Impact of specialized fatigue and backhand smash on the ankle biomechanics of female badminton players.

During fatigued conditions, badminton players may experience adverse effects on their ankle joints during smash landings. In addition, the risk of ankle injury may vary with different landing strategies. This study aimed to investigate the influence of sport-specific fatigue factors and two backhand smash actions on ankle biomechanical indices. Thirteen female badminton players (age: 21.2 ± 1.9 years; height: 167.1 ± 4.1 cm; weight: 57.3 ± 5.1 kg; BMI: 20.54 ± 1.57 kg/m2) participated in this study. An 8-camera Vicon motion capture system and three Kistler force platforms were used to collect kinematic and kinetic data before and after fatigue for backhand rear-court jump smash (BRJS) and backhand lateral jump smash (BLJS). A 2 × 2 repeated measures analysis of variance was employed to analyze the effects of these smash landing actions and fatigue factors on ankle biomechanical parameters. Fatigue significantly affected the ankle-joint plantarflexion and inversion angles at the initial contact (IC) phase (p < 0.05), with both angles increasing substantially post-fatigue. From a kinetic perspective, fatigue considerably influenced the peak plantarflexion and peak inversion moments at the ankle joint, which resulted in a decrease the former and an increase in the latter after fatigue. The two smash landing actions demonstrated different landing strategies, and significant main effects were observed on the ankle plantarflexion angle, inversion angle, peak dorsiflexion/plantarflexion moment, peak inversion/eversion moment, and peak internal rotation moment (p < 0.05). The BLJS landing had a much greater landing inversion angle, peak inversion moment, and peak internal rotation moment compared with BRJS landing. The interaction effects of fatigue and smash actions significantly affected the muscle force of the peroneus longus (PL), with a more pronounced decrease in the force of the PL muscle post-fatigue in the BLJS action(post-hoc < 0.05). This study demonstrated that fatigue and smash actions, specifically BRJS and BLJS, significantly affect ankle biomechanical parameters. After fatigue, both actions showed a notable increase in IC plantarflexion and inversion angles and peak inversion moments, which may elevate the risk of lateral ankle sprains. Compared with BRJS, BLJS poses a higher risk of lateral ankle sprains after fatigue.

F-actin/DRP1 axis-mediated mitochondrial fission promotes mitophagy in diabetic submandibular glands.

BACKGROUND: Diabetes is accompanied by a high prevalence of hyposalivation, causing severe damage to oral and systemic health. Mitochondrial dynamics play important roles in the pathogenesis of various diabetic complications; however, little is known about their roles in diabetic hyposalivation. MATERIALS AND METHODS: A diabetic mouse model and a high glucose (HG)-induced diabetic submandibular gland (SMG) cell model were employed. RESULTS: More mitochondria surrounded by autophagosomes and higher expression of mitophagy-related proteins were detected in the SMGs of diabetic mice and HG-treated SMG cells. In diabetic SMGs, dynamin-related protein 1 (DRP1) was upregulated, whereas mitofusin-2 was downregulated both in vivo and in vitro. Shortened mitochondria and impaired mitochondrial functions were observed in the HG group. A DRP1-specific inhibitor, mdivi-1, suppressed mitochondrial fission and mitophagy, as well as restored mitochondrial functions in the HG condition. Moreover, the interaction of F-actin and DRP1 was enhanced in the diabetic group. Inhibiting F-actin with cytochalasin D repaired the injured effects of HG on mitochondrial dynamics and functions. Conversely, the F-actin-polymerization-inducer jasplakinolide aggravated mitochondrial fission and dysfunction. CONCLUSIONS: F-actin contributes to HG-evoked mitochondrial fission by interacting with DRP1, which induces mitophagy and impairs mitochondrial function in SMG cells, ultimately damaging the SMG.

The difference of affect improvement effect of music intervention in aerobic exercise at different time periods.

