Daytime sleepiness in Chinese professional, semi professional and students soccer players in the Shanghai lockdown.

PURPOSE: April-May 2021 Shanghai city was under strict lockdown. Soccer players suffered from the restrictions, being unable to train and have a social life. The aim of this study was to compare differences in daytime sleepiness between genders and qualification levels in a cohort university Chinese soccer player under 0 Covid policy restrictions in the urban area of Shanghai. METHODS: 491 questionnaires of Epworth Sleepiness Scales (ESS) were compiled online by male and female Soccer Students (SS), Semi-Professional players (SP) and Professional Players (PP) during the ongoing restriction measures post Shanghai lockdown. ANOVA was performed for players levels and gender. RESULTS: Significant differences were found between the 3 levels and between males and females. PP showed a very low score in the ESS (5,97) well below the threshold of 8 for daytime sleepiness, while SS and SP showed an ESS score above the threshold. Female showed higher scores in comparison to males. Differences between males and females reflect the confinement conditions in the ESS items, showing more difference in the item of ESS which are related with indoor situations. CONCLUSIONS: This study shows the first data on sleepiness in Chinese soccer players of different level of qualification immediately post lockdown condition. Professional male's players sleepiness was lower, than females, SS and SP after the exceptional lockdown measures. The reasons can reside in the more ordered lifestyle of PP in comparison to SS and SP, which mitigated the effects of the lockdown. Our results suggest that measures to improve sleep in females' soccer player should be adopted if these exceptional conditions will happen again.

Patellofemoral Pain, Q-Angle, and Performance in Female Chinese Collegiate Soccer Players.

Background and objective: Female sports injuries have been neglected by science, and few relevant studies have considered female subjects. Knee pain in female soccer players is more common than in male soccer players. The number of days of absence from training and competition has been shown to be higher in females than males. The reporting of knee pain is common in female soccer players, but whether knee pain is associated with morphological features is unclear. The Q-angle of the knee has been hypothesized to be a causal factor in knee pain. Asian females have shown higher levels of valgus than non-sporting Caucasian populations, but no data exist for female Chinese players. The aim of our study was to investigate whether there are associations between knee pain, the Q-angle of the lower limb, jump performance, play time, and perceived exertion in female Chinese collegiate soccer players. Materials and Methods: We measured the Q-angle, patellofemoral/anterior knee pain (SNAPPS questionnaire), and CMJ and SJ performance of 21 subjects (age: 20.09 ± 1.13 years, weight: 56.9 ± 6.26 kg, height: 164.24 ± 4.48 cm, and >10 years of practice) before and after a match; Borg scale and play time results were also recorded. Results: We found that our studied group had higher Q-angles in comparison to other ethnic groups reported in the literature, as well as an association of the Q-angle with the age, height, and weight of the players; however, contrary to other studies, we did not find any association between the Q-angle and knee pain, jumps, play time, or perceived exertion. Knee pain was not associated with any of the measured variables. Conclusions: Female Chinese soccer players showed higher Q-angles than players of other ethnic groups, a result that was associated with anthropometrics. The Q-angle was not found to be associated with knee pain, for which the sole determinant was body height.

The Moderating Role of Sociability and Social Connection for the Relationship between Soccer Participation and Teamwork Ability among Chinese College Students.

In order to provide empirical evidence for soccer's promotion of teamwork ability and to examine whether sociability and social connection have an effect on this promotion, we explored the relationship between soccer participation (volume, duration), teamwork ability and sociability and social connection (SSC). Using the method of stratified sampling, a questionnaire survey was carried out in four universities in Shanghai. All the respondents are undergraduate students, which include the specially recruited soccer athletes and the soccer participants from ordinary college students. The findings from this study indicate that participating in soccer can positively predict the teamwork ability of college students, and SSC can negatively moderate the effect of soccer participation on teamwork ability. The effect of soccer participation on teamwork ability was different in the collegiate soccer athletes and collegiate soccer participants groups. An important value of soccer, which is often overlooked, is the help it provides college students, who have insufficient sociability and social connections, in better integrating into the team and in improving their teamwork ability. We highly recommend that college students participate in soccer to improve their teamwork skills in study and work and to better prepare for their careers.

The Mediating Effect of Coping Style on Physical Activity and Negative Affect Caused by Public Health Emergencies: Evidence from Chinese College Students.

In this study, we explored the relationship between physical activity (PA), coping style (CS) and negative affect caused by public health emergencies (PHENA), to examine if CS can play a mediating role between PA and PHENA, and analyzed the different effects of positive coping (PC) and negative coping (NC). Using the method of random sampling, 700 students from four universities in Beijing and Shanghai were recruited to complete questionnaires about PA, CS and PHENA. Data collection was conducted through online and offline questionnaires. Firstly, there is a significant correlation between PA, CS and PHENA. Secondly, PA can negatively predict PHENA, and PA has positive impact on PC and negative impact on NC. Thirdly, the mediating role of NC related to PHENA is significant, the mediating role of PC related to PHENA is not significant. College students' participation in physical activity can reduce the probability of adopting negative coping mechanisms, thereby alleviating the PHENA.

