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To solve the problem of rapid following and advancing speed of support in the fully mechanized mining face, a distributed liquid supply system based on accumulators was proposed and tested in the S1204 working face in Ningtiaota Coal Mine. The speed of advancing support movement in the middle of working face was determined based on the coal mining process and capacity requirements, and a simulation model was established for the existing liquid supply system to simulate the advancing process of single, double, and triple supports, and the factors affecting the advancing time of supports were analyzed. The results showed that the following speed should reach 12 m/min to meet the capacity requirements which is 10 million tons per year of the working face. The double or triple support moving in groups was necessary to meet the requirements of advancing time. To solve the problem of large pressure fluctuations and easy support loss in this working condition, the distributed energy storage and pressure stabilization promoting scheme was proposed to balance the contradiction between insufficient instantaneous flow supply and excessive average flow supply capacity in the hydraulic system of the working face by installing “accumulator+check valve” on the hydraulic support. The design method of accumulators based on the flow compensation was also provided. The simulation results showed that after installing the accumulator, the advancing time for double and triple support movement in groups was reduced by 6.2% and 11.5% respectively. Especially after continuous interference, the advancing time for double support movement in groups could be reduce by 15%. The underground application results showed that after installing the distributed accumulators in the liquid supply system, the advancing speed of the supports was significantly improved, and the phenomenon of loss in group pulling was significantly reduced. It played an important supporting role in increasing the average daily footage of the working face from 16.7 to 19.8 cuts, with a normalized daily footage of 22 cuts, achieving an annual production capacity of 10 million tons. This study provides an effective solution method to achieve rapid movement of support in groups.

The petrographical, mineralogical, whole-rock geochemical, and zircon U-Pb geochronological and Lu-Hf isotopic studies were carried out for investigating the provenance and genetic mechanism of the high-grade coal-bearing kaolin within the coal seams of the Permo-Carboniferous Taiyuan Formation in the Xiaoyu mine of the Datong coalfield, Shanxi Province. The coal-bearing kaolin is composed mainly of well-ordered kaolinite with no detrital quartz, feldspars and muscovite. Some samples contain boehmite that were formed through the desilication of kaolinite. The zircons in the coal-bearing kaolin are typically igneous origin with only one age population of ca. 300 Ma, same with the depositional age of the coal, confirming that the coal-bearing kaolin was altered from volcanic ash. Besides, the coal-bearing kaolin commonly contains tabular/columnar and vermicular kaolinite that are also diagnostic feature of alteration from volcanic ash. These coarse-grained kaolinites are thought to be pseudomorphic kaolinite altered from crystal fragments in volcanic ash, such as plagioclase and biotite. The zircon εHf(t) is dominant by a wide range of negative values, indicative of their formation from magma generated by substantial remelting of ancient continental crust, coinciding with that of contemporaneous magmatic rocks formed from continental arc volcanism in the Inner Mongolia Paleo-Uplift at the northern margin of North China. This suggests their cognate relationship. The geochemical fingerprints of trace element of zircons also indicate that they were crystalized from continental arc magma. The northern margin of the North China Craton (NCC) is an Andean-type continental margin in the late Paleozoic. During the coal-accumulating period of the Late Carboniferous to Early Permian in North China, the Paleo-Asian Ocean (PAO) plate was continuously southward subducted beneath the NCC, resulted in a frequent continental arc volcanism. The emitted volcanic ash fell into peat swamps developed in a paralic environment in North China, which were subjected to an intensive leaching and altered to the coal-bearing kaolin.

Metal Nanoclusters (MNCs) have shown great potential applications in the field of food safety due to their unique physical and chemical properties. Through the template synthesis method, the specific size, shape and dispersion of MNCs can be regulated, thereby improving their functional characteristics. Based on the recent studies on MNCs, the mechanism of template-assisted synthesis of MNCs and their applications in the detection of food contaminants, food packaging materials, antimicrobial agents and food additives are reviewed. It provides a scientific basis for template synthesis of MNCs, and to provide insights and directions for MNCs in food safety monitoring.

Supergravity is a noncontact volumetric force; when there is a density difference between the two phases, supergravity can strengthen their separation. The removal of nonmetallic inclusions in steel by supergravity technology not only does not cause molten steel to stir back to the mixing but also promotes the rapid floating of inclusions and shortens their floating time in the molten steel. Small inclusions that are difficult to remove can be removed using a supergravity field. The shape of the inclusions affects their floating behavior in molten steel. To study this effect, this study uses the fluid–structure interaction method to track the computational fluid–solid interface state, constructs three inclusions with different aspect ratios in a two-dimensional longitudinal section, and performs simulation studies of the floating behavior of the inclusions in a supergravity field. The effects of the different initial angles of the inclusions on their floating behavior were also compared. The simulation results show that the floating velocity of the inclusions is related to their shape and floating angle, and the faster the floating velocity, the closer the aspect ratio is to 1, or the floating angle is too vertical. For a given length, inclusions with a larger equivalent diameter float faster. In the supergravity field of G = 1000, the inclusions with a length of 1 μm did not undergo rotation; the inclusions with lengths of 10 and 20 μm rotated from the initial angle (45°, 90°) to the horizontal and then floated steadily. The floating velocity of inclusions is related to the real-time angle of inclusions. The rotational state of the inclusions gradually decreases as the gravity coefficient decreases. When G = 50, the inclusions with a length of 20 μm (initial angle of 90°) fail to rotate completely, which also proves that the inclusions are more likely to rotate when initially inclined instead of vertically. In addition, it was concluded that supergravity does not cause anisotropy in steel properties and that the method of removing inclusions from steel by supergravity does not have a substantial negative effect on steel properties. Finally, this study noted that the prediction of the supergravity treatment time using this model should be based on the floating velocity of the inclusions in the horizontal state, and an approximate time for the floating removal of the inclusions is provided based on this conclusion.

