Smart Diffraction Gratings Based on the Shape Memory Effect.

The shape memory effect is the capability of a structure or a material that can be deformed into a certain temporary shape under external stimulus, and the shape will be fixed without the stimulus. The recovery process can be triggered by the same stimulus. The intelligent tunable device based on the shape memory effect has a wide range of applications in many fields. In the optical field, smart diffraction gratings can accomplish in situ optical diffractions according to requirements, meeting the high demand in the next generation of smart optical systems. However, it is essential to construct high-precision grating structures based on shape memory materials. Here, a smart diffraction grating based on UV-curable shape memory polymers (SMPs) via two-beam interference is reported, with nano-scale precision, excellent deformability and recovery ability, and adjustable spectroscopic performance. More importantly, based on the shape memory effect, grating structures that surpass the precision of the fabrication system can be obtained. The smart grating exhibits rapid deformation and recovery upon heating and long-term storage capability, which facilitates them to be applied in optics, electronics, and integrated sensing.

Mapping and characterization of major QTL for spike traits in common wheat.

The spike traits of wheat can directly affect yield. F2 and F2:3 lines derived from the cross of the multi-spikelet female 10-A and the uni-spikelet male BE89 were used to detect QTLs for spike length (SL), total spikelet number per spike (TSS), kernel number per spike (KNS) and thousand-kernel weight (TKW) in four different environments. A total of 1098 SNP and 5 SSR were used to construct genetic map of 2398.1 cM with the average distance of 2.2 cM between markers. A total of 11 QTLs were identified for spike traits, including three QTLs for SL, five QTLs for TSS, two QTLs for KNS and one QTL for TKW. The QTLs mapped to chromosomes 2D, 4A, 6A, 7A and 7B explained 8.2-37.8% of the phenotypic variation in single environment. The major QTL confidence interval with distance of 0.5 cM was located on chromosome 4A and detected in multiple environments, which can explain more than 30% of the phenotypic variation for SL, TSS and KNS. Combining IWGSC RefSeq v1.0 and RNA-seq data for 10-A and BE89, we identified 16 genes expressed on spike or grain in four QTL regions. These findings provide insights into improving wheat yield through increasing spikletes in wheat, particularly through the use of the multi-spikelet female 10-A for breeding.

Evaluating the Efficacy of Atorvastatin on Patients with Carotid Plaque by an Innovative Ultrasonography.

BACKGROUND: The present study aimed to explore the efficacy of atorvastatin on patients with carotid plaque, applying superb microvascular imaging (SMI), and contrast-enhanced ultrasound (CEUS) for evaluating carotid intraplaque neovascularization. METHODS: A total of 82 patients (82 carotid plaques) who were randomized into treatment group and control group underwent conventional ultrasound, CEUS, and SMI examinations. Patients in treatment group received a dose of 20 mg atorvastatin per day for 6 months while those in control group received placebo instead. Lipid parameters were assessed and intraplaque neovascularization were evaluated by CEUS and SMI before and 6 months after atorvastatin treatment. RESULTS: No significant differences were found between the 2 groups at the study entry. Patients with atorvastatin treatment received marked improvement in total cholesterol, triglyceride, and LDL-cholesterol compared with those in control group (P < .001). In treatment group, SMI-detected intraplaque neovascularization reduced from 69.23% to 48.72% while CEUS-detected ones reduced from 76.92% to 69.23%. By contrast, the percentage of intraplaque neovascularization in control group did not change too much either by SMI (65.12%, 67.44%) or CEUS (74.41%, 74.41%). The consistency between CEUS and SMI was above .75 at all assessments (P < .001). CONCLUSIONS: Atorvastatin treatment works for patients with carotid plaque by reducing LDL-cholesterol and improving plaque regression. Second, the consistency between SMI and CEUS in visualizing intraplaque neovascularization is good. That indicates a high possibility to identify carotid plaque instability by a safer and cheaper ultrasonography without contrast agent.

[The effect of cgVEGF164 on the growth of murine hair follicles].

