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.

Liver diseases cannot be easily detected in the early stage， and although invasive diagnostic methods， such as liver biopsy， are relatively accurate， they tend to have a low degree of acceptance， which greatly limits the improvement in diagnosis and treatment techniques for liver diseases. Therefore， it is of great importance to search for new biomarkers and therapeutic targets. As an emerging biomarker for liquid biopsy， tRNA-derived small RNA （tsRNA） is abnormally expressed in various liver diseases including viral hepatitis， fatty liver disease， liver injury， and liver cancer， and it can affect the development and progression of liver diseases by regulating the biological functions such as gene expression， epigenetic regulation， and protein translation. This article reviews the origin， classification， and biological function of tsRNA， as well as the research advances in tsRNA as biomarkers and potential therapeutic targets for liver diseases， so as to provide ideas for the early diagnosis and treatment of liver diseases.

Intravitreal injection of anti-vascular endothelial growth factor(VEGF)agents has become the primary treatment for macular edema associated with retinal vascular disease such as diabetic retinopathy and retinal vein occlusion, but there are limitations such as variable treatment efficacy and insufficient durability of therapeutic effects. As the first bispecific antibody applied in ophthalmic treatment, Faricimab achieves favorable outcomes by simultaneously targeting both VEGF-A and angiopoietin-2(Ang-2)pathways. Based on evidence from recent clinical trials and real-world studies, this article reviews the research progress on Faricimab for the treatment of diabetic macular edema(DME), retinal vein occlusion-associated macular edema(RVO-ME)and refractory macular edema compared to the therapeutic effects of other agents. Additionally, based on Faricimab's safety characteristics and future potential, its therapeutic prospects for macular edema associated with retinal vascular diseases are discussed. This review aims to provide evidence-based references for optimizing clinical treatment strategies, thereby contributing to mitigating the risk of vision loss due to macular edema.

Glycosylation is one of the most important reactions in living organisms as it results in the formation of glycoconjugates with diverse biological functions. Sugar nucleotides are structurally composed of sugar and nucleoside diphosphate or monophosphate, which are widespread within a variety of biological cells. As glycosyl donors for the transglycosyl reactions catalyzed by Leloir-type glycosyltransferases, sugar nucleotides are essential for the synthesis of glycans and glycoconjugates. However, high costs and limited availability of nucleotide sugars prevent applications of biocatalytic cascades on an industrial scale. Therefore, attentions on synthetic strategies of sugar nucleotides have been increasing to achieve their wide applications in various fields. The 9 common sugar nucleotides in mammals have been fully studied with large-scale synthesis through chemical, enzymatic (chemo-enzymatic) and cell factory strategies. In addition to common sugar nucleotides, many rare sugar nucleotides are present in plants and bacteria. Although unnatural sugar nucleotides cannot be synthesized in organisms, they have great potential in research as substrates for glycosyltransferases in carbohydrate synthesis, as enzyme inhibitors in biochemical studies, and as components of glycoconjugate biosynthesis. Therefore, increasing attention has been paid to explore the efficient synthesis of unnatural sugar nucleotides. Currently, strategies for chemical synthesis of sugar nucleotides have been greatly improved, such as the use of effective catalysts for forming pyrophosphate bonds and the development of entirely new synthesis protocols. Multiple sugar nucleotides, especially unnatural sugar nucleotides, are synthesized chemically. However, chemical synthesis requires tedious protection and deprotection steps, resulting in complex steps, high cost and low yield. In contrast, enzymatic (chemo-enzymatic) and cell factory methods have significant advantages such as high yield, easy operation and easy process scale-up in the preparation of sugar nucleotides. Hence, they are prominent strategies for sugar nucleotide preparation. Herein, the biosynthesis and application of sugar nucleotides are reviewed, mainly focusing on the 9 sugar nucleotides common in mammals. The early strategies for enzymatic synthesis of sugar nucleotides generally used de novo synthesis pathway. With the discoveries of enzymes involved in salvage pathway of sugar nucleotide synthesis and the development of one-pot multienzyme (OPME) method, the synthesis of sugar nucleotides was greatly simplified. Cell factory method employs the microbial living cells as a “processing plant” by engineering their metabolic pathways through genetic engineering technology. The cell factory method has high yield, and has been applied for efficient synthesis of several sugar nucleotides. Moreover, the strategy of gram-scale synthesis of multiple rare sugar nucleotides by cascade reactions from common sugar nucleotides using sugar nucleotides synthases cloned from different sources was illustrated. In recent years, the synthesis cost of sugar nucleotides has been further reduced through various ways, such as regeneration of nucleotides, regeneration of organic cofactors, and application of immobilized enzyme technology. Furthermore, through the continuous improvement of sugar nucleotide purification process, the use of high concentration of multi-enzyme cascade and rapid non-chromatographic purification process, the synthesis of multiple sugar nucleotides and their derivatives from monosaccharides was achieved, which gradually broke the limitations of the existing strategy. With the efficient synthesis of sugar nucleotides, their applications in various fields have been increasingly explored, including the synthesis of glycans and glycoconjugates, biochemical characterization of glycosyltransferases and bioorthogonal labeling strategies, which are of great significance to the research of biochemistry, glycobiology and the development of related pharmaceutical products.

