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In order to study the deformation law of roadway roof in the reuse retaining roadway stage of “110” construction method and determine the reasonable roadway support load, and to solve the safety hazards of the reuse of the retained roadway, taking the return airway of 214202 working face of Hanjiawan Coal Mine as the research background, the mechanical structure model of the short-arm beam of the roof cutting in the reuse of the retained roadway was established, and the numerical simulation and field measurement were used to study the roof deformation law of the advance section of the roadway and the mining influence zoning when the retained roadway was disturbed by the secondary mining. The research shows that during the reuse of the return airway, the roof support strength required for the advance influence area is 12 152.98 kN. Based on the theoretical calculation, the proposed advance reinforcement support scheme can rednce the deformation of roadway roof to 118-134 mm after reinforcement, which is 58% lower than that before reinforcement; the advance influence area of the working face can be divided into four areas.

Abstract To address coal pillar instability, the study focuses on the 3−1 coal seam coal pillar at Nanliang Coal Mine. It analyzes the bending deformation energy of the main roof and the pre-yield elastic energy of the coal pillar’s elastic zone through theoretical analysis, similar simulation, and field measurements. The formula for the bending elastic energy of the main roof is derived by establishing the mechanical model of the roadway’s main roof near the goaf side. Based on the side abutment stress distribution of the coal pillar, the calculation of the pre-yield elastic energy distribution along the width direction of the coal pillar’s elastic zone is conducted, leading to the derivation of the instability energy criterion for the coal pillar. The range analysis method is used to analyze the influencing factors and distribution patterns of the bending elastic energy of the main roof and the pre-yield elastic energy of the coal pillar’s elastic zone. Findings indicate that the main roof’s tensile strength is the primary factor influencing bending elastic energy. Higher tensile strength of the main roof, and smaller load, larger thickness and elastic modulus on the overlying strata, lead to higher bending elastic energy in the main roof. The internal friction angle, width of the coal pillar, and elastic modulus of the coal seam notably impact the pre-yield elastic energy of the coal pillar’s elastic zone. A larger internal friction angle and coal pillar width, along with a smaller elastic modulus, result in higher pre-yield elastic energy in the coal pillar’s elastic zone. Using the working face of 3−1 coal seam in Nanliang Coal Mine as the engineering context, the study calculates the minimum coal pillar width required for stability. Physical simulations and field monitoring demonstrate that with a 9 m—wide coal pillar, there is no apparent deformation or failure in the surrounding rock of the roadway, indicating good internal rock stability.

In order to explore the influence of the remaining coal pillar in the upper coal seam on the stress of the floor and the reasonable layout of the mining roadway in the lower coal seam, taking Tangshangou Coal Mine as the research object, the theoretical analysis and numerical simulation methods and a variety of influencing factors were used to construct the collaborative bearing structure model of the remaining coal pillar and the hinged rock block in the upper coal seam and the stress transfer calculation model of the floor, and the stress and influencing factors of the floor under the remaining coal pillar in the upper coal seam are studied. The research shows that the influence of the remaining coal pillars in the upper coal seam on the stress of the floor is mainly vertical stress, and the influence degree decreases with the increase of floor depth. The stress-increasing area of the floor under the remaining coal pillar is ellipsoidal. The influencing factors of the stress-increasing area of the floor are analyzed, and the quantitative relationship between the influence of different factors on the range of the stress-increasing area is obtained. The peak stress of the coal pillar plays a decisive role in the distribution of the stress-increasing area of the floor. According to the stress distribution of the floor and the results of theoretical calculation and numerical simulation, it is determined that the reasonable stagger distance between the 8 coal pillar and the 11−1 coal mining roadway in Tangshangou Coal Mine should be 20—25 m. This study reveals the stress transfer mechanism of the lower floor of the coal pillar left in the upper coal seam, clarifies the distribution and influencing factors of the floor stress increase area, and obtains the determination method of the reasonable stagger value of the roadway-coal pillar, which can provide a theoretical basis for the reasonable layout of the lower coal seam mining roadway.

Abstract To investigate the significant deformation of the surrounding rock within the dynamic pressure zone of the gateroad, this study utilized the tailgate of the 1506 longwall face in Anyang Coal Mine as the engineering context. A combined approach of field measurement and numerical analysis was employed to explore the deformation and failure mechanisms of the surrounding rock under dynamic pressure. The findings indicate that before the exploitation of the 1506 longwall face, there was a notable reduction in stress across the floor and immediate roof, with minimal stress concentration observed in the coal pillar and the entity rib side. The plastic zone surrounding the tailgate was limited, suggesting a high degree of stability in the entry's surrounding rock. However, during the extraction of the 1506 longwall face, the tailgate, extending 60 m ahead of the working face, was subjected to dynamic pressure, leading to a marked increase in stress within the floor, coal pillar, and immediate roof. Stress concentration was more pronounced on the entity rib side than on the pillar rib side. This resulted in significant fissuring and severe deformation of the entry's surrounding rock. The primary failure mechanism involved damage to both the roof and floor corners, with the severity of damage escalating alongside the stress in the surrounding rock. This culminated in the failure of roof corner bolts and anchor cables, thereby compromising the stability of the entry within the dynamic pressure zone.

