bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the Power Grid Automation System Architecture Based on Distributed Scheduling
Authors: Zheng Xiangyu
Published: December 2021

As the core content of urban power dispatching operation in the new era, power grid automation can ensure the safety and stability of urban power consumption on the basis of reducing resource consumption. Using the distributed scheduling method in the system can not only improve the quality of power transmission, but also improve the speed of system operation. Therefore, on the basis of understanding the distributed task scheduling method, this paper analyzes the independent task dynamic optimization level scheduling algorithm based on MPSoC, and carries on the in-depth understanding of the practical application effect, so as to prove the positive role of distributed scheduling in the application of power grid automation system.
Vibration Analysis of Civil Engineering Structure Based on Fuzzy Control Algorithm
Authors: Hua Qianqian
Published: December 2021

In the continuous development of China’s industrialization process, urban industrial land is more and more tight, the distance between planning roads or rail transit and buildings is getting closer and closer, and the vibration propagation caused by the load of the ground or underground rail transit is easy to cause the surrounding buildings to vibrate, so as to affect the normal life of urban residents. Therefore, during the design and construction of modern building engineering, in order to fully understand the impact of traffic load on the structure of building vibration, it is necessary to use effective methods to predict the vibration phenomenon caused by various reasons, and thus to conduct in-depth discussion on the overall structure design. On the basis of understanding the traditional vibration analysis method, this paper uses the fuzzy control algorithm to study the influence of single source or compound source fuzzy number on the structure vibration, and carries on the empirical analysis accordingly.
Research and Design on the Coordinate Control System of Once-through Boiler Power Unit
Authors: Qin Zhiming , Cui Hongwei
Published: December 2021

Taking the 1000 MW ultra supercritical unit as an object of study, The nonlinear model is builded through mechanism analysis, which is linearized based on small error, the multi-variable decoupling controller is designed to achieve full decoupling of the input and output variables, and finally the three-input-three-output coordinated control system (CCS) is established. The control system is verified by coal quality and the specific enthalpy of feed water disturbance when load changing, the simulation result shows that the improved CCS has good control performance.
Design and Research of High Precision Dynamic Torque Measurement System
Authors: Su Yang , Cheng Lei , Wang Lifang
Published: December 2021

In this paper, through the FPGA technology and torque measurement system design method for analysis and research, through the use of photoelectric coding circurling measurement function and the difference between the multi-channel code disk torque measurement. In this paper, the characteristics and state of the output signal of the multi-channel code tray are classified, and the principle of torque measurement is analyzed and studied. In this paper, the logic control, data statistics, latch and other contents involved in hardware FPGA technology are analyzed and studied, so as to effectively simplify the system circuit. When the counting data, status signal and other contents are uploaded to the master computer for processing, it is convenient to monitor the vibration of torque signal in real time. By using the upper computer part of the virtual instrument to receive the relevant data of the microcontroller, so as to store, call and process the data, it not only improves the intelligence of the system, but also reduces the use cost of hardware resources.
Analysis of Total Hydrocarbon Exceeding Standard in Oil Chromatogram of a 500kV Main Transformer
Authors: Wang Linan , Ma Yunfei , Han Jinhua , Zheng Yusheng , Zhang Xiaopeng , Guo Xiaofeng , Zheng Hanbo , Shao Guangqi
Published: December 2021

Oil chromatographic analysis is widely used in transformer fault diagnosis However, the problem of excessive total hydrocarbons in the oil chromatogram caused by the failure of the transformer submersible pump is different from the failure of the transformer body. Technicians need to be able to accurately identify these two types of failure. For this problem, this article proposes a method of judging by manually starting and stopping the submersible pump and monitoring the change law of the transformer chromatographic data. This article first finds out suspicious submersible pumps through current data. Subsequently, the operator starts and stops the submersible pump and monitors the change law of the transformer chromatographic data. From this, the correlation between the start or stop of the submersible pump and the chromatographic data was found. Finally, the effectiveness of this method is verified by the submersible pump disassembly inspection and simulated live test.
Substation Secondary Cable Path Optimization Design Based on 3D Simulation and Improved Dijkstra Algorithm
Authors: Li Shengqing , Zhang Yi , Ling Zhiyong , Zhang Xiaobing
Published: December 2021

In order to accurately predict the length of secondary cable laying in substation construction project and avoid the problem of resource waste in engineering construction, a secondary cable path optimization model based on 3D simulation and Dijkstra algorithm was established. Firstly, through the application of Bentley software, the three-dimensional model of substation is established, and the workflow of BRCM cable laying software is introduced. Secondly, the common and the improved Dijkstra algorithm are used to carry out the path planning on the raster map respectively, and the experimental simulation is carried out. Finally, the simulation results show that the path length of the improved algorithm is 24.32% and 28.66% less than that of the traditional Dijkstra. It is 12.34% less than that of the ant colony algorithm, which provides some useful theoretical references for the secondary cable laying in the future substations.
A Photo-Voltaic Invert-er Cluster Resonance Suppression Method Based on Capacitor Voltage Feed-Forward
Authors: Li Shengqing , Yao Xin , Peng Ziran , Shen Zhichao
Published: December 2021

