N）模型，并将该模型用于高效液相色谱中溶质保留行为的预测．研究了烷烃、烷基苯及对羟基苯甲酸酯等化合物的容量因子与流动相组成、容量因子与碳数、保留时间与温度、保留时间与碳数的关系，并建立了相应的数学模型，经验证，预测结果良好．     

高效液相色谱-串联质谱法分离鉴定单唾液酸四己糖神经节苷脂中的杂质

用高效液相色谱法（HPLC）分析了单唾液酸四己糖神经节苷脂(GM1)药物的冻干粉、中间体和注射液各6个批号的样品,以期查找出采用不同工艺生产的成品中造成临床副反应的可能杂质。在用HPLC对多个批号GM1成药的对比分析中,发现某个批号的GM1干粉中多出2个杂质峰,其保留时间与制作该批号的GM1中间体的2个杂质峰保留值相同。对该批号的GM1干粉和相应批号的GM1中间体中的目标杂质进行半制备级收集,经冷冻干燥除溶剂富集35倍后,用电喷雾-四极杆-飞行时间质谱（ESI-Q-TOF MS）定性分析,对主分子离子峰进行了二级质谱分析。经谱图解析后,推断在GM1干粉和中间体中存在的保留值相同的杂质可能是同种组分。两个杂质峰的结构皆为岩藻糖(Fuc)-GM1,仅是神经酰胺上的长链基团有所不同,峰1的该基团由16个CH2组成,而峰2的该基团由18个CH2组成。临床数据表明含有上述两种杂质的2批GM1注射液都有副反应,而没有上述杂质的4批GM1注射液都没有临床副反应,而且这两批有临床副反应的GM1注射液都是用同一个批号的含有这两种杂质的中间体制成的,因此推断上述两个杂质可能是引起副反应的主要组分。     

Membrane properties of mixed ganglioside GM1/phosphatidylcholine monolayers

The interaction between ganglioside G_M1 (GM1) and --dipalmitoylphosphatidylcholine (DPPC) in mixed monolayers was investigated using surface pressure measurements and atomic force microscopy (AFM), and the effects of GM1, surface pressure and temperature on the properties of the membranes were examined. Mixed GM1/DPPC monolayers were deposited on mica using the Langmuir–Blodgett (LB) technique for AFM. GM1 and DPPC were miscible below the 0.2 mole fraction of GM1 and there was attractive interaction between GM1 and DPPC. The AFM images for the GM1/DPPC monolayers (X_GM1 < 0.2) at 30 mN m⁻¹ and 25 °C indicated a percolation pattern which means a micro phase separation: namely, the mixed film composed of GM1 and DPPC phase-separated from the DPPC liquid-condensed film. The AFM images for the mixed monolayers at 33 mN m⁻¹ indicated a specific morphology when the surface pressure was varied from 30 to 40 mN m⁻¹. The percolation pattern in the AFM image at 25 °C came to be destroyed with increasing temperature and completely disappeared at 45 °C. The change in the morphology of mixed GM1/DPPC monolayers on varying the surface pressure and temperature is thought to be related to signal transduction and a preventive mechanism against viral infections in the human body.     

CHARACTERIZATION OF MOLECULAR MASS OF SIX WATER-SOLUBLE POLYSACCHARIDE -PROTEIN COMPLEXES FROM GANODERMA TSUGAE MYCELIUM

Six water-soluble polysaccharide-protein complexes coded as GM1, GM2, GM3, GM4, GM5 and GM6 wereisolated from the mycelium of Ganoderma tsugae by extracting with 0.2 mol/L phosphate buffer solution at 25, 40 and80℃, water at 120℃, 0.5 mol/L aqueous NaOH solution at 25 and 65℃, consecutively. Their chemical components wereanalyzed by using IR, GC, HPLC and ~(13)C-NMR, and some new results were obtained. The four samples GM1, GM2, GM3and GM4 are heteropolysaccharide-prote in complexes, in which, α- (1→3) linked D-glucose is the major monosaccharidewhile galactose, mannose and ribose are the secondary ones. GM5 and GM6 are β-(1→3)-D-glucan-protein complexes. Theprotein content increased from 32% to 69% with the progress of isolation. Weight-average molecu1ar mass M_w and theintrinsic viscosity [η] of the GM samples in 0.5 mol/L aqueous NaCl solution at 25℃ were measured systematically by laserlight scartering (LLS), size exclusion chromatography (SEC) combined with LLS, and viscometry. The M_w of GM1 to GM6are 35.5, 46.8, 58.9, 41.6, 3.3 and 22.0×10~4, respectively. The conformation and molecular mass of the two fractions of sample GM5 were characterized satisfactorily by SEC-LLS without further fractionation.     

Membrane properties of binary and ternary systems of ganglioside GM1/dipalmitoylphosphatidylcholine/dioleoylphosphatidylcholine

The membrane properties of the ganglioside GM1 (GM1)/dioleoylphosphatidylcholine (DOPC) binary system and GM1/dipalmitoylphosphatidylcholine (DPPC)/DOPC ternary system were investigated using surface pressure measurements and atomic force microscopy (AFM), and the effect of surface pressure on the properties of the membranes was examined. Mixed GM1/DPPC/DOPC monolayers were deposited on mica using the Langmuir-Blodgett technique for AFM. GM1 and DOPC were immiscible and phase-separated. The AFM image of the GM1/DOPC (1:1) monolayer showed island-like GM1 domains embedded in the DOPC matrix. There was no morphological change on varying surface pressure. The surface pressure-area isotherm of the GM1/DPPC/DOPC (2:9:9) monolayer showed a two-step collapse as in the DPPC/DOPC (1:1) monolayer. The AFM image for the GM1/DPPC/DOPC monolayer showed DPPC and GM1 domains in the DOPC matrix, and the DPPC-rich phase containing GM1 showed a percolation pattern the same as the GM1/DPPC (1:9) monolayer. The percolation pattern in the GM1/DPPC/DOPC monolayer changed as the surface pressure was varied. The surface pressure-responsive change in morphology of GM1 was affected by the surrounding environment, suggesting that the GM1 localized in each organ has a specific role.     

Analyzing energy landscapes for folding model proteins

A new benchmark 20-bead HP model protein sequence (on a square lattice), which has 17 distinct but degenerate global minimum (GM) energy structures, has been studied using a genetic algorithm (GA). The relative probabilities of finding particular GM conformations are determined and related to the theoretical probability of generating these structures using a recoil growth constructor operator. It is found that for longer successful GA runs, the GM probability distribution is generally very different from the constructor probability, as other GA operators have had time to overcome any initial bias in the originally generated population of structures. Structural and metric relationships (e.g., Hamming distances) between the 17 distinct GM are investigated and used, in conjunction with data on the connectivities of the GM and the pathways that link them, to explain the GM probability distributions obtained by the GA. A comparison is made of searches where the sequence is defined in the normal (forward) and reverse directions. The ease of finding mirror image solutions are also compared. Finally, this approach is applied to rationalize the ease or difficulty of finding the GM for a number of standard benchmark HP sequences on the square lattice. It is shown that the relative probabilities of finding particular members of a set of degenerate global minima depend critically on the topography of the energy landscape in the vicinity of the GM, the connections and distances between the GM, and the nature of the operators used in the chosen search method.