BackgroundThe current landscape of acne therapeutics is notably lacking in targeted treatments, highlighting a critical need for the discovery of new drug targets to improve treatment outcomes.ObjectivesThis study aims to investigate the connections between proteomics and genetics in relation to acne across extensive population cohorts, aspiring to identify innovative preventive and therapeutic approaches.MethodsEmploying a longitudinal cohort of 54,306 participants from the UK Biobank Pharmacological Proteomics Project (UKB-PPP), we performed an exhaustive evaluation of the associations between 2,923 serum proteins and acne risk. Initial multivariate Cox regression analyses assessed the relationship between protein expression levels and acne onset, followed by two-sample Mendelian Randomization (TSMR), Summary-data-based Mendelian Randomization (SMR), and colocalization to identify genetic correlations with potential protein targets.ResultsWithin the UKB cohort, we identified 19 proteins significantly associated with the risk of acne. Subsequent analysis using Two-Sample Mendelian Randomization (TSMR) refined this to two specific proteins: FSTL1 and ANXA5. Each one-standard deviation increase in the expression levels of FSTL1 and ANXA5 was associated with a 24% and 32% increase in acne incidence, respectively. These results were further validated by additional Summary-data-based Mendelian Randomization (SMR) and differential expression analyses.ConclusionsOur comprehensive analysis of proteomic and genetic data from a European adult cohort provides compelling causal evidence that several proteins are promising targets for novel acne treatments.

2D-3D registration is increasingly being applied in various scientific and engineering scenarios. However, due to appearance differences and cross-modal discrepancies, it is demanding for image and point cloud registration methods to establish correspondences, making 2D-3D registration highly challenging. To handle these problems, we propose a novel and automatic solution for 2D-3D registration in Manhattan world based on line primitives, which we denote as VPPnL. Firstly, we derive the rotation matrix candidates by establishing the vanishing point coordinate system as the link of point cloud principal directions to camera coordinate system. Subsequently, the RANSAC algorithm, which accounts for the clustering of parallel lines, is employed in conjunction with the least-squares method for translation vectors estimation and optimization. Finally, a nonlinear least-squares graph optimization method is carried out to optimize the camera pose and realize the 2D-3D registration and point colorization. Experiments on synthetic data and real-world data illustrate that our proposed algorithm can address the problem of 2D-3D direct registration in the case of Manhattan scenes where images are limited and sparse.

Given the potential for dynamic load-induced support crushing that may occur during mining under an interval goaf through an isolated coal pillar (ICP) in shallow closely spaced coal seams, this paper systematically explored this issue through a case study of the 30,103 working face at the Nanliang Coal Mine. We employed a combined approach of similarity simulations, theoretical analyses, numerical simulations, and field measurements to investigate the catastrophic failure mechanisms and prevention strategies for dynamic pressure-related hazards encountered when mining a lower coal seam that passes through an ICP. The findings indicated that the synchronous cutting instability of the interlayer effective bearing stratum (IEBS) and double-arch bridge structure of the ICP roof were the primary causes of dynamic load-induced support crushing at the working face. A mechanical model was developed to characterize the IEBS instability during mining under an interval goaf. The sources and transmission pathways of dynamic mining pressure during mining passing through the ICP were clarified. The linked instability of the double-arch bridge structure of the ICP roof was induced by IEBS failure. The UDEC numerical model was utilized to elucidate the instability of the IEBS during mining in the lower coal seam and to analyze the vertical stress distribution patterns in the floor rock strata of the interval goaf. A comprehensive prevention and control strategy for roof dynamic pressure, which includes pre-releasing concentrated stress in the ICP, strengthening the support strength of the working face, and accelerating the advancement speed was proposed. The effectiveness of this prevention and control strategy was validated through actually monitoring the characteristics of mining pressure data from the 30,103 working face following pressure relief. The findings provide valuable insights for rock stratum control of shallow and closely spaced coal seam mining under similar conditions.

Shallow coal seam mining results in the formation of various bearing structures in key strata, leading to varying degrees of surface subsidence and severe disruption to the surface ecological environment. To investigate the coupled evolution characteristics of key strata fracture-bearing structures and surface subsidence in shallow coal seam mining, with a focus on the 1–2 coal seam mining at Longhua Coal Mine in northern Shaanxi as the research background, this study employed physical similarity simulation to establish the correlation between key strata fracture-bearing structures and surface subsidence. The study also utilized theoretical calculations to develop models for the trapezoidal hinged arch structure and the coupling between key strata-bearing structures and surface subsidence. Mechanical properties of bearing structures and the coupled evolution characteristics of surface subsidence were examined, and the scientific validity of the models was verified through field monitoring. The research reveals that the inclined section of the working face in shallow coal seam mining forms a trapezoidal hinged arch structure, where stress transmission actually resembles an arch shape. Based on the fracture characteristics of rock strata, this structure can be categorized into three types: a full-trapezoidal hinged arch structure, a semi-trapezoidal hinged arch structure, and a trapezoidal-like hinged arch structure. A mechanical calculation model for the trapezoidal hinged arch structure was constructed, and the mechanical calculation formula for this structure was derived based on mechanical equilibrium conditions. Using a masonry beam mechanical model, the formula for calculating the subsidence of key blocks in the key strata fracture was obtained. Based on the “masonry beam” mechanical model, a formula was derived to calculate the subsidence of key blocks in fractured key strata. The relationship between key strata-bearing structures and surface subsidence curves was analyzed, leading to the development of a calculation model for both. This model reveals the coupled evolution between rock movement and surface subsidence. Field measurements indicate a maximum surface subsidence of 1.93 m, with a subsidence coefficient of 0.65, showing that the surface helps suppress and reduce the overall subsidence.

