Exercise fatigue is a complex physiological and psychological phenomenon that includes peripheral fatigue in the muscles and central fatigue in the brain. Peripheral fatigue refers to the loss of force caused at the distal end of the neuromuscular junction, whereas central fatigue involves decreased motor output from the primary motor cortex, which is associated with modulations at anatomical sites proximal to nerves that innervate skeletal muscle. The central regulatory failure reflects a progressive decline in the central nervous system’s capacity to recruit motor units during sustained physical activity. Emerging evidence highlights the critical involvement of central neurochemical regulation in fatigue development, particularly through neurotransmitter-mediated modulation. Alterations in neurotransmitter release and receptor activity could influence excitatory and inhibitory signal pathways, thus modulating the perception of fatigue and exercise performance. Increased serotonin (5-HT) could increase perception of effort and lethargy, reduce motor drive to continue exercising, and contribute to exercise fatigue. Decreased dopamine (DA) and noradrenaline (NE) neurotransmission can negatively impact arousal, mood, motivation, and reward mechanisms and impair exercise performance. Furthermore, the serotonergic and dopaminergic systems interact with each other; a low 5-HT/DA ratio enhances motor motivation and improves performance, and a high 5-HT/DA ratio heightens fatigue perception and leads to decreased performance. The expression and activity of neurotransmitter receptors would be changed during prolonged exercise to fatigue, affecting the transmission of nerve signals. Prolonged high-intensity exercise causes excess 5-HT to overflow from the synaptic cleft to the axonal initial segment and activates the 5-HT1A receptor, thereby inhibiting the action potential of motor neurons and affecting the recruitment of motor units. During exercise to fatigue, the DA secretion is decreased, which blocks the binding of DA to D1 receptor in the caudate putamen and inhibits the activation of the direct pathway of the basal ganglia to suppress movement, meanwhile the binding of DA to D2 receptor is restrained in the caudate putamen, which activates the indirect pathway of the basal ganglia to influence motivation. Furthermore, other neurotransmitters and their receptors, such as adenosine (ADO), glutamic acid (Glu), and γ‑aminobutyric acid (GABA) also play important roles in regulating neurotransmitter balance and fatigue. The occurrence of central fatigue is not the result of the action of a single neurotransmitter system, but a comprehensive manifestation of the interaction between multiple neurotransmitters. This review explores the important role of neurotransmitters and their receptors in central motor fatigue, reveals the dynamic changes of different neurotransmitters such as 5-HT, DA, NE, and ADO during exercise, and summarizes the mechanisms by which these neurotransmitters and their receptors regulate fatigue perception and exercise performance through complex interactions. Besides, this study presents pharmacological evidence that drugs such as agonists, antagonists, and reuptake inhibitors could affect exercise performance by regulating the metabolic changes of neurotransmitters. Recently, emerging interventions such as dietary bioactive components intake and transcranial electrical stimulation may provide new ideas and strategies for the prevention and alleviation of exercise fatigue by regulating neurotransmitter levels and receptor activity. Overall, this work offers new theoretical insights into the understanding of exercise central fatigue, and future research should further investigate the relationship between neurotransmitters and their receptors and exercise fatigue.

Objective To analyze the effect of residual cholesterol (RC) on hearing loss in noise-exposed workers. Methods A total of 3 412 workers engaged in noise operation work in an underground railway enterprise were selected as the research subjects using the judgment sampling method. Their occupational health examination data were collected to analyze the relationship between RC and hearing loss. Results The noise intensity of workplace in the underground rail enterprise was 80.0-85.0 (81.4±3.2) dB(A). The detection rate of hearing loss was 20.2% (691/3 412). The rates of abnormal total cholesterol, triacylglycerol, high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol were 35.6%, 25.7%, 9.5% and 42.4%, respectively. The median and the 25th and 75th percentiles [M(P₂₅,P₇₅)] of RC level were 0.24 (0.15, 0.37) mmol/L. The levels of total cholesterol, triacylglycerol and RC of workers in hearing loss group were higher than those in normal hearing group [M(P₂₅,P₇₅): 4.91(4.37, 5.58) vs 4.84(4.30, 5.46) mmol/L, 1.29(0.91, 1.93) vs 1.16(0.82, 1.67) mmol/L, 0.26(0.16, 0.41) vs 0.24(0.14, 0.37) mmol/L, all P<0.05]. The detection rate of hearing loss in abnormal triglyceride group was higher than that in normal triglyceride group (24.8% vs 18.7%, P<0.01), and the detection rate of hearing loss in abnormal HDL-C group was higher than that in normal HDL-C group (25.0% vs 19.8%, P<0.05). The higher the serum RC level, the higher the detection rate of hearing loss (P<0.01). Multivariate logistic regression result showed that individual with older age, longer work time and higher serum RC level had higher risk of hearing abnormality (all P<0.05), and the risk of hearing abnormality was higher in patients with abnormal fasting blood glucose than patients with normal faseing blood glucose (P<0.05) after controlling for confounding factors such as gender, alcohol consumption, body mass index, and elevated blood pressure. However, abnormal triacylglycerol and HDL-C levels were not significantly related to the risk of hearing abnormality (both P>0.05). Conclusion Serum RC levels are an independent risk factor for hearing loss among noise-exposed workers exposed to noise level of 80.0-85.0 dB(A) in the workplace.