Vascular endothelial growth factor (VEGF) is a dimeric glycoprotein that induces proliferation and migration of vascular endothelial cells as well as regulation of capillary formation around hair follicles which affects the growth and development of hair follicles. cgVEGF164 is a major splice variant of the cashmere goat VEGF-A gene, but its regulation on hair follicles is rarely known. In order to investigate the role of cgVEGF164 on the growth of murine hair follicles, we produced keratin 14 promoter-driven cgVEGF164 transgenic mice via pronuclear microinjection. Firstly, the diameter and density of hair follicles of transgenic mice were compared with non-transgenic control mice in paraffin sections stained by hematoxylin-eosin (H&E). Then, protein expression levels and the phosphorylation of ERK1/2, AKT1 and LEF1 were examined by Western blot. There are five positive individuals among the neonatal mice (positive rate is 8.5%). Compared with non-transgenic control mice, the diameter and density of hair follicles in transgenic mice are both obviously increased. The expression levels of P-ERK1/2/ERK1/2, P-AKT1/AKT1 and P-LEF1/LEF1 are significantly higher in transgenic mice than those in non-transgenic control mice. Based on these results, we conclude that cgVEGF164 as a growth factor can improve the growth of hair follicles which might be mediated by increasing the levels of ERK1/2, AKT1, and LEF1 protein phosphorylation.

Isolation, Purification and Structural Characterization of Two Novel Water-Soluble Polysaccharides from Anredera cordifolia.

Anredera cordifolia, a climber and member of the Basellaceae family, has long been a traditional medicine used for the treatment of hyperglycemia in China. Two water-soluble polysaccharides, ACP1-1 and ACP2-1, were isolated from A. cordifolia seeds by hot water extraction. The two fractions, ACP1-1 and ACP2-1 with molecular weights of 46.78 kDa ± 0.03 and 586.8 kDa ± 0.05, respectively, were purified by chromatography. ACP1-1 contained mannose, glucose, galactose in a molar ratio of 1.08:4.65:1.75, whereas ACP2-1 contained arabinose, ribose, galactose, glucose, mannose in a molar ratio of 0.9:0.4:0.5:1.2:0.9. Based on methylation analysis, ultraviolet and Fourier transform-infrared spectroscopy, and periodate oxidation the main backbone chain of ACP1-1 contained (1→3,6)-galacturonopyranosyl residues interspersed with (1→4)-residues and (1→3)-mannopyranosyl residues. The main backbone chain of ACP2-1 contained (1→3)-galacturonopyranosyl residues interspersed with (1→4)-glucopyranosyl residues.

Role of thymosin beta 4 in hair growth.

Although thymosin beta 4 (Tß4) is known to play a role in hair growth, its mechanism of action is unclear. We examined the levels of key genes in a Tß4 epidermal-specific over-expressing mouse model and Tß4 global knockout mouse model to explore how Tß4 affects hair growth. By depilation and histological examination of the skin, we confirmed the effect of Tß4 on hair growth, the number of hair shafts and hair follicle (HF) structure. The mRNA and protein expression of several genes involved in hair growth were detected by real-time PCR and western blotting, respectively. Changes in the expression of ß-catenin and Lef-1, the two key molecules in the Wnt signaling pathway, were similar to the changes observed in Tß4 expression. We also found that compared to the control mice, the mRNA and protein expression of MMP-2 and VEGF were increased in the Tß4 over-expressing mice, while the level of E-cadherin (E-cad) remained the same. Further, in the Tß4 global knockout mice, the mRNA and protein levels of MMP-2 and VEGF decreased dramatically and the level of E-cad was stable. Based on the above results, we believe that Tß4 may regulate the levels of VEGF and MMP-2 via the Wnt/ß-catenin/Lef-1 signaling pathway to influence the growth of blood vessels around HFs and to activate cell migration. Tß4 may have potential for the treatment of hair growth problems in adults, and its effects should be further confirmed in future studies.

Hypoxia-induced resistance to cisplatin-mediated apoptosis in osteosarcoma cells is reversed by gambogic acid independently of HIF-1α.

In vitro evidence of hypoxia-induced resistance to cisplatin (CDDP)-mediated apoptosis exists in human osteosarcoma (OS). Gambogic acid (GA) is a promising chemotherapeutic compound that could increase the chemotherapeutic effectiveness of CDDP in human OS cells by inducing cell cycle arrest and promoting apoptosis. This study examined whether GA could overcome OS cell resistance to CDDP. Hypoxia significantly reduced levels of CDDP-induced apoptosis in the OS cell lines MG63 and HOS. However, combined treatment with GA and CDDP revealed a strong synergistic action between these drugs, and higher protein levels of the apoptosis-related factor Fas, cleaved caspase-8 and cleaved caspase-3 and lower expression of hypoxia-inducible factor (HIF)-1α are detected in both cell lines. Meanwhile, drug resistance was not reversed by exposure to the HIF-1α inhibitor 2-methoxyestradiol. These findings strongly suggest that hypoxia-induced resistance to CDDP is reversed by GA in OS cells independently of HIF-1α. Furthermore, in vivo studies using xenograft mouse models revealed that combination therapy with CDDP and GA exerted increased antitumor effects by inducing apoptosis. Taken together, our results demonstrate that GA may be a new potent therapeutic agent useful for targeting human OS cells.