The high-intensity mining of shallow-buried coal seams leads to the fracture of the bearing strata to form a combined bearing structure, which complicates the distribution of cracks in the overlying rock and causes serious damage to the surface. In order to study the relationship between the evolution law of the overburden fissures and the bearing structure of the bearing rock in the mining of the shallow coal seam group, and the working resistance value of the support to keep the bearing rock stable, the coal mining of Hanjiawan Coal Mine 2−2 and 3−1 in the Shenfu mining area in northern Shaanxi was studied. In the background, through field observation and similar simulation experiments, the evolution law of coal seam group mining cracks, the combined bearing structure of bearing rock layers and the relationship between the two were obtained. The mechanical model of combined bearing structure was established by theoretical calculation method, and the support work of the combined bearing rock layer to maintain stability was studied. resistance. The research shows that the evolution process of overlying fissures in coal seam mining can be divided into four stages: the upper coal seam mining rapid growth stage, the upper coal seam mining steady growth stage, the lower coal seam mining rapid growth stage, and the lower coal seam mining stable growth stage. This leads to different fissure evolution forms and subsidence characteristics on the surface. The surface of the “step rock beam” structure subsides in steps, and the surface of the “hinge rock beam” structure subsides continuously; The fractured structure of the bearing rock formation in the lower coal seam is obtained from the filling rate and mining height of the interlayer, and it is revealed that the fractured combined structure of the bearing rock formation in the shallow buried coal seam mining group is “step-hinged” structure, “hinged-hinged” structure, “hinged-hinged” structure. The combined form of the “step” structure and the “step-step” structure. Based on the fractured composite structure of the bearing rock, the mechanical model of the bearing rock bearing structure of the shallow buried coal seam group mining is established, and the calculation method of the working resistance of the bearing rock to maintain the stability of the support is obtained, and the field measurement results are verified.

Introduction: This study focuses on investigating the characteristics of overburden failure and ground pressure behavior in shallow coal seam mining beneath a gully. The research is conducted at the 135201 working face of Shaliang Coal Mine in the Shenfu Mining Area.Methods: The study employs physical similarity simulation tests, theoretical analysis, and field measurements to analyze the ground pressure and overburden failure characteristics at the working face.Results: The research findings indicate that the ground pressure is stronger in the uphill section compared to the gully bottom and downhill sections. The weighting interval in the uphill section is the smallest. A mechanical analysis model for the failure structure of the key stratum in the uphill section is established based on monitored ground pressure data and physical simulation test results. A calculation formula for the weighting interval in the uphill section is derived. The relationship between the caving interval, the thickness of the key stratum in the uphill section, and the gully slope is also analyzed. The on-site measurements align well with the theoretical results.Discussion: The study proposes a prediction method for ground pressure and suggests hazard prevention and control measures for shallow coal seam mining beneath a gully based on the research findings.

The roof water inrush of shallow buried coal seam is caused by the water flowing fractured zone through the aquifuge. With the downward mining of coal seam group, the mechanism of synergistic water isolation between soil layer and bedrock layer needs to be clarified. In order to analyze the failure mechanism of aquiclude under the background of downward mining of coal seam group, so as to accurately predict the water inrush problem of coal mine roof, taking the downward mining of 2−2, 3−1 and 4−2 coal seams in Han Jiawan Coal Mine of Shenfu Mining Area in Northern Shaanxi as the research background, the differences in the properties of aquiclude at different depths were obtained by in-situ borehole coring experiments. The development form of cracks is described by establishing the mechanical model of seepage expansion of upper aquifuge soil layer. Using the mechanical model of soil-rock composite aquiclude, the mechanical criterion of the lower aquiclude in the overall stable state is calculated under the condition of ‘given deformation’. The research shows that the aquiclude can be divided into upper aquiclude and lower aquiclude according to its different properties. By comparing the total load with the tensile strength of the upper aquifuge, when the total load is less than or equal to the tensile strength of the upper aquifuge, the crack no longer develops downward to obtain the crack development length. Under the condition of ‘given deformation’, when the tensile stress generated at the middle position of the long side of the aquiclude is less than or equal to the tensile strength threshold, the overall structure of the lower aquiclude is in a stable state, and no tensile failure will occur. According to the geological conditions of Han Jiawan coal mine, the numerical simulation results are consistent with the theoretical analysis results. The research can provide reference for roof water inrush prediction under similar geological conditions.

As the depth of coal seams increases and the demand for coal grows, the deformation and failure of roadways and coal pillars also intensify. To address the instability of roadways, it is crucial to study the appropriate dimensions for coal pillars. This paper focuses on the 1513 working face of the No. 5 coal seam at Anyang Coal Mine to address the issue of insufficient basis for determining coal pillar width. Through field observations and physical similarity simulations, this study examines the overlying strata failure patterns above coal pillars post-mining and the bearing structure formed by key layers. The relationship between these factors is analyzed using theoretical analysis and physical similarity simulations. A mechanical model of the coal pillar and the “hinged-hinged” overlying strata failure structure is established, analyzing the fracture characteristics of the overlying strata and the bearing structure of the coal pillar to determine the optimal coal pillar width under these conditions. The results indicate that when the coal pillar width is optimized from 25 m to 14 m, the overlying bearing layer is disrupted by the mining activities at the working face, with the lower key layer forming a “hinged” structure upon fracture. As mining progresses, the height of the overlying strata fractures gradually increases, causing the upper key layer to also fracture and form a “hinged-hinged” structure between the high and low bearing layers. According to the “three zones” development law, the height of overlying strata failure does not continue to increase indefinitely, and the coal pillar is affected by the “hinged-hinged” structure of the bearing strata. A mechanical model of the coal pillar bearing structure is established based on the fracture combination structure of the bearing strata. By calculating the load on the “hinged-hinged” structure of the overlying strata, the appropriate coal pillar width is determined to be 15 m. Theoretical calculations, physical similarity simulation experiments, and field applications show that without changing the support conditions, the deformation of the roadway is greater when the coal pillar is narrowed, compared to its original width. The maximum deformation, located 60 m ahead of the working face, increased by 41–42%, while deformation in other areas was relatively minor. This validates the reasonableness of the determined coal pillar width.