Previous studies have delved into slope break zones in faulted basins, yet foreland basins, with their gentle slopes toward the forebulge, underdeveloped large-scale structures, and small terrain undulations, have received limited research on slope-fault belts. During the deposition periods of the 4th and 5th members of the Late Triassic Xujiahe Formation, a foreland basin developed in the Sichuan Basin. Scholars have noted the control exerted by the gentle slope break zone on the sedimentary lithofacies in the central and western Sichuan, particularly in the west of the Luzhou-Kaijiang Paleo-uplift, but related studies remain limited. By interpreting the tectonic slope break zones in seismic reflection profiles of the Sichuan Basin and incorporating existing regional geological data, this study employed particle flow numerical simulation to clarify the types of slope break zones in the central and western Sichuan regions, as well as their relationship with gravity sliding structures. It also analyzed the characte-ristics of new types of oil and gas traps associated with gravity-sliding structures. The findings are as follows: (1) The study area developed a fault slope break zone, with each side bounded by a "front squeezing and rear extension" tectonic combinations formed by gravity sliding. The tectonic deformation is weaker than those of gravity-sliding structures at passive continental margins. (2) The edge fault of the tectonic slope break zone controls the sedimentary facies and sand body types. (3) In the gentle slope zone, the stretching area of gravity-sliding structures lead to the uplift of the footwalls of normal faults, forming syndepositional anticlines with developed sandstones. These sandstones, juxtaposed with organic-rich mudstones within the contemporaneous fault depression, form "side-generated and lateral storage" hydrocarbon reservoirs. (4) In the steep slope zone, gravity sliding forms syndepositional anticlines in the 5th member of the Xujiahe Formation, which are bounded by flank mudstones and post-sliding deposited mudstones, forming in-source sand body reservoirs. (5) Syndepositional anticline hydrocarbon reservoirs related to gravity-sliding structures represent a new type of in-source hydrocarbon accumulation. The 5th member of the Xujiahe Formation in the study area likely contains such reservoirs, distributed in a NE-trending pattern parallel to the slope break zone.

Cereal foods are the primary source of daily energy, protein, and dietary fiber intake for humans. With the continuous improvement of people's living standards, cereal foods' nutritional value, safety, and food quality have attracted much attention. Cereal metabonomics, as a new and rapidly developing branch of "metabonomics", has made rapid progress in quantifying and analyzing various metabolites. This article reviews the analysis process of metabolomics technology, and its application in the detection of component identification, the identification of flavor substances, the traceability of origin, and the product of new developments in cereal foods, and the development trend of metabonomics in cereal food field has prospected, to provide a reference for the in-depth development and application of cereal foods.

In response to the difficult problem of gas control in soft and low permeability outburst coal seam, gas control technology is proposed to use physical modification hydraulic punching to improve permeability. Theoretical calculations and FLAC3D numerical simulation methods were used to analyze the plastic failure characteristics of coal bodies around holes under different drilling spacing conditions, and the corresponding stress evolution characteristics were quantitatively characterized. After hydraulic punching, the radial stress of coal bodies between holes significantly decreased, and the closer they were to the holes, the greater the reduction; the influence range of tangential stress is equivalent to the range of plastic failure zone; the peak vertical stress showed a significant increase, and as the spacing between boreholes decreased, the vertical stress curve evolved from a bimodal curve to a unimodal curve; it was found that the pore space provides a free surface for coal unloading, which can remove the confining pressure and transfer concentrated stress to the coal between the pores. Subsequently, based on the relationship between gas coal permeability and three-dimensional stress and gas pressure, the evolution characteristics of permeability under different drilling spacing conditions were quantitatively characterized. Compared with the original coal, the permeability of the coal around the holes was greatly increased, which promoted the gas desorption and flow, and determined the reasonable spacing of the holes, and a reasonable drilling spacing was determined. Field experiments have shown that hydraulic punching greatly increases the exposed area of soft coal bodies, provides pressure relief and transparency space for coal bodies, gas flow and concentration is significantly increased in high negative pressure extraction branch pipes, and the pure gas extraction volume fluctuates within the range of 6.20-9.8 m3/min. The gas concentration is above 34%.

Due to software and hardware differentiation, the problem of false positives mistakenly identified as network attack behavior caused by inconsistent mimic decision results frequently occurs.Therefore, a mimic decision method based on deep learning was proposed.By constructing an unsupervised autoencoder-decoder deep learning model, the deep semantic features of diverse normal response data were explored from different executions and its statistical rules were analyzed and summarized.Additionally, the offline learning-online decision-making mechanism and the feedback optimization mechanism were designed to solve false positive problem, thereby accurately detecting network attacks and improving target system security resilience.Since statistical rules of normal response data was understood and mastered by deep learning model, the mimic decision results among different executions could remain consistent, indicating that the target system was in a secure state.However, once the target system was subjected to a network attacks, the response data outputted by the different executions was deviated from statistical distribution of deep learning model.Therefore, inconsistent mimic decision results were presented, indicating that the affected execution was under attack and the target system was exposed to potential security threats.The experiments show that the performance of the proposed method is significantly superior to the popular mimic decision methods, and the average prediction accuracy is improved by 14.89%, which is conducive to integrating the method into the mimic transformation of real application to enhance the system’s defensive capability.

ObjectivesThis paper aims to study the free vibration characteristics of complicated shape plate coupled with fluid under elastic boundary conditions. MethodsTo this end, the rectangular domain enveloping the complicated shape plate domain is selected, and the plate displacement is expressed by the improved Fourier series in the rectangular domain. Combined with the Rayleigh integral, the relationship between the plate displacement and the surface sound pressure is established, and the integral formula is transformed into polar coordinates to avoid singularity. Aiming at the problem that it is difficult to obtain the explicit expression of the boundary curve in the variable limit integral in local polar coordinates, the structural boundary curves are treated by "replacing curve with straight" to simplify the Rayleigh integral. Based on the energy principle, a semi analytical method for analyzing the free vibration characteristics of complicated shape plate contacting with water on one side is established. ResultsThe numerical examples of rectangular plate, circular plate and some complicated shape plates are given. Compared with the finite element method and literature results, the convergence and accuracy of the method are verified, and the influence of elastic boundary conditions on the added virtual mass incremental (AVMI) factor of plate is discussed. The AVMI factor of each mode reaches the maximum near the dimensionless displacement spring stiffness of 103. At this time, the structure is relatively most affected by the fluid. ConclusionsThis method has strong adaptability and high calculation efficiency. It reveals the free vibration law of complicated shape plate coupled with fluid, and has certain engineering guiding significance.

In order to improve the quality of rice bread and reveal the effects of transglutaminase (TGase) on the quality of rice flour, rice dough and rice bread, and reveal the relationship among the indexes. The silty properties and pasting properties of TGase containing different mass fractions in rice flour, the water distribution, rheological properties and fermentation capability of rice dough, and the specific volume, gas cells and texture of bread were tested. The results showed that 0.60% TGase could improve the silty and pasting properties of rice flour, and increase the stabilization time of rice flour to 8.00±0.77 min. The peak viscosity (PV), valley viscosity (VV) and final viscosity (FV) were increased to 5801.00±30.41, 3805.67±76.14 and 5836.33±106.17 cP, respectively. Breakdown (BD) and setback (SB) of rice flour were reduced to 1990.00±128.11 and 1991.67±34.08 cP. At the same time, TGase increased the tightness of water binding, improved the rheological properties and fermentation capability of rice dough, increased S21 to 9.24%±13.07%, decreased T21 and T22 to 1.40±1.80 and 30.45±2.28 ms, and increased Hm to 8.60±0.11 mm. The porosity was increased to 50.51%±0.90%, which reduced the hardness, adhesiveness and chewiness of rice bread, improved the springiness of rice bread and improved the textural properties of rice bread. Correlation analysis showed that T23 was negatively correlated with the formation time, and Hm was positively correlated with C3, C3~C2 and VV. And BD and SB were negatively correlated, chewiness was positively correlated with C1, specific volume was positively correlated with FV and PV were positively correlated. The results showed that TGase improved the quality of rice flour, rice dough and rice bread, and there were different degrees of correlation among the improved indexes.

