A magnetar-powered X-ray transient as the aftermath of a binary neutron-star merger.

Mergers of neutron stars are known to be associated with short γ-ray bursts1-4. If the neutron-star equation of state is sufficiently stiff (that is, the pressure increases sharply as the density increases), at least some such mergers will leave behind a supramassive or even a stable neutron star that spins rapidly with a strong magnetic field5-8 (that is, a magnetar). Such a magnetar signature may have been observed in the form of the X-ray plateau that follows up to half of observed short γ-ray bursts9,10. However, it has been expected that some X-ray transients powered by binary neutron-star mergers may not be associated with a short γ-ray burst11,12. A fast X-ray transient (CDF-S XT1) was recently found to be associated with a faint host galaxy, the redshift of which is unknown13. Its X-ray and host-galaxy properties allow several possible explanations including a short γ-ray burst seen off-axis, a low-luminosity γ-ray burst at high redshift, or a tidal disruption event involving an intermediate-mass black hole and a white dwarf13. Here we report a second X-ray transient, CDF-S XT2, that is associated with a galaxy at redshift z = 0.738 (ref. 14). The measured light curve is fully consistent with the X-ray transient being powered by a millisecond magnetar. More intriguingly, CDF-S XT2 lies in the outskirts of its star-forming host galaxy with a moderate offset from the galaxy centre, as short γ-ray bursts often do15,16. The estimated event-rate density of similar X-ray transients, when corrected to the local value, is consistent with the event-rate density of binary neutron-star mergers that is robustly inferred from the detection of the gravitational-wave event GW170817.

[Research progress on the mechanism of pyroptosis in airway epithelial barrier injury in asthma].

Pyroptosis is a novel form of programmed cell death mediated by cleavage of Gasdermin family proteins by activated caspases, which plays an important role in the control of acute and chronic diseases. Asthma is a chronic inflammatory airway disease with varying degrees of airflow obstruction. The airway epithelial barrier plays an important role in initiating host defenses and controlling immune responses. Accumulating evidence suggests that pyroptosis is involved in the impairment of airway epithelial barrier function and abnormal immune regulation in asthma. This article aims to review the latest regulatory mechanism of pyroptosis involved in airway epithelial barrier injury in asthma under various environmental exposure factors, and to provide a new method for targeted therapy of asthma.

[Clinical and ultrasonic characteristics of male gout patients with normal serum uric acid].

The clinical data and joint ultrasound characteristics of 140 male patients aged from 18 to 70 years who were diagnosed with acute gout from June 2017 to June 2021 in Department of Rheumatology and Immunology of the Third Hospital of Hebei Medical University were selected for the retrospective analysis. According to the serum uric acid levels, the patients were divided into normal uric acid group (sUA≤420 µmol/L, 38 cases) and hyperuric acid group (sUA>420 µmol/L, 102 cases).The results suggested that the lower limb joints were the most affected in gout patients. The deposition of MSU crystal were still found in male gout patients with normal serum uric acid, and the standard urate-lowering therapy should also be carried out. Ultrasound can be used as an important supplementary tool for the diagnosis of gout. Group with high level serum uric acid may be more serious.

[Interventional effect and mechanism of fermentation liquid of Dendrobium officinale leaves on alcoholic hepatitis mice].