BackgroundHepatocellular carcinoma (HCC) is a malignant tumor with a high rate of recurrence and m metastasis that does not respond well to current therapies and has a very poor prognosis. Disulfidptosis is a novel mode of cell death that has been analyzed as a novel therapeutic target for HCC cells.MethodsThis study integrated bulk ribonucleic acid (RNA) sequencing datasets, spatial transcriptomics (ST), and single-cell RNA sequencing to explore the landscape of disulfidptosis and the immune microenvironment of HCC cells.ResultsWe developed a novel model to predict the prognosis of patients with HCC based on disulfidptosis. The model has good stability, applicability, and prognostic and immune response prediction abilities. N-myc downregulated gene1 (NDRG1) may contribute to poor prognosis by affecting macrophage differentiation, thus allowing HCC cells to evade the immune system.ConclusionOur study explores the disulfidptosis of HCC cells through multi-omics and establishes a new putative model that explores possible targets for HCC treatment.

Abstract The large‐scale mining of coal resources promotes the formation of section coal pillar groups between working faces. The overlying strata are supported by coal pillars, which leads to the formation of a unique fracture‐bearing structure in the key stratum, resulting in the evolution of fissures (cracks) and a generally high load on the supports. Studying the fracture‐bearing structure formed by coal pillars and overlying strata (fissures) is the basis for realizing rational mining of working faces. Here, the evolution characteristics of coal pillar‐overburden rock (fissures) in shallow coal seam mining and the working resistance of the support with stable fracture bearing structure of section coal pillar and overburden rock were studied in the No. 1‐2 coal mining of Longhua Coal Mine in Shenmu City, Northern Shaanxi. The fissure evolution characteristics on both sides of the coal pillar and the fracture‐bearing structure of the rock stratum were obtained by physical similarity simulation experiment. The mechanical calculation model of the coal pillar‐overburden rock (fissure) structure was established by theoretical derivation and calculation, and the working resistance of advanced support with a stable mechanical structure was studied. The research shows that the fracture evolution and rock fracture characteristics of a shallow coal seam mining face can be divided into three zones. Through the reanalysis of the mechanical structure of coal pillar‐overburden rock (fissure), the combined mechanical structure of the subkey stratum consisting of a lagging broken step rock beam structure and the main key stratum consisting of a hinged rock beam structure was obtained. Combined with the failure characteristics of the section coal pillar, a mechanical structure calculation method suitable for the bearing characteristics of section coal pillar support in shallow coal buried layers was obtained, and the field measurement results were verified.

Lubricating grease plays an important role in the rolling screw transmission of the actuation system and is particularly concerned with the performance stability of long-term storage in aerospace applications. In this article, a batch of ball screws that were lying flat in the warehouse for about eight years were selected to extract lubricating grease from the screw raceway after being stored in situ. The oxidation performance, friction performance and rheological properties of lubricating grease were tested and compared to those of fresh grease to analyze and summarize the performance changes in lubricating grease. The transmission efficiency, friction torque, and temperature rise of ball screws without removing the original grease and those filled with fresh grease after cleaning were tested and compared. The impact of grease degradation on the transmission performance of ball screws was analyzed to provide a reference for ball screw lubrication schemes and further accelerated storage experimental design.

As a traditional nourishing Chinese herbal medicine, Cornus officinalis Sieb. et Zucc. has a long history of application. At present, only the flesh of the fruit of Cornus officinalis is used as a medicine, which wastes a large quantity of ingredients in the nutlet. To improve the comprehensive utilization efficiency of the fruit’s nutlet, which could be used when there is a shortage of the plant’s fruit in the market, this study used Fourier transform-infrared spectroscopy (FT-IR), gas chromatography-mass spectrometry (GC-MS), thermogravimetric (TG) analysis, pyrolysis-gas chromatography-mass spectrometry (PY-GC-MS), and nuclear magnetic resonance (NMR) techniques to analyze the Cornus officinalis nutlet. The results showed that the active ingredients of Cornus officinalis nutlet have great medicinal value and could become a substitute for the fruit. After extracting the active ingredients, the residue can be used as a good biomass liquid fuel, providing reference for the future to replace fossil fuels. This study provides the scientific basis for the comprehensive utilization of high-quality resources for Cornus officinalis.

Antibacterial materials are preferable for water treatment a medical applications. In the present study, to improve the antimicrobial performance of flexible polyurethane (PU) foams, copper nanoparticles were in situ generated. The Cu nanoparticles were formed on the surface of polyurethane cell walls with sizes of 100–130 nm, and exhibited high affinity with the PU matrix. Although the cell structure of the nanocomposite PU foams was not greatly influenced, the open cell content decreased slightly from 97.42 to 96.64%. The bound metal nanoparticles on the cell walls could strengthen the cell skeleton improved the mechanical strength of the resulting foams. The mechanical parameters were dramatically improved, such as tensile and compressive strength of the nanocomposite PUs were improved from 78.1 to 94.2 kPa and from 3.80 to 5.63 kPa, respectively. Besides, these nanocomposite foams showed great antibacterial activity that can be considered for antibacterial applications in water treatment and medical fields.

