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Multistage hydraulic fracturing of horizontal wells (MFHW) is a promising technology for controlling coal burst caused by thick and hard roofs in China. However, challenges remain regarding the MFHW control mechanism of coal burst and assessment of the associated fracturing effects. In this study, these challenges were investigated through numerical modelling and field applications, based on the actual operating parameters of MFHW for hard roofs in a Chinese coal mine. A damage parameter (D) is proposed to assess the degree of hydraulic fracturing in the roof. The mechanisms and effects of MFHW for controlling coal burst are analyzed using microseismic (MS) data and front-abutment stress distribution. Results show that the degree of fracturing can be categorized into lightly-fractured (D≤0.3), moderately fractured (0.3

Abstract Background To develop and validate a nomogram model based on Gd-EOB-DTPA enhanced MRI for differentiation between hepatocellular carcinoma (HCC) and focal nodular hyperplasia (FNH) showing iso- or hyperintensity in the hepatobiliary phase (HBP). Methods A total of 75 patients with 49 HCCs and 26 FNHs randomly divided into a training cohort (n = 52: 34 HCC; 18 FNH) and an internal validation cohort (n = 23: 15 HCC; 8 FNH). A total of 37 patients (n = 37: 25 HCC; 12 FNH) acted as an external test cohort. The clinical and imaging characteristics between HCC and FNH groups in the training cohort were compared. The statistically significant parameters were included into the FAE software, and a multivariate logistic regression classifier was used to identify independent predictors and establish a nomogram model. Receiver operating characteristic (ROC) curves were used to evaluate the prediction ability of the model, while the calibration and decision curves were used for model validation. Subanalysis was used to compare qualitative and quantitative characteristics of patients with chronic hepatitis and cirrhosis between the HCC and FNH groups. Results In the training cohort, gender, age, enhancement rate in the arterial phase (AP), focal defects in uptake were significant predictors for HCC showing iso- or hyperintensity in the HBP. In the training cohort, area under the curve (AUC), sensitivity and specificity of the nomogram model were 0.989(95%CI: 0.967-1.000), 97.1% and 94.4%. In the internal validation cohort, the above three indicators were 0.917(95%CI: 0.782-1.000), 93.3% and 87.5%. In the external test cohort, the above three indicators were 0.960(95%CI: 0.905-1.000), 84.0% and 100.0%. The results of subanalysis showed that age was the independent predictor in the patients with chronic hepatitis and cirrhosis between HCC and FNH groups. Conclusions Gd-EOB-DTPA enhanced MRI nomogram model may be useful for discriminating HCC and FNH showing iso- or hyperintensity in the HBP before surgery.

Abstract Background As a vital soil-borne pathogenic bacterium, Ralstonia solanacearum can cause wilt disease in multiple Solanaceae plants. Several phages, such as ϕPB2, could infect R. solanacearum acting as a potential biological control agent in soil. In addition, some nanoparticles, especially copper preparation, also showed high toxicity on R. solanacearum with low toxicity on plant. However, whether they can be administered in combination and how effective they are in inhibiting the plant disease caused by R. solanacearum is known very little. Results In this work, the characterization of CuONPs using scanning electron microscope, transmission electron microscope, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction ascertained the presence of CuONPs which were nanometer particle of 83 nm. Then it was found that combined application of CuONPs with phage (ϕPB2) was superior to that of ϕPB2 or CuONPs alone in controlling tobacco bacterial wilt, with the CuONPs (250 mg/mL) and phage (106 PFU/mL) ratio being the best, at 79.1%. The combination of CuONPs and ϕPB2 also showed no obvious toxicity on tobacco growth than control like single application of CuONPs or ϕPB2. Furthermore, the transcriptome changes of R. solanacearum analysis indicated that the combination application and single allocation of CuONPs could inhibit “biofilm formation”, molecular function, biological processes, cellular components, metabolic process, and so on. In addition, the combination application showed higher inhibition of motility and biofilm, and better enhancement of cell membrane permeability, protein leakage, MDA concentration, and enzyme activity of their respiratory chain dehydrogenase than single application of CuONPs or phage (ϕPB2). Transcriptomes analysis also supported that the addition of ϕPB2 enhanced the toxicity of CuONPs by influencing the ABC transporters and quorum sensing, metabolic processes, and cellular biosynthetic processes of R. solanacearum. Conclusion In total, our work not only proposed a novel way to increase the bactericidal effect of nanomaterials by adding phage, but also discovered the influence, synergistic effects, and mechanisms, which is useful to design novel way to combat phytopathogenic bacteria in the complicated environment. Graphical abstract

Adenomatoid tumors (ATs) are uncommon, benign tumors of mesothelial origin, most frequently found in the genital tracts of both sexes. Extragenital localization sites, such as adrenal glands, are extremely rare. Since patients with adrenal ATs have no obvious clinical symptoms, imaging examination has become important evidence for diagnosis. Although previous literature noted that the imaging findings of adrenal ATs were nonspecific, no relevant studies have confirmed this. We herein present two novel cases of adrenal ATs, confirmed by immunohistochemistry, and that were initially misdiagnosed as other, more common adrenal tumors based on clinical findings and preoperative imaging. Including our cases, we collected a total of 33 previously reported adrenal ATs and extracted all available imaging information from them, aiming to find some radiological characteristics of this rare tumor. Through the review, we identified some nonspecific imaging features of adrenal ATs; however, the final diagnosis still depends on pathology and immunohistochemistry results.

