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Events of stratospheric intrusions to the surface (SITS) can lead to severe ozone (O 3 ) pollution. Still, to what extent SITS events impact surface O 3 on a national scale over years remains a long-lasting question, mainly due to difficulty of resolving three key SITS metrics: frequency, duration and intensity. Here, we identify 27,616 SITS events over China during 2015-2022 based on spatiotemporally dense surface measurements of O 3 and carbon monoxide, two effective indicators of SITS. An overview of the three metrics is presented, illustrating large influences of SITS on surface O 3 in China. We find that SITS events occur preferentially in high-elevation regions, while those in plain regions are more intense. SITS enhances surface O 3 by 20 ppbv on average, contributing to 30-45% of O 3 during SITS periods. Nationally, SITS-induced O 3 peaks in spring and autumn, while over 70% of SITS events during the warm months exacerbate O 3 pollution. Over 2015-2022, SITS-induced O 3 shows a declining trend. Our observation-based results can have implications for O 3 mitigation policies in short and long terms. The authors analyze the frequency, duration and intensity of stratospheric intrusions to the surface in China over 2015-2022 and find that such intrusions enhance surface ozone pollution, especially in spring and autumn, followed by summer.

The seismic performance of earth-rock dams on deep overburdens has long been a central focus in dam engineering. Understanding the propagation law of seismic waves within a deep overburden is key to revealing the mechanisms of the dynamic response. In this study, the propagation characteristics of horizontal and vertical seismic waves in a deep overburden were systematically investigated using large-scale shaking table tests, with analysis based on acceleration and pore pressure data combined with stockwell transforms and coherence function methods. The results show clear differences in how the deep overburden modulates seismic waves in different directions. Horizontally, seismic waves exhibit an amplitude pattern that first decreases and then increases during propagation, with low-frequency components dominating and high-frequency components being strongly filtered. Vertically, the peak acceleration at the overburden top was higher than that in the lower layers; however, the frequency content changed slightly, and high-frequency filtering was weak. The weak interlayer has an obvious filtering effect on high-frequency horizontal seismic waves. For the pore pressure response, the accumulation of excess pore pressure across different depths was generally similar; however, liquefaction was only observed at the top of the overburden.

We describe the trace representations of two families of binary sequences derived from the Fermat quotients modulo an odd prime p （one is the binary threshold sequences and the other is the Legendre Fermat quotient sequences） by determining the defining pairs of all binary characteristic sequences of cosets, which coincide with the sets of pre-images modulo p2 of each fixed value of Fermat quotients. From the defining pairs, we can obtain an earlier result of linear complexity for the binary threshold sequences and a new result of linear complexity for the Legendre Fermat quotient sequences under the assumption of 2p-1≠ 1 mod p2.

Background Insufficient evidence existed about the prognostic role of the advanced lung cancer inflammation index (ALI) for gastric cancer patients who underwent curative resection. The aim of this study was to identify the predictive ability of ALI for survival after curative gastrectomy. Methods We retrospectively analyzed 328 gastric cancer patients who received curative gastrectomy from the database of Chongqing University Cancer Hospital, and investigated the prognostic role of the preoperative ALI compared with clinicopathological variables and other serum biomarkers, such as preoperative neutrophil-to-lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR) and Lymphocyte-monocyte ratio (LMR). To minimize intergroup differences, propensity score matching (PSM) analysis was employed. Additionally, we performed a meta-analysis of four cohort studies published up to October 2023 following the PRISMA guidelines. Results In the overall cohort, patients in the low ALI group had a significantly worse overall survival compared to those in the high ALI group ( P  < 0.0001). Subgroup analysis identified that ALI maintained its prognostic significance across different subgroups. In addition, ROC analysis showed that ALI had a higher AUC value for 3-year overall survival compared to NLR, PLR, and LMR (0.576 vs. 0.573 vs. 0.557 vs. 0.557). Multivariate analysis indicated that ALI, other than other serum biomarkers, was an independent risk factor for decreased overall survival in GC patients following curative surgery (HR = 1.449; 95%CI: 1.028–2.045; P  = 0.034). Consistently, PSM analysis supported all of these findings. The meta-analysis including 4 studies evaluating 2542 patients, confirmed the association between the low ALI and poor survival outcomes. Conclusion The preoperative ALI was an independent prognostic factor for survival in gastric cancer patients who underwent curative gastrectomy.