Objectives: A randomized controlled experimental design that combines exercise and music intervention was adopted in this study to verify whether this approach could help improve human affect. The differences in the effect of music listening on affective improvement were compared in four different periods: before, during, and after aerobic power cycling exercise and the whole exercise course. Method: A total of 140 subjects aged 19-30 years (average age: 23.6 years) were recruited and randomly divided into four music intervention groups, namely, the pre-exercise, during-exercise, post-exercise, and the whole-course groups. The subjects' demographic and sociological variables and daily physical activities were collected using questionnaires. Individual factors, such as the subjects' noise sensitivity, personality traits, and degree of learning burnout, were collected via scale scoring. A laboratory in Zhejiang Normal University was selected as the experimental site. The testing procedure can be summarized as follows. In a quiet environment, the subjects were asked to sit quietly for 5 min after completing a preparation work, and then they were informed to take a pre-test. The four subject groups wore headphones and completed 20 min of aerobic cycling (i.e., 7 min of moderate-intensity cycling [50%*HRR + RHR] + 6 min of low-intensity interval cycling [30%*HRR + RHR] + 7 min of moderate-intensity cycling [50%*HRR + RHR] after returning to a calm state (no less than 20 min) for post-testing. The affect improvement indicators (dependent variables) collected in the field included blood pressure (BP), positive/negative affect, and heart rate variability indicators (RMSSD, SDNN, and LF/HF). Results: 1) Significant differences were found in the participants' systolic BP (SBP) indices and the effect of improvement of the positive affect during the exercise-music intervention among the four groups at different durations for the same exercise intensity (F = 2.379, p = 0.030, ɳp 2 = 0.058; F = 2.451, p = 0.043, ɳp 2 = 0.091). 2) Music intervention for individuals during exercise contribute more to the reduction of SBP than the other three time periods (F = 3.170, p = 0.047, ɳp 2 = 0.068). Improvement in the participants' negativity affective score was also better during exercise, and it was significantly different than the other three time periods (F = 5.516, p = 0.006, ɳp 2 = 0.113). No significant differences were found in the improvement effects of the other effective indicators for the four periods. Conclusion: Exercise combined with music intervention has a facilitative effect on human affect improvement, and listening to music during exercise has a better impact on affective improvement than music interventions at the other periods. When people perform physical activities, listening to music during exercise positively affects the progress effect among them.

Exostoisns (EXT1/2) in Head and Neck Cancers: An In Silico Analysis and Clinical Correlates.

OBJECTIVES: The exostosins (EXT), which are responsible for heparan sulfate backbone synthesis and play a vital role in tissue homeostasis, have been reported to be correlated with prognosis of various cancers. However, the expression, prognostic value, and immune infiltration of EXT1 and EXT2 in head and neck squamous cell carcinoma (HNSC) remain uncertain. METHODS: GEPIA, UALCAN, and Xiantao bioinformatics tools were used to explore the EXT1 and EXT2 expression level in HNSC. GEPIA and Sangerbox were utilised to obtain the prognostic value of EXT1 and EXT2 in HNSC. Genetic alterations, immune cell infiltration, and single-cell analysis were conducted in cBioPortal, TIMER, and TISCH2. In addition, the expressions of EXT1 and EXT2 were validated by real-time polymerase chain reaction (PCR) in HNSC samples. RESULTS: EXT1 and EXT2 were highly expressed in HNSC, especially in malignant cells. Only EXT2 was significantly negatively correlated to the prognosis of patients with HNSC. EXT1 and EXT2 were found to be associated with focal adhesin and cell adhesin molecule binding. EXT1 expression levels were considerably connected with CD8+ T cell infiltrating levels, whilst EXT2 expression levels were considerably negatively connected with infiltrating levels of CD4+ T cells, macrophages, neutrophils, and dendritic cells in HNSC. The gene mutation rates of EXT1 and EXT2 in HNSC were 7% and 2.8%, respectively. Moreover, EXT2 was validated to be highly expressed in HNSC samples by real-time PCR. CONCLUSION: EXT2 was highly expressed and presented negative correlation with the prognosis and immune infiltration of HNSC, which might be a potential biomarker for HNSC.

Effect of Dental Rehabilitation on Masticatory Function Following Jaw Reconstruction.

