Objective: To explore the network structure of dietary intake and physical fitness subtypes among junior and senior high school students, so as to provide precise and efficient intervention guidance for improving abnormal physical health issues in adolescents. Methods: Based on the 2020-2021 Database of Youth Health (DYH), a total of 9 730 junior and senior high school students in Shandong Province were included for analysis. Dietary intake was assessed using a modified Chinese Dietary Quality Questionnaire, and physical fitness was evaluated according to the "2014 National Student Physical Fitness Standard". The Kmeans clustering algorithm was employed to identify potential subtypes of physical fitness in junior and high school students. Network analysis was used to construct a network linking dietary intake and physical fitness symptoms and to identify clusters of dietary behaviors and physical fitness symptoms among adolescents of different genders. Results: The physical fitness among junior and senior high school students of different genders were categorized into two subtypes: the baseline steady type (3 427 male students, 4 039 female students) and the morphological deviation type (1 294 male students, 970 female students). Statistically significant differences were observed in network strength and network connectivity strength among different genders and physical fitness subtypes (all P<0.05). Connections between food intake and physical health symptom clusters across different genders and physical health types among junior and senior high school students were primarily achieved through instant noodle intake and physical fitness (males of morphological deviation type, weight=0.06), fruit intake and physical fitness (males of baseline steady type, weight=-0.07), potato intake and vital capacity (females of morphological deviation type, weight=0.09), and processed meat intake and vital capacity (females of baseline steady type, weight=0.05). Conclusions Dietary intake serves as a significant modifiable risk factor for the physical fitness of junior and high school students. Interventions should focus on promoting healthy eating habits.

OBJECTIVE： To explore the ways to improve the efficiency and quality of ethical review in multi-center clinical trial. METHODS： After issuing the policy of Opinions on Deepening the Reform of Approval System and Encouraging the Innovation of Pharmaceutical Medical Devices and Measures for the Administration of Drug Registration （Revised Version）， combined with the practice of our center， the methods to improve the efficiency and quality of ethical review， the possible problems of complete filling system and the way to improve the efficiency and quality of ethical review in multi-center clinical trial were analyzed in our center. RESULTS & CONCLUSIONS： Our center adopted a variety of review methods （conference review， rapid review， filing system， etc.）， implemented hierarchical management and differential review process for research projects， and formulated defined rules of filling system operation and other ways to improve the efficiency and quality of review， doubled the review efficiency， increased the number of follow-up review and field visit. In the process of exploration， the ethics committee of our center believes that the complete implementation of the filing system will lead to problems such as the difficulty to evaluate the quality of the ethical review of the leader unit， different research qualifications and conditions of each center， etc. In order to improve the efficiency and quality of the ethical review of multi-center clinical research， the measures are can be adopted， such as improving the quality of the ethical review of the center， strengthening the communication and mutual recognition of the ethics committees of each center， and establishing the preliminary review system of the secretary of the ethics committee， so as to realize the balance of efficiency and quality.

BACKGROUNDLocally advanced lung cancer includes IIIA and IIIB lung cancer that tumors are localized within the chest and with no clinic and pathologic distal metastasis. In this study the results of extended resection of a portion of heart or great vessels with cardiopulmonary bypass was summarized in the treatment of locally advanced lung cancer.

METHODSLobectomy or pneumonectomy combined with extended partial excision of the heart or great vessels were carried out in 10 patients with locally advanced lung cancer. The operations included aortic resection and reconstruction with left heart bypass in 2 cases, extended resection of left atrium with normal cardiopulmonary bypass in 5 cases, and resection and reconstruction of superior vena cava in 3 cases respectively.

RESULTSThe patients had no operative complication except for one haemothorax, which was controlled by re-exploration. One patient died of brain metastasis 6 months after operation and another one died of multiple metastasis 26 months after operation. The others were alive.

CONCLUSIONSCPB is a safe and effective anesthetic procedure during extended resection of locally advanced lung cancer although it is controversial for aggravating operative trauma, complex technique and higher cost.

Objective　To estimate the value of applying left heart bypass technique in esophageal carcinoma resection and gastroesophageal reconstruction. Methods　The operation was performed under lef t he art bypass. Results　Applying left heart bypass during esophagea l carcinoma resection and gastroesophageal reconstruction increased the probabil ity of the resection. The patient lived better and without operative complicatio n. Conclusion　In case of esophageal carcinoma with invasion of descending aorta by carcinoma, left heart bypass may increase the probability of the resection and enhance the safety of surgical treatment.