Predicting the Water-conducting fracture zone height (WFZH) and determining the mining zones that require water conservation operations are critical for the mine sustainability. In this paper, mathematical statistics, multiple regression and spatial analysis methods were employed to analyze the mechanisms of longwall parameters contributing to WFZH and construct a nonlinear correlation of WFZH versus mining height, depth of cover, and retreat rate. Based on the WFZH equation and aquifer depressurization threshold, Yushen Coalfield is zoned into different conditions: Under the case 1, the water resources safe exploitation (WRSE) area in the mining area is 4.24×109 m2, accounting for 82%, and Non-WRSE area is 920 835 911.3 m2, accounting for 18%; Under the case 2, the WRSE area in the mining area is 3.87×109 m2, accounting for 77%, and Non-WRSE area is 1.14×109 m2, accounting for 23%; Under the case 3, the WRSE area in the mining area is 3.78×109 m2, accounting for 73%, and Non-WRSE area is 1.38×109 m2, accounting for 27%. The water protection level is further detailed by comparing the three conditions, further suggesting the mine that needs higher focus. The results help provide macro decision-making basis for mine planning and longwall design, enriching the theory and technology for water conservation mining.

The structure of a certain graphite ore in Heilongjiang province belongs to gneiss type graphite ore, the gangue minerals are mainly quartz, feldspar and mica, and the metal minerals contain a small amount of limonite. The total fixed carbon content of the raw ore is 8.03%. The fixed carbon content of + 100 mesh large scale graphite in the raw ore accounts for 37.58% of the total fixed carbon content. After the process of one roughing, one scavenging and eight regrinding and eight cleaning, the fixed carbon grade of concentrate is 90.53% and the fixed carbon recovery rate of concentrate is 94.07%. Among them, the fixed carbon grade of + 0.15 mm concentrate is 95.26%, the fixed carbon recovery rate is 17.67%, and the protection rate of +0.15 mm large scale graphite is 47.02%.

Metal-Organic Frameworks (MOFs) are porous crystalline materials formed by self-assembly of metal centers and organic ligands through coordination. MOFs have the characteristics of strong stability, large specific surface area, high porosity, and reusability. As a new type of immobilized carrier material, it has a wide range of application prospects. In this article, the synthesis method of biological enzyme immobilized on MOFs carrier is mainly summarized and analyzed, the characteristics and application of MOFs-biological enzyme composite material, and the future research direction of the synthetic method of enzyme immobilized on MOFs carrier are prospected. A theoretical basis would be provided for the development research and applications in the biological and pharmaceutical industries.

In recent years, with the rapid development of the stainless steel industry in China, a large number of Cr-containing solid wastes are produced. Chromium resources in China are very scarce, and China mainly dependent on imported chromium. In the current situation of a limited supply of chromium ore in the world, determining the efficient utilization of chromium resources will become very important. The recovery of chromium in various solid wastes produced by the stainless steel industry has practical economic significance. In addition, an uncontrolled emission of Cr-containing solid wastes will endanger the ecological environment and hamper biological safety. Further, the large scale of China’s stainless steel industry has caused urgent environmental problems, i.e., the whole manufacturing process has produced a large number of Cr-containing solid wastes, including stainless steel slag, stainless steel dust, stainless steel rolled iron scale, and pickling sludge. The detoxification/solidification of Cr to obtain long-term safety performance is an important factor that must be considered in the development of a comprehensive utilization process technology for a large amount of Cr-containing solid wastes generated by the stainless steel industry. This paper reviewed the previous research work in this field, including the work regarding the chemical and phase compositions of the stainless steel industrial solid waste, the existing forms of chromium in different Cr-containing solid wastes, the cycle enrichment rule, and the toxicity of chromium in the environment. The evolution law of Cr-bearing mineral phases and the solidification mechanism of Cr in different mineral phases were discussed. The research progress of various inorganic materials such as cement, glass ceramics, and sintered ceramics prepared using Cr-containing solid wastes in the stainless steel industry was summarized. Bottleneck problems in the preparation of various inorganic materials from chromium-containing solid wastes in the stainless steel industry were analyzed to provide a basis for the future harmless, high-value, resource-based treatment of stainless steel Cr-containing solid wastes and the realization of industrial applications in China.

Firstly, the development trend of cloud-network integration technology in recent years, the new problems and challenges it faces were analyzed.Then, based on the heterogeneous computing power, the sinking of computing power, and the new changes in computing-network linkage in business development, six major computing and network capabilities were proposed.Convergence requirements, combined with multi-cloud connection, differentiated bearer, and hierarchical security, discussed the case of building new capabilities and new business experience around the computing network.The analysis results show that it can be concluded that the computing network and the cloud network are closely related in the technical system, and the integration of the computing network is the inevitable result of the development and evolution of the integration of the cloud and the network, and it is also an inevitable choice for the development of the digital economy.

In order to meet the nursing needs of the elderly and disabled patients with mobility difficulties， a standing and lying nursing wheelchair that can assist standing and assisting lying is designed. The design scheme and working principle of the wheelchair mechanism are expounded. Based on the principle of ergonomics， three-dimensional gait analysis and motion system are used to analyze the movement trajectory of normal joints during the process of standing up and lying down. The geometric relationship between wheelchair mechanisms is established， and the kinematics analysis of the mechanism carried out. Combining the anthropometric data， the parameters of each component are determined and a virtual prototype is established. By using the Adams software， the motion simulation of the mechanism is carried out， the mechanism runs smoothly in the simulation. The simulation results show that the sitting， standing and lying nursing wheelchair assists the human body to sit， stand， and lie down in accordance with the laws of healthy human movement， which verifies the rationality of the mechanism design.

