Effects of qufeng xuanfei formula in guinea pig model of airway hyperergy.

This work aimed to clarify the potential regulating effects of Qufeng Xuanfei formula (QFXF) on airway neurogenic inflammation and its underlying target signal pathway. Guinea pig model of airway hyperergy (AHR) was used. The relative susceptibility of major proteins to airway neurogenic inflammation was assessed using Western blot immunoassay followed by being separated by SDS-PAGE. Compared to the model group, QFXF of all concentrations effectively depressed the capsaicin enhanced cough in guinea pigs and the peak values of airway resistance significantly decreased. The results illustrated that QFXF alleviated cough symptom in guinea pigs and reduced airway neurogenic inflammation when compared to AHR model group. Airway inflammation and damage, as well as the levels of NGF, SP and c-Fos in QFXF decreased the most in the high-dose group. The mechanism of antitussive activity may be associated with reducing airway inflammation. QFXF displayed effect on chronic cough through reducing the levels of neuropeptides, attenuating airway inflammation and promoting recovery from disease to decrease the airway neuro sensitivity, suggesting that the potential mechanism may be related to Ras/ERK/c-Fos pathway.

Construction and Validation of a 6-Ferroptosis Related Gene Signature for Prognosis and Immune Landscape Prediction in Melanoma.

Ferroptosis is a newly discovered form of non-apoptotic cell death that relies on iron-mediated oxidative damage, playing a crucial role in the progression and therapy resistance of melanoma. Hence, the potential value of ferroptosis-related genes (FRGs) as a prognostic model and therapeutic target in melanoma requires further investigation. In this study, the relationship between FRGs and melanoma was revealed by analyzing the mRNA expression profiles from The Cancer Genome Atlas (TCGA) and Gene Expression Synthesis (GEO). A 6-FRGs signature was constructed by Univariate, multivariate, and lasso Cox regression analyses in the TCGA cohort. The GEO database was used to validate the efficacy of the signature. The protein and mRNA expression level of the signature genes were examined in real-world melanoma tissues via immunohistochemical and quantificational real-time polymerase chain reaction (qRT-PCR). Functional enrichment analysis and immune-related analysis were conducted to identify the potential biological functions and pathways of the signature. Ten putative small molecule drugs were predicted by Connectivity Map (CMAP). As a result, a 6-FRGs signature was constructed to stratify melanoma patients into two risk groups. Compared with the low-risk group, patients in the high-risk group had a worse prognosis and a lower ImmuneScore. Immune-related pathways were enriched in the low-risk group. Immune Function and immune cell infiltration of the low-risk group were significantly higher than that of the high-risk group. The differential expression of these six FRGs in melanoma and adjacent normal tissues was confirmed. Moreover, higher expression of immune checkpoint molecules and a greater sensitivity to immunotherapy were observed in the low-risk group. Some small molecular drugs in the CMAP database hold the potential to treat melanoma. Overall, we identified a novel FRGs signature for prognostic prediction in melanoma. Based on the signature-related immune infiltration landscape found in our study, targeting the FRGs might be a therapeutic alternative for melanoma.

Effects of Astragalus Polysaccharides on CD8+ Tissue-Resident Memory T Cells in Mice with Herpes Simplex.

