Objective:To investigate the selenium levels in hair, grain, and soil samples collected from residents in typical Keshan disease (KD) endemic and non-endemic areas of Yunnan Province and Inner Mongolia Autonomous Region (referred to as Inner Mongolia), and to provide basic data for evaluating the effectiveness of KD prevention and control strategies.Methods:In 2018, one county with a history of severe KD and one non-endemic county with a similar environment were selected from each of Yunnan Province and Inner Mongolia. Within each county, one natural village was selected as the survey site. Ten soil samples were collected from each village. Ten households were stratified based on their annual per capita income levels of low, medium, and high (3, 4, 3 households, respectively). Three samples of hair and three samples of grain were collected from each household, and selenium level was measured using hydride atomic fluorescence spectrometry.Results:A total of 118 hair samples, 125 grain samples, and 39 soil samples were collected. The selenium levels in the hair of residents from KD endemic areas were significantly lower than those from non-endemic areas within the same province ( P < 0.05), and there was no statistically significant difference in selenium levels in grain and soil ( P > 0.05). The selenium level in the hair of residents in Yunnan Province [0.36 (0.31, 0.41) mg/kg] was higher than that in Inner Mongolia [0.31 (0.25, 0.35) mg/kg, Z = - 3.87, P < 0.001]. The proportion of sufficient hair selenium levels (≥0.30 mg/kg) was 86.7% (52/60) in Yunnan Province and 55.2% (32/58) in Inner Mongolia, with a statistically significant difference (χ 2 = 14.26, P < 0.001). Selenium levels in grain and soil in Yunnan Province were lower than those in Inner Mongolia ( P < 0.001). The proportion of sufficient grain selenium levels (> 0.02 mg/kg) was 5.7% (4/70) in Yunnan Province and 12.7% (7/55) in Inner Mongolia, with a significant difference (χ 2 = 11.88, P = 0.003). The selenium levels in soil in both provinces reached the sufficient level (≥0.20 mg/kg). Conclusions:The selenium levels in the population of KD endemic areas are lower than those in non-endemic regions, and the selenium deficiency among residents in Inner Mongolia is more prominent than in Yunnan Province. The selenium levels in Inner Mongolia's grain and soil are higher than those in Yunnan Province. In the future prevention and control of KD attention should be paid to monitoring the selenium nutrition level of the population in KD areas, especially in Inner Mongolia areas located in the north.

Intracranial aneurysms are a common cerebrovascular disease and the leading cause of subarachnoid hemorrhage.With the development of endovascular interventional techniques,more and more patients are being treated with stents or flow diverter.For this reason,antiplatelet therapy has become a routinely administered drug before and after endovascular interventions.This review intends to summarize the common antiplatelet drug classes,drug mechanisms,platelet function tests and clinical applications.

Paraclinoid aneurysms of the internal carotid artery are common unruptured intracranial aneurysms,which are closely related to the anterior clinoid process,dural ring and optic nerve at the base of the skull,and are classified in various ways.This article reviewed the definition,anatomical structure,and imaging interpretation of paraclinoid aneurysms,with the aim of clearly identifying the relationship between this site of aneurysm and the dural ring,so as to provide reference for optimal treatment plan.

