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Long non-coding RNAs (lncRNAs) have been widely studied and play crucial roles in cervical cancer (CC) progression. Here, we investigated the function and mechanism of lncRNA PGM5-AS1 action in CC cells. Using real-time quantitative polymerase chain reaction or western blotting, PGM5-AS1 and decorin (DCN) were downregulated in CC tissues and cells, whereas miR-4284 was upregulated. Luciferase assay, RNA pull-down assay, and western blotting showed that PGM5-AS1 could sponge miR-4284 to upregulate DCN expression in CC cells. Additionally, cell functional experiments showed that PGM5-AS1 overexpression led to decreased proliferation, migration, and invasion of CC cells. However, the inhibitory effect of PGM5-AS1 overexpression on CC cells was partly relieved by DCN knockdown because of the targeting interaction between PGM5-AS1, miR-4284, and DCN. In summary, this study identified that PGM5-AS1 negatively regulates CC cell malignancy by targeting miR-4284/DCN.

Circular RNA (circRNA) circ_0008717 has been revealed to promote cell carcinogenesis in non-small cell lung cancer (NSCLC). Exosomal circRNA packaged into exosomes has been defined as a potential diagnostic and therapeutic biomarker of cancers. However, little attention is focused on the role of circRNAs within exosomes in NSCLC. Exosomes were isolated by ultracentrifugation method and qualified by nanoparticle tracking analysis and Western blot. Levels of circ_0008717, microRNA (miR)-1287-5p, and P21-activated kinase 2 (PAK2) were detected using qRT-PCR and western blot. The interaction between miR-1287-5p and circ_0008717 or PAK2 was investigated. The phenotypes of NSCLC cells with circ_0008717 downregulation were tested. Circ_0008717 was highly expressed in NSCLC. Functionally, circ_0008717 deficiency suppressed cell malignant phenotypes in NSCLC

In this study, novel aerogels of Nicandra physaloides (L.) Gaertn seed gum (NPG) and Nicandra physaloides (L.) Gaertn seed gum/Carboxymethyl chitosan (NPG/CMC) were prepared by freeze-drying method for removing tetracycline (TC) from water. Scanning electron microscope (SEM), X-ray diffraction (XRD),Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET) were used to characterize structure and morphology of NPG and NPG/CMC aerogels. The average pore diameter of NPG and NPG/CMC were 3.04 and 1.2 nm, the specific surface areas were 2.67 and 0.73 m2/g, respectively. The maximum adsorption capacity of NPG and NPG/CMC aerogels for TC based on Langmuir isotherm was 266.7 and 332.23 mg/g respectively. Through thermodynamic and kinetic studies, it was found that the adsorption processes of the two adsorbents were spontaneous and followed the pseudo-second-order kinetic model. And the process of NPG adsorption of TC was endothermic, while NPG/CMC was exothermic.

Although the response of plant productivity and soil biogeochemical processes to nutrient addition has been widely investigated, little is known about the effects of N and P addition on soil aggreg...

In this study, a novel composite aerogel of Nicandra physaloides(L.) Gaertn seed, gum/graphene oxide (NPG/GO), was prepared by using a vacuum freeze drying method for methylene blue (MB) adsorption. The techniques, including Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), were adopted for studying the structure and surface characteristics of NPG/GO, with thermogravimetric analysis (TGA) being adopted for testing thermal properties. The effects of pH value, initial dye concentration, temperature and adsorbent dosage on adsorption performance were elaborately analysed. The adsorption kinetic studies showed that the process of adsorption follows Langmuir isotherm and a pseudo-second-order kinetic model. When the mass ratio of NPG to GO was 1.25:1, the adsorption capacity was the highest. According to Langmuir isotherm, the maximum adsorption capacity of 408.16 mg/g was higher than that of NPG. The specific surface area and average pore diameter of NPG/GO was measured as 2.70 m2/g and 4.8 nm, respectively. Thermodynamic analysis revealed that the adsorption process of methylene blue on NPG/GO was a spontaneous and endothermic process. In general, the prepared nanocomposites were excellent candidates for adsorption and removal process because of simple synthesis, low cost, high efficiency, non-toxicity, environment protection and degradability.

There is a vast difference between theatrical traditions of China and England as the two countries are geographically apart. Tang Xianzu (汤显祖 1550–1616) and Philip Sidney (1554–1586) lived at oppos...

