Objective: To analyze the change trends in the body shape indicators and proportions of students in Harbin from 2010 to 2024, and to investigate ergonomic compatibility of functional dimensions of school desks and chairs with current student shape indicators, so as to provide a reference for revising furniture standards of desks and chairs. Methods: Between September and November of both 2010 and 2024, a combination of convenience sampling and stratified cluster random sampling was conducted across three districts in Harbin, yielding samples of 6 590 and 6 252 students, respectively. Anthropometric shape indicators cluding height, sitting height, crus length, and thigh length-and their proportional changes were compared over the 15-year period. The 2024 data were compared with current standard functional dimensions of school furniture. The statistical analysis incorporated t-test and Mann-Whitney U- test. Results: From 2010 to 2024, average height increased by 1.8 cm for boys and 1.5 cm for girls; sitting height increased by 1.5 cm for both genders; crus length increased by 0.3 cm for boys and 0.4 cm for girls; and thigh length increased by 0.5 cm for both genders. The ratios of sitting height to height, and sitting height to leg length increased by less than 0.1 . The difference between desk chair height and 1/3 sitting height ranged from 0.4-0.8 cm. Among students matched with size 0 desks and chairs, 22.0% had a desk to chair height difference less than 0, indicating that the desk to chair height difference might be insufficient for taller students. The differences between seat height and fibular height ranged from -1.4 to 1.1 cm; and the differences between seat depth and buttock popliteal length ranged from -9.8 to 3.4 cm. Among obese students, the differences between seat width and 1/2 hip circumference ranged from -20.5 to -8.7 cm, while it ranged from -12.2 to -3.8 cm among non obese students. Conclusion Current furniture standards basically satisfy hygienic requirements; however, in the case of exceptionally tall and obese students, ergonomic accommodations such as adaptive seating allocation or personalized adjustments are recommended to meet hygienic requirements.

BACKGROUND:The sports medicine community has widely called for the use of machine learning technology to efficiently process the huge and complicated sports data resources,and construct intelligent sports injury prediction models,enabling accurate early warning of sports injuries.It is of great significance to comprehensively summarize and review such research results so as to grasp the direction of early warning model improvement and to guide the construction of sports injury prediction models in China. OBJECTIVE:To systematically review and analyze relevant research on sports injury prediction models based on machine learning technology,thereby providing references for the development of sports injury prediction models in China. METHODS:Literature search was conducted on CNKI,Web of Science and EBSCO databases,which mainly searched for literature related to machine learning techniques and sports injuries.Finally,61 articles related to sports injury prediction models were included for analysis. RESULTS AND CONCLUSION:(1)In terms of external risk feature indicators,there is a lack of competition scenario indicators,and the inclusion of related feature indicators needs to be further improved to further enrich the dimensions of the dataset for model training.In addition,the inclusion feature weighting methods of the sports injury prediction model are mainly based on filtering methods and the use of embedding and wrapping weighting methods needs to be strengthened in order to enhance the analysis of the interaction effects of multiple risk factors.(2)In terms of model body training,supervised learning algorithms become the mainstream choice.Such algorithms have higher requirements for the completeness of sample labeling information,and the application scenarios are easily limited.Therefore,the application of unsupervised and semi-supervised algorithms can be increased in the later stage.(3)In terms of model performance evaluation and optimization,the current studies mainly adopt two verification methods:HoldOut crossover and k-crossover.The range of AUC values is(0.76±0.12),the range of sensitivity is(75.92±11.03)%,the range of specificity is(0.03±4.54)%,the range of F1 score is(80.60±10.63)%,the range of accuracy is(69.96±13.10)%,and the range of precision is(70±14.71)%.Data augmentation and feature optimization are the most common model optimization operations.The accuracy and precision of the current sports injury prediction model are about 70%,and the early warning effect is good.However,the model optimization operation is relatively single,and data augmentation methods are often used to improve model performance.Further adjustments to the model algorithm and hyperparameters are needed to further improve model performance.(4)In terms of model feature extraction,most of the internal risk profile indicators included are mainly based on anthropometrics,training load,years of training,and injury history,but there is a lack of sports recovery and physical function indicators.