Abstract Background P16INK4A is a surrogate signature compensating for the specificity and/or sensitivity deficiencies of the human papillomavirus (HPV) DNA and Papanicolaou smear (Pap) co‐test for detecting high‐grade cervical squamous intraepithelial lesions or worse (HSIL+). However, traditional p16INK4A immunostaining is labour intensive and skill demanding, and subjective biases cannot be avoided. Herein, we created a high‐throughput, quantitative diagnostic device, p16INK4A flow cytometry (FCM) and assessed its performances in cervical cancer screening and prevention. Methods P16INK4A FCM was built upon a novel antibody clone and a series of positive and negative (p16INK4A‐knockout) standards. Since 2018, 24 100‐women (HPV‐positive/‐negative, Pap‐normal/‐abnormal) have been enrolled nationwide for two‐tier validation work. In cross‐sectional studies, age‐ and viral genotype‐dependent expression of p16INK4A was investigated, and optimal diagnostic parameter cut‐offs (using colposcopy and biopsy as a gold standard) were obtained. In cohort studies, the 2‐year prognostic values of p16INK4A were investigated with other risk factors by multivariate regression analyses in three cervicopathological conditions: HPV‐positive Pap‐normal, Pap‐abnormal biopsy‐negative and biopsy‐confirmed LSIL. Results P16INK4A FCM detected a minimal ratio of 0.01% positive cells. The p16INK4A‐positive ratio was 13.9 ± 1.8% among HPV‐negative NILM women and peaked at the ages of 40–49 years; after HPV infection, the ratio increased to 15.1 ± 1.6%, varying with the carcinogenesis of the viral genotype. Further increments were found in women with neoplastic lesions (HPV‐negative: 17.7 ± 5.0–21.4 ± 7.2%; HPV‐positive: 18.0 ± 5.2–20.0 ± 9.9%). Extremely low expression of p16INK4A was observed in women with HSILs. As the HPV‐combined double‐cut‐off‐ratio criterion was adopted, a Youden's index of 0.78 was obtained, which was significantly higher than that (0.72) of the HPV and Pap co‐test. The p16INK4A‐abnormal situation was an independent HSIL+ risk factor for 2‐year outcomes in all three cervicopathological conditions investigated (hazard ratios: 4.3–7.2). Conclusions FCM‐based p16INK4A quantification offers a better choice for conveniently and precisely monitoring the occurrence of HSIL+ and directing risk‐stratification‐based interventions.

This study addresses the issue of large deformation in soft rock roadways, using the 50213 tailgate of Guantun Coal Mine as a case study. Field investigations were conducted to assess the condition of roadway bolts, anchor cables, and the internal damage characteristics of the surrounding rock. The upper bound method of limit analysis in plastic mechanics was utilized to construct a failure model for the surrounding rock and derive the upper limit solution of roof failure by integrating the principle of virtual work and variational extremum theorem. Physical similarity simulations were employed to investigate the fracture distribution and evolution law of the surrounding rock. Based on the deformation and instability mechanism of the roadway, optimized support parameters for soft rock roadways were proposed and verified through numerical simulation. The results indicate that the surrounding rock of the sharp corner of the roadway is initially destroyed and develops upward with increasing stress. The interconnected horizontal separation cracks at the anchorage end of the anchor cable and shear fracture zones at the two corners ultimately lead to the overall instability of the anchorage arch. Furthermore, the theoretical calculation boundary exhibited significant similarity with the failure evolution law and distribution pattern. Following the adoption of the optimized support scheme, roof subsidence decreased by 46.7% compared to the original scheme, and the amount of movement on both sides decreased by 36.2%. The control effect of the surrounding rock was favorable, and its internal stability was significantly improved, thereby effectively resolving the issue of large deformation in soft rock roadways.

In order to address the issue of slow excavation speed caused by various factors affecting the stability of the roof in the excavation face and the unreasonable distance of the unsupported roof, a mechanical model of the roof in the excavation face area is established. This model is based on the superposition method in the material mechanics. The immediate roof deflection curve equation and the maximum unsupported roof distance discriminant formula of the heading head are derived. The allowable deflection is used as the discriminant method of the maximum unsupported roof distance. The calculation method of the key parameters in the formula is obtained and compared with the existing maximum unsupported roof distance calculation formula. Using the single-variable sensitivity analysis method and the bivariate interaction analysis method, we determine the key factors affecting the deformation of the roof in the excavation face and their interaction relationships. The results indicate that among the 10 factors affecting the deformation of the roof in the temporary support area of the excavation face, there are 3 key factors. Under unchanged geological and mechanical conditions, the deformation of the roof primarily depends on the length of the temporary support area and the temporary support load. To provide a practical example, we calculate the maximum unsupported roof distance of 30304 tailgate in the Yanghuopan Coal Mine to be 3.4 m. Numerical simulation and field monitoring results confirm that the deformation of the roof in the excavation face is minimal, and the stability of the rock is good.

To study the deformation and failure mechanisms of soft rock mining roadways, the 1506 return airway of Anyang Coal Mine is taken as the engineering background. Based on limit analysis theory, a failure model based on a rigid slider system is constructed to assess the failure of the soft rock surrounding a roadway. The formulas for calculating the self-weight power of the slider in the velocity discontinuity line of the rock surrounding the roadway, the work power of the surrounding rock pressure, and the energy dissipation rate of the velocity discontinuity line are derived, and the upper limit objective function of the velocity discontinuity line height is obtained. The failure characteristics and fracture evolution process of the surrounding rock under different mining stresses are analyzed by means of physical similarity simulations. The simulation results show that shear failure occurs first on the roadway side due to stress concentration. The fissures expand along the bottom angle of the roadway to the blind support area and the low-intensity support area. The cracks weaken the support strength of the angled anchor cable and bolt in the roadway shoulder. Under the action of roof pressure, the status of the rock mass inside and outside the shear slip zone changes from static to dynamic. This causes deformation and failure of the roadway roof, side, and floor.

