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Due to the attractive potential in avoiding the elaborate definition of anchor attributes, anchor-free-based deep learning approaches are promising for object detection in remote sensing imagery. CornerNet is one of the most representative methods in anchor-free-based deep learning approaches. However, it can be observed distinctly from the visual inspection that the CornerNet is limited in grouping keypoints, which significantly impacts the detection performance. To address the above problem, a novel and effective approach, called GroupNet, is presented in this paper, which adaptively groups corner specific to the objects based on corner embedding vector and corner grouping network. Compared with the CornerNet, the proposed approach is more effective in learning the semantic relationship between corners and improving remarkably the detection performance. On NWPU dataset, experiments demonstrate that our GroupNet not only outperforms the CornerNet with an AP of 12.8%, but also achieves comparable performance to considerable approaches with 83.4% AP.

For photovoltaic (PV) modules, dust accumulation is one of the reasons for the reduction of output power, while conventional cleaning is expensive and inefficient for large scale PV power plants. Therefore, the research of superhydrophobic self-cleaning thin film on PV modules is proposed in this paper. The preparation of superhydrophobic film combines the low surface energy layer and anti-reflection layer which enhances the adhesion between the superhydrophobic film and the glass substrate by forming the stable covalent bonds. Its fundamental characteristics were tested and analyzed including transmittance, contact angle, micromorphology and energy spectrum. Finally, the effect of the superhydrophobic film on the self-cleaning performance and improvement of output power were investigated after coating the film on PV modules. The comparison results show that the prepared superhydrophobic thin film not only has anti-reflection and self-cleaning ability to improve the transmittance and output power of the PV modules, but also has excellent weatherability by forming stable covalent bonds through dehydration reactions.

Adiabatic calorimeters (ARCs) are critical in thermal analysis and thermal hazard assessment. As testing equipment continually improves, analyzing changes in physical fields in sample pools during thermal decomposition reactions is increasingly essential. Therefore, this study analyzed the thermal decomposition of tert-butyl peroxyacetate (TBPA). On the basis of the computational fluid dynamics (CFD) numerical simulation method and the kinetic model of TBPA thermal decomposition, a full-scale model of an adiabatic reactor for the thermal decomposition of TBPA was constructed. The temperature rise curve obtained after monitoring the temperature of the system during thermal decomposition was compared with that obtained during the experiment; thus, the rationality of the CFD model was verified. Accordingly, the temperature field, temperature rate, and velocity field in the reactor were analyzed. The temperature distribution of the system was relatively uniform during thermal decomposition under completely adiabatic conditions, resulting in an effectively nonexistent temperature gradient. At the same time, the self-heat rate (dT/dt) of the system in the process of thermal decomposition was analyzed. It was found that self-heat rate (dT/dt) of the system in the full sensing state was much larger than that in the experimental process, maximum self-heat rate ((dT/dt)max) reaching 15℃/min, while in the experimental process was only 1.074℃/min.

The prognosis of metastasis gastric cancer patients remains poor and the identification of novel molecular markers will improve the management of gastric cancer patients. The present study aimed to investigate the clinical significance and functional role of miR-466 in gastric cancer peritoneal metastasis. miR-466 expression was confirmed by RT-qPCR. The biological functions were examined by MTT assay, Transwell migration, and invasion assays. The Kaplan-Meier survival curve and multivariate Cox regression analysis were used to investigate the clinical role of miR-466. The logistic regression analysis was performed to reveal the risk factors associated with peritoneal metastasis. miR-466 expression was downregulated in gastric cancer cell lines, tumor tissues, and peritoneal metastasis tissues compared with respective controls. Increased miR-466 expression inhibited proliferation, migration, and invasion of gastric cancer cells. Besides, the lower expression of miR-466 in gastric cancer patients was associated with peritoneal dissemination. Furthermore, multivariate Cox proportional hazard regression analyses demonstrated miR-466 expression level as an independent predictor of prognosis of gastric cancer. The present study provides novel evidence for the clinical and biological significance of miR-466 expression as a possible biomarker for the prognosis and identifying patients with peritoneal metastasis, as well as a potential therapeutic target in patients with gastric cancer.

Objective The aim of this study was to assess the diagnostic value of several markers for tuberculosis pleural effusion (TPE) using the combined analysis of Lactate dehydrogenase (LDH), Carbohydrate antigen 125 (CA125), Cytokeratin-19 fragment (CYFRA21-1). Methods From January to December in 2018, a total of 37 patients with pleural effusion (22 cases of transudative pleural effusion, 15 cases of tuberculosis pleural effusion and 22 cases of Transudative pleural effusion who were hospitalized in our hospital were reviewed. Receiver operating characteristic (ROC) curves and logistic regression equations was used to evaluate the diagnostic efficiency of each marker. Results The levels of LDH and CYFRA21-1 of tuberculosis pleural effusions were obviously higher than those of transudative pleural effusion with statistically significant difference ( Conclusions The study showed a high diagnostic sensitivity and specificity of combined speculation of LDH, ADA and CYFRA21-1 in Tuberculosis pleural effusion.

Wireless communication with unmanned aerial vehicle (UAV) has attracted much attention due to its flexibility and low-cost in providing wireless connectivity. In this article, we investigate the spectrum sharing between UAV and terrestrial wireless communication. Two scenarios are considered in this work. Scenario 1: the UAV is energy sufficient to transmit the required data. In this case, our objective is to minimize the time that is needed to complete data transmission. Scenario 2: the battery of the UAV is energy insufficient. In this case, the goal becomes maximizing the size of data that can be transmitted. Different scenarios require different placement of the UAV. When the UAV flies towards the primary user (PU), the sensing result will be more accurate and more opportunities can be utilized to transmit data. However, the interference to primary receiver (PR) and the propulsion energy due to UAV’s movement will be increased. In this article, the sensing performance, the power allocation and the UAV’s position are jointly optimized to satisfy different requirements of the UAV system. To efficiently utilize the licensed spectrum, a hybrid transmission mode is proposed for the UAV system, in which sensing and power control are jointly employed to protect the PR. Then, efficient iterative algorithms are proposed to solve the optimization problems. Simulations results show that proposed designs can significantly reduce the time that is required to complete data transmission in energy sufficient scenario and enhance the size of data that can be transferred in energy insufficient scenario.