In this work, a novel soybean oil-based urethane acrylate polyol called ADSO was synthesized by the condensation reaction of hydroxyethyl acrylate modified isophorone diisocyanate with chlorinated ...

Retaining elongated grain microstructure during thermo-mechanical processes would be attractive for obtaining high-strength aluminium alloys with good toughness. A small Zr addition promotes the fo...

Purpose Hepatic injury is a common side effect following tyrosine kinase inhibitor (TKI) therapy and our understanding usually comes from clinical trials. In this retrospective study, we aimed to investigate the characteristics, risk factors and regimen-related differences of epidermal growth factor receptor (EGFR)-TKI -related hepatic toxicity in patients with advanced lung adenocarcinoma (LAD). Patients and Methods Liver function tests were documented in 424 patients admitted into the Shanghai Chest Hospital between January 2014 and December 2016 with advanced (IIIB/IV) LAD who received first-line gefitinib, erlotinib or icotinib. Hepatotoxicity was graded according to the Common Terminology Criteria for Adverse Events (CTCAE), version 4.0. The clinical spectrum and onset time of hepatic injury were evaluated. The risk factors of hepatic dysfunction were determined using a logistic regression analysis. Results A total of 87 (20.5%) patients experienced hepatotoxicity and 5.7% were of grade 3/4 liver dysfunction. The median onset time of hepatotoxicity was 7 weeks. Presence of hepatitis virus (HR: 2.593, 95% CI: 1.090-6.170, P=0.031) and pretreatment liver impairment (HR: 3.460, 95% CI: 1.746-6.855, P

Background Bacterial resistance to antibiotics has become a major public health concern. This study aimed to determine the resistance mechanisms to carbapenem in clinical isolates of Pseudomonas aeruginosa. Methods A total of 62 clinical isolates of carbapenem-resistant P. aeruginosa (CRPA) were collected from 2015 to 2017. Imipenem (IPM)-EDTA disk synergy test was used to screen strains that produced metallo-β-lactamase. In addition, the genes for outer membrane protein OprD2, metallo-β-lactamase and mexR gene were amplified and sequenced. Expression of mexA was detected by real-time PCR. Results Disk synergy test showed that 51.6% (32/62) of the strains were positive for metallo-β-lactamase. PCR showed that 84.4% of the strains were SIM-positive (27/32), 15.6% of the strains were IMP-positive (5/32), and 12.5% of the strains were VIM-positive (4/32). SPM-positive and GIM-positive strains were not detected. In addition, 5 of the 62 strains had small deletions and/or point mutations in OprD2. Three strains had a high expression of mexA, while eight strains were positive for the regulatory gene mexR with no mutations detected by DNA sequencing. Conclusion Expression of metallo-β-lactamase is the main resistance mechanism of P. aeruginosa to carbapenem. Mutations in OprD2 and/or the overexpression of efflux pump MexAB-OprM may contribute to P. aeruginosa resistance to carbapenem.

The optimisation process and results are classified and stored to guide the future workshop scheduling and improve the retrieval efficiency. The results show that the random inertia weight strategy...

Purpose: This study aimed to evaluate the efficacy of upfront whole-brain radiotherapy (WBRT) in EGFR-mutant lung adenocarcinoma patients with multiple brain metastases (BM). Methods: In this study, 195 patients with EGFR mutations who had multiple BM at preliminary diagnosis were included and retrospectively reviewed. Patients were admitted to receive the following treatments in a multi-disciplinary setting: upfront WBRT followed by EGFR-TKI, concurrent EGFR-TKI and WBRT and upfront EGFR-TKI followed by WBRT. A disease-specific graded prognostic assessment (DS-GPA) was performed for all the patients. The treatment response and overall survival (OS) were assessed as well. Results: The median OS of these patients was 27 months. Objective response rate (ORR) was significantly better in upfront WBRT group than other two groups (P=0.004). Moreover, patients who received upfront WBRT (n=67) had longer OS than the concomitant group (36 vs 25 months; P=0.006) and the upfront EGFR-TKI group (36 vs 25 months; P

This study uses panel data from the North China Water Resources Survey in 2004 and 2016 to update the status of groundwater. In the past two decades, groundwater irrigation has spread to mo...