[Regional characteristic analysis of alkaloids and chlorogenic acid in wild Phellodendri Amurensis Cortex].

In the present research, 674 wild medicinal material samples of Phellodendri amurensis Cortex were collected from 31 sampling sites in the whole distribution of its original plant Phellodendron amurense. The samples were collected under the premise that the stem diameter of sampling plant, sampling position and time were controlled. And the sampling sites were set at the interval of a latitude. The content of 6 kinds of active ingredients, palmatine chloride, berberine hydrochloride, phellodendrine chloride, jatrorrhizine hydrochloride, magnoflorine, chlorogenic acid, etc in the medicinal material samples were determined, and the results showed that the content of most active ingredients in the medicinal materials showed significant differences due to the difference of sampling sites. Among them, the medicinal materials from Liaoning region had the highest content of active ingredients, followed by Beijing and Jilin regions, and that from Heilongjiang region had the lowest content. The study has important directive significance to the exploration of environmental factors for the formation of active constituent and artificial planting regionalization of high quality Phellodendri amurensis Cortex.

[Evaluation for heavy metal pollution of soil and herb from main producing area of Phellodendron amurense in China].

In order to evaluate the heavy metal potential pollution of soil and medicinal materials in main producing area of Phellodendron amurense, we collected 32 soil samples and 32 herb samples from northeast and north of China covering four provinces. In this study, the detection of heavy metal contents was conducted by ICP emission spectroscopy and atomic fluorescence spectrometry. The results showed that the soil from all areas of Ph amurense generally reached the national standard. As, Hg, Cr, Cd, Pb and Cu content of herb samples met the requirtment of the national standard except Hg content exceeding standard slight in a few samples. The reason of excessive Hg was the ability of Hg accumulation in Ph. amurense and atmospheric environment was polluted. So, national standard and Good Agricultural Practice (GAP) must be carried out severely in Ph. amurense resources production.

Matrine inhibits the growth and induces apoptosis of osteosarcoma cells in vitro by inactivating the Akt pathway.

Matrine, a natural product, has been demonstrated to be a promising chemotherapeutic drug for some cancers. Using flow cytometric analysis of the cell cycle and apoptosis, we found that matrine inhibited the proliferation and induced apoptosis in the human osteosarcoma (OS) cell lines MG63, HOS, U2OS, and SAOS2 in vitro in a dose-dependent manner. We therefore assessed the role of the serine/threonine kinase Akt in the regulation of matrine-mediated cell growth inhibition and apoptosis induction in human OS cell lines. After treatment for 48 h, matrine induced G0/G1-stage cell cycle arrest in MG63, U2OS, and SAOS2 cells associated with an increase in the expression of p27(Kip1) and a decrease in the expression of Akt, glycogen synthase kinase 3 (GSK3)-ß (Ser9), and cyclin D1. Furthermore, the pro-apoptotic factor Bax was upregulated. Overall, our findings suggest that matrine may be an effective anti-osteosarcoma drug due to its ability to inhibit proliferation and induce apoptosis in OS cells, possibly through the involvement of Akt signaling.

The CUSUM analysis of the learning curve for endoscopic thyroidectomy by the breast approach.

OBJECTIVES: To evaluate the learning curve for endoscopic thyroidectomy by the breast approach (ETBBA) based on the cumulative summation (CUSUM) technique. METHODS: The study included 110 consecutive patients who underwent ETBBA by a single surgeon between January 2009 and May 2012 at the Xiangya Hospital of Central South University, Changsha, China. The learning curve was evaluated using the CUSUM technique. The patients were chronologically arranged into 3 phases by the CUSUM analysis for operative time. Demographic data and operative parameters were also analyzed. RESULTS: The mean operative time (OT) was 125.3 minutes. The conversion rate for technical difficulties and the definitive complication rate were 6.4% and 10%, respectively. The learning curve was analyzed mainly by OT using the CUSUM technique. There was a significant improvement in the average OT (P < .05) after the first 27 patients and again after the first 67 patients (P < .05). A downward trend in OT was found up to the last patient. There were similarities in gender, tumor size, extent of surgery, blood loss, histology, hospital stay, conversion rate, and complications among the 3 phases. Comparison of 2 neighboring phases also showed no significant differences in age. CONCLUSIONS: ETBBA performed by surgeons has a remarkable learning curve. There were 27 cases in the early stage of the learning curve, whereas mastery level could be achieved with 67 cases.