Designing van der Waals' heterostructures with prominent properties is crucial to improve the performance of nanoscale optoelectronic devices. In this article, the structural stability and electronic properties of Sb/AlAs heterostructures were investigated by comprehensive first-principles calculations. It is worth noting that Sb/AlAs heterostructures have good thermal stability and a small lattice mismatch. Owing to suitable direct-gap and intrinsic type-II band alignment, effective separation of photogenerated carriers occurs at the interface, which has numerous optoelectronic properties suitable for use in photodetectors. Furthermore, the heterostructure undergoes transition from indirect-gap to direct-gap under vertical strain. When an external electric field is applied, the charge transfer is significantly enhanced and a semiconductor–metal transition is accomplished. The biaxial strain can induce indirect–direct–indirect transition, and the effective mass of electrons and holes exhibit notable anisotropy, which can be modulated by tensile and compressive strain. The above-mentioned results provide valuable theoretical guidance for designing high-quality Sb-based heterostructures and specify an orientation for high-performance photodetector applications.

Ship detection from synthetic aperture radar (SAR) images is inherently subject to the special imaging mechanism of SAR. In recent years, deep-learning-based techniques for detecting objects from optical images have rapidly advanced and promoted the development of SAR image detection technology. However, the strong speckle noise in SAR images degrades low-level feature learning in shallow layers, hindering the higher level learning of semantic features for object detection. In view of the problems encountered in direct end-to-end feature learning for object detection and the close relationship between objects and auxiliary cues, a multitask learning-based object detector (MTL-Det) is proposed in this article to distinguish ships in SAR images. The proposed approach models the ship detection problem, not as a single object detection task, but as three cooperative tasks. The model involves two auxiliary subtasks that are focused on learning object-specific cues (e.g., texture and shape) for the ship detection task, which is constrained by the pseudoground truth generated by the main task. Assisted by auxiliary subtasks, the low-level features are robust to speckle noise and reliably support high-level feature learning. Compared with traditional single-task-based object detectors, more discriminative object-specific features are learned by multitask learning without the extra cost of manual labeling. The experiments conducted in this study help demonstrate the advantages of MTL-Det in improving the ship detection performance on two SAR datasets: high-resolution SAR images dataset and large-scale SAR ship detection dataset-v1.0.

Objectives The purpose of the present paper was to study isolated meniscal ramp lesions without obvious ACL rupture. Their biomechanical mechanisms were analyzed and their clinical characteristics were reviewed. The clinical effects of an all‐inside horizontal mattress suture for isolated ramp lesions were evaluated. Materials and Methods Twenty isolated meniscal ramp lesion patients without obvious ACL rupture from 2015 to 2017 were retrospectively reviewed. Preoperative MRI showed intact ACL and signs of ramp lesions. These isolated ramp lesions were arthroscopically confirmed and repaired through an all‐inside horizontal mattress suturing method. MRI was performed 3 months postoperatively to assess isolated ramp lesion healing. The Tegner–Lysholm score and the visual analog scale score were recorded preoperatively and at 2 years postoperatively. The Wilcoxon rank sum test was performed to determine statistical significance. Results Arthroscopic exploration confirmed isolated ramp lesions and longitudinal ACL splits or degeneration without obvious ACL rupture. MRI 3 months postoperatively showed healing of the isolated ramp lesions. At 2 years postoperatively, the VAS scores were significantly decreased and the Tegner–Lysholm scores were significantly increased. Knee function, without pain, was restored in all patients, including walking, climing and descending stairs, and squatting. Conclusion Isolated meniscal ramp lesions without obvious ACL rupture may exist because of ACL longitudinal splits or degeneration and can be repaired through anterolateral and anteromedial portals with an all‐inside horizontal‐mattress suturing method., All‐inside horizontal mattress suture method with the 12° OMNISPAN Meniscal Repairing System for isolated ramp lesions without obvious ACL rupture in the right knee.

Unmanned aerial vehicle- (UAV-) assisted communication has great potential to provide on-demand wireless services and improve the outdoor link throughput. In this paper, a UAV-based cognitive radio network (CRN) is investigated in which the UAV works as a secondary user (SU). Considering the overlay spectrum sensing mode, the UAV can operate on the licensed spectrum bands of primary user (PU) only when PU is idle. In each working frame structure, both sensing time slot and transmission time slot are analysed in radians. Specifically, our objective is to maximize the spectrum efficiency (SE) of the UAV by jointly optimizing the sensing radian and the number of radians. For the single-radian and multiradian schemes, the dichotomy and alternative iterative optimization (AIO) algorithm are proposed to solve the SE optimization problem. Simulation results show that the proposed multiradian cooperative spectrum sensing (CSS) scheme can achieve better performance on ensuring the quality-of-service (QoS) of the PU, and it can significantly enhance the SE of the UAV especially in the severe channel environments.

Objectives To establish and evaluate a first generation patient-derived xenograft (PDX) model in nude mice using tumors resected from pancreatic cancer (PC) patients for the identification of key factors that influence xenograft success and prediction of patient prognosis. Methods Primary tumor samples harvested from PC patients who underwent curative resection between May 2016 and April 2018 at our hospital were xenografted into nude mice. Tumor size was evaluated for 2 months. Patients’ baseline characteristics and follow-up data were analyzed. Results Tumor xenograft models were generated from 67 patients; 30 (44.8%) were successful and 37 (55.2%) failed. Xenograft models could recapitulate the pathology and genetic information of the primary tumors. Univariate analysis identified tumor engraftment, post-operation CA19-9, tumor size, lymph node status, and lymphovascular invasion as significant predictors (P=0.000, 0.023, 0.004, 0.035 and 0.005, respectively) of disease-free survival (DFS). Multivariate Cox regression analysis confirmed tumor engraftment, tumor size and lymphovascular invasion function as independent risk factors for DFS (P=0.000, 0.039 and 0.025, respectively). The hazard ratio of tumor engraftment for DFS was 0.239 (95% confidence interval, 0.109 to 0.524). Kaplan–Meier analysis of DFS indicated an unfavorable outcome in the engraftment group compared to that in the failed engraftment group (6.2 vs. 12.2 months, log rank P=0.000). Conclusion The pathology and genetic information of primary PC tumors are recapitulated in the PDX tumor model in nude mice. Furthermore, engraftment success is an effective predictor of disease recurrence in patients after surgery.