Objective: To explore the intervention effect and mechanism of Dendrobium officinale leaf fermentation liquid on alcoholic hepatitis (AH) mice. Methods: Seventy inbred C57BL/6J male mice aged 6-8 weeks were selected and randomly divided into normal group (NG), model group (MG), liquid feed control group (CG), silybum group (SI), low-dose group (DL), medium-dose group (DM), and high-dose group (DH) of Dendrobium officinale fermentation liquid, with 10 mice in each group. NG group was given common feed, CG group was given control feed (LB alcoholic liquid control feed), SI group was given LB alcoholic liquid feed and silybum by gavage, DL, DM and DH groups were given LB alcoholic liquid feed and 25%, 50% and 100% concentration of Dendrobium officinale leaf fermentation liquid by gavage. An AH model was established by feeding LB alcoholic liquid feed for 8 weeks.At week 8, alanine Transaminase (ALT), triglyceride (TG), transferrin (TRF), interleukin (IL)-6, IL-10, and IL-1ß, tumor necrosis factor-α(TNF-α), interferon-γ(IFN-γ) were detected in eye blood of mice. Liver tissues were stained with HE, Oil Red O, Prussian blue and immunofluorescence ROS. The contents of glutathione(GSH) and malondialdehyde (MDA) in liver tissue homogenate were detected. To analyze the intervention effect and mechanism of Dendrobium officinale leaf fermentation solution on AH mice, the mRNA and protein relative expression levels of adenylate activated protein kinase (AMPK), AMPKß1, phosphorylated AMPKß1 (p-AMPKß1), tumor suppressor gene p53 (p53), solsolic vector family 7 member 11 (SLC7A11), glutathione peroxidase 4 (GXP4) were detected by polymerase chain reaction (PCR) and Western blot. Results: Compared with MG group, the serum ALT and TG levels in the DL, DM, and DH groups were all reduced [ALT: (45.94±19.85), (45.73±22.62), and (41.68±7.13) vs (75.51±17.76) U/L, respectively; TG: (0.90±0.23), (0.69±0.22) and (0.41±0.20) vs (1.28±0.19) mmol/L, respectively, all P<0.05]; IL-6, IL-1ß, TNF-α, IFN-γ were decreased (all P<0.05). The serum TRF and IL-10 levels in the DM and DH groups were increased (all P<0.05). Compared with MG group, the liver tissue MDA of mice in DL, DM and DH groups was decreased [(0.41±0.05), (0.40±0.03), and (0.43±0.14) vs (0.64±0.06)µmol/g, respectively], GSH was increased (all P<0.05). Compared with MG, mRNA expression levels of AMPK (1.36±0.11, 1.61±0.17, 1.68±0.11 vs 0.80±0.12, respectively), SLC7A11 (0.91±0.12, 0.97±0.12, 0.99±0.13 vs 0.60±0.14, respectively) and GPX4 (0.51±0.11, 0.63±0.17, 0.83±0.15 vs 0.42±0.14, respectively) in the liver tissue of DL, DM and DH groups were all increased (all P<0.05). Compared with MG group, DL, DM and DH groups showed the relative expression levels of AMPKß1, p-AMPKß1, SLC7A11 and GPX4 were increased in the liver tissue of mice, while the relative expression levels of p53 protein were decreased (all P<0.05). Compared with MG group, DL, DM and DH groups reduced the degree of hepatic steatosis and inflammation in the lobules, while the iron and ROS staining in the liver tissue became lighter. Conclusion: Dendrobium officinale leaf fermentation liquid can alleviate the severity of AH in mice, and its mechanism may be related to the up-regulation of AMPK to inhibiting the p53/SLC7A11/GPX4 mediated Ferroptosis pathway.

[Establishment and validation of nomogram prediction model for complicated acute appendicitis].

