1.Construction and Practice Evaluation of an Integrated Traditional Chinese and Western Medicine Postoperative Rehabilitation Teaching Model Supported by MedOncoGPT
Can BAI ; Zi-Jian WU ; Xian-Jun HAN ; Yuan GAO ; Yong TANG
Progress in Biochemistry and Biophysics 2026;53(5):1264-1278
ObjectiveTo enhance teaching in postoperative cancer rehabilitation, this study developed an integrative Chinese-Western medicine postoperative oncology rehabilitation system, termed the medical oncology generative pre-trained transformer (MedOncoGPT). By introducing MedOncoGPT as an intelligent assistant, an integrated teaching model combining Chinese and Western medicine was established. The study evaluated its impact on students’ integrative clinical reasoning and practical abilities, providing support for instructional reform in related courses. MethodsUsing teaching resources as the knowledge base, MedOncoGPT was built upon the open-source ChatGLM model and incorporated Low-Rank Adaptation (LoRA) fine-tuning and retrieval-augmented generation (RAG) techniques to address postoperative integrative oncology scenarios. The system was applied in courses and clinical clerkships related to integrative oncology. In alignment with course objectives, a five-stage instructional process—pre-class preparation, in-class inquiry, simulated multidisciplinary consultation, clinical reinforcement, and teaching reflection—was designed to guide students in completing syndrome differentiation, comprehensive assessment, and follow-up planning within real or simulated case contexts. Comparative analyses of student engagement, syndrome differentiation thinking, evidence-based awareness, and interdisciplinary integration skills before and after the teaching reform were conducted using questionnaires, course assessments, classroom observations, and semi-structured interviews. ResultsFollowing the implementation of MedOncoGPT, students demonstrated improved performance in case analysis, prescription formulation, and integrative Chinese-Western medical evaluation compared with those receiving traditional instruction. Classroom participation and the relevance of student inquiries also increased. Self-assessment results indicated high levels of satisfaction with respect to clarity of integrative clinical reasoning, ability to retrieve and apply guideline-based evidence, and awareness of appropriate use of intelligent tools in clinical decision-making. More than 92% of students reported that the system facilitated understanding of abstract theoretical concepts presented in textbooks. Instructors noted that the system helped reduce lesson preparation time, enriched typical case materials and discussion scenarios, and promoted the translation of research findings into classroom teaching. Pilot data showed that, with MedOncoGPT assistance, the mean time for initial syndrome differentiation decreased from 18.4 min to 12.1 min, and the agreement rate increased from 68.3% to 82.5%. In the teaching pilot, the experimental group achieved a higher mean score on the final case analysis assessment than the control group (82.6 vs. 74.3). ConclusionThe integration of MedOncoGPT into teaching on postoperative integrative cancer rehabilitation enabled the establishment of a stable instructional process within existing curricula and enhanced students’ integrative clinical reasoning and evidence-based practice capabilities. The approach demonstrates positive potential for advancing the integration of research, clinical practice, and education and represents a valuable exploratory strategy for instructional reform in courses on integrative Chinese-Western medicine.
