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When shield machine traverses through hard rock mass, disc cutters will be abraded to different degrees. Excessive height difference exists between adjacent disc cutters, which critically affects the rock-breaking efficiency. Relying on a shield section of hard rock mass in Qingdao, the disc cutter abrasions are measured on site, and the reason for low construction efficiency is analysed. Subsequently, the discrete element method is used to study the rock-breaking law under different height differences of disc cutters. The ultimate cutter height difference for rock breaking is obtained. According to this, the cutter adjustment scheme is proposed to reduce the cutter height differences on site. Comparing shield tunnelling parameters before and after the cutter adjustment, it is found that the construction efficiency is significantly improved. The results are of great significance for improving the rock-breaking efficiency and increasing advancing speed of shield in hard rock mass. [ABSTRACT FROM AUTHOR]

Highly active and durable Pd-based electrocatalysts for ethanol oxidation reaction (EOR) play a crucial role in the commercialization of direct ethanol fuel cells (DEFCs). However, the poisonous intermediates (especially adsorbed CO species (COad)) formed during the EOR process can easily adsorb and block the active sites on Pd electrodes, which in turn limits the catalytic efficiency. Hence, we present a series of Pd-based composites with a strong coupling interface consisting of Pd nanosheets and amorphous Bi(OH)3 species. The incorporation of Bi(OH)3 can induce an electron-rich state adjacent to the Pd sites and effectively separate the Pd ensemble, leading to excellent CO tolerance. The optimal Pd-Bi(OH)3 NSs catalyst manifests a mass activity of 2.2 A·mgPd−1, which is 5.7 and 2.0 times higher than that of Pd NSs and commercial Pd/C catalyst, respectively. Further CO-stripping experiments and CO-DRIFTS tests confirm the excellent CO tolerance on Pd-Bi(OH)3 NSs electrode, leading to the enhanced EOR durability. [ABSTRACT FROM AUTHOR]

Rare germline variations contribute to the missing heritability of human complex diseases including cancers. Given their very low frequency, discovering and testing disease‐causing rare germline variations remains challenging. The tag‐single nucleotide polymorphism rs17728461 in 22q12.2 is highly associated with lung cancer risk. Here, we identified a functional rare germline variation rs548071605 (A>G) in a p65‐responsive enhancer located within 22q12.2. The enhancer significantly promoted lung cancer cell proliferation in vitro and in a xenograft mouse model by upregulating the leukemia inhibitory factor (LIF) gene via the formation of a chromatin loop. Differential expression of LIF and its significant correlation with first progression survival time of patients further supported the lung cancer‐driving effects of the 22q‐Enh enhancer. Importantly, the rare variation was harbored in the p65 binding sequence and dramatically increased the enhancer activity by increasing responsiveness of the enhancer to p65 and B‐cell lymphoma 3 protein, an oncoprotein that assisted the p65 binding. Our study revealed a regulatory rare germline variation with a potential lung cancer‐driving role in the 22q12.2 risk region, providing intriguing clues for investigating the "missing heritability" of cancers, and also offered a useful experimental model for identifying causal rare variations. [ABSTRACT FROM AUTHOR]

A ternary compound of Li6NiNb2O9 with a rock-salt structure was prepared by the conventional mixed oxide route, and after the ceramic preparation processes, its microwave dielectric properties were investigated. Ceramics with a single phase and a rock-salt crystal structure can be obtained under our optimized sintering conditions, and a disordered rock-salt structure for Li6NiNb2O9 compound can be confirmed by the Rietveld method. Relatively dense microstructures can be obtained under the sintering conditions of 1080°C/2.0 h, with microwave dielectric properties of ε = 13.5, Q × f = 20,600 GHz (9.4 GHz) and τf = −33.9 ppm/°C. Although decomposition of such phase occurred when high sintering temperature was applied (> 1100°C), the density and microwave dielectric properties of the ceramics showed anomalous increases. [ABSTRACT FROM AUTHOR]

