We quantitatively analyzed the thermodynamic contributions of 12-base pairing to DNA duplex dissociation and association using differential scanning calorimetry (DSC) and isothermal titration calorimetry (ITC). DNA duplexes consisting solely of A-T base pairs were systematically replaced with G-C base pairs and their thermodynamic properties were analyzed. Circular dichroism confirmed the formation of B-DNA, and DSC revealed that both the melting temperature and calorimetric enthalpy change increased in proportion to GC content, indicating enhanced thermal stability, mainly because of base stacking interactions. The more stable structure of DNA with high GC content was also supported by oligonucleotide binding analysis using ITC. The ITC titration profiles showed that the binding enthalpy of the oligonucleotide to its complementary strand initially reached a maximum exothermic value and then stabilized, suggesting a transition from a flexible single-stranded conformation to a more ordered duplex structure.

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SrFeO3-δ with a tetragonal or orthorhombic perovskite structure at room temperature undergoes structural phase transition to cubic perovskite with a random distribution of oxide-ion vacancies at an elevated temperature. The cubic phase attracts much interest as an oxide-ion and hole mixed conducting material; however, there were contradictions in literatures on the structural phase transition behaviors because the specimens with a homogeneous and well-controlled amount of oxide-ion vacancies had not been prepared. In this account, the development of the preparation method of homogeneous SrFeO3-δ with a controlled oxygen content using thermogravimetric data is described. Using thus prepared specimens, the miscibility gap between the tetragonal and orthorhombic phases and their structural phase transition behaviors of the both phases are clarified for the first time. The effect of the structural phase transitions to the cubic phase on thermal expansion and electrical conducting properties is also elucidated.

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Pyrolysis mass spectrometry (pyrolysis-MS) offers chemically and physically rich insights into polymer materials. However, its broader application has been limited by the inherently non-quantitative nature of MS, primarily due to ionization-efficiency variability among fragment species. To overcome this limitation, we present a reference-free, datadriven analytical framework that enables robust quantitative analysis without requiring any pure-component reference spectra. By eliminating the need to prepare actual standard materials, this approach allows system components to be flexibly defined—including virtual or hypothetical entities—based on the analytical objective. As a result, phenomena previously considered incompatible with conventional compositional analysis, such as monomer sequence distributions and degrees of polymer degradation, can now be quantified within a unified framework. This advancement transforms pyrolysis-MS from a qualitative diagnostic into a versatile quantitative tool, offering new capabilities for thermal analysis, material design, and lifecycle evaluation in polymer science.

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