Steel, aluminium and magnesium are important engineering materials owing to their excellent mechanical properties. However, their applications are limited due to inadequate corrosion resistance. Va...

Ming-Jun Zheng,1,2,* Jing Wang,1,2,* Hui-Min Wang,1,2 Ling-Ling Gao,1,2 Xiao Li,1,2 Wen-Chao Zhang,1,2 Rui Gou,1,2 Qian Guo,1,2 Xin Nie,1,2 Juan-Juan Liu,1,2 Bei Lin1,2 1Department of Gynaecology and Obstetrics, Shengjing Hospital Affiliated to China Medical University, Heping District, Shenyang 110004, Liaoning, China; 2Key Laboratory of Maternal-Fetal Medicine of Liaoning Province, Key Laboratory of Obstetrics and Gynecology of Higher Education of Liaoning Province, Liaoning, China *These authors contributed equally to this work Aim: The aim of this study was to explore the expression of peroxiredoxin1 (PRDX1) in epithelial ovarian cancer, analyze the relationship between PRDX1 and clinicopathologic parameters of patients with ovarian cancer, including their prognosis, and describe changes and the mechanisms involved in malignant biologic behavior of ovarian cancer cells when PRDX1 expression is inhibited.Methods: The expression of PRDX1 was detected immunohistochemically in 15 samples of normal ovarian tissue, 21 benign, 11 borderline, and 101 malignant epithelial ovarian tumors. Changes in ovarian cancer cell proliferation, invasion, and metastasis before and after inhibiting PRDX1 expression were assessed by cell function assay. Additionally, gene set enrichment analysis (GSEA) of PRDX1 was performed by the Cancer Genome Atlas database. A protein–protein interaction network was then constructed and a pathway function analysis of the genes in the network was conducted.Results: PRDX1 expression was mainly localized to the cytoplasm, as well as the nucleus of cells. The expression rate of PRDX1 in epithelial ovarian malignant tissues (96.04%) was significantly higher than that in borderline (72.72%) and benign (57.14%) epithelial ovarian tumors, and normal ovarian tissue (20%; all P

While photogrammetry has become popular in archaeology and heritage management as an effective, low-cost method for generating detailed three-dimensional models, it remains to be established that the accuracy of model-derived measurements is sufficient for analytical purposes. Based on an expedient, in-field model processing protocol, we report preliminary results concerning the accuracy of artifact provenience information derived from photogrammetry models of excavation surfaces at the Upper Palaeolithic site of Shuidonggou Locality 2 in China. Error in model-derived provenience can range easily into the centimeter scale; accuracy in some spatial axes are significantly, but weakly, affected by the size of the sampled surface. While the observed error range is larger than thresholds proposed for Palaeolithic excavations, it is arguably acceptable in settings where the analytical demand for provenience precision is lower. We identify possible sources of error and discuss how model accuracy can be i...

Overexpression of microRNA-185-5p (miR-185-5p) in glucocorticoid (GC)-sensitive acute lymphoblastic leukemia (ALL) was identified using a microarray and reverse transcription polymerase chain reaction and was further confirmed in ALL cell lines. A reporter assay confirmed that the Rictor-one component of mammalian target of rapamycin complex 2 (mTORC2) is a target of miR-185-5p. Decreased mTORC activity was also confirmed in GC-sensitive patients. Overexpression of miR-185-5p significantly enhanced GC sensitivity in CEM-C1 cells (GC resistance) by increasing the rate of cell apoptosis and cycle arrest, and decreasing cell survival, accompanied by a decrease in mTORC activity and an increase in GC-induced glucocorticoid receptor (GR) expression. Rapamycin, an mTORC1 inhibitor, showed similar effects to miR-185-5p. These results demonstrated that miR-185-5p enhances GC sensitivity via suppression of mTORC activity by enhancing GR autoupregulation and that miR-185-5p is a potential target for the diagnosis and reversion of GC resistance.

One new flavonoid, 5,7,8,4'-tetrahydroxy-3-methoxyflavone-8-O-β-d-xylopyranoside (2), along with other four known flavones (1, 3-5) were isolated from the aerial parts of Solanum rostratum. 8-hydroxyflavonoid was isolated from series Androceras for the first time. The structure of the new compound 2 was determined on the basis of spectroscopic techniques, including IR, NMR and HRESI-MS. The chemotaxonomic significance of these compounds was summarised.