Photo-voltaic inverts usually use LCL filter for filtering, and LCL filter will bring resonance problems to the system. This paper focuses on invert-er side current feedback control (invert-er side current feedback, ICF). This paper proposes a method for suppressing resonance of photo-voltaic invert-er clusters based on capacitor voltage feed-forward. First, establish the ICF mathematical model based on HPF and CVF under the weak grid, qualitatively analyze the resonance mechanism of the cluster invert-er, then analyze the system control structure and stability according to the proposed method, and finally verify the effectiveness of the proposed method through simulation and experiment sexuality and correctness.
Control Strategy of Photovoltaic Grid Connected System Based on PI and QPR Double Closed Loop Control
Authors: Li Shengqing , Deng Na , Zheng Jian , Yu Jiaxing
Published: December 2021

The traditional proportional integral (PI) controller in photovoltaic three-phase inverter system has the problems of no static error tracking and poor resonance suppression effect. In order to improve the resonance suppression effect and current control effect of photovoltaic three-phase inverter system, a control strategy of photovoltaic three-phase inverter system based on PI and quasi proportional resonance (QPR) double closed-loop control is proposed. The control strategy and control block diagram based on PI and QPR double closed-loop control are designed to realize no static error tracking of incoming current, which has better waveform of incoming current and resonance suppression effect, and improves system stability. Finally, the effectiveness of the control strategy are verified by simulation.
Subway Traction Power Supply System Based on PWM Rectifier
Authors: Liu Xudong
Published: December 2021

At present, PWM rectifier is widely used in various high power and high voltage situations because of its high energy, low harmonic content, constant voltage and bidirectional energy. The energy supply system of subway traction power supply system based on PWM rectifier shows the topology of a dual transformer with three winding transformers and four PWM rectifiers in parallel, which is superior to the modular model. Finally, the correctness of the control strategy is verified by Matlab/Initial simulation.
Experimental Study on Voltage Sag Tolerance of LED Electronic Display
Authors: Song Yidan , Guan Shangshu , Yao Haijiang , Tao Shun
Published: December 2021

Widely used LED electronic displays have high requirements for power quality. Because of the status quo of LED technology update and the lack of related experimental work, this paper first analyzes the hardware composition of LED electronic display and switching power supply module. In addition, the paper points out that the transient tolerance of LED screens is mainly determined by switching power supply modules. Then, a test platform was built, and a certain type of LED screen was selected to investigate the influence of voltage temporary drop value and duration, phase jump, and initial Angle of temporary drop on the tolerance of LED electronic display. It provides data support for evaluating and managing the effects of voltage sags on LED electronic displays and the design of power supply schemes.
Comparative Study on Characteristics of Partial Discharge Optical Pulse and UHF Pulse in Switch Equipment
Authors: Chen Ping , Miao Jin , Gu Yin , Huang Fen , Zhou Xinyang , Leng Zhaoyun , Wan Jiefeng , Li Chen
Published: December 2021

The article explores the performance of the new silicon photoelectric sensor in partial discharge detection, and compares the measured optical pulse with the traditional UHF pulse. Through optical and electrical synchronous partial discharge experiments, the article analyzes and discusses the detection performance, working characteristics and statistical characteristics of various sensors, and explores the advantages and feasibility of silicon photoelectric partial discharge sensors in actual discharge monitoring; In addition, the statistical performance of the two physical phenomena of partial light radiation and electromagnetic radiation was obtained through the analysis of optical and electrical synchronous monitoring data. Compared with UHF sensor, silicon photoelectric sensor under the optimal working voltage has a higher signal-to-noise ratio (SNR); Under the electromagnetic interference of the high-frequency motor, silicon photoelectric sensor exhibits better anti-electromagnetic interference ability; Discharge phase interval and characteristics reflected by the PRPD obtained by two detection methods maintain good consistency; Pulse repetition rate has the same trend with applied voltage, but statistical frequency of optical pulses obtained is higher than that of electromagnetic pulses because silicon photoelectric sensor has a higher SNR and single-photon sensitivity.
Control Strategy Research of Based on Resonance Feedforward and Current Estimate of the Photovoltaic Grid Inverter
Authors: Li Shengqing , Jiang Yu , Luo Zhaoxu
Published: December 2021

Due to poor quality of grid-connected current and large impedance value of grid are caused in weak grid environment. Therefore, a control strategy combining multiple resonant feedforward and current estimation method is adopted in this paper. Firstly, in order to make the positive feedback channel have the feedback effect only at the main background harmonics, the low-order harmonics of the grid are extracted by using the method of multi-resonance feedforward control. At the same time, under the premise that the suppression effect of LCL natural resonant frequency remains unchanged, the current estimation method is added into the control strategy, so as to reduce the system cost. Finally, the simulation results show that thus verifying the correctness and effectiveness of the control strategy.
Intelligent Fault Diagnosis of Photoelectric Pod Bearing Based on Multi-information Fusion
Authors: Wang Chaoyu , Liu Zhi , Wang Yakun
Published: December 2021