Objective: To establish and internally validate a nomogram model for predicting complicated acute appendicitis (CA). Methods: The clinical data from 663 acute appendicitis patients from the First Affiliated Hospital of Anhui University of Traditional Chinese Medicine from October 2015 to October 2022 were retrospectively analyzed. There were 411 males and 252 females, aged (M (IQR)) 41 (22) years (range: 18 to 84 years). There were 516 cases of CA and 147 cases of uncomplicated acute appendicitis. The minimum absolute contraction and selection operator regression model was used to screen the potential relative factors of CA, and the screened factors were included in the Logistic regression model for multivariate analysis. Software R was used to establish a preoperative CA nomogram prediction model, the receiver operating characteristic curve of the model was drawn, and the value of area under the curve (AUC) was compared to evaluate its identification ability, and the Bootstrap method was used for internal verification. Results: The elderly (age≥60 years) (OR=2.428, 95%CI: 1.295 to 4.549), abdominal pain time (every rise of 1 hour) (OR=1.089, 95%CI: 1.072 to 1.107), high fever (body temperature≥39 ℃) (OR=1.122, 95%CI: 1.078 to 1.168), total bilirubin (every rise of 1 µmol/L) (OR=2.629, 95%CI: 1.227 to 5.635) were independent relative factors of CA (all P<0.05). The AUC of this model was 0.935 (95%CI: 0.915 to 0.956). After internal verification using the Bootstrap method, the model still had a high discrimination ability (AUC=0.933), and the predicted CA curve was still in good agreement with the actual clinical CA curve. Conclusion: The clinical prediction model based on the elderly (age≥60 years), prolonged abdominal pain time, high fever (body temperature≥39 ℃), and increased total bilirubin can help clinicians effectively identify CA.

[The value of cardiac MRI in the risk stratification in patients with hypertrophic cardiomyopathy].

Objective: To explore the value of cardiac magnetic resonance imaging (CMR) in the risk stratification of hypertrophic cardiomyopathy (HCM). Methods: HCM patients who underwent CMR examination in Fuwai Hospital between March 2012 and May 2013 were retrospectively enrolled. Baseline clinical and CMR data were collected and patient follow-up was performed using telephone contact and medical record. The primary composite endpoint was sudden cardiac death (SCD) or and equivalent event. The secondary composite endpoint was all-cause death and heart transplant. Patients were divided into SCD and non-SCD groups. Cox regression was used to explore risk factors of adverse events. Receiver operating characteristic (ROC) curve analysis was used to assess the performance and the optimal cut-off of late gadolinium enhancement percentage (LGE%) for the prediction of endpoints. Kaplan-Meier and log-rank tests were used to compare survival differences between groups. Results: A total of 442 patients were enrolled. Mean age was (48.5±12.4) years and 143(32.4%) were female. At (7.6±2.5) years of follow-up, 30 (6.8%) patients met the primary endpoint including 23 SCD and 7 SCD equivalent events, and 36 (8.1%) patients met the secondary endpoint including 33 all-cause death and 3 heart transplant. In multivariate Cox regression, syncope(HR=4.531, 95%CI 2.033-10.099, P<0.001), LGE% (HR=1.075, 95%CI 1.032-1.120, P=0.001) and left ventricular ejection fraction (LVEF) (HR=0.956, 95%CI 0.923-0.991, P=0.013) were independent risk factors for primary endpoint; Age (HR=1.032, 95%CI 1.001-1.064, P=0.046), atrial fibrillation (HR=2.977, 95%CI 1.446-6.131, P=0.003),LGE% (HR=1.075, 95%CI 1.035-1.116, P<0.001) and LVEF (HR=0.968, 95%CI 0.937-1.000, P=0.047) were independent risk factors for secondary endpoint. ROC curve showed the optimal LGE% cut-offs were 5.1% and 5.8% for the prediction of primary and secondary endpoint, respectively. Patients were further divided into LGE%=0, 0

[A case of corrosive digestive tract and lung injury caused by ingestion of pipeline dredging agent].

Ingestion of corrosive substances can severely burn the upper digestive tract leading to bleeding or perforation, and may even be life-threatening. Less commonly, damage to the trachea and bronchi is involved. In this paper, a case of corrosive digestive tract injury and lung injury after oral administration of pipeline dredging agent (the main components are hydroxide, sodium carbonate, sodium hypochlorite, etc.) was analyzed. After active rescue treatment, the patient died of massive hemoptysis. It is suggested that serious complications may occur after ingestion of corrosive substances. Timely diagnosis and reasonable medical management are needed to improve the level of recognition and treatment of such diseases.

[One case of severe exogenous lipoid pneumonia complicated with lung abscess caused by diesel inhalation].