With the deep application of artificial intelligence and big data in education, adaptive learning has become a new research hotspot in online education. Based on the systematic review of the connotation and research progress of adaptive learning, a new definition of adaptive learning is given. By literature analysis, this paper points out the challenges faced by adaptive learning research, such as the lack of cognition of brain and technology, the bottleneck of the model of emotion domain, the separation of education and technology, the security of data management and the risk of privacy leakage. These challenges can be summarized into two aspects: one is mechanical issues, the other is safety issues. Different from traditional research perspectives, the paper opens a new research window, and puts forward countermeasures from the perspectives of cognitive principles, zone of proximal development theory in technology, breakthrough in the emotional domain model, learning data management and privacy security. In view of the centralization of learning data management nowadays, the concept of code chain and the decentralized management mode based on code chain are proposed. Different from the traditional adaptive learning recommendation technology, a new adaptive learning pulling model is proposed.

With the gradual increase in the mining depth of coal resources, the destruction of the rock structure of the inter-layered rock of the near coal seam under the influence of mining has led to the frequent occurrence of water-inrush disasters in mines, which seriously affects the safety of mine production and the safety of the people in the underground. Therefore, it is important to study the mechanism of the water inrush of the rock between the coal seams under the influence of mining to control the occurrence of water inrush disasters and protect the loss of groundwater resources. This paper takes the Hanjiawan coal mine with typical stratigraphic characteristics as the background for research and studies the structural characteristics of interlayer rock breakage and the solid–liquid coupling inrush water disaster mechanism during the mining of 2−2 and 3−1 coals. The study shows that according to the damage degree and destruction depth of the inter-layered rock caused by the mining of the upper and lower coal seams, combined with the slip line theory and the “three bands” collapse theory, the inter-layered rock is classified into a completely fractured inter-layer, a fractured–broken stacked inter-layer, and a fractured–broken–fractured combined inter-layered rock using L≤hm+Hk2′, L>hm+Hk2′, and L≥hm+Hli2′ as the discriminating criteria. Combined with the structural classification of inter-layer rock and the discriminating criteria, we used similar simulation experiments and on-site research to analyze the evolution law and distribution characteristics of four types of inter-layer rock water-inrush fractures in different mines and put forward the classification of inter-layer rock water-inrush channels based on the width, length, and penetration of the fractures. Based on the characteristics of the water-inrush channel of inter-layer rock, we constructed the network-boundary inrush water calculation model of inter-layered rock and network-attach-boundary inrush water calculation model, solved the water movement of the water-inrush channel in the model by transforming the flat flow state, fracture to flow state, and pore-fracture flow state, and finally revealed the mechanism of the disaster by which water-inrush of inter-layer rocked was induced. Finally, we revealed its mechanism of inducing the inter-layer rock inrush water disaster. Our research enriches the theory and research ideas of the water-inrush disaster, provides theoretical support and a basis for the control of water-inrush disasters in similar conditions, and ensures the safe production of mines.

Shallow coal seam mining makes the evolution form of mining fissures in rock and soil layers diversified, which leads to the easy penetration of mining fissures as the main channel of water, sand inrush, and air leakage. In order to reveal the co-evolution mechanism of broken rock beam structure and mining fissures in key strata, taking Hanjiawan Coal Mine as the research background, the relationship between mining fissures and rock beam structure, fissure activation period, propagation characteristics, and connectivity of working face was studied by means of field observation, physical similarity simulation, and theoretical derivation. The research shows that the fracture structure of key strata in shallow coal seam mining mainly includes hinged rock beam and step rock beam structures. Through the analysis of the rock beam structure, we found that the types of mining fissures in the overlying strata of key strata were up and down I-I and I-II mining fissures, and the heights of fissure development were 44.38 m and 98.35 m, respectively. The key block rotation made the mining fissures undergo five dynamic activation processes. The calculation formula of the fissure activation cycle was established, and the rock breaking angle, mining fracture lag distance, and fissure penetration discriminant were obtained and verified by field measurement results.

This study aimed to establish three-dimensional models of the biliary tract of Chinese people using the Hisense computer-aided surgery (CAS) system and to explore the branching patterns and variation types of the biliary system under the study of 3D reconstruction of the biliary tract. Three-dimensional models of the biliary tract were reconstructed in 50 patients using the Hisense CAS system. The branching patterns of intrahepatic bile ducts were observed. The biliary tract was classified according to the confluence of the right posterior sectoral duct (RPSD), right anterior sectoral duct (RASD) and left hepatic duct (LHD), and the presence or absence of accessory hepatic ducts. The 3D models of the bile ducts were successfully reconstructed in 50 Chinese patients. The branching patterns of the bile ducts were classified into seven types. The anatomy of the bile ducts was typical in 54% of cases (n = 27), showed triple confluence in 10% (n = 5), and crossover anomaly in 14% (n = 7), which means anomalous drainage of the RPSD into the LHD, anomalous drainage of the RPSD into the common hepatic duct (CHD) in 10% (n = 5), anomalous drainage of the RPSD into the cystic duct (CD) in 2% (n = 1), absence of left main hepatic duct in 1% (n = 1), presence of accessory duct in 8% (n = 4). Among them, there were three cases of accessory hepatic ducts coexisting with other variation types. By using the Hisense CAS system to establish 3D models of the biliary tract of the Chinese people, we established the branching model of the second-order bile ducts, which has important value for the classification of the biliary system and its variation types.

