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Volume 37 (2010)
- Issue 5 Pages 183-
- Issue 4 Pages 137-
- Issue 3 Pages 95-
- Issue 2 Pages 57-
- Issue 1 Pages 1-
Volume 37, Issue 1
Displaying 1-7 of 7 articles from this issue
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Preface
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Hirohisa Yoshida2010 Volume 37 Issue 1 Pages 1
Published: January 25, 2010
Released on J-STAGE: November 20, 2022
JOURNAL FREE ACCESSDownload PDF (756K)
Review
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Kohsaku Kawakami2010 Volume 37 Issue 1 Pages 2-8
Published: January 25, 2010
Released on J-STAGE: November 20, 2022
JOURNAL FREE ACCESSMolecular conformation/arrangement of active pharmaceutical ingredients and excipients in the solid state has great impact on physicochemical characteristics of the formulations including solubility and stability. Although various methodologies are available for their investigation, thermal analysis has great advantages in terms of its high sensitivity and flexibility. In this paper, thermal analysis for the evaluation of polymorphism and amorphous state is described from practical viewpoint in the pharmaceutical industry.View full abstractDownload PDF (1523K) -
Yoshihiro Sambongi, Masaru Yamanaka, Jun Hasegawa, Susumu Uchiyama2010 Volume 37 Issue 1 Pages 9-16
Published: January 25, 2010
Released on J-STAGE: November 20, 2022
JOURNAL FREE ACCESSCytochrome c is found in a variety of bacterial species, from mesophiles to hyperthermophiles. Cytochrome c functions in respiratory electron transport chain, and is one of the best-characterized ones not only in terms of molecular biology such as biogenesis and evolution, but also in biophysical terms such as protein structure, stability, and folding. Four homologous cytochromes c, mesophilic Pseudomonas aeruginosa cytochrome c551 (PA c551), moderately thermophilic Hydrogenophilus thermoluteolus cytochrome c552 (PH c552), thermophilic Hydrogenobacter thermophilus cytochrome c552 (HT c552), and hyperthermophilic Aquifex aeolicus cytochrome c555 (AA c555) have been subjected to mutagenesis and structural analyses and provided substantial clues to the mechanism underlying protein stability at the amino-acid level. HT c552 is stabilized through five specific amino acid residues compared with PH c552 and PA c551. AA c555 is further stabilized by an additional helix structure compared with the other three proteins. As to folding, the apo AA c555 polypeptide can intrinsically form a holo-like structure without heme binding, this being the first case for a cytochrome c polypeptide. Molecular mechanisms underlying protein stability and folding in these bacterial homologous cytochromes c with different thermal stability are understood.View full abstractDownload PDF (507K) -
Evgeny Zhuravlev, Christoph Schick2010 Volume 37 Issue 1 Pages 17-25
Published: January 25, 2010
Released on J-STAGE: November 20, 2022
JOURNAL FREE ACCESSFast scanning calorimetry becomes more and more important because an increasing number of materials are created or used far from thermodynamic equilibrium. Fast scanning, especially on cooling, allows for the in-situ investigation of structure formation, which is of particular interest in a wide range of materials like polymers, metals, pharmaceuticals to name a few. Freestanding silicon nitride membranes are commonly used as low addenda heat capacity fast scanning calorimetric sensors. A differential setup based on commercially available sensors is described. To enhance performance of the device a new power compensation scheme was developed. The fast analog amplifiers allow calorimetric measurements up to 100,000 K s－1. The lower limit is defined by the sensitivity of the device and is 1 K s－1 for sharp melting or crystallization events in metals and ca. 100 K s－1 for broad transitions in polymers. A few examples to demonstrate the performance of the device are given.View full abstractDownload PDF (1642K) -
Marcelo Jaime2010 Volume 37 Issue 1 Pages 26-33
Published: January 25, 2010
Released on J-STAGE: November 20, 2022
JOURNAL FREE ACCESSProduction of very high magnetic fields in the laboratory has relentlessly increased in quantity and quality over the last five decades, as the focus periodically shifted back and forth from research in magnet technology to studies of the fundamental physics of novel materials in high fields. New strategies designed to understand microscopic mechanisms at play in materials surfaced recently, with methods to extract fundamental energy scales and thermodynamic properties from thermal probes up to 60 tesla. Here we summarize developments in the area of specific heat of materials in high magnetic fields, with emphasis in the original study of the Kondo Insulator system Ce3Bi4Pt3.View full abstractDownload PDF (3418K) -
Seiji Sawamura2010 Volume 37 Issue 1 Pages 34-41
Published: 2010
Released on J-STAGE: November 20, 2022
JOURNAL FREE ACCESSPartial molar volumes of hydrophobic solutes such as alkylbenzenes, naphthalene, etc. in water estimated from high-pressure solubility have been reviewed. We found positive volume changes (∆hhV) for the hydrophobic hydration though only negative ones have been observed for a long time since Kauzmann (1959), and also found that the ∆hhV increases changing the sign from negative to positive as a rotational diameter of the solutes increases from methylene group (0.50 nm) to anthracene (0.67 nm). Another feature for the hydrophobic hydration is negative isothermal compressibility of the partial molar volume of hydrophobic solutes in water. But we found it is positive for naphthalene, anthracene, etc. in water. These results make us see the hydrophobic hydration in perspective. High-pressure solubility is an useful method to estimate the partial molar volume for insoluble solutes, e.g., naphthalene in water, for which a vibrating-tube densitometer is useless.View full abstractDownload PDF (2410K)
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2010 Volume 37 Issue 1 Pages 42-43
Published: January 25, 2010
Released on J-STAGE: November 20, 2022
JOURNAL FREE ACCESSDownload PDF (231K)
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