With the acceleration of global population aging， the assessment and prediction of brain aging have become an important research direction in neuroscience. Brain age， as an indicator for measuring the biological age of the brain， can be used to assess individual cognitive function and predict the risk of neurodegenerative diseases. Neuroimaging techniques can reveal the structure and functional state of the brain， providing an important basis for brain age prediction. The hypoxic environment at high altitudes may accelerate brain aging， and its neuroimaging features provide a unique perspective for assessing brain aging. This article reviews the latest research advances in brain aging and brain age prediction under a high-altitude hypoxia environment， with a focus on the construction of brain age prediction models， the application of sMRI/DTI/fMRI， and the impact of high-altitude hypoxia on brain structure， function， and mechanisms， in order to provide a reference and directions for future research.
Neuroimaging

BACKGROUND:Plate fixation is the mainstream method for the surgical treatment of distal femoral fractures.The intramedullary nailing has the advantages of minimally invasive,such as less soft tissue injury and bone blood supply destruction.At the same time,it is a central fixation and has better biomechanical effect.Therefore,retrograde intramedullary nailing has become another option for the internal fixation of distal femoral fractures.OBJECTIVE:The biomechanical characteristics of new retrograde intramedullary nail on lateral femur condyle,common femoral retrograde intramedullary nail,and lateral femur condyle anatomical locking plate for the treatment of A2-type distal femoral fractures were compared using finite element analysis,and the advantages of new retrograde intramedullary nail on lateral femur condyle was studied.METHODS:A new retrograde intramedullary nail on lateral femur condyle was designed,which was inserted into the bone cortex in front of the insertion point of the lateral collateral ligament of the lateral femoral condyle.A CT scan was performed on the lower limb bone of a male volunteer,and a three-dimensional model of the femur was established.The model was then segmented to create a three-dimensional model of a femoral distal A2-type fracture,The three-dimensional models of small(small group),standard type retrograde intramedullary nail on the lateral femoral condyle(standard group),common retrograde intramedullary needle(common group),and lateral femur condyle anatomical locking plate(plate group)were established respectively.The axial stresses of 600,1 800 N and the torsional load of 4 000,8 000 N·mm were applied to the models,and the displacement and stress of femur and the displacement,stress and shear force of internal fixators were observed in each group.RESULTS AND CONCLUSION:(1)When subjected to axial load of 600 and 1 800 N,the femoral peak displacement,the femoral peak stress,and the peak stress of interal fixation in the standard group were the lowest among the four groups.(2)When subjected to torsional load of 4 000 and 8 000 N·mm,the femoral peak displacement and peak displacement of the internal fixation in the standard group were the lowest among the four groups.(3)Compared with femoral lateral condylar locking plate and common retrograde intramedullary needle,the new retrograde intramedullary needle on lateral femur condyle has mechanical advantages of reducing stress concentration and decreasing the risk of internal fixation failure.

BACKGROUND:Plate fixation is the mainstream method for the surgical treatment of distal femoral fractures.The intramedullary nailing has the advantages of minimally invasive,such as less soft tissue injury and bone blood supply destruction.At the same time,it is a central fixation and has better biomechanical effect.Therefore,retrograde intramedullary nailing has become another option for the internal fixation of distal femoral fractures.OBJECTIVE:The biomechanical characteristics of new retrograde intramedullary nail on lateral femur condyle,common femoral retrograde intramedullary nail,and lateral femur condyle anatomical locking plate for the treatment of A2-type distal femoral fractures were compared using finite element analysis,and the advantages of new retrograde intramedullary nail on lateral femur condyle was studied.METHODS:A new retrograde intramedullary nail on lateral femur condyle was designed,which was inserted into the bone cortex in front of the insertion point of the lateral collateral ligament of the lateral femoral condyle.A CT scan was performed on the lower limb bone of a male volunteer,and a three-dimensional model of the femur was established.The model was then segmented to create a three-dimensional model of a femoral distal A2-type fracture,The three-dimensional models of small(small group),standard type retrograde intramedullary nail on the lateral femoral condyle(standard group),common retrograde intramedullary needle(common group),and lateral femur condyle anatomical locking plate(plate group)were established respectively.The axial stresses of 600,1 800 N and the torsional load of 4 000,8 000 N·mm were applied to the models,and the displacement and stress of femur and the displacement,stress and shear force of internal fixators were observed in each group.RESULTS AND CONCLUSION:(1)When subjected to axial load of 600 and 1 800 N,the femoral peak displacement,the femoral peak stress,and the peak stress of interal fixation in the standard group were the lowest among the four groups.(2)When subjected to torsional load of 4 000 and 8 000 N·mm,the femoral peak displacement and peak displacement of the internal fixation in the standard group were the lowest among the four groups.(3)Compared with femoral lateral condylar locking plate and common retrograde intramedullary needle,the new retrograde intramedullary needle on lateral femur condyle has mechanical advantages of reducing stress concentration and decreasing the risk of internal fixation failure.

