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 investigate the effects of calcitriol on sepsis-induced immunosuppression and its potential mechanism. METHODS A sepsis-induced immunosuppression mice model was established using cecal ligation and puncture （CLP）. The 7-day survival rate， serum levels of tumor necrosis factor- α （TNF- α）， interleukin-6 （IL-6）， and IL-1β were determined in sham operation group， CLP group and calcitriol group （1 μg/kg）； the morphological changes of lung tissue in mice were observed. Lipopolysaccharide （LPS） tolerance macrophage models （representing sepsis-induced immunosuppression） were established using mice macrophage cell line RAW264.7 cells. The levels of TNF-α and IL-6 in cell supernatants as well as mRNA expressions of IL-1β， nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3 （NLRP3）， IL-18 and caspase-1 were assessed in culture medium group， LPS group， LPS tolerance group， and calcitriol （5 μmol/L） group. The following parameters were measured： propidium iodide （PI）-positive cell ratio， caspase-1 activity， lactate dehydrogenase （LDH） release， and Ca2+ levels. RESULTS Compared with CLP group， 7-day survival rate and serum levels of TNF-α， IL-6 and IL-1β were increased significantly in calcitriol group （P＜0.05）. Additionally， pulmonary tissue damage was markedly attenuated in calcitriol group. Compared with LPS tolerance group， the levels of TNF-α and IL-6 in cell supernatants， mRNA expressions of IL- 1β， NLRP3， IL-18 and caspase-1， PI-positive cell ratio， caspase-1 activity， LDH release， and Ca2+ levels were all increased significantly in calcitriol group （P＜0.05）. CONCLUSIONS Calcitriol can reverse sepsis-induced immunosuppression， and the mechanism of action may be E-mail：yarfwy@163.com achieved by the binding of calcitriol to vitamin D receptor，which promotes the release of Ca2+ from the endoplasmic reticulum， thereby driving the NLRP3/caspase-1-mediated pyroptosis pathway.

ObjectiveTo observe the clinical effectiveness and safety of Hewei Anshen Formula （和胃安神方） for stress-induced insomnia. MethodsA total of 104 male patients with stress-induced insomnia were randomly divided into a treatment group and a control group， with 52 cases in each group. The treatment group was given Hewei Anshen Formula once a day， while the control group was given zolpidem tartrate tablets 10 mg per time and once a day， and both groups were treated for 4 weeks. The Pittsburgh Sleep Quality Index （PSQI） was applied to evaluate sleep quality before and after treatment， Ford Insomnia Response to Stress Test （FIRST） was used to evaluate insomnia susceptibility， MOS 36-tem Short Form Health Survey （SF-36） ［which includes the domains of Physical Component Summary （PCS） and Mental Health Component Summary （MCS）， with the PCS including the General Health （GH）， Physical Functioning （PF）， Role Physical （RP）， and Body Pain （BP）， and the MCS including Role Emotional （RE）， Social Functioning （SF）， Vitality （VT）， Mental Health （MH）］ was used to evaluate the quality of life， and Fatigue Scale 14 （FS-14） ［including somatic fatigue and brain fatigue scores］ to evaluate the degree of fatigue， and the traditional Chinese medicine （TCM） syndrome scores using a self-developed TCM syndrome survey for insomnia. Clinical effectiveness and TCM syndrome improvement were determined after treatment. The occurrence of adverse events and adverse reactions was recorded during treatment. ResultsThe total effective rate of clinical effectiveness was 90.38% （41/52） in the treatment group and 80.77% （42/52） in the control group， and the difference between the two groups was not statistically significant （P＞0.05）. The total effective rate of TCM syndrome effectiveness in the treatment group was 80.77% （42/52）， which was higher than 44.23% （23/52） in the control group， and the difference was statistically significant （P＜0.01）. The TCM syndrome score， FIRST score， brain fatigue scores， brain fatigue score and total score of FS-14 score all reduced after treatment in both groups， and all scores were lower in the treatment group than those in the control group after treatment （P＜0.05）. All transformed scores of SF-36 scores were higher in both groups after treatment than before treatment in this group， and they were better than the control group in the four dimensions of PF， RP， VT， and MH （P＜0.05）. There were no adverse events and adverse reactions in the two groups. ConclusionHewei Anshen Formula can improve patients' sleep quality， effectively relieve clinical symptoms such as fatigue and pain， alleviate TCM syndromes， enhance the quality of life， reduce the susceptibility to insomnia， and shows good safety.

