等高线图解分析法:评价药物相互作用的方法

药物相互作用的性质是研究复方制剂的基础,随着药物合并应用的发展,等高线图解分析法应运而生,逐渐成为评价药物相互作用的“黄金标准”,广泛地应用于药理学各个领域。本文就等高线图解分析法的基本理论及应用做一综述。

土地利用混合度对出行方式选择的影响

为研究土地利用混合度对出行方式选择的影响,提出了一种基于地理信息系统(geographic information system,GIS)的度量土地利用混合度的相互作用法,通过提取不同土地利用类型之间的公共边线并赋予相应的权值,进一步定量计算各交通小区土地利用混合度;利用居民出行调查数据,借助STATA软件研究不同土地利用混合度指标对出行方式选择的影响,并以天水市为对象进行了具体研究.结果表明:相互作用指标对居民出行行为的解释性优良,土地混合利用有助于引导居民选择非机动化出行方式,研究结果对小城市规划和交通政策的制定具有指导意义.

用扩展的Istomin-Palm模型估算双向延伸化合物R1-Y-R2生成焓(英文)

Istomin和Palm曾提出用模型ΔfH0(RX)=h[R]+h[X]+φ[R]φ[X](式中h[R]和h[X]分别为烷基R和取代基X对单取代烷烃生成焓ΔfH0(RX)的贡献,φ[R]φ[X]则表示R与X之间的相互作用对ΔfH0(RX)的贡献)来表示单取代烷烃生成焓ΔfH0(RX).对于双向延伸化合物R1-Y-R2,其取代基Y位于分子链的中间,与两个烷基(R1和R2)相连.此类化合物分子内取代基与烷基之间的相互作用,较单取代烷烃的相比更为复杂.因此,Istomin-Palm模型在R1-Y-R2体系中应用必须进行修正.本文把取代基Y、烷基R1和R2三者之间的相互作用对R1-Y-R2类化合物生成焓ΔfH0(R1-Y-R2)的贡献分为三部分:R1Y与R2之间的相互作用(φ[R2]φ[R1Y]),YR2与R1之间的相互作用(φ[R1]φ[YR2]),以及两烷基R1与R2之间的相互作用(ψ[R1]ψ[R2]).用以上三项替换φ[R]φ[X],扩展Istomin-Palm模型,建立一个新的经验模型ΔfH0(R1-Y-R2)=h[R1]+h[R2]+h[Y]+φ[R1]φ[YR2]+φ[R2]φ[R1Y]+ψ[R1]ψ[R2],来表示ΔfH0(R1-Y-R2)(式中h[R1]、h[R2]和h[Y]分别为烷基R1、R2和取代基Y对ΔfH0(R1-Y-R2)的贡献,后三项则表示烷基R1、R2和取代基Y两两之间相互作用对ΔfH0(R1-Y-R2)的贡献).进而,采用本研究组最近报道的相互作用势指数IPI(X)(Wu,Y.X.;Cao,C.Z.;Yuan,H.Chin.J.Chem.Phys.2012,25(2),153.)表示取代基Y对烷基的固有作用(φ[Y]),从而建立两个定量估算生成焓的通用模型.其中,一个用于估算硫醚、仲胺、醚和酮类化合物生成焓,另一个用于估算酯类化合物生成焓.这两个模型均得到良好的结果,与采用G3和G3MP2方法相比具有同样的精度,还可以避免大量繁琐的计算.

Wheel slip-sinkage and its prediction model of lunar rover

In order to investigate wheel slip-sinkage problem, which is important for the design, control and simulation of lunar rovers, experiments were carried out with a wheel-soil interaction test system to measure the sinkage of three types of wheels in dimension with wheel lugs of different heights and numbers under a series of slip ratios (0-0.6). The curves of wheel sinkage versus slip ratio were obtained and it was found that the sinkage with slip ratio of 0.6 is 3-7 times of the static sinkage. Based on the experimental results, the slip-sinkage principle of lunar's rover lugged wheels (including the sinkage caused by longitudinal flow and side flow of soil, and soil digging of wheel lugs) was analyzed, and corresponding calculation equations were derived. All the factors that can cause slip sinkage were considered to improve the conventional wheel-soil interaction model, and a formula of changing the sinkage exponent with the slip ratio was established. Mathematical model for calculating the sinkage of wheel according to vertical load and slip ratio was developed. Calculation results show that this model can predict the slip-sinkage of wheel with high precision, making up the deficiency of Wong-Reece model that mainly reflects longitudinal slip-sinkage.