Interpretable machine learning identifies metabolites associated with glomerular filtration rate in type 2 diabetes patients.

Objective: The co-occurrence of kidney disease in patients with type 2 diabetes (T2D) is a major public health challenge. Although early detection and intervention can prevent or slow down the progression, the commonly used estimated glomerular filtration rate (eGFR) based on serum creatinine may be influenced by factors unrelated to kidney function. Therefore, there is a need to identify novel biomarkers that can more accurately assess renal function in T2D patients. In this study, we employed an interpretable machine-learning framework to identify plasma metabolomic features associated with GFR in T2D patients. Methods: We retrieved 1626 patients with type 2 diabetes (T2D) in Liaoning Medical University First Affiliated Hospital (LMUFAH) as a development cohort and 716 T2D patients in Second Affiliated Hospital of Dalian Medical University (SAHDMU) as an external validation cohort. The metabolite features were screened by the orthogonal partial least squares discriminant analysis (OPLS-DA). We compared machine learning prediction methods, including logistic regression (LR), support vector machine (SVM), random forest (RF), and eXtreme Gradient Boosting (XGBoost). The Shapley Additive exPlanations (SHAP) were used to explain the optimal model. Results: For T2D patients, compared with the normal or elevated eGFR group, glutarylcarnitine (C5DC) and decanoylcarnitine (C10) were significantly elevated in GFR mild reduction group, and citrulline and 9 acylcarnitines were also elevated significantly (FDR<0.05, FC > 1.2 and VIP > 1) in moderate or severe reduction group. The XGBoost model with metabolites had the best performance: in the internal validate dataset (AUROC=0.90, AUPRC=0.65, BS=0.064) and external validate cohort (AUROC=0.970, AUPRC=0.857, BS=0.046). Through the SHAP method, we found that C5DC higher than 0.1µmol/L, Cit higher than 26 µmol/L, triglyceride higher than 2 mmol/L, age greater than 65 years old, and duration of T2D more than 10 years were associated with reduced GFR. Conclusion: Elevated plasma levels of citrulline and a panel of acylcarnitines were associated with reduced GFR in T2D patients, independent of other conventional risk factors.

Identification of UDP-glucuronosyltransferase (UGT) isoforms involved in the metabolism of Chlorophenols (CPs).

Chlorophenols (CPs) are a group of pollutants that pose a great threat to the environment, they are widely used in industrial and agricultural wastes, pesticides, herbicides, textiles, pharmaceuticals and plastics. Among CPs, pentachlorophenol was listed as one of the persistent organic pollutants (POPs) by the Stockholm convention. This study aims to identify the UDP-glucosyltransferase (UGT) isoforms involved in the metabolic elimination of CPs. CPs' mono-glucuronide was detected in the human liver microsomes (HLMs) incubation mixture with co-factor uridine-diphosphate glucuronic acid (UDPGA). HLMs-catalyzed glucuronidation metabolism reaction equations followed Michaelis-Menten or substrate inhibition type. Recombinant enzymes and chemical reagents inhibition experiments were utilized to phenotype the main UGT isoforms involved in the glucuronidation of CPs. UGT1A6 might be the major enzyme in the glucuronidation of mono-chlorophenol isomer. UGT1A1, UGT1A6, UGT1A9, UGT2B4 and UGT2B7 were the most important five UGT isoforms for metabolizing the di-chlorophenol and tri-chlorophenol isomers. UGT1A1 and UGT1A3 were the most important UGT isoforms in the catalysis of tetra-chlorophenol and pentachlorophenol isomers. Species differences were investigated using rat liver microsomes (RLMs), pig liver microsomes (PLMs), dog liver microsomes (DLMs), and monkey liver microsomes (MyLMs). All these results were helpful for elucidating the metabolic elimination and toxicity of CPs.

The association between plasma free amino acids and type 2 diabetes mellitus complicated with infection in Chinese patients.