PURPOSE: This study examined the effect of dental implant rehabilitation on masticatory function following jaw reconstruction. MATERIALS AND METHODS: Patients who received dental rehabilitation after jaw reconstruction with a fibular or iliac bone flap from 2012 to 2018 were examined for masticatory efficiency, electromyographic (EMG) activity of the masticatory muscles, and the distribution of occlusal force. The masticatory efficiency was measured by a spectrophotometer. The asymmetry index of the masticatory muscle was calculated by EMG measurement, and the asymmetry index of the occlusal force was calculated by T-scan analysis. RESULTS: A total of 32 patients were examined, 13 with implant-retained fixed dental prostheses, 9 with implant-retained removable dental prostheses, and 10 with removable dental prostheses. Masticatory efficiency was significantly lower in the removable dental prosthesis group (2.29 ± 0.19) than in the implant-retained removable dental prosthesis (2.45 ± 0.03, P < .05) and implant-retained fixed dental prosthesis groups (2.45 ± 0.03, P < .05). Moreover, the asymmetry index of the masticatory muscle while chewing and clenching was significantly higher in the removable dental prosthesis group (0.099 ± 0.046 and 0.107 ± 0.042, respectively) than in the implant-retained removable dental prosthesis (0.032 ± 0.019 and 0.035 ± 0.021, respectively; P < .01) and implant-retained fixed dental prosthesis groups (0.038 ± 0.021 and 0.046 ± 0.023, respectively; P < .01). The asymmetry index of the occlusal force was also significantly higher in the removable dental prosthesis group than in the implant-retained removable dental prosthesis (0.38 ± 0.08, P < .01) and implant-retained fixed dental prosthesis groups (0.36 ± 0.11, P < .05). CONCLUSION: The results of this study suggest that dental implant prostheses have a greater effect on masticatory function following jaw reconstruction, improving masticatory efficiency, EMG activity of the masticatory muscles, and occlusal force.

A Biomechanical Study on Failed Snatch Based on the Human and Bar Combination Barycenter.

Objective: The purpose of this research was to use a new method the human and bar combination barycenter to exposit the differences between successful and failed characteristics of snatch attempts in competition. Try to establish an effective biomechanical method that can uncover the main factors for the failed snatch. The obtained results will provide valuable information for weightlifters to improve the success rate in snatch by altering their technical issues accordingly. Methods: A 3-D video analysis method was used to compare the characteristics of the heaviest successful and failed attempts of ten elite weightlifters in the men's 73 kg category. The video was captured under competitive conditions at the 2019 World Weightlifting Championships, the 2019 Asian Weightlifting Championships, and the 2020 China Olympic Trial. The video data were digitized using the SIMI°Motion7.50 3-D system (Germany). Results: Significant difference (P > 0.05) was not found between the successful and failed attempts in the parameters, such as the maximal vertical rising velocity, the maximal vertical height, and the vertical displacement of the barbell. The maximal descending acceleration of the human body, the time duration, the angles of the hip, and knee joints were no significant difference. However, significant differences were found in the variation of the human and bar combination barycenter on the X-axis in the inertial ascent stage and the squat support stage (t = 2.862, P < 0.05; t = 3.376, P < 0.05). Conclusions: A probable cause of the failed snatch is that the displacement of human and bar combination barycenter on the X-axis is not enough to reach the position for supporting barbell during the inertial ascent stage and the squat support stage. The reason is that the strength of reclining of torso at the end of the force phase is insufficient. Insufficient knee flexion in the knee flexion phase (M2), which leads to a lower maximum vertical velocity of barbell, may be an indirect factor leading to the failed snatch. The cumulative variation of human and bar combination barycenter on the X-axis can effectively determine the technical characteristics between the success and failure in snatch.

Mandibular Reconstruction With the Iliac Flap Under the Guidance of A Series of Digital Surgical Guides.