It has been found in the recent studies that the CO2 geological storage is one of the efficient methods to achieve a large amount of CO2 reduction, while the understanding of the transport law of CO2 in the rock pore space is fundamental to the flexibility of a safe and long-term CO2 geological storage scheme. The pore network model based on the core micro-structure reconstruction can not only reflect the real core pore and throat distribution law, but also reflect the distribution of pore space and its development characteristics, which is of importance in the field of multi-phase flow research in porous media. The Berea sandstone, which is more common in the reservoir, was selected to obtain two-dimensional CT images based on the micro-focus X-ray computed tomography (micro-CT) technology, and the digital images of core samples were reconstructed in ImageJ software through a series of image processing processes such as size cropping, noise reduction filtering and threshold segmentation, and binarized in the Matlab software via extraction functions. Then, via the maximum sphere algorithm, the pore-throat topological equivalent network in the experimental core samples was extracted through three main steps, including searching the maximum sphere, establishing the maximum sphere connectivity, identification of pores and throats and parameter calculation, and visualized by using Amira software to equate the pores and throats to a spherical rod models. By comparing the structural parameters of core porosity, coordination number, pore and throat geometry and shape factor obtained via different image processing and pore network extraction methods, a digital core reconstruction and pore network model extraction method that can better reflect the spatial characteristics of real core pores was determined, such as model 7: the mean value is set to 1.5 and median value is set to 2 during filtering. The Otsu algorithm was selected for threshold segmentation and the minimum aperture was set to 1 when the digital core was extracted by the maximum sphere method. The pore structure parameters of Berea core were measured as follows: the coordination number was distributed within 30 and the peak value was around 5. The pore radius was distributed within 80 μm and concentrated around 20 μm. The throat radius was distributed within 60 μm and concentrated around 10 μm. The pore shape factor and throat shape factor were distributed within 0.07, the peak of pore shape factor was around 0.03, and the peak of throat shape factor was around 0.035. Finally, based on the pore network two-phase seepage simulation program developed by Imperial College of Technology, the seepage simulation of CO2-replaced brine in porous media was carried out under the reservoir conditions of 50 ℃ and 12.4 MPa by characterizing brine with 0.103 mol/kg NaCl solution. Then, the capillary pressure curve and relative permeability curve during the drainage and imbibition cycle were analyzed in detail. The influence of the pore network extraction method on the multi-phase flow process in porous media was elucidated, and the reliability of the pore network modeling method and the accuracy of the obtained modeling parameters were demonstrated again.

Objective： This study aimed to provide the basis of quantity traceability for the analysis of amoxicillin residues in milk. At the same time, it can also provide quantity standards for ensuring the effective implementation of amoxicillin monitoring in milk and combating the abuse of amoxicillin in the country and regions. Methods： Two healthy middle-class dairy cows were injected with amoxicillin intramuscularly. After the natural metabolism of the drug for a period of time, the milk containing the target drug amoxicillin was collected and made into milk matrix reference material containing amoxicillin by vacuum freeze-drying technology. The uniformity test, stability test, fixed value and uncertainty evaluation of the prepared milk lyophilized powder matrix reference material were carried out. Results： In the uniformity test, the F value obtained is 0.05, The results showed that the preparation of the standard milk powder was homogeneous; In the stability test, the short-term stability test （25, 4, -20 ℃; 2 weeks） and long-term stability test （4, -20 ℃; 6 months） showed good stability;The reference materials were jointly calibrated by 8 laboratories, and the final calibration result was 4.05 μg/kg, the total uncertainty being 0.2 μg/kg. Conclusion： The prepared amoxicillin matrix reference material in milk freeze-dried powder has good uniformity and stability, which can be used as a carrier to trace the amount of amoxicillin in milk, and can be widely used in the methodology verification and quality control of amoxicillin detection in milk.

