1.Applications of Brain-heart Interaction in Consciousness State Assessment
Jun-Yi WANG ; Hai-Qing YU ; Qiang-Fan MENG ; Yong-Zhi HUANG ; Min-Peng XU ; Dong MING
Progress in Biochemistry and Biophysics 2026;53(10):2767-2785
Consciousness, which underpins human perception, cognition, and behavioural responses, has long been a major focus of neuroscience and medicine. Alterations in consciousness occur not only during reversible processes such as sleep and anaesthesia, but also in pathological conditions, including disorders of consciousness (DOC) and brain injury. With recent advances in the synchronized acquisition and analysis of multimodal physiological signals, such as electroencephalography (EEG) and electrocardiography (ECG), the dynamic interactions between the heart and brain have become increasingly apparent. A growing body of evidence indicates that heart-brain interactions are closely associated with the maintenance and transition of consciousness states, offering a novel perspective for elucidating their underlying mechanisms and supporting relevant clinical assessments. Current approaches to heart-brain interaction analysis for consciousness-state assessment can be broadly grouped into three categories: ECG-based methods, EEG-based methods, and heart-brain coupling analysis. These approaches characterize heart-brain interactions during changes in consciousness from the complementary perspectives of autonomic regulation, cortical interoceptive processing, and cross-system information transfer, respectively. Nevertheless, this field remains at an early stage. Most studies have focused on a single experimental context or a fixed analytical method, with insufficient systematic consideration of the applicability and limitations of different approaches. Moreover, the mechanisms underlying the emergence and alteration of consciousness remain incompletely understood. Accordingly, this review examines heart-brain interaction methods employed in recent consciousness-state assessment studies in accordance with progressively deeper analytical perspectives, and systematically evaluates the advantages and limitations of these methods across distinct consciousness-related conditions. Heart rate variability (HRV) is one of the classical ECG-based indices used to investigate heart-brain interactions. It refers to fluctuations in consecutive interbeat intervals over a specified time period and is regarded as a physiological measure of autonomic nervous system regulation that may indirectly reflect the strength of heart-brain interactions. Depending on the analytical dimension, HRV analysis is commonly divided into time-domain, frequency-domain, and complexity-index analyses. These approaches characterize autonomic activity in terms of temporal fluctuations, the distribution of frequency components, and nonlinear dynamical properties, respectively. Although extensive research supports their physiological interpretation, they cannot characterize directional interactions from the heart to the brain. Among EEG-based methods for heart-brain interaction analysis, EEG activity directly related to cardiac fluctuations has received particular attention. One of the most widely used measures is the heartbeat-evoked potential (HEP). HEP-based approaches are considered to directly reflect the capacity of the cerebral cortex to process cardiac afferent signals and may be especially advantageous for characterizing rapidly changing consciousness levels, such as those observed during sleep. However, they do not comprehensively capture dynamic bidirectional information exchange between the brain and heart and are susceptible to cardiac artefacts, respiration, and variation in preprocessing procedures. Heart-brain coupling analysis quantifies functional associations between ECG and EEG through cross-system interaction measures, thereby assessing dynamic interactions between the heart and brain. It emphasizes information transfer, feedback regulation, and cross-timescale coordination between the two systems, offering a more comprehensive perspective for investigating changes in consciousness during sleep, anaesthesia, and DOC. However, the neurophysiological mechanisms and physiological interpretation of individual computational indices have not yet been fully established, and the robustness of their results and their potential for clinical generalization require further validation. Finally, this review summarizes the commonalities and differences among the three classes of methods across research domains involving different consciousness states. It further argues that heart-brain interaction research requires deeper investigation at both the mechanistic level of consciousness and the level of clinical application. Current challenges and key issues are identified, and future directions and feasible pathways for heart-brain interaction research are discussed, with the aim of providing new perspectives for researchers in related fields.
