1.Exploring the pathogenesis and treatment methods of irritable bowel syndrome from the
Yan XU ; Fang YANG ; Rongshi SHAO ; Huili SUN ; Juan LI ; Xin CHEN ; Jing HAN
Journal of Beijing University of Traditional Chinese Medicine 2026;49(1):10-15
This article adopts Professor CHEN Chaozu′s " sanjiao composed by membrane-striae" theory as its foundation to explore the relationship between irritable bowel syndrome and functional/structural abnormalities of the membrane-striae. Sanjiao encompasses both the tangible membrane and the intangible striae. These striae permeate the entire body,and their pathological changes comprehensively reflect qi,body fluids,and fasciae. Based on the physiological function of the membrane-striae in regulating qi and fluids,the pathogenesis of irritable bowel syndrome is characterized by a disharmony of membrane-striae and an imbalance of the qi-fluid interactions. In the early stage,external pathogens,emotional factors,or dietary stimuli often cause membrane-striae constriction and disordered qi-fluid circulation. In the middle stage,stagnant fluids gradually transform into phlegm retention,leading to membrane-striae obstruction. In the late stage,deficiency of vital qi becomes predominant,manifesting as laxity of membrane-striae with impaired control or weakened conduction. The treatment of irritable bowel syndrome should adopt " unblocking" as the guiding principle. In the early stage,therapy should focus on eliminating pathogenic factors and soothing membrane-striae to promptly restore qi-fluid circulation,thereby attaining unblocking through spasm relief. In the middle stage,treatment should focus on resolving tangible obstructions in membrane-striae,achieving unblocking via dredging. In the late stage,the emphasis should shift to reinforcing healthy qi,particularly by strengthening spleen-kidney yang qi,and achieving unblocking through supplementation. Concurrently,throughout the entire treatment process,the regulation of mental state and easing of emotional tension should be integrated to alleviate patient′s anxiety,achieving the goal of holistic treatment of both body and mind.
2.Ionizing Radiation-induced Lens Injury: Epidemiology, Dose-effect Relationship, and Molecular Mechanisms
Cheng-Hao HU ; Shao-Han REN ; Hai-Tao ZHANG ; Jing-Ming ZHAN
Progress in Biochemistry and Biophysics 2026;53(3):688-696
The crystalline lens of the eye is recognized as one of the most radiosensitive tissues in the human body. While the International Commission on Radiological Protection (ICRP) has classified ionizing radiation (IR)-induced cataracts as a tissue reaction (deterministic effect) and subsequently reduced the occupational equivalent dose limit for the lens, significant uncertainties remain regarding the precise dose threshold and the complex biological pathways driving lens opacification. This review provides a comprehensive synthesis of current knowledge concerning radiation-induced lens damage, integrating epidemiological exposure characteristics with dose-response modeling and mechanistic molecular insights. First, we analyze exposure characteristics through four epidemiological dimensions: dose, time, space, and population. Clinical evidence suggests that radiation cataracts—particularly posterior subcapsular opacities—exhibit a distinct latency period that is inversely correlated with dose. We highlight that risk is not confined to acute high-dose scenarios (such as in atomic bomb survivors) but is increasingly relevant in chronic low-dose occupational settings (e.g., interventional radiology) and medical diagnostics (e.g., CT scans). Crucially, individual susceptibility is modified by genetic background, age, and environmental co-factors, complicating risk assessment. Second, we critically examine the dose-effect relationship. Although the ICRP suggests a threshold of 0.5 Gy, emerging data challenge the traditional threshold model, with some studies advocating for a linear non-threshold (LNT) relationship. We further discuss the critical roles of radiation quality and dose rate. High linear energy transfer (LET) radiation demonstrates a significantly higher relative biological effectiveness (RBE) for cataractogenesis compared to low-LET radiation. Paradoxically, and