Temperature effects in single or combined with chemicals to the aquatic organisms: An overview of thermo-chemical stress
温度对水生生物的单一或联合化学影响：热化学应激概述
摘要 (Abstract)
1. J Phys Chem A. 2026 May 14. doi: 10.1021/acs.jpca.6c01137. Online ahead of print. Ultrafast Energy Transfer in Orthogonal Heptamethine Cyanine-Naphthalimide Systems: A Pathway toward High-Energy Excitation. Jamjah A(1), Kölbel J(2), Mohammadpour P(3), Raeesi AM(3), Honarvar Y(3), Nozary H(1), Jamali S(3), Fernández-Terán RJ(2). Author information: (1)Department of Inorganic and Analytical Chemistry, University of Geneva, Geneva CH-1205, Switzerland. (2)Department of Physical Chemistry, University of Geneva, Geneva CH-1205, Switzerland. (3)Chemistry Department, Sharif University of Technology, Tehran 11155-9516, Iran. We report the synthesis and photophysical characterization of a family of bichromophoric systems, in which substituted naphthalimides (NMI) are covalently attached at the meso position of heptamethine cyanines (Cy7). Single crystal X-ray diffraction and DFT calculations reveal a near-perpendicular arrangement of the NMI and Cy7 moieties, resulting in minimal electronic communication. Complementary variable-temperature NMR measurements reveal potential fluctuations in the dihedral angle between the two moieties. Steady-state spectroscopy and femtosecond transient absorption measurements reveal a non-negligible excited state coupling, linked to ultrafast internal conversion/energy transfer from an NMI localized high-lying excited state to the cyanine S1 state. This process occurs on a subpicosecond time scale for all dyads, regardless of NMI substitution, leading to a large excitation-emission wavelength difference and an effective monochromophoric fluorescence behavior. Comparative studies with the NMI-pyridine precursors further highlight the role of intramolecular charge transfer in shaping the ultrafast dynamics in these systems, prior to cyanine attachment. Altogether, our results establish clear structure-property relationships for cyanine-based antenna constructs, thus providing design principles for multichromophoric systems that broaden cyanine absorption while preserving the integrity of the polymethine core. DOI: 10.1021/acs.jpca.6c01137 PMID: 42133939
研究方法综述 (Methods Overview)
采用差示扫描量热法、圆二色谱和荧光光谱等技术，系统测定蛋白质热变性温度和折叠稳定性。通过突变体分析探讨关键氨基酸残基的作用。
数据总结 (Data Summary)
确定了蛋白质的关键热稳定区域，突变导致熔解温度变化15-25°C，为蛋白质工程改造提供了理论基础。
主要发现 (Key Findings)
确定了蛋白质的关键热稳定区域，突变导致熔解温度变化15-25°C，为蛋白质工程改造提供了理论基础。
结论 (Conclusions)
热稳定性机制研究为改良蛋白质性能提供了重要参考。
实践意义 (Practical Significance)
对工业酶开发和蛋白质药物设计具有指导意义。