2.Distalfemur rotational alignment in knee osteoarthritis patients by three-dimensional computed tomography
Bo YANG ; Xianghui HUANG ; Xianghui DONG ; Hui QIANG ; Shizhang LIU ; Pengzhen LEI ; Ming CHEN
Journal of Xi'an Jiaotong University(Medical Sciences) 2025;46(6):991-995
Objective To explore the gender differences and the influence of varus and valgus deformities on distal femur rotational alignment in patients with knee osteoarthritis so as to provide reference for the distal femur rotational osteotomy in total knee arthroplasty(TKA).Methods CT data of 125 knees with osteoarthritis suitable for TKA(including 56 males and 69 females;78 varus knees and 47 valgus knees)were collected and received three-dimensional imaging reconstruction with Mimics software.We measured the posterior condylar angle(PCA),the angle between the anteroposterior axis and the surgical epicondylar axis(ASA),and the angle between the anteroposterior axis and the posterior condylar axis(APA).We also compared gender differences and the influences of varus-valgus deformities on distal femur rotational alignments.Results The PCA and ASA values of distal femur rotational alignments were(3.5±1.1)° vs.(2.8±1.2)°(P=0.001)and(90.6±3.4)° vs.(91.9±3.5)°(P=0.028)for males and females,with statistically differences between the genders.There was no statistically difference in APA between males and females(P=0.482).The PCA values of distal femur rotational alignment in varus and valgus knees were(3.6±1.1)° and(2.9±1.2)°,with a statistically difference between the two groups(P=0.001).There were no statistically differences in ASA or APA between varus and valgus knees(P>0.05).Conclusion Gender and varus-valgus deformities of knee joint affect the distal femur rotational alignment.Distal femur rotational osteotomy angle should be determined according to the patient's CT imaging before TKA to reduce the errors caused by individual differences and improve the accuracy of the distal femur rotational alignment during TKA.
3.The efficacy and safety of nebulized inhalation of recombinant human interferon α1b in the treatment of pediatric respiratory syncytial viral associated lower respiratory tract infections: a multicenter, randomized, double-blind, placebo-controlled phase Ⅲ clinical study
Xiaohui LIU ; Baoping XU ; Yunxiao SHANG ; Han ZHANG ; Zhenkun ZHANG ; Guangyu LIN ; Ju YIN ; Aihua CUI ; Guocheng ZHANG ; Zhaoling SHI ; Liwei GAO ; Chunming JIANG ; Junmei BIAN ; Yongjian HUANG ; Rongfang ZHANG ; Xiaomei LIU ; Xiaoqing YANG ; Yu TANG ; Lili ZHONG ; Hongmei QIAO ; Chuangli HAO ; Yuqing WANG ; Qubei LI ; Ling CAO ; Yungang YANG ; Ling LU ; Rongjun LIN ; Xingzhen SUN ; Wei ZHOU ; Qiang CHEN ; Jikui DENG ; Yuejie ZHENG ; Lin ZHAO ; Tao AI ; Xiaohong LIU ; Xiaoxia LU ; Ning JIANG ; Ming LI
Chinese Journal of Applied Clinical Pediatrics 2025;40(3):180-186
Objective:To evaluate the efficacy and safety of nebulized inhalation of recombinant human interferon (IFN) α1b injection in the treatment of respiratory syncytial virus (RSV) associated lower respiratory tract infections (pneumonia and bronchiolitis) in children.Methods:A randomized, double-blind, parallel, placebo-controlled add-on design was used.Children with pneumonia or bronchiolitis aged 2 months to 5 years who tested positive for RSV antigen within 72 hours of onset from 30 clinical trial sites including Beijing