Synovial sarcomas (SSs) are a rare group of malignant tumors originating from pluripotential mesenchymal cells, which commonly occur as the primary tumor in the soft tissues near the articular surface, tendons, and articular synovium. Herein, we report a rare case of mediastinal SS in an 18-year-old teenager who initially presented with cough as the primary symptom. In this case, plain chest CT and contrast-enhanced CT clearly revealed the lesion presenting as a round-like and uneven density mass in the mediastinum with heterogeneous enhancement, which compressed the trachea and invaded the adjacent vessels. Based on the results of immunohistochemistry and fluorescence in situ hybridization (FISH), combined with the differential diagnosis with other types of tumors in the mediastinum on imaging, we were able to diagnose the tumor as an SS located in the mediastinum. Subsequent resection of the lesion coupled with chemotherapy and immunotherapy led to an improvement in the patient’s symptoms.

In order to mitigate the risk of roof-dominated coal burst in underground coal mining, horizontal long borehole staged hydraulic fracturing technology has been prevailingly employed to facilitate the weakening treatment of the hard roof in advance. Such weakening effect, however, can hardly be evaluated, which leads to a lack of a basis in which to design the schemes and parameters of hydraulic fracturing. In this study, a combined underground–ground integrated microseismic monitoring and transient electromagnetic detection method was utilized to carry out simultaneous evaluations of the seismic responses to each staged fracturing and the apparent resistivity changes before and after all finished fracturing. On this basis, the comparable and applicable fracturing effects on coal burst prevention were evaluated and validated by the distribution of microseismic events and their energy magnitude during the mining process. Results show that the observed mining-induced seismic events are consistent with the evaluation results obtained from the combined seismic-electromagnetic detection method. However, there is a limited reduction effect on resistivity near the fractured section that induces far-field seismic events. Mining-induced seismic events are concentrated primarily within specific areas, while microseismic events in the fractured area exhibit high frequency but low energy overall. This study validates the rationality of combined seismic-electromagnetic detection results and provides valuable insights for optimizing fracturing construction schemes as well as comprehensively evaluating outcomes associated with underground directional long borehole staged hydraulic fracturing.

Plaque rupture is a critical concern due to its potential for severe outcomes such as cerebral infarction and myocardial infarction, underscoring the urgency of noninvasive early diagnosis. Magnetic resonance imaging (MRI) has gained prominence in plaque imaging, leveraging its noninvasiveness, high spatial resolution, and lack of ionizing radiation. Ultrasmall iron oxides, when modified with polyethylene glycol, exhibit prolonged blood circulation and passive targeting toward plaque sites, rendering them conducive for MRI. In this study, we synthesized ultrasmall iron oxide nanoparticles of approximately 3 nm via high-temperature thermal decomposition. Subsequent surface modification facilitated the creation of a dual-modality magnetic resonance/fluorescence probe. Upon intravenous administration of the probes, MRI assessment of atherosclerotic plaques and diagnostic evaluation were conducted. The application of Flash-3D sequence imaging revealed vascular constriction at lesion sites, accompanied by a gradual signal amplification postprobe injection. T1-weighted imaging of the carotid artery unveiled a progressive signal ratio increase between plaques and controls within 72 h post-administration. Fluorescence imaging of isolated carotid arteries exhibited incremental lesion-to-control signal ratios. Additionally, T1 imaging of the aorta demonstrated an evolving signal enhancement over 48 h. Therefore, the ultrasmall iron oxide nanoparticles hold immense promise for early and noninvasive diagnosis of plaques, providing an avenue for dynamic evaluation over an extended time frame.

The variation of hard roof thickness is an essential contributor in triggering rock bursts during longwall mining. Case analysis and numerical modeling were used to study the stress and energy characteristics of the coal and rock mass and its fracture behaviour in the roof thickness variation zone (RTVZ). The results show that the coal seam has higher initial stress if overlain by a thicker hard roof, whose stress monitoring value is 1.8–2.6 times that of the thin zone. The increasing variation in the roof thickness or the roof properties causes a greater initial stress change in the coal seam. In the thick roof zones, the superposition of the advanced abutment pressure and the increased initial stress will result in a high-stress concentration area, where the stress mutation coefficient value can be up to 1.08–1.15. A higher rock burst risk might thus present in the roadway near the longwall in the thick roof zone, where more intensive elastic energy was released in the coal/rock mass. Also, it is more likely to have a significant dynamic load in the thin roof zone due to the higher possibility of roof breakage, and the total microseismic energy can reach 1.8–3.2E + 08J. HighlightsCase analysis and numerical modelling were used to study the formation mechanism of stress anomaly in coal seams, energy evolution characteristics of the coal/rock mass and its fracture behaviour in the RTVZ.The mechanism of rock bursts induced by coal mining in the RTVZ is determined. The thick roof zone has high-stress concentration, where more intensive elastic energy is released in the coal/rock mass. Due to easier roof breakage, it is more likely to have a significant dynamic load in the thin roof zone.The prevention and control method of rock bursts in the RTVZ is put forward. The rock bursts can be relieved by reducing the initial stress increased in the thick roof zone. Strengthening roadway support can reduce the influence of dynamic load on the roadway.