Exogenous lipoid pneumonia is an inflammatory response to the lungs caused by inhaled lipid substances, which is prone to secondary bacterial infection, resulting in the formation of local abscesses, which can be life-threatening in severe cases. This paper reports a case of a 55-year-old patient with diesel aspiration, secondary to Klebsiella pneumoniae (ESBL positive) and Candida glabrata infection resulting in lung abscess formation. He was treated with a variety of antibacterial drugs for anti-infection, non-invasive ventilator ventilation, bronchoalveolar lavage, glucocorticoids, phlegm and other medical treatments. Finally, he underwent middle lobectomy for improvement and was discharged from the hospital, and he recovered well with regular follow-up.

Neutral particles pushed or pulled by laser pulses: erratum.

We present an erratum to our Letter [Opt. Lett.41, 230 (2016)10.1364/OL.41.000230]. This erratum corrects three typing errors. The corrections have no influence on the results and conclusions of the original Letter.

[Pathogenic spectrum and laboratory indicators of fungal infections in the central nervous system].

Central nervous system (CNS) fungal infections are challenging and difficult to diagnose and treat. This article introduces the high risk factors, pathogen spectrum and laboratory indicators that cause CNS fungal infection. As patients with CNS fungal infections are often accompanied by immunodeficiency, it is especially necessary for clinical early detection, early prevention, and early diagnosis, and timely and effective implementation of optimized diagnosis and treatment programs to prevent further deterioration of the disease.

[The incidence of myopia and myopic progression from 2019 to 2020 in school-age children in Zhuozhou].

Objective: To analyze the changes in refractive status and prevalence of myopia in 6-to 14-year-old children at 2 time points in Zhuozhou, Hebei Province. Methods: In the current cohort study, the visual acuity and refractive status of primary and secondary school students aged 6 to 14 years were examined from June to August 2019 and reexamined from June to August 2020. A total of 30 412 subjects with examination data were enrolled, including 15 861 males (52.2%) and 14 551 females (47.8%), with an average age of (10.0±2.7) years. The participants underwent autorefraction without cycloplegia and a naked eye visual acuity test with a standard logarithmic visual acuity chart. Myopia was screened by the standard of equivalent spherical refraction less than -0.75 diopter (D). The categorical data were analyzed by the Chi-square or Fisher's exact test. Clopper-Pearson was used to estimate the 95% confidence intervals for the incidence of myopia. Results: After the 1-year interval, the change of equivalent spherical refraction was(-0.67±1.11) D and(-0.76±1.11) D, respectively, in male and female participants, and their visual acuity decreased by 0.11±0.19 and 0.12±0.21, respectively. There were significant inter-group differences in the annual change of spherical power in different age groups (χ²=276.23, P<0.001). The naked eye visual acuity reduction was greatest in the 10-year-old students. The incidence of myopia was 42.2% (95% confidence intervals of 41.47% to 42.93%) during the 1-year follow-up period. The incidence of myopia was highest at the age of 14 (52.0% in males and 54.2% in females) and lowest at the age of 6 (31.0% in males and 33.1% in females). Conclusions: The 1-year follow-up revealed an obvious myopic shift in the refractive status of school students in Zhuozhou, with their naked eye visual acuity decreased. The incidence of myopia was higher in females than that in males.

MicroRNA-20a suppresses RANKL-modulated osteoclastogenesis and prevents bone erosion in mice with rheumatoid arthritis through the TLR4/p38 pathway.