Children′s Hospital, Capital Medical University between February 2021 and December 2022 were included in this study and randomly divided into 2 groups at a ratio of 1∶1 based on a stratified-block method.Both groups received basic treatments such as cough control, asthma relieving, expectorant treatment, fever reduction, oxygen therapy, etc.The experimental group received additional nebulized inhalation of IFN α1b injection at a dose of 2.0 μg/(kg·time), twice a day.The control group received nebulized inhalation of placebo twice a day.Clinical efficacy was evaluated based on indicators such as the duration of clinical symptoms and signs, and the Kaplan-Meier method was used to calculate the median and 95% CI of the duration of clinical symptoms and signs.The Log-rank test was used to compared data between groups.Safety was assessed through the incidence of adverse reactions and laboratory tests, and the Chi-square test was used to analyze the difference between groups. Results:There were 123 children in the experimental group and 122 children in the control group.The median durations of all the 5 clinical symptoms and signs [including shortness of breath, wheezing, dyspnea (visible retractions), decreased transcutaneous oxygen saturation, and abnormal mental state] in the experimental group after treatment were slightly shortened than those in the control group [2.7 d(95% CI: 1.9-3.0 d)] vs.[2.9 d(95% CI: 2.6-3.6 d), P=0.027].The improvement in dyspnea (retractions) was especially pronounced in the experimental group, with a relief rate of 50.0% (0, 100%) on the first day of administration[compared with 0 (0, 50.0%) in the control group ( Z=2.002, P=0.025)].The median duration of dyspnea in the experimental group was nearly 1 day shorter than that in the control group [1.0 d(95% CI: 0.7-1.7 d) vs.1.8 d(95% CI: 1.0-2.5 d), P=0.046].There were no significant difference in hospital stay [6.0(5.0, 8.0) d vs.6.5(5.0, 8.0) d, Z=0.675, P=0.500], oxygen therapy duration [32.0(14.0, 96.3) h vs.39.0 (24.0, 83.2) h, Z=0.094, P=0.925], the recovery rate from clinical symptoms during treatment [(105/106, 99.1%) vs.(96/101, 95.0%)], and recurrence rate [(0/106, 0) vs.(2/101, 2.0%)] between the 2 groups (all P>0.05).However, the above-mentioned four indicators in the experimental group showed a trend of clinical benefits.The quantitative virus detection results showed that the RSV viral load in both groups decreased after treatment compared to before treatment.After 2 days of treatment, the decline rate of RSV viral load from the baseline was 0.90 lg copies/(mL·d) in the experimental group and 0.25 lg copies/(mL·d)in the control group, with a statistically significant difference ( P<0.05).Furthermore, there was no statistically significant difference in the incidence of adverse reactions between the 2 groups ( P>0.05).Importantly, no drug-related serious adverse reactions occurred in both groups. Conclusions:The nebulized inhalation therapy of IFN α1b demonstrates efficacy and safety in treating pediatric RSV associated lower respiratory tract infections.It particularly offers outstanding clinical therapeutic value for severe children.
4.Association of higher serum follicle-stimulating hormone levels with successful microdissection testicular sperm extraction outcomes in nonobstructive azoospermic men with reduced testicular volumes.