The surface of photovoltaic (PV) modules exposed under sunlight are always covered with pollutants, which often lead to the increase of leakage current and potential induced degradation (PID). For investigating the indistinct mechanism and effect of pollutants on PV leakage current, activation energy, and power degradation, an experimental prototype was set up in an environmental chamber. Then different masses of pollutants were smeared on PV modules' surface to investigate their influence on leakage current. The polluted leakage current model was established by measuring the PV modules’ leakage current and calculating the activation energy with different humidity and pollutant mass. The experimental results indicate that the leakage current model proposed in this paper can predict the polluted leakage current, and the proposed pollutant correlation coefficient can reveal the degradation rate and guide for the economic operation of cleaning PV modules.

This paper considers a multiple-input multiple-output (MIMO) secure simultaneous wireless information and power transfer (SWIPT) system aided by the intelligent reflecting surface (IRS), where the transmitter (T), the information receiver (IR) and energy receiver (ER) are all equipped with multiple antennas. Assuming that the ER may be potential eavesdropper (Eve), we aim to maximize the secrecy rate via jointly designing the precoding matrix, the artificial noise (AN) covariance, and the phase shift matrix, subject to the harvested energy and unit modulus reflect coefficient (RC) constraints. The formulated secrecy rate maximization (SRM) problem is non-convex with multiple coupled variables. To tackle it, an inexact block coordinate descent (IBCD) method is proposed, where the unit modulus constraint is handled by the penalty majorization-minimization (MM) and the complex circle manifold (CCM) methods. Finally, simulation results validate the effectiveness of IRS in enhancing the security.

In this study, first-principles calculations based on the density functional theory (DFT) are exploited to investigate the electronic capabilities of SiC/InSe heterostructures. According to our results, the SiC/InSe heterostructure possesses an inherent type-II band alignment, which displays a noticeable Stark effect on the band gap under a stable electric field. Besides, the heterostructure exhibits a low carrier effective mass and a narrower band gap when it is subject to tensile strain. More interestingly, the transition from an indirect to a direct band gap occurs when 8% of compressive strain is applied. Taken together, findings in this study indicate that the SiC/InSe heterostructure opens up a new avenue for its application in the fields of optoelectronics and microelectronics.

First-principles based on density functional theory (DFT) are used to calculate the structural and electronic properties of InSe/arsenene heterostructure. The results show that the InSe/arsenene bilayer forms a type-II van der Waals heterostructure with a direct band gap of 0.876 eV, which is favorable for the separation of photogenerated electron-hole pairs. The properties of InSe/arsenene heterojunction can be effectively regulated by applying an external electric field and uniaxial strain. When an external electric field is applied, the heterostructure experiences a transition from semiconductor to metal. In addition, due to the presence of built-in electric field, the positive and negative electric fields have different effects on the electronic properties of heterostructure. When uniaxial strain is applied, the heterostructure can withstand larger tensile strain than compression strain without damaging the structure and the band gap is more easily decreased by X-direction strain. In addition, the heterostructure undergoes a direct-indirect bandgap transition under strain. When compressive strain is applied in the Y direction, especially e

Thermal polymerization of styrene in a lab-scale batch reactor was simulated using computational fluid dynamics (CFD). The corresponding hydrodynamic model of thermal polymerization of styrene was combined with the fluid–solid coupling model of a simulated heat exchanger by using the CFD method to construct the corresponding reactor model. The effects of stirring rate, cooling temperature, and cooling flow rate were investigated under the runaway conditions of thermal polymerization of styrene. The results showed that the increase in temperature during the reaction was sensitive to different runaway conditions. The stirring rate and cooling flow rate greatly influenced the increase in temperature during the reaction. Based on the temperature distribution inside the reactor, the optimal location of the temperature monitor was determined by employing the divergence (DIV) criterion.

This paper makes research on a secure hybrid satellite-terrestrial communication network with eavesdroppers at the primary and secondary receivers. To secure the transmitted messages, we adopt the null space beamforming to the amplified-and-forward (AF) relay protocol and weighted fractional data carrying artificial noise (WFDCAN) to the decoded-and-forward (DF) relay protocol at the satellite. Considering the time delay may be brought by the WFDCAN, we introduce a parameter θ to indicate the delay severity. The secrecy capacity is combined with θ to derive the maximum secrecy delay constrain. The secrecy capacity, the ASER of the up-link channel and the delay constrain of the down-link channel are applied as factors for a three level relay protocol selection scheme. To simplify the analyses and expressions, the models of the AF protocol and the DF protocol are integrated to form a new transmission model. Furthermore, the secrecy performance at the destination receiver is considered for terrestrial relay selection to enhance the security performance. We also apply the columns of the frequency hopping based multi-term weighted fractional fourier transform (FH-MWFRFT) matrix as signal processing vector to the base station of the terrestrial network to minimize the interference it brings to the terrestrial relays. The simulation results demonstrate that the proposed system could maintain the security at the relays and the secondary receiver while reducing the delay at the satellite in some conditions.

Green energy powered cognitive radio is proposed as a promising method to improve the energy efficiency (EE) and spectrum efficiency (SE). We consider the green power farms that harvest energy from solar and wind, which is used for the primary transmitter and the cognitive sensor network (CSN). The primary transmitter has priority to utilize the spectrum and the energy, and then the energy powered for the CSN may not be sufficient. Both the energy management and energy harvesting process will affect the throughput of the cognitive sensors (CSs). In this paper, we aim to design the system parameters in the CSN (including the sensing threshold, the sensing time, the final decision threshold in the fusion center, and the number of cooperating CSs) that can improve the utilization efficiency of the harvested energy and maximize the CSs’ throughput. Since the parameters are intertwined with the energy causality constraint and the average throughput, we decouple the influence of final decision threshold on the throughput from the influence of the sensing time and sensing threshold. The optimization problem is divided into two sub-problems. Algorithm 1 and Algorithm 2 are proposed to solve sub-problem 1 and sub-problem 2, respectively. The simulation results show that the proposed scheme can improve the average throughput significantly, and is able to achieve the best tradeoff between SE and EE.