Intelligent fault diagnosis technology has become the focus of research in various fields. Its realization depends on the acquisition of equipment state by sensors. Because the fault information provided by a single sensor has limitations and cannot fully reflect the fault state of the tested object, we need to use multiple sensors to collect and fuse the fault information of rolling bearings to ensure the accuracy and accuracy of intelligent fault diagnosis. Based on this, this paper analyzes the application of fuzzy rules of multi-sensor information fusion technology in the fault diagnosis of bearings in the optoelectronic pod, so as to provide a reference for the realization of intelligent fault diagnosis of each structure in the optoelectronic pod.
A Review of Routing Algorithms Based on Multi-Layer Satellite Networks
Authors: Zhang Xialu , Hu Xiaoxi , Xie Tianjiao
Published: December 2021

Compared with single layer satellite network, satellite distribution of multi-layer satellite networks in the double layer or multilayer orbital plane, combines all the advantages of engaging subjects of the satellite, therefore contains its low vulnerability, good robustness, high stability, high spectrum efficiency and system throughput, channel characteristics such as large capacity, in the satellite network is a very promising direction. Multilayer satellite network also has some inevitable disadvantages, that is, the number of nodes and the number of links is large, so it has the characteristics of frequent changes in network topology, which requires higher routing algorithm. There are many researches on routing algorithms based on multi-layer satellite networks at home and abroad. This paper introduces the general situation of multi-layer satellite network, classifies the existing routing algorithms of multi-layer satellite network according to different standards, analyzes several typical routing algorithms in detail, points out the advantages and disadvantages, and summarizes the future development trend.
RETRACTED: Research on the Communication Transformation and Its Risk Prevention Method in the Background of Big Data
Authors: Zhu Haoyang
Published: December 2021

The communication based on big data technology is an organized communication form built with data and algorithms as the core, which has a very serious risk of liquefaction in the practical development. Therefore, based on the understanding of the transformation of communication ontology and the uncertainty of the subject under the background of big data technology, this paper studies and analyzes the risk prevention countermeasures based on streaming big data analysis according to the alienated risks it presents.
Research on Reactive Power Optimization of Power System Based on Improved Particle Swarm Algorith
Authors: Li Kang , Gao Guige
Published: December 2021

Artificial intelligence algorithms are widely used to optimize problems in power systems, and reactive power optimization in power systems has achieved good results in particle swarm optimization, but there are also problems. This paper optimizes the particle swarm algorithm. The particle swarm algorithm is improved mainly by increasing the inertia weight and improving the convergence parameters. This algorithm overcomes the blindness of local optimization solution and particle swarm algorithm, and improves the calculation speed. At the same time, MATLAB is used to compile the calculation program, and the simulation results are used to verify the feasibility of the reactive power optimization algorithm used in the research of power system.
Design of Robot Vision Servo Control System Based on Image
Authors: Xing Guansheng , Meng Weichuan
Published: December 2021

Visual servo is a closed-loop control system of robot, which takes the image information obtained by visual sensor as feedback. Generally speaking, visual servo plays an important role in robot control, which is one of the main research directions in the field of robot control and plays a decisive role in the development of intelligent robots. In order to make the robot competent for more complex tasks and work more intelligently, autonomously and reliably, it is necessary not only to improve the control system of the robot, but also to obtain more and better information about the working environment of the robot. This paper introduces the principle and basic realization method of robot visual servo based on image, and expounds the problems and solutions in image feature extraction and visual servo controller design. In order to further expand the application field of robots and improve the operation performance of robots, robots must have higher intelligence level and stronger adaptability to the environment, so as to manufacture intelligent robots that can replace human labor.
Intelligent Cabinet Lock Control System Based on Cloud Technology
Authors: Lin Lizong , Du Sunhui , Ouyang Baibing , Yan Mi
Published: December 2021

With the rapid development of wireless communication and Internet of things, intelligent products have been widely used in living and industrial places. The purpose of this paper is to develop an intelligent controller and intelligent lock cabinet for the monitoring of optical cable handover box. It can monitor the temperature, humidity, fire, flood, vibration and the identity of the personnel in and out of the optical cable box, and send the data information to the management server through wireless communication, so as to realize the purpose of monitoring and management of the optical cable box. The products under development include intelligent controllers, smart keys and electronic locks. The smart key is used in conjunction with the electronic lock.
Research on Visual Awareness Interface Design Based on Human-Computer Interaction Task
Authors: Wu Zhengxin , Jin Tao
Published: December 2021

By using the form and specific process of human-computer interaction to comprehensively understand and judge whether users can accurately and quickly recognize products, it has a positive effect on the current visual and perceptual interface design work. On the basis of understanding the achievements of current related scientific research projects, this paper analyzes how to construct and design a new visual and perceptual interface based on human-computer interaction tasks by studying the main factors that affect users’ cognition of visual information interface.
Research on the Construction of Big Data Classification System Based on Distributed Data Flow
Authors: Zhou Han
Published: December 2021

