求翻译：先导化学物。特点：快速、短期、化学物样本量消耗量少、灵活、动态、根据实际情况不断地调整和完善、不受GLP规范约束的毒性筛选和评价。主要包括、短期和高通量毒性筛选、毒理学模型、相似性化学物特征性基因组和蛋白质组表达谱、代谢谱预测标志物(preditive marker)、替代终点(sumoagereddpoint)等的分析,从而预测和评价化学物的毒性。是什么意思？

Precursor chemicals. Characteristics: quick, short-term, less chemical consumption of sample size, flexible, dynamic, continuous adjustment and perfect, not subject to GLP specifications toxicity screening and evaluation of a constraint. Include, short and high throughput toxicity screening, toxicology models, similarity of chemical characteristics of the genome and proteome expression profile, metabolic markers for spectrum prediction (preditive marker), alternative destination (sumoagereddpoint), analysis, forecasting and evaluating the toxicity of chemicals.