To understand Helicobacter pylori's drug resistance,genetic diversity,and relationship with clinical diseases in the Guiyang and Qiannan minority areas of Guizhou Province,we collected samples through endoscopy,and isolated and cul-tured H.pylori.The drug resistance and genotype characteristics were determined.The differences in different regions and dis-ease types were compared,and the structural characteristics of H.pylori and mixed infections with different strains of H.py-lori in Qiannan Prefecture were analyzed.A difference in the composition ratio of EPYIA typing in the cagA variable region was observed between the two areas(P=0.012),and the composition ratio of the vacA genotype differed(P=0.000).A total of 94.6％(53/56)new sequences of H.pylori strains from two regions were obtained by MLST.The rate of infection by H.pylori mixed with different strains was 44.4％in Qiannan Pre-fecture,and no significant difference was observed in the com-position of H.pylori mixed infections among patients with dif-ferent clinical diseases(P=0.349).Differences in EPI YA typ-ing and the vacA genotype composition ratio in the cagA varia-ble region of H.pylori were observed between the Qiannan Prefecture and Guiyang City.

Objective To observe the value of ultrasound microvascular flow imaging(MV-Flow)combined with maternal serum vascular endothelial growth factor(VEGF)expression level for diagnosis of fetal growth restriction(FGR).Methods Totally 87 pregnant women with FGR(FGR group,including 43 cases of gestational week＜28 weeks[＜28 weeks subgroup]and 44 cases of ≥28 weeks[≥28 weeks subgroup])and 112 normal pregnant women with normal fetuses(normal control group,55 with gestational week＜28 weeks[NC 1 subgroup]and 57 with ≥28 weeks[NC 2 subgroup])were prospectively enrolled.MV-Flow technology was used to measure placental microvascular index(MVI),and the placental microvascular circulation was evaluated.The expression level of maternal serum VEGF was detected simultaneously,also of placental maternal surface immediately after delivery.The receiver operating characteristic curves were drawn to explore the value of placental MVI,maternal serum VEGF and the combination of placental MVI,maternal serum VEGF for diagnosing FGR.Results The levels of placental MVI and maternal serum VEGF in 2 subgroups of FGR group were both lower than those in control group(all P＜0.01).Placental VEGF expression level in FGR group was significantly lower than that in control group(P＜0.01).The area under the curve(AUC)of placental MVI,maternal serum VEGF and their combination for diagnosing FGR＜28 weeks was 0.981,0.870 and 0.997,respectively,while for diagnosing FGR≥28 weeks was 0.991,0.867 and 0.993,respectively.AUC of maternal serum VEGF alone for diagnosing in 2 subgroups of FGR were both lower than that of placental MVI and combination of placental MVI and maternal serum VEGF(all P＜0.05),while no significant difference of AUC was found between placental MVI and combination of maternal serum VEGF and placental MVI(both P＞0.05).Conclusion Both placental MVI and maternal serum VEGF level could be used to screen FGR,and the former was more valuable.