In the context of the comprehensive popularization of network technical services and database construction system, more and more data are used by enterprises or individuals. It is difficult for the existing technology to meet the technical analysis requirements of the development of the era of big data. Therefore, in the development of practice, we should continue to explore new technologies and methods to reasonably use big data. Therefore, on the basis of understanding the current big data technology and its system operation status, this paper designs relevant algorithms according to the big data classification model, and verifies the effectiveness of the analysis model algorithm based on practice.
Research on Decision Model of Emergency Material Distribution Based on Random Information
Authors: Liu Chen
Published: December 2021

As an important link of emergency logistics, emergency material distribution has been widely concerned and applied in the development of today’s society. From the consideration of the fairness and efficiency of material distribution, there is a kind of negative and negative relationship between them. As a lever, information updating can be used to solve the problems of fairness and efficiency in the distribution of emergency supplies. Based on fuzzy objective programming, the classification decision model of emergency materials is discussed in this paper.
Design, analysis, and validation of an orderly recruitment valve for bio-inspired fluidic artificial muscles
Authors: Vemula Dheeraj , Kim Jeong Yong , Mazzoleni Nicholas , Bryant Matthew
Published: December 2021

Biological musculature employs variable recruitment of muscle fibers from smaller to larger units as the load increases. This orderly recruitment strategy has certain physiological advantages like minimizing fatigue and providing finer motor control. Recently fluidic artificial muscles (FAM) are gaining popularity as actuators due to their increased efficiency by employing bio-inspired recruitment strategies such as active variable recruitment (AVR). AVR systems use a multi-valve system (MVS) configuration to selectively recruit individual FAMs depending on the load. However, when using an MVS configuration, an increase in the number of motor units in a bundle corresponds to an increase in the number of valves in the system. This introduces greater complexity and weight. The objective of this paper is to propose, analyze, and demonstrate an orderly recruitment valve (ORV) concept that enables orderly recruitment of multiple FAMs in the system using a single valve. A mathematical model of an ORV-controlled FAM bundle is presented and validated by experiments performed on a proof-of-concept ORV experiment. The modeling is extended to explore a case study of a 1-DOF robot arm system consisting of an electrohydraulic pressurization system, ORV, and a FAM-actuated rotating arm plant and its dynamics are simulated to further demonstrate the capabilities of an ORV-controlled closed-loop system. An orderly recruitment strategy was implemented through a model-based feed forward controller. To benchmark the performance of the ORV, a conventional MVS with equivalent dynamics and controller was also implemented. Trajectory tracking simulations on both the systems revealed lower tracking error for the ORV controlled system compared to the MVS controlled system due to the unique cross-flow effects present in the ORV. However, the MVS, due to its independent and multiple valve setup, proved to be more adaptable for performance. For example, modifications to the recruitment thresholds of the MVS demonstrated improvement in tracking error, albeit with a sacrifice in efficiency. In the ORV, tracking performance remained insensitive to any variation in recruitment threshold. The results show that compared to the MVS, the ORV offers a simpler and more compact valving architecture at the expense of moderate losses in control flexibility and performance.
Universal quantum computation via quantum controlled classical operations
Authors: Horvat Sebastian , Gao Xiaoqin , Dakić Borivoje
Published: December 2021

A universal set of gates for (classical or quantum) computation is a set of gates that can be used to approximate any other operation. It is well known that a universal set for classical computation augmented with the Hadamard gate results in universal quantum computing. Motivated by the latter, we pose the following question: can one perform universal quantum computation by supplementing a set of classical gates with a quantum control, and a set of quantum gates operating solely on the latter? In this work we provide an affirmative answer to this question by considering a computational model that consists of 2n target bits together with a set of classical gates controlled by log (2n + 1) ancillary qubits. We show that this model is equivalent to a quantum computer operating on n qubits. Furthermore, we show that even a primitive computer that is capable of implementing only SWAP gates, can be lifted to universal quantum computing, if aided with an appropriate quantum control of logarithmic size. Our results thus exemplify the information processing power brought forth by the quantum control system.
Mechanical and microstructural characterization of Ti-SiC reinforced AA5083 surface composites fabricated via friction stir process
Authors: Rahman Md Ziyaur , Khan Zahid A , Siddiquee Arshad Noor , Abidi Mustufa Haider , Aboudaif Mohamed K , Al-Ahmari Abdulrahman
Published: December 2021

A mixture of Titanium and silicon-carbide powders was embedded in the AA5083 matrix by Friction Stir Processing (FSP). Experiments were performed as per Taguchi L8 orthogonal array, and the effect of reinforcement on hot strength (at 100 °C), processed zone (PZ) geometry, and microstructure were investigated. The effect of PZ geometry on the surface properties was also analyzed. The effect of heating the tensile test specimens to 540 °C on the strength at 100 °C was also separately investigated. It was observed that surface hardness was significantly enhanced by FSP, and the highest mean hardness of 90.4 HV was observed. Furthermore, it was observed that the surface properties also significantly depend on PZ geometry. From experimental results, it was found that the specimens with the lowest width to depth ratio bears the highest hardness and vice versa. A clear effect of parameters was evident on the geometry of processed zones with a deep bowl, and shallow cup-shaped zones were formed with smaller and larger shoulder diameters, respectively. The samples were processed at 355 rpm, 63 mm min−1, 17 mm shoulder, and 355 rpm, 80 mm min−1. The 20 mm shoulder showed high tensile strength 292 MPa and 294 Mpa, respectively. The strength of these samples did not reduce much even after heating to 540 °C.
Evaluation of TG202 inhibitor for tubing steels in 15% hydrochloric acid by electrochemical noise technology
Authors: Zhao Mifeng , Zhang Juantao , Hu Fangting , Fu Anqing , Wang Kelin , Yin Chengxian , Yuan Juntao , Fan Lei
Published: December 2021