ObjectiveTo investigate the possible mechanism of Hewei Anshen Formula （和胃安神方） in the treatment of insomnia. MethodsSixty male SD rats were randomly divided into the normal group， the model group， the eszopiclone group and the low-， medium- and high-dose Hewei Anshen Formula groups. The insomnia model was constructed by intraperitoneal injection of p-chlorophenylalanine （PCPA） for 2 days in all groups except the normal group. After successful modelling， the eszopiclone group was given 0.33 mg/（kg·d） eszopiclone aqueous solution by gavage， the low-， medium- and high-dose Hewei Anshen Formula groups were given 10 ml/kg of Hewei Anshen Formula with a concentration of 1， 2 and 4 g/ml， respectively， and the rats in the normal group and the model group were given 10 ml/kg of saline by gavage， once a day for 7 consecutive days. The general condition of the rats was observed during the experiment， and the body mass of the rats was measured every day after medication administration. The following day after the last medication administration， pentobarbital sodium co-test was used to observe the sleep condition， and the sleep latency and sleep duration were recorded； immunohistochemistry and Western blot were used to detect the expression of hypothalamic clock rhythm regulating protein （CLOCK） and brain and muscle aromatic hydrocarbon receptor nuclear transporter-like protein 1 （BMAL1） in the rats. ResultsThe body mass of rats in the model group was lower than that of rats in the normal group at all time points （P＜0.01）； compared with the same time in the eszopiclone group， the body mass of rats in the low-dose Hewei Anshen Formula group was elevated on the 5th， 6th and 7th days of medication administration （P＜0.05）. Compared with the normal group， the sleep duration of rats in the model group was shortened （P＜0.01）； compared with the model group， the sleep duration of rats in each dosage group increased （P＜0.01）， and the difference between the high-dose Hewei Anshen Formula group and the eszopiclone group showed no statistically significant （P＞0.05）， while the sleep duration of the low- and medium-dose Hewei Anshen Formula groups were shorterned than the eszopiclone group （P＜0.01）. The difference in sleep latency showed no statistically significant among each group （P＞0.05）. The results of both immunohistochemistry and Western blotting showed that the expression of CLOCK and BMAL1 in the hypothalamus of rats in the model group was significantly reduced compared with that in the normal group （P＜0.01）； the expression of CLOCK and BMAL1 in the hypothalamus of rats in the low- and high-dose Hewei Anshen Formula groups increased than that in the model group （P＜0.05 or P＜0.01）. ConclusionHewei Anshen Formula can improve insomnia in model rats， and its mechanism of action may be related to the up-regulation of the expression of the hypothalamic biological clock genes CLOCK and BMAL1 protein.

Artificial chord is a mature mitral valve repair technique, especially in adult mitral valve repair. It is still challenging to repair mitral valve in children with artificial chords because the quality of mitral valve is soft and immature. There are some differences in the methods of suture, the choice of suture size and the number of artificial chords. Although the artificial chords could not grow naturally, we found through the long-term research that most children did not have mitral valve restriction or even chords rupture due to itself can compensate through the growth of the flap and papillary muscle. This article summarizes the recent research progress on the treatment of mitral valve insufficiency in children with artificial chords, providing reference for clinical treatment.

