ObjectiveThe frequency difference limen (FDL) serves as a fundamental metric utilized for effectively quantifying the precise perceptual capabilities of the central auditory system. However, traditional measurement methods rely heavily on the active behavioral responses of subjects and are consequently highly susceptible to the negative influence of confounding subjective factors. Furthermore, existing research paradigms frequently employ uniform stimulus configurations that overlook critical individual perceptual differences. Based on brain-computer interface (BCI) technology, this comprehensive study aims to establish an objective and quantitative evaluation method for auditory frequency discrimination by systematically analyzing and decoding the specific neural responses elicited at the exact threshold state. MethodsWe designed a personalized rapid serial auditory presentation (RSAP) paradigm customized based on each individual’s precise FDL. A cohort of eleven healthy participants was recruited to evaluate the paradigm using pure-tone sequences at a baseline frequency of 4 000 Hz. This experimental paradigm simulates a realistic auditory perception environment through the continuous presentation of acoustic stimuli, thereby allowing for an in-depth investigation into the specific neural representations evoked by weak frequency deviations at the threshold state. Given that auditory stimulus-evoked response features exhibit complex and differentiated spatiotemporal distribution patterns across multiple frequency domains, this study further deeply integrates the cross-scale feature interaction module with the dynamic spatiotemporal attention allocation strategy, innovatively proposing the Multi-Scale Spatial-Temporal Dual Attention Network (MS-STAMNet). Specifically, the network constructs parallel processing branches with multiple receptive fields and introduces a dynamic adaptive weighting strategy to precisely localize core neural activity signals, further deeply integrating multi-scale information through cross-branch feature information interaction to achieve robust single-trial decoding of weak auditory evoked responses. ResultsThe comprehensive electrophysiological data analysis demonstrated that subtle auditory frequency deviation stimuli presented at the threshold level successfully elicited pronounced N2 and P3 event-related potential features, reflecting pre-attentive mismatch detection and subsequent cognitive evaluation, which were prominently distributed over the frontal, central, and temporal regions of the scalp. In the complex time-frequency domain, the extracted neural response characteristics exhibited distinct, statistically significant event-related synchronization within both the low-frequency δ and θ frequency bands, which was simultaneously accompanied by a widespread, prominent event-related desynchronization within the higher α band. A comparative analysis of model performance demonstrated that MS-STAMNet achieved an average unweighted average recall (UAR) of (69.67±6.12)% and area under the curve (AUC) of 0.761 8±0.07, significantly outperforming the established baseline models such as EEGNet and PLNet. Furthermore, a distinct dissociation phenomenon was verified between neural decoding and behavioral performance through regression analysis (R²=0.016, P=0.709), indicating that this model can effectively capture the implicit features of subtle frequency deviations, even when they fail to trigger explicit conscious responses. Additionally, attention weight visualization analysis further reveals the highly accurate focus of the network on key features concentrated over the bilateral temporal and fronto-parietal regions. ConclusionThis study systematically and comprehensively uncovers the multi-dimensional spatiotemporal evolutionary patterns of complex neural responses processing subtle acoustic variations under long-sequence threshold auditory stimulation. Concurrently, it verifies the efficacy and robustness of the proposed MS-STAMNet architecture in accurately deciphering weak, single-trial electroencephalogram signals amidst complex background noise. Ultimately, these neurophysiological and algorithmic findings lay a solid theoretical and methodological foundation for the objective and quantitative evaluation of individual auditory cognitive capabilities in clinical applications, transcending the fundamental limitations of traditional behavioral paradigms and providing robust technical support for future auditory research and related clinical assessments.