Background and objective With the popularization of chest computed tomography (CT) early screening for lung cancer, the detection rate of lung cancer combined with multiple primary malignancies (MPM) in other organs has been increasing. In this paper, the incidence, pathological characteristics, diagnosis and treatment characteristics and prognosis were discussed and analyzed to provide research basis for improving the clinical diagnosis and treatment of this disease. Methods From September 2011 to September 2015, a total of 5,570 patients with lung cancer were treated in Jiangsu Cancer Hospital. The clinicopathological characteristics of 61 patients with lung cancer combined with MPM in other organs were retrospectively analyzed. Results The incidence rate of lung cancer combined with MPM in other organs in this group was 1.1%, of which 15 cases were synchronous MPM (SMPM), 46 cases were metachronous MPM (MMPM). Colorectal cancer, breast cancer and thyroid cancer accounted for the top three of lung cancer combined with MPM in other organs. The overall 5-year survival rate was 39.3% and 71.4% of patients died from metastasis or recurrence of lung cancer. Multivariate analysis showed that the clinical stage of lung cancer patients, the order of occurrence of lung cancer and other tumors, the treatment status of patients with other organ tumors and the presence of epidermal growth factor receptor (EGFR) gene mutation were important factors for the survival of the patients. Conclusion The incidence rate of lung cancer combined with MPM in other organs is not uncommon. Lung cancer is the main cause of death compared with other organs tumors. Patients with advanced lung cancer, SMPM, lung cancer first, combined with tumor only receiving palliative treatment and without EGFR gene mutation had a poor prognosis.

In a frequency division duplex communication system,precoding at the base station usually requires terminal feedback channel state information.In a distributed array system,the channel conditions between the terminal and different access nodes in the cell are different because multiple access nodes are arranged at different locations in the cell.When the resources for feedback channel state information are limited,the allocation method of feedback bit needs to be optimized to improve the overall performance of the system.In a multi-user distributed array system,an access node selection method based on distance threshold was adopted.Based on this method,the quantization characteristics of the random vector quantization codebook and the Taylor expansion method were used to derive the system quantization capacity loss,and then an approximate expression was given.Based on this expression,a feedback bit allocation method was proposed.Compared with other allocation methods,the method of this paper was more universal because it did not limit the number of access nodes selected by the user.The simulation results show that the strategy proposed is superior to the traditional equal-bit allocation scheme and can obtain better performance when the feedback resources are limited.

For the mmWave MIMO system using a partially-connected structure,in order to improve the spectral efficiency,the antenna composition of each subarray will be dynamically adjusted according to the channel conditions.However,the optimal grouping of antennas requires exhaustive searching for all possible antenna combinations according to certain criteri,which leads to unacceptable complexity.In response to the problem,a low-complexity sub-array dynamic allocation method was proposed.The core was to introduce certain rules when grouping array elements,thereby significantly reducing the number of combinations and reducing the search range.Specifically,two low-complexity antenna combination algorithms were proposed.Firstly,considering the strong correlation between mmWave antennas,multiple adjacent antennas were virtualized as an array element,thereby reducing the search space.Secondly,by dividing all antennas into upper and lower half areas,the antenna combination based on partition was realized,and the search space was also reduced.Simulation results show that the proposed method can achieve a good trade-off between performance and complexity.

Facing the combination of computing and network connection in the future network,and the development trend of computing and network integration,a computing power network orchestration model based on centralized and distributed control schemes was proposed.From the perspective of solution analysis,the computing power network orchestration scheme based on the convergence of telco cloud and bearer network can meet the future business needs of mobile edge computing (MEC) site better.With scheduling capabilities coordinated for both computing and networking,the network’s perception of services can be optimized.The specific choice of centralized or distributed control scheme is closely related to the operator’s telco cloud capabilities and the evolution stage of the bearer network.

With the advantages of both Cu and Al, including high conductivity, good corrosion resistance, low density, and easy connectivity, Cu–Al-laminated composites become a substitute for copper plates which can be applied widely in the fields of telecommunication, the petrochemical industry, transportation, decorative buildings, and the aerospace, national defense, and military industries. Cu–Al-laminated composites can be prepared via various methods, such as the explosive combined method, rolling combined method, and cast-rolling combined method. However, all these methods are limited because of the complicated metal surface treatment which poses a restriction on the development of this kind of plate. To resolve this issue, a new process of horizontal continuous casting composite forming (HCCF) for bimetal composite plates with an interface of metallurgical bonding, which is regarded as a short and more efficient process, was presented in this paper. Cu–Al composite plates with a section size of 70 mm × 24 mm (width × thickness) were fabricated, whose feasible preparation parameters were further studied, along with the investigation of the microstructure and properties of the composite plate. The results show that consisting of intermetallic compounds and eutectic phase, an interfacial layer is formed during the preparation and formation of the Cu–Al composite plate. Layer II of θ is formed via a solid–liquid transition during the solidification of liquid Al on the solid Cu plate. With the Cu atoms continuously diffusing into the Al liquid, layer I of γ is formed via a solid–solid transition with a certain content of Cu atoms, while layer III of α + θ is formed via eutectic transformation under the eutectic temperature. Making of Cu–Al intermetallic compounds, Layer I and layer II are the main areas of crack generation and expansion, thus, the thickness of the interface layer plays an important role that can control bonding strength. The temperature distribution of the composite Cu–Al plate during solidification is optimized by adjusting the parameters and controlling the formation of the composite layer. Therefore, a reasonable matching of the process parameters is the key to improving the microstructure of the composite layer and increasing the bond strength of the clad plate.

First of all,the main issues in current operator metro network were analyzed,the background of why intelligent metro network and the main technologies of the application were introduced.Then the network deployment plans and service organization plans according to the scale of the metro network and the timeline for introduction of all related technologies were introduced.At last,a stage-by-stage exposition regarding to the fusion mode of communication cloud and intelligent converged metro network during deployment process was presented.Based on a series of analysis,it was pointed out that the construction of intelligent metro network played a very important role in the process of SDN/NFV network reconfiguration and cloud network fusion.It’s of great value to bear existing metro network services synthetically and cope with future services on the collaboration of cloud,network and edge.It’s necessary to accumulate operation experiences continuously in the deployment process.