Objective: To investigate the occupational health status of medical radiation workers in Hangzhou City, so as to provide the basis for their occupational health risk assessment. Methods: Data on medical radiological workers who underwent occupational health examinations from 2021 to 2022 were collected through the Physical Examination Information Management System of the Hangzhou Occupational Disease Prevention and Control Hospital. The physical examination data including blood routine, eye lens, thyroid ultrasound, thyroid function, liver function, renal function and blood lipid were collected, and the abnormal rates of occupational health examinations among workers with different genders, working years and occupational exposure types were analyzed. Results: A total of 3 968 medical radiation workers were investigated, including 2 310 males (58.22%) and 1 658 females (41.78%). There were 2 039 (51.39%), 821 (20.69%) and 1 108 (27.92%) workers with 1-<6, 6-<10 years and 10 years and above of work, respectively. Diagnostic radiology was the predomenant type of exposure, with 2 240 workers accounting for 56.45%. The abnormal rates of thyroid ultrasound and blood lipid were 47.73% and 45.21%, respectively, which were relatively higher than other items. The abnormal rates of micronucleus rate, thyroid ultrasound, thyroid function and renal function were higher in females than in males, while the abnormal rates of lymphocyte count, liver function and blood lipid in males were higher in males than in females (all P<0.05). With the increase of working years, the abnormal rates of micronucleus rate and blood lipid showed upward trends (both P<0.05). There were statistically significant differences in the abnormal rates of thyroid ultrasound, liver function and blood lipid among different occupational exposure types (all P<0.05). Conclusion Long-term low-dose ionizing radiation environment affects the thyroid, micronucleus rate and blood lipid of medical radiation workers in Hangzhou City, with differences observed among workers with different genders and occupational exposure types.

ObjectiveTo investigate the difference in bilateral lower limb muscle synergy mode during gait in patients after unilateral anterior cruciate ligament reconstruction. MethodsElectromyography from bilateral lower limb muscles during gait were collected from twelve male and eight female patients after unilateral anterior cruciate ligament reconstruction in Affiliated Hospital of Wuhan Sports University, from April to June, 2023. The data were analyzed using non-negative matrix decomposition algorithm to extract the number of muscle synergies in the affected and unaffected legs, the time to peak activation of muscle synergies and the relative weights of the muscles. ResultsSix types of muscle synergy were identified in the unaffected leg of males during gait, while five types were identified in the affected leg, lacking synergy 2 that mainly from the tibialis anterior muscle. Six types of muscle synergy were identified in both legs in females during gait. There was no significant difference in the time to peak activation of muscle synergies between both legs in males (P > 0.05). However, the time to peak activation of muscle synergies increased in females in the affected leg for synergy 3 and synergy 5 (P < 0.05). The relative weight of the rectus femoris was lower in synergy 1 in the affected leg in males (P < 0.05). For female, the relative weight of the vastus lateralis was higher and the relative weight of the biceps femoris was lower in synergy 2 in the affected leg in females (P < 0.05); while the relative weight of the rectus femoris was lower in synergy 3 (P < 0.05), and the relative weight of the biceps femoris was lower in synergy 6 (P < 0.05). ConclusionMales would freeze the muscle synergy dominating ankle dorsiflexion in affected leg to enhance ankle stability, and reduce the relative weight of rectus femoris during the loading response phase to weaken the knee landing cushioning. However, females would delay the activation of synergies dominating in loading response phase and the mid-stance phase, enhance the relative weight of vastus lateralis during the loading response phase, and reduce the relative weights of rectus femoris in the loading response phase and the relative weight of biceps femoris in the mid-stance phase, to limit knee flexion.