Unmanned Aerial Vehicle (UAV) aided communication has the potential to provide on-demand wireless services and improve the outdoor link throughput. Applications for UAVs are rapidly growing with the development of Internet of Things. Because of limited battery energy, the UAVs need time-limited spectrum access to complete data transmission. Hence there are two challenges for the UAV-based communication: 1) Spectrum-efficient design; 2) Energy-efficient design. In this paper, we investigate the optimization of spectrum efficiency (SE) and energy efficiency (EE) for cognitive UAV network based on location information. Because of high mobility, the cognitive radio (CR) based UAVs operate on different frequency bands that vary with time and space. Thus, one spectrum band that is available in one region may not be necessarily available in another region. Based on location information of the primary transmitter and the UAV, we propose a hybrid mode in which the sensing performance and UAV's transmit power can be adjusted simultaneously to satisfy the outage constraint of the primary user. The multi-objective optimization theory is used to solve the tradeoff between SE and EE. The UAV's transmit power, sensing time and sensing threshold are optimized jointly to solve the tradeoff problem. To further improve the SE and EE performance, we propose a multi-frame combined sensing scheme, in which multiple frames are bundled together. Simulation results are provided to show the SE-EE tradeoff design, to validate the effectiveness of the proposed hybrid mode, and to show the advantages of the multi-frame combined sensing scheme in EE performance.

When evaluating noise-related cardiovascular risk, noise is generally solely assessed as the major stressor. However, cardiovascular effect of other simultaneous exposure events, such as unhealthy lifestyle and genetic variation, is easily neglected. The aim of this study is to estimate the combined effect of noise and lifestyle on blood pressure alteration, particularly under different genetic background. This study included 536 workers from a tobacco factory in Wuhan, China, who were divided into high exposure group and low exposure group according to noise measurement in their working area. All participants took annual physical examination and questionnaire survey to provide information on individual systolic and diastolic blood pressure (SBP and DBP) and lifestyle (smoking, drinking and physical activity). Single nucleotide polymorphism at genes related to stress hormone production were determined. Moderated moderation models were constructed to investigate the interaction effect of noise exposure and lifestyle factors on blood pressure with regard to different genetic background. We identified an expected trend in association between noise exposure and SBP among active smokers (P = 0.086). The moderated moderation analysis showed significant three-way interaction effect (COMT rs4680 × smoking status × noise exposure levels) on SBP or DBP (both P 0.05). For COMT rs4680 GA+AA genotype carriers, active smoking significantly moderated the association between noise exposure and SBP or DBP (both P 0.05). The results indicated that for COMT rs4680 A allele carriers, tobacco and noise exposure contribute collectively to blood pressure alteration, supporting that stress hormone production may play a certain role in the smoke-and-noise-induced cardiovascular effect.

Understanding the socially influenced decision-making process that determines voluntary vaccination is essential for developing strategies and interventions of vaccine-preventable diseases. Both theoretical and experimental studies have suggested that a variety of factors, such as safety of vaccines, severity of diseases, information and advice from healthcare professionals, influence an individual's intention to vaccinate. However, limited research has been conducted on analysing systematically how individuals’ vaccine acceptance decisions are made from their beliefs and judgements on the influential factors. In particular, there is lack of quantitative analysis on how individuals’ beliefs and judgements may evolve from the spreading of vaccination-related information in a social network, which further affects their decision making. In this paper, an integrated model is first proposed to characterise the socially influenced vaccination decision-making process, in which each individual's beliefs and subjective judgements on the decision criteria are formulated as belief distributions in the framework of multiple criteria decision analysis (MCDA). The spreading of social influence in the network environment is further incorporated into the information aggregation process for supporting informed vaccination decision analysis. A series of simulation-based analyses on a real-world social network is conducted to demonstrate that the overall vaccination coverage is determined primarily by individuals’ beliefs and judgements on the decision criteria, and is also affected sensitively by the characteristics of influence spreading (including the content and amount of vaccination-related information) in the social network.

BackgroundTo investigate the feasibility, safety and therapeutic efficacy of arthroscopy in managing the 3 most common soft tissue complications, peripatellar impingement (PI), arthrofibrosis (AF) and generalized synovitis (GS), after total knee arthroplasty (TKA).MethodsA retrospective review of patients undertaking arthroscopy for PI, AF and GS was conducted. Outcome measures included complications, postoperative range of motion (ROM), Knee Society Score (KSS) and rates of symptom recurrence, prosthesis revision. Intraoperative findings and surgical procedures were also recorded. Pairedttest, Fisher’s exact test, Kruskal-Wallis test and post hoc analysis with Bonferroni correction were used for statistical evaluation.ResultsA total of 74 patients, including 35 patients with peripatellar impingement, 25 patients with arthrofibrosis and 14 patients with generalized synovitis, with a mean age of 66.1 ± 7.9 years, were analysed. The mean follow-up (FU) duration was 81.3 ± 40.6 months. All patients underwent arthroscopic surgery safely without intraoperative complications. However, there were 4 postoperative complications, including 1 acute myocardial infarction and 3 periprosthetic joint infections. Overall, patients acquired improvements in ROM from 81.7 ± 23.1° to 96.8 ± 20.5° (p< 0.05), in KSS knee score from 64.2 ± 9.6 to 78.7 ± 12.1 (p< 0.05) and in KSS function score from 61.1 ± 7.4 to 77.3 ± 12.2 (p< 0.05) postoperatively. Patients in all 3 groups had improvements in ROM (p< 0.05), KSS knee score (p< 0.05) and KSS function score (p< 0.05). The overall recurrence rate was 22.9% (95% confidence interval (CI) 15.1–34.9%), and the overall revision rate was 14.9% (95% CI 8.6–25.6%). There were significant differences in both the symptom recurrence and prosthesis revision rates among the groups (p< 0.05). The PI group had a significantly lower symptom recurrence rate (11.4%, 95% CI 4.5–28.7%) and revision rate (8.6%, 95% CI 2.9–25.3%) (p< 0.017), while the GS group had a significantly higher recurrence rate (42.9%, 95% CI 23.4–78.5%) and revision rate (35.7%, 95% CI 17.6–72.1%) (p< 0.017).ConclusionsIn the setting of symptomatic TKA, although carrying certain risks for PJI and other complications, arthroscopic intervention could be feasible and provide clinical improvement in most cases at an average of 81.3 months follow-up. Patients with PI had the best outcomes, while patients with GS had the worst outcomes.Level of evidenceLevel IV

