Specific heats of lipid dispersions in single phase regions.
Specific heats of lipid dispersions in single phase regions.
复制标题
单相区域中脂质分散体的比热。
DOI：
10.1016/0005-2736(82)90584-3
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
Nagle,JF
中科院分区：
文献类型：
--
作者：
Wilkinson,DA;Nagle,JF
差示扫描量热法已被用于第一次测量的比热，Cp，作为一个函数的温度在单相区域的主要相变温度，Tm以上和以下，饱和磷脂酰胆碱和磷脂酰乙醇胺的分散体。在误差范围内Cp，当以每克表示时，不以任何系统的方式随链长或头基而变化。它的温度依赖性在这两个单相区定性类似的正构烷烃。计算了链内振动和链间货车德瓦耳斯相互作用对Cp的贡献，并解释了几乎所有高于Tm的Cpat温度。然而，这些贡献不产生所观察到的温度依赖性低于Tm。它是adhertured，这样的温度依赖性产生的不阻碍的链振动的脂质进行热膨胀，并提出了支持这一猜想的初步计算的结果。
Differential scanning calorimetry has been used for the first time to measure the specific heat,Cp, as a function of temperature in the single phase regions above and below the main phase transition temperature,Tm, for dispersions of saturated phosphatidylcholines and phosphatidylethanolamines. Within error limitsCp, when expressed per gram, does not vary in any systematic way with chain length or headgroup. Its temperature dependence in both single phase regions qualitatively resembles that ofn-alkanes. Contributions toCpfrom intrachain vibrations and interchain van der Waals' interactions have been calculated and account for nearly all the measuredCpat temperatures aboveTm. However, these contributions do not yield the observed temperature dependence belowTm. It is conjectured that such a temperature dependence arises from the unhindering of chain vibrations as the lipids undergo thermal expansion, and the result of a preliminary calculation which supports this conjecture is presented.