Objective To design a search and rescue simulation training system to enhance medical command,search and rescue capabilities of the PLA air force.Method A search and rescue simulation training sysgtem was designed based on the war gaming theory and developed with C/S architecture,C++language and MongoDB database for data storage,which was composed of four subsystems for scenario setting,action coordination and commanding operation simulation.The scenario setting subsystem included 3 modules of map editing setting,scenario editing and organization preparation;the action coordination subsystem had 5 modules of deduction process control,deduction coordination intervention,deduction status monitoring,perspective control and addition of deduction conditions;the commanding operation subsystem involved in 3 modules of command and control,real-time information query and operation command;the operation simulation subsy-stem consisted of 3 modules of agent search,rescue and treatment simulation,operation ruling and operation intelligence management.Results The system developed facilitated search,rescue and commanding training-related teaching and search and rescue program rehearsal verification,and thus comprehensively enhanced the trainee's capabilities in search,rescue,commanding and decision making.Conclusion The system developed integrates effectively medical commanding with operational commanding during search and rescue,providing a novel means for air force search and rescue operations and medical service simulation training.[Chinese Medical Equipment Journal,2025,46(4):15-20]

Objective To propose an EBT3 film technology-based quality control measurement method for the INTRABEAM PRS500 intraoperative radiotherapy equipment to solve the problems of the traditional methods in cumbersome operation and setup error.Methods According to HJ 1198-2021 Requirements of radiation safety and protection for radiotherapy and GBZ 121-2020 Requirements for radiological protection in radiotherapy,the environmental radiation testing of the INTRABEAM PRS500 intraoperative radiotherapy equipment was carried out point by point by means of the radiation inspection instrument.The INTRABEAM PRS500 intraoperative radiotherapy equipment was characterized by a point X-ray source(XRS),and the XRS was detected in terms of the probe linearity,radiation dose,dynamic deviation,isotropy and dose rate.The EBT3 film technology was used to verify the symmetry and isotropy of the XRS planar dose of INTRABEAM PRS500 intraoperative radiotherapy equipment.Results The X-γ dose equivalent rate of each monitoring site of the INTRABEAM PRS500 intraoperative radiotherapy device was lower than the method detection limit(MDL).The results of SQA quality control showed that the INTRABEAM PRS500 intraoperative radiotherapy equipment XRS met the quality control requirements in terms of the probe linearity,radiation dose,dynamic deviation and etc,and the isotropy differences in the+X,-X,+Y,and-Y axis directions ranged from-1.40％to 1.79％,which were all within the allowable range of measurement tolerance(5.60％to 5.65％).The results of measuring the isotropy of the INTRABEAM PRS500 intraoperative radiotherapy equipment based on the EBT3 film technology showed that the dose distribution of the XRS in the directions of the+X,-X,+Y,and-Y axes at the same plane was well isotropic,and that the doses in the directions of the X and Y axes were symmetrically distributed,and that the maximum skewness value for the isotropy of the XRS in the XY plane was-1.581％,which met the requirements of AAPM TG61 report on the reference dosimetry of low-energy and medium-energy X-rays for radiotherapy and radiobiology of≤±5.3％.Conclusion The EBT3 film technology-based measurement method gains high simplicity and feasibility for the isotropy of the INTRABEAM PRS500 intraoperative radiotherapy equipment in the directions of the+X,-X,+Y,and-Y axes at the same planet,which realizes the dynamic monitoring of the dosimetric changes and facilitates the whole-process quality control management of the intraoperative radiotherapy equipment.[Chinese Medical Equipment Journal,2025,46(6):47-53]