The consensus reaching process is a dynamic and iterative process for improving group's consensus level before making a final decision in group decision-making GDM. As the experts will express their opinions under their own intellectual level from different aspects, it is natural that the experts’ weights should reflect their judgment information. This paper proposes a dynamic way to adjust weights of decision-makers DMs automatically when they are asked to give original judgment information for GDM problems, in which the DMs express their judgment information by hesitant fuzzy preference relations HFPRs. Two indices, an individual consensus index of hesitant fuzzy preference relation ICIHFPR and a group consensus index of hesitant fuzzy preference relation GCIHFPR, are introduced. Normalisation of HFPRs with different numbers of possible values is taken into consideration for better computation and comparison. An iterative consensus reaching algorithm is presented with DMs’ weighting vector changing in each consensus reaching process and the process terminates until both the ICIHFPR and GCIHFPR are controlled within predefined thresholds. Finally, an example is illustrated and comparative analyses demonstrate the effectiveness of the proposed methods.

This paper deals with the two-dimensional satellite module polygon packing problem. Based on the duality of material and space, it regards the polygon packing problem as a space allocation problem, which involves allocating the container space to the given polygons reasonably and efficiently. Ant colony’s labour division is essentially a kind of task allocation. Using this task allocation to achieve the space allocation in polygon packing problems, a flexible labour division approach (FLD) is proposed based on the response threshold model. According to the characteristics of space allocation in polygon packing problems, FLD designs three actions for polygons to occupy the container space. With the interaction between environmental stimulus and response threshold, each polygon takes an appropriate action to complete the space allocation and a layout that meets the requirements of satellite module layout is obtained. The results of standard test instances demonstrate the effectiveness of FLD when compared w...

In this paper, we study the initial boundary value problem of Newtonian filtration equation in a cone-like do main , where , , with . Let denote the smallest Dirichlet eigenvalue for the Laplace–Beltrami operator on and let l denote the positive root of . We prove that if , then the problem has no global nonnegative solutions for any nonnegative unless ; if , then the problem has global solutions for some .

In order to improve blast furnace efficiency, reduce CO2 emission and accelerate energy utilisation, a new preparation process of iron coke hot briquette (ICHB) based on the raw materials conditions in China, a new type blast furnace ironmaking burden, was experimentally investigated in this paper. The new preparation process was researched and optimised through single factor experiment and orthogonal experiment. Meanwhile, the reactivity and the post-reaction strength of ICHB prepared under the optimised conditions were tested and the effect of ICHB on the thermal performance of conventional coke was researched. In addition, softening and dripping properties of mixed burden with optimised ICHB charging was simultaneously investigated. The results showed that the optimised preparation parameters of ICHB include 15% iron ore, 65% bituminous coal, 350°C hot briquetting temperature, 1100°C carbonisation temperature and 4 hours carbonisation time. The reactivity and the post-reaction strength of ICHB prepared...

A novel blast furnace operation of coke oven gas (COG) injection simultaneously with hot burden charging has been proposed to solve the problem of insufficient heat in the BF shaft zone under the condition of COG injection and make full use of the abundant sensible heat of high temperature burden. In this paper, the novel process has been simulated with a multifluid blast furnace model. The results show that, in comparison with the operation of COG injection only, under the operation of COG injection together with hot burden charging, the temperature in the upper zone of the shaft increases while that in lower zone decreases. Furthermore, the reduction of iron bearing material is improved in the top zone, and the cohesive zone tends to descend and narrow. The coke ratio, fuel ratio and CO2 emissions of the operation of charging hot pellet and coke with the temperature of 800°C are decreased by 4.0, 4.7 and 5.3% respectively, while the hot metal productivity is increased by 7.14%. Therefore, COG injection ...

The aim of this paper is to put forward a consensus reaching method for multi-attribute group decision-making MAGDM problems with linguistic information, in which the weight information of experts and attributes is unknown. First, some basic concepts and operational laws of 2-tuple linguistic label are introduced. Then, a grey relational analysis method and a maximising deviation method are proposed to calculate the incomplete weight information of experts and attributes respectively. To eliminate the conflict in the group, a weight-updating model is employed to derive the weights of experts based on their contribution to the consensus reaching process. After conflict elimination, the final group preference can be obtained which will give the ranking of the alternatives. The model can effectively avoid information distortion which is occurred regularly in the linguistic information processing. Finally, an illustrative example is given to illustrate the application of the proposed method and comparative analysis with the existing methods are offered to show the advantages of the proposed method.