Acid fracturing is an effective technology for increasing oil and gas production. However, the acid will cause serious corrosion to the tubing. In this paper, the inhibition performance of the TG202 inhibitor for acidizing of high temperature and high-pressure gas wells on N80 carbon steel and 13Cr martensitic stainless-steel tubing in 15% hydrochloric acid was studied by electrochemical noise technology. The results showed that with the increase of TG202 inhibitor content, the noise resistance increased and the corrosion rate of tubing steel decreased. Under the same condition, the order of corrosion rate of tubing steels: 13Cr > HP-13Cr > N80 > P110. The pitting corrosion of HP-13Cr and 13Cr is significant. The research showed that the TG202 inhibitor had a protective effect on tubing during acidizing. The inhibition mechanism of the TG202 inhibitor was discussed.
Elastic behavior, pressure-induced doping and superconducting transition temperature of GdBa2Cu3O7−x
Authors: Agora Jared O , Otieno Calford , Nyawere Philip W O , Manyali George S
Published: December 2021

Doping superconductors are known to vary the superconducting transition temperature

T

C

depending on the degree of holes or electrons introduced in a system. In this study, we report how pressure-induced hole doping influences the

T

C

of GdBa2Cu3O7−x superconducting perovskite. The study was carried out in the framework of density functional theory (DFT) using the Quantum espresso code. Ultrasoft pseudopotential with generalized gradient approximation (GGA) functional was used to calculate the ground state energy using the plane waves (PW). The stability criterion was satisfied from the calculated elastic constants. The BCS theory and the Mc Millan’s equation was used to calculate the

T

C

of the material at different conditions of pressure. The underdoped regime where the holes were less than those at optimal doping was found to be below 20 GPa of doping pressure. Optimal doping where the material achieved the highest

T

C

(max) ∼ 20 GPa of the doping pressure. Beyond the pressure of ∼20 GPa was the over doping regime where a decrease in

T

C

was recorded. The highest calculated

T

C

(max) was ∼141.16 K. The results suggest that pressure of ∼20 GPa gave rise to the highest

T

C

in the study.
Two-dimensional molybdenum disulfide artificial synapse with high sensitivity
Authors: Huang Hao , Liu Lu , Jiang Chengpeng , Gong Jiangdong , Ni Yao , Xu Zhipeng , Wei Huanhuan , Yu Haiyang , Xu Wentao
Published: December 2021

This paper reports the fabrication of an artificial synapse (AS) based on two-dimensional molybdenum disulfide (MoS2) film. The AS emulates important synaptic functions such as paired-pulse facilitation, spike-rate dependent plasticity, spike-duration dependent plasticity and spike-number dependent plasticity. The spike voltage can mediate ion migration in the ion gel to regulate the conductance of MoS2 channel, thereby realizing the emulation of synaptic plasticity. More importantly, the AS stably exhibits high sensitivity in response to spike stimuli (100 mV) and low-energy consumption (∼33.5 fJ per spike). In addition, the device emulates some synaptic functions and realizes the synaptic expression of Morse code. The development of this device represents an important step toward constructing high-performance and multifunctional neuromorphic system.
Constructing discrete harmonic functions in wedges
Authors: Hoang Viet , Raschel Kilian , Tarrago Pierre
Published: December 2021

We propose a systematic construction of signed harmonic functions for discrete Laplacian operators with Dirichlet conditions in the quarter plane. In particular, we prove that the set of harmonic functions is an algebra generated by a single element, which conjecturally corresponds to the unique positive harmonic function.
A reproducibility analysis-based statistical framework for residue–residue evolutionary coupling detection
Authors: Si Yunda , Zhang Yi , Yan Chengfei
Published: December 2021

Direct coupling analysis (DCA) has been widely used to infer evolutionary coupled residue pairs from the multiple sequence alignment (MSA) of homologous sequences. However, effectively selecting residue pairs with significant evolutionary couplings according to the result of DCA is a non-trivial task. In this study, we developed a general statistical framework for significant evolutionary coupling detection, referred to as irreproducible discovery rate (IDR)-DCA, which is based on reproducibility analysis of the coupling scores obtained from DCA on manually created MSA replicates. IDR-DCA was applied to select residue pairs for contact prediction for monomeric proteins, protein–protein interactions and monomeric RNAs, in which three different versions of DCA were applied. We demonstrated that with the application of IDR-DCA, the residue pairs selected using a universal threshold always yielded stable performance for contact prediction. Comparing with the application of carefully tuned coupling score cutoffs, IDR-DCA always showed better performance. The robustness of IDR-DCA was also supported through the MSA downsampling analysis. We further demonstrated the effectiveness of applying constraints obtained from residue pairs selected by IDR-DCA to assist RNA secondary structure prediction.
Prophylactic retrorectus mesh versus no mesh in midline emergency laparotomy closure for prevention of incisional hernia (PREEMER): study protocol for a multicentre, double-blinded, randomized controlled trial
Authors: Mäkäräinen Elisa , Tolonen Matti , Sallinen Ville , Mentula Panu , Leppäniemi Ari , Ahonen-Siirtola Mirella , Saarnio Juha , Ohtonen Pasi , Muysoms Filip , Rautio Tero
Published: December 2021

