线粒体体外代谢热动力学研究

线粒体是细胞重要的细胞器之一，有细胞的“能源工厂”之称．因为线粒体内有许多酶，是特殊的酶催化氧化反应的场所山；所有动、植物细胞的线粒体都能通过各种营养物的氧化而产生“富能”物质ATP．采用一定的技术可将线粒体从细胞中分离出来，分离出来的线粒体中的酶系统还有一定的活性，而且线粒体内也有一定的营养物质，这样酶系统就能利用这些营养物进行代谢，从而释放出一定的能量．我们用微量热法对两种鱼肝脏线粒体进行了测量，发现线粒体代谢过程分四个阶段：停滞期、活性恢复期、稳定期、活性衰减期．在活性恢复期和活性衰减期，…     

线粒体体外代谢热动力学模型及其演化优化研究

导出了线粒体体外代谢的热动力学方程，探讨了它和指数模型的关系，将演化计算技术引入生物热化学领域，用ＭＴＤ方程和演化计算技术，对文献报导的八种鱼肝线粒体体外代谢的热动力学参数进行了全局优化。     

差示扫描量热研究水稻线粒体能量释放动力学

线粒体是细胞的一个重要的亚细胞器．它通过呼吸作用为细胞各项活动提供能量，有细胞'动力戒'之称．生物摄取的食物通过代谢分解形成小分子产物之后，被输送至线粒体，经过氧化作用将其中贮存的能量逐步释放出来，并转化为三磷酸腺苦（ATP）以供生命机体各种活动的需要，因而它     

线粒体和亚线粒体体外代谢及漆酶影响的微量热研究

首次将微量热用于亚细胞层次的研究，测定了鲤鱼肝脏线粒体和亚线粒体代谢的热谱及其漆树漆酶的影响，并用ＭＴＤ方程和演化计算技术对它们的代谢热动力学参数进行了全局优化。     

细胞不同代谢类型的热化学研究Ⅰ.生长、非生长及内源代谢水平的量热测定

细胞是生命的基本单位．对其代谢过程能量输出水平的直接测定，对细胞生理学来说是重要的实验基础数据，对于生物生理和研究能量代谢方面也有一定的理论意义．当然细胞的多样性及其代谢过程的复杂性使这一研究工作相当困难·作为开展研究的第一步我们选择便于培养处理的单细胞生物大肠杆菌作为研究对象，并对其所进行时三种基本代谢类型29Llxi：L谢；非生长依队和内派代谢分别进行研究，本文分别测定了＊烟三种不同类型代谢的热功率输出水平，得到了单个细胞在上述代谢过程热功率输出的定量数据．实验结果表明，不同类型代谢的能量输出水平…     

高灵敏宽温区吸附热测定装置的建立

 描述了一个适于气／固体系的宽温区、高灵敏的微分吸附热测定装置．在该装置中，吸附放热由Setaram公司热流式微量热量计测定，吸附量由MKS公司电容式压力传感器测定．此外，设计、制作了可在高真空和宽温区内进行吸附热测定的试样池以及对高活泼金属催化剂进行预处理的试样处理池．用标准物质对热量计进行了标定．为验证该装置对吸附热测定的可靠性，测定了H2在Pt／SiO2和γ－Mo2N上的吸附热，所得结果与文献值一致．数据的误差分析结果表明，吸附热测定的相对误差在4％以内．     

水稻线粒体能量释放的量热研究

水稻线粒体能量释放的量热研究＊周培疆＊＊（新疆大学化学系乌鲁木齐８３００４６）谢昌礼屈松生周涵韬＊＊＊凌杏元朱英国（武汉大学化学系武汉大学生命科学学院武汉４３００７２）关键词水稻线粒体能量释放量热热力学动力学中图分类号Ｏ６４２．０３线粒体是真核细胞中...     

不同条件下离体大鼠肝脏线粒体能量代谢微量热分析

为了探究线粒体的能量代谢过程,本文以离体大鼠肝脏线粒体为模型,利用多通道、高灵敏度的热活性检测仪TAM Ⅲ,实时监测了不同线粒体浓度、不同底物、不同缓冲液、几种呼吸抑制剂以及Ca²⁺和线粒体渗透转换孔抑制剂CsA存在时线粒体的能量代谢,获得了完整的热功率―时间曲线,并通过计算得到了线粒体能量代谢的热动力学参数。通过分析发现：（1）线粒体浓度越大,代谢越快;（2）直接底物琥珀酸钠使线粒体代谢更快;（3）高浓度Ca²⁺能够刺激线粒体快速产热,且在长期代谢进程中,线粒体渗透转换孔抑制剂CsA并不能改变Ca²⁺造成的影响;（4）不同缓冲液对线粒体代谢的影响基于其组分的不同,缓冲液中含有呼吸底物;（5）呼吸抑制剂都能抑制线粒体的能量代谢,尤其是复合物IV的抑制剂NaN₃,高浓度下使代谢停止。     