Rock failure process as a natural response to mining activities is associated with seismic events, which can pose a potential hazard to mine operators, equipment and infrastructures. Mining-induced seismicity has been found to be internally correlated in both time and space domains as a result of rock fracturing during progressive mining activities. Understanding the spatio-temporal (ST) correlation of mining-induced seismic events is an essential step to use seismic data for further analysis, such as rockburst prediction and caving assessment. However, there are no established methods to perform this critical task. Input parameters used for the prediction of seismic hazards, such as the time window of past data and effective prediction distance, are determined based on site-specific experience without statistical or physical reasons to support. Therefore, the accuracy of current seismic prediction methods is largely constrained, which can only be addressed by quantitively assessing the ST correlations of mining-induced seismicity. In this research, the ST correlation of seismic event energy collected from a study mine is quantitatively analysed using various statistical methods, including autocorrelation function (ACF), semivariogram and Moran's I analysis. In addition, based on the integrated ST correlation assessment, seismic events are further classified into seven clusters, so as to assess the correlations within individual clusters. The correlation of seismic events is found to be quantitatively assessable, and their correlations may vary throughout the mineral extraction process.

(1) Background: Acute ischemic stroke (AIS) is time-sensitive. The accurate identification of the infarct core and penumbra areas in AIS patients is an important basis for formulating treatment plans, and is the key to dual-layer spectral detector computed tomography angiography (DLCTA), a safer and more accurate diagnostic method for AIS that will replace computed tomography perfusion (CTP) in the future. Thus, this study aimed to investigate the value of DLCTA in differentiating infarct core from penumbra in patients with AIS to establish a nomogram combined with spectral computed tomography (CT) parameters for predicting the infarct core and performing multi-angle evaluation. (2) Methods: Data for 102 patients with AIS were retrospectively collected. All patients underwent DLCTA and CTP. The patients were divided into the non-infarct core group and the infarct core group, using CTP as the reference. Multivariate logistic regression analysis was used to screen predictors related to the infarct core and establish a nomogram model. The receiver operating characteristic (ROC) curve, the calibration curve, and decision curve analysis (DCA) were used to evaluate the predictive efficacy, accuracy, and clinical practicability of the model, respectively. (3) Results: Multivariate logistic analysis identified three independent predictors: iodine density (OR: 0.022, 95% CI: 0.003–0.170, p < 0.001), hypertension (OR: 7.179, 95% CI: 1.766–29.186, p = 0.006), and triglycerides (OR: 0.255, 95% CI: 0.109–0.594, p = 0.002). The AUC–ROC of the nomogram was 0.913. Calibration was good. Decision curve analysis was clinically useful. (4) Conclusions: The spectral CT parameters, specifically iodine density values, effectively differentiate between the infarct core and penumbra areas in patients with AIS. The nomogram, based on iodine density values, showed strong predictive power, discrimination, and clinical utility to accurately predict infarct core in AIS patients.

This paper focuses on the problem that the current path planning algorithm is not mature enough to achieve the expected goal in a complex dynamic environment. In light of the ant colony optimization (ACO) with good robustness and strong search ability, and the rolling window method (RWM) with better planning effect in local path planning problems, we propose a fusion algorithm named RACO that can quickly and safely reach the designated target area in a complex dynamic environment. This paper first improves the ant colony optimization, which greatly improves the convergence performance of the algorithm and shortens the global path length. On this basis, we propose a second-level safety distance determination rule to deal with the special problem of the research object encountering obstacles with unknown motion rules, in order to perfect the obstacle avoidance function of the fusion algorithm in complex environments. Finally, we carry out simulation experiments through MATLAB, and at the same time conduct three-dimensional simulation of algorithm functions again on the GAZEBO platform. It is verified that the algorithm proposed in this paper has good performance advantages in path planning and dynamic obstacle avoidance.

In this paper, a novel inverse model is designed for multivariable disturbance observer-based (MDOB) control system. A new interaction measure, generalized relative input disturbance gain (GRIDG), is proposed to quantify the disturbance rejection capabilities of different inverse model structures. Consequently, an inverse model with partially coupled structure can be determined for better disturbance rejection performance. Besides, by defining a relative input disturbance gain array (RIDGA), the values of GRIDG under different input-output pairings and structures can be derived in an intuitive manner, which greatly facilitates the structure selection of the inverse model. And then, to overcome the difficulty of implementing the partially coupled inverse model, a V canonical structure is used without introducing model approximation. It also has the advantage of simple calculation and being easy to generalize to high-dimensional systems. Finally, simulation examples of several multivariable industrial processes are given to illustrate the design procedure and demonstrate the effectiveness of the proposed strategy.