BACKGROUND:The repair and clinical outcome of bone defects remains a hot and difficult area of clinical research,which is a common problem that plagues clinicians.Constructing suitable,reproducible and infinitely close to clinical animal experimental models and their scientific evaluation are essential for further clinical treatment of related diseases. OBJECTIVE:To retrospectively analyze the preparation methods and characteristics of common animal models of femoral bone defects and to assess their strengths and weaknesses,thereby providing some reference for relevant researchers to select appropriate animal models of femoral bone defects. METHODS:PubMed,Web of Science,Medline,and CNKI were retrieved for relevant literature published from January 1,2000 to August 1,2022.The keywords were"bone defect,bone,bones,defect,defects,defective,animal model,animal,model,laboratory,laboratory animal,animal laboratory"in English and"bone defect,animal model,experiment"in Chinese. RESULTS AND CONCLUSION:Twenty-seven randomized controlled animal experiments involving rats,mice,New Zealand rabbits,and sheep were included,analyzed and assessed.The most common types of bone defects were cylindrical bone defects and segmental osteotomy bone defects,generally found in the middle and distal femur.These models are mostly used to evaluate the effects of bone repair materials,drugs,drug-loaded active substances and physical therapy on bone defect repair and explore defect healing mechanisms,particularly the weight-bearing bone defect repair mechanism.Different defect kinds and femoral bone defect ranges have been found in different animal experiments.Researchers can select the suitable animal model and bone defect type based on the goal of the experiment and then set an acceptable bone defect value.Current studies have shown that cylindrical and segmental osteotomy-induced bone defects,mainly in the distal and middle femur,are mostly used in the animal models of femoral bone defects and that the surgical methods and postoperative management are more mature and operable to provide mature experimental animal models.In terms of cylindrical bone defects,rats and New Zealand rabbits are more suitable,whereas segmental osteotomy has no special requirements and all types of animals can meet the experimental requirements.

BACKGROUND:Accurate reduction of ankle fractures under direct vision has become a common understanding among foot and ankle surgeons.How to fully expose free or compressed fragments of the posterior ankle remains one of the most challenging problems. OBJECTIVE:To explore the clinical efficiency of the para-Achilles tendon approach in exposing and repositioning the posterior malleolus sandwich fracture. METHODS:A retrospective study was made for 26 patients with posterior malleolus sandwich fracture treated with open reduction and internal fixation via para-Achilles tendon approach from January to December 2020 in The Second People's Hospital of Dalian.21 of 26 cases were managed with the lateral approach of Achilles tendon and 5 cases were managed with the medial approach of Achilles tendon.There were 19 males and 7 females,with the age of 24-69 years,averagely 38.6 years.The operation time and postoperative complications were recorded.The fracture reduction condition was evaluated by Burwell-Charnley imaging standard.Before operation,3 months after operation and last follow-up,visual analog scale score,ankle plantar flexion and dorsiflexion and American Orthopedic Foot&Ankle Society Ankle Hind Score were used to evaluate the treatment effect. RESULTS AND CONCLUSION:(1)All 26 patients were followed up for an average of 14.6 months(range 13-18 months).The operation time was 52-85 minutes(average 64.2 minutes).(2)Part of the skin edge of the lateral malleolus incision was necrotic in one patient and healed completely after a dressing change.Incision healing of the other patients was in one stage.(3)Through Burwell-Charnley imaging standard,anatomical reductions were obtained in 24 of 26,and good reductions were in 2 of 26,with an excellent and good rate of 100%.(4)At the last follow-up,the visual analog scale score(1.19±0.40)was significantly lower than the preoperative score(6.81±0.80)(P<0.01).Ankle plantar flexion(33.5±5.02)° and ankle plantar back stretch(17.23±0.99)° were significantly increased compared with preoperative data(14.58±2.50)° and(5.81±1.02)°(P<0.01).American Orthopedic Foot&Ankle Society Ankle Hind Score was improved to(89.31±3.62)points compared to preoperative(46.00±5.45)points(P<0.01).The results were excellent in 23 patients and good in 3 patients,with an excellent and good rate of 100%.(5)It is concluded that the open reduction and internal fixation via the para-Achilles tendon approach for the treatment of posterior malleolus sandwich fracture were efficient with decreased operation time,satisfying fracture reduction,fewer complications,satisfactory motion range,and functional recovery.

Objective: To analyze the disease burden and risk factors of colorectal cancer in Zhejiang Province from 1990 to 2019, so as to provide the basis for prevention and control of colorectal cancer. Methods: Based on data of 2019 Global Burden of Disease (GDB 2019), disease burden and risk factors of colorectal cancer in Zhejiang Province from 1990 to 2019 was assessed using years of life lost (YLL), years lived with disability (YLD), disability-adjusted life years (DALY). Results: In 2019, the YLL rate, YLD rate and DALY rate caused by colorectal cancer in Zhejiang Province were 496.15/105, 31.81/105 and 527.96/105, respectively. From 1990 to 2019, the YLL rate, YLD rate and DALY rate caused by colorectal cancer in Zhejiang Province increased by 114.90%, 482.60% and 123.38%, respectively, showing increasing trends (average annual percent change values were =2.663, 6.283 and 2.800, respectively,all P<0.05). From 1990 to 2019, the YLL rate, YLD rate and DALY rate in the age groups of 15 to 49 years, 50 to 69 years and 70 years and older showed increasing trends (all P<0.05). In 1990, the top ten risk factors for colorectal cancer in Zhejiang Province were diet low in calcium, diet low in milk, diet low in whole grains, smoking, alcohol use, low physical activity, high fasting plasma glucose, diet high in red meat, diet low in fiber and high body mass index. In 2019, the top ten risk factors for colorectal cancer in Zhejiang Province were diet low in milk, diet low in whole grains, diet low in calcium, alcohol use, diet high in red meat, high body mass index, high fasting plasma glucose, low physical activity, diet low in fiber and diet high in processed meat. Conclusions The disease burden of colorectal cancer in Zhejiang Province showed an upward trend from 1990 to 2019. The top ten risk factors for colorectal cancer remained between 1990 and 2019, while there was a slight change in ranking.