2.Efficacy Analysis of RCT of Arsenic-containing TCM Compound in Treatment of Myelodysplastic Syndrome Based on MMRM and Win Ratio
Daxiang SUN ; Peizhen JIANG ; Haixia DI ; Bing WU ; Qifeng LIU ; Jian LIU ; Jiahe LIANG ; Xudong TANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(7):251-259
ObjectiveThis paper aims to conduct a secondary analysis of a randomized controlled trial on the treatment of myelodysplastic syndrome (MDS) with deficiency of both the spleen and kidney and blockage of toxin and blood stasis with an arsenic-containing traditional Chinese medicine compound, by applying the mixed model for repeated measure (MMRM) and the method of stratified composite outcome with win ratio. The analysis includes the assessment of hematological efficacy and the composite outcome evaluation of adverse reactions, so as to more comprehensively assess the therapy of this regimen. MethodsThe MMRM and win ratio methods were used to evaluate the efficacy of a prospective,multi-center,double-blind,randomized controlled study. The blood routine (hemoglobin concentration,neutrophil count, and platelet count) and biochemical indexes (aspartate aminotransferase,alanine aminotransferase,serum creatinine,and serum ferritin) of the patients were detected at the time of enrollment and at the end of each course of treatment in the laboratory department of Xiyuan Hospital. The patients' syndromes at the time of enrollment and after treatment were recorded and scored according to the therapy standard of traditional Chinese medicine for diseases and syndromes. MMRM was used to analyze the blood routine indexes of the experimental group and the control group. This method has the advantages of high data reliability and dynamic efficacy under intervention and time. The win ratio method was used to evaluate the composite outcome of traditional Chinese medicine syndrome scores and biochemical indexes according to the priority and to verify the clinical safety of arsenic-containing traditional Chinese medicine compound. ResultsThe results of MMRM analysis showed that the hemoglobin concentration of patients in the group with arsenic-containing traditional Chinese medicine compound increased significantly compared with that before treatment in the group,while that in the placebo group decreased significantly (P<0.01). When compared with that after treatment in the placebo group,the hemoglobin concentration of patients in the group with arsenic-containing traditional Chinese medicine compound increased significantly,and the mean difference of least squares (LS) was statistically significant (P<0.01). When compared with those before treatment in the group,there were no statistically significant differences in the neutrophil count and platelet count in both groups. After treatment,there were no statistically significant differences in the neutrophil count, platelet count, and the mean difference of LS between the two groups. The analysis results of win ratio showed that the group with arsenic-containing traditional Chinese medicine compound had a significant advantage in the comparison of composite outcomes,with a win ratio (95% CI) of 2.01 (1.24-3.27) (P<0.01),and that the possibility of "winning" in terms of safety was 2.01 times that of the placebo group. The safety advantage of the group with arsenic-containing traditional Chinese medicine compound mainly came from the traditional Chinese medicine syndrome scores,renal function indexes, and iron reserve capacity indexes,and the number of winning times was less than that of losing times in the comparison of liver function outcomes. ConclusionThe MMRM analysis proves that the arsenic-containing traditional Chinese medicine compound can significantly improve the hemoglobin concentration of patients with myelodysplastic syndrome with refractory cytopenia and multilineage dysplasia (MDS-RCMD) of the type of deficiency of both the spleen and kidney and blockage of toxin and blood stasis. This conclusion is not interfered with by time trends and individual relationships and methodologically improves the credibility of the therapy of the arsenic-containing traditional Chinese medicine compound in treating MDS. Four outcomes are evaluated by the win ratio method,namely traditional Chinese medicine syndromes,liver function,renal function, and iron reserve capacity,proving that the arsenic-containing traditional Chinese medicine compound has the comprehensive advantages of improving the survival quality of the patients and reducing adverse reactions. The win ratio outcome provides clear comparative indexes for the evaluation of adverse reactions,making it easier for regulatory authorities,medical staff, and patients to understand the safety of the arsenic-containing traditional Chinese medicine compound in clinical application.