Ewing’s sarcoma is a part of a rare group of malignant neoplasms, whose pathological morphological features are small round cells. Extraskeletal Ewing’s sarcoma is a more uncommon primary tumor. Herein, we report the case of a 66-year-old man who complained of chest tightness. Subsequent chest CT scans revealed an irregular and uneven density mass on the right side of the anterior mediastinum with invasion of the superior vena cava, pericardium and right lung. The patient’s clinical symptoms were improved after performing excision of the mediastinal lesions under cardiopulmonary bypass. Based on histological and immunohistochemical findings, the tumor was diagnosed as extraskeletal Ewing’s sarcoma.

Fe3O4@PVA microcapsule catalyst with dissolution as trigger condition was synthesized by utilizing nano Fe3O4 catalyst as core material and water-soluble polyvinyl alcohol as shell material. The microcapsule catalyst was loaded in poly(lactic-co-glycolic acid)(PLGA) membrane to prepare the freshwater/seawater degradable Fe3O4@PVA/PLGA composite films.Transmission electron microscopy (TEM) and dynamic light scattering (DLS) particle size distribution were used to test the morphology of Fe3O4@PVA. The shell thickness of Fe3O4@PVA core-shell particles is 2-3 nm. The structural characteristics, magnetic and mechanical properties of Fe3O4@PVA core-shell particles and Fe3O4@PVA/PLGA composite membrane were determined by FTIR, XPS, TG, VSM and electronic universal material tests. The degradation properties of Fe3O4@PVA/PLGA composite films in freshwater, seawater, air, darkness and low temperature environments were discussed. The results show that the maximum degradation ratio of Fe3O4@PVA/PLGA composite films is 97.79% at 120 days in seawater and 99.75% at 120 days in freshwater. Fe3O4@PVA/PLGA composite films are degraded in the seawater and the mass average molecular weight decreases from 28440 to 1396.

Artificial construction of a weakening zone over the roadway is an essential method for preventing coal bursts and rock bursts caused by strong mining tremors. However, concerning the seismic absorption and load reduction capabilities of an artificial structural weakening zone, the degree of rock mass damage to the roadway under weakening zone protection remains unclear. This study employed principles of elasticity and UDEC (Universal Distinct Element Code) to explore the seismic attenuation and load reduction capabilities of the weakening zone. The results indicate that the absorbing ability of the weakening zone increases exponentially with its weakening coefficient. Under the same dynamic load disturbance, when the weakening coefficient rises from 0.00 to 0.99, the sidewall displacement from the elastic wave source side changes from 0.400 m to 0.228 m. The total number of cracks in the roadway-surrounding rock, and the ranges of overstressed zones decreased linearly. The critical threshold of the roadway resisting the mining tremor disturbance increased. In particular, when the mining tremor is located directly above the roadway, the initial deformation of the roof is the largest, and the cumulative deformation of the rib is greater than the roof. By creating a weakening zone with a coefficient exceeding 0.95, the roadway remains unaffected by the 20 MPa dynamic loading. The study provides a theoretical basis for controlling coal burst that is triggered by mining tremors.

AbstractThe occurrence of coal burst in underground coal mines is complex, abrupt, and diverse, and the evaluation and prediction of coal burst hazard is the premise of effective prevention and control of coal burst. In this study, a coal burst carrier system model under the synergistic action of roof, coal seams, and floor was established, and the evolution of coal burst in underground coal mines was discussed based on the stress-vibration-energy coupling principle. On this basis, an integration method of bursting strain energy and seismic velocity tomography for coal burst assessment was proposed. With the deep and complex panel in a mine as the research object, the coal burst risk of the panel during excavation was evaluated in time and space domains, respectively. Results showed that the bursting strain energy and the active seismic velocity tomography technology can accurately identify both the positive anomalies and the negative anomalies of stress field and energy field in the mining period. Moreover, the method can not only evaluate the coal burst risk of the panel in the temporal domain but also predict the area with potential strong seismic events in the spatial domain. The research conclusions can accurately illustrate the whole complex evolution process of coal burst in underground coal mines.

Fault is a common geological structure that has been revealed in the process of underground coal excavation and mining. The nature of its discontinuous structure controls the deformation, damage, and mechanics of the coal or rock mass. The interaction between this discontinuous structure and mining activities is a key factor that dominates fault reactivation and the coal burst it can induce. This paper first summarizes investigations into the relationships between coal mining layouts and fault occurrences, along with relevant conceptual models for fault reactivation. Subsequently, it proposes mechanisms of fault reactivation and its induced coal burst based on the superposition of static and dynamic stresses, which include two kinds of fault reactivations from: mining-induced quasi-static stress (FRMSS)-dominated and seismic-based dynamic stress (FRSDS)-dominated. These two kinds of fault reactivations are then validated by the results of experimental investigations, numerical modeling, and in situ microseismic monitoring. On this basis, monitoring methods and prevention strategies for fault-induced coal burst are discussed and recommended. The results show that fault-induced coal burst is triggered by the superposition of high static stress in the fault pillar and dynamic stress from fault reactivation. High static stress comes from the interaction of the fault and the roof structure, and dynamic stress can be ascribed to FRMSS and FRSDS. The results in this paper could be of great significance in guiding the monitoring and prevention of fault-induced coal bursts.