Objective To investigate the differences in clinical characteristics,surgical outcomes,and prognosis between sporadic intracranial hemangioblastoma(IC-HB)and von Hippel-Lindau(VHL)syndrome-associated IC-HB.Methods A retrospective consecutive series of patients who underwent microsurgical resection at the Department of Neurosurgery,Xuanwu Hospital,Capital Medical University,between April 2014 and January 2024,with postoperative pathological confirmation of IC-HB,was included.Clinical and imaging data were collected,including demographics(sex,age),preoperative clinical manifestations(asymptomatic,headache,dizziness,vertigo or imbalance,blurred vision or papilledema,nausea or vomiting,other symptoms),number of symptoms,lesion type(solid or solid-cystic),lesion size(volume,longest diameter,anteroposterior diameter,superoinferior diameter,transverse diameter),lesion location(cerebellar region:hemisphere,vermis;brainstem region:medulla oblongata,fourth ventricle;skull base region:cerebellopontine angle,jugular foramen,petroclival region),Karnofsky performance status(KPS)score(preoperative,postoperative;KPS score＞70 and 70),surgical information,and follow-up data.Based on past medical history,family history,and VHL gene test results,patients were classified into sporadic IC-HB and VHL syndrome-associated IC-HB groups.Differences in clinical characteristics,surgical outcomes,and follow-up status were compared between the groups.Improved outcomes were defined as increases in KPS scores over 0 at 6-month follow-ups in comparison with preoperative KPS,while non-improved outcomes were defined by unchanged or decreased(＞0 point)KPS scores.Survival outcomes,including postoperative recurrence(newly occurring abnormally enhancing nodules at the surgical site or periphery with continuous development during follow-ups.Recurrence could be verified through the combination of imaging enhancement features,clinical manifestations and post-operative pathological examinations),postoperative KPS improvement,and death of any cause during follow-up.The outcomes of postoperative KPS improvement versus non-improvement(unchanged or worsened)were analyzed through univariate analysis with the Firth penalized maximum likelihood Logistic regression model.Variables meeting the criteria(P＜0.05 in univariate analysis,clinical importance,statistical model feasibility)were included in a multivariate Logistic regression model to identify independent factors influencing functional outcomes.Survival outcomes were analyzed using Cox proportional hazards regression models.Kaplan-Meier survival analysis was used to assess recurrence-free survival rates between groups with the Log-rank test.Furthermore,univariate and multivariate Logistic regression analyses were performed separately for the sporadic IC-HB and VHL syndrome-associated IC-HB subgroups to explore independent factors for postoperative KPS improvement.Results A total of 82 IC-HB patients(41 male,41 female),aged 11-73 years(mean[42±15]years),were included.Among which,68 had sporadic IC-HB and 14 had VHL syndrome-associated IC-HB.39 patients had improved postoperative KPS and 43 patients showed no improvements in KPS scores.(1)For clinical characteristics,the age of onset was younger in the VHL syndrome-associated IC-HB group([35±14]years vs.[44±15]years,P=0.044).Lesions in VHL syndrome-associated IC-HB patients were more likely to involve the brainstem and adjacent critical structures(8/14 of which involved medulla oblongata),while sporadic IC-HB was more common in the cerebellar hemispheres(70.6％[48/68]).The distribution of lesion location across cerebellar,skull base,and brainstem regions differed significantly between groups(P=0.015),while other characteristics showed no significant differences(all P＞0.05).(2)For treatment and follow-ups,all patients underwent gross total microsurgical resection.Preoperative angiography via femoral artery was performed in 22 patients,with partial preoperative embolization in 4 patients.Postoperatively,KPS improved in 39 patients,remained unchanged in 33 patients,and worsened in 10 patients.The change in KPS scores pre-to post-operatively did not differ significantly between groups(P=0.707).The recurrence rate was higher in the VHL syndrome-associated IC-HB group(4/14 vs.5.9％[4/68],P=0.026),but there was no significant difference in mortality(P=0.999).