Background and objective Cyclic RNA (circRNA) is a new type of non-coding RNA (ncRNA) which is different from traditional linear RNA. More and more studies suggest that circRNA can be used as a biological marker of many malignant tumors and becomes a potential target for treatment. Therefore, searching for new molecular targets of lung adenocarcinoma from the circRNA will help to reveal the new mechanism of the occurrence and development of lung adenocarcinoma, and provide new ideas for clinical diagnosis and treatment. In this study, the biological function of circ_0007766, a highly expressed circRNA found in a screen of lung adenocarcinoma tissue, was verified and analyzed in vitro, so as to preliminarily explore the mechanism of circ_0007766 in promoting the proliferation of lung adenocarcinoma. Methods The expression level of circ_0007766 in lung adenocarcinoma cells was detected by qPCR. Then siRNA was used to knock down the expression of circ_0007766. The effects of knockdown of circ_0007766 on proliferation, cell cycle and apoptosis of lung adenocarcinoma cells were detected by CCK8, scratch test, PI staining and Annexin V/PI double staining. In addition, the biological mechanism of circ_0007766 in lung adenocarcinoma was preliminarily studied by qPCR and Western blots. Results The expression of circ_0007766 in lung adenocarcinoma cell lines was detected by qPCR. The expression of circ_0007766 was interfered in SPCA-1 cells. The proliferation and migration abilities of cells were inhibited. The cell cycle was arrested in G0/G1 phase, but the apoptosis was not affected. The deletion of circ_0007766 did not affect the expression of ERBB2, but influenced the mRNA and protein expression of Cyclin D1/Cyclin E1/CDK4. Conclusion In vitro functional studies have shown that circ_0007766 may promote the proliferation and migration of lung adenocarcinoma cells. Further molecular mechanism studies have found that circ_0007766 can up-regulate the expression of Cyclin D1/Cyclin E1/CDK4, which are the key proteins of cell cycle, and thus promote the malignant proliferation of lung adenocarcinoma. From the perspective of circRNA, this study will provide new clues for the pathogenesis, development and prognosis of lung adenocarcinoma, and provide new target for clinical treatment.

As a new extension of dynamic fault trees,time delay gate was proposed.This new mechanism can be used to model the time delay on the fault propagation from the lower level subsystems to the higher level system.The dynamic Bayesian networks was extend to solve the dynamic fault trees containing time delay gates.An algorithm based on SMT to support the optimized failure distribution under the nondeterministic range constraint of basic events was also proposed.The effectiveness is shown by comparison with existing tools on analyzing and solving real systems,and the effects of range constraints and gate parameter on the failure distribution of systems is illustrated.

In the massive MIMO system, the only full digital baseband precoding（FD-BP）scheme（such as full complexity zero forcing）requires the same number of radio frequency（RF）chains as the number of antenna elements, which leads to extreme high hardware cost, the hybrid precoding can reduce the number of RF chain heavily and approach the performance of the FD-BP, so the hybrid precoding for massive MIMO is necessary and worth studying. The adaptive digital and analog hybrid precoding（AHP）can further reduce the hardware complexity compared with the conventional digital and analog hybrid precoding （conventional hybrid precoding）and which combined with V-BLAST can get the array gain and multiplexing gain simultaneously. Simulation results confirm the proposed scheme can obtain the higher spectral efficiency, the lower hardware complexity and more ideal BER performance.

Background and objective MiR-145 functions as a protective miRNA identified in tumor tissues of lung adenocarcinoma patients. The aim of this study is to investigate the relationship between miR-145 and proliferation of lung cancer stem cells and involved molecular mechanisms in human lung adenocarcinaoma A549 cell line. Methods MicroRNA microarray technology was conducted to compare miRNA signature between tumor and adjacent normal tissue of lung adenocarcinaoma. The potential target gene of miR-145 was predicted by online bioinformatic softwares. Pre-miR-145 mimics and anti-miR-145 inhibitor were transfected into A549 cell line by lipofectamine 2000. miR-145 expression in each group was detected by real time PCR. The OCT4 protein level was analyzed by Western blot. The predicted miR-145 binding site in OCT4 3’-untranslated region (UTR) was validated by dual-luciferase reporter gene assay. CCK-8 assay was employed to observe the proliferation activity of A549 cells. The ratio of CD133 positive cells in each group was analyzed by flow cytometry. Results miR-145 expression was significantly down-regulated in lung adenocarcinoma compared with ajacent normal tissue. OCT4 is a potential target gene of miR-145 predicted by miRanda. Compared with control group, miR-145 was significantly up-regulated and down-regulated in the pre-miR-145 mimics and anti-miR-145 inhibitor groups respectively. Overexpression of miR-145 inhibited the proliferation of A549 cells. Both the OCT4 protein level and CD133 positive ratio were remarkably decreased in the pre-miR-145 mimics group, whereas significantly increased in the anti-miR-145 inhibitor group. Dual-luciferase reporter gene assay validated the predicted miR-145 binding site of OCT4 3’UTR. Conclusion MiR-145 can inhibit the proliferation of lung cancer stem cells in A549 cell line via down-regulating OCT4 expression. MiR-145 is a potential protective miRNA of lung cancer.

林宏宇 张帅 【摘要】本文尝试对2010年以来中美两国在国际安全领域的大国博弈以及由此形成的中国国家安全环境负面化态势做出一个系统阐释。2010年中国GDP首次超过日本，成为仅次于美国的世界第二大经济体，中国崛起不再是国际关系学者的纸上谈兵，而是确确实实的国际关系现状，这种状况客观上打破了东亚国际安全格局的平衡，对已有的安全结构造成有力冲击。深感“权力转移”之忧的美国试图以重返亚太（又称“再平衡”）战略来缓阻中国崛起的势头。此战略客观上极大刺激了东亚地区某些国家借美抗华的念头，它们试图以制造事端来“引美入亚”，希望美国“主持公道”。美国也愿借助这些国家对华挑衅来增强其再平衡战略的效果。面对某些东亚国家对华核心国家利益的挑战，和平崛起的中国不得不严峻应对，其后果是中国落个“四处树敌”、国家安全环境负面化的态势。但中国不会就此终结和平崛起之路，美国也不会轻易放弃其国际霸权，这就意味着中美此轮安全博弈会持续相当长一段时间，可能出现一段相当长时间的安全困境。然而主客观条件决定中美不会爆发新冷战，更不会爆发世界大战。面对挑战，中国不应采取同美国针锋相对的战略，而应在美国不威胁中国核心国家利益与安全的基础上，对内继续坚持以经济建设为中心，对外继续坚持“韬光养晦”和“不结盟”，努力构建中美新型大国关系，走出安全困境。 This paper attempts to make a systematic explanation of the big game that has unfolded between China and the United States since 2010 in the field of international security and led to a deterioration of China’s national security environment. In 2010, the GDP of China surpassed the GDP of Japan for the first time, and China became the second largest economic entity in the world, surpassed only by the U.S. The rise of China was no longer just empty talk of a few scholars in the field of international relations. On the contrary, the rebalancing of international security relations changed and shook the existing security architecture in East Asia. As a consequence, the U.S. tried to use a pivot/rebalancing strategy to corrode China’s rising momentum which objectively stimulated some of the countries in East Asia to oppose China with the help of the U.S. The U.S. also wanted to strengthen its rebalancing strategy’s effectiveness via these countries’ actions. In the face of the challenges from these countries on China’s core national interests, China had to take the consequences seriously. But China will continue to adhere to the path of its peaceful rise whereas the U.S. will not give up its international hegemony easily as well. This means that the Sino-U.S. game will continue for quite a long period of time as will the security dilemma. However, it will not lead to a new cold war, let alone the outbreak of an extensive world war between China and the U.S. In the face of challenges, China should not take on the same strategy as the U.S. Only if the U.S. does not threaten the core national interests and the security of China, China should focus on economics internally and externally adhering to the "keeping a low profile" and "non-alignment" principles. China should also strive towards building a new type of relationship between China and the U.S. so that the security dilemma can end.