In this study, “attenuation” and “substitution” strategies were applied to improve the inherent safety designs of exothermic reaction processes. The two strategies were implemented in the exothermic process of the esterification of methanol with acetic anhydride. Process simulation technology was used to compare the two strategies, and the process with moderate increases in temperature–pressure curves was identified. Large quantities of thermally inert and high-boiling-point reactants can be added to a reaction system to dilute the system. Thus, “attenuation” can reduce the values of process parameters such as temperature and pressure. The flammability, explosiveness, toxicity, and thermal inertness of the reaction system were examined for investigating the inherent safety characteristics of the solvent. Selecting a high-safety solvent considerably improves the inherent safety of processes. Transforming the strongly exothermic batch reaction process into a semibatch production process or a continuous production process reduces the severity of thermal runaway and improves process controllability. Thus, “substitution” of a process that has low inherent safety with a process that has high safety was realized.

In this study, the InSb/InSe heterostructure is systematically examined in terms of its electronic properties through first-principles calculations. According to our findings, the InSb/InSe heterostructure is a kind of unique direct band gap semiconductor, which has inherent type-II band alignment, resulting in significant photogenerated electron–hole pair separation in space. When the external electric field is applied, the Stark effect is observed in the band gap. Interestingly, in the application of the −0.3 V A−1 electric field, such a heterostructure is transformed into type-I from type-II. Simultaneously, the band gap is also effectively controlled by uniaxial strain. In particular, high carrier mobility is obtained at a compressive strain of 4% on the Y-axis. To sum up, based on the results in the present work, the InSb/InSe heterostructure can be potentially used in nanoelectronic and optoelectronic devices.

Background To study isolated meniscal ramp lesion without obvious ACL rupture, analysis its clinical characteristics and evaluate clinical effect of all-inside horizontal mattress suture. Methods From 2015-2017, there are 20 isolated meniscal ramp lesion patients without obvious ACL rupture in our hospital. These isolated ramp lesions were arthroscopically repaired through all-inside horizontal mattress suturing method with 12 0 Mitek Omnispan meniscal repairing system. MRI was performed preoperatively and postoperatively 3 months later during follow-up. The Tegner-lysholm score and VAS score were recorded preoperatively and postoperatively at 2 years follow-up. T-test was performed to detect statistical significance. Results MRI postoperatively 3 months later shows healing of the isolated ramp lesion. Postoperatively at 2 years follow-up, VAS score was significantly decreased and Tegner-lysholm score was significantly raised comparing preoperatively. All patients recover their knee function without pain, including walking, stairs climbing and descending, squatting et al. Conclusion Isolated meniscal ramp lesion without obvious ACL rupture may exist because of ACL longitudinal splits. Through all-inside horizontal mattress suturing method with 12 0 Mitek Omnispan meniscal repairing system, isolated ramp lesion can be repaired through routine anterolateral and anteromedial portal.

Up to now, the fiber/powder porous media is getting more and more attention as a new development direction in the field of vacuum insulation panels. In this paper, the random generation-growth method is used to generate the structure of the fiber/powder porous media. The numerical simulation method is used to simulate the thermal conductivity of the fiber/powder porous media based on Fourier's law to study the correlation between the effective thermal conductivity and the microstructure of the fiber/powder porous media under vacuum conditions. The model was verified with experimental and theoretical data. The effect of different microstructure parameters such as powder diameter and fiber orientation angle on the effective thermal conductivity of the fiber/powder porous media is introduced in detail. The results show that the finer the diameter of the powder leads to the smaller the pore size of the fiber/powder porous media and has the stronger the ability to maintain a lower effective thermal conductivity under higher pressure. In addition, the more inconsistent between the fiber axial direction and the heat transfer direction, the better the thermal insulation performance. The results are very important for the optimization of the core material of the vacuum insulation panel.

With the continuous development of space rendezvous technology, more and more attention has been paid to the study of spacecraft orbital pursuit-evasion differential game. Therefore, we propose a pursuit-evasion game algorithm based on branching improved Deep Q Networks to obtain a space rendezvous strategy with non-cooperative target. Firstly, we transform the optimal control of space rendezvous between spacecraft and non-cooperative target into a survivable differential game problem. Next, in order to solve this game problem, we construct Nash equilibrium strategy and test its existence and uniqueness. Then, in order to avoid the dimensional disaster of Deep Q Networks in the continuous behavior space, we construct a TSK fuzzy inference model to represent the continuous space. Finally, in order to solve the complex and timeconsuming self-learning problem of discrete action sets, we improve Deep Q Networks algorithm, and propose a branching architecture with multiple groups of parallel neural Networks and shared decision modules. The simulation results show that the algorithm achieves the combination of optimal control and game theory, and further improves the learning ability of discrete behaviors. The algorithm has the comparative advantage of continuous space behavior decision, can effectively deal with the continuous space chase game problem, and provides a new idea for the solution of spacecraft orbit pursuit-evasion strategy.

Thermal runaway is a hazardous problem frequently occurring in the chemical productions. An effective way to avoid accidents caused by thermal runaway is preliminary hazard analysis which can help determine the comparatively safe operating condition in the design phase. In this paper, a series of batch reactor thermal runaway scenarios based on esterification of isopropyl propionate has been studied and according to mixing law the optimal inhibitor injection location has been confirmed. The reactor model is established by computational fluid dynamics (CFD) technology and verified by RC1e test. The effect of cooling temperature, cooling velocity and stirring speed are investigated in detail. Based on the failure status analyses, the appropriate location of temperature probe was then determined by the divergence (DIV) criterion. Finally, the inhibitory mixing performances were evaluated by a global mixing criterion. The results indicated the mixing time and inhibitory region were greatly influenced by the injection location.