Abnormal osteoclast formation plays a significant part in rheumatoid arthritis (RA). As potent therapeutic biomarkers, microRNAs (miRNAs) have obtained increasing attention. Recently, treatment regimens regarding miRNAs have been implicated in skeletal diseases. The aim of this study is to assess the expression and function of miR-20a during osteoclast proliferation and differentiation and its correlation with bone erosion in RA mice. The expression of miR-20a was observed to be diminished in the ankle tissues of RA mice relative to that in normal controls evaluated by RT-qPCR. Hematoxylin and eosin staining, Safranin O-fast green staining, and tartrateresistant acid phosphatase staining were used to evaluate the effects of miR-20a on RA symptoms. The proliferation and differentiation of osteoclasts, and bone erosion were repressed by agomiR-20a injection. 3'UTR luciferase reporter assays were conducted to validate the putative binding between miR-20a and receptor activation of nuclear factor-κB ligand (RANKL). The protein expression and phosphorylation level of toll-like receptor4 (TLR4)/p38 pathway-related factors were detected by Western blot. miR-20a inhibited proliferation and differentiation potentials to osteoclasts partly through the TLR4/p38 pathway. The current work provides evidence that miR-20a hinders proliferation and differentiation of osteoclasts by targeting RANKL through the TLR4/p38 pathway.

[Effect of splenectomy on the risk of hepatocellular carcinoma development among patients with liver cirrhosis and portal hypertension: a multi-institutional cohort study].

Objective: To identify whether splenectomy for treatment of hypersplenism has any impact on development of hepatocellular carcinoma(HCC) among patients with liver cirrhosis and hepatitis. Methods: Patients who underwent splenectomy for hypersplenism secondary to liver cirrhosis and portal hypertension between January 2008 and December 2012 were included from seven hospitals in China, whereas patients receiving medication treatments for liver cirrhosis and portal hypertension (non-splenectomy) at the same time period among the seven hospitals were included as control groups. In the splenectomy group, all the patients received open or laparoscopic splenectomy with or without pericardial devascularization. In contrast, patients in the control group were treated conservatively for liver cirrhosis and portal hypertension with medicines (non-splenectomy) with no invasive treatments, such as transjugular intrahepatic portosystemic shunt, splenectomy or liver transplantation before HCC development. All the patients were routinely screened for HCC development with abdominal ultrasound, liver function and alpha-fetoprotein every 3 to 6 months. To minimize the selection bias, propensity score matching (PSM) was used to match the baseline data of patients among splenectomy versus non-splenectomy groups. The Kaplan-Meier method was used to calculate the overall survival and cumulative incidence of HCC development, and the Log-rank test was used to compare the survival or disease rates between the two groups. Univariate and Cox proportional hazard regression models were used to analyze the potential risk factors associated with development of HCC. Results: A total of 871 patients with liver cirrhosis and hypertension were included synchronously from 7 tertiary hospitals. Among them, 407 patients had a history of splenectomy for hypersplenism (splenectomy group), whereas 464 patients who received medical treatment but not splenectomy (non-splenectomy group). After PSM,233 pairs of patients were matched in adjusted cohorts. The cumulative incidence of HCC diagnosis at 1,3,5 and 7 years were 1%,6%,7% and 15% in the splenectomy group, which was significantly lower than 1%,6%,15% and 23% in the non-splenectomy group (HR=0.53,95%CI:0.31 to 0.91,P=0.028). On multivariable analysis, splenectomy was independently associated with decreased risk of HCC development (HR=0.55,95%CI:0.32 to 0.95,P=0.031). The cumulative survival rates of all the patients at 1,3,5,and 7 years were 100%,97%,91%,86% in the splenectomy group,which was similar with that of 100%,97%,92%,84% in the non-splenectomy group (P=0.899). In total,49 patients (12.0%) among splenectomy group and 75 patients (16.2%) in non-splenectomy group developed HCC during the study period, respectively. Compared to patients in non-splenectomy group, patients who developed HCC after splenectomy were unlikely to receive curative resection for HCC (12.2% vs. 33.3%,χ²=7.029, P=0.008). Conclusion: Splenectomy for treatment of hypersplenism may decrease the risk of HCC development among patients with liver cirrhosis and portal hypertension.

[Research progress on non-steady state noise-induced hearing loss].

