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.

Background In the context of global climate change, heatwaves pose an increasing threat to human health. Emergency ambulance calls are an important outcome indicator of acute health response in populations during heatwave weather. However, studies on the association between emergency ambulance calls and heatwaves in China have primarily focused on the southern regions, and less attention is paid to the northern regions, which hinders a comprehensive assessment of acute health impact posed by extreme heat. Objective To quantify the association between heatwaves and emergency ambulance calls in Dezhou City, Shandong Province. Methods The data on daily records of emergency ambulance calls, meteorological factors, and air pollution from May to September of 2020 to 2022 in Dezhou City, Shandong Province were collected. Heatwaves were defined by combining thresholds at the 90th, 92.5th, 95th, and 97.5th percentiles (P₉₀, P_92.5, P₉₅, and P_97.5) of the year-round daily mean temperature and durations of ≥2, 3, or 4 consecutive days, respectively. A generalized additive model with a distributed lag nonlinear model was used to estimate the relative risk of emergency ambulance calls during heatwave days compared with non-heatwave days. Results During the study period, a total of 143393 emergency ambulance calls were analyzed, with 59.75% of individuals aged <65 years, 53.38% male, and 44.94% due to respiratory causes. Compared to non-heatwave periods, all 12 types of defined heatwaves were significantly associated with an increased risk of emergency ambulance calls. The heatwave effect intensified progressively with higher temperature thresholds and longer durations. The cumulative relative risk rose from 1.12 (95%CI: 1.07, 1.17) for the P₉₀_2d type to 1.26 (95%CI: 1.14, 1.40) for the P_97.5_4d type. No significant gender difference was observed in the association between heatwaves and emergency ambulance calls. Regarding age, older adults were more vulnerable, with a relative risk of 1.60 (95%CI: 1.42, 1.81) for the most severe heatwave type P_97.5_4d compared with non-heatwave periods. Among the different causes of calls, the association between respiratory diseases and heatwaves was the most pronounced, with the relative risk increasing from 1.22 (95%CI: 1.15, 1.29) for the mildest heatwave type P₉₀_2d to 1.72 (95%CI: 1.54, 1.93) for the most severe heatwave type P_97.5_4d. Conclusion In Dezhou City, Shandong Province, heatwaves are significantly associated with an increased risk of emergency ambulance calls. The effects of heatwaves on emergency ambulance calls vary by age and disease type, with the elderly and patients with respiratory diseases being more susceptible. These groups should take protective measures.

Aim To achieve efficient loading of doxo-rubicin(doxorubicin,dox)by synthesizing fluorinated nanomaterials,and to study the mechanism of nano-medicine against multidrug resistance in tumors.Methods The physicochemical properties of nano dox(nano-doxorubicin)at different degrees of fluorination(PF4 and PF8)were evaluated through various physi-cochemical parameters,and nano dox formulations were screened out with superior fluorination.The mechanism of nano dox in overcoming multidrug resist-ance in tumors was investigated and in vitro anti-tumor activity was studied through research on cytotoxicity,cellular uptake,apoptosis,and resistance against the P-glycoprotein(P-glycoprotein,P-gp)efflux pump.Results By examining various physicochemical indi-cators,PF8 exhibited superior nano performance in loading doxorubicin compared to PF4.Cytotoxicity ex-periments demonstrated that the IC50 value of nano dox was only 1/40 of free dox,indicating excellent in vitro activity of nano dox in overcoming resistance and inhib-iting cell proliferation.Cell uptake and apoptosis stud-ies indicated that nano dox could effectively enhance the uptake of doxorubicin in MCF-7/ADR cells and successfully enter the cell nucleus,ultimately leading to apoptosis-induced anticancer activity.Studies on drug efflux mediated by P-glycoprotein indicated that nano dox could rapidly enter MCF-7/ADR cells through an efficient cellular uptake pathway,effective-ly bypassing the P-glycoprotein efflux pump.This dual action resulted in increased drug uptake within resistant cells and a reduction in efflux,demonstrating the po-tential of nano doxorubicin to overcome drug resist-ance.Conclusions The design of fluorinated nano dox effectively circumvents the efflux of drug molecules by P-glycoprotein,enhancing drug uptake within re-sistant tumor cells and reducing efflux.This results in an effective strategy in combating multidrug resistance in tumors.