Objective: This study aimed to explore whether astragalus polysaccharides (APS) could treat herpes simplex by increasing tissue-resident memory CD8+ T cells (CD8+ TRM cells) and analyze its potential mechanism using the network pharmacologic approach. Methods: C57BL/6J male mice aged 6-8 weeks were divided into a model group with HSV-1 infection treated by saline, a control group without HSV-1 infection but treated by saline, and an APS group with HSV-1 infection treated by APS. Clinical signs were observed, and the disease score was recorded every day. The skin lesions on day 9 after infection were taken for flow cytometric analysis to evaluate CD8+ TRM cells. Network pharmacologic analysis was performed to select the potential protein targets of astragalus associated with herpes simplex. Besides, Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed. The peripheral blood from the retroorbital venous plexus was collected to evaluate the levels of serum interferon-γ (IFN-γ) and interleukin 12 (IL-12). The comparisons of clinical signs, the disease score, CD8+ TRM cells, the serum IFN-γ, and IL-12 levels were performed among the three groups. Results: Compared with the model group, the disease score in the APS group was significantly lower (p < 0.05). On the day 9 after HSV-1 infection, there was no significant difference in the body weight of mice among the three groups. However, compared with the control group or model group, the spleen weight in the APS group increased significantly (p < 0.05). The surface antigens of CD8+ TRM cells had no significant difference between the control group and the model group, while compared with the model group, the surface antigens of CD8 (p < 0.05), CD69 (p < 0.05), and CD103 (p < 0.05) in the APS group increased significantly. Moreover, the serum IL-12 (p < 0.05) and IFN-γ (p < 0.01) levels in the APS group increased significantly compared with the model group. Conclusion: Our study suggested that APS could alleviate the symptoms of the mice infected with HSV-1, and CD8+ TRM cells in the skin lesions and the levels of IL-12 and IFN-γ in the serum of mice with HSV-1 infection increased after the APS treatment, of which the specific underlying mechanism requires further experiments to clarify. In addition, the antiviral effect of APS might be worthy of further development and utilization.

Ferroptosis: Mechanism and connections with cutaneous diseases.

Ferroptosis is a recognized novel form of programmed cell death pathway, featuring abnormalities in iron metabolism, SystemXc-/glutathione axis, and lipid peroxidation regulation. A variety of ferroptosis inducers can influence glutathione peroxidase directly or indirectly via diverse pathways, leading to decreased antioxidant capacity, accumulated cellular lipid peroxides, and finally inducing ferroptosis. To date, mounting studies confirm the association of ferroptosis with various cutaneous diseases, including skin homeostasis, neoplastic diseases, infectious diseases, genetic skin disease, inflammatory skin diseases, and autoimmune diseases. There are shared characteristics regarding ferroptosis and various cutaneous diseases in terms of pathophysiological mechanisms, such as oxidative stress associated with iron metabolism disorder and accumulated lipid peroxides. Therefore, we summarize the current knowledge regarding the mechanisms involved in the regulation of ferroptosis for further discussion of its role in the pathogenesis and prognosis of skin diseases. Gaining insight into the underlying mechanisms of ferroptosis and the associated dermatological disorders could illuminate the pathogenesis and treatments of different cutaneous diseases.

Integrating Chinese and western medicine for COVID-19: A living evidence-based guideline (version 1).

BACKGROUND: The coronavirus disease 2019 (COVID-19) has turned into a pandemic and resulted in huge death tolls and burdens. Integrating Chinese and western medicine has played an important role in the fight against the COVID-19 pandemic. PURPOSE: We aimed to develop a living evidence-based guideline of integrating Chinese and western medicine for COVID-19. STUDY DESIGN: Living evidence-based guideline. METHODS: This living guideline was developed using internationally recognized and accepted guideline standards, dynamically monitoring the release of new clinical evidence, and quickly updating the linked living systematic review, evidence summary tables, and recommendations. Modified Delphi method was used to reach consensus for all recommendations. The certainty of the evidence, resources, and other factors were fully considered, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to rate the certainty of evidence and the strength of recommendations. RESULTS: The first version of this living guidance focuses on patients who are mild or moderate COVID-19. A multidisciplinary guideline development panel was established. Ten clinical questions were identified based on the status of evidence and a face-to-face experts' consensus. Finally, nine recommendations were reached consensus, and were formulated from systematic reviews of the benefits and harms, certainty of evidence, public accessibility, policy supports, feedback on proposed recommendations from multidisciplinary experts, and consensus meetings. CONCLUSION: This guideline panel made nine recommendations, which covered five traditional Chinese medicine (TCM) prescription granules/decoction (MXXFJD, QFPD, XFBD, TJQW, and JWDY), three Chinese patent medicines (LHQW granules/capsule, JHQG granules, and LHQK granules), and one Chinese herbal injection (XBJ injection). Of them, two were strongly recommended (LHQW granules/capsule and QFPD decoction), and five were weakly recommended (MXXFJD decoction, XFBD decoction, JHQG granules, TJQW granules, and JWDY decoction) for the treatment of mild and moderate COVID-19; two were weakly recommended against (XBJ injection and LHQK granules) the treatment of mild and moderate COVID-19. The users of this living guideline are most likely to be clinicians, patients, governments, ministries, and health administrators.