To explore the differences in biological gas production in the waterlogged zone of a coal seam fire-affected area, in this study the in-situ gas production experiment was conducted with the mine water from aquitard layers in coal seam fire zones in Xinjiang. The results showed that the biogas production first increased and then decreased with the increase in distance, and the highest gas production reached 216.55 mL. The changes in key metabolic pathways during the anaerobic fermentation of coal were analyzed, which showed that as the distance from the aquitard layer in the coal seam fire zone increased, the methanogenesis pathways gradually shifted from acetic acid decarboxylation and carbon dioxide reduction to acetic acid decarboxylation and methylamine methanogenesis. The significant variability in the in-situ mine water reservoir conditions contributed to the differences. In addition, the reservoir pressure and temperature increased as the distance from the fire zone became longer, and the salinity of the farthest mine water in the reverse fault was the highest due to the lack of groundwater supply. Pearson correlation analysis revealed significant correlations of microbial communities with key functional genes and the types and concentrations of ions. The ions significantly influencing microbial enzymatic metabolic activities included Al³⁺, Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Mg²⁺, PO₄^3-, and Mo⁶⁺. The differences in metabolic pathways were attributed to the integrated effects of a co-occurring environment with multiple ions. The gas production simulation experiments and metagenomic analyses provide data support for the practical application of in-situ biogas experiments, laying a foundation for engineering applications.
Biofuels ; Coal ; Methane/biosynthesis* ; Fires ; Groundwater ; Coal Mining ; Fermentation ; China ; Anaerobiosis

High-altitude headache （HAH） is a type of headache associated with disorder of homoeostasis， and it often appears after ascent to 2 500 m or higher and resolves within 24 hours after descent to below 2 500 m. HAH may occur independently or in association with the onset of acute mountain sickness and chronic mountain sickness. This article describes the clinical features of HAH and discusses the possible pathogenesis， risk factors， preventive measures， treatment， and prognosis of HAH， in order to provide a theoretical basis for further research on HAH.
Headache

Objective To investigate the causal relationship between circadian rhythm disruption and inflammatory bowel disease(IBD)and the mediating effect of gut microbiota based on Mendelian randomization(MR).Methods Summary statistics of Genome-wide Association Study(GWAS)for circadian rhythm disruption(n=205 527)and IBD(n=214 053)were obtained from IEU OpenGWAS database.Summary statistics of GWAS for the gut microbiota were obtained from the MiBioGen database(n=18 340).Two-sample MR analysis was used to estimate the genetic correlation and causality between circadian rhythm disruption and IBD,and the mediating effect of the gut microbiota was analyzed by two-step MR analysis.Results There was a suggestive causal relationship between circadian rhythm disruption and IBD(odds ratio=1.255,P＜0.05).Rikenellaceae id.967 played a mediating role in the causal chain between them(the mediating effect was-0.028 740).Sensitivity analysis confirmed that the results were not interfered by level pleiotropy and heterogeneity.Conclusion There is a genetic correlation between circadian rhythm disruption and IBD,and gut microbiota may play a mediating role between them.

The integration of multi-source data and the establishment of early warning indicator systems constitute pivotal elements for advancing surveillance and early warning capacities in respiratory infectious diseases. Given the multifaceted transmission mechanisms and complex contributing factors inherent in respiratory infectious diseases, surveillance datasets and associated early warning indicators demonstrate notable heterogeneity and sophisticated interrelationships. Furthermore, as surveillance and early warning requirements significantly vary across diverse epidemiological scenarios, accurate assessment of the value and applicability of distinct data types and indicators is imperative. This paper systematically reviews and synthesizes recent advancements in surveillance data and early warning indicators for respiratory infectious diseases, drawing on both domestic and international research. Particular attention is dedicated to analyzing the applicability and efficacy of various data types and indicators within multiple practical contexts, aiming to provide robust theoretical frameworks and methodological guidance to facilitate the development of resilient and efficient surveillance and early warning systems for respiratory infectious diseases.