Objective To propose an EBT3 film technology-based quality control measurement method for the INTRABEAM PRS500 intraoperative radiotherapy equipment to solve the problems of the traditional methods in cumbersome operation and setup error.Methods According to HJ 1198-2021 Requirements of radiation safety and protection for radiotherapy and GBZ 121-2020 Requirements for radiological protection in radiotherapy,the environmental radiation testing of the INTRABEAM PRS500 intraoperative radiotherapy equipment was carried out point by point by means of the radiation inspection instrument.The INTRABEAM PRS500 intraoperative radiotherapy equipment was characterized by a point X-ray source(XRS),and the XRS was detected in terms of the probe linearity,radiation dose,dynamic deviation,isotropy and dose rate.The EBT3 film technology was used to verify the symmetry and isotropy of the XRS planar dose of INTRABEAM PRS500 intraoperative radiotherapy equipment.Results The X-γ dose equivalent rate of each monitoring site of the INTRABEAM PRS500 intraoperative radiotherapy device was lower than the method detection limit(MDL).The results of SQA quality control showed that the INTRABEAM PRS500 intraoperative radiotherapy equipment XRS met the quality control requirements in terms of the probe linearity,radiation dose,dynamic deviation and etc,and the isotropy differences in the+X,-X,+Y,and-Y axis directions ranged from-1.40％to 1.79％,which were all within the allowable range of measurement tolerance(5.60％to 5.65％).The results of measuring the isotropy of the INTRABEAM PRS500 intraoperative radiotherapy equipment based on the EBT3 film technology showed that the dose distribution of the XRS in the directions of the+X,-X,+Y,and-Y axes at the same plane was well isotropic,and that the doses in the directions of the X and Y axes were symmetrically distributed,and that the maximum skewness value for the isotropy of the XRS in the XY plane was-1.581％,which met the requirements of AAPM TG61 report on the reference dosimetry of low-energy and medium-energy X-rays for radiotherapy and radiobiology of≤±5.3％.Conclusion The EBT3 film technology-based measurement method gains high simplicity and feasibility for the isotropy of the INTRABEAM PRS500 intraoperative radiotherapy equipment in the directions of the+X,-X,+Y,and-Y axes at the same planet,which realizes the dynamic monitoring of the dosimetric changes and facilitates the whole-process quality control management of the intraoperative radiotherapy equipment.[Chinese Medical Equipment Journal,2025,46(6):47-53]

Objective To design a search and rescue simulation training system to enhance medical command,search and rescue capabilities of the PLA air force.Method A search and rescue simulation training sysgtem was designed based on the war gaming theory and developed with C/S architecture,C++language and MongoDB database for data storage,which was composed of four subsystems for scenario setting,action coordination and commanding operation simulation.The scenario setting subsystem included 3 modules of map editing setting,scenario editing and organization preparation;the action coordination subsystem had 5 modules of deduction process control,deduction coordination intervention,deduction status monitoring,perspective control and addition of deduction conditions;the commanding operation subsystem involved in 3 modules of command and control,real-time information query and operation command;the operation simulation subsy-stem consisted of 3 modules of agent search,rescue and treatment simulation,operation ruling and operation intelligence management.Results The system developed facilitated search,rescue and commanding training-related teaching and search and rescue program rehearsal verification,and thus comprehensively enhanced the trainee's capabilities in search,rescue,commanding and decision making.Conclusion The system developed integrates effectively medical commanding with operational commanding during search and rescue,providing a novel means for air force search and rescue operations and medical service simulation training.[Chinese Medical Equipment Journal,2025,46(4):15-20]