BACKGROUND: Type 2 diabetes mellitus (T2DM), one of the most common public diseases threatening human health, is always accompanied by infection. Though there are still a variety of flaws in the treatment of some infectious diseases, metabolomics provides a fresh perspective to explore the relationship between T2DM and infection. Our research aimed to investigate the association between plasma free amino acids (PFAAs) and T2DM complicated with infection in Chinese patients. METHODS: A cross-sectional study was conducted from May 2015 to August 2016. We retrieved the medical records of 1032 inpatients with T2DM from Liaoning Medical University First Affiliated Hospital and we used mass spectrometry to quantify 23 PFAAs. Infections contained 15 individual categories that could be retrieved from the database. Principal component analysis was used to extract factors of PFAAs. Multi-variable binary logistic regression was used to obtain odds ratios (OR) and their 95% confidence intervals (CI). RESULTS: Among 1032 inpatients,109 (10.6%) had infectious diseases. Six factors, accounting for 68.6% of the total variance, were extracted. Factor 4 consisted of Glu, Asp and Orn. Factor 5 consisted of Hcy and Pip. After adjusting for potential confounders, factor 4 was positively correlated with T2DM complicated with infection in Chinese T2DM patients (OR: 1.27, 95%CI: 1.06-1.52). Individual Hcy in factor 5 was positively associated with T2DM complicated with infection (OR: 1.33, 95%CI: 1.08-1.64). Furthermore, factor 4 (OR: 1.44, 95%CI: 1.11-1.87), Orn (OR: 1.01, 95%CI: 1.00-1.02) and Hcy (OR: 1.56, 95%CI: 1.14-3.14) were positively associated with bacterial infection in Chinese T2DM patients, while factor 5 (OR: 0.71, 95%CI: 0.50-1.00) was negatively associated with bacterial infection. CONCLUSIONS: Urea cycle-related metabolites (Orn, Asp, Glu) and Hcy were positively associated with T2DM complicated with infection in China. Orn and Hcy were positively associated with bacterial infection in T2DM patients in China.

[Correlation between dissolution in vitro and absorption in vivo of chuanping sustained release tablets].

OBJECTIVE: To investigate the correlation between dissolution in vitro and absorption in vivo of Chuanping sustained release tablets. METHOD: The ephedrine, pseudoephedrine were chosen as marker components, dissolution in vitro of Chuanping sustained release tablets in the different pH were tested by the rotating basket method and HPLC; urine drug levels were determined by HPLC and absorption fractions were calculated according to Wagner-Nelson's formula and deconvolution technique. RESULT: The linear regressive equation between the absorption percentage in vivo F and accumulative release percentage in vitro of Chuanping sustained release tablets was established as F(ephedrine) = 1.572 5f-20. 729 (R2 = 0.974 5); F(pseudoephedrine) = 1.237f-0.147 6 (R2 = 0.959 5). CONCLUSION: The results suggested that there was fine correlation between the absorption percentage in vivo and the accumulative release percentage in vitro of Chuanping sustained release tablets.

[Phosphorus Adsorption in Water and Immobilization in Sediments by Lanthanum-modified Water Treatment Sludge Hydrochar].

Using water treatment sludge and lanthanum chloride as raw materials, lanthanum-modified water treatment sludge hydrothermal carbon was prepared through one-step hydrothermal carbonization and loading lanthanum. SEM-EDS, BET, FTIR, XRD, and XPS were used to characterize the materials. The initial pH of the solution, adsorption time, adsorption isotherm, and adsorption kinetics were investigated to study the adsorption characteristics of phosphorus in water. The results showed that the specific surface area, the pore volume, and the pore size of the prepared materials were significantly increased, and the phosphorus adsorption capacity was greatly improved compared with that of the water treatment sludge. The adsorption process conformed to the pseudo-second-order kinetic model, and the Langmuir model fitted the maximum phosphorus adsorption capacity to 72.69 mg·g-1. The main adsorption mechanisms were electrostatic attraction and ligand exchange. Adding lanthanum-modified water treatment sludge hydrochar into the sediment could effectively control the release of endogenous phosphorus from the sediment to the overlying water. According to the analysis of phosphorus forms in sediment, the addition of hydrochar promoted the transformation of unstable NH4Cl-P, BD-P and Org-P into the very stable HCl-P in the sediment, which reduced the content of potential active phosphorus and also significantly reduced the content of biologically available phosphorus. This indicated that lanthanum-modified water treatment sludge hydrochar could effectively adsorb and remove phosphorus in water and could also be used as sediment improvement material to effectively stabilize endogenous phosphorus in sediment and control phosphorus content in water.

