bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Fidelity Simulation of Space Electromagnetic Environment Radiation Source
Authors: Wang Yuan , Tan Wei , Kong Rong , Ren Zhaorui
Published: May 2021

This paper proposes to model and simulate radiation sources in complex electromagnetic environments in space from three aspects of real-time, dynamic and parameter completeness, which solves the problem of fidelity simulation under the high dynamic conditions of multiple radiation sources in the space electromagnetic environment. This paper proposes the parameters covered by the real-time, dynamic and parameter completeness of the radiation source, and designs the basic model, which provides design ideas for the spacecraft’s adaptive simulation in the space electromagnetic environment, and provides for the design and development of the spacecraft’s anti-jamming capability Technical Reference.
A research on integrated district energy system planning considering hydrogen production
Authors: Zhang Wanqiu , Liu Li
Published: May 2021

In this paper, the comprehensive energy system of wind power hydrogen production plant is considered. Firstly, wind power hydrogen production model, electrolysis hydrogen production model and comprehensive energy system model containing wind power hydrogen production are proposed, combining the operation model in the comprehensive energy system, electric heating load demand and the operation characteristics of the power system. Secondly, the objective function of the integrated energy system is to optimize for the lowest total operating cost, establish an optimization model, and restrict its overall power balance and the relevant constraints of each part. Finally, energyplan is adopted for simulation operation. The results show that the integrated energy system considering wind power for hydrogen production can better absorb wind energy, reduce the phenomenon of wind abandonment, and convert wind abandonment into hydrogen resources, which can improve economic benefits and make full use of energy.
Dynamic feedback H ∞ optimal control for singular systems
Authors: Zhao Lina , Qiu Zhanzhi
Published: May 2021

Time delay and packet loss often occur in the process of information transmission in descriptor systems, and H∞ optimal control is adopted to deal with this phenomenon. Firstly, the stability of singular systems is proved by using Lyapunov function, secondly, the existence of H∞ controller and-suboptimal control are proved, and finally, the necessary and sufficient condition of H ∞-optimal controller is proved. The validity and feasibility of the proposed method are verified by numerical simulation.
Analysis on the Circuit Design of Fire Alarm
Authors: Kang Shaoxuan
Published: May 2021

In the large airtight cinema and school, there are a lot of people in public places, thus the fire safety problems always attach great importance to everyone. The appearance of fire alarms can definitely help audience who are immersed in watching movies and students who are listening to the teachers carefully to remind them of a fire, so they can leave the scene in time and reduce property losses. This paper will take the fire alarm circuit as an example to realize the combined logic circuit by using various integrated circuits of different scales. This design is very flexible, effective and operable. In the actual process of use, the appropriate scheme can be selected according to the design requirements and the resource of the device. The object of study is a logic circuit, which is composed of an integration gate or a medium scale synthesizer. The experimental methods include practical ideas, application of Boolean logic principles, and sampling of data from others through the Internet, which are mentioned at the end of the paper. The conclusion is that abstract logic can be used step by step to design a practical and effective circuit diagram.
Flexible Load Scheduling Methods for Load Aggregators
Authors: Zhang Chenggang , Du Zeyu , Wu Pengtao , Sun Qianhao , Li Yunhao , Zhang Yao
Published: May 2021

Four typical flexible load resources in the customer side, i.e., industrial users, central air-conditioning load, electric vehicles, and energy storage stations, are first considered and modelled in this paper. Then, we present the combined dispatching model for load aggregators involving four flexible load resources mentioned above. Our results of numerical experiments demonstrate that on one hand, four typical flexible load resources on the user side can be dispatched to decrease peak-load as well as increase valley-load. On the other hand, scheduling the load resources with energy storage properties operates in accordance with pre-instructions. Compared with independent scheduling, the combined scheduling of various flexible loads can achieve significant advantages of various load characteristics and strengthen the dispatching ability of load aggregators. The methodology proposed in this paper can effectively promote renewable energy integrations, improve grid stability, and then reduce operating costs of load aggregators.
A New Microwave Heating Method Via the Combination of Rotation and Boundary Movement
Authors: Jiang Min , Tang Zhengming , Hong Tao , Hu Yusong
Published: May 2021

The local overheating may occur in microwave heating process, which results in poor heating uniformity. In order to improve the heating performance, in this paper, the boundary movement with periodical movement is added to the traditional rotating turntable model. The continuous algorithm based on moving mesh is adopted to simulate the heating process, and the results of calculation show that the proposed method can not only maintain the uniformity of the traditional rotating turntable method but also increase nearly 30% of the average temperature of the heated object.
CT reconstruction algorithm based on truncated TV
Authors: Shi Hongyan , Wu Aidi , Yang Shidi , Ji Dongjiang
Published: May 2021