Antagonist Muscle Prefatigue Increases the Intracortical Communication between Contralateral Motor Cortices during Elbow Extension Contraction.

To investigate the cortico-cortical coupling changes related to antagonist muscle prefatigue, we recorded EEG at FC3, C3, FC4, and C4 electrodes of twelve young male volunteers during a 30-second-long, nonfatiguing isometric elbow extension contraction with a target force level of 20% MVC before and after a sustained fatiguing elbow flexion contraction until task failure. EEG-EEG phase synchronization indices in alpha and beta frequency bands were calculated for the pre- and postfatigue elbow extension contractions. The phase synchronization index in the beta frequency band was found significantly increased between EEG of FC3-C3. The increased phase synchronization index may reflect an enhanced intracortical communication or integration of the signals between contralateral motor cortices with antagonist muscle prefatigue, which may be related to the central modulation so as to compensate for the antagonist muscle prefatigue-induced joint instability.

Early Mitochondrial Adaptations in Skeletal Muscle to Obesity and Obesity Resistance Differentially Regulated by High-Fat Diet.

The mechanism for different susceptibilities to obesity after short-term high-fat diet (HFD) feeding is largely unknown. Given the close association between obesity occurrence and mitochondrial dysfunction, the early events in skeletal muscle mitochondrial adaptations between HFD-induced obesity (DIO) and HFD-induced obesity resistant (DIO-R) lean phenotype under excess nutritional environment were explored.ICR/JCL male mice were randomly divided into 2 groups, as follows: low-fat diet (LFD) and HFD groups. After 6 weeks on HFD, HFD-fed mice were classified as DIO or DIO-R according to their body weight gain. Serum parameters, oxidative stress biomarkers, the activation of AMPK/ACC axis, and the expression profiles of mitochondrial biogenesis were measured by using corresponding methods among the LFD control, DIO, and DIO-R groups. Serum glucose, total cholesterol, low-density lipoprotein, and high-density lipoprotein levels were significantly increased in DIO and DIO-R mice compared with LFD controls. However, DIO-R mice had significantly higher MDA levels and exhibited a significantly higher level of AMP-activated protein kinase (AMPK) activation and acetyl-CoA carboxylase (ACC) inactivation than DIO mice. Furthermore, the transcript and protein levels of transcriptional coactivator peroxisome proliferator-activated receptor γ (PPARγ) coactivator 1α (PGC-1α) and estrogen-related receptor-α (ERRα) in DIO-R mice were significantly up-regulated compared with the DIO mice. Although the body weight gain differed, the DIO and DIO-R mice had similar metabolic disturbance of glucose and lipids after short-term HFD consumption. The diverse alterations on fatty acid oxidation and mitochondrial biogenesis pathway induced by AMPK activation might be involved in different susceptibilities to obesity when consuming HFD.

In vitro antioxidant activity and in vivo antifatigue effect of layered double hydroxide nanoparticles as delivery vehicles for folic acid.

Folic acid antioxidants were successfully intercalated into layered double hydroxides (LDH) nanoparticles according to a previous method with minor modification. The resultant folic acid-LDH constructs were then characterized by X-ray powder diffraction and transmission electron microscopy. The in vitro antioxidant activities, cytotoxicity effect, and in vivo antifatigue were examined by a series of assays. The results showed that folic acid-LDH antioxidant system can scavenge 1,1-diphenyl-2-picrylhydrazyl and hydroxyl free radicals and chelate pro-oxidative Cu(2+). The in vitro cytotoxicity assays indicated that folic acid-LDH antioxidant system had no significant cytotoxic effect or obvious toxicity to normal cells. It also prolonged the forced swimming time of the mice by 32% and 51% compared to folic acid and control groups, respectively. It had an obvious effect on decreasing the blood urea nitrogen and blood lactic acid, while increasing muscle and hepatic glycogen levels. Therefore, folic acid-LDH might be used as a novel antioxidant and antifatigue nutritional supplement.

The in vitro sustained release profile and antitumor effect of etoposide-layered double hydroxide nanohybrids.

Magnesium-aluminum layered double hydroxides intercalated with antitumor drug etoposide (VP16) were prepared for the first time using a two-step procedure. The X-ray powder diffraction data suggested the intercalation of VP16 into layers with the increased basal spacing from 0.84-1.18 nm was successful. Then, it was characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, thermogravimetry and differential thermal analysis, and transmission electron microscopy. The prepared nanoparticles, VP16-LDH, showed an average diameter of 62.5 nm with a zeta potential of 20.5 mV. Evaluation of the buffering effect of VP16-LDH indicated that the nanohybrids were ideal for administration of the drugs that treat human stomach irritation. The loading amount of intercalated VP16 was 21.94% and possessed a profile of sustained release. The mechanism of VP16-LDH release in the phosphate buffered saline solution at pH 7.4 is likely controlled by the diffusion of VP16 anions from inside to the surface of LDH particles. The in vitro cytotoxicity and antitumor assays indicated that VP16-LDH hybrids were less toxic to GES-1 cells while exhibiting better antitumor efficacy on MKN45 and SGC-7901 cells. These results imply that VP16-LDH is a potential antitumor drug for a broad range of gastric cancer therapeutic applications.