Objective To introduce and enhance an experimental technique for intraventricular drug delivery via an implantable osmotic pump.Methods Eight-week-old male SD rats were selected and the requisite equipment and reagents were prepared.The osmotic pump was assembled and brought to operational status before conducting the implantation surgery.Following anesthesia,the rats underwent skin preparation and the upper surface of the skull was surgically exposed.A point directly above the ventricle was located using a brain stereotaxic apparatus,and a small hole was drilled at that location with a high-speed cranial drill.The pump body was then implanted subcutaneously in the neck and the needle was inserted into the drilled hole,and secured with dental cement.Once solidified,the needle base was removed,the subcutaneous soft tissue and scalp were sutured in layers,and the animal was returned to its cage for rearing in isolation.Results The osmotic pump was successfully implanted subcutaneously in the rat's neck,the needle was securely fixed to the skull,and the catheter interface remained intact.The rats were sacrificed and the brain tissue was removed.Examination of the extracted brain tissue revealed no significant hematoma around the puncture site or needle tract,and the presence of blue dye in the ventricular and adjacent tissues indicated successful drug delivery to the ventricle.Conclusions The introduction of a brain stereotaxic apparatus to aid localization,coupled with enhancements to the operational procedure,may improve the accuracy and safety of the implantation process resulting in a high success rate for intraventricular drug administration.

Urachal carcinoma (UrC)is a rare urological malignancy. UrC is not obvious in its early symptoms, and is mostly in the advanced stage at diagnosis, with a poor prognosis. Surgical treatment was preferred by partial cystectomy + resection of complete umbilical and umbilical urinary catheter ± pelvic lymph node dissection, and more than 90% of UrC were confirmed as adenocarcinoma through postoperative pathology. Systemic treatment is often based on treatment protocols for bladder adenocarcinoma or colorectal adenocarcinoma.This article reviews recent domestic and international research on UrC, summarizing its incidence, clinical characteristics, diagnosis, and treatment.

Objective To explore the clinical significance and antimicrobial resistance of group B Streptococcus(GBS)isolated from midstream urine culture,aiming to provide a basis for the diagnosis and treatment of clinical urinary tract infection(UTI).Methods Information about GBS strains isolated from midstream urine culture of in-patients and outpatient in a hospital in Nanjing from February 2020 to December 2022 were retrieved through labora-tory information system,strains with complete data were screened out.Case data,urine routine,and antimicrobial susceptibility testing results were reviewed.Results A total of 9 081 non-repetitive bacterial strains were detected from midstream urine culture,including 425 GBS strains,accounting for 4.7％,ranking sixth.Strains with incom-plete data were excluded,a total of 365 patients were included in the study.169(46.3％)were males and 196(53.7％)were females,with an average age of(55.4±15.2)years.365 patients who were detected GBS were from 17 de-partments,with the highest proportion being department of urology(n=237,64.9％).The underlying diseases of patients mainly included hypertension(n=136),diabetes(n=95),urolithiasis(n=120)and urinary tumors(n=98).211 patients underwent urological surgery,all were treated with antimicrobial agents before surgery,and 205 patients underwent indwelling urinary catheters after surgery;9 patients were detected GBS from urine during the middle and advanced stage of pregnancy.36.4％(n=133),38.9％(n=142)and 24.7％(n=90)patients had GBS colony count ≤104 CFU/mL,104-105 CFU/mL,and ≥105 CFU/mL,respectively.Patients with symptoms of UTI accounted for 24.9％(n=91),and asymptomatic bacteriuria accounted for 75.1％(n=274).The incidence of UTI symptoms in males was lower than that in females(19.5％vs 29.6％,P＜0.05).As the GBS colony count in urine culture increased,the proportion of patients with symptoms of UTI showed an upward trend(P＜0.05).On the day of urine culture,the positive rates of urine routine white blood cells,leukocyte esterase,and nitrite were 53.2％,50.1％,and 3.8％,respectively.The positive rates of urine occult blood,leukocyte esterase,white blood cells,and urine protein in patients with symptomatic UTI were all higher than those with asymptomatic bacteriuria patients(all P＜0.05).No GBS were found to be resistant to penicillin,ampicillin,vancomycin,linezolid,and tigecycline.The resistance rate to levofloxacin and moxifloxacin was about 40％,and resistance rate to tetracycline and clindamycin was over 60％.Conclusion GBS isolated from urine is more common in non-pregnant adults,and only a small percentage have symptoms of UTI.The results of urine culture and urine routine should be comprehen-sively judged based on patient's clinical symptoms and signs.GBS in urine is susceptible to multiple antimicrobial agents,and clinical medication should be adopted rationally based on antimicrobial susceptibility testing result.