ABSTRACT: The authors aimed to evaluate the accuracy of mandibular reconstruction with the iliac flap under the guidance of a series of digital surgical guides. Seven patients were enrolled to evaluate the accuracy of reconstruction immediately after surgery. Patients underwent mandibular reconstruction with a vascularized iliac flap guided by a series of digital surgical guides at the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, from September 2017 to June 2018.All flaps survived. Chromatographic analysis showed that the area with a chromatographic difference of ≤1 mm between preoperative virtual surgical planning model and postoperative mandible accounted for 73.97% ±â€Š3.89% of mandible surface, the area ≤2 mm accounted for 87.21% ±â€Š2.65%, and the area ≤3 mm accounted for 94.09% ±â€Š2.50%. In all of the 7 cases, the mean of maximum deviation was 6.25 ±â€Š1.00 mm, and the mean of average deviation was 0.95 ±â€Š0.13 mm. The authors conclude that mandibular reconstruction with the iliac flap under the guidance of a series of digital surgical guides is accurate and effective.

Expression levels of ARHI and Beclin1 in thyroid cancer and their relationship with clinical pathology and prognosis.

Expression levels of autophagy-related genes ARHI and Beclin1 in thyroid cancer and their relationship with clinical pathology and prognosis were investigated. The expression levels of ARHI and Beclin1 proteins in 80 cases of thyroid cancer and adjacent tissues were detected by western blot analysis. According to the expression levels of ARHI and Beclin1, low- and high-expression groups were determined and the relationship of the expression levels with the pathological parameters and prognosis in thyroid cancer was compared between the two groups. The correlation between the ARHI and Beclin1 protein expression level was analyzed by Pearsons correlation analysis. The levels of ARHI and Beclin1 proteins in thyroid cancer tissues were significantly lower than those in adjacent tissues (P<0.05). There was a significant difference in the expression levels of ARHI and Beclin1 in terms of pathological stage and differentiation degree of cancer tissues (P<0.001); however, there was no significant difference in the expression levels of ARHI and Beclin1 for different types of cancer tissues (P>0 05). There was a positive correlation between the expression levels of Beclin1 and ARHI (r=0.5187, P<0.001). The 3-year survival rates of patients with low-expression level of ARHI and Beclin1 proteins were significantly lower than those of patients with high expression (P<0.05). In conclusion, the expression levels of Beclin1 and ARHI were low in thyroid cancer, and were significantly associated with the pathological stage, differentiation degree and prognosis in thyroid cancer. Beclin1 and ARHI can be used as predictors for the development and prognosis of thyroid cancer.

Dental Implant Rehabilitation After Jaw Reconstruction Assisted by Virtual Surgical Planning.

PURPOSE: To evaluate effects of preoperative virtual planning and jaw reconstruction guided by dental implant rehabilitation on dental prosthesis rehabilitation after jaw reconstruction. MATERIALS AND METHODS: Patients indicated for segmental jaw resection and who agreed to receive jaw reconstruction procedures were enrolled in the study. Appropriate surgical procedures were determined by a maxillofacial surgeon and a prosthodontist before surgery. The virtual design was created according to preoperative computed tomography. Patients were divided into navigation and non-navigation groups. Implant surgery was performed 6 months after reconstruction surgery. After treatment completion, factors such as survival rate of implants, site of reconstruction, type of graft, and type of prosthesis were compared. RESULTS: In total, 29 patients were included in the study, with 16 patients in the non-navigation group and 13 in the navigation group. A total of 101 implants were inserted, and the implant success rate was 98.02% (2 implants extracted due to peri-implantitis). All patients received prosthetic treatment. Of the 13 navigation group patients, 9 received fixed implant-supported prostheses, whereas the other 4 received removable dentures. Of the 16 non-navigation group patients, 9 eventually received fixed implant-supported prostheses and 7 received removable dentures. There were no significant intergroup differences in terms of prosthesis type (P = .702). However, the proportion of fixed implant-supported prostheses in the navigation group was higher compared with the non-navigation group. CONCLUSION: Preoperative virtual planning and dental implant rehabilitation-guided jaw reconstruction through preoperative designing can provide a good opportunity to achieve high rates of implant success and dental rehabilitation. This method can also benefit fixed implant-supported prosthetic restorations. Moreover, the use of navigation after virtual planning has no effect on the type of prosthetic reconstruction.