3.Construction and Practice Evaluation of an Integrated Traditional Chinese and Western Medicine Postoperative Rehabilitation Teaching Model Supported by MedOncoGPT
Can BAI ; Zi-Jian WU ; Xian-Jun HAN ; Yuan GAO ; Yong TANG
Progress in Biochemistry and Biophysics 2026;53(5):1264-1278
ObjectiveTo enhance teaching in postoperative cancer rehabilitation, this study developed an integrative Chinese-Western medicine postoperative oncology rehabilitation system, termed the medical oncology generative pre-trained transformer (MedOncoGPT). By introducing MedOncoGPT as an intelligent assistant, an integrated teaching model combining Chinese and Western medicine was established. The study evaluated its impact on students’ integrative clinical reasoning and practical abilities, providing support for instructional reform in related courses. MethodsUsing teaching resources as the knowledge base, MedOncoGPT was built upon the open-source ChatGLM model and incorporated Low-Rank Adaptation (LoRA) fine-tuning and retrieval-augmented generation (RAG) techniques to address postoperative integrative oncology scenarios. The system was applied in courses and clinical clerkships related to integrative oncology. In alignment with course objectives, a five-stage instructional process—pre-class preparation, in-class inquiry, simulated multidisciplinary consultation, clinical reinforcement, and teaching reflection—was designed to guide students in completing syndrome differentiation, comprehensive assessment, and follow-up planning within real or simulated case contexts. Comparative analyses of student engagement, syndrome differentiation thinking, evidence-based awareness, and interdisciplinary integration skills before and after the teaching reform were conducted using questionnaires, course assessments, classroom observations, and semi-structured interviews. ResultsFollowing the implementation of MedOncoGPT, students demonstrated improved performance in case analysis, prescription formulation, and integrative Chinese-Western medical evaluation compared with those receiving traditional instruction. Classroom participation and the relevance of student inquiries also increased. Self-assessment results indicated high levels of satisfaction with respect to clarity of integrative clinical reasoning, ability to retrieve and apply guideline-based evidence, and awareness of appropriate use of intelligent tools in clinical decision-making. More than 92% of students reported that the system facilitated understanding of abstract theoretical concepts presented in textbooks. Instructors noted that the system helped reduce lesson preparation time, enriched typical case materials and discussion scenarios, and promoted the translation of research findings into classroom teaching. Pilot data showed that, with MedOncoGPT assistance, the mean time for initial syndrome differentiation decreased from 18.4 min to 12.1 min, and the agreement rate increased from 68.3% to 82.5%. In the teaching pilot, the experimental group achieved a higher mean score on the final case analysis assessment than the control group (82.6 vs. 74.3). ConclusionThe integration of MedOncoGPT into teaching on postoperative integrative cancer rehabilitation enabled the establishment of a stable instructional process within existing curricula and enhanced students’ integrative clinical reasoning and evidence-based practice capabilities. The approach demonstrates positive potential for advancing the integration of research, clinical practice, and education and represents a valuable exploratory strategy for instructional reform in courses on integrative Chinese-Western medicine.
4.Effect of preoperative intestinal prehabilitation on the recovery of delayed postoperative ileus in sarcopenic gastric cancer patients
Jian-Jun WU ; Guo-Zhong YAO ; Chu-Ming ZHU ; Jiang YAN ; Yu SHEN ; Shai-Di TANG ; Die WU
Parenteral & Enteral Nutrition 2025;32(5):283-287,292
Objective:To evaluate the effects and underlying mechanisms of preoperative intestinal microbiota modulation on the recovery of prolonged postoperative ileus(PPOI)in gastric cancer patients with sarcopenia Methods:Skeletal muscle mass(SMM)was assessed using bioelectrical impedance analysis(BIA),and the skeletal muscle index(SMI)was calculated.A total of 156 gastric cancer patients with sarcopenia who underwent surgery at the Department of Gastrointestinal Surgery,Liyang People's Hospital,from January 2022 to December 2024 were randomly assigned to either the control group or the experimental group.The control group received conventional prehabilitation interventions,including nutritional support,respiratory function training,and physical exercise.The experimental group received probiotic-based intestinal microbiota modulation in addition to conventional prehabilitation interventions.Postoperative recovery indicators,including time to first flatus,incidence of postoperative complications,length of hospital stay,and hospitalization costs,were compared between the two groups.Results:Among the 156 sarcopenic gastric cancer patients,121 were male,and 35 were female.Statistically significant differences were observed between the two groups in terms of time to first flatus,incidence of postoperative complications,and length of hospital stay(P<0.05).Postoperative complications occurred in 38 patients(24.3%),with 10 cases(6.4%)in the experimental group and 28 cases(17.9%)in the control group.The time to first flatus in the experimental group was significantly shorter than in the control group(48.0 hours vs 72.0 hours,P<0.001).Conclusion:Preoperative intestinal microbiota modulation significantly reduces the incidence of PPOI and postoperative complications in gastric cancer patients with low SMI,thereby promoting postoperative gastrointestinal function recovery.