Enthalpies Estimation of Formation of Monosubstituted Alkanes by Interaction Potential Index

The interaction potential index IPI（X） of 16 Br, C1, I, NO2, CN, CHO, COOH, CH3, CH： kinds of substituents X （X---OH, SH, NH2, ：CH2, C-CH, Ph, COCH3, COOCH3） were proposed, which are derived from the experimental enthalpies of formation △fHФ （g） values of monosubstituted straight-chain alkanes. Based on the IPI（X） and polarizability effect index, a simple and effective model was constructed to estimate the △fHФ （g） values of monosubstituted alkanes RX （including the branched derivatives）. The present model takes into account not only the contributions of the alkyl R and the substituent X, but also the contribution of the interaction between R and X. Its stability and prediction ability was confirmed by the results of leave-one-out method. Compared with previous reported studies, the obtained equation can be used to estimate enthalpies of formation for much more kinds of monosubstituted alkanes with less parameters. Thus, it is recommended for the calculation of the △fHФ（g） for the RX.

Effect of climate change on seasonal water use efficiency in subalpine Abies fabri

Abies fabri is a typical subalpine dark coniferous forest in southwestern China. Air temperature increases more at high elevation areas than that at low elevation areas in mountainous regions,and climate change ratio is also uneven in different seasons. Carbon gain and the response of water use efficiency(WUE) to annual and seasonal increases in temperature with or without CO_2 fertilization were simulated in Abies fabri using the atmospheric-vegetation interaction model(AVIM2). Four future climate scenarios(RCP2.6,RCP4.5,RCP6.0 and RCP8.5) from the Coupled Model Intercomparison Project Phase 5(CMIP5) were selectively investigated. The results showed that warmer temperatures have negative effects on gross primary production(GPP) and net primary production(NPP) in growing seasons and positive effects in dormant seasons due to the variation in the leaf area index. Warmer temperatures tend to generate lower canopy WUE and higher ecosystem WUE in Abies fabri. However,warmer temperature together with rising CO_2 concentrations significantlyincrease the GPP and NPP in both growing and dormant seasons and enhance WUE in annual and dormant seasons because of the higher leaf area index(LAI) and soil temperature. The comparison of the simulated results with and without CO_2 fertilization shows that CO_2 has the potential to partially alleviate the adverse effects of climate warming on carbon gain and WUE in subalpine coniferous forests.

Dynamic Evolution with Limited Learning Information on a Small-World Network

This paper investigates the dynamic evolution with limited learning information on a small-world network.In the system, the information among the interaction players is not very lucid, and the players are not allowed to inspectthe profit collected by its neighbors, thus the focal player cannot choose randomly a neighbor or the wealthiest one andcompare its payoff to copy its strategy.It is assumed that the information acquainted by the player declines in theform of the exponential with the geographical distance between the players, and a parameter V is introduced to denotethe inspect-ability about the players.It is found that under the hospitable conditions, cooperation increases with therandomness and is inhibited by the large connectivity for the prisoner's dilemma; however, cooperation is maximal atthe moderate rewiring probability and is chaos with the connectivity for the snowdrift game.For the two games, theacuminous sight is in favor of the cooperation under the hospitable conditions; whereas, the myopic eyes are advantageousto cooperation and cooperation increases with the randomness under the hostile condition.

银杏叶、黄芪总黄酮的协同抗氧化作用考察

目的:考察银杏叶、黄芪醇提物中总黄酮的相互抗氧化作用。方法:采用UV测定总黄酮含量,检测波长507 nm。以清除率和半数抑制率质量浓度(IC50)为指标,通过DPPH自由基清除试验与等辐射分析法探讨银杏叶、黄芪醇提物单独和复配(质量浓度比分别为1∶1.08,1∶3.22,1∶9.70)后总黄酮的抗氧化作用。结果:银杏叶、黄芪醇提物中总黄酮的IC50分别为3.45,12.01 mg·L-1,表明二者对DPPH自由基具有明显的清除作用。等辐射分析中银杏叶、黄芪醇提物复配后的效应点均在相加线及95%可信限的下方,复配组(x珋±s,n=4)的理论值IC50 add分别为(5.49±0.05),(7.53±0.04),(9.82±0.07)mg·L-1,试验值IC50 mix分别为(4.95±0.09),(6.56±0.15),(8.61±0.15)mg·L-1,相互作用指数分别为0.90,0.86,0.88。结论:银杏叶总黄酮清除DPPH自由基能力较黄芪总黄酮强,银杏叶、黄芪醇提物间存在协同抗氧化效应。