(3)For analysis of factors influencing postoperative KPS improvement,univariate Logistic regression showed preoperative asymptomatic(OR,0.05,95％CI0.00-0.39,P=0.002),preoperative dizziness(OR,2.62,95％CI 1.09-6.47,P=0.031),vertigo/imbalance(OR,3.60,95％CI 1.04-15.45,P=0.043),nausea/vomiting(OR,4.49,95％CI 1.65-13.53,P=0.003),preoperative symptoms(OR,2.27,95％CI 1.46-3.86,P＜0.01)and preoperative KPS ≤70(OR,7.65,95％CI 1.60-74.47,P=0.009)were strongly associated with KPS improvement.Multivariate Logistic regression only identified the number of preoperative symptoms as an independent predictor of postoperative KPS improvement(OR,2.44,95％CI 1.04-6.32,P=0.049).(4)For survival outcome analysis,no significant differences in the risk of postoperative recurrence,KPS improvement,or death were observed between the VHL syndrome-associated and sporadic IC-HB patients(recurrence:HR,4.88,95％CI 0.97-24.69,P=0.055;KPS improvement:HR,0.60,95％CI 0.25-1.43,P=0.246;mortality:P=0.999).Kaplan-Meier curves showed no statistically significant difference in recurrence-free survival rate between groups(P=0.053).(5)In the subgroup analysis,in sporadic IC-HB patients,multivariate Logistic regression identified the number of preoperative symptoms as an independent predictor of postoperative KPS improvement(OR,1.97,95％CI 1.14-3.68,P=0.021).Due to the small sample size,reliable parameter estimation was not possible for the VHL syndrome-associated IC-HB subgroup due to the small sample size.Conclusions VHL syndrome-associated IC-HB patients have a higher risk of recurrence in comparison with sporadic IC-HB patients.The number of preoperative symptoms can guide survival ending assessment.

OBJECTIVE:To explore the efficacy of different exercise regimens to reduce fall risks in older adults.METHODS:PubMed,Embase,Web of Science,The Cochrane Library,WanFang,and CNKI were searched for studies about exercise interventions on fall risk in healthy older adult individuals at the age of 60 years and above.The search timeframe should cover from the inception of each database to July 2023.Quality assessment and risk-of-bias were assessed using the Cochrane risk of bias tool.Meta-analysis,subgroup analysis,sensitivity analysis,and publication bias were conducted using Review Manager 5.3 and Stata 16.0.RESULTS:A total of 45 papers containing 54 studies with 3 074 participants were included in the analysis.Overall,exercise intervention can improve the interventional effects on balance(the unipedal stance test with eyes open,functional reach,Timed"Up & Go",and Berg balance scale),lower limb muscle strength(30-second chair-stand test,Five-Times Sit-To-Stand Test,and Short Physical Performance Battery),and fall-efficacy(Falls Efficacy Scale-International),leading to reduced fall risk(P＜0.05).The Meta-analysis results revealed a dosage effect of different exercise regimens to reduce fall risk in the elderly.Mind-body exercise could efficiently increase scores of the unipedal stance test[mean difference(MD)=6.81,95％confidence interval(CI)(2.17,11.44),P＜0.01];resistance exercise could efficiently increase the scores of the Timed"Up & Go"[MD=-3.12,95％CI(-5.72,-0.52),P＜0.05]and the 30-second chair-stand test[MD=1.22,95％CI(0.37,2.08),P＜0.01];and multicomponent physical activity could efficiently increase the scores of functional reach[MD=4.50,95％CI(2.58,6.42),P＜0.01],Berg Balance Scale[MD=1.05,95％CI(0.39,1.71),P＜0.01],Five-Times Sit-To-stand Test[MD=-3.15,95％CI(-4.80,-1.50),P＜0.01],Short Physical Performance Battery[MD=0.55,95％CI(0.37,0.74),P＜0.01],and Falls Efficacy Scale-International[MD=-0.41,95％CI(0.69,-0.13),P＜0.01].Conclusion:Exercise interventions can effectively improve balance,enhance limb strength and functional ability,and reduce fear of falling,and lower the risk of falls in older adults.The components of different intervention programs(such as type of exercise,duration,frequency,and session length)have varying dose-response relationships with the results of fall risk screening tests in older adults.