As a leading scholar in the field of sustainable development research, Herman Daly developed original and unique thoughts on sustainable development that have had world-class impacts on the theories, indicators, and policies in this field. Based on the frame-work of ' Ends-Means,' Daly's thoughts on sustainable development focus on the Ultimate End (well-being improvement) and the Ulti-mate Means (natural capital). Daly advocated that to use natural capital to promote human well-being in a sustainable manner, the cur-rent growth economy has to be transformed into a steady-state economy. Because economic growth has biophysical properties and is re-stricted by many factors, such as the laws of thermodynamics and planetary boundaries, unlimited growth is impossible. When its marginal ecological and social costs begin to be larger than its economic benefits, economic growth would turn into uneconomic growth. In this sense, unlimited growth is undesirable. As an alternative to the growth economy, the steady-state economy advocates promoting hu-man well-being within ecological limits and demands that stocks of material wealth be used efficiently and equitably. The steady-state economy is one of the most effective ways of achieving sustainable development. Along the main line of transforming the growth economy into the steady-state economy, as required by sustainable development, this paper reviews Daly's main thoughts on sustainable development on the following topics: ' a new perspective of economic production,' ' unlimited growth is impossible,' ' unlimited growth is undesirable,' and ' the steady-state economy is compatible with sustainable development.' Based on this review, the paper points out that, Daly's thoughts on sustainable development provide theoretical support and ideological implications for China's high-quality development from a different perspective, and broaden the theoretical horizon of China's high-quality development. [ABSTRACT FROM AUTHOR]

Background and purpose: There is a consensus within the medical community regarding the perioperative treatment of locally advanced gastric cancer (LAGC), yet the selection of an efficient and safe treatment strategy remains a contentious issue. Previous studies have validated the effectiveness of chemotherapy in conjunction with immune checkpoint inhibitor (ICI) and anti-angiogenic agents in the perioperative treatment of LAGC. This study aimed to investigate the perioperative treatment regimen combining ICI, anti-angiogenic drugs and chemotherapy, in order to provide additional references for the selection of perioperative treatment strategies for patients with LAGC. Methods: This was a prospective, single-arm exploratory study designed to assess the efficacy and safety of perioperative treatment with penpulimab combined with anlotinib and chemotherapy for potentially resectable stage T3-4N+M0 LAGC. Patients diagnosed with LAGC at the Inner Mongolia Autonomous Region People’s Hospital from January 2022 to December 2023 were enrolled in the study. The primary endpoints were pathological complete response (pCR) rate and major pathological remission (MPR) rate, while secondary endpoints included surgical conversion rate, objective response rate (ORR), disease-free survival (DFS), progression-free survival (PFS) and adverse reactions. Quality of life before and after treatment was evaluated using the European Organization for Research on Treatment of Cancer (EORTC) QLQ-STO22 Chinese version questionnaire. This study was reviewed and approved by the Ethics Committee of Inner Mongolia Autonomous Region People’s Hospital (number: 202404604L). Results: A total of 32 patients participated in the study, with an ORR of 78.1% (25/32). Of these, 18 patients underwent surgical treatment, achieving a pCR rate of 22.2% (4/18) and a MPR rate of 38.9% (7/18). The median PFS for patients who did not undergo surgery was 9.8 months (95% CI: 7.6-13.1), and the median follow-up duration was 16.4 months (95% CI: 11.7-22.5). For patients who received radical surgical resection, the median DFS was not reached, and the 1-year DFS rate was 88.8% (16/18). Common adverse reactions following the treatment included myelosuppression, liver function abnormalities, diarrhea and neurotoxicity, with most adverse events being grade 1-2, a few grade 3 adverse events, and no grade 4 or 5 adverse events. According to the EORTC QLQ-STO22 Chinese version questionnaire, significant improvements were observed in the domains of difficulty swallowing, pain and eating restrictions. Additionally, improvements were noted in anxiety and reflux symptoms, while changes in body image were less pronounced. Conclusion: In the perioperative treatment of LAGC, the combination therapy of oxaliplatin, tegafur, anlotinib and penpulimab can improve the efficacy while ensuring safety, and is expected to become a new treatment for LAGC.

Concerns about fresh food quality have continuously increased in recent years. Reducing the spoilage and loss of fresh foods and ensuring their safety for consumption are of great significance to facilitating the high-quality development of the food industry and meeting people’s growing needs for a better life. Active composite packaging films have demonstrated remarkable efficacy in enhancing the quality of fresh foods. Metal nanoparticle-polymer composite films can inhibit microbial growth and metabolism, slow down the oxidation process of foods, and reduce harmful substances in the storage microenvironment, thereby improving the safety of foods and finally extending the shelf life. As such, active composite packaging films have become a research hotspot in the field of food preservation. This review first summarizes the fabrication strategies and characteristics of metal nanoparticle-polymer composite films. Subsequently, a comprehensive analysis of the mechanism of food preservation by the composite films is conducted from the aspects of antibacterial effect, antioxidant effect, ethylene removal, and high barrier properties. Additionally, the sensing function and biosafety of the composite films are explored. Finally, the current challenges for the application of the composite films are elaborated, and an outlook on future opportunities is provided with a view to promoting the research and application of composite films in the field of fresh food packaging.

This study focuses on the investigation of the mechanical properties and corrosion resistance of 430 ferritic stainless steel with an addition of 0.30% Sn， by incorporating varying amounts of Cu into the experimental steel. The results of room temperature and high temperature tensile tests reveal that Cu atoms act as solid solution strengtheners in the matrix， enhancing the tensile strength of the stainless steel. However， the formation of a significant amount of Cu-rich phase at grain boundaries leads to a decrease in the steel's plasticity. The uniform corrosion resistance of the steel initially increases and then decreases with increasing Cu content， reaching the highest effectiveness at 0.45% Cu. Similarly， Cu exhibits a comparable pattern in its resistance to intergranular corrosion in the experimental steel， achieving the best outcomes at a content of 0.98% Cu.