unlike many other tissues, the lens may exhibit an “inverse dose-rate effect,” where fractionated or protracted exposures potentially enhance biological damage—a finding that challenges classical radiobiological paradigms. Third, drawing upon the “cataractogenic load” hypothesis and the unique physiological constraints of the lens, this review elucidates the multidimensional molecular mechanisms driving radiation-induced opacification. Key mechanisms include four aspects. (1) DNA damage and repair: IR induces DNA double-strand breaks (DSBs) that, due to the lens’ limited repair capacity (modulated by genes such as ATM, Ptch1, and Ercc2), lead to the accumulation of damage. (2) Antioxidant defense system: dysfunction of the Nrf2/HO-1 antioxidant axis results in redox imbalances, triggering NF-κB-mediated inflammation and protein aggregation. (3) Cell proliferation and senescence: IR disrupts cell cycle regulation, causing a dichotomy of effects—driving premature senescence in some cell populations (evidenced by ATM nuclear foci) while inducing aberrant proliferation via growth factor upregulation (FGF2, TGFβ) in others. (4) Cell migration and adhesion: activation of the Wnt/β‑catenin pathway and alterations in the E-cadherin complex promote the abnormal migration of epithelial cells to the posterior capsule, a hallmark of radiation-induced cataracts. In conclusion, radiation-induced cataractogenesis is a multifactorial process in which genetic susceptibility and environmental stressors converge to overwhelm the lens’ homeostatic thresholds. Future research must prioritize longitudinal cohort studies to refine dose thresholds and employ multi-omics approaches to map the crosstalk between DNA damage responses and matrix remodeling. Establishing a robust mechanistic model is essential for developing targeted radioprotective strategies and optimizing radiation protection standards for occupational and medical safety.
3.Mechanisms of Huanglian Jiedutang and Its Major Active Constituents in Inhibiting LPS-induced M1 Polarisation of BV2 Microglia
Haojia ZHANG ; Kai WANG ; Kunjing LIU ; Xin LAN ; Zijin SUN ; Chunyu WANG ; Wenyuan MA ; Wei SHAO ; Jinhua HAN ; Liyang DONG ; Changxiang LI ; Xueqian WANG ; Youxiang CUI ; Fafeng CHENG ; Qingguo WANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(11):44-55
ObjectiveTo investigate whether Huanglian Jiedutang (HLJD) and its major active constituents (geniposide, baicalin, and berberine) can inhibit the inflammatory response of BV2 cells under lipopolysaccharide (LPS) stimulation via the high-mobility group protein B1 (HMGB1)/Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway, and to explore differences in therapeutic efficacy among the three monomers, their combined formula, and HLJD under equal content ratios. MethodsBV2 microglial cells were used as the primary experimental model. Cell viability was assessed using the cell counting kit-8 (CCK-8) method to examine the effects of different concentrations of dimethyl sulfoxide (DMSO, 0.8%, 0.4%, 0.2%, 0.1%, and 0.05%) on cell viability. IncuCyte was employed to monitor the growth of cells under different concentrations of HLJD (200, 100, 50, 25, 12.5, 6.25 mg·L-1). Nitric oxide (NO) assay was used to screen the optimal HLJD concentration. High-performance liquid chromatography (HPLC) determined the content of geniposide, baicalin, and berberine in HLJD, and experimental groups were subsequently established according to the relative proportions of these constituents. CCK-8 assay evaluated cell viability under different treatments. Enzyme-linked immunosorbent assay (ELISA) measured levels of inflammatory factors (TNF-α, IL-1β, IL-6, IL-10) in the supernatant. Flow cytometry assessed the effects of treatments on M1-type polarization of BV2 cells. Western blot determined the expression levels of HMGB1, TLR4, and NF-κB-related proteins. ResultsCompared with the blank group, DMSO at concentrations ≤0.2% did not affect cell viability within 48 h. BV2 cell growth plateaued at 24 h after treatment with 200 mg·L-1 HLJD. Under stimulation with 2 mg·L-1 LPS, this concentration of HLJD effectively reduced NO release, and 6 h pre-treatment had a stronger inhibitory effect on NO than direct administration. HPLC