This paper proposes a simultaneous algebraic reconstruction technique (SART) based on truncated total variation (truncated TV), called SART-truncated TV algorithm (SART-TTV). Truncated TV is particularly effective in removing unimportant details while preserving significant edges. Moreover, the truncated TV only penalizes part of the gradient of the image, so it can solve the problem of excessive smoothness caused by the classic TV penalizing larger gradient amplitude. In this paper, the classic Shepp-Logan model is simulated and the results of sparse angle reconstruction are compared and analyzed. The results show that the quality of the reconstructed image obtained by the SART-TTV algorithm is the highest.
Improved calculation method of dynamic current carrying capacity of transmission line
Authors: Zhang Ruopeng , Tian Mingxing , Sun Lijun , Su Zhaoxu
Published: May 2021

The calculation of the dynamic current carrying capacity of transmission lines in a domestic traction network is based on IEEE 738 standard. However, because IEEE 738 standard is derived under specific climate and geographical conditions, only when the climate and geographical conditions are stable can the accurate ampacity be calculated. However, in practical application, due to the rapid change of climate factors and large meteorological monitoring error, the results calculated by IEEE 738 standard have large errors. Therefore, this paper puts forward the method of using convective heat dissipation coefficient and equivalent radiation heat dissipation coefficient to deal with the problems caused by unstable meteorological factors. By this method, the dynamic current carrying capacity of the transmission line can be calculated only by measuring the conductor temperature and ambient temperature, which simplifies the calculation process of the dynamic current carrying capacity of the transmission line and reduces the dependence on meteorological parameters.
Research on seismic wave first arrival Picking Based on improved U-Net
Authors: Liu Ping , Yao Mengrou , Han Zhenhua , Li Yanrong , Li Xinrui , Shi Juncai
Published: May 2021

For the current problem of low accuracy of seismic wave phase pickup, this paper proposes a method based on the improved U-Net seismic wave P-wave and S-wave first-to-arrival pickup. Firstly, in order to reduce the impact of pre-processing operations such as filtering, the 20,000 three-component seismic waveform data will be normalized as input. Secondly, in order to reduce the loss of information during the seismic waveform extraction and increase the amount of information of effective features at the starting point, the Residual Unit is added to the encoder part of U-Net only, instead of adding it to the decoder part. In order to reduce the loss of high frequency information of seismic waveform, convolution operation is used instead of pooling operation. Finally, the probability distributions of P-wave, S-wave and noise are used as the output. The results show that the accuracy of the first-to-arrival pickup of P-wave is 93% and the accuracy of the first-to-arrival pickup of S-wave is 90% of the test set. The improved U-Net increased 30.9% and 6.2% in P-wave accuracy, 7.6% and 2.8% in S-wave accuracy, 39.6% and 4.0% in the P-wave recall, and 41.5% and 4.7% in the S-wave recall, respectively, compared with the conventional STA/LTA and U-Net. The improved U-Net outperforms the other two models in both evaluation metrics of recall and accuracy. The research results of this paper are of great practical significance in the localization of earthquakes, the interpretation of the earthquake gestation mechanism, and the prevention and mitigation of earthquakes.
Restoration control decision of distribution network based on dynamic evaluation of restoration value
Authors: Jiang Ke , Yu Chen , Chen Keyi , Yuan Guichuan , Yang Lintao , Hao Lili
Published: May 2021

The power outage scenario, recovery process, and load function in emergency situations will all affect the urgency of the load to restore power supply during distribution network restoration. Usually the importance level of the object to be restored is statically set according to its value of restoration, which restricts the refined management of limited restoration resources. This paper proposes a dynamic evaluation method of bus restoration value that integrates restoration benefits, costs and risks, which considers the influence of the cold load pick-up and the functional coupling relationship between the load on the recovery value of the load unit, the potential recovery value brought by the bus recovery to other surrounding objects to be recovered, and the system power supply shortage, recovery cost and uncertainty of recovery operation. Based on this, a multi-process optimization model for distribution network restoration and a partition parallel restoration decision-making method are established. Finally, simulation analysis verifies that the strategy proposed in this paper can effectively improve the utilization of recovery resources.
Research on typical failure modes of hybrid integrated quartz flexible accelerometer servo circuit caused by multi-layer ceramic capacitors
Authors: Zhang Ming , Wan Huanhuan , Xu Xin , Ruan Xiaoming , Gao Weidong , Xiao Zeping
Published: May 2021

The quartz flexible accelerometer servo circuit is one of the key components in the inertial measurement system, and the multi-layer ceramic capacitor is an important electronic component in the quartz flexible accelerometer servo circuit. This paper introduced the typical failure modes of hybrid integrated quartz flexible accelerometer servo circuit caused by multi-layer ceramic capacitors. These phenomena are analysed and studied using the circuit failure mode matching method, and improvements are proposed. The measures are of guiding significance for improving the failure analysis technology and enhancing the reliability of hybrid integrated circuit.
Transfer learning and its application research
Authors: Zhou Yancong , Zhang Xuemei , Wang Yan , Zhang Bo
Published: May 2021

