Objective To optimize the measurement and analysis method for carbon-14 in environmental biological samples, and to provide technical support for the formulation of standard methods for carbon-14 measurement in environmental biological samples. Methods Through the optimization research on the carbon dioxide absorption method, the moisture content and carbon content of biological samples were measured with the moisture meter and the element analyzer according to the simplified personnel operation and the optimized process steps of the method, and intra- and inter-laboratory validation of the method was carried out. Results Under typical conditions, the lower limit of detection of the method reached 3 Bq/kg, and there were a relative standard deviation within laboratories of less than 17% and a relative standard deviation between laboratories of less than 14%, with a relative error of less than 19%. Most of the sample pretreatment was directly completed by the instrument and equipment, which improved the precision and accuracy of the measurement of moisture content and carbon content in samples, and reduced the influence of experiment personnel’s operation differences on the test results. Conclusion The lower limit of detection, precision, and accuracy of the optimized method meet the relevant requirements for the determination of carbon-14 in biological samples.

Immunotherapy represented by PD-1/PD-L1 inhibitors has become the main treatment of malignant tumors. However, the adverse events caused by immunotherapy can not be ignored. Among them, dermatological immune-related adverse events (irAEs) occur with the highest incidence. Most dermatological irAEs belong to grade Ⅰ-Ⅱ, which does not affect the application of PD-1/PD-L1 inhibitors. The pathogenesis of dermatological irAEs is not fully understood. The most common types of dermatological irAEs are rash, pruritus and vitiligo. The domestic PD-1 inhibitor camrelizumab has unique adverse reactions of reactive cutaneous capillary endothelia proliferation (RCCEP) . It is found that dermatological irAEs can predict the clinical efficacy of PD-1/PD-L1 inhibitors in patients with malignant melanoma and non-small cell lung cancer (NSCLC) , especially RCCEP can be used as a potential biomarker of the efficacy of camrelizumab in the treatment of NSCLC, hepatocarcinoma, and esophageal cancer.