5.Construction of CD8+T cell-associated Risk Model in Hepatocellular Carcinoma Based on Bulk and Single-cell RNA-seq Data
Xin-Tong ZHANG ; Jian-Jun ZHU ; Jin WU ; Hao WU ; Fan LU ; Wen-Tao ZHANG ; Jing-Jia CHANG ; Ting TANG ; Zhi-Gao OU ; Feng-Feng JIA ; Li LI ; Peng-Fei YU ; Ming LIU
Chinese Journal of Biochemistry and Molecular Biology 2025;41(10):1511-1528
Hepatocellular carcinoma(HCC),which is essentially primary liver cancer,is closely related to CD8+T cell immune infiltration and immune suppression.We constructed a CD8+T cells related risk score model to pre-dict the prognosis of HCC patients and provided therapeutic guidance based on the risk score.Using integrated bulk RNA sequencing(RNA-seq)and single-cell RNA sequencing(scRNA-seq)datasets,we identified stable CD8+T cell signatures.Based on these signatures,a 3-gene risk score model,comprised of KLRB1,RGS2,and TN-FRSF1B was constructed.The risk score model was well validated through an independent external validation co-hort.We divided patients into high-risk and low-risk groups according to the risk score and compared the differ-ences in immune microenvironment between these two groups.Compared with low-risk patients,high-risk patients have higher M2-type macrophage content(P<0.0001)and lower CD8+T cells infiltration(P<0.0001).High-risk patients predict worse response to immunotherapy treatment than low-risk patients(P<0.01).Drug sensitivity a-nalysis shows that PI3K-β inhibitor AZD6482 and TGFβRII inhibitor SB505124 may be suitable therapies for high-risk patients,while the IGF-1R inhibitor BMS-754807 or the novel pyrimidine-based anti-tumor metabolic drug Gemcitabine could be potential therapeutic choices for low-risk patients.Moreover,expression of these 3-gene mod-el was verified by immunohistochemistry.In summary,the establishment and validation of a CD8+T cell-derived risk model can more accurately predict the prognosis of HCC patients and guide the construction of personalized treatment plans.
6.Early differential diagnosis of acute myocardial infarction and acute myocarditis in young patients
Jian HUANG ; Xinyi ZHU ; Chao TANG ; Hui LI ; Yanni WU ; Chengpeng ZHANG ; Jing ZHU
Chinese Journal of Preventive Medicine 2025;59(3):365-374
To explore the value of general information and rapid laboratory tests obtained from the emergency department in the early diagnosis and prevention of young patients with acute myocardial infarction and acute myocarditis, in order to prevent the disease from progressing to a critical stage. This study employs a retrospective observational study, compiling clinical data from young patients diagnosed with acute myocardial infarction or acute myocarditis who were admitted to the Department of Cardiology or Emergency Department of the Second Affiliated Hospital of Soochow University from January 2015 to September 2024. Demographic information and laboratory test results from both the outpatient and emergency departments were retrieved. The acute myocardial infarction group comprised 267 patients (257 males, 10 females) aged 23-44 ys, while the acute myocarditis group included 134 patients (93 males, 41 females) aged 18-44 ys. A comparative analysis of the clinical data between the two groups was conducted, encompassing variables such as age, gender, comorbidities, high-risk factors, emergency blood routine tests, high-sensitivity C-reactive protein levels, coagulation profiles, renal function tests, NT-proBNP levels, myocardial injury markers, electrocardiogram readings, blood pressure, and heart rate. The results showed that:Compared