BackgroundThe clinical benefit of hepatectomy in patients with liver metastases from gastrointestinal stromal tumors (GIST) has not been well defined in this era of tyrosine kinase inhibitor (TKI). Our study aims to demonstrate the survival advantage of adding hepatectomy in patients with GIST liver metastases.MethodsInformation on patients with metastatic GIST treated or consulted between January 2006 and December 2018 was retrieved. Patients without extrahepatic metastases were included and classified into the surgical (S group) and non-surgical (NS group). Clinicopathological features were compared and their association with survival was assessed.ResultsA total of 119 patients were included in this retrospective analysis, 62 in the S group and 59 in the NS group. Comparison of clinicopathological features showed that a markedly higher proportion of patients in the S group had ≤3 hepatic lesions (79.0% vs. 29.8%, p

Untethered magnetoresponsive soft materials that can transform between various complex 3D shapes are of growing interests in diverse areas such as soft robotics, flexible electronics, and biomedical engineering. Previous approaches are difficult to precisely encode continuous 3D magnetization profiles in small‐scale 3D structures. Herein, a novel method to produce magnetoresponsive soft materials for shape‐morphing systems across different length scale is reported. The magnetization profiles are programmed by the mechanically‐guided 4D printing with high precision and time‐cost efficiency. A theoretical model and model‐based simulation method are developed to quantitatively predict shape‐morphing of printed structures under applied magnetic fields, and guide the design of complex 3D shapes. A broad set of structures with complex transformations are fabricated to illustrate the capability of the methods. Diverse typical functional applications from centimeter‐ to millimeter‐scale, including soft crawling robots, flexible grippers, bionic butterfly, and multistate magnetic switch, are further demonstrated.

BackgroundIt is controversial whether adjuvant treatment could be recommended for hepatocellular carcinoma (HCC) after curative hepatectomy. Thus, we performed a network meta-analysis (NMA) to assess adjuvant treatment’s benefit and determine the optimal adjuvant regimen.MethodsWe systematically searched PubMed, Embase, and Cochrane Library for randomized controlled trials comparing adjuvant therapy versus no active treatment after curative hepatectomy among patients with HCC. Pooled data on recurrence and overall survival (OS) were analyzed within pairwise meta-analysis and NMA.ResultsTwenty-three eligible trials (3,940 patients) reporting eight treatments were included. The direct meta-analysis showed that adjuvant therapy prevented the recurrence (OR = 0.65; 95% CI: 0.55, 0.77; P = 0.177; I2 = 21.7%) and contributed to OS (HR = 0.63; 95% CI: 0.54, 0.73; P = 0.087; I2 = 31.1%) in comparison to the observation. In the NMA, internal radiotherapy (IRT; OR = 0.55; 95% CI: 0.39, 0.77; SUCRA = 87.7%) followed by hepatic artery infusion chemotherapy (HAIC; OR = 0.6; 95% CI: 0.36, 0.97; SUCRA = 77.8%), and HAIC (HR = 0.44; 95% CI: 0.21, 0.87; SUCRA = 82.6%) followed by IRT (HR 0.54; 95% CI:0.36, 0.81; SUCRA = 69.7%) were ranked superior to other treatments in terms of preventing recurrence and providing survival benefit, respectively.ConclusionsThe addition of adjuvant therapy lowers the risk of recurrence and provide survival benefit after surgical resection for HCC. HAIC and IRT are likely to be the two most effective adjuvant regimens.Systematic Review Registrationhttps://inplasy.com/inplasy-2020-11-0039/.

Decolorization of dyeing/printing wastewater by carbon-based materials has been carried out to study the adsorption of dye molecules onto adsorbent. Biomass-derived activated carbon (SAC) was sampled from cornstalk pyrolysis in the presence of K2CO3 as an activator. Adsorption of methylene blue (MB) and gentian violet (GV) onto SAC was examined to probe the mechanisms, isotherms, and kinetics of dye removal in single- or two-component systems. According to the adsorption rate in a single-component system, three stages were identified. The equilibrium adsorption capacity for MB onto SAC in the single-component system is 274.84 mg g−1 which is higher than that for GV of 266.57, meanwhile the pseudo-second-order (PSO) model would describe the adsorption kinetics with the correlation coefficient higher than 0.99. In the binary GV-MB system, presence of GV promoted MB adsorption to 325.15 mg g−1 and 287.73 mg g−1 at different GV concentrations while the PSO model was also applicable. Furthermore, differences between experimental and calculated values by the Freundlich and Langmuir isotherms indicated the occurrence of competitive adsorption in the two-component system. The gained insights are beneficial for removing the multiple dyes from industrial wastewater, economically and effectively and thus paving the way to the establishment of a greener society.

Perovskite solar cells (PSCs) are a promising and fast-growing type of photovoltaic cell due to their low cost and high conversion efficiency. The high efficiency of PSCs is closely related to the quality of the photosensitive layer, and the high-quality light absorbing layer depends on the growth condition of the crystals. In the formation of high-quality crystals, annealing is an indispensable and crucial part, which serves to evaporate the solvent and drive the crystallization of the film. Various annealing methods have different effects on the promotion of the film growth process owing to the way they work. Here, this review will present a discussion of the growth puzzles and quality of perovskite crystals under different driving forces, and then explain the relationship between the annealing driving force and crystal growth. We divided the main current annealing methods into physical and chemical annealing, which has never been summarized before. The main annealing methods currently reported for crystal growth are summarized to visualize the impact of annealing design strategies on photovoltaic performance, while the growth mechanisms of thin films under multiple annealing methods are also discussed. Finally, we suggest future perspectives and trends in the industrial fabrication of PSCs in the future. The review promises industrial manufacturing of annealed PSCs. The review is expected to facilitate the industrial fabrication of PSCs.