An ultraviolet (UV) photodetector based on ZnO-reduced graphene oxide (ZnO-rGO) composites have been successfully fabricated. A pure ZnO photodetector was also fabricated by similar method. In comparison with the pure ZnO UV photodetector, the ZnO-rGO photodetector exhibits a much larger photocurrent and a better light-to-dark-current-ratio. The mechanism of photocurrent enhancement was investigated using I-V characteristics, photoluminescence (PL) spectra, transmittance spectra and time-dependent photocurrent analysis. Results show that the photocurrent enhancement of the ultraviolet photodetector is due to the improvement of the carrier lifetime, because the carrier recombination of ZnO were reduced by rGO. It provides a potential way to fabricate high-response UV photodetectors.

Music has a long history of healing or mitigating physical and mental illness in the clinical setting. We aimed to test changes in behavioral cognition and serum proteomics in rats undergoing music intervention (MI). The Morris water maze (MWM) was used to evaluate spatial learning and memory in rats. Serum protein expression profiling was examined using magnetic bead-based matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF-MS). MI improved spatial learning and memory in both male and female rats. Peak 1708.61 (m/z values) was significantly increased in MI females vs. female controls. Peak 3925.09 (m/z values) was significantly reduced in MI males versus male controls. The two differential serum peptide peaks (m/z values: 1708.61, 3925.09) were further sequence identified as regions of proteins Desmin and Acsm1. Western blot and immunofluorescence testing of Desmin expression showed consistent results on proteomics analysis. MI plays an important role in behavioral cognition and protein expression in rats. This study provides a foundation in proteomics that suggests that MI might improve spatial learning and memory ability.

Dust deposition on photovoltaic (PV) modules is related to environmental and weather conditions and results in a reduction in power generation efficiency over time. The effects of films on the transmittance can be obtained by testing sample glasses coated with silicon and fluorine super-hydrophobic films with a spectrophotometer. Red soil particles with a diameter of 25 μm were selected to simulate the process of natural dust deposition on PV module samples, and an incubator of constant temperature and humidity was used to simulate the condensation process. PV module samples were irradiated by a solar simulator after the aforementioned simulation process, and the effects of different amounts of sediment in unit areas on the photovoltaic properties and spectral characteristics were determined. The experimental results indicate that the influence of dust on the power generation efficiency of PV modules coated with fluorine super-hydrophobic film is smaller than that for PV modules coated with silicon super-hydrophobic film and that the super-hydrophobic films can not only greatly reduce the dust accumulation on the surface of PV modules but also increase the generating efficiency.

In recent years, high-speed electric railway has become a major means of transport. Messenger wire is the main bearing part of electrified railway catenary, and once the damage occurs, it will easily cause a serious accident. In the harsh areas of climate, the messenger wire is covered with ice for a long time. To identify damages of electrical messenger wire in the icing environment, a synergetic damage recognition approach was put forward. On the basis of the synergetic principle, a dynamic decision-making mechanism was established. And the feature extraction and evaluation method for active acoustic emission signal was studied. Subsequently, a reconstruction method of damage status vector by using training sample fusion algorithm was introduced. Experiments were conducted in icing environment. Firstly, the impact of messenger wire galloping on identification performance was studied and found such influence can be ignored. In experiment of damage type recognition, the experimental results show that the proposed approach can identify different types of damages well. And compared with the cluster learning algorithm, the correct rate of recognition increased by 5% when training samples fusion method was adopted. This proposed approach demonstrates a strong anti-noise-interference ability, and it can provide a theoretical basis for the separation of stress wave modals in subsequent messenger wire structural damage monitoring imaging.

A new scene analysis method of reactor thermal explosion accident based on process simulation and CFD method is proposed. The thermal runaway of batch reactor with methanol and acetic anhydride is simulated by Aspen Plus. The molecular weight and component concentration of steam after explosion overpressure are studied. The vapor cloud explosion is simulated by Fluent. The propagation law of vapor cloud explosion pressure wave and flame front is analyzed based on the simulation results.

In this work, we investigate the secrecy energy efficiency (SEE) optimization problem for a multiple-input single-output (MISO) cognitive radio (CR) network based on a practical nonlinear energy-harvesting (EH) model. In particular, the energy receiver (ER) is assumed to be a potential eavesdropper due to the open architecture of a CR network with simultaneous wireless information and power transfer (SWIPT), such that the confidential message is prone to be intercepted in wireless communications. The aim of this work is to provide a secure transmit beamforming design while satisfying the minimum secrecy rate target, the minimum EH requirement, and the maximum interference leakage power to primary user (PU). In addition, we consider that all the channel state information (CSI) is perfectly known at the secondary transmitter (ST). We formulate this beamforming design as a SEE maximization problem; however, the original optimization problem is not convex due to the nonlinear fractional objective function. To solve it, a novel iterative algorithm is proposed to obtain the globally optimal solution of the primal problem by using the nonlinear fractional programming and sequential programming. Finally, numerical simulation results are presented to validate the performance of the proposed scheme.

Finding a new, sustainable and scalable approach to fabricate high-performance, durable triboelectric nanogenerators (TENGs) is an ongoing pursuit. In this study, surface-constrained supercritical carbon dioxide (scCO2) foaming was employed to produce skinless porous thermoplastic polyurethane (TPU) film as a novel tribopositive friction material. The skinless porous structure contributed to 340% and 460% enhancement in the output voltage and current, respectively. The performance was further enhanced by over 40% when the concave structured porous TPU film was paired with convex structured polydimethylsiloxane (PDMS) film by constructing a complementary contact state. With an output voltage of 260 V and a current of 46 μA, the optimized TENG achieved a high power density of 4.6 W/m2 on a 3.3 × 106 Ω external load, and displayed the ability to light LEDs, charge capacitors, and power small electronics. The superb flexibility and robustness of TPU and PDMS rendered the flexible TENG excellent stability and durability, as well as the capability to serve as a versatile self-powered sensor that can detect the impact force, various deformations, and monitor human walking behaviours. This work provides an efficient and scalable green approach to produce triboelectric porous films for high-performance TENGs and provides insights into the rational design of friction layers with complementary shapes to boost the energy output.