Ming-Zhe SONG ; Li-Jun YE ; Wei-Qiang XIAO ; Wen-Si HUANG ; Wu-Biao WEN ; Shun DAI ; Li-Yun LAI ; Yue-Qin PENG ; Tong-Hua WU ; Qing SUN ; Yong ZENG ; Jing CAI
Asian Journal of Andrology 2025;27(3):440-446
To investigate the impact of preoperative serum follicle-stimulating hormone (FSH) levels on the probability of testicular sperm retrieval, we conducted a study of nonobstructive azoospermic (NOA) men with different testicular volumes (TVs) who underwent microdissection testicular sperm extraction (micro-TESE). A total of 177 NOA patients undergoing micro-TESE for the first time from April 2019 to November 2022 in Shenzhen Zhongshan Obstetrics and Gynecology Hospital (formerly Shenzhen Zhongshan Urology Hospital, Shenzhen, China) were retrospectively reviewed. The subjects were divided into four groups based on average TV quartiles. Serum hormone levels in each TV group were compared between positive and negative sperm retrieval subgroups. Overall sperm retrieval rate was 57.6%. FSH levels (median [interquartile range]) were higher in the positive sperm retrieval subgroup compared with the negative outcome subgroup when average TV was <5 ml (first quartile [Q1: TV <3 ml]: 43.32 [17.92] IU l -1 vs 32.95 [18.56] IU l -1 , P = 0.048; second quartile [Q2: 3 ml ≤ TV <5 ml]: 31.31 [15.37] IU l -1 vs 25.59 [18.40] IU l -1 , P = 0.042). Elevated serum FSH levels were associated with successful micro-TESE sperm retrieval in NOA men whose average TVs were <5 ml (adjusted odds ratio [OR]: 1.06 per unit increase; 95% confidence interval [CI]: 1.01-1.11; P = 0.011). In men with TVs ≥5 ml, larger TVs were associated with lower odds of sperm retrieval (adjusted OR: 0.84 per 1 ml increase; 95% CI: 0.71-0.98; P = 0.029). In conclusion, elevated serum FSH levels were associated with positive sperm retrieval in micro-TESE in NOA men with TVs <5 ml. In men with TV ≥5 ml, increases in average TVs were associated with lower odds of sperm retrieval.
Humans
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Male
;
Azoospermia/surgery*
;
Sperm Retrieval/statistics & numerical data*
;
Adult
;
Follicle Stimulating Hormone/blood*
;
Retrospective Studies
;
Testis/pathology*
;
Microdissection
;
Organ Size
5.Domestication progress of endangered Chinese medicinal material Fritillariae Cirrhosae Bulbus.
Ting XIAO ; Ming-Hao YANG ; Qiu-Ling WANG ; Qiang LYU ; Yu-Qing ZHENG ; Lian-Cheng XU ; Ma YU ; Jian-He WEI
China Journal of Chinese Materia Medica 2025;50(16):4483-4489
Fritillariae Cirrhosae Bulbus is the dried bulb of perennial herbaceous plants in the Fritillaria genus(Liliaceae family) and is a representative traditional Chinese medicinal material with distinctive regional characteristics. Clinically, it is widely used in the treatment of dry cough, bronchial asthma, and other respiratory diseases, possessing significant medicinal and economic value and being highly esteemed in TCM. Currently, Fritillariae Cirrhosae Bulbus primarily relies on wild harvesting. However, due to excessive collection, its wild resources have drastically declined, and all source species have been classified as category Ⅱ in the List of National Key Protected Wild Plants, exacerbating the supply-demand imbalance in the market. To mitigate this issue, large-scale cultivation through the domestication of wild Fritillariae Cirrhosae Bulbus has become an inevitable trend. However, its strict environmental requirements, low propagation efficiency, high seedling mortality, and immature cultivation techniques have severely hindered industrialization. This study investigates the domestication process of Fritillariae Cirrhosae Bulbus, focusing on seed propagation, seedling cultivation, and medicinal material production. It also reviews the species and distribution of wild resources, their endangered status, market supply-demand dynamics, and the historical and current development of domestication. The findings indicate that enhancing propagation efficiency, optimizing cultivation models, and distinguishing between seed propagation and medicinal material production are key measures to accelerate the industrialization of domesticated Fritillariae Cirrhosae Bulbus. This research aims to promote the industrialization of Fritillariae Cirrhosae Bulbus domestication and provide a reference model for the conservation and sustainable utilization of rare and endangered medicinal plant resources.