Point-based networks have been widely used in the semantic segmentation of point clouds owing to the powerful 3D convolution neural network (CNN) baseline. Most of the current methods resort to intermediate regular representations for reorganizing the structure of point clouds for 3D CNN networks, but they may neglect the inherent contextual information. In our work, we focus on capturing discriminative features with the interactive attention mechanism and propose a novel method consisting of the regional simplified dual attention network and global graph convolution network. Firstly, we cluster homogeneous points into superpoints and construct a superpoint graph to effectively reduce the computation complexity and greatly maintain spatial topological relations among superpoints. Secondly, we integrate cross-position attention and cross-channel attention into a single head attention module and design a novel interactive attention gating (IAG)-based multilayer perceptron (MLP) network (IAG–MLP), which is utilized for the expansion of the receptive field and augmentation of discriminative features in local embeddings. Afterwards, the combination of stacked IAG–MLP blocks and the global graph convolution network, called IAGC, is proposed to learn high-dimensional local features in superpoints and progressively update these local embeddings with the recurrent neural network (RNN) network. Our proposed framework is evaluated on three indoor open benchmarks, and the 6-fold cross-validation results of the S3DIS dataset show that the local IAG–MLP network brings about 1% and 6.1% improvement in overall accuracy (OA) and mean class intersection-over-union (mIoU), respectively, compared with the PointNet local network. Furthermore, our IAGC network outperforms other CNN-based approaches in the ScanNet V2 dataset by at least 7.9% in mIoU. The experimental results indicate that the proposed method can better capture contextual information and achieve competitive overall performance in the semantic segmentation task.

Abstract Background CA125 is a prevalently used serum biomarker for detecting ovarian cancer over the last three decades. However, it has a significant deficiency in screening for early-stage cancer. With the purpose of exploring an effective approach to improve its performance in early diagnosis, we investigated the postprandial fluctuation pattern of cancer-derived CA125 and the underlying mechanism. Methods In two medical centers, 551 patients sonographically diagnosed with ovarian (adnexal) cysts (

Objective To identify the prognostic factors for local recurrence of giant cell tumor of bone (GCTB) through assessment of the preoperative imaging features of the tumor border. Methods Patients with GCTBs treated with intralesional procedures in the proximal tibia and distal femur were prospectively enrolled and then followed up for at least 2 years. The GCTBs were grouped according to their preoperative imaging features. GCTBs treated with en bloc resection were enrolled for investigation of the pathologic basis of specific imaging features. Differences between rates were evaluated by the chi-square test or Fisher’s exact test; independent factors were identified by multivariate logistic regression analysis. Results Fifty-three patients were enrolled and successfully followed up. Relapse occurred in 22 patients. Patients with a “paintbrush borders” sign (n = 21) had a significantly higher rate of local recurrence (71.43%) than patients without this sign (21.88%). The “paintbrush borders” sign was identified as an independent prognostic factor for local recurrence. Other imaging features were not significantly associated with recurrence. The “paintbrush borders” sign showed a correlation with local invasion of bone. Conclusion The “paintbrush borders” sign on preoperative magnetic resonance imaging is an independent prognostic factor for local recurrence of GCTB.

Cisplatin is commonly used in ovarian cancer chemotherapy, however, chemoresistance to cisplatin remains a great clinical challenge. Oncogenic transcriptional factor FOXM1 has been reported to be overexpressed in ovarian cancer. In this study, we aimed to investigate the potential role of FOXM1 in ovarian cancers with chemoresistance to cisplatin. Our results indicate that FOXM1 is upregulated in chemoresistant ovarian cancer samples, and defends ovarian cancer cells against cytotoxicity of cisplatin. FOXM1 facilitates DNA repair through regulating direct transcriptional target EXO1 to protect ovarian cancer cells from cisplatin-mediated apoptosis. Attenuating FOXM1 and EXO1 expression by small interfering RNA, augments the chemotherapy efficacy against ovarian cancer. Our findings indicate that targeting FOXM1 and its target gene EXO1 could improve cisplatin effect in ovarian cancer, confirming their role in modulating cisplatin sensitivity.

Multi-channel Peer-to-Peer (P2P) Video-on-Demand (VoD) systems can be categorized into independent-channel P2P VoD systems and correlated-channel P2P VoD systems. Streaming capacity for a channel is defined as the maximal streaming rate that can be received by every user of the channel. In this paper, we study the streaming capacity problem in multi-channel P2P VoD systems. In an independent-channel P2P VoD system, there is no resource correlation among channels. Therefore, we can find the average streaming capacity for the independent-channel P2P VoD system by finding the streaming capacity for each individual channel, respectively. We propose a distributed algorithm to solve the streaming capacity problem for a single channel in an independent-channel P2P VoD system. The average streaming capacity for a correlated-channel P2P VoD system depends on both the intra-channel and cross-channel resource allocation. To better utilize the cross-channel resources, we first optimize the server upload allocation among channels to maximize the average streaming capacity and then propose cross-channel helpers to enable cross-channel sharing of peer upload bandwidths. We demonstrate in the simulations that the correlated-channel P2P VoD systems with both intra-channel and cross-channel resource allocation can obtain a higher average streaming capacity compared to the independent-channel P2P VoD systems with only intra-channel resource allocation.