Van der Waals (vdW) heterostructures are ordinarily employed to furnish more possibilities for two-dimensional (2D) semiconductor materials. In this work, we explore thoroughly the electronic and optical properties of AlN/C2N heterostructure based on first-principles. The results reveal that the heterostructure with an indirect bandgap is a semiconductor material that is stable in energy and made by vdW interaction. The AlN/C2N heterostructure has type-II band alignment that can availably facilitate the segregation of photogenerated carriers and prolong the longevity of the carriers, and the built-in electric field (Eint ) formed inside the heterostructure can further encourage them. The band edge position crossing the water-splitting redox potential states that the heterostructure can serve to water-splitting catalytic process, while water oxidation and reduction reactions befell in the AlN layer and the C 2 N layer, respectively. Moreover, the heterostructure has higher carrier mobility and stronger light absorption capacity in the near-ultraviolet and visible light regions compared to two monolayers. It is worth noting that the light absorption of the heterostructure has redshift under compressive biaxial strain. The work demonstrates that the 2D AlN/C 2N heterostructure has the compelling potential to be used as an efficient water-splitting photocatalyst and used for other optical devices.

The photocatalytic efficiency of monolayer materials can be greatly improved by constructing two-dimensional van der Waals heterostructures. In this work, the electronic properties and photocatalytic mechanism of the MoTe2/BAs heterostructure with a stable structure are explored via the density functional theory. According to our results, the heterostructure, with a direct band gap value of 0.70 eV, has an intrinsic type-II band alignment that provides indispensable conditions for photocatalytic applications. The built-in electric field formed at the interface accelerates the reorganization of photogenerated holes in MoTe2 and photogenerated electrons in BAs, which results in the photogenerated electrons and holes in the heterostructure accumulate in CB of MoTe2 and VB of BAs, respectively. The spatial separation of photoexcited electrons and holes prolongs the lifespan of carriers and enhances the photocatalytic efficiency of the MoTe2/BAs heterostructure. Besides, these results demonstrate that the heterostructure possesses higher carrier mobility and a higher light absorption coefficient than two monolayers. The MoTe2/BAs heterostructure also has a remarkable solar-to-hydrogen efficiency. These distinguishing features confirm the truth that the MoTe2/BAs heterostructure has promising prospects in the sphere of photocatalysis for water splitting.

Objective: To explore biological mechanisms underlying the traditional Chinese medicine theory of “lung governing the regulation of water passage” by observing effects of mechanical ventilation on urine volume and related bioactive substances. Methods: A total of 16 male rabbits were randomly divided into control and lung expansion model groups (n = 8 per group), which were examined during the following four respiratory intervention stages (10 minutes each): (1) free breathing without any respiratory intervention; (2) lung expansion induced by mechanical ventilator; (3) free breathing without ventilator intervention; (4) cutting of bilateral sympathetic, vagus, and depressor nerves with mechanical ventilation. Data for breathing rate, blood pressure, and urine drops were recorded with a Medlab data acquisition system. Levels of nitric oxide (NO), antidiuretic hormone (ADH), endothelin 1 (ET-1), angiotensin II (AngII), prostaglandin E2 (PGE2), and atrial natriuretic peptide (ANP) were detected in lung tissue, kidney tissue, and serum by enzyme-linked immunosorbent assay. Protein expression of aquaporins 1 and 2 (AQP1 and AQP2) was detected in kidney tissue by immunohistochemistry, while Aqp1 mRNA and Aqp2 mRNA levels in kidney tissue were detected by real-time quantitative polymerase chain reaction. Histopathological changes in lung and kidney tissues were examined by hematoxylin and eosin staining. Results: Compared with the control group, number of urine drops during the second and fourth stages is significantly decreased in the model group (P

Background: Standardized training of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS- TBNA) is available only in highly developed countries. Objective: To compare the skill differences in the performance of EBUS-TBNA by pulmonologists trained under different learning methods. Methods: We performed a retrospective study of 145 EBUS-TBNA cases. We set up 3 comparative training groups: a standardized training group, a teaching group, and a self-study group. The main clinical outcomes were sensitivity, specificity and accuracy of EBUS-TBNA. Cumulative sum analysis was used to track EBUS-TBNA proficiency of the 3 groups. Results: The sensitivities of EBUS-TBNA in the different groups were 90, 88, and 67%, respectively. The accuracies of the different groups were 91, 90, and 71%, respectively. With respect to the sensitivity and accuracy, there was no significant difference between the standardized training group and teaching group. However, the self-study group was inferior to the other 2 groups. By comparing the learning curve among the groups, we found that the minimum number of operations needed to reach a 90% accuracy for the standardized training group, the teaching group and the self-study group was 17, 32 and 40 cases, respectively. Conclusion: Compared with the teaching and self-study groups, the standardized training group resulted in practitioners achieving high skill levels following the performance of a lower number of cases. Pulmonologists trained in the teaching group achieved a similar level of skills, but required more experience to reach this level. Practitioners in the self-study group did not achieve a satisfactory level of skills, despite performing a high number of cases.

In this letter, we investigate the outage-constrained robust secure design in a multiple-input single-output (MISO) energy harvesting (EH) cognitive radio network (CRN), where the malicious energy receivers (ERs) may wiretap the desired information and hence can be treated as potential eavesdroppers (Eves). In particular, considering a non-linear energy harvesting (EH) model, our objective is to design the transmit covariance matrix to maximize the secrecy energy efficiency (SEE) under the given outage probability and transmit power constraints, while satisfying the EH and quality-of-service (QoS) requirements. To tackle the original non-convex problem, we resort to semi-definite relaxation (SDR) and Bernstein-type inequality (BTI)-based approximations to reformulate it into a tractable form. Then, the original problem becomes decomposable and can be efficiently solved by handling a two-stage optimization problem. At last, numerical results are provided to demonstrate the effectiveness and superior performance of the proposed design in comparison with the existing schemes.

Background: Previous clinical studies reported low molecular weight heparin (LMWH) monotherpay has been utilized for the treatment of recurrent abortion (RCA) with antiphospholipid system (APS). However, its efficacy is still inconclusive. This systematic review aims to assess its efficacy and safety for patients with RCA and APS. Methods: A systematic literature search for article up to February 2019 will be conducted in 9 databases: Cochrane Library, EMBASE, MEDILINE, Cumulative Index to Nursing and Allied Health Literature, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, VIP Information, and Wanfang Data. Inclusion criteria are randomized control trials of LMWH monotherpay for patients with RCA and APS. The Cochrane risk of bias tool will be used to evaluate the methodological quality for each qualified study. The summary results will be showed by using fixed-effects and random-effects models for pooling the data based on the heterogeneity of included studies. Results: This systematic review will assess the clinical efficacy and safety of LMWH monotherpay in treating RCA with APS. The primary outcome is pregnancy loss. The secondary outcomes include frequency of preterm delivery, live birth rates, maternal and fetal complications, as well as adverse events. Conclusion: The findings of this study will summarize the present evidence to judge whether LMWH monotherpay is an effective therapy for patients with RCA and APS. Dissemination and ethics: The findings of this study will be published by through peer-reviewed journals. This study does not needs ethic documents, because it will not analyze individual patient data. Systematic review registration: PROSPERO CRD42019121064.