Considering that there may exist some interactions between membership function and non-membership function of different dual hesitant fuzzy sets (DHFSs), in this paper we present some new operational laws from the probability point of view and give a geometric interpretation of the new operations. Based on which, a new class of dual hesitant fuzzy aggregation operators are developed, including dual hesitant fuzzy weighted interaction averaging operator, dual hesitant fuzzy weighted interaction geometric operator, dual hesitant fuzzy ordered weighted interaction averaging operator, dual hesitant fuzzy ordered weighted interaction geometric operator, dual hesitant fuzzy hybrid interaction averaging operator, and dual hesitant fuzzy hybrid interaction geometric operator. The properties of these aggregation operators are investigated. The key advantage of these operators is that the interactions between non-membership function and membership function of different DHFSs are considered, and much more informatio...

This article uses the Graph Model for Conflict Resolution methodology to systematically model and analyze strategic aspects of an existing conflict over the distribution and utilization of water in the Zhanghe River basin in China. This formal systems investigation reveals that a win/win resolution occurs when the downstream provinces of Henan and Hebei agree to cooperate to purchase water at a proper price from the upstream province of Shanxi. This resolution is possible with upgraded infrastructure and with facilitation by the Zhanghe River Upstream Management Bureau. Moreover, an integrated water management system for the entire watershed is recommended.

There are variations in soil respiration across vegetation types; however, it is unclear which factors are mainly responsible for the variations. A field experiment was conducted in 2008 and 2009 in a semiarid region of China to investigate the daytime and monthly variation of soil respiration across vegetation types and to determine the factors controlling the variation. An automated portable soil carbon dioxide (CO2) flux measurement system was used to measure the soil respiration in shrubland, grassland, fallow land, and cropland during the growing periods. The results showed that the relative daytime variation amplitude of soil respiration in the fallow land and cropland was as small as that of shrubland and grassland during July, but greater than that of shrubland and grassland during August and October. A hysteresis effect for the relationship between the daytime soil respiration and daytime soil temperature was observed for all four vegetation types. There was also a hysteresis effect for t...

Einstein product and Einstein sum are good alternatives to the algebraic product and algebraic sum, respectively. Nevertheless, it seems that in the literature there is little investigation on aggregation techniques using the Einstein operations on IFS for aggregating a collection of intuitionistic fuzzy value (IFV). The induced ordered weighted averaging operator is more suitable for aggregating individual preference relations into a collective fuzzy preference relation. In order to deal with more complex group decision-making problem with intuitionistic fuzzy information, the paper develops an I-IFOWA ϵ operator which generalizes some of the intuitionistic fuzzy Einstein aggregation operators, such as the IFWA ϵ operator, IFOWA ϵ operator, IFA ϵ , as well as IF maximum operator and IF minimum operator. Furthermore, the authors apply the I-IFOWA ϵ operator and the IFWA ϵ operator to multiple attribute group decision-making with intuitionistic fuzzy information, and give an illustrative example to show th...

The eastern route of south-to-north water diversion (SNWD) project is a large-scale multi-source, multi-objective and multi-project inter-basin system. Constructed to pump, store and supply water to achieve rational water distribution in North China, the project is close to completion currently, and faced with optimal operations management problems. Based on the project practice, this article develops a supply chain system for the SNWD project, where a Stackelberg game model under decentralized decisions, an asymmetric Nash bargaining model, and an asymmetric Nash bargaining model with risk of breakdown and discount are respectively built, and numerical analysis are carried out for managerial insights. This study suggests that: (i) asymmetric Nash bargaining provides a more efficient mechanism for south-to-north water diversion supply chain to achieve cooperative operations through non-cooperative way; (ii) the Agent's sharing profit earned is positively related to his bargaining power, and the optimal wh...