Objective To investigate the influence of helical tomographic radiotherapy plans with different combinations of lead gate width,pitch and algorithms on threading effects.Methods A target model was established with a Cheese Phantom used as the simulated human body,then three lead gate widths(1.0,2.5,and 5.0 cm),six screw pitches(0.143,0.172,0.215,0.287,0.430,and 0.500)and two computational grids(Fine algorithm and Normal algorithm)were respectively combined for designing the helical tomography radiotherapy plans.The radiotherapy plans with a pitch of 0.143,0.172,0.215,0.287 or 0.430 were enrolled into an experimental group,and the plans with a pitch of 0.500 were divided into a control group.The dosimetric parameters including maximum dose(Dmax),minimum dose(Dmin)and mean dose(Dmean)of the target area PTV1 and PTV2 were evaluated by the dose volume histogram(DVH).The dose homogeneity index(HI)of the target area was calculated,and the single rotation time and total treatment time of each plan were recorded and counted.SPSS 27.0 software was used for statistical analysis.Results No significant threading effect appeared regardless of the pitch value when the lead gate width was 1.0 cm.The threading effects in the experimental group were weaker than those in the control group when the lead gate width was 2.5 or 5.0 cm.The threading effect gradually rose with the pitch increased when the lead gate width was 5.0 cm.The most significant difference was found between the threading effect in case of the screw pitch being 0.500 and that with the screw pitch being 0.143,with the differenes being statistically obvious(P<0.05).The lead gate width had significant effects on the Dmax,Dmin,Dmean and HI of PTV1 and PTV2.When the lead gate width was 5.0 cm,high HI value and uneven dose distribution were detected and lowered screw pitch weakened the threading effect.The single rotation time first remained constant and then increased with the screw pitch was enlarged,with the changing points occurring in case of the screw pitches of 0.287 and 0.430.With a certain lead gate width,the treatment time for plans was shortened with the decrease of the pitches in case of the pritches lower than 0.287,and tended to be constant after the screw pitches reached 0.287.The changes of the computational grid had no significant effects on the results of radiotherapy plans when the lead gate width and screw pitch were kept constant.Conclusion When designing a spiral tomotherapy plan with conventional doses,a lead gate width of 1.0 or 2.5 cm and a screw pitch of 0.287 or 0.430 should be selected in order to minimize the threading effect while ensuring the efficiency of plan implementation.[Chinese Medical Equipment Journal,2025,46(8):58-66]

Objective To investigate the influence of helical tomographic radiotherapy plans with different combinations of lead gate width,pitch and algorithms on threading effects.Methods A target model was established with a Cheese Phantom used as the simulated human body,then three lead gate widths(1.0,2.5,and 5.0 cm),six screw pitches(0.143,0.172,0.215,0.287,0.430,and 0.500)and two computational grids(Fine algorithm and Normal algorithm)were respectively combined for designing the helical tomography radiotherapy plans.The radiotherapy plans with a pitch of 0.143,0.172,0.215,0.287 or 0.430 were enrolled into an experimental group,and the plans with a pitch of 0.500 were divided into a control group.The dosimetric parameters including maximum dose(Dmax),minimum dose(Dmin)and mean dose(Dmean)of the target area PTV1 and PTV2 were evaluated by the dose volume histogram(DVH).The dose homogeneity index(HI)of the target area was calculated,and the single rotation time and total treatment time of each plan were recorded and counted.SPSS 27.0 software was used for statistical analysis.Results No significant threading effect appeared regardless of the pitch value when the lead gate width was 1.0 cm.The threading effects in the experimental group were weaker than those in the control group when the lead gate width was 2.5 or 5.0 cm.The threading effect gradually rose with the pitch increased when the lead gate width was 5.0 cm.The most significant difference was found between the threading effect in case of the screw pitch being 0.500 and that with the screw pitch being 0.143,with the differenes being statistically obvious(P<0.05).The lead gate width had significant effects on the Dmax,Dmin,Dmean and HI of PTV1 and PTV2.When the lead gate width was 5.0 cm,high HI value and uneven dose distribution were detected and lowered screw pitch weakened the threading effect.The single rotation time first remained constant and then increased with the screw pitch was enlarged,with the changing points occurring in case of the screw pitches of 0.287 and 0.430.With a certain lead gate width,the treatment time for plans was shortened with the decrease of the pitches in case of the pritches lower than 0.287,and tended to be constant after the screw pitches reached 0.287.The changes of the computational grid had no significant effects on the results of radiotherapy plans when the lead gate width and screw pitch were kept constant.Conclusion When designing a spiral tomotherapy plan with conventional doses,a lead gate width of 1.0 or 2.5 cm and a screw pitch of 0.287 or 0.430 should be selected in order to minimize the threading effect while ensuring the efficiency of plan implementation.[Chinese Medical Equipment Journal,2025,46(8):58-66]