Objective To investigate the differences in clinical characteristics,surgical outcomes,and prognosis between sporadic intracranial hemangioblastoma(IC-HB)and von Hippel-Lindau(VHL)syndrome-associated IC-HB.Methods A retrospective consecutive series of patients who underwent microsurgical resection at the Department of Neurosurgery,Xuanwu Hospital,Capital Medical University,between April 2014 and January 2024,with postoperative pathological confirmation of IC-HB,was included.Clinical and imaging data were collected,including demographics(sex,age),preoperative clinical manifestations(asymptomatic,headache,dizziness,vertigo or imbalance,blurred vision or papilledema,nausea or vomiting,other symptoms),number of symptoms,lesion type(solid or solid-cystic),lesion size(volume,longest diameter,anteroposterior diameter,superoinferior diameter,transverse diameter),lesion location(cerebellar region:hemisphere,vermis;brainstem region:medulla oblongata,fourth ventricle;skull base region:cerebellopontine angle,jugular foramen,petroclival region),Karnofsky performance status(KPS)score(preoperative,postoperative;KPS score＞70 and 70),surgical information,and follow-up data.Based on past medical history,family history,and VHL gene test results,patients were classified into sporadic IC-HB and VHL syndrome-associated IC-HB groups.Differences in clinical characteristics,surgical outcomes,and follow-up status were compared between the groups.Improved outcomes were defined as increases in KPS scores over 0 at 6-month follow-ups in comparison with preoperative KPS,while non-improved outcomes were defined by unchanged or decreased(＞0 point)KPS scores.Survival outcomes,including postoperative recurrence(newly occurring abnormally enhancing nodules at the surgical site or periphery with continuous development during follow-ups.Recurrence could be verified through the combination of imaging enhancement features,clinical manifestations and post-operative pathological examinations),postoperative KPS improvement,and death of any cause during follow-up.The outcomes of postoperative KPS improvement versus non-improvement(unchanged or worsened)were analyzed through univariate analysis with the Firth penalized maximum likelihood Logistic regression model.Variables meeting the criteria(P＜0.05 in univariate analysis,clinical importance,statistical model feasibility)were included in a multivariate Logistic regression model to identify independent factors influencing functional outcomes.Survival outcomes were analyzed using Cox proportional hazards regression models.Kaplan-Meier survival analysis was used to assess recurrence-free survival rates between groups with the Log-rank test.Furthermore,univariate and multivariate Logistic regression analyses were performed separately for the sporadic IC-HB and VHL syndrome-associated IC-HB subgroups to explore independent factors for postoperative KPS improvement.Results A total of 82 IC-HB patients(41 male,41 female),aged 11-73 years(mean[42±15]years),were included.Among which,68 had sporadic IC-HB and 14 had VHL syndrome-associated IC-HB.39 patients had improved postoperative KPS and 43 patients showed no improvements in KPS scores.(1)For clinical characteristics,the age of onset was younger in the VHL syndrome-associated IC-HB group([35±14]years vs.[44±15]years,P=0.044).Lesions in VHL syndrome-associated IC-HB patients were more likely to involve the brainstem and adjacent critical structures(8/14 of which involved medulla oblongata),while sporadic IC-HB was more common in the cerebellar hemispheres(70.6％[48/68]).The distribution of lesion location across cerebellar,skull base,and brainstem regions differed significantly between groups(P=0.015),while other characteristics showed no significant differences(all P＞0.05).(2)For treatment and follow-ups,all patients underwent gross total microsurgical resection.Preoperative angiography via femoral artery was performed in 22 patients,with partial preoperative embolization in 4 patients.Postoperatively,KPS improved in 39 patients,remained unchanged in 33 patients,and worsened in 10 patients.The change in KPS scores pre-to post-operatively did not differ significantly between groups(P=0.707).The recurrence rate was higher in the VHL syndrome-associated IC-HB group(4/14 vs.5.9％[4/68],P=0.026),but there was no significant difference in mortality(P=0.999).