The bone marrow microenvironment plays a role in myeloma cell proliferation and adhesion-mediated drug resistance. In this study, we investigated microRNA-21 (miR-21) expression changes in myeloma cells that adhered to bone marrow stromal cells (BMSCs). In addition, we studied the synergistic effect of miR-21 inhibition with dexamethasone (Dex), doxorubicin (Dox), or bortezomib (Bort) on myeloma cell survival. We found that up-regulation of miR-21 expression was partially driven by nuclear factor-κB (NF-κB) signaling via myeloma cell adhesion to BMSCs. We also confirmed that RhoB is a miR-21 regulation target gene. Moreover, miR-21 inhibition combined with cytotoxic drug Dex or Dox inhibited myeloma cell survival more effectively than either treatment alone. These results suggest that the regulatory mechanisms of miR-21 expression may be a promising target for fine-tuning anti-myeloma therapy.

In this paper, fibre‐diameter‐dependent light scattering during measurment of wool colour was quantified using the extended multiplicative signal correction technique. Furthermore, a simple‐to‐apply model has been developed to correct each of the CIE (International Commission on Illumination) X, Y and Z values obtained from colour measurement of fibrous masses. The model was successfully applied to both polypropylene (PP) and wool fibres, though different parameter values were used in each case, indicating different patterns of internal light scattering between PP and wool fibres. After the model corrections, the diameter dependence of measured wool yellowness (Y – Z) was either eliminated or significantly reduced for each of seven sheep flocks distributed widely over the wool‐growing regions of Australia.

Based on the lubrication theory of mould flux, a mathematical model of dynamic pressure in mould flux channel was developed, and the distribution of dynamic pressure and its variation during non-sinusoidal oscillation were investigated. The effects of casting speed and non-sinusoidal oscillation parameters, including the degree of non-sinusoidal operation (non-sinusoidal factor), amplitude and frequency of oscillation on the dynamic pressure in the mould flux channel, were studied. The results indicate that the maximum negative pressure is decreased, and the maximum positive pressure is increased with increasing non-sinusoidal factor. The optimum value of non-sinusoidal factor is ∼0·2. With increasing amplitude and frequency of oscillation, both the negative and positive pressure are increased; moreover, the increment of positive pressure is obviously greater than that of negative pressure; especially when the oscillation frequency is increased, the increment of negative pressure is very little. W...

To identify a proliferation-inducing ligand (APRIL) expression profile in tumor tissue and sputum of lung cancer, and evaluate the possibility of an assistant diagnosis of lung cancer by real-time fluorescence quantitative polymerase chain reaction (RTQ-PCR) in sputum as well, the authors analyzed the expression of APRIL mRNA in 75 tissue samples and 71 corresponding sputum samples of lung cancer by RTQ-PCR and analyzed their correlation. APRIL protein expression was also observed in tumor tissues by Western blot and immunohistochemistry. The expression analysis revealed APRIL expression was elevated in non-small cell lung cancer (NSCLC) and the expression of APRIL protein was located in the membrane and cytoplasm of tumor cells by immunohistochemiscal staining. Compared to benign pulmonary disease and healthy volunteers, the expression of APRIL mRNA in sputum of lung cancer was elevated (both P

Evaluation of CAS-OB refining slags showed that the melting temperature and viscosity were very high and could further increase during the CAS-OB refining process, causing excessive slag to stick to the snorkel with resulting operational problems. To avoid this, B2O3–CaO (mass ratio 1 : 1) and CaF2–CaO (mass ratio 1 : 1) were employed as modifiers added to the slag. The fusibility (melting temperature and viscosity) and desulphurising capacity of modified slag were investigated. Both B2O3–CaO and CaF2–CaO can effectively lower the melting temperature and viscosity of slag. The results of experiments on sulphur partition equilibrium between metal and slag indicate that the sulphur content of metal can be further decreased by the modified slag.

Nitration of pyrene adsorbed on silica particles by various gases, including NO2, HNO2, HNO3 and their mixtures, was studied in simulated atmosphere under dark and room light conditions. Not only HNO3 but also HNO2 acted as a catalyst. The nitration of the adsorbed pyrene by NO2 proceeded most rapidly when it was catalyzed by a mixed gas of HNO2 and HNO3, and even faster than the sum of what individually catalyzed by HNO3 and HNO2 gases. These results imply that the nitration of polycyclic aromatic hydrocarbons via reaction with the mixed gas of NO2, HNO3 and HNO2 may contribute to the nighttime formation of nitro polycyclic aromatic hydrocarbons in the atmosphere.