This study was carried out to explore the mechanism between athlete participation and team cohesion for adolescent school soccer players. We examined the mediating role of athlete engagement and collective self-esteem between athlete participation and team cohesion for adolescent soccer players. A comprehensive investigation of 1659 primary and middle school soccer players was conducted using the Athlete Participation Scale, Athlete Engagement Questionnaire, Collective Self-Esteem Scale, and Team Cohesion Scale, and we conducted correlation, regression and pathway analyses among the variables. We found the following for adolescent soccer players: (1) Athlete engagement plays a complete mediating role between athlete participation and team cohesion. (2) Collective self-esteem plays a complete mediating role between athlete participation and team cohesion. (3) Athlete participation does not directly predict team cohesion, but can influence team cohesion through the chain mediation of athlete engagement and collective self-esteem. This study built a chain mediation model showing that athlete engagement and team cohesion mediated athlete participation and team cohesion, to investigate its mediating role for adolescent soccer players. This study provides theoretical guidance and an empirical basis for the intervention of athlete participation on team cohesion in soccer sports among adolescents.

Background: Methamphetamine use disorder (MUD) is a global health problem. Studies have shown Tai Chi is a potential treatment for MUD. We aimed to explore the effectiveness of Tai Chi in improving drug cravings, attention bias, and physical fitness in men with MUD compared with aerobic exercise. Methods: A total of forty-eight participants (mean age 39.1 ± 8.7 years) were randomly assigned to either the Tai Chi group (TC) or the running group (RG). The TC performed 60 min of moderate-intensity (65–75% HR_max) Tai Chi exercise three times a week. The RG performed 60 min of moderate-intensity (65–75% HR_max) running on a treadmill three times a week. Before and after the intervention, drug cravings, attention bias, and physical fitness were evaluated. Results: After 12 weeks, we found the TC significantly improved in attention bias (F (1, 43) = 6.023, p = 0.019, d = −0.42) and reaction time (F (1, 43) = 6.181, p = 0.017, d = −0.72). No significant improvement was found in other variables in the TC, compared to the RG (p > 0.05). Conclusions: The 12-week Tai Chi intervention improved attention bias and reaction time, compared to RG. Tai Chi exercise might be a potential auxiliary method for the rehabilitation for men with MUD.

This study investigates the kinematic characteristics of the free vertical split with 720° turn (C 807). C 807 is the international designation in rhythmic gymnastics for a free vertical split with a 720° turn. This research holds significant importance in enhancing the technical proficiency of gymnasts and reducing their risk of injury. Eight national-level female gymnasts (age = 20 ± 3 years) performed the C 807. Kinematic data were collected using a 3D motion capture system. The movement was divided into four phases, and Visual 3D (V6.0, CMotion, Germantown, MD, USA) software was used for data processing and analysis. The joint angles of the upper and lower limbs, as well as the torsion angles of the lower limb joints, were analyzed. Key findings included tibial torsion, knee hyperextension in the support leg, and changes in elbow flexion during each phase. The center of mass (COM) trajectory showed that, during the backward preparatory swing phase, COM height gradually decreased and slightly increased before the initiation phase. In the initiation phase, COM height initially decreased and then increased, while the rotation phase showed fluctuating but stable COM height. The results highlight the importance of joint angle control and COM fluctuations during movement. Training should focus on leg swing speed, lower limb strength, knee stability, and upper limb coordination to enhance balance, improve rotation speed, and prevent injuries.

遗传性血色病是一种铁代谢障碍性疾病，较为罕见。现报道1例转铁蛋白受体（TFR）2基因突变相关血色病患者，临床表现为皮肤色素沉着、糖尿病、肝硬化，血清铁蛋白（8 548.9 ng/ml）、转铁蛋白饱和度（116.77%）明显升高，肝活检示肝硬化，肝内铁沉积（重度Ⅳ级），对其血液标本进行全外显子捕获和高通量测序，并经Sanger测序验证，发现在TFR2基因10号和7号外显子上检测到2个杂合突变（c.1288G＞A，p.G430R和c.960T＞A，p.Y320X），前者已有文献报道与血色病的发病密切相关；后者罕见报道，是TFR2基因新变异点，该突变可使肽链终止。