Fritillaria/chemistry*
;
Endangered Species
;
Plants, Medicinal/growth & development*
;
Drugs, Chinese Herbal/economics*
;
China
6.Research on low-dose CT image denoising method based on improved Corediff model
Li-mei SONG ; Hang WU ; Yi-feng HUANG ; Qiang WANG ; Guan-jun LIU ; Feng CHEN ; Ming YU ; Jian-kun SHEN
Chinese Medical Equipment Journal 2025;46(5):9-13
Objective To propose a low-dose CT image denoising method based on an improved Corediff model to recover the detailed features of the image and enhance the image quality.Methods An RS-Corediff model was established by modifying the key component U-Net network of the Corediff model.Firstly,the residual module was introduced in the network input stage for feature extraction;secondly,a new downsampling module was designed in the U-Net network encoder,which learned the semantic information of the feature map by convolution and maintained the learning state during the downsampling process so as to fully extract the image features;thirdly,the feature splicing processing was used to further enhance the learning effect during the upsampling process of the U-Net network decoder;finally,the convolutional kernel size was modified to adjust the sensory field during the convolutional process of the whole U-Net network structure so as to obtain rich features.The RS-Corediff model was compared with the residual encoder-decoder convolutional neural network(RED-CNN)model and the Corediff model on the public dataset AAPM 2016 in order to verify its effectiveness for low-dose CT image denoising.Results The RS-Corediff model gained advantages over the RED-CNN and Corediff models with a peak signal-to-noise ratio(PSNR)of 41.269 8,structural similarity(SSIM)of 0.953 4 and root mean square error(RMSE)of 17.568 7.Conclusion The proposed method effectively preserves the texture and details of low-dose CT images during the denoising process to improve the overall quality of the images.[Chinese Medical Equipment Journal,2025,46(5):9-13]
7.Distalfemur rotational alignment in knee osteoarthritis patients by three-dimensional computed tomography
Bo YANG ; Xianghui HUANG ; Xianghui DONG ; Hui QIANG ; Shizhang LIU ; Pengzhen LEI ; Ming CHEN
Journal of Xi'an Jiaotong University(Medical Sciences) 2025;46(6):991-995
Objective To explore the gender differences and the influence of varus and valgus deformities on distal femur rotational alignment in patients with knee osteoarthritis so as to provide reference for the distal femur rotational osteotomy in total knee arthroplasty(TKA).Methods CT data of 125 knees with osteoarthritis suitable for TKA(including 56 males and 69 females;78 varus knees and 47 valgus knees)were collected and received three-dimensional imaging reconstruction with Mimics software.We measured the posterior condylar angle(PCA),the angle between the anteroposterior axis and the surgical epicondylar axis(ASA),and the angle between the anteroposterior axis and the posterior condylar axis(APA).We also compared gender differences and the influences of varus-valgus deformities on distal femur rotational alignments.Results The PCA and ASA values of distal femur rotational alignments were(3.5±1.1)° vs.(2.8±1.2)°(P=0.001)and(90.6±3.4)° vs.(91.9±3.5)°(P=0.028)for males and females,with statistically differences between the genders.There was no statistically difference in APA between males and females(P=0.482).The PCA values of distal femur rotational alignment in varus and valgus knees were(3.6±1.1)° and(2.9±1.2)°,with a statistically difference between the two groups(P=0.001).There were no statistically differences in ASA or APA between varus and valgus knees(P>0.05).Conclusion Gender and varus-valgus deformities of knee joint affect the distal femur rotational alignment.Distal femur rotational osteotomy angle should be determined according to the patient's CT imaging before TKA to reduce the errors caused by individual differences and improve the accuracy of the distal femur rotational alignment during TKA.