with the young myocarditis group, the myocardial infarction group was older (ys)[38(35, 42) vs 30(25, 37), U=7 893, P<0.001], more male [257(96.3%) vs 93(69.4%), χ2=57.95, P<0.001], more smoking [211(79.0%) vs 38(28.4%), χ2=97.32, P<0.001], drinking history [125(46.8%) vs 22(16.4%), χ2=35.51, P<0.001], family history of coronary heart disease [45(16.9%) vs 3(2.2%), χ2=18.09, P<0.001], hypertension [100(37.5%) vs 12(9.0%), χ2=36, P<0.001] and diabetes [42(15.7%) vs 4(3.0%), χ2=14.27, P<0.001]. Systolic blood pressure (mmHg)[126(114, 144) vs 119(101, 126), U=11 389.50, P<0.001], diastolic blood pressure (mmHg)[80(70, 93) vs 72(62, 81), U=12 220.50, P<0.001], total white blood cell count (10 9/L)[11.3(9.2, 14.1) vs 8.5(6.6, 11.2), U=10 825.50, P<0.001], hemoglobin (g/L)[157(147, 166) vs 143(129, 154), U=9 404.50, P<0.001], platelet count (10 9/L)[244(206, 297) vs 207(173, 253), U=11 680, P<0.001], uric acid (μmol/L)[380(315, 446) vs 347(265, 412), U=14 805.50, P=0.005], ST segment elevation [204(76.4%) vs 57(42.5%), χ2=73.03, P<0.001] and Q wave formation [76(28.5%) vs 17(12.7%), χ2=12.47, P<0.001] in ECG were higher than those in myocarditis group. The duration of onset (hs) [6(3, 25) vs 48(24, 73), U=27911, P<0.001], heart rate (beats/min)[82(74, 92) vs 92(78, 103), U=22 347, P<0.001], D-dimer (μg/ml)[0.23(0.17, 0.51) vs 0.61(0.30, 1.38), U=25 806, P<0.001], High-sensitivity troponin T/99th percentile upper reference limit [5(1, 36) vs 16(8, 39), U=22 577, P<0.001], NT-proBNP (pg/ml) [204(64, 644) vs 824(189, 4 043), U=25 134, P<0.001], C-reactive protein (mg/L)[6(3, 9) vs 24(6, 55), U=26 349.50, P<0.001] and body temperature (℃) [36.50(36.30, 36.60) vs 37.35(36.50, 38.50), U=26 961, P<0.001] were significantly lower than those in myocarditis group, the symptoms of chest pain in myocardial infarction group was significantly higher than those in myocarditis group [262(98.1%) vs 83(61.9%), χ2=97.24, P<0.001], and the history of prodromal infection [12(4.5%) vs 112(83.6%), χ2=261.26, P<0.001], syncope [11(4.1%) vs 18(13.4%), χ2=11.53, P<0.001] and shock [6(2.2%) vs 22(16.4%), χ2=27.59, P<0.001] in myocardial infarction group were significantly lower than those in myocarditis group. With acute myocardial infarction as the target outcome, 8 influencing factors selected by LASSO regression, and 5 independent influencing factors were found after multiple Logistic regression, those were age ( OR=1.21, 95% CI: 1.12-1.31; P<0.001), pre-infection ( OR=0.02, 95% CI: 0.01-0.06; P<0.001), body temperature ( OR=0.37, 95% CI: 0.18-0.77; P=0.008), chest pain ( OR=26.75, 95% CI: 5.87-121.81; P<0.001) and white blood cell count ( OR=1.27, 95% CI: 1.12-1.44; P<0.001). Younger age, high body temperature and pre-infection are independent predictors for acute myocarditis, while chest pain and elevated white blood cell count are independent predictors for acute myocardial infarction. The five influencing factors selected by multivariate logistic regression and their combined diagnostic model were subjected to ROC analysis. The AUC reached 0.969, sensitivity reached 0.940 and specificity reached 0.925. Calibration curve and decision curve analysis(DCA) demonstrate that the model possesses excellent clinical application value. In conclusion, age, chest pain, pre-infection, body temperature and white blood cell count were independent factors in distinguishing acute myocardial infarction and acute myocarditis in young people. The clinical differential diagnosis model based on 5 independent factors may has high efficiency and good clinical practicability.