Transfer learning relaxes the assumption’s limitation requirements of the independent and identical distribution of training data and test data in machine learning. It aims to help the target domain complete the learning task by learning one or more source domains similar to the target domain, solve the problem of scarcity of annotation data and enhance the model’s robustness and generalization performance. The article is a survey on the progress of transfer learning. According to “how to transfer”, transfer learning is divided into four categories: instance-based transfer learning, feature-based transfer learning, model-based transfer learning, and relation-based transfer learning. The paper introduces the basic assumptions, main research questions, common methods, related research of various transfer learning algorithms, and the application of the transfer learning. Finally, we try to point out future research trends.
Vehicle tracking algorithm based on deep learning
Authors: Feng Xiao , Piao Yan , Sun Sitong
Published: May 2021

Vehicle detection is one of the most important detection targets in target detection. overcoming this problem is of great significance in the field of traffic detection and automatic driving. In this paper, based on yolov4, firstly, the slice module is added to the input, and the silce module slices the image into the backbone to get the sampling feature map without information loss. Then, the SPP module is added to the neck of neck module, and then the Kitti dataset is trained, detected and tested. Experiments show that adding slice module in the input circuit and spp module in the neck can effectively improve the accuracy of vehicle detection Map@0.5 3.4%.
Noise Reduction Method for Low Voltage Power Line Carrier Communication
Authors: Li Fei , Shen Hongtao , Shi Lun , Wang Hongxi , Gao Bo
Published: May 2021

In order to improve the performance of electricity information collection system, this paper studies and proposes a new method of low-voltage power line carrier signal frequency domain noise reduction. It includes frequency domain decomposition of carrier signal, filtering noise reduction and signal frequency domain restoration. Then compared our method with the wavelet packet noise reduction method based on multi-resolution. The experimental results show that the proposed algorithm is better than the comparison algorithm under different modulation modes and carrier frequencies, especially suitable for carrier signal noise reduction under bad channel conditions. The algorithm proposed in this paper has good anti signal attenuation performance, and it can effectively enhance the SNR, and ensure the transmission performance and system reliability of the electricity information collection system.
Removal methods of EMG Artifacts from EEG Signals
Authors: Yu Mohan
Published: May 2021

Electromyography (EMG) is the superposition of motor unit action potential (MUAP) in many muscle fibers in time and space. In real measurement, EMG signals will contaminate Electromyography signals, therefore they bring great difficulties to the qualified analysis and interpretation of EEG signals, and it is a momentous step to remove EMG artifacts from EEG signals. In the recent years, new methods were developed for EEG artifacts removal such as Multivariate Empirical Mode Decomposition and Singular Spectrum Analysis. In particular, some researchers combined the two methods and used their respective advantages to remove artifacts more thoroughly without affecting the EEG signal, such as the combination of Independent Component Analysis and Wavelet Method. In this paper, new methods for muscular artifacts removal from EEG above are discussed. Moreover, traditional methods including signal transform, filtering methods and Blind source separation (BSS) are also reviewed.
Design of data encryption storage module for coal mine law enforcement record terminal
Authors: Li Qiwei
Published: May 2021

Coal mine law enforcement record terminal is mostly used in Android operating system. Aiming at the data security problem of Android system, this paper designs a data encryption storage module based on Threadx real-time operating system with i.MX RT1021 processor as the core. This paper introduces the hardware and software design of the encryption storage module in detail. Using DSA data encryption algorithm, combined with the characteristic information, through the actual test, this storage module realizes the reliable encryption storage of audio, video and text data of the law enforcement record terminal, which can effectively prevent the electronic evidence from being tampered with.
A technique of Data Acquisition and Processing in Fiber Grating Sensing System
Authors: Li Nan
Published: May 2021

The multi-channel intelligent optical sensing technology is used in the gyroscope, and the optical fiber sensing technology is optimized through the fiber grating sensing system for data acquisition and processing. The MAX120 chip is used to realize the A/D conversion of the initial spectral signal, the hardware system connects the optical fiber sensor to realize the organic integration between the circuit components. And the preprocessing process of the intelligent information signal is realized through the two steps of data transformation filtering and improving the spectral resolution of the signal. It can solve the problems of slow acquisition speed and low signal-to-noise ratio in the traditional spectral acquisition system. After system testing, it is concluded that compared with the traditional spectral acquisition system, the time of primary spectral acquisition in the intelligent information signal spectral acquisition system based on optical fiber sensing is saved by 1.47s, and the signal-to-noise ratio is improved by 14dB.
Intelligent Course Scheduling System Based on Case-based Reasoning
Authors: Zhang Suqi , Wang Xinxin
Published: May 2021

In view of the current situation of tight teaching resources, the intelligent scheduling system alleviates this problem to a certain extent, and the advantages and disadvantages of the scheduling method determine the performance of the scheduling system. a method based on Case-based reasoning is presented in this paper to solve the course scheduling problem. Using graph theory, a case representation model is built for the course scheduling problem, a measure is established for case similarity, and a case retrieval method based on maximum common subgraph selection is brought forward. Finally, the validity of the proposed method for solving course scheduling problem based on case-based reasoning is verified through an experiment.
Antenna Performanc Evaluation Method for 5G AGPS Wireless Devices
Authors: Wang Na , Chen Lei , Liu Xianhui , Liang Panpan , Zhang Qinjuan
Published: May 2021