Objective To study whether there is a difference in the percentage consonants correct(PCC)of children with functional speech sound disorders(SSD)at different ages,and to explore the distribution in types of consonant errors at different ages.Methods A total of 172 children with ages from 4 to 7 years who were diagnosed with functional speech sound disorders and admitted to the Department of Rehabilitation of the Third Xiangya hospi-tal of Central South University participated in the study.The children were divided into three groups according to their ages:Groups 1 to 3.Groups 1,2,and 3 consisted of 97,45,and 30 children,respectively(Group 1:63 boys and 34 girls,aged 4 to＜5 years;Group 2:36 boys and 9 girls,aged 5 to＜6 years;and Group 3:36 boys and 9 girls,aged 6 to＜7 years).Picture-naming task was used to assess children's phonology.The types of consonant error were recorded and the percentage consonants correct(PCC)and the incidence of consonant errors in different places of articulation(stopping,affrication,frication,nasalization,and lateralization)was calculated.Results ①There was no significant difference in the PCC results among the three groups(P＞0.05).②There was a significant difference in omission errors(Z=6.531,P=0.038＜0.05),but not for substitution and distortion errors among the three groups(P＞0.05).③The omission of the lateral/l/was major among the three groups of children.④There were more stopping,affrication and frication in all three groups of children,yet no significant difference in the results of incidence of consonant errors in different places of articulation(stopping,nasalization,affrication,frica-tion and lateralization)among the three groups(P＞0.05).Conclusion There was no significant difference in the PCC among children with functional speech sound disorders at different ages.There were obvious differences in the distribution of omission errors in different age groups,suggesting idiosyncrasy.Children with SSD demonstrated similar characteristics of consonant phonetic errors at different age stages,included mainly the omission of the lateral/1/and more stopping,affrication and frication.

AIM:To investigate the anti-fibrotic effect of Panax notoginseng saponins(PNS)in arecoline(ANE)-induced oral submucous fibrosis,and to analyze the effect of PNS on nuclear factor E2-related factor 2(Nrf2)/glu-tamate-cysteine ligase catalytic subunit(GCLC)signaling pathway.METHODS:CCK-8 assay was used to evaluate the effects of different concentrations of PNS and arecoline on the survival rate of human immortalized keratinocyte cell line Ha-CaT.The results of CCK-8 were used to select 75 mg/L arecoline,and 25,50 and 100 mg/L PNS as subsequent experi-mental concentrations.The cells were set as blank control group,model group,and low,medium and high doses(25,50 and 100 mg/L)of PNS groups.The protein and mRNA expressions of collagen type I(COL-I),E-cadherin,Nrf2,GCLC and glutathione reductase(GR)in each group were detected by Western blot and RT-qPCR.Immunofluorescence method was used to detect the entry of Nrf2 into the nucleus.Biochemical kits were used to detect the content of glutathione(GSH),nicotinamide adenine dinucleotide phosphate(NADPH)and malondialdehyde(MDA),and superoxide dis-mutase(SOD)activity in each group of cells.DCFH-DA fluorescent probe was used to detect the content of intracellular reactive oxygen species(ROS).RESULTS:Compared with the blank control group,the protein and mRNA expression of COL-I in the model group was up-regulated,and the protein and mRNA levels of E-cadherin,Nrf2,GCLC,nuclear Nrf2 and GR were down-regulated.The content of NADPH,MDA and ROS in the cells increased,and the content of GSH and the activity of SOD was significantly reduced.Compared with the model group,the protein and mRNA expression of COL-I was down-regulated,and the protein and mRNA expression of E-cadherin,Nrf2,GCLC,nuclear Nrf2 and GR were up-regulated in PNS 50 and 100 mg/L groups.Compared with the model group,the content of NADPH,MDA and ROS in cells decreased,and the content of GSH and the activity of SOD was significantly enhanced(P<0.05 or P<0.01).CON-CLUSION:Panax notoginseng saponins have anti-fibrosis effects in HaCaT cells,and their mechanism may be related to the activation of Nrf2/GCLC signaling pathway,thereby resisting oxidative stress and improving oral submucosal fibrosis.