7.Expert consensus on the basic research and clinical application of circadian clock for the precision diagnosis and treatment of oral and maxillofacial squamous cell carcinoma
Kai YANG ; Moyi SUN ; Longjiang LI ; Zhangui TANG ; Wei GUO ; Guoxin REN ; Zhiwei ZHANG ; Hong TANG ; Jie ZHANG ; Zhijun SUN ; Qing XI ; Chunjie LI ; Xin HUANG ; Heming WU ; Wei SHANG ; Jian MENG ; Jichen LI ; Hong MA ; Guiquan ZHU ; Yi LI ; Yaoxu LI ; Haitao HE ; Fugui ZHANG ; Jie ZHANG ; Dan ZHAO ; Deping SUN ; Xiaoqiang LV ; Dan CHEN ; Fujun ZHANG ; Rui CHEN ; Yadong LI ; Jinsong ZHANG ; Xiaojuan FU ; Li XIANG ; Shouyi LI ; Shilin YIN
Journal of Practical Stomatology 2025;41(2):149-156
Recent studies have shown that the physiological homeostasis of oral mucosal cells is regulated by the circadian clock.Dis-ruption or dysfunction of the circadian clock is closely associated with the development of oral squamous cell carcinoma(OSCC).Research based on the circadian clock offers a novel perspective on the pathogenesis and therapeutic strategies for OSCC.However,there is current-ly limited research on this topic,and people generally have insufficient understanding and recognition of the circadian clock.Given the complexity and challenges of circadian clock which is the fourth dimension of medical research,we organize relevant experts based on summarizing the current research results of circadian clock in the pathogenesis and precision diagnosis and treatment of OSCC,combining the scientific principles of the circadian clock's role and their long-term research experience,then summarizes and recommends the con-sensus opinions for the research of circadian clock in the pathogenesis mechanism and precision diagnosis and treatment of human OSCC,with the hope of providing guidance for the basic research and clinical application of circadian clock or circadian rhythm in the pathogene-sis mechanism and precision diagnosis and treatment of oral and maxillofacial squamous cell carcinoma.
8.Expert consensus on integrated diagnosis and treatment techniques for oropharyngeal squamous cell carcinoma
Wei SHANG ; Haoyue XU ; Zongxuan HE ; Xiaoying LI ; Haijun LU ; Xiaohong ZHAN ; Dapeng HAO ; Yan SUN ; Wei GUO ; Zhangui TANG ; Guoxin REN ; Zhijun SUN ; Jian MENG ; Jie ZHANG ; Jichen LI ; Yue HE ; Chunjie LI ; Jianhua WEI ; Lizheng QIN ; Yaowu YANG ; Qing XI ; Wei WU ; Kai YANG ; Bing HAN ; Lingxue BU ; Shuangyi WANG ; Kai SONG ; Jiaqi ZHU ; Hongyu HAN ; Yu KONG ; Jieying LI ; Man HU ; Mingjin XU ; Moyi SUN
Journal of Practical Stomatology 2025;41(6):725-736
In recent decades,the incidence of human papillomavirus(HPV)-associated oropharyngeal squamous cell carcinoma(OPSCC)has shown a marked increase.Significant changes have also occurred in the OPSCC diagnosis and treatment paradigm.Deter-mining HPV status prior to treatment is now essential,and radiotherapy/chemotherapy,immunotherapy,and minimally invasive surgical techniques have progressively emerged as key modalities for managing OPSCC.However,alongside these paradigm shifts,a comprehen-sive technical consensus guiding the entire diagnostic and therapeutic process for OPSCC patients is currently lacking.Given China's large population base and the rising incidence of OPSCC,an expert panel convened to develop a clinical technical consensus on OPSCC diagno-sis and management tailored to China's specific context.This consensus aims to further enhance and standardize understanding of OPSCC management techniques among relevant healthcare professionals.