Sinomenine Attenuated Capsaicin-Induced Increase in Cough Sensitivity in Guinea Pigs by Inhibiting SOX5/TRPV1 Axis and Inflammatory Response.

BACKGROUND: Chronic cough is a common complaint which affects a large number of patients worldwide. Increased cough sensitivity is a very important cause of chronic persistent cough. However, there are limited clinical diagnosis and treatment for increased cough sensitivity. Transient receptor potential vanilloid-1 (TRPVl) is a member of the transient receptor potential (TRP) family of channels which is very closely associated with respiratory diseases. However, the mechanism through which TRPV1 that influences downstream events is still poorly understood. RESULTS: Capsaicin induced increase in cough sensitivity by upregulating the protein level of TRPV1, leading to the secretions of Substance P and neurokinin A which stimulated neurogenic inflammation. However, sinomenine, a component of traditional Chinese medicine, significantly attenuated the capsaicin-induced cough by inhibiting the expression of TRPV1 in guinea pigs. In addition, capsaicin increased the expression of SOX5 which mediated the transcriptional upregulation of TRPV1. However, pretreatment with sinomenine reduced the expression of SOX5. CONCLUSION: These results indicate that capsaicin induced increase in cough sensitivity by activating neurogenic inflammation, while sinomenine attenuated the increase in cough sensitivity by inhibiting the expressions of SOX5 and TRPV1 in guinea pigs. This finding may provide a novel target for the treatment of aggravated cough sensitivity.

Research progress and perspective in metabolism and metabolomics of psoriasis.

ABSTRACT: Psoriasis is considered a systemic disease associated with metabolic abnormalities, and it is important to understand the mechanisms by which metabolism affects pathophysiological processes both holistically and systematically. Metabolites are closely related to disease phenotypes, especially in systemic diseases under multifactorial modulation. The emergence of metabolomics has provided information regarding metabolite changes in lesions and circulation and deepened our understanding of the association between metabolic reprogramming and psoriasis. Metabolomics has great potential for the development of effective biomarkers for clinical diagnosis, therapeutic monitoring, prediction of the efficacy of psoriasis management, and further discovery of new metabolism-based therapeutic targets.

Tapering and discontinuation of systemic medications in psoriasis patients with low disease activity.

Psoriasis is a chronic disease and often requires long-term treatment, especially in patients with moderate-to-severe psoriasis. It remains controversial whether the doses of systemic medications could be tapered or if these medications could be discontinued among patients in clinical remission. In this review, we summarize whether it is possible to taper or discontinue methotrexate, cyclosporine, and biologics while controlling the relapse rates of psoriasis. Based on the current evidence, methotrexate and biologics should not be discontinued for psoriasis patients with low disease activity. However, the doses of these medications could be tapered by reducing the maintenance dose or increasing the between-dose intervals. If the disease recurs, methotrexate and biologics should be restarted at their standard doses, and for cyclosporine, the dose can be maintained or discontinued progressively. If patients relapse, cyclosporine can be given again. The decisions to taper or discontinue anti-psoriasis drugs need to account for both benefits and risks and should be individualized according to patients' disease severity, quality of life, and presence of comorbidities.

