More than 70%of tumor patients require radiotherapy.Medical electron linear accelerators are important high-end radiotherapy equipment for tumor radiotherapy.With the application of artificial intelligence technology in medical electron linear accelerator,radiotherapy has evolved from ordinary radiotherapy to today's intelligent radiotherapy.This study introduces the development history,working principles and system composition of medical electron linear accelerators.It outlines the key technologies for improving the performance of medical linear electron accelerators,including beam control,multi-leaf collimator,guiding technology and dose evaluation.It also looks forward to the development trend of major radiotherapy technologies,such as biological guided radiotherapy,FLASH radiotherapy and intelligent radiotherapy,which provides references for the development of medical electron linear accelerators.

Dynamic multi-leaf collimator, which has the function of radiation beam shaping, is a key executive component of tumor precise radiotherapy, and plays a core role in improving the accuracy, efficiency and quality of radiotherapy. A new type of collimator leaf end structure with circular arc and plane combination was studied, and collimator penumbra performance analysis model combining analytical expression and graphic analysis was developed. The influence of leaf end structure on penumbra was analyzed quantitatively, and a set of three-dimensional structure design of dynamic multi-leaf collimator was completed. The feasibility of the structural design and analysis model was verified through experimental measurements.
Humans ; Radiotherapy Planning, Computer-Assisted/methods* ; Particle Accelerators ; Neoplasms ; Radiotherapy Dosage

Objective:To explore the effect of applying the multi-disciplinary team（MDT）model led by specialized nursing care in the treatment carried out at early stage in intensive care unit of hyperbaric oxygen（ICU-HBO）for patients with brain complications after Stanford type A aortic dissection（AD）surgery.Method:From January 2018 to December 2020，a total of 18 patients with brain complications after AD surgery were included and treated by ICU-HBO with MDT model. The patients’ ventilator tolerance and weaning time，outcome，occurrence of adverse events，and satisfaction rate of nursing care were observed.Results:（1）Fifteen mechanically ventilated patients were successfully weaned off the machine after 1-5 times of ICU-HBO treatment.（2）Sixteen patients regained their consciousness to the normal level after 2-13 times of ICU-HBO treatments，with the total effective rate of 88.89%；two patients in persistent vegetative state（deep coma）discontinued the treatment after two times of ICU-HBO treatments as their family gave up. During the follow-up period of six months to two years，11 cases were found clinically cured，one case was considered effective，four cases lost contact，and the two cases that had gave up treatment died of complications.（3）No adverse medical event（related to safety）occurred during the ICU-HBO treatment.（4）The satisfaction rate of nursing care was 100%.Conclusion:In the early ICU-HBO treatment of patients with brain complications after Stanford type A AD surgery，the application of MDT mode led by specialized nursing care is beneficial to the treatment risk control，ensure the treatment effectiveness，and improve the long-term prognosis，and quality of life of AD patients.

Objective:To explore the effect of applying the multi-disciplinary team（MDT）model led by specialized nursing care in the treatment carried out at early stage in intensive care unit of hyperbaric oxygen（ICU-HBO）for patients with brain complications after Stanford type A aortic dissection（AD）surgery.Method:From January 2018 to December 2020，a total of 18 patients with brain complications after AD surgery were included and treated by ICU-HBO with MDT model. The patients’ ventilator tolerance and weaning time，outcome，occurrence of adverse events，and satisfaction rate of nursing care were observed.Results:（1）Fifteen mechanically ventilated patients were successfully weaned off the machine after 1-5 times of ICU-HBO treatment.（2）Sixteen patients regained their consciousness to the normal level after 2-13 times of ICU-HBO treatments，with the total effective rate of 88.89%；two patients in persistent vegetative state（deep coma）discontinued the treatment after two times of ICU-HBO treatments as their family gave up. During the follow-up period of six months to two years，11 cases were found clinically cured，one case was considered effective，four cases lost contact，and the two cases that had gave up treatment died of complications.（3）No adverse medical event（related to safety）occurred during the ICU-HBO treatment.（4）The satisfaction rate of nursing care was 100%.Conclusion:In the early ICU-HBO treatment of patients with brain complications after Stanford type A AD surgery，the application of MDT mode led by specialized nursing care is beneficial to the treatment risk control，ensure the treatment effectiveness，and improve the long-term prognosis，and quality of life of AD patients.

Third-grade class A hospitals undertake three tasks-medical service,scientific research and teaching.scientific research is the motivation for third-grade class A hospitals' continuous development and also an important symbol of their medical and academic level.On the purpose of evaluating overall scientific level of such hospitals this thesis analyze the scientific projects and the outcomes of 34 hospitals by using the method of literature research and questionnaire,extracting advantages for scientific research,seeking their problems and coming up with corresponding strategy.have analyzed the achievements we acquired as well as the problems still existing.According to the reality of Fujian Province,some suggestions are coming up with so as to improve the scientific research.