9.Comparison of Biomechanical Properties of Ilizarov External Fixator with Three Configurations for Treating Humeral Stem Defects
Yuanyang REN ; Liang JI ; Qingsong LI ; Yanchun HU ; Dengnan WU ; Jian TANG ; Xiang QIAO
Journal of Medical Biomechanics 2025;40(4):916-921
Objective The biomechanical performance of Ilizarov fixator models with different configurations for humeral shaft defect was compared,so as to provide a biomechanical basis for selecting the appropriate circular external fixation structure for the clinical treatment of humeral shaft defects using Ilizarov technology.Methods Based on CT data of the humerus from a healthy volunteer,the external fixators with three configurations,namely,hybrid frame,semi-ring frame and 90° fan frame were established.The finite element method was used to simulate the displacement and stress distribution under different loading conditions,and the finite element results were validated by biomechanical tests.Results Finite element analysis results:in terms of displacement,under compression,tensile and torque conditions,the displacement of 90° fan model was smaller than that of hybrid and semi-ring models.In terms of stress,the 90° fan model had the smallest displacement under tensile condition.In compression and torque tests,the semi-annular model had the lowest stress.Biomechanical test results:the semi-ring model exhibited the smallest displacement under axial compression,but there was no significant difference between the three models(P>0.05).Conclusions The semi-ring and 90° fan frames can achieve a similar stability as the traditional hybrid frame through the strategy of'reducing the ring and increasing the stem'.The unilateral structure of the 90° fan frame has the advantages of small size,light weight,and structural stability,as well as a small impact on the shoulder and elbow joints,which makes it more valuable in clinical applications.
10.Quantification of Atmospheric Total Reactive Nitrogen Oxides by Thermal Decomposition-Broadband Cavity Enhanced Absorption Spectroscopy
Dou SHAO ; Min QIN ; Wu FANG ; Bao-Bin HAN ; Ke TANG ; Jian-Ye XIE ; Xia-Dan ZHAO ; Zhi-Tang LIAO ; En-Bo REN
Chinese Journal of Analytical Chemistry 2025;53(3):387-396
Nitrogen oxides(NOx=NO+NO2)are important precursors of ozone(O3),and NOx and its oxides together constitute reactive nitrogen oxides(NOy)in the atmosphere.A comprehensive understanding of the total NOy level in the atmosphere is of great significance for a deeper understanding of the atmospheric nitrogen cycle and oxidation,as well as for formulating strategies for air pollution prevention and control.In this work,a thermal decomposition-broadband cavity enhanced absorption spectroscopy(TD-BBCEAS)technique for online measurement of total NOy in the atmosphere was developed.With this method,the NOy was efficiently converted into NO2,and the total NOy concentration in the atmosphere was indirectly obtained by measuring NO2.Focusing on the key factors affecting the measurement of total NOy,the influence of NO titration efficiency and other NOy component TD efficiency on measurement accuracy was emphasized.By changing the oxygen(O2)flow rate through the mercury lamp to alter the O3 concentration for titrating NO,the conversion efficiency of NO was evaluated.At O2 flow rate of 6 mL/min,the conversion efficiency of NO was greater than 99%.TD efficiency testing and analysis on NO2,peroxyacetyl nitrate(PAN),nitric acid(HNO3),and nitrous acid(HONO),which account for a large proportion of atmospheric NOy components,was carried out using 680℃as the optimal TD temperature for efficient conversion of NOy.With NO and HONO sample gases as typical verification gases,the conversion efficiency of NOy and the accuracy of NOy measurement by TD-BBCEAS system were verified by switching the on and off modes of mercury lamp and TD device.At integration time of 60 s,the detection limit of the system for NOy was 2.83×1010 molecules/cm3(60 s,2σ).A comparative measurement of actual atmospheric NOy was conducted between the TD-BBCEAS system and the NOy analyzer.The observation results showed a correlation coefficient(R2)of 0.98 and a slope of 0.93,further verifying the feasibility and accuracy of applying the TD-BBCEAS system to measurement of total NOy.

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