At present, the C-arm structure accelerators commonly used in radiotherapy equipment are complex in operation and have potential safety hazards when realizing non-coplanar treatment. By combining with medical robotic arm technology, a spherical radiotherapy accelerator motion system is designed. The beam module is clamped by the medical robotic arm structure to achieve three-dimensional multi-angle irradiation treatment within the non-coplanar angle range. Firstly, the rotating mechanism, beam module, and MLC module of the spherical radiotherapy equipment are designed. Then, the double-plane counterweight method is used to calculate the dynamic balance of the equipment, ensuring that the beam center point does not rotate during the treatment process. Finally, the strength check and reliability analysis of the transmission component gear are conducted. The results show that the designed spherical radiotherapy accelerator motion system can meet the requirements of stable, accurate, and fast precision radiotherapy, which is conducive to improving the treatment efficiency.
Particle Accelerators/instrumentation* ; Equipment Design ; Reproducibility of Results ; Radiotherapy/instrumentation*

Objective To investigate the impact of endplate fracture on the clinical efficacy of minimally invasive percutaneous pedicle screwing for thoracolumbar burst fractures.Methods From September 2012 to June 2016,35 patients with thoracolumbar burst fracture underwent minimally invasive percutaneous pedicle screwing at Department of Orthopaedics,The First Affiliated Hospital to Nanjing Medical University.They were divided into 2 groups according to the severity of endplate fracture:a mild fracture group of 17 cases and a severe fracture group of 18 cases.Their clinical data were recorded and compared between the 2 groups before surgery,before discharge,6 months after surgery and at the last follow-up with respects to kyphosis cobb angle and height compression rate of the injured vertebra,and visual analogue scale (VAS),Oswestry disability index (ODI) and the MOS 36-item Short Form Health Survey (SF-36) scores.Results The kyphosis cobb angle and height compression rate of the injured vertebra,and VAS,ODI and SF-36 scores before discharge,6 months after surgery and at the last follow-up were all significantly improved in all the patients compared to the values before surgery (P ＜ 0.05).There were no significant differences between the 2 groups in the kyphosis cobb angle of the injured vertebra before surgery,before discharge,6 months after surgery or at the last follow-up (P ＞ 0.05).At the last follow-up,the height compression rate of the injured vertebra,and VAS,ODI and SF-36 scores in the mild fracture group were significantly lower than in the severe fracture group (P ＜ 0.05),and the height compression rate of the injured vertebra,and VAS,ODI and SF-36 scores of the severe fracture group were significantly higher than the values 6 months before (P ＜ 0.05).Conclusions The severity of endplate fracture may have no significant impact on the recovery of vertebral height in the early-to-mid stage after minimally invasive percutaneous pedicle screwing for thoracolumbar burst fractures.However,the patients complicated with severe endplate fracture are likely to suffer a height loss of the injured vertebral body and decreased quality of life in the long run.

Three kinds of fortified biscuits and bread were given as breakfast for 5 months to 106 preschool children 4-6 years old lodged in a kindergarten, with a control group taking common biscuits and bread without fortification. 6 g protein and 160 kcal were supplied by 50 g of fortifed foods in which 0.25 g lysine, 0.25 g lysine and 0.8 mg riboflavin, and cod liver oil and calcium in addition to lysine and riboflavin were fortified respectively. The results showed that a diet with intake of 2.1 g protein and 71 kcal/kg body weight fortified on the average by 228 mg lysine or 228 mg lysine and 1.1 mg riboflavin increased the monthly increment of body weights, heights, and urinary excretions of creatinine per day. There was also a tendency of improvement, in nitrogen retention. The urinary excretion of riboflavin in load test was increased in the group taking the second kind of fortified foods.