Haematitum and Limonitum are two iron-containing mineral medicines included in the 2020 edition of the Chinese Pharmacopoeia. They have similar main components and major differences in their property, flavor, channel tropism, and clinical uses. In this study, we investigated the surface properties, mineral composition, mineral dissociation, elemental composition, and iron state of Haematitum and Limonitum to explore their mineralogical differences. Scanning electron microscopy(SEM), specific surface and porosity analyzer, X-ray diffractometer(XRD), X-ray photoelectron spectrometer(XPS), and advanced mineral identification and characterization system(AMICS) were used to analyze the mineralogy of Haematitum and Limonitum. The results showed that Haematitum had an angular surface with granular attachments and a specific surface area of 17.04 m~2·g~(-1). In comparison, Limonitum had a smooth and flat surface with a bundled acicular crystal structure and a specific surface area of 46.29 m~2·g~(-1). Haematitum consists of 31 detectable minerals containing 18 elements, with the major element, iron(44.5% Fe~(2+) and 55.5% Fe~(3+)) distributed in 17 minerals, including hematite, iron oxide, knebelite, siderite, and magnesioferrite. Limonitum consists of 32 detectable minerals containing 17 elements, with the major element, iron(14.5% Fe~(2+) and 85.5% Fe~(3+)) distributed in 19 minerals, including limonite, iron oxide, chlorite, and knebelite. In summary, the elemental composition of Haematitum and Limonitum does not differ greatly, but there are large differences in the mineral composition and iron state. The large specific surface area and strong adsorption capacity of Limonitum may be one of the mechanisms of its anti-diarrheal action. The Fe_2O_3 and illite contained in Haematitum and Limonitum may be the key substances for their hemostasis effects. The mineralogical differences are expected to provide a reference for explaining the scientific connotation of mineral medicine and laying a material foundation for studying its mechanism of action.
Iron/analysis* ; Minerals/chemistry* ; Drugs, Chinese Herbal/chemistry* ; X-Ray Diffraction ; Microscopy, Electron, Scanning ; Photoelectron Spectroscopy

Reactive astrocytes, which exhibit a correlation with the degeneration of dopaminergic neurons, are present in a considerable number during the progression of Parkinson's disease (PD). However, the underlying factors shaping astrocyte reactivity and neuroinflammation in PD remain inadequately elucidated. Here, we demonstrate that fibroblast growth factor 7 (FGF7)/FGF receptor 2 (FGFR2) autocrine signaling intensifies astrocyte reactivity and inflammation. Genetic deletion of Arrb2, β-Arrestin2 encoding gene, led to escalated astrocyte reactivity in MPTP-treated mice, which was further substantiated in astrocyte-specific Arrb2 knockdown mice. RNA sequencing profiling of Arrb2 knockout astrocytes identified Fgf7 as a critical effector of astrocyte reactivity. Subsequently, conditional knockdown of Fgf7 and its receptor Fgfr2 in astrocytes elicited advantageous effects for MPTP-treated mice by restraining the inflammatory phenotypic transition of reactive astrocytes. Furthermore, deletion of astrocytic Fgf7 mitigated MPTP-induced pathology in Arrb2 knockout mice. Mechanistically, STAT1 was distinguished as the transcription factor suppressing Fgf7 expression, while β-Arrestin2 counteracted the proteasomal degradation of STAT1 by binding to RNF220, an E3 ubiquitin ligase for STAT1. More importantly, selectively engaging dopamine D2 receptor (Drd2)/β-Arrestin2-biased signaling using the agonist UNC9995 exhibited therapeutic potential in MPTP-treated mice via moderation of astrocytic FGF7 production, thereby restoring balance in astrocyte reactivity. Collectively, our study bridges a crucial knowledge gap by elucidating the novel functions of FGF family members within the central nervous system, particularly within the context of PD. The autocrine signaling of FGF7/FGFR2 represents a novel mechanism and a potential druggable target for modulating astrocyte-derived inflammation.