(3)For analysis of factors influencing postoperative KPS improvement,univariate Logistic regression showed preoperative asymptomatic(OR,0.05,95％CI0.00-0.39,P=0.002),preoperative dizziness(OR,2.62,95％CI 1.09-6.47,P=0.031),vertigo/imbalance(OR,3.60,95％CI 1.04-15.45,P=0.043),nausea/vomiting(OR,4.49,95％CI 1.65-13.53,P=0.003),preoperative symptoms(OR,2.27,95％CI 1.46-3.86,P＜0.01)and preoperative KPS ≤70(OR,7.65,95％CI 1.60-74.47,P=0.009)were strongly associated with KPS improvement.Multivariate Logistic regression only identified the number of preoperative symptoms as an independent predictor of postoperative KPS improvement(OR,2.44,95％CI 1.04-6.32,P=0.049).(4)For survival outcome analysis,no significant differences in the risk of postoperative recurrence,KPS improvement,or death were observed between the VHL syndrome-associated and sporadic IC-HB patients(recurrence:HR,4.88,95％CI 0.97-24.69,P=0.055;KPS improvement:HR,0.60,95％CI 0.25-1.43,P=0.246;mortality:P=0.999).Kaplan-Meier curves showed no statistically significant difference in recurrence-free survival rate between groups(P=0.053).(5)In the subgroup analysis,in sporadic IC-HB patients,multivariate Logistic regression identified the number of preoperative symptoms as an independent predictor of postoperative KPS improvement(OR,1.97,95％CI 1.14-3.68,P=0.021).Due to the small sample size,reliable parameter estimation was not possible for the VHL syndrome-associated IC-HB subgroup due to the small sample size.Conclusions VHL syndrome-associated IC-HB patients have a higher risk of recurrence in comparison with sporadic IC-HB patients.The number of preoperative symptoms can guide survival ending assessment.

Objective To develop a three-compartment kinetic fatigue model for the isometric muscle endurance of the hip,knee,and ankle joints at 50％IPT(isometric peak torque),so as to provide a theoretical basis for simulation-based assessments and load evaluations in biomechanics and sports science.Methods The IPT of the hip,knee,and ankle joints was measured in 40 male university students.Isometric endurance tests were then performed on all three joints at 50％IPT until exhaustion.Electromyography data and endurance time(ET)of major lower limb muscles were collected concurrently.The differences between ETs predicted by models based on previously recommended F and R parameters and actual ETs were analyzed.Subsequently,experimental ETs were used in a grid search to optimize Fand R parameters,allowing for the development of an accurate three-compartment kinetic model.Results The ET of the hip and ankle joints was significantly longer than that of the knee joint(P＜0.001).Models using previously recommended Fand R parameters overestimated ET,with significantly higher predicted values than experimentally measured ET(P＜0.001),as well as elevated root mean squared error(RMSE)and mean relatvie error(MRE)values.The grid search successfully identified Fand R parameters for the three-compartment model in isometric endurance tests of lower limb joints,with no statistical difference between model-predicted ET and experimental ET(P＞0.05).Conclusions The developed model in this study can serve as an indirect measurement tool for evaluating load in similar activities.

Cerebral proliferative angiopathy(CPA)was initially regarded as a variant of arteriovenous malformation.However,its distinct histological,angiographic,and pathophysiological features have led to its reclassification as an independent entity.CPA is an exceptionally rare form of cerebral vascular malformation,its pathogenesis is primarily linked to diffuse vascular proliferation secondary to chronic hypoperfusion.Clinically,CPA presents with a heterogeneous spectrum of manifestations,most commonly severe headaches and epileptic seizures.Neuroimaging(MR)typically reveals a complex interplay of aberrant vessels within the brain parenchyma,which may complicate the clinical management and lead to a higher rate of poor prognosis.This article reviewed current knowledge on the pathogenesis,epidemiology,clinical features,diagnostic approaches,and treatment options for CPA,with the aim of enhancing understanding of its underlying mechanisms and guiding future therapeutic strategy optimizations.