Non-steady state noise has become the main type of workplace noise. Compared with steady state noise, non-steady state noise may cause more serious hearing loss. This paper reviews the new situation of occupational hearing loss caused by non-steady state noise exposure, the overview of international noise exposure assessment standards and new challenges, and the new evidence of non-steady state noise induced hearing loss, so as to provide the basis for the future research of non-steady state noise induced hearing loss.

[The effect of different diagnostic standards on the diagnosis of suspected occupational noise-induced deafness].

Objective: To explore the effect of different diagnostic criteria on occupational noise-induced deafness (Onid) , and to provide theoretical basis for the revision of ONID diagnostic criteria. Methods: From January 2016 to January 2018, the physical examination results of noise-exposed workers during occupational health examination in Qingyuan Occupational Disease Prevention and Treatment Hospital were retrospectively investigated in September 2019, with Gbz 49-2014《diagnosis of occupational noise deafness》as the study object, 471 workers suspected of Onid were weighted with different combinations of high frequency hearing threshold, and the better ear weight was calculated, compared with the diagnostic criteria of 2007 and 2014, the degree of hearing loss was evaluated. SPSS 22.0 was used for statistical analysis, χ(2) test was used for counting data, and non-parametric test was used for measuring bias data. Results: The average age of 471 subjects was (40.32±7.01) years, and the average age of exposure to noise was (7.11±3.44) years. On the basis of the 2007 edition diagnostic standard, the suspected ONID diagnostic rate of different high frequency auditory threshold was increased by 16.35% and 30.15% at 3.0 kHz, 6.0 kHz increased by 20.17%, 3.0 kHz+4.0 kHz increased by 22.29%, 3.0 kHz+6.0 kHz increased by 17.20%, 4.0 kHz+6.0 kHz increased by 25.27%, the differences were statistically significant (P<0.05) , the frequency of 3.0 kHz+4.0 kHz+6.0 kHz increased by 22.29%. Using the 2014 edition diagnostic standard, the diagnostic rate of Onid was reduced by 30.15% and 13.80%, 6 kHz is 9.98% lower, 3.0 kHz+4.0 kHz is 7.86% lower, 3.0 kHz+6.0 kHz is 12.95% lower, 4.0 kHz+6.0 is 4.88% lower, the high frequency of 3.0 kHz+4.0 kHz+6.0 kHz decreased by 7.86%, the differences were statistically significant (P<0.05) . Conclusion: The diagnosis rate of suspected Onid is increased by weighting different high frequency hearing threshold, in which the weighted 4kHz high frequency has the greatest influence on the result, and the weighted 3 kHz high frequency has the least.

MiR-20a Promotes kidney injury in sepsis rats through autophagy.

The aim of this work was to study the effects of micro ribonucleic acid (miR)-20a on acute kidney injury (AKI) in sepsis rats and its key molecular mechanism. Sprague-Dawley rats were randomly divided into healthy rat group (H group, n=3), sham group (S group, n=3), sepsis rat group (D group, n=3), sepsis rat + negative control transfection group (N group, n=3) and sepsis rat + miR-20a inhibitor transfection group (M group, n=3). At 6 h, 12 h and 24 h, serum creatinine (Scr) and blood urea nitrogen (BUN) were detected, the changes in miR-20a expression in kidney tissues were determined via reverse transcription-polymerase chain reaction (RT-PCR), the expression of autophagy marker protein microtubule-associated protein 1 light chain 3 (LC3) was measured via Western blotting, and the inflammatory cell infiltration in kidney tissues was detected using hematoxylin-eosin (HE) staining. There was no obvious change in each index in S group compared with H group. D group, N group and M group had higher levels of Scr, BUN and LC3 in kidney tissues than S group. The levels of Scr, BUN and LC3 in kidney tissues were lower in M group than those in N group. MiR-20a may cause AKI in sepsis rats via activating autophagy.

Genetic signature of hybridization between Chinese spot-billed ducks and domesticated ducks.