Background

Despite the fact that emergency midline laparotomy is a risk factor for an incisional hernia, active research on hernia prevention in emergency settings is lacking. Different kinds of meshes and mesh positions have been studied in elective abdominal surgery, but no randomized controlled trials in emergency settings have been published thus far.

Method

The PREEMER trial (registration number NCT04311788) is a multicentre, patient- and assessor-blinded, randomized controlled trial to be conducted in six hospitals in Finland. A total of 244 patients will be randomized at a 1 : 1 ratio to either the retrorectus mesh group, featuring a self-gripping prophylactic mesh, or to the no mesh (control) group, both closed by small-stitch 4 : 1 closure with continuous slowly absorbable monofilament suturing. The primary outcome of the PREEMER trial is the incidence of incisional hernia 2 years after surgery, which will be detected clinically and/or radiologically. Secondary outcomes are the Comprehensive Complication Index score, incidence of surgical-site infections and fascial dehiscence within 30 days of surgery; the incisional hernia repair rate and mesh- or hernia-related reoperations within the 2- and 5-year follow-ups; the incidence of incisional hernia within the 5-year follow-up; and quality of life measured by RAND-36, the Activities Assessment Scale and the PROMIS questionnaire within 30 days and 2 and 5 years from surgery. Additionally, health–economic explorative measures will be explored.

Conclusion

The PREEMER trial will provide level 1 evidence on incisional hernia prevention in an emergency setting.

Registration number

NCT04311788 (http://www.clinicaltrials.gov). Registered 7 March 2020.
Evolution of Monetary Policy in Peru: An Empirical Application Using a Mixture Innovation TVP-VAR-SV Model
Authors: Portilla Jhonatan , Rodríguez Gabriel , Castillo B. Paul
Published: December 2021

This article discusses the evolution of monetary policy (MP) in Peru in 1996Q1–2019Q4 using a mixture innovation time-varying parameter vector autoregressive (VAR) model with stochastic volatility (TVP-VAR-SV) as proposed by Koop, Leon-Gonzales and Strachan. The main empirical results are: (i) the VAR coefficients and volatilities change more gradually than the contemporaneous coefficients over time; (ii) the volatility of MP shocks was higher under the pre-Inflation Targeting (IT) regime; (iii) a surprise increase in the interest rate produces gross domestic product (GDP) growth falls and reduces inflation in the long run; (iv) the interest rate reacts more quickly to aggregate supply shocks than to aggregate demand shocks; (v) MP shocks explain a high percentage of domestic variables behavior under the pre-IT regime but their contribution decreases under the IT regime. Overall, these results show that MP has contributed in Peru to lower macroeconomic volatility by (i) reducing average long-term inflation, (ii) increasing the response of GDP growth rate to interest rate, and (iii) by becoming more predictable. (JEL codes: C11, C32, and E52).
The modularity of random graphs on the hyperbolic plane
Authors: Chellig Jordan , Fountoulakis Nikolaos , Skerman Fiona
Published: December 2021

Modularity is a quantity which has been introduced in the context of complex networks in order to quantify how close a network is to an ideal modular network in which the nodes form small interconnected communities that are joined together with relatively few edges. In this article, we consider this quantity on a probabilistic model of complex networks introduced by Krioukov et al. (2010, Phys. Rev. E, 82, 036106). This model views a complex network as an expression of hidden popularity hierarchies (i.e. nodes higher up in the hierarchies have more global reach), encapsulated by an underlying hyperbolic space. For certain parameters, this model was proved to have typical features that are observed in complex networks such as power law degree distribution, bounded average degree, clustering coefficient that is asymptotically bounded away from zero and ultra-small typical distances. In the present work, we investigate its modularity and we show that, in this regime, it converges to one in probability.
Legal: Use of Force in Self-Defence to Recover Occupied Territory
Authors: Akande Dapo , Tzanakopoulos Antonios
Published: December 2021

This article argues that, in certain circumstances, it is legal for a state to use force in self-defence in order to recover territory unlawfully occupied by another state as a result of an armed attack. Where occupation follows from an unlawful armed attack, the occupation is a continuing armed attack, and the attacked state does not lose its right to self-defence simply because of passage of time. It is argued that while it is trite law that territorial disputes cannot be resolved by recourse to force, it is important to draw the distinction between a territorial dispute, on the one hand, and a situation of armed attack resulting in occupation of territory, on the other. Furthermore, where years pass between the initial attack and the use of force in self-defence, that may suggest that there is no other reasonable means of bringing the armed attack and occupation to an end, rendering the use of force in self-defence the ultima ratio – which is precisely the point of the necessity requirement. On this view, time runs against, rather than in favour of, the aggressor.
Individualized dorsal basal segment (S10) resection using intersegmental veins as the landmark
Authors: He Zhicheng , Pan Xianglong , Li Zhihua , Wang Qi , Wang Jun , Wen Wei , Zhu Quan , Wu Weibing , Chen Liang
Published: December 2021

OBJECTIVES

The individualized thoracoscopic dorsal basal (S10) resection remains one of the most challenging procedures. Our goal was to detail the role of intersegmental veins (inter-SVs) in facilitating such a complex operation and evaluate its safety and efficacy.