Erdheim-Chester disease (ECD) is a rare and systemic non-Langerhans cell histiocytosis. Recently, ECD was classified as an inflammatory medullary tumor that affects a diverse group of organ systems. The purpose of this report is to present the radiological features of this disease in a 51-year-old man with intestinal obstruction as the initial presentation. In this case, X-ray computed tomography (CT) and emission computed tomography (ECT) clearly showed lesions in various systems, especially in the skeletal images. The survival benefit of treatment with interferon α (IFN-α) and BRAF inhibitors is well established, while other treatments focus on symptom relief.

In the current paper, a hybrid depth neural network model, TBLC-rAttention, aiming at Chinese text emotion recognition, is proposed to identify the emotional tendency of the Chinese medical reviews. The model includes the following steps: acquiring and preprocessing the Chinese corpus; mapping the preprocessed text into the word vectors; using Bi-directional Long Short-Term Memory network (Bi-LSTM) with the attention mechanism to acquire the context semantic features of the text; using Convolutional Neural Network (CNN) to obtain local semantics features on the basis of the context semantic features; and inputting the final feature vectors into the classification layer to complete the task of emotion recognition and the classification of the Chinese medical reviews. In this experiment, the corpus data is the comments of 999 cold medicine on a large e-commerce platform. All corpus are divided into three types, including high praise, medium praise and bad review. Classical machine learning models (SVM, NB) and neural network models (CNN, LSTM, Bi-LSTM, BiLSTM-Attention and RCNN) are performed as the comparison benchmarks to assess the category performance of TBLC-rAttention model. All the results were obtained when the training accuracy and test accuracy were stable after 1000 cycles of repeated calculation. The results show that TBLC-rAttention can get better text feature than the reference models, and the text classification accuracy reaches to 99%. In conclusion, the TBLC-rAttention model can identify semantic feature information to the greatest extent. In addition, this study also completes the numerical quantification of the predicted results.

Collaborative filtering has become one of the most widely used methods for a variety of commercial recommendations. The key to collaborative filtering is use similarity calculation formula to find similar neighbors or projects. However, most similarity calculation methods only use the user common score and provide bad recommendations. This paper proposes a new similarity measure method, which effectively utilizes the user context information. The new method uses a singularity factor to adjust nonlinear equation and takes into account the user scoring habits. It can improve the accuracy of the prediction. The new method has been tested on the dataset and compared with other algorithms. The results show that the proposed method can improve the recommendation quality.

Nonlinear system modeling using Deep Belief Network (DBN) is currently a research hotspot. However, the training process of DBN needs large amount of data to guarantee accuracy, and the traditional DBN may not meet the requirement of high-precision modeling. In this paper, we first improve the original DBN and Variational Mode Decomposition (VMD) algorithms, and on this basis, we then proposed a parallel Momentum Deep Belief Networks (MDBN) with Adaptive Variational Mode Decomposition (AVMD). Parallel AVMD-MDBN is an improved modeling method based on the deep learning model DBN. Firstly, a single raw dataset is decomposed into a specific number of sub-datasets using AVMD. Then these sub-datasets are distributed among a number of improved MDBNs. A single raw dataset learning model and algorithm is extended to multiple feature extraction nodes to learn the characteristics of multiple sub-datasets in parallel. Finally, the results of the multiple nodes are transmitted to the main feature extraction node to complete the regression calculation. In order to verify the effectiveness of the model, the proposed parallel AVMD-MDBN model is tested on a nonlinear dynamic system modeling, a Mackey-Glass time-series prediction and a financial stock prediction. Our experimental results show that the proposed parallel AVMD-MDBN has better performances in terms of improving feature learning ability than that of other methods.

Investigation of acoustic emission (AE) characteristics during laboratory tests of coal samples can provide useful guidance on the recognition of microseismicity (MS) precursors for seismic hazards in underground coal mining. In this study, a methodology, involving fractal dimension indices and a fuzzy comprehensive evaluation model, was developed and demonstrated using AE monitoring data in a uniaxial loading test of coal samples, which allows for a better and quantitative recognition of AE/MS precursors to seismic hazards associated with rock failures. In this methodology, the fractal dimension indices include six information dimension indices as well as three previously used capacity dimension indices. The assessment results were initially characterised as probabilities belonging to each of four risk levels (none, weak, moderate, and strong), and then output as a comprehensive result corresponding to one of these four risk levels. The results indicated that this developed methodology was able to recognise the AE precursors for rock failures.