results showed that 1 mg of HLJD freeze-dried powder contained approximately 24 μg of geniposide, 15 μg of baicalin, and 30 μg of berberine. Based on these ratios, experimental groups were blank, LPS (2 mg·L-1), HLJD (200 mg·L-1), monomer combination, geniposide (4.8 mg·L-1), baicalin (3 mg·L-1), and berberine (6 mg·L-1). The monomer combination group consisted of all three active constituents dissolved together. LPS and HLJD or its active constituents did not affect cell viability compared with the blank group. LPS significantly increased TNF-α, IL-1β, IL-6, and IL-10 in the supernatant (P<0.01). HLJD and its active constituents significantly reduced pro-inflammatory factors TNF-α, IL-1β, and IL-6 (P<0.05, P<0.01) while upregulating anti-inflammatory IL-10 (P<0.01), with the monomer combination showing the strongest effect (P<0.05, P<0.01). Compared with the blank group, LPS significantly increased the proportion of CD80⁺CD86⁺ (M1-type) BV2 cells (P<0.01). HLJD and its constituents partially inhibited M1 polarization (P<0.05, P<0.01), with the monomer combination exhibiting the most pronounced effect (P<0.05, P<0.01). Compared with the blank group, LPS upregulated HMGB1, TLR4, and NF-κB-related proteins (P<0.01), whereas HLJD and its active constituents significantly reduced their expression (P<0.05, P<0.01), with the monomer combination having the strongest regulatory effect (P<0.05, P<0.01). ConclusionHLJD and its major active constituents (geniposide, baicalin, berberine) can inhibit LPS-induced inflammatory responses in BV2 cells. The combination of the three active constituents demonstrates the most potent anti-inflammatory effect, significantly attenuating M1-type polarization of BV2 cells via the HMGB1/TLR4/NF-κB signaling pathway.
4.Expert consensus on clinical application of parenteral direct thrombin inhibitors in perioperative period
Mingyu JIANG ; Yuan BIAN ; Lizhu HAN ; Qinan YIN ; Fengjiao KANG ; Anhua WEI ; Danjie ZHAO ; Lin WANG ; Ying SHAO ; Li TANG ; Yi WANG ; Shuhong LIANG ; Huijuan LIU ; Guirong XIAO ; Yue LI
China Pharmacy 2026;37(6):689-699
OBJECTIVE To form an expert consensus on the clinical application of parenteral direct thrombin inhibitors (DTIs) in patients during the perioperative period. METHODS Led by Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital (the Affiliated Hospital of UESTC), a multidisciplinary working group was established. Through literature review and the Delphi method, clinical questions related to the rational perioperative use of parenteral DTIs were identified. A structured design was adopted using the “Population-Intervention-Comparison-Outcome” framework; systematic searches were conducted in CNKI, Medline, Embase and other databases. Relevant evidence from randomized controlled trials and cohort studies was included and synthesized. Evidence quality was assessed using the Grades of Recommendations Assessment,Development and Evaluation (GRADE) approach, and recommendations were formulated through multiple rounds of Delphi surveys and expert consensus meetings. RESULTS &CONCLUSIONS Seven recommendations (each with an expert consensus rate exceeding 90%) on the use of parenteral DTIs in perioperative patients were developed. These recommendations specify drug selection, dosing ranges, key monitoring points, and safety management strategies for parenteral DTIs in various scenarios, including the perioperative period of ventricular assist device implantation, the perioperative period of cardiac surgery, perioperative patients with lower-extremity atherosclerotic disease, the perioperative period of percutaneous coronary intervention in patients with acute coronary syndrome, the perioperative period of carotid artery stenting in patients with carotid stenosis, the perioperative period of patients with right heart thrombosis, and patients who develop related thrombosis and dysfunction after a central venous catheter insertion. In addition, warning and management pathways for perioperative bleeding and thrombotic events were proposed. This expert consensus, which is formulated based on the best available evidence, provides evidence-based guidance for standardized and individualized use of parenteral DTIs in perioperative period.