In this study, we analyzed 93 whole genomes from Chinese spot-billed ducks (CSB), meat-type ducks (MET), and egg and dual purpose-type ducks (EDT) to characterize the genetic material flowing between the CSB and modern ducks. Using a frequency of shared identical-by-descent method, approximately 10.9 Mb introgression segments containing 140 genes were identified showing the signatures of introgression between CSB and EDT. Meanwhile, nearly 10.6 M introgression regions containing 149 genes were identified between CSB and MET. Based on the haplotypes tree of each segment, we found that the introgression between CSB and domesticated ducks was asymmetric with a high level of gene flow from domestic to CSB and a low level of migration in the opposite direction. Moreover, we identified several genes that were introgressions from CSB and showed the signature of positive selection, which may contribute to the breeding of modern ducks. Our results provide new insight into the evolution and breeding history of domestic ducks and may be useful for the future management of wild and domestic duck populations.

[Expert consensus for diagnosis and treatment of thrombocytopenia in China].

Thrombocytopenia is the main clinical manifestation or common complication of multiple diseases, but there is still a lack of systematic understanding of pathogenesis, underlying diseases and treatment strategies of thrombocytopenia. Based on evidence-based medicine, this consensus summarizes seven aspects related to thrombocytopenia, including definition, epidemiology, pathogenesis, clinical manifestations, laboratory examination, diagnosis and treatment. This consensus provides an important reference for the diagnosis and treatment of thrombocytopenia.

Deep ultraviolet light-emitting diodes with improved performance via nanoporous AlGaN template.

We report the performance enhancement of AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs) using AlGaN nanoporous template (NPT). The NPT was fabricated by the electrochemical etching method and served as the dislocation filtering layer and strain relieving layer. The n-AlGaN laterally regrown on NPT showed reduced dislocation density and mitigated compressive strain comparing with that on the as-grown template (AGT). A 23% improvement of internal quantum efficiency was achieved for the multiple quantum wells thereon. Moreover, the nanopores in the NPT transformed into elongated air voids during high temperature growth process, which could facilitate the escaping of photons by scattering and thus improve the light extraction efficiency. As a consequence, the DUV LED based on NPT demonstrated an increase of the light outpower by 50% at 20 mA than that on AGT.

Spatial association between outdoor air pollution and lung cancer incidence in China.

BACKGROUND: Lung cancer is the most common cancer in China. Previous studies have indicated that lung cancer incidence exhibits remarkable spatial heterogeneity, and lung cancer is related to outdoor air pollution. However, the non-linear spatial association between outdoor air pollution and lung cancer incidence in China remains unclear. METHODS: In this study, the relationships between the lung cancer incidence of males and females from 207 counties in China in 2013 with annual concentrations of PM2.5, PM10, SO2, NO2, CO and O3 were analysed. GeoDetector q statistic was used for examining the non-linear spatial association between outdoor air pollution and incidence of lung cancer. RESULTS: An apparent spatial and population gender heterogeneity was found in the spatial association between outdoor air pollution and lung cancer incidence. Among the six selected pollutants, SO2 has the greatest influence on lung cancer (q = 0.154 in females) in north China. In the south, each selected pollutant has a significant impact on males or females, and the mean q value in the south is 0.181, which is bigger than that in the north (q = 0.154). In addition, the pollutants have evident non-linear interaction effects on lung cancer. In north China, the interaction between SO2 and PM2.5 is the dominant interaction, with q values of 0.207 in males and 0.334 in females. In the south, the dominant interactive factors are between SO2 and O3 in males and between SO2 and CO in females, with q values of 0.45, 0.232 respectively. Smoking is a substantial contributor to lung cancer among men, either in South or North China, with q value of 0.143 and 0.129 respectively, and the interaction between smoking and air pollutants increases this risk. CONCLUSIONS: This study implies that the influence of SO2 and PM2.5 on lung cancer should be focused on in north China, and in the south, the impact of O3 and CO as well as their interaction with SO2 need to be paid more attention. Smoking, particularly in men, remains a significant risk factor for lung cancer in both North and South China.