The hazardous effect of a mine earthquake on a roadway is not only related to its energy scale but also to its distance from the roadway. In this study, a signal attenuation model and a disaster-causing model were established to evaluate the mine earthquake effects based on peak particle velocity (PPV) data recorded for 37221-1 upper roadway of the Dongxia Coal Mine, China. The characteristic of dynamic loads due to mine earthquake propagation to roadway surfaces was researched, and critical PPV values were identified using FLAC3D numerical simulation, which can be used to evaluate the roadway anti-burst performance under the existing support system. The results show that the support system is able to resist a mine earthquake with energy below 2.33 × 103 J; however, considering the energy accumulation volume of surrounding rocks and the range of source fracture, the maximum resistible mine earthquake energy can be up to 7.09 × 106 J when the roadway is 50 m away from the source. The validity and applicability of the disaster-causing models was verified by two rockburst cases that occurred during the excavation of the working face.

Extraskeletal osteosarcoma is an uncommon and high-grade soft tissue malignancy. The incidence is even lower when the lung and pulmonary artery are the primary site. The purpose of this report is to present the radiological features of this neoplasm in a 52-year-old man. In our case, contrast-enhanced CT and 3D-CT reconstruction clearly showed the primary lesion and its invasion into surrounding tissues. Although wide local excision of the primary tumor is the treatment of choice, local recurrence and metastasis rates remain high, and this progression can be clearly shown on CT and SPECT/CT examinations.

Rock bursts have become one of the most severe risks in underground coal mining and its early warning is an important component in the safety management. Microseismic (MS) monitoring is considered potentially as a powerful tool for the early warning of rock burst. In this study, an MS multi-parameter index system was established and the critical values of each index were estimated based on the normalized multi-information warning model of coal-rock dynamic failure. This index system includes bursting strain energy (BSE) index, time-space-magnitude independent information (TSMII) indices and time-space-magnitude compound information (TSMCI) indices. On the basis of this multi-parameter index system, a comprehensive analysis was conducted via introducing the R-value scoring method to calculate the weights of each index. To calibrate the multi-parameter index system and the associated comprehensive analysis, the weights of each index were first confirmed using historical MS data occurred in LW 402102 of Hujiahe Coal Mine (China) over a period of four months. This calibrated comprehensive analysis of MS multi-parameter index system was then applied to pre-warn the occurrence of a subsequent rock burst incident in LW 402103. The results demonstrate that this multi-parameter index system combined with the comprehensive analysis are capable of quantitatively pre-warning rock burst risk. Keywords: Rock burst, Microseismic (MS) monitoring, Multi-parameter indices, Comprehensive early warning

Abstract This study aimed to evaluate the imaging quality of head and neck computed tomographic angiography (CTA) in pediatric patients at a lowered radiation dose by combining an iterative model reconstruction (IMR) with low voltage scanning. Eighty-three pediatric patients were randomized into two groups as follows: Group A (n = 42), 100 kV/50 ml contrast media (CM), using filtered back projection (FBP); and Group B (n = 41), 80 kV/30 ml CM, using IMR. The enhanced CT value of the arteries, the image noise, the signal-to-noise ratio (SNR)/contrast-to-noise ratio (CNR), the image quality, the effective radiation dose (ED) and the iodine intake were compared between the two groups. The mean ED and iodine intake of group B were reduced by 69.8% and 40.0%, respectively, compared to those of group A. The mean CT values of the arteries in group B were higher than those in group A (p

Numerous tremors occur during excavation and mining periods in coal mines, and low-energy tremors often occur before strong tremors. In addition, it is found that not all strong tremors cause rockbursts. Therefore, generating behaviors of strong tremors and the triggering criterion for the occurrence of the rockburst must be investigated. In this study, generating behaviors of strong tremors were inferred by velocity tomograms and energy density clouds. An innovative facility capable of applying dynamic disturbance to roadway models was developed to study the triggering criterion for rockbursts. Velocity tomograms indicated that the stress concentration extended to the syncline region with the advance of the coalface. High-energy-density clouds expanded rapidly and regularly in some areas that were parts of the high-velocity region, indicating that the stress increased rapidly in these areas, until strong tremors took place nearby. AE activities suggested that the modelled roadway offered good resistance as the dynamic loading energy grew from 29.4 J to 117.6 J. Then, sharp AE activity at the dynamic loading energy of 147 J indicated the ultimate shock resistance of the roadway was almost reached. Finally, bursting failure of the modelled roadway was observed at a dynamic loading energy of 176.4 J.