5.Herbal Textual Research on Inulae Flos in Famous Classical Formulas
Caixia LIU ; Yue HAN ; Yanzhu MA ; Lei GAO ; Sheng WANG ; Yan YANG ; Wenchuan LUO ; Ling JIN ; Jing SHAO ; Zhijia CUI ; Zhilai ZHAN
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(3):210-221
In this paper, by referring to ancient and modern literature, the textual research of Inulae Flos has been conducted to clarify the name, origin, production area, quality evaluation, harvesting, processing and others, so as to provide reference and basis for the development and utilization of famous classical formulas containing this herb. After textual research, it could be verified that the medicinal use of Inulae Flos was first recorded in Shennong Bencaojing of the Han dynasty. In successive dynasties, Xuanfuhua has been taken as the official name, and it also has other alternative names such as Jinfeicao, Daogeng and Jinqianhua. The period before the Song and Yuan dynasties, the main origin of Inulae Flos was the Asteraceae plant Inula japonica, and from the Ming and Qing dynasties to the present, I. japonica and I. britannica are the primary source. In addition to the dominant basal species, there are also regional species such as I. linariifolia, I. helianthus-aquatili, and I. hupehensis. The earliest recorded production areas in ancient times were Henan, Hubei and other places, and the literature records that it has been distributed throughout the country since modern times. The medicinal part is its flower, the harvesting and processing method recorded in the past dynasties is mainly harvested in the fifth and ninth lunar months, and dried in the sun, and the modern harvesting is mostly harvested in summer and autumn when the flowers bloom, in order to remove impurities, dry in the shade or dry in the sun. In addition, the roots, whole herbs and aerial parts are used as medicinal materials. In ancient times, there were no records about the quality of Inulae Flos, and in modern times, it is generally believed that the quality of complete flower structure, small receptacles, large blooms, yellow petals, long filaments, many fluffs, no fragments, and no branches is better. Ancient processing methods primarily involved cleaning, steaming, and sun-drying, supplemented by techniques such as boiling, roasting, burning, simmering, stir-frying, and honey-processing. Modern processing focuses mainly on cleaning the stems and leaves before use. Regarding the medicinal properties, ancient texts describe it as salty and sweet in taste, slightly warm in nature, and mildly toxic. Modern studies characterize it as bitter, pungent, and salty in taste, with a slightly warm nature. Its therapeutic effects remain consistent across eras, including descending Qi, resolving phlegm, promoting diuresis, and stopping vomiting. Based on the research results, it is recommended that when developing famous classical formulas containing Inulae Flos, either I. japonica or I. britannica should be used as the medicinal source. Processing methods should follow formula requirements, where no processing instructions are specified, the raw products may be used after cleaning.
6.Herbal Textual Research on Inulae Flos in Famous Classical Formulas
Caixia LIU ; Yue HAN ; Yanzhu MA ; Lei GAO ; Sheng WANG ; Yan YANG ; Wenchuan LUO ; Ling JIN ; Jing SHAO ; Zhijia CUI ; Zhilai ZHAN
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(3):210-221
In this paper, by referring to ancient and modern literature, the textual research of Inulae Flos has been conducted to clarify the name, origin, production area, quality evaluation, harvesting, processing and others, so as to provide reference and basis for the development and utilization of famous classical formulas containing this herb. After textual research, it could be verified that the medicinal use of Inulae Flos was first recorded in Shennong Bencaojing of the Han dynasty. In successive dynasties, Xuanfuhua has been taken as the official name, and it also has other alternative names such as Jinfeicao, Daogeng and Jinqianhua. The period before the Song and Yuan dynasties, the main origin of Inulae Flos was the Asteraceae plant Inula japonica, and from the Ming and Qing dynasties to the present, I. japonica and I. britannica are the primary source. In addition to the dominant basal species, there are also regional species such as I. linariifolia, I. helianthus-aquatili, and I. hupehensis. The earliest recorded production areas in ancient times were Henan, Hubei and other places, and the