Background: Diabetes Mellitus (DM) has become the third chronic non-communicable disease that hits patients after tumors, cardiovascular and cerebrovascular diseases, and has become one of the major public health problems in the world. Therefore, it is of great importance to identify individuals at high risk for DM in order to establish prevention strategies for DM.Methods: Aiming at the problem of high-dimensional feature space and high feature redundancy of medical data, as well as the problem of data imbalance often faced. This study explored different supervised classifiers, combined with SVM-SMOTE and two feature dimensionality reduction methods (Logistic stepwise regression and LAASO) to classify the diabetes survey sample data with unbalanced categories and complex related factors. Analysis and discussion of the classification results of 4 supervised classifiers based on 4 data processing methods. Five indicators including Accuracy, Precision, Recall, F1-Score and AUC are selected as the key indicators to evaluate the performance of the classification model.Results: According to the result, Random Forest Classifier combining SVM-SMOTE resampling technology and LASSO feature screening method (Accuracy = 0.890, Precision = 0.869, Recall = 0.919, F1-Score = 0.893, AUC = 0.948) proved the best way to tell those at high risk of DM. Besides, the combined algorithm helps enhance the classification performance for prediction of high-risk people of DM. Also, age, region, heart rate, hypertension, hyperlipidemia and BMI are the top six most critical characteristic variables affecting diabetes.Conclusions: The Random Forest Classifier combining with SVM-SMOTE and LASSO feature reduction method perform best in identifying high-risk people of DM from individuals. And the combined method proposed in the study would be a good tool for early screening of DM. [ABSTRACT FROM AUTHOR]

Background: Brucellosis is a major public health problem that seriously affects developing countries and could cause significant economic losses to the livestock industry and great harm to human health. Reasonable prediction of the incidence is of great significance in controlling brucellosis and taking preventive measures.Methods: Our human brucellosis incidence data were extracted from Shanxi Provincial Center for Disease Control and Prevention. We used seasonal-trend decomposition using Loess (STL) and monthplot to analyse the seasonal characteristics of human brucellosis in Shanxi Province from 2007 to 2017. The autoregressive integrated moving average (ARIMA) model, a combined model of ARIMA and the back propagation neural network (ARIMA-BPNN), and a combined model of ARIMA and the Elman recurrent neural network (ARIMA-ERNN) were established separately to make predictions and identify the best model. Additionally, the mean squared error (MAE), mean absolute error (MSE) and mean absolute percentage error (MAPE) were used to evaluate the performance of the model.Results: We observed that the time series of human brucellosis in Shanxi Province increased from 2007 to 2014 but decreased from 2015 to 2017. It had obvious seasonal characteristics, with the peak lasting from March to July every year. The best fitting and prediction effect was the ARIMA-ERNN model. Compared with those of the ARIMA model, the MAE, MSE and MAPE of the ARIMA-ERNN model decreased by 18.65, 31.48 and 64.35%, respectively, in fitting performance; in terms of prediction performance, the MAE, MSE and MAPE decreased by 60.19, 75.30 and 64.35%, respectively. Second, compared with those of ARIMA-BPNN, the MAE, MSE and MAPE of ARIMA-ERNN decreased by 9.60, 15.73 and 11.58%, respectively, in fitting performance; in terms of prediction performance, the MAE, MSE and MAPE decreased by 31.63, 45.79 and 29.59%, respectively.Conclusions: The time series of human brucellosis in Shanxi Province from 2007 to 2017 showed obvious seasonal characteristics. The fitting and prediction performances of the ARIMA-ERNN model were better than those of the ARIMA-BPNN and ARIMA models. This will provide some theoretical support for the prediction of infectious diseases and will be beneficial to public health decision making. [ABSTRACT FROM AUTHOR]

At present, the research results on the stability and reinforcement range of the subgrade when the high-speed railway traverses the edge of a large goaf are still scarce. Taking Guinan high-speed railway traversing the edge of the mined-out area of the Dapan well as the research object, high-speed rail load transfer depth and height of goaf impact were analyzed, Researching the stability of high-speed railway subgrade and the reinforcement range of goaf. The results show that Mined-out edge cracks more obvious development, High-speed railway subgrade at the edge of the goaf is more harmful than when located directly above the goaf; On the No.1 well goaf, the overlap zone between the height of the caving fissure zone and the depth of influence of the high-speed railway load appears, but the height of the goaf in the extremely soft rock will extend to the surface; The high-speed railway subgrade is mainly affected by the residual deformation of the gob of the Dapan well. At last, the reasonable reinforcement range is given through the finite element numerical calculation. [ABSTRACT FROM AUTHOR]