Glycyrrhizic Acid Inhibits Proliferation of Gastric Cancer Cells by Inducing Cell Cycle Arrest and Apoptosis.

PURPOSE: Glycyrrhizic acid (GA) is the main active ingredient extracted from Chinese herb licorice root, and it shows anti-tumor effects in many cancer types, while its role in gastric cancer (GC) is still unknown. In this study, we evaluated the effects of GA on GC cells and explored the underlying mechanisms. METHODS: The anti-proliferation effect of GA on GC cells was assessed by CCK-8, colony formation, and EdU assay. The effects of GA on cell cycle and apoptosis were detected by flow cytometer. Western blotting was performed to explore the underlying mechanisms. RESULTS: Our results showed that GA had a time- and dose-dependent inhibitory effect on proliferation of GC cells. Flow cytometer analysis demonstrated that GA would lead to G1/S-phase arrest and apoptosis. GA treatment down-regulated the levels of G1 phase-related proteins, including cyclin D1, D2, D3, E1, and E2. In terms of apoptosis, GA treatment up-regulated the levels of Bax, cleaved PARP, and pro-caspase-3, -8, -9, but did not influence their cleavage patterns. The expression of Bcl-2, survivin and p65 was attenuated after treatment. Besides, GA would down-regulate the phosphorylation of PI3K/AKT pathway. CONCLUSION: This study focused on inhibitory effect of GA on GC cells by inducing cell cycle arrest and apoptosis. Several important cyclins- and apoptosis-related proteins were involved in the regulation of GA to GC cells, and phosphorylated PI3K and AKT were attenuated. The results of this study indicated that GA is a potential and promising anti-cancer drug for GC.

Efficacy and Safety of Traditional Chinese Medicine in Idiopathic Pulmonary Fibrosis: A Meta-Analysis.

Objective: To evaluate the efficacy and safety of traditional Chinese medicine (TCM) on lung function and quality of life of idiopathic pulmonary fibrosis (IPF) patients by meta-analysis. Methods: Randomized controlled trials (RCTs) related to TCM and IPF were searched on PubMed, EMBASE Cochrane Library, ClinicalTrials, China National Knowledge Infrastructure (CNKI), Wanfang Database, Chin VIP Information (VIP), and Chinese Biomedical Database (CBM) until December 2018. Standard mean difference (SMD) and 95% CI were calculated for the measurements related to lung function (FEV1/FVC, FVC%, FEV1%, TLC%, DLCO% or DLCO, and VC%) and other parameters (PO2, 6MWD, and SGRQ) when comparing TCM treatment to the control group. Relative risk (RR) and 95% CI of adverse events (AEs) were calculated to assess the safety of TCM. Results: A total of 40 RCTs comparing TCM to western medicine (WM) and involving 3194 IPF patients were eligible for the meta-analysis. The pooled results showed that TCM treatment improved significantly PO2 (SMD = 0.80, 95% CI 0.54 to 1.06, p < 0.001), FEV1% (SMD = 0.57, 95% CI 0.42 to 0.71, p < 0.001), DLCO% (SMD = 0.38, 95% CI 0.28 to 0.48, p < 0.001), 6MWD (SMD = 0.70, 95% CI 0.56 to 0.84, p < 0.001) and other measurements and reduced SGRQ scores (SMD = −0.51, 95% CI −0.70 to −0.22, p < 0.001). Subgroup analysis of different study durations (3 months, ≥ 6 months) and comparison models (TCM vs. WM, TCM + WM vs. WM or TCM vs. placebo) showed similar results. No significant difference of risk of AEs was observed between both groups (RR = 0.66, 95% CI: 0.27­1.60, p=0.352). There was no obvious publication bias, and the pooled results were stable according to sensitivity analysis. Conclusion: To the best of our knowledge, the present study had the largest sample size. Our results indicated that TCM treatment may help provide benefit to the lung function, exercise capacity, and quality of life of IPF patients, alone or combined with WM, when compared to WM. More rigorous RCTs were needed in the future.