In order to investigate the change in proline metabolism of two varieties of Hami melon fruits during low-temperature storage, ‘Xizhoumi 25’ and ‘Gashi’ melons were pre-cooled for 24 h and then placed for up to 42 days in a mechanical cold storage at (3.0 ± 0.5) ℃. Chilling injury symptoms were recorded, and chilling injury index, free proline content and proline metabolism-related indexes were measured every seven days . The results showed that the symptoms of chilling injury in ‘Gashi’ melon were significantly milder than those in ‘Xizhoumi 25’ melon, and as the storage time increased, free proline content, Δ1-pyrrolidine-5-carboxylic acid synthase (P5CS) activity, ornithine transaminase (OAT) activity and their relative gene expression increased significantly for both varieties; all these indicators were significantly higher in ‘Gashi’ melon than ‘Xizhoumi 25’ melon. The activity and relative gene expression of proline dehydrogenase (ProDH) decreased, indicating that both varieties of Hami melon fruits could resist chilling injury by increasing the free proline content and the activities of P5CS and OAT, the key enzymes for proline synthesis, and decreasing the activity of ProDH, the key enzyme for proline degradation. The metabolomics study revealed that the amino acid content of ‘Xizhoumi 25’melon decreased when the chilling injury became more serious, while the amino acid content of ‘Gashi’ melon showed an opposite trend. Whole gene synthesis of CmP5CS, a key enzyme gene involved in the proline metabolic pathway of Hami melon fruits, revealed that the Hami melon CmP5CS gene had the closest relatedness to melon (LOC103485529) P5CS, indicating functional similarity between them.

The traditional method of joint calibration of fixed baseline interferometer with multiple errors requires more than three calibration emitters to achieve real-time calibration of the interferometer in orbit, but the performance of the traditional method will be reduced or even failed when the number of calibration emitters is insufficient. For the situation that the number of calibration emitters is insufficient, a single or double emitters calibration method for fixed baseline interferometer is proposed. Under the condition of relative motion between the interferometer and the calibration emitters, a set of phase differences of calibration signals is obtained firstly by multiple measurements, and a set of equations about the systematic errors of the interferometer is listed by using the obtained phase differences, finally the systematic errors are solved by the Penrose inverse matrix assisted iterative least squares method. The simulation results verify the feasibility of the proposed method. On this basis, the influence of the emitter selection on the positioning performance of the interferometer after calibration is analyzed qualitatively by means of numerical simulation, decomposing the parameters of the emitter selection. The analysis results show that the calibration emitter located near the sub-star in the single emitter case or two calibration emitters located far apart both can make the interferometer obtain better positioning performance after calibration.

In order to investigate the stress corrosion cracking behavior of ultra-high strength stainless steel， the influence of Nb microalloying on the corrosion fatigue properties of Cr-Co-Ni-Mo series ultra-high strength stainless steel was studied by OM， XRD， TEM and other testing methods in combination with corrosion fatigue test. The results show that the steel has stress corrosion sensitivity in 3.5% NaCl solution， and the stress corrosion cracking mechanism of the steel was a mixed mechanism involving hydrogen embrittlement and anodic dissolution. Niobium alloying improved the corrosion fatigue performance of the steel， that is， the corrosion fatigue strength of steel increases from 440 MPa to 495 MPa after adding 0.11% Nb. The main reason is that niobium alloying refined the grain size of steel， promoted the precipitation of irreversible hydrogen trap of NbC in steel， and increased the amount of prior austenite grain boundaries， the proportion of low-angle grain boundaries， the number of Σ3 grain boundaries， and the volume fraction of austenite in steel.

To improve coal mine safety management level and reduce accident rate, the system dynamics（ＳＤ） method was used to construct the SD model of the influence of incentive strategies on the active safety behavior of miner groups from the aspects of survival, relationship and growth incentives. Based on the questionnaire survey method, 571 questionnaires were collected to determine the simulation parameters, and Vensim software was used to simulate the influence of incentive strategies on the active safety behavior of miner groups. The results show that different types of incentive strategies have different effects on the active safety behavior of miner groups. Survival incentive, growth incentive, relationship incentive effect decreased in turn. The level of active safety behavior of low-educated miner groups are more likely to be promoted by survival incentive and growth incentive, and the relationship incentive has more obvious influence on the improvement of active safety behavior of high-educated miner groups. Therefore, coal mine safety managers should adopt different incentive strategies for different miner groups to more effectively promote the implementation of miners’ active safety behaviors.

Objective To establish and validate a drug in vitro absorption model of MDCK-MDR1 cells for research on the mechanism of oral drug absorption and transport. Methods MDCK-MDR1 cells with different concentrations (group L with 1.0×108/L, group M with 2.5×108/L, and group H with 5.0×108/L) were inoculated onto a 24-well Transwell plate and cultured for 1-7 d. Optical density (OD) was measured to plot the growth curve of MDCK-MDR1 cells, and cell morphology was observed at different time points of culture. Transepithelial electrical resistance (TEER) was measured at different time points to determine the optimal cell inoculation concentration and culture time for the formation of a monolayer structure. Lucifer yellow transfer assay was used to validate the monolayer structure formed at different concentrations and time points. Results The groups L, M, and H showed the formation of the monolayer structure on days 5, 3, and 1, respectively, after inoculation, and OD reached the peak value on days 5, 4, and 3, respectively, For group L, TEER reached 300 Ω·cm2 on day 5 of inoculation and tended to be stable on days 5-7. Therefore, 1.0×108/L was selected as the optimal cell inoculation concentration, with an optimal culture time of 5 d. Lucifer yellow transfer assay showed that the monolayer structure had a Lucifer yellow apparent permeability coefficient of 4.27×10-7 cm/s, which was lower than 5.0×10-7 cm/s determined by the permeability test. Conclusion The MDCK-MDR1 cell model established in this study has validated monolayer structural integrity and permeability and can be used as an in vitro model to simulate the absorption and transport mechanisms of oral drugs.