BACKGROUND:Surface electromyography has been extensively utilized for monitoring muscle fatigue. However,traditional electromyographic metrics typically focus on individual muscles and fail to assess the variations in a muscle group during the fatigue process. OBJECTIVE:To establish a muscle functional network to extract complex network parameters and investigate the topological property changes of the muscle functional network under different levels of fatigue,aiming to provide theoretical and methodological foundations for fatigue monitoring and prevention. METHODS:Eleven participants performed single-leg leg press exercise at 50％ of one-repetition maximum until exhaustion. Simultaneously,electromyographic signals of seven muscles (rectus femoris,vastus lateralis,vastus medialis,biceps femoris,tibialis anterior,lateral gastrocnemius,and medial gastrocnemius),electrocardiographic signals,and Borg CR-10 scale scores were collected. The Borg CR-10 scale was used to categorize three fatigue stages:mild,moderate,and severe. Heart rate and heart rate variability were calculated to validate the effective division of fatigue stages. Using the coherence of muscle signals,a muscle functional network was constructed with the seven muscles as nodes,and four complex network parameters (clustering coefficient,average weighted degree,global efficiency,and eigenvector centrality) were extracted. Additionally,four electromyographic indices (root mean square,median frequency,instantaneous mean frequency,and co-activation ratio) were extracted and compared under the three levels of fatigue. RESULTS AND CONCLUSION:(1) Differences in heart rate and heart rate variability were observed across three fatigue stages,indicating the effectiveness of fatigue stage delineation. (2) Electromyographic indicators for different muscles under three levels of fatigue:root mean square and co-activation ratio showed no differences;however,median frequency exhibited robust fatigue trends in vastus lateralis,vastus medialis,and biceps femoris,while instantaneous mean frequency demonstrated robust fatigue trends in rectus femoris,vastus lateralis,vastus medialis,and biceps femoris. Instantaneous mean frequency outperformed median frequency and root mean square,yet all three indicators showed robust trends only for the major working muscle groups,unaffected by fatigue factors,unlike the co-activation ratio. (3) The connectivity strength between vastus lateralis and vastus medialis,vastus lateralis and biceps femoris,vastus lateralis and gastrocnemius medialis,and vastus medialis and biceps femoris gradually increased,showing significant differences in average weighted degree,clustering coefficient,and global efficiency post-fatigue,significantly correlated with fatigue levels. To conclude,changes in connectivity strength reflect the synergy and complementarity among muscles during fatigue. Clustering coefficient,average weighted degree,and global efficiency serve as fatigue markers reflecting overall muscle changes.

Objective:To propose a functional method for locating the shoulder joint center of rotation aimed at rapid estimation of the upper limb reachable domain envelope, thereby informing ergonomic design and task optimization.Methods:In March 2024, shoulder kinematics during gait were recorded from ten adults using a three-dimensional motion-capture system. Assuming the existence of a point near the glenohumeral joint that maintains a fixed spatial relationship to the humerus and the acromion, we estimated both static and dynamic centers of rotation. Localization accuracy was quantified by the standard deviation of distance residuals to upper-arm markers. Upper-limb joint angles and anthropometric parameters were modeled via regression; combined with maximal joint ranges of motion, these were used to infer the reachable domain envelope.Results:The static center of rotation was located approximately twenty-two millimeters medial to the acromial landmark in the coronal plane and thirty-seven millimeters inferior to it. The standard deviation of the residuals for the distances from the dynamic shoulder joint center of rotation to upper-arm markers averaged 1.02 mm, which was 47.42% lower than that of the static center of rotation and 66.56% lower than that of the acromion. Moreover, the trajectory of this dynamic center showed a strong correlation with upper-limb joint angles ( R2>0.7) . Conclusion:The proposed method enables rapid and accurate estimation of the upper limb reachable domain envelope to support ergonomic design and may help reduce the risk of work-related musculoskeletal disorders.