Bioinformatics analysis of the prognosis and biological significance of HMGB1, HMGB2, and HMGB3 in gastric cancer.

High mobility group box (HMGB) consists primarily of HMGB1, HMGB2, and HMGB3 proteins. Although abnormal HMGB expression is associated with various tumors, the relationship with gastric cancer (GC) remains unclear. In this study, HMGB1, HMGB2, and HMGB3 expression was analyzed using the Oncomine and TCGA databases. Correlations between HMGB1, HMGB2, and HMGB3 and clinicopathological factors were analyzed. cBioPortal was used to analyze HMGB1, HMGB2, and HMGB3 genetic alterations and its gene regulation network in GC tissue. HMGB1, HMGB2, and HMGB3 expression was higher in tumor tissues than in normal tissues, especially in GC. High HMGB1, HMGB2, and HMGB3 expression may predict a poor prognosis among patients with GC (hazard ratios [HR] = 1.90; 95% confidence interval [CI]: [1.30-2.78]) and human digestive system neoplasm (HR = 1.85; 95% CI [1.64-2.10]). These findings suggest that HMGB1, HMGB2, and HMGB3 may be useful prognostic indicators for patients with GC.

[Expert consensus statement on Pudilan Xiaoyan Oral Liquid in clinical practice].

Pudilan Xiaoyan Oral Liquid has effects in clearing away heat and detoxifying,and is used to treat pharynx and throat swelling caused by the syndrome of excessive heat and toxin accumulation. Its efficacy is to relieve swelling and pain( redness,swelling and hot pain). It is included in the Chinese Pharmacopoeia of 2015 Edition,and has been listed in provincial health insurance directories of Shaanxi,Jiangsu,Liaoning,Hunan,Tianjin,Xinjiang and Hebei. It has been recommended by health departments of Beijing,Chongqing and other provinces as a preferred drug for the prevention and treatment of H1 N1 and HFMD,and listed in the diagnosis and Treatment Guide of HFMD by the Ministry of Health,the Clinical Application Guide of Chinese Patent Medicine edited by the Lung Department Disease Branch of China Association of Chinese Medicine,and the Clinical Practice Guide of Single Administration/Combined Administration of Antibiotics in Treatment of Common Infectious Diseases by China Association of Chinese Medicine. To further improve the clinician's understanding of drugs and better guide the rational clinical application,we invited front-line clinical experts from respiratory department,infectious department and dermatology of traditional Chinese and Western medicine to develop and compile the expert consensus. The consensus fully considered the clinical evidence and the expert clinical experience to give recommendations for clinical problems with evidence support and consensus suggestions for clinical problems without evidence support by the nominal group method.This consensus is based on clinical research evidence and expert experience in a simple and clear format,which provides a preliminary reference for the clinical use of the drug.

Effects of Feiwei granules in the treatment of idiopathic pulmonary fibrosis: a randomized and placebo-controlled trial.

OBJECTIVE: To document the therapeutic effects of Feiwei granules (FGs) for idiopathic pulmonary fibrosis (IPF). METHODS: One hundred cases with IPF were randomized into the treatment group (80) and control group (20). Both groups were given basic treatment with prednisone. The treatment group was given FGs, and the control group was given Jinshuibao capsules (JCs). Treatment lasted for 6 months. The Medical Research Council Dyspnea Scale (MRCDS), the Saint George's Hospital Respiratory Questionnaire (SGHRQ), pulmonary function, the Traditional Chinese Medicine Syndrome Score (TCMSS), 6-min walking test (6MWT) and blood gas analyses were recorded before the study as well as 3 months and 6 months after treatment. RESULTS: FGs showed greater efficacy than the control in certain parameters between before the study and 6 months, and between 3 months and 6 months, in the MRCDS, some indicators in the SGHRQ, and the TCMSS. There were no significant differences between the treatment group and control group in the remainder of the indices evaluated. In the treatment group, there were significant differences in before and after treatment in the MRCDS, SGHRQ, TCMSS and 6MWT. CONCLUSION: FGs were similar to JCs for IPF treatment.