In order to improve the secure transmission performance of polarization-based satellite communications, an anti-interception communication method based on double-layer multi-parameter weighted-type fractional Fourier transform (DL-MPWFRFT) is proposed. In proposed scheme, DL-MPWFRFT is applied to the two orthogonal polarization amplitude-phase joint modulation signals, and then signals are uploaded to the wireless channel by utilizing digital-to-analog conversion (DAC) and radio frequency (RF) processing. The simulation results show that our proposed scheme makes the constellation of the transmitted signal rotate and diffuse, which improves the anti-scanning ability and the anti-interception ability of the system.

This work studies a beamforming design for down-link transmission of a multi-user multiple-input single-output (MISO) system where each legitimate user employs a power splitting (PS) based simultaneous wireless information and power transfer (SWIPT) technique. The transmitter intends to send confidential information to its legitimate users in the presence of purely unknown eavesdroppers. Since the transmitter does not have any knowledge of the eavesdroppers' channel state information (CSI), we consider an artificial noise (AN) approach to establishing secure communication. This beamforming design is developed by maximizing the AN power to interfere with the eavesdropper as much as possible. Based on the assumption of imperfect CSI of legitimate users at the transmitter, two robust design approaches for the joint beamforming and PS ratio have been studied to maximize the AN power under both energy harvesting (EH) and signal-to-interference-plus-noise ratio (SINR) requirements at each legitimate user. In the first robust design, we consider the bounded channel uncertainties, and employ semidefinite relaxation (SDR) and a linear matrix inequality (LMI) representation to transform the original problem into a semidefinite program (SDP). In the second robust design, we consider the statistical channel uncertainties, and show that the proposed problem can be reformulated into another form of SDP through both SDR and Bernstein-type inequality. In addition, the non-linear energy harvesting (EH) model is incorporated in this work as it could reflect the characteristics of practical radio frequency(RF)-EH conversion circuit. Simulation results have been provided to demonstrate the performance of our proposed robust designs.

To construct a preeminent photoelectric appliance, effective carrier separation is the critical question. In this study, a novel inherent staggered type-II van der Waals (vdW) heterostructure composed of zinc oxide (ZnO) and boron phosphide (BP) is designed with being simulated by a first-principle calculation. In the heterostructure, electrons and holes are localized in the monolayer of BP and ZnO respectively. That leads to the separation of photoinduced electron-hole pairs. Furthermore, it shows a prominent absorption coefficient of 104 cm−1 from the ultraviolet to infrared region. Interestingly, the band edges can be regulated and changed to a direct band gap at K point when applying an external electric field donating further separation of carriers. Besides, the heterostructure displays a robust type-II band alignment under −2% ~ +2% strain. These results suggest that two-dimensional (2D) ZnO/BP heterostructure will exhibit widespread application prospects in future photovoltaic and optoelectronic nanodevices.

// Dongdong Tong 1, 2 , Lingyu Zhao 1, 2 , Kang He 1, 2, 3 , Hongfei Sun 1, 2 , Donghui Cai 1, 2 , Lei Ni 1 , Ruifang Sun 4 , Su’e Chang 5 , Tusheng Song 1, 2 , Chen Huang 1, 2 1 Department of Cell Biology and Genetics, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Shaanxi, P. R. China 2 Key Laboratory of Environment and Genes Related to Diseases, Xi’an Jiaotong University, Ministry of Education of China, Shaanxi, P. R. China 3 Department of Periodontology, Stomatology Hospital of Xi’an Jiaotong University College of Medicine, Xi’an, Shaanxi, P. R. China 4 Department of pathology, College of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi, P. R. China 5 Department of Orthopaedics, the Second Affiliated Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi, P. R. China Correspondence to: Chen Huang, email: hchen@mail.xjtu.edu.cn Keywords: gastric cancer, MECP2, miR-338, BMI1, proliferation Received: October 19, 2015 Accepted: March 31, 2016 Published: May 06, 2016 ABSTRACT The methyl-CpG-binding protein 2 (MECP2), a transcriptional suppressor, is involved in gene regulation by binding to methylated promoters. We found that MECP2 is overexpressed in gastric cancer (GC), and that Mecp2 knockdown affects the growth of GC cells both in vitro and in vivo . MECP2 can directly bind to the methylated-CpG island of miR-338 promoter and suppress the expression of two mature microRNAs, namely, miR-338-3p and miR-338-5p. Furthermore, miR-338-5p can suppress GC cell growth by targeting BMI1 (B lymphoma Mo-MLV insertion region 1 homolog). We additionally found that decreased miR-338-5p expression in GC tissues, relative to normal tissues, was significantly negatively correlated with increased BMI1 expression. Silencing MECP2 can indirectly lead to reduced expression of P-REX2, which has been identified as the miR-338-3p target, as well as BMI1 and increasing expression of P16 or P21 both in vitro and in vivo . Altogether, our results indicate that MECP2 promote the proliferation of GC cells via miR-338 (miR-338-3p and miR-338-5p)-mediated antitumor and gene regulatory effect.

This paper explores the use of Model Predictive Control (MPC) techniques to solve vehicle lateral motion control problem on highway scenarios. In particular, the problem of autonomously driving a vehicle along a desired path is formulated, where safety constraints and performance levels must be guaranteed for all possible road curvatures within a con [pact set. Safety constraints are translated into a maximum lateral deviation and orientation error w.r.t. a desired path, while performance requirements are formulated in terms of bounded lateral acceleration and velocity. Preliminary simulation results ahoy that the designed controller is capable of delivering acceptable performance at the cost of limited online computational costs. (C) 2016, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.