literature records that it has been distributed throughout the country since modern times. The medicinal part is its flower, the harvesting and processing method recorded in the past dynasties is mainly harvested in the fifth and ninth lunar months, and dried in the sun, and the modern harvesting is mostly harvested in summer and autumn when the flowers bloom, in order to remove impurities, dry in the shade or dry in the sun. In addition, the roots, whole herbs and aerial parts are used as medicinal materials. In ancient times, there were no records about the quality of Inulae Flos, and in modern times, it is generally believed that the quality of complete flower structure, small receptacles, large blooms, yellow petals, long filaments, many fluffs, no fragments, and no branches is better. Ancient processing methods primarily involved cleaning, steaming, and sun-drying, supplemented by techniques such as boiling, roasting, burning, simmering, stir-frying, and honey-processing. Modern processing focuses mainly on cleaning the stems and leaves before use. Regarding the medicinal properties, ancient texts describe it as salty and sweet in taste, slightly warm in nature, and mildly toxic. Modern studies characterize it as bitter, pungent, and salty in taste, with a slightly warm nature. Its therapeutic effects remain consistent across eras, including descending Qi, resolving phlegm, promoting diuresis, and stopping vomiting. Based on the research results, it is recommended that when developing famous classical formulas containing Inulae Flos, either I. japonica or I. britannica should be used as the medicinal source. Processing methods should follow formula requirements, where no processing instructions are specified, the raw products may be used after cleaning.
7.Cost–utility analysis of lecanemab and donanemab for early Alzheimer’s disease in China
Wei SHAO ; Fei YU ; Ying LIU ; Lixin SHU ; Dan HAN
Journal of Pharmaceutical Practice and Service 2026;44(7):376-382
Objective To evaluate the cost–utility of lecanemab and donanemab in the treatment of early Alzheimer’s disease (AD) in China. Methods A Markov model was developed from a societal perspective to compare standard of care (SOC), lecanemab plus SOC, and donanemab plus SOC in terms of costs, quality-adjusted life years (QALY), and incremental cost–utility ratios (ICUR). Deterministic and probabilistic sensitivity analyses were conducted to assess parameter uncertainty. Results Both intervention strategies increased QALY compared with SOC but were associated with substantially higher costs, and neither was cost-effective under the current willingness-to-pay threshold. Conclusion Lecanemab and donanemab may be more appropriately considered within a multi-tiered healthcare reimbursement framework in China rather than relying solely on basic medical insurance.
8.Hypoxia Exercise Mediates The miR-27/PPARγ Pathway to Improve Lipid Metabolism in Obese Rats at Target Genes and Protein Levels
Wei KONG ; Jie SHAO ; Teng ZHAI ; Qian CHENG ; Fang-Zheng HAN ; Yi QU ; Lei ZHU
Progress in Biochemistry and Biophysics 2025;52(6):1386-1400
ObjectiveTo explore the sequential effects of hypoxic exercising on miR-27/PPARγ and lipid metabolism target gene and protein expression levels in the obesity rats’ liver. Methods13-week-old male diet-induced obesity rats were randomly divided into three groups (n=10): normal oxygen concentration quiet group (N), hypoxia quiet group (H), hypoxic exercise group (HE). Exercise training on the horizontal animal treadmill for 1 h/d, 5 d/week for a total of 4 week, and the intensity of horizontal treadmill training was 20 m/min (hypoxic concentration was 13.6%). Comparison of the weights of perirenal fat and epididymal fat in rats across different groups and calculation of Lee’s index based on body weight and body length of rats in each group were done. And the serum concentrations of total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) levels were detected. RT-PCR and Western Blot were used to detect the levels of miR-27, PPARγ, CYP7A1 and CD36. ResultsHypoxic exercise decreased the expression levels of miR-27 in the obese rats’ liver, however, the expression level of PPARγ was gradually increased. The expression levels of miR-27 in HE group were significantly lower than N group (P<0.05). The expression levels of PPARγ mRNA in N group were significantly lower than H group (P<0.05), especially lower than HE group (P<0.01). The protein expression of PPARγ protein in N group was significantly