Objective The aim of this study was to explore the role and mechanism of ferroptosis in SiO2-induced cardiac injury using a mouse model. Methods Male C57BL/6 mice were intratracheally instilled with SiO2 to create a silicosis model.Ferrostatin-1(Fer-1)and deferoxamine(DFO)were used to suppress ferroptosis.Serum biomarkers,oxidative stress markers,histopathology,iron content,and the expression of ferroptosis-related proteins were assessed. Results SiO2 altered serum cardiac injury biomarkers,oxidative stress,iron accumulation,and ferroptosis markers in myocardial tissue.Fer-1 and DFO reduced lipid peroxidation and iron overload,and alleviated SiO2-induced mitochondrial damage and myocardial injury.SiO2 inhibited Nuclear factor erythroid 2-related factor 2(Nrf2)and its downstream antioxidant genes,while Fer-1 more potently reactivated Nrf2 compared to DFO. Conclusion Iron overload-induced ferroptosis contributes to SiO2-induced cardiac injury.Targeting ferroptosis by reducing iron accumulation or inhibiting lipid peroxidation protects against SiO2 cardiotoxicity,potentially via modulation of the Nrf2 pathway.

Maternal depression can cause physical and mental harm to herself. This condition can lead to poor physical development in early offspring (newborns). However, the effect of maternal depression on the long-term physical development of offspring remains controversial. Studies have shown that offspring exposed to maternal depression in developed countries are at an increased risk of obesity. In view of the high incidence of maternal depression and childhood obesity in China, this article reviews the correlation between maternal depression and offspring obesity, aiming to provide insights for relevant research in China and offer references for the prevention and intervention of maternal depression and childhood obesity.

Objective:To analyze the clinicopathological features of gastric oxyntic gland neo-plasms.Methods:Forty-nine cases of stomach oxyntic gland neoplasms including oxyntic gland adenoma(OGA)and gastric adenocarcinoma of the fundic gland type(GA-FG)diagnosed in the Sec-ond Hospital of Shandong University from January 2016 to December 2020 were selected.The clini cal information,endoscopic appearance,histological features and immunophenotype were analyzed retrospectively,and followed up.Results:Age of the gastric oxyntic gland neoplasm patients ranged from 19 to 83 years old,with an average age of(57.3±2.4)years old.The male-to-female ratio was 24:25.Most of the lesions were located in the gastric body(27/49)and fundus(15/49).There were four endoscopic phenotypes:flat bulging,polypoid,flat and depression.In some lesions,there were dilated dendritic vessels.48 cases were single onset.The mean maximum diameter of lesions was(3.9±0.5)mm(1.0～7.0 mm).Seven cases showed submucosal invasion,and the inva-sion depth was less than 500 μm.The tumor consists of the dense glandular and the glandular con-nects to form a strip shape,which is irregularly branched and labyrinthlike under the microscope.These tumor cells were well differentiated and the morphology was similar to oxyntic gland cells.The chief cells were the predominant cells.The nucleus was mildly enlarged with slight pleomorphism and the mitosis was uncommon.The oxyntic gland neoplasms of the stomach were diffusely posi-tive for Mucin-6(MUC6)(100％)and Pepsinogen Ⅰ(83％),focally positive for H+/K+-ATPase(58％).Conclusions:The stomach oxyntic gland neoplasm is a new histology type with unique clinico-pathological features.The incidence of this neoplasm is low and the prognosis is good but it still needs long-term follow-up.