Effects of combining low­dose aspirin with a Chinese patent medicine on follicular blood flow and pregnancy outcome.

The aim of the present study was to investigate the clinical value of low­dose aspirin in combination with Tiao Jing Cu Yun pills in patients with polycystic ovary syndrome (PCOS) by measuring follicular peripheral blood flow parameters and the clinical efficacy. The study involved 78 infertile females with PCOS who were randomly divided into experimental (n=38) and control (n=40) groups. The subjects in the experimental group were treated with letrozole in combination with aspirin and Tiao Jing Cu Yun pills, and the control group was treated with letrozole alone. Transvaginal color Doppler ultrasonography was used to measure the endometrial thickness, pulsatility index (PI), resistance index (RI), peak systolic velocity and end diastolic velocity (EDV) of the follicular peripheral artery on the day of human chorionic gonadotropin administration. The patients who failed to become pregnant in the control group were reintegrated into the experimental group in the subsequent cycle and the clinical effect was observed. In the experimental group, subject perifollicular blood flow was more plentiful, and the PI and RI of the perifollicular blood flow were significantly reduced, while the EDV of the perifollicular blood flow and the rate of clinical pregnancy were markedly elevated compared with the subjects in the control group. Low­dose aspirin combined with Tiao Jing Cu Yun pills effectively improved perifollicular artery blood flow, and enhanced the oocyte quality and rate of clinical pregnancy.

[Treating influenza patients of wind-heat affecting Fei syndrome by jinhua qinggan granule: a double-blinded randomized control trial].

OBJECTIVE: To assess the effect and safety of Jinhua Qinggan Granule (JHG) in treating influenza patients of wind-heat affecting Fei syndrome (WHAFS). METHODS: Totally 136 influenza patients of WHAFS were randomized by stratification into 3 groups, the high dose JHG group (44 cases, 10 g each time), the low dose JHG group (45 cases, 5 g JHG + 5 g placebo each time), and the placebo control group (47 cases, 10 g placebo each time). All medication was administered three times daily for 5 days. The fever disappearance time, the fever disappearance rate, efficacy of TCM syndrome, the disappearance rate of main symptoms and physical signs of flu, the negative rate of virus nucleic acid in the pharyngeal secretion, and safety indicators were assessed. RESULTS: The median fever disappearance time was 32.8 h (95% CI: 22.5-41.0 h) in the high dose JHG group, 26.0 h (95% CI: 14.5-36.5 h) in the low dose JHG group, 39.5 h (95% CI: 29.0-46.0 h) in the placebo control group. There was statistical difference in the median fever disappearance time between the low dose JHG group and the placebo control group (P = 0.011). Three days after treatment, the markedly effective rate of TCM symptoms in the low dose JHG group was 66.7%, higher than that of the placebo control group (38.3%), and its effective rate was superior to that of the high dose JHG group (P = 0.043). Five days after treatment, the recovery rate of the low dose JHG group (42.2%) was higher than that of the high dose JHG group (25.0%, P = 0.026) and that of the placebo control group (14.9%, P = 0.002). The markedly effective rate of the low dose JHG group (86.7%) was higher than that of the placebo control group (55.3%, P = 0.001). Similar effects were obtained in the low dose JHG group and the high dose JHG group, but slightly poor in partial indicators of the high dose JHG group. There was no statistical difference in adverse reaction among these three groups (P > 0.05). CONCLUSIONS: JHG was effective and safe in treating influenza patients of WHAFS. Routinely low dose was the optimal dosage of JHG.

[Study of the "weekend effect" of O3, NOx and other pollutants in summer of Beijing].