The 5G AGPS positioning technology has been widely used in wireless devices. The principle, test method and test system of the 5G AGPS positioning technology are presented in this paper. This method can evaluate positioning antenna performance in simulated environment that is close to real use. The test results show that the system can reflect the positioning antenna performance of EUT very well and provide the test guarantee for user experience.
Design of an intelligent underground parking guided and charging system based on WiFi
Authors: Su Mingxia , zhou Fang
Published: May 2021

With the development of the society, the improvement of people’s living standards, countless underground parking lots seem to be difficult to park and find cars. Underground parking lot was built under the thick concrete. Because the underground parking lot is built under the thick steel and cement, the GPS satellite signal can not penetrate the thick bunker, which leads to the problem that the navigation accuracy in the building is too low to be able to locate accurately. In order to solve this problem which is put forward an intelligent underground parking guidance system based on the wifi, the system install wifi routers on the underground parking lot, and mobile phones own wifi module scan wifi hotspots around the information, and then match the cloud database tagged wifi hotspots information, and get wifi hot spot on the map coordinate information. According to the mobile phone access to the location of the WIFI hotspot intensity information, the system gets to the phone’s current location information, and the coordinates of the map is updated. Fianlly, according to the system for the whole test, the test results show that the system has achieve the expected goals, and the operation is convenient, has certain market practical value.
A Method for Pulse Signal Denoising Based on VMD Parameter Optimization and Grey Wolf Optimizer
Authors: Zhang Lin , Yu Chengbo , Tan Yong
Published: May 2021

Aiming at the difficulty of parameter determination when using variational modal decomposition algorithm (VMD) to decompose photoplethysmographic(PPG) pulse wave signals, α VMD parameter optimization method based on Grey Wolf Optimizer (GWO) is proposed. In this paper, the envelope entropy of the K eigenmode component (IMF) after VMD decomposition is used as the fitness function, and the grey wolf optimization algorithm (GWO) is used to find the K sum corresponding to the minimum envelope entropy of the eigenmode component α, to determine the optimal value of the VMD algorithm parameters, and then use the parameter optimized VMD algorithm to filter out the noise in the PPG signal. The experimental results show that after decomposing the PPG signal using the algorithm in this paper, the effective component and the noise component of the signal are well separated. After selecting the appropriate IMF component for reconstruction, the noise in the PPG signal is effectively filtered out.
Study on Shot peening Coverage of Metal Surface Based on Deep Learning
Authors: Qiu Jiyuan , Li Wenrui , wang Fushuai , Yao Qi
Published: May 2021

The surface shot peening coverage of industrial parts will affect the performance of the parts. Therefore, it is of great significance for the identification of the metal surface shot peening coverage area and the uncovered area for the metallurgical process. This paper uses the idea of image semantic segmentation, using CCD industrial camera to select and shoot the metal surface of 67%,89% and 98% shot peening coverage. Based on UNet and UNet++ model, the shot peening area is segmented. After training 200 epoch, the network converges and the training accuracy can reach 98.45%. Comparing the two kinds of network training results, using the UNet++ model with good results to predict the selected 18 metal surfaces, the proportion of shot peening coverage area and uncovered area is counted, and then the K-means clustering algorithm is used to classify. The classification accuracy can reach 100%.
Radar detection of multi-target vital signs based on blind source separation
Authors: Zhang Jilin , Li Xingguang , Ma Lingzhe
Published: May 2021

Radar non-contact monitoring of vital signs has a broad application prospect in clinical monitoring. Aiming at the problem of strong interference in non-contact vital signs detection (Such as multi-target, random body motion), a blind source separation (BSS) signal detection method based on Fast-ICA is proposed to reduce the interference of multi-target. In this algorithm, entropy is used to evaluate the non Gaussian property, and the appropriate transformation matrix is selected, according to the statistical independence of the signals, the source signals are separated from the observed mixed signals. On this basis, the traditional blind source separation process is improved, and the wavelet transform preprocessing algorithm based on translation invariant is added to suppress the interference of static clutter. The feasibility of this method is verified by simulation experiments.
Research on control algorithm of a automatic driving robot based on improved model predictive control
Authors: Wang Zengxi , Zhang Qingyu , Jia Tong , Zhang Sulin
Published: May 2021

The automatic driving robot can replace the driver in the traditional test and ADAS test; Model Predictive Control (MPC) is used in the horizontal and vertical control process of high-speed driving. According to the uncertainties and complex constraints of automatic driving horizontal and vertical control, the adaptive improvement of MPC is proposed, which can better adapt to the characteristics of self driving vehicles, sensors and tyres. This paper proposes a multi-layer and multi time automatic driving control strategy based on improved MPC. Visual studio is used to write the upper computer software of the automatic driving robot, which realizes good human-computer interaction. The automatic driving robot is verified in real vehicle test. The experimental results show that the transverse and longitudinal control strategy of the improved model predictive control is stable, and the automatic driving robot can realize the high precision and high dynamic control of vehicle steering, pedal and shift.
Mask Recognition Method Based on Graph Convolutional Network
Authors: Ye Qing , Li Rui
Published: May 2021

