Objective:To compare the diagnostic efficiency of colloidal gold dipstick method (PTH dipstick method) with that of doctors’ experience method based on nano-carbon method for rapid identification of parathyroid gland in thyroidectomy of thyroid cancer.Methods:From March to July 2020, 90 patients underwent thyroid surgery in the Friendship Hospital, Capital Medical University participated in the experimental study, and 155 samples underwent empirical judgment, parathyroid dipstick and pathological examination. All operations were performed by senior specialists. SPSS statistics 17.0 software was used for statistical analysis.Results:Seventy-four cases of parathyroid gland confirmed by both pathology and empirical judgment, and 81 cases of non-parathyroid gland confirmed by pathology; 130 cases of parathyroid glands confirmed by both PTH dipstick method and pathology, and 22 cases of non-parathyroid glands confirmed by pathology. The accuracy rate of PTH dipstick method was 85.53% which was much higher than that of empirical judgment method (47.74%). The data were statistically significant ( χ2=49.14, P<0.05). The sensitivity of PTH method was 95.89%, the specificity of PTH method was 75.94%, and the Youden index was 0.7183. The sensitivity of empirical judgment method was 81.3%, the specificity of empirical judgment method was 47.74%, and the Youden index was 0.2904. Conclusions:The diagnostic efficiency of the PTH method is higher than that of empirical judgment method to identify parathyroid gland in thyroid surgery. The two methods can be used together to increase the protection of parathyroid gland during operation.

Objective To evaluate the characteristics of spatial distribution and time accumulation of impact acceleration at different parts of human body during backward falling process. Methods Four healthy men and four healthy women (20-20 years old) were enrolled. The tri-axial acceleration on head, chest, left/right arm/hand/foot, left/right front/back hip, left/right femur head, sacrum and coccyx throughout the backward falling were measured by ADXL335 tri-axial acceleration sensor. Systemic acceleration distribution of backward falling was polynomial fitted by signal magnitude vector (SMV) of its first peak. Besides, parameters of impulse mechanics such as zero-g time, total falling time, peak SMV, relative pressure impulse of the vulnerable sites (head, hip and its related sites) were also calculated. Results Compared with the other parts of the body, the peak SMV and relative impulses of left/right back hip and head were significantly higher (P＜0.05). Acceleration that paralleled to the ground in left/right back hip was also relatively large. The rotational transform angles of left/right back hip, left/right femur head, sacrum and coccyx were significantly larger (P＜0.05). In addition, during the process of falling backward to the ground, a sliding tendency toward the sagittal plane 53.58°±6.75° occurred at all testing sites. Conclusions Head and hips are vulnerable during backward falling, and their zero-g time (0.26±0.05) s can be used as the longest starting time of falling protection devices. The large change angle of left/right hip, left/right femoral head, sacrum and coccyx may be the important cause of the sprain during backward falling.