Protrusive facial deformities, characterized by the forward displacement of the teeth and/or jaws beyond the normal range, affect a considerable portion of the population. The manifestations and morphological mechanisms of protrusive facial deformities are complex and diverse, requiring orthodontists to possess a high level of theoretical knowledge and practical experience in the relevant orthodontic field. To further optimize the correction of protrusive facial deformities, this consensus proposes that the morphological mechanisms and diagnosis of protrusive facial deformities should be analyzed and judged from multiple dimensions and factors to accurately formulate treatment plans. It emphasizes the use of orthodontic strategies, including jaw growth modification, tooth extraction or non-extraction for anterior teeth retraction, and maxillofacial vertical control. These strategies aim to reduce anterior teeth and lip protrusion, increase chin prominence, harmonize nasolabial and chin-lip relationships, and improve the facial profile of patients with protrusive facial deformities. For severe skeletal protrusive facial deformities, orthodontic-orthognathic combined treatment may be suggested. This consensus summarizes the theoretical knowledge and clinical experience of numerous renowned oral experts nationwide, offering reference strategies for the correction of protrusive facial deformities.
Humans ; Orthodontics, Corrective/methods* ; Consensus ; Malocclusion/therapy* ; Patient Care Planning ; Cephalometry

Objective To investigate the differential expression of miR-124-3p in peripheral blood and clinical sig-nificance of patients with β-thalassemia.Methods Peripheral blood samples were collected from 33 patients with β-thalassemia and 30 healthy controls in Ningde Municipal Hospital Affiliated to Ningde Normal University from June 2021 to August 2022.The expression level of miR-124-3p was detected.Luciferase reporter gene was used to verify the interaction between miR-124-3p and ERF 3'UTR.The correlation between differential expression of miR-124-3p and β-thalassemia was analyzed and the clinical diagnostic value of miR-124-3p for β-thalassemia was eval-uated.Results Compared with healthy control individuals,the expression of miR-124-3p was significantly up-reg-ulated in patients with β-thalassemia(P＜0.001).The genotype of miR-124-3p high expression group was 84.2%β0(16/19),the genotype of low expression group was 55.6%β+(10/18).ROC curve analysis showed that miR-124-3p had predictive efficacy for β-thalassemia(AUC:0.842).Luciferase reporter gene analysis showed that ERF gene was the regulatory target of miR-124-3p.Conclusions The differential expression of miR-124-3p in patients with β-thalassemia is closely related to the genotype and clinical severity of thalassemia,and ERF is negatively reg-ulated by miR-124-3p.miR-124-3p may be an effective diagnostic biomarker for β-thalassemia.

Objective To investigate the clinical experience of cochlear implantation(CI)in patients with postlingual hearing loss accompanied by cholesterol granuloma(CG)in the middle ear.Methods A retrospective study was conducted on the clinical data of 6 patients with postlingual hearing loss who underwent CI with middle ear CG at Fuyang hospital of Anhui Medical University from December 2018 to December 2022.The selection of surgical methods,surgical efficacy,and postoperative complications of patients undergoing CI surgery during the same period were summarized and analyzed.The categories of auditory performance(CAP)and speech intelligibility rating(SIR)were used to evaluate the effectiveness of auditory speech rehabilitation.Results Six patients were treated by individualized surgical methods based on preoperative CT findings and successfully completed cochlear im-plant surgery.According to the scope of the lesion,three patients were treated with canal wall up mastoidectomy(CWUM)and CI,the other three patients were treated with radical mastoidectomy(RM),CI and middle ear clo-sure(MEC).All patients did not experience complications such as incision infection,facial paralysis,labyrinthitis,intracranial infection,recurrence,or electrode exposure after surgery and during follow-up.The CAP and SIR scores of postoperative patients were significantly improved compared to preoperative with statistical significance(P＜0.05).Conclusion For patients with severe sensorineural hearing loss and middle ear CG,simultaneous cochlear implantation can achieve good auditory rehabilitation effects.However,appropriate surgical methods should be se-lected based on the lesion range,and the lesion must be completely removed to prevent postoperative complications.