A hybrid method for extraction of protein-protein interactions from literature

In this work, a hybrid method is proposed to eliminate the limitations of traditional protein-protein interactions （PPIs） extraction methods, such as pattern learning and machine learning. Each sentence from the biomedical literature containing a protein pair describes a PPI which is predicted by first learning syntax patterns typical of PPIs from training corpus and then using their presence as features, along with bag-of-word features in a maximum entropy model. Tested on the BioCreAtIve corpus, the PPIs extraction method, which achieved a precision rate of 64%, recall rate of 60%, improved the performance in terms of F1 value by 11% compared with the component pure pattern- based and bag-of-word methods. The results on this test set were also compared with other three extraction methods and found to improve the performance remarkably.

共载多西他赛和藤黄酸白蛋白纳米粒的处方优选和质量评价

目的:利用星点设计-效应面法优化共载多西他赛(DTX)和藤黄酸(GA)白蛋白纳米粒(DTX-GA-BSA NPs)的处方,制备DTX-GA-BSA NPs并评价其质量。采用两药相互作用指数(CDI)筛选DTX和GA的最佳协同配比,为该纳米粒的应用与推广提供实验依据。方法:采用Nab^TM法制备DTX-GA-BSA NPs,以牛血清白蛋白(BSA)为载体材料。利用Design-Expert8.0.6软件设计实验和处理数据,以粒径和多分散性指数(PDI)的总评"归一值"(OD)以及包封率为评价指标,测定DTX-GABSA NPs的粒径,PDI,包封率和Zeta电位。利用噻唑蓝比色法分别测定DTX和GA对MGC-803和HGC-27细胞增殖的单独和协同抑制作用。结果:DTX-GA-BSA NPs的最优处方为BSA质量浓度5 g·L^-1,水油体积比(水相与油相的体积比) 1∶17,药载比(药物与载体的质量比) 1∶10;模型预测值与实测值偏差较小,具有优良的预测性。DTX-GA-BSA NPs的平均粒径135.8 nm,PDI=0.09,Zeta电位-21.4 mV。当DTX和GA浓度分别为0.004,0.12μmol·L^-1时,二者对MGC-803细胞的协同增殖抑制作用最显著;当DTX和GA浓度分别为0.004,1μmol·L^-1时,二者对HGC-27细胞的协同增殖抑制作用最显著。结论:优选的DTX-GA-BSA NPs处方工艺稳定可靠,建立的数学模型具有良好预测能力和实用性。DTX和GA联用对MGC-803,HGC-27细胞均具有协同作用,但不呈浓度依赖性。

Tricritical and Critical Exponents in Microcanonical Ensemble of Systems with Long-Range Interactions

We explore the tricritical points and the critical lines of both Blume Emery Griffiths and Ising model within long-range interactions in the microcanonical ensemble.For K = Kmtp,the tricritical exponents take the valuesβ = 1/4,1 =γ^-≠γ^+ = 1/2 and 0 =α^-≠α^+ =-1/2,which disagree with classical(mean ffeld) values.When K > Kmtp,the phase transition becomes second order and the critical exponents have classical values except close to the canonical tricritical parameters(Kctp),where the values of the critical expoents become β = 1/2,1 = γ^-≠γ^+= 2and 0 =α^-≠α^+ = 1.

Electronic Casimir–Polder Force in a One-dimensional Tight-Binding Nanowire at Finite Temperature

We study the effect of two non-interacting impurity atoms near by a one-dimensional nanowire, which is modeled as a tight-binding hopping model. The virtual single-electron hopping between two impurities will induce an additional energy depending on the distance of two impurities, which gives a electronic Casimir–Polder effect. We find that the Casimir–Polder force between the two impurities decreases with the impurity-impurity distance exponentially.And the effects of nanowire and finite temperature on the Casimir–Polder force are also discussed in detail, respectively.