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The problem of soil heavy metal pollution in decommissioned sites has become an environmental threat and challenge faced by countries around the world. Establishing a high-precision 3D model of contaminants is essential for pollution risk assessment and accurate monitoring of contaminated sites. In this study, 3D geological model and SSA-XGBoost model are proposed to predict heavy metal concentration in a site. These models can effectively improve the prediction accuracy of soil heavy metals, and the RMSE of the XGBoost model optimized by the SSA algorithm is reduced by 24.3%-34.3%. Compared with other machine learning models, the SSA-XGBoost model has optimal performance in improving the prediction accuracy of soil heavy metals. It is suitable for the areas with significant spatial heterogeneity of soil heavy metals. Using the SSA-XGBoost model and 3D geological model, the 3D spatial distribution characteristics of heavy metals in contaminated soil are determined. The concentration of soil pollutants ranked as As>Pb>Mo, and the overall pollution degree decreases gradually from top to bottom. The pollutants are mainly distributed in the production workshop area in the southwest of the site, and the miscellaneous fill layer is the main soil layer that needs to be remediated. [ABSTRACT FROM AUTHOR]

This study investigated the potential factors that predict the risk of preterm birth (PTB) in pregnancies with a short cervix. These factors were used to create nomogram, which might be highly sensitive tools to predict the incidence of PTB. This retrospective cohort study enrolled pregnancies with a short cervix from 1 January 2017 to 1 January 2018. The primary outcomes were preterm birth <37 and 34 weeks. Logistic regression model was used to identify potential predictors of PTB. The identified risk factors were used to establish nomograms, which were validated using the receiver operating characteristic (ROC) curve and calibration curve. In the multivariate analysis, overweight or obesity, parity ≧3 times, twin pregnancy, in vitro fertilization and embryo transfer (IVF-ET), gestational age at first observation of short cervix, cervical length (CL) at first observation of short cervix, history of PTB, and autoimmune disease were found to be predictors of PTB <37 weeks, while twin pregnancy, gestational age at first observation of short cervix, CL of short cervix, history of PTB, and prepregnancy hypertension were predictors of PTB <34 weeks. The area under the ROC curve of the nomogram predicting PTB <37 weeks and PTB <34 weeks were 0.803 and 0.771, respectively. Both models showed good discrimination Gestational age at first observation of short cervix, CL of short cervix and other factors are strong predictors of PTB in pregnancies with a short cervix. Both nomograms showed good discrimination and calibration, and hence might be effective in predicting PTB for this population. [ABSTRACT FROM AUTHOR]

Illegal mining activities on offshore sands have recently increased dramatically in China owing to the strong demand of the construction industry and restriction of river sand mining. By studying the loss mechanism of marine sand resources, this study proposes a simplified linear programming model to quantitatively analyse the control effects related to resource loss and law enforcement costs. To accurately simulate the effectiveness of law enforcement activity, a set of variables is designed in the model to describe the severity of illegal mining and enforcement skills of the officers. Subsequently, based on different settings of law enforcement capability, the model can not only make reasonable projections for sand losses but also provide a minimum cost solution for marine sand control for government agencies. Finally, various regulatory measurements and suggestions are discussed to improve the effectiveness of the government's regularisation and cost optimisation for law enforcement. [ABSTRACT FROM AUTHOR]

Newly dredged fills feature a high moisture content and a high floating mud content. Based on the conventional vacuum preloading (CVP) method, this article presents a new method of air-booster vacuum preloading (AVP) to reinforce newly dredged fills for different air-booster periods (45, 60 and 90 min). Compared with other methods, this new method features no sand cushion and adopts a self-developed air-booster pipe and a water–air separation device. A series of laboratory model tests were performed to explore the effect of the improved AVP method for the enhancement of newly dredged fills. A comparison of variables monitored during reinforcement (vacuum pressure, surface settlement, water discharge and pore-water pressure) and after reinforcement (water content, vane shear strength, SEM and MIP) indicates that the reinforcement effect of the AVP method is superior to that of the CVP method; the former can effectively alleviate the problem of prefabricated vertical drain (PVD) clogging, greatly reducing engineering costs and significantly shortening construction periods. [ABSTRACT FROM AUTHOR]

Gold nanorods (GNRs) have become an attractive candidate in photothermal ablation against cancer cells for their excellent photothermal transduction effect. However, the applications of GNRs in nanomedicine have been obstructed by the high cytotoxicity from the surfactant. Mass efforts have been attempted to develop the GNRs with high photothermal transduction efficiency and exploit modification materials to low the cytotoxicity of the GNRs. In this paper, (+)-catechin, a natural polyphenol extracted from green tea with anti-oxidization activity, was chosen as an effective reductant through seedless method to synthesize GNRs with a high quality, which also exhibited an excellent photothermal transduction efficiency (57.9%). Red blood cells (RBC) membranes were exploited as the biomimetic coating materials to encapsulate the GNRs to enhance the biocompatibility and photothermal stability, which could finally realize the highly photothermal ablation effect against the melanoma cells. Such cell membrane-based biomimetic nanomaterials might have a great potential in future photothermal therapy. [ABSTRACT FROM AUTHOR]