The rapid spread of COVID-19 worldwide has exacerbated the health crisis and affected our daily lives. Medical researchers have shown that wearing masks in public places is essential to reduce the spread of COVID-19 infection. The increase in the accuracy of the identification of masks in public places can effectively prevent the further spread of the epidemic. In this paper, we propose a mask recognition network based on graph convolutional network, D-GCN. The network adopts the method of combining convolutional neural network and graph convolutional neural network. First, Dense Net 101 is used to extract features of the real-time image to be tested, and then GCN processes the training label information to form a directed graph through the word embedding vector, it forms a new classifier based on the label connection between the training pictures, and processes the extracted feature vectors. Finally the classification result is output and completing the recognition. The experiment is carried out on the mask dataset and MAFA dataset, and the recognition accuracy is significantly improved compared with previous methods.
EnMCB: an R/bioconductor package for predicting disease progression based on methylation correlated blocks using ensemble models
Authors: Yu Xin , Kong De-Xin
Published: May 2021

Motivation

Based on the concept that contiguous cytosine-phosphorothioate-guanine (CpG) sites in the same DNA strand may be modified by a methyltransferase or demethylase together, current study found that the combination of multiple CpGs into a single block may promote cancer diagnosis. However, there is no R package available for building models based on methylation correlated blocks.

Results

Here, we present a package named stacked ensemble of machine learning models for methylation correlated blocks (EnMCB) to build signatures based on DNA methylation correlated blocks for survival prediction. The Cox regression, support vector regression, mboost and elastic-net model were combined in the ensemble model. Methylation profiles from The Cancer Genome Atlas were used as real datasets. The package automatically partitions the genome into blocks of tightly co-methylated CpG sites, termed methylation correlated blocks. After partitioning and modeling, the diagnostic capacities for predicting patients’ survivals are given.

Availability and implementation

EnMCB is freely available for download at GitHub (https://github.com/whirlsyu/EnMCB/) and Bioconductor (http://bioconductor.org/packages/release/bioc/html/EnMCB.html).

Supplementary information

Supplementary data are available at Bioinformatics online.
A framework to decipher the genetic architecture of combinations of complex diseases: applications in cardiovascular medicine
Authors: Yin Liangying , Chau Carlos Kwan-Long , Lin Yu-Ping , Rao Shitao , Xiang Yong , Sham Pak-Chung , So Hon-Cheong
Published: May 2021

Motivation

Currently, most genome-wide association studies (GWAS) are studies of a single disease against controls. However, an individual is often affected by more than one condition. For example, coronary artery disease (CAD) is often comorbid with type 2 diabetes mellitus (T2DM). Similarly, it is clinically meaningful to study patients with one disease but without a related comorbidity. For example, obese T2DM may have different pathophysiology from nonobese T2DM.

Results

We developed a statistical framework (CombGWAS) to uncover susceptibility variants for comorbid disorders (or a disorder without comorbidity), using GWAS summary statistics only. In essence, we mimicked a case–control GWAS in which the cases are affected with comorbidities or a disease without comorbidity. We extended our methodology to analyze continuous traits with clinically meaningful categories (e.g. lipids), and combination of more than two traits. We verified the feasibility and validity of our method by applying it to simulated scenarios and four cardiometabolic (CM) traits. In total, we identified 384 and 587 genomic risk loci respectively for 6 comorbidities and 12 CM disease ‘subtypes’ without a relevant comorbidity. Genetic correlation analysis revealed that some subtypes may be biologically distinct from others. Further Mendelian randomization analysis showed differential causal effects of different subtypes to relevant complications. For example, we found that obese T2DM is causally related to increased risk of CAD (P = 2.62E−11).

Availability and implementation

R code is available at: https://github.com/LiangyingYin/CombGWAS.

Supplementary information

Supplementary data are available at Bioinformatics online.
Incidence of hepatocellular carcinoma in patients with non-alcoholic fatty liver disease: A meta-analysis and meta-regression
Authors: Orci L , Caballol B , Sanduzzi-Zamparelli M , Sapena V , Colucci N , Torres F , Bruix J , Reig M , Toso C
Published: May 2021

Objective

Nonalcoholic fatty liver disease (NAFLD) may be a risk factor for hepatocellular carcinoma (HCC), but the extent of this association still needs to be addressed. Pooled-incidence rates of HCC across the disease spectrum of NAFLD have never been estimated by meta-analysis.

Methods

In this systematic review, we searched Web of Science, Embase, Pubmed, and the Cochrane library from January 1st, 1950 through July 30th, 2020. We included studies reporting on HCC incidence in patients with NAFLD. The main outcomes were pooled HCC incidences in patients with NAFLD at distinct severity stages. Summary estimates were calculated with random-effects models. Sensitivity analyses and meta-regression analyses were carried out to address heterogeneity. The protocol for this review was registered in Prospero (CRD42018092861).

Results

Eighteen studies, with a total of 470,404 patients were included. In patients with NAFLD at a stage earlier than liver cirrhosis, HCC incidence was of 0.03 per 100 person-years (PYs) (95% confidence interval 0.01-0.07, I2=98%). This rate rose to 3.78 per 100PYs (2.47-5.78, I2=93%) when considering studies that only included patients with liver cirrhosis. Among the latter patients, those undergoing regular HCC screening displayed an incidence of 4.62 per 100PYs (2.77-7.72, I2= 77%).

Conclusion

Patients with NAFLD-related liver cirrhosis have a risk of developing HCC similar to that reported for patients with cirrhosis from other etiologies. Evidence documenting the risk in patients with NASH or simple steatosis is limited, but HCC incidence in these populations may lie below thresholds used to recommend HCC screening. Well-designed prospective studies in these subsets of patients are needed.
Omentin attenuates angiotensin II-induced abdominal aortic aneurysm formation in apolipoprotein E-knockout mice
Authors: Fang Lixin , Ohashi Koji , Otaka Naoya , Ogawa Hayato , Hiramatsu-Ito Mizuho , Kawanishi Hiroshi , Bando Yasuko K , Shibata Rei , Shimizu Yuuki , Kato Katsuhiro , Takikawa Tomonobu , Ozaki Yuta , Takefuji Mikito , Murohara Toyoaki , Ouchi Noriyuki
Published: May 2021

Aims 

Abdominal aortic aneurysm (AAA) is an increasing and life-threatening disease. Obesity contributes to an increased risk of AAA. Omentin is a circulating adipokine, which is downregulated in obese complications. Here, we examined whether omentin could modulate angiotensin (Ang) II-induced AAA formation in apolipoprotein E-knockout (apoE-KO) mice.

Methods and results 

apoE-KO mice were crossed with transgenic mice expressing the human omentin gene in fat tissue (OMT-Tg mice) to generate apoE-KO/OMT-Tg mice. apoE-KO/OMT-Tg and apoE-KO mice were subjected to continuous Ang II infusion by using osmotic mini pumps. apoE-KO/OMT-Tg mice exhibited a lower incidence of AAA formation and a reduced maximal diameter of AAA compared with apoE-KO mice. apoE-KO/OMT-Tg mice showed attenuated disruption of medial elastic fibres in response to Ang II compared with apoE-KO mice. apoE-KO/OMT-Tg mice also displayed reduced expression levels of matrix metalloproteinase (MMP) 9, MMP2, and pro-inflammatory genes in aortic walls compared with apoE-KO mice. Furthermore, systemic administration of omentin also attenuated AAA formation and disruption of medial elastic fibres in response to Ang II in apoE-KO mice. Treatment of human monocyte-derived macrophages with omentin protein attenuated expression of MMP9 and pro-inflammatory mediators, and MMP9 activation after stimulation with lipopolysaccharide. Treatment of human vascular smooth muscle cells (VSMCs) with omentin protein reduced expression and activation of MMP2 after stimulation with tumour necrosis factor α. Omentin treatment increased phosphorylation levels of Akt in human macrophages and VSMCs. The suppressive effects of omentin on MMP9 and MMP2 expression were reversed by inhibition of integrin-αVβ3/PI3-kinase/Akt signalling in macrophages and VSMCs, respectively.

Conclusion 

These data suggest that omentin acts as an adipokine that can attenuate Ang II-induced development of AAA through suppression of MMP9 and MMP2 expression and inflammatory response in the vascular wall.
DOP01 Efficacy and safety of the IL-6 trans-signalling inhibitor olamkicept: a phase 2 randomized, placebo-controlled trial in moderately to severely active Ulcerative Colitis
Authors: Chen B , Zhang S , Wang B , Chen H , Li Y , Cao Q , Zhong J , Xie M , Ran Z , Tang T , Yang M , Guo T , Xu B , Cai Z , Schreiber S , Chen M
Published: May 2021

Background

Total inhibition of IL-6 or its receptor represents a potent anti-inflammatory therapy with considerable side effects. Selective targeting IL-6 trans-signalling may have safety advantages that differentiates it from current pan-IL-6 inhibitors. We evaluated the efficacy and safety of olamkicept, a soluble gp130-Fc fusion protein that binds to the IL-6 and soluble IL-6 receptor complex, as induction therapy for active ulcerative colitis (UC).

Methods

This multi-national, randomized, double-blind, placebo-controlled phase 2 trial (NCT03235752) enrolled patients with active UC (full Mayo score ≥5, rectal bleeding (RB) score ≥1, endoscopy score (ES) ≥2) with an inadequate response to at least conventional therapy, in a 1:1:1 ratio to receive either placebo, olamkicept 300 mg or 600 mg biweekly for 12 weeks. Primary efficacy endpoint was clinical response (decrease in Mayo score from baseline ≥3 and ≥30%, including RB ≤1 or RB decrease ≥1) at week 12. Secondary endpoints were mucosal healing (ES 0 or 1) and clinical remission (Mayo score ≤2, with no subscore >1 and RB=0). The efficacy endpoints were analysed by logistic regression. All p-values were 2-sided without adjustment for multiplicity.

Results

Of 91 treated patients (30 in placebo, 31 in olamkicept 300 mg group and 30 in 600 mg group), 88 patients (29:30:29) were evaluable for efficacy. Baseline disease and demographic characteristics were similar among the groups (Table 1). Most patients (94.5%) were bio-naïve. The percentage of patients achieving clinical response at week 12 was significantly greater for olamkicept 600 mg than placebo (58.6% vs 34.5%, P=0.032). Clinical remission at week 12 occurred in 0% (placebo), 6.7% (olamkicept 300 mg) and 20.7% (olamkicept 600 mg, P<0.001) of patients. Mucosal healing at week 12 occurred in 3.4%, 10% and 34.5% (P<0.001) of patients, respectively (Figure 1). Incidence of treatment emergent adverse events (TEAEs) was similar across the groups. The most common TEAEs included upper respiratory tract infection, increased AST levels, and increased urine bilirubin levels, which were mild to moderate and mostly transient. Serious adverse events (SAEs) were reported in 6.7%, 3.2% and 3.3% of patients, respectively. There were no deaths, or other severe AEs associated with current IL-6 inhibitors, such as perforations, severe infections, neutropenia or thrombocytopenia.

Conclusion

Biweekly 600 mg olamkicept induction therapy demonstrated clinical efficacy with respect to achieving clinical response, clinical remission and mucosal healing in patients with active UC. Olamkicept was well tolerated with a favourable safety profile. The positive results of this phase 2 study support further development of olamkicept in IBD.
DOP14 Ultra-high magnification endocytoscopy and molecular markers for defining endoscopic and histologic remission in Ulcerative Colitis
Authors: Iacucci M , Nardone O M , Jeffery L , Acharjee A , Zardo D , Smith S C , Bazarova A , Cannatelli R , Shivaji U N , Williams J , Georgios G , Ghosh S
Published: May 2021

Background

Endoscopic and histological remission are important goals to achieve in patients with ulcerative colitis (UC). We aimed to define deep remission by assessing cellular architecture, expression of molecular markers and their correlation with endoscopic scores by using ultra-high-magnification endocytoscopy and histological indices

Methods

We conducted a prospective study enrolling 29 UC patients (18 males, mean age 41y) referred at a tertiary academic centre for assessing endoscopic remission (ER). All patients underwent colonoscopies with 520-fold magnification endocytoscope. The inflammatory activity was scored using the Mayo Endoscopic Score (MES). ER was defined as MES 0. To assess the grade of inflammation using ECS we set an ECS score (ECSS), whose parameters were summarized in table 1.

Biopsies were taken targeting either the worst affected area of inflammation or the most representive area of ER and scored according to Nancy Histopatological Index (NHI) and Robarts Histopatological Index (RHI). Histological remission (HR) is defined as NHI≤1, and RHI≤3 without neutrophils in the epithelium and lamina propria.The correlation between ECSS and MES and with histological scores were determined.

Soluble analytes relevant to inflammation were measured in serum and mucosal culture supernatants using Procartaplex Luminex assays and studied by Partial Least Square Discriminant Analysis (PLS-DA) and logistic model. Mucosal RNA sequencing and gene enrichment analysis (GO, KEGG) were performed to define differentially expressed genes/pathways.

Results

ECSS correlated strongly with RHI (r=0.89 [95%CI 0.51–0.98] and NHI (r=0.86 [95%CI 0.42–0.98] but poorly with MES (r=0.28 [95%CI-0.27–0.70]). We identified that BDNF, MIP-1α and sVCAM-1 predicted HR. Mucosal biopsy cultures also identified sVCAM-1 associated with healed mucosa. RNA-seq analysis identified genes expressed in colonic biopsies that discriminated between healed and non-healed mucosa and overlapped gene expression shared between ECSS, RHI or NHI defined healing. Based on PLS-DA, for healing vs. non healing comparison as defined by RHI, Nancy, Mayo and ECCS we found 32, 83, 127 and 60 differentially genes respectively. These included genes relevant to TGF-b signaling, macrophage recruitment into tissues, neutrophil and plasma cell function and tumour suppressor genes (Fig.1)

A number of those identified were shared by MES and ECSS defined healing as well as histological criteria defined healing.

Conclusion

ECS may sit between endoscopy and histology but closer to the latter and identifies gene expression markers and pathways that are also detected by histology.

*OMN,LJ,AA equal authors
DOP22 Integrative -omic analysis reveals microbiota mediated molecular mechanisms influencing host mucosal gene expression in Crohn’s Disease
Authors: Sudhakar P , Andrighetti T , Verstockt S , Caenepeel C , Ferrante M , Sabino J , Verstockt B , Vermeire S
Published: May 2021

Background

Mechanistic evidence linking gut microbial changes and host mucosal barrier responses in patients with Crohn’s disease (CD) is lacking. In this study, we used a computational approach to integrate gut microbial and intestinal gene expression in CD patients.

Methods

Bacterial species, bacterial genes/transcripts with enhanced abundances/transcriptional activity in CD (t-statistic of > 2 and Q-value < 0.05), as well as mucosal (ileum/rectum) differentially expressed genes (DEGs) between CD (n =43) and non-IBD (n=22) subjects were retrieved from the Inflammatory Bowel Disease Meta -Omics Database (IBDMDB). The impact of bacterial proteins on host gene expression was inferred using MicrobioLink, a computational tool for inferring microbe-host interactions. Drug target information was retrieved from OpenTargets. Paired 16S read-outs from stool samples and gene expression data from ileal biopsies in CD patients (n=20) and non-IBD controls (n=15), cross-sectionally collected at our IBD referral center, were used for independent validation.

Results

Across the 8 identified bacterial species enriched in CD, 3.7% (n= 743) of the orthologous groups were identified as being able to bind to human proteins. Network diffusion analysis uncovered bacterial proteins which could cumulatively modulate the expression of 42% of the genes differentially expressed in the ileum of CD patients. Topological and pathway analysis of the inferred signaling network modulated by the microbiota revealed several key hub proteins and immune-related pathways associated with IL-4, IL-2 and IL-13 signaling, receptor tyrosine-kinases, NFkB, and toll-like receptors including TLR4. Seventy-eight percent of the DEGs in our discovery cohort were also differentially expressed in the validation cohort (R2 = 0.907). Bacterial proteins post-translationally modifying host receptors resulted in the up-regulation of several pro-inflammatory cytokines via critical hub proteins such as NFkB (Figure 1). We observed different levels of locational specificity (from 35 to 61%) for the top regulators such as SPI1, STAT1 and NFKB1in terms of genes regulated by them in ileum and rectum. 24 proteins including ITGA4 and JAK1 from the ileal and rectal signaling networks are existing targets of CD drugs such as vedolizumab and tofacitinib, filgotinib and upadacitinib respectively.

Conclusion

Our findings outline the potential mechanisms of microbiome-induced host responses and provide insights into designing microbiome-mediated therapies to prevent and/or treat CD.
DOP34 Long-term outcome of Acute Severe Ulcerative Colitis responsive to intravenous steroid: A multicenter study of the Italian Group for the study of Inflammatory Bowel Disease (IG-IBD)
Authors: Festa S , Scribano M L , Aratari A , Bezzio C , Principi M , Pugliese D , Ribaldone D G , Furfaro F , Mocci G , Spagnuolo R , Vernia P , Costa F , Cosintino R , De Biasio F , Saibeni S , Armuzzi A , Papi C
Published: May 2021

Background

The appropriate maintenance treatment for patients with acute severe ulcerative colitis (ASUC) responsive to intravenous steroids (IVS) is still a matter of debate. Although major Guidelines consider thiopurine maintenance an option in this setting, the long-term benefit of early immunomodulator (IMMs) initiation is not well established. The aim of our study was to explore the long-term outcome of patients with ASUC responsive to IVS who received different maintenance strategies

Methods

In a multicenter retrospective study, all patients with ASUC hospitalized between January 2005 and December 2017 in 14 Italian IBD referral centres were reviewed. Thiopurine and biologic-naïve patients experiencing their first acute severe attack and who responded to IVS were included in the study. Maintenance treatment was prescribed by attending physicians according to their clinical judgment. The main outcomes were recurrent flares requiring escalation of therapy, new hospitalization, and long-term colectomy rate. The Kaplan-Meier survival method was used to estimate the cumulative probability of a course without the main outcomes. Differences between curves were tested using the log-rank test. A propensity score matching analysis was performed to establish comparable groups of patients who received different maintenance treatment

Results

Overall 372 patients were reviewed. Of these, 141 met the inclusion criteria (males 61.7%, median age 34.5 (IQR 23–50). After response to IVS, 82 patients (58.1%) received maintenance treatment with aminosalicylates, 42 (29.8%) received IMMs and 17 (12.1%) were maintained with scheduled infliximab (IFX) + thiopurines. After a median follow-up of 48 (IQR 25–90) months, 94 patients (68.8%) experienced a flare requiring escalation of therapy, 51 (36.1%) required new hospitalization and 18 (12.8%) underwent colectomy. After 12, 36 and 60 months after the acute attack, the cumulative probability of a course without escalation of therapy was 59.6%, 33.3% and 23.1%; the cumulative probability of a hospitalization-free course was 83.9%, 67.4% and 59.5%; the cumulative probability of a colectomy-free course was 96.3%, 90.2%, and 88.9%. No differences were observed between patients receiving aminosalicylates, IMMs or IFX as maintenance treatment (log-rank test: p= 0.39; p = 0.41; p = 0.11 respectively). After a propensity score matching analysis, no significant difference in main outcomes was observed between patients maintained with aminosalicylates or IMMs/IFX

Conclusion

IMM-naïve ASUC patients responsive IVS remain at risk of relapse requiring escalation of therapy. Early IMMs introduction after the acute attack did not reduce the risk of escalation of therapy, hospitalization or colectomy