Background Scoliosis is a common abnormal curvature of the spine. Patients with mild scoliosis are usually treated with outpatient physiotherapy, but satisfactory efficacy is associated with appropriate treatment time and frequency. The efficacy of offline physiotherapy may be affected by limited medical resources and patients' treatment time and geographical location. Remote rehabilitation may save patients' treatment time and increase the geographical accessibility of physiotherapy, making the therapy more simple and convenient. Objective To explore the efficacy of remote rehabilitation combined with outpatient treatment in mild adolescent idiopathic scoliosis (AIS) . Methods Fifty-eight eligible mild AIS patients were selected from Department of Rehabilitation Medicine, Tianjin Hospital from September 2020 to September 2021, and divided into three groups according to patients and their parents' selection of treatment: online group (n=18), combined group (n=20) and offline group (n=20). The online group received WeChat- and Tencent Video-based physiotherapeutic scoliosis specific exercise (PSSE), the combined group received both outpatient and WeChat- and Tencent Video-based PSSE treatment, and the offline group received outpatient PSSE treatment. Data of three groups were collected, including the main curve Cobb angle, coronal balance (CB), thoracic kyphosis (TK) angle, lumbar lordosis (LL) angle, sagittal vertical axis (SVA), angle of axial trunk rotation (ATR), parietal vertebra rotation (Raimondi), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), muscle activation rate (MAR) on both sides of paraspinal vertebrae, root mean square ratio (RMSR) of paraspinal muscles on both sides of paraspinal vertebrae, and the score of SRS-22 before and after treatment. Results The main curve Cobb angle, TK, SVA, ATR, Raimondi, SS, MAR on paraspinal vertebrae, RMSR on the concave side of the parietal vertebra and SRS-22 self-image and mental health domain scores were significantly different from those before treatment in all groups (P

Helically coiled tube (HCT) is widely used in nuclear engineering and other fields due to its effective compactness, excellent structure robustness, heat transfer efficiency and flow stability. As one of the most important gasliquid twophase flow patterns in HCT, the characteristic of annular flow has a great influence on the heat transfer performance of helical oncethrough steam generator. Especially, the circumferential distribution of liquid film thickness in annular flow directly determines the dryout onset location. Although the liquid film flow in straight tubes has been extensively studied, due to the limitation of measurement technology, the precise measurement data of liquid film thickness in HCT are still very rare. In this paper, based on the selfdeveloped noninvasive contact ringisland array sensor (RIAS), airwater twophase flow experiments were carried out to study the threedimensional spatialtemporal distribution of liquid film thickness in vertical HCT with different structures. According to the results, four typical liquid film flow regimes were defined based on the circumferential position of the thicker liquid film appearing in the tube wall. That is, the bottom distribution (BD) dominated by gravity force, the outside distribution (OD) dominated by liquid centrifugal force, the inside distribution (ID) dominated by gas centrifugal force and the insideoutside distribution (IOD) dominated by secondary flow. The effects of coil diameter and coil pitch of HCT as well as gas and liquid velocities on the distribution of liquid film flow regimes were detailed analyzed. It is implied that the coil diameter determines the intensity of centrifugal force and secondary flow. Generally, the smaller the coil diameter, the easier the circumferential distribution forms of OD, ID and IOD are to appear. Also, increasing the coil pitch weakens the effect of centrifugal force on the liquid film. Then a small coil pitch normally results in the circumferential distribution form of OD while it is ID for large coil pitch. It is also found that the IOD occurs only when both gas and liquid velocities are large enough. By taking the influence of HCT geometry and fluid parameters into account, a general submap of liquid film flow in HCT was proposed using the modified Dean number De* and the modified LockhartMartinelli parameter X*. The transition criteria between different liquid film flow regimes were also established and verified with experimental data in present work and previous references. From this work, the mechanism of curvatureinduced centrifugal force and secondary flow on the spatiotemporal evolution of liquid film in HCT is revealed.

For studying the effects of different addition ways of graphene on the properties of polyaniline/epoxy coatings, the in - situ polymerization method was applied to synthesize polyaniline (PANI)/graphene(G) composite powders on graphene surface, and the as - prepared powders were characterized by X - ray diffractometer, Fourier transform infrared spectrometer and scanning electron microscope. The as - synthesized composite powders, the mixed powders of PANI and G, and the PANI powders were uniformly dispersed in epoxy resin respectively to prepare coatings on the surface of AZ91D magnesium alloy. Subsequently, the effects of different graphene addition methods on the properties of polyaniline/epoxy coatings were studied through electrochemical impedance measurement, water absorption, etc. Results showed that after an immersion within 2 160 h in 3.5% (mass fraction) NaCl solution, the coating added with PANI/G composite powders not only had a higher impedance value in comparision with those added with PANI powders or with PANI/G powders, but also had better flexibility and impact resistance. Compared with the mixed powders of PANI and G, the PANI/G composite powders obtained through in - situ polymerization could better exhibit the shielding effect of G and the corrosion inhibition effect of PANI, and therefore provid better protection to magnesium alloy.

Objective To investigate the incidence and potential risk factors of postoperative hypoxemia in a post-anesthesia care unit (PACU). Methods The retrospective cohort assessed 14 604 postoperative patients who were admitted to PACU in a period of one year. Clinical data were collected, the incidence and potential risk factors for postoperative hypoxemia were statistically analyzed. Results The incidence of hypoxemia was 2.79%. Multiple regression analysis indicated that the risk factors were age (≥65-year old), body mass index (BMI≥25), American Society of Anesthesiologists (ASA ≥Ⅱ), limb surgery, and thoracic surgery. Conclusions Hypoxemia is common in postoperative patients in PACU. Age, BMI, ASA classification, and surgical site are associated with postoperative hypoxemia. Doctors should pay attention and give timely treatment to high-risk patients to prevent hypoxemia in PACU.

Objective The aim of this study is to investigate the influence of cone beam computed tomography (CBCT) and micro-ultrasound technique for the treatment of three mesial canals in mandibular first molars. The three mesial canals according to Pomeranz's classification were characterized. Methods A total of 75 permanent mandibular first molars for root canal treatment were randomly selected from patients belonging to the age group of 14-60 years. After preparing the access cavity and locating the main canals, the middle mesial canal orifices in all teeth were determined with an endodontic explorer under direct vision (StageⅠ), under magnification with the aid of micro-ultrasound (Stage Ⅱ), and with the combined use of CBCT and micro-ultrasound to remove the dentin wall and calcifications (Stage Ⅲ). Results Middle mesial canals were detected in 4.0%, 18.7%, and 22.7% of the teeth in StagesⅠ-Ⅲ, respectively. Statistical analysis showed significant differences (P<0.05) between StagesⅠand Ⅱ with regard to middle mesial canal detection. The number of Stage Ⅲ was more than that of Stage Ⅱ. The difference between the two stages was no significant. Among the 17 middle mesial canals, "confluent", "fin" and "independent" anatomies were 52.9%, 35.3%, and 11.8%. Conclusion When used with adjunctive aids, including CBCT, micro-ultrasound facilitates dental clinicians in the location and treatment of middle mesial canals.