lower than that other groups (P<0.01). The expression of lipid metabolism-related genes and proteins increased in the obese rats’ liver. The expression of CYP7A1 mRNA in N group was significantly lower than H group (P<0.05), especially lower than HE group (P<0.01). The expression of CYP7A1 protein in the obese rats’ liver in N group was extremely lower than H group and HE group (P<0.01). The protein expression of CD36 in N group was significantly lower than that in HE group (P<0.05). Hypoxia exercise improved the related physiological and biochemical indexes of lipid metabolism disorder. The perirenal fat weight of obese rats in HE group was extremely lower than N group and H group (P<0.01), and the perirenal fat weight in N group was significantly higher than H group (P<0.05). The epididymal fat weight in N group was significantly higher than H group (P<0.05), and extremely higher than HE group (P<0.01). The Lee’s index in HE group was extremely lower than N group and H group (P<0.01). The serum concentration of TC in obese rats in HE group was extremely lower than N group and H group (P<0.01). The serum concentration of TG in HE group was extremely lower than N group and H group (P<0.01). The serum concentration of LDL-C in N group was extremely higher than HE group (P<0.01). The serum concentration of HDL-C in N group was extremely lower than H group (P<0.01). ConclusionHypoxia and hypoxia exercise may negatively regulate the levels of PPARγ by inhibiting miR-27 in the obese rats’ liver, thereby affecting the expression of downstream target genes CYP7A1 and CD36, and promoting cholesterol, fatty acid oxidation and HDL-C transport in the liver, and ultimately the lipid levels in obese rats were improved. The effect of hypoxia exercise on improving blood lipid is better than simple hypoxia intervention.
9.Investigation and Analysis of Deacclimatization in Tibetan College Students Upon First Visit to Low-Altitude Regions
Weihua ZHANG ; Kezhen HAN ; Li SHAO ; Chao YANG ; Kexin ZHAO ; Zhao JIANG
Journal of Sichuan University (Medical Sciences) 2025;56(1):254-261
Objective To investigate the correlation between changes in physiological indicators and altitude,age,and sex among ethnic Tibetan college students living in Xizang on long-term basis upon their first ever visit to a low-altitude region,thereby providing health guidance for long-term residents of high-altitude regions when they visit low-altitude environments for the first time.Methods A cluster random sampling method was used to select 170 healthy first-year college students of Tibetan ethnicity(85 males and 85 females),from Xizang Minzu University.The participants did not have any respiratory,circulatory,or nervous system diseases,nor any family history of such conditions.Based on their responses to questionnaires and the monitoring data of their physiological indicators,an analysis was conducted to assess the incidence and duration of deacclimatization symptoms among these Tibetan college students during the first month after their arrival at a low-altitude region.In addition,the R programming language and the SPSS software were used to analyze the correlation between changes in blood pressure,heart rate,and body weight and the participants'age,sex,and the altitude of their long-term residence in Xizang before and after their arrival at a low-altitude region.Results Statistical analysis revealed that Tibetan college students experienced deacclimatization symptoms within the first week of their first ever visit to a low-altitude region,primarily characterized by dizziness,fatigue,and drowsiness.The incidence was 41.9%among female students and 22.5%among male students.Furthermore,after arriving at low-altitude region,the participants experience an initial decrease followed by a recovery in both blood pressure and heart rate.They gained an average of 1.5 kg in body mass compared with their initial measurements upon arrival in a low-altitude region.Significant differences in blood pressure,heart rate,and body mass were observed among Tibetan students of different sexes and altitudes of their long-term residence in Xizang after their arrival in a low-altitude region.Conclusion After arriving at a low-altitude region,Tibetan college students exhibit marked changes in physiological indicators,showing strong correlations between systolic blood pressure,body mass,etc.,and sex,altitude,and other parameters.
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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