Objective To introduce a partially nested design based on the characteristics of TCM in treating the same disease with different treatments and syndrome differentiation and treatment.Methods Partially nested design was used for standardized treatment of complex interventions.The TCM group was divided into multiple subsets according to"syndrome type-treatment method-prescription"(with nested structure),while the control group was treated with standardized Western medicine(without nested structure);taking a case study of"different treatments for the same disease"data for ulcerative colitis,this design type was applied and analyzed using a multi-level model.Results The partially nested design was consistent with the feature of TCM of"different treatments for the same disease"and met the methodological requirements for evidence-based evaluation.Multilevel models allowed analyses with this type of data.Conclusion The use of partially nested design enables the evaluation of the comprehensive effectiveness of"different treatments for the same disease",which can provide a methodological reference for the assessment of clinical effectiveness of TCM.

Objective:To evaluate the safety and effectiveness of laparoscopic ventral mesh rectopexy (LVMR) +anal sphincter plasty for complete rectal prolapse.Methods:From Jan 1, 2018 to Dec 31, 2022, 45 patients with complete rectal prolapse diagnosed in Beijing Erlong Road Hospital received laparoscopic ventral mesh rectopexy +anal sphincter plasty were included in this study.Result:There was no mortality rate associated with LVMR in this study cohort. The follow-up period was 8-76 months, with a median follow-up period of 59 months. There were 2 cases of recurrence, with a recurrence rate of 4%. Patients with concomitant fecal incontinence symptoms had a preoperative Jorge Wexner fecal incontinence score of 13.8±2.0, and postoperative Jorge Wexner fecal incontinence scores of 7.5±1.5, 5.3±1.3, 4.3±1.1, 2.8±1.0, and 1.8±0.5 at 3, 6, 12, 36, and 60 months, respectively, all P<0.001. Patients with concomitant constipation had a preoperative Wexner constipation score of 15.7 ± 1.5, and a postoperative Wexner constipation score of 9.0±1.8, 6.8±1.5, 5.2±1.4, 4.1±0.7, 2.0±0.0 at 3, 6, 12, 36, and 60 months, respectively, all P<0.001. Conclusions:LVMR +anal Sphincter plasty is safe and effective for the treatment of complete rectal prolapse, and there are few complications related to biological patches. Anal sphincter plasty can effectively improve anal function.

Hydrogen sulfide(H2S)is an emerging endogenous neuromodulator that holds significant potential in the realm of neurological diseases.Its role encompasses reducing neuronal damage,inhibiting excessive activation of striatal astrocytes,and regulating cerebrovascular function,among other physiopathological pathways.Conversely,microRNAs(miRNAs)are widely recognized as pivotal regulators of neurological diseases.They primarily target the 3'untranslated region of the target gene mRNA,impeding mRNA translation and hindering its expression to impart neuroprotective effects.Recent findings have underscored the crucial involvement of H2S and miRNAs in the pathogenesis of various neurological disorders such as Parkinson's disease,stroke,and spinal cord diseases,thereby garnering significant attention.This paper comprehensively summarizes the protective effects arising from the interplay between H2S and miRNAs in neurological diseases,while also delving into the potential therapeutic efficacy they hold for such conditions.

Objective To explore the automated identification and diameter measurement methods for inferior vena cava (IVC) based on clinical ultrasound images of IVC. Methods An automated identification and localization method based on topology and automatic tracking algorithm was proposed. Tracking algorithm was used for identifying and continuously locating to improve the efficiency and accuracy of measurement. Tests were conducted on 18 sets of ultrasound data collected from 18 patients in intensive care unit (ICU),with clinicians' measurements as the gold standard. Results The recognition accuracy of the automated method was 94.44％ (17/18),and the measurement error of IVC diameter was within the range of±1.96s (s was the standard deviation). The automated method could replace the manual method. Conclusion The proposed IVC automated identification and localization algorithm based on topology and automatic tracking algorithm has high recognition success rate and IVC diameter measurement accuracy. It can assist clinicians in identifying and locating IVC,so as to improve the accuracy of IVC measurement.