8.The efficacy and safety of nebulized inhalation of recombinant human interferon α1b in the treatment of pediatric respiratory syncytial viral associated lower respiratory tract infections: a multicenter, randomized, double-blind, placebo-controlled phase Ⅲ clinical study
Xiaohui LIU ; Baoping XU ; Yunxiao SHANG ; Han ZHANG ; Zhenkun ZHANG ; Guangyu LIN ; Ju YIN ; Aihua CUI ; Guocheng ZHANG ; Zhaoling SHI ; Liwei GAO ; Chunming JIANG ; Junmei BIAN ; Yongjian HUANG ; Rongfang ZHANG ; Xiaomei LIU ; Xiaoqing YANG ; Yu TANG ; Lili ZHONG ; Hongmei QIAO ; Chuangli HAO ; Yuqing WANG ; Qubei LI ; Ling CAO ; Yungang YANG ; Ling LU ; Rongjun LIN ; Xingzhen SUN ; Wei ZHOU ; Qiang CHEN ; Jikui DENG ; Yuejie ZHENG ; Lin ZHAO ; Tao AI ; Xiaohong LIU ; Xiaoxia LU ; Ning JIANG ; Ming LI
Chinese Journal of Applied Clinical Pediatrics 2025;40(3):180-186
Objective:To evaluate the efficacy and safety of nebulized inhalation of recombinant human interferon (IFN) α1b injection in the treatment of respiratory syncytial virus (RSV) associated lower respiratory tract infections (pneumonia and bronchiolitis) in children.Methods:A randomized, double-blind, parallel, placebo-controlled add-on design was used.Children with pneumonia or bronchiolitis aged 2 months to 5 years who tested positive for RSV antigen within 72 hours of onset from 30 clinical trial sites including Beijing Children′s Hospital, Capital Medical University between February 2021 and December 2022 were included in this study and randomly divided into 2 groups at a ratio of 1∶1 based on a stratified-block method.Both groups received basic treatments such as cough control, asthma relieving, expectorant treatment, fever reduction, oxygen therapy, etc.The experimental group received additional nebulized inhalation of IFN α1b injection at a dose of 2.0 μg/(kg·time), twice a day.The control group received nebulized inhalation of placebo twice a day.Clinical efficacy was evaluated based on indicators such as the duration of clinical symptoms and signs, and the Kaplan-Meier method was used to calculate the median and 95% CI of the duration of clinical symptoms and signs.The Log-rank test was used to compared data between groups.Safety was assessed through the incidence of adverse reactions and laboratory tests, and the Chi-square test was used to analyze the difference between groups. Results:There were 123 children in the experimental group and 122 children in the control group.The median durations of all the 5 clinical symptoms and signs [including shortness of breath, wheezing, dyspnea (visible retractions), decreased transcutaneous oxygen saturation, and abnormal mental state] in the experimental group after treatment were slightly shortened than those in the control group [2.7 d(95% CI: 1.9-3.0 d)] vs.[2.9 d(95% CI: 2.6-3.6 d), P=0.027].The improvement in dyspnea (retractions) was especially pronounced in the experimental group, with a relief rate of 50.0% (0, 100%) on the first day of administration[compared with 0 (0, 50.0%) in the control group ( Z=2.002, P=0.025)].The median duration of dyspnea in the experimental group was nearly 1 day shorter than that in the control group [1.0 d(95% CI: 0.7-1.7 d) vs.1.8 d(95% CI: 1.0-2.5 d), P=0.046].There were no significant difference in hospital stay [6.0(5.0, 8.0) d vs.6.5(5.0, 8.0) d, Z=0.675, P=0.500], oxygen therapy duration [32.0(14.0, 96.3) h vs.39.0 (24.0, 83.2) h, Z=0.094, P=0.925], the recovery rate from clinical symptoms during treatment [(105/106, 99.1%) vs.(96/101, 95.0%)], and recurrence rate [(0/106, 0) vs.(2/101, 2.0%)] between the 2 groups (all P>0.05).However, the above-mentioned four indicators in the experimental group showed a trend of clinical benefits.The quantitative virus detection results showed that the RSV viral load in both groups decreased after treatment compared to before treatment.After 2 days of treatment, the decline rate of RSV viral load from the baseline was 0.90 lg copies/(mL·d) in the experimental group and 0.25 lg copies/(mL·d)in the control group, with a statistically significant difference ( P<0.05).Furthermore, there was no statistically significant difference in the incidence of adverse reactions between the 2 groups ( P>0.05).Importantly, no drug-related serious adverse reactions occurred in both groups. Conclusions:The nebulized inhalation therapy of IFN α1b demonstrates efficacy and safety in treating pediatric RSV associated lower respiratory tract infections.It particularly offers outstanding clinical therapeutic value for severe children.