Objective To compare the performance and efficacy of prognostic models constructed by different machine learning algorithms in predicting the survival period of lung transplantation (LTx) recipients. Methods Data from 483 recipients who underwent LTx were retrospectively collected. All recipients were divided into a training set and a validation set at a ratio of 7:3. The 24 collected variables were screened based on variable importance (VIMP). Prognostic models were constructed using random survival forest (RSF) and extreme gradient boosting tree (XGBoost). The performance of the models was evaluated using the integrated area under the curve (iAUC) and time-dependent area under the curve (tAUC). Results There were no significant statistical differences in the variables between the training set and the validation set. The top 15 variables ranked by VIMP were used for modeling and the length of stay in the intensive care unit (ICU) was determined as the most important factor. Compared with the XGBoost model, the RSF model demonstrated better performance in predicting the survival period of recipients (iAUC 0.773 vs. 0.723). The RSF model also showed better performance in predicting the 6-month survival period (tAUC _{6 months} 0.884 vs. 0.809, P = 0.009) and 1-year survival period (tAUC _{1 year} 0.896 vs. 0.825, P = 0.013) of recipients. Based on the prediction cut-off values of the two algorithms, LTx recipients were divided into high-risk and low-risk groups. The survival analysis results of both models showed that the survival rate of recipients in the high-risk group was significantly lower than that in the low-risk group (P<0.001). Conclusions Compared with XGBoost, the machine learning prognostic model developed based on the RSF algorithm may preferably predict the survival period of LTx recipients.

The increasing prevalence of aging has led to a rising incidence of comorbidity of sarcopenia and obesity, posing significant burdens on socioeconomic and public health. Current research has systematically explored the pathogenesis of each condition; however, the mechanisms underlying their comorbidity remain unclear. This study reviews the current literature on sarcopenia and obesity in the aging population, focusing on their shared biological mechanisms, which include loss of autophagy, abnormal macrophage function, mitochondrial dysfunction, and reduced sex hormone secretion. It also identifies metabolic mechanisms such as insulin resistance, vitamin D metabolism abnormalities, dysregulation of iron metabolism, decreased levels of nicotinamide adenine dinucleotide, and gut microbiota imbalances. Additionally, this study also explores the important role of genetic factors, such as alleles and microRNAs, in the co-occurrence of sarcopenia and obesity. A better understanding of these mechanisms is vital for developing clinical interventions and preventive strategies.
Humans ; Sarcopenia/physiopathology* ; Obesity/physiopathology* ; Aging/physiology* ; Autophagy/physiology* ; Insulin Resistance ; Comorbidity ; Vitamin D/metabolism* ; Gonadal Steroid Hormones/metabolism* ; Gastrointestinal Microbiome ; Mitochondria ; MicroRNAs

Chrysophanol(Chr)and physcion(Phy)are primary active ingredients of a well-known traditional Chinese medicine namely rhubarb(Chinese name:Dahuang),and their glucuronides have been revealed as the dominant forms presenting in rats after oral administration.Either Chr or Phy has two glycosylation sites,resulting in a pair of positional isomers for glucuronides of either compound(CG1&CG2 and PG1&PG2).To confirmatively identify these glucuronides,energy-resolved mass spectrometry(ER-MS)was used to pursue the fragmentation trajectories of the targeted fragment ions,and the resultant breakdown graphs that were described by the optimal collision energy(OCE)were expected to exhibit the differences of glycosidic bond cleavage between the isomers.Quantum chemical calculation was thereafter conducted to produce the bond dissociation energy(BDE)of the glycosidic bonds.The isomers were unambiguously identified through applying the positive correlation rule between OCE and BDE.Fortunately,the glucuronides of Chr and Phy in vivo were observed through liver microsomes incubationin vitro.ER-MS was utilized to collect the Gaussian-shaped breakdown graphs in response to the neutral loss of 176 Da,and the absolute values of OCE were compared between positional isomers.The results revealed that CG1(-32.31 eV)>CG2(-31.61 eV),and nonetheless,PG1(-30.00 eV)Chr-8-GluA(-48.787 kJ/mol),and nonetheless,Phy-1-GluA(-48.672 kJ/mol)