Rockburst is a major instability issue faced by underground excavation projects, which is induced by the instantaneous release of a large amount of strain energy stored in rock mass. Because of its disastrous damage to infrastructures and facilities, more and more studies have been focused on rockburst prediction. However, due to highly nonlinear relationships between the occurrence of rockburst and potential triggering factors, traditional mechanism-based prediction methods have great difficulties in providing the reliable results. In this study, a multivariate adaptive regression splines (MARS) model and a novel deep forest algorithm were applied to predict and classify rockburst intensity of a database including 344 rockburst cases collected worldwide. The t-distributed stochastic neighbor embedding method (t-SNE) was utilized for nonlinear dimensionality reduction and visualization of the original input features. After that, the Gaussian mixture model was adopted to relabel original data to determine relative intensity of these rockburst cases. Then, the MARS model and deep forest model were constructed with these newly labeled data. Their performances were compared with some widely used machine learning methods, such as random forest, extreme gradient boost, and ANN model. The results clearly proved the capability of the proposed models to assess and forecast rockburst risk. It also proved that these approaches should be used as cross-validation against each other. The Shapley additive explanations method was adopted to investigate the relative importance of input features of the developed MARS model. The result shows that σθ and σc are the most important features for rockburst intensity prediction, where σθ is the tangential stress around underground opening and σc refers to uniaxial compressive strength of the rock.

To investigate the effects of aerosols on lightning activity, the Weather Research and Forecasting (WRF) Model with a two-moment bulk microphysical scheme and bulk lightning model was employed to simulate a multicell thunderstorm that occurred in the metropolitan Beijing area. The results suggest that under polluted conditions lightning activity is significantly enhanced during the developing and mature stages. Electrification and lightning discharges within the thunderstorm show characteristics distinguished by different aerosol conditions through microphysical processes. Elevated aerosol loading increases the cloud droplets numbers, the latent heat release, updraft and ice-phase particle number concentrations. More charges in the upper level are carried by ice particles and enhance the electrification process. A larger mean-mass radius of graupel particles further increases non-inductive charging due to more effective collisions. In the continental case where aerosol concentrations are low, less latent heat is released in the upper parts and, as a consequence, the updraft speed is weaker, leading to smaller concentrations of ice particles, lower charging rates and fewer lightning discharges.

This paper examines the deformation characteristics of energy piles subjected to horizontal loads in sandy soil. A model energy pile was subjected to ten heating and cooling cycles. The temperature of the pile and soil around the pile, pile top horizontal displacement, pile strain, and horizontal soil pressure in front of the pile were measured. Furthermore, the bending moment and displacement of the pile body were calculated and analyzed. The results show that the horizontal displacement of the pile top consistently increased. The temperature variation caused significant changes in the pile body displacement, which increased in the heating process and decreased in the cooling process, showing an overall increasing trend. However, the increment of pile body displacement gradually reduced. The temperature variation considerably changed the pile's bending moment; the pile body's maximum bending moment appeared at a depth of 3.5 D (D is the pile diameter). The pile bending moment increased during heating but decreased during cooling. The pile bending moment increased with the number of heating–cooling cycles.

The changes in groundwater level in coral islands are more common than those in inland areas. In this paper, a series of shaking table tests were performed to investigate the influence of the groundwater level on the seismic response of a coral sand foundation–superstructure system. The responses of excess pore pressure, acceleration, displacement and bending moment of the model structure were measured and analysed in detail. The results illustrate that owing to the rise in the groundwater level, the natural frequency of the coral ground drops, while the damping ratio increases; in addition, the rising groundwater level has a softening effect on the model ground. Moreover, the excess pore pressure ratios of coral sands increase with rising groundwater level, and the increase in the ratios significantly grows with increasing earthquake strength. The amplification factors of the soil–structure acceleration response decrease with the increase in the groundwater level, regardless of whether the ground motion is weak or strong. Furthermore, both the settlement and horizontal displacements of the model structure increase when the groundwater level rises. In terms of the bending moment, the rise in the groundwater level will reduce the response of the column bending moment irrespective of the earthquake strength.

Background The role of epithelial-mesenchymal transition (EMT) in the pathogenesis of keloids is currently raising increasing attention. Long noncoding RNAs (lncRNAs) govern a variety of biological processes, such as EMT, and their dysregulation is involved in many diseases including keloid disease. The aim of this study was to identify differentially expressed EMT-related lncRNAs in keloid tissues versus normal tissues and to interpret their functions. Results Eleven lncRNAs and 16 mRNAs associated with EMT were identified to have differential expression between keloid and normal skin tissues (fold change > 1.5, P  < 0.05). Gene Ontology (GO) analysis showed that these differentially expressed mRNAs functioned in the extracellular matrix, protein binding, the positive regulation of cellular processes, the Set1C/COMPASS complex and histone acetyltransferase activity. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated that these mRNAs are involved in pathways in cancer. The lncRNA, XLOC_000587 may promote cell proliferation and migration by enhancing the expression of ENAH, while AF268386 may facilitate the invasive growth of keloids by upregulating DDR2. Conclusions We characterized the differential expression profiles of EMT-related lncRNAs and mRNAs in keloids, which may contribute to preventing the occurrence and development of keloids by targeting the corresponding signaling pathways. These lncRNAs and mRNAs may provide biomarkers for keloid diagnosis and serve as potential targets for the treatment of this disease.