Optical rotatory dispersion and spectral data of some steroidal ring D ketol acetates of the 14β-series

Zusammenfassung Die optische Rotationsdispersion sowie die UV- und IR-Spektren der Epimeren von 17-Acetoxy-16-keto-bzw. 16-Acetoxy-17-keto-14-steroiden wurden gemessen. Mögliche Beziehungen zwischen Rotationsdispersion und Stereochemie der untersuchten Verbindungen werden diskutiert.

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Paper LXI ofOptical Rotatory Dispersion Studies. For Paper LX seeC. Djerassi, Science134, 649 (1961).     

Ionophore A23187 disrupts membrane structure by modifying protein-lipid interactions.

The physiological function of membrane-boudn protein clearly depends on the nature of its neighbouring lipid. However, the question of how critical the protein is to the structure and function of membrane lipid has received much less attention. There is some evidence that lipid surrounding membrane protein, 'boundary lipid', may be more ordered than continuum lipid. Protein can also alter the enthalpy and temperature of pure lipid-phase transitions. However, controversy surrounds the question of whether membrane proteins determine long-range aspects of lipid structure or merly perturb their local environments. Here, we demonstrate that a lipophilic substance, the calcium ionophore, A23187 (Lilly), dramatically disorders the lipid structure of the membrane and that this phenomenon depends on the presence of proteins.     

均匀细圆环和均匀薄圆盘对任意轴线的转动惯量

分别运用一般方法和投影法计算了均匀细圆环和均匀薄圆盘对任意轴线的转动惯量,在验证投影法计算结果正确性的基础上,对计算结果进行了讨论,可以用于对实际问题的分析研究.