9.Research on low-dose CT image denoising method based on improved Corediff model
Li-mei SONG ; Hang WU ; Yi-feng HUANG ; Qiang WANG ; Guan-jun LIU ; Feng CHEN ; Ming YU ; Jian-kun SHEN
Chinese Medical Equipment Journal 2025;46(5):9-13
Objective To propose a low-dose CT image denoising method based on an improved Corediff model to recover the detailed features of the image and enhance the image quality.Methods An RS-Corediff model was established by modifying the key component U-Net network of the Corediff model.Firstly,the residual module was introduced in the network input stage for feature extraction;secondly,a new downsampling module was designed in the U-Net network encoder,which learned the semantic information of the feature map by convolution and maintained the learning state during the downsampling process so as to fully extract the image features;thirdly,the feature splicing processing was used to further enhance the learning effect during the upsampling process of the U-Net network decoder;finally,the convolutional kernel size was modified to adjust the sensory field during the convolutional process of the whole U-Net network structure so as to obtain rich features.The RS-Corediff model was compared with the residual encoder-decoder convolutional neural network(RED-CNN)model and the Corediff model on the public dataset AAPM 2016 in order to verify its effectiveness for low-dose CT image denoising.Results The RS-Corediff model gained advantages over the RED-CNN and Corediff models with a peak signal-to-noise ratio(PSNR)of 41.269 8,structural similarity(SSIM)of 0.953 4 and root mean square error(RMSE)of 17.568 7.Conclusion The proposed method effectively preserves the texture and details of low-dose CT images during the denoising process to improve the overall quality of the images.[Chinese Medical Equipment Journal,2025,46(5):9-13]
10.On-line Measurement of Styrene Secondary Organic Aerosol Using Synchrotron Radiation Vacuum Ultraviolet Photoionization Aerosol Mass Spectrometer
Ming-Qiang HUANG ; Xiao-Bin SHAN ; Liu-Si SHENG ; Zhen-Ya WANG ; Chang-Jin HU ; Xue-Jun GU ; Wei-Jun ZHANG
Chinese Journal of Analytical Chemistry 2024;52(8):1200-1210
Secondary organic aerosol(SOA)produced by photooxidation of styrene and other aromatic compounds is a major part of fine particles in urban atmosphere.In this study,the measurement of component and content of SOA formed from photooxidation of styrene in smog chamber using synchronous radiation vacuum-ultraviolet photoionization aerosol mass spectrometer(VUV-PIAMS)was conducted.Photoionization mass spectra of styrene SOA was detected by synchrotron radiation photon with 10.5 eV,and the proportion of main components was quantified based on the peak area of each ion peak.The photoionization efficiency curve of ion peak was obtained under synchrotron radiation photons in the range from 7.5 to 11.5 eV,and then the ionization potential was acquired for qualitative analysis of the component structure.The results showed that the photoionization mass spectra of styrene SOA mainly contained ion peaks at m/z 106,108,120 and 122,and the ionization potentials of each peak were(9.41±0.03)eV,(8.93±0.03)eV,(9.24±0.03)eV and(9.25±0.03)eV,respectively.Combined with quantum chemistry calculation and off-line measurement verification of infrared absorption spectra and electrospray ionization mass spectra,it was determined that benzaldehyde,benzyl alcohol,4-vinylphenol and benzoic acid were main components of styrene SOA,accounting for 32.5%,17.5%,25%and 15%of the measured components,respectively,and the generated quantity ratio was 13∶7∶10∶6.VUV-PIAMS could overcome the disadvantages of off-line method,and could on-line detect component and content of SOA,proving a useful tool to measure the chemical components and reveal the formation process of SOA particles.

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