In order to obtain the dynamic stress of invert and its filling in the high-speed railway tunnel under the vibration load of the train, this paper uses the field measurement method to arrange the resistance strain gauge inside the invert of the Lanzhou–Urumqi high-speed railway Fuchuan tunnel. The dynamic stress of the invert and its filling was measured, and the measurement results were verified by numerical analysis, the results obtained by the two were consistent. The results show that under the action of CRH5 electric multiple units, the dynamic stress time history curve of the invert and its filling has 16 peaks, with V-shape on both sides and W-shape in the middle. When the train load speed is constant, the dynamic stress in the tunnel invert and invert filling decreases with the increase of the depth. The dynamic stress at 0.5 m below the track bed is attenuated by about 23.1% compared to 0.2 m, the dynamic stress at 2.0 m below the track bed is attenuated by 67.5% compared to 0.2 m. Tunnel invert and its filling are the main carriers of train vibration load. The dynamic stress attenuation law of the invert and its filling conforms to the exponential function distribution. Through the data fitting, the calculation formula of the dynamic stress in different depths is given. The research results provide a new method for obtaining the dynamic stress of the invert and its filling in high-speed railway tunnel. [ABSTRACT FROM AUTHOR]

β‐Lactam antibiotics are generally perceived as one of the greatest inventions of the 20th century, and these small molecular compounds have saved millions of lives. However, upon clinical application of antibiotics, the β‐lactamase secreted by pathogenic bacteria can lead to the gradual development of drug resistance. β‐Lactamase is a hydrolase that can efficiently hydrolyze and destroy β‐lactam antibiotics. It develops and spreads rapidly in pathogens, and the drug‐resistant bacteria pose a severe threat to human health and development. As a result, detecting and inhibiting the activities of β‐lactamase are of great value for the rational use of antibiotics and the treatment of infectious diseases. At present, many specific detection methods and inhibitors of β‐lactamase have been developed and applied in clinical practice. In this Minireview, we describe the resistance mechanism of bacteria producing β‐lactamase and further summarize the fluorogenic probes, inhibitors of β‐lactamase, and their applications in the treatment of infectious diseases. It may be valuable to design fluorogenic probes with improved selectivity, sensitivity, and effectiveness to further identify the inhibitors for β‐lactamases and eventually overcome bacterial resistance. [ABSTRACT FROM AUTHOR]

In order to ensure the safety of horseshoe-shaped pipeline during tunnel blasting excavation, the vibration test and dynamic response of horseshoe-shaped pipeline were investigated. The velocity and frequency of tunnel blasting vibration were analyzed. Sodev's empirical formula was used for regression analysis of the velocity of blasting vibration. 3D numerical model of a horseshoe-shaped pipelines was established with ALE algorithm using ANSYS/LS-DYNA. The propagation law of a blasting seismic wave was analyzed, and the transverse and longitudinal vibration response characteristics of pipelines under tunnel blasting vibration were studied. The velocity of the pipeline increases gradually and the frequency tends to decrease with the decrease of the distance away from the explosion source center under the same charge. The principal frequency of vibration in the Z direction is mainly distributed from 50 to 80 Hz, which is difficult to generate resonance with the pipelines. The maximum relative error between the simulated and measured velocity of X, Y and Z directions was 8.2%. It was reliable to study the dynamic response of pipelines under blasting vibration based on this numerical model. The blasting seismic wave first reached the bottom of the pipeline right above the explosive. Subsequently, seismic waves propagated along the transverse and the longitudinal axes of the pipeline, and the pressure on the pipeline increased gradually. And when it attenuated completely in the soil, the pipeline stopped its response. The peak value of tensile stress of each element of the vault is the largest. However, the velocity of the bottom plate and the arch roof of pipeline are the largest. The peak values of velocity and tensile stress exist in 0 to 4 m away from the explosion source, and gradually decrease as the distance away from the explosion source increases. [ABSTRACT FROM AUTHOR]