METHODS

We retrospectively reviewed patients who underwent S10 or S10 plus an adjacent segment or subsegment resection (individualized S10) from January 2015 through September 2020. Individualized S10 resections were conducted for nodules of 2 cm or less with a ground-glass opacity evident in thin-slice computed tomography. A simplified method of using inter-SVs as the landmark in surgical planning and segmentectomy was described. The efficacy and safety of this technique were also evaluated in comparison with those aspects of the lower lobectomy.

RESULTS

In total, 46 patients who underwent individualized S10 through an inferior pulmonary ligament approach were included. All patients received R0 resection with a surgical margin of 22.45 mm. No patient was converted to an extended resection such as an entire basal or lower lobar resection. Three patients whose situation was complicated with an air leak had non-urgent interventions. Comparable results were obtained between the segmental and lobar arms in terms of blood loss (49.13 vs 45.98 ml), postoperative hospital stay (4.96 vs 5.18 days) and persistent air leak (6.52% vs 4.01%).

CONCLUSIONS

A strategy guided by the inter-SVs permits one to tailor the surgical planning for S10 nodules without compromising the surgical margin. It could also facilitate target bronchial recognition and intersegmental plane division. However, long-term follow-up and large clinical studies are needed to further justify its clinical benefits.
Valve-sparing aortic root replacement and aortic valve repair for a 2-year-old girl with Loeys–Dietz syndrome
Authors: Shiraishi Shuichi , Okita Yutaka , Watanabe Maya , Tsuchida Masanori
Published: December 2021

We report the case of a 2-year-old girl with Loeys–Dietz syndrome complicated by aortic root dilatation and aortic regurgitation. We performed valve-sparing aortic root replacement with reimplantation technique and aortic valve repair using central plication and free-margin reinforcement simultaneously. The postoperative course was uneventful and the latest echocardiography, 5 years after procedure, revealed trivial aortic insufficiency.
Crime, Violence, and Political Participation
Authors: Boulding Carew , Mullenax Shawnna , Schauer Kathryn
Published: December 2021

The paper explores the relationship between crime victimization and political participation, making the argument that the observed (and oft-cited) relationship in surveys is the result of response bias. We show that people who are more extroverted, efficacious, and opinionated are more likely to respond positively to a question about victimization, and they are more likely to participate in politics. The implications of this finding are important and widespread—both for survey researchers interested in sensitive questions and for research on the relationship between crime and political engagement.
Student perception of academic advising in a school of pharmacy
Authors: Sierra Caroline M , Koch Jessa , Gonzalez Jody , Bahjri Khaled
Published: December 2021

Objectives

Literature assessing the optimal means of providing academic advisement in pharmacy education is limited. The objective of this study was to describe students’ perception of advising within a school of pharmacy.

Methods

A 27-question survey was developed utilizing Qualtrics and sent to all students at one school of pharmacy. Baseline descriptive data regarding frequency and format of meeting with the assigned advisor were collected, as well as students’ opinions of these meetings.

Key findings

Of 282 students who were sent the survey, 90 responded (31.9%). The majority of students preferred to meet with their faculty advisor in a group as compared with one-on-one (59 versus 29, 67%). Most students found the advisor/advisee relationship beneficial (n = 77, 85%).

Conclusions

There was no statistically significant difference in student perception of the quality or value of advisor/advisee meetings between students who met in a group or one-on-one with their advisors.
Ectopic uterus? A rare presentation of a giant leiomyoma in the posterior mediastinum
Authors: Tarmohamed Murad , Mashambo Abednego , Sadiq Adnan , Mremi Alex , Chilonga Kondo
Published: December 2021

Leiomyomas are benign mesenchymal tumors derived from smooth muscles. Uterus is the commonest site of origin for leiomyomas; however, unusual growth patterns and locations have been reported posing diagnostic challenges, clinically and radiologically. Histological diagnosis remains the gold standard of diagnosis. Here, we present a 17-year-old female with a 3-month history of chest pain, cough, difficulty in breathing and chest tightness. Chest CT scan showed a 12.3 cm × 14.4 cm × 22.8 cm mass occupying the entire left posterior hemithorax. The patient underwent thoracotomy and recovered well after surgery. Histopathology of the excised specimen confirmed it to be leiomyoma. Despite its rarity, primary mediastinal leiomyoma should be considered in the differential diagnosis of an unexplained mediastinal mass. Its accurate pre-operative diagnosis is difficult. Respiratory compromise and risk of transformation to sarcoma mandate complete surgical resection for a definitive diagnosis and good prognosis.
Acquired FVII Deficiency and Acute Myeloid Leukemia: A Case Report and Literature Review
Authors: Hammami Emna , Borgi Wijden El , Lakhal Fatma Ben , Salem Sarra Fekih , Neji Hend Ben , Gouider Emna
Published: December 2021