硫酸氢钾(KHSO4,A.R.)的低温热容和热化学性质

硫酸氢钾（ＫＨＳＯ4,Ａ．Ｒ）是一种重要的无机化工原料。在化肥工业中,它是生产复合肥硫酸铵钾（ＫＮＨ４ＳＯ４）的主要原料之一。为了找到工业上生产复合肥硫酸铵钾的最佳工艺条件,提高其产率和经济效益,并且开发其新的应用领域,迫切需要该化合物准确的热力学数据作为理论分析的依据。 硫酸氢钾的导热系数,溶解度,熔点等部分热物性数据［１－３］已有报道,但是,迄今为止,文献中未见到它的低温热容和热分解过程的详细报道。本文用精密自动绝热热量计直接测定了硫酸氢钾在７８－３７３Ｋ温区的热容,并且将实验热容值用最小二乘…     

可固定性荧光探针:线粒体成像的可靠工具

线粒体是一种具有双层膜结构的细胞器,参与细胞新陈代谢过程的能量循环以及离子平衡过程,在细胞生理过程中具有极其重要的意义。一些小分子荧光染料/探针结构中带有正电荷,因受到线粒体内膜负电势的牵引而标记在线粒体上,为研究线粒体的形态或功能提供了重要的可视化成像工具。然而,大多数线粒体染料/探针对线粒体的靶向标记稳定性仍不够理想,因为线粒体电势处于不断的动态变化中,当电势降低时,对染料的亲和力相应降低。尤其在病理条件下(比如细胞凋亡)细胞代谢受到阻滞时,线粒体膜电势显著降低,阳离子染料将扩散离开线粒体,造成非特异性荧光。最近,Kim团队和本人课题组提出可固定线粒体探针的新概念,用活性基团将荧光分子探针通过共价键固定在线粒体中,开发了稳定靶向线粒体中的定量探测微环境p H值、粘度、膜电势荧光探针。我们认为,对于追踪和探测具有高度动态变化特性的线粒体而言,开发可固定的线粒体荧光分子探针是必然趋势,因此本文进行评述和展望。     

Thermal transitions in PHEA hydrogels by thermomechanical analysis. A comparison with DSC data

The thermal transitions observed in hydrogels are frequently explained by invoking the existence of different kinds of water such as ‘bound’ and ‘free’ water. However these interpretations are intuitive and do not consider neither the thermodynamics of phase equilibrium nor kinetic aspects. Alternatively, the complicated experimental DSC thermograms have been simply explained in a thermodynamic framework with the help of a transitions diagram where the temperature of the transitions is plotted versus water concentration in the gel. In this work we further support the interpretation of the DSC thermograms on the basis of this diagram by comparing those thermograms with TMA results. The volume changes in the cooling and heating scans can be correlated with the enthalpy changes in the material and can be explained with the transition diagram.     

Calorimetric and DSC studies of mitochondria isolated from cytoplasmic male sterile line of rice

In this paper, the thermogenesis and differential scanning calorimetry (DSC) curves of energy release of the mitochondria isolated from variant strains of cytoplasmic male sterile lines of rices have been determined by using an LKB2277 Bioactivity Monitor and a DuPont 910 differential scanning calorimeter. The regularity and characteristics of the energy release of the mitochondria at constant and changing temperature were investigated, the differences in shape of the curves and the thermodynamic and kinetic characteristics of the thermogenesis of the mitochondria were compared, the thermodynamic and kinetic parameters of energy release of the mitochondria in the thermogenesis increasing stage were calculated, and the experimental thermokinetic equations describing the different thermogenesis processes were established. This revised version was published online in July 2006 with corrections to the Cover Date.     

Hydration kinetics of tricalcium silicate by calorimetric methods

The kinetics of the cement hydration reaction is a relevant issue in the cement research field, particularly in the presence of additional inorganic and organic components that consistently increase the complexity of the cement paste. In the present study, the hydration reaction of pure tricalcium silicate has been monitored by different calorimetric approaches: the conventional Isothermal Conduction Calorimetry (IC) and a novel Differential Scanning Calorimetry (DSC) protocol. The measured hydration curves have been modeled by using the Boundary Nucleation and Growth Model (BNGM) to extract thermodynamic parameters of the early stages of the hydration reaction. IC and DSC methods provide similar results in terms of rate constants, linear growth, and nucleation rates even though the IC accesses the total evolved heat while DSC discloses the fraction of unreacted water. The validation of the DSC approach as a reliable analytical method to the study of cement hydration kinetic is of particular importance because it allows following very long hydration processes, such as those of pastes containing organic retarders or superplasticizers. The thermodynamic and kinetic parameters for the tricalcium silicate setting has been also evaluated and discussed as a function of the surface area of the powder.     