Objective To observe the consistency of 5.0T and 1.5T MR spectroscopy(MRS)for quantitating proton density fat fraction(PDFF)of liver.Methods Lipid emulsion models with lipid content of 0,5％,10％,15％,20％,25％and 30％were prepared.1H-MRS were collected using 5.0T and 1.5T MR scanners,respectively,and PDFF were obtained with jMRUI software.Totally 23 people,including 11 cases of fatty liver and 12 healthy adults were prospectively collected,and volume of interest(VOI)in the liver were selected to acquire 1H-MRS,and PDFF were obtained with jMRUI software and corresponding workstation,respectively.The consistencies of PDFF measured with different methods were analyzed.Results PDFF of lipid emulsion models with lipid content of 0,5％,10％,15％,20％,25％and 30％measured with jMRUI software and workstations based on 5.0T and 1.5T 1H-MRS all had good consistencies and being positively correlated,so were PDFF of liver tissue measured with jMRUI software and workstations based on 5.0T and 1.5T 1H-MRS.Conclusion 5.0T and 1.5T 1H-MRS had good consistency for quantitating liver PDFF.Measuring liver PDFF with workstation in clinical practice was helpful to simplifying workflow.

Objective: This study aimed to evaluate the effects of 2 endoscopic spine surgeries on the biomechanical properties of normal and osteoporotic spines. Methods: Based on computed tomography images of a healthy adult volunteer, 6 finite element models were created. After validating the normal intact model, a concentrated force of 400 N and a moment of 7.5 Nm were exerted on the upper surface of L3 to simulate 6 physiological activities of the spine. Five types of indices were used to assess the biomechanical properties of the 6 models, range of motion (ROM), maximum displacement value, intervertebral disc stress, maximum stress value, and articular protrusion stress, and by combining them with finite element stress cloud. Results: In normal and osteoporotic spines, there was no meaningful change in ROM or disc stress in the 2 surgical models for the 6 motion states. Model N1 (osteoporotic percutaneous transforaminal endoscopic discectomy model) showed a decrease in maximum displacement value of 20.28% in right lateral bending. Model M2 (unilateral biportal endoscopic model) increased maximum displacement values of 16.88% and 17.82% during left and right lateral bending, respectively. The maximum stress value of L4–5 increased by 11.72% for model M2 during left rotation. In addition, using the same surgical approach, ROM, maximum displacement values, disc stress, and maximum stress values were more significant in the osteoporotic model than in the normal model. Conclusion In both normal and osteoporotic spines, both surgical approaches were less disruptive to the physiologic structure of the spine. Furthermore, using the same endoscopic spine surgery, normal spine biomechanical properties are superior to osteoporotic spines.

Objective: This study aimed to evaluate the effects of 2 endoscopic spine surgeries on the biomechanical properties of normal and osteoporotic spines. Methods: Based on computed tomography images of a healthy adult volunteer, 6 finite element models were created. After validating the normal intact model, a concentrated force of 400 N and a moment of 7.5 Nm were exerted on the upper surface of L3 to simulate 6 physiological activities of the spine. Five types of indices were used to assess the biomechanical properties of the 6 models, range of motion (ROM), maximum displacement value, intervertebral disc stress, maximum stress value, and articular protrusion stress, and by combining them with finite element stress cloud. Results: In normal and osteoporotic spines, there was no meaningful change in ROM or disc stress in the 2 surgical models for the 6 motion states. Model N1 (osteoporotic percutaneous transforaminal endoscopic discectomy model) showed a decrease in maximum displacement value of 20.28% in right lateral bending. Model M2 (unilateral biportal endoscopic model) increased maximum displacement values of 16.88% and 17.82% during left and right lateral bending, respectively. The maximum stress value of L4–5 increased by 11.72% for model M2 during left rotation. In addition, using the same surgical approach, ROM, maximum displacement values, disc stress, and maximum stress values were more significant in the osteoporotic model than in the normal model. Conclusion In both normal and osteoporotic spines, both surgical approaches were less disruptive to the physiologic structure of the spine. Furthermore, using the same endoscopic spine surgery, normal spine biomechanical properties are superior to osteoporotic spines.