Objective:To explore the application value of compute tomography(CT)scan with 16cm wide body detector in chest examination of patients who could not cooperate with breath-holding.Methods:A total of 100 patients who could not cooperate with breath-holding during chest examination in the second affiliated hospital of Shenyang Medical College from May to August in 2022 were selected,and they were randomly divided into observation group and control group,with 50 patients in each group.The collimation width of CT scan with 16cm wide body detector was 256 mm×0.625 mm in the observation group,and that with 8 cm wide body detector was 128 mm×0.625 mm in the control group,and other parameters of two groups were same.A series of indicators included age,height,weight and body mass index(BMI)of patients were recorded,and the CT dose index(CTDIvol),dose length product(DLP),effective dose(ED)were measured and calculated.And then,the Contrast to Noise ratio(CNR),signal to noise(SNR)and Standard Deviation(SD)between two groups were compared,and the image quality was evaluated objectively and subjectively.Results:The average age and the average weight of the patients in the observation group were respectively(78.81±6.84)years old and(64.46±9.86)kg,and the mean values of BMI,CTDIvol,DLP,ED and exposure time were respectively(22.89±3.09)kg/m2,(4.61±1.00)mGy,(1 471.02±345.25)mGy·cm,(20.59±4.83)mSv,(1.01±0.61)s.The average age and the average weight of the patients in the control group were respectively(77.70±6.76)years old and(62.84±4.75)kg.The mean values of BMI,CTDIvol,DLP,Ed and exposure time were respectively(22.89±2.29)kg/m2,(14.5±0.00)mGy,(4 561.70±346.32)mGy·cm,(63.86±4.85)mSv and(4.07±0.12)s.The differences of subjective evaluations of main pulmonary artery,right inferior pulmonary vein trunk and aortic arch between the observation group and the control group were not significant(P>0.05).The subjective scores of image qualities both two groups were larger than 4,and the image qualities of two groups could meet the diagnostic requirements.The CTDIvol,DLP,ED and exposure time of observation group were significantly lower than those in control group(t=-69.42,-44.231,-44.234,-107.10,P<0.05),respectively.Conclusion:Compared with the CT scan with conventional 8 cm detector,the CT scan with 16 cm wide body detector can greatly shorten the scanning time and reduce the radiation dose in the chest CT scan of patients with free breathing,and the image quality of that can meet the requirement of clinical diagnosis,which has very high application value in the fast diagnosis of clinical emergency.

The medical metaverse is a combination of medicine and other cutting-edge technologies such as computer and information ones. In the medical metaverse, medical knowledge in the real world will be transformed into a digital form, so that activities concerning diagnosis, treatment, education and clinical practice can be carried out in a virtual environment. Based on the latest research advances at home and abroad, this review expounds on the medical metaverse from the aspects of supporting technologies, applications in clinic and medical education, current deficiencies and future development.

Objective:To explore the relevant risk factors and prognosis of patients with intrahepatic cholangiocarcinoma (ICC) who experienced recurrence within 6 months after surgeryMethods:This retrospective study included a total of 259 patients with ICC a treated at He'nan Provincial People's Hospital and He'nan Cancer Hospital from Jan 2018 to Jan 2020. The clinical and pathological data ,differences between the group with recurrence within 6 months and the group without recurrence within 6 months were compared using the chi-square test. Logistic regression analysis was used to determine the relevant risk factors for recurrence within 6 months. Kaplan-Meier method was used to construct survival and recurrence curves, and survival rates were calculated.Results:The overall survival and recurrence-free survival of patients in the group with recurrence within 6 months were significantly shorter. CA19-9, tumor longitudinal diameter, microvascular invasion, and neural invasion were identified as independent risk factors for recurrence within 6 months after ICC surgery ( P<0.001). Conclusion:The patient population experiencing recurrence within 6 months after ICC surgery has an extremely poor prognosis and possesses a specific tumor microenvironment. CA19-9, tumor longitudinal diameter, microvascular invasion, and neural invasion were identified as independent risk factors for recurrence within 6 months after ICC surgery.

Objective To explore the risk factors and countermeasures of the perfusionist-related near-miss event (NME) in cardiopulmonary bypass (CPB). Methods The clinical data of the patients who underwent cardiac surgery in the Department of Cardiovascular Surgery, Nanfang Hospital, Southern Medical University from March 2020 to July 2021 were retrospectively analyzed. According to whether NME occurred during the operation, the patients were divided into an NME group and a non-NME group. The clinical data of the two groups were compared, and the risk factors for NME were analyzed. Results A total of 702 patients were enrolled, including 424 males and 278 females with a median age of 56.0 years. There were 125 patients in the NME group and 577 patients in the non-NME group. The occurrence rate of NME was 17.81%. Univariate analysis showed that there were statistical differences between the two groups in the gender, body surface area, CPB time, European system for cardiac operative risk evaluation score, emergency surgery, type of surgery, night CPB initiation, modified ultrafiltration use, multi-device control, average operation time, et al. (all P<0.05). The above variables were dimensionality reduction processed by least absolute shrinkage and selection operator regression, and the λ of minimum mean square error of 10-fold cross validation was 0.014. The variables of the corresponding model were selected as follows: multi-device control, night CPB initiation, minimum hematocrit, modified ultrafiltration use, CPB time. The results of multivariate logistic regression showed that night CPB initiation [OR=9.658, 95%CI (4.735. 19.701), P<0.01] and CPB time [OR=1.003, 95%CI (1.001, 1.006), P=0.014] were independent risk factors for NME. Conclusion Night CPB initiation and CPB time are independent risk factors for NME during CPB, which should be recognized and early warned in clinical work.