Laboratorio de Investigación en Toxicología, Hospital Juárez de México, Av. Instituto Politécnico Nacional #5160 Col. Magdalena de Las Salinas, Ciudad de México, Mexico, C.P. 07760, Mexico.
Departamento de Biofísica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio Y Plan de Ayala S/N, Col. Santo Tomás, Ciudad de México, Mexico, C.P. 11340, Mexico.
Sci Rep. 2020 Jul 9;10(1):11240. doi: 10.1038/s41598-020-67838-1.
UV light is a group of high-energy waves from the electromagnetic spectrum. There are three types of UV radiations: UV-A, -B and -C. UV-C light are the highest in energy, but most are retained by the ozone layer. UV-A and -B reach the earth's surface and cause damage on living organisms, being considered as mutagenic physical agents. Numerous test models are used to study UV mutagenicity; some include special lamps, cell cultures and mathematical modeling. Mercury lamps are affordable and useful sources of UV-C light due to their emission at near the maximum absorption peak of nucleic acids. E. coli cultures are widely used because they have DNA-damage and -repairing mechanisms fairly similar to humans. In here we present two simple models that describe UV-C light incidence on a genome matrix, using fundamental quantum-mechanical concepts and considering light as a particle with a discontinuous distribution. To test the accuracy of our equations, stationary phase cultures of several E. coli strains were exposed to UV-C light in 30 s-intervals. Surviving CFUs were counted and survival/mortality curves were constructed. These graphs adjusted with high goodness of fit to the regression predictions. Results were also analyzed using three main parameters: quantum yield, specific speed and time of mortality.
紫外线是电磁光谱中一组高能波。有三种类型的紫外线辐射：UVA、UVB 和 UVC。UVC 光能量最高，但大部分被臭氧层吸收。UVA 和 UVB 到达地球表面并对生物体造成损害，被认为是诱变物理因子。有许多测试模型用于研究紫外线致突变性；其中一些包括特殊的灯、细胞培养和数学建模。由于汞灯在接近核酸最大吸收峰处发射，因此是经济实惠且有用的 UV-C 光源。大肠杆菌培养物被广泛使用，因为它们具有与人类相当相似的 DNA 损伤和修复机制。在这里，我们提出了两个简单的模型，使用基本的量子力学概念来描述 UV-C 光对基因组矩阵的入射，并将光视为具有不连续分布的粒子。为了测试我们方程的准确性，将几种大肠杆菌菌株的静止相培养物以 30 秒的间隔暴露于 UV-C 光下。计算存活 CFU，并构建存活/死亡曲线。这些图形与回归预测高度拟合。结果还使用三个主要参数进行分析：量子产率、特定速度和死亡率时间。