The data of O3, NOx (NO and NO2), CO and SO2 observed at Beijing 325m meteorological tower from June 25 to July 7, 2000 and from July 26 to August 22, 2000 are used to analyze the difference of pollutant concentrations on weekends and weekdays, and its causes. Results show that except SO2, the correlations of O3, NOx, NO, NO2 and CO concentrations between weekends and weekdays are very significant,since they all pass the t-test significance level at alpha = 0.05. The correlation coefficients (R) are 0.99, 0.61, 0.56, 0.80 and 0.61 for O3, NOx, NO, NO2 and CO3, respectively. Weekend NO, and CO concentrations are lower than weekday concentrations in rush hours (06:00-08:00), and the mean deviations for NOx and CO concentrations are -28% and -9%, respectively. The regression coefficient of O3 concentrations between weekends and weekdays is 1.25 +/- 0.02. Furthermore, the maximum 1-h average O3 concentration and maximum 8-h average O3 concentration on weekends are 23% and 26% higher than those on weekdays, respectively, indicating an obvious O3 "weekend effect".

[Comparison of nocturnal ecosystem respiration measured with eddy covariance and chamber system at two agricultural sites in Sanjiang plain].

Measurements of nocturnal ecosystem respiration were conducted in a rice paddy of Sanjiang from July to September in 2004 and in a soybean field from June to September in 2005, using eddy covariance (EC) and dark chamber-gas chromatography (DC-GC). The differences of simultaneous data measured by two methods were not significant when night turbulent mixing was well. The correlations between two methods can be improved under more large friction velocity. EC measurements were poorly correlated to night ecosystem respiration estimated by chamber models for the variability inherent to EC measurements (R2 = 0.06, 0.23 for rice and soybean, respectively). However, this correlation can be improved by aggregating measurements over longer time period (R2 = 0.16, 0.75 for rice and soybean field, respectively). In general, whatever comparison with simultaneous chamber measurements or modeled results, eddy covariance measurements were consistently lower 4% - 30% than chambers, and this bias varied with crop growing stage, which were maximum in middle and minimum in early and late growing stage.

[Analysis of the relationship between NO, NO2 and O3 concentrations in Beijing].

Ozone (O3) is a primary gaseous contaminant in urban ambient, and its variation correlates well with nitrogen oxides (NO(x) = NO+ NO2). Continuous monitoring in the urban area from August 2004 to July 2005 was carried out in Beijing, using 49C ozone analyzer and 42CTL NO-NO2-NO(x) gas analyzer. The results show that peak O3 and oxidant (OX = O3 + NO2) concentrations in Beijing often appear at about 15:00 in the early afternoon, the diurnal variation of NO, concentrations show a very clear cycle with two peaks, one appears at about 07:00 in the morning and the other is at 23:00 in the evening. However, concentrations variation in four seasons are not same. The highest concentrations of O3 and NO(x) appear in summer and winter, respectively. The NO, crossover point occurs at about 100 x 10(-9) volume ratio. At lower level, NO2 is the major component of NO(x), whereas NO dominates at higher mixing ratio. It is also shown that the level of OX is made up of two contributions, regional contribution and local contribution. The former is affected by regional background O3 level, with the maximum in spring, whereas the latter is effectively correlates with the level of primary pollution, with the maximum in summer. Diurnal variation also appears in the concentrations of the components of oxidants.

[Measurements of atmospheric boundary layer O3, NOx and CO in summer with Beijing 325 m meteorological tower].

Based on the Beijing 325 m meteorological tower, O3, NOx and CO concentrations and meteorological parameters in urban atmospheric boundary layer were measured in July 2002. The variations of O3 concentration were remarkably different among the five levels. Contrasted with the higher levels, the daily variations were clear and the difference values between day and night were large in the lower levels. It was also found that the photochemistry reaction was an important source in boundary layer in daytime and precipitation process could arouse marked change of O3 concentration.