Visible-Light-Induced, Palladium-Mediated Desaturation/Sulfonation Cascade To Access 4-Sulfonyltetrahydropyridine Scaffolds.

Herein, we report a visible-light-induced, palladium-catalyzed desaturation/sulfonation cascade, offering a concise route to a series of highly valuable 4-sulfonyltetrahydropyridine scaffolds from inexpensive and readily available piperidine derivatives with sodium sulfinates. The key to the success of this transformation is the well-designed sequence of palladium-mediated 1,5-hydrogen atom transfer/ß-hydride elimination/allylic sulfonation process, which demonstrates the synthetic potentials for orchestrating synthetic events by rationally taking advantage of varied catalytic modes.

Dynamic evaluation of the cervical spine by kinematic MRI in patients with cervical spinal cord injury without fracture and dislocation.

BACKGROUND: The pattern of changes in the cervical spine and the spinal cord and their dynamic characteristics in patients with cervical spinal cord injury without fracture and dislocation remain unclear. This study aimed to evaluate the dynamic changes in the cervical spine and spinal cord from C2/3 to C7/T1 in different positions by using kinematic magnetic resonance imaging in patients with cervical spinal cord injury without fracture and dislocation. This study was approved by the ethics committee of Yuebei People's Hospital. METHODS: Using median sagittal T2-weighted images for 16 patients with cervical spinal cord injury without fracture and dislocation who underwent cervical kinematic MRI, the anterior space available for the cord, spinal cord diameter, posterior space available for the cord from C2/3 to C7/T1, and Muhle's grade were determined. The spinal canal diameter was calculated by adding the anterior space available for the cord, spinal cord diameter, and posterior space available for the cord. RESULTS: The anterior space available for the cord, posterior space available for the cord, and spinal canal diameters at C2/3 and C7/T1 were significantly higher than those from C3/4 to C6/7. Muhle's grades at C2/3 and C7/T1 were significantly lower than those at the other levels. Spinal canal diameter was lower in extension than in the neutral and flexion positions. In the operated segments, significantly lesser space was available for the cord (anterior space available for the cord + posterior space available for the cord), and the spinal cord diameter/spinal canal diameter ratio was higher than those in the C2/3, C7/T1, and non-operated segments. CONCLUSION: Kinematic MRI demonstrated dynamic pathoanatomical changes, such as canal stenosis in different positions, in patients with cervical spinal cord injury without fracture and dislocation. The injured segment had a small canal diameter, high Muhle's grade, low space available for the cord, and high spinal cord diameter/spinal canal diameter ratio.

[Comparison of Regional Transportation and Transformation Models of Atmospheric Polycyclic Aromatic Hydrocarbons and Research on Key Influencing Factors: Take the Beijing-Tianjin-Hebei Region as Example].

In this study, taking the Beijing-Tianjin-Hebei region as an example, CMAQ and BETR models were constructed to carry out numerical simulation for the pyrene (Pyr) and benzo[a] pyrene (BaP) in 2014. The model results were compared and evaluated for the atmospheric transportation and transformation of PAHs. Additionally, the XGBoost model was used to identify the key atmospheric physicochemical processes and parameters that affect the environmental behavior of PAHs in the CMAQ. The results showed that the ratio of the simulated value of BETR and annual average value of CMAQ to the measured annual average value was between 1/2 and 2, and the seasonal trend of the simulated concentrations of Pyr and BaP from the CMAQ model were basically consistent with the measured values, which verified the reliability of the two types of models. At the same time, the simulated concentration of the CMAQ model averaged from 9 km grid to 27 km grid and was comparable to the BETR concentration. The results showed that the average concentrations of Pyr and BaP in the BETR model were approximately 1.59 and 1.38 times those of the CMAQ simulation concentrations, respectively, indicating that the two models had good comparability in terms of average annual concentration level and spatial distribution. The SHAP-based variable importance on the XGBoost model showed that boundary layer height was the most significant meteorological factor affecting the transportation and transformation of Pyr and BaP, accounting for 22%-35% of all factors, and sometimes even exceeded the emissions for certain cities and pollutants. The boundary layer height was significantly negatively correlated with the concentration of PAHs. Wind speed was a secondary factor affecting the concentration of PAHs and was negatively correlated with the PAHs, whereas the influence of wind direction on the concentration of PAHs varied.