Objective To compare the biomechanical characteristics of novel retrograde intramedullary nail,common femoral retrograde intramedullary nail,and medial femoral condyle locking plate for treating distal femur type A fractures by finite element analysis,and study the advantages of retrograde intramedullary nail on medial femoral condyle.Methods A novel retrograde intramedullary nail on medial femur condyle was designed.CT scan was performed on lower limb bones of a male volunteer,and a three-dimensional(3D)model of the femur was established.The model was then segmented to create models of distal femur type A2 and A3 fractures.The 3D models of internal fixator were established.The small and standard retrograde intramedullary nail on medial femoral condyle,common femoral retrograde intramedullary nail,locking plate on medial femoral condyle were used for internal fixation on A2 type fracture.A3 type fracture was fixed with one of the above internal fixators combined with lateral condylar plate respectively.The 600 N axial load and 4 N·m torsional load were applied to the models.The displacement and stress of femurs,the displacement and stress of internal fixators,the micro-momentum between the internal fixator and the bone,the relative displacement of the two fracture broken ends were observed in each group.Results Among the A2 and A3 type fractures under axial loads,the correponding standard group and corresponding standard combined group had the smallest peak displacement and peak stress of internal fixation.Among the A2 and A3 type fractures under torsional loads,the correponding standard group and corresponding standard combined group had the smallest peak displacement of the femur and internal fixation.The relative displacement of the two broken ends in the standard combined group was the smallest.Conclusions Compared with femoral medial condylar locking plate and common retrograde intramedullary nail,this novel retrograde intramedullary nail on medial femur condyle has a mechanical advantage of reducing stress concentration and reducing the risk of internal fixation failure,and it can be used alone for distal femur type A2 fracture,or in combination with the lateral condylar plate to fix distal femur type A3 fracture.

Purpose In this study,tract-based spatial statistical analysis was used to analyze the diffusion tensor imaging(DTI)data of breast cancer patients after chemotherapy,to observe the changes of white matter microstructure after chemotherapy and their correlation with neuropsychological cognitive test results,and to provide imaging markers for the evaluation of brain injury after chemotherapy for breast cancer.Materials and Methods A total of 29 patients with breast cancer before chemotherapy treatment and 30 patients with breast cancer after chemotherapy treatment were enrolled in the study from November 2022 to June 2023 in the Affiliated Taizhou People's Hospital of Nanjing Medical University.Neuropsychological cognitive test[Montreal cognitive assessment(MoCA),mini-mental state examination(MMSE)]and whole brain DTI examination were respectively performed in the two groups.Fractional anisotropy(FA)and mean diffusivity(MD)were used to compare the differences between the two groups at the structural level.The correlation between the results of DTI and neuropsychological cognitive test was analyzed.Results Compared with the patients with breast cancer before chemotherapy treatment group,patients with breast cancer after chemotherapy treatment group had decreased FA values in bilateral anterior corona radiata,superior corona radiata,corpus callosum body and genu,left posterior thalamic radiation,left external capsule,bilateral superior longitudinal fasciculus,and increased MD values in bilateral anterior corona radiata,superior corona radiata,right posterior corona radiata,corpus callosum body and genu,right posterior thalamic radiation,bilateral superior longitudinal fasciculus.The FA values of left superior corona radiata(r=0.302)and left external capsule(r=0.370)were positively correlated with MMSE results,and the FA values of left outer capsule(r=0.328)were positively correlated with MoCA results(all P<0.05).The MD values of corpus callosum body(r=-0.343)and genu(r=-0.378),left superior corona radiata(r=-0.311),right posterior corona radiata(r=-0.376),right posterior thalamic radiation(r=-0.341)and right superior longitudinal fasciculus(r=-0.392)were negatively correlated with MMSE results(all P<0.05).Conclusion In the chemotherapy group,FA and MD values in multiple brain regions are abnormal,and there is a certain correlation between FA and MD values in some brain regions and neurocognitive test results.The changes of FA and MD values in different brain areas may be potential imaging markers of the abnormal white matter microstructure in breast cancer patients treated with chemotherapy.