Gob-side entry retaining by roof cutting (GERRC) is a new technique regarding a non-pillar mining method based on the "cutting cantilever beam theory" proposed in recent years. In this technology, the composition, formation mechanism, load transfer mode and stability mechanism of roadways are quite different from those of traditional coal mining methods. Based on the technical principle of the GERRC, the formation mechanism of the sidewall composed by collapsed gangues is clarified. Also, on basis of the observation of engineering site, the movement characteristics of the gangues in goaf are analyzed, and the movement processes are mainly divided into two stages, i.e. the rapid collapse stage and the slow compaction stage. Then, the interaction between the gangues and retaining structures in different movement stages is revealed. Meanwhile, a mechanical model of the roadside gangues was established, and the mechanical characteristics of the retaining structures were analyzed. Besides, a control concept, considering both dynamic and static pressure in the lateral direction and making it extensible to release pressure in the axial direction, was put forward to support the gangues in goaf based on the interaction characteristics of the gangues and the retaining structures. At last, three different retaining structures for the gangues were proposed in view of different mining heights, and the roadside gangues control system was established, which has been proved to be of good practicality in the engineering site. The research results can provide technical guidances for the control of roadside gangues in the GERRC and accelerate the process of popularization and application of the GERRC, which is of positive significance. [ABSTRACT FROM AUTHOR]

• The Ag nanoparticle/ZnO nanorod heterostructure was synthesized. • The content of Ag in the heterostructure could reach the maximum value. • High performances for the degradation of typical dye molecules were obtained. • Natural sunlight could be efficiently employed. Synthesis of silver/zinc oxide heterostructured nanorods (Ag/ZnO HNRs) is demonstrated via a simple one-step solvothermal method. The size of silver nanoparticles (AgNPs) on zinc oxide nanorods (ZnO NRs) are tuned by controlling the amount of AgNO 3 and the optimized decoration of AgNPs significantly enhance the utilization of visible light. Particularly, the Ag/ZnO HNRs samples are used to examine the photocatalytic degradation of methyl orange (MO) and reduction of potassium dichromate (K 2 Cr 2 O 7). The obtained results display that the Ag/ZnO HNRs possess surprising photocatalytic activities towards the removal of MO and reduction of K 2 Cr 2 O 7. Further, the photocatalytic activities are related with the size of AgNPs and the length of ZnO NRs. Finally, the investigation towards the degradation of other dye molecules such as rhodamine B (RhB), and methyl blue (MB) along with MO at higher concentrations from morning to evening upon exposing sunlight under static condition. The present work could provide a further insight into the synthesis of ZnO based heterostructured photocatalysts and their application in efficient water treatment under natural conditions. [ABSTRACT FROM AUTHOR]

The use of solar energy to drive organic reactions under mild conditions provides a sustainable pathway for green synthesis and has been one of the primary goals pursued by scientists. In this research, the cadmium indium sulfide (CdIn2S4) photocatalyst was prepared using a simple solvothermal method and was thoroughly characterized using X-ray powder diffraction, UV-visible absorption spectra, nitrogen adsorption–desorption isotherms, scanning electron microscopy, transmission electron microscopy and X-ray spectroscopy measurements. The photocatalytic performance of the CdIn2S4 photocatalyst was evaluated using photocatalytic synthesis of Schiff base compounds in a coupled system of aromatic alcohols and nitrobenzene under visible light irradiation. The yield of N-benzylideneaniline reached up to 32% in the coupled system of benzyl alcohol and nitrobenzene under visible light illumination for 8 h. Furthermore, the changes for the amounts of aromatic aldehydes and AL as intermediate products during the photocatalytic process were also investigated. Using isotopic tracing, a possible reaction mechanism for the photocatalytic synthesis of N-benzylideneaniline and the redox reactions in the coupled system of benzyl alcohol and nitrobenzene was proposed. It is hoped that this strategy can provide an effective pathway for the traditional organic synthesis and transformation using photocatalytic technology under mild conditions. [ABSTRACT FROM AUTHOR]