Rockburst is a sudden and dynamic failure of rock that can cause serious injury to miners and damage to the underground excavations. Stress path, dynamic disturbance, and support system play important and different roles in the generation processes of rockbursts, resulting rockbursts with variety of reasons and failure modes. A test facility that was capable of simulating such factors was developed to study shock behaviour and bursting failure of roadways. The results demonstrate that the modeled roadway was in good condition and retained a shock resistance capacity after three drop loads. Until the acceleration amplitude increased to a certain level at the time of the fourth dynamic loading, sudden bursting failure of modeled roadway occurred. Many large fragments ejected from the upper and middle regions of the roadway, accompanied with loud noise. A deep pit was observed after the bursting failure. The axial of the fan-shaped pit had an angle above the vertical. In addition, shock behaviour of the modeled roadway had been changed by the anchor-net support. Significant differences appeared between the acceleration signals measured in two roadway sections with and without the anchor-net support. The acceleration magnitude of the supported roadway section was strongly reduced by the presence of the anchor-net support. Even when the unsupported roadway section underwent a sudden injection failure, the roadway with anchor-net support was in good condition. This study may eventually lead to a methodology for studying the rockbursting resistance capacity of underground roadways.

The patient was contaminated with multiple radionuclides 38 years ago due to an accident. To investigate the effects of radionuclide contamination on humans, he has been followed up by examinations for many years. Long-term effects gradually emerge in these years. Lung cancer was diagnosed by medical examinations. Besides, chronic gastritis with intestinal metaplasia was indicated by gastroscopic biopsies, while colorectal polyps found by colonoscopy. All 13 colorectal polyps were removed, and radical surgery for lung cancer was performed. Fortunately, pathological examinations indicated that it was early lung cancer. The ground glass nodule (GGN) in left lung identified during the follow-up will be resected when needed. It is speculated that multiple manifestations of the patient may be related to radiation, and different lesions in the organs may be related to systemic adaptive response. However, longer follow-up is needed due to a lack of effective and direct evidence. This work is expected to provide experiences for similar patients’ treatment and follow-up.

In view of the slow convergence speed, difficulty of escaping from the local optimum, and difficulty maintaining the stability associated with the basic whale optimization algorithm (WOA), an improved WOA algorithm (REWOA) is proposed based on dual-operation strategy collaboration. Firstly, different evolutionary strategies are integrated into different dimensions of the algorithm structure to improve the convergence accuracy and the randomization operation of the random Gaussian distribution is used to increase the diversity of the population. Secondly, special reinforcements are made to the process involving whales searching for prey to enhance their exclusive exploration or exploitation capabilities, and a new skip step factor is proposed to enhance the optimizer’s ability to escape the local optimum. Finally, an adaptive weight factor is added to improve the stability of the algorithm and maintain a balance between exploration and exploitation. The effectiveness and feasibility of the proposed REWOA are verified with the benchmark functions and different experiments related to the identification of the Hammerstein model.

The aim of this study was to assess the clinical efficacy and safety of acupuncture for climacteric depression. Two reviewers searched major databases independently. The quality assessment and data analysis were evaluated by Cochrane reviews 5.3.0. Seventeen clinical trials were included, contained 1,369 cases. Meta-analysis of acupuncture comparing with medicine showed that: a) Affective rate: [OR = 1.44, 95% CI (1.02, 2.04)], the difference had statistically significance; b) HAMA score : [MD = -2.12, 95% CI (-2.85, -1.40)], the difference had statistically significance; c) HAMD score: The difference of the 2nd week, 4th week, 6th week, 8th week, or 12th week was not statistically significant; d) Kupperman score: [MD = -5.05, 95% CI (-11.94, 1.84)] showed no statistical significance; e) Incidence of adverse events of acupuncture (2.7%) was significantly less than the control group (20%). In conclusion acupuncture will help to improve depressive symptoms of climacteric and decrease adverse reactions.

The paper proposed a design scheme of intelligent temperature control system of combustion chamber of limekiln. The system takes temperature of lower combustion chamber as control objective and gas flow as adjusting object, uses fuzzy neural network to dynamically adjust setting value of gas flow, uses particle swarm optimization algorithm to achieve optimization of parameters of the fuzzy neural network, and uses inverse control system of the least squares support vector machine to track and control gas flow, and it achieves precise control of temperature of the combustion chamber of limekiln. The simulation result showed that the system has fast response, good stability, strong anti-interference ability and robustness.

Combination of coal mining dynamic load and high static stress can easily induce such dynamic disasters as rock burst, coal and gas outburst, roof fall, and water inrush. In order to obtain the characteristic parameters of mining dynamic load and dynamic mechanism of coal and rock, the stress wave theory is applied to derive the relation of mining dynamic load strain rate and stress wave parameters. The in situ test was applied to study the stress wave propagation law of coal mine dynamic load by using the SOS microseismic monitoring system. An evaluation method for mining dynamic load strain rate was proposed, and the statistical evaluation was carried out for the range of strain rate. The research results show that the loading strain rate of mining dynamic load is in direct proportion to the seismic frequency of coal-rock mass and particle peak vibration velocity and is in inverse proportion to wave velocity. The high-frequency component damps faster than the low-frequency component in the shockwave propagating process; and the peak particle vibration velocity has a power functional relationship with the transmitting distance. The loading strain rate of mining dynamic load is generally less than class 10−1/s.