Estimation of kinetic parameters for curing of epoxy-anhydride compositions by DSC

The kinetics of the curing process of epoxy resin (ED-22) in the presence of the anhydride hardeners (iso-methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, and dodecylsuccinic anhydride) and accelerators (2-methyl imidazole and n-butyltriphenylphosphonium bromide) has been investigated by DSC method in the dynamic mode. Processing of experimental DSC thermograms recorded at different heating rates was carried out within the frameworks of isoconvertional analysis in two versions, namely "model-free" method of Friedman and the Ozawa—Flynn—Wall method. The possibility to describe the kinetics of epoxy compositions curing in the frameworks of one-step autocatalytic reaction model has been demonstrated. Obtained kinetic parameters were used to predict the curing kinetics under isothermal conditions and for comparative analysis of the compositions.     

Oxygen chemisorption by an anthracite from peñarroya (Spain). A comparative study using dynamic and isothermal gravimetric methods

The chemisorption of oxygen (P = 1 atm, flow rate, 200 ml min^?1) by an anthracite from Peñarroya and on other adsorbents prepared from the starting sample has been studied in isothermal and dynamic conditions using gravimetric methods.Hypotheses to justify the thermograms have been established and comparative information on the energetic aspects determining both gasification stages has been obtained.Some kinetic and thermodynamic aspects are studied from oxygen chemisorption isotherms.     

4-甲氟基香豆素衍生物的热力学特性研究

This paper describes the DSC study of 4-trifluorocoumarin derivatives, C_(481), C_(485), C_(500) and C_(480), providing their DSC thermograms and thermodynamic parameters during the phase transitions of these compounds. Singlemelting peaks were observed on DSC thermogram respectively.Experimental results show the existence of certain correlations between the melting point, heat of fusion and molecular structure for this series of compounds.     

Critical thermodynamic analysis of differential scanning calorimetry for studying chemical kinetics

A critical thermodynamic analysis of differential thermal calorimetry is reported herein to gain further insight into the phenomena leading to the reported differences between kinetic parameters extracted from isothermal DSC methods and those from dynamic DSC methods. The sources have been identified for the variations observed in the total heat of reaction as a function of the heating rate in dynamic DSC experiments. The analysis clearly indicates that these variations are, in fact, to be anticipated. The relationships necessary for extracting kinetic data from both isothermal and dynamic experiments are derived rigorously by resorting to classical thermodynamics. This work was supported by the Cooperative State Research Service, U.S. Department of Agriculture, under Agreement No. 92-37500-7911.     

Effect of chain defects on the morphology and thermal behavior of solution-grown single crystals of syndiotactic polypropylene

The morphology of solution-grown single crystals of syndiotactic polypropylene with different degree of stereoregularity is compared. A sector formation phenomenon, found in some monolayer single crystals, is discussed in terms of possible crystallographic fold planes, growth planes, and gemination planes. A correlation between thermodynamic and morphological properties such as apparent enthalpy of fusion, critical long spacing, critical annealing temperature, and the number of configurational chain defects along the macromolecule has been found. Two endothermic peaks are observed in the DSC thermograms of single-crystal aggregates of syndiotactic polypropylene. The low-temperature peak is attributed to melting of crystals or parts of crystals with incorporated chain defects. The high-temperature peak corresponds to the melting endotherm of more regular crystalline zones. The peak-area ratio seems to depend on the degree of stereoregularity.     

种子萌发生长的微量热及非平衡热力学研究

生命系统中发生的许多过程都有放热和吸热现象.人们对于生命过程的热现象进行了很多研究.对于植物生长的能量效应研究也做了一些工作[1—4].种子萌发生长的热释出是植物产热的一个很好例子,在种子萌发生长过程中伴随着物质和能量的转化,用微量热法测定种子萌发生长热谱并解析这些热谱,将有助于我们认识种子萌发生长机理及其影响因素.Ｐｒａｔ等人曾对小麦、玉米及一些蔬菜种子的萌发生长进行过较为系统的研究[1,2].他们的工作为用量热法研究植物产热开辟了道路.但由于当时测量技术与仪器设计的限制,其研究结果是粗糙的,且与种子萌发的实际情…