Factor VII (FVII) deficiency is the most common among all rare inherited bleeding disorders. However, acquired FVII deficiency (aFVIID) is uncommon. Only few cases in the literature have been reported. Herein, we present a case of an aFVIID associated with acute myeloid leukemia (AML), along with a literature review regarding this condition. A 50 year old Arab male patient was diagnosed with AML at the hematology department of our institution. At admission, coagulation tests showed a prolonged prothrombin time (PT) with a normal activated partial thromboplastin time (aPTT) and a slightly elevated fibrinogen level. Prothrombin complex coagulation factors dosing (PCCFD) revealed a decrease only in FVII levels. The patient, however, did not experience any bleeding. The evolution of the health of the patient was marked by a normalization of PT and FVII levels and complete remission.
A Case of Trimethoprim-Sulfamethoxazole-Induced Aseptic Meningitis Masquerading as Septic Shock
Authors: Hatcher Vishaka R , Brooks Robert M , Barker Karen B , Coop Christopher A
Published: December 2021

Trimethoprim-sulfamethoxazole-induced aseptic meningitis (TSIAM) is a rare adverse reaction to a commonly prescribed antibiotic. We describe a case of severe TSIAM which resembled septic shock. A 30-year-old male with relapsed Hodgkin’s lymphoma 25 days status post autologous stem cell transplant presented to our clinic for evaluation of trimethoprim-sulfamethoxazole (TMP-SMX) hypersensitivity. After review of patient’s history and records, we had a low suspicion for a TMP-SMX adverse reaction and conducted an oral challenge to one 160 mg/800 mg tab of TMP-SMX. Four hours later, the patient developed vomiting, lightheadedness, and disorientation with progression to rigors, fever, tachycardia, and hypotension. He was admitted for fluid resuscitation and broad-spectrum antibiotic coverage for neutropenic fever and possible septic shock. A lumbar puncture performed due to complaints of headache, photophobia, and neck pain showed 375 white blood cells/µL with 73% neutrophil predominance, normal glucose (75 mg/dL), and elevated protein (101 mg/dL); additional cerebrospinal fluid (CSF) studies were negative for infectious etiologies. Fever and headache resolved by hospital day 4, at which time patient was discharged home. We believe this case represents TSIAM given the characteristic timing of symptom onset, CSF findings, and timing of symptom resolution without other clear etiology found on extensive infectious evaluation. It is important for allergists to recognize TSIAM, including its potential presentation as shock, in order to appropriately diagnose and counsel patients who seek evaluation for TMP-SMX adverse reactions.
Efficacy and safety of filgotinib alone and in combination with methotrexate in Japanese patients with active rheumatoid arthritis and limited or no prior exposure to methotrexate: Subpopulation analyses of 24-week data of a global phase 3 study (FINCH 3)
Authors: Atsumi Tatsuya , Tanaka Yoshiya , Matsubara Tsukasa , Amano Koichi , Ishiguro Naoki , Sugiyama Eiji , Yamaoka Kunihiro , Westhovens René , Ching Daniel W.T , Messina Osvaldo Daniel , Burmester Gerd R , Bartok Beatrix , Pechonkina Alena , Kondo Akira , Yin Zhaoyu , Guo Ying , Tasset Chantal , Sundy John S , Takeuchi Tsutomu
Published: December 2021

Objectives

To evaluate the efficacy and safety of filgotinib for Japanese patients with rheumatoid arthritis (RA) and limited or no prior methotrexate (MTX) exposure.

Methods

Data up to 24 weeks were analysed for 71 Japanese patients from a 52-week global Phase 3 study. Patients with RA and limited or no prior MTX exposure were randomised in a 2:1:1:2 ratio to filgotinib 200 mg plus MTX, filgotinib 100 mg plus MTX, filgotinib 200 mg, or MTX. Maximum MTX dose was 15 mg/week. Primary endpoint was proportion achieving 20% improvement in American College of Rheumatology criteria (ACR20) at Week 24.

Results

Week 24 ACR20 rates in Japanese patients were 82.6%, 90.9%, 83.3%, and 80.0% for filgotinib 200 mg plus MTX, filgotinib 100 mg plus MTX, filgotinib 200 mg, and MTX, respectively. Greater ACR20 rates with filgotinib vs MTX occurred at Week 2. Greater proportions receiving filgotinib vs MTX achieved DAS28-CRP <2.6 at Weeks 12 and 24. Adverse event rates were comparable across treatments and between the Japanese and overall populations.

Conclusions

While Week 24 ACR20 rates were similar, filgotinib provided faster responses and higher remission rates vs MTX. In Japanese patients with RA and limited or no prior MTX exposure, filgotinib was generally well tolerated.