Objective:To investigate the clinical characteristics of first-episode and recurrent acute hypertriglyceridemic pancreatitis (HTGP).Methods:The retrospective cohort study was con-ducted. The clinical data of 313 patients with HTGP admitted to 26 medical centers in China in the Chinese Acute Pancreatitis Clinical Research Group (CAPCTG)-PERFORM database from November 2020 to December 2021 were collected. There were 219 males and 94 females, aged 38(32,44)years. Of the 313 patients, 193 patients with first-episode HTGP were allocated into the first-episode group and 120 patients with recurrent HTGP were allocated into the recurrent group. Observation indica-tors: (1) propensity score matching and comparison of general data of patients between the two groups after matching; (2) comparison of severity and prognosis in the course of disease within 14 days between the two groups; (3) the association between recurrent HTGP and the risk of persistent organ failure (POF); (4) follow-up. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent sample t test. Measurement data with skewed distribution were represented as M( Q1, Q3), and comparison between groups was conducted using the Wilcoxon rank sum test. Count data were expressed as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test. Comparison of ordinal data was conducted using the Wilcoxon rank sum test. The Kaplan-Meier method was used to plot the cumulative recurrence rate curve and Log-Rank test was used for survival analysis. The Logistic regression model was used for multivariate analysis, and continuous variables were converted into categorical variables according to the mean value or common criteria. Propensity score matching was performed by 1∶1 nearest neighbor matching method, with caliper value of 0.02. Paired t test or Wilcoxon rank sum test and McNemar′s test were used for comparison between matched groups. Results:(1) Propensity score matching and comparison of general data of patients between the two groups after matching. Of the 313 patients,208 cases were successfully matched, including 104 cases in the first-episode group and 104 cases in the recurrent group. After propensity score matching, there was no significant difference in demographic characteristics, severity of illness scores and laboratory test between the two groups ( P>0.05). The elimination of gender, acute physiology and chornic health evaluation (APACHE) Ⅱ score, computed tomography severity index score, systemic inflammatory response syndrome score, sequential organ failure assessment score, apolipoprotein E, C-reactive protein, creatinine, lactic acid dehydrogenase, procal-citonin confounding bias ensured comparability between the two groups. (2) Comparison of severity and prognosis in the course of disease within 14 days between the two groups. There were signifi-cant differences in POF and local complications between the first-episode group and the recurrent group ( P<0.05). (3) The association between recurrent HTGP and the risk of POF. Results of uncor-rected univariate analysis showed that there was no association between recurrent HTGP and the risk of POF ( odds ratio=0.78, 95% confidence interval as 0.46-1.30, P>0.05). Results of multivariate analysis after adjusting for covariates such as gender, age, APACHE Ⅱ score, C-reactive protein, triglyceride and total cholesterol showed that compared with first-episode HTGP, recurrent HTGP was associated with a higher risk of POF ( odds ratio=2.22, 95% confidence interval as 1.05-4.71, P<0.05). Results of subgroup analysis showed that age<40 years was associated with an increased risk of POF ( odds ratio=3.31, 95% confidence interval as 1.09-10.08, P<0.05). (4) Follow-up. Twelve of the 313 patients died during hospitalization, including 9 cases in the first-episode group and 3 cases in the recurrent group. The rest of 301 surviving patients, including 184 cases in the first-episode group and 117 cases in the recurrent group, were followed up for 19.2(15.5, 21.9)months. Results of follow-up showed that for 184 survived patients of the first-episode group, 164 cases were followed up and 24 cases experienced recurrence, for 117 survived patients of the recurrent group,29 cases experienced recurrence, showing a significant difference between the two groups ( χ2=4.67, P<0.05). Conclusion:Compared with first-episode HTGP, patients with recurrent HTGP are more prone to POF and local complications, and are more prone to recurrence after discharge. The risk of POF in recurrent HTGP patients is 2.22 times that of those with first-episode, and the risk is higher in patients with age <40 years.

Objective This study aimed to investigate the potential relationship between urinary metals copper (Cu), arsenic (As), strontium (Sr), barium (Ba), iron (Fe), lead (Pb) and manganese (Mn) and grip strength. Methods We used linear regression models, quantile g-computation and Bayesian kernel machine regression (BKMR) to assess the relationship between metals and grip strength.Results In the multimetal linear regression, Cu (β=-2.119), As (β=-1.318), Sr (β=-2.480), Ba (β=0.781), Fe (β= 1.130) and Mn (β=-0.404) were significantly correlated with grip strength (P < 0.05). The results of the quantile g-computation showed that the risk of occurrence of grip strength reduction was -1.007 (95％ confidence interval:-1.362, -0.652; P < 0.001) when each quartile of the mixture of the seven metals was increased. Bayesian kernel function regression model analysis showed that mixtures of the seven metals had a negative overall effect on grip strength, with Cu, As and Sr being negatively associated with grip strength levels. In the total population, potential interactions were observed between As and Mn and between Cu and Mn (Pinteractions of 0.003 and 0.018, respectively).Conclusion In summary, this study suggests that combined exposure to metal mixtures is negatively associated with grip strength. Cu, Sr